When the activity of the NPF circuit is reduced below normal, flies are less sensitive to the intoxicating effects of alcohol (i.e. they exhibited fewer signs of "drunkenness"). The vice versa has also been observed to be true.

The authors will argue in this paper that they have discovered an explanation for how addictive substances/experiences can affect a fly's behavior and neurobiology. Understanding the effect of reward on an organism is important because it can lead to a better understanding of addiction (which can be seen as an abnormal response to a rewarding substance).

The rewards the authors use here are mating (sex) and ethanol (alcohol). The authors cite previous research to show that flies find alcohol to be rewarding and that they demonstrate addictionlike behaviors in pursuit of alcohol. These distinctions are important to demonstrate the similarities between fly and human responses to alcohol. They then build upon this previous research for their own experiments.

An important advantage of Cas13 over Cas9 is that it does not have a PAM or PFS that is required for it to target a specific site. To expand the number of sequences that Cas9 can target, researchers must use Cas9 proteins from different species (which have different associated PAM sequences). This can complicate the development and testing of gene editing systems that use Cas9.

In terms of precision, i.e., on-target editing, we can compare REPAIR to other base editors.

For instance, cytidine editors contain the cytidine deaminase APOBEC1 and convert C-G pairs to A-T pairs. The activity of APOBEC1, directed by Cas9, is not restricted to only one C but extends for several bases away from the PAM sequence. Recent work has demonstrated that the editing window of APOBEC may be reduced to 1-2 nucleotides by modifying of the deaminase.

Similarly, the precision of ADAR2 may be increased by placing a C across from the target A, creating a mismatch that is ideal for ADAR2 editing.

The authors of the paper looked at the crystal structure of the ADAR deaminase with the RNA duplex and predicted that ADAR might also operate on RNA-DNA duplexes. Later, they experimentally confirmed this prediction.

The RNA molecule is transcribed in the nucleus and then exported to the cytoplasm. It can be recognized and cleaved by Cas13 at any moment along this way.

Previously, the authors used nuclear localization sequences (NLS) and nuclear export sequences (NES) to determine at what point during the transcription and export process Cas13 is most efficient. They tested knockdown efficiency of LwaCas13a with either NLS or NES tags.

They found that constructs with a nuclear localization sequence (NLS) were most efficient. However, this observation cannot be generalized to all Cas13 orthologs, which must be tested individually.

Previous work has shown that ADAR works better when an RNA molecule contains a mismatch at a target site. This may be because it makes it easier for the deaminase to flip the target base, which has to happen for editing. Panel B shows what base flipping looks like: Zheng, Y., Lorenzo, C., & Beal, P. A. (2017). DNA editing in DNA/RNA hybrids by adenosine deaminases that act on RNA. Nucleic Acids Research, 45(6), 3369–3377. http://doi.org/10.1093/nar/gkx050

Previously, ADAR2 was randomly mutated, and protein variants with improved activity were selected. The protein with a substitution at the 488 position showed the highest activity.

Later, another group tried the same thing with ADAR1. The group compared protein sequences and found the corresponding amino acid position on ADAR1 and performed the same substitution, which resulted in the same increase in activity. See the image below for a comparison of ADAR1 and ADAR2:

Tomaselli, S., Bonamassa, B., Alisi, A., Nobili, V., Locatelli, F., & Gallo, A. (2013). ADAR Enzyme and miRNA Story: A Nucleotide that Can Make the Difference. International Journal of Molecular Sciences, 14(11), 22796–22816. http://doi.org/10.3390/ijms141122796

Previously, the authors tested 15 orthologs of the Cas13a nuclease for their ability to knock down RNA. In this study, they expanded their search to other members of the Cas13 family, including a, b, and c variants.

In addition to the functional ADAR1 and ADAR2 enzymes, there is a catalytically inactive ADAR3 enzyme in the human genome. Although it cannot deaminate RNA, ADAR3 might still regulate gene expression, for example by inhibiting its two functional homologs (ADAR1 and ADAR2).

Similar to the gut cells, the nerve ganglia of the rat also show transient expression of catecholamine during development.

This study focused on the neurotransmitter expression changes in the embryonic stages of development. At embryonic day 11.5, the neurons express the attributes of noradrenergic cells. However, these traits are lost by embryonic day 14.5. The uptake system for norepinephrine remains intact in these neurons.

Scientists studied the mitochondrial DNA of 654 domestic dogs and 38 wolves, and were able to separate the dogs into four main clades (A, B, C, D), groups that contain an ancestor and all of its descendants. A fifth clade, E, was a very small, isolated group.

A 2013 study used whole genome sequencing to trace the ancestry of Chinese native dogs. They compared the DNA of four gray wolves—three from different parts of Russia, one Chinese—three native Chinese dogs (dogs present in China for a very long time), and three dogs considered very diverse from each other; a German Shepard, Belgian Malinois, and Tibetan Mastiff.

They suggest a Southeastern Asia origin for dogs, and domestication of Chinese indigenous dogs occurred 32,000 years ago.

The Sarloos breed was created by Leendert Saarloos, in an attempt to create a superior police dog. He bred a male German Shepard and a female wolf. Despite the efforts of Mr. Saarloos, the dog was never a successful police dog and was not formally recognized as a new breed.

Wang et al. studied the genomes of 12 gray wolves, 27 ancient dog breeds, and 19 diverse dog breeds from all over the world. They discovered that dogs from Southeast Asia have higher genetic diversity and their DNA is less mixed, meaning that they are the most related to wolves; they estimate that domestication occurred there 33,000 years ago. Dogs were isolated to this region for several thousand years, and about 15,000 years ago they migrated to other parts of the world.

Scientists studied DNA from wolves (one each from East Asia, the Middle East, and Europe—all regions where domestication had potentially occurred) and two ancient dog breeds. A third group, the golden jackal, was included as a comparison. The scientists found that none of the wolves were more closely related to dogs than the other, which suggested that dogs were not domesticated separately in the three different areas. The scientists thus concluded that domestication must have happened just once.

Dogs were tamed from wild animals (wolves) long before—several thousand years before—any other domestic animal (e.g. pigs), and before farming practices began, according to the archaeological record. Some studies estimate that farming practices and farm animal domestication started place 9000-12,000 years ago, and dog domestication took place at least 15,000 years ago.

Check out this 2018 paper on the spread of dogs alongside farming in Europe. Find the full PDF in the "Related content" tab.

In 2000, Ellstrand and Schierenbeck proposed hybridization as a catalyst for the evolution of invasion.

The authors cited performed studies that ants are a very important predators in tropical forest ecosystems.

Previously, a link has been discovered between the methylation of genes undergoing stress, and the ability of one genotype to produce more than one phenotype in order to adapt to its environment.

As described by past research of Talbert and Heinkoff, they're are a variety of epigentic mechanisms that are influenced by different amounts of stress drawn by the environment. One of these are the now testing of the recently discovered histone variants and and how each histone respond to environmental stress such as toxins.

Multiple research studies previously conducted show that brevetoxins are produced during FRT's.

Gavery and Roberts view the oyster as one of the best ways to speculate and monitor the progress of DNA methylation. They used this oyster model to view how the toxins can influence the rate of methylation and how stress affects epigentics factors.

Toxins are known to disrupt cell actions. The scientists expand on this idea by using the experimental model of an oyster because oysters can be used to determine epigenetic modifications passed down through generations, ultimately showing red tide effects.

Yimizu, Chou, and Bando initially studied the structure of brevetoxin, and deemed it the most potent toxin found in Florida Red Tide.

González-Romero has previously conducted research on the stability and function of the H2A protein, concluding that it participates in the unfolding of chromatin fibers and therefore modifying enzymes and polymerases that facilitate gene expression.

Understanding the life cycle of plants helps us understand part of the world's plant diversity. This shows how phenology can make contributions to conservation biology.

Phenology can be used as a tool to aid in management decisions for plant restoration. This is a great example of how phenology can help make contributions to conservation biology. This study looked at a forest that developed under the selective pressure of fire which allowed scientist to study the forests reproductive phenology and how it was effected by the fire. They found that fire effects the timing of plant reproduction at community and landscape levels. This is a great example of how plant phenology can be used as a tool to aid in management decisions for plant restoration. This is a great example of how phenology can help make contributions to conservation biology.

Scientists are trying to gain an understanding on how relationships between plants and insects are affected by the changing climate. This helps us to understand how phenology can be used to study the effects of climate change.

Van der Sleen and colleagues determined that higher concentrations of atmospheric CO2 (as a result of human activities) increase plant photosynthetic rates and improve plants' water use efficiency. Increased CO2 increases the rate at which carbon can be used by plants as carbohydrates in light-independent reactions. However, photosynthesis rates eventually plateau as a result of another limiting factor (light intensity, temperature, etc).

Chuine and Beaubien used a process-based model (PHENOFIT) to predict species distribution. This model focuses on survival and reproductive success in relation to climatic variations. They determined that the phenology of plant species as it relates to variations in climate is a major determinant for species distribution. This model could potentially be used to predict the future distribution of plant species and make adjustments to our current practices accordingly.

Rosenzweig and colleagues noted that some major changes in phenology can be attributed to climate change. For example, rising oceanic temperatures are known to impact marine and freshwater biological systems in terms of phenology, migration, and community composition in algae, plankton, and fish.

In this study, it was found that a small amount (17%) of the caterpillar (aka Lepidoptera) were found to be feeding on the Ficus in both the highlands and lowlands.

The study was done on the different species of caterpillar that fed in the highlands, in the lowlands and those that didn't feed on ficus as well. The results showed them which caterpillar species was dominant on the species on ficus in the lowlands and which were dominant on the species of ficus in the montane habitats/ highlands. The ones that were found to be dominant in the lowlands, typically did not feed on the highlands and vise versa.

A Comparison of Caterpillar (Lepidoptera) Assemblages on Ficus Trees in Papua New Guinea

In this study from 2009, the results of diversification, when subpopulations with independent genetic modifications emerge, were concluded not to be homogenous in their relation to performance. This concept is further analyzed through this experiment in the speciation and the variation of defense strategies.

The main point the author is trying to make here is that there is a direct correlation between increase in plant defense and increase in land covered by plants as well as speciation of plants. He also explains that due to the expansion, rapid evolution of defenses begin to take place. The herbivores eating these plants do differ in tactics from region to region, increasing the amount of different defense strategies in the plants. He explains an alternative viewpoint stating that predators do not influence speciation much, therefore defenses are similar amongst most plants.

This statement addresses the variables that must be acknowledged when trying to analyze different plants and their different defense strategies. The "resource limitation across habitats" that the author is referring to is what in the environment can the plant use to defend itself in its habitat from threats such as herbivorous insects.

Herbivorous insects are constantly eating plants, creating competition between the plants and insects. What is stated here is that optimal defense may be impacted by the plants environment, giving it access to certain nutrients and materials needed to produce the desired defense mechanism, such as poisonous leaves or indigestible tissues.

http://onlinelibrary.wiley.com.ezproxy.fiu.edu/doi/10.1890/12-1920.1/full#i0012-9658-94-8-1764-Coley2

The idea in place here is the observation of evolution in herbivorous in correlation to the environment and all its factors.

The study provides proof of evolution in herbivorous in respect to the environment by analyzing adaptive radiation. It includes the third trophic level, omnivores and carnivorous that eat these herbivorous. This is an important factor that is part of the ecological niche of these herbivorous. It includes the third trophic level, omnivores and carnivorous that eat these herbivorous. This is an important factor that is part of the ecological niche of these herbivorous.

To further understand adaptive radiation watch [(https://www.brightstorm.com/science/biology/evolution/adaptive-raditaion/)

The sources mention, that in a habitat with a low amount of productivity there is a good amount of strong plants/ plants that are "rich in chemical defenses". In a habitat with lower productivity, the plants are thought to do this in order to increase its life span. Therefore, as the productivity and the amount of herbivores changes the strength and and amount of the resources changes.

For more information check out: Tropical Blackwater Rivers, Animals, and Mast Fruiting by the Dipterocarpaceae

In Africa, there is a food crisis leaving millions of people without corn, a very important crop for Africa. The reason for these crops not being edible is that a certain species of worm invaded a field of corn and rapidly spread to neighboring farms, killing millions of corn crops leaving thousands hungry. This proves the point how insects differ from each-other depending on what type of plants are around, since this worm is always flocking to this one crop.

National Science Foundation – Ecosystems. Causes and implications of dry season control of tropical wet forest tree growth at very high water levels: direct vs. indirect limitations (CARBONO - VERANO project).

National Science Foundation – Polar Programs. Arctic Observing Networks: Collaborative Research: Sustaining and amplifying the ITEX AON through automation and increased interdisciplinarity of observations (AON)

NSF-Arctic Natural Sciences. Collaborative Research; cold-season gas exchange of arctic plants - resolving winter carbon and water balances of Alaskan arctic tundra (Coldseason project).

NSF -IPY Arctic Observing Networks Study of Arctic ecosystem changes in the IPY using the International Tundra Experiment. (ITEX-IPY)

DOE-NICCR. Response of carbon dioxide, water, and energy exchange of peat and marl wetlands in the Florida Everglades to changes in hydroperiod (Evergladesflux).

NSF-Biocomplexity. Biocomplexity Associated with the Response of Tundra Carbon Balance to Warming and Drying Across Multiple Scales. Barrowbiocomplexity (this project has sunsetted). Effects of increased season length on plant phenology, community composition, productivity, and ecosystem carbon fluxes in Alaskan tundra Season project (this project has sunsetted)

Carbon stockes and fluxes in a tropical rain forest in Costa Rica Carbono project

NSF- Integrated carbon program. Understanding interannual NEE variability in a tropical rain forest using constrained estimates of carbon exchange. S.F. Oberbauer, D.A. Clark, M. Ryan, D.B. Clark. Carbono-Towers

National Science Foundation - Biocomplexity of the Environment Coupled Biogeochemical Cycles. Complex interactions among water, nutrients and carbon stocks and fluxes across a natural fertility gradient in tropical rain forest. (CICLOS PROJECT).

Researchers had previously noted the presence of secondary metabolites in the lichen cortex. The researchers initially looked for a correlation between the main fungal species (lecanoromycetes) and the production of these secondary metabolites, but could not determine a correlation.

Perhaps this is easiest to understand with a picture. If you look closely, you can see two layers within the cortex. Photo from University of California Berkeley's Museum of Paleontology.

Several natural scientists in the mid-1800s began to suspect that the lichen was in fact a mixture of two organisms, but it was the Swiss botanist Simon Schwendener who demonstrated that lichens were composed of fungi and algae for the first time in 1869. Initially, he thought the relationship must be antagonistic—that the fungi were “imprisoning” the algae. Ten years later, the German botanist Anton de Bary proposed the idea of mutually beneficial symbiosis for the lichen system.

Read more about Schwendener's discovery and the controversy it caused here. Find the full PDF in the "Related content" tab.

While these two lichens look very similar, there is an important distinction. There is evidence that Bryoria fremontii has been used and consumed by Indigenous populations for centuries, while Bryoria tortuosa contains a yellowish substance, vulpinic acid, that is toxic to mammals. Indigenous peoples soaked Bryoria collected for food, and it is thought this may have helped rinse background levels of vulpinic acid from mixed samples. Despite this difference between the two lichen species, scientists had been unable to determine a phylogenetic distinction.

Read more in Scientific American: https://blogs.scientificamerican.com/artful-amoeba/2-lichen-mysteries-solved-reveal-a-greater-hidden-truth/

When the amount of NPF receptor present in the brains of baby fruit flies (still in the larval stage) is artificially increased, these flies become more likely to consume noxious—that is, bitter or unpleasant—food.

Past research has shown that interactions between neuropeptide F and its corresponding receptor can alter how much flies are affected by alcohol consumption.

Past research has shown that individual differences in alcohol tolerance amongst C. elegans are related to natural variations in the amount of neuropeptide Y receptor found in their brains.

We know that memories associated with food (for example where food is located, how good/bad the food is, etc.) are modulated by hunger levels. Typically, flies that are hungrier tend to form more robust food-associated memories, and vice versa. In the study referenced here, the researchers showed that a similar behavior can be elicited using NPF—artificially activating NPF neurons promotes better formation of food-associated memories.

When the NPF circuit in Drosophila is artificially activated, flies do not seem bothered by stressful things in the environment that under normal conditions would have provoked some sort of avoidance behavior.

Extremely young Drosophila spend the majority of their time eating, whereas older larvae start to engage in behaviors such as moving around and cooperating with fellow larvae. This change in behavior from young to old larvae is correlated with a reduction in the amount of NPF in the brain, suggesting that this molecule regulates feeding behaviors in the fly.

Past research has also shown that the amount of neuropeptide Y found in a rodent's brain is related to the amount of stress they might experience during their life.

A mammalian version of neuropeptide F. This molecule is found in the human brain.

Scientists studied the DNA of a Siberian wolf thought to have lived 35,000 years ago (based on radiocarbon dating). The Siberian wolf's DNA mutated at a rate of 0.45 × 10^−8 per generation, much slower than the previously assumed mutation rate of 1.0 × 10^−8. This meant that wolf-dog divergence must have occurred much longer ago (27,000-40,000 years ago) than previous estimates suggested (11,000-16,000 years ago).

The majority of research findings up until this point suggested that domestication occurred just once, so this became the most acceptable theory for how domestication occurred. Based on their findings, the authors disagree with the null hypothesis (reject the null hypothesis), and because of this, they go to great lengths to prove their alternative hypothesis.

Through archaeological evidence, we know that dogs were present in Europe about 15,000 years ago. The fact that the Finnish Spitz is the only European dog breed that kept its basal genetic signature suggests that the original European dogs were mostly replaced.

Effective computer search algorithms need to have the ability to scale in order to handle data sets of different sizes and levels of complexity.

For example, while a brute-force method would work well if you only had to compare a few images, it becomes slow to the point of being impossible when you want to compare all the images on the internet.

There are other methods (like the space-partitioning method) that work well for many images, but only if those images are very simple—that is, their feature vectors are very small.

In order to handle complicated problems like searching high-resolution images on the web, it's therefore extremely important for researchers to find algorithms that can scale to handle both large and complex data sets.

Caron et al. developed a special tracing technique that allowed them to track the connections between KCs and PNs using a glowing, light-activated protein.

By observing the activity between the two, they found that KCs combine input information from a random combination of PNs. That is, they found no specific pattern or organization that relates the type of odor to the PNs that are activated. In addition, they didn't identify any preferred pathways between groups of PNs and individual KCs.

To learn more about the glowing, light-activated protein used in this research, check out this annotated resource from Science in the Classroom.

In 2016, Stevens determined that PNs in the olfactory circuit use what's called a "maximum entropy code."

A maximum entropy distribution means that the olfactory circuit can encode the most number of stimuli using a fixed number of neurons. This means that even though the average firing rate of all the PNs will depend on the concentration of a specific odor, the response to all odors is statistically the same.

In other words, if you took 10 PNs and 10 odors, recorded the firing rate of each of the PNs in response to each of the odors, and created a histogram from the data, that histogram would always look the same—regardless of which 10 neurons and which 10 odors you chose.

Lin et al. discovered the neurological process that controls why so few olfactory neurons make up each odor "tag."

The reason is because when the cells that receive odor information, called Kenyon cells (KCs), become active, the anterior paired lateral neuron responds by slowing the activity of the KCs. The more active the KCs become, the harder the anterior paired lateral neuron works to block their activity. The few KCs that are left active after this process form the odor tag.

In a mutagenesis experiment in the late 1970's, scientists found and XXY male. This rare finding spurred the thought that is only takes a single Y to become male as long as X dosage can be overcome by other mutations.

The female-lethality phenomenon seen in the last experiment has been observed before in fruit flies when upstream genes are misregulated and there is an imbalance of gene products between the sex chromosomes and autosomes.

If a mutation occurs within a gene, it is more likely that it will code for the same amino acid than a different one. This is due to redundancy in the amino acid code and due to evolutionary and selective pressures on organisms to produce functional proteins.

Insect species employ a variety of different genetic mechanisms to confer either the female or male sex. The default mode, generally, is the development of female embryos; but there is not much understanding of the factors that lead to male-specific development.

Though details on insect sex determination are scare, a year before this study was published, Hall et al. (2015) discovered a male determining factor (M factor) in another disease-causing mosquito, Aedes aegypti.

In other flies, there is a female "default" mode of sex determination. Only a maleness signal on the Y chromosome can initiate the male pathway.

In the "default" mode of sex determination, a male fly will be produced. In this case Sxl, tra and dsx are expressed, but pre-mRNA processing results in non-functional SXL and TRA proteins as they both contain premature stop codons. The exons that contain these stop codons are spliced out in the female mRNA isoforms. Both males and females express DSX protein, but each have a different version due to sex-specific splicing. Check out this figure from Chromosomal Sex Determination in Drosophila

In 2014, Suzuki et al. discovered a new structure in proteins featuring five specific amino acids held closely together.

The structure begins with an amino acid called serine somewhere on a protein next to an amino acid called cysteine. They link to another cysteine next to an amino acid called histidine in such a way that a fifth amino acid, called aspartic acid and located between the two pairs is held closely to them in 3D space.

Vertommen et al. had shown that enzymes that help degrade PET act preferentially to the less organized, amorphous portions of the polymer, over the highly organized, crystalline portions.

Using satellite pictures and infrared satellite imagery, it is possible to assign hurricanes into different categories depending on characteristic patterns.

As a tropical cyclone develops, there tends to be certain characteristics depending on the intensity of the storm. Those visual characteristics in the swirls of clouds and moisture change in a predictable fashion as a storm system strengthens.

This technique has been compared to aircraft measurements in order to test its accuracy and has some of the highest accuracy in gauging hurricanes in the North Atlantic and North Pacific Oceans.

Check out NOAA's website for more information: http://www.aoml.noaa.gov/hrd/tcfaq/H1.html

It has been found that cocaine users and their non–drug using siblings both had a deficit in response control. Siblings who were not exposed to cocaine showed a deficit in response control and similar changes in brain regions as their cocaine-using counterparts.

This suggests that there are inherent traits such as impulsivity and poor inhibitory control that are caused by differences in brain physiology. This means that even before someone starts taking drugs, they may be vulnerable to drug addiction.

It is possible that siblings of drug-dependent people have other traits that protect them from being vulnerable to drug addiction, i.e. traits making them less likely to start seeking drugs in the first place. This suggests that changes in brain physiology in drug-dependent people are not all cocaine-induced, and that there are some heritable (both genetically and epigenetically) differences in brain structure and function that can predispose people to addiction.

Previous work has looked at how the decision-making process informs goal-directed behaviors. The systems that govern goal-directed behaviors and habitual behaviors are spread across the corticostriatal regions of the brain.

Normally, these two systems operate in parallel (at the same time, but not necessarily together). With extended training or repetition of a specific behavior or use of stimulant drugs, the habit system can start to play a larger role over behavior and diminish the role of the goal-directed system.

Once a behavior (like drug-seeking) has become habitual, the behavior will still occur even when the reward is removed (e.g., when the effects of the drug no longer feel good).

Injection of NPY can have either sleep or wakefulness promoting effects on a mouse, depending on where exactly in the brain the molecule is injected, as well as context.

Similar to work done in flies on the role of NPF in regulating responses to physical stressors (see previous paragraph), studies in mice have also shown that when the activity of NPY is increased, stress responses are decreased. The vice versa has also been observed to be true.

When mice experience fasting, neurons in their brain containing NPY become more active, promoting feeding behavior.

Superfolder GFP is a protein derived from GFP, a "reporter" that can be added to genes to see where and when they are expressed in an organism. GFP lights up when it is exposed to a specific wavelength of light.

Superfolder GFP has several mutations that improve its folding properties and stability in comparison to regular GFP. In this particular experiment, the researchers fused a msfGFP (Superfolder GFP) domain to Cas13 to serve as a reporter and to increase the stability of the nuclease.

To learn more about GFP, check out this Science in the Classroom resource.

Several groups have built programmable RNA-editing techniques based on the ADAR deaminase. The groups used different approaches to direct the editor to target mRNAs and demonstrated that these systems are efficient.

However, none of the groups have extensively studied how accurately these systems find target sequences, or the effects systems have when they hit the wrong target. This is important, because a gene editor must be highly accurate (specific) to be useful for most applications.

This is very important because it means that ADAR catalytic domain can be used independently of any other cofactors (which help enzymes catalyze reactions). As a result, it can still catalyze the deamination reaction when fused to another protein.

For CRISPR/Cas9 to work, there must be a special sequence (called a PAM sequence) next to the target site. Cas9 uses this PAM sequence to target a certain part of the DNA molecule.

Different versions of Cas9 can use different PAM sequences. Researchers have experimented with different natural and artificial Cas9 enzymes to expand the range of sequences we can edit. However, there are still some sequences that we cannot edit because we do not have a version of Cas9 (or another enzyme) that can target them.

Raes and colleagues found through 16S rDNA sequencing that time since last bowel movement was linked to Akkermansia abundance, a bacterial genus that has been linked to improved metabolic health.

Heaton and colleagues showed that the BSS could be used to indirectly measure the rate at which food moves through the digestive tract.

Wu and colleagues quantified gut oxygen levels in mice and found that there was a correlation between the distribution of oxygen and nutrients and the microbiome composition.

Hallem and Carlson conducted an analysis to determine how the fly's olfactory neurons would change their behavior in response to different types and concentrations of odor.

They found that the average strength of the receptors' response (i.e. the number of times the neurons were triggered) was dependent on the concentration of the odor. High concentrations brought on strong responses (a high rate of triggered neurons) from multiple receptor neurons, while low concentrations elicited a slower rate of neurons firing.

In 2015, Stevens identified a three-step code that the fly olfactory circuit uses to identify and respond to specific odors.

1. Receptor neurons send odor information to specialized structures called glomeruli, which contain projection neurons.
2. Projection neurons send the information to Kenyon cells in the mushroom body.
3. These Kenyon cells form the odor label, or tag, and then pass the information along to another stage of neurons that then direct the fly's behavior.

Multi-template polymerase chain reaction (PCR) is a technique to amplify multiple targets in a single PCR experiment. However, this technique sometimes produces bias and overamplifications in specific templates.

To learn more, check out this seminal paper by Polz and Cavanaugh (1998).

Researchers have compared the genomes of these two lichen species and found that, for the most part, these two organisms have the same sets of genes.

Researchers have tried to create a lichen in the laboratory by only mixing an algae and a fungus known to produce lichens in the wild. These attempts were not successful as the cortex layer did not develop.

Previous work by Ronkvist et al. and Sulaiman et al. had shown that enzymes called cutinases could sometimes degrade PET if the temperature, polymer properties, and pH of the solution were right.

Nimchua et al. found in two different studies that Fusarium oxysporum, a recently discovered fungus, and Fusarium solani, another fungus, produced the enzymes needed and were able to break down PET film.

Link to Ronkvist et al: https://pubs.acs.org/doi/abs/10.1021/ma9005318

Earlier, Smith et al. found minor degradation of PET by a few enzymes, along with no response by other, more common enzymes. Several labs determined that changing the structure of the polymer backbone to resemble more biodegradable polymers could make a new PET-like polymer biodegradable.

Chain mobility is a measure of the flexibility of a polymer chain. A more flexible polymer chain will have higher chain mobility. In 2005, Marten et al. showed that polymers with lower chain mobilitites, including PET, are more challenging for enzymes to degrade.

In 2015, J. R. Jambeck et al. calculated that about 8 million tons of plastic make it into the ocean each year.

In a 2001 National Human Activity Pattern Survey of 9,386 people in the United States found that on average 87% of time is spent in buildings and 6% of time is spent inside automobiles. Indoor air quality is an important issue, since on average 93% of time is spent indoors.

A previous study measured the amounts of VOCs present in outdoor air in Pasadena, California from 15 May to 15 June in 2010. The research included both measurements on the ground and measurements via aircraft.

This study is using those measurements to test their model.

Hydroxyl radical (OH) concentrations that are measured have been lower than what is predicted by models. This implies that other species or processes not included in the model must account for the difference between the model and the measurements.

A previous study on residential buildings combined measurements from 77 separate studies to examine the typical levels of VOCs in average households. The study only used measurements from U.S. households and those of countries with similar styles of living.

Another study on commercial buildings made measurements of the levels of VOCs in 37 different small and medium-sized commercial buildings in California. This allowed the researchers to quantify typical VOC exposure in commercial buildings.

This study is using these two experimental studies to test their model.

A primary instrument used for determining the VOC components in air is a mass spectrometer. Learn more about mass spectrometers by watching the following video. https://www.youtube.com/watch?v=J-wao0O0_qM

Researchers have looked at various volatile organic molecules to track emissions. The types of molecules that researchers examine have an influence on conclusions drawn. Many studies have not looked for some of the volatile organic molecules that come from household products. This could explain why many models have underestimated the contribution of household products to volatile organic emissions.

Only a very small percentage of organic molecules in soaps that are disposed of in drains have the potential to negatively impact air quality. Overwhelmingly, organic molecules used in soaps and detergents end up being disposed of down the drain into sewer systems. These molecules then end up in sewer treatment plants. Most of these organic molecules are then either physically or chemically removed from the water at the treatment plant.

Based on Fig. 1, around 97% of the mass of water and organic molecules in soaps and detergents end up being disposed of down the drain.

Changes in how engines operate (air/fuel ratios, use of catalytic converters, etc.) have led to substantial decreases in automotive emissions. In major U.S. cities (New York, Los Angeles, and Houston) from 1990 to 2010 some hazardous emissions have decreased by 80% to 90% even as car traffic has increased. Hazardous emissions from vehicle exhaust are expected to remain at approximately this same level as vehicles continue to utilize technologies to reduce hazardous emissions.

One possible explanation of why some temperate species' ranges would expand with climate change is that these species evolved in the tropics, and have not lost a high tolerance for heat, even as they moved further north. Therefore, even as temperatures heat up in the southern regions of their current ranges, these temperature still do not approach their ancestral tolerances, and species can continue to live there. This could explain why species in the tropics are currently suffering under warming climates; the increase in temperature is surpassing their ancestral heat tolerance.

Whitehorn and colleagues took laboratory colonies of a common European bumblebee species (Bombus terrestris), and exposed them to levels of neonicotinoids similar to what they might be exposed to near a farm field. They found that colonies exposed to these levels had slower growth rates and produced less queens than "control" colonies that were not exposed.

Every living organism has certain traits. For example, reptiles have scaly skin, birds have feathers, mammals produce milk, and so on. These traits are inherited from the organisms' parents, of course, but ultimately, those traits tend to remain similar across very large periods of time.

We can trace how traits change over evolutionary time scales, and show that some traits tend to remain quite similar, even though a huge amount of time might have passed. Traits like a species' tolerance to heat are like this: This trait tends to remain similar across evolutionary time, despite the fact that a species might evolve and change in many other ways, even splitting into two or more different species. In other words, it's hard to evolve tolerance to hotter temperatures—at least for many species.

In one study, Chen and colleagues put together a huge analysis of 1367 species from the United Kingdom and some other places around the world. Those authors looked at whether the places those species were found had changed over time. On average, those species were shifting toward cooler areas at about 17 kilometers every 10 years. They were also shifting upward in elevation by about 11 meters every ten years, reflecting the fact that it is generally cooler at higher elevations than at lower elevations.

The Chen study is called a meta-analysis, where they take results from many other studies and put them all together into one big analysis. That work focused especially on butterflies, which are very sensitive to climate change, but it did not include critical pollinator species, like bumblebees.

The preparation of MOF-801 was described by the same group in a previous study. The method consists of heating the organic component in a solvent with a reagent containing the metal ions. This forms the MOF as a solid that can then be filtered.

The authors built their simulation model based on previous studies about adsorption processes defining the important parameters to optimize the adsorption process.

MOFs are composed of metal ions connected by small organic molecules. Both these small building blocks can be varied to afford a large diversity of different MOFs with properties tailored for specific applications.

One of the numerous applications of MOFs has been the ability to induce selective chemical reactions between substrates. The metal ions within the MOF enable the reaction to occur only for the substrates that are able to enter in the cavities.

In 1997, Andrei Broder invented MinHash, which is a type of LSH that allows a user to quickly estimate how similar two data sets are. In his seminal paper on this topic, Broder discussed the math behind this idea and applied it specifically to the process of comparing two documents on the internet.

Olsen, Bhandawat, and Wilson showed that the fly olfactory circuit uses a specific type of processing known as divisive normalization. This process ensures that the strength of a neuron's output stays within a certain range.

This is important because a complex stimulus (e.g. one consisting of multiple odors) might elicit several different responses from a single neuron based on all the different aspects of the stimulus (type, concentration, molecular make-up, etc.). But thanks to divisive normalization, a neuron's response will look more like an average of all its responses rather than the sum of them.

Turner, Bazhenov, and Laurent quantified the sparsity of KCs by recording the spiking activity of the cells in response to input from the PNs. They discovered that at least three factors explain why such a small number (~5%) become active:

1. The inputs from PNs last a very short time, which doesn't give KCs much time to build up their activity.
2. Only a few PNs connect to each KC, so overall input levels are low.
3. KC firing thresholds are high, meaning each KC must have very strong inputs in order to obtain the energy it needs to fire.

Andoni and Indyk explored how LSH algorithms can be applied to solving nearest-neighbor search problems. They showed that nearest-neighbor search problems are useful for any task where you want to find two similar objects, whether you're trying to retrieve information, recognize a pattern, or analyze data.

Achlioptas explored two specific applications of the Johnson-Lindenstrauss lemma that are particularly relevant to computer database applications. In doing so, he discovered a method of projecting points from a higher to lower dimensional space that was simpler and faster than other known methods. In fact, he showed that it was possible to perform this faster embedding process without affecting the quality of the results.

Earlier work found examples of enzymes that partially break down PET. These enzymes increased the hydrophilicity, or desire to dissolve in water, of PET. The previous work developed a range of different methods to measure PET modification from these enzymes, including SEM imaging, measuring the pH (which changes over the course of the degradation), and spectroscopy—a technique that involves shining different types of light at a sample and measuring what light passes through.

Sinha et al. (2010) detail the wide use of PET plastic, particularly in beverage bottles and describe possible methods of recycling. They focus particularly on tertiary, or chemical, recycling. Chemical recycling breaks down the polymer chain into smaller pieces using chemicals that are often harsh or corrosive. At the time Sinha et al.'s review was written, no biological methods of breaking down PET were known.

Two factors that help determine how well a species will track climate change are dispersal (how well the species can move to new areas and start new populations) and persistence (how well the species can maintain and grow these new populations).

From analysis of aerial surveys, Gehrig-Fasel and colleagues found that about 4% of upward shifts in tree line (i.e. trees growing further uphill than previously) from 1985 to 1997 could be attributed directly to climate change. The rest were attributed to changes in land-use.

Cameron, Hines, and Williams used DNA sequence data on 218 of the 250 currently known bumblebee species to create a phylogeny (phylogenetic tree).

Using museum records, Bartomeus and colleagues found that bumblebee species richness in northeastern North America has decreased significantly since 1877.

More recently, a 2017 study found that one third of bumblebee species are in decline.

Goulson and colleagues review the various global change drivers that are causing declines in bees, and by extension their pollination services.

This infographic from their study shows some of the main drivers and how they may interact together. (c) Goulson et al. 2015

By modelling the probability of extinction for lizards in Mexico, Sinervo and colleagues found that unabated climate change would result in the extinction of 58% of species in the Schleporus genus. They determined that increasing temperatures forced Schleporus lizards to spend more time in cool refuges avoiding the heat, therefore limiting time for foraging and reproduction, and reducing population growth rates. They also found that high-elevation species were particularly at risk from increased competition as low-elevation species moved higher.

Most species that have been studied so far are expanding further north as climate warming makes these areas habitable for them, but are still able to tolerate to increasing temperatures in the equator-ward regions of their ranges. In other words, it appears that climate change has helped many species increase their total range sizes! (Although it likely still affects their ability to live within these expanded ranges.)

Here, the authors are showing that their research is something that no scientist had known or been able to do before. The purpose of this sentence is to show why an analysis like the one in this research might be important and tell us something that we had not known previously.

Various technologies are being engineered to reduce particle emissions from diesel engines. Use of VCPs that lead to formation of aerosols is not decreasing as fast. VCPs' contribution to aerosol formation will become increasingly important.

Aerosols are directly emitted by natural (e.g., wildfires) and human activities (e.g., driving). The fossil total of aerosols refers to those from human activities. In Los Angeles, 40% of human-activity aerosols are soot-like aerosols directly emitted from engine exhaust. Diesel engines are the main contributors. The other 60% form in the atmosphere from emissions of gaseous VOCs, such as from automobiles or VCPs.

A different aerosol formation model, published by Robinson et al. (2007). The authors of this study used both this and the SOM model to predict aerosol formation in their box model.

Co-author Christopher D. Cappa and other researchers developed the model used in this study to predict the formation of aerosol particles from VOCs. Using data from their aerosol formation model in this study's box model, the authors predicted the amount of aerosol particles that will be formed in Los Angeles.

Ozone in the stratosphere (10,000 - 50,000 km above Earth's surface) is a net positive as it absorbs potentially harmful UV radiation. However, ozone at or near ground level (tropospheric) is a health-risk. Ozone that is inhaled into the body reacts with cells in the respiratory tract. This leads to increased respiratory disease and is correlated with increased mortality rates.

See more about the hazardous effects of ozone at the EPA: https://www.epa.gov/ozone-pollution-and-your-patients-health/health-effects-ozone-general-population#intro

The study cited here by Kossin and Velden found that there was a latitudinal bias in the way scientists were utilizing the Dvorak scheme to estimate storm intensity. At different latitudes, atmospheric pressures remain stable at different heights (e.g. air expands in warmer temperatures, near the equator).

There was no bias in estimating atmospheric pressure around the 23°N, but estimates for the latitudes both closer to the equator and farther north to the poles needed to be reconsidered.

They found that the pressure estimates based on satellite images needed correcting, but that estimates of wind speeds was still useful and accurate enough.

The authors are referring to the change from visual, human eye-balled categorizations of satellite images to computer-based algorithms.

The transition from humans to computers in cataloging storm system removed some of the personal subjectivity between tropical storm analysts.

The article they reference is "On the quality of the Australian tropical cyclone data base" where Greg Holland studied a subset of global data in order to see how enhanced observational technology has improved the detection of intense tropical storms.

He found that prior to the use of satellite imagery to recognize storms, records tend to underestimate the true number of events. This may be due to the amount of storms which form and remain far offshore which did not make it into historical records. Thus in the 1960's when satellites really started getting widespread usage for tracking weather, scientists "saw" more hurricanes than previously reported.

In order for a hurricane to form, there are multiple environmental conditions that must align. First off, an area of low pressure over the tropical ocean known as a "pre-existing disturbance" must form in an environment favorable for development.

Other conditions include: Ocean temperatures must be above 26°C (80°F), sufficient moisture in the air, enough distance from the equator to establish a cyclonic movement, and atmospheric conditions that support thunderstorm development are necessary for a hurricane to develop.

For more information visit the University of Rhode Island's 'Hurricanes: Science and Society' site: http://www.hurricanescience.org/science/science/hurricanegenesis/

The relationship between a change in temperature and a change in saturation vapor pressure is nonlinear, as in when plotted against each other the results do not form a straight line. This means that an increase in temperature causes an increase in vapor pressure much larger than would be the case in a linear relationship.

Here is an example of how temperature affects vapor pressure: Image from Lyndon State College.

In one study, researchers introduced a type of diet that reduced dopamine function in healthy human participants to assess whether it would control the shift between goal-directed action to habitual action.

The participants did not have reduced ability to learn associations between a stimulus and a response. They were also sensitive to outcome devaluation. However, they showed impairments in the slip-of-action test.

Note: the above was shown to occur in women only.

Previous work has shown how chronic stress and cocaine can affect normal behavior in rats by making them less sensitive to outcome devaluation and more likely to develop stimulus-driven behaviors from previously goal-directed behaviors.

Over time, people who regularly use drugs may start to use them habitually. This means that they no longer use drugs because it makes them feel good, but because that's just what they do.

When a habit is compulsive, it is performed even without regard to its negative consequences.

In one study, rats that had learned to do a specific task in order to get cocaine tended to continue doing the task even when cocaine consumption was paired with a negative event (here, injection with lithium chloride, which makes rats feel sick).

Aberrant learning processes refer to the transition of drug seeking and taking from a goal-directed behavior to a habitual behavior. This transition can be artificially enhanced by cocaine. Over time, the habitual brain system can play a larger role and leave someone vulnerable to compulsive behaviors (seeking and taking drugs without a goal, like desiring a rush or avoiding feelings of discomfort).

Hominin footprints were found near Ileret, Kenya, and are believed to be 1.5 million years old. It is thought the prints were made by Homo erectus.

Casts had been made of the original tracks before the site was covered. This protected the original tracks yet made visualization of what they were like.

Some researchers hypothesized that over time, hominin species increased in stature. This increase coincided with the migration of these species into other regions. This hypothesis is not supported by the authors' work.

Earlier work by other researchers supported a hypothesis that variability in hominin stature was linked to sexual dimorphism or the environment. They also hypothesized that size did not increase over time with Australopithecines exhibiting the same stature as later Homo species including Homo sapiens.

Earlier work determined that the footprints at Site G were located on a specific level of the Footprint Tuff. The authors of this paper question this conclusion since the conclusion is based on an average of all the Laetoli sites and does not provide specific data regarding soil characteristics or photographs.

Based on fossil evidence, the body proportions of Homo sapiens are different from those of Australopithecus. To use these dimensions as the basis for determining the stature, body mass, and walking speed of Australopithecus would not provide an accurate picture.

Numerous researchers have studied the fossil tracks left by various wildlife species. The types of animals present provide additional information about the ecology of the region and helps confirm the age of the trackways.

The discovery of the first Laetoli trail during an expedition led by Dr. Mary Leakey helped to settle one of the great paleoanthropological debates. Some argued that upright posture and bipedalism had to evolve before the hands would be free to make tools. Stone toolmaking was thought to be the critical factor in the evolution of hominins. The analysis of hominid bones could not provide the answer. The discovery of the Laetoli footprints provided evidence that dated bipedalism to 3.6 million years ago. The earliest stone tools are known to be around 2.6 million years old. The feet came first.

In 1978, Dr. Leakey and colleagues discovered fossils of Australopithecus afarensis at Laetoli. Other hominin fossils had been found in the area during work done in 1938. All together, the bones of about 23 individuals had been unearthed. They dated between 3.76 and 3.46 million years old. The fossil footprints in the volcanic tuff dated to about 3.56 million years ago. Based on the evidence, Dr. Leaky and others attributed the footprints to A afarensis.

Estimates of the body mass and degree of sexual dimorphism of early hominins are based on a limited number of fossils. Often, the fossil evidence (bones and footprints) was referenced to modern humans of known body mass. It is likely that the inferred sizes are inaccurate.

More recent evidence indicates that modern humanlike size first appeared around 3–3.5 million years ago in Australopithecus afarensis.

Plant species on the archipelago are dependent on the nutrients from guano. Guano, bird poop, is rich with minerals and nutrients, like Nitrogen and Phosphorus. The plant species richness has been found to increase as the nutrient availability increases.

Owald and Waddell discovered that the fly olfactory circuit is able to recall previously-learned odors through the help of specialized dopamine neurons. After a fly smells an odor, these dopamine neurons trigger changes in parts of the olfactory circuit that cause the specific neurons associated with the odor (aka the "tag") to fire.

Reactivating the tag causes the fly to remember the odor, as well as the values/meanings/context associated with it. The fly can then exhibit the appropriate behavior based on its prior learning (e.g. avoidance if the odor is associated with danger or approach if the odor is associated with a reward).

In the paper by J. Halaj et al. food webs are studied using the ratio of an isotope of nitrogen and carbon to see how much of it exists in different trophic levels and how the food web interacts both above and below ground. This study shows more of the direct effects of top down tropic cascades which are shown by the predation of sea birds by foxes in the study by Croll which also elaborates on the indirect effects of predators on the environment through the predation of sea birds decreasing nutrients to the system and changing the plant community structure. There is also isotope testing being used in this study to see its distribution across different species and soils between the fox infested and fox free islands.

According to Hairston et al. the populations of producers, consumers, and decomposers are limited by the resources they depend upon which are subject to limitation by the tropic levels both above through predation and below through low abundance. These limitations of herbivores by predation is helpful to the plant communities below as well. The Hairston et al. study provided the basis for the study of direct effects on top predators to terrestrial systems but this study further looks into the indirect effects of predation on plant communities. Providing evidence for indirect effects of nutrient deprivation due to predation using a large scale system that has room for replication.

The two experiments are similar because they take proboscis dimensions into account. The previous experiment that the author is talking about, measured out the thickness of the proboscis and how they can be efficient in transferring pollen.

In the experiment above, the author took into account on how the length and width of the proboscis can play a role in pollination. Since both the width and length of the proboscis were measured, more information was able to be attained. With these two different approaches, some differences can be taken into account and can be compared.

It is well known that insects use their proboscides or mouthparts to sip nectar and collect pollen. However, according to new research, the proboscis actually works more like a paper towel than a straw.

This research demonstrates how we can deal with issues that face threatened species through a series of field surveys, conservation assessments, and molecular research.

The Caribbean Island Biodiversity Hotspot has a great need to practice conservation since it has been subject to many events that are threatening of native species.

It is difficult to examine the exploratory behavior of a free moving fish because the data typically used do not accurately describe the fish's behavior. The EOD geometry and the electric images are complex because they can change based on the fish's movement. The movement changes the source of the electric organs and in laboratory setting the behaviors that use electroreception are hard to maintain. The difficulty experienced in a control laboratory setting to examine the certain behaviors, makes collecting and analyzing data of a free moving fish rather challenging.

Organic compounds emitted from gasoline exhaust have decreased from 1990 - 2010. The decrease is due to increased combustion efficiency and catalytic converters. Organic compounds that come from other sources have increased during this same time period.

Vehicle emissions contribute to air pollution. This includes increases in ozone and aerosol concentrations. Vehicular emissions alone cannot account for the increased ozone and and aerosol concentrations measured in the atmosphere. Additional sources of emission must exist to account for the increase, but where those sources come from is still uncertain.

The Environmental Protection Agency (EPA) sets legal limits for exposure to various environmental toxins. In studying Medicare recipients it was found that increases to PM2.5 and ozone exposure cause an increase in mortality rate. A 10 microgram per cubic meter increase of PM2.5 caused a 7.3% increase in mortality.

https://www.youtube.com/watch?v=ycBoiBwHuGE

Long-tongued bee populations are declining due to climate change. However, bumble bees that change what flowers they choose to forage may be better at surviving the changes to their habitat.

Release of juvenile hormone is determined by their blood meal, and their meal determines whether glucose will be absorbed to their muscle and fat cells.

Previous studies have suggested that this helps move the force from the contractions from the head towards the tail.

The maximum frequency at which a fish can move its tail is limited by the twitch contraction time of the white lateral muscle. The maximum swimming speed is then predictable if the distance moved forwards on completion of each oscillation (the stride) is known.

Zhang and Schlyter suggest that the diversity in mixed forests interferes with host choice guided by smell.

As the level of pheromones (semiochemicals) increase, herbivores disturbance increases.

Research conducted by Dyer et al. provides information on chemicals the Piper plant produces and trade-offs that affect the Piper plant in relation to these chemicals.

In this comprehensive review, Wahid and colleagues discuss how plants respond to high temperatures.

They describe the physiological responses, adaptations, and mechanisms plants implement in response to heat stress.

McGill and colleagues measured functional traits by focusing on four different themes: traits, environmental gradients, the interaction environment, and performance currencies (seed output, energy intake and expenditure, etc.).

They showed that focusing on quantitative functional traits allows for identification of general plant patterns, allowing for better prediction. This helps in understanding historical aspects of the community, assembly, trait evolution, and phylogenetic structure.

Serves as a manual for analyzing soils of past geological eras.

The trackway discovered by Dr. Leakey and colleagues has been covered in order to prevent erosion and the encroachment of plant roots. These measures were taken to guarantee that the footprints will not be destroyed. As a consequence, a careful analysis of the soil layers at Site G cannot be conducted.

Analysis of the footprints discovered by Dr. Leakey and colleagues determined that the big toes of the hominids leaving the trail aimed forward and that the toes were not distinctly different from each other. This is not true of the feet of hominids such as the chimpanzee.

Source of image ttps://corewalking.com/chimpanzee-feet-vs-human-feet/

Modern humans do not exhibit a high degree of sexual dimorphism. However, other hominid relatives, such as gorillas and orangutans, are highly dimorphic. Based on a limited number of fossils, it has been assumed that early hominins were highly dimorphic. Knowing more about the degree of sexual dimorphism would provide information about mating behavior and social organization.

In A New Determination of the Orbit of Mercury and its Perturbations (1843), Urbain Jean Joseph Le Verrier reported a peculiar precession of Mercury's orbit that was not accounted for by Newtonian mechanics.

Relativity theory, however, provides a robust account of Mercury's motion.

Euclid was a mathematician in Ancient Greece. His book Elements is arguably the first mathematics textbook. In the text, Euclid describes the geometry we seem to experience in our everyday lives in which parallel lines do not intersect.

This is also the same geometry we still learn in high schools across the country (2000 years after Euclid wrote it).

The Eötvös experiment measured the correlation between inert and heavy mass (or inertia of a body and its weight) and showed that these two masses have the same value although are conceptually distinct.

Einstein came up with the theory of special relativity before general relativity.

Special relativity assumes the laws of physics are constant in all inertial frames of reference (frames of reference that are assumed to be stationary).

General relativity expands on this, and describes the fabric of space-time on the scale of the universe (which Einstein suggests is warped by massive bodies).

Einstein expanded special relativity to general relativity over the course of about 10 years as he realized that special relativity was insufficient to explain some phenomena in the universe.

Aristotle contemplates absolute and relative motion in his book On the Heavens. He describes how heavy bodies move down and lighter bodies (like air or fire) move up relative to the center of the universe.

Read more: https://plato.stanford.edu/entries/spacetime-theories/#2

Again, this was found by Arthur Eddington and Frank Watson Dyson in their paper.

Maxwell's equations describe how electric and magnetic fields manifest from charged particles. Together, Maxwell's equations suggest the speed of electromagnetic waves (i.e. light) is constant.

The Lorentz Force Law says that the force felt by some charged particle is related to the surrounding electric and magnetic fields.

Together their work describes special relativity, but only for electromagnetism.

Einstein's "English colleagues" are Arthur Eddington and Frank Watson Dyson, astronomers who obtained experimental evidence of Einstein's theory of relativity.

Modern physicists have debated whether the error bars in the Eddington experiment were larger than the effect they measured. Nevertheless, the results have been confirmed.

Read Eddington and Dyson's work here.

In the image below, the solar gravitational field influences the sun's rays framing the moon. Notice that the light bends around the moon due to the gravitational field, rather than forming a spherical halo.

Understanding the causes of disease and death are crucial to better health outcomes. A look at health data from 1990 to 2015 identified factors that lead to negative health outcomes. Exposure to increased air pollution primarily leads to increased respiratory and cardiovascular disease.

Alexander originally obtained this equation to calculate estimates of dinosaur speeds.

Researchers have been able to visualize where and how quickly mRNA translation is occurring during development, but not for single molecules.

Researchers have described how fluorescent markers can be used to visualize and describe transcription in vivo, but the present study is the first to do so for translation.

This data set was developed and maintained by the Climatic Research Unit in the United Kingdom. It provides several climate values for locations covering the globe, on a monthly basis, from 1901–2009. The data set covers the world's land surface (excluding Antarctica) and is reported in a 0.5° x 0.5° grid. The climate variables, including temperature and precipitation, are based on actual observations from a number of sources, using appropriate methods to integrate the different sources and calculate the values for locations that are missing data.

In this study they use SRAP marker which is sequence-related amplified polymorphism to study the genetic diversity of plant species. It is a technique that helps detect genetic variation within plants.

This paper focuses on the environmental issues such as natural occurrences that affect land, water, and soil loss.

This article talks about the different areas that have been built in order to increase preservation. There has been some limitations in terms of funding, administrative authority, and proper development. They continue to address these concerns and find possible ways to create more protected areas.

In a recent study it was discovered that Dendrobium orchids can be sustainably harvested once a year if harvesters only take the old stems that have already produced fruit and flowers so that the younger stems will be allowed to reproduce.

Publication accounts for confusion among scientific and Chinese names for this orchid, and provides clarification on taxonomy and nomenclature.

This paper discusses efforts to reduce poaching of wild tigers by breeding tigers to increase their numbers and in theory, reduce their [tigers generally] worth. However, the argument is made that wild tigers cannot be substituted by farmed tigers to alleviate poaching because they are not valued the same by hunters. Because of this difference in worth (perceived or real) flooding the market with farmed tigers will have no effect on the demand for wild tigers.

China’s government authority have employed new park policies in Yunnan, where explicit management zoning systems are implemented towards the local people. Tourism has been known to provide a source of income for these environmental programs.

Using 12 years of seizure records covering nearly 1000 seizures from ivory to live reptiles, the authors review and describe current status of illegal trading of wildlife and wildlife products. The authors conclude that regulation and enforcement are not enough to control illegal trade, but that education at the community scale combined with empowerment of locals to value their own wildlife, international regulation and ground-level enforcement will result in more effective control.

This group surveyed all of the plants on Hainan Island and published a checklist.

This group looked at the conservation status of over 1300 native orchids distributed among 543 reserves in order to assess their status, and make recommendations for improving efforts where needed.

This paper reviews the progress made toward the national objectives for reducing biodiversity loss using time-series data sets against national indicators. Substantial movement forward was achieved, with stable increases in forest resources, improvements in marine ecosystem integrity, stable water quality, etc. as of 2009.

Looking at translocation efforts (including introduction, reintroduction and augmentation of wild populations) for conservation and supplementing declining species to return to self-sustaining numbers.

Although other studies have mentioned that orchids have certain compounds such as alkaloids that help combat illnesses, there are not enough clinical studies (except for animals) to support its medical use.

Sox10 is expressed in melanoblasts, which are the precursors of melanocytes, that do not contain Ednrb. Ednrb is expressed in embryos that do not contain Sox10. Therefore, Sox10 expression does not depend on the expression of Ednrb.

Studies show that there is a high expression of VEGF in human melanoma tumors, indicating that VEGF can serve as a marker for melanoma prognosis. Moreover, tumors with a high vascular density (VD) were also associated with poor prognosis.

Alcohol use in humans alters brain regions involved in goal-directed behaviors, which can lead to an increase in habit-learning behaviors in these patients.

There is a shift from goal-directed actions towards habitual actions in patients with alcohol dependency. It is possible that alcohol-seeking behavior alters the capacity of individuals to shift between these two types of behaviors.