a continuation...

Genetic engineering and optimization of the process.

Estimates of e-waste that is properly recycled.

In 1977, Porsolt et al. described a new method for assessing the effectiveness of antidepressent treatments, in which mice are dropped into a cylinder of water with a diameter of 10 cm, height of 25 cm, and water height of 6 cm. Porsolt et al. had observed that most mice are able to find the exit within 10 minutes, but some display a "state of despair", where they believe there is no escape from the situation, and resort to simply floating, only making movements that are needed to keep their head above the water. Porsolt et al. used this method to test a large range of antidepressants by injecting the mice intraperitoneally 1 hour before the forced swim test. In Porsolt et al.'s results, three drugs known to be therapeutic in depression (iprindole, mianserin, and viloxazine) resulted in a reduction in immobility of the mice (32).

The elevated plus maze has been widely used to assay the anti-anxiety effects of certain drugs on rodents. The EPM is comprised of four arms that are oriented in an "X"; two of the arms are open/without walls and two are enclosed by walls. The rat would be placed at the junction of those four arms, with a starting position that has them face an open arm. During the course of five minutes, a video-tracking system as well as the observer will record the number of entries and duration the rodent spends in each arm. An increase in open arm activity (duration or entries) is viewed as anti-anxiety behavior (31).

Since D2R and SST2/4R are linked to inhibitory effects, there increased coexpression in CRF neurons might inhibit CRF production.

Previous work establishes that somatostatin signaling is activated by different stressors, and describes somatostatin as having anti-stress effects by blunting endocrine, autonomic, behavioral, and visceral gastrointestinal motor responses (24). Nocturnal animals function optimally in dark conditions; thus, an increase in day exposure would be considered a stressor for them. Somatostatin is, therefore, expected to be elevated in the long day exposure condition.

In a review article on reserve pool neuron transmitter respecification, Dulcis et al. provide a helpful analogy for understanding reserve pools. In this analogy, the role of reserve pools is compared to having two jobs, and following certain physiological stimuli, one of those jobs is relinquished. Dulcis et al. defines reserve pool neurons as "cells that share inputs and outputs with adjacent core pools of neurons but express different neurotransmitters." In one situation, the neurons from both pools could be expressing the same transmitters, but the core neurons also express a secondary transmitter; following the change in circuit activity, the neurons of the reserve pool will stop expressing the transmitter that it has in common with the core pool of neurons. In an alternative scenario, these two pools of neurons could be expressing different neurotransmitters, and the change in circuit activity results in the neurons of the reserve pool acquiring the expression of the transmitter that is already expressed by the core neurons (23).

A study elucidating the counter-regulatory mechanisms used to maintain energy balance in response to environmental or physiological stressors revealed that neurons important for energy homeostasis can be regenerated in adult feeding centers (a region of the hypothalamus). The results of Kokoeva et al. indicate that de novo neurogenesis might serve as a compensatory mechanism to regulate energy balance in the presence of environmental or physiological insults (22). Based on previous work, the researchers have decided to examine whether the inverse relationship they have found between somatostatin and dopamine numbers in the three photoperiods is due to neurons forming or from the neuron switching to produce more SST and less dopamine, or vice versa.

During synaptic vesicle fusion, the nervous system relies on neurotransmitters to transmit signals between neurons. Fluorescent false neurotransmitters have previously been used as substrates for VMAT2, and have served as probes for the imaging of dopamine release in the striatum (17).

In 2009, Ashkenazy et al. performed experiments on Sand rats, diurnal animals, and showed that shortening their exposure to daylight resulted in anxious and depressed behaviors (11). In 2006, there was a study conducted at four Canada centers to compare the effectiveness of light therapy versus the antidepressant fluoxetine for patients with winter seasonal depression. The study suggested that exposure to placebo light 30 minutes/day had similar efficacy to the administration of fluoxetine (12). Since previous work had shown that for diurnal animals, shorter photoperiods can be anxiety or depression inducing (11), and longer light exposure can have anti-depression effects (12), the researchers have proceeded to hypothesize that longer photoperiods will have the opposite effect on nocturnal adult mammals.

With an increase of electronic equipment production, it is rapidly becoming the fastest growing waste stream in the world. If this electronic waste is not handled correctly it could result in many health problems. Most of this electronic waste cannot be recycled. This paper discusses the uses of pyrometallurgical, hydrometallurgical, and biohydrometallurgical means to separate metals from electronic waste.

Mechanical Property tests were run for Ecoflex comparing it to polydimethylsiloxane and polycarbonate. Here it was observed that the great elasticity of Ecoflex made it better suited to be used on the robot based on the movement patterns of the robot.

Previous test were run on Ecoflex and while it was not a translucent as substances such as polycarbonate it showed greater ability to stretch than other competitors which made it ideal for robot.

Electrowetting is a method by which electric fields are used in order to manipulate liquids on the surface of an object. For example, water droplets on the surface of paper can be manipulated in order to create a reflective surface.

Electrofluidics is technique that is a successor to electrowetting. Here liquid dispersion forces are used in order to pull colored oil from a reservoir and into an observable area greatly increasing the ability to see color.

In 2003 Antoni Rogalski published his work on detectors that can see into the infrared spectrum (IR) here he highlighted three different IR detection mechanism and presented their specific benefits over conventional photon detectors. Here he highlighted resistive bolometers, pyroelectric detectors, and termopile as ways of detecting IR waves. Specifically these techniques make vast improvements in terms of thermal imagining which is used for detecting creatures using camouflage.

In the past Robert Shephard has been a pathfinder in the field of soft robotics. He has published several articles that introduce the world to what soft robotics are and detail his work building soft robotic machine such as his soft quadrupedal robot. References 6 and 7 detail his previous work more extensively

In the past scientist have conducted multiple studies as to how and why different organisms change colors. In nature, organisms rely on specialized cells in order to change color where the author it turning to less biomechanical techniques and using microchannels instead.

Past studies have derived that different species may use camouflage for different reasons. However, the techniques that most organism use are widely the same. All organisms will use either background matching, disruptive coloration, or disguise. The author uses these principles for further development for soft robotics. For example, if a doctor was using a soft machine in a surgery and was having a difficult time differentiating the device from its environment. They could utilize the principle of disruptive coloration in order to differentiate the device from a background.

The dynamic covalent chemistry principle states that when a system is under constant entropy then the system will start to approach a minimum value of internal energy. In this case, polyimine is constantly having its covalent bonds broken, which is the constant entropy, and this makes the internal energy of the polyimine lower. With this lower energy, it is easier to break and reattach the covalent bonds within the polyimine, meaning that self-healing is easier.

Dr. Xu and associates have developed a soft microfluidic sensor that could accommodate the human skin. The result was a soft sensor that could sit on the surface of the skin and monitor physiological markers wirelessly.

Dr. Choi and associates developed a nanocomposite made of silver and gold that optimizes conductivity and stretchability. This nanocomposite was used to make implantable implants that could integrate into the human skin.

Dr. Gao and associates have developed a flexible wearable sensor that provides real time signals for certain biomarkers. Gao's devices analyzes sweat to determine real time data for glucose, lactose, electrolytes, and also the temperature of the skin.

The tendency of female blacktip sharks to congregate in shallow waters during the daytime was most strongly connected to water temperature. Other factors considered were tide height and moon phase. The behavior seemed to be for purposes of thermoregulation, not foraging for food.

An analysis of 16 bird and mammal species was conducted to determine if these carnivores were typically finding enough food to satisfy their hunger and energetic needs in the course of a day. The model concludes that the animals typically find all of the food that they need with time to spare that is instead spent digesting.

It has been well-established that prey follow certain schedules to reduce the risk that they could be captured by a predator. How quickly can these schedules change when the risk of predation is reduced? Scientists assumed that there would be a slow response, if any, when the number of predators was reduced, until Mccauley and colleagues put this idea to the test.

By observing fish behavior on reefs where predators had been mostly eradicated by human behavior, the researchers found that fish typically thought of as nocturnal were 6-8 times more likely to be active on the reef during the day, representing a drastic change in what was thought to be a fixed behavioral pattern.

The same authors studied the chemical and physical activity of the shark stomach. They found that gastric acid secretion was continuous, regardless of the timing of feedings. Although the size and type of food did have an impact on stomach activity, the daily temperature cycle seemed to have the greatest influence on activity.

This conclusion naturally lead to the current study which is examining temperature as a factor driving more aspects of the behavior of this shark.

This 2009 study built upon the ideas presented in the 2006 study that first proposed the ODBA method using data collected from cormorants. The same methodology was applied to a range of terrestrial animals (including humans, skunks, geese, penguins, chickens, and armadillos) to test the validity of the method across species.

The authors concluded that ODBA was a valid method to predict oxygen consumption and metabolic rate for all of the animals included in the study, so the authors of the present paper on shark activity can expect a similar finding for their own species of interest.

A 2006 study on cormorants introduced a major shift in thinking about how to study the way in which animals use and acquire energy. The two major methods that were used before this point were 1) monitoring heart-rate or 2) measuring carbon dioxide production using the doubly labeled water method. The ODBA method employs accelerometers (devices to measure the rate of change in the velocity of an object) to measure the rate of energy expenditure for specific animal activities.

The amount of incoming energy from the sun changes drastically between night and day, and varies throughout the year, yet these variations don't affect Earth's surface temperatures as much as would be expected. Tyndall linked the ability of the atmosphere to absorb infrared radiation to this dampening of temperature variation.

Croll's work made important contributions to the understanding of Earth's climate. However, one problem with his theory was that it led to the conclusion that glacial periods occurred at different times in the Northern and Southern hemispheres.

We now know this is not correct; ice ages are global. But at the time Arrhenius wrote this paper, the geological record of the ice ages was not understood well enough to rule out this possibility of separate glacial periods in the hemispheres.

A study in 2 June 2009 conducted by Philip P. Molloy explored the relations with the age of the marine reserves and of the recovery of different species of fish. The studies showed that older marine reserves (15 years and older) were more effective than younger ones. They harbored more fish.

The authors recognize the significant achievement and potential of what others have done, but also note the ways in which the previous work can be improved. The goal of this paper is to build upon others' results and to develop new ideas to try to improve upon what has been done.

Childers and colleagues demonstrated that Everglades hydrology was co-varying with changes in greenhouse warming potentials, energy fluxes and C dynamics which proved that hydrology is important for creating and maintaining conditions sufficient for wetland ecosystem and structure

Jimenez and colleagues studied the effects of carbon balance in wetland ecosystems before the planned Everglades restoration of historical water flow. They trajected that there would be an alteration on the carbon dynamics of the Everglades as a whole.

Dugan examined wetlands in the United States and the total loss of thus ecosystem. This atlas was able to divide the world’s regions into 19 sections and develop information on the wetlands.

Schein, H. (1975). Aspects of the aggressive and sexual behaviour of alpheus heterochaelis say. Marine Behaviour and Physiology, 3(2), 83–96. https://doi.org/10.1080/10236247509378498

This previous work studies aggressive and sexual behavior in snapping shrimp. Although the snapping shrimps studied were found in North Carolina, their behavior reflects the behavior of the genus. Here they established that males seek females using chemical cues, and in general a male with a larger claw/larger body size favors larger females that can produce more offspring. Also, males with larger claws are stronger and can out compete smaller males. In relation to this publication, this previous work establishes a background of the behavior of the snapping shrimp. Understanding their natural behavior helps in understanding how the authors of this publication reached their conclusion. (JP)

Knowlton, N. (1986). Cryptic and Sibling Species among the Decapod Crustacea. Journal of Crustacean Biology, 6(3), 356-363. doi:10.2307/1548175

This previous work defines the term sibling species. According to Knowlton, sibling species are species that have been shown to be very closely related using biochemical techniques such as electrophoretic analysis. Sibling species are not the same species. This publication also uses electrophoretic analyses, known as starch gel electrophoresis, to differentiate between species of snapping shrimp. (JP)

Knowlton, Nancy & Mills, DeEtta. (1992). The Systematic Importance of Color and Color Pattern: Evidence for Complexes of Sibling Species of Snapping Shrimp (Caridea: Alpheidae: AZ'heus) from the Caribbean and Pacific Coasts of Panama. Proceedings of the San Diego Society of Natural History. 18.

This past publication explains how loosely related, or distantly related, species in the genus Afpheus Fabricius (snapping shrimp) can be distinguished based on color morphology such as differences in color patterns. This relates with this publication because both are related to the speciation of snapping shrimp in the Isthmus of Panama. Both publications find methods to differentiate between species; while this paper uses mtDNA and allozymes to compare genetic distance, the other paper uses careful analyses of color patterns to separate species. (JP)

Sexual selection and dimorphism in two demes of a symbiotic, pair-bonding snapping shrimp Knowlton, N. (1980), SEXUAL SELECTION AND DIMORPHISM IN TWO DEMES OF A SYMBIOTIC, PAIR-BONDING SNAPPING SHRIMP. Evolution, 34: 161–173. doi:10.1111/j.1558-5646.1980.tb04802.x

This previous work provides evidence on how differences between mates affects mate choice and, with environmental constraints, can lead to sexual dimorphism which is a distinct difference in size or appearance between the sexes of the same species. This study found that snapping shrimp are very aggressive and territorial to other shrimps of the same sex. By having these type of aggressive traits, compatibility would decrease as species are more separated. This supports one of the results found in this publication. (JP)

Svitil, K.A. (1993). "Oceans Divided". Discover, pp.1-2.

A magazine article by Kathy Svitil talks about the closure of the Isthmus of Panama. She talked about how the rise of Panama 3.5 million years ago separated Atlantic and Pacific species before the land-bridge could even form. This was caused by the shift in tetonic plates, where the Pacific Ocean floor shifted underneath the Carribean plate before melting/solidifying by lava. She states how animals felt the influence of the rifts coming together, even quoting Nancy Knowlton on the speciation of snapping shrimps on either sides of Isthmus since these shrimps used to live in deeper depths of the ocean.

~(J.D.A.)

Knowlton, N. & Keller, B.D. (1982). "Symmetric Fights as a Measure of Escalation Potential in a Symbiotic, Territorial Snapping Shrimp." Behavioral Ecology And Sociobiology, 10(4): 289-292.

This journal goes into detail the behavioral aspect of the Alpheus shrimp. This species readily defends its territory using its large snapping claw. Results gathered focused on symmetric fights of shrimps in regards to sex, size, and resources. According to this study, larger females are more likely to defend their anemone territories and showed more aggressiveness than the male shrimps. The losers of these contests experienced severe injuries by these large females than any other type of shrimps.

~(J.D.A.)

Glynn, P.W. (1985). “El Nino-Associated disturbance to coral reefs and post disturbance mortality by Acanthaster planci.” Marine Ecology Progress Series, 26(17): pp. 295–300.

Another study shows how in 1985 the coral reefs in eastern Pacific (Panama included) got ruined by El Nino due to very high water temperatures (average of 31 Celsius) and depth penetration (over 100 m). Since most habitats in coral reefs were destroyed, many species were easily exposed to predators. This may affect the results obtained by Mills and co. because barely a decade has passed for the marine habitats in Panama to recuperate.

~(J.D.A.)

Read, A., McTeague, J., & Govind, C. (1991). "Morphology and behavior of an unusually flexible thoracic limb in the snapping shrimp, Alpheus heterochelis". The Biological Bulletin, 181(1): pp. 158-168.

This journal explains the morphology of the snapping shrimp Alpheus. Their second thoracic limb is thinner, flexible, bilaterally symmetrical, and possess larger ganglion. This type of limb is almost always active in regards to grooming and foraging for food. The major cheliped, or the larger claw, is used to produce loud popping noises as a defense mechanism against predators.

~(J.D.A.)

Bermingham, E. & Lessios, H.A. (1993). “Rate Variation of Protein and Mitochondrial DNA Evolution as Revealed by Sea Urchins Separated by the Isthmus of Panama.” Proceedings of the National Academy of Sciences, 90(7): pp. 2734–2738.

Another research was made in regards to the closure of Isthmus of Panama 3 MA based on changes in oxygen/carbon ratios in sea water. The main subject studied was sea urchins. Bermingham and Lessios compared mtDNA and protein divergence among three differ species of sea urchins--Diadema, Echinometra, & Eucidaris. Results concluded that protein divergence between Atlantic and Pacific sea urchin species only differed by 1 order of magnitude, so no significant difference. The Diadema species had an overlap of allele frequencies whereas the other two species displayed fixed loci for differ alleles of both shores, which may hint towards gradual genetic drift or mutations.This proves that other marine life besides the Alpheus shrimp community were also affected by a change in the environment via closure of Panama Isthmus.

~(J.D.A.)

Amyloid beta accumulation creates synaptic impairment and learning and memory deficits in AD patients. The impairment of neurons as opposed to neuronal loss maybe the mechanism behind cognitive impairment in AD patients. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3385944/)

Phase amplitude coupling measures the coupling between theta and gamma waves in the hippocampus. The theta and gamma waves are associated with learning and memory. Figure I shows virtually no phase amplitude frequency in the mice with Alz compared to Alz free mice, especially in the APP23p38𝛾-/- mice. Such low frequencies would suggest those mice would have the most problems with learning and memory.

http://www.physiology.org/doi/abs/10.1152/jn.00106.2010

Researchers have found the binding of tau and fyn have been associated with Alzheimer’s disease pathology. Fyn is a kinase that phosphorylates tau and co-localizes with tau in the neurons of Alzheimer’s patients with tau tangles. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4870772/

E. S. Musiek, D. M. Holtzman, Nat. Neurosci. 18, 800–806 (2015). Amyloid-beta is a key initiator of all the downstream processes that cause Alzheimer’s. One process Aβ leads to is initiating tau tangles. Even though Aβ is a key player, Aβ can not cause Alzheimer’s by itself.

K. Iqbal, F. Liu, C.-X. Gong, A del C. Alonso, I. Grundke-Iqbal, Acta Neuropathol. 118, 53–69 (2009). Neurodegeneration from tau implications can be caused from different protein kinases hyperphosphorylating tau. Hyperphosphorylated tau can misfold, create tangles, and not able to stabilize microtubules, all which can all lead to loss of connectivity between neurons.

L. M. Ittner et al., Cell 142, 387–397 (2010)

APP23 mice have increased Aβ toxicity which is the main contributor to the deficits seen in APP23 mice. Deficits include premature death, increased Aβ at young ages, decreased memory, and irregular neuronal circuits.

Hardingham and Bading show that NMDAR responses depend on receptor location. Synaptic NMDARs promotes cell survival, while stimulation of extrasynaptic NMDARs promotes cell death. The unequal stimulation of these receptors cause neuronal dysfunction, while stimulation of synaptic receptors could be used a protective therapy.

In normal physiological conditions tau is used to stabilize microtubular cytoplasmic components in neurons.

APP23 is a version of APP that will develop into AB plaques and aggregates that are associated with Alzheimer’s disease. The APP23 mouse in the experiment overexpressed the APP23 protein.

Previous work: Animals can produce amyloid-beta independently of using APP precursor protein. However, when animals have APP23 mutation, the APP is overexpressed and amyloid beta plaques and intracellular amyloid beta aggregates form. The APP23 has been linked to synapse loss and dendrite degeneration. The APP23 is a Swedish mutation in CNS neurons. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4046770/ )

Ittner and Gӧtz review new findings showing the interactions of tau and amyloid beta. Tau can shift from the axon to the dendrite helping to increase amyloid beta toxicity.

L. M. Ittner et al., Cell 142, 387–397 (2010).: In this article, Ittner and others show that the absence of tau in amyloid beta-forming mice lessens the severity of amyloid beta toxicity. These results suggest that tau and amyloid beta together increases the symptoms and progression of Alzheimer’s disease.

Beall, C. M. (2007). Two routes to functional adaptation: Tibetan and Andean high-altitude natives. Proceedings of the National Academy of Sciences, 104(Supplement 1), 8655-8660. doi:10.1073/pnas.0701985104

These are some of the physiological traits that were found to be different between populations of Tibetan highlanders and Han Chineese. These include but are not limited to: less oxygen in the arteries, higher breathing rate at rest, loss of low oxygen induced blood vessel constriction, and lower occurrences of decreased birth weight, as well as decreased hemoglobin concentrations.

This paper discusses the effect of gender on hemoglobin levels in Han Chinese and Tibetan Plateau inhabitants as a mechanism for high altitude adaptation. In Han populations a correlation was seen between increased altitude and increased hemoglobin levels (men having higher hemoglobin concentration than women), this correlation was not see in Tibetan highland inhabitants, or between genders of Tibetan highland individuals.

It has been noted that protein divergence increases as divergence time increases, thus being said as time increases more protein divergence occurs. To learn more click here. http://www.pnas.org/content/94/24/13028.full.pdf

• Jake Barbee

S.F. Oberbauer's previous work:

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-ITEX).

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).

RW

The way that organisms respond to their environment is ultimately through gene expression. For example, growth is caused by production of growth hormones, among other factors, which are turned on and off. Eukaryotic organisms use histone regulation as one way to respond to environmental changes. It has been found that exchange of histones can occur due to changes in temperature and season, during conflict, movement, learning, and more. AT

H2A.Z.1 is a well documented histone variant. It plays a role in keeping genome integrity, They are highly conserved, even more than H2A.X. AT

Recent research on mollusc DNA has found that they do use methylation systems to regulate their expression. This was determined by using bisulfate PCR. The bisulfate creates a tag on a methylated amino acid in the protein sequence, and PCR is a way to generate many different copies of a single strand of DNA. Using different mapping techniques the locations of methyl group were determined. A methyl group added to a DNA structure serves to wrap the DNA tighter around the histone in order to block transcription. AT

The histone variant H2A.Z Is the most important regarding environmental epigenetic responses. environmental epigenetic are everyday factors in an organism’s life that affect how their genes are expressed that does not create a change in their DNA. AM

H2A.Z was found to have four different subtypes in the Cyprinus carpio, due to the organisms high sense of acclimatization (an individual organisms ability to adjust to a change in its environment such a s a change in altitude, temperature, and humidity). The four subtype variants aid in the thermoregulation (process that allows the body to maintain a core internal temperature) and stability of the organism. KM

H2A.Z.2.2 is found in all human (and some primate species) cell lines but it is found mostly in the brain. It is achieved through alternative splicing of the H2AZ variant. Through biochemical fractionation, the paper results suggest that Z.2.2 causes major structural changes and significantly destabilizes nucleosomes. The findings add to the list of known variants of the H2A.Z family. EM

The papers research clear differences in the structure of the two H2A variants: one in amino acid 38 and one in the structures of the L1 loop. Through mutational analysis, the paper concluded that the amino acid difference at position 38 is partially responsible for the unique functional specializations of H2AZ.1 and H2AZ.2. EM

H2AZ has experienced multiple rounds of specialization which gave rise to new variants. Most vertebrates exhibit the H2AZ.1 and H2AZ.2 variants encoded by independent genes. While their protein products are similar, their promoter regions are very different, suggesting they are each tasked with different roles. The research utilized phylogenetic analysis of the promoter regions to conclude that they evolved separately during vertebrate evolution. EM

They determined that the H2A.Z.1 and H2A.Z.2 are functionally different by individually turning them off and on by knocking out/deleting the gene that codes for the protein. By doing this they discovered that each gene codes for a different protein. Then they discovered that the knockout of each protein resulted in the loss of a distinct function. This work was done in several different studies using different types of cells, such as chicken and human. AT

Highly dynamic chromatin state means that the chromatin is quickly unraveling and raveling to allow transcription, this happens because the histones are rapidly being exchanged from a core to a variant. The variants each give different functions and change the rate of transcription. AM

H2A.Z was derived from H2A through a series of mutations that resulted in it being 60% different from the core H2A. This was determined using a system called GWLA methodology which synthesizes two protein structure determining methods. It breaks the protein into fragments and then sequences it. The H2A.Z is highly conserved throughout eukaryotes meaning that the sequence is the same. Because there are few or no mutations this means that the function is very important and a mutation would be lethal. AT

The family of H2A histone proteins are essential in understanding the biochemistry of chromatin-associated proteins in Mollusca. H2AZ is a variant form of the histone protein that regulates a mediated thermosensory response. The H2A.X variant form contributes to the formation of the nucleosome and its structural integrity.

KM

The papers discuss several structural studies on core histones and linker histone variants. The papers focused on the roles of nucleosome stability, with data showing that histone variability plays an important role in regulation of chromatin metabolism. EM

They determined the structure of histone proteins through crystallography which uses a computer modeling system to determine the atomic structure and how it assembles to form a superhelix model. KM

In the Drosophila group, members of the Drosophila group have either one or two X chromosomes and two sets of autosomes. Sex determination is determined for females by having balanced female determinants on the X chromosome. For males of the Drosophila group sex determination is based on the determinants on the autosomes. If there is only one X chromosome present in a diploid cell the member of the Drosophila group is male, this is shown by the ratio of (1X:2A). To learn more click here https://www.ncbi.nlm.nih.gov/pubmed/18956315 -Jake Barbee

Heck, K. L. (1977). Comparative species richness, composition, and abundance of invertebrates in Caribbean seagrass (Thalassia testudinum) meadows (Panamá). Marine Biology, 41(4), 335–348. https://doi.org/10.1007/BF00389099

This previous work compares the species composition and abundance of invertebrates in the Caribbean coast of Panama and the Panama Canal Zone. While discussing some factors that could have affected this experiment, the author of this publication noted that the Panama Canal zone could have led to the displacement and death of many snapping shrimp. This previous work observed that species composition of invertebrates (which include snapping shrimp) were the same in tropical and subtropical seagrass meadows, however, different species of shrimp had a lower total abundance. This could mean that the formation of the Isthmus of Panama, followed by the construction of the Panama Canal, had an effect on speciation of several species of shrimp. (JP)

Knowlton, N. (1986). Cryptic and Sibling Species among the Decapod Crustacea. Journal of Crustacean Biology, 6(3), 356-363. doi:10.2307/1548175

This previous work defines the term sibling species. According to Knowlton, sibling species are species that have been shown to be very closely related using biochemical techniques such as electrophoretic analysis. Sibling species are not the same species. This publication also uses electrophoretic analyses, known as starch gel electrophoresis, to differentiate between species of snapping shrimp. (JP)

Schein, H. (1975). Aspects of the aggressive and sexual behaviour of alpheus heterochaelis say. Marine Behaviour and Physiology, 3(2), 83–96. https://doi.org/10.1080/10236247509378498

This previous work studies aggressive and sexual behavior in snapping shrimp. Although the snapping shrimps studied were found in North Carolina, their behavior reflects the behavior of the genus. Here they established that males seek females using chemical cues, and in general a male with a larger claw/larger body size favors larger females that can produce more offspring. Also, males with larger claws are stronger and can out compete smaller males. In relation to this publication, this previous work establishes a background of the behavior of the snapping shrimp. Understanding their natural behavior helps in understanding how the authors of this publication reached their conclusion. (JP)

Sexual selection and dimorphism in two demes of a symbiotic, pair-bonding snapping shrimp Knowlton, N. (1980), SEXUAL SELECTION AND DIMORPHISM IN TWO DEMES OF A SYMBIOTIC, PAIR-BONDING SNAPPING SHRIMP. Evolution, 34: 161–173. doi:10.1111/j.1558-5646.1980.tb04802.x

This previous work provides evidence on how differences between mates affects mate choice and, with environmental constraints, can lead to sexual dimorphism which is a distinct difference in size or appearance between the sexes of the same species. This study found that snapping shrimp are very aggressive and territorial to other shrimps of the same sex. By having these type of aggressive traits, compatibility would decrease as species are more separated. This supports one of the results found in this publication. (JP)

Knowlton, Nancy & Mills, DeEtta. (1992). The Systematic Importance of Color and Color Pattern: Evidence for Complexes of Sibling Species of Snapping Shrimp (Caridea: Alpheidae: AZ'heus) from the Caribbean and Pacific Coasts of Panama. Proceedings of the San Diego Society of Natural History. 18.

This past publication explains how loosely related, or distantly related, species in the genus Afpheus Fabricius (snapping shrimp) can be distinguished based on color morphology such as differences in color patterns. This relates with this publication because both are related to the speciation of snapping shrimp in the Isthmus of Panama. Both publications find methods to differentiate between species; while this paper uses mtDNA and allozymes to compare genetic distance, the other paper uses careful analyses of color patterns to separate species. (JP)

Bermingham, E. & Lessios, H.A. (1993). “Rate Variation of Protein and Mitochondrial DNA Evolution as Revealed by Sea Urchins Separated by the Isthmus of Panama.” Proceedings of the National Academy of Sciences, 90(7): pp. 2734–2738.

Another research was made in regards to the closure of Isthmus of Panama 3 MA based on changes in oxygen/carbon ratios in sea water. The main subject studied was sea urchins. Bermingham and Lessios compared mtDNA and protein divergence among three differ species of sea urchins--Diadema, Echinometra, & Eucidaris. Results concluded that protein divergence between Atlantic and Pacific sea urchin species only differed by 1 order of magnitude, so no significant difference. The Diadema species had an overlap of allele frequencies whereas the other two species displayed fixed loci for differ alleles of both shores, which may hint towards gradual genetic drift or mutations.This proves that other marine life besides the Alpheus shrimp community were also affected by a change in the environment via closure of Panama Isthmus.

~(J.D.A.)

Read, A., McTeague, J., & Govind, C. (1991). "Morphology and behavior of an unusually flexible thoracic limb in the snapping shrimp, Alpheus heterochelis". The Biological Bulletin, 181(1): pp. 158-168.

This journal explains the morphology of the snapping shrimp Alpheus. Their second thoracic limb is thinner, flexible, bilaterally symmetrical, and possess larger ganglion. This type of limb is almost always active in regards to grooming and foraging for food. The major cheliped, or the larger claw, is used to produce loud popping noises as a defense mechanism against predators.

~(J.D.A.)

Knowlton, N. & Keller, B.D. (1982). "Symmetric Fights as a Measure of Escalation Potential in a Symbiotic, Territorial Snapping Shrimp." Behavioral Ecology And Sociobiology, 10(4): 289-292.

This journal goes into detail the behavioral aspect of the Alpheus shrimp. This species readily defends its territory using its large snapping claw. Results gathered focused on symmetric fights of shrimps in regards to sex, size, and resources. According to this study, larger females are more likely to defend their anemone territories and showed more aggressiveness than the male shrimps. The losers of these contests experienced severe injuries by these large females than any other type of shrimps.

~(J.D.A.)

Svitil, K.A. (1993). "Oceans Divided". Discover, pp.1-2.

A magazine article by Kathy Svitil talks about the closure of the Isthmus of Panama. She talked about how the rise of Panama 3.5 million years ago separated Atlantic and Pacific species before the land-bridge could even form. This was caused by the shift in tetonic plates, where the Pacific Ocean floor shifted underneath the Carribean plate before melting/solidifying by lava. She states how animals felt the influence of the rifts coming together, even quoting Nancy Knowlton on the speciation of snapping shrimps on either sides of Isthmus since these shrimps used to live in deeper depths of the ocean.

~(J.D.A.)

Glynn, P.W. (1985). “El Nino-Associated disturbance to coral reefs and post disturbance mortality by Acanthaster planci.” Marine Ecology Progress Series, 26(17): pp. 295–300.

Another study shows how in 1985 the coral reefs in eastern Pacific (Panama included) got ruined by El Nino due to very high water temperatures (average of 31 Celsius) and depth penetration (over 100 m). Since most habitats in coral reefs were destroyed, many species were easily exposed to predators. This may affect the results obtained by Mills and co. because barely a decade has passed for the marine habitats in Panama to recuperate.

~(J.D.A.)

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. (DB)

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. (DB)

Exposure to ultraviolet (UV) radiation is a risk factor for the development of melanoma. Researchers have shown that people who sunburned in childhood are at a greater risk of developing melanoma than are people who sunburned in adulthood. This study suggests that age is associated with the susceptibility of skin to environmental carcinogens. (DB)

There is an increase in the amount of Ednrb in most cell lines. This is significant because Ednrb expression is increased in melanoma metastases. (DB)

Ednrb encodes a G-protein-coupled receptor that is necessary for the development of melanocytes. Studies have shown that Ednrb is not necessary for the development of early melanoblasts but is essential for the expression of the differentiation marker tyrosinase. Ednrb wild-type cultures must be able to generate the KIT ligand. Moreover, a soluble KIT ligand allows tyrosinase to be expressed in cultures that do not contain sufficient amounts of Ednrb. (DB)

Mutations in genes that code for Edn3 result in deficiencies in melanocytes. Edn3 serves as a stimulator of melanoblast proliferation and differentiation. When melanoblasts differentiate, they become melanocytes. (DB)

Researchers have shown that individual melanocytes produce multipotent cells that are able to regenerate during consecutive subcloning. This indicates that the multipotent cells display stem cell qualities. Edn3 encourages the maintenance of the multipotent cells. Moreover, Edn3 stimulates the proliferation of melanoblasts, which are the precursors of melanocytes. (DB)

Cells proliferate in the presence of Edn3. The cells that are produced are melanoblasts, which subsequently become melanocytes. (DB)

Researchers isolated Edn1 to determine its function. Edn1 was shown to be responsible for an increase in blood pressure. Expression of the gene was controlled by factors that affect blood vessels, suggesting that there is a cardiovascular control system. (DB)

A study in 2 June 2009 conducted by Philip P. Molloy explored the relations with the age of the marine reserves and of the recovery of different species of fish. The studies showed that older marine reserves (15 years and older) were more effective than younger ones. They harbored more fish.

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

-Otniel Gonzalez

Previous work said that the sharks were traveling to different habitats to find food.

McCauley, D.J., Young, H.S., Dunbar, R.B., Estes, J.A., Semmens, B.X., and Micheli, F. (2012). Assessing the effects of large mobile predators on ecosystem connectivity. Ecol. Appl. 22, 1711–1717.

-RKL

The scanning and tail probing behavior of fish is the process in which they use certain tail movement around an object in order to discover the depth and size of objects in their environment. Think about what happens when you put a goldfish into bowl after it has been in an plastic bag. It will immediately start swimming around and swishing its tail around. That is a process of scanning and tail probing behavior. - Kierra Hobdy

From previous articles, the testing IN Drosophila melanogaster, the gene Sex-lethal (Sxl) controls the processes of sex determination, sexual behavior, and dosage compensation (the products of the X-linked genes are present in equal amounts in males and females. Sxl produces two temporally distinct sets of transcripts corresponding to the function of the female-specific early and non-sex-specific late promoters, respectively -Melanie Learn more: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448812/

Genes exist in genome as either single copy or duplication. The efficiency of gene expression ranges from low (producing few proteins) to very high (producing many proteins).

Mechanical property of single DNA molecule, assays of biomolecules with nanoscale control, single-molecule detection of ribosomes binding with other proteins, etc. add to our current understanding of transcriptional and translational events at molecular levels.

Electric eels have been used as a model in the study of bioelectrogenesis, which is the study of electricity produced by living organisms. The species is of some interest to researchers, who make use of its acetylcholinesterase and adenosine triphosphate.

a brief and single electric shock(stimulus) triggers a signal (action potential) in the muscle. After an activation delay ( due to the time it takes for the signal to reach its target) a muscle contraction occurs. The muscle usually relaxes after a few milliseconds unless another contraction signal is send out before the muscle fully relaxes where the muscle contracts again. The contraction that happens after the second contraction is greater that the first because it equals the sum of the tension from both signals being greater. Each of these signals causes the specie to involuntarily twitch and lose control over motor neuron and therefore movement.

Winnik and Manners et. al. used Karstedt's catalysts to cross-link polyisoprene in order to create micelles of varying morphologies. They were able to apply this technique for the development of noncentrosymmetric micelles.

Prior to this article, despite the usefulness of CDSA, many of the structures synthesized were centrosymmetric since growth can happen from both ends of the micelle core. This article presents the development of a method to overcome this limitation.

After the discovery of CDSA, the synthetic strategy has been used with a range polymers including conducting, biocompatible, metal-containing, etc.

Previous Work: During CDSA, the crystalline core of the micelle is partially "exposed" to the solvent. When unimers are added to the micelle solution, they are able to grow on existing micelle. However, if the chemical structure of the core prevents crystallization/is not a lattice match, then micelle growth will not happen. This technique has been widely used with a variety of materials such as diblock polymers and nanotubes to create unique self-assemblies.

This technique was first introduced in 2007 by Winnik and Manners et. al. where they discovered a "living" form of micellization. The term "living" in this scenario is derived from the phase "living polymerization" where monomers form long chains by continuous addition to the reactive chain ends, without termination. In the same way, certain micelles specifically those that had crystalline cores exhibited the ability to elongate when additional block copolymers are added to the micelle solution.


Previous study demonstrated that HDAC6 has the capacity to bind both polyubiquitinated misfolded proteins and dynein motors, thereby acting to recruit misfolded protein cargo to dynein motors for transport to aggresomes.

Cells deficient in HDAC6 fail to clear misfolded protein aggregates from the cytoplasm, cannot form aggresomes properly, and are hypersensitive to the accumulation of misfolded proteins.

This study reported the design and synthesis of a potent and selective HDAC6 inhibitor.

In a previous work, scientists investigated whether ubiquitin chain binding affects HDAC6 activity. To generate a ubiquitin-chain binding deficient mutant of HDAC6, they mutated several residues in the BUZ finger that were predicted to make contacts with ubiquitin. It was found that W1182A point mutation markedly disrupted the ability of HDAC6 to bind free ubiquitin chains.

In a previous work, scientists investigated whether ubiquitin chain binding affects HDAC6 activity. To generate a ubiquitin-chain binding deficient mutant of HDAC6, they mutated several residues in the BUZ finger that were predicted to make contacts with ubiquitin. It was found that W1182A point mutation markedly disrupted the ability of HDAC6 to bind free ubiquitin chains.

In a previous work, the authors found the histone deacetylase 8 was required for centrosome cohesion and influenza A virus entry.

Previously, the DNA analysis of the genome of prehistoric wolves and dogs support the idea of a two-step domestication process. The first one was the evolution of wolves through a mutually beneficial relationship with humans, sharing food and space. The second one was the active breeding of dogs by humans in order to select dogs which were adapted to the current needs (hunting, tracking, pet).

Furthermore, there are two main hypotheses to explain the first domestication step (http://www.americanscientist.org/issues/pub/early-canid-domestication-the-farm-fox-experiment):

1) “Self-domestication” by the wolves: Some wolves lived in the vicinity of the camps of the nomadic hunter-gatherers to eat the garbage left by the prehistoric people. Those that were less anxious thrived and continued to follow the humans, generation after generation, and gradually the first dogs emerged from this group.

2) The prehistoric people actively selected wolf pups and let only the most docile ones reproduce. After several generations, the first dogs emerged. This hypothesis has been being tested in Novosibirsk since 1959, where foxes are being bred for “tamability.”

In ref. 5, a genome-wide array of SNP between dogs and wolves suggest that dogs originate from Middle East.

However, ref. 6, the comparison between dog and wolf mitochondrial DNA suggests East Asia as the center of dog origin.

The authors collected the mtDNA sequences previously published by other teams in order to get more data to analyze and a larger diversity of samples.

Some of the phenotypic adaptation can be observed, such as: shorter fangs and claws alteration of some brain areas.

By comparing the DNA of phenotypically domesticated canids and actual dogs and identifying the genes which are responsible of the domesticate phenotype, it is possible to understand which genes have been altered by domestication and when they have been altered.

In ref. 5, a genome-wide array of SNP between dogs and wolves suggest that dogs originate from Middle East.

However, ref. 6, the comparison between dog and wolf mitochondrial DNA suggests East Asia as the center of dog origin.