5,169 Matching Annotations
  1. Aug 2018
    1. high performance liquid chromatography

      High performance liquid chromatography (HPLC) is a technique commonly used in analytical chemistry to help separate, identify and quantify components in an organic mixture.

    2. Lipid assays

      Lipid assays include utilizing synthetic lipids to construct a lipid bilayer similar to the cell membrane. Lipid assay kits may be used to measure concentrations of lipid mixtures in comparison to membrane proteins in a cell membrane.

    3. previtellogenic stage (PVGS), an ovarian resting stage (ORS) and a vitellogenic stage (VGS)

      One of the most significant stages of the reproductive cycle is vitellogenesis which involves massive production of yolk protein and their accumulation in developing oocytes. Vitellogenesis is dependent on the availability of a blood meal and, as a consequence, is linked to transmission of pathogens. Therefore, vitellogenesis and other aspects of mosquito reproductive physiology is critical for their management of disease. The ovarian resting stage in the reproductive cycle of female mosquitoes is a time when the eggs are not being produced. In addition, the ovaries will not develop beyond a resting stage until a blood meal of adequate size has been taken.

    4. RNA interference (RNAi)

      RNA Interference is a response to double-stranded RNA that is responsible for the resistance of pathogenic nucleic acids such as certain mutations in base pairs, and regulates how genes express a particular protein.

    5. corpora allata (CA)

      Found in the head of insects. It is responsible for the regulation of metamorphosis and reproductive functions in most insects.

    6. signaling pathway

      A signaling pathway allows an activation process to occur for a cell to have a specific function. In this case, communication takes place between these two different hormones, juvenile and insulin. These hormones work with energy to develop an insect.

    7. juvenile hormone

      A chemical signal that regulates larva development and metamorphosis in insects.

    1. transport

      Movement of chemicals away from their initial emission source.

    2. intermediate-volatility organic compounds (IVOCs)

      Molecules that contain carbon atoms that somewhat evaporate into the gas-phase at typical pressures and temperatures.

    1. Parafilm

      Primarily used in laboratories. It is commonly used for sealing or protecting vessels (such as flasks or cuvettes). It is a ductile, malleable, waterproof, odorless, translucent, and cohesive thermoplastic.

    2. euthanized

      Put to death with minimal pain.

    3. they would incur an increased maintenance cost (Karasov, 1986) for repairing damaged tissue

      They would injure themselves too much, potentially leading to death.

    4. cruising specialist

      A type of fish that swim around and look for their prey, which are widely dispersed. They also have a stiff body with minimal drag when they swim. Sharks and salmon are also cruise specialists.

    5. red muscle

      Type of skeletal muscle in a fish; slow-twitch muscle on the outer sides of a fish.

      https://esi.stanford.edu/exercise/exercise6.htm

    6. ecomorphology

      The study of the relationship between the ecological role of an individual and its morphological (i.e. structure/form) adaptations.

    7. teleosts

      Members of a large and extremely diverse group of ray-finned fishes.

    8. Billfishes are considered to be among the fastest swimmers in the oceans.

      Billfish have long bills (elongated upper jaw), which allows them to cut through water, and aerodynamic bodies so they can swim in speeds of up to 120 kilometers per hour. Billfish include sailfish, swordfish, and marlin.

    1. ported

      Transferred.

    2. clustering

      In statistics, this is the process of organizing a set of objects (such as data points) into groups (or clusters) based on similar features.

    3. semantic

      Related to the meaning of words in a language.

    4. lemma

      Known in mathematics as a "helping theorem," this is a proposition that forms one part of a larger or more general theorem.

    5. distance metric

      A mathematical expression that defines the distance between any two elements in a set. Finding the distance between each of the elements in two feature vectors (each representing an image) would let you determine how similar those two images are. That is, the smaller the distance between the elements, the more similar the images are.

    6. vector

      A row of numbers.

    7. inhibitory

      Blocking an action or making it less likely to occur.

    8. locality-sensitive

      A type of hashing that aims to reduce the size of a large data set by mapping it into a table with fewer entries than pieces of data. To do this, similar pieces of data are assigned to the same entry in the table.

    9. algorithm

      A set of instructions that tells a computer how to carry out a task or solve a problem.

    1. Alopex lagopus

      Binomial nomenclature for the arctic fox. They are native to the arctic regions in the northern hemisphere, and are commonly found in the arctic tundra biome. They are carnivorous with a common diet of birds, hares and insects in the Aleutian islands.

    1. Phylogenetic distance

      The amount of time that has passed since two species have shared their most recent common ancestor.

    2. Brownian motion model of evolution

      In Brownian motion model of evolution, traits change randomly in distance and direction.

      The model uses two parameters: the population mean trait and the evolutionary rate parameter.

      This model is used in biology to compare traits between individual species and create phylogenetic trees.

    3. phylogenetic signal

      The likelihood that taxas with a shared common ancestor will have similarities in their appearance, behavior, and in their interactions with others.

    4. terpenes

      A large and diverse group of organic compounds that are present in many plants and insects.

      Terpenes are often found in conifers, which release a distinct scent.

    5. volatility compounds

      Mixtures that can readily become vapors or gases.

    6. transects

      Narrow paths through which one collects information on the species that is being studied.

    7. pantropical genus

      A taxonomic category that can be found throughout the tropics.

    8. divergent selection

      The process of choosing that leads to the formation of new species due to the accumulation of differences between species.

    9. qualitative

      A characteristic that can be measured based on an observable standard or quality.

    10. quantitative

      A characteristic that can be measured based off of its amount or quantity.

    11. niche

      The job/role that an organism performs in its environment.

    1. lateral gene transfer

      When an organism picks up new DNA from another organism that is not its parent.

    2. Michaelis constant

      Indicates how much of a chemical per volume (concentration) in a solution with a given amount of enzyme needed to make the reaction go at half of its maximum possible rate.

      https://www.chem.wisc.edu/deptfiles/genchem/netorial/modules/biomolecules/modules/enzymes/enzyme4.htm

    3. gene homologs

      Sets of DNA in different organisms that encode similar traits in different organisms. Homologs are often used to show how certain traits, like the ability to digest PET, developed over the course of evolution.

    4. Integr8 fully sequenced genome database

      A publicly accessible database with information gathered on all the DNA from all the organisms who have had their genome sequenced.

    5. gene cluster

      A section of DNA that contains information to build at least two proteins. Those proteins then perform related functions in a cell.

    6. transporter

      Types of proteins that go through a cell membrane. A transporter will help carry a molecule from the outside to the inside of a cell and vice versa.

    7. Extracellular

      A process that occurs outside of the cell.

    8. metabolism

      We often think of metabolism as the process by which humans break down food into energy; however, it can also be used to describe the process by which a cell breaks down a molecule, like PET in this case, for energy.

    9. transcriptomes

      The total population of mRNA in a cell. mRNA is the compound that helps carry information carried in DNA to the parts of the cell that use it to create proteins.

    10. RNA-sequenced

      Reads all of the RNA in a cell and records the order of base pairs.

    11. supernatant

      The liquid above a solid sample. In this case, the solid sample is composed of l. sakaiensis cells.

    12. substrate specificity of PETase

      In this case, a highly specific enzyme would degrade PET but not other esters.

    13. Substrate specificity

      Describes how much an enzyme prefers one chemical to others.

    14. glass transition temperature

      The temperature above which a polymer becomes flexible and pliable. Below the glass transition temperature the polymer will be hard and brittle, like glass.

    15. highly crystallized

      Indicating a material that is very ordered on a microscopic scale, like a grain of salt or a diamond. An amorphous solid, for example, lacks this order.

    16. BHET

      The basic monomer of PET. It is made up of TPA with two ethylene glycol groups attached to opposite ends.

    17. Bootstrap values

      Used to show what percent of times a node, or a place where two different branches originate, shows up in a phylogenic tree. The tree is recreated many times using slightly different data samples. Higher bootstrap values suggest the node is more likely to be correct.

    18. phylogenetic tree

      A diagram that shows how different organisms or biological species, like enzymes in this case, are related to each other. A node, where there is a branch in the tree, represents when the two species have evolutionarily diverged from each other.

    19. liquid chromatography

      A technique for separating different compounds. The compounds are dissolved in some solvent and run through a thin tube called a column lined with a solid substance. Compounds that are attracted to the solid substance come out of the column after the compounds that are less attracted to the solid in the sample.

    20. catalytic residues

      Amino acids that are directly involved with speeding up a reaction. In this case, the degradation of PET.

    21. open reading frame (ORF)

      A stretch of DNA that the cell is able to read and translate into mRNA which can be used to make a single protein.

    22. secreted enzymes

      Enzymes that are built inside a cell, but later sent outside the cell. In this case, the secreted enzymes end up on the PET film.

    23. adherent cells

      A cell that is sticking to a surface.

    24. SEM

      Stands for Scanning Electron Microscope. The microscope uses an electron beam that produces signals about the sample's surface and then converts that information into a picture. SEM allows us to see things too small to visualize with a more common light microscope.

    25. protozoa

      A type of single-celled organism. There is a lot of diversity among the different types of protozoa. Although they are single-celled like bacteria, they have different forms and behaviors. They typically lack a cell wall, for example, and many will survive by eating other organisms rather than by photosynthesis.

    26. morphological

      The morphology of a PET fiber describes its shape and surface texture. For example, we might describe its morphology as being rough, smooth, or flat. If there are morphological changes, that implies something about the bacteria changed the shape of the PET film.

    27. microbial consortium

      A set of microscopic organisms, typically bacteria, from two or more species.

    28. mineral medium

      A solution of water and whatever chemicals an organism, in this case these fungi, need to grow. It will often include vitamins, minerals, and some type of food source.

    29. Fusarium oxysporum and F. solani,

      These are types of fungi. Both fungi cause disease in some plants and F. solani also causes disease in humans. Previous research has shown that they can produce enzymes that can degrade PET to some extent.

    30. terephthalic acid

      The simplest form of the monomer, or repeating unit, of the polymer PET.

    31. aromatic

      Any compound that has six carbons bonded together in a ring and sharing three double bonds. Aromatic compounds tend to be unusually stable.

    1. X-linked nephrogenic diabetes insipidus

      Nephrogenic diabetes insipidus (NDI) is a congenital disease characterized by the body's inability to make concentrated urine. It can be caused by mutations in two different genes, including AVPR2.

    1. biotite
    2. Augite Biotite Tuff

      The tuff is situated on top of the Footprint Tuff, therefore it was more recently formed.

    3. Hadar and Maka

      Palaeontology sites in Ethiopia. Lucy, the well-known early hominin fossil, was found near Hadar.

    4. Plio-Pleistocene

      By grouping the Pliocene and Pleistocene epochs, scientists have informally created a time period that runs from about 2.5 to 1.5 million years ago. This is when Australopithecus expanded into East Africa. https://www.grossmont.edu/people/bonnie-yoshida-levine/online-lectures/plio-pleistocene.aspx

    5. Standard Error of Estimate

      A statistical calculation to determine the accuracy of predictions made using the regression line.

    6. least squares technique

      A form of linear regression used to determine the best fit line.

    7. trilateration

      A survey technique used to determine the location of points. Distances along the sides of a triangle are measured and angles computed. By constructing a series of adjacent triangles, distances between points can be accurately determined.

    8. morphometric

      A method of taxonomic analysis involving the external measurement of the form of an object, organism, or landform.

    9. putative

      Generally considered or reputed to be.

    10. sensu lato

      Means "in the broad sense."

    11. Ma

      Represents a time unit of one million years. 1.0 Ma means one million years before the present.

    12. linear regressions

      A way to statistically summarize the relationship between two quantitative variables.

    13. equids

      A family that includes horses, zebras, and other related mammals.

    14. giraffids

      A family that includes the modern-day giraffe. Giraffids share a common ancestor with bovids.

    15. Madoqua-like bovids

      These are antelopes such as Kirk's dik-dik.

    16. ichnological

      The branch of science that studies fossilized footprints, animal burrows, and other traces of the existence of an animal and its behavior.

    17. undulating

      Here, undulating indicates that the upper edge of the soil layer has a continuous up and down shape. It is not flat.

    18. Homogeneous

      Particles that are of the same kind.

    19. clods deriving from disarticulation of desiccation polygons

      Desiccation polygons are areas bordered by cracks in the mud found in sedimentary rocks and mud flats. Disarticulation suggests that the polygons separated from the mud and formed individual clods of earth or rock.

    20. micro- to cryptocrystalline

      Describes the surface of a rock or mineral that is made up of crystals too small to be seen with without magnification.

    21. augite

      A mineral involved in the formation of many igneous and metamorphic rocks.

    22. Photomosaic

      A large-scale photograph made up of many smaller photographs.

    23. gully

      A water-worn trench.

    24. contemporaneous

      Existing or occurring in the same period of time.

    25. bovid

      A mammal of the cattle family.

    26. EW-trending fault

      That is, a fault line running east to west.

    27. scarp

      The side of a cliff or a steep slope. It can form as a result of faulting or erosion.

    28. terrace

      A raised flat land area with sides that slope.

    29. stratigraphic

      Stratigraphy is the study of rock layers. An analysis of a stratigraphic sequence would be looking at the types of sedimentary deposits, their age, and distribution from one area to another.

    30. Tuff

      A soft, porous rock that is formed from volcanic ash and or cinders. Over time it is compacted into solid rock.

    31. holotype

      The single specimen that is used by the author of an article to describe and name a new species. It could also refer to two or more specimens described by the author when a single holotype is not identified.

    32. metamorphic rocks

      Formed when preexisting rocks are subjected to intense heat and pressure. This results in the original rocks changing both physically and chemically. Common examples are marble, slate, and schist.

    33. trackways

      In this case, a series of fossil footprints made by hominids or other animals.

    34. polygynous

      Animals that typically have more than one mate.

    35. sexual dimorphism

      Refers to differences in appearance and size between males and females of the same species. Modern humans show a low level of difference in size and appearance. Differences between the sexes is much more pronounced in early hominins and in primates such as gorillas and orangutans.

    36. Pliocene

      A period during Earth's history that occurred between 23 million and 5.3 million years ago.

    37. palaeosurface

      A land surface resulting from erosion that occurred during ancient times.

    38. Tanzania

      A country located south of the equator in East Africa. (See the map of Africa in Figure 1 for the location of Tanzania and Laetoli.)

    1. malaria

      Malaria is a flu-like disease caused by a parasite. The parasite infects and kills blood cells while also releasing toxins. If left untreated, this infection can result in organ failure and death. It is transmitted by certain species of mosquitoes.<br>

    2. larval stage

      Mosquito larvae live in the water and feast on microorganisms. They go through four growth spurts before becoming a pupa.

    3. pupal stage

      The pupal stage is the time at which the mosquito transforms from a water-inhabiting larvae to a wing-bearing adult. Much like butterfly metamorphosis, the mosquito is encased in a hard but thin shell-like structure.

    4. r.1A>C

      This is a denotation for a nucleotide change. This is ribonucleotide 1 changed from an A to a C.

    5. transfected

      A technique to deliver nucleic acids to eukaryotic cells through membranes. There are many ways to do this, but two common ones are through chemicals or electricity.

    6. pools

      A collective sample. In this case, mRNA samples from multiple female mosquito embryos of the same age were combined before being sequenced. The same was done across different time points and for male mosquitoes. Because mosquitoes are small organisms, there is not enough cells/RNA to perform a quality sequencing reaction. Thus, several or maybe even hundreds of organisms must be combined in order to have enough material. When looking at sequencing data from "pools", you are actually observing the "average", but since these are laboratory raised mosquitoes, it is assumed that they are genetically identical. So the "average" is likely true for all organisms in the population.

    7. resistance

      Changes in the mosquito genome have made them no longer susceptible or at least not as sensitive to insecticides. Much the same as bacteria developing genetic resistance to antibiotics.

    8. ectopic

      In an abnormal place. In this case, nucleic acids are injected into mosquito larvae leading to expression of a gene that is not normally there.

    9. maternal tra mRNA

      The female egg cell is a rather large cell compared to the fertilizing male sperm cell. This large egg cell has more mRNA in the cytoplasm (as well as things like mitochondria) than the sperm cell. When the zygote is formed, there is a large maternal contribution of cytoplasmic goodies.

    10. dosage compensation

      A process by which the expression of genes on the autosomes (all the other chromosomes that are not sex chromosomes) and sex chromosomes (in both sexes) are balanced through either inactivation of chromosomes or increased gene expression from a chromosome.

    11. isoform

      A particular version of an expressed gene (mRNA), may or may not have all of the exons encoded by the gene.

    12. transgenic

      An organism that has some amount of genetic material from another unrelated organism.

    13. irradiation

      Exposure to radioactive compounds.

    14. cytogenetic

      Referring to chromosomes.

    15. triploid

      Having three sets of chromosomes. Most animals are diploid, having two sets of chromosomes, one from mom, one from dad.

    16. knockdown

      Reduced expression of a gene, not complete removal.

    17. heterogametic

      Having two different sex chromosomes. In humans, males are the heterogametic sex.

    18. homogametic

      Having two of the same sex chromosomes. In humans, females are the homogametic sex.

    19. lepidopteran

      Order of butterflies and moths.

    20. up-regulation of transcription

      Increased expression of genes.

    21. loss-of-function mutations

      Any change in DNA that results in a non-functional protein. Many different types of mutations can accomplish this, nonsense mutation and large deletions are the first thing that come to mind. They can render a protein non-functional by it being completely absent. Even missense mutations that change a single amino acid can render a protein non-functional if it hits a functional domain, even if the protein itself is present.

    22. karyotype

      A visualization of the number and kinds of chromosomes present in an organism. This term is used loosely here, as XY males were determined through PCR, not the traditional means of visualizing chromosomes under a microscope.

    23. cassette

      A mobile DNA sequence that contains a gene. In genetic engineering, these sequences can be moved between plasmids or other useful vectors through restriction or recombination sites.

    24. green fluorescent protein (GFP)

      A protein derived from jellyfish that emits a neon green light when excited by UV or blue light.

    25. plasmid

      A continuous circular molecule of DNA. Originally derived from bacteria, plasmids have proven to be a useful delivery system of DNA in molecular biology.

    26. coinjected

      Injecting two or more things (in this case nucleic acids) at once.

    27. secondary structure

      This level of structure in a protein is when the amino acid chain begins to have three-dimensional shape. Side chains of the amino acids fold and interact through chemical forces like hydrogen bonds, van der Waals interactions and hydrophobic interactions. The most common secondary structures are helices, sheets, loops and turns.

    28. helix-loop-helix motif

      This type of secondary structure in an amino acid chain is comprised of two alpha helices connected by a loop. This type of structure is indicative of the protein's ability to bind DNA as a transcription factor.

    29. premature stop codon

      A stop codon (UAA, UAG or UGA (RNA)) that occurs earlier in the sequence than intended, usually due to a change in the DNA. This results in a truncated (not full length) protein.

    30. initiation codon

      Start codon (ATG (DNA) AUG (RNA))

    31. purifying selection

      Selection against deleterious traits (negative selection).

    32. open reading frames (ORFs)

      A stretch of DNA sequence that has the ability to be translated into protein (exons only). An ORF usually begins with a start codon (ATG) and ends with a stop codon (TAA, TAG or TGA).

    33. nonsynonymous

      Changes in DNA that end up coding for a different amino acid in the protein product.

    34. synonymous substitutions

      Changes in DNA that ends up coding for the same amino acid in the protein product.

    35. Reverse transcription (RT)–PCR analysis

      Similar to PCR, RT-PCR is a method that first converts mRNA in to DNA by use of a RT polymerase (enzymes like this are used in viruses like HIV). Once the RNA is in DNA form, the traditional PCR method can be used to amplify transcripts of interest.

    36. in vivo

      in vivo inside of a living organism. In this case an experiment that was done in a cell line (in vitro) and worked, was then done in a living organism to see if it would also work in the context of the whole animal.

    37. cell line

      A population of cells derived from a single cell isolated from an organism. Thus, all cells in the culture are genetically identical. Often different cell lines have unique experimental qualities to them. In this case, this line lacks the Y chromosome, which may have been genetically engineered or may have occurred by chance.

    38. in vitro–synthesized mRNA

      mRNA molecules that were made in a tube (in vitro outside of a living organism).

    39. gel loading control

      A control that helps to ensure that the same amount of RNA is added from each sample, so that if lower or higher levels of RNA are seen in different samples you can ensure it's due to biological differences and not just human loading error.

    40. zygotic expression

      There is a maternal to zygotic transition (MZT) in the zygote after blastoderm formation but before gastrulation. During this process maternally deposited RNAs from the egg are degraded and the new genome of the zygote is activated and begins transcription and translation of genes. The zygote is now on its own, without the support of good old mom.

    41. orthologs

      Similar genes in different species that derived from a common ancestor.

    42. blastoderm

      A single layer of cells (about 4,000) that surround the outside of the zygote. In the fruit fly, this happens about 3 hours after fertilization.

    43. oviposition

      The process of laying eggs in a fly.

    44. scaffold

      A section of genomic DNA sequence. As genome sequences are assembled computationally, scientists first call long sections of sequence a scaffold. They can experimentally determine where this section comes from (in this case the Y chromosome) but know that it is not all the sequences on the Y chromosome. In the mosquito, the Y chromosome is approximately 150 kilobases (kb), but this scaffold only represents 1/3 of the sequence (48 kb).

    45. reads

      A small segment of DNA sequence, approximately 100 bp in length. Before being sequenced, DNA (in this case RNA is converted back to DNA before sequencing) is chopped up into small fragments. Each of those small fragments are "read" before being computationally aligned to a reference genome sequence to determine where it comes from in the genome.

    46. transcriptomes

      The entirety of a cell, organ, organism's gene expression profile. Just like genomics (looking at the whole genome, instead of one gene at a time), transcriptomics looks at all of the transcripts (mRNAs) at once instead of one molecule at a time.

    47. sex-specific morphologies

      In most animal species, biological males and females have different outward appearances in addition to the different reproductive organs. Birds are some of the most obvious examples. Male peacocks have long and brightly colored tail feathers while female are a dull brown/green.

    48. X chromosome–linked signal elements (XSE)

      DNA sequences on the X chromosome that "signal" the presence of the X chromosome

    49. upstream genes

      If you think of genetic and signaling pathways like a river, the genes at the very beginning of the pathway are the originating headwaters, or upstream. Whereas genes involved at the end of the pathway are downstream. What is upstream or downstream of you is relative to where you are in the pathway.

    50. sex determination system

      Not all sex determination pathways are like humans using the X and Y chromosomes. Over the course of evolution, organisms have developed different ways of genetically indicating male and female.

    51. primary sex-determining signal

      This is a genetic signal that is at the beginning of the sex determination pathway.

    1. solids

      Solids are 3D objects, such as cubes, spheres, or pyramid structures.

    2. inert and heavy masses

      Inert mass (m) is conceptually different from heavy mass (M). Heavy mass is a value that determines the strength of gravitational attraction, whereas inert mass (or inertial mass) is a value that indicates how resistant a thing is to a change of motion.

      Modern physicists use the term "gravitational mass" instead of "heavy mass."

    3. physical laws

      Physical laws are mathematical expressions that generalize physical phenomena. Physical laws explain and predict experimental results. Conservation of energy (ΔE=0) is one example of a physical law.

    4. perpetual motion never occurs in ordinary experience

      This kind of motion is impossible because it would require an infinite energy source, which violates the first law of thermodynamics (the Law of Conservation of Energy: The total energy of an isolated system is constant).

    5. kinematics

      Kinematics is a branch of mechanics concerned with the geometry of motion.

      (Einstein clarifies what he means by "kinematics" throughout the paper. When Einstein says kinematics, he specifically refers to the physics that treats space and time as separable entities.)

    6. inertia-system

      An inertia system of coordinates is a coordinate system that we can approximate to be stationary.

      For instance, we can describe the displacement of a baseball (the object of interest) relative to the baseball field (an inertia system of the baseball). Since both the baseball and the field are subject to the same rotational motion of Earth, the movement of the baseball can be described relative to the seemingly stationary field.*

      Einstein gives us a way to determine if a system of coordinates is an inertia system:

      A system of coordinates moving in the same direction and at the same rate as a system of inertia is itself a system of inertia.

      *For the purposes of this example, we have ignored the (negligible) effect of Earth's rotation. An observer on the surface of Earth must be accelerating to follow a circular path, and the entire system is subject to the non-inertial effects of gravity.

    7. systems of coordinates

      Systems of coordinates indicate the location of a point in space in reference to some other point. In doing so, systems of coordinates form a mathematical map of physical space.

      In Einstein's example, the system of coordinates for the railway train is the ground.

    8. the analytic, not the synthetic method

      Einstein says the analytic method is used to form theories of principle, whereas the synthetic method is used to form constructive theories. We can understand the methods as contrasts.

      The synthetic method supposes premises that help explain natural phenomena, while the analytic method reduces all natural phenomena to their common denominator. The synthetic method is a bottom-up approach, whereas the analytic method is a top-down approach.

      Another way to think about the difference is that the analytical approach starts with observations, whereas the synthetic method starts with hypotheses.

      (For those who are philosophy-inclined, Immanuel Kant discusses this distinction between the analytic and the synthetic.)

    9. kinetic theory of gases

      The kinetic theory of gases describes the motion of atoms in the gas phase and makes a number of assumptions such as:

      1. The gas molecules have negligible volume compared to their container.
      2. The molecules are constantly moving.
      3. All collisions are perfectly elastic.
  2. Jul 2018
    1. "a warp in space."

      Euclidian geometry presumes a uniform and constant arrangement of space. However, Einstein proposed (and others demonstrated) that space is "warped" around objects depending on their mass. The larger the mass, the greater the degree of warping.

      Because time is connected to space, it is also warped around massive objects.

    2. theory of relativity

      Einstein's theory of relativity is a two-part theory. Together, the two parts explain the motion of subatomic particles and gargantuan masses and address some of the shortcomings of earlier theories of motion.

      The theory is well known for combining the concepts of space and time, revealing that they are inseparable.

    3. principles from which mathematical formula are deduced of such a kind that they apply to every case which presents itself

      The analytical method begins with empirical observations, from which principles and formula are inferred (which can be applied to other cases).

    4. empirically

      Empirical methods involve observation and experience, rather than logical deduction alone.

    5. inert mass

      A value that indicates how resistant a thing is to a change of motion.

      Modern physicists use the term "inertial mass" instead of "inert mass."

    6. Modern physicists call "inert" and "heavy" masses "inertial" and "gravitational," respectively.

    1. Weathering

      Weathering is when pieces of plastic are mechanically broken up into smaller pieces. This is a problem because marine organisms can eat the smaller pieces but are unable to digest them. See the annotation for reference 16 for more information.

    2. Arctic sea ice

      Ice covers the Arctic Ocean. Over the course of a year, ice increases during fall and winter and melts during spring and summer. All of the ice does not melt entirely during the spring and summer; some of the ice persists from one year to the next.

    3. waste management infrastructure

      Waste management infrastructure is the collection of processes and facilities that properly dispose of wastes and reduce pollution. A major goal of waste management is often to reduce the amount of waste deposited in landfills by reuse or recycling.

    4. market sector

      Market sector is an economics term that describes a part of the economy made up of multiple industries. Examples of market sectors include energy, health care, consumer goods, media, utilities, etc.

    1. aerosol

      Suspended particles in air. Dust, soot, and water droplets are some examples of aerosols.

    2. multigenerational aging schemes

      After a chemical is emitted it undergoes reactions in the atmosphere. The products of the initial chemical reaction then undergo additional reactions in the atmosphere. Multigenerational aging accounts for the reactions that occur after the initial reaction.

    3. hydroxyl radical (OH)

      The primary reactant in the atmosphere that oxidizes hydrocarbons.

    4. fresh emission conditions

      The chemical make-up of an emission before any additional chemical reactions take place.

    5. chemical speciation

      Able to tell the difference between similar chemicals.

    6. source apportionment studies

      Studies designed to determine how various compounds are emitted into the atmosphere.

    7. higher-volatility

      Evaporate more quickly into the gas phase.

    8. anthropogenic

      From human activities.

    9. organic solvents

      Hydrocarbon liquid environments that dissolve chemicals responsible for the functioning of a product.

    10. fossil origin

      Comes from products derived from oil and natural gas.

    11. detailed mass balance

      A way to keep track of where all of the atoms and molecules are formed and where they end up.

    12. volatile chemical products (VCPs)

      Substances used by people that give off gas-phase molecules.

    13. transportation emissions

      Molecules that exit the tailpipe of a vehicle while driving.

    1. causal relationship

      A causal relationship means that the data suggests that one variable has a direct influence on another.

    2. Global modeling results

      Climate models are created using complex mathematical representations of the interactions between the atmosphere, oceans, land surface, ice, and the sun. Such models are tested against real world data and once they can realistically reproduce past climate conditions, then they are used to simulate future conditions.

      Different models might use different mathematical equations in their calculations, some of which may have large uncertainties involved for certain environmental interactions. As our understanding of the environment improves, the models also improve in their predictive capabilities but because of the complexity of the global Earth environment there is still more to discover about the world around us.

      For more about the reliability of climate models, visit Skeptical Science: https://www.skepticalscience.com/climate-models.htm

    3. mid-tropospheric

      The atmosphere is not all uniform. There are layers of the atmosphere which differ in gas concentrations, temperatures, and density.

      The troposphere is the lowest layer and extends from sea level up to about 6.2 miles (10 km) into the atmosphere. This region is where weather occurs and the layer above is known as the stratosphere.

      Image from the University Corporation for Atmospheric Research.

    4. vertical shear

      Vertical wind shear is a change in wind speed or direction with change in altitude. So if wind moves rapidly upwards or downwards, it would be a vertical shear.

      Strong vertical wind shear tends to inhibit cyclone development, but may also extend the lifetimes of individual thunderstorms.

    5. hurricane intensity

      In order to be called a hurricane (or a typhoon or tropical cyclone) the storm system must reach sustained winds of 74 miles (119 km) per hour or higher.

    6. tropical cyclones

      Meteorologists use the generic term 'tropical cyclone' to describe a rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters. These large scale air masses tend to spiral around an atmospheric region of low pressure.

      Different places around the world will call these storm systems by different terms: hurricane, typhoon, or tropical cyclone.

      For more information visit: https://oceanservice.noaa.gov/facts/cyclone.html

    7. named storms

      According to the National Oceanic and Atmospheric Administration (NOAA) hurricane "storms are given short, distinctive names to avoid confusion and streamline communications."

      The US began using female names for hurricanes in 1953 and started including male names in 1978.

      For more information visit NOAA's website: https://oceanservice.noaa.gov/facts/storm-names.html