James Clerk Maxwell and Hendrik Antoon Lorentz were physicists of the late 1800s and early 1900s. Their work is the foundation of the branch of physics called electromagnetism.

This is the second kind of theory that Einstein delineates. He tells us that a theory of principle is one that is formed from the most consistent and basic observations seen across all natural phenomena.

A constructive theory is one that is built up (i.e., constructed) from assumptions to explain a natural phenomenon.

A proposition states a claim that can be either true or false.

The science that studies the relationship between heat (thermo) and work or movement (dynamic).

In its original condition; unspoiled.

Causing harm or damage.

Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce.

Widely or constantly encountered; common or widespread.

Not part of the essential nature of someone or something; coming or operating from outside.

Belonging naturally; essential.

Provide a nutrient source to animal mutualists, which in turn provide anti-herbivore protection.

A substitute, especially a person acting for another in a specific role or office.

Originating in human activity (chiefly of environmental pollution and pollutants).

To prevent the occurrence of something.

To prevent (someone) from accomplishing something.

Present, appearing, or found everywhere.

Make (something) clear; to explain.

An insect whose larvae live as parasites that eventually kill their hosts.

Life stage of some insects undergoing transformation between immature and mature stages.

A phase between two periods of molting in the development of an insect larva or other invertebrate animal.

Order of insects that includes butterflies and moths.

A table showing the distribution of one variable in rows and another in columns, used to study the association between the two variables.

Omnibus tests are statistical tests that are designed to detect any of a broad range of departures from a specific null hypothesis.

A taxonomic category, as a species or genus.

A phase between two periods of molting in the development of an insect larva or other invertebrate animal.

Of, on, or relating to the earth.

Causing harm or damage.

Subtropical dry broadleaf forest biome, also known as tropical dry forest, monsoon forest, vine thicket, vine scrub and dry rain forest is located at tropical and subtropical latitude.

The process of breeding animals in controlled environments within well-defined settings, such as wildlife reserves, zoos and other commercial and noncommercial conservation facilities.

The first host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts - similar to ectoparasitism.

A plant upon which an organism (such as an insect or mildew) lodges and subsists.

Experiments used by ecologists to determine the effectiveness of putative plant pollination vectors.

The number of organisms of a particular kind as a percentage of the total number of organisms of a given area or community.

Species diversity is defined as the number of species and abundance of each species that live in a particular location.

Hypermorphic refers to mutations in the gene that result in an increase of gene expression. Therefore, hypermorphic alleles result in hyper-pigmentation as described in the paper.

Prostaglandin are a group of fatty acids that act as hormones in the body. For example, during pregnancy the contractions are stimulated by a prostaglandin.

Hypoxia refers to the condition in the body where there is a deprivation of oxygen to the tissues.

Heterotypic refers things that are different in form or type. So, heterotypic cell to cell adhesion is adhesion between two different types of cells.

Catenin is a type of protein in the human body that is in charge of regulation and coordination of cell to cell adhesion.

Synergistic effects refers to an effect where the combination of both is greater than the sum of the individual parts. So the whole is greater than its individual parts.

Irradiation refers to treating something with radiation, in this case UV light.

Aberrant refers to something that differs from the accepted standard, so it could be something that is abnormal. For example aberrant Edn3 expression is that expression which differs from the norm.

Melanomagenesis refers to the development of melanoma through the multistep process of genetic mutations.

Cutaneous refers to something in the body relating to the skin. Therefore, non-cutaneous refers to something that does not have to do with the skin. For example non-cutaneous melanocytes would be those that grow in areas not relating the the skin.

Melanoblasts are precursors to melanocytes. So, they are the cells that come before the melanocytes.

This study was done on the neural crests taken from murine cultures, so it is also an in vitro study of the effects of endothelin on the development on melanocytes but this time on a different species.

The sciatic nerve is a long nerve in the body that runs from the bottom of the spine to the back of the leg and above the knee joint.

Transdifferentiation is when a cell, other than a stem cell, differentiates into a different type of cell.

Induce refers to the production or promoting of something. So if the Edn3 induces proliferation, it brings about proliferation.

Contact inhibition is a process in the body that regulates cell growth. For example, when the cells come in contact with each other, its a sign that its time to stop growing, hence the name contact inhibition.

In vitro refers to a study that took place outside of the living organism, so in a test tube or culture dish, etc. The opposite would be an in vivo experiment that takes pace inside the organism.

A chemotactic response is a response to a chemical stimulus that results in the movement of the body.

A dorsolateral pathway is one that is on the dorsal and lateral surfaces. Lateral refers to something away from the mid line of the body and dorsal refers to the upper back of an animal.

Melanoblasts are cells that become melanocytes. They proliferate and pile up in the migrating stage area. Then they become part of developing hair follicles, where they differentiate into melanocytes.

Endogenous refers to something that originates from within an organism, or something that has an internal cause or origin. A promoter that is endogenous originates from within.

Aganglionosis is characteristic in megacolon and it means that there are no ganglia present. Ganglia, or ganglion cells, are a type of nerve cell responsible for moving food in the colon. As a result, their absence can lead to constipation.

Megacolon is an abnormal dilation of the colon. So, the colon widens and oftentimes the movement of the bowels can stop.

Melanin is the skin-darkening pigment produced in melanocytes. Therefore, melanogenic refers to a melanocytes ability to produce melanin. If a substance is melanogenic it stimulates a cell to produce melanin.

Mitogenic refers to stimulating a cell to start dividing through mitosis. For example, a mitogen is a chemical that stimulates division in a cell, so it has mitogenic properties.

A kinase is an enzyme that catalyzes the transfer of a phosphate group from ATP to a desired molecule. For example, a nonreceptor tyrosine kinase is in charge of transferring a phosphate group from ATP to tyrosine in proteins. Tyrosine is one of the 20 amino acids found in proteins.

An enzyme that is in charge of catalyzing the formation of cyclic AMP into ATP. To catalyze means to increase the rate of the reaction, so this enzymes speeds up the rate at which ATP is produced from cyclic AMP. ATP is the energy molecule of the body.

Phospholipase is an enzyme that hydrolyzes, or breaks down, phospholipids into fatty acids. There are four types of these enzymes: A, B, C, and D.

Cardiomyocytes are cardiac muscle cells. For example, the heart is made up of cardiac muscle, and thus these cells.

Refers to a macromolecule that is made up of at least three subunits where one of the subunits of the molecule differs from the other two. A G-Protein is an example, because it is made up of an alpha, beta, and gamma subunits.

G-Protein Coupled Receptors are located in the cell membrane of eukaryotes. Their function is to receive signals from the outside, that will then produce a cellular response. There are many different types of these receptors talked about in the paper.

Paracrine Factors are produced by certain cells in order to communicate with adjacent cells around them. They are a form of signaling between cells to alter the behavior of cells around them.

A receptor antagonist functions by blocking a biological response by binding to the receptor that would have previously stimulated this response. For example, for the endothilin receptor type b (Ednrb) discussed in this paper, an antagonist would bind to it and block the response that would have been produced originally. So they function as biological blockers.

Metastases refers to when a malignant tumor grows at a site away from the original site. For example, if you say that lung cancer metastasized to the liver it means that the lung cancer is now also found in the liver. It developed at a site away from the original, in this case from the lungs to the liver.

In cells, differentiation refers to a cell that is less specialized becoming more specialized. This occurs during development, so melanocyte differentiation is when developing cells specialize into melanocytes.

A precursor is something that happens before something else. So in terms of biology it refers to a cell or tissue that will give rise to another cell or tissue that is more specialized, or mature. In this paper, a melanocyte precursors are cells that came before and will differentiate into melanocytes.

The neural crest is an embryonic structure in vertebrates that gives rise to many types of cells, primarily cells of the peripheral nervous system. So during embryonic development, the neural crest differentiates and migrates to give rise to specialized cell types. They also give rise to melanocytes which will be further discussed in the paper.

Melanocytes are skin cells that produce the pigment melanin. Melanin is the skin darkening pigment that is known for protecting the skin from harmful rays.

Endothelin is a vasoconstrictive peptide produced in endothelial cells. Vasoconstriction means that these peptides constrict blood vessels, increasing blood pressure as a result. These peptides are composed of 21 amino acids and there are three types: endothelin 1, endothelin 2, and endothelin 3.

A chronic disorder characterized by uncontrollable repetition of behaviors and uncontrollable thoughts.

The likelihood of an individual developing a disease or being injured.

Characteristics, symptoms, or behaviors that are shared across different psychological diseases and that may represent similar underlying causes.

The authors use the term to highlight the similarities between CUD and obsessive-compulsive disorder. The connection may represent a similar underlying mechanism and suggests that CUD patients could be more prone to developing compulsive habits.

Two diseases or medical conditions that occur simultaneously in a patient.

Symptoms like anxiety, irritability, depression, and drug cravings that often occur when an addicted person stops using a drug.

Values associated with stimuli. It allows individuals to perceive or react positively or negatively to a presented stimulus.

The flow of dopamine within the striatum.

The striatum is a part of the brain that is involved in the motor and reward system. This part of the brain receives dopamine to mediate motor and reward behaviors.

Dopaminergic neurotransmission is the regulation of the release of dopamine from the terminal end of a neuron (axon), the clearance of it (mediated by transporters), diffusion, and its metabolism.

A drug that competes with dopamine for binding to the dopamine receptor. When the drug binds to the dopamine receptor, dopamine can no longer bind to it, preventing the effect of dopamine signaling.

A variable that is predicted to interact with the variable being tested in a study (and that might affect the outcome of the study).

The continued use of the drug (cocaine) regardless of health and social consequences.

Evidence gathered using model systems like rats and mice. Model organisms are useful for understanding how a treatment or therapy might affect humans, and are often used extensively before human trials begin.

Something that comes before. Here, "antecedent stimuli" means a stimuli that comes before drug use.

Affected.

Characterized by a desire to seek pleasure.

Intended as punishment.

Relating to the use and effects of medicines.

A locus in DNA where the Melanogenesis Associated Transcription Factor (MITF) binds to exert its effects on gene expression.

MITF earned its name because it is a transcription factor associated with pigmentation. So, MITF binding sites are likely to be near genes involved in pigmentation.

The F_ST is the fixation index, which describes genetic differences between populations by measuring genetic differences among and between populations.

An F_ST value close to 1.0 indicates that the populations being compared are highly divergent (very different) from one another.

A lysosome is an organelle in animal cells where unwanted material gets digested. A lysosomal protein is a molecule that performs its function inside (or on the surface of) the lysosome.

The uneven distribution of species in an area.

This is an organization that works with partners in the Amazonia and they research on things like soil nutrition.

This is a graphical technique for representing a data set, it shows one or more variables and their relationships.

A pressed plant sample deposited and used for future research, this is used when a specific plant cannot be determined during the field work, so it is later researched to determine its species.

Shannon was who introduced the concept of entropy. Entropy is the disorder in the universe.

The amount of species there are in a given plot.

One third of the acre.

Touching or sharing a border.

Describes plots of different vegetation involved.

Set boundaries or limits.

Used to measure the distribution of organisms. The land and the species found there are separated into continuous quadrants.

How species are arranged in an area.

Study of rate of growth.

1 hectare plot = 100 acres.

The Amazon basin covers 40% of South America. It is the part that is drained by the Amazon river. Most is covered by rain forests.

The picogram is equal to one trillionth of a gram.

Plot method where, the lines are laid out one after the other without attempting to maintain a set direction.

The ratio of the standard deviation to the mean. Used to measure variability.

Describes how the flowers are arranged.

The number of different species in a given ecological community.

A large gradual change in nonliving factors through space such as change in tree structure.

Stems and leaves of the tree.

Carbon stored in the forest.

This field inventory method is a way to carefully screen the species that are present

Neotropic forests are found in South and the North American regions of Central America. The Neotropic includes more tropical rainforest than any other realm. These rainforest are one of the most important reserves of biodiversity on Earth.

The variability of different tree species in the ecosystem.

The total mass of the plants' structures that are above the ground (excludes roots) in a given area or volume.

Per capita is a Latin phrase which means for each person. Here, the authors are looking at the mass of waste generated per person per year.

Fragmentation is the process of being broken into smaller pieces or parts.

A standard ton is 2000 pounds, while a metric ton is 1000 kilograms (2205 pounds).

Long term carbon storage.

The global concentration of carbon dioxide. This fluctuates annually.

Average total amount of rain recorded during a certain amount of time.

Coastal wetlands that are flooded and drained by salt water brought in by tides

Freshwater marsh ecosystems are those areas in which fresh water, obtained from groundwater or precipitation surplus, covers the surface for a portion of the year, and where flora and fauna able to survive those conditions, reside.

The capacity of the environment to absorb by-products of production and consumption.

Biogeochemical model that simulates carbon and nitrogen fluctuations in the atmosphere, plants, and soil. Data on the soil, hydrology and temperatures have to be inputted prior to the model working.

Results from temperature differences, instability in the atmosphere.

A slow process that allows the system to be very close to equilibrium.

This is the measure of mass of water per mass of dry soil. This is done by weighing the soil sample, drying it, then weighing the soil dry.

This is the sum of all the respiration that is occurring by the living organisms that inhabit the ecosystem.

This is a measure of the quantity of carbon entering and leaving an ecosystem.

A species that plays a significant role in a biotic community, however with much less importance than the dominant species.

Two or more species that are equally dominant in a biotic community.

Bowen Ratio is the mathematical method that is typically used to calculate heat loss or heat gained in a substance.

Environments and ecosystems perturbed due to human interference.

The biological system includes bacteria, fungi and invertebrates. Fungi colonizes the leaves once they fall in the stream and break down the carbon.

SRP is a measure of the filterable portion of phosphate known as orthophosphate.

Dissolved inorganic nitrogen is the combination of nitrogen forms nitrate, nitrite and ammonium. This is the most available form of nitrogen used by algae.

These forests shed annually and litter the streams, giving them an organic carbon source.

This is organic carbon that can be dissolved in water and run through a filter; it is smaller compared to particulate organic carbon.

Co-limitation is the limiting of growth caused by two factors, both must be present in a set ratio to have an effect.

There is further visualization in figure 2, where the co-limitation of nitrogen and phosphorus are presented.

Terrestrially derived carbon is a source of carbon obtained from land materials such as twigs and leaves.

Particulate organic carbon is a source of carbon for the ocean obtained from living organisms and detritus; it is larger compared to dissolved organic carbon.

An increase in nutrients in nearby river has led to an increase in the levels of algae in these rivers, some of these which are toxic to people.

Read more in nwi.com: http://www.nwitimes.com/business/toxic-algae-once-a-nuisance-now-a-severe-nationwide-threat/article_2b1decfa-43c9-5d80-bf64-173e51a95248.html

These are permanent bodies of waters found interior to the coastal waters. These bodies include rivers, lakes and reservoirs.

This is a carbon source found on land commonly in biotic organisms.

Sequestration is the collection and storage of carbon dioxide.

In this case, the carbon is being removed from the water and depletes the riverine food webs.

Produced by the organism.

Technique that allows high-definition viewing of microscopic samples in 3D.

Open Reading Frames (ORFs) are sequences of DNA that are not transcribed. They can be used to search for transcripts that code for specific proteins of interest.

An organism that lives in close association with a "host" organism.

The relationship may be positive for both the host and the symbiont (mutualistic), positive for the symbiont and neutral for the host (commensal), or positive for the symbiont and negative for the host (parasitic).

Symbiosis: It's Complicated

Membrane-bound "bubbles" that shuttle proteins to different locations in a cell.

Nonhuman animals are used to study, or model, diseases and understand the role of genes or proteins in processes, such as skin pigmentation. Thanks to shared ancestry, there are many similarities between human and nonhuman animals at the cellular and genetic levels. Thus, animals can be used to do experiments than can't be done in people.

Structure, shape, appearance (as opposed to function).

Cells in the basal layer of the epidermis that form a barrier against environmental damage.

Indigenous populations found in Malaysia, Philippines, Indonesia, and Australia.

A cell that produces melanin.

The building or breaking down of pyrimidines in cells—pyrimidines include the DNA/RNA bases uracil, thymine, and cytosine.

A database of results from published studies related to mouse phenotypes.

When one gene (or variant of a gene) has multiple effects on seemingly unrelated traits.

A consensus motif is a pattern of the most frequent nucleotides that are bound by a particular protein, in this case SOX2.

A numeric scale that specifies the acidity (low pH) or basicity (high pH) of a solution (or in this case, cell). The number is based on the molar concentration of hydrogen ions in the sample.

The pH of cells affects the activity of many enzymes and other proteins.

A protein that spans the cell membrane, allowing chloride ions (and sometimes other ions) to enter or exit the cell under specific conditions.

Loss of variation in the DNA near a mutation that has increased in the population due to positive selection.

The KWRS test is a statistical test used to determine whether samples have the same distribution, and unlike the MWW test it can be used on more than two samples. If samples do not have the same distribution, that means something is significantly different between them.

When genetic variants are referred to as "tightly linked," it means that they are close together and usually inherited together.

An ovarian follicle is a group of cells inside of the ovary that releases an egg cell during ovulation. These follicles must be maintained for a female mammal to retain fertility.

An E3 ubiquitin ligase assists in transferring a ubiquitin onto a protein substrate. Ubiquitin is a protein that occurs ubiquitously in mammalian tissues, and is a regulatory molecule that can affect proteins in many ways, including marking them for destruction, causing them to move to a different part of the cell, or altering their ability to interact with other proteins.

Parts of a protein that span the cell membrane.

A pseudogene is a stretch of DNA that looks similar to a gene, but has lost some or all of its function.

An individual with two identical alleles for a given locus.

Bonferroni correction (or adjustment) compensates for the increased likelihood of rejecting the null hypothesis incorrectly due to testing multiple hypotheses (testing multiple hypotheses increases the chance that a rare event occurs).

This correction is performed by dividing the significance level desired (generally 0.05) by the number of hypotheses to be tested (for example, if testing two hypotheses), and testing each individual hypothesis against this new number (for example, 0.05/2 = 0.025).

Primary refers to cells (in this case, human melanocytes) that have been taken from a tissue (human skin) and are growing in a dish without further alterations.

Integrated haplotype score: A statistical test to measure how far from the SNP of interest haplotype homozygosity extends on the ancestral compared to the derived allele. Haplotype homozygosity measures the likelihood of selecting two identical haplotypes at random from a population.

If a SNP is under selection, it will often occur with longer haplotype homozygosity than expected (on either the ancestral or derived allele), and extreme iHS values will result.

A synonymous variant is a change in the DNA that does not lead to a change in the amino acid sequence of the protein encoded by the gene.

This can happen because each amino acid is encoded by a stretch of three nucleotides in the DNA, called a codon, and there are multiple codons for the same amino acid.

A skin condition characterized by patches of skin losing pigment and appearing white.

The most recent common ancestor (MRCA) of a group of organisms is the most recent individual (in this case, a hominid) from which all the organisms in the group are directly descended.

The MRCA of a population is hard or even impossible to determine for a large population, but the time when this individual lived (the time to most recent common ancestor, TMRCA) can be estimated based on mathematical modeling and knowledge of the genetic variation in the population.

A nonsynonymous mutation is a change in the DNA sequence that leads to a different amino acid being used in the encoded protein.

A lentivirus is a type of virus that is often used in research to deliver DNA into cells because it is efficient at doing so across many types of cells. In this case, lentivirus delivered DNA that encodes shRNAs.

A derived allele is an allele that is different from that carried by the common ancestor of the populations being examined.

Proteins in the cell membrane that facilitate the movement of small molecules or ions across the cell membrane.

The MWW test is a statistical test used to determine whether a value selected from one sample at random will be equally likely to be greater than or less than a value selected at random from another sample.

In this case, the test is used to check for allelic imbalance. In heterozygotes, the level of expression of each allele may not be equal; if one is expressed more than the other, this is called allelic imbalance. In homozygotes, expression from the two alleles is more even because they are the same variant.

A difference in expression between the two alleles at a particular locus.

For most genes, expression is usually equal from each of the two alleles a person has. If there is allelic imbalance, one allele will be expressed more than the other.

H3K27ac refers to a specific alteration to a DNA packaging protein that is associated with transcriptional activity, and often occurs on enhancer regions which are considered active when this mark is present.

H3 stands for Histone H3, a protein that DNA is wrapped around in chromatin. K27 refers to the 27th amino acid Lysine in the Histone H3 protein. ac stands for acetylation, a modification in which an acetyl group is added to a protein.

Diversity measure of classified data.

Percent composition of a species compared to the total number of species in the same area.

Measure of the statistical dependence among species' trait values due to their ancestral genetic relationship.

Pressed plant specimen deposited for reference.

Relating to the arrangement of the physical features of an area.

Different in kind.

Abbreviation for hectare which is a unit of area.

A region near the Earth's equator where trade winds of the Southern and Northern hemispheres join to make hot air rise and falls as thunderstorms.

Refers to the relative abundance of species in a community.

Removal of trees in a specific site or area.

Changes in a forest that negatively affect the structure and function of a particular site leading to a diminished capacity to provide services.

The process of removing, and destroying forests, to be replaced by something else.

Also called biodiversity hotpot; a biogeographic area with high levels of organismal and community diversity likely under threat.