5,190 Matching Annotations
  1. May 2018
    1. Neotropical Forests

      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.

    1. marsh ecosystems

      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.

    2. DAYCENT

      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.

  2. Apr 2018
    1. biological processing of C

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

    2. dissolved inorganic nitrogen (DIN)

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

    3. co-limitation

      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.

    4. particulate organic C (POC)

      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.

    1. symbiont

      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

    1. animal models

      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.

    2. pH

      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.

    3. Kruskal-Wallis Rank Sum (KWRS) Test

      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.

    4. E3 ubiquitin ligases

      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.

    5. Bonferroni adjusted

      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).

    6. iHS

      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.

    7. synonymous variant

      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.

    8. time to most recent common ancestor (TMRCA)

      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.

    9. lentivirally

      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.

    10. Mann-Whitney-Wilcoxon (MWW) test

      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.

    11. allelic imbalance

      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.

    12. H3K27ac

      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.

    13. folate degradation

      Folate is a B vitamin, and is important for many aspects of health including the prevention of anemia and certain birth defects.

      Folate can be broken down by UV radiation (sun exposure), leading to lower levels in people with high UV exposure.

    14. genetic basis

      Many factors can contribute to differences between individuals of the same species. Some differences are due to differences in DNA; these are referred to as the "genetic basis" for variation.

    15. alternative splicing

      A process by which a single gene can encode multiple proteins.

      RNA splicing is the removal of introns from the transcript made from a gene, leaving only the exons to be expressed. In alternative splicing, exons are excluded, introns are included, or different junctions are used between the introns and exons, leading to proteins with a different amino acid sequence.

    16. trophic cascades

      An ecological effect caused by the addition or removal of predators with changes to both the populations of predators and prey. The trophic cascade effect can either be top-down (predator to prey) or down-up (prey to predator). In a simplified food chain, if there is an increase (or decrease) in top predators then there would be a decrease (or increase) in herbivore prey and an increase (or decrease) in plant prey communities.

    17. DNase I hypersensitive sites

      Regions of chromatin that are highly sensitive to cutting by DNase I, an enzyme that cleaves DNA at many locations in the genome.

      Genomic regions are more sensitive to DNase I cleavage if their chromatin has lost its condensed structure, indicating that these regions would also be available for binding by transcription factors and subsequent transcription. Therefore, DNase I hypersensitive sites are associated with regions of the genome that control transcription.

    18. mRNA

      mRNA stands for messenger ribonucleic acid. mRNA is made based on the sequence of DNA that encodes it, and specifies the amino acid sequence that will be used by the ribosome to make a protein product.

    1. Inter-Tropical Convergence Zone

      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.

    1. phenology

      Phenology is the study of periodic plant and animal life cycle events and the how the processes are influenced by seasonal and interannual differences in climate and habitat factors.

    2. Bonferroni tests

      A test which is used in statistical analysis in which there are many comparison test being practiced. Even if the statistical data has no significance, the Bonferroni tests will allow significance to emerge in the data due to multiple testing.

    3. Bonferroni correction

      Bonferroni correction is an adjustment made to P values when several dependent or independent statistical tests are being performed at the same time on a single data set. A Bonferroni correction is performed by dividing the critical P value (α) by the number of comparisons being made.

    4. Post hoc tests

      Post hoc tests are run to confirm where differences in means are when using multiple groups. They are only run after an ANOVA test confirms that there are statistically significant differences between the groups.

    5. Monte Carlo Markov Chain

      The Monte Carlo method is a tool used in statistics which can be applied to scientific research in which a distribution of the possible outcomes in a data set can be produced.

      Since the same experiment can be repeated many times we must have outcomes that show the probabilities of different outcome happening.

    6. STRUCTURE, version 2.3

      A program developed by the Pritchord lab at Stanford uses genotype data to investigate population structure. Its uses include discovering distinct populations, assigning individuals to populations, studying hybrid zones, identifying migrants and mixed individuals, and estimating population allele frequencies.

    7. biomass

      Biomass: Total mass of an organism or the mass of the organism in a a specific area.

      The weight was taken when the plant was dry for the simple reason that different species can hold different amounts of water. In order to obtain a precise measurement and compare the different species, the plant had to be dried.

    8. Mettler balance

      Mettler balance is a laboratory balance used to measure small masses to the sub milligram range. It can measure from .1 mg to .0001 mg depending on the model.

    9. phenolic

      Phenolic compounds are a class of plant secondary metabolites. These include a range of compounds such as phenolic acids, flavonoids, and other substances. They are responsible for fruit color.

    10. low-density

      Founding populations of invasive species are often small, so they experience the founders effect. The founders effect is a loss of a genetic variation due to a smaller population size.

    1. high-powered

      A study is referred to as high-powered, if the size of the sample from which data is collected is large enough that it becomes highly probable (at least 80% probability) that an effect of interest that exists in the population would actually be found in this data.

      For example, let’s say we were interested in finding out whether cupcake consumption increases well-being. Because we cannot ask every person on the planet to please report their well-being, eat a cupcake, and then report their well-being again, we have to restrict our investigation to a certain sample of people.

    1. meter layers of each ocean

      Scientists measure distances in meters and not miles, where 1 meter is roughly 3 feet and 1000 meters is about 0.6 miles.

      The average depth of the ocean is about 3,688 meters (12,100 ft), and reaches the deepest depth of 10,994 meters (6.831 mi) in the Mariana Trench in the West Pacific Ocean.

      Check out this Tech Insider video about how deep the ocean really is: https://www.youtube.com/watch?v=UwVNkfCov1k

    2. joules

      A joule is a derived unit of energy that is equal to the energy transferred to (or work done on) an object. One joule can be thought of as the work required to produce one watt of power for one second.

    3. world ocean

      There are 5 ocean basins: the Atlantic Ocean, Arctic Ocean, Indian Ocean, Pacific Ocean, and Southern Ocean. These oceans are all connected and can be defined as a global or world ocean.

    4. density

      Density measures the degree of compactness of a substance. The density of seawater depends on the dissolved salt content as well as the temperature. A high salt content and cold temperatures make seawater more dense.

    1. Endosomal trafficking and protein turnover

      To function properly, cells are constantly creating, recycling, and transporting proteins. Interruptions in this process can be a cause of disease.

    2. neuronal cell adhesion

      Neurons express special proteins that allow them to adhere to each other and to other cell types. The ability to bind to each other is important for neurons' ability to communicate properly.

    3. gene dosage-dependent

      "Gene dosage" refers to the number of copies of a gene in a particular genotype. A gene is dosage-dependent if a certain number of copies is necessary for proper function.

      Although there are many factors that influence gene expression, in general more copies of a gene will result in more protein product (either directly from the gene or as a result of regulatory mechanisms).

    4. stop codon

      A stop codon (or termination codon) is a series of three nucleotides that stops the translation process.

      It works by binding special proteins called "release factors." When these release factors reach the ribosome (the site of protein translation), they cause the new amino acid chain to separate from the ribosome, stopping translation.

    5. forward screen

      A "forward" screen is used to identify the mutation(s) that leads to a given phenotype.

      A "reverse" screen is used to identify the resulting phenotype from a given mutation.

    6. We propose renaming this gene DIA1 (deleted in autism-1)

      The authors propose renaming c3orf58 to deleted in autism-1 (DIA1) because they found evidence that it was causative of autism in patient AU-3101.

      Genes are commonly renamed from "generic" names such as c3orf58 to more specific names that provide information about their function. Because there is no formal regulation of gene names, many genes have misleading names or multiple names.

    7. RNA interference (RNAi) knock-down

      A biological pathway, found in many eukaryotes, in which RNA molecules inhibit gene expression. This is usually caused by the destruction of certain mRNA molecules.

      This pathway is used by researchers to increase or decrease the activity of genes of interest.

    8. “neural activity–regulated” genes

      Genes that are "activated" by neural activity will typically be transcribed more following a depolarization event (i.e., an action potential).

    9. blind to the genetic study

      To increase the reliability of the results, the researchers may have removed information identifying samples as "experimental" or "control." This can decrease bias in the analysis of results.

    10. transcription

      The process of "reading" DNA to create mRNA, which then exits the cell nucleus to eventually be translated into a protein. This is the first step in protein synthesis.

    11. hemizygous

      The deletion is homozygous (present on both chromosomes) in the boy, but present on only one chromosome from each parent.

      Thus, the boy inherited the deletion from both parents.

    12. single-nucleotide polymorphism (SNP)

      A variation of a single nucleotide in a DNA sequence. When less than 1% of a population carries the nucleotide at this position, this variation is classified as a SNP. Some SNPs are associated with certain diseases.

    13. Marriage between first cousins increases the prevalence of neurological birth defects by about 100%

      Because first cousins share a larger portion of their genome than two unrelated individuals, there is a higher chance that a child will inherit disease-causing mutations.

    14. copy number variants

      Phenomenon in which sections of the genome are repeated, deleted, or inverted. It has been shown that CNVs at specific locations increase the risk to develop autism.

    15. de novo mutation

      A mutation is de novo when it appears for the first time in an individual, rather than being inherited.

      It is usually the result of a mutation in the germ line (the cells that produce sperm and eggs) of one of the parents, or a mutation that arises in the fertilized egg itself.

      It is also known as a new mutation.

    16. heterogeneous disorders

      Disorders like autism that can result from many different genetic anomalies.

      Autism is difficult to characterize not only because there are many different genetic causes, but also because autism sometimes results when several otherwise benign mutations come together in the genome of an individual.

    17. homozygosity mapping

      A method for mapping genes involved in rare, recessive disorders. It is used in inbred populations (populations where many individuals are related to each other). Because these populations are very highly related, individuals will share large areas of their chromosomes in areas surrounding target genes.

    18. level of expression changes in response to neuronal activity

      Synapses (the electric signals that transfer information in the nervous system) regulate the expression of some genes.

      Among the genes regulated by neuronal activity are those that are involved in learning.

    19. mapped several loci

      Locus (pl. Loci.) : The locus of a gene is its physical location on a specific chromosome.

      "Mapping" a locus means finding out where it is physically located on a chromosome.

      Example: location of the genes BRCA 1 and BRCA 2:

      Example: location of the genes *BRCA *1 and *BRCA *2

    20. autism-spectrum disorders

      Autism-spectrum disorders (ASD), sometimes referred to collectively as "autism," are a family of developmental disorders that have different symptoms and intensities.

    1. Mann–Whitney test (post hoc)

      Non-parametric (not assuming a normal distribution) statistical test that is used to compare two sample means that come from the same population, and used to test whether two sample means are equal or not. The authors conducted the Mann-Whitney test post hoc (after the Kruskal-Wallis test) in order to compare the groups (to investigate which groups significantly differ) but with corrections to control for inflation of type I error (false positive – determining differences in the dataset when there actually is none).

    2. tubular flowers

      A type of flower that has a long, thin, tube-like structure. The tube-like structure is formed by the pedals and often separate the mouth into a flared shape.

    1. spatiotemporal

      Data or information that is specific to both a time and location. In this case, the "spacio-" aspect is the set of 0.5° x 0.5° grid points across the Mediterranean land mass. The "-temporal" aspect is the specific time period examined— either in the past or future.

    1. allelopathy

      A mechanism plants use to ensure their survival.

      The plant produces one or more biochemicals that affect neighboring competitors in their growth and/or reproduction.

    1. drip irrigated

      a type of micro-irrigation that has the potential to save water and nutrients by allowing water to drip slowly to the roots of plants, either from above the soil surface or buried below the surface

    2. chlorophyl

      a green pigment, present in all green plants and in cyanobacteria, responsible for the absorption of light to provide energy for photosynthesis. Its molecule contains a magnesium atom held in a porphyrin ring

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  3. Mar 2018
    1. Pearson correlation coefficient (r) = 0.59

      A measurement of the strength of a linear correlation (relationship) between two variables.

      A coefficient value close to +1 indicates a strong positive linear correlation: When one variable increases, the other also increases. A value of 0 indicates no linear correlation.

    2. temperature-limited

      The balance of some ecosystems may be upset by changes in temperature.

      Extreme temperatures may limit survival of some species, such as plants which cannot tolerate freezing temperatures or animals which experience heat stress at high temperatures.

      Changes in the timing of seasonal temperature may affect life cycles; for example, early springlike temperatures can change the timing of reproduction or migration.

    3. ecosystems

      A complex, interacting community of living organisms (plants, animals, microorganisms) and nonliving matter and energy.

      Ecosystems can be very different in complexity and size. Some are small, like a decaying log or a home aquarium. Examples of large ecosystems are deserts, lakes, and rainforests.

    4. latitude

      A measure of how far north or south a point on Earth is, recorded in degrees. The latitude of the Equator is 0°.

      Compared to lower latitudes, higher latitudes are farther from the Equator and tend to experience lower average temperatures and more seasonal climate variability.