Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes, ...Read More
We propose a reversed-phase high-performance liquid chromatographic method using fluorescence detection for the determination of residual levels of bisphenols A and F in noncured epoxy resins prepared under various conditions. This method optimizes the conditions of synthesis of bisphenol diglycidyl ether epoxy resins so that migration of these monomers from materials that will come into contact with foodstuffs falls within legal limits. The method is sensitive, as proven by the high slopes of the calibration lines; it is also free from interferences because the intercepts of the calibration lines are not significantly different than zero (α = 0.05, degrees of freedom= 6). The results are linear over a wide range of concentrations covering two orders of magnitude (from 10 to 1,000 ppb). Detection limits are about 4 ppb for bisphenol F and 6 ppb for bisphenol A. Precision along the calibration lines is revealed by the error index percentages (lower than 3.5) and determination coefficients (better than 0.997).
We present a fast and flexible software package--SimPhy--for the simulation of multiple gene families evolving under incomplete lineage sorting, gene duplication and loss, horizontal gene transfer--all three potentially leading to species tree/gene tree discordance--and gene conversion. SimPhy implements a hierarchical phylogenetic model in which the evolution of species, locus, and gene trees is governed by global and local parameters (e.g., genome-wide, species-specific, locus-specific), that can be fixed or be sampled from a priori statistical distributions. SimPhy also incorporates comprehensive models of substitution rate variation among lineages (uncorrelated relaxed clocks) and the capability of simulating partitioned nucleotide, codon, and protein multilocus sequence alignments under a plethora of substitution models using the program INDELible. We validate SimPhy's output using theoretical expectations and other programs, and show that it scales extremely well with complex models and/or large trees, being an order of magnitude faster than the most similar program (DLCoal-Sim). In addition, we demonstrate how SimPhy can be useful to understand interactions among different evolutionary processes, conducting a simulation study to characterize the systematic overestimation of the duplication time when using standard reconciliation methods. SimPhy is available at https://github.com/adamallo/SimPhy, where users can find the source code, precompiled executables, a detailed manual and example cases.
Formulae were derived to predict genetic response under various selection schemes assuming an infinitesimal model. Account was taken of genetic drift, gametic (linkage) disequilibrium (Bulmer effect), inbreeding depression, common environmental variance, and both initial segregating variance within families (σAW02) and mutational (σM2) variance. The cumulative response to selection until generation t(CRt) can be approximated asCRt≈R0[t−β(1−σAW∞2σAW02)t24Ne]−Dt2Ne,where Ne is the effective population size, σAW∞2=NeσM2 is the genetic variance within families at the steady state (or one-half the genic variance, which is unaffected by selection), and D is the inbreeding depression per unit of inbreeding. R 0 is the selection response at generation 0 assuming preselection so that the linkage disequilibrium effect has stabilized. β is the derivative of the logarithm of the asymptotic response with respect to the logarithm of the within-family genetic variance, i.e., their relative rate of change. R 0 is the major determinant of the short term selection response, but σM2, Ne and β are also important for the long term. A selection method of high accuracy using family information gives a small Ne and will lead to a larger response in the short term and a smaller response in the long term, utilizing mutation less efficiently.
Environmental persistence is one of the few shortcomings of plastic materials. As a consequence, alternative plastics labeled as compostable are replacing polyolefins in some commercial applications, such as food bags and trash bags. A rapid, high-throughput, and environmentally relevant method to assess the potential biodegradability in marine conditions is used to assess these materials already on the market, as well as novel bio-based polymers still in development. By fitting experimental data to a non-linear logistic model, ultimate biodegradability can be calculated without regard for incubation time. Whereas the commercial products show negligible or very low marine biodegradability, one of the novel materials exceeds the 20% biodegradation threshold relative to fully marine biodegradable PHB after 28 days. In addition, the sensitivity of the method can be enhanced and its duration reduced, at the expense of labor-demanding preconditioning of the microbial inoculum, by increasing the bacterial density in the incubation vessels. In contrast, pre-exposure of the inoculum to plastic, either in laboratory or field conditions, does not enhance the performance of the test.
Fingerprinting has become a powerful device in food authentication activities. Food products can be verified based on their chemical composition, geographical origin, specified botanical sources or possible adulterations by fingerprinting gas chromatographic chemical analysis and a subsequent multivariate data analysis. Although fingerprinting approaches have already been used successfully in many research projects, feasibility and employment in routine daily tests and food composition monitoring are not still widespread. Within this review, food fingerprinting studies in gas chromatographic methods for different food product categories were selected by a systematic search method. The studies were examined for chemometrics techniques, identification of effective variables, method validation and quality assurance parameters. In this way, the research activities could be considered as an effective starting point to establish fingerprinting techniques for food authentication in wide industrial scale in the future.
Quantitative genetics is the study of continuously varying traits which make up the majority of biological attributes of evolutionary and commercial interest. This book provides a much-needed up-to-date, in-depth yet accessible text for the field. In lucid language, the author guides readers through the main concepts of population and quantitative genetics and their applications. It is written to be approachable to even those without a strong mathematical background, including applied examples, a glossary of key terms, and problems and solutions to support students in grasping important theoretical developments and their relevance to real-world biology. An engaging, must-have textbook for advanced undergraduate and postgraduate students. Given its applied focus, it also equips researchers in genetics, genomics, evolutionary biology, animal and plant breeding, and conservation genetics with the understanding and tools for genetic improvement, comprehension of the genetic basis of human diseases, and conservation of biological resources.
The linear least-squares analysis of 420 blood pressure (BP) profiles sampled for 48 hours in 233 pregnant women indicates a statistically significant BP elevation in women with gestational hypertension or preeclampsia as compared to healthy pregnant women in all three trimesters of gestation. These results provide sensitive parameters for use in early risk assessment and as a guide to preventive intervention during pregnancy.
