Global light transport is composed of direct and indirect components. In this paper, we take the first steps toward analyzing light transport using high temporal resolution information via time of ...flight (ToF) images. The time profile at each pixel encodes complex interactions between the incident light and the scene geometry with spatially-varying material properties. We exploit the time profile to decompose light transport into its constituent direct, subsurface scattering, and interreflection components. We show that the time profile is well modelled using a Gaussian function for the direct and interreflection components, and a decaying exponential function for the subsurface scattering component. We use our direct, subsurface scattering, and interreflection separation algorithm for four computer vision applications: recovering projective depth maps, identifying subsurface scattering objects, measuring parameters of analytical subsurface scattering models, and performing edge detection using ToF images.
How the essential pre-mRNA splicing factor U2AF(65) recognizes the polypyrimidine (Py) signals of the major class of 3' splice sites in human gene transcripts remains incompletely understood. We ...determined four structures of an extended U2AF(65)-RNA-binding domain bound to Py-tract oligonucleotides at resolutions between 2.0 and 1.5 Å. These structures together with RNA binding and splicing assays reveal unforeseen roles for U2AF(65) inter-domain residues in recognizing a contiguous, nine-nucleotide Py tract. The U2AF(65) linker residues between the dual RNA recognition motifs (RRMs) recognize the central nucleotide, whereas the N- and C-terminal RRM extensions recognize the 3' terminus and third nucleotide. Single-molecule FRET experiments suggest that conformational selection and induced fit of the U2AF(65) RRMs are complementary mechanisms for Py-tract association. Altogether, these results advance the mechanistic understanding of molecular recognition for a major class of splice site signals.
To address the role of insect herbivores in adaptation of plant populations and the persistence of selection through succession, we manipulated herbivory in a long-term field experiment. We ...suppressed insects in half of 16 plots over nine years and examined the genotypic structure and chemical defense of common dandelion (Taraxacum officinale), a naturally colonizing perennial apomictic plant. Insect suppression doubled dandelion abundance in the first few years, but had negligible effects thereafter. Using microsatellite DNA markers, we genotyped > 2500 plants and demonstrate that insect suppression altered the genotypic composition of plots in both sampling years. Phenotypic and genotypic estimates of defensive terpenes and phenolics from the field plots allowed us to infer phenotypic plasticity and the response of dandelion populations to insect-mediated natural selection. The effects of insect suppression on plant chemistry were, indeed, driven both by plasticity and plant genotypic identity. In particular, di-phenolic inositol esters were more abundant in plots exposed to herbivory (due to the genotypic composition of the plots) and were also induced in response to herbivory. This field experiment thus demonstrates evolutionary sorting of plant genotypes in response to insect herbivores that was in same direction as the plastic defensive response within genotypes.
This article details the stability of Delta(9)-tetrahydrocannabinol (THC) in oral fluid during collection, extraction and storage. Oral fluid is being increasingly used as the specimen of choice for ...the detection of drug use in various applications. Studies to determine the extraction efficiency of THC from the collection buffer and stability under various laboratory storage conditions were carried out. THC was extracted from the collection pad and buffer with an average efficiency over 80% and was stable in Quantisal oral fluid extraction buffer when stored at refrigerated temperatures. Fluorescent lighting caused THC losses of over 50%, however the presence of the pad reduced the loss. In the dark, the loss of THC at room temperature was approximately 20% over 14 days. When stored with the serum separators in place, THC losses were significant. After 3 days, THC concentration was reduced by almost 30%, and after 14 days, 60% of the drug was lost and the losses were not concentration dependent.
Reducing emissions from deforestation and forest degradation (REDD+) policies, projects, and interventions are among the most prominent of recent attempts to mitigate climate change. Because REDD+ ...projects focus on forests, they simultaneously affect socioeconomic and ecological outcomes at local, subnational, national, regional, and global levels. This review assesses the promise of REDD+ for the continued ability of forests to provide multiple benefits to human societies at multiple scales. We survey REDD+ efforts at different levels, examining them through an actor-oriented approach. The article highlights the criticality of collaborative action to enhance desired outcomes of REDD+ efforts. In summarizing major REDD+ future trends, the paper emphasizes the need to learn from past forestry, agricultural, biodiversity, and development policies, and for adaptive policy making.
Indirect genetic effects (IGEs) occur when the phenotype of an individual, and possibly its fitness, depends, at least in part, on the genes of its social partners. The effective result is that ...environmental sources of phenotypic variance can themselves evolve. Simple models have shown that IGEs can alter the rate and direction of evolution for traits involved in interactions. Here we expand the applicability of the theory of IGEs to evolution in metapopulations by including nonlinear interactions between individuals and population genetic structure. Although population subdivision alone generates some dramatic and nonintuitive evolutionary dynamics for interacting phenotypes, the combination of nonlinear interactions with subdivision reveals an even greater importance of IGEs. The presence of genetic structure links the evolution of interacting phenotypes and the traits that influence their expression (“effector traits”) even in the absence of genetic correlations. When nonlinear social effects occur in subdivided populations, evolutionary response is altered and can even oppose the direction expected due to direct selection. Because population genetic structure allows for multilevel selection, we also investigate the role of IGEs in determining the response to individual and group selection. We find that nonlinear social effects can cause interference between levels of selection even when they act in the same direction. In some cases, interference can be so extreme that the actual evolutionary response to multilevel selection is opposite in direction to that predicted by summing selection at each level. This theoretical result confirms empirical data that show higher levels of selection cannot be ignored even when selection acts in the same direction at all levels.
In intimate ecological interactions, the interdependency of species may result in correlated demographic histories. For species of conservation concern, understanding the long-term dynamics of such ...interactions may shed light on the drivers of population decline. Here, we address the demographic history of the monarch butterfly, Danaus plexippus, and its dominant host plant, the common milkweed Asclepias syriaca (A. syriaca), using broad-scale sampling and genomic inference. Because genetic resources for milkweed have lagged behind those for monarchs, we first release a chromosome-level genome assembly and annotation for common milkweed. Next, we show that despite its enormous geographic range across eastern North America, A. syriaca is best characterized as a single, roughly panmictic population. Using approximate Bayesian computation with random forests (ABC-RF), a machine learning method for reconstructing demographic histories, we show that both monarchs and milkweed experienced population expansion during the most recent recession of North American glaciers 10,000–20,000 years ago. Our data also identify concurrent population expansions in both species during the large-scale clearing of eastern forests (∼200 years ago). Finally, we find no evidence that either species experienced a reduction in effective population size over the past 75 years. Thus, the well-documented decline of monarch abundance over the past 40 years is not visible in our genomic dataset, reflecting a possible mismatch of the overwintering census population to effective population size in this species.
•A new, chromosome-level assembly and annotation is provided for common milkweed•Milkweed forms an enormous, panmictic population across its North American range•Monarchs and milkweeds both had two concurrent population expansions in the past•Neither species shows signs of recent declines in effective population size
Boyle et al. find correlated population histories for the monarch butterfly and its common milkweed food plant over the past 25,000 years. Using genomic data and a new, chromosome-level milkweed assembly, they find expansions in both species corresponding to the recession of glaciers and to the more recent clearing of North American forests.
Summary
Objectives: Soluble fibre supplements are recommended to reduce the levels of low‐density lipoprotein cholesterol (LDL‐C). Limited information exists on the interaction between fibre and ...hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors (statins). The purpose of the present study was to evaluate the per se effect of psyllium (10 g/day) and lovastatin (20 mg/day) alone and in combination on serum lipids in normal human volunteers.
Methods: In a 4‐week open label, randomised, parallel study, subjects were randomised to receive 20 mg of lovastatin, 10 g of psyllium or 20 mg of lovastatin plus 10 g of psyllium in evening daily. Levels of total cholesterol (TC), LDL‐C, high‐density lipoprotein cholesterol (HDL‐C), TC/LDL‐C ratio, LDL‐C/HDL‐C ratio and triglycerides were determined after 1, 2, 3 and 4 weeks of treatment.
Results: The study group comprised 36 adult, male subjects. All treatments were well tolerated, and after 4 weeks the mean LDL‐C, TC and TG levels in the group receiving 20 mg of lovastatin plus 10 g of psyllium fell by 30.88%, 26.88% and 26.21% from baseline, compared with 24.78%, 19.55% and 32.88% in the group receiving 20 mg of lovastatin and 3.58%, 2.90% and 10.95% in the group receiving 10 g of psyllium respectively. Although additive effect was observed in the group receiving combination compared with group receiving lovastatin, the observed difference was not statistically significant. No significant changes from baseline in HDL‐C levels occurred.
Conclusions: Psyllium soluble fibre should be considered as a safe and well‐tolerated dietary supplement option to enhance cholesterol lowering.
When Is Science Significant? Understanding the p Value Rohrich, Rod J; Agrawal, Nikhil A; Savetsky, Ira ...
Plastic and reconstructive surgery (1963),
2020-October, 2020-10-00, 20201001, Letnik:
146, Številka:
4
Journal Article
PDF
