Social interactions are rarely random. In some instances, animals exhibit homophily or heterophily, the tendency to interact with similar or dissimilar conspecifics, respectively. Genetic homophily and heterophily influence the evolutionary dynamics of populations, because they potentially affect sexual and social selection. Here, we investigate the link between social interactions and allele frequencies in foraging flocks of great tits (Parus major) over three consecutive years. We constructed co‐occurrence networks which explicitly described the splitting and merging of 85,602 flocks through time (fission–fusion dynamics), at 60 feeding sites. Of the 1,711 birds in those flocks, we genotyped 962 individuals at 4,701 autosomal single nucleotide polymorphisms (SNPs). By combining genomewide genotyping with repeated field observations of the same individuals, we were able to investigate links between social structure and allele frequencies at a much finer scale than was previously possible. We explicitly accounted for potential spatial effects underlying genetic structure at the population level. We modelled social structure and spatial configuration of great tit fission–fusion dynamics with eigenvector maps. Variance partitioning revealed that allele frequencies were strongly affected by group fidelity (explaining 27%–45% of variance) as individuals tended to maintain associations with the same conspecifics. These conspecifics were genetically more dissimilar than expected, shown by genomewide heterophily for pure social (i.e., space‐independent) grouping preferences. Genomewide homophily was linked to spatial configuration, indicating spatial segregation of genotypes. We did not find evidence for homophily or heterophily for putative socially relevant candidate genes or any other SNP markers. Together, these results demonstrate the importance of distinguishing social and spatial processes in determining population structure. 相似文献
Probiotic supplements can contribute to maintaining health and ameliorating various disease symptoms. Probiotics can be delivered in many forms with crucial differences in their survival during gastrointestinal (GI) passage. Previously, a novel encapsulation, Probiotic Pearls™ Acidophilus, Integrative Therapeutics, LLC, USA (Pearls), was shown to increase survival in vitro after exposure to gastric conditions. Here, we compare fecal recovery in human volunteers consuming Pearls or a conventional hard-shelled gelatin capsule. We performed a randomized double-blinded, two-armed trial, with six healthy subjects in each 12-day study arm. In fecal samples collected at baseline, twice during the intervention period, and after washout, we compared colony counts between the two encapsulation methods. The identity of the colonies was confirmed by colony morphology, strain-specific PCR, and 16S rRNA gene sequencing. We further performed a comprehensive 16S rRNA gene sequencing-based analysis to identify differential effects on overall microbiota composition. We detected an average log increase in bifidobacteria of 0.152 cfu/g with gelatin and 0.651 cfu/g with Pearls capsules (p > 0.05). Total lactobacilli counts increased in both groups with no difference between the groups. However, the supplemented Lactobacillus acidophilus NCFM decreased to baseline levels within 7 days after end of supplementation with gelatin capsules while 3.11 log cfu/g higher counts compared to baseline (p = 0.05) remained for Pearls. Targeted qPCR largely confirmed the trends observed by viable plate counts. Protecting the probiotic strains by Pearls encapsulation results in higher recovery rates of the supplemented lactobacilli and bifidobacteria in fecal samples and increased persistence, suggesting an improved survival and viability that might increase efficacy towards achieving desired health benefits.
The bulbuls comprise an ecologically important group of frugivorous, seed‐dispersing birds found in Asia and Africa. Although several studies have examined the phylogenetic relationships of subsets of bulbul species, a comprehensive phylogeny of the family Pycnonotidae has hitherto been lacking. We used publicly available sequences generated from previous phylogenetic studies, augmented by new sequences from several unstudied taxa, to create a supermatrix from which to infer the phylogeny of the family. In all, we compared 121 of the 130 bulbul species. Our tree supports the monophyly of the family and comprises an exclusively African and a predominantly Asian clade. Several genera were found not to be monophyletic and we suggest taxonomic changes to provide a more accurate classification based on phylogeny. 相似文献
Current analgesics have drawbacks such as delays in acquisition, lag-times for effect, and side effects. We recently presented a preliminary report of a new analgesic method involving a two-minute sciatic nerve press, which resulted in immediate short-term relief of pain associated with dental and renal diseases. The present study investigated whether this technique was effective for pain associated with other disease types, and whether the relief was effective for up to one hour.
Methods
This randomized, placebo-controlled, parallel-group trial was conducted in four hospitals in Anhui Province, China. Patients with pain were sequentially recruited by participating physicians during clinic visits, and 135 patients aged 15 – 80 years were enrolled. Dental disease patients included those with acute pulpitis and periapical abscesses. Renal disease patients included those with kidney infections and/or stones. Tumor patients included those with nose, breast, stomach and liver cancers, while Emergency Room patients had various pathologies. Patients were randomly assigned to receive a "sciatic nerve press" in which pressure was applied simultaneously to the sciatic nerves at the back of both thighs, or a "placebo press" in which pressure was applied to a parallel region on the front of the thighs. Each fist applied a pressure of 11 – 20 kg for 2 minutes. Patients rated their level of pain before and after the procedure.
Results
The "sciatic nerve press" produced immediate relief of pain in all patient groups. Emergency patients reported a 43.5% reduction in pain (p < 0.001). Significant pain relief for dental, renal and tumor patients lasted for 60 minutes (p < 0.001). The peak pain relief occurred at the 10 – 20th minutes, and the relief decreased 47% by the 60th minutes.
Conclusion
Two minutes of pressure on both sciatic nerves produced immediate significant short-term conduction analgesia. This technique is a convenient, safe and powerful method for the short-term treatment of clinical pain associated with a diverse range of pathologies.
Trial registration
Current Controlled Trials ACTRN012606000439549 相似文献
The endometrium is commonly infected with bacteria leading to severe disease of the uterus in cattle and humans. The endometrial
epithelium is the first line of defence for this mucosal surface against bacteria and Toll-like receptors (TLRs) are a critical
component of the innate immune system for detection of pathogen associated molecular patterns (PAMPs). Antimicrobial peptides,
acute phase proteins and Mucin-1 (MUC-1) also provide non-specific defences against microbes on mucosal surfaces. The present
study examined the expression of innate immune defences in the bovine endometrium and tested the hypothesis that endometrial
epithelial cells express functional receptors of the TLR family and the non-specific effector molecules for defence against
bacteria. 相似文献
The degree to which haematozoan parasites can exploit a range of vectors and hosts has both ecological and evolutionary implications for their transmission and biogeography. Here we explore the extent to which closely related mosquito species share the same or closely related haematozoan parasites, and examine the overlap in parasite lineages with those isolated from avian hosts, Zosterops species, sampled across the same study sites. Mosquito samples were collected and analysed (14 species, n = 804) from four islands in Vanuatu and the main island of New Caledonia. Using polymerase chain reaction, 15.5% (14/90) of pooled mosquito (thoracic) samples showed positive amplifications. Subsequent phylogenetic analysis of the cytochrome b gene identified four genetically distinct Plasmodium and two Haemoproteus lineages from these samples, five of which were identical to parasite lineages (n = 21) retrieved from the avian hosts. We found that three Plasmodium lineages differing by a maximum of 0.9% sequence divergence were recovered from different species and genera of mosquitoes and two Haemoproteus lineages differing by 4.6% sequence divergence were carried by 10 distantly related (11-21% divergent) mosquito species. These data suggest a lack of both cospeciation and invertebrate host conservatism. Without experimental demonstration of the transmission cycle, it is not possible to establish whether these mosquitoes are the biological vectors of isolated parasite lineages, reflecting a limitation of a purely polymerase chain reaction-based approach. Nonetheless, our results raise the possibility of a new transmission pathway and highlight extensive invertebrate host shifts in an insular mosquito-parasite system. 相似文献
Loblolly pine (LP, Pinus taeda) is the primary commercial species in southern forests of the US. Somatic embryogenesis (SE) is an effective technique to
implement clonal tree production of high-value genotypes from breeding and genetic engineering programs. Unlike angiosperm
embryos with attached cotyledons as seed storage organs, the diploid conifer embryo is surrounded by the unattached haploid
female gametophyte (FG). The FG is not present in culture. This presents a dilemma if the FG produces necessary or regulatory
compounds for embryo growth, since in culture these important compounds would be missing and would have to be added as supplements.
We report here the direct evidence that extracts from early-stage FG indeed stimulate early-stage somatic embryo (SME) growth
and multiplication, whereas extracts from late-stage FG inhibit early-stage SME growth. Furthermore, we have now isolated
this stimulatory substance from early-stage FG tissue, and identified this substance as citric acid on the basis of NMR and
mass spectrometry. We then demonstrated that topical application of citric acid to SMEs stimulates embryo colony growth at
P = 0.05. Moreover, we find that there is a good correlation between the amount of citric acid isolated from FG tissue (65
nmoles per stage 2–3 FG) and the amount of citric acid that stimulates colony growth (25–50 nmoles) when applied topically
to SMEs. This approach of isolating and characterizing a molecule from plant tissue, and investigating its role on SE processes
can provide valuable information leading to further applications of these molecules to improve LP SE protocols. 相似文献
Sexual differentiation of the brain has traditionally been thought to be driven by gonadal hormones, particularly testosterone (T). Recent studies in songbirds and other species have indicated that non-gonadal sex steroids may also be important. For example, dehydroepiandrosterone (DHEA) - a sex steroid precursor that can be synthesized in the adrenal glands and/or brain - can be converted into active sex steroids, such as 17β-estradiol (E2), within the brain. Here, we examine plasma DHEA and E2 levels in wild developing European starlings (Sturnus vulgaris), from hatch (P0) to fledging (P20). Blood samples were collected from either the brachial vein (n = 143) or the jugular vein (n = 129). In songbirds, jugular plasma is enriched with neurally-synthesized steroids and, therefore, jugular plasma is an indirect measure of the neural steroidal milieu. Interestingly, brachial DHEA levels were higher in males than females at P4. In contrast, jugular DHEA levels were higher in females than males at P0 and P10. Brachial E2 levels were higher in males than females at P6. Surprisingly, jugular E2 levels were not high and showed no sex differences. Also, we calculated the difference between brachial and jugular steroid levels. At several ages, jugular steroid levels were lower than brachial levels, particularly in males, suggesting greater neural metabolism of circulating DHEA and E2 in males than females. At a few ages, jugular steroid levels were higher than brachial levels, suggesting neural secretion of DHEA or E2 into the general circulation. Taken together, these data suggest that DHEA may play a role in brain sexual differentiation in songbirds. 相似文献
A recent study reported the incidence of intraspecific brood parasitism (IBP) in the blue tit, based on differences in pigmentation between eggs within clutches and the appearance of multiple eggs within a nest in a single day. Here we present data from another population of blue tits Cyanistes caeruleus in which we show that such evidence is not necessarily indicative of IBP. As in many other studies of birds, we found that the patterning and degree of pigmentation on eggs is individually highly characteristic of a female. As in the previous study of blue tits, a minority of clutches (about 3% of 904 clutches) contained one, two or three eggs that were distinctly different from the other eggs in the clutch, either in size or patterning, but not both. Molecular genetic analyses of parentage in a sample of these clutches with suspected IBP demonstrated unequivocally that all eggs within each clutch had in fact been laid by a single female, in all cases the social parent. We also found no evidence of IBP from paternity analyses of a sample of 3,529 offspring from 427 broods in this population, adding to previous evidence of the absence of IBP in this species. These findings cast doubt on the utility of purely observational approaches to provide evidence of intraspecific brood parasitism; our study suggests that egg morphology and records of laying patterns are inadequate to enable the identification of IBP. 相似文献