Intestinal Regulatory Systems of Invertebrates and Their Probable Evolution in Multicellular Animals

A wide distribution of regulatory (endocrine, nerve) cells in the digestive tract epithelium has been shown in representatives of taxons at different levels of the evolutionary tree, and their brief comparative characteristics are presented. The hypothesis is put forward that the intestinal regulatory systems, on having initially appeared based on predominantly nerve elements, were subsequently complicated due to the appearance of various endocrine cells originating from the epithelial ones. In the course of evolution, the spatial separation occurred of this heterogeneous system into the intraepithelial endocrine and subepithelial nerve components, this process running in parallel in the rows of protostomian and deuterostomian animals.     

Estimation of Disease Prevalence from a Screening Program

The estimation problem of disease prevalence from a screening program is considered. Due to the imperfect nature of a screening test, the estimate should be adjusted based upon the sensitivity and the specificity of the screening test. Several approximate methods of constructing the confidence interval of prevalence are given and the score method is proposed in detail. A simulation study is also presented and discussed.     

被捕食动物对捕食者的识别研究及在放归中的应用

对捕食者的认知能力是当前生态学研究的一个热点。一些物种具有对捕食者先天的识别能力,而一些物种必须通过后天学习才能获得对捕食者的认知能力,还有许多动物通过社会学习和文化传播获得对捕食者的识别能力。本文就国外被捕食动物对捕食者的识别的研究进展进行综述,并讨论了该项研究对野外放归工作提供的重要理论意义和应用价值。     

Hospital-Based Program to Increase Child Safety Restraint Use among Birthing Mothers in China

Objective

To evaluate a hospital-based educational program to increase child safety restraint knowledge and use among birthing mothers.

Methods

A prospective experimental and control study was performed in the Obstetrics department of hospitals. A total of 216 new birthing mothers from two hospitals (114 from intervention hospital and 102 from comparison hospital) were recruited and enrolled in the study. Intervention mothers received a height chart, an 8-minute video and a folded pamphlet regarding child safety restraint use during their hospital stay after giving birth. Evaluation data on the child safety seat (CSS) awareness, attitudes, and use were collected among both groups before and after the intervention. An additional phone interview was conducted among the intervention mothers two months after discharge.

Results

No significant differences existed between groups when comparing demographics. Over 90% of the intervention mothers found the educational intervention to be helpful to some extent. A significantly higher percentage of mothers in the intervention than the comparison group reported that CSS are necessary and are the safest seating practice. Nearly 20% of the intervention mothers actually purchased CSS for their babies after the intervention. While in both the intervention and comparison group, over 80% of mothers identified the ages of two through five as needing CSS, fewer than 50% of both groups identified infants as needing CSS, even after the intervention.

Conclusion

The results indicated that child safety restraint education implemented in hospitals helps increase birthing mothers'' overall knowledge and use of CSS. Further efforts are needed to address specific age-related needs to promote car seats use among infants.     

Food Preference,Keeper Ratings,and Reinforcer Effectiveness in Exotic Animals: The Value of Systematic Testing

Food preference describes the behavior of selecting between items for consumption; reinforcer effectiveness is the functional effect of that item in controlling behavior. Food preference and reinforcer effectiveness were examined in giant pandas (Ailuropoda melanoleuca) and African elephants (Loxodonta africana). A pairwise comparison between food items was used to assess food preference. High-, moderate-, and low-preference items were selected and tested for reinforcer effectiveness. High-preference items controlled behavior more effectively than less-preferred items. Caregiver ratings of food preferences were also collected for each subject, but these reports did not necessarily coincide with actual subject preferences. Caregiver ratings correlated with the food preferences of only 1 individual of each species; thus, preferences of 1 nonhuman animal may be falsely generalized to all animals of that species. Results suggest that food choice and reinforcer effectiveness should be investigated empirically and not rely on anecdotal reports.     

Mowing Reduces Exotic Annual Grasses but Increases Exotic Forbs in a Semiarid Grassland

Cheatgrass (Bromus tectorum) and other exotic winter‐active plants can be persistent invaders in native grasslands, growing earlier in the spring than native plants and pre‐empting soil resources. Effective management strategies are needed to reduce their abundance while encouraging the reestablishment of desirable native plants. In this 4‐year study, we investigated whether mowing and seeding with native perennial grasses could limit growth of exotic winter‐actives, and benefit growth of native plants in an invaded grassland in Colorado, United States. We established a split‐plot experiment in October 2008 with 3 mowing treatments: control, spring‐mowed, and spring/summer‐mowed (late spring, mid‐summer, and late summer), and 3 within‐plot seeding treatments: control, added B. tectorum seeds, and added native grass seeds. Cover of plant species and aboveground biomass were measured for 3 years. In March and June of 2010, 2011, and March of 2012, B. tectorum and other winter‐annual grasses were half as abundant in both mowing treatments as in control plots; however, cover of non‐native winter‐active forbs increased 2‐fold in spring‐mowed plots and almost 3‐fold in spring/summer‐mowed plots relative to controls. These patterns remained consistent 1 year after termination of treatments. Native cool‐season grasses were most abundant in spring‐mowed plots, and least abundant in control plots. There was higher cover of native warm‐season grasses in spring/summer‐mowed plots than in control plots in July 2011 and 2012. The timing of management can have strong effects on plant community dynamics in grasslands, and this experiment indicates that adaptive management can target the temporal niche of undesirable invasive species.     

A Gene Regulatory Program for Meiotic Prophase in the Fetal Ovary

The chromosomal program of meiotic prophase, comprising events such as laying down of meiotic cohesins, synapsis between homologs, and homologous recombination, must be preceded and enabled by the regulated induction of meiotic prophase genes. This gene regulatory program is poorly understood, particularly in organisms with a segregated germline. We characterized the gene regulatory program of meiotic prophase as it occurs in the mouse fetal ovary. By profiling gene expression in the mouse fetal ovary in mutants with whole tissue and single-cell techniques, we identified 104 genes expressed specifically in pre-meiotic to pachytene germ cells. We characterized the regulation of these genes by 1) retinoic acid (RA), which induces meiosis, 2) Dazl, which is required for germ cell competence to respond to RA, and 3) Stra8, a downstream target of RA required for the chromosomal program of meiotic prophase. Initial induction of practically all identified meiotic prophase genes requires Dazl. In the presence of Dazl, RA induces at least two pathways: one Stra8-independent, and one Stra8-dependent. Genes vary in their induction by Stra8, spanning fully Stra8-independent, partially Stra8-independent, and fully Stra8-dependent. Thus, Stra8 regulates the entirety of the chromosomal program but plays a more nuanced role in governing the gene expression program. We propose that Stra8-independent gene expression enables the stockpiling of selected meiotic structural proteins prior to the commencement of the chromosomal program. Unexpectedly, we discovered that Stra8 is required for prompt down-regulation of itself and Rec8. Germ cells that have expressed and down-regulated Stra8 are refractory to further Stra8 expression. Negative feedback of Stra8, and subsequent resistance to further Stra8 expression, may ensure a single, restricted pulse of Stra8 expression. Collectively, our findings reveal a gene regulatory logic by which germ cells prepare for the chromosomal program of meiotic prophase, and ensure that it is induced only once.     

Evaluating the Impact of a Humane Education Summer-Camp Program on School-Aged Children's Relationships with Companion Animals

ABSTRACT

This study evaluated the impact of children's participation in a five-day humane education summer-camp program on the quality of their relationships with and treatment of companion animals. We measured changes from pre- to post-program in 77 children (50 girls, 27 boys) aged 6–12 years. The program promoted positive interactions between children and animals in natural settings, with a focus on either companion animals or farm/forest animals. The Companion Animal Bonding Scale, the Pet Friendship Scale, the Comfort from Companion Animal Scale, the Children's Treatment of Animal Questionnaire, and a drawing task were administered to children prior to the beginning of the camp on day one and again at the end of day five. Overall, the results showed that after five days of humane education in summer camp, children reported sharing significantly closer bonds and friendships with their companion animals. These results were more pronounced for girls versus boys, among younger (aged 6 to 8 years) versus older (aged 9 to 12 years) children, and among children receiving the companion-animal versus farm/forest-animal curriculum. Older boys reported significantly lower scores on the humane treatment of their companion animals, compared with younger boys, and both older and younger girls. Comparisons by type of curriculum also suggested that the humane education curriculum that focused on farm/forest animals resonated more with the girls versus the boys. The implications for camp- and classroom- based humane education programs are discussed.     

BMP1基因在动物卵泡发生和胚胎发育中的表达规律及调控机制的研究进展

骨形态发生蛋白1(BMP1)是一类属于虾红素家族的金属蛋白酶,它在细胞外基质的形成以及调控TGFβ信号通路的过程中发挥重要作用。BMP1基因在动物卵泡发育过程中具有不同程度表达,并以某种形式参与了动物胚胎的发生和发育过程。开展对BMP1基因的研究将有助于人们从基因角度进一步阐明动物卵泡的形成和胚胎发育的机制,对医学和畜牧业等领域将产生积极的影响。着重从BMP1基因在动物胚胎发育过程中的表达定位、功能及其机制进行综述。     

Feeding of Ticks on Animals for Transmission and Xenodiagnosis in Lyme Disease Research

Transmission of the etiologic agent of Lyme disease, Borrelia burgdorferi, occurs by the attachment and blood feeding of Ixodes species ticks on mammalian hosts. In nature, this zoonotic bacterial pathogen may use a variety of reservoir hosts, but the white-footed mouse (Peromyscus leucopus) is the primary reservoir for larval and nymphal ticks in North America. Humans are incidental hosts most frequently infected with B. burgdorferi by the bite of ticks in the nymphal stage. B. burgdorferi adapts to its hosts throughout the enzootic cycle, so the ability to explore the functions of these spirochetes and their effects on mammalian hosts requires the use of tick feeding. In addition, the technique of xenodiagnosis (using the natural vector for detection and recovery of an infectious agent) has been useful in studies of cryptic infection. In order to obtain nymphal ticks that harbor B. burgdorferi, ticks are fed live spirochetes in culture through capillary tubes. Two animal models, mice and nonhuman primates, are most commonly used for Lyme disease studies involving tick feeding. We demonstrate the methods by which these ticks can be fed upon, and recovered from animals for either infection or xenodiagnosis.