Heart rate and respiratory patterns in mild hypoxia in unanaesthetized newborn mammals

The heart rate and respiratory patterns in hypoxia are not well documented in unanaesthetized intact newborn animals. We studied heart rate and respiratory patterns during quiet sleep in 17% inspired O2 in 31 unanaesthetized newborns of five species: lamb, piglet, puppy, kitten, and rabbit. There was no significant change in mean heart rate and respiratory rate with hypoxia for any species. Brief apneas greater than 5 s were frequent (5-8/h), both in 21 and 17% O2 only in lambs and puppies. No sustained periodic breathing was induced by hypoxia. Thus, mild hypoxia has little steady-state effect on heart rate and respiratory rate and pattern in these unanaesthetized newborns. These findings are compatible with depressed chemoreceptor threshold, but indicate a remarkably mature respiratory pattern in full-term newborns of these species.     

The diet of coastal breeding hooded crows corvus corone comix

Three methods of analysis were used to determine the diet of territorial hooded crows at Lough Hyne Marine Reserve, Co Cork, Ireland The regular collection of prey Items from these sites at Lough Hyne was integrated with pellet and stomach analysis to determine diet Intertidal organisms occurred in over 80% of pellets and 43% of stomachs and occupied over 77% of the total wet weight of foods identified in pellets All prey items recovered from drop sites originated from the intertidal habitat, involved either large-sized species or larger individuals of smaller-sized species, and were only dropped during October to February Twenty-five intertidal species were identified but only a few of these species contributed to the bulk of the diet Hooded crows were shown to consume a wide range of intertidal species throughout the year, though the species composition in the diet was seasonally influenced Depletion and weight loss of intertidal molluscs through the winter was shown to have a minimal effect on selection suggesting that prey switching was driven by the birds nutritional requirements     

Untangling spider silk evolution with spidroin terminal domains

Background  

Spidroins are a unique family of large, structural proteins that make up the bulk of spider silk fibers. Due to the highly variable nature of their repetitive sequences, spidroin evolutionary relationships have principally been determined from their non-repetitive carboxy (C)-terminal domains, though they offer limited character data. The few known spidroin amino (N)-terminal domains have been difficult to obtain, but potentially contain critical phylogenetic information for reconstructing the diversification of spider silks. Here we used silk gland expression data (ESTs) from highly divergent species to evaluate the functional significance and phylogenetic utility of spidroin N-terminal domains.     

Inhalation of an Ethanol-Based Zileuton Formulation Provides a Reduction of Pulmonary Adenomas in the A/J Mouse Model

Potential efficacy of zileuton, a 5-LOX inhibitor, was evaluated for the reduction of pulmonary adenomas in the A/J murine model when administered via nose-only inhalation. Development of pulmonary adenomas was induced with benzo(a)pyrene. Animals were treated with a zileuton solution (5 mg/mL in 85:15 ethanol/water) either twice weekly or five times a week via nose-only inhalation; The placebo solution (85:15 EtOH/H₂O, no active) was also evaluated. Dose delivered was calculated to be 1.2 mg/kg per exposure for each zileuton group. After 20 weeks of treatment, surface tumors were enumerated and histologically assessed. A significant reduction in tumor count was noted for both the twice weekly administration (40%) and the five times a week administration (59%). The data also showed a significant reduction for the group, which received the placebo (approximately 58%). The treatment groups were also found to have an impact on the histological stages of adenoma development.     

Direct Comparisons of 2D and 3D Dental Microwear Proxies in Extant Herbivorous and Carnivorous Mammals

The analysis of dental microwear is commonly used by paleontologists and anthropologists to clarify the diets of extinct species, including herbivorous and carnivorous mammals. Currently, there are numerous methods employed to quantify dental microwear, varying in the types of microscopes used, magnifications, and the characterization of wear in both two dimensions and three dimensions. Results from dental microwear studies utilizing different methods are not directly comparable and human quantification of wear features (e.g., pits and scratches) introduces interobserver error, with higher error being produced by less experienced individuals. Dental microwear texture analysis (DMTA), which analyzes microwear features in three dimensions, alleviates some of the problems surrounding two-dimensional microwear methods by reducing observer bias. Here, we assess the accuracy and comparability within and between 2D and 3D dental microwear analyses in herbivorous and carnivorous mammals at the same magnification. Specifically, we compare observer-generated 2D microwear data from photosimulations of the identical scanned areas of DMTA in extant African bovids and carnivorans using a scanning white light confocal microscope at 100x magnification. Using this magnification, dental microwear features quantified in 2D were able to separate grazing and frugivorous bovids using scratch frequency; however, DMTA variables were better able to discriminate between disparate dietary niches in both carnivorous and herbivorous mammals. Further, results demonstrate significant interobserver differences in 2D microwear data, with the microwear index remaining the least variable between experienced observers, consistent with prior research. Overall, our results highlight the importance of reducing observer error and analyzing dental microwear in three dimensions in order to consistently interpret diets accurately.     

Emerging infectious diseases and animal social systems

Emerging infectious diseases threaten a wide diversity of animals, and important questions remain concerning disease emergence in socially structured populations. We developed a spatially explicit simulation model to investigate whether—and under what conditions—disease-related mortality can impact rates of pathogen spread in populations of polygynous groups. Specifically, we investigated whether pathogen-mediated dispersal (PMD) can occur when females disperse after the resident male dies from disease, thus carrying infections to new groups. We also examined the effects of incubation period and virulence, host mortality and rates of background dispersal, and we used the model to investigate the spread of the virus responsible for Ebola hemorrhagic fever, which currently is devastating African ape populations. Output was analyzed using regression trees, which enable exploration of hierarchical and non-linear relationships. Analyses revealed that the incidence of disease in single-male (polygynous) groups was significantly greater for those groups containing an average of more than six females, while the total number of infected hosts in the population was most sensitive to the number of females per group. Thus, as expected, PMD occurs in polygynous groups and its effects increase as harem size (the number of females) increases. Simulation output further indicated that population-level effects of Ebola are likely to differ among multi-male–multi-female chimpanzees and polygynous gorillas, with larger overall numbers of chimpanzees infected, but more gorilla groups becoming infected due to increased dispersal when the resident male dies. Collectively, our results highlight the importance of social system on the spread of disease in wild mammals.     

Detailed flow patterns in the nasal cavity.

The human nasal cavity filters and conditions inspired air while providing olfactory function. Detailed experimental study of nasal airflow patterns has been limited because of the complex geometry of the nasal cavity. In this work, particle image velocimetry was used to determine two-dimensional instantaneous velocity vector fields in parallel planes throughout a model of the nasal cavity that was subjected to a nonoscillatory flow rate of 125 ml/s. The model, which was fabricated from 26 computed tomography scans by using rapid prototyping techniques, is a scaled replica of a human right nasal cavity. The resulting vector plots show that the flow is laminar and regions of highest velocity are in the nasal valve and in the inferior airway. The relatively low flow in the olfactory region appears to protect the olfactory bulb from particulate pollutants. Low flows were also observed in the nasal meatuses, whose primary function has been the subject of debate. Comparison of sequentially recorded data suggests a steady flow.     

Glucoraphasatin: Chemistry, occurrence, and biological properties

Glucoraphasatin is an atypical glucosinolate mainly found in Raphanus sativus roots and sprouts. This review focuses on the chemistry, the occurrence, and the biological properties of glucoraphasatin.