Intersexual conflict influences female reproductive success in a female-dispersing primate

In group-living mammals, individual efforts to maximize reproductive success result in conflicts and compromises between the sexes. Females utilize counterstrategies to minimize the costs of sexual coercion by males, but few studies have examined the effect of such behaviors on female reproductive success. Secondary dispersal by females is rare among group-living mammals, but in western gorillas, it is believed to be a mate choice strategy to minimize infanticide risk and infant mortality. Previous research suggested that females choose males that are good protectors. However, how much female reproductive success varies depending on male competitive ability and whether female secondary dispersal leads to reproductive costs or benefits has not been examined. We used data on 100 females and 229 infants in 36 breeding groups from a 20-year long-term study of wild western lowland gorillas to investigate whether male tenure duration and female transfer rate had an effect on interbirth interval, female birth rates, and offspring mortality. We found that offspring mortality was higher near the end of males’ tenures, even after excluding potential infanticide when those males died, suggesting that females suffer a reproductive cost by being with males nearing the end of their tenures. Females experience a delay in breeding when they dispersed, having a notable effect on birth rates of surviving offspring per female if females transfer multiple times in their lives. This study exemplifies that female counterstrategies to mitigate the effects of male-male competition and sexual coercion may not be sufficient to overcome the negative consequences of male behavior

Thin-film flow in helically wound rectangular channels with small torsion

Laminar gravity-driven thin-film flow down a helically-wound channel of rectangular cross-section with small torsion in which the fluid depth is small is considered. Neglecting the entrance and exit regions we obtain the steady-state solution that is independent of position along the axis of the channel, so that the flow, which comprises a primary flow in the direction of the axis of the channel and a secondary flow in the cross-sectional plane, depends only on position in the two-dimensional cross-section of the channel. A thin-film approximation yields explicit expressions for the fluid velocity and pressure in terms of the free-surface shape, the latter satisfying a non-linear ordinary differential equation that has a simple exact solution in the special case of a channel of rectangular cross-section. The predictions of the thin-film model are shown to be in good agreement with much more computationally intensive solutions of the small-helix-torsion Navier–Stokes equations. The present work has particular relevance to spiral particle separators used in the mineral-processing industry. The validity of an assumption commonly used in modelling flow in spiral separators, namely that the flow in the outer region of the separator cross-section is described by a free vortex, is shown to depend on the problem parameters

An Introduction to Sheep and Goat Parasite Management in Hawaii

This guide describes parasites in goats and sheep. It details symptoms, prevention, treatment of parasites, particularly gastrointestinal worms

Ocular attention-sensing interface system

The purpose of the research was to develop an innovative human-computer interface based on eye movement and voice control. By eliminating a manual interface (keyboard, joystick, etc.), OASIS provides a control mechanism that is natural, efficient, accurate, and low in workload

Seven Day E-cigarette Vapor Exposure Does Not Modify Ventilation Patterns in Long-Evans Rats

Electronic nicotine delivery systems or e-cigarettes are devices used to deliver aerosolized liquids often containing nicotine and other chemicals. These devices were originally created as a way to assist with smoking cessation in adults; however, use of these devices is increasing in adolescent and young adult populations. The long and short term effects of vaping are still under active investigation. PURPOSE: The purpose of this study was to investigate the effects of 7 days of e-cigarette vapor exposure in adult rats on lung function and lung tissue inflammatory cytokine expression, specifically IL-1. METHODS: Using random assignment, 10 adult male long-evans rats were assigned to vape (experimental) or air (control) groups. The animals were exposed to either air (n = 4) or 5% nicotine vapor (n=6) using a whole-body exposure chamber, twice a day for ten minutes for seven consecutive days. Ventilation recordings were completed on day 0 (before exposure) and day 8 (after exposure) using unrestrained whole-body plethysmography. Minute ventilation, tidal volume, and breathing frequency were assessed. Blood was collected on day 8 to look for the presence of cotinine (a nicotine metabolite). Whole lung tissue was also collected on day 8 for inflammatory cytokine assay, IL-1 ELISA. RESULTS: Cotinine was found to be present in the serum samples of the vape groups (86.6 ng/ml +/- 1.0 ng/mL) but not the air groups (0.0 ng/mL) confirming drug exposure. Baseline ventilation data collected on day 0 and post-exposure ventilation data collected on day 8 were compared between air and vape groups across three different parameters: minute ventilation, frequency, and tidal volume. These parameters were compared resulting in three distinct two-way ANOVAs comparing the variables time and treatment. No significant difference was found among any of the comparisons (p \u3e 0.05 for all). Similarly, no difference in lung inflammatory cytokine IL-1 was observed in the lung tissue of the air (85.6 pg/mL +/- 10.2 pg/mL) or vape (82.7 pg/mL +/- 14.9 pg/mL) exposure groups (p \u3e 0.05, t-test). CONCLUSIONS: In this study, 7 days of e-cigarette vapor exposure did not affect ventilation parameters or increase the presence of inflammatory cytokine, IL-1, in whole lung tissue. Limitations to this study include a small sample size (n = 10) and unreliable negative-pressure which were used to produce the vapor for the e-cigarette exposure. Future studies will modify the vape exposure system and include a larger sample size

Follicle Structure Influences the Availability of Oxygen to the Oocyte in Antral Follicles

The ability of an oocyte to successfully mature is highly dependent on intrafollicular conditions, including the size and structure of the follicle. Here we present a mathematical model of oxygen transport in the antral follicle. We relate mean oxygen concentration in follicular fluid of bovine follicles to the concentration in the immediate vicinity of the cumulus-oocyte complex (COC). The model predicts that the oxygen levels within the antral follicle are dependent on the size and structure of the follicle and that the mean level of dissolved oxygen in follicular fluid does not necessarily correspond to that reaching the COC

Analytical modeling of the structureborne noise path on a small twin-engine aircraft

The structureborne noise path of a six passenger twin-engine aircraft is analyzed. Models of the wing and fuselage structures as well as the interior acoustic space of the cabin are developed and used to evaluate sensitivity to structural and acoustic parameters. Different modeling approaches are used to examine aspects of the structureborne path. These approaches are guided by a number of considerations including the geometry of the structures, the frequency range of interest, and the tractability of the computations. Results of these approaches are compared with experimental data