Cloacal erection promotes vent apposition during forced copulation in the New Zealand stitchbird (hihi): implications for copulation efficiency in other species

Cloacal protuberances (CP) in male birds result from spermatic engorgement of storage tubules around the cloaca during the breeding season. We examined seasonal changes in the volume and orientation of the CP in the New Zealand stitchbird Notiomystis cincta. The male stitchbird has one of the largest recorded CPs for any species (max = 1,570 mm³), with CP volume increasing by almost 400% between the non-breeding and breeding seasons. While sperm competition has been positively correlated with the magnitude of CP storage in other species, no evidence previously existed for the CP improving copulation efficiency. By measuring the relative orientation of the CP throughout the year, we show that not only does the CP increase in size as males become sexually active, it also changes its orientation by approximately 60°. This results in it shifting from facing posteriorly to becoming almost perpendicular to the abdomen. This cloacal erection improves the apposition of the male and female cloacal openings during face-to-face forced copulation in this species. This provides the first reported evidence supporting the copulation efficiency hypothesis of the avian CP. While the magnitude of seasonal changes in female cloacal volume was similar to males, female cloacal orientation remained virtually unchanged across seasons. This difference between the sexes is likely to reflect differing selection pressures for optimizing sperm transfer. In females, a posterior-facing cloaca is ideal for both waste evacuation and sperm reception, whereas, for the male, a posterior-facing cloaca is well suited for waste evacuation, but possibly hinders sperm delivery. Changes in male cloacal orientation from the non-breeding to the breeding season are a likely reflection of conflict in this dual function. Evidence of changes in CP orientation in another passerine species suggests this phenomenon is widespread and also important for understanding related fields such as sperm competition, forced copulation and constraints on the evolution of the avian intromittent organ.     

Driving restrictions post-stroke: Physicians' compliance with regulations

Objective: Suffering a stroke might lead to permanent cognitive and/or physical impairment. It has been shown that these impairments could have an impact on an individual's fitness to drive. In Sweden, as in many other countries, there are regulations on driving cessation post-stroke. Information on driving cessation should be given to all patients and noted in the journal. The present study sought to determine physician's compliance to driving regulations post-stroke as well as follow-up and gender aspects.

Method: A retrospective study of medical records on stroke patients was carried out. The study covered all of the medical records on stroke incidents (n = 342) during a year at a typical medium to large-sized hospital in Sweden.

Results: A journal entry on driving cessation post-stroke was missing in 81% of the medical records. Only 2% of the patients were scheduled for a follow-up meeting specifically concerning fitness to drive. Significantly more men than women had an entry on driving in the journal.

Conclusions: We conclude that the Swedish regulations on driving cessation post-stroke were not followed at the participating hospital. It is crucial that all stroke patients receive information on driving cessation because their condition might affect fitness to drive. Analysis of follow-up records showed that there was no consistent method for assessment of a patient's fitness to drive. There was also a gender difference in the material, which warrants further investigation.     

Inactivation of hepatitis A virus and murine norovirus on surfaces of plastic,steel and raspberries using steam-ultrasound treatment

Food and Environmental Virology - The leading causes of foodborne viral disease outbreaks are human norovirus and hepatitis A virus (HAV). Their environmental persistence enables contamination of...     

Air-mediated pollen flow from genetically modified to conventional crops.

Tools for estimating pollen dispersal and the resulting gene flow are necessary to assess the risk of gene flow from genetically modified (GM) to conventional fields, and to quantify the effectiveness of measures that may prevent such gene flow. A mechanistic simulation model is presented and used to simulate pollen dispersal by wind in different agricultural scenarios over realistic pollination periods. The relative importance of landscape-related variables such as isolation distance, topography, spatial configuration of the fields, GM field size and barrier, and environmental variation are examined in order to find ways to minimize gene flow and to detect possible risk factors. The simulations demonstrated a large variation in pollen dispersal and in the predicted amount of contamination between different pollination periods. This was largely due to variation in vertical wind. As this variation in wind conditions is difficult to control through management measures, it should be carefully considered when estimating the risk of gene flow from GM crops. On average, the predicted level of gene flow decreased with increasing isolation distance and with increasing depth of the conventional field, and increased with increasing GM field size. Therefore, at a national scale and over the long term these landscape properties should be accounted for when setting regulations for controlling gene flow. However, at the level of an individual field the level of gene flow may be dominated by uncontrollable variation. Due to the sensitivity of pollen dispersal to the wind, we conclude that gene flow cannot be summarized only by the mean contamination; information about the frequency of extreme events should also be considered. The modeling approach described in this paper offers a way to predict and compare pollen dispersal and gene flow in varying environmental conditions, and to assess the effectiveness of different management measures.     

Catalytic TiO2 oxidation of ethanethiol for environmentally begnin air pollution control of sulphur compounds

Volatile organic compounds containing reduced sulphur such as thiols and thioethers are released mostly from biological activities and a number of manufacturing processes, such as papermaking and petroleum refining. Environmentally benign and cost-effective air pollution control technology for reduced sulphur compounds is still a topic of research, e.g., in pulp and paper industry. Due to its advantages, photocatalytic oxidation over titanium dioxide presents a potential alternative for the air treatment strategies. The temperature influence on the reaction pathway and kinetics of gas-phase photocatalytic oxidation and thermal catalytic decomposition of ethanethiol over Degussa P25 TiO₂ was established by a continuous flow method in a simple tubular reactor at temperatures from 373 to 453 K. Kinetic parameters for ethanethiol were: adsorption enthalpy −45 kJ mol⁻¹ and activation energy 42 kJ mol⁻¹. Sulphur dioxide, carbon monoxide, carbon dioxide, acetic acid and water were identified as by-products.     

Weighting waiting in collective decision-making

Animals searching for food, mates, or a home often need to decide when to stop looking and choose the best option found so far. By re-analyzing experimental data from experiments by Mallon et al. (Behav Ecol Sociobiol 50:352–359, 2001), we demonstrate that house-hunting ant colonies are gradually more committed to new nests during the emigration. Early in house-hunting, individual ants were flexibly committed to new nest sites. However, when carrying to a new nest had started, ants hardly ever switched preference. Using a theoretical model based on experimental data, we test at which stage flexible commitment influences speed and accuracy most. We demonstrate that ant colonies have found a good compromise between impatience and procrastination. Early flexibility combined with later rigidity is identically effective as other strategies that include flexible commitment, but it is particularly good when emigration conditions are harsh.     

塔基图穆保护区——库克群岛的社区所属生态旅游明星

塔基图穆保护区 1996年创建于库克群岛的拉罗汤加岛 , 其目标是为了当前和未来生产者的利 益而对生物多样性实施保护 . 只有当地人民对其土地和资源拥有所有权 . 生态旅游将成为该 保护区的主要经济活动 . 在土地所有者同意和支持下 , 一个有指导的 “ 大自然漫步 “ 已经组 织起来 .     

Deponiegas

Investigations were performed concerning whether or not the composition of volatile halogenated carbons in landfill gas (LFG) change when they uncontrolledly leave the aerobic surface of landfill. For this reason, the aerobic biological degradation of chlorofluorocarbons (CFCs), chlorofluorohydrocarbons (HCFCs), and vinyl chloride (VC), which were often measured in LFG of old household-landfills, was investigated. In 1-liter and 126-liter laboratory test reactors, the aerobic milieu conditions of the surface of landfills were simulated. Air with methane and trichlorofluoromethane (R11), dichlorodifluoromethane (R12), and their reductive metabolites dichlorofluoromethane (R21), chlorodifluoromethane (R22), and vinyl chloride (VC) were continuosly pumped through marl and a mixture of biowaste and compost. R21, R22, and VC were degraded, probably cometabolically by methanotrophic bacteria. They have inhibited the methane oxidation. The degradation rates of R21 (only in biowaste and compost) and R22 were up to 2.8 and 10 mg/m³ _material/h, respectively. The maximum degradation rate of VC was 1,3000 mg/m³ _material/h in marl. Under aerobic milieu conditions, a biodegradation of R11 and R12 was not detected.     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.