Among-year variation in deer population density index estimated from road count surveys

A method for obtaining a relative deer population density index with low cost and effort is urgently needed in wildlife protection areas that need their own deer management guidelines. We recorded the number of deer sighted during our daily trips on forest roads by car in Ashiu Forest at Kyoto University, Japan, beginning in 2006. We used generalized additive mixed models (GAMMs) to estimate among-year trends in the number of deer sighted. We applied models for the total number of deer (TND), number of adults (NA), and number of fawns (NF) sighted, which included both current-year and 1-year-old fawns. Full models included the terms of year (2007, 2008, 2009, and 2010), weather (fine, cloudy, and rain/snow), and nonlinear effects of season (date) and time (time). The optimal GAMMs for TND, NA, and NF did not include the effect of weather but included those of time, date, and year. The detected among-year trends in deer population may be influenced by differences in snow environments among the years. The modeling of road count data using GAMM quantitatively determined among-year variation in the number of deer sighted. This trend was similar to that of the population density estimated using a block count survey conducted in Ashiu Forest.     

Root response to aerobic conditions in rice,estimated by Comair root length scanner and scanner-based image analysis

Precise evaluation of root system architecture is important for understanding how rice plants are adapted to non-puddled and non-flooded conditions in aerobic culture. The objective of this study was to compare estimates of root length by the Comair root length scanner and a flat bed scanner and image analysis software in rice grown in aerobic, near-saturated and flooded fields. Fine roots (diameter < 0.2 mm) accounted for >80% of root length in all hydrological conditions. The Comair root length scanner detected fewer fine roots than the software; root length estimated by the Comair scanner was between that of roots wider than 0.1 mm and roots wider than 0.2 mm estimated by image analysis software. Importantly, total root length under aerobic and near-saturated conditions was 10–30% of that under flooding by image analysis software, but not by the Comair scanner. Digital image analysis detected genotypic differences in fine root development in the subsurface layer in aerobic culture that the Comair root length scanner would have missed. Although root length measurement by image analysis software is still under development, this new tool will facilitate the phenotyping of root system architecture and shed light on the roles of fine roots in water-saving rice cultivation.     

Open Heart Surgery with Deep Hypothermia and Cardiopulmonary Bypass in Small and Toy Dogs

Objective: To evaluate open heart surgery with deep surface‐induced hypothermia (sHT) and low‐flow cardiopulmonary bypass (CPB) in small and toy‐breed dogs. Study Design: Case series. Animals: Small breed dogs (n=8) weighing <5.5 kg with naturally occurring cardiac disease. Methods: Deep sHT under isoflurane anesthesia and low‐flow rate CPB with a small‐volume prime circuit were used. Ventricular septal defect was closed directly in 2 dogs and severe mitral regurgitation was corrected with mitral valvuloplasty (MVP) in 5 dogs and mitral valve replacement in 1 dog. Results: All dogs survived surgery; 1 dog died 6 days and 1 died 2 months after MVP. The other 6 dogs lived (mean follow‐up, 32.8 months; range, 12–65 months). Mean body weight at surgery was 3.6 kg (range, 2–5.3 kg). Mean lowest esophageal temperature was 21.4°C (range, 19.8–23.8°C). Mean lowest pump flow volume was 29.2 mL/kg/min (range, 9.4–57.7 mL/kg/min) during aortic cross‐clamping (mean, 53.5 minutes; range, 25–79 minutes). Mean hematocrit before CPB was 38.6% (range, 33–47%) and 20.3% (range, 13–24%) during CPB with a small circuit priming volume of 225–260 mL. Conclusion: Deep sHT with low‐flow rate CPB may be used for open heart surgery in small dogs weighing <5.5 kg. Clinical Relevance: Open heart surgery for selected congenital defects and acquired defects in small and toy‐breed dogs may be successfully performed using deep sHT and CPB.     

Mobility of the forearm skeleton in the Asiatic black (Ursus thibetanus), brown (U. arctos) and polar (U. maritimus) bears

In several primates and carnivores, pronation/supination angles of the forearm skeleton were examined, and it is thought that a larger angle is useful to acquire dexterous behaviors in feeding and/or life style, including climbing. In this study, the pronation/supination angles in Asiatic black, brown and polar bears were nondestructively examined. These specimens were classified as adult or non-adult. Three or four carcasses of each group of Asiatic black and brown bears were used for CT analysis, whereas only one adult polar bear was used. The forearms were positioned within the gantry of a CT scanner in both maximally supinated and pronated states. Extracted cross-sectional CT images of two positions were superimposed by overlapping the outlines of each ulna. The centroids of the radii were detected, and then the centroid of each radius and the midpoint of a line which connects between both ends of the surface of each radius facing the ulna, were connected by lines to measure the angle of rotation as an index of pronation/supination. In adult brown and polar bears, the angles were smaller as compared with the other groups (Asiatic black and non-adult brown bears). Asiatic black and non-adult brown bears can climb trees, whereas adult brown bears and polar bears cannot. This suggests that the pronation/supination angle is related to arboreal activity in Ursidae.     

Relationship between the temperature and the overwintering of water lettuce (Pistia stratiotes) at Kowataike,a branch of Yodogawa River,Japan

The successful overwintering of water lettuce (Araceae, Pistia stratiotes L.) is reported in Kowataike, a pond in Kyoto Prefecture, Japan, in the temperate climate zone. Overwintering was observed in the northern zone of Kowataike, where warm water discharge flows from an upstream electrical appliance factory. From December 2007 to January 2008, several overwintering water lettuce plants were observed in the northern zone where the water temperature was abnormally high (average: 21.9°C; low: 19.5°C). Water in the central zone of Kowataike was isolated from the warm water discharge. The temperatures here were much lower (average: 8.2°C; low: 4.2°C) and no water lettuce plant survived here. The overwintering in the northern zone fluctuated annually. This fluctuation appeared to be correlated with the period of warm water discharge, which varied from year to year and resulted in higher water temperatures most, but not all, of the winter. The results suggest that artificial environmental factors, such as anthropogenic warm water discharge, could enable water lettuce to overwinter. In the northern zone of Kowataike under the influence of the warm water discharge, only small water lettuce plants overwintered. This may be attributed to the presence of older plants with larger leaves that seemed to protect the small rosettes from frost. Second, the air warmed by the warm discharge accumulated in the space under the piles of dead large leaves, which created conditions similar to those of a greenhouse. These two mechanisms apparently allow the small water lettuce plants to be surrounded by moderate atmospheric conditions.     

Prevalence of avian haematozoa in wild birds in a high-altitude forest in Japan

The infection dynamics of avian haematozoa, which includes the genera Plasmodium, Haemoproteus, and Leucocytozoon, are complicated by a variety of environmental factors and host-parasite interactions. In Japan, the prevalence of haematozoa in wild birds has recently been determined in several local areas. However, no information on the annual prevalence of avian haematozoa in a single study site has been reported. Here, we investigated the long-term infection dynamics of haematozoa in wild birds inhabiting a mountain forest of Japan. Blood samples were collected from 415 wild birds captured in the Chichibu mountains in Saitama Prefecture at an altitude of 1650 m between 2007 and 2010. All obtained samples were examined for haematozoan infection using nested polymerase chain reaction (PCR) of the cytochrome b (cytb) genes of haematozoa. A total of 62 out of 415 (14.9%) forest birds were PCR positive for haematozoa. Relatively high infection rates of Leucocytozoon were found among several bird species (Parus ater, 64.3%; Parus montanus, 81.8%) and may be due to the host preference of vector black flies and host nestling pattern in this forest. Phylogenetic analysis of amplified cytb sequences revealed for the first time that a variety of lineages of avian haematozoa are distributed among wild bird hosts in a high-altitude forest stand in Japan. Notably, significant seasonal changes of the prevalence of avian haematozoa were not observed; however, continuous investigation will likely provide detailed information on host-parasite interactions, including local environmental factors, that influence the dynamics of avian haematozoan infections.     

基于遗传算法(GA)解甘蔗收割顺序最优化问题的研究

本研究以已建立的栽培方法、收割时期预测甘蔗单产和含糖量的数学模型为基础,提出将寻求最佳收割顺序、收割期归结为最优化组合问题,并探讨了遗传算法(GA)的解题适用性,同时进行了几种基本设定的栽培方法推移、栽培方法构成项量、行列式特性的定性分析,为求最佳的甘蔗收割顺序、收割期、不同栽培方法的面积等提供解析方法.为不使栽培方法的构成比例发生变化,与通常GA算法采用交叉在不同个体问互相交替进行不同,开发了适用本研究的GA的自己交叉具体解析法.将收割第1年期作为过渡状态,第2年期为安定状态,将两期目的函数的合并作为一个适应度进行评价.