Effects of captivity and testosterone on the volumes of four brain regions in the dark‐eyed junco (Junco hyemalis)

This study investigates the effects of captivity and testosterone treatment on the volumes of brain regions involved in processing visual and spatial information in adult dark‐eyed juncos (Junco hyemalis). We treated captive and free‐living male juncos with either testosterone‐filled or empty implants. Captive juncos had a smaller hippocampal formation (HF) (both in absolute volume and relative to telencephalon) than free‐living birds, regardless of hormone treatment. Testosterone‐treated males (both captive and free‐living) had a smaller telencephalon and nucleus rotundus, but not a smaller HF or ectostriatum, than controls. We found that free‐living testosterone‐treated males had larger home ranges than free‐living controls in agreement with earlier experiments, but we found no corresponding difference in HF volume. We discuss the implications of the effect of captivity on HF volume for past and future laboratory experiments. © 2000 John Wiley & Sons, Inc. J Neurobiol 43: 244–253, 2000     

Spatiotemporal Clusters and Trend of Trichomonas vaginalis Infection in Korea

This study was done to provide an overview of the latest trichomoniasis status in Korea by finding disease clusters and analyzing temporal trends during 2012–2020. Data were obtained from the Health Insurance Review & Assessment Service (HIRA) of Korea. SaTScan and Joinpoint programs were used for statistical analyses. Gyeonggi-do had the highest average population and highest number of cases. The high incidence of T. vaginalis infections were observed among women aged 40–49 and 30–39 years (33,830/year and 33,179/year, respectively). Similarly, the 40–49 and 30–39 age group in men showed the highest average cases (1,319/year and 1,282/year, respectively). Jeollabuk-do was the most likely cluster, followed by Busan/Gyeongsangnam-do/Ulsan/Daegu and Jeju-do and Gwangju. Urban and rural differences were prominent. Trichomoniasis has decreased significantly in most clusters, except for Incheon. Trichomoniasis was decreasing in women recently after peaking around 2014. Men showed different trends according to age. Trichomoniasis was increasing in the 10–39 age groups, but decreasing in the 40–59 age groups. This study might provide an analytic basis for future health measures, policy-makers, and health authorities in developing effective system for prevention of trichomoniasis.     

达乌尔黄鼠种群空间分布型研究及其应用

本文根据1987年在内蒙古东北部低山丘陵区和平原区草原的调查资料,应用频数分布比较法研究了达乌尔黄鼠的空间分布型。结果表明：在抽样单位(样方)大小为1公项(1OO米×100米)时,4个样地内达乌尔黄鼠交尾期和幼鼠分居期的空间分布型均属poisson分布(随机分布)。环境与密度制约因素的影响不明显。并经回归分析得到：种群密度(m)与零样方频率(Po)和有鼠样方频率(Px )的曲线关系分别为m=4.5451-0.96721nPo和m=4.5451-0.96721n(1-Px)。经X²检验与poisson分布理论曲线基本一致(x²《x^{2 _0.05},P>0.05)。为达乌尔黄鼠种群密度估计提供了理论依据.     

江西省弋阳叠山书院园林变迁钩沉——基于元明清社会环境视角

采用文献考证法、田野调查法与逻辑演绎法,以元明清社会环境为视角,分析弋阳叠山书院园林变迁及其动力。自元代至清代,从变迁形式来看,书院园林选址从郊野山林迁入为城市高胜地,布局从单轴线前祀后学的建筑空间形态发展成双轴多进深多院落的园林空间形态,园林文化从以儒学文化为主转变为儒道释俗文化共存。从变迁动力来看,政治环境和经济支持是书院园林建设发展的基础,政体态度决定了书院园林存亡及其社会意义,经济支持在书院维系和官学化方面具有显著影响力,文化环境受政治环境影响,包容的政治环境允许延续宋儒品格,严苛的政治环境禁锢自由文风,因此文化环境对书院园林的选址、空间布局与文化确立起到关键作用力。     

五种温带森林土壤微生物生物量碳氮的时空格局

土壤微生物是森林生态系统中的重要分解者,在碳和氮循环中起着重要作用,同时也是对环境变化的敏感指示者。采用氯仿熏蒸浸提法测定了我国东北地区5种温带森林土壤微生物生物量碳(Cmic)和氮(Nmic)的季节动态及其在土壤中的垂直变化。结果表明:林型之间Cmic和Nmic差异显著(P0.01)。落叶松林、红松林、蒙古栎林、杨桦林、硬阔叶林的Cmic的变化范围依次为:278937mgkg-1、2181020mgkg-1、313891mgkg-1、5101092mgkg-1、4401911mgkg-1;其Nmic的变化范围依次为:1872mgkg-1、18103mgkg-1、2495mgkg-1、43125mgkg-1、40208mgkg-1。所有林型的Cmic和Nmic均随土壤深度的增加而下降。Cmic和Nmic基本上呈现出生长季开始之前下降、生长季结束时上升、其中出现12个峰值的季节变化格局,但峰值大小和出现时间随林型和土壤层次而变。010cm土层的Cmic和Nmic季节变化较大。Cmic和Nmic与凋落叶量、土壤有机碳含量和土壤总氮含量呈显著正相关。Cmic与土壤含水量呈正相关,而与土壤温度呈负相关。不同林型凋落物数量和组成、土壤理化性质的差异是导致其土壤微生物生物量时空格局差异的主要因素。     

Thermotactile thresholds at the fingertip: Effect of contact area and contact location

Thresholds for the detection of changes in temperature are used to indicate neuropathy, but a variety of different contact areas and contact locations are used. This study was designed to determine the effects of variations in contact area and contact location on both warm and cool thresholds at the fingertip. With 20 healthy subjects (10 females and 10 males aged 20–30 years), warm thresholds and cool thresholds were determined in two separate sessions using the method of limits. In the first part of each session, thresholds were determined around the centre of the whorl using circular contactors with five different diameters (3, 6, 9, 12, and 55 mm). In the second part of each session, thresholds were determined using two contactors (6- and 12-mm diameter) at three locations along the fingertip: (i) distal (5 mm from the nail), (ii) middle (centre of whorl), and (iii) proximal (3 mm from the distal interphalangeal joint). With increasing contact area, the warm thresholds decreased, the cool thresholds increased, and the inter-subject variability in both warm and cool thresholds decreased. Using the 6-mm diameter contactor, warm thresholds were independent of location but cool thresholds increased from distal to proximal locations. It is concluded that temperature sensitivity at the fingertip increases with increasing area of contact, with the variability in thresholds consistent with the existence of warm and cool “insensitive fields”. The findings show that the influence of contact area and contact location should be considered when assessing thermotactile thresholds at the fingertip.     

毛乌素沙地南缘沙漠化临界区域土壤养分的空间异质性

毛乌素沙地南缘沙漠化临界区域是沙地-草地景观界面的关键部位,研究该区域土壤养分的空间格局和生态学过程,对于土地沙漠化的机理研究具有重要的意义。采用经典统计与地统计学相结合的方法,通过半变异函数及其模型、克里格局部插值估计、空间分布图等研究了毛乌素沙地南缘沙漠化临界区域土壤养分的空间异质性特征。结果表明:研究区土壤速效钾含量符合球状模型,全氮和速效磷含量符合指数模型;速效钾含量具有强空间自相关性,其结构方差比为0.882,而全氮和速效磷含量表现为中等程度的空间自相关性,其结构方差比分别为0.501和0.514;3种土壤养分空间自相关距离存在差异,其中全氮和速效钾的变程均为511m,而速效磷的变程为143m;3种土壤养分的分布格局呈现明显的空间规律性,从牛枝子群落到黑沙蒿群落,速效钾和速效磷含量先降低后升高,与研究区的界面变化过程一致,而全氮含量逐渐降低,与研究区的植被覆盖度变化一致;3种土壤养分的标准差都较小,Kriging插值结果比较可靠。     

9-Methyl-β-carboline-induced cognitive enhancement is associated with elevated hippocampal dopamine levels and dendritic and synaptic proliferation

β-Carbolines (BCs) belong to the heterogenous family of carbolines, which have been found exogenously, that is, in various fruits, meats, tobacco smoke, alcohol and coffee, but also endogenously, that is, blood, brain and CSF. These exogenous and endogenous BCs and some of their metabolites can exert neurotoxic effects, however, an unexpected stimulatory effect of 9-methyl-β-carboline (9-me-BC) on dopaminergic neurons in primary mesencephalic cultures was recently discovered. The aim of the present study was to extend our knowledge on the stimulatory effects of 9-me-BC and to test the hypothesis that 9-me-BC may act as a cognitive enhancer. We found that 10 days (but not 5 days) of pharmacological treatment with 9-me-BC (i) improves spatial learning in the radial maze, (ii) elevates dopamine levels in the hippocampal formation, and (iii) results after 10 days of treatment in elongated, more complex dendritic trees and higher spine numbers on granule neurons in the dentate gyrus of 9-me-BC-treated rats. Our results demonstrate that beyond its neuroprotective/neurorestorative and anti-inflammatory effects, 9-me-BC acts as a cognitive enhancer in a hippocampus-dependent task, and that the behavioral effects may be associated with a stimulatory impact on hippocampal dopamine levels and dendritic and synaptic proliferation.     

Is there an associational resistance of winter pea–durum wheat intercrops towards Acyrthosiphon pisum Harris?

Acyrthosiphon pisum Harris (Aphididae: Hemiptera), the pea aphid, is an important pest in organic farming systems. In this work, the objective was to gather empirical field data on the associational resistance of durum wheat–winter pea intercrops towards the pea aphid, compared with pure stands of winter pea. Our results showed that intercropping winter pea with durum wheat significantly decreased A. pisum abundance in all the situations. Moreover, it was systematically observed that pea grew bigger in pure than in intercropped stands but after considering pea dry mass as a covariate, it appeared that the durum wheat–winter pea intercrop was still significantly less attacked by pea aphids than the sole crop. Intercrop sowing designs had an incidence on infestation levels: substitutive diversification systems of different types are more effective in decreasing the level of aphid infestation than does the additive system. In addition, substitutive row intercrop is significantly less infested than substitutive mixture. These results suggest that a mechanism related to the resource concentration hypothesis may explain the associational resistance of the IC of durum wheat–winter pea towards A. pisum.