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681.
Suppression pheromone and cockroach rank formation 总被引:1,自引:0,他引:1
Although agonistic behaviors in the male lobster cockroach (Nauphoeta cinerea) are well known, the formation of an unstable hierarchy has long been a puzzle. In this study, we investigate how the unstable
dominance hierarchy in N. cinerea is maintained via a pheromone signaling system. In agonistic interactions, aggressive posture (AP) is an important behavioral
index of aggression. This study showed that, during the formation of a governing hierarchy, thousands of nanograms of 3-hydroxy-2-butanone
(3H-2B) were released by the AP-adopting dominant in the first encounter fight, then during the early domination period and
that this release of 3H-2B was related to rank maintenance, but not to rank establishment. For rank maintenance, 3H-2B functioned
as a suppression pheromone, which suppressed the fighting capability of rivals and kept them in a submissive state. During
the period of rank maintenance, as the dominant male gradually decreased his 3H-2B release, the fighting ability of the subordinate
gradually developed, as shown by the increasing odds of a subordinate adopting an AP (OSAP). The OSAP was negatively correlated
with the amount of 3H-2B released by the dominant and positively correlated with the number of domination days. The same OSAP
could be achieved earlier by reducing the amount of 3H-2B released by the dominant indicates that whether the subordinate
adopts an offensive strategy depends on what the dominant is doing. 相似文献
682.
683.
Inorganic arsenic exposure and its relation to metabolic syndrome in an industrial area of Taiwan 总被引:1,自引:0,他引:1
Past arsenic exposure was found associated with increased incidence of type 2 diabetes. However, the mechanisms remain unclear. Metabolic syndrome has been shown as a strong predictor for diabetes occurrence. We aimed at examining the association of inorganic arsenic exposure and the prevalence of metabolic syndrome. The authors recruited 660 age and gender stratified random population of residents in central Taiwan during 2002-2003. They received home interviews and health examinations at local health care units, where blood and hair specimens were collected. Hair arsenic (H-As) concentrations were determined by inductively coupled plasma-mass spectrometry. Metabolic syndrome was defined as the presence of three or more of the following risk factors: elevated levels of blood pressure, plasma glucose, and triglycerides, also the body mass index, and reduced high-density lipoprotein. Prevalence of metabolic syndrome increased from the 2nd tertile (0.034 ug/g) of H-As levels (odds ratio=2.54, 95% confidence interval: 1.20-5.39, p=0.015) after the adjustment for age, gender, occupation and life styles including cigarette smoking. We further found linear relation between H-As concentrations and increased levels of plasma glucose and lipids, and blood pressures. This first report may help identify modifiable factors associated with diabetogenesis and cardiovascular disease progression and thus be worth following for community health. 相似文献
684.
685.
Xiaoming Xu Jie Tang Zhaoyang Li Chang Liu Weizheng Han 《Mitigation and Adaptation Strategies for Global Change》2011,16(6):721-731
In this study, paddy fields in Jilin province which are flooded parcel of arable lands used for growing rice (Oryza sativa Linn.) were selected as the object. Long-term exploitation of paddy fields led to variations of soil organic carbon (SOC) and green
house gases (GHGs) emissions which might contribute to global warming. In order to calculate the amount of global warming
potentials (GWPs) of emissions from ricepaddies and find the correlations among rice yield, SOC storage and GWP, DeNitrification-DeComposition
(DNDC) model was used to simulate SOC densities and fluxes of main GHGs emitted from paddy fields. After verification, simulation
results were used to calculate SOC storages and 100-year GWPs from 1949 to 2009. Results indicated that SOC densities in depths
of 0–10 cm, 10–20 cm and 20–30 cm all kept increasing. Average methane (CH4) and nitrous oxide (N2O) fluxes were 278.55 kg carbon (kgC) ha−1 a−1 and 2.22 kg nitrogen (kgN) ha−1 a−1. The SOC storage (0–30 cm) had increased from 3.96 × 109kgC in 1949 to 47.85 × 109kgC in 2009. In addition, GWP emission was increasing exponentially in the past 61 years, from 0.16 × 106 Mg carbon dioxide equivalents (CO2-equivalents) to 66.36 × 106 Mg CO2-equivalents. Both SOC storage and GWP presented obviously linear relation to rice yields. Overall, the research suggested
that long-term rice yields could be used to estimate the SOC storage and GWP variations. 相似文献
686.
介绍了液化烃的特性及主要火灾爆炸伤害模型,分析了诱发火灾爆炸的原因,并从本质化安全技术角度,提出了前期管理无缺陷的主要对策措施。 相似文献
687.
688.
以聚乙烯亚胺、巯基乙酸为原料,通过酰胺化反应合成了一种新型高分子重金属絮凝剂巯基乙酰聚乙烯亚胺(MAPEI),研究其处理含镉废水的性能,并对几个影响因素进行了考察。实验结果表明:①该絮凝剂对Cd2+有很好的捕集性能,最高去除率可达99.9%以上;②水中常见阳离子Na+、K+、Mg2+对Cd2+的去除起促进作用;③水中常见阴离子C l-、SO42-、NO3-对Cd2+的去除也起促进作用;④pH值在6.0至8.0范围内变化时,pH值越高去除Cd2+的效果越好;⑤Cd2+和致浊物质共存时,会相互促进彼此的去除。 相似文献
689.
690.
Chiung-Ting Chang 《Environmental Hazards》2016,15(2):178-187
Studies on mortality attributed to tropical cyclones often concern large-scale disasters. Attention is rarely paid to small-scale mortality over the long term. To understand the relationship between the environment and the behavior that contributes to mortality, this article uses a classification table to review the 1556 deaths attributed to tropical cyclones, named typhoons, in Taiwan during the period 2000–2014. The results demonstrate that the majority of outdoor deaths are associated with work-related activities, while most indoor deaths occur during non-work-related activities. Taking action, such as stopping the car on a bridge if the tail lights of a vehicle in front disappear, and not walking on the roadside when the road is flooded by muddy water, may help to reduce the likelihood of typhoon-attributed death. The findings also help to dispel four myths associated with typhoon-attributed mortality. 相似文献