Mortality rate and confidence interval estimation in humanitarian emergencies

Surveys are conducted frequently in humanitarian emergencies to assess the health status of the population. Most often, they employ complex sample designs, such as cluster sampling. Mortality is an indicator commonly estimated in such surveys. Confidence limits provide information on the precision of the estimate and it is important to ensure that confidence limits for a mortality rate account for the survey design and utilise an acceptable methodology. This paper describes the calculation of confidence limits for mortality rates from surveys using complex sampling designs and a variety of software programmes and methods. It contains an example that makes use of the SAS, SPSS, and Epi Info software programmes. Of the three confidence interval methods examined—the ratio command approach, the modified rate approach, and the modified proportion approach—the paper recommends the ratio command approach to estimate mortality rates with confidence limits.     

Avian Mortality at Oil Pits in the United States: A Review of the Problem and Efforts for Its Solution

Oil production operations produce waste fluids that may be stored in pits, open tanks, and other sites accessible to wildlife. Birds visit these fluid-filled pits and tanks (“oil pits”), which often resemble water sources, and may become trapped and die. The US Fish and Wildlife Service (USFWS) has a program to reduce these impacts by locating problem pits, documenting mortality of protected wildlife species, and seeking cleanup or corrective action at problem pits with the help of state and federal agencies regulating the oil industry. Species identification and verification of protected status for birds recovered from oil pits are performed at the USFWS National Fish and Wildlife Forensics Laboratory. From 1992 to 2005, a minimum of 2060 individual birds were identified from remains recovered from oil pits, representing 172 species from 44 families. The taxonomic and ecological diversity of these birds indicates that oil pits pose a threat to virtually all species of birds that encounter them. Ninety-two percent of identified bird remains belonged to protected species. Most remains identified at the Forensics Laboratory were from passerines, particularly ground-foraging species. Based on Forensics Laboratory and USFWS field data, oil pits currently cause the deaths of 500,000–1 million birds per year. Although law enforcement and industry efforts have produced genuine progress on this issue, oil pits remain a significant source of mortality for birds in the United States.     

地质封存CO_2泄漏对蚯蚓的毒性效应

二氧化碳捕集与封存技术(CO_2 capture and storage, CCS)是当前国际上公认的CO_2减排的有效措施,但封存在地下的CO_2仍然因为各种不稳定因素存在泄漏风险,对土壤环境及土壤生态系统产生威胁。选择赤子爱胜蚓为研究对象,通过模拟高浓度CO_2对蚯蚓形态与生理变化的影响,探究CCS泄漏所产生的土壤高浓度CO_2对蚯蚓的毒性效应。研究表明,土壤高浓度CO_2使蚯蚓出现生殖环带肿大、尾部串珠以及断尾等外部形态变化,皮肤和刚毛受到损伤并且表皮发生褶皱等现象;随着CO_2浓度的增加以及暴露时间的延长,蚯蚓的死亡率不断增加,土壤高浓度CO_2对蚯蚓的7 d和14 d半致死浓度分别为26.39%和17.78%;蚯蚓体腔细胞溶酶体中性红保留时间(NRRT)减少。因此,蚯蚓有望作为监测CO_2泄漏的指示生物,NRRT可作为识别CO_2泄漏的敏感指标。     

Memento Mori: The development and validation of the Death Reflection Scale

Despite its potential for advancing organizational behavior (OB) research, the topic of death awareness has been vastly understudied. Moreover, research on death awareness has predominantly focused on the anxiety‐provoking aspect of death‐related cognitions, thus overlooking the positive aspect of death awareness, death reflection. This gap is exacerbated by the lack of a valid research instrument to measure death reflection. To address this issue, we offer a systematic conceptualization of death reflection, develop the Death Reflection Scale, and assess its psychometric properties across four studies. Further, using a sample of 268 firefighters, we examine whether death reflection buffers the detrimental impact of mortality cues at work on employee well‐being and safety performance. Results provide strong support for the psychometric properties of the Death Reflection Scale. Further, moderation analysis indicates death reflection weakens the negative effect of mortality cues on firefighters' safety performance. Overall, these findings suggest the newly developed Death Reflection Scale will prove useful in future research on death‐related cognitions.     

Effects of Roads on the Structure of Freshwater Turtle Populations

Abstract:  Road mortality has the potential to alter the structure of turtle populations because turtle populations are highly sensitive to additive sources of adult mortality. To address the issue, we captured painted turtles (   Chrysemys picta ; n = 174) and snapping turtles (   Chelydra serpentina ; n = 56) in 18 wetlands surrounded by low road density (≤1.5 km roads/km² of landscape) and 17 wetlands surrounded by high road density (>1.5 km/km²) in central New York in 2002. High road density was associated with male-biased sex ratios in painted turtles (74% vs. 54% males; p = 0.01) and snapping turtles (95% vs. 74% males; p = 0.08), whereas turtle morphology and abundance were not associated with road density. Disproportionate road mortality of females on nesting migrations is the most likely cause of skewed sex ratios.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.     

利用秀丽小杆线虫Caenorhabditis elegans监测厦门岛海水水质

采用野生型秀丽小杆线虫与带有hsp16启动子的转基因虫株分别对厦门岛附近5个站位的表层水样污染程度进行了监测,并将致死率和染色率的检测结果进行比较.结果表明,秀丽小杆线虫的致死率和染色率具有相关性.应用模式生物秀丽小杆线虫对环境及污染物的监测的方法可行,用转基因的秀丽小杆线虫能够提高检测的灵敏度,缩短检测时间.     

Effects of the Interaction between Genetic Diversity and UV-B Radiation on Wood Frog Fitness

Abstract:  Genetic diversity may buffer amphibian populations against environmental vicissitudes. We hypothesized that wood frogs (  Rana sylvatica ) from populations with lower genetic diversity are more susceptible to ultraviolet-B (UV-B) radiation than those from populations with higher diversity. We used RAPD markers to obtain genetic diversity estimates for 12 wood frog populations. We reared larval wood frogs from these populations and exposed experimental groups of eggs and larvae to one of three treatments: unfiltered sunlight, sunlight filtered through a UV-B-blocking filter (Mylar), and sunlight filtered through a UV-B-transmitting filter (acetate). In groups exposed to UV-B, larval mortality and deformity rates increased significantly, but egg mortality did not. We found a significant negative relationship between genetic diversity and egg mortality, larval mortality, and deformity rates. Furthermore, the interaction between UV-B treatment and genetic diversity significantly affected larval mortality. Populations with low genetic diversity experienced higher larval mortality rates when exposed to UV-B than did populations with high genetic diversity. This is the first time an interaction between genetic diversity and an environmental stressor has been documented in amphibians. Differences in genetic diversity among populations, coupled with environmental stressors, may help explain patterns of amphibian decline.     

抚顺城区大气悬浮颗粒物污染与呼吸系统疾病死亡率相关性的定量分析

为了定量分析大气总悬浮颗粒物(TSP)对居民呼吸系统疾病死亡率的影响,采用单因素泊松(Poisson)回归分析法,研究了辽宁省抚顺市城区TSP浓度变化与市区1999～2003年呼吸系统疾病死亡率的相关关系.结果发现,在消除了时间、气象等因素影响后,滞后4日TSP浓度每增加50μg·m-3,呼吸系统疾病总人群组死亡率相对危险度(OR)增加1.02195(95%CI=1.00195～1.04245),即滞后4日TSP浓度变化造成总人群组呼吸系统疾病死亡率明显增加的超额死亡率为2.195%.抚顺城区大气TSP污染可能是市区居民呼吸系统疾病死亡率增加的原因之一.     

How motorcycle helmets affect trauma mortality: Clinical and policy implications

Background: Motorcycles are the most popular vehicles in Taiwan, where more than 14.8 million motorcycles (1 motorcycle per 1.6 people) are in service. Despite the mandatory helmet law passed in 1997, less than 80% of motorcyclists in Taiwan wear helmets.

Objective: The objective of this study was to analyze the effect of using motorcycle helmets on fatality rates.

Methods: A clinical data set including 2,868 trauma patients was analyzed; the cross-sectional registration database was administered by a university medical center in Central Taiwan. A path analysis framework and multiple logistic regressions were used to estimate the marginal effect of helmet use on mortality.

Results: Using a helmet did not directly reduce the mortality rate but rather indirectly reduced the mortality rate through intervening variables such as the severity of head injuries, number of craniotomies, and complications during therapeutic processes. Wearing a helmet can reduce the fatality rate by 1.3%, the rate of severe head injury by 34.5%, the craniotomy rate by 7.8%, and the rate of complications during therapeutic processes by 1.5%. These rates comprise 33.3% of the mortality rate for people who do not wear helmets, 67.3% of the severe head injury rate, 60.0% of the craniotomy rate, and 12.2% of the rate of complications during therapeutic processes.

Discussion: Wearing a helmet and trauma system designation are crucial factors that reduce the fatality rate.