癌症与土壤环境中Sn元素的关系

利用土壤环境资料中关于锡元素的32335个数据,癌死亡调查资料787080例,研究了胃癌、食管癌、肝癌、宫颈癌、肺癌、大肠癌、白血病、鼻咽癌、乳腺病死亡率与人鲜生活区土壤环境中锡元素的关系,结果表明。食管癌死亡率与生活区土壤中锡元素质量分数的相关性显著,肝癌、宫颈癌、鼻咽癌死亡率与生活区土壤中锻元素质量分数的相关性极显著,而胃癌、肺癌、大肠癌、白血病、乳腺癌死亡率与生活区土壤中锡元素质量分数的相共性下显著。     

An individual-based stochastic hazard model of eastern king prawn (Melicertus plebejus) migration with spatially and temporally varying fishing effort

This paper describes an individual-based stochastic model of eastern king prawn migration along the eastern Australian coast. Migration is treated as one-dimensional diffusion with drift. Capture of a prawn is seen as a failure event driven by movement through a spatially and temporally variable fishing mortality hazard. This hazard is combined with a uniform natural mortality hazard. We use a Monte Carlo method to estimate parameters by comparing expected numbers of tag-returns predicted from the model with previously published tag-release data. As the previous study used a discrete compartmental model, with compartments corresponding to zones of constant fishing effort, we used the same zones and fishing effort in our comparison. The marginal distribution of yield in each zone per single recruit is determined, providing more information compared with the deterministic approach to yield-per-recruit. Using our model we also derive the constant fishing mortality rate equivalent to a spatially variable fishing mortality rate in its impact on the proportion of prawns surviving the migration to reach spawning grounds. Determination of this proportion could contribute significantly to a sustainability assessment of the fishery. It is demonstrated using the AIC that better fits to the data of the previous study and greater parsimony are obtained using our model than were found in the deterministic compartmental analysis of that study. This improvement results from the ability of our model to account separately for average speed of movement and average dispersal rate, whereas in the previous deterministic compartmental model, movement is governed by just one parameter. Our individual-based model includes a parameter that explicitly accounts for dispersal of prawns in migration, so it can distinguish between speed effects and dispersal effects in the data. It also models both types of mortality as processes distinct from those of movement. This enables it to better separate movement and mortality effects compared to the compartmental approach, in which movement and mortality are treated as similar departure processes from a compartment. This separation reduces confounding of movement and mortality effects when parameters are estimated.     

Model of coral population response to accelerated bleaching and mass mortality in a changing climate

We model coral community response to bleaching and mass mortality events which are predicted to increase in frequency with climate change. The model was parameterized for the Arabian/Persian Gulf, but is generally applicable. We assume three species groups (Acropora, faviids, and Porites) in two life-stages each where the juveniles are in competition but the adults can enter a size-refuge in which they cannot be competitively displaced. An aggressive group (Acropora species) dominates at equilibrium, which is not reached due to mass mortality events that primarily disadvantage this group (compensatory mortality, >90% versus 25% in faviids and Porites) roughly every 15 years. Population parameters (N individuals, carrying capacity) were calculated from satellite imagery and in situ transects, vital rates (fecundity, mortality, and survival) were derived from the model, field observations, and literature. It is shown that populations and unaltered community structure can persist despite repeated 90% mortality, given sufficiently high fecundity of the remaining population or import from connected populations. The frequency of disturbance determines the dominant group—in low frequency Acropora, in high frequency Porites. This is congruent with field observations. The model of an isolated population was more sensitive to parameter changes than that of connected populations. Highest sensitivity was to mortality rate and recruitment rate. Community composition was sensitive to spacing of disturbances and level of catastrophic mortality. Decreased mortality led to Acropora dominance, increased mortality led to Acropora extinction. In nature, closely spaced disturbances have severely disadvantaged Acropora populations over the last decade. Unless a longer (>10 years) disturbance-free interval can be maintained, a permanent shift away from Acropora dominance will be observed. A mortality rate of 99% in Acropora, as observed in 1996, is not sustainable if repetitive and neither is a disturbance frequency <15 years—each leading to population collapse. This shows that the severity and/or the spacing of the 1996–1998–2002 disturbances were unusual in frequency and duration.     

Toxicity of metals to tadpoles of the common Sunda toad,Duttaphrynus melanostictus

Tadpoles of the common freshwater Sunda toad, Duttaphrynus melanostictus (Amphibia, Bufonidae), were exposed for a 4-day period under laboratory conditions to copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminum (Al), and manganese (Mn) at various concentrations. Mortality was assessed and median times of death (LT₅₀) and lethal concentrations (LC₅₀) were calculated. LT₅₀ and LC₅₀ increased with the decrease in mean exposure times and concentrations for all metals. LC₅₀ (96?h) for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.03, 0.3, 4.2, 1.5, 8.8, 0.4, 1.9, and 39?mg?L^?1, respectively. Cu was the most toxic to D. melanostictus, followed by Cd, Fe, Al, Pb, Zn, Ni, and Mn (Cu?>?Cd?>?Fe?>?Al?>?Pb?>?Zn?>?Ni?>?Mn). Duttaphrynus melanostictus is similarly sensitive to these metals as other amphibian tadpoles.     

New insights into the determinants of the total fertility rate,infant mortality rate and life expectancy

SUMMARY

Data on 127 countries from the World Development Report (1993) are examined with respect to associations between the total fertility rate (TFR), infant mortality rate, life expectancy, female primary education, GNP and domestic water supply. A marked negative association between quantity of domestic water and the total fertility rate, independent of infant mortality, GNP and women's education, was found. However, water was not significantly associated with infant mortality, after controlling for CNP, female education and TFR. Further research at the micro- (community and individual) and macro-level is suggested to understand why and how water plays such an important role in TFR. At the same time, development policies and programmes need to give high priority to the domestic water supply at community as well as national levels.     

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.     

Suicide bombings: process of care of mass casualties in the developing world

In recent times Pakistan's biggest city, Karachi, has witnessed numerous terrorist attacks. The city does not have an emergency response system and only one of the three public sector hospitals has a trauma centre. We describe the pattern of injuries and management of two terror-related mass casualty incidents involving suicide bombers in a developing nation with limited resources. The first incident occurred in May 2002 with 36 casualties, of whom 13 (36%) died immediately and 11 (30.5%) died at the primary receiving hospitals. The second incident was targeted against the local population in May 2004. The blast resulted in 104 casualties, of which 14 (13.46%) died at the site. All patients had their initial assessment and treatment based on Advanced Trauma and Life Support principles and documented on a trauma form.     

Decomposition analysis of the effects of vehicle safety technologies on the motor vehicle collision–related mortality rate from 1994 to 2015

Abstract

Objective: Though the mortality rate for motor vehicle collisions (MVCs) has been decreasing since the 1960s with the advent of the first federal seat belt laws in 1968, MVC remains a leading cause of death for individuals aged 1 to 44 years. The purpose of this study is to examine the effects of frontal (FABs) and side airbags (SABs) and electronic stability control (ESC) on the components of the MVC mortality rate.

Methods: The MVC mortality rate from 1994 to 2015 was separated into its components of exposure of vehicles, exposure of travel, collision density, injury incidence, and case fatality rate. Year was categorized on the availability of safety technology in vehicles: 1994–1997 (first-generation FABs mandated), 1998–2001 (sled-certified, second-generation FABs mandated), 2002–2006 (increasing prevalence of SABs and ESC), 2007–2011 (advanced airbags mandated), and 2012–2015 (ESC mandated, SAB in over 90% of vehicles, introduction of advanced safety systems). Relative contributions (RCs) of the components to changes in the MVC-related mortality rate were calculated as the absolute value of the component’s beta coefficient divided by the sum of the absolute values of all components’ beta coefficients. Negative binomial regression–estimated rate ratios (RRs) for the changes in the rate of each component by year category compared to the prior year category.

Results: Significant decreases in the MVC mortality rate were observed for 2007–2011 and 2012–2015. The decrease in 2007–2011 was due in most part to an 18% decrease in the injury incidence (RR?=?0.82, P?<?.0001, RC?=?63%), though there was a noted contribution by the decrease in vehicle miles traveled (RR?=?0.95, P?<?.0001, RC?=?15%). The continued decrease in mortality in 2012–2015 was due is most part to the 10% decreased case fatality rate (RR?=?0.90, P?<?.0001, RC?=?66%) because there was no significant change in the vehicle miles traveled and injury incidence.

Conclusions: The results of this study highlight the effects of vehicle safety technologies on the MVC-related mortality rate and can help direct prevention efforts. Through the study period, there was no meaningful contribution to decreases in the MVC-related mortality rate due to components related to exposure (i.e., vehicles per population and the rate of vehicle miles traveled), suggesting that prevention efforts at decreasing exposure prevalence would have little effect on the MVC-related mortality rate. Instead, prevention efforts should continue to focus on event-phase methods to decrease injury occurrence and mitigate injury severity during the collision.     

Hemolysis,Fish Mortality,and LC-ESI-MS of Cultured Crude and Fractionated Golden Alga (Prymnesium parvum)1

Schug, Kevin A., Theodore R. Skingel, Sandra E. Spencer, Carlos A. Serrano, Cuong Q. Le, Christopher A. Schug, Theodore W. Valenti, Jr., Bryan W. Brooks, Laura D. Mydlarz, and James P. Grover, 2010. Hemolysis, Fish Mortality, and LC-ESI-MS of Cultured Crude and Fractionated Golden Alga (Prymnesium parvum). Journal of the American Water Resources Association (JAWRA) 46(1):33-44. DOI: 10.1111/j.1752-1688.2009.00389.x Abstract: Erythrocyte lysis and fish mortality assays, in combination with high performance liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analysis, were investigated for bioassay-guided fractionation of cultured golden alga (Prymnesium parvum). Intracellular constituents from isolated cell pellets and extracellular supernatant growth medium were fractionated by a variety of common separation modes, including reversed phase and normal phase solid phase extraction step fractionation procedures. For reversed phase fractionation of extracellular growth medium, one fraction was obtained that displayed hemolytic activity and adversely affected fish survival. Effective dose concentrations for this sample were similar in both assays and the LC-ESI-MS analysis of the fraction showed a number of mass spectral signals which were distinct to this fraction. Fractions obtained from separation of an ethanol extract of the lyophilized cell pellet provided one sample that was highly hemolytic, but not toxic to fish. Discrepancies such as this, along with notable fish behavioral responses from other nonhemolytic cell pellet fractions, problems with the use of unbonded silica gel for fractionation, and misleading mass spectral signatures are interesting in the context of our current understanding of P. parvum toxicity and remain to be investigated further. This work provides an account of ongoing research aimed toward comprehensive elucidation of toxic constituents produced by golden alga for the purpose of providing a better understanding and means to potentially remediate the ecological impact of this harmful bloom organism.