Extinction in a hyperdiverse endemic Hawaiian land snail family and implications for the underestimation of invertebrate extinction

The International Union for Conservation of Nature (IUCN) Red List includes 832 species listed as extinct since 1600, a minuscule fraction of total biodiversity. This extinction rate is of the same order of magnitude as the background rate and has been used to downplay the biodiversity crisis. Invertebrates comprise 99% of biodiversity, yet the status of a negligible number has been assessed. We assessed extinction in the Hawaiian land snail family Amastridae (325 species, IUCN lists 33 as extinct). We did not use the stringent IUCN criteria, by which most invertebrates would be considered data deficient, but a more realistic approach comparing historical collections with modern surveys and expert knowledge. Of the 325 Amastridae species, 43 were originally described as fossil or subfossil and were assumed to be extinct. Of the remaining 282, we evaluated 88 as extinct and 15 as extant and determined that 179 species had insufficient evidence of extinction (though most are probably extinct). Results of statistical assessment of extinction probabilities were consistent with our expert evaluations of levels of extinction. Modeling various extinction scenarios yielded extinction rates of 0.4‐14.0% of the amastrid fauna per decade. The true rate of amastrid extinction has not been constant; generally, it has increased over time. We estimated a realistic average extinction rate as approximately 5%/decade since the first half of the nineteenth century. In general, oceanic island biotas are especially susceptible to extinction and global rate generalizations do not reflect this. Our approach could be used for other invertebrates, especially those with restricted ranges (e.g., islands), and such an approach may be the only way to evaluate invertebrates rapidly enough to keep up with ongoing extinction.     

A critique of statistical aspects of ecological studies in spatial epidemiology

In this article, the mathematical assumptions of a number of commonly used ecological regression models are made explicit, critically assessed, and related to ecological bias. In particular, the role and interpretation of random effects models are examined. The modeling of spatial variability is considered and related to an underlying continuous spatial field. The examination of such a field with respect to the modeling of risk in relation to a point source highlights an inconsistency in commonly used approaches. A theme of the paper is to examine how plausible individual-level models relate to those used in practice at the aggregate level. The individual-level models acknowledge confounding, within-area variability in exposures and confounders, measurement error and data anomalies and so we can examine how the area-level versions consider these aspects. We briefly discuss designs that efficiently sample individual data and would appear to be useful in environmental settings.     

No evidence for the work-conflict hypothesis in the eusocial naked mole-rat (Heterocephalus glaber )

The work-conflict hypothesis (Reeve 1992) postulates that in eusocial naked mole-rat (Heterocephalus glaber) colonies there is potential conflict between the breeding female and her non-breeding colony mates over how much aid they provide in support of her reproduction. Non-breeders may withhold aid either because they are hopeful reproductives and/or because they have less to gain in terms of inclusive fitness. Breeding females should, therefore, preferentially direct aggression in the form of shoving (prolonged pushes usually involving nose-to-nose contact) towards large (hopeful reproductives) and less related non-breeders to incite them to provide aid. This study tested the following predictions of the work-conflict hypotheses. (1) There is kin bias in the shove rate of breeding females and work rates of non-breeders; (2) Shoving activates work in non-breeders. We found no evidence to suggest that the breeding female shove rate and the amount of colony maintenance activities performed by non-breeders is influenced by relatedness. Body size was a better predictor of work rate and shove rate; large animals were shoved more and worked less. Furthermore, shoving did not affect the work rate of non-breeders and rarely incited activity in inactive mole-rats. Individual mole-rats were also more likely to be shoved when already active than when resting in the nest. These results suggest that shoving by the breeding female may have functions other than the incitement of activity, such as the reproductive suppression of non-breeders. Received: 17 January 1996 / Accepted after revision: 21 September 1996     

Female sensory bias may allow honest chemical signaling by male Iberian rock lizards

Some mate choice theories propose that only male signals that are honest and condition-dependent can be stable, while another hypothesis states that males evolve signals that exploit the sensory system of females. However, sensory traps might evolve into honest signals if they are differentially costly for males. We tested whether a pre-existing sensory bias for food chemicals explained chemosensory preferences of female Iberian rock lizards for male scents. We manipulated hunger levels of females and found that food-deprived females had increased chemosensory responses to chemical stimuli from both invertebrate prey and femoral secretions of males, but not to control water. Further tests suggested that cholesta-5,7-dien-3-ol (provitamin D₃), a lipid found in both prey and males’ scent, may be one of the chemicals eliciting these responses. Moreover, hungry females spent more time on scent marks of males that had experimentally increased cholesta-5,7-dien-3-ol than on scent marks of males alone, whereas for control females this effect was not significant. We suggest that preexisting sensory bias for essential nutrients (i.e., provitamin D) may be the origin of similar female responses to male chemicals. However, previous studies have suggested that the allocation of these chemicals to ornaments is costly and only high quality males can afford it. Therefore, preexisting sensory bias for essential nutrients may further allow the evolution and maintenance of honest sexual displays.     

Correction Factors for Covariance between Concentration and Deposition Velocity on CASTNes HNO3 Deposition Estimates

The covariance between hourly concentration (C) and depositionvelocity (V) for various atmospheric species may act to bias the dry deposition (D) computed from the product of the weeklyaverage C and V. This is a potential problem for the CASTNet filter pack (FP) species, nitric acid (HNO₃). Using ozone (O₃) behavior as a surrogate for HNO₃, correctionfactors (CF) are developed to estimate this bias. Weekly CF for O₃ depend on both site and season, and seasonal average weekly CF for O₃ at a given site may be as high as 1.25.The seasonal magnitude of this CF is generally largest in summerand is ordered: summer fall spring > winter. The CF is drivento a large extent by the diurnal correlation between C andV (i.e., both are generally higher during the day and lower at night). However, since the diurnal C profile at elevated sites is relatively constant, the resulting correlation between C and V is small, and the CF at montane sites is generally negligiblysmall. The sampling protocol using daytime integrated sampling for a week and nighttime integrated sampling for a week capturesthe diurnal correlation between C and V adequately and may be used to aggregate relatively unbiased weekly D estimates. Day-night CF for O₃ are close to unity, and limited results suggest similar behavior for HNO₃. Using these limited FP results, the site- and seasonally-specific weekly CF forO₃are refined to estimate the corresponding CF for HNO₃. Worst-case adjustments for HNO₃ as high as 30% are indicated for summer periods at a given site.     

Optimal policy instruments for externality-producing durable goods under present bias

When consumers exhibit present bias, the standard solution to market failures caused by externalities—Pigouvian pricing—is suboptimal. I investigate policies aimed at externalities for present-biased consumers. Optimal policy includes an instrument to correct the externality and an instrument to correct the present bias. Either instrument can be an incentive-based policy (e.g. a tax on fuel economy) or a command-and-control policy (e.g. a fuel economy mandate). Under consumer heterogeneity, a command-and-control policy may dominate an incentive-based policy. Calibrated to the US automobile market, simulation results suggest that the second-best gasoline tax is 3–30% higher than marginal external damages. The optimal price policy includes a gasoline tax set about equal to marginal external damages and a fuel economy tax that increases the price of an average non-hybrid car by about $550–$2200 relative to the price of an average hybrid car.     

“精密度偏性分析”是环境监测质量保证的重要手段

“精密度偏性分析”是环境监测质量保证的重要手段。通过它可以了解其方法的误差和检出限是否达到要求,同时也了解实验室和操作人员对该方法的适应性。     

浅析教育与素质教育--对当前教育的反思

"素质教育"是我们在新的历史时期对教育中出现问题的有所针对的强调提法.可是,这恰恰说明了我们在教育理念认识上的偏差,"素质教育"这一概念本身就已经切割了教育的整体内涵,说明我们在教育中已经将文化素质的培养作为教育的全部,忽视了教育对其他素质的培养功能.正是由于我们教育理念的偏差,忽视了心理素质、道德素质、思想素质、政治素质等综合素质的培养,直接导致了教育的畸形与"迫害性".     

化学氧化法处理资源回收后的J-酸和吐氏酸染料中间体废液

萘系磺酸染料中间体Ｊ－酸和吐氏酸废母液经有用资源的回收后,尚须进行最终出水的达标处理．通过吐氏酸和Ｊ－酸废母液萃余液的后处理试验,确定了盐回收－混凝沉淀－化学氧化的达标处理工艺方案,并确定了相应的工艺参数．其中化学氧化采用Ｆｅｎｔｏｎ试剂（以双氧水作氧化剂,绿矾为催化剂）,在经济合理的投量范围内经２—４ｈ反应,萃余液ＣＯＤＣｒ去除率达８０％以上,最终出水ＣＯＤｃｒ在２００ｍｇ／Ｌ以下,满足有关工业废水排放标准．     

大气中痕量挥发性有机物分析方法研究

利用自行研制的累积式大气采样装置、大气痕量有机物二步冷冻浓缩进样系统和气相色谱/质谱(GC/MS)联用技术对大气中的痕量挥发性有机物进行分析(CCS-GC/MS),并对分析方法进行了评估.结果表明,CCS-GC/MS系统将单纯GC/MS分析大气中痕量挥发性有机物检测下限体积分数值从10^-6量级扩展到10^-12,39种目标化合物平均响应因子为2.9×10^-12A^-1,1000cm³进样量最低检出限体积分数值为7×10^-12～40×10^-12;流出峰保留时间定性分析相对平均偏差<2.5s,对目标化合物定性分析准确率达到100%;0～400×10^-9浓度范围内外标定量曲线r²平均值大于0.99;回收率为88%～111%,平均值100.8%±5.6%;精密度误差2%～14%,平均6.6%.