Characterization of storm wave asymmetries with functional data analysis

Functional data analysis (FDA) is a set of tools developed to perform statistical analysis on data having a functional form. In our case we consider the one-dimensional wave surface profiles registered during a North-Sea storm as functional data. The data is split into 20 min intervals within which an individual wave is defined as the profile between two consecutive downcrossings. After registration of these individual waves to the interval [0, 1], the mean wave profile for the entire 20 min interval is obtained along with the first two derivatives of this mean profile. We analyze the shape of these mean waves and their derivatives and show how they change as a function of the significant wave height, which is a measure of the severity of the sea for the corresponding time interval. We also look at the evolution of the energy, as represented by the phase diagram, as a function of significant wave height. The results show the asymmetry in vertical and horizontal scales for real data. Comparison with a Gaussian wave simulation model calculated from the actual wave spectra shows important differences in symmetry and shape of the average wave and seem to indicate that the greatest difference in the distribution of energy during the wave cycle lies in the second and fourth quarters of the wave period. FDA can be applied to derive information on the individual and average wave profiles and also provide an understanding of the variation in energy throughout the wave phase.     

Helper contributions to reproductive success in the splendid fairy-wren (Malurus splendens)

Summary In Malurus splendens, helpers were present in 65% of 226 group-years with at least one helper female in 37% of group-years. Most females helped for only one year, while many males did so for at least two years. Most were offspring of one or both present breeders, and in 53% of helper-years, helped both parents. For 159 helpers of known age and parentage, the mean coefficient of relatedness to the offspring was 0.47. Novice females with or without helpers produced fewer fledglings per season than females with one year breeding experience and the same level of help. Helpers did not affect production of fledglings per year by females with one year of experience. Females with two or more years experience and at least two helpers produced more fledglings than equivalent birds with one or no helpers. Experience and helpers have little effect on production of fledglings per nest but they lead to more females renesting after a first brood has been raised. Fewer than 20% of novices renest after fledging one brood, while for females with at least two years experience, the percent renesting after success is 40% with no help, 56% with one helper and 69% with 2 or more helpers. Experienced females begin their first clutch earlier than novices, and helpers reduce the time to renest after success from 66 days for an experienced female with no helpers to 50 days for females with at least two years experience and two or more helpers. Breeding females with helpers survive better (76%) than those with no helpers (55%), and helpers thus gain future indirect fitness. Despite their close relatedness to breeders and offspring, in only 19% of group-years did helpers increase their indirect fitness from an increase in productivity.     

Sediment Parameters of Northwest Black Sea Shelf and Slope: Implications for Transport of Heavy Metals and Radionuclides

In June 1990, sediment cores were obtained from several locations in the Northwest Black Sea shelf and slope by a joint US/USSR scientific team aboard the survey vessel R/V VODYANITSKY. the goal of this investigation was to determine the distribution and levels of radioactivity resulting from the Chernobyl 1986 nuclear accident. the sediment was characterized for texture, mineral composition, redox state, heavy metals, and radionuclides. Correlations emerging from these data reveal paths of dispersal and transport of materials from river sources to deposition sites on the shelf and slope. Kaolinite in the clay mineral suite clearly reflects a dispersal pattern originating in the Danube River and progressing in an easterly direction across the shelf. Sand-size gypsum and the elemental heavy metals Zn, Cu, Cr, and Pb (probable industrial source) as well as the elements Al and Mg (probable terrigenous source) also show a dispersal pattern from the Danube station location in an easterly direction across the shelf. the dispersal direction indicated by these materials is not in conflict with recent existing notions concerning the hydrology of the Northwest Black Sea. Barium anomalies at a midshelf location may be related to operations in the Lebada oil fields situated updrift. Heavy mineral dispersal reflect the Danube and -Crimean Provinces established for the shelf and relate to terrestrial source areas. in addition, the heavy mineral monazite correlates with the radioactive Th 232 found most abundantly in the Crimean Province. Local anomalies of Mn, Fe and U in the sediment at station locations are related to redox (Eh) conditions and other factors. Cs^134/137 data, reported by Curtis and Broadway (1991), correspond to transport and dispersal patterns implicit in the mineralogic, anthropogenic indicators, and sediment characteristics of the study area.     

THE OPTIMIZATION OF THE OPERATION OF A MULTI-PURPOSE WATER RESOURCE SYSTEM1

The objective of any water resource system is to transform the natural waters of a river basin into a form such that optimal use of these waters will result. Thus the water may be transformed into electrical energy, transferred in space for water supply and irrigation, transferred in time for flood control and maintenance of adequate streamflows, or simply retained for use as a means for achieving water-based recreation.     

Enhanced susceptibility to infection in mice after exposure to dilute exhaust from light duty diesel engines

A series of experiments was conducted in which groups of mice were first exposed for various durations to diluted exhaust from light duty diesel engines and then briefly to an infectious aerosol generated by nebulizing cultures of a bacterial pathogen (Streptococcus). Typically, postinfection mortality was significantly greater in groups exposed to exhaust than in their corresponding control groups exposed to purified air only. Data of recent diesel and of past diesel- and catalyst-treated gasoline engine exhaust experiments suggest a somewhat greater excess mortality from (enhanced susceptibility to) bacterial infection in mice exposed to diesel exhaust than in those exposed to catalytic gasoline exhaust. Limited data on acute tests of NO₂ and acrolein vapor alone suggest that the infectivity-enhancing effect of diesel exhaust could be accounted for in large part by these components. Exposures to diesel exhaust, NO₂, or acrolein did not enhance the mortality response to a viral pathogen (A/PR8-34).     

论科学、保护与政府的目的地球的功能整体性并不是生物多样性的问题

20年来,人们一直把保护的目的更多地集中在"生物多样性"的保存上,强调物种丧失所可能造成的损失.所提出的解决办法,也一直是建立公园和保护区,以保护那些"热点地区",特别是在生物多样性程度非常高的热带地区.对于生物多样性的保存,常常还包括建立保护区之间的联系,以允许生物在保护区之间移动.这种方法已经得以法规化,例如<美国濒危物种法案(Endangered Species Actinthe United States)>和<生物多样性公约(Biodiversity Treaty)>.这两个法案都逐一列出了应当保护的濒危物种,但都存在着明显的缺陷.这些做法可能是适当的,但是作为拥有60亿人口、掌握着毁灭性技术、为了直接的人类利益而事实上开发了所有的地球资源的世界性保护活动,却是不充分的.作为包括人类在内的所有生物体的栖息地,生物圈的功能正在迅速衰退,这并不是因为物种的消失,而是因为自然群落的不断贫化,这种贫化是由于全球性、普遍存在的人类活动的慢性破坏而产生的.这种自然群落的贫化导致了演变中的环境功能的紊乱,功能紊乱的累积,最后导致了物种的消失.其实,远在物种消失这一问题变得如此重要之前,局地的生物生态型就受到损失了,这在遗传学上是非常清楚的,而且它们赖以发育的自然群落就变得贫化,功能出现了紊乱.最明显的影响是气候上的,这是每一个生态系统都经历的环境的全球变化.自然保护区的最精细、最谨慎的连结方式也无法发挥作用,因为其环境气候发生了改变,而且生物多样性将大幅度丧失.尽管所建立的公园就是为了避免这种丧失,但是在这之前,人类环境就将遭受显著破坏.自然保护的目的,是保存景观(以及水体)的功能整体性.其重点往往是地球上天然林区的森林,因为森林占据了地球上很大的面积,而且对环境的每一方面都有很大影响.在大多数地方,功能的整体需要85%或以上的天然林区结构的整体性.当然,这还需要科学界的客观测定和定义.这样看来,自然保护的实质就发生了变化,它并不是所谓的生物多样性的保存,而是人类环境功能整体性的保存,其核心目的是要求我们以民主形式建立的政府,定义并保护公共利益.现在已经不是迫切需要科学界和保护界认识这种转变、定义新的保护目的以及将这种转变告诉公众的时候了,而是迫切需要政府承担起在这样的责任,即在一个可以栖息的生物圈之中保护公众的利益.