Salinity tolerance during early development of threatened Murray hardyhead (Craterocephalus fluviatilis) to guide environmental watering

1. The worldwide reduction in wetlands has led to the large‐scale decline of wetland‐dependent species. In Australia, to redress some of the decline, partial restoration of the hydrology of a small number of wetlands has been attempted using allocations of environmental water.
2. A common goal of the watering is the maintenance and enhancement of native fish communities, which historically have included populations of the salt tolerant Murray hardyhead (Craterocephalus fluviatilis), a small, short‐lived fish, endemic to the lower Murray–Darling Basin.
3. Despite the addition of environmental water to several sites at which the species is known to persist, populations continue to decline. This decline is, at least in part, suspected to be a consequence of salinities that conflict with the breeding ecology and survival of early life stages.
4. Here the effect of salinity on egg hatch rate and the upper salinity tolerance of larval and juvenile Murray hardyhead was determined under laboratory conditions. It was found that eggs were vulnerable to elevated salinities, whereas juveniles were capable of tolerating salinities up to 105 ppt.
5. Based on the results of the experiment, brackish wetlands managed for Murray hardyhead should be maintained, where possible, between 12 and 45 ppt. Such a salinity regime will necessitate less intensive management of salinity, and a reduced volume of environmental water, providing both environmental and fiscal benefits. The research highlights the benefits of investment in targeted research.

     

瘤胃乙酸与丙酸摩尔比例的改变对瘤胃发酵及血液指标的影响

通过向瘤胃灌注乙酸：丙酸：丁酸的摩尔比例分别为75：15：10，65：25：10，55：35：10和45：45：10溶液，并在连续灌注的作用下，以期达到最终改变瘤胃液中乙酸：丙酸：丁酸摩尔比例的目的。研究表明：（1）随着灌注液中丙酸浓度的提高，最终瘤胃液中丙酸的比例增加，乙酸的比例逐渐下降，与对照组差异显著（P＜0.05），丁酸的摩尔比例无论与对照组，还是各处理间均无差异；（2）向瘤胃灌注的VFA溶液提供高于维持能量水平30％以上的能量，使瘤胃中总的VFA浓度、VFA产生速率、丙酸的产生速率及VFA的总产量均显著增加（P＜0.01）；但是对基础混合日粮的干物质（DM）、有机物（OM）、中洗纤维（NDF）、酸洗纤维（ADF）、半纤维素（HCF）等养分的消化率不构成显著影响；（3）当灌注溶液中丙酸所占摩尔比例增加到35％，粪氮和尿氮的排出量显著减少（P＜0.05），从而提高日粮氮的沉积能力。进一步研究表明，当灌注液中丙酸的摩尔比例进一步提高至45％时，血糖浓度及胰岛素的浓度才显著增加（P＜0.05）；但胰岛素与胰高血糖素的比值对于不同的处理或对照组，基本保持稳定。     

Inclusion body myositis in spring peepers (Pseudacris crucifer).

In 2000, 2 adult captive spring peepers (Pseudacris crucifer) from the same zoological park were humanely euthanized. Histologically, both frogs had degeneration, atrophy, and necrosis of striated myofibers of the tongue admixed with chronic lymphohistiocytic inflammation. One frog had similar lesions in the skeletal muscles of the body wall. Several degenerate and necrotic myofibers contained single, eosinophilic, intranuclear inclusion bodies. Ultrastructural examination of the inclusions revealed nonenveloped, icosahedral, virus-like particles averaging 20-24 nm in diameter. This is the first reported case of inclusion body myositis in frogs and is believed to be due to parvoviral infection.     

Causes of mortality in captive Attwater's prairie chickens (Tympanuchus cupido attwateri) at the San Antonio Zoo, 1997-2000.

Necropsy records for 102 Attwater's prairie chickens (Tympanuchus cupido attwateri) that had been captive-reared and had died at the San Antonio Zoo over a 4-yr period were evaluated to determine the causes of mortality. Gross necropsy, histopathology, and bacterial culture findings are summarized. Mortality was highest in young birds (<6 mo) and embryos. Husbandry- and gastrointestinal-related diseases were the most common causes of mortality.     

The genomic sequence of the bovine T cell receptor gamma TRG loci and localization of the TRGC5 cassette

The bovine and ovine TRG genes have previously been shown to be located in two loci, TRG1 and TRG2, in contrast to human and mouse TRG genes that are located in a single locus. The bovine TRG1 and TRG2 loci are located on chromosome 4 at 4q3.1 and 4q1.5-2.2, respectively. The complete genomic organization of the two bovine loci is described: each locus comprises three cassettes, each one includes one or several variable genes (TRGV) and one or several joining genes (TRGJ) preceding a constant (TRGC) gene. The location of the TRGC5 cassette is conclusively described in 5' of the TRG1 locus. Analysis of 17 TRGV belonging to 10 different subgroups, 8 TRGJ and 6 TRGC genes is conducted which comprises the most comprehensive list to date.     

十字花科芸薹属种间杂种营养优势的利用研究

选用4个油菜雄性不育系和三种类型十字花科芸薹属种, 研究了不同杂交组合的亲和性, 杂种一代的营养优势表现和杂种营养优势的生理基础以及品质性状表现. 结果表明: 利用油菜雄性不育系与其它十字花科芸薹属种间杂交可以显著提高种间杂交的亲和性, 并具有细胞质遗传效应. 通过杂交制种可以获得大量的杂种应用于生产. 十字花科     

Analysis on the Disposal of the Industrial Solid Waste in the Three Gorges Region

The second step of water storage for Three Gorges Reservoir will be executed in Jue,2003. Because there is still a large quantity of industrial solid waste(ISW) dumped on the reservoir bottom where should be cleaned before water storage and wastes should be disposed. After a full investigation and analyze, the total amount of ISW in the Chongqing reservoir area is about 1.66 million tons. According the principles of safe, economical and reliable, this paper describes the ISW's treatment. The ordinary ISW which is harmless and non toxic after identification should be treated on-site, the ISW that exceeds the national standards should be removed and be disposed in the landfill, and the hazardous waste should be removed for disposition or storage.     

Analyses of Interlayer Stresses and Strain Transfer in Smart Laminated Structures

A new model is proposed to analyze the strain/stress transfer relation between host materials and piezoceramic sensors/actuators under bending and axial stress loading. The finite thickness of the adhesive is taken into account. The physical layers of the piezoceramic, adhesive and structure material are further subdivided into thinner layers as fine as necessary in order to improve the accuracy of stress analysis. In each thin layer the in-plane stresses are assumed to vary linearly across the thickness. By satisfying equilibrium equations, constitutive equations and displacement-strain relations, all components of stress, strain and displacement can be expressed as functions of the in-plane forces and the moments of the thin layers. The differential equations governing the in-plane forces and the moments are obtained. Then, this analytical model is used to predict strain transfer from the structure material to the sensor. It is found, both experimentally and theoretically, that the axial strain of the host material is considerably larger than the strain of the sensor, which is directly related to the output voltage. By introducing the so-called strain transfer factor, a relationship between the output voltage of the sensor and the strain of the measured material is derived. The model is used to predict interlayer stress distributions and strain transfer, which are induced by actuator strain. The result was compared with existing experiments and FEM. There is stress concentration between the actuator and adhesive around the edge of the smart structures, which may cause debonding under high stress loading.