Lead poisoning of spectacled eiders (Somateria fischeri) and of a common eider (Somateria mollissima) in Alaska

Lead poisoning was diagnosed in four spectacled eiders (Somateria fischeri) and one common eider (Somateria mollissima) found dead or moribund at the Yukon Delta National Wildlife Refuge, Alaska (USA) in 1992, 1993, and 1994. Ingested lead shot was found in the lower esophagus of one spectacled eider and in the gizzard of the common eider. Lead concentrations in the livers of the spectacled eiders were 26 to 38 ppm wet weight, and 52 ppm wet weight in the liver of the common eider. A blood sample collected from one of the spectacled eiders before it was euthanized had a lead concentration of 8.5 ppm wet weight. This is the first known report of lead poisoning in the spectacled eider, recently listed as a threatened species by the U.S. Fish and Wildlife Service.     

Match+Guardian: a secure peer-to-peer trading card game protocol

In trading card games (TCGs), players create a deck of cards from a subset of all cards in the game to compete with other players. While online TCGs currently exist, these typically rely on a client/server architecture and require clients to be connected to the server at all times. Instead, we propose, analyze and evaluate Match+Guardian (M+G), our secure peer-to-peer protocol for implementing online TCGs. We break down actions common to all TCGs and explain how they can be executed between two players without the need for a third party referee (which usually requires an unbiased server). In each action, the player is either prevented from cheating or if they do cheat, the opponent will be able to prove they have done so. We show these methods are secure and may be shuffled into new styles of TCGs. We then measure moves in a real trading card game to compare to our implementation of M+G and conclude with an evaluation of its performance on the Android^TM platform, demonstrating that M+G can be used in a peer-to-peer fashion on mobile devices.     

浅谈大同市排水管网的改造

结合大同市的城市排水规划,指出对现状欠合理的城市排水管网进行改造,是城市发展过程中不可回避的问题,针对这些现状排水管网,文中阐述了对其改造的一些建议和方案,以实现城市排水管网的合理性,促进其建设的可持续发展.     

Bioinspired Materials with Self-Adaptable Mechanical Properties

Natural structural materials, such as bone, can autonomously modulate their mechanical properties in response to external loading to prevent failure. These material systems smartly control the addition/removal of material in locations of high/low mechanical stress by utilizing local resources guided by biological signals. On the contrary, synthetic structural materials have unchanging mechanical properties limiting their mechanical performance and service life. Inspired by the mineralization process of bone, a material system that adapts its mechanical properties in response to external mechanical loading is reported. It is found that charges from piezoelectric scaffolds can induce mineralization from surrounding media. It is shown that the material system can adapt to external mechanical loading by inducing mineral deposition in proportion to the magnitude of the stress and the resulting piezoelectric charges. Moreover, the mineralization mechanism allows a simple one-step route for fabricating functionally graded materials by controlling the stress distribution along the scaffold. The findings can pave the way for a new class of self-regenerating materials that reinforce regions of high stress or induce deposition of minerals on the damaged areas from the increase in mechanical stress to prevent/mitigate failure. It is envisioned that the findings can contribute to addressing the current challenges of synthetic materials for load-bearing applications from self-adaptive capabilities.     

Methods for the determination of cyclopropenoid fatty acids V. A spectrophotometric method for cottonseed oils based upon the Halphen-test reaction

A spectrophotometric method of analysis for the quantitative estimation of cyclopropenoid fatty acids in cottonseed oil based upon the Halphen-test reaction has been described. Various parameters involved in the reaction have been investigated and two pigment fractions responsible for the characteristic Halphen-test cherry-red color have been isolated. The method is applicable to relatively small amts of sample material. The average deviation from the actual cyclopropenoid acid contents as determined by the stepwise HBr titration method was less than ±0.02% in both the refined and crude oil series. S. Utiliz. Res. Dev. Div., ARS, USDA.     

Adhesion and surface analysis of carbon fibres electrochemically oxidized in aqueous potassium nitrate

Type II carbon fibres (PAN-based) have been electrochemically oxidized in aqueous potassium nitrate to varying electron charge densities (0–4294 Cg-1). The fibres were subsequently characterized by angle-resolved X-ray photoelectron spectroscopy (ARXPS) and ion scattering spectroscopy (ISS) and the results were correlated to acid/base surface titrations and BET surface area measurements. Relative to the as-received fibres (commercially treated, but unsized), the electrochemical treatments increased the ARXPS O/C atomic ratios by approximately 50%–100% and the concentration of oxidized carbon became more uniform within the XPS sampling depth (10 nm). At the same time, the number of acidic functions titrated by sodium hydroxide rose from about 2.6 eq g-1 to 1078 eq g-1, and the BET surface area increased from 0.67 m2 g-1 to 2.9 m2 g-1. A large portion of the increase in acidic groups was due to the increased fibre oxidation below the XPS sampling depth. The surface densities of acidic functions (functions/nm2) determined from NaOH uptake and nitrogen BET surface area experiments were far larger than is physically possible. Thus, it is postulated that aqueous NaOH solutions are able to access a much larger surface region than can be measured by nitrogen BET. A model involving subsurface pores, voids, crevasses, etc., which become available via swelling during solvation in aqueous NaOH, but are at least partially closed off when dry (during BET measurements), was proposed. The quantity of acidic functions introduced (detected by NaOH) was directly proportional to the extent of oxidation as referenced to the electron charge density (C g-1). The ISS spectra suggest that the surface density of carbon/oxygen groups was also increased. Single-fibre fragmentation tests (using an epoxy resin matrix) revealed that in most cases the interfacial shear strengths (IFSS) increased with increasing ARXPS O/C atomic ratio probably due to enhanced fibre/matrix chemical bonding and/or mechanical interlocking. As the extent of the electrochemical oxidation progressed above 1500 C g-1 the IFSS of single filament specimens then began to decrease. This was due to a continuing decrease in filament tensile strength as the extent of electro-oxidation increased. The critical transfer length, Lc, also decreased from 0.36 mm to 0.18 mm as the extent of electro-oxidation proceeded. Electrochemically oxidized fibres were compared to nitric acid-oxidized fibres in terms of acidic groups generated, BET surface areas, acidic group surface densities, dye adsorption with methylene blue and the role of aqueous NaOH in exposing some of the microstructure created by oxidative processes. © 1998 Kluwer Academic Publishers     

猪肉组织的近场太赫兹成像检测研究

利用搭建的基于光电导微探针的近场太赫兹(Terahertz,THz)系统对新鲜猪肉组织切片进行了成像检测研究,结果发现近场THz成像可以很好地区分猪肉组织中的脂肪组织区域和肌肉组织区域,其成像效果明显优于传统远场THz时域光谱成像系统。研究表明了基于光电导微探针的近场THz成像技术在生物样品检测方面的可行性,展示出该技术在生物医学检测领域具有很好的应用前景。     

The new temperance movement in the United States: what happened to macrostructural factors in alcohol problems?

BACKGROUND: Pulmonary tuberculosis can produce unusual radiographic appearances and negative results of sputum and bronchoscopic examinations are common. This study assessed the value of ultrasound guided aspiration biopsy in the diagnosis of pulmonary tuberculosis with unusual radiographic appearances. METHODS: Thirteen patients, ultimately diagnosed as having tuberculosis, underwent a chest ultrasonographic examination between June 1984 and August 1991. All had sputum available for examination and nine were also examined by bronchoscopy. Ten patients who had a negative sputum smear and negative bronchoscopic brushing smears underwent ultrasound guided aspiration or biopsy. Percutaneous aspiration was performed with a 22 gauge needle. If the smear did not reveal acid fast bacilli, a biopsy sample was taken with a 16 gauge Tru-cut needle to obtain a histological diagnosis. RESULTS: The ultrasonographic examination delineated the more complex nature of the lesions better than the chest radiograph. Ultrasound guided aspiration biopsy provided the diagnosis in nine of 10 patients, while the sputum smear and culture provided diagnosis in five of 13, and bronchoscopy in four of nine. In terms of rapid diagnosis, ultrasound guided aspiration biopsy gave the diagnosis in eight of 10 cases. No patient developed a major complication. CONCLUSION: Ultrasonography can direct the needle to the most suitable part of a lesion to obtain the relevant specimens. The diagnostic yield is high and the procedure is relatively safe. It is especially helpful in patients with negative results of sputum and bronchoscopic examinations.     

Increasing or decreasing interest in activities: The role of regulatory fit.

What makes people’s interest in doing an activity increase or decrease? Regulatory fit theory (E. T. Higgins, 2000) provides a new perspective on this classic issue by emphasizing the relation between people’s activity orientation, such as thinking of an activity as fun, and the manner of activity engagement that the surrounding situation supports. These situational factors include whether a reward for good performance, expected (Study 1) or unexpected (Study 2), is experienced as enjoyable or as serious and whether the free-choice period that measures interest in the activity is experienced as enjoyable or as serious (Study 3). Studies 1–3 found that participants were more likely to do a fun activity again when these situational factors supported a manner of doing the activity that fit the fun orientation—a reward or free-choice period framed as enjoyable. This effect was not because interest in doing an activity again is simply greater in an enjoyable than a serious surrounding situation because it did not occur, and even reversed, when the activity orientation was important rather than fun, where now a serious manner of engagement provides the fit (Study 4a and 4b). (PsycINFO Database Record (c) 2010 APA, all rights reserved)