Disulfide-dependent multimeric assembly of resistin family hormones

Resistin, founding member of the resistin-like molecule (RELM) hormone family, is secreted selectively from adipocytes and induces liver-specific antagonism of insulin action, thus providing a potential molecular link between obesity and diabetes. Crystal structures of resistin and RELMbeta reveal an unusual multimeric structure. Each protomer comprises a carboxy-terminal disulfide-rich beta-sandwich "head" domain and an amino-terminal alpha-helical "tail" segment. The alpha-helical segments associate to form three-stranded coiled coils, and surface-exposed interchain disulfide linkages mediate the formation of tail-to-tail hexamers. Analysis of serum samples shows that resistin circulates in two distinct assembly states, likely corresponding to hexamers and trimers. Infusion of a resistin mutant, lacking the intertrimer disulfide bonds, in pancreatic-insulin clamp studies reveals substantially more potent effects on hepatic insulin sensitivity than those observed with wild-type resistin. This result suggests that processing of the intertrimer disulfide bonds may reflect an obligatory step toward activation.     

3种藏药复方抗ORFV作用研究

将岩青、轮叶棘豆等3种藏药材按一定比例配成复方,采用乙醇提取法进行提取,将浓缩药液用细胞维持液配制成1g／L的药液,并根据对兔肾细睁（PRK）安全浓度的测定结果,稀释成不同梯度浓度,分别与脓疱皮炎病毒（ORFV）加入到已培养24h的单层PRK中,通过M1TI’法测定OD值,分析其对ORFV病毒增殖的影响。经回归分析,复方药液在7．81—62·5mg／mL浓度范围内,药物浓度与活细胞存在线性关系,对病毒增势有显著的抑制作用（P〈0·05）。表明藏药材复方药液具有抗脓疱皮炎病毒感染的作用。     

Communicating food safety: Ethical issues in risk communication

This paper discusses two paradigms of risk communication that guide strategies for communicating food safety issues. Built on the principles of social utility and paternalism, the first paradigm heavily relies on science and technical experts to determine food safety regulations and policies. Risk communication, in this context, is a unidirectional process by which experts from the industry or government regulatory agencies inform or alert potentially affected publics about the hazards they face and the protective actions they can take. However, public trust and confidence in government and industry have considerably declined. Experts are being questioned about the objectivity of their assessments of risks. Policy makers are being challenged on such risk management decisions as tolerance guidelines, food labeling laws, and emergency warning systems. Concomitantly, some segments of the public, especially consumer advocates and environmental groups, are demanding increased input into the decision making process as they call for the recognition of lay perceptions and interpretations of risk as a legitimate counterpart to technically-assessed risk. Hence, instead of the linear, persuasion-oriented communication process, there are evolving efforts to shape risk communication into a more dialogical, interactive, and democratic exchange of information among different stakeholders (i.e., technical experts, government policy makers, industry, interest groups, and the general public). Reflecting a more Jeffersonian approach, this second paradigm argues that decisions about food safety are so complex and multi-dimensional that they must not be left to experts alone. However, both paradigms present ethical dilemmas. Determining the risks and relative safety of foods is not a totally objective and concise process. Since it involves social, economic, political, and personal values, how can the public not be involved in the exchange of ideas and information concerning food risks and safety? On the other hand, can we afford to let public opinion govern decisions pertaining to food risks and safety without consideration for the merits of scientific risk assessment? This paper raises questions regarding some assumptions of these two risk communication paradigms, and explores and discusses some of the salient ethical questions inherent in each framework.     

Effects of rectilinear acceleration and optokinetic and caloric stimulations in space

During the flight of Spacelab 1 the crew performed a number of experiments to explore changes in vestibular function and visual-vestibular interactions on exposure to microgravity. Measurements were made on the threshold for detection of linear oscillation, vestibulo-ocular reflexes elicited by angular and linear movements, oculomotor and posture responses to optokinetic stimulations, and responses to caloric stimulation. Tests were also conducted on the ground, during the 4 months before and on days 1 to 6 after flight. The most significant result was that caloric mystagmus of the same direction as on the earth could also be evoked in the weightless environment.     

Regulation of fasted blood glucose by resistin

The association between obesity and diabetes supports an endocrine role for the adipocyte in maintaining glucose homeostasis. Here we report that mice lacking the adipocyte hormone resistin exhibit low blood glucose levels after fasting, due to reduced hepatic glucose production. This is partly mediated by activation of adenosine monophosphate-activated protein kinase and decreased expression of gluconeogenic enzymes in the liver. The data thus support a physiological function for resistin in the maintenance of blood glucose during fasting. Remarkably, lack of resistin diminishes the increase in post-fast blood glucose normally associated with increased weight, suggesting a role for resistin in mediating hyperglycemia associated with obesity.     

Latent infection by bovine herpesvirus type-5 in experimentally infected rabbits: virus reactivation, shedding and recrudescence of neurological disease.

Latent infection with bovine herpesvirus type-5 (BHV-5) was established in rabbits inoculated with two South American isolates (EVI-88 and 613) by intranasal or conjunctival routes. Nine rabbits (613, 8/27; EVI-88, 1/34) developed neurological disease and died during acute infection and other three (613, n=2; EVI-88, n=1) developed a delayed neurological disease, at days 34, 41 and 56 post-inoculation (p.i.). Between days 56 and 62 p.i., the remaining rabbits were submitted to five daily administrations of dexamethasone (Dx) to reactivate the infection. Twenty-five out of 44 rabbits (56.8%) shed virus in nasal or ocular secretions after Dx treatment. Virus shedding was first detected at day two post-Dx and lasted from one to 11 days. The highest frequencies of virus reactivation were observed in rabbits inoculated conjunctivally (10/15 versus 15/29); and among rabbits infected with isolate 613 (12/16 versus 13/28). Virus reactivation upon Dx treatment was accompanied by neurological disease in nine rabbits (20.4%), resulting in six deaths (13.6%). Virus in moderate titers and mild to moderate non-suppurative inflammatory changes in the brain characterized the neurological infection. Three other rabbits showed severe neurological signs followed by death after 31 to 54 days of Dx treatment. Virus, viral nucleic acids and inflammatory changes were detected in their brains. The late-onset neurological disease, after acute infection or Dx treatment, was probably a consequence of spontaneous virus reactivation. These results demonstrate that BHV-5 does establish a latent infection in rabbits and that clinical recrudescence may occur upon reactivation.     

Twentieth-Century Sea Surface Temperature Trends

An analysis of historical sea surface temperatures provides evidence for global warming since 1900, in line with land-based analyses of global temperature trends, and also shows that over the same period, the eastern equatorial Pacific cooled and the zonal sea surface temperature gradient strengthened. Recent theoretical studies have predicted such a pattern as a response of the coupled ocean-atmosphere system to an exogenous heating of the tropical atmosphere. This pattern, however, is not reproduced by the complex ocean-atmosphere circulation models currently used to simulate the climatic response to increased greenhouse gases. Its presence is likely to lessen the mean 20th-century global temperature change in model simulations.     

Repellent effects of different products of the neem tree on the red locust,Nomadacris septemfasciata Serv., in maize fields in the southwestern parts of Madagascar

The repellent effect of 3 different neem formulations was tested on red locust,Nomadacris septemfasciata Serv., in a maize field in the southwest of madagascar. A simple water extract from neem seed kernels (200 l and 600 l per ha), an enriched neem ULV-formulation (2 l per ha) and a dust, prepared on the base of neem seed cake (5 kg per ha) were applied. All four treatment provided protection from attack for at least five days. The water extract was significantly active until 7 days, the neem-ULV-formulation until 9 days after treatment. The application of neem seed kernel water extract could be a simple means for Malagasy farmers to protect their fields against red locust. N. septemfaxciata is a very interesting test organism because it is much easier to work with this species compared to the taxonomical closely related desert locust (Schistocerca gregaria Forsk.).

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Zusammenfassung Drei verschiedene Niemprodukte wurden auf ihre fraßabschreckende Wirkung auf die rote WanderheuschreckeNomadacris septemfasciata in einem Maisfeld im Südwesten Madagaskars überprüft. Ein einfacher Wasserextrakt aus 50 g gemahlenen Niemsamen pro Liter wurde in zwei Applikationsvolumina (200 l und 600 l pro ha) gespritzt. Eine angereicherte Niem-ULV-Formulierung wurde mit Hilfe eines ULV-Spritzgerätes bei 2 l/ha appliziert. Fünf kg aus Niempreßkuchen hergestellter Puder pro ha wurde ebenfalls ausgebracht. Alle 4 Behandlungen schützten den Mais mindestens für 5 Tage vor Fraßschäden durchN. septemfasciata. Der Wasserextrakt verminderte den Befall über 7 Tage und die Niem-ULV-Formulierung über 9 Tage signifikant. Der leicht herzustellende Wasserextrakt könnte ein für die Maisbauern geeignetes Mittel sein, um ihre Felder vor dem Befall vonN. septemfasciata wirksam zu schützen. Da es auf Grund ihrer Biologie viel einfacher ist, mitN. septemfasciata als mit der taxonomisch sehr eng verwandten Wüstenheuschrecke (Schistocerca gregaria Forsk.) zu arbeiten, eignet sichN. septemfasciata hervorragend als Modellorganismus für Versuche mit Niemprodukten im Freiland.

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Growth and Location of Economic Activity: The Spatial Dynamics of Industries in Canada 1971–2001

ABSTRACT A growing literature has accumulated that points to the stability of industrial location patterns. Can this be reconciled with spatial dynamics? This article starts with the premise that demonstrable regularities exist in the manner in which individual industries locate (and relocate) over space. For Canada, spatial distributions of employment are examined for seventy‐one industries over a thirty‐year period (1971–2001). Industry data is organized by “synthetic regions” based on urban size and distance criteria. “Typical” location patterns are identified for industry groupings. Industrial spatial concentrations are then compared over time using correlation analysis, showing a high degree of stability. Stable industrial location patterns are not, the article finds, incompatible with differential regional growth. Five spatial processes are identified, driving change. The chief driving force is the propensity of dynamic industries to start up in large metro areas, setting off a process of diffusion (for services) and crowding out (for manufacturing), offset by the centralizing impact of greater consumer mobility and falling transport costs. These changes do not, however, significantly alter the relative spatial distribution of most industries over time.