(+)-α-Selinene,and enantiomeric eudesmane fromChiloscyphus polyanthus (L.) corda

Zusammenfassung Nachweis des optischen Isomeren eines Sesquiterpens im LebermoosChiloscyphus polyanthus mit (+)--Selinen als Hauptanteil.

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This work has been supported, in part, by a National Institutes of Health grant No. GM-18143.     

Collaboration,interdisciplinarity, and the epistemology of contemporary science

Over the last decades, science has grown increasingly collaborative and interdisciplinary and has come to depart in important ways from the classical analyses of the development of science that were developed by historically inclined philosophers of science half a century ago. In this paper, I shall provide a new account of the structure and development of contemporary science based on analyses of, first, cognitive resources and their relations to domains, and second of the distribution of cognitive resources among collaborators and the epistemic dependence that this distribution implies. On this background I shall describe different ideal types of research activities and analyze how they differ. Finally, analyzing values that drive science towards different kinds of research activities, I shall sketch the main mechanisms underlying the perceived tension between disciplines and interdisciplinarity and argue for a redefinition of accountability and quality control for interdisciplinary and collaborative science.     

Iron deposits in the chronically inflamed central nervous system and contributes to neurodegeneration

Neurodegenerative disorders are characterized by the presence of inflammation in areas with neuronal cell death and a regional increase in iron that exceeds what occurs during normal aging. The inflammatory process accompanying the neuronal degeneration involves glial cells of the central nervous system (CNS) and monocytes of the circulation that migrate into the CNS while transforming into phagocytic macrophages. This review outlines the possible mechanisms responsible for deposition of iron in neurodegenerative disorders with a main emphasis on how iron-containing monocytes may migrate into the CNS, transform into macrophages, and die out subsequently to their phagocytosis of damaged and dying neuronal cells. The dying macrophages may in turn release their iron, which enters the pool of labile iron to catalytically promote formation of free-radical-mediated stress and oxidative damage to adjacent cells, including neurons. Healthy neurons may also chronically acquire iron from the extracellular space as another principle mechanism for oxidative stress-mediated damage. Pharmacological handling of monocyte migration into the CNS combined with chelators that neutralize the effects of extracellular iron occurring due to the release from dying macrophages as well as intraneuronal chelation may denote good possibilities for reducing the deleterious consequences of iron deposition in the CNS.     

Dog owners and hydatid disease in Sanpete County, Utah

A questionnaire survey was conducted in Sanpete County, Utah, to determine the knowledge of dog owners concerning hydatid disease and an identification of some basic sheep management practices there. The households surveyed included 21 (Group I) that had one or more dogs infected with Echinococcus granulosus tapeworms at more than one annual field clinic, and 19 others (Group II) that had one or more dogs infected when the study first began in 1971–72, but had not had any infected dogs identified at field clinics during subsequent years. The results showed that 92.5 percent of households knew the cause of the disease and how it is transmitted, and that 90 percent knew of someone who had been operated on for surgical removal of hydatid cysts. There was no significant difference in the level of knowledge of the disease between the two groups of respondents, nor in their sheep management practices. Even though the level of infection of the parasite in dogs has decreased since the project started, certain sheep management practices persist among respondents in both groups that allow for continued transmission of the parasite in this region.     

Field clinic procedures for diagnosing Echinococcus granulosus in dogs

Echinococcus granulosus is the causative parasite of hydatid disease in humans and represents a significant public health problem within endemic foci in all major continents of the world. This report gives a detailed set of instructions whereby four trained individuals can examine 15–20 dogs per hour for the presence of this organism. The procedure permits the baseline determination of the prevalence of this parasite within any specific population of dogs and also allows the periodic examination of the same animals to determine if recommended preventive and control measures for hydatid disease are being followed by sheep and dog owners in any region where the parasite is known to occur.     

Three-year surveillance for cestode infections in sheep dogs in central Utah

During the summers of 1982, 1983, and 1984, 269 sheep dogs from an area endemic for hydatid disease were examined for cestodes ( Echinococcus granulosus and Taenia spp.). Each dog was given an oral purge of arecoline hydrobromide and then following purgation received a subcutaneous injection of praziquantel (Droncit ® ). During the three-year study period, 205 dogs were examined one time only, 48 dogs were examined two of the three years, and 16 dogs were examined each of the three years (= 349 separate examinations). In 1982, 45 of 91 dogs examined (49.5%) harbored at least one species of cestode. Those data for 1983 and 1984 were 55 positive of 141 examined (39.0%) and 34 positive of 117 examined (29.1%), respectively. The marked drop in dogs infected during the second and third year of the study suggests that many sheep ranchers were implementing some of the control measures recommended for prevention of E. granulosus infections. The numbers of separate purgations showing specific cestodes detected in all positive dogs (some dogs naturally with more than one species of cestode) were: E. granulosus, 16 (4.6%); T. hydatigena, 34 (9.7%); T. ovis krabbei, 46 (13.2%); T. pisiformis, 47 (13.5%); and T. serialis, 24 (6.9%).     

Beaver herbivory of willow under two flow regimes: a comparative study on the Green and Yampa rivers

The effect of flow regulation on plant-herbivore ecology has received very little attention, despite the fact that flow regulation can alter both plant and animal abundance and environmental factors that mediate interactions between them. To determine how regulated flows have impacted beaver ( Castor Canadensis ) and sandbar willow ( Salix exigua ) ecology, we first quantified the abundance and mapped the spatial distribution of sandbar willow on alluvial sections of the flow-regulated Green River and free-flowing Yampa River in northwestern Colorado. We then established 16 and 15 plots (1 m x 2.7 m) in patches of willow on the Green and Yampa Rivers, respectively, to determine whether rates of beaver herbivory of willow differed between rivers (Green versus Yampa River), seasons (fall-winter versus spring-summer), and years (spring 1998-spring 1999 versus spring 1999-spring 2000). Areal extent of willow was similar on each river, but Green River willow patches were smaller and more numerous. Beavers cut more stems during fall and winter than spring and summer and cut over 6 times more stems (percentage basis) on the Green River than on the Yampa River. We attribute the between-river difference in herbivory to higher availability of willow, greater beaver density, and lower availability of young Fremont cottonwood ( Populus deltoids subsp. wislizenii ; an alternative food source) on the Green River. Flow regulation increased willow availability to beaver by promoting the formation of island patches that are continuously adjacent to water and feature a perimeter with a relatively high proportion of willow interfacing with water.     

Oncogene-induced senescence is part of the tumorigenesis barrier imposed by DNA damage checkpoints

Recent studies have indicated the existence of tumorigenesis barriers that slow or inhibit the progression of preneoplastic lesions to neoplasia. One such barrier involves DNA replication stress, which leads to activation of the DNA damage checkpoint and thereby to apoptosis or cell cycle arrest, whereas a second barrier is mediated by oncogene-induced senescence. The relationship between these two barriers, if any, has not been elucidated. Here we show that oncogene-induced senescence is associated with signs of DNA replication stress, including prematurely terminated DNA replication forks and DNA double-strand breaks. Inhibiting the DNA double-strand break response kinase ataxia telangiectasia mutated (ATM) suppressed the induction of senescence and in a mouse model led to increased tumour size and invasiveness. Analysis of human precancerous lesions further indicated that DNA damage and senescence markers cosegregate closely. Thus, senescence in human preneoplastic lesions is a manifestation of oncogene-induced DNA replication stress and, together with apoptosis, provides a barrier to malignant progression.     

Exchange of water between the harbor porpoise,Phocoena phocoena,and the environment

Summary During determination of total body water and net water turnover in the harbor porpoise,Phocoena phocoena, it was demonstrated that the porpoise exchanged water with an isosmotic environment by way of free diffusion and with hypo- or hyperosmotic environment by way of osmosis.