The keystone saguaro (Carnegiea gigantea,Cactaceae): a review of its ecology,associations, reproduction,limits, and demographics

This paper reviews the basics of a Sonoran Desert keystone cactus species, including the ecology of its establishment and high mortality, its association with nurse plants to provide ameliorated conditions for survival, and variability in longevity and reproduction over its range such as delayed reproduction in hotter and more arid populations where this delay is met with longer lifespans. The production of flowers, branches, and spines from areoles is reviewed, as well as current methods for estimating individual age despite great variability in growth rates, most notably linked to summer rainfall. Possible implications of anthropogenic influences that impact populations as well as global climate change are discussed as are implications for potential range shifts in the future. This paper also provides a table listing of over 100 birds, mammals, insects, reptiles, and other animal species that use Carnegiea and highlighting its keystone status.     

Structure,function, and protein taxonomy

This paper considers two recent arguments that structure should not be regarded as the fundamental individuating property of proteins. By clarifying both what it might mean for certain properties to play a fundamental role in a classification scheme and the extent to which structure plays such a role in protein classification, I argue that both arguments are unsound. Because of its robustness, its importance in laboratory practice, and its explanatory centrality, primary structure should be regarded as the fundamental distinguishing characteristic of protein taxonomy.     

The Ecosystem as a Multidimensional Concept: Meaning,Model, and Metaphor

The ecosystem is a fundamental ecological concept that is not as simple as it first appears. We explore three key dimensions of the concept that make it both complex and broadly useful—its basic definition, its application via models to concrete or specific situations, and its metaphorical connotations as used in general communication within the domain of science and with the public at large. Clarity in identifying what the dimensions are and how they are related can help to maintain the rigor of the concept for specific scientific uses while also allowing enough flexibility for its use in the integration of scientific principles, as well as in public discourse. This analysis of the ecosystem as a multidimensional concept is likely to be generalizable to other important concepts in ecology. Received 28 February 2001; accepted 5 September 2001.     

An Alien Species,Sisymbrium orientale (Brassicaceae) , Emerged in Yunnan,China

A alien plant species , Sysimbrium orientale L . (Brassicaceae ) is recorded in Yunnan , China in the paper . The species has been found invading the ecosystems of croplands and grasslands in Australia . Although it was previously recorded in China, there′s no alert report about it .Because the very small and mass-produced seed in siliques was dispersed by wind , the species can be potentially invasive . The result of our investigation indicated that there was a spreading trend of S. orientale in suburbs of Kunming, Central Yunnan . The biological characteristics and current status in Kunming were reported. We appealed to relevant government departments to make efforts to make a further investigation of its distribution and its invasion route . Assessment of its invasiveness in China is needed to eradicate it as early as possible to avoid its diffusion .     

Managed care. Origins,principles, and evolution.

Managed care has entered the lexicon of healthcare reform, but confusion and ignorance surround its meaning and purpose. It seeks to cut the costs of health care while maintaining its quality, but the evidence that it is able to achieve these aims is mixed. As well as raising awareness and understanding of the issues surrounding managed care, this series considers whether managed care is desirable for the NHS. Developed in the United States as a response to spiralling healthcare costs and dysfunctional fragmented services, managed care is not a discrete activity but a spectrum of activities carried out in a range of organisational settings. Due to its constantly changing nature, managed care is a slippery concept--but all its permutations have in common an attempt to influence and modify the behaviour and practice of doctors and other health professionals towards cost effective care. Whatever potential managed care may hold in this regard, careful appraisal of its implications is essential.     

Cholesterol,GM1, and Autism

Disruption of cholesterol metabolism has been hypothesized to contribute to dementia, possibly due to its role in maintaining membrane fluidity as well as the integrity of lipid rafts. Previously, we reported an apparent inverse relationship between membrane cholesterol levels and those of GM1, another lipid that can be found in rafts. This paper describes the observation that red blood cell (RBC) membranes isolated from blood drawn from children diagnosed with autism have on the average significantly less cholesterol and significantly more GM1 than RBC membranes isolated from blood obtained from control children. While cholesterol in the circulation does not cross the blood brain barrier, a generalized defect in its synthesis could affect its concentration in the central nervous system and that, coupled with a change in ganglioside expression, could contribute to development of the behaviors associated with autism.     

Synthesis,oxygen radical absorbance capacity,and tyrosinase inhibitory activity of glycosides of resveratrol,pterostilbene, and pinostilbene

The stilbene compound resveratrol was glycosylated to give its 4′-O-β-D-glucoside as the major product in addition to its 3-O-β-D-glucoside by a plant glucosyltransferase from Phytolacca americana expressed in recombinant Escherichia coli. This enzyme transformed pterostilbene to its 4′-O-β-D-glucoside, and converted pinostilbene to its 4′-O-β-D-glucoside as a major product and its 3-O-β-D-glucoside as a minor product. An analysis of antioxidant capacity showed that the above stilbene glycosides had lower oxygen radical absorbance capacity (ORAC) values than those of the corresponding stilbene aglycones. The 3-O-β-D-glucoside of resveratrol showed the highest ORAC value among the stilbene glycosides tested, and pinostilbene had the highest value among the stilbene compounds. The tyrosinase inhibitory activities of the stilbene aglycones were improved by glycosylation; the stilbene glycosides had higher activities than the stilbene aglycones. Resveratrol 3-O-β-D-glucoside had the highest tyrosinase inhibitory activity among the stilbene compounds tested.     

Isolation, structure elucidation, and antioxidant evaluation of cydonioside A, an unusual terpenoid from the fruits of Cydonia vulgaris

A novel terpenoid, cydonioside A (1), was isolated from the fruits of Cydonia vulgaris Pers. Its structure and relative configuration were elucidated on the basis of in-depth spectroscopic analyses, including 2D-NMR experiments as well as MM+ calculations. Compound 1 was assayed for its radical-scavenging activity towards the DPPH radical and the superoxide radical anion (O2*-), as well as for its overall antioxidant activity, as assessed by the formation of a phosphomolybdenum complex.     

Levan and levansucrases: Polymer,enzyme, micro-organisms and biomedical applications

Abstract

Nowadays, levan synthesis and its biocatalysis is a step claiming attention due to its promising uses in biomedical field. Levansucrase, as the enzyme responsible of levan biocatalysis is studied in this work concerning sequence homology, signal peptide, metal binding, etc. More than 650 different levansucrase sequences were studied and many interesting results were obtained such as phylogenetic trees and conserved residues that could be essential for biocatalysis machinery. Moreover, a review of levan applications in biomedicine and health field was made. It is showed the advances in applications such as a film agent, a carrier for drug delivery systems, an anti-inflammatory compound or its potential use for functional food as prebiotic.     

Trehalose: Chemical structure,biological functions,and practical application

Up-to-date information concerning the chemical structure and properties of trehalose, its natural occurrence and biological functions in plants, fungi, and prokaryotes, as well as its practical application, mainly in medicine and biotechnology, are reviewed. A special section deals with the role of trehalose and other protective polyols in stress processes in fungi.     

The metabochip, a custom genotyping array for genetic studies of metabolic, cardiovascular, and anthropometric traits

Genome-wide association studies have identified hundreds of loci for type 2 diabetes, coronary artery disease and myocardial infarction, as well as for related traits such as body mass index, glucose and insulin levels, lipid levels, and blood pressure. These studies also have pointed to thousands of loci with promising but not yet compelling association evidence. To establish association at additional loci and to characterize the genome-wide significant loci by fine-mapping, we designed the "Metabochip," a custom genotyping array that assays nearly 200,000 SNP markers. Here, we describe the Metabochip and its component SNP sets, evaluate its performance in capturing variation across the allele-frequency spectrum, describe solutions to methodological challenges commonly encountered in its analysis, and evaluate its performance as a platform for genotype imputation. The metabochip achieves dramatic cost efficiencies compared to designing single-trait follow-up reagents, and provides the opportunity to compare results across a range of related traits. The metabochip and similar custom genotyping arrays offer a powerful and cost-effective approach to follow-up large-scale genotyping and sequencing studies and advance our understanding of the genetic basis of complex human diseases and traits.     

安徽华阳洞穴假褐钩虾属一新种(甲壳纲,端足目,假褐钩虾科)

记述了采自安徽华阳洞的假褐钩虾属1新种,洞穴假褐钩虾Pseudocrangonyx cavernarius sp.nov.。该种区别于同属其它种为：第1小颚内叶具4根刚毛,第2尾肢外肢为内肢的66％,第3尾肢肢节为柄节的3．25倍,尾节末端微裂。文中附有详细的特征图。模式标本保存于中国科学院动物研究所。     

HEMATOLOGY AND BLOOD CHEMISTRY OF A BRYDE'S WHALE, BALAENOPTERA EDENI, ENTRAPPED IN THE MANNING RIVER, NEW SOUTH WALES, AUSTRALIA

A Bryde's whale, Balaenoptera edeni , was rescued after having been entrapped in the Manning River, Australia, for 100 d. Blood, skin, and epidermal tissue were analyzed to determine the whale's taxonomic status, gender, and health. This paper reports the results of these analyses and discusses the findings in relation to the potential physiological damage to the whale from its protracted stay in the river. Molecular genetic analysis of epidermal tissue identified the whale as a male of the rare pygmy form of Bryde's whale. The 10.3-m whale was diagnosed as emaciated, parasitized, under stress, and in a state of profound catabolism at the time of its rescue. Although it had greatly depleted its energy reserves, the whale was rescued from the river before the onset of ill health or irreparable physiological damage. No organ dysfunction was evident with the possible exception of some deterioration in kidney function most likely caused by parasitism. The whale swam away srongly on release, and its chances of survival appeared to be good.     

A New Cytological Technic, Tannin-Iron Iii, For Nucleoli And Plastids

Tannin-iron Iii, as a technic, differs very little from Salazar's tannin-iron I, and must be considered as a new modification of the latter¹. But the results obtained are very different and its use in plant cytology will be found very advantageous due to its specificity for certain cellular organs.     

Recombinant expression, isotope labeling, refolding, and purification of an antimicrobial peptide, piscidin

An antimicrobial peptide, piscidin, was overexpressed as a fused form with the ubiquitin molecule in Escherichia coli, and the fusion protein was purified using immobilized metal affinity chromatography (IMAC). The peptide was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The expression and purification process of piscidin encountered several problems such as the lysis of the bacterial cell upon induction of the peptide production, the unwanted cleavage of the fusion protein inside the bacterial cell, and high tendency to aggregate in the aqueous environment. Such problems were alleviated by employing ubiquitin as a fusion partner for piscidin, growing the cells at a lower temperature, and changing the order of the purification steps. The yields of the fusion protein and the peptide were around 15 and 1.5 mg per liter of LB or minimal medium, respectively. The recombinant expression and purification of piscidin will enable its structural and dynamic studies using multidimensional NMR spectroscopy.     

Acrylamide: its metabolism, developmental and reproductive effects, genotoxicity, and carcinogenicity

Monomeric acrylamide is an important industrial chemical primarily used in the production of polymers and copolymers. It is also used for producing grouts and soil stabilizers. Acrylamide's neurotoxic properties have been well documented. This review will focus on pertinent information concerning other, non-neurotoxic, effects observed after exposure to acrylamide, including: its genotoxic, carcinogenic, reproductive, and developmental effects. It will also cover its absorption, metabolism, and distribution. The data show that acrylamide is capable of inducing genotoxic, carcinogenic, developmental, and reproductive effects in tested organisms. Thus, acrylamide may pose more than a neurotoxic health hazard to exposed humans. Acrylamide is a small organic molecule with very high water solubility. These properties probably facilitate its rapid absorption and distribution throughout the body. After absorption, acrylamide is rapidly metabolized, primarily by glutathione conjugation, and the majority of applied material is excreted within 24 h. Preferential bioconcentration of acrylamide and/or its metabolites is not observed although it appears to persist in tests and skin. Acrylamide can bind to DNA, presumably via a Michael addition-type reaction, which has implications for its genotoxic and carcinogenic potential. The available evidence suggests that acrylamide does not produce detectable gene mutations, but that the major concern for its genotoxicity is its clastogenic activity. This clastogenic activity has been observed in germinal tissues which suggest the possible heritability of acrylamide-induced DNA alterations. Since there is 'sufficient evidence' of carcinogenicity in experimental animals as outlined under the U.S. EPA proposed guidelines for carcinogen risk assessment, acrylamide should be categorized as a 'B2' carcinogen and therefore be considered a 'probable human carcinogen.' The very limited human epidemiological data do not provide sufficient evidence to enable one to judge the actual carcinogenic risk to humans. Acrylamide is able to cross the placenta, reach significant concentrations in the conceptus and produce direct developmental and post-natal effects in rodent offspring. It appears that acrylamide may produce neurotoxic effects in neonates from exposures not overtly toxic to the mothers. Acrylamide has an adverse effect on reproduction as evidenced by dominant lethal effects, degeneration of testicular epithelial tissue, and sperm-head abnormalities.     

外来植物黄顶菊的入侵警报及防控对策

一种菊科外来植物最近出现在我国华北地区的天津市和河北省的衡水与廊坊市。专家鉴定结果证明这是一种我国从未报道过的外来物种Flaveria bidentis。本文拟定了它的中文名称：黄顶菊,并对其原产地、扩散范围以及形态学、生理学、生态学等方面的特征进行了介绍。通过分析其特性,我们认为黄顶菊是一种入侵性极高的一年生杂草,特别是对农牧业生态系统有极大的破坏性。为了防治、控制和根除这种新入侵的有害物种,本文借鉴国内外入侵物种防治的经验提出了一些建议,供有关方面参考,并呼吁各有关人员和部门积极行动起来,调查其入侵途径,分析其可能入侵的区域,评估其入侵性,拟定科学的防控方案。     

A Ruthenocene-PNA Bioconjugate - Synthesis, Characterization, Cytotoxicity, and AAS-Detected Cellular Uptake

Labeling of peptide nucleic acids (PNA) with metallocene complexes is explored herein for the modulation of the analytical characteristics, as well as biological properties of PNA. The synthesis of the first ruthenocene-PNA conjugate with a dodecamer, mixed-sequence PNA is described, and its properties are compared to a ferrocene-labeled analogue as well as an acetylated, metal-free derivative. The synthetic characteristics, chemical stability, analytical and thermodynamic properties, and the interaction with cDNA were investigated. Furthermore, the cytotoxicity of the PNA conjugates is determined on HeLa, HepG2, and PT45 cell lines. Finally, the cellular uptake of the metal-containing PNAs was quantified by high-resolution continuum source atomic absorption spectrometry (HR-CS AAS). An unexpectedly high cellular uptake to final concentrations of 4.2 mM was observed upon incubation with 50 μM solutions of the ruthenocene-PNA conjugate. The ruthenocene label was shown to be an excellent label in all respects, which is also more stable than its ferrocene analogue. Because of its high stability, low toxicity, and the lack of a natural background of ruthenium, it is an ideal choice for bioanalytical purposes and possible medicinal and biological applications like, e.g., the development of gene-targeted drugs.     

Identification of human plasma lysophospholipase D,a lysophosphatidic acid-producing enzyme,as autotaxin,a multifunctional phosphodiesterase

We purified human plasma lysophospholipase D that produces physiologically active lysophosphatidic acid and showed that it is a soluble form of autotaxin, an ecto-nucleotide pyrophosphatase/phosphodiesterase, originally found as a tumor cell motility-stimulating factor. Its lower K(m) value for a lysophosphatidylcholine than that for a synthetic substrate of nucleotide suggests that lysophosphatidylcholine is a more likely physiological substrate for autotaxin and that its predicted physiological and pathophysiological functions could be mediated by its activity to produce lysophosphate acid, an intercellular mediator. Recombinant autotaxin was found to have lysophospholipase D activity; its substrate specificity and metal ion requirement were the same as those of the purified plasma enzyme. The activity of lysophospholipase D for exogenous lysophosphatidylcholine in human serum was found to increase in normal pregnant women at the third trimester of pregnancy and to a higher extent in patients in threatened preterm delivery, suggesting its roles in induction of parturition.