Host defense mechanisms of cephalopods

Humoral and cellular mechanisms of defense have been described for cephalopods, a relatively advanced group of mollusks. Typical of other mollusks, cephalopod agglutinins are the most documented component of humoral immunity. Lectins, which have agglutinating properties, have been described and characterized from octopuses. Agglutinins from cephalopod hemolymph have also been shown to agglutinate a variety of vertebrate red blood cells, as well as potential bacterial pathogens. Hemocytes are the primary component of cellular immunity. Although the hemocyte role in phagocytosis has been extensively studied in other mollusks, the mechanisms of phagocytosis have not been described extensively for cephalopods. Cephalopod hemocytes have phagocytic capabilities and may function in encapsulation and neutralization of foreign substances; however, the effects of environmental factors and the full extent of phagocytic capabilities of cephalopod hemocytes have not been reported. Hemocytes from cephalopods have a role in wound healing and inflammation which have been reported in detail by several investigators.     

Biomass estimation of orange roughy: a summary and evaluation of techniques for measuring stock size of a deep-water fish species in New Zealand

A number of techniques have been employed to measure biomass of orange roughy in New Zealand. Time series of stratified random trawl surveys in a number of areas over periods of 5–10 years have given relative abundance indices, which have been used in stock reduction analyses to estimate true biomass. This has given confident results for the Chatham Rise stock, and surveys have also shown strong trends in other regions. Acoustic surveys have been carried out on three grounds. They can give relative indices of orange roughy abundance in areas of fiat or medium sloping bottom, and have the potential for estimation of absolute biomass from a single survey. Egg production surveys have been employed on two grounds on the east coast of the North Island, where conditions of tight spawning aggregations and steep bottom topography have limited the success of other methods. Both daily fecundity reduction and annual egg production methods have been used. These have given estimates of true biomass from one-off surveys, although results are imprecise. Both unstandardized and standardized analyses of commercial catch-per-unit-effort data have given relative indices of abundance, which have formed an important part of stock assessment for several fisheries. No single technique used to measure the size of orange roughy stocks has proven ideal or appropriate in all New Zealand situations. All have advantages and disadvantages, depending on the characteristics of the fishing area and fish behaviour. For two areas, a combination of methods have been applied, which has given more confident results than those from a single technique.     

《西北植物学报》2004～2006年载文来源基本信息分析

对《西北植物学报》2004~2006年载文来源基本信息进行统计分析,表明《西北植物学报》自2004年以来,投稿量逐年增加,稿源的地区分布范围进一步扩大,所载论文第一作者具有硕士以上学位的达55%,具有副高以上职称的占30.8%,40岁以下作者占76.4%,刊发论文的作者合作率达97%,论文项目的机构协作率达57%,基金论文达91%,学报影响因子逐年提高,2006年达到0.863.说明《西北植物学报》影响范围不断扩大,载文的作者具有较深厚的学术研究底蕴和较高的研究水平,论文能及时而真实地反映我国植物学领域的研究前沿动态和研究水平,载文的学术水平和影响力得到进一步提升.     

Genome evolution of allopolyploids: a process of cytological and genetic diploidization

Allopolyploidy is a prominent mode of speciation in higher plants. Due to the coexistence of closely related genomes, a successful allopolyploid must have the ability to invoke and maintain diploid-like behavior, both cytologically and genetically. Recent studies on natural and synthetic allopolyploids have raised many discrepancies. Most species have displayed non-Mendelian behavior in the allopolyploids, but others have not. Some species have demonstrated rapid genome changes following allopolyploid formation, while others have conserved progenitor genomes. Some have displayed directed, non-random genome changes, whereas others have shown random changes. Some of the genomic changes have appeared in the F1 hybrids, which have been attributed to the union of gametes from different progenitors, while other changes have occurred during or after genome doubling. Although these observations provide significant novel insights into the evolution of allopolyploids, the overall mechanisms of the event are still elusive. It appears that both genetic and epigenetic operations are involved in the diploidization process of allopolyploids. Overall, genetic and epigenetic variations are often associated with the activities of repetitive sequences and transposon elements. Specifically, genomic sequence elimination and chromosome rearrangement are probably the major forces guiding cytological diploidization. Gene non-functionalization, sub-functionalization, neo-functionalization, as well as other kinds of epigenetic modifications, are likely the leading factors promoting genetic diploidization.     

Means and extremes: building variability into community‐level climate change experiments

Experimental studies assessing climatic effects on ecological communities have typically applied static warming treatments. Although these studies have been informative, they have usually failed to incorporate either current or predicted future, patterns of variability. Future climates are likely to include extreme events which have greater impacts on ecological systems than changes in means alone. Here, we review the studies which have used experiments to assess impacts of temperature on marine, freshwater and terrestrial communities, and classify them into a set of ‘generations’ based on how they incorporate variability. The majority of studies have failed to incorporate extreme events. In terrestrial ecosystems in particular, experimental treatments have reduced temperature variability, when most climate models predict increased variability. Marine studies have tended to not concentrate on changes in variability, likely in part because the thermal mass of oceans will moderate variation. In freshwaters, climate change experiments have a much shorter history than in the other ecosystems, and have tended to take a relatively simple approach. We propose a new ‘generation’ of climate change experiments using down‐scaled climate models which incorporate predicted changes in climatic variability, and describe a process for generating data which can be applied as experimental climate change treatments.     

湖南山茶属植物种质资源调查、收集和利用的研究

调查研究表明:湖南山茶属植物种质资源极为丰富,种类由原来的29种,增加到现在的52种,特有种由原来的4种,增加到12种,发现了湖南白山茶、小红花茶和假长果连芯茶3新种和变色小红花茶1变种。山茶属植物较为集中地分布于湖南南部和西南部,向东西扩散而逐渐减少;我们对41种进行了果实性状、种子含油率、油脂理化性质、油脂脂肪酸组成及其规律等分析,其结果表明:山茶属植物油脂含量丰富、质好,无污染,耐贮藏,是理想的食用和工业用油,具有较高经济利用价值。首次发现山茶属植物油脂中含有廿二碳烯酸。     

Climate change and amphibian declines: is there a link?

Abstract. Global climates have been changing, sometimes rapidly and dramatically, throughout the evolutionary history of amphibians. Therefore, existing amphibian species have been derived from those that have survived major climatic disturbances. Although recent global climate change has resulted in warming in many regions, temperatures in some areas to date have not changed measurably, or have even cooled. Declines of some amphibian populations have been correlated with climate events, but demonstrations of direct causal relationships need further research. Data are available indicating some indirect effect of climate change on the initiation of breeding activities of some amphibians that occur earlier than in previous springs, but the costs and benefits of these changes are just beginning to be investigated. Climate may also play an indirect role in facilitating epidemics of infectious disease. Regardless of the role that climate changes may have played in past and current amphibian declines, future shifts in climate, should they prove as dramatic as predicted, will certainly pose challenges for surviving amphibian populations and for successful recovery efforts of species that have suffered declines.     

Biodiversity among haptophyte algae

The division Haptophyta is represented only by about 300 extant species showing wide diversity in morphology, biochemistry and ecology. They have a world-wide distribution and are numerically important in phytoplankton populations in nearly all marine environments. Evidence from the geological record shows that they have been the major constituent of calcareous deposits since the Late Triassic and, as they have evolved quickly through time, their coccoliths have always shown wide morphological diversity. In today's oceans they occasionally produce extensive blooms, visible by satellite imagery, which have ecological impact. As a consequence of these blooms the haptophyte algae are now receiving greater attention, as their role in the global sulphur and carbon cycles may influence the world's climate, and their potential as nuisance bloom algae have implications for commercial fishing and the marine ecosystem. As it is likely that these organisms have always produced such blooms, these effects may have been in operation for the last 200 million years.     

Wallace P. Rowe lecture. Poxviruses of laboratory animals

Currently the subfamily Chordopoxvirinae, the poxviruses of vertebrates, is subdivided into eight genera, containing some 20-30 species; an inexact figure because the birdpox viruses have not yet been properly investigated taxonomically. I have discussed seven species belonging to three genera, all of which have caused infection and usually disease in mammals commonly used in the laboratory. The list could have been extended had I included chickens and swine as laboratory animals, for that would have meant that I would have spoken about the birdpox viruses and swinepox virus as well. However, I think I have said enough to remind you of the importance of this family of viruses to those of you concerned with laboratory animal medicine. I believe that Wally Rowe would have been interested, for every case I have described presents problems in the ecology of viruses, and like my mentor Macfarlane Burnet, Wally approached virology from an ecological point of view, whether he was thinking about the DNA provirus of retroviruses and the host chromosome, the pathogenesis of disease, or the spread of viruses in animal populations, all topics to which he made major contributions.     

A kinetic model of peroxidation in a lipid bilayer

The structure, thermodynamic, and kinetic features of polyunsaturated fatty acids derivatives as the main substratum of lipid peroxidation (POL) have been considered. The heats of key POL reactions have been estimated. Kinetic consequences of these estimations have been analyzed. The dependence of POL rate on O2 concentration have been considered in detail both in the absence and in the presence of antioxidants. The essential features of POL processes in lipid bilayers resulting from the specific structure and molecular dynamics have been discussed.     

Riboregulators in kidney development and function

The discovery of microRNAs has brought in another level of intricacy in gene regulation. These microRNAs are small non-coding RNAs that have dual ability to act as repressors or inducers of gene activity. MicroRNAs have been implicated in a wide spectrum of biological processes and their expressions have been found to be dysregulated in several diseases. Recently, microRNAs have emerged as a new area of interest in renal development and pathology. MicroRNA profilings have revealed a number of microRNAs that are specific to the kidney or restricted to certain regions of the organ suggesting possible exclusive roles therein. Recently, knockout studies have shown that these riboregulators are critical for normal renal growth and functional renal system. Individual microRNAs have also been identified in renal disease models including kidney cancers, diabetic nephropathy and polycystic kidney disease. Several mechanisms of modulating microRNA activity have also been introduced in recent years. Further progress in the understanding of microRNA activity, identification of microRNA signatures in different states as well as advancement of microRNA manipulation techniques will be valuable for kidney research.     

Development of a gas chromatography mass spectrometry assay for the two eosinophil chemotactic factors of anaphylaxis

Gas chromatography mass spectrometry has been used for over a decade for the determination of the amino acid sequences of fragment peptides derived from larger parent molecules. The majority of these fragments have from four to seven residues and several different methods of derivatization have been devised. Few reports have been published in which similar techniques have been used for the quantification of such peptides, but there is a growing list of small peptides which have been shown to have biological activity in their own right. This report is concerned with the development of a gas chromatographic mass spectrometric assay for the two eosinophil chemotactic peptides, Val-Gly-Ser-Glu and Ala-Gly-Ser-Glu, which appear to have a role to play in the course of the inflammatory process in skin disorders.     

In vitro regulation of corticotropin-releasing hormone

Studies involving regulation of corticotropin-releasing hormone (CRH) in vitro have been used to validate findings obtained in vivo and more importantly have been used as model systems to better understand signalling mechanisms responsible for the expression of the CRH gene and peptide. Many in vitro studies examining CRH have utilized hypothalamic tissue while a few have focused on the amygdala. Clonal cell lines have also been utilized as models of central nervous system CRH neurons. Stimuli that have been implicated in regulating hypothalamic CRH regulation in vitro include protein kinase A (PKA) and protein kinase C (PKC) activators, glucocorticoids, biogenic amines, cytokines and the gaseous neurotransmitters. Amygdalar CRH levels in vitro are affected by some of the same stimuli that regulate hypothalamic CRH; however there is evidence supporting differential regulation of CRH in these two brain regions by some of the same stimuli. Only a few studies in aggregate have investigated signal transduction mechanisms and these studies have focused on PKA- and glucocorticoid-mediated changes in CRH expression. Thus, much more investigative work in better understanding CRH regulation in vitro is needed.     

Proteomic analysis of mitochondria from the Bos taurus heart. III. Identification of mitochondrial inner memrane proteins

We have conducted a research of mitochindrial internal membrane proteins. This fraction has been received in the form of submitochondrial particles (SMP). SMP have been processed by trypsinum, and the received peptides have been separated from so-called "smoothfaced vesicles". "Smoothfaced vesicles" were blasted, proteinse and peptides were processed by cyanogen bromide and trypsinum. We have received two groups of tryptic peptides and analyzed them separately with the help of proteomic methods, such as chromatography, mass spectrometry and protein identification in different databases. To identify more proteins and find minor components of mitochindrial proteome we have considered possible non-specific fragmentation of proteins. 298 proteins have been identified, we also have conducted the analisys of their functions and cell localization.     

Cyclooxygenase enzymes: catalysis and inhibition

Scientists working in the field of cyclooxygenase enzymes have witnessed several major advances in the past two years. Crystal structures of fatty acid substrate and prostaglandin product complexes have been elucidated. Elegant site-directed mutagenesis studies have pinpointed the roles of key amino acids within the active site. Together, these results have provided key insights into the overall reaction mechanism. Detailed kinetics, spectroscopic and crystallographic studies have shed new light on the complex mechanism of inhibition of these fascinating enzymes. Finally, novel substrates of cyclooxygenase-2 have been identified.     

Conformational states of cowpea chlorotic mottle virus ribonucleic acid components.

The conditions determining conformational changes in the four ribonucleic acid components of cowpea chlorotic mottle virus have been studied. All four components have at least two electrophoretically separable conformers, the occurrence of which can be regulated by both monovalent and polyvalent cations. This phenomenon also occurs, in a much less striking way, in the ribonucleic acids of the two other members of the bromovirus group, brome mosaic virus and broad bean mottle virus. Although specific in some respects, these changes have much in common with effects which have been observed in tRNAs, 55 RNAs and rRNAs. A provisional interpretation of the conformational behaviour of the viral RNAs is given in terms which have been proposed for certain tRNAs which have been studied in great detail.     

Animal-microbial symbioses in changing environments

The environments in which animals have evolved and live have profound effects on all aspects of their biology. Predictable rhythmic changes in the physical environment are arguably among the most important forces shaping the evolution of behavior and physiology of animals, and to anticipate and prepare for these predictable changes, animals have evolved biological clocks. Unpredictable changes in the physical environment have important impacts on animal biology as well. The ability of animals to cope with and survive unpredictable perturbations depends on phenotypic plasticity and/or microevolution. From the time metazoans first evolved from their protistan ancestors they have lived in close association with a diverse array of microbes that have influenced, in some way, all aspects of the evolution of animal structure, function and behavior. Yet, few studies have addressed whether daily or seasonal rhythms may affect, or be affected by, an animal’s microbial symbionts. This survey highlights how biologists interested in the ecological and evolutionary physiology of animals whose lifestyles are influenced by environmental cycles may benefit from considering whether symbiotic microbes have shaped the features they study.