Isolation of Eikenella corrodens in a General Hospital

The carbon source markedly influenced the qualitative and quantitative composition of cellular hydrocarbons in Cladosporium resinae. Total lipid and hydrocarbon content was greater in cells grown on n-alkanes than in cells grown on glucose or glutamic acid. Glucose-grown cells contained a spectrum of aliphatic hydrocarbons from C(7) to C(36); pristane and n-hexadecane comprised 98% of the total. Cells grown on glutamic acid contained C(7) to C(23) hydrocarbons; n-tridecane, n-tetradecane, n-hexadecane, and pristane made up 74% of the total. n-Decane-grown cells yielded C(8) to C(32) compounds, and n-hexadecane (96%) was the major hydrocarbon. Cells grown on individual n-alkanes from C(11) to C(15) all contained C(11) to C(28) hydrocarbons, and cells grown on n-hexadecane contained C(11) to C(32) hydrocarbons. In n-undecane-grown cells, n-hexadecane and pristane made up 92% of the total, but in cells grown on C(12) to C(16)n-alkanes the major cellular hydrocarbon was the one on which the cells were grown. This suggests that cells cultured on n-alkanes of C(12) or longer accumulate n-alkanes prior to oxidizing them.     

Changes in ecosystem carbon stocks in a grassland ash (Fraxinus excelsior) afforestation chronosequence in Ireland

Aims Government policy in Ireland is to increase the national forest cover from the current 10% to 18% of the total land area by 2020. This represents a major land use change that is expected to impact on the national carbon (C) stocks. While the C stocks of ecosystem biomass and soils of Irish grasslands and coniferous forests have been quantified, little work has been done to assess the impact of broadleaf afforestation on C stocks.Methods In this study, we sampled a chronosequence of ash (Fraxinus excelsior) forests aged 12, 20, 27, 40 and 47 years on brown earth soils. A grassland site, representative of the pre-afforestation land use, was sampled as a control.Important findings Our results show that there was a significant decline (P < 0.05) in the carbon density of the soil (0–30cm) following afforestation from the grassland (90.2 Mg C ha^-1) to the 27-year-old forest (66.7 Mg C ha^-1). Subsequently, the forest soils switched from being a C source to a C sink and began to sequester C to 71.3 Mg C ha^-1 at the 47-year-old forest. We found the amount of C stored in the above- and belowground biomass increased with age of the forest stands and offset the amount of C lost from the soil. The amount of C stored in the above- and belowground biomass increased on average by 1.83 Mg C ha^-1 year^-1. The increased storage of C in the biomass led to an increase in the total ecosystem C, from 90.2 Mg C ha^-1 at the grassland site to 162.6 Mg C ha^-1 at the 47-year-old forest. On a national scale, projected rates of ash afforestation to the year 2020 may cause a loss of 290 752 Mg C from the soil compared to 2 525 936 Mg C sequestered into the tree biomass. The effects of harvesting and reforestation may further modify the development of ecosystem C stocks over an entire ash rotation.     

Cell-surface nucleolin is involved in lipopolysaccharide internalization and signalling in alveolar macrophages

C23 (nucleolin) shuttling between the nucleus, cytoplasm and cell surface has been implicated in controlling regulatory processes and may play a role in pathogen infection and autoimmune diseases. It has been reported that cell surface-expressed C23 on THP-1 monocytes is involved in the inflammatory response induced by LPS (lipopolysaccharide). This study investigates whether C23 is a membrane receptor for LPS during LPS-induced AMs (alveolar macrophages) activation. First, using immunofluorescence and microscopy, we detected the expression of C23 on the surface of AMs. Second, using LPS affinity columns, we demonstrated that C23 directly binds to LPS. Third, we found that LPS colocalized with C23 on both the cell surface and in the cytoplasm. Finally, knockdown of C23 expression on the cell surface using siRNA (small interfering RNA) led to significant reductions in the internalization of LPS, in LPS-induced NF-κB (nuclear factor κB)-DNA binding and in the protein expression of TNF (tumour necrosis factor)-α and IL-6 (interleukin-6). These findings provide evidence that cell-surface C23 on AMs may serve as a receptor for LPS and are essential for internalization and transport of LPS. Furthermore, C23 participates in the regulation of LPS-induced inflammation of AMs, which indicates that cell-surface C23 is a new and promising therapeutic target for the treatment of bacterial infections.     

Protein kinase implication in prolactin signaling in bovine oocyte-cumulus complexes

The mechanisms of prolactin signal transduction in generative and somatic cells of mammalian ovarian follicles are poorly understood. In this work, participation of tyrosine kinases and protein kinase C in mediation of the previously revealed modulating effects of prolactin on the nuclear maturation of bovine oocytes and the morphologic and functional state of surrounding cumulus cells in vitro has been investigated. It was found that a tyrosine kinase inhibitor genistein suppresses the stimulating action of prolactin on the completion of oocyte nuclear maturation and cumulus expansion, whereas a protein kinase C inhibitor calpostin C does not affect the hormonal effect. Furthermore, both genistein and calpostin C inhibited the inducing influence of prolactin on the proliferative activity of cumulus cells. At the same time, the retarding action of prolactin on destructive processes in cumulus cells was blocked only in the presence of calpostin C. These results show that the stimulating influence of prolactin on oocyte nuclear maturation accompanied by cumulus expansion is achieved with participation of tyrosine kinases, whereas the modulating action of the hormone on the functional state of cumulus cells depends on activation both of tyrosine kinases and protein kinase C.     

Role of protein kinases in prolactin signaling in bovine oocyte-cumulus complexes

Mechanisms of prolactin signal transduction in generative and somatic cells of mammalian ovarian follicles have been studied only to a small extent. In the present work, the involvement oftyrosine kinases and protein kinase C in mediating of the previously revealed modulating effects of prolactin on the nuclear maturation of bovine oocytes and the morphologic-functional state of surrounding cumulus cells was investigated in vitro. Tyrosine kinase inhibitor, genistein, was found to suppress the stimulating action of prolactin on the completion of oocyte nuclear maturation and cumulus expansion, whereas protein kinase C inhibitor, calpostin C, did not affect these hormonal effects. Furthermore, both genistein and calpostin C inhibited the inducing influence of prolactin on the proliferative activity of cumulus cells. At the same time the retarding action ofprolactin on destructive processes in cumulus cells was blocked only in the presence of calpostin C. The results of the study suggest that the stimulatory influence of prolactin on oocyte nuclear maturation and attendant cumulus expansion is achieved with the participation of tyrosine kinases, whereas the modulating action of the hormone on the functional state of cumulus cells depends on activation of not only tyrosine kinases, but also protein kinase C.     

The effects of alterations in temperature and flow regime on organic carbon dynamics in Mediterranean river networks

It is only recently that freshwaters have been identified as important quantitative components of the carbon (C) cycle at global and regional scales. To date there are no studies that quantitatively predict the effects of alterations in temperature and flow regimes, individually, or in concert, on organic C dynamics in streams. To address this need, we applied a mechanistic model to simulate organic C dynamics in Mediterranean river networks under 27 different scenarios of altered temperature and flow regimes. We predict that the organic C dynamics in freshwaters in the Mediterranean, as well as in other semiarid regions, will be highly sensitive to global climate change owing to major increases in the degree of intermittency as well as in flood frequency and magnitude. Results indicate that flow regime alterations increase C export rates, whereas temperature alterations increase instream metabolism of organic C. However, flow regime alterations exhibit a much greater influence on C dynamics than do changes in the temperature regime. Reservoirs partly counteract the effects of flow extremes on C export rates, and their role in the C dynamics increases with increasing flow variability. The present study is one of the first studies to quantify the complex interactions between the flow and the temperature regime on C dynamics, emphasizing the key role of extreme events such as dry periods and floods, compared with overall trend effects. This information is pivotal in understanding the impact of future climate change on global C dynamics.     

Rafting in Antarctic Collembola

Darwin was an early exponent of the importance of 'occasional means of dispersal' in accounting for the present-day distribution of plants and animals. This study examined the implications of capture on the water surface of meltwater and seawater for the local and long-range dispersal of Antarctic springtails. Individuals of the maritime Antarctic collembolan Cryptopygus antarcticus , were floated on tap water and seawater at 0, 5 and 10°C. LT₅₀s on seawater were 34 (10°C), 65 (5°C) and 75 (0°C) days. On tap water, LT₅₀s were 69 (10°C), 126 (5°C) and 239 (0°C) days. Less than 20% escaped from the water surface. A significantly greater proportion of springtails moulted on tap water and viable offspring were produced on both tap water and seawater. Comparison across treatments of survival of moulting and non-moulting individuals found significantly greater survival in moulting animals for three of the treatment combinations. It is suggested that moult exuviae facilitate survival on the water film through the simultaneous provision of a flotation aid and a source of nourishment – that is, an 'edible raft'. A separate experiment measuring changes in haemolymph osmolality over time on tap water and seawater at 2 and 5°C found significant differences in all treatments. Causes of mortality are discussed in relation to osmoregulatory failure and starvation.     

Support for a trimeric collar of myosin binding protein C in cardiac and fast skeletal muscle, but not in slow skeletal muscle

Myosin-binding protein C (MyBPC) is proposed to take on a trimeric collar arrangement around the thick filament backbone in cardiac muscle, based on interactions between cardiac MyBPC domains C5 and C8. We have now determined, using yeast two-hybrid and in vitro binding assays, that the C5:C8 interaction is not dependent on the 28-residue cardiac-specific insert in C5. Furthermore, an interaction of similar affinity occurs between domains C5 and C8 of fast skeletal muscle MyBPC, but not between these domains of the slow skeletal muscle protein. These data have implications for the role and quaternary structure of MyBPC in skeletal muscle.     

Changes in the correlation of electroencephalograms connected with rhythmic movements

Estimation of the correlation (C) between EEG processes is usually based on time averaging. Event-related changes in C around the mean level can be extracted with the help of ensemble averaging (synchronous accumulation). Fast and small non-stationary oscillations of C can be reliably distinguished in such a way. Curves of sign correlation averaged for 64 cycles were measured during rhythmic movements. It has been shown that the mean values of the curves coincide with the known ones. A high value of C for symmetric EEG recording and C dependence on the distance between the electrodes, etc. were found. Additional data were obtained on the relationship between changes in C and movement phases (an increase in C at the onset and the end of movement cycles multiphasic form of the C curves, etc.) and on the relation between the phases of various curves of C.     

水稻高代回交置换系穗颈长度的遗传分析

对以籼稻品种9311为受体、粳稻品种日本晴为供体的3个控制穗颈长度性状的高代回交置换系(C031、C108和C115)进行了农艺性状测定和遗传基础分析。结果表明, 除穗颈长度外, 3个置换系的株高与9311之间也存在显著或极显著差异, 置换系C031的每穗总粒数和千粒重与9311差异显著。通过遗传背景检测, 发现置换系C031和C115均含有2个日本晴置换片段, 置换系C108含有3个日本晴置换片段。遗传分析表明, 3个F₂分离群体中穗颈长度的分离均由单个孟德尔因子控制, 其加性效应分别为3.09、3.05和-2.04。连锁分析表明, C031和C108与携带置换片段上的分子标记均不连锁, C115与第12号染色体的分子标记存在不同程度的连锁, 表明控制C115穗颈长度表型的基因位于第12号染色体上, 将其命名为qPNL- 12。研究结果为精细定位和克隆该基因奠定了基础。     

Genetic systems development in the clostridia

Abstract: This review describes recent developments in the genetic manipulation of the solventogenic clostridia, Clostridium acetobutylicum and C. beijerinckii . It is to be noted that our laboratory stock of C. acetobutylicum ATCC 824, which was obtained from the American Type Culture Collection, has recently been re-identified as C. beijerinckii NCIMB 8052 based on DNA similarity studies using the S1 nuclease method (personal communication, Dr. Jiann-Shin Chen, Virginia Polytechnic Institute and State University). Reference to our laboratory 824 culture has been changed to C. beijerinckii NCIMB 8052 throughout this paper in order to be consistent with this finding. The focus of this review specifically involves the characterization of an M13-like genetic system for the clostridia based on the pCAK1 phagemid, as well as preliminary work on development of a plasmid-based vector based on the indigenous pDM11 plasmid recovered from C. acetobutylicum NCIB 6443. The construction of a C. beijerinckii strain with amplified endoglucanase activity was achieved by inserting the engB gene from C. cellulovorans into C. beijerinckii . The successful expression of a heterologous engB gene from C. cellulovorans in C. beijerinckii NCIMB 8052 has important industrial significance for the eventual utilization of cellulose by this acetone-butanol-ethanol fermentation microorganism.     

A role of protein kinase C in signal reactions in outer segments of the bovine retinal rods

The effect of modulators of protein kinase C activity on Ca2+ translocation in dark-adapted and bleached retinal rod outer segments (ROS) was studied. The activators (1,2-diacyl glycerol and phorbol-12-myristate-13-acetate) and the inhibitor (chelerythrine chloride) of protein kinase C were shown to stimulate and inhibit the ATP-dependent Ca(2+)-uptake in dark-adapted retinal ROS, correspondingly. Apparently, this action is due to the influence of protein kinase C on Ca(2+)-ATPase activity in these vesicular structures. No involvement of modulators of protein kinase C activity on ATP-dependent Ca(2+)-uptake in bleached retinal ROS was found. The influence of protein kinase C on Ca(2+)-release from retinal ROS was observed. It was shown that the activators and inhibitors of protein kinase C increased the efficiency of this process both in dark-adapted and bleached retinal ROS. The mechanisms of action of the protein kinase C activity modulators on the Ca(2+)-uptake and Ca(2+)-release in retinal ROS are discussed.     

Distribution of keratinophilic fungi in animal folds in Kuwait

Soil samples from seventeen animal herds (camels, goats, sheep, cows) were surveyed for the occurrence of keratinophilic fungi. Twenty four species related to eleven genera were recovered on defated wool baits. Eleven Chrysosporium species were reported in the following order of dominance: C. keratinophilum, C. tropicum, C. indicum, C. queenslandicum, C. pannicola, C. carmichaelii, C. state of Arthroderma curreyi, C. zonatum, C. state of A. cuniculi and Chrysosporium state of Renispora flavissima. The Aphanoascus teleomorph of C. keratinophilum, C. indicum and C. tropicum were frequently reported in soils from cow and sheep folds. Scopulariopsis, Cephaliophora and Sepedonium, although not keratinolytic, were also recorded on wool baits of soils from cow herds which are slightly acidic. The frequency and distribution of these fungi are discussed in relation to animal species and the general ecological conditions of desert soils.     

Multimeric C9 within C5b-9 deposits in unique locations in the cell wall of Salmonella typhimurium

We have shown previously that multimeric C9 within C5b-9 (C9:C5b-8 greater than 3:1) is needed for killing of a rough strain of Escherichia coli. We now extend these studies using serum sensitive, rough (R) and serum resistant, wild type (WT) strains of Salmonella typhimurium as well as a mutant S. typhimurium strain (TS) with a temperature sensitive mutation in synthesis of keto-deoxy-octulosonate, a constituent within the deep core structure of Salmonella LPS. Both R and TS required multimeric C9 within C5b-9 to be killed. Addition at 37 degrees C of increasing inputs of C9 to TS or R bearing C5b-9 led to a dose-related increase in C9 binding and killing. In contrast, addition of high inputs of C9 to the same strains at 4 degrees C, a procedure that limits the C9:C5b-8 ratio to 1:1, resulted in low C9 binding and minimal killing. Bactericidal C5b-9 formed at 37 degrees C on R and TS with high inputs of C9 co-sedimented with the bacterial outer membrane on sucrose density gradient analysis. Non-bactericidal C5b-9 on R, WT, and TS co-sedimented near the inner membrane, despite the presumed lack of association between these constituents. Whereas 125I C9 within the non-bactericidal pools immunoprecipitate with anti-C5, 125I C9 within bactericidal pools did not immunoprecipitate with anti-C5, anti-C7, or anti-C9. These findings suggest that bactericidal C5b-9 may be deposited in a unique location or configuration within the bacterial cell wall.     

Proline: an essential intermediate in arginine degradation in Saccharomyces cerevisiae.

Results of studies on proline-nonutilizing (Put-) mutants of the yeast Saccharomyces cerevisiae indicate that proline is an essential intermediate in the degradation of arginine. Put- mutants excreted proline when grown on arginine or ornithine as the sole nitrogen source. Yeast cells contained a single enzyme, delta 1-pyrroline-5-carboxylate (P5C) dehydrogenase, which is essential for the complete degradation of both proline and arginine. The sole inducer of this enzyme was found to be proline. P5C dehydrogenase converted P5C to glutamate, but only when the P5C was derived directly from proline. When the P5C was derived from ornithine, it was first converted to proline by the enzyme P5C reductase. Proline was then converted back to P5C and finally to glutamate by the Put enzymes proline oxidase and P5C dehydrogenase.     

Cholesterol-multilipid interactions in bilayers

To extend our knowledge of model membrane systems based upon one lipid component, multi-lamellar bilayers were made of cholesterol with two phospholipids in equimolar ratio, and the enthalpy change delta H of the main phase transition of the temary mixture was measured by differential scanning calorimetry (DSC) as a function of increasing cholesterol concentration c. The lipids were saturated phosphatidylcholines CnPC of acyl chain length n, and as the n of the two lipids became more different (from C13PC/C14PC to C14PC/C15PC to C14PC/C18PC to C14PC/C19PC) distinct breaks in the delta H versus c plots were observed. These mixtures displayed only one broad DSC endotherm. Mixtures of an unsaturated lipid C18: 1PC (dioleoyl) with C16PC or with C18PC showed two peaks, with each peak being associated with its parent lipid. However, the delta H versus c plots for each of these peaks showed an initial independence of cholesterol concentration followed by a dependence on cholesterol concentration. These results indicate that, in lipid mixtures, the type of interaction of cholesterol with each lipid component depends on the concentration of cholesterol present.     

土壤侵蚀预报模型中的植被覆盖与管理因子研究进展

植被覆盖和土地管理措施是土支离破碎中侵蚀的主要抑制因素之一,通用土壤流失方程（USLE）中的植被覆盖与田间管理因子（C）是评价这种抑制作用的有效指标,并被广泛采用和深入研究。我国在这方面的研究还不能满足土壤侵蚀预报和水土保持规划的要求,在系统回顾该因子的研究历史的基础上,介绍了USLE和RUSLE中C因子估计方法及其不断改进和完善的过程,并概述了中国的覆盖与田间管理因子的研究进展。此外,总结国内在（C）因子估计值以及植被覆盖度,地面覆盖物和植被根系对土壤侵蚀的影响等方面研究成果,分析了目前我国覆盖与田间管理因子研究中存在的3个方面问题,并提出了前景展望。     

Phosphatidylcholine bilayers: subtransitions in pure and in mixed lipids

Aqueous dispersions of C14, C16, C17 and C18 phosphatidylcholines (PC, where Cn denotes di-acyl of n carbons per chain), and mixtures of C14/C16PC and C16/C17PC were prepared and their thermal properties studied by differential scanning calorimetry (d.s.c.) after sample storage at 2-6 degrees C for up to 22 days. C16PC and C18PC display subtransitions at 22 degrees C and 29 degrees C, respectively, as previously reported by Chen et al. (Proc. Natl. Acad. Sci. U.S.A. 77 (1980) 5060-5063). C17PC shows two subtransitions at 21 degrees C and 26 degrees C, respectively, which are independent of each other. Although C16PC and C17PC individually develop subtransitions, an equimolar mixture does not. However, mixtures of C14/C16PC containing 10 or more mol% of C14PC do display a subtransition. These results underscore the primary dependence of subtransition formation in phosphatidylcholine dispersions on acyl chain structure.     

磷有效性对大豆根冠中碳分配的影响

在水培条件下,研究不同浓度磷影响大豆根冠中碳分配的结果表明：磷有效性对大豆根冠中碳分配的影响依赖于磷浓度与胁迫时间。磷浓度高于0．125mmol．L^-1或低磷胁迫7d以内,大豆根冠中碳分配受到的影响不显著。低磷胁迫14d的大豆的净光合速率和根呼吸速率均显著下降,根冠比显著提高。这显示长期低磷胁迫下大豆碳同化总量和根呼吸消耗的碳量虽然减少,但根系生长的碳消耗则增加,光合碳同化形成的碳水化合物向根部的分配是受到促进的。     

Detecting changes in soil carbon in CO2 enrichment experiments

After four growing seasons, elevated CO₂ did not significantly alter surface soil C pools in two intact annual grasslands. However, soil C pools in these systems are large compared to the likely changes caused by elevated CO₂. We calculated statistical power to detect changes in soil C, using an approach applicable to all elevated CO₂ experiments. The distinctive isotopic signature of the fossil-fuel-derived CO₂ added to the elevated CO₂ treatment provides a C tracer to determine the rate of incorporation of newly-fixed C into soil. This rate constrains the size of the possible effect of eievated CO₂ on soil C. Even after four years of treatment, statistical power to detect plausible changes in soil C under elevated CO₂ is quite low. Analysis of other elevated CO₂ experiments in the literature indicates that either CO₂ does not affect soil C content, or that reported CO₂ effects on soil C are too large to be a simple consequence of increased plant carbon inputs, suggesting that other mechanisms are involved, or that the differences are due to chance. Determining the effects of elevated CO₂ on total soil C and long-term C storage requires more powerful experimental techniques or experiments of longer duration.