875 research outputs found
The Identification of cis-II, I2-Methylene-2-hydroxyoctadecanoic Acid from \u3ci\u3eThiobacillus thiooxidans\u3c/i\u3e
A polar fatty acid has been observed as a component of an
ornithine-containing lipid of Thiobacillus thiooxidans. A
comparison of thin layer chromatographic mobilities of reference
compounds to those of the natural acid and its derivatives
suggested that the acid was a 2-hydroxy fatty acid.
The presence of a cyclopropane function in the acid was
indicated by l4e-Iabeling experiments and infrared spectroscopy.
Mass spectrometry of the methyl ester and the acetylated
methyl ester of the natural acid provided a molecular
weight for the acid. Equivalent chain lengths were determined
for the natural acid, the acid obtained by oxidative
decarboxylation of the natural acid with permanganate, and
the acids derived through reductive ring cleavage of the
cyclopropane group in the ester of the oxidatively decarboxylated
natural acid. The mass spectral data, the equivalent
chain length determinations, and the permanganate oxidation
study clearly indicated that the acid possessed an 18-
carbon chain with a methylene bridge and a 2-hydroxyl
function. The equivalent chain length determinations
further suggested that the cyclopropane group had the cis
configuration. Mass spectrographic analysis of the branched
chain esters obtained by reductive cleavage of the ester
which was in turn derived through oxidative decarboxylation
of the natural acid allowed the assignment of the 11,12
position for the cyclopropane group. Based on these data,
the polar acid is proposed to be cis-ll, 12-methylene-2-
hydroxyoctadecanoic acid
Phospholipids of \u3ci\u3eThiobacillus thiooxidans\u3c/i\u3e
Cells and spent growth media from sulfur- and thiosulfate-grown cultures of Thiobacillus thiooxidans were analyzed. The phosphatides were examined by thinlayer chromatography, and the products of their hydrolysis by hydrochloric acid and methanolic potassium hydroxide were separated by paper chromatography. The phospholipids in both cells and spent growth media were identified as phosphatidyl ethanolamine, phosphatidyl N-monomethylethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol. These comprised about 97% of the total lipid phosphorus. Lyso-phosphatidyl-N-monomethylethanolamine and lysophosphatidylglycerol accounted for the remaining 3%. The percentage of the total lipid phosphorus accounted for by each phospholipid depended on the age of the culture
The effects of stimulus modality and task integrality: Predicting dual-task performance and workload from single-task levels
The influence of stimulus modality and task difficulty on workload and performance was investigated. The goal was to quantify the cost (in terms of response time and experienced workload) incurred when essentially serial task components shared common elements (e.g., the response to one initiated the other) which could be accomplished in parallel. The experimental tasks were based on the Fittsberg paradigm; the solution to a SternBERG-type memory task determines which of two identical FITTS targets are acquired. Previous research suggested that such functionally integrated dual tasks are performed with substantially less workload and faster response times than would be predicted by suming single-task components when both are presented in the same stimulus modality (visual). The physical integration of task elements was varied (although their functional relationship remained the same) to determine whether dual-task facilitation would persist if task components were presented in different sensory modalities. Again, it was found that the cost of performing the two-stage task was considerably less than the sum of component single-task levels when both were presented visually. Less facilitation was found when task elements were presented in different sensory modalities. These results suggest the importance of distinguishing between concurrent tasks that complete for limited resources from those that beneficially share common resources when selecting the stimulus modalities for information displays
Ex. 277-US-415
The 2004 annual report on riverine movements of adult Lost River, shortnose, and Klamath largescale suckers in the Williamson and Sprague rivers, Orego
Ex. 277-US-415
The 2004 annual report on riverine movements of adult Lost River, shortnose, and Klamath largescale suckers in the Williamson and Sprague rivers, Orego
The Pentameric Vertex Proteins Are Necessary for the Icosahedral Carboxysome Shell to Function as a CO\u3csub\u3e2\u3c/sub\u3e Leakage Barrier
Background
Carboxysomes are polyhedral protein microcompartments found in many autotrophic bacteria; they encapsulate the CO2 fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) within a thin protein shell and provide an environment that enhances the catalytic capabilities of the enzyme. Two types of shell protein constituents are common to carboxysomes and related microcompartments of heterotrophic bacteria, and the genes for these proteins are found in a large variety of bacteria. Methodology/Principal Findings
We have created a Halothiobacillus neapolitanus knockout mutant that does not produce the two paralogous CsoS4 proteins thought to occupy the vertices of the icosahedral carboxysomes and related microcompartments. Biochemical and ultrastructural analyses indicated that the mutant predominantly forms carboxysomes of normal appearance, in addition to some elongated microcompartments. Despite their normal shape, purified mutant carboxysomes are functionally impaired, although the activities of the encapsulated enzymes are not negatively affected. Conclusions/Significance
In the absence of the CsoS4 proteins the carboxysome shell loses its limited permeability to CO2 and is no longer able to provide the catalytic advantage RubisCO derives from microcompartmentalization. This study presents direct evidence that the diffusion barrier property of the carboxysome shell contributes significantly to the biological function of the carboxysome
Genomic Organization, Splice Variants and Expression of CGMl, a CD66-related Member of the Carcinoembryonic Antigen Gene Family
The tumor marker carcinoembryonic antigen (CEA) belongs to a family of proteins which are composed of one immunogiobulin variable domain and a varying number of immunoglobulin constant-like domains. Most of the membrane-bound members, which are anchored either by a glycosylphosphatidylinositol moiety or a transmembrane domain, have been shown to convey cell adhesion in vitro. Here we describe two splice variants of CGMI. a transmembrane member of the CEA family without immunoglobulin constant.like domains. CGM1a and CGM1c contain cytopiasmic domains of 71 and 31 amino acids, respectively, The cytoplasmic region of CGM1a is encoded by four exons (Cyt1-Cyt4). Differential splicing of the Cyt1 exon (53 bp)..
Characterization of Newcastle Disease Viruses Isolated from Cormorant and Gull Species in the United States in 2010
Newcastle disease virus (NDV), a member of the genus Avulavirus of the family Paramyxoviridae, is the causative agent of Newcastle disease (ND), a highly contagious disease that affects many species of birds and which frequently causes significant economic losses to the poultry industry worldwide. Virulent NDV (vNDV) is exotic in poultry in the United States; however, the virus has been frequently associated with outbreaks of ND in cormorants, which poses a significant threat to poultry species. Here, we present the characterization of 13 NDV isolates obtained from outbreaks of ND affecting cormorants and gulls in the states of Minnesota, Massachusetts, Maine, New Hampshire, and Maryland in 2010. All 2010 isolates are closely related to the viruses that caused the ND outbreaks in Minnesota in 2008, following the new evolutionary trend observed in cormorant NDV isolates since 2005. Similar to the results obtained with the 2008 isolates, the standard United States Department of Agriculture F-gene real-time reverse-transcription PCR (RRT-PCR) assay failed to detect the 2010 cormorant viruses, whereas all viruses were detected by a cormorant-specific F-gene RRTPCR assay. Notably, NDV-positive gulls were captured on the eastern shore of Maryland, which represents a significant geographic expansion of the virus since its emergence in North America. This is the first report of vNDV originating from cormorants isolated from wild birds in Maryland and, notably, the first time that genotype V vNDV has been isolated from multiple wild bird species in the United States. These findings highlight the need for constant epidemiologic surveillance for NDV in wild bird populations and for consistent biosecurity measures to prevent the introduction of the agent into domestic poultry flocks
レã‚シテ゠ニンゲンガク カラ ミタ ニホン ノ シンタイ ブンカ : ベルリン ジユウ ダイガク デノ コクサイ ワーク ショップ ニホン ノ シンタイ ブンカ ã‚«ã‚¿ ト ソノ ブンカ オウダンテ゠デンタツ ホウコク ãƒãƒ³ãƒ–ン 1
Am 22. September 2008 führten Hirota und Ishida die internationale Werkstatt
"Japanische Kultur -durch 'KATA'(Form/Muster) erleben" in der Freien Universität
Berlin durch. An diesem Tag gab es ungefähr 20 Teilnehmer: Professor Ch. Wulf und die
'Historische Anthropologie' Studenten/innen,die einige Übungen erfuhren. In unserer
Werkstatt haben sie erst unter Leitung von Ishida die Schwertkunst,Stockkunst und
Aikido erfahren. Dann hat Hirota ihnen einigen Bewegungsübung als japanische
kulturelle Essenz angeboten. Dieser Artikel besteht aus einem Bericht dieser
Werkstatt und dem Nachdenken von KATA,sonst (1) ist der Teil von Ishida
The Pentameric Vertex Proteins Are Necessary for the Icosahedral Carboxysome Shell to Function as a CO2 Leakage Barrier
BACKGROUND: Carboxysomes are polyhedral protein microcompartments found in many autotrophic bacteria; they encapsulate the CO(2) fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) within a thin protein shell and provide an environment that enhances the catalytic capabilities of the enzyme. Two types of shell protein constituents are common to carboxysomes and related microcompartments of heterotrophic bacteria, and the genes for these proteins are found in a large variety of bacteria. METHODOLOGY/PRINCIPAL FINDINGS: We have created a Halothiobacillus neapolitanus knockout mutant that does not produce the two paralogous CsoS4 proteins thought to occupy the vertices of the icosahedral carboxysomes and related microcompartments. Biochemical and ultrastructural analyses indicated that the mutant predominantly forms carboxysomes of normal appearance, in addition to some elongated microcompartments. Despite their normal shape, purified mutant carboxysomes are functionally impaired, although the activities of the encapsulated enzymes are not negatively affected. CONCLUSIONS/SIGNIFICANCE: In the absence of the CsoS4 proteins the carboxysome shell loses its limited permeability to CO(2) and is no longer able to provide the catalytic advantage RubisCO derives from microcompartmentalization. This study presents direct evidence that the diffusion barrier property of the carboxysome shell contributes significantly to the biological function of the carboxysome
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