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Author (up) Adachi, R.; Osada, H.; Shingai, R. file  url
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  Title Phase-dependent preference of thermosensation and chemosensation during simultaneous presentation assay in Caenorhabditis elegans Type Journal Article
  Year 2008 Publication BMC Neuroscience Abbreviated Journal BMC Neurosci  
  Volume 9 Issue Pages 106  
  Keywords Animals; Caenorhabditis elegans; Chemotactic Factors; Chemotaxis--physiology; Choice Behavior; Cold Temperature; Pentanols; Psychomotor Performance--physiology; Sensation; Sensory Receptor Cells--physiology; Sodium Chloride; Thermosensing--physiology  
  Abstract BACKGROUND: Multi-sensory integration is necessary for organisms to discriminate different environmental stimuli and thus determine behavior. Caenorhabditis elegans has 12 pairs of amphid sensory neurons, which are involved in generating behaviors such as thermotaxis toward cultivation temperature, and chemotaxis toward chemical stimuli. This arrangement of known sensory neurons and measurable behavioral output makes C. elegans suitable for addressing questions of multi-sensory integration in the nervous system. Previous studies have suggested that C. elegans can process different chemoattractants simultaneously. However, little is known about how these organisms can integrate information from stimuli of different modality, such as thermal and chemical stimuli. RESULTS: We studied the behavior of a population of C. elegans during simultaneous presentation of thermal and chemical stimuli. First, we examined thermotaxis within the radial temperature gradient produced by a feedback-controlled thermoregulator. Separately, we examined chemotaxis toward sodium chloride or isoamyl alcohol. Then, assays for simultaneous presentations of 15 degrees C (colder temperature than 20 degrees C room temperature) and chemoattractant were performed with 15 degrees C-cultivated wild-type worms. Unlike the sum of behavioral indices for each separate behavior, simultaneous presentation resulted in a biased migration to cold regions in the first 10 min of the assay, and sodium chloride-regions in the last 40 min. However, when sodium chloride was replaced with isoamyl alcohol in the simultaneous presentation, the behavioral index was very similar to the sum of separate single presentation indices. We then recorded tracks of single worms and analyzed their behavior. For behavior toward sodium chloride, frequencies of forward and backward movements in simultaneous presentation were significantly different from those in single presentation. Also, migration toward 15 degrees C in simultaneous presentation was faster than that in 15 degrees C-single presentation. CONCLUSION: We conclude that worms preferred temperature to chemoattractant at first, but preferred the chemoattractant sodium chloride thereafter. This preference was not seen for isoamyl alcohol presentation. We attribute this phase-dependent preference to the result of integration of thermosensory and chemosensory signals received by distinct sensory neurons.  
  Call Number Serial 262  
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Author (up) Buguet, A. file  url
doi  openurl
  Title Sleep under extreme environments: effects of heat and cold exposure, altitude, hyperbaric pressure and microgravity in space Type Journal Article
  Year 2007 Publication Journal of the Neurological Sciences Abbreviated Journal J Neurol Sci  
  Volume 262 Issue 1-2 Pages 145-152  
  Keywords Adaptation, Physiological/physiology; Atmospheric Pressure; *Climate; Cold Temperature/adverse effects; *Environment; Hot Temperature/adverse effects; Humans; Sleep/*physiology; Sleep Wake Disorders/etiology/*physiopathology; Space Flight; Weightlessness/adverse effects  
  Abstract Human sleep is sensitive to the individual's environment. The present review examines current knowledge of human sleep patterns under different environments: heat exposure, cold exposure, altitude, high pressure and microgravity in space. Heat exposure has two effects. In people living in temperate conditions, moderate heat loads (hot bath, sauna) prior to sleep provoke a delayed reaction across time (diachronic reaction) whereby slow-wave sleep (SWS) augments in the following night (neurogenic adaptive pathway). Melanoids and Caucasians living in the Sahel dry tropical climate experience diachronic increases in SWS throughout seasonal acclimatization. Such increases are greater during the hot season, being further enhanced after daytime exercise. On the contrary, when subjects are acutely exposed to heat, diachronic decreases in total sleep time and SWS occur, being often accompanied by synchronic (concomitant) diminution in REM sleep. Stress hormones increase. Nocturnal cold exposure provokes a synchronic decrease in REM sleep along with an activation of stress hormones (synchronic somatic reaction). SWS remains undisturbed as it still occurs at the beginning of the night before nocturnal body cooling. Altitude and high pressure are deleterious to sleep, especially in non-acclimatized individuals. In their controlled environment, astronauts can sleep well in microgravity. Exercise-induced sleep changes help to understand environmental effects on sleep: well-tolerated environmental strains may improve sleep through a neurogenic adaptive pathway; when this “central” adaptive pathway is overloaded or bypassed, diachronic and synchronic sleep disruptions occur.  
  Call Number Serial 1141  
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Author (up) Denner, E.B.; Mark, B.; Busse, H.J.; Turkiewicz, M.; Lubitz, W. file  url
doi  openurl
  Title Psychrobacter proteolyticus sp. nov., a psychrotrophic, halotolerant bacterium isolated from the Antarctic krill Euphausia superba Dana, excreting a cold-adapted metalloprotease Type Journal Article
  Year 2001 Publication Systematic and Applied Microbiology Abbreviated Journal Syst Appl Microbiol  
  Volume 24 Issue 1 Pages 44-53  
  Keywords Adaptation, Biological/*physiology; Animals; Antarctic Regions; Bacterial Proteins/isolation & purification; Bacterial Typing Techniques; Cold Temperature; Crustacea/*microbiology; DNA, Ribosomal/genetics; Drug Resistance, Microbial; Fatty Acids/analysis; Gammaproteobacteria/classification/enzymology/*isolation & purification; Gram-Negative Aerobic Rods and Cocci/enzymology/*isolation & purification; Metalloendopeptidases/*secretion; Molecular Sequence Data; RNA, Ribosomal, 16S/genetics; Salts/pharmacology  
  Abstract An Antarctic marine bacterium (strain 116) excreting an extracellular cold-adapted metalloprotease was subjected to a detailed polyphasic taxonomic investigation. Strain 116 was previously isolated from the stomach of a specimen of the Antarctic krill Euphasia superba Dana and tentatively characterized as Sphingomonas paucimobilis 116. The 16S rDNA sequence analysis showed that the strain is in fact related to species of the genus Psychrobacter, next to Psychrobacter glacincola (97.4% similarity). Sequence similarities between strain 116 and other Psychrobacter species ranged from 96.9% (with P. urativorans) to 95.4% (with P. immobilis). Key phenotypic characteristics as well as chemotaxonomic features of the bacterium were congruent with the description of the genus Psychrobacter i.e. cells were strictly aerobic, strongly oxidase-positive, psychrotrophic, halotolerant, gram-negative non-motile coccobacilli, with ubiquinone-8 as the main respiratory lipoquinone and 18:1 cis 9, 16:1 cis and 17:1 (omega8c being the predominant cellular fatty acids. The G+C content of the DNA was 43.6 mol%. DNA-DNA hybridization studies showed that the relatedness between strain 116 and Psychrobacter glacinola is only 62.2%. Further differences were apparent in whole-cell SDS-PAGE protein pattern, cellular fatty acid profile and in a number of physiological and biochemical characteristics as well as in enzymatic activities. Tolerance to 5% bile salts, nitrate reduction, citrate utilization, acid production from carbohydrates, alkaline phosphatase, acid phosphatase, C4 esterase, C14 lipase and valine arylamidase were found to differentiate strain 116 from Psychrobacter glacincola. On the basis of this phenotypic and molecular evidences, strain 116, previously known as Sphingomonas paucimobilis 116, was recognized as a new species of the genus Psychrobacter for which the name Psychrobacter proteolyticus is proposed. Strain 116 has been deposited in the Collection de l'Institut Pasteur, France, as CIP106830T and in the Deutsche Sammlung von Mikroorganismen and Zellkulturen, as DSM13887.  
  Call Number Serial 436  
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Author (up) DeRidder, B.P.; Crafts-Brandner, S.J. file  url
doi  openurl
  Title Chilling stress response of postemergent cotton seedlings Type Journal Article
  Year 2008 Publication Physiologia Plantarum Abbreviated Journal Physiol Plant  
  Volume 134 Issue 3 Pages 430-439  
  Keywords Betaine/metabolism; Carbon Dioxide/metabolism; *Cold Temperature; Cotyledon/physiology; Gossypium/growth & development/*physiology; Photoperiod; Plant Leaves/physiology; Plant Transpiration; Seedlings/*physiology; *Stress, Physiological; Temperature; Water/physiology  
  Abstract Early season development of cotton is often impaired by sudden episodes of chilling temperature. We determined the chilling response specific to postemergent 13-day-old cotton (Gossypium hirsutum L. cv. Coker 100A-glandless) seedlings. Seedlings were gradually chilled during the dark period and rewarmed during the night-to-day transition. For some chilled plants, the soil temperature was maintained at control level. Plant growth, water relations and net photosynthesis (P(n)) were analyzed after one or three chilling cycles and after 3 days of recovery. Three chilling cycles led to lower relative growth rate (RGR) compared with controls during the recovery period, especially for plants with chilled shoots and roots. Treatment differences in RGR were associated with net assimilation rate rather than specific leaf area. Both chilling treatments led to loss of leaf turgor during the night-to-day transition; this effect was greater for plants with chilled compared with warm roots. Chilling-induced water stress was associated with accumulation of the osmolyte glycine betaine to the same extent for both chilling treatments. Inhibition of P(n) during chilling was related to both stomatal and non-stomatal effects. P(n) fully recovered after seedlings were returned to control conditions for 3 days. We conclude that leaf expansion during the night-to-day transition was a significant factor determining the magnitude of the chilling response of postemergent cotton seedlings.  
  Call Number Serial 1145  
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Author (up) Kosova, K.; Vitamvas, P.; Prasil, I.T.; Renaut, J. file  url
openurl 
  Title Plant proteome changes under abiotic stress--contribution of proteomics studies to understanding plant stress response Type Journal Article
  Year 2011 Publication Journal of Proteomics Abbreviated Journal J Proteomics  
  Volume 74 Issue 8 Pages 1301-1322  
  Keywords Arabidopsis/genetics; Cold Temperature/adverse effects; Droughts; Gene Expression Profiling; Herbicides/pharmacology; Hot Temperature/adverse effects; Metals, Heavy/adverse effects; Oryza sativa/genetics; Plant Proteins/*genetics; Plants/*genetics; Protein Processing, Post-Translational; Proteome/*genetics; Stress, Physiological/*genetics  
  Abstract Plant acclimation to stress is associated with profound changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. In this review, proteomics studies dealing with plant response to a broad range of abiotic stress factors--cold, heat, drought, waterlogging, salinity, ozone treatment, hypoxia and anoxia, herbicide treatments, inadequate or excessive light conditions, disbalances in mineral nutrition, enhanced concentrations of heavy metals, radioactivity and mechanical wounding are discussed. Most studies have been carried out on model plants Arabidopsis thaliana and rice due to large protein sequence databases available; however, the variety of plant species used for proteomics analyses is rapidly increasing. Protein response pathways shared by different plant species under various stress conditions (glycolytic pathway, enzymes of ascorbate-glutathione cycle, accumulation of LEA proteins) as well as pathways unique to a given stress are discussed. Results from proteomics studies are interpreted with respect to physiological factors determining plant stress response. In conclusion, examples of application of proteomics studies in search for protein markers underlying phenotypic variation in physiological parameters associated with plant stress tolerance are given.  
  Call Number Serial 229  
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