Changes in productivity and carbon storage of grasslands in China under future global warming scenarios of 1.5°C and 2°C

Aims The impacts of future global warming of 1.5°C and 2°C on the productivity and carbon (C) storage of grasslands in China are not clear yet, although grasslands in China support ~45 million agricultural populations and more than 238 million livestock populations, and are sensitive to global warming.     

The growth of dermatophytes at 4° C and 37° C; The relation of this character to others

Summary The ability of the generaEpidermophyton, Microsporon andTrichopyton to grow on some media at 4° C and 37° C was studied. It has been shown that specific differences exist among these fungi in the capability or rapidity of the growth at extreme temperatures.There is high positive correlation among perfect state production, isolation from the soil and growth at 4° C (group of characters A) and between pathogenicity and growth at 37° C (group of characters B). Between the groups A and B of characters exists a slighter negative correlation. Some prognosis about the five characters by certain species of dermatophytes may be given.     

Dark-recovery of Gamma- and UV-irradiated Saccharomyces carlsbergensis at 4° C

Experiments were carried out to find the effect of dark-holding in distilled water at 4° C on recovery of Gamma- and UV-irradiated cells of a haploid strain ofSaccharomyces carlsbergensis. It was found that there was an appreciable increase in survival of the irradiated cells following 4 to 24 hours' holding while no increase in the number of control cells was observed following similar treatment. It is suggested that some common type of damage induced by both Gamma- and UV-radiations inS. carlsbergensis may be repaired efficiently under metabolic conditions associated with growth at 4° C in distilled water.     

Metabolic differences inBacillus stearothermophilus grown at 55°C and 37°C

Summary Bacillus stearothermophilus was adapted to grow at 55°C and 37°C in a complex medium with almost equivalent yields in cell mass. In both temperature ranges the maximum specific growth rates (μ_max) were identical. Cellular extracts of this bacterium showed remarkable differences in the activity levels of several enzymes, depending on the respective growth temperature. High activities of glyceraldehyde-3-phosphate dehydrogenase and alcohol dehydrogenase were observed in bacteria from thermophilic cultures (55°C) and the respiratory quotient exceeded 1.0. Under anaerobic conditions at 55°C μ_max was the same as in aerobic cultures. No alcohol dehydrogenase was detected in cells from mesophilic cultures (37°C), however, and the level of glyceraldehyde-3-phosphate dehydrogenase was also extremely low under mesophilic conditions. Succinate dehydrogenase and isocitrate dehydrogenase activity appeared to be higher in bacteria grown at 37°C; the resspiratory quotient was always lower than 1.0. At 37°C, acetoin formation was observed regularly, a fermentation product which was never detected in 55°C-cultures. Under anaerobic conditions at 37°C a very low growth rate was found. When adapted to grow at 37°C or 55°C,B. stearothermophilus is apparently able to use different catabolic systems.     

Tolerance of cold-acclimated and unacclimated rats to hypoxia at 1.7°C

Cold-acclimated and unacclimated rats were exposed for 4 hours to 6.6 or 4.9% O₂ in N₂ at 1.7°C. Unacclimated rats tolerated both degrees of hypoxia better than cold-acclimated rats. Cold-acclimated rats showed relatively greater increases in serum concentrations of GOT and GPT, aldolase and LDH immediately after exposure to 4.9% O₂ and a greater concentration of GPT at 6.6% O₂ than unacclimated rats. In both groups serum urea nitrogen and plasma corticosterone were elevated. Serum glucose was increased above air flow controls (20.9% O₂) in both groups by 50% at 6.6% O₂ and 100% at 4.9% O₂. Blood lactic acid levels were elevated by about 130%. The cold-acclimated rats had a higher incidence of renal tubular dilatation, fatty changes in striated muscles, and severe hepatic glycogen depletion. All rats in both groups showed myocardial inflammatory foci one day after exposure which persisted for 4 days. Cold-acclimated rats maintained higher body temperatures. The reduced tolerance of the cold-acclimated rats is attributed to an increased metabolism which increased tissue hypoxia.

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Zusammenfassung Kälteakklimatisierte und nicht akklimatisierte Ratten wurden 4 Stunden in 6.6 und 4.9% O₂ im N₂ bei 1, 7°C exponiert. Kälteakklimatisierte Tiere waren gegen beide Hypoxiegrade weniger resistent als nicht akklimatisierte. Sie zeigten einen relativ höheren Anstieg der Serumaktivität von GOT und GPT, Aldolase und LDH unmittelbar nach Uebergang in 4, 9% O₂ und eine höhere Aktivität von GPT bei 6, 6% O₂ als unakklimatisierte Ratten. In beiden Gruppen waren der Serum Harnstoff-N und Plasmakortikosteron erhöht. Serumglukose war über normoxische Kontrollen in beiden Gruppen bei 6, 6% O₂ auf 50% und bei 4, 9% O₂ auf ungefähr 100% erhöht. Die kälteakklimatisierten Ratten wiesen in höherem Masse Dilatationen der Nierentubuli auf, fettige Veränderungen in den gestreiften Muskeln und starke Depletierung des Leberglukogens. Entzündungsherde im Myokard traten nach einem Tag Exponierung auf, die 4 Tage lang bestanden. Kälteakklimatisierte Tiere behielten höhere Körpertemperaturen. Die verminderte Toleranz der kälteakklimatisierten Tiere ist Folge des erhöhten Stoffwechsels, der die Gewebshypoxie verstärkt.

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Resume On a exposé des rats acclimatés et non acclimatés durant quatre heures à des concentrations de 6, 6 et 4, 9% de O₂ dans de l'azote à 1, 7°C. Des bêtes acclimatées au froid se sont avérées moins résistantes aux deux taux d'hypoxie que leurs congénères non acclimatés. Ils présentaient une hausse relativement plus accentuée de l'activité du sérum (GOT, GPT, aldolase et LDH) immédiatement après leur séjour à 4, 9% de O₂ et une activité accrue de GPT à 6, 6% de O₂ par rapport à leurs congénères non acclimatés. De même, l'urée azotée du sérum et la corticostérone du plasma étaient plus élevées chez les deux groupes. Le glucose du sérum, déterminé par rapport à des bêtes de contrôle (20, 9% de O₂), était plus élevé dans les deux groupes de 50% à 6, 6% de O₂ et de 100% pour 4, 9% de O₂. Le taux d'acide lactique du sang a atteint alors 130%. Les rats acclimatés au froid présentaient une plus grande dilatation des tubes rénaux, des modifications lipoidiques dans les muscles striés et un épuisement rapide du glucogène du foie. Après une exposition d'un jour, on a constaté dans le myocarde des foyers d'inflammation qui se sont maintenus durant 4 jours. Les animaux acclimatés au froid présentaient des températures du corps plus élevées. La tolérance réduite des animaux acclimatés au froid est la conséquence d'un métabolisme accentué qui renforce l'hypoxie des tissus.

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A preliminary report presented to the Sixth International Biometeorological Congress, Noordwijk, The Netherlands, 3–9 September 1972.     

Bioaccumulation of Gold by Filamentous Cyanobacteria Between 25 and 200°C

Plectonema boryanum UTEX 485 was reacted with aqueous AuCl ₄ ^? solutions ( ～ 2 mM Au) at 25 to 100°C for 1 month, and 200°C for one day. Addition of AuCl₄ ^? to cyanobacteria killed the cultures instantly, and Au was precipitated throughout the cells as nanoparticles. Precipitation of octahedral crystal platelets of Au occurred in the aqueous fluid, with particle size increasing with increase in temperature from about 1.5 μ m at 25°C to 10 μ m at 100°C. Addition of AuCl₄ ^? to suspensions of the dead, autoclaved cyanobacteria also precipitated Au from solution, suggesting that the presence of cell degradation products caused instability of AuCl₄ ^? .     

Thyroliberin is rapidly transferred to the nucleus of GH3 pituitary cells at both 4°C and 37°C

The time-course of thyroliberin transfer to the nucleus of GH3/B6 rat pituitary prolactin cells was studied by both autoradiography and cell fractionation of intact cells exposed to [³H]thyroliberin at 4°C or 37°C. It was previously shown that thyroliberin is not degraded in these conditions. It is found by autoradiography that [³H]-thyroliberin is transferred to the nucleus of GH3/B6 cells within 5 min at least at both 37° C and 4°C. Consistent results are obtained by fractionation of cells exposed to [³H]thyroliberin at 37°C. However after binding at 4°C 50% of the cell radioactivity is extractible by glutaraldehyde and after fractionation the isolated nuclei retain only 1–1.5% of the cell radioactivity. This suggests the existence of both tightly bound and loosely bound internalized thyroliberin molecules.     

Kinetics and characteristics of 70 °C, VFA-grown, UASB granular sludge

We studied in batch reactors the kinetics and characterization of 70 °C, volatile fatty acids (VFAs)-grown, upflow anaerobic sludge blanket granular sludge with 55 and 35 °C sludge as reference. The half-saturation constant (K _s), the inhibition constant (K _i), the maximum specific methane production rate (μ_CH4max), and the inhibition response coefficient (n) of the 70 °C sludge were 6.15 mM, 48.2 mM, 0.132 h⁻¹, and 2.48, respectively, while no inhibition occurred at 55 and 35 °C, where the K _s was 3.67 and 3.82 mM, respectively. At 70 °C, the highest initial specific methanogenic activity (ISMA, 0.311 gCH₄-COD per gram volatile solids per day) on VFAs was about 12–15% lower than that on acetate and three to four times less than the ISMA for the 55 and 35 °C sludge. In the acetate conversion study, residual acetate (79 mg l⁻¹) at 70 °C was three to five times higher than that at 55 and 35 °C. Further, the methane produced as percentage of the acetate consumed at 70 °C (89%) was lower than that at 55 (95%) and 35 °C (97%). At 70 °C, 10% of the ISMA remained after 15 days of starvation as compared to 26% (55 °C) and 92% (35 °C) after 30 days of starvation. Thus, the kinetics of the 70 °C granular sludge seem to differ from those at 55 and 35 °C. Received: 1 February 1999 / Accepted: 20 March 1999     

Muscle,Skin and Core Temperature after ?110°C Cold Air and 8°C Water Treatment

The aim of this investigation was to elucidate the reductions in muscle, skin and core temperature following exposure to −110°C whole body cryotherapy (WBC), and compare these to 8°C cold water immersion (CWI). Twenty active male subjects were randomly assigned to a 4-min exposure of WBC or CWI. A minimum of 7 days later subjects were exposed to the other treatment. Muscle temperature in the right vastus lateralis (n = 10); thigh skin (average, maximum and minimum) and rectal temperature (n = 10) were recorded before and 60 min after treatment. The greatest reduction (P<0.05) in muscle (mean ± SD; 1 cm: WBC, 1.6±1.2°C; CWI, 2.0±1.0°C; 2 cm: WBC, 1.2±0.7°C; CWI, 1.7±0.9°C; 3 cm: WBC, 1.6±0.6°C; CWI, 1.7±0.5°C) and rectal temperature (WBC, 0.3±0.2°C; CWI, 0.4±0.2°C) were observed 60 min after treatment. The largest reductions in average (WBC, 12.1±1.0°C; CWI, 8.4±0.7°C), minimum (WBC, 13.2±1.4°C; CWI, 8.7±0.7°C) and maximum (WBC, 8.8±2.0°C; CWI, 7.2±1.9°C) skin temperature occurred immediately after both CWI and WBC (P<0.05). Skin temperature was significantly lower (P<0.05) immediately after WBC compared to CWI. The present study demonstrates that a single WBC exposure decreases muscle and core temperature to a similar level of those experienced after CWI. Although both treatments significantly reduced skin temperature, WBC elicited a greater decrease compared to CWI. These data may provide information to clinicians and researchers attempting to optimise WBC and CWI protocols in a clinical or sporting setting.     

Phospholipid metabolism in Mycobacterium smegmatis ATCC 607 grown at 37° C and 27° C

The rate of synthesis and degradation of phospholipids in Mycobacterium smegmatis ATCC 607, grown at 27° C and 37° C was studied by incorporation of ³²P into phospholipids and chase of radioactivity of the pulse-labelled phospholipids. A relatively low rate of synthesis and degradation of phospholipids in cells growth at 27° C was observed as compared to those grown at 37° C. Phosphatidylethanolamine (PE) had the maximum turnover at 37° C. However, at 27° C, cardiolipin (CL) showed a turnover rate higher than PE. Phosphatidylinositol mannosides (PIMs) were metabolically more active at 37° C than at 27° C. The differences in metabolic activity of the phospholipids at the two temperatures have been discussed.     

Effect of in vitro storage at 4 °C on survival and proliferation of poplar shoots

Shoot explants of in vitro proliferating cultures of Populus tremula (L.) x Populus tremuloides (L.) were stored for three months at 4°C, in dark or light, in basal culture medium with or without 2-isopentenyladenine (2iP), and in rooting medium with naphthalene acetic acid. They were transferred to cold at different times after subculturing. One hundred percent of shoots survived all tested conditions, in spite of leaf browing and necrosis. After transfer to 24°C for 2 weeks and a normal multiplication cycle, the shoots proliferated at a rate similar to controls or at a higher rate in the case of shoots introduced into the cold 7 or 14 days after subculture and stored in dark on medium containing 2iP.Abbreviations 2iP 2-isopentenyladenine - NAA naphthaleneacetic acid - MS Murashige & Skoog (1962) medium     

Properties of sodium and potassium channels of the squid giant axon far below 0°C

Summary Squid giant axon could be excited in concentrated glycerol solutions containing normal concentrations of electrolytes, when osmolalities of solutions inside and outside the axon were matched. These glycerol solutions did not freeze at the temperature as low as –19°C. The nerve excitation in these solutions were observed at this low temperature. The excitation process at this low temperature was slowed down and time constants of the excitation kinetics were several hundredfold larger than those in normal seawater at 10°C, under which temperature the squid habituated. The temperature coefficients for the electrophysiological membrane parameters under this condition were larger than those in normal seawater above 0°C. The Q₁₀ value for the conduction velocity was 2.0 and that of the duration of the action potential was around 8.5. The time course of the membrane currents was also slowed with the Q₁₀ value of around 5 and the magnitude decreased with the Q₁₀ value of around 2 as the temperature was lowered. The Q₁₀ values for the kinetics of the on process of the Na-channel were around 4.5 and were almost the same as those of the off process of the Na-channel in the wide range of the temperature below 0°C. The Q₁₀ value of the on process of K-channel was around 6.5 and was larger than those for Na-channel. The Q₁₀ values increased gradually as the temperature was lowered.     

The biochemical diversity of life near and above 100°C in marine environments

Hyperthermophilic micro-organisms grow at temperatures above 90 °C with a current upper limit of 113 °C. They are a recent discovery in the microbial world and have been isolated mainly from marine geothermal environments, which include both shallow and deep sea hydrothermal vents. By 16S rRNA analyses they are the most slowly evolving of all extant life forms, and all but two of the nearly 20 known genera are classified as Archaea (formerly Archaebacteria). Almost all hyperthermophiles are strict anaerobes. They include species of methanogens, iron-oxidizers and sulphate reducers, but the majority are obligate heterotrophs that depend upon the reduction of elemental sulphur (S°) to hydrogen sulphide for significant growth. The heterotrophs utilize proteinaceous materials as carbon and energy sources, although a few species are also saccharolytic. A scheme for electron flow during the oxidation of carbohydrates and peptides and the reduction of S° has been proposed. Two S°-reducing enzymes have been purified from the cytoplasm of one hyperthermophile (T(opt) 100 °C) that is able to grow either with and without S°. However, the mechanisms by which S° reduction is coupled to energy conservation in this organism and in obligate S°-reducing hyperthermophiles is not known. In the heterotrophs, sugar fermentation is achieved by a novel glycolytic pathway involving unusual ADP-dependent kinases and ATP synthetases, and novel oxidoreductases that are ferredoxin- rather than NAD(P)-linked. Similarly, peptide fermentation involves several unusual ferredoxin-linked oxidoreductases not found in mesophilic organisms. Several of these oxido-reductases contain tungsten, an element that is rarely used in biological systems. Tungsten is present in exceedingly low concentrations in normal sea water, but hydrothermal systems contain much higher tungsten concentrations, more than sufficient to support hyperthermophilic life.     

In vitro Storage of Strawberry and Raspberry in Calcium-Alginate Beads at 4°C

Three-millimeter-long shoot tips of strawberry 'Senga Sengana' and raspberry 'Norna' encapsulated in calcium alginate were stored in vitro at 4 °C in the dark. The cultures which were donors for the shoot tips were grown before encapsulation on shoot multiplication media (Boxus medium with 2.2 µM BAP and 2.46 µM IBA for strawberry, and MS medium with NH₄NO₃ and KNO₃ reduced by 50%, and with 3.55 µM BAP and 0.49 µM IBA for raspberry) as well as on these media supplemented with 10 g l^–1 mannitol or paclobutrazol (1.7 µM for strawberry and 3.4 µM for raspberry). Sodium alginate was dissolved in water, water with sugar or in a culture medium without growth regulators. Regrowth ability of the stored explants and in vitro multiplication in three successive subcultures were evaluated. The encapsulated shoot tips could be stored for 9 months in beads containing sugar or a culture medium. The pre-conditioning of the donor cultures on a mannitol containing medium was beneficial for regrowth ability. The multiplication rate of strawberry and raspberry shoots in the first subculture after storage was lower than that of non-stored cultures. Particularly low multiplication was obtained for strawberry which had been stored for 9 months and for raspberry stored for 3 and 6 months, in combinations where the beads were prepared by dissolving sodium alginate in water. Multiplication of strawberry in the second subculture was generally higher than in non-stored cultures, but multiplication of raspberry was lower also in the second subculture, with the exception of the combination stored for 9 months and pre-cultured on mannitol. In the third subculture, shoot multiplication in both species was similar to that in non-stored cultures.     

Comparative antigenic proteins and proteomics of pathogenic Yersinia enterocolitica bio-serotypes 1B/O: 8 and 2/O: 9 cultured at 25°C and 37°C

Yersinia enterocolitica is a Gram-negative enteric pathogen responsible for a number of gastrointestinal disorders; the most pathogenic bio-serotype is 1B/O: 8. In this study, we compared the antigenicity of the outer membrane proteins and proteomics of the whole-cell proteins of a pathogenic bio-serotype 2/O: 9 isolated in China and a bio-serotype 1B/O: 8 strain isolated in Japan. Using two-dimensional gel electrophoresis, we showed that the outer membrane proteins A (OmpA), C (OmpC) and F (OmpF) were the major antigens for both strains, although proteins located on the bacterial cell membrane and enzymes involved in energy metabolism were also identified as antigenic. We compared the whole-cell proteins of the two strains cultured at 25°C and 37°C and found portions of the outer membrane proteins (OmpX, OmpF and OmpA) were downregulated when the bacteria were cultured at 37°C, whereas urease subunit gamma (UreA), urease subunit alpha (UreC) and urease accessory protein (UreE), which are involved in urease synthesis, were upregulated when the bacteria were grown at 37°C. These observations will lay a foundation to selection of diagnostic markers for pathogenic Yersinia enterocolitica, and maybe contribute to choose the vaccine targets.     

Population increase and damage by three species of mites on wheat at 20°C and two humidities

Twenty bisected grains of wheat infested with five pairs of the three commonest British grain-storage mites,Acarus siro L., Glycyphagus destructor (Shrank) andTyrophagus longior (Gervais), were examined every week for 20 weeks. Mite populations, the resulting damage to germ and endosperm, and visible fungal growth were observed at 20°C and relative humidities (r.h.) of 90% and 75%.At 90% r.h.,A. siro populations reached nearly 14000 per test-tube before slowly dropping to 5000. The mites ate the germ before the endosperm, leaving an impenetrable layer of crushed endosperm cells between these regions. TheG. destructor population reached only 800 before declining to 300; these mites ate over 75% of the germ and small amounts of endosperm.Tyrophagus longior populations rose to 2200 mites before crashing at week 12 to the initial population level; these mites ate over 75% of the germ and small amounts of endosperm.At 75% r.h., bothA. siro andT. longior populations were lower than at the higher r.h., peaking at 3000 and 1000 respectively and decreasing to 500 and 600 mites respectively.Glycyphagus destructor did markedly better than at 90% r.h., reaching 1500 before falling to 400. The damage at this humidity was slower to occur but was similar to that at 90% r.h. at the end of 20 weeks.At both humidities visible fungus was always less abundant on infested grain that uninfested grain.     

Degradation of polycyclic aromatic hydrocarbons and long chain alkanes at 6070 °C by Thermus and Bacillus spp

Although polycyclic aromatic hydrocarbons (PAH) and alkanesare biodegradable at ambient temperature, in some cases low bioavailabilities are thereason for slow biodegradation. Considerably higher mass transfer rates and PAH solubilities and hence bioavailabilities can be obtained at higher temperatures. Mixed and pure cultures of aerobic, extreme thermophilic microorganisms (Bacillus spp., Thermus sp.) were used to degrade PAH compounds and PAH/alkane mixtures at 65 °C. The microorganismsused grew on hydrocarbons as sole carbon and energy source. Optimal growthtemperatures were in the range of 60–70 °C at pH values of 6–7. The conversion of PAH with 3–5 rings (acenaphthene, fluoranthene, pyrene, benzo[e]pyrene) was demonstrated. Efficient PAH biodegradation required a second, degradable liquid phase. Thermus brockii Hamburg metabolized up to 40 mg (l h)^-1 pyrene and 1000 mg(1 h)^-1 hexadecane at 70 °C. Specific growth rates of 0.43 h^-1 were measured for this strain with hexadecane/pyrene mixtures as the sole carbon and energy source in a 2-liter stirred bioreactor. About 0.7 g cell dry weight were formed from 1 g hydrocarbon. The experiments demonstrate the feasibility and efficiency of extreme thermophilic PAH and alkane biodegradation.