Drastic Temperature Changes Research Articles

Dynamics of CO2 fluxes and environmental responses in the rain-fed winter wheat ecosystem of the Loess Plateau, China

Chinese Loess Plateau plays an important role in carbon balance of terrestrial ecosystems. Continuous measurement of CO2 fluxes in cropland ecosystem is of great significance to accurately evaluate the carbon sequestration potential and to better explain the carbon cycle process in this region. By using the eddy covariance system we conducted a long-term (from Sep 2009 to Jun 2010) CO2 fluxes measurement in the rain-fed winter wheat field of the Chinese Loess Plateau and elaborated the responses of CO2 fluxes to environmental factors. The results show that the winter wheat ecosystem has distinct seasonal dynamics of CO2 fluxes. The total net ecosystem CO2 exchange (NEE) of −218.9±11.5gCm−2 in the growing season, however, after considering the harvested grain, the agro-ecosystem turned into a weak carbon sink (−36.2gCm−2). On the other hand, the responses of CO2 fluxes to environmental factors depended on different growth stages of winter wheat and different ranges of environmental variables, suggesting that the variations in CO2 exchange were sensitive to the changes in controlling factors. Particularly, we found the pulse response of ecosystem respiration (Reco) to a large rainfall event, and the strong fluctuations of CO2 fluxes usually appeared after effective rainfall events (daily precipitation>5mm) during middle growing season. Such phenomenon also occurred in the case of the drastic changes in air temperature and within 5days after field management (e.g. tillage and plough).

Kampo Extract of Shinbuto Improved Refractory Diarrhea in Milroy's Disease

Milroy's disease is a hereditary congenital lymphedema caused by lymphatic obstruction. The legs are most commonly affected, but impaired intestinal lymphatic flow can cause loose bowel movements. Here, we report the use of the Kampo extract of shinbuto for successful treatment of and abdominal pain in a patient with Milroy's disease. Milroy's disease was diagnosed because of left leg lymph-edema with onset at birth. Conservative therapy with a compression bandage was applied. However, when the patient moved to Manila at 35 years of age, she was exposed to drastic temperature changes between the air-conditioned cold environment in her room and the hot and humid environment outside. She developed a constitutional state of coldness as in hiesho (冷え症). Then sudden lower abdominal pain and diarrhea began to occur 3 times per week and lasted at least 1 hour, sometimes accompanied by vomiting. It happened particularly when she was exposed to the cold environment and was not related to meals. Conventional anti-cholinergic or antidiarrhetic drugs had no therapeutic effect. These attacks continued in the same frequency for 3 years, so the patient visited a Kampo (traditional Japanese medicine) clinic, where her diagnosis of Milroy's disease–associated diarrhea and abdominal pain was augmented by the Kampo diagnosis of hiesho, suitai (body fluid retention). She was prescribed 7.5 g of shinbuto extract per day (TJ-30; Tsumura Co, Tokyo, Japan). The shinbuto extract significantly reduced abdominal pain and refractory diarrhea to about 2 days per month, and it tapered off completely in 3 months. Shinbuto is usually used against cold-induced diarrhea. Rewarming and water movement by shinbuto resulted in significant improvement in symptoms induced by hiesho and suitai triggered by the cold environment, though the patient's leg swelling did not change.

A global model for the uptake of atmospheric hydrogen by soils

A simple process‐based model for the consumption of atmospheric hydrogen (H2) has been developed. The model includes a description of diffusion and biological processes which together control H2flux into the soil. The model was incorporated into the LPJ‐WHyMe Dynamic Global Vegetation Model, and used to simulate H2 fluxes over the 1988–2006 period. The model results have been confronted with field and laboratory measurements. The model reproduces observed seasonal cycles of H2 uptake at different sites and shows a realistic sensitivity to changes in soil temperature and soil water content in comparisons with field and laboratory measurements. A recent study, based on 3D atmospheric model inversion, found an increase of the global H2 sink from soils, with a trend of −0.77 Tg a−2 for the 1992–2004 period (fluxes are negative as soils act as a sink for atmospheric H2). For the same period, however, our process‐based model calculates a trend of only −0.04 Tg a−2. Even when forced with drastic changes in soil water content, soil temperature and snow cover depth, our model is unable to reproduce the trend found in the inversion‐based study, questioning the realism of such a large trend.

Salinity and temperature tolerance of brown-marbled grouper Epinephelus fuscoguttatus

Grouper have to face varied environmental stressors as a result of drastic changes to water conditions during the storm season. We aimed to test the response of brown-marbled grouper to drastic and gradual changes in temperature and salinity to understand the grouper's basic stress response. The results can improve the culture of grouper. Brown-marbled grouper, Epinephelus fuscoguttatus (6.2 ± 0.8 g) were examined for temperature and salinity tolerances at nine different environmental regimes (10, 20, and 33 ‰ combined with 20, 26 and 32 °C), in which the fish were subjected to both gradual and sudden changes in temperature and salinity. The critical thermal maximum (50 % CTMAX) and the upper incipient lethal temperature (UILT) were in the ranges of 35.9-38.3 and 32.7-36.5 °C, respectively. The critical thermal minimum (50 % CTMIN) and the lower incipient lethal temperature (LILT) were in the ranges of 9.8-12.2 and 14.9-22.3 °C, respectively. The critical salinity maximum (50 % CSMAX) and the upper incipient lethal salinity (UILS) were in the ranges of 67.0-75.5 and 54.2-64.8 ‰, respectively. Fish at temperature of 20 °C and a salinity of 33 ‰ tolerated temperatures as low as 10 °C when the temperature was gradually decreased. Fish acclimated at salinities of 10-33 ‰ and a temperature of 32 °C tolerated salinities of as high as 75-79 ‰. All fish survived from accumulating salinity after acute transfer to 20, 10, 5, and 3 ‰. But all fish died while transferred to 0 ‰. Relationships among the UILT, LILT, 50 % CTMAX, 50 % CTMIN, UILS, 50 % CSMAX, salinity, and temperature were examined. The grouper's temperature and salinity tolerance elevated by increasing acclimation temperature and salinity. On the contrary, the grouper's temperature and salinity tolerance degraded by decreasing acclimation temperature and salinity. The tolerance of temperature and salinity on grouper in gradual changes were higher than in drastic changes.

The relationship between temperature and sales

PurposeThe influence of weather on business activities and human behaviour has been explored in several fields (e.g. finance and psychology), but little research about weather and retail sales is found in the retail or fashion literature. The purpose of the study is to analyse the relationship between temperature, one aspect of weather, and retail sales of seasonal garments.Design/methodology/approachThe researchers collected sales data from a retailer of branded women's business wear in the Seoul‐Kyunggi area in South Korea. Along with the sales data for seasonal basic styles, corresponding daily and weekly average temperature data were collected and evaluated. The analysis for the study was drawn using descriptive statistics including graphical evaluations, correlation analysis and paired samples t‐test. Interviews with the retailer's merchandisers were used to supplement interpretation of the statistical data.FindingsResults of this study provide strong evidence that fluctuations in temperature can impact sales of seasonal garments. During sales periods when drastic temperature changes occurred, more seasonal garments were sold. However, the temperature changes from day to day or week to week did not affect the number of garments sold for the whole season. Of the seasonal garments expected to sell within the same season, the selling periods of each product category differed depending on type of fabric and design. For some seasonal garments, the actual sales dates were one week to two weeks in variance from the merchandisers' forecasts.Research limitations/implicationsLimitations in the sample (i.e. product category) and location of stores (i.e. geographic region) prevent the generalization of results to all seasonal garments or retailers. In spite of these limitations, this study can be a pilot study that supports the significant relationship between temperature and sales of seasonal basic products by quantifying the temperature effects on sales of particular products. Therefore, future studies are needed to establish generalized conclusions with a larger sample.Originality/valueAs little academic research is available about weather's effect on sales of garments, the present study contributes to the field of clothing and retail distribution by providing evidence of significant relationships between temperature and sales of seasonal clothing.

Dynamic voids surrounded by shocked conventional polytropic gas envelopes

With proper physical mechanisms of energy and momentum input from around the centre of a self-gravitating polytropic gas sphere, a central spherical "void" or "cavity" or "bubble" of very much less mass contents may emerge and then dynamically expand into a variety of surrounding more massive gas envelopes with or without shocks. We explore self-similar evolution of a self-gravitating polytropic hydrodynamic flow of spherical symmetry with such an expanding "void" embedded around the center. The void boundary supporting a massive envelope represents a pressure-balanced contact discontinuity where drastic changes in mass density and temperature occur. We obtain numerical void solutions that can cross the sonic critical surface either smoothly or by shocks. Using the conventional polytropic equation of state, we construct global void solutions with shocks travelling into various envelopes including static polytropic sphere, outflow, inflow, breeze and contraction types. In the context of supernovae, we discuss the possible scenario of separating a central collapsing compact object from an outgoing gas envelope with a powerful void in dynamic expansion. Initially, a central bubble is carved out by an extremely powerful neutrinosphere. After the escape of neutrinos during the decoupling, the strong electromagnetic radiation field and/or electron-positron pair plasma continue to drive the cavity expansion. In a self-similar dynamic evolution, the pressure across the contact discontinuity decreases with time to a negligible level for a sufficiently long lapse and eventually, the gas envelope continues to expand by inertia. We describe model cases of polytropic index $\gamma=4/3-\epsilon$ with $\epsilon>0$ and discuss pertinent requirements to justify our proposed scenario.

STABILITY OF THE ALMOND BLOOMING DATE IN A CHANGING CLIMATE

Although global warming is increasing the medium air temperature over time, this negative temperature trend cannot be yet appreciated in some areas. Analysis of air temperatures in the Ebro Central Valley (Zaragoza, Spain) during the last 24 years shows drastic changes in temperature during winter and spring and high variability among years. Under these conditions, there is an excess of chill and most almond cultivars satisfy their chilling requirements very early, during the first two weeks of December, when endodormancy finishes. As a consequence, bloom dates are ruled mainly by the heat requirements. Early-blooming almond cultivars showed a higher variation in dates of full bloom because they are more dependent on warm temperatures during January and February, where heat accumulation is slower. Late-blooming cultivars showed more stable blooming dates because their greater heat requirements are quickly satisfied by the higher March temperatures. Cultivars with high cold and heat requirements are desirable for stable late blooming. This characteristic and its relationship with local climatic conditions is essential in choosing cultivars to be planted in a given region, especially to avoid frost risks.

The effect of drastic temperature changes on the performance of MBR treating municipal wastewater

A study has been carried out to define the effect of drastic temperature changes on the performance of lab-scale hollow-fibre MBR in treating municipal wastewater at a flux of 10 L m(-2) h(-1) (LMH). The objectives of the study were to estimate the activated sludge properties, the removal efficiencies of COD and NH(3)-N and the membrane fouling tendency under critical conditions of drastic temperature changes (23, 33, 42 & 33 °C) and MLSS concentration ranged between 6,382 and 8,680 mg/L. The study exhibited that the biomass reduction, the low sludge settleability and the supernatant turbidity were results of temperature increase. The temperature increase led to increase in SMP carbohydrate and protein, and to decrease in EPS carbohydrate and protein. The BRE of COD dropped from 80% at 23 °C to 47% at 42 °C, while the FRE was relatively constant at about 90%. Both removal efficiencies of NH(3)-N trended from about 100% at 33 °C to less than 50% at 42 °C. TMP and BWP ascended critically with temperature increase up to 336 and 304 mbar respectively by the end of the experiment. The values of suspended solids (SS) and the turbidity in the final effluent were negligible. The DO in the mixed liquor was varying with temperature change, while the pH was within the range of 6.7-8.3.

Spatial heterogeneity in the effects of climate change on the population dynamics of a Mediterranean tortoise

AbstractClimatic shifts may increase the extinction risk of populations, especially when they are already suffering from other anthropogenic impacts. Our ability to predict the consequences of climate change on endangered species is limited by our scarce knowledge of the effects of climate variability on the population dynamics of most organisms and by the uncertainty of climate projections, which depend strongly on the region of the earth being considered. In this study, we analysed a long‐term monitoring programme (1988–2009) of Hermann's tortoise (Testudo hermanni) aimed at evaluating the consequences of the drastic changes in temperature and precipitation patterns predicted for the Mediterranean region on the demography of a long‐lived species with low dispersal capability and already suffering a large number of threats. Capture–recapture modelling of a population in the Ebro Delta (NE Spain) allowed us to assess the effect of climate variability on the survival of tortoises. Winter rainfall was found to be the major driver of juvenile and immature survival, whereas that of adults remained high and constant across the study. Furthermore, local climate series obtained ad hoc from regional climate simulations, for this and 10 additional Mediterranean locations where tortoises occurred, provided us with reliable future climate forecasts, which were used to simulate the fate of these populations under three precipitation scenarios (mean, wet and dry) using stochastic population modelling. We show that a shift to a more arid climate would have negative consequences for population persistence, enhancing juvenile mortality and increasing quasiextinction risk because of a decrease in recruitment. These processes varied depending on the population and the climate scenario we considered, but our results suggest that unless other human‐induced causes of mortality are suppressed (e.g. poaching, fire, habitat fragmentation), climate variability will increase extinction risk within most of the species’ current range.

Genome Sequence of Sphingomonas sp. S17, Isolated from an Alkaline, Hyperarsenic, and Hypersaline Volcano-Associated Lake at High Altitude in the Argentinean Puna

The high-altitude Andean lakes (HAAL) in the Argentinean Puna-high Andes region represent an almost unexplored ecosystem exposed to extreme conditions (high UV irradiation, hypersalinity, drastic temperature changes, desiccation, and high pH). Here we present the first genome sequence, a Sphingomonas sp., isolated from this extreme environment.

G060072 2成分系水溶液を用いた垂直円筒周りの凝固プロセスに関する研究([G06007]熱工学部門一般セッション(7):蓄熱,および空調)

An experimental study of solidification is performed for a hypoeutectic sodium nitrate solution in a confined rectangular vessel with varying initial concentration. The experiments have been conducted by heating the lower wall of the vessel and cooling the vertical cylinder. We investigate the development of its temperature and concentration distribution in the liquid region during the solidification and its effect on the solid layer thickness formed around the cylinder. The growth of the solid layer, which accompanies solute ejection to liquid region, leads to double-diffusive convection and form a sharp density interface. Across the interface a drastic change of temperature and concentration is observed. Therefore, the solid layer thickness undergoes a dramatic change when the interface passes.

A Study of Temperature Distribution Across a Solid Oxide Fuel Cell Stack

In this work, a three-dimensional model of a solid oxide fuel cell (SOFC) stack is developed to predict the temperature distribution across the stack. The model simulates a particular SOFC stack comprising of five single cells. Isothermal and adiabatic walls are chosen as the different boundary conditions in order to simulate the real situation, which lies somewhere in between. In the situation where adiabatic walls are assumed, the result shows that heat convection dominates the heat transfer process. However, heat conduction plays a major role when the isothermal walls are assumed. It is found that the highest temperature found in the isothermal stack is 1135 K at an operating temperature of 1073 K. The temperature difference is significant with the hottest point located in the middle of the active area. In the adiabatic stack, the temperature is at its maximum of 1574 K near the outlets of fuel and air at the same operating temperature. It should be kept in mind that both situations will have effects on the temperature behavior of the stack in reality. The temperature and current distributions of stack models in this work are also plotted in three dimensions and the analyses of stack performances are given. By comparing the results of five-cell and ten-cell stack models, the temperature differences of the five-cell stack and the ten-cell stack are 62 and 109 K, respectively. This indicates that there is a drastic temperature change throughout the stack when the stack size is increased.

Variations on Sun’s role in climate change

I was rather disturbed to read the opinion article by Nicola Scafetta and Bruce West, which discussed the global surface temperature anomaly in relation to solar variability. Some important issues regarding their work should prompt readers to question their motivation and whether their conclusions come from an unbiased perspective. I offer those key concerns.The authors use global temperature data that extend back only to 1890 and cover a short period of time, rather than data from other techniques, such as icecore sampling, that cover a longer time span.The authors claim that the increase in temperature, and the consequent change in climates, since 1900 is largely due to solar variability. Climates are often defined as average temperatures over 30 years—also a short time scale. However, if we are observing large temperature changes on time scales shorter than 30 years, it is certainly believable that those changes are due to human activity.More fundamental, though, from a physical viewpoint is that if solar variability were to influence temperatures as much as Scafetta and West claim, that variability should exist over Earth’s entire life span. It should be present in all possible temperature data from prerecorded times. If the Sun were truly having more variability in its output now than it ever has in its past, climate change is not our greatest worry.More disturbing on a personal, moral level is that the authors are putting forth an argument that attempts to distance us from our responsibility for climate change. Ultimately, that gives readers—including politicians and the general public—justification to continue down the path we started with industrialization around 1900. Many people find that perspective very comforting because it means we don’t have to change our ways of doing things.The political perspective of Scafetta and West’s opinion is disturbing because the current administration has repeatedly promoted policies that deny human-induced climate change. And the primary funding for the research in this Opinion piece came from the US Army Research Office. Furthermore, the majority of the references Scafetta and West cite are written by one or the other or both of them and have all been published during the current administration.The authors are entitled to their opinion. Many other scientists, though, and the Intergovernmental Panel on Climate Change hold another opinion: that solar variability has had a negligible effect on climate. Surely, if solar variability were causing such drastic temperature changes, the IPCC would have incorporated it into its models and findings. Instead of trying to blame climate change on solar variability or other galactic events, we should rethink how we live our lives and whether our lifestyles are fundamentally compatible with the needs of other species on Earth. This is the only home we have; we can’t use it up and throw it away in the same manner that we leave our trash at the curbside.© 2008 American Institute of Physics.

Whole genome amplification from polar bodies and single blastomeres is efficient for pre-implantation genetic diagnosis

OBJECTIVE: Pre-implantational genetic diagnosis (PGD) from polar bodies or blastomeres has to be performed on single cells after whole genome amplification without allele drop out (ADO). Recently, an isothermal DNA amplification method, termed multiple displacement amplification (MDA) has been applied to single cells, leading to the synthesis of DNA with limited sequence representation bias. Thus, we aimed to determine the efficacy of MDA in amplifying the whole genomic DNA from polar bodies and single blastomeres intended for subsequent sequence tandem repeat amplification by polymerase chain reaction (STR-PCR) as performed for single gene disorders testing.DESIGN: Prospective laboratory study.MATERIALS AND METHODS: After biopsy, polar bodies (n=8) and blastomeres (n=8) were individually transferred to tubes containing 2μL of ultra-pure water and submitted to drastic temperature changes by immersion in N2L for cell rupture. This material was subjected to the MDA protocol by addition of non-specific primers and DNA polymerase phi29 following the manufacturers' instruction (REPLI-g Mini Kit, Qiagen Inc., USA). After the isothermal amplification, DNA was quantified by spectrophotometry and an aliquot of 0.5 ng/μL was transferred to another tube containing the PCR master mix for amplification of 15 sequence tandem repeats (STR) (loci: Penta E, D18S51, D21S11, TH01, D3S1358, FGA, TPOX, D8S1179, vWA, Amelogenin, Penta D, CSF1PO, D16S539, D7S820, D13S317 and D5S818) and amelogenin for 32 thermal cycles. STR peaks were detected in an automatic DNA sequencer. Allele drop out was estimated by another two subsequent MDAs, each one followed by a new STR analysis for comparison to result obtained from the first MDA/STR-PCR.RESULTS: DNA concentrations after the first MDA of whole genome of second polar bodies and blastomeres were 1.7±0.27 μg of DNA/ μL (mean ± standard error) and 3.8±0.42 μg of DNA/ μL. Analysis of PCR amplifications of STR resulted in 14.25±0.12 peaks after the first MDA. The second MDA/STR-PCR produced 12.37±0.18 peaks and the third MDA/STR-PCR produced 10.5±0.15 peaks. The mean allele drop out was 14.15%.CONCLUSIONS: Multiple displacement amplification is an efficient technique for amplification of the whole genome of second polar bodies and single blastomeres and the resulting amplicons can be subjected to multiple downstream applications such as, DNA sequencing, short tandem repeat analysis, and mutation analysis. OBJECTIVE: Pre-implantational genetic diagnosis (PGD) from polar bodies or blastomeres has to be performed on single cells after whole genome amplification without allele drop out (ADO). Recently, an isothermal DNA amplification method, termed multiple displacement amplification (MDA) has been applied to single cells, leading to the synthesis of DNA with limited sequence representation bias. Thus, we aimed to determine the efficacy of MDA in amplifying the whole genomic DNA from polar bodies and single blastomeres intended for subsequent sequence tandem repeat amplification by polymerase chain reaction (STR-PCR) as performed for single gene disorders testing. DESIGN: Prospective laboratory study. MATERIALS AND METHODS: After biopsy, polar bodies (n=8) and blastomeres (n=8) were individually transferred to tubes containing 2μL of ultra-pure water and submitted to drastic temperature changes by immersion in N2L for cell rupture. This material was subjected to the MDA protocol by addition of non-specific primers and DNA polymerase phi29 following the manufacturers' instruction (REPLI-g Mini Kit, Qiagen Inc., USA). After the isothermal amplification, DNA was quantified by spectrophotometry and an aliquot of 0.5 ng/μL was transferred to another tube containing the PCR master mix for amplification of 15 sequence tandem repeats (STR) (loci: Penta E, D18S51, D21S11, TH01, D3S1358, FGA, TPOX, D8S1179, vWA, Amelogenin, Penta D, CSF1PO, D16S539, D7S820, D13S317 and D5S818) and amelogenin for 32 thermal cycles. STR peaks were detected in an automatic DNA sequencer. Allele drop out was estimated by another two subsequent MDAs, each one followed by a new STR analysis for comparison to result obtained from the first MDA/STR-PCR. RESULTS: DNA concentrations after the first MDA of whole genome of second polar bodies and blastomeres were 1.7±0.27 μg of DNA/ μL (mean ± standard error) and 3.8±0.42 μg of DNA/ μL. Analysis of PCR amplifications of STR resulted in 14.25±0.12 peaks after the first MDA. The second MDA/STR-PCR produced 12.37±0.18 peaks and the third MDA/STR-PCR produced 10.5±0.15 peaks. The mean allele drop out was 14.15%. CONCLUSIONS: Multiple displacement amplification is an efficient technique for amplification of the whole genome of second polar bodies and single blastomeres and the resulting amplicons can be subjected to multiple downstream applications such as, DNA sequencing, short tandem repeat analysis, and mutation analysis.

Seasonal Occurrences of Epiphytic Algae on the Commercially Cultivated Red Alga Kappaphycus Alvarezii (Solieriaceae, Gigartinales, Rhodophyta)

Common problems faced in farming of the red algal genus Kappaphycus/Eucheuma are “ice-ice disease” and the occurrence of epiphytes. Considerable work has been documented on “ice-ice disease” and it's mode of infection but limited information is available on the emergence of epiphytes. The present study addresses the phenomenon of epiphyte infection, its prevalence in commercially cultivated red alga, Kappaphycus alvarezii, and their variability associated with seasonality. Cultured seaweed became susceptible to epiphytes in the dry seasons (1) between March – June and (2) September – November. Findings revealed Neosiphonia savatieri (Hariot) M. S. Kim et I. K. Lee, as the dominant infecting epiphyte, representing up to 80–85% of the epiphyte present during peak seasons. Besides N. savatieri, Neosiphonia apiculata, Ceramium sp., Acanthophora sp. and Centroceras sp. were observed in smaller quantities. SEM (Scanning Electron Microscope) micrographs revealed the epiphyte's attachment to the host. Further histological study showed the extent of penetration of epiphytes into the host's cortex tissues and condition of its surrounding tissues. The outbreak of epiphytic filamentous red algae also correlated with drastic changes in seawater temperature and salinity during March– June and September – November.

Mechanical alloying and electronic simulations of 2Mg–Fe mixture powders for hydrogen storage

2Mg–Fe powder mixture was milled in hydrogen atmosphere to prepare materials for hydrogen storage. The microstructure and dehydrogenating property of the milled system were examined. Then energy and electronic structure of the hydride phase were investigated by using a first-principles plane-wave pseudopotential method to explain the experimental results from XRD, DSC and TGA analysis. By calculating the heats of formation of MgH 2, (MgFe)H 2 solid solutions and Mg 2FeH 6 compound, the forming process of Mg 2FeH 6 was assumed as that magnesium was first dissolved in some H atoms to form MgH 2, second, iron atom progressively dissolved into MgH 2 lattice to form (MgFe)H 2 solid solutions, finally the (MgFe)H 2 solid solution can be changed into Mg 2FeH 6 phase. For DSC curves as a function of temperature for all the powders milled for different time, a drastic change of dissociation temperature is never found, this kind of relatively sluggish change can be explained using the idea on forming process of Mg 2FeH 6. Since MgH 2 phase is still the major phase in the coexistence mixtures of two types of hydrides β-MgH 2 and Mg 2FeH 6, Mg 2FeH 6 reduces the negative formation heat of the mixture compared with that of MgH 2, which indicates that Mg 2FeH 6 lowers the desorption temperature of MgH 2 through a catalytic effect and the milled powder containing duplex β-MgH 2 + Mg 2FeH 6 exhibits the most rapid desorption rate among all the powders studied from TGA analysis.

Specialised Vascular Structures in the Pododerma of the Camel Footpad (Camelus dromedarius)

Aims: The even‐hoofed, unguligrade tylopods display a well‐developed eponymous footpad that absorbs most of the body weight in locomotion and is particularly adapted to the sandy ground surface of the natural environment of dromedaries. Considering the drastic changes in temperature occurring in the desert sand, specialised thermoregulatory vascular and nervous structures are to be expected in the modified pododerma of this footpad. Therefore, the aim of the study was to demonstrate the angioarchitecture of the camelid footpad and to detect specialised vascular structures related to these specific functions.Material and Methods: Corrosion casting of fore and hind feet of dromedaries (Camelus dromedarius); scanning electron microscopy of micro‐corrosion castsResults and Discussion: The dense angioarchitecture of the dromedary footpad, like that of unmodified skin, can be subdivided into separate plexus arranged at different levels: a subcutaneous plexus, a profound dermal plexus, a superficial dermal plexus and a subepidermal plexus.The subepidermal blood vessels run very close to the dermo‐epidermal borderline and thus the subepidermal angioarchitecture consists of densely vascularised conical papillae comprised of centrally situated papillary arteriole and venule ensheathed in a dense subepidermal capillary network. At the tip of the papillae, the central papillary arteriole and venule form a peripheral capillary loop, acting as a thoroughfare channel. This dermal angioarchitecture of the dromedary footpad is comparable to the papillary system described in the bulbs of the highly specialised digital end organs of many other odd‐ and even‐hoofed mammals, particularly the equine hoof and the bovine claw.Within the subcutaneous and the deep dermal plexus of the dromedary foot pad, unique glomus‐like vascular structures were detectable, presumably associated with cutaneous thermoregulation as described for the unmodified hairy skin.

SIMULATION AND EXPERIMENT OF EXTINCTION OR ADAPTATION OF BIOLOGICAL SPECIES AFTER TEMPERATURE CHANGES

Can unicellular organisms survive a drastic temperature change, and adapt to it after many generations? In simulations of the Penna model of biological aging, both extinction and adaptation were found for asexual and sexual reproduction as well as for parasex. These model investigations are the basis for the design of evolution experiments with heterotrophic flagellates.

Microcolonial fungi: survival potential of terrestrial vegetative structures.

So far mainly spores or other "differentiated-for-survival" structures were considered to be resistant against extreme environmental constraints (including extraterrestrial challenges). Microcolonial fungi (MCF) are unique growth structures formed by eukaryotic microorganisms inhabiting rock varnish surfaces in terrestrial deserts. They are here proposed as a new object for exobiological study. Sun-exposed desert rocks provide surface habitats with intense solar radiation, a scarce water supply, drastic changes in temperature, and episodic to sporadic availability of nutrients. These challenging conditions reduce the diversity of life to MCF, whose resistance to desiccation and tolerance for ultraviolet (UV) radiation make them survival specialists. Based upon our studies of MCF, we propose that the following mechanisms are universally employed for survival on rock surfaces: (1) compact tissue-like colony organization formed by thermodynamically optimal round cells embedded in extracellular polymeric substances, (2) the presence of several types of UV-absorbing compounds (melanins and mycosporines) and antioxidants (carotenoids, melanins, and mycosporines) that convey multiple stress resistance to desiccation, temperature, and irradiation changes, and (3) intracellular developmental mechanisms typical for these structures.

Fluid inclusions record thermal and fluid evolution in reservoir sandstones, Khatatba Formation, Western Desert, Egypt: A case for fluid injection

A fluid inclusion and petrographic study, focused on quartz overgrowths, was performed in reservoir sandstones from the Jurassic Khatatba Formation (Salam oil field, Egypt's Western Desert). The combination of detailed fluid inclusion petrography and scanning electron microscope (SEM) cathodoluminescence imaging has allowed us to relate individual fluid inclusion assemblages, that is, the most finely discriminated groups of petrographically associated fluid inclusions, to specific growth zones of authigenic quartz, establishing the relative timing of entrapment of the inclusions. After entrapment, fluid inclusions in authigenic quartz have been preserved without reequilibration, as indicated by the narrow ranges of homogenization temperatures (<4-5 degreesC) in most fluid inclusion assemblages. Three main growth zones are distinguished under SEM cathodoluminescence in the quartz overgrowths and are termed Q1, Q2, and Q3 from the oldest to the youngest. Zone Q1 is further subdivided into three subzones and contains abundant primary aqueous inclusions. Their homogenization temperatures range from 162 to 130 degreesC, with the earliest assemblages having the highest temperatures and with some large temperature fluctuations indicated between successive assemblages. Most Q1 inclusions have salinities in the freshwater to seawater range, with a trend toward increasing salinity through time. Zone Q2 contains primary aqueous inclusions with homogenization temperatures (overall range 148-125 degreesC) also recording large temperature fluctuations and cooling events. The Q2 fluid inclusions have high salinities (~5-20 wt. % NaCl equivalent), with salinity increasing through time. Zone Q3 contains both aqueous and oil inclusions of primary origin. The Q3 aqueous inclusions have homogenization temperatures (overall range 134-112 degreesC) recording overall cooling and high salinities (21-24 wt. % NaCl equivalent). In early Q3 subzones, oil inclusions appear to be of medium gravity, undersaturated with respect to gas. In later Q3 subzones, oil inclusions are of gas-saturated lighter oil. Our results indicate that fluid flow, involving drastic changes in temperature and salinity, was responsible for the precipitation of some of the quartz cement. The earliest quartz (Q1) precipitated from freshwater and seawater at temperatures significantly higher than those expected from the burial history and thermal maturity of these rocks. This quartz is interpreted to have precipitated during cooling of injected fluids that originated as hot connate fluids from deeper parts of the basin. The Q2 precipitation is interpreted to have resulted from episodes of injection of hot saline brines from below. Late quartz cement (Q3) precipitated during oil charge, from progressively cooler and more saline brines interpreted to have refluxed from the surface; it preserves a record of increasing oil maturity and gas saturation through time.