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.     

Respiration,ATP level,and sugar accumulation in potato tubers during storage at 4°

A kinetic study was made of the relationship between respiration rate, sugar content and ATP levels, in fresh and aged potato tubers stored at 4°. The ATP content in tubers rose rapidly immediately after the chilling stress, while respiration rate decreased below the initial rate and sugar accumulation was not detected. After 4 days of storage, the ATP level declined and the sugars started to accumulate. The typical increase in respiration rate that usually follows chilling stress, appeared only in fresh tubers (at about the 6th day of storage). In dinitrophenol-treated tubers, the ATP level remained below the initial level and sugar accumulation was blocked completely. The evidence presented suggests that ATP elevation is not generated by the respiration burst.     

Spatial-temporal variability of ultraplankton vertical distribution in the Antarctic frontal zones within 60–66°E, 43–46°S

The vertical distribution of heterotrophic bacteria and four ultraphytoplanktonic (<10 µm) groups (Prochlorococcus, Synechococcus, pico- and nanoeukaryotes) was investigated by flow cytometry at three process stations located in three different sub-systems belonging to the Antarctic Circumpolar Current frontal zone and to the Southern Indian Ocean (60–66°E, 43–46°S; ANTARES 4 cruise, January-February 1999): the Subtropical Zone (STZ), the Convergence Zone and the Polar Frontal Zone (PFZ). In each sub-system, short-term variability of cell abundance and flow cytometric parameters (right-angle light scatter and chlorophyll autofluorescence) was assessed through a times series of up to 24 h with a 2 h sampling frequency. The ultraphytoplankton vertical distribution exhibited a high spatial variability, with dominance of Prochlorococcus in the STZ (mean: 762.85×10¹⁰ cells m^–2), whereas picoeukaryotes (<3 µm) were dominant in the PFZ (55.46×10¹⁰ cells m^–2), a typically high-nutrient low-chlorophyll zone. Heterotrophic bacteria abundance was maximum (9.84×10¹³ cells m^–2) in the frontal zone, between the Agulhas Front and the Subtropical Front. Nanoeukaryotes showed the largest (up to 80%) variations between two consecutive sampling periods (2 h). Abundance variations could not be assigned to the same water mass during the time series due to the highly variable hydrodynamics of the study area. Trends of short-term abundance variations were opposite between the PFZ (lowest at night) and north of the Subtropical Front (highest at night). The observed spatial and short-term variations illustrate the complexity of the water masses in the Indian sector of the Southern Ocean, and highlight the challenge of extrapolating discrete measurements over space and time for use in evaluating carbon budgets in such dynamic areas.     

Effects of Cadmium, Lead, Mercury and Zinc on °-Aminolevulinic Acid Dehydratase Activity from Radish Leaves

The purpose of the present study was to investigate the in vitro and the in vivo effects of cadmium, zinc, mercury and lead on -aminolevulinic acid dehydratase (ALA-D) activity from radish leaves. The in vivo effect of these metals on growth, DNA and protein content was also evaluated. The results demonstrated that among the elements studied Cd²⁺ presented the highest toxicity for radish. 50% inhibition of ALA-D activity (IC₅₀) in vitro was at 0.39, 2.39, 2.29, and 1.38 mM Cd²⁺, Zn²⁺, Hg²⁺ and Pb²⁺, respectively. After in vivo exposure Cd²⁺, Zn²⁺, Hg²⁺ and Pb²⁺ inhibited ALA-D by about 40, 26, 34 and 15%, respectively. Growth was inhibited by about 40, 10, 25, and 5% by Cd²⁺, Zn²⁺, Hg²⁺, and Pb²⁺, respectively. DNA content was reduced about 35, 30, 20, and 10% for Cd²⁺, Zn²⁺, Hg²⁺, and Pb²⁺, respectively. The metal concentration in radish leaves exposed to Cd²⁺, Zn²⁺, Hg²⁺, and Pb²⁺ was 18, 13, 6, and 7 mol g^–1, respectively. The marked ability of radish to accumulate Cd²⁺ and Zn²⁺ raises the possibility of using this vegetable as a biomonitor of environmental contamination by these metals.     

Rooster spermatozoan motility,forward progression,and fertility after storage at 25, 5, or −196 °C in various extenders

Rooster spermatozoa were stored at 25, 5, or ?196 °C in either TC199, a pyruvate-lactate mouse ova culture medium, or as undiluted semen. There was a linear decrease in percent of motile sperm during storage at 25 or 5 °C in all cases, and a curvilinear decrease with increasing storage times at ?196 °C. Percent of motile sperm present after increasing storage time suggested pyruvate-lactate is a better extender than TC199 at the three storage temperatures studied. Pullets inseminated with 1 × 10⁸ motile sperm using fresh sperm diluted in TC199 or pyruvate-lactate, or stored 24 hr at 5 or ?196 °C produced 68.7, 74.1, 20.6, and 10.8% fertile eggs, respectively. The differences in fertility between controls or between samples stored at 5 and ?196 °C were not significant. However, fertility from sperm stored at 5 and ?196 °C was significantly lower (p < .05) than both control groups. Thus, it can be concluded that TC199 or pyruvate-lactate may be used to dilute fresh rooster semen collections prior to insemination. In contrast, fertility of rooster sperm is not satisfactorily maintained after 5 or ?196 °C storage for 24 hr in a pyruvate-lactate extender.     

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.     

Acetate and hydrogen metabolism in intact and disintegrated granules from an acetate-fed, 55° C,UASB reactor

Summary To investigate mass-transfer resistance in granules, the effect of disintegration on the specific methanogenic activity (SMA) of acetate-grown anaerobic, thermophilic (55°C) granules was measured. Four different methods of disintegration were used; vortex mixing, ultra-sound, blending and repeated syrine aspiration. When H₂/CO₂ was used as the substrate, disintegrated granules showed a higher SMA than intact granules. However, with acetate as substrate, no effect was observed when granules disintegrated using a vortex mixer or ultra-sound, whereas both the blender- and syringe-treated granules had lower SMAs compared to intact granules. An effectiveness factor, , the ratio of the SMA of disintegrated granules to the SMA of intact granules, was presented and found useful for describing the effectiveness of disintegration to relieve mass-transfer limitation on the granules. Offprint requests to: B. K. Ahring     

Partial molar volumes,expansibilities, and compressibilities of oligoglycines in aqueous solutions at 18–55°C

We have determined the partial molar volumes, expansibilities, and adiabatic compressibilities of glycine, diglycine, triglycine, tetraglycine, and pentaglycine over the temperature range 18–55°C. These data were analyzed and interpreted in terms of the hydration of these short oligoglycines and their constituent groups. From our results, we have estimated the contributions of the peptide group to the partial molar volume and the partial molar adiabatic compressibility of these oligoglycines. Based on these data, we propose that each of the polar atomic groups of the peptide bond forms approximately two hydrogen bonds with adjacent water molecules. Furthermore, the temperature dependence of the partial molar volume suggests that water that solvates the polar groups of a peptide linkage behaves more like a “normal” liquid than does bulk water, which exhibits its well-known anomalous liquid properties. © 1994 John Wiley & Sons, Inc.     

Benthic foraminiferal distributions in Chilean fjords: 47°S to 54°S

Surface sediment samples collected from the fjord region of southern Chile (47° to 54° South) were analyzed for benthic foraminifera. A total of 175 species were identified including agglutinated and calcareous benthic taxa. Hierarchical cluster analysis of the foraminiferal data resulted in the recognition of three distinct biofacies: inner-fjord, intermediate fjord and channel, and oceanic biofacies, geographically controlled by relative position between the Pacific Ocean and fjord heads. Similarity percentage (SIMPER) analysis identified key taxa in the definition of the biofacies that include Globocassidulina rossensis, Cassidulina laevigata and Bulimina notovata. Principal components analysis resulted in two principal components representing sediment size, and bottom water temperature and salinity.Regional distributions are strongly controlled by the oceanographic conditions influenced from the Pacific in the west and the glacial/freshwater input from the east. Localized distributions of foraminifera are controlled by conditions influenced by the physiography of the individual fjords and channels. The distribution of Chilean fjord foraminifera and their environmental associations are consistent with results from other temperate to high latitude fjord foraminiferal studies.     

Thermal properties of enzymes from Bacillus flavothermus,grown between 34 and 70°C

The activity and stability of several enzymes from the facultative thermophile Bacillus flavothermus, grown within the mesophilic and thermophilic region at 34 degrees C, 43 degrees C, 52 degrees C and 70 degrees C, have been examined. While the temperature optima and maxima of all enzymes tested were found to remain unchanged at all growth temperatures, it was demonstrated that the heat stability of the proteins increased with ten perature, however, not uniformly for all enzymes. One exception was acetate kinase and the intrinsic stability of pyruvate kinase was found to increase only slightly. With all other proteins tested (alanine dehydrogenase, isocitric dehydrogenase and glucose-6-phosphate dehydrogenase, glutamate-oxalacetate and glutamate-pyruvate transaminase and myokinase) the intrinsic stability was found to increase to about 55 degrees C, but stayed unaltered at higher growth temperatures. Except for acetate kinase and myokinase, the enzymes could be stabilized by their respective substrates and the heat stability of the ES-complexes was found also to depend on the growth temperature of the cells. These data lead to the conclusion that the enzymes undergo a transition from heat-labile to thermostable within the growth temperature range between 44 degrees C and 51 degrees C while the thermal characteristics are not changed below and beyond this crucial region.     

Does feeding regime affect physiologic and thermal responses during exposure to 8, 20, and 27° C?

When the loss of body heat is accelerated by exposure to low environmental temperatures, additional substrates must be oxidized to provide energy to sustain temperature homeostasis. Therefore, the present investigation examined the relation between feeding regime [pre-experimental carbohydrate feeding (FED) vs a fast (FAST)], during 120 min of exposure to 8, 20, and 27° C in well-nourished men. The following were examined: tissue insulation (I; °C · m² · W^–1), rectal temperature (T _re; °C), and oxygen consumption ( O₂; ml · kg^–1 · min^–1). O₂, T _re, and I revealed no significant differences between treatments (FED vs FAST) at any temperature. At 27° C, I was less (P < 0.05) than at 20 and 8° C, and decreased (P < 0.05) as exposure time increased. At 8° C, O₂was higher (P < 0.5) than at 20 or 27°C, and O₂increased as time increased (P < 0.05). T _re decreased (P < 0.05) as time increased for all conditions. Respiratory exchange ratio (R) differed (P < 0.05) between treatments (FED vs FAST), temperature (8 vs 20° C), and across time. Values for R suggests that carbohydrate accounted for 56% and 33% of caloric utilization during the FED vs FAST conditions, respectively. At 8 vs 20° C, R represented 54% vs 30% of cabohydrate utilization. Across time, R demonstrated that in both conditions (FED vs FAST) there was a decreased reliance on carbohydrate utilization for energy provision. From these data it appears that while substrate utilization differed between dietary treatment and across time this did not differentially affect O₂or T _re during protracted exposure to 8, 20, and 27° C. The higher R in the 8° C condition for both dietary treatments demonstrates that carbohydrate utilization is increased in shivering cold-exposed humans. However, the reduction in R across time suggests that fat oxidation is also involved in metabolic heat production and core temperature maintenance during shivering in the cold.     

α°- and β°- Thalassemia in a Thai family: unusually mild homozygous β°-thalassemia without α-globin gene deletion

Summary Alpha-globin genes were analyzed by the direct method of DNA mapping using - and -globin specific probes in a Thai family in which the proposita was an unusually mild °-thalessemia homozygote. °-Thalessemia was found to be segregating in the family, inherited from the proposita's father by one of her younger sisters. However, °-thatlessemia was not detected by this DNA mapping in the proposita. The mild homozygous °-thalessemia in this family may result from interactions of a non-deletion -thalassemia, a gene responsible for high proteolytic activity permitting more balanced globin-chain levels, or from an unusually active hemoglobin F production in the proposita.     

Survival of mouse oocytes after being cooled in a vitrification solution to -196°C at 95° to 70,000°C/min and warmed at 610° to 118,000°C/min: A new paradigm for cryopreservation by vitrification

There is great interest in achieving reproducibly high survivals of mammalian oocytes (especially human) after cryopreservation, but the results to date have not matched the interest. A prime cause of cell death is the formation of more than trace amounts of intracellular ice, and one strategy to avoid it is vitrification. In vitrification procedures, cells are loaded with high concentrations of glass-inducing solutes and cooled to −196 °C at rates high enough to presumably induce the glassy state. In the last decade, several devices have been developed to achieve very high cooling rates. Nearly all in the field have assumed that the cooling rate is the critical factor. The purpose of our study was to test that assumption by examining the consequences of cooling mouse oocytes in a vitrification solution at four rates ranging from 95 to 69,250 °C/min to −196 °C and for each cooling rate, subjecting them to five warming rates back above 0 °C at rates ranging from 610 to 118,000 °C/min. In samples warmed at the highest rate (118,000 °C/min), survivals were 70% to 85% regardless of the prior cooling rate. In samples warmed at the lowest rate (610 °C/min), survivals were low regardless of the prior cooling rate, but decreased from 25% to 0% as the cooling rate was increased from 95 to 69,000 °C/min. Intermediate cooling and warming rates gave intermediate survivals. The especially high sensitivity of survival to warming rate suggests that either the crystallization of intracellular glass during warming or the growth by recrystallization of small intracellular ice crystals formed during cooling are responsible for the lethality of slow warming.     

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.     

The vegetation history of a coastal stone-age and iron-age settlement at 70°N,Norway

The Holocene vegetation history of the islet of Melkøya at Hammerfest, Norway (70°42N, 23°36E) is documented by several pollen profiles sampled close to excavated stone-age and iron-age settlements. Local paludification began c. 9700 cal B.P. and oligotrophication from c. 7300 cal B.P. onwards. A Betula pubescens—B.nana heath/woodland persisted until c. 8500 cal B.P., when a mixed Betula pubescens—Pinus sylvestris forest developed. Development towards an open heath is recorded from c. 4700 cal B.P. and culminates around 2700 cal B.P. A weak, possibly anthropogenic, impact is recognisable from c. 9200 cal. BP, but a marked local impact by man begins with the climate improvement and local forest development around 8500 cal B.P. The anthropogenic impact on the vegetation was the cutting of local woodland with an increase in grasses and herbs, the latter partly originating from the nitrophilous seashore vegetation. Forest clearance is recognisable at c. 6200 cal B.P., following a short period of re-growth after a burning event. Several anthropogenically related charred layers were formed in the peat before a longer period of abandonment from c. 3100 cal B.P. to c. 2000 cal B.P.     

Human thermoregulatory responses during prolonged walking in water at 25, 30 and 35°C

Eight healthy and physically well-trained male students exercised on a treadmill for 60 min while being immersed in water to the middle of the chest in a laboratory flowmill. The water velocity was adjusted so that the intensity of exercise correspond to 50% maximal oxygen uptake of each subject, and experiments were performed once at each of three water temperatures: 25, 30, 35°C, following a 30-min control period in air at 25°C, and on a treadmill in air at an ambient temperature of 25°C. Thermal states during rest and exercise were determined by measuring rectal and skin temperatures at various points, and mean skin temperatures were calculated. The intensity of exercise was monitored by measuring oxygen consumption, and heart rate was monitored as an indicator for cardiovascular function. At each water temperature, identical oxygen consumption levels were attained during exercise, indicating that no extra heat was produced by shivering at the lowest water temperature. The slight rise in rectal temperature during exercise was not influenced by the water temperature. The temperatures of skin exposed to air rose slightly during exercise at 25°C and 30°C water temperature and markedly at 35°C. The loss of body mass increased with water temperature indicating that both skin blood flow and sweating during exercise increased with the rise in water temperature. The rise in body temperature provided the thermoregulatory drive for the loss of the heat generated during exercise. Heart rate increased most during exercise in water at 35°C, most likely due to enhanced requirements for skin blood flow. Although such requirements were certainly smallest at 25°C water temperature, heart rate at this temperature was slightly higher than at 30°C suggesting reflex activation of sympathetic control by cold signals from the skin. There was a significantly greater increase in mean skin and rectal temperatures in subjects exercising on the treadmill in air, compared to those exercising in water at 25°C. Accepted: 22 May 1998     

Ichthyoplankton distribution off the Peninsula de Mejillones, Chile (23° S, 71° W), under variable hydrographic conditions during the austral summer and winter of the 1997 El Niño

This paper identifies the larval fish community distribution, emphasizing non-commercial species, in the coastal zone and the adjacent oceanic area off the Peninsula de Mejillones (23°S, 71°W) during the 1997 El Niño. We performed one survey in the austral summer (January) and one in the austral winter (July). In January, cold, upwelled water dominated the area off the Peninsula de Mejillones with a cold-water filament extending 60 nm offshore. In July, warm Subtropical Surface Waters affected the area. We identified a total of 56 taxa, which included taxa from different adult habitats (coastal, epipelagic, epi-mesopelagic and mesopelagic). The most abundant species were Engraulis ringens (18% and 21%), Bathylagus sp. (4% and 5%), Diogenichthys laternatus(12% and 39%), Lampanyctus parvicauda (9% and 2%), Triphoturus mexicanus (14% and 3%) and Vinciguerria spp. (21% and 23%), in January and July, respectively. A multidimensional scaling (MDS) ordination and similitude dendograms revealed changes in the larval fish community structure influenced by hydrographic conditions. The rank correlations between the assemblage similarity matrix and the physical variables matrix indicate the importance of the distance from shore and production processes (represented by chlorophyll-a) on the assemblage distributions. Off the Mejillones' coast, there is a complex spatial and temporal hydrographic system where ichthyoplankton of coastal and oceanic fish species coexist. Despite both short-term and longer-term disruptive oceanographic processes (e.g., mesoscale filaments, El Niño events), it seems that the numerically dominant species persist in the area due to their various behavioral strategies and physiological adaptations.