Microorganisms of the Upper Atmosphere: III. Relationship between Altitude and Micropopulation

Simultaneous sampling for microorganisms was accomplished at altitudes of 690, 1,600, and 3,127 meters. The location of temperature inversions in relation to the collection altitude determined, to a great extent, the micropopulation. High micropopulations were found when an inversion was above the sampling altitude, and low populations when the inversion was below the sampling altitude. Diurnal periodicity which could be generally correlated with periods of minimal and maximal convective activity was observed. Evidence is presented showing that the micropopulation is more stable at higher altitudes than at lower altitudes.     

Microorganisms of the Upper Atmosphere: II. Microorganisms in Two Types of Air Masses at 690 Meters over a City

The viable micropopulation found, at altitude over a city, in a land air mass was significantly higher than that found in a marine-influenced air mass. The percentage distribution of bacteria and fungi was approximately equal in both types of air masses. This indicates that, under the conditions of the experiment, the marine air mass was influenced by the land area over which it traveled during passage from its source to the sampling area. Activities taking place within the city significantly increased the micropopulation at altitude. This increase was quantitatively so small that it was not identifiable when the micropopulation moving into the city was high-as in a land air mass-but was recognizable when the micropopulation was low-as in a marine-influenced air mass. The modification of the micropopulation at altitude by temperature inversions was shown.     

Microorganisms of the Upper Atmosphere: IV. Microorganisms of a Land Air Mass as It Traverses an Ocean

The viable micropopulation at three altitudes (152, 1,066, and 1,981 meters) of a land air mass as it traversed an ocean was determined. At the low altitude, a consistent pattern of decrease in numbers of land-originating microorganisms with increasing distance from shore was observed. At the higher altitudes, the observed pattern was one of irregularity. At the lower altitude the percentages of bacteria and fungi were approximately equal near the coast, but as distance from the coast increased, fungi predominated over the bacteria at all sampling locations. The greatest number of different genera of both bacteria and fungi were obtained at or near the coast. Fungi of the genera Alternaria, Hormodendron, Penicillium, and Aspergillus, and bacteria of the genera Micrococcus and Bacterium predominated at all altitudes and locations.     

Effect of altitude on the primary products of photosynthesis and the associated enzymes in barley and wheat

There is little information available on the primary products of photosynthesis and the change in the activity of the associated enzymes with altitude. We studied the same in varieties of barley and wheat grown at 1300 (low altitude, LA) and 4200 m (high altitude, HA) elevations above mean sea level in the western Himalayas. Plants at both the locations had similar photosynthetic rates, leaf water potential and the chlorophyll fluorescence kinetics. The short-term radio-labelling experiments in leaves showed appearance of ¹⁴CO₂ in phosphoglyceric acid and sugar phosphates in plants at both the LA and HA, suggesting a major role of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in CO₂ fixation in the plants at two altitudes, whereas the appearance of labelled carbon in aspartate (Asp) and glutamate (Glu) at HA suggested a role of phosphoenolpyruvate carboxylase (PEPCase) in photosynthesis metabolism. Plants at HA had significantly higher activities of PEPCase, carboxylase and oxygenase activity of Rubisco, aspartate aminotransferase (AspAT), and glutamine synthetase (GS). However, the activities of malate dehydrogenase, NAD-malic enzyme and citrate synthase were similar at the two locations. Such an altered metabolism at HA suggested that PEPCase probably captured CO₂ directly from the atmosphere and/or that generated metabolically e.g. from photorespiration at HA. Higher oxygenase activity at HA suggests high photorespiratory activity. OAA thus produced could be additionally channelised for Asp synthesis using Glu as a source of ammonia. Higher GS activity ensures higher assimilation rate of NH₃ and the synthesis of Glu through GS-GOGAT (glutamine:2-oxoglutarate aminotransferase) pathway, also as supported by the appearance of radiolabel in Glu at HA. Enhanced PEPCase activity coupled with higher activities of AspAT and GS suggests a role in conserving C and N in the HA environment.     

Fluid movements during water-vapour absorption by the desert burrowing cockroach, Arenivaga investigata

The desert cockroach supplements its water intake by condensing atmospheric water onto the surface of protruded hypopharyngeal bladders. An associated pair of structures, the frontal bodies, produce a fluid which is conveyed to the bladder surface and added to by condensation. Reduced water activities on the bladder surface are maintained apparently by continuous removal of frontal-body fluid and condensate. This removal was demonstrated through application of nl quantities of fluorescent and radioactive tracer solutions to the bladder surface. Cuticular hairs are arranged on the bladder so as to divide it into a small (< 60 pl) suprasurface compartment and a large (32 nl) subsurface compartment. Rapid disappearance of fluorescent tracer from the bladder surface indicated movement of fluid from the suprasurface to the subsurface compartment. Radioactive tracer solutions were removed from the bladder, traversed the posterior hypopharynx, and accumulated in the oesophagus and crop. It is suggested that condensed fluid is conveyed to the crop in the same way. Tracer solutions were restricted to cuticular surfaces of the bladders, posterior hypopharynx, oesophagus and crop; other mouthparts are not involved in fluid movements. Movement of fluid into the subsurface compartment, and the small proportion of tracer solution which could be recovered from the bladder by Millipore filters with a pore size of 0.1 μm suggested the maintenance of considerable surface tensions on the bladder surface. Rapid removal of condensed fluid from the suprasurface compartment, where fluid is exposed to the atmosphere, suggests that the absorption mechanism is not dependent upon the properties of a hygroscopic solution. Over 99% of such a solution would be in the subsurface compartment, not exposed to the atmosphere, and would therefore be unavailable for the reduction of water activity.     

Simulated high altitude diving experiment for the underwater construction operation

The simulated dive experiments were conducted at the high altitude of 4500 meters and 5000 meters, for the requirement of diving operation in the lakes at the altitude of 4442 meters for the construction of large-scale hydroelectric power station. The high & low pressure chamber-complex was used, and 15 professional divers participated in the experiment. The divers were stayed at the altitude of 4500 and 5000 meters for 7-9 days. Totally 85 persons-times of dives to the depths of 30-50 meters were operated; they stayed under the water for 30-90 minutes while processing physical activities. During the experiment, we studied the pressurization procedure, decompression table, and physiological functions of the divers. The results indicate that, although the relative pressure differences between the surface and underwater was larger at high altitude than at sea level, the appropriate prolongation of the compression time was able to prevent the difficulty in pressure regulation for the divers to avoid the injury of middle ear. Four tables of the decompression A, B, C and D was calculated with Haldane's theory, and the speed of decompression increased in the order from A to D. The safest procedure was C, and there was no decompression sickness and bubbles in body of the divers. The methods of decompression included underwater stage decompression, surface decompression, oxygen-breathing decompression, and repetitive diving decompression. The surface decompression was the most suitable method for the high altitude, as it could greatly decrease the time in the cold water for the divers. The power spectrum analysis of EEG (electroencephalogram) indicated that, when the divers were exposed to the altitude of 5000 meters, the delta activity in EEG increased, alpha and beta activity decreased. And the delta activity decreased, the alpha and beta activity increased while diving during a dry condition. According to the diving and decompression procedure studied under simulated conditions, 272 person-times of diving training and underwater operations were processed in a high altitude hydroelectric power station at the altitude of 4442 meters, including photographing, video-recording, measuring, and drilling. There were no signs and symptoms of decompression sickness and bubbles.     

档案馆库房中微生物的研究

通过对安徽省不同地区档案馆库房中微生物的研究,结果表明：被污染的档案馆库房中的微生物主要优势菌为霉菌,细菌为其次,同时也有一定数量放线菌。不同管理层次档案馆库房中的微生物数量相差较大。     

Features of genetic variability in microsatellite DNA loci in the French Bulldog dog breed

Genetic variability in microsatellite markers PEZ1, PEZ3, PEZ6, PEZ8, FHC2010, and FHC2054 from a panel recommended by the International Society for Animal Genetics has been assessed for a micropopulation of dogs of the French Bulldog breed. The number and size of alleles, the number of alleles per locus, the effective number of alleles, the polymorphism index, expected and actual heterozygosity, and Wright’s fixation index have been determined to characterize each locus investigated. Deficit of heterozygous genotypes was observed in the micropopulation investigated, which is indicative of inbreeding. The relationship between the degree of homozygosity for six microsatellite loci and the degree of inbreeding has been analyzed. The results obtained point at a trend for increase of the relative abundance of homozygous loci upon an increase in the inbreeding coefficient of individuals.     

A simple VCG system with temporal dimension,directional reference and display of component loops

A vectorcardiogram (VCG) represents the cardiac electrical activity as continuous vector loops in three mutually perpendicular planes, namely frontal, transverse and sagittal.This technical note describes a simple system developed to record VCG with an ordinary x-y oscilloscope and simple camera. Facilities exist for recording VCG with temporal dimension, directional reference and display of specific component loops of a cardiac cycle. The system is in use for recording VCG at rest and during stress tests involving exercise and hypoxia at simulated altitude. Its performance has been found satisfactory and the system highly reliable.     

Adenylate cyclase activity and motor behavior following cerebral ischemia in the unanesthetized gerbil

Five minutes of bilateral carotid occlusion in unanesthetized gerbils produced substantial changes in spontaneous locomotor activity. Behavior was decreased after 1 hr of reperfusion and was increased at 24 hrs post-ischemia. Adenylate cyclase activity was measured in homogenates of frontal cortex and hippocampus at 90 min and 24 hrs following 5 min of cerebral ischemia. Enzyme activity was determined in the absence and presence of the activators guanosine-5'-triphosphate (GTP), guanylyl-5'-imidodiphosphate (GppNHp), isoproterenol (Iso) plus GTP, and forskolin (Fors) plus GTP. Homogenates responded with expected increases over basal adenylate cyclase activity with addition of all activators. An additional small increase in isoproterenol-stimulated activity was observed in frontal cortex homogenates at 90 min post-ischemia. No other significant changes in adenylate cyclase activity were observed after either 90 min or 24 hrs of reperfusion. The substantial increases in locomotor activity evident at 24 hrs after transient ischemia are not associated with measurable changes in adenylate cyclase activity in homogenates of frontal cortex or hippocampus.     

Circadian Rhythms in Locomotor Activity of the Hagfish, Eptatretus burgeri VI. The Effects of Cutting the Spinal Cord

The present study is designed to clarify the mechanism by which the circadian pacemaker controls the locomotor activity of the hagfish and also to estimate the role of brain and spinal cord in the swimming behavior of the animal. We examined the effect of cutting the spinal cord at the 6 different positions on the circadian rhythm and the locomotor behavior of the animal. The most frontal cut was located between the brain and spinal cord, and the other 5 cuts were given to every 1/6 the length of the spinal cord. The relation between the locomotor activity and the cut position of spinal cord was summarized as follows. (1) When the ratio of frontal part before the cut was 0/6-1/6, the animal locomoted under initiative of caudal part, in random direction at the bottom and showed neither nocturnal rhythm in LD nor circadian rhythm in DD. (2) When the ratio of the frontal part before the cut was 4/6-5/6, the animal swam up to the surface under initiative of frontal part, and showed both nocturnal rhythm in LD and circadian rhythm in DD. (3) When the frontal ratio of spinal cord was 2/6 or 3/6, the animal showed both kinds of swimming behavior of (1) and (2). These results suggest that the descending system from the brain enable the hagfish to swim up to the surface and to express the rhythmicity of locomotor activity under control of the circadian pacemaker when at least frontal 2/6 of the spinal cord is connected to the brain by neuronal networks not by humoral factors.     

Spatial distribution of fleas (Siphonaptera) in the burrows of the greater gerbil in the south central Kara-Kum

It has been established that only a negligible part of fleas occurs on animals while the main habitats where the greater part of micropopulation is concentrated from April to September are mouth, passages and food chambers situated at a depth up to 60 cm. In March, October, November and December fleas are restricted to the passages of burrows at a depth over 100 cm.     

Dispersion and the size composition of the aerial insect fauna

Abstract. 1. Beetles sampled in Louisiana at higher levels in the atmosphere were significantly smaller than those sampled at lower levels, which suggests that passive buoyancy is important in high altitude dispersal.
2. A model of long-range dispersal is suggested which combines both active flight and passive buoyancy.     

Enzyme activities in red and white muscles of guinea-pigs and rabbits indigenous to high altitude.

The activities of several enzymes functioning in different areas of fuel catabolism were measured under standardized conditions, using crude homogenates of sartorius and ventricular muscle from outbred guinea-pigs and rabbits indigenous to high or low altitude. The activities of sartorius and myocardium were found to reflect the metabolic patterns known to be associated with white and red muscle. Both species had right ventricular hypertrophy at high altitude. The enzyme activities in the high altitude guinea-pig were not significantly different from those in the sea level animals. In the high altitude rabbit, compared with the low altitude rabbit, the activities of glyceraldehyde-3-phosphate deydrogenase and phosphofructokinase were greater in both the sartorius and myocardium. In addition, mitochondrial glycerol-3-phosphate dehydrogenase activity was greater in the sartorius at high altitude, while aspartate aminotransferase and beta-hydroxyacylcoenzyme A dehydrogenase activities were greater in the myocardium at high altitude. Succinate dehydrogenase activity was comparable at the two altitudes for both tissues. There was a greater proportion of skeletal muscle type lactate dehydrogenase in the high altitude rabbit myocardium but no difference was found with the guinea-pig.     

Seasonal changes in the body and muscle heat resistance of the green toad

A study was made of the dynamics of seasonal changes in heat resistance of the organism and muscles of the green toad taken from micropopulation living in the North-Eastern suburbs of Tashkent. The heat resistance of the organism was determined by the time of onset of the irreversible heat shock caused by the immersion of animals into water at 39 +/- 0.1 degrees C. The heat resistance of muscles (m. gastrocnemius) was determined by the time of the loss of response to electrical stimulus during heating in the Ringer solution (41 +/- 0.1 degrees). It has been shown that the organism as a whole is much more dependent on seasonal variations of environmental temperature as compared with muscle tissue. Of much importance for the changes in the heat resistance of muscle tissue are cyclic hormonal changes in the organism associated with the process of reproduction and preparation to it.     

高粱和苏丹草酯酶同工酶分析

采用聚丙烯酰胺凝胶电（PAGE）分析了6个高粱和4个苏丹草的酯酶同工酶差异,并通过聚类分析方法对10个品种的种质关系进行分层聚类。结果表明酯酶同工酶谱可以作为鉴别苏丹草和高粱的有效生化标记。     

Brazilian Páramos II. Macro- and mesoclimate of the campos de altitude and affinities with high mountain climates of the tropical Andes and Costa Rica

Aim This paper presents a basic analysis of the macro- and mesoclimate of the Brazilian campos de altitude, a series of cool–humid, mountaintop grasslands in southeastern Brazil, and compares results with data from other tropical as well as temperate alpine sites. Location Beginning at altitudes of 1800–2000 m, the campos de altitude are found atop the highest summits of the main ranges of the southeastern Brazilian Highlands, between the states of Santa Catarina and Minas Gerais/Espírito Santo. Methods Macro- and mesoclimatic parameters for the campos de altitude are derived from both original data and previously reported results. Parameters include approximate radiation budgets, temperature lapse rates, seasonal and diurnal patterns in temperature, occurrence of frost, elevational gradients in precipitation, and interannual and seasonal patterns in precipitation. Using multivariate techniques and simple numerical contrasts, the climate of the campos de altitude is compared to climates of other tropical as well as temperate alpine sites. Results With respect to patterns of seasonality and the marked influence of polar frontal activity, the macroclimate of the campos de altitude is typically tropical-marginal. However, in reference to actual temperature and precipitation values, the length and profundity of the dry season, average humidities and cloudiness, the climate of the campus de altitude more closely corresponds to that of more inner-tropical systems. These commonalities are best developed with respect to páramo climates of the northern Andes and, especially, Costa Rica. Main conclusions Their very different latitudinal and geographic positions notwith- standing, the campos de altitude and high mountain formations of the N. Andean and Central American Cordillera show clear macroclimatic congruities. In these congruities reside both the environmental basis for strong Andean–southeast Brazilian biogeographic connections, and the context within which evolutionary and ecological parallelisms have developed in the biota of these two widely separate neotropical mountain systems.     

Autonomic Cardiovascular Responses in Acclimatized Lowlanders on Prolonged Stay at High Altitude: A Longitudinal Follow Up Study

Acute exposure to hypobaric hypoxia at high altitude is reported to cause sympathetic dominance that may contribute to the pathophysiology of high altitude illnesses. The effect of prolonged stay at high altitude on autonomic functions, however, remains to be explored. Thus, the present study aimed at investigating the effect of high altitude on autonomic neural control of cardiovascular responses by monitoring heart rate variability (HRV) during chronic hypobaric hypoxia. Baseline electrocardiography (ECG) data was acquired from the volunteers at mean sea level (MSL) (<250 m) in Rajasthan. Following induction of the study population to high altitude (4500–4800 m) in Ladakh region, ECG data was acquired from the volunteers after 6 months (ALL 6) and 18 months of induction (ALL 18). Out of 159 volunteers who underwent complete investigation during acquisition of baseline data, we have only included the data of 104 volunteers who constantly stayed at high altitude for 18 months to complete the final follow up after 18 months. HRV parameters, physiological indices and biochemical changes in serum were investigated. Our results show sympathetic hyperactivation along with compromise in parasympathetic activity in ALL 6 and ALL 18 when compared to baseline data. Reduction of sympathetic activity and increased parasympathetic response was however observed in ALL 18 when compared to ALL 6. Our findings suggest that autonomic response is regulated by two distinct mechanisms in the ALL 6 and ALL 18. While the autonomic alterations in the ALL 6 group could be attributed to increased sympathetic activity resulting from increased plasma catecholamine concentration, the sympathetic activity in ALL 18 group is associated with increased concentration of serum coronary risk factors and elevated homocysteine. These findings have important clinical implications in assessment of susceptibility to cardio-vascular risks in acclimatized lowlanders staying for prolonged duration at high altitude.     

The brain catecholamine systems in the regulation of dominance

Effect was studied of catecholamine systems of the brain in the establishment of dominant-subordinate relations in artificial micropopulations formed of six males. Decrease of norepinephrine and dopamine content by the injection of alpha-methyl-DL-tyrosine and decrease of norepinephrine alone by means of FLA-57 and also norepinephrine decrease and dopamine increase caused by combined injection of FLA-57 and alpha-DOPA were accompanied by a transfer of dominant and subdominant animals into the rank of subordinates. Changes of correlation between catecholamines probably had specific effect on zoosocial dominance of animals in micropopulation because changes were not found in the motor activity against the background of these preparations. Conclusion is made that brain catecholamines have a principle significance in dominance control.     

High Altitude Bird Migration at Temperate Latitudes: A Synoptic Perspective on Wind Assistance

At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured migration layers at varying altitude up to 3 km. Using long-term vertical profiling of bird migration by C-band Doppler radar in the Netherlands, we find that such migration layers occur nearly exclusively during spring migration in the presence of a high-pressure system. A conceptual analytic framework providing insight into the synoptic patterns of wind assistance for migrants that includes the altitudinal dimension has so far been lacking. We present a simple model for a baroclinic atmosphere that relates vertical profiles of wind assistance to the pressure and temperature patterns occurring at temperate latitudes. We show how the magnitude and direction of the large scale horizontal temperature gradient affects the relative gain in wind assistance that migrants obtain through ascending. Temperature gradients typical for northerly high-pressure systems in spring are shown to cause high altitude wind optima in the easterly sectors of anticyclones, thereby explaining the frequent observations of high altitude migration in these synoptic conditions. Given the recurring synoptic arrangements of pressure systems across temperate continents, the opportunities for exploiting high altitude wind will differ between flyways, for example between easterly and westerly oceanic coasts.