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: I. Instrumentation for Isokinetic Air Sampling at Altitude

An aircraft-mounted air-sampling system for the collection of microorganisms from the upper air is described. The system is highly suitable for use in upper air sampling from an aircraft because (i) it is an isokinetic system, (ii) it is simple to operate, (iii) it employs a dry filter, (iv) the volume sampled can be easily determined, and (v) it operates efficiently at all altitudes and ambient temperatures.     

Terrestrial Microorganisms at an Altitude of 20,000 m in Earth's Atmosphere

A joint effort between the U.S. Geological Survey's (USGS) Global Desert Dust and NASA's Stratospheric and Cosmic Dust Programs identified culturable microbes from an air sample collected at an altitude of 20,000 m. A total of 4 fungal (Penicillium sp.) and 71 bacteria colony-forming units (70 colonies of Bacillus luciferensis believed to have originated from a single cell collected at altitude and one colony ofBacillus sphaericus) were enumerated, isolated and identified using a morphological key and 16S rDNA sequencing respectively. All of the isolates identified were spore-forming pigmented fungi or bacteria of terrestrial origin and demonstrate that the presence of viable microorganisms in Earth's upper atmosphere may not be uncommon.     

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.     

N-乙酰氨基葡萄糖转移酶V与肿瘤的关系

最近的研究认为,GnT—V在肿瘤发展及转移过程中是一个双功能蛋白质。GnT—V是一个高尔基体酶,但在某些肿瘤细胞中,GnT-V同类分子在高尔基体不能成簇,分子间二硫键介导的同类蛋白质寡聚体不能形成,GnT—V单体易受蛋白酶攻击,最终分泌到培养基中,分泌出细胞的GnT-V在生理浓度范围内能引起肿瘤血管生成。     

Estimation of the Hydrocarbon-Oxidizing Activity of Microorganisms

A method allowing microorganisms growing on substrates with low water solubility (oil, fuel oil, resins, and asphalthenes) to be isolated and counted was developed. The method makes it possible to estimate the oil-utilizing activity of each strain visually according to the decolorized zones formed during its growth on oil products. The sizes of these zones indicate which oil-degrading strains are most active.     

褐藻糖胶的结构及构效关系研究

综述了褐藻糖胶结构方面的研究进展,以及褐藻糖胶的抗凝血活性和抗病毒活性与结构之间的关系。     

Passive Electrical Properties of Microorganisms: V. Low-Frequency Dielectric Dispersion of Bacteria

Very high dielectric constants have been observed for bacteria at low frequencies. High dielectric constants such as these can be explained by a theory which has been developed for the low-frequency dielectric dispersion of porous charged particles and which has been tested successfully through measurements with ion exchange resins. The bacterial cell wall is electrically similar to an ion exchange resin. Observations show that the theory provides a quantitative explanation for the low-frequency dielectric dispersion of bacteria.     

The Relationship between Structure and Activity of Taurolin

Taurolin [Bis(1,1-dioxo-perhydro-1,2,4 thiadiazinyl-4)methane] is an antimicrobial compound formed by the condensation of two molecules of taurine with three of formaldehyde. It has been suggested that it releases formaldehyde in contact with bacteria. Evidence from TLC, HPLC and NMR spectroscopy indicates that taurolin is mostly hydrolysed in aqueous solution to release one molecule of formaldehyde and two monomeric molecules (1,1-dioxo-perhydro-1,2,4-thiadiazine and its carbinolamine derivative). A stable equilibrium is established. Antibacterial activity is not entirely due to adsorption of free formaldehyde but also to reaction with a masked (or latent) formaldehyde, as the activity of taurolin is greater than formaldehyde. The monomer is only slightly active by comparison.     

Relationship between Stereoisomerism and Biological Activity of Pyrethroids

(+)-trans-Homochrysanthemic acid, when boiled in dilute sulfuric acid, gives (+)-trans-ε-hydroxy-dihydrohomochrysanthemic acid, m.p. 176–7°, together with (+)-δ, δ-dimethyl-γ-isobutenyl-δ-valerolactone. The formation of optically active lactone from (+)-trans-homochrysanthemic acid provides another cogent evidence for the structure of the lactone previously deduced on the racemic compound.

The Arndt-Eistert reaction of the homo-acids give further higher homologues such as (±)-,(+)-trans-β-(3-isobutenyl-2, 2-dimethylcyclopropane-1)-propionic acids and (±)-cis-3-isobutenyl-2, 2 dimethylcyclobutane-1-acetic acid. Both trans-acids, in boiling dilute sulfuric acid, give the same (±)-γ-(1′, 1′, 4′-trimethyl-pent-2′-enyl)-butyrolactone together with the corresponding hydroxy-acids, optically inactive and active, respectively.

Complete resolution of (±)-trans-homochrysanthemic acid and (±)-trans-β-(3-isobutenyl-2, 2-dimethycyclopropane-1)-propionic acid was achieved by means of optically active α-phenylethylamine.     

Relationship between two proprioceptive measures and stiffness at the ankle.

Previous research has investigated the role of proprioception and stiffness in the control of joint stability. However, to date, no research has been done on the relationship between proprioception and stiffness. Therefore, the purpose of this study was to determine the relationship between force sense, joint reposition sense, and stiffness at the ankle. A heterogeneous sample was obtained for this study; 20 of the 40 participants had a history of ankle sprains, and 13 of the 20 had been diagnosed by a physician (two mild ankle sprains, seven moderate sprains, four severe sprains). All subjects were asymptomatic and active at the time of the study. Active joint reposition sense was measured using a custom-built ankle goniometer, force sense was measured unilaterally and contralaterally with a load cell, and ankle muscle stiffness was measured via transient oscillation using a custom-built inversion-eversion cradle. We found no significant correlations between stiffness and joint reposition sense, with values of r ranging from 0.01 to 0.21. Significant correlations were found between stiffness and force sense. Specifically, contralateral force sense reproduction was significantly correlated to stiffness in the injured or "involved" ankle (r's ranging from 0.47 to 0.65; P< or =0.008). Whether the decreased ability to appropriately sense force (increased error) sends information to the central nervous system to increase muscle stiffness in response to an unexpected loss of stability, or whether these two phenomena function independently and both change concurrently as a result of injury to the system requires further investigation.     

Occurrence and Activity of Microorganisms in Shrimp Waste

This study aimed to determine the occurrence and respiration activity of heterotrophic bacteria and fungi in shrimp shell waste and to evaluate the role of chitinolytic bacteria and fungi in its decomposition. The highest levels of bacteria were found in shrimp heads sections and the lowest in exoskeletons. The level of fungi was much lower, with the highest proportion present in heads sections and the lowest in exoskeletons. Chitinolytic bacteria constituted a small percentage of the total heterotrophic bacteria in fresh shrimp waste, averaging 4% in exoskeletons, 2.4% in all parts, and 2% in heads. No chitinolytic bacteria were detected in stored waste. In contrast, the percentage of chitinolytic fungi in shrimp waste was much higher than that of bacteria. Chitinolytic fungi constituted 25–60% of the total fungi in fresh waste and 15–40% in stored waste. Chitinolytic bacteria isolated from heads sections were characterized by the highest chitinolytic activity, averaging 11.2 nmol of methylumbelliferyl · mg⁻¹ protein · h⁻¹, whereas the lowest activity was in strains from exoskeletons, averaging 3.2 nmol of methylumbelliferyl · mg⁻¹ protein · h⁻¹. The chitinolytic activity of fungi isolated from all parts waste, head sections, and exoskeletons was similar. The respiration activity of microorganisms in fresh and stored waste was similar. Oxygen consumption activity increased during incubation and approached a saturation value between days 4 and 5. No correlation between the end value of respiratory activity in the analyzed section of shrimp discard after 5 days and the level of bacteria and fungi was observed. The only significant correlation observed was between the respiratory activity of the shrimp and the level of fungi. The respiration activity significantly depended on the analyzed section of shrimp discard (p < 0.000).     

Altitude adaptation. V. (conclusion). Morbidity and mortality. Literature]

The ability to adapt to extreme conditions is a continously working principle of man's evolution, in a permanent orientation to an optimal equilibrium between man and environment. A paradigm of biological adaptation is the condition of hypoxia at high altitudes, as one of the few environment constellations to which a pure biological and thus genetically based answer could be possible. The majority of adaptations are influenced by technological actions, which partially modify the environment in compensating unfavourable constellations (heating, clothing, housing, etc.). It is discussed, how far the adaptation to high altitudes produces transitory or permanent alterations with reference to constitution, perseverance, cold-sensitivity, diseases, duration of life, fertility, course of pregnancy, adaptations at the organ- and tissue-level, blood-composition, fluid-equilibrium of the body etc., which guarantee the survival of the individual and its successful reproduction with regard to the continuance of a mendel population. The elucidation of the question on genetic determination of features characteristic for high altitude inhabitants is difficult because we know next to nothing about the genetic determination of physiologic parameters. Studies on ethnic marker-genes (Ethiopia, South-America) give no reference to population differences. Remarkable is a striking prevalence of the blood-group O for all populations of high altitudes, but one must consider the effects of isolation in terms of the increase in the homozygote recessive alleles. We can propose, that in the primary settlement at high altitudes a "hard selection" was working, a kind of biological assortation-process from the beginning, which eliminated those individuals, who proved to be (for genetic reasons?) not adaptable. A good example for this are observations of cattle, from which 50% do not develop pulmonary hypertension when exposed to altitude, that means they already have a higher initial fitness. The non-adaptable animals have to be returned to the lowlands. In the F1-generation only 2% of the animals remaining at high altitude, develop "brisket disease". Possibly that means a sort of "out-mendeling" of "pulmonary-hypertension-genes", which may manifest themselves in the condition of hypoxia. Also the good adaptation of llamas is partially due to the fact that the camelids per se possess an outstanding O2 affinity and morphologically different red blood cells, which predispose this species to inhabit high altitudes. Parallel to considerations like these it could be imaginable, that e.g. the indianids of mongoloids in general, are genetically composed as fit to inhabit lowlands as well as highlands, in contrast to caucasoids and negroids. The largest mountain areas of the world (the Andes: 12 X 10(6)), the Himalayas 12 X 10(6)) are inhabited by populations of mongoloid ancestry, for about 10,000 years, a period, which ought to be long enough to make possible genetic specialisation, although it is not yet possible to prove it...     

生长素结构与其活性关系的揭示

生长素结构与活性之间关系是长期以来悬而未决的一个难题。最近的研究证明,生长素分子像“胶水”一样将受体TIR1与效应蛋白Aux／IAA“粘合”后,形成SCF^TIR1-生长素-Aux／IAA复合物,进而激活泛素连接酶3（SCF^TIR1）,起着促使Aux／IAA泛素化后的降解,转录因子ARFs得到活化后,启动一系列生长素响应基因的转录,于是植物表现出相应的生长发育状态。     

油菜甾醇内酯类化合物结构与活性的相关性

比较了19种油菜甾醇内酯类似物和有关甾体化合物在水稻叶片倾斜及萝卜幼苗生长试验中的生物活性。表油菜甾醇内酯(24—Epi—BR)在两个系统中都具有很强的生物活性。C_2位失去羟基(香蒲甾醇)仅在水稻试验中有高活性,改变C_22位侧链结构(2α,3α双羟基—6—酮—23,24—双失碳—β—高-5α—胆烷酸甲酯)在萝卜试验中仍有活性。     

Isolation and Characterization of Microorganisms with Alternan Hydrolytic Activity

Alternan is an unusual α-D-glucan containing alternating (1 → 3), (1 → 6) linkages that exhibits remarkable resistance to enzymatic hydrolysis. The commercial potential of the polysaccharide may be enhanced by the ability to economically modify the native form into fractions of varying molecular weight. By employing isolation procedures with covalently dyed alternan as the substrate, several bacterial isolates that produced endohydrolytic activity were obtained in pure culture. The activity was confirmed by decreases in viscosity and by direct examination of the hydrolysis products with thin layer chromatography. Analysis of the hydrolysis products established that all isolates produced enzymes with identical alternan depolymerizing activity, producing a cyclic tetrasaccharide as a major product. All alternanase activity was shown to be extracellularly located. A single strain exhibited constitutive production of alternanase, while all other isolates required the presence of alternan in the growth media for enzyme production. All isolates were phenotypically similar, produced heat-resistant spores, and were tentatively identified as members of the genus Bacillus.     

Ribosomal RNA genes ofPhaseolus coccineus V. Relationship between rDNA phenotype and somatic differentiation

Summary Size variations in the intergenic spacer of ribosomal DNA were detected between individual plants of openly pollinatedPhaseolus coccineus. Eleven days after sowing, two plant samples were examined: slowly developing plants with a length less than 40 cm; and fast developing plants with a length greater than 70 cm. The two samples were characterized by different plant weight and, at maturity, by highly distinctive seed yield. They also exhibited distinct patterns of protein expression as analyzed by 2-D electrophoresis. In particular a 38 kDa protein, related to malate dehydrogenase on the basis of its N-terminal sequence, was present at higher concentration and higher activity levels in fast developing plants. Intergenic spacer length variants were detected in both samples at approximately 180 bp intervals. More than one spacer length variant was present in each individual plant. At least 13 different intergenic spacer hybridization patterns were in fact detected: some patterns occurred equally in both slowly and fast developing samples while the majority of patterns was significantly different between the two samples.Abbreviations FDP fast developing plants - IGS intergenic spacer - MDH malate dehydrogenase - rDNA SLV spacer length variant of ribosomal DNA - SDP slowly developing plants