Microorganisms of the Upper Atmosphere: V. Relationship between Frontal Activity and the Micropopulation at Altitude

The relationship between frontal activity and the micropopulation of the atmosphere at altitude is described. It is shown that certain of the meteorological events associated with frontal activity quantitatively modify the micropopulation of the atmosphere. Precipitation associated with frontal passage reduces the micropopulation at altitude, whereas frontal activity with high levels of associated surface and atmospheric turbulence results in great increases in micropopulations of the upper atmosphere-particularly in those situations where surface conditions are conductive to the development of dust.     

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.     

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.     

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.     

Passive Electrical Properties of Microorganisms: III. Conductivity of Isolated Bacterial Cell Walls

The dielectric properties of isolated Micrococcus lysodeikticus cell walls have been studied to establish more firmly the view that wall-associated ions play a major role in the conduction of low frequency electric current by intact bacterial cells. The conductivity of isolated walls was found to be about 0.40 mho/m. If counterions associated with fixed, ionized groups in the wall have average mobilities equal to that of sodium ions in free solution, the fixed charge concentration required to account for the measured conductivity is between 75 and 95 meq/liter of wet wall volume. Estimates of the numbers of titratable amino and carboxyl groups in wall polymers indicate that conductivity is more closely related to net wall charge than to total wall charge. The measured wall conductivity was used to predict a value of 0.15 ± 0.03 mho/m for whole cell conductivity. This prediction is close to the measured value of 0.25 ± 0.05 mho/m and it is thought that much of the disparity in values is related to changes in wall structure and composition during the isolation procedures.     

Suppression of reaginic antibody formation. III. Relationship between immunogenecity and tolerogenicity of hapten-carrier conjugates.

From the study of the effect of epitope density on the immunogenicity of haptenated ovalbumin (DNP-OA) it was concluded that the lightly haptenated conjugate, DNP0-5-OA, induced, on the one hand, only low titers of anti-DNP hemagglutinating antibody and no reaginic antibodies to the hapten and, on the other, high reaginic and high hemagglutinating antibody responses to the carrier. The conjugate with a slightly higher degree of haptenation, i.e., DNP2.3-OA, induced both reaginic and hemagglutinating antibodies to both the hapten and the carrier. By contrast, the heavily haptenated conjugate, DNP20-OA, elicited reaginic and hemagglutinating antibodies only against the hapten but not against the carrier. Specific suppression of anti-hapten reaginic antibody formation had been achieved by treatment of mice with a tolerogen consisting of the hapten (DNP) conjugated covalently to isologous gamma globulins (MgammaG). The epitope density of the DNPx-MgammaG conjugates was shown to play a dominant role in determining whether or not the conjugate was tolerogenic. Thus, lightly haptenated conjugates (DNP0.5-MgammaG, DNP1.3-MgammaG or DNP1.9-MgammaG) were not tolerogenic, moderately haptenated conjugates (DNP4.2-MgammaG, DNP8-MgammaG, and DNP 14-MgammaG) were tolerogenic, and heavily haptenated conjugates (DNP32-MgammaG and DNP53-MgammaG) were immunogenic, being capable of priming the recipients for the DNP hapten. Further evidence for the nonimmunogenicity of DNP 8-MgammaG conjugate was inferred from its rate of clearance in tolerized and normal mice. Thus, the half-life of 125I-labeled DNP8-MgammaG in circulation was not significantly different for normal and tolerized mice; it was 3.7 and 3.5 days, respectively, which is within the range of data reported for clearance of normal MgammaG. These results suggest that DNP8-MgammaG was catabolized at a rate similar to that of nonconjugated, isologous MgammaG. Moreover, there was no significant difference in the localization of DNP8-MgammaG in identical difference in the localization of DNP8-MgammaG in identical organs (spleen, thymus, kidney, and liver) of normal and tolerized mice. All the multivalent DNPx-MgammaG conjugates were shown to be able to elicit passive cutaneous anaphylaxis (PCA) reaction on i.v. challenge of rats which had been pre-sensitized i.d. with anti-DNP reaginic antibodies.     

闽东北山地海拔高度与板栗产量关系研究

采用随机区组试验设计法对不同海拔高度与板栗产量的关系进行研究,通过对比分析,结果表明:不同海拔高度板栗之间的果苞数和产量差异显著,板栗产量与海拔高度未成比例关系,合适海拔高度的板栗产量高、经济效益好。适宜板栗种植的海拔高度为400~800 m。     

Fatty acid synthesis by spinach chloroplasts III. Relationship between fatty acid synthesis and photophosphorylation

The modes of actions of photosynthetic inhibitors on photosynthesisand fatty acid synthesis were examined. DCMU, an electron transport inhibitor, inhibited fatty acidsynthesis and photophosphorylation to the same extent, suggestingdependence of fatty acid synthesis on photosynthesis. The samewas also the case with FCCP, a photophosphorylation uncoupler.In contrast, NH₄Cl and phlorizin at concentrations completelysuppressing ATP formation, only partially inhibited the fattyacid synthesis. These facts suggest that a certain level ofhigh-energy intermediate (state) is responsible for the lightenhancement of fatty acid synthesis. This idea is further supportedby the fact that the partial inhibition of fatty acid synthesisby NH₄Cl was relieved by addition of DCCD at low concentrationssuppressing the ATP formation but not completely destroyingthe high energy intermediate. The lag period in the initial period of fatty acid synthesiswas shortened by preillumination of chloroplasts, even in theabsence of ADP. This indicates that the light dependent fattyacid synthesis is closely associated with the high-energy intermediate(state), but not directly with ATP formation by photophosphorylation. ¹ Present address: Radioisotope Centre, University of Tokyo,Yayoi, Bunkyo, Tokyo 113, Japan. (Received August 26, 1974; )     

Relationship between the flagellates and the ciliates.

The flagellates and the ciliates have long been considered to be closely related because of their unicellular nature and the similarity in the structures of the axoneme of the flagella and cilia in both groups. Most protozoologists believe that the ciliates arose from a flagellate. The flagellates that are most similar in structure to the ciliates are the dinoflagellates and two genera of uncertain taxonomic position, Colponema and Katablepharis. Structurally, dinoflagellates have a number of similarities with ciliates. These include the similarity of the cortical alveoli in the ciliates to the thecal vesicles in the dinoflagellates, the possession of tubular cristae, the similarity of the parasomal sac of the ciliates to the pusule of the dinoflagellates, the possession of similar trichocysts and mucocysts, and some similarity in the feeding apparatus. Colponema spp. are probably related to the dinoflagellates and have many of the same similarities with the ciliates. Katablepharis spp. are very similar in structure to the swarmer (embryo) of the suctorian ciliates. Indeed, reduction in the number of cilia to two in the suctorian swarmer and elimination of the macronucleus would result in a cell that is very similar to the Katablepharis cell. The feeding apparatus of Katablepharis spp. and the rest of the ciliates consists of two concentric microtubular arrays associated with vesicles. Information available from nucleotide sequencing of rRNA places the dinoflagellates in an ancestral position to the ciliates. The rRNA of Colponema and Katablepharis spp. has not yet been investigated. The use of stop codons in mRNA is discussed in relation to phylogeny.     

纤维素分解菌与无机磷细菌的相互作用

大多数土壤全磷含量较高 ,但由于其固定能力很强 ,不仅有效磷含量较低 ,而且施入的水溶性磷肥很快转化为无效形态。活化土壤中无效磷库 ,提高其有效性 ,是一个具有重要实践意义的研究课题。研究结果表明 ,土壤中存在许多具活化无效磷功能的微生物 ,尤其在根际土壤中解磷微生物的数量比非根际要多[8] ,这些微生物统称为解磷菌。增加土壤或根际解磷菌的数量 ,就能活化土壤中的无效磷 ,提高磷的利用率。但土壤中的解磷菌大多数是腐生性的 ,其生长繁殖需要碳源 ,而多数情况下 ,土壤碳源很少 ,且主要是农作物残体 ,其主要成分是纤维素和半纤维素 …     

Predominant Catalase-negative Soil Bacteria. III. Agromyces, gen. n., Microorganisms Intermediary to Actinomyces and Nocardia

The occurrence of filamentous, branching, catalase-negative bacteria as a numerically predominant microflora of various soils was demonstrated by using a dilution frequency isolation procedure. The major characteristics of these organisms were those of the order Actinomycetales. However, they could not be placed in any of the present genera of this order and, therefore, a new genus, Agromyces, was proposed for these organisms. This genus includes catalase-negative, nutritionally-fastidious microorganisms whose cells produce a true branching mycelium that fragments into coccoid and diphtheroid forms. Also, they have an oxidative metabolism, are microaerophilic to aerobic, and contain neither diaminopimelic acid nor lysine as major constituents of the cell wall glycopeptide. The type species would be Agromyces ramosus, gen. n., sp. n. The possible importance of these organisms in clarifying certain phylogenetic relationships of the Actinomycetales is discussed.     

The Relationship between Nonalcoholic Fatty Liver Disease and Retinopathy in NHANES III

BackgroundNonalcoholic fatty liver disease (NAFLD), an emerging multisystem disease, has the similar pathogenesis with diabetes and is prevalent in diabetes. This study investigated whether NAFLD is associated with retinopathy in individuals with diabetes and without diabetes.MethodsThe association between NAFLD and retinopathy was investigated in 5963 participants aged 40 years and older who participated in the NHANES III, a nationally representative, population-based and cross-sectional study. NAFLD was detected via ultrasonography, and fundus photographs were obtained to grade retinopathy patterns. We performed multivariate logistic regression analysis to investigate the relationship between the presence of retinopathy and NAFLD and diabetes.ResultsAfter adjusting for multiple covariates, NAFLD population had no evidence of retinopathy increase in population without diabetes (odds ratio [OR]: 0.77; 95% confidence interval [CI]: 0.48 to 1.26). In addition, NAFLD in individuals with diabetes was not significantly associated with retinopathy (OR: 0.77; 95% CI: 0.47 to 1.26), independent of age, gender, ethnicity, waist circumference, serum high-density lipoprotein (HDL) cholesterol, serum triglycerides, systolic blood pressure, and glycated hemoglobin.ConclusionsIn the US general population, NAFLD is not a precipitating factor of retinopathy in population with or without diabetes.     

Application of Rice-Straw Biochar and Microorganisms in Nonylphenol Remediation: Adsorption-Biodegradation Coupling Relationship and Mechanism

Biochar adsorption presents a potential remediation method for the control of hydrophobic organic compounds (HOCs) pollution in the environment. It has been found that HOCs bound on biochar become less bioavailable, so speculations have been proposed that HOCs will persist for longer half-life periods in biochar-amended soil/sediment. To investigate how biochar application affects coupled adsorption-biodegradation, nonylphenol was selected as the target contaminant, and biochar derived from rice straw was applied as the adsorbent. The results showed that there was an optimal dosage of biochar in the presence of both adsorption and biodegradation for a given nonylphenol concentration, thus allowing the transformation of nonylphenol to be optimized. Approximately 47.6% of the nonylphenol was biodegraded in two days when 0.005 g biochar was added to 50 mg/L of nonylphenol, which was 125% higher than the relative quantity biodegraded without biochar, though the resistant desorption component of nonylphenol reached 87.1%. All adsorptive forms of nonylphenol (f_rap, f_slow, f_r) decreased gradually during the biodegradation experiment, and the resistant desorption fraction of nonylphenol (f_r) on biochar could also be biodegraded. It was concluded that an appropriate amount of biochar could stimulate biodegradation, not only illustrating that the dosage of biochar had an enormous influence on the half-life periods of HOCs but also alleviating concerns that enhanced HOCs binding by biochar may cause secondary pollution in biochar-modified environment.