Origin of microbial life hypothesis: a gel cytoplasm lacking a bilayer membrane, with infrared radiation producing exclusion zone (EZ) water, hydrogen as an energy source and thermosynthesis for bioenergetics

The hypothesis is proposed that pre-biotic bacterial cell(s) and the first cells capable of growth/division did not require a cytoplasmic membrane. A gel-like microscopic structure less than a cubic micrometer may have had a dual role as both an ancient pre-cytoplasm and a boundary layer to the higher-entropy external environment. The gel pre-cytoplasm exposed to radiant energy, especially in the infrared (IR) region of the EM spectrum resulted in the production of an exclusion zone (EZ) with a charge differential (−100 to −200 mV) and boundary that may have been a possible location for the latter organization of the first cytoplasmic membrane. Pre-biotic cells and then-living cells may have used hydrogen as the universal energy source, and thermosynthesis in their bioenergetic processes. These components will be discussed as to how they are interconnected, and their hypothesized roles in the origin of life.     

Direct measurements of the compressive properties of single proteoglycan aggregates

Proteoglycan aggregate is a major component of the extracellular matrix in articular cartilage and is considered to be responsible for the resistance to compression of this tissue. The reduced stiffness of articular cartilage due to the loss of proteoglycan aggregate has been reported in osteoarthritis. In order to understand the mechanical properties of extracellular matrix in articular cartilage at molecular level, the compressive properties of 36 single molecules of proteoglycan aggregate were directly measured using a laser tweezers/interferometer system. The proteoglycan aggregates showed resistance when compressed to approximately 30% of their contour length. The stiffness of proteoglycan aggregates increased non-linearly from 2.6+/-3.8 pN/microm (compressed to 30-35% of their contour length) to 115.5+/-30.9 pN/microm (compressed to 2.5-5% of their contour length).     

Osmotic water permeability measurements using confocal laser scanning microscopy

 We have developed a method for measurement of plasma membrane water permeability (P _f) in intact cells using laser scanning confocal microscopy. The method is based on confocal recording of the fluorescence intensity emitted by calcein-loaded adherent cells during osmotic shock. P _f is calculated as a function of the time constant in the fluorescence intensity change, the cell surface-to-volume ratio and the fractional content of the osmotically active cell volume. The method has been applied to the measurement of water permeability in MDCK cells. The cells behaved as linear osmometers in the interval from 100 to 350 mosM. About 57% of the total cell volume was found to be osmotically inactive. Water movement across the plasma membrane in intact MDCK cells was highly temperature dependent. HgCl₂ had no effect on water permeability, while amphotericin B and DMSO significantly increased P _f values. The water permeability in MDCK cells transfected with aquaporin 2 was an order of magnitude higher than in the intact MDCK cell line. The water permeability of the nuclear membrane in both cell lines was found to be unlimited. Thus the intranuclear fluid belongs to the osmotically active portion of the cell. We conclude that the use of confocal microscopy provides a sensitive and reproducible method for measurement of water permeability in different types of adherent cells and potentially for coverslip-attached tissue preparations. Received: 12 June 1999 / Revised version: 21 February 2000 / Accepted: 25 February 2000     

The distribution of the radionuclides in the main components of lake ecosystems within the Chernobyl NPP exclusion zone

The results of the studies devoted to the distribution of radionuclides 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am in 1998-2003 in main components of Glubokoe Lake and Dalekoe-1 Lake located within Krasnensky flood lands of the Pripyat River (inner exclusion zone of the Chernobyl NPP) were analysed. The data about the radionuclide content in bottom sediments, in water, in seston, in macrozoobenthos (including bivalvia molluscs), in gasteropods molluscs, in higher aquatic plants and in fish are presented.     

Effects of simulated submergence on survival and recovery growth of three species in water fluctuation zone of the Three Gorges reservoir

Paspalum distichum, Cynodon dactylon and Hemarthria altissima distribute widely in natural water fluctuation zone of the Three Gorges region. To investigate whether they are suitable for growing in the artificial water fluctuation zone, which has longer submergence time and different submergence rhythm, of the Three Gorges reservoir, three complete submergence depths (0.5, 1 and 2 m) were conducted for about 6 months (from 12 November 2007 to 30 April 2008), and the survival and recovery growth of the three species were recorded after re-emergence for two weeks. The three species could start recovery growth within one week and more than 50% plants could survive. Among the three species, P. distichum had the largest increments in branch number and maximum stem length, and the smallest root shoot ratio. C. dactylon, however, had the smallest maximum stem length increment, and its survival and branch number increment were both larger than those of H. altissima. For C. dactylon and H. altissima, the survival and branch number increment significantly increased, while maximum stem length increment tended to decrease when submergence depth went higher. For P. distichum, the survival and the shoot mass were the lowest after 2 m submergence depth, but the other parameters were not different among different submergence treatments. Compared with control plants, submergence increased root shoot ratio of C. dactylon and H. altissima, but did not affect that of P. distichum. These results demonstrated that the three species are submergence-tolerant and can be applied in vegetation reconstruction in water fluctuation zone of the Three Gorges reservoir. Meanwhile, the results also suggested that the three species developed different survival tactics during the long-term submergence.     

New judgement on the source of soil water in extremely dry zone

There is always a relatively high moisture content in the shallow soil layer in Gobi area on the top of the Mogao Grottoes in the extremely dry zone. This paper gives out a new judgement on soil water source through field experiments using the isolated water method, simulated rainfall method and greenhouse method. Under the condition of typical hyper-arid climate far away from rainfall effect and after cutting off the connection of soil and groundwater the simulated rainfall experiment was conducted, through putting up a plastic greenhouse to obtain a relatively closed space and extracting the condensed water on the film surface, the soil water output from the greenhouse was monitored. The experimental results show that generally the rainfall can be completely evaporated in about 20 days under the isolated condition. In the relatively closed space sheltered by arched greenhouse in the Gobi area water can be continuously transferred outward from subsoil and condensed on the roof film, with a daily output quantity of 3–5 g/m²d. After prolonged output soil water content remains significantly higher than that of the control and before covering by arched shed. Comprehensively judging from this, groundwater is an important source of soil water in addition to precipitation. The new judgement has a very important practical significance to the water research of the groundwater–soil–plant-atmosphere circle (GSPAC) and the recovery of the desertified environment.     

封丘地区小麦耗水量与水分利用率研究

根据水量平衡方程式计算,雨养麦田5个试验麦季的耗水量分别为435.5、326.0、293.8、277.2和365.9mm,可代表该区过湿、一般和干旱年份的小麦耗水量.研究结果表明,小麦地上部分生物量与其总耗水量的相关关系不显着(r=0.67).在耗水量中,土壤储水的贡献占50%.在降雨少而土壤储水丰足的年份,其贡献高达60%,是小麦水分的重要来源.在充分施肥条件下,5个麦季的水分利用率≥11.25kg·ha^-1·mm^-1,表明适当增加肥料投入可提高农田水分利用率.     

高斯光束中细胞横向受力分析

按照几何光学的原理建立了高斯光束中细胞受力的力学模型,并利用数值计算,得到了细胞偏离光轴受到的向轴回复力大小与细胞的离轴距离X0、直径2R等的关系.结果表明高斯光束对大小不同的细胞有相同的光学势阱宽度,对较大细胞势阱较深所以较容易稳定俘获.讨论了光钳设计中注意的问题.     

农牧交错带不同耕作方式土壤水分动态变化特征

从耕作方式、覆盖和轮作3个因素系统地对莜麦整个生育期土壤含水量进行了动态的观测研究,结果表明,干旱地区单纯的免耕在提高土壤水分含量上作用不太明显,尤其是降低了表层土壤的含水量,免耕只有在覆盖下,才能真正起到增加土壤水分含量,提高水分利用效率的作用;而对于深松处理,无论是覆盖还是不覆盖,与传统翻耕处理相比,土壤水分均明显提高;同种耕作措施覆盖与无覆盖相比,覆盖处理下土壤含水量明显高于无覆盖处理;说明保护性耕作之所以能够提高土壤水分含量,关键因素在于残茬覆盖;同种耕作方式下轮作种植土壤水分含量与水分利用效率明显高于连作。可以看出,从理论上轮作深松覆盖处理是当地应采用的最佳耕作方式,然而,由于当地缺乏覆盖材料,因此,轮作深松是目前当地最适合的耕作方式。     

Aeration status in the root zone of maize in relation to soil water content

The aeration status of a silt loam placed in microcolumns was measured in the maize root zone using an oxygen microelectrode. At soil moisture saturation, the O₂ concentration was found to be zero. Maize evapotranspiration led to a fast increase in O₂ concentration against time (2% O₂ after 2 days, atmospheric concentration after 7 days). Surprisingly, for specified soil moisture levels, no significant O₂ concentration differences were observed between planted and fallow soils. These results are discussed to explain observations on the denitrification process in the root zone of plants.     

Use of exclusion by a chimpanzee (Pan troglodytes) during speech perception and auditory-visual matching-to-sample

An adult female chimpanzee showed responding through use of exclusion in an auditory to visual matching-to-sample procedure. The chimpanzee had previously learned to associate specific visuographic symbols called lexigrams with real world referents and the spoken English words and photographs for those referents. On some trials, an unknown spoken English word was presented as the sample, and the match choices could consist of photographs or lexigrams that already were associated with known English words as well as unknown lexigrams or photos of objects without associated lexigrams. The chimpanzee reliably avoided choosing known comparisons for these unknown samples, instead relying on exclusion to choose comparisons that were of unknown lexigrams or photographs of items without associated lexigram symbols.     

Formation of the transition zone by Mks5/Rpgrip1L establishes a ciliary zone of exclusion (CIZE) that compartmentalises ciliary signalling proteins and controls PIP2 ciliary abundance

Cilia are thought to harbour a membrane diffusion barrier within their transition zone (TZ) that compartmentalises signalling proteins. How this “ciliary gate” assembles and functions remains largely unknown. Contrary to current models, we present evidence that Caenorhabditis elegans MKS‐5 (orthologue of mammalian Mks5/Rpgrip1L/Nphp8 and Rpgrip1) may not be a simple structural scaffold for anchoring > 10 different proteins at the TZ, but instead, functions as an assembly factor. This activity is needed to form TZ ultrastructure, which comprises Y‐shaped axoneme‐to‐membrane connectors. Coiled‐coil and C2 domains within MKS‐5 enable TZ localisation and functional interactions with two TZ modules, consisting of Meckel syndrome (MKS) and nephronophthisis (NPHP) proteins. Discrete roles for these modules at basal body‐associated transition fibres and TZ explain their redundant functions in making essential membrane connections and thus sealing the ciliary compartment. Furthermore, MKS‐5 establishes a ciliary zone of exclusion (CIZE) at the TZ that confines signalling proteins, including GPCRs and NPHP‐2/inversin, to distal ciliary subdomains. The TZ/CIZE, potentially acting as a lipid gate, limits the abundance of the phosphoinositide PIP₂ within cilia and is required for cell signalling. Together, our findings suggest a new model for Mks5/Rpgrip1L in TZ assembly and function that is essential for establishing the ciliary signalling compartment.     

不同土壤水分条件下北方稻田耗水规律研究

采用田测法研究不同土壤水分条件下稻田需水规律．试验采用淹灌、湿润灌和间歇灌3种灌水处理．结果表明,在整个生育期内由田测法测得的淹灌、湿润灌和间歇灌3种处理的蒸散量分别为889．1、635．9和775．9mm．蒸散速率分别为6．9、4．9和6．0mm·d^-1．与淹灌处理相比．湿润灌和间歇灌处理分别节水28．5％和12．7％．在充分供水的情况下,由Penman法计算的潜在蒸散值分别比田测法小29．30％．淹灌、湿润灌和间歇灌3种处理的生物产量分别为16438．22、15887．94和15757．88kg·hm^-2．经济产量分别为8014．01、7828．91和7853．93kg·hm^-2．统计分析结果表明．3种处理间的产量差别不显著．淹灌、湿润灌和间歇灌3种处理的水分利用效率(WUE)分别为9．01、12．31和10．12kg·hm^-2·mm^-1．淹灌的WUE分别比湿润灌和间歇灌减少26．8％和11．0％．对比分析结果表明．湿润灌的节水效果最好．     

Direct measurement of the rupture force of single pair of decorin interactions

Decorin is one important member of the family of small leucine-rich proteoglycans, which are widely distributed in connective tissues in the body such as tendon and ligament. Decorin may be responsible for collagen fibril connection in those tissues. A recent hypothesis suggests that decorin may bind to collagen with its core protein while binding to another decorin through the interaction with their glycosaminoglycan (GAG) chains. However, there is no direct evidence supporting this hypothesis to date. In this study, the interaction of decorin GAG chains was directly determined for the first time. The rupture force of single bonds between decorins (GAG chains interaction) was determined directly as 16.5+/-5.1 pN using a laser tweezers/interferometer single molecular nanomechanical testing system. This information can improve our understanding of the mechanical properties of connective tissues at the molecular level.     

Radioecological problems of aquatic ecosystems of the chernobyl exclusion zone

The dynamics of the main contaminating radionuclides in the components of aquatic ecosystems within the Chernobyl APP exclusion zone is considered. The possible causes are analyzed for the marked increase in the specific activity of ⁹⁰Sr in water and hydrobionts of the lakes at the dammed left bank of river Pripyat. Notable is the elevated frequency of chromosomal aberrations in the root meristems of aquatic higher plants (up to 17%) and in the embryonal tissues of gastropod mollusks (up to 27%), alterations in the hematological indices for gastropods, and high infestation of aquatic higher plants by parasitic fungi and gall arthropods in the most radiocontaminated reservoirs.     

Alignment of biological microparticles by a polarized laser beam

The optical alignment of biological samples is of great relevance to microspectrometry and to the micromanipulation of single particles. Recently, Bayoudh et al. (J. Mod. Opt. 50:1581–1590, 2003) have shown that isolated, disk-shaped chloroplasts can be aligned in a controlled manner using an in-plane-polarized Gaussian beam trap, and suggested that this is due to their nonspherical shape. Here we demonstrate that the orientation of various micrometer-sized isolated biological particles, trapped by optical tweezers, can be altered in a controlled way by changing the plane of linear polarization of the tweezers. In addition to chloroplasts, we show that subchloroplast particles of small size and irregular overall shape, aggregated photosynthetic light-harvesting protein complexes as well as chromosomes can be oriented with the linearly polarized beam of the tweezers. By using a laser scanning confocal microscope equipped with a differential polarization attachment, we also measured the birefringence of magnetically oriented granal chloroplasts, and found that they exhibit strong birefringence with large local variations, which appears to originate from stacked membranes. The size and sign of the birefringence are such that the resulting anisotropic interaction with the linearly polarized laser beam significantly contributes to the torque orienting the chloroplasts.     

Effects of spring flood and water level draw-down on methane dynamics in the littoral zone of boreal lakes

1. The annual dynamics of methane (CH₄) in a temporarily flooded meadow, mire bank, lacustrine sedge fen, temporarily and continuously inundated sedge ( Carex sp.) and reed ( Phragmites australis ) marshes were studied from June to November in the humic mesoeutrophic Lake Mekrijärvi and in eutrophicated parts of the mesotrophic Lake Heposelkä in the southern part of East Finland. The effects of water level and temperature on littoral CH₄ fluxes were determined. Vegetation zonation along the moisture gradient, and associated CH₄ fluxes, were evaluated.
2. The CH₄ flux increased along the moisture gradient from –0.2 to 14.2 mg CH₄ m^–2 h^–1, and was highest in the permanently inundated marshes. The duration of anoxia in the sediment caused differences in the CH₄ flux. Estimated emissions for the period 1 June – 30 September in continuously inundated sparse reed and sedge marshes, drying sedge marsh, and lacustrine sedge fen were 13, 11 and 6 g CH₄ m^–2, respectively.
3. In continuously inundated vegetation, the fluxes were highest in late July/early August. The seasonal CH₄ flux pattern suggested that the fluxes were regulated by the supply of organic matter during the course of the summer and the water level. In the temporarily flooded zone, the seasonal CH₄ flux dynamics was greatly affected by changes in the lake water level, the fluxes being highest during the spring flood in early June.     

Field measurements of nitrogen-fixing activity of intact saplings ofAlnus maximowiczii in the subalpine zone of Mt Fuji

Nitrogen-fixing (acetylene-reducing) activity of intact saplings ofAlnus maximowiczii was measured under natural conditions in the subalpine zone of Mt Fuji. The nitrogen-fixing activity was detected from the middle of June when expansion of leaves had just begun to the end of October when the shedding of leaves was almost completed. Diurnal changes in the activity were almost parallel with those of ground temperature. The measured nitrogen-fixing activity was related to ground temperature and total leaf area. Using this relation, annual nitrogen fixation was estimated from the data of ground temperature and leaf area measured in the field. The amount of annual nitrogen fixation was almost the same as that of nitrogen used for annual growth. It was concluded that nitrogen fixation by nodules made a considerable contribution to the nitrogen economy in the saplings ofA. maximowiczii.     

Ground water flow paths in relation to nitrogen chemistry in the near-stream zone

Interactions between ground water flow paths and water chemistry were studied in the riparian zone of a small headwater catchment near Toronto, Ontario. Significant variations in oxygen — 18 and chloride indicated the presence of distinct sources of water in the ground water flow system entering the near-stream zone. Shallow ground water at the upland perimeter of the riparian zone had nitrate-N, chloride and dissolved oxygen concentrations which ranged between 100–180 µg L^–1, 1.2–1.8 mg L^–1 and 4.6–9.1 mg L^–1 respectively. Concentrations of nitrate — N in deep ground water flowing upward beneath the riparian wetland were < 10 µg L^–1, whereas chloride and dissolved oxygen ranged between 0.6–0.9 mg L^–1 and 0.4–2.2 mg L^–1 respectively. Ammonium — N concentrations (20–60 µg L^–1) were similar in shallow and deep ground water. Ground water was transported through the wetland to the stream by three hydrologic pathways. 1) Shallow ground water emerged as springs near the base of the hillslope producing surface rivulets which crossed the riparian zone to the stream. 2) Deep ground water flowed upward through organic soils and entered the rivulets within the wetland. 3) Deep ground water reached the stream as bed and bank seepage. Springs were higher in nitrate and chloride than rivulets entering the stream, whereas bank seeps had lower concentrations of nitrate and chloride and considerably higher ammonium concentrations than the rivulets. These contrasts in nitrate and chloride concentrations were related to initial differences in the ion chemistry of shallow and deep ground water rather than to element transformations within the riparian wetland. Differences in ammonium concentration between seeps and rivulets were caused by immobilization of ammonium in the substrates of aerobic rivulets, whereas little ammonium depletion probably occurred in deep ground water flowing upward through reduced subsurface organic soils around the stream perimeter.