Effects of Orthophosphates and Condensed Phosphates on Chemical and Spectral Properties of the Humus Derivatives of Phosphorus and Metals

Inorganic orthophosphates and condensed phosphates strongly affected the acidic-basic properties of soil humus substances, which was expressed by the degree of their hydrolyzability in alkaline, acidic, and neutral media. The humus substances modified by phosphates were characterized by increased electron donor (basic, after Lewis) properties, as compared to the native substances, due to accumulation of C=C-bonds. They exerted an especially strong dissolving effect on Fe- and Al-containing soil minerals and had a greater affinity to exogenous Zn. The pattern of distribution of phosphorus in ortho- and pyrophosphates among a fraction of humus substances was studied.     

Agonist-Induced Stimulation of Inositol Phosphates in Primary Rabbit Retinal Cultures

Carbachol, noradrenaline, and serotonin stimulated the accumulation of inositol phosphates in a dose-dependent manner and maximally by 172.4%, 71.2%, and 51.6%, respectively, in 3-day-old rabbit retinal cultures. In contrast, dopamine, nicotine, isoproterenol, clonidine, 8-OH-dipropylaminotetralin, and gamma-aminobutyric acid were ineffective. In older cultures identified as containing primarily Müller cells, only carbachol and noradrenaline were able to induce a significant stimulatory response. The carbachol-, noradrenaline-, and serotonin-induced responses were pharmacologically characterized and shown to be mediated by muscarinic, alpha 1-adrenergic, and 5-hydroxytryptamine2 receptors, respectively. The results of the present study show that primary retinal cultures of 3 days of age give results comparable with those of the intact retina. Furthermore, it is demonstrated for the first time that putative Müller cells in cultures possess functional muscarinic and alpha 1-adrenergic receptors.     

The Correlation between Antiesterase Activities and Chemical Structure of Saligenin Cyclic Phosphates

The effect of substituents on phosphorus of saligenin cyclic phosphorus esters on inhibitory activities toward cholinesterases and ali-esterases in vitro and in vivo was studied. The most insecticidal methyl derivative was the strongest inhibitor of insect cholinesterase both in vitro and in vivo. When the size of the substituent increased, the specificity toward ali-esterase increased, while decreased toward cholinesterase. The inhibitor ratio (I₅₀ ChE/I₅₀ AliE) appears to relate closely with insecticidal activity. Non-insecticidal aryl derivatives are very specific to inhibit insect ali-esterase. They are very weak inhibitors of insect cholinesterase in vivo. Their thiono analogs are stronger in vivo than corresponding oxo analogs.     

Chemical Analysis and Plant Sources of Maytansinoids

By high performance liquid chromatography (HPLC) and mass spectrometry (MS), maytansine, maytanprine and maytanbutine, three anticancer maytansinoids were successfully isolated and identified from ten species of plants belonging to Celastraceae. These plants are: Maytenus graciliramula, M. austroyunnanensis, M. orbiculata, M. hookeri Loes var. longiradiata, M. inflata, M. berberoides, M. esquirolii, M. variabilis, M. royleana and M. senegalensis. This result shows that the plant resources containing maytansinoids in China are rather aboundant.     

山东植物区系的演变和来源

1　现代植物区系山东省位于我国东部、黄河下游 ,北濒渤海 ,东临黄海 ,地理范围介于北纬 34°2 3′～38°2 4′,东经 1 1 4°4 8′～ 1 2 2°4 3′之间。全省总面积为 1 5.72万 km2 ,占全国总面积的 1 .6%。属暖温带季风气候 ,沿海比较湿润 ,地带性植被主要是暖温带落叶阔叶林和松、栎类针阔叶混交林。山东省在中国植物区系的分区地位隶属于泛北极植物区、中国 -日本森林植物亚区、华北植物地区 [1 ]。据最近研究统计 ,现有野生维管植物 1 47科、61 4属 ,约 1 547种 (包括变种 ,下同 )。其中蕨类植物 2 4科 39属 1 0 5种 ,裸子植物 3科 3属 …     

Chemical Ecology and Biomolecular Evolution

The belief in the Darwinian theory of evolution appeared to be shaken when one tried to interpret statements of molecular biology in it. As a consequence there arose a theory of non-Darwinian neutral evolution. The supporters of this theory believe that under natural conditions no factors exist which can distinguish and select organisms on their internal (molecular) structure. In the opinion of these neutralists natural selection cannot in principle control the molecular constitution of organisms. Contrary to the viewpoint of the critics of neutralism it is impossible to admit that nucleic acids, proteins and other biomolecules can evolve without the participation of natural selection. This controversy in contemporary theoretical biology can be solved by integrating the conceptions of molecular ecology with Darwinian theory. Molecular ecology acknowledges the interactions of organisms by means of chemical substances synthesized by them. Such chemical ecological factors play a leading part in the selective stages of biomolecular evolution. These diverse chemical ecological interrelations take place intensively when living beings interact with parasitic microbes.     

Rubber-The Primary Sources For American Production

Despite extensive war-time investigations of other rubber-containing latex plants, the Pará rubber tree of Brazil remains, by any measure, the world's foremost source, and only guayule and the Russian dandelion display any possibility of becoming secondary sources of commercial importance.     

Sources of Canopy Chemical and Spectral Diversity in Lowland Bornean Forest

Sources of variation among the chemical and spectral properties of tropical forest canopies are poorly understood, yet chemical traits reveal potential ecosystem and phylogenetic controls, and spectral linkages to chemical traits are needed for remote sensing of functional and biological diversity. We analyzed 21 leaf traits in 395 fully sunlit canopies, representing 232 species and multiple growth forms, in a lowland mixed dipterocarp forest of Sarawak, Malaysia. Leaf traits related to light capture and growth (for example, photosynthetic pigments, nutrients) were up to 55% lower, and defense traits (for example, phenols, lignin) were 15–40% higher, in the dominant family Dipterocarpaceae and in its genus Shorea, as compared to all other canopy species. The chemical variation within Dipterocarpaceae and Shorea was equivalent to that of all other canopy species combined, highlighting the role that a single phylogenetic branch can play in creating canopy chemical diversity. Seventeen of 21 traits had more than 50% of their variation explained by taxonomic grouping, and at least 16 traits show a connection to remotely sensed spectroscopic signatures (RMSE < 15%). It is through these chemical-to-spectral linkages that studies of functional and biological diversity interactions become possible at larger spatial scales, thereby improving our understanding of the role of species in tropical forest ecosystem dynamics.     

Evolution of Primary Hemostasis in Early Vertebrates

Hemostasis is a defense mechanism which protects the organism in the event of injury to stop bleeding. Recently, we established that all the known major mammalian hemostatic factors are conserved in early vertebrates. However, since their highly vascularized gills experience high blood pressure and are exposed to the environment, even very small injuries could be fatal to fish. Since trypsins are forerunners for coagulation proteases and are expressed by many extrapancreatic cells such as endothelial cells and epithelial cells, we hypothesized that trypsin or trypsin-like proteases from gill epithelial cells may protect these animals from gill bleeding following injuries. In this paper we identified the release of three different trypsins from fish gills into water under stress or injury, which have tenfold greater serine protease activity compared to bovine trypsin. We found that these trypsins activate the thrombocytes and protect the fish from gill bleeding. We found 27 protease-activated receptors (PARs) by analyzing zebrafish genome and classified them into five groups, based on tethering peptides, and two families, PAR1 and PAR2, based on homologies. We also found a canonical member of PAR2 family, PAR2-21A which is activated more readily by trypsin, and PAR2-21A tethering peptide stops gill bleeding just as trypsin. This finding provides evidence that trypsin cleaves a PAR2 member on thrombocyte surface. In conclusion, we believe that the gills are evolutionarily selected to produce trypsin to activate PAR2 on thrombocyte surface and protect the gills from bleeding. We also speculate that trypsin may also protect the fish from bleeding from other body injuries due to quick contact with the thrombocytes. Thus, this finding provides evidence for the role of trypsins in primary hemostasis in early vertebrates.     

Evolution of Associative Learning in Chemical Networks

Organisms that can learn about their environment and modify their behaviour appropriately during their lifetime are more likely to survive and reproduce than organisms that do not. While associative learning – the ability to detect correlated features of the environment – has been studied extensively in nervous systems, where the underlying mechanisms are reasonably well understood, mechanisms within single cells that could allow associative learning have received little attention. Here, using in silico evolution of chemical networks, we show that there exists a diversity of remarkably simple and plausible chemical solutions to the associative learning problem, the simplest of which uses only one core chemical reaction. We then asked to what extent a linear combination of chemical concentrations in the network could approximate the ideal Bayesian posterior of an environment given the stimulus history so far? This Bayesian analysis revealed the ‘memory traces’ of the chemical network. The implication of this paper is that there is little reason to believe that a lack of suitable phenotypic variation would prevent associative learning from evolving in cell signalling, metabolic, gene regulatory, or a mixture of these networks in cells.     

Solvent and Chemical Impurities as Sources of Gibberellin-like Growth-Promoting Activity

Experiments are described in which a standard procedure usedfor the extraction of endogenous gibberellin-like substancesfrom plants was carried out in the absence of plant materialto give ‘blank’ extracts. Acidic, basic, and neutralfractions of blank extracts all showed variable gibberellin-likeactivity on d-5 dwarf maize and lettuce hypocotyls, though oftenat a low level. Acidic fractions showed activity on d-2 dwarfmaize, but none of the fractions was active on dwarf peas oron tomato seedlings. One sample of sodium bicarbonate appearedto be contaminated by two gibberellin-like substances. Someactivity was observed in ethanol, chromatography paper, andammonium acetate, but none in methanol or redistilled ethylacetate. There were wide variations between the results of comparableexperiments. In the light of these results possible precautionsfor experiments involving extraction of endogenous gibberellin-likesubstances are discussed.     

Chemical Evolution and Meteorites: An Update

Carbonaceous chondrites are a primitive group of meteorites, which contain abundant organic material and provide a unique natural record of prebiotic chemical evolution. This material comprises a varied suite of soluble organic compounds that are similar, sometimes identical, to those found in the biosphere, such as amino acids, carboxylic acids, and sugar derivatives. Some amino acids of this suite also show L-enantiomeric excesses, and suggest the possibility they may have contributed to terrestrial homochirality by direct input of meteoritic material to the early Earth. This optical activity appears to be limited to the subgroup of alpha-methyl amino acids which, although not common in the extant biosphere, would have been well suited to provide the early earth with both enantiomeric excesses and means for their amplification by subsequent chemical evolution. We can also envision this exogenous delivery of carbonaceous material by meteorites and comets as having coincided with the endogenous formation of prebiotic precursors and influenced their evolution by complementary reactions or catalysis.     

Cycles and the Qualitative Evolution of Chemical Systems

Cycles are abundant in most kinds of networks, especially in biological ones. Here, we investigate their role in the evolution of a chemical reaction system from one self-sustaining composition of molecular species to another and their influence on the stability of these compositions. While it is accepted that, from a topological standpoint, they enhance network robustness, the consequence of cycles to the dynamics are not well understood. In a former study, we developed a necessary criterion for the existence of a fixed point, which is purely based on topological properties of the network. The structures of interest we identified were a generalization of closed autocatalytic sets, called chemical organizations. Here, we show that the existence of these chemical organizations and therefore steady states is linked to the existence of cycles. Importantly, we provide a criterion for a qualitative transition, namely a transition from one self-sustaining set of molecular species to another via the introduction of a cycle. Because results purely based on topology do not yield sufficient conditions for dynamic properties, e.g. stability, other tools must be employed, such as analysis via ordinary differential equations. Hence, we study a special case, namely a particular type of reflexive autocatalytic network. Applications for this can be found in nature, and we give a detailed account of the mitotic spindle assembly and spindle position checkpoints. From our analysis, we conclude that the positive feedback provided by these networks'' cycles ensures the existence of a stable positive fixed point. Additionally, we use a genome-scale network model of the Escherichia coli sugar metabolism to illustrate our findings. In summary, our results suggest that the qualitative evolution of chemical systems requires the addition and elimination of cycles.     

The Temporal Evolution of Anthropogenic Phosphorus Consumption in China and Its Environmental Implications

Modern human activities greatly disturb substance flows in nature and senselessly discard massive amounts of precious resources to natural waste reservoirs; phosphorus (P) is a good example of this. In this article, substance flow analysis is employed to quantify and explore the temporal evolution of China's P consumption in main metabolic nodes from 1984 to 2008, and then the environmental implications for P flows into both surface waters and natural soil are investigated. Results show that the metabolic nodes of human life and animal husbandry have demanded increasingly more P inputs, while disseminating more and more P wastes, with the waste recycling ratios of these processes dropping, respectively, from 65.9% and 66.1% in 1984 to 50.7% and 40.6% by 2008. These change traits were closely related to national polices including the Household Contract Responsibility System and the Shopping Basket Program, as well as the policy vacuum existing between China's agricultural and environmental administration departments. To achieve high crop yield, increasingly more inorganic P fertilizers have been utilized in China, but their use efficiency has decreased by 46.3%. From 2003 to 2008, the total P load into surface waters was stabilized at about 900.0 kilotons (kt), while the total P load into natural soil increased by more than 3.8 times to 3,131.3 kt P in 2008. City life and the intensive breeding of crops are identified as the main targets for further pollution control and nutrient recycling in China. Some suggestions for achieving environmentally sound practices and resource sustainability in China are proposed at the end of this article.     

丛枝菌根促进植物根系吸收难溶态磷的研究进展(综述)

从扩大植物根系吸收面积、改善根际微环境、促进磷元素运输等方面综述丛枝菌根促进植物活化、吸收难溶态磷的最新研究概况。     

A Center of Primary Sources for Plains Indian History

Abstract

Preservation of the nation’s Indian records is recogni: zed as a task of national importance. Public access to government documents and data is now possible at ten regional records centers across the country. The material stored provides detailed and analytic accounts of daily activity and business at Indian agencies. The nature and content of the data relevant to Plains Indian agencies is described in this paper.