Food webs: experts consuming families of experts

Food webs of habitats as diverse as lakes or desert valleys are known to exhibit common "food-web patterns", but the detailed mechanisms generating these structures have remained unclear. By employing a stochastic, dynamical model, we show that many aspects of the structure of predatory food webs can be understood as the traces of an evolutionary history where newly evolving species avoid direct competition with their relatives. The tendency to avoid sharing natural enemies (apparent competition) with related species is considerably weaker. Thus, "experts consuming families of experts" can be identified as the main underlying food-web pattern. We report the results of a systematic, quantitative model validation showing that the model is surprisingly accurate.     

Retention of memory traces in rats subjected to 10-minute clinical death procedure

Retention of memory traces was tested on the 12th day after 10-min clinical death (CD) produced by the total cessation of blood circulation in Albino rats previously trained for operant food conditioning in a multiple alternative maze. It was found that the structure of memory trace (sequence of operant actions in the maze), motivation activity and habit organization after the resuscitation were completely preserved in all rats independently of the number of the memory traces formed. Short-term negative changes were revealed only in the character of habit realization: the efficiency and reproduction parameters such as "readiness", mobilization activity, and stability of habit realization had lower values during 2-3 sessions. The rate of their recovery after the CD depended on rat's initial motivation state: the higher was the initial motivation, the faster recovered all the reproduction parameters. It is suggested that the observed negative changes in habit realization were nonspecific and were provoked by the CD-induced hyperexcitability of rats.     

Organization of the Escherichia coli genome

A review of literature data reveals that for the last years, the molecular biology techniques have been of an increasing use in the study of the Escherichia coli genome, having supplemented the standard genetic mapping. For the proper understanding of the Escherichia coli genome organization, recombinational events occurring in the course of evolution should be considered. The bacterial genome seems to carry traces of both "long-term" evolution, possibly responsible for appearance of the bacterial cell itself, and "current" evolution, consisting mainly of periodic genome entering by new plasmid-originated genes. It is supposed that in the process of stabilization within a genome, every new gene undergoes a stage of the "transgene", that is the gene situated in a transposon on the chromosome. In parallel with integration of new genes into the genome, some genes deleting should also take place. The formation of deletions could occur by unequal crossing over in segments of direct homologous repeats which seem to be ordinarily revealed in the experimental study of the tandem gene duplications.     

Polyamines in representative taxa of coryneform and other bacteria

The composition of polyamines is studied for the first time in representatives of the genus Micrococcus and taxon "conglomeratus", strains Staphylococcus aureus CCM 209, Deinococcus erythromyxa CCM 706 as well as of Erwinia carotovora ATCC 15713 polyamines, which are not extracted by perchloric acid. Considerable amounts of spermine and rarely of spermidine are revealed in cells of Gram positive microorganisms, that differs them from Gram negative bacteria possessing high concentrations of putrescine, spermidine and their derivatives. A procedure is developed for detection of polyamines in cells of Gram positive microorganisms. It is recommended to use the hydrolysis of their cells by 6N HCl for 4 at 120 degrees C or for 8-10h at 100 degrees C with the subsequent electrophoretic separation. Putrescine, as well as comparable with it amount of agmatine and spermidine traces are found in Erwinia carotovora ATCC 15713 cell hydrolyzates, whereas putrescine and agmatine traces are found in perchloric extracts of intact cells. Spermine is not observed in the cells. The binding of polyamines with biopolymers of cells of Gram positive bacteria and their difference by the given character from the Gram negative procaryotes are under discussion.     

利用RAPD标记研究荔枝品种的新缘关系

采用改进的ＣＴＡＢ方法提取３４个荔枝品种的基因组ＤＮＡ为模板,从５０个１０碱基的随机引物中获得了３７个多态性ＲＡＰＤ标记,聚类分析结果表明这３４个荔枝品种可以分成４组,第一组有“状元红”、“元红”、“桂林”、“宋家香”、“台湾荔”、“下番枝”、“东刘一号”、“妃子笑”、“白糖罂”、“香丸”、“绿沙”;第二组有“无栗子”、“水东”、“乌叶”、“蔡家肉丸”、“青壳糯米糍”、“糯米糍”;第三组有“桂味”     

Occurrence and taxonomic significance of cysteine sulphoxides in the genus Allium L. (Alliaceae)

Methiin was present in all investigated samples. In the genus Allium, methiin-dominated species (rarely used by man) were common, but the occurrence of the other cysteine sulphoxides was variable and was largely correlated with use as spices or vegetables. Two major chemical types (named according to the species where they occur) could be distinguished, and at least two more may be recognized. Isoalliin dominates in the widely used "onion-type", which includes chive (A. schoenoprasum) and top onion (A.xproliferum). Pearl onion and leek (A. ampeloprasum) have higher relative amounts of methiin and propiin, respectively. Alliin dominates in the widely used "garlic-type", which includes wild leek (A. obliquum) and sand leek (A. scorodoprasum). Alliin and isoalliin rarely co-dominate, being only found in the cultivated Chinese leek (A. tuberosum). A triple mix of almost equal amounts of methiin, alliin and isoalliin is present in ramson (A. ursinum). General trends in the three evolutionary lines of the genus Allium were apparent. In the first lineage, high amounts of methiin were more frequent, and propiin, although being a minor component in all three evolutionary lines, was present in the highest amounts. Most of the species in the second line showed only traces of cysteine sulphoxides. In the third line, the "onion-type" dominates, the "garlic type" is characteristic for subgenus Allium, and co-dominating alliin and isoalliin also occur. Generally, the total cysteine sulphoxide amount increased, and the complexity of cysteine sulphoxide patterns decreased in the transition from the first to the third evolutionary line.     

Echinoid bioerosion from the Pliocene of NE Spain

In the present study a series of rasping traces onshells and limestone pebbles from the Pliocene of l'Empordà (Catalunya, NE Spain) are described. The traces have been attributed to the ichnospecies Gnathichnus pentaxBromley, 1975. This type of rasping traces is produced today by regular echinoids. Comparison with the traces produced by P. lividus (Lmk) of the Catalan coast confirms its origin.     

Microsatellite DNA and RAPD fingerprinting,identification and genetic relationships of hybrid poplar (<Emphasis Type="Italic">Populus x canadensis</Emphasis>) cultivars

Microsatellite DNA markers of ten SSR loci and 248 RAPD loci (resolved by 26 RAPD primers) were used for DNA fingerprinting and differentiation of 17 widely grown Populus x canadensis syn. Populus x euramericana (interspecific Populus deltoides x Populus nigra hybrids) cultivars ("Baden 431", "Blanc du Poitou", "Canada Blanc", "Dorskamp 925", "Eugenei", "Gelrica", "Grandis", "Heidemij", "I-55/56", "I-132/56", "I-214", "Jacometti", "Ostia", "Regenerata", "Robusta", "Steckby" and "Zurich 03/3"), and determination of their genetic interrelationships. Informativeness of microsatellite and RAPD markers was also evaluated in comparison with allozyme markers for clone/cultivar identification in P. x canadensis. High microsatellite DNA and RAPD genetic diversity was observed in the sampled cultivars. All of the 17 P. x canadensis cultivars could be differentiated by their multilocus genotypes at four SSR loci, and were heterozygous for their parental species-specific alleles at the PTR6 SSR locus. Except for "Canada Blanc" and "Ostia", which had identical RAPD patterns, all cultivars could also be differentiated by RAPD fingerprints produced by each of the two RAPD primers, OPA07 and OPB15. For microsatellites, the mean number of alleles, polymorphic information content, observed heterozygosity, observed number of genotypes and the number of cultivars with unique genotypes per locus was 5.2, 0.64, 0.67, 5.7 and 2.2, respectively. For RAPD markers, the number of haplotypes per locus, and the number of cultivars with unique RAPD profiles per locus were 1.06 and 0.72, respectively. Overall, microsatellite DNA markers were the most informative for DNA fingerprinting of P. x canadensis cultivars. On the per locus basis, microsatellites were about six-times more informative than RAPD markers and about nine-times more informative than allozyme markers. However, on the per primer basis, RAPD markers were more informative. The UPGMA cluster plots separated the 17 cultivars into two major groups based on their microsatellite genotypic similarities, and into three major groups based on their RAPD fragment similarities. Both the microsatellite and RAPD data suggest that the cultivars "Baden 431", "Heidemij", "Robusta" and "Steckby" are genetically closely related. The inter-cultivar genetic relationships from microsatellite DNA and RAPD markers were consistent with those observed from allozyme markers, and were in general agreement with their speculated origin. Microsatellite DNA and RAPD markers could be used for clone and cultivar identification, varietal control and registration, and stock handling in P. x canadensis.     

Flavonoids from the stem bark of Lonchocarpus xuul

The stem bark of Lonchocarpus xuul (Leguminosae) has yielded four flavonoids which have been identified by spectroscopic methods as the novel 4beta,5-dimethoxy-6",6"-dimethyl-2H-pyrano-(2",3":7,6)-fl avan (xuulanin), 3beta,4beta,5-trimethoxy-6",6"-dimethyl-2H-pyrano-(2",3":7,6 )-flavan (3beta-methoxyxuulanin). 4beta-ethoxy-5-methoxy-6",6"-dimethyl-2H-pyrano-(2",3":7,6)- flavan (4beta-demethylxuulanin-4beta-ethyl ether), and the known 5,7-dihydroxy-6,8-di(3-methylbut-2-enyl)flavanone (spiniflavanone-B). The ethyl derivative is considered likely to be an artefact.     

Systematic synthesis of four epicatechin series procyanidin trimers and their inhibitory activity on the Maillard reaction and antioxidant activity

A systematic synthesis of four natural epicatechin series procyanidin trimers [[4,8:4",8"]-2,3-cis-3,4-trans: 2",3"-cis-3",4"-trans: 2,3-trans-(-)-epi-catechin-(-)-epicatechin-(+)-catechin, [4,8:4",8"]-2,3-cis-3,4-trans: 2",3"-cis-3",4"-trans: 2,3-cis-tri-(-)-epicatechin: procyanidin C1, [4,8:4",8"]-2,3-cis-3,4-trans: 2",3"-trans-3",4"-trans: 2,3-trans-(-)-epicatechin-(+)-catechin-(+)-catechin: procyanidin C4, and [4,8:4",8"]-2,3-cis-3,4-trans: 2",3"-trans-3",4"-trans: 2,3-cis-(-)-epicatechin-(+)-catechin-(-)-epicatechin] is described. Condensation of (2R,3R,4S)-5,7,3'4'-tetra-O-benzyl-4-(2"-ethoxyethyloxy)flavan derived from (-)-epicatechin as an electrophile with the dimeric nucleophiles in the presence of TMSOTf followed by deprotection yielded trimers. Inhibitory activities on the Maillard reaction and antioxidant activity on lipid peroxide of the synthesized oligomers were also investigated.     

Mechanisms of the otolith signal processing

A series of current hypotheses of mechanisms of the otolith signals processing and organization of adaptive responses of the oculomotor system to gravito-sensitive (otolith) inputs are reviewed: the "frequency segregation of the otolith signals", "gravito-inertial force resolution", "spatio-temporal transformation of the angular vestibulo-ocular reflex", "inertial processing of the vestibular signals", "asymmetry of the otolith signals", and their experimental corroboration.     

Taxonomic Study of Dimocarpus longan by Random Amplified Polymorphic DNA Technique

The classification and relationship among 35 samples of longan (Dimocarpus longan Lour. ) have been studied by RAPD (random amplified polymorphic DNA) and statistical cluster analysis. These results showed that it was unlikely possible that "Lizhiben" and "Lizhi kongyan" were hybrid progeny of longan and litchi ( Litchi chinensis Sonn. ) as what some people believe. The "Lizhiben", and "Nanhu Jiaohe" were highly mutant varieties. There were some variance among the "Jiaohe" wilted-nut longan cultivars. Different cuhivars given the same name, such as "Dongbf', "Honghezi" and some other cultivar, were also possible. It was concluded that longan cultivars which have been tested in this research could be classified into 6 groups. The first group, including 12 cultivars such as "Shuizhang", "Youtanben", "Wulongling" etc., which were the well known best cultivars appropriate for producing dry longan, was named as Shuizhang-Wulongling group. The second group, including 11 cultivars like "Chike", "Jiaoyan", "Fuyan", "Chushuben" etc., was named as Chike-Chushuben group. The Dongbi series cuhivars were named after their cultivars as the Dongbi group. The special cuhivars, "Lidongben", "Nanhu Jiaohe" and "Lizhiben" were named respectively as Lidongben group, Nanhu Jiaohe group, and Lizhiben group, because of their more characteristic DNA polymorphism tested in all respective cuhivars. The results indicate that the application of RAPD technique in the taxonomic study has gained some resolution which could not be obtained by morphological analysis and has provided available data for developing longan production and for breeding new longan cultivars.     

Disinfectants and main sanitary and preventive measures for protection of ventilation and air-conditioning systems from Legionella contamination

The study was devoted to selection and assessment of disinfecting preparations for prevention of contamination by Legionella. Using system of criteria for quality assessment of disinfectants, seven newdomestic ones belonging to quaternary ammonium compounds class or to oxygen-containing preparations and designed for disinfecting of air-conditioning and ventilation systems were selected. Antibacterial and disinfecting activities of working solutions of disinfectants were tested in laboratory on the test-surfaces and test-objects of premises' air-conditioning and ventilation systems contaminated with Legionella. High antimicrobial and disinfecting activity of new preparations "Dezactiv-M", "ExtraDez", "Emital-Garant", "Aquasept Plus", "Samarovka", "Freesept", and "Ecobreeze Oxy" during their exposure on objects and materials contaminated with Legionella was shown. Main sanitary and preventive measures for defending of air-conditioning and ventilation systems from contamination by Legionella species were presented.     

Usefulness of amplitude as a rheographic-cardiographic parameter for evaluation of degree of heart failure]

Impedance rheographic-cardiography has been performed in 40 patients with chronic congestive heart failure. At the same time, polycardiographic data have been recorded and used for the correlative analysis. A curve dZ/dt has been analysed and "S", "X", "A", "O" waves amplitudes together with A/S and X/S ratios have been calculated, depending on the degree of heart failure. It was found, that rheographic-cardiography may be valuable technique for the assessment of the degree of heart failure. Curve dZ/dt in patients with more advanced heart failure is of hypodynamic character (decrease in "S", "X", and "A" waves amplitude with an increase in "O" wave amplitude), being similar to sinusoidal curve. The most valuable rheographic-cardiograph parameters enabling the assessment of heart failure are: "S" and "O" waves amplitudes, and A/S and X/S ratios. Correlative analysis has also shown several important relationships between rheographic-cardiographic and polycardiographic parameters, which may facilitate the assessment of heart failure.     

Evaluation of embryological potential of soybean cultivars zoned in forest, steppe, and marshy woodlands of Ukraine as essential stage for the further transformation

Seven soybean (Glycine max (L.) Merr.) cultivars zoned in forest-steppe and marshy woodlands of Ukraine: "Chernuatka", "Vasylkivska", "Kyivska-91", "Kyivska-27", "Marjana", "Chernobura" and "Altair" were established in vitro for somatic embryogenesis inducing. Cultivars "Marjana" (88%) and "Vasylkivska" (86%) demonstrated the highest embryogenic capacity among all the tested cultivars. During the further plant regeneration cultivars "Marjana" and "Kyivska-91" showed the best capacity to form adult plants despite the fact that embryogenic capability of the cultivar "Kyivska-91" was 71%. According to the obtained data three genotypes were selected for the further investigation of effective methods of biolictic transformation of ukrainian cultivars.     

On the definition, nomenclature and classification of water channel proteins (aquaporins and relatives)

A water channel protein (WCP) or a water channel can be defined as a transmembrane protein that has a specific three-dimensional structure with a pore that provides a pathway for water permeation across biological membranes. The pore is formed by two highly conserved regions in the amino acid sequence, called NPA boxes (or motifs) with three amino acid residues (asparagine-proline-alanine, NPA) and several surrounding amino acids. The NPA boxes have been called the "signature" sequence of WCPs. WCPs are a family of proteins belonging to the Membrane Intrinsic Proteins (MIPs) superfamily. In addition, in the MIP superfamily (with more than 1000 members) there are also proteins with no channel activity. The WCP family include three subfamilies: aquaporins, aquaglyceroporins and S-aquaporins. (1) The aquaporins (AQPs) are water selective or specific water channels, also named by various authors as "orthodox", "ordinary", "conventional", "classical", "pure", "normal", or "sensu strictu" aquaporins); (2) The aquaglyceroporins are permeable to water, but also to other small uncharged molecules, in particular glycerol; this family includes the glycerol facilitators, abbreviated as GlpFs, from glycerol permease facilitators. The "signature" sequence for aquaglyceroporins is the aspartic acid residue (D) in the second NPA box. (3) The third subfamily of WCPs have little conserved amino acid sequences around the NPA boxes, unclassifiable to the first two subfamilies. I recommend to use always for this subfamily the name S-aquaporins. They are also named "superaquaporins", "aquaporins with unusual (or deviated) NPA boxes", "subcellular aquaporins", or "sip-like aquaporins". I also recommend to use always the spelling aquaporin (not aquaporine), and, for various AQPs, the abbreviation AQP followed immediately by the number, (e.g. AQP1), with no space or - which might create confusions with "minus".     

The way of the germline, its developmental cycle and epigenetic network

The long-awaited second edition of the International Symposium on "Epigenome Network, Development and Reprogramming of Germ Cells" hosted by Hiroyuki Sasaki took place at the Kyushu University School of Medicine, in Fukuoka, Japan from 22 to 24 November 2010. This meeting brought together again the crème de la crème of the Japanese research community investigating germline development, reprogramming and genetic networks as well as eminent international scientists. Novel trend concepts including the "reprogramming expressway", "canalization", "licensing", "epigenetic barrier", "flex points" and "hydroxymethylation" were introduced and discussed in the context of development, reprogramming and pluripotency.     

我国哺乳动物就地保护状况评估

自然保护区被公认为是生物多样性就地保护最有效的方式之一。基于全国自然保护区基础调查,通过分析我国自然保护区内野生哺乳动物种群数量的分布情况,在全国尺度上对自然保护区内591种哺乳动物的就地保护状况进行了评估。根据评价指标体系,将我国哺乳动物就地保护水平划分为"有效保护""较好保护""一般保护""较少保护""未受保护""保护状况不明""未予评价"等7个等级。结果表明,除未予评价的35种外,其余参评的556种物种中,共有534种在自然保护区内得到一定程度的保护,占总数的90.36%。其中有效保护、较好保护、一般保护、较少保护的物种分别有145、60、100种和229种,分别占总数的24.53%、10.15%、16.92%和38.75%。此外,有22种物种保护状况不明。针对不同保护体系中的哺乳动物的就地保护状况进行评价,研究共涉及国家重点保护野生动物140种和列入中国物种红色名录的427种,其中分别有109种和409种在保护区内得到不同程度的保护。总体来说,虽然有90.36%的哺乳动物在保护区内得到不同程度的保护,但保护状况良好(包括有效保护和较好保护)的比例明显较低,保护状况仍然不容乐观,保护力度有待加强;对于保护状况不明的物种,有必要对保护区开展更加全面、细致的科学考察以进一步确定其保护现状;对于确未受到自然保护区就地保护的物种,需要通过完善保护区网络,将其纳入自然保护体系之中。