Crimean-Congo hemorrhagic fever in Rostov Province: the epidemiological characteristics of an outbreak

The results of the epidemiological analysis of the outbreak of hemorrhagic fever which was caused by Crimean-Congo hemorrhagic fever virus and occurred during the period of July 3-19, 1999, in the Oblivskaya district of Rostov Province are presented. The specific epidemiological features of the outbreak have been determined. The possible versions of the appearance of the focus of infection and the role of Ixodes ticks in the circulation of the infective agent are discussed.     

Intra-annual genetic variation in the downstream larval drift of sutchi catfish (Pangasianodon hypophthalmus) in the Mekong river

Larvae of the sutchi catfish Pangasianodon hypophthalmus were collected during peak downstream drift in the Lower Mekong river on four occasions over an 8-week period during the 2003 spawning season, and genotyped using seven microsatellite loci. We provide evidence for several heterogeneous groups within and among the temporally discrete larval peak samples. Strong evidence for a significant deficit of heterozygotes was observed for each larval sample and the pooled sample, possibly due to population admixture. Although individual-based assignment tests suggested that each larval peak sample was admixed, significant but low genetic differentiation was observed among larval samples ( F _ST = 0.0052, P  < 0.01). The lack of significant relatedness confirms the multifamily composition of each larval group, excluding family bias to explain the observed genetic heterogeneity. Both the entire larval peak and each temporally separated larval peak originated from spawning groups with heterogeneous allelic composition involving several distinct spawning events. We propose three explanations to account for our findings: (1) the ecological match/mismatch hypothesis; (2) the genetic 'sweepstakes' selection hypothesis; and (3) life-history-specific characteristics of the spawning populations. Finally, an intra-annual shift in the contribution of the spawning populations to the larval drift was detected on successive occasions.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 719–728.     

Insecticidal activities of Ginkgo biloba seed coat extracts against Spodoptera exigua (Lepidoptera: Noctuidae)

The present study relates to a methanol extract of the seed coat of Ginkgo biloba, and tested particularly on the third instar larvae of Spodoptera exigua. The extract was found to have an inhibitory effect on the growth of the larvae besides bringing a change in the nutrient reserves in the body of the insect. Topical application of five different doses of the methanol extract resulted in a mortal effect to third instar larvae of S. exigua that is very much dependent on the dose as well as duration of exposure. Lower doses revealed lower mortality after 24 h of application. At doses of 1.00, 2.00, 4.00, 8.00 and 16.00 ng/larva, mortalities were 9.25, 26.07, 50.32, 56.28 and 92.44%, respectively. The dose for 50% mortality (LD₅₀) of methanol extracts by applied by a topical method with 1 µL of acetone solution was 1.92 ng/larva. Nutrient reserves like protein, glycogen and lipid are known to regulate pupation and adult emergence. These reserves have been found to be lower in treated larvae, indicating the insecticidal role of methanol extracts from G. biloba against third instar larvae of S. exigua.     

Riccia fruticulosa O.F.Müll., 1782 and blue Metzgeria (Marchantiophyta) in Europe

Riccia fruticulosa O.F.Müll., 1782 from Norway is a valid name, referring to Riccardia palmata (Hedw.) Carruth. In 1785 Dickson misidentified British plants of a blue Metzgeria as R. fruticulosa . The European blue species of Metzgeria is conspecific with M. violacea (Ach.) Dumort., which replaces M. fruticulosa auct. The true origin of the type of Jungermannia violacea Ach., 1805 is probably Tierra del Fuego (rather than Dusky Bay, New Zealand), where the species is widespread. Reports from Australasia, Asia and Africa are all erroneous. The blue colour of Jungermanniales is found only in living plants and is derived from the oil-bodies. In contrast, that of Metzgeria appears only after death; its biological function is unknown.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142 , 229−235.     

The effect of the adhesion pili of Yersinia pestis on the physiological activity of the leukocytes and macrophages in experimental animals

The data on the influence of the preparation of Y. pestis adhesion pili on peritoneal macrophages in white mice and guinea pigs are presented. Y. pestis adhesion pili have been found to induce the dose-dependent increase of cell chemiluminescence. They have also been found to induce a number of biochemical changes in target cells: the secretion of myeloperoxidase, an increase in the activity of cAMP-dependent protein kinases.     

Variations in the life-history parameters of Hemipyrellia ligurriens (Diptera: Calliphoridae) in response to larval competition for food

Abstract. 1. Larval rearing densities of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae) in standardized carrion were manipulated in order to investigate changes in life-history parameters in response to larval competition for food.
2. Competition was of the typical scramble type. Survivorship remained high at densities up to 32 larvae g liver^-1 but decreased rapidly as larval density increased further.
3. Emergent adults were undersized with reduced fecundity and longevity. Variations in adult body size apparently reduced the effects of competition on larval mortality.
4. Females of dry weight corresponding to only 10.4% of the potential maximum emerged at the highest rearing densities of 128 larvae g liver-1. However, these females had a nearly four-fold increase in reproductive investment (per unit weight) when compared to the largest individuals.
5. The duration of larval development declined when competition was intense (i.e. at high larval densities).
6. The short adult life of H.ligurriens, combined with the unpredictability of larval habitat availability, may reduce the value of long-range dispersal so that females 'do better' by maintaining reproductive investment despite a concomitant decline in dispersal ability.     

The effect of the "37 degrees C--low pH" signal on cells of Yersinia pestis

It is established that the synthesis of adhesion piles registered by the results of immunoenzyme analysis and immunoblotting starts 90 min after the action on apilated cells of plaque microbe EB-76 of the signal "37 degrees C-low pH" (cultivation at 37 degrees C and acidic pH). Under these conditions a part of cell piline is in a form connected with cells and only inconsiderable part (to 20%) is represented in a form of "classical" piles possessing hemagglutinating activity. It is shown that in first 7h after the interaction of the signal "37 degrees-low pH" synthesis of adhesion piles quantitatively prevails over the synthesis of antigen of the fraction I of plaque microbe.     

金黄地鼠视皮层通过胼胝体顺行和逆行激活的神经元的电活动和分布

用细胞外记录技术研究了金黄地鼠一侧视皮层神经元对电刺激另一侧相应部位的反应及其对视觉刺激反应的特点。(1)在17—18a 交界区大多数(78%)细胞能被电刺激对侧相应点所驱动。在17区内部,被驱动细胞数随离开17—18a 交界距离增加而减少。(2)按对电刺激的反应形式,记录的细胞可分为四类:a.逆行驱动细胞,占17—18a 交界区记录细胞数的20%;b.顺行驱动细胞,占52%中;c.自发发放因电刺激而减少或完全停止的细胞,占6%,d.其余细胞(22%)对电刺激没有可察觉的反应。(3)在17—18a 交界,除了Ⅰ层以外的各层都可记录到顺行驱动细胞,而逆行驱动细胞则主要集中在Ⅲ及Ⅴ层。(4)17—18a 交界细胞感受野(RF)多位于垂直中线附近的对侧视野内,有些 RF 跨越中线,其边界延伸到同侧约10°处。(5)逆行驱动细胞包括刁和 Blakemore 以前在视皮层中记录到的所有细胞类型和各种程度的眼优势,但单眼细胞的比例增加,非对称式 RF 和中心对称式的给-撤型 RF 的比例有所减少。     

Dynamics of the isolation and biological properties of Vibrio cholerae cultures,serogroups 01 and 0139, isolated from water reservoirs and sewage water on the territory of the city of Rostov-on-Don

The dynamics of the isolation of V. cholerae cultures from various water objects on the territory of Rostov-on-Don during the period of 1994-2001 was analyzed and biological properties of 14 such cultures were studied. In the absence of epidemic complications during the above-mentioned period, a growth in the amount of V. cholerae isolates, serogroups 01 and 0139, including toxigenic V. cholerae 01, was registered. The microbiological and epidemiological aspects of the monitoring of surface reservoirs and sewage were considered and the expediency of the profound and systematic study of its results for epidemiological surveillance on cholera was emphasized.