OALib Journal期刊

ISSN: 2333-9721




2020 ( 34 )

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匹配條件: “Peter Vallo” ,找到相關結果約32344條。
Yellow-bellied or white-bellied? Identity of Arabian house bats (Vespertilionidae: Scotophilus) revealed from mitochondrial DNA and morphology
Peter Vallo
African Zoology , 2012,
Abstract: The yellow-bellied Scotophilus dinganii is the only African house bat species reported to occur in the Arabian Peninsula. Formerly, the Arabian house bats were referred to similar-looking white-bellied S. leucogaster, which differs from S. dinganii mainly by the colour of ventral pelage. We reassessed the taxonomic status of house bats from southwestern Yemen using genetic and morphological analyses. The Yemeni specimens clustered within two distantly related mitochondrial lineages of African Scotophilus: East African S. aff. dinganii, which is a paraphyletic group to S. dinganii s. str. from South Africa, and West African S. leucogaster. This taxonomic assignation was based on published sequences of reference museum specimens. Differences in external and cranial measurements also indicated the presence of two distinct taxa in Yemen. The Yemeni and comparative Ethiopian populations of S. aff. dinganii showed close morphological similarity to the type specimen of S. nigrita colias from Kenya. Because the Yemeni and Ethiopian yellow-bellied house bats cannot be synonymized with S. dinganii, the designation S. colias is tentatively suggested for this particular East African and Yemeni lineage of the S. dinganii complex. However, final correspondence of this name with the respective populations or applicability of some of other available names must yet be explored. Based on environmental differences of the Yemeni localities of origin, S. colias appears to be ecologically delimited to mountainous habitats, while S. leucogaster to harsh lowland deserts. This is consistent with known habitats of African populations of both species.
Le Corps de l'ennemi. Pratiques et représentations autour des cadavres ennemis dans la Première Guerre mondiale
Michel Vallo
Atelier du Centre de Recherches Historiques , 2010, DOI: 10.4000/acrh.2411
Abstract: Thèse soutenue le 15 juin 2009.Composition du juryStéphane Audoin - Rouzeau (directeur de thèse), Annette Becker (présidente du jury), Leonard V. Smith, Carine Trevisan, Georges Vigarello.Mention : Très Honorable avec félicitations du jury à l’unanimité.RésuméLes cadavres des adversaires occupent une place majeure dans l’expérience combattante et dans l’imaginaire des sociétés belligérantes de la Première Guerre mondiale, qui connut une mortalité inou e, une immobilisation des fronts, et la ...
Nitric Oxide Synthase Inhibitors as Antidepressants
Gregers Wegener,Vallo Volke
Pharmaceuticals , 2010, DOI: 10.3390/ph3010273
Abstract: Affective and anxiety disorders are widely distributed disorders with severe social and economic effects. Evidence is emphatic that effective treatment helps to restore function and quality of life. Due to the action of most modern antidepressant drugs, serotonergic mechanisms have traditionally been suggested to play major roles in the pathophysiology of mood and stress-related disorders. However, a few clinical and several pre-clinical studies, strongly suggest involvement of the nitric oxide (NO) signaling pathway in these disorders. Moreover, several of the conventional neurotransmitters, including serotonin, glutamate and GABA, are intimately regulated by NO, and distinct classes of antidepressants have been found to modulate the hippocampal NO level in vivo. The NO system is therefore a potential target for antidepressant and anxiolytic drug action in acute therapy as well as in prophylaxis. This paper reviews the effect of drugs modulating NO synthesis in anxiety and depression.
Unilateral pitting edema of the leg as a manifestation of Graves’ disease: a case report
Volke Vallo,Matjus Svetlana
Journal of Medical Case Reports , 2012, DOI: 10.1186/1752-1947-6-258
Abstract: Introduction Graves’ hyperthyroidism has a number of well-recognized but relatively rare extrathyroid manifestations such as thyroid acropachy, pretibial myxedema, and congestive heart failure. Case presentation A 38-year-old Caucasian woman presented to the out-patient clinic with symptoms of hyperthyroidism lasting for approximately five months. Remarkably, she had developed pitting edema of her left leg four months before. She had gone through a conventional assessment, but the reason for the edema was not revealed. At presentation to the endocrinology clinic, the skin of both legs was of normal color and pitting edema on her left leg was of a diffuse nature and spread from her toes to two thirds of her leg. The skin surface of her left leg was smooth and had no elevations or discoloration, whereas her right leg appeared normal. Based on signs and symptoms of thyrotoxicosis and suppressed thyroid-stimulating hormone level (less than 0.001mIU/L, local reference of 0.4 to 4), treatment of 10mg of thiamazole three times a day was started. Additional blood tests revealed marked Graves’ hyperthyroidism with elevated free T4 and anti-thyroid receptor antibodies. Within a month, the free T4 level was normalized and the edema was completely cleared and never reappeared during the treatment course of 12 months. Conclusions To the best of our knowledge, this is the first description of unilateral treatment-responsive leg edema as a manifestation of Graves’ hyperthyroidism. However, the pathophysiological mechanism underlying this case of edema remains unclear.
Bat Distribution Size or Shape as Determinant of Viral Richness in African Bats
Ga?l D. Maganga, Mathieu Bourgarel, Peter Vallo, Thierno D. Dallo, Carine Ngoagouni, Jan Felix Drexler, Christian Drosten, Emmanuel R. Nakouné, Eric M. Leroy, Serge Morand
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0100172
Abstract: The rising incidence of emerging infectious diseases (EID) is mostly linked to biodiversity loss, changes in habitat use and increasing habitat fragmentation. Bats are linked to a growing number of EID but few studies have explored the factors of viral richness in bats. These may have implications for role of bats as potential reservoirs. We investigated the determinants of viral richness in 15 species of African bats (8 Pteropodidae and 7 microchiroptera) in Central and West Africa for which we provide new information on virus infection and bat phylogeny. We performed the first comparative analysis testing the correlation of the fragmented geographical distribution (defined as the perimeter to area ratio) with viral richness in bats. Because of their potential effect, sampling effort, host body weight, ecological and behavioural traits such as roosting behaviour, migration and geographical range, were included into the analysis as variables. The results showed that the geographical distribution size, shape and host body weight have significant effects on viral richness in bats. Viral richness was higher in large-bodied bats which had larger and more fragmented distribution areas. Accumulation of viruses may be related to the historical expansion and contraction of bat species distribution range, with potentially strong effects of distribution edges on virus transmission. Two potential explanations may explain these results. A positive distribution edge effect on the abundance or distribution of some bat species could have facilitated host switches. Alternatively, parasitism could play a direct role in shaping the distribution range of hosts through host local extinction by virulent parasites. This study highlights the importance of considering the fragmentation of bat species geographical distribution in order to understand their role in the circulation of viruses in Africa.
Fertilización del kiwi (Actinidia deliciosa (A. Chev.) C. F. Liang & A. R. Ferguson, cv. Hayward) durante la etapa de implantación en el sudeste bonaerense (Argentina)
Godoy,Carlos; Videla,Cecilia; Vallo,Matías;
Revista de la Facultad de Ciencias Agrarias. Universidad Nacional de Cuyo , 2012,
Abstract: the effects of nitrogen and potassium fertilization on kiwifruit plant growth during plant establishment (season 2008 - 2009) were assessed at an orchard placed in balcarce (buenos aires. province, argentina). the following fertilization treatments were applied: t: control without fertilization, n: nitrogen (48 kg/ha n), k: potassium (60 kg/ha k), and nk: nitrogen and potassium (48 kg/ha n - 60 kg/ha k respectively). stem and top internode length, and leaf area were sampled at regular intervals. stem diameter was assessed at the end of season, and roots arrangement in the soil profile was measured during rest. leaf macronutrient content, soil mineral n, anaerobic n (nan), and organic c (co) were also analyzed. soil was classified as argiudol; the levels of nan were between 85 - 100 mg/kg and levels of co were 45 - 50 g/kg, in the first 30 cm. our results concerning shoot growth do not support the need to apply either nitrogen or potassium fertilizers under our experimental conditions. leaf nitrogen and potassium contents were maintained within normal standards in all treatments including the control. root system, as observed through the rest period, benefited from the nitrogen fertilization. within the 10-20 cm soil layer, an average of 61 roots/cm2 were found in n, while lower values were recorded in the other treatments: 40 roots/cm2 in nk, 28 roots/cm2 in k, and 19 roots/cm2 in the control.
Artifical Microorganism Infection in Aviation Kerosene
Franti?ek Bla?ko,Igor Kvasnica,?ubica Kvasnicová,Du?an Vallo
Acta Montanistica Slovaca , 2004,
Abstract: The fuel used in the aviation engineering has to be clean and dry, it may not contain mechanical impurities and water. Water inaviation kerosene may occur in soluble and insoluble form. The danger inheres in the insoluble form, which may drop out in the crystallineform and cause various failures, such as those caused by mechanical impurities. The water assists in the biological matter formation createdby various species of microorganisms (bacteria, mould fungi and yeast). The microorganisms, present in water phase occurring on thebottom of tanks or on the interface water phase kerosene, grow and reproduce and subsequently may pollute (impair) the fuel by thebiomass or by the products of their metabolism. There is a possibility to infect the fuel artificially by a selected reference microorganismstrain, which usually occur in contaminated fuel, or by microorganisms which cause a biological contamination of aviation kerosene.Out of the selected reference strains used in the experiments, the reference strains of Proteus vulgaris, Sacharamyces cerevisiae andClostridium perfringens were not cultivated in the sterile aviation kerosene and the propagating nutrient medium. The aviation kerosene actsas a biocide medium for the presented reference microorganism strains.
Male mice with deleted Wolframin (Wfs1) gene have reduced fertility
Klari Noormets, Sulev K?ks, Ants Kavak, Andres Arend, Marina Aunapuu, Aivi Keldrimaa, Eero Vasar, Vallo Tillmann
Reproductive Biology and Endocrinology , 2009, DOI: 10.1186/1477-7827-7-82
Abstract: Wfs1KO mice were generated by homologous recombination. Both Wfs1KO and wild type (wt) male mice were mated with wt female mice. The number of litters and the number of pups were counted and pregnancy rates calculated. The motility and morphology of the sperm and the histology of testes were analysed. Serum testosterone and FSH concentrations were also measured.The pregnancy rate in wt females mated with Wfs1KO males was significantly lower than in the control group (15% vs. 32%; p < 0.05), but there was no significant difference in litter size. Analysis of male fertility showed that, in the Wfs1KO group, eight males out of 13 had pups whereas in the control group all 13 males had at least one litter. Sperm motility was not affected in Wfs1KO mice, but Wfs1KO males had less proximal bent tails (14.4 +/- 1.2% vs. 21.5 +/- 1.3 p < 0.05) and less abnormal sperm heads (22.8 +/- 1.8 vs. 31.5 +/- 3.5, p < 0.05) than wt males. Testes histology revealed significantly reduced number of spermatogonia (23.9 +/- 4.9 vs. 38.1 +/- 2.8; p < 0.05) and Sertoli cells (6.4 +/- 0.5 vs. 9.2 +/- 1.0; p < 0.05) in Wfs1KO mice. Serum testosterone and FSH concentrations did not differ between the two groups.The impaired fertility of Wfs1KO male mice is most likely due to changes in sperm morphology and reduced number of spermatogenic cells. The exact mechanism through which the Wfs1 gene influences sperm morphology needs to be clarified in further studies.Wolfram syndrome (WS), also known as DIDMOAD syndrome, was first described by Wolfram and Wagener in 1938. It is an autosomal recessive disorder usually diagnosed in childhood when non-autoimmune type I diabetes occurs with optic atrophy, cranial diabetes insipidus and sensorineural deafness [1,2]. Other abnormalities related to this syndrome are dilated renal outflow tracts, multiple neurological abnormalities and various neurological and psychiatric disorders [2-5]. Involvement of the hypothalamus, brain stem (central sleep apnoea), and
Modification of nitrifying biofilm into nitritating one by combination of increased free ammonia concentrations, lowered HRT and dissolved oxygen concentration

Ivar Zekker,Ergo Rikmann,Toomas Tenno,Anne Menert,Vallo Lemmiksoo,Alar Saluste,Taavo Tenno,Martin Tomingas,

環境科學學報(英文版) , 2011,
Abstract: Nitrifying biomass on ring-shaped carriers was modified to nitritating one in a relatively short period of time (37 days) by limiting the air supply, changing the aeration regime, shortening the hydraulic retention time and increasing free ammonia (FA) concentration in the moving-bed biofilm reactor (MBBR). The most efficient strategy for the development and maintenance of nitritating biofilm was found to be the inhibition of nitrifying activity by higher FA concentrations (up to 6.5 mg/L) in the process. Reject water from sludge treatment from the Tallinn Wastewater Treatment Plant was used as substrate in the MBBR. The performance of high-surfaced biocarriers taken from the nitritating activity MBBR was further studied in batch tests to investigate nitritation and nitrification kinetics with various FA concentrations and temperatures. The maximum nitrite accumulation ratio (96.6%) expressed as the percentage of NO2??-N/NOx??-N was achieved for FA concentration of 70 mg/L at 36°C. Under the same conditions the specific nitrite oxidation rate achieved was 30 times lower than the specific nitrite formation rate. It was demonstrated that in the biofilm system, inhibition by FA combined with the optimization of the main control parameters is a good strategy to achieve nitritating activity and suppress nitrification.
Wfs1-deficient mice display altered function of serotonergic system and increased behavioral response to antidepressants
Tanel Visnapuu,Sirli Raud,Maarja Loomets,Sulev K?ks,Vallo Volke,Aet Alttoa,Jaanus Harro,Eero Vasar
Frontiers in Neuroscience , 2013, DOI: 10.3389/fnins.2013.00132
Abstract: It has been shown that mutations in the WFS1 gene make humans more susceptible to mood disorders. Besides that, mood disorders are associated with alterations in the activity of serotonergic and noradrenergic systems. Therefore, in this study, the effects of imipramine, an inhibitor of serotonin (5-HT) and noradrenaline (NA) reuptake, and paroxetine, a selective inhibitor of 5-HT reuptake, were studied in tests of behavioral despair. The tail suspension test (TST) and forced swimming test (FST) were performed in Wfs1-deficient mice. Simultaneously, gene expression and monoamine metabolism studies were conducted to evaluate changes in 5-HT- and NA-ergic systems of Wfs1-deficient mice. The basal immobility time of Wfs1-deficient mice in TST and FST did not differ from that of their wild-type littermates. However, a significant reduction of immobility time in response to lower doses of imipramine and paroxetine was observed in homozygous Wfs1-deficient mice, but not in their wild-type littermates. In gene expression studies, the levels of 5-HT transporter (SERT) were significantly reduced in the pons of homozygous animals. Monoamine metabolism was assayed separately in the dorsal and ventral striatum of naive mice and mice exposed for 30 min to brightly lit motility boxes. We found that this aversive challenge caused a significant increase in the levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of 5-HT, in the ventral and dorsal striatum of wild-type mice, but not in their homozygous littermates. Taken together, the blunted 5-HT metabolism and reduced levels of SERT are a likely reason for the elevated sensitivity of these mice to the action of imipramine and paroxetine. These changes in the pharmacological and neurochemical phenotype of Wfs1-deficient mice may help to explain the increased susceptibility of Wolfram syndrome patients to depressive states.

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