bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of Superinfection and the Evolution of Viral Latency
Authors: Berngruber Thomas W. , Weissing Franz J. , Gandon Sylvain 
Published: July 2010

ABSTRACT

Latent viruses generally defend their host cell against superinfection by nonlatent virulent mutants that could destroy the host cell. Superinfection inhibition thus seems to be a prerequisite for the maintenance of viral latency. Yet viral latency can break down when resistance to superinfection inhibition, known as ultravirulence, occurs. To understand the evolution of viral latency, we have developed a model that analyzes the epidemiology of latent infection in the face of ultravirulence. We show that latency can be maintained when superinfection inhibition and resistance against it coevolve in an arms race, which can result in large fluctuations in virulence. An example is the coevolution of the virulence and superinfection repressor protein of phage λ (
cI
) and its binding target, the λ
oLoR
operator. We show that this repressor/operator coevolution is the driving force for the evolution of superinfection immunity groups. Beyond latent phages, we predict analogous dynamics for any latent virus that uses a single repressor for the simultaneous control of virulence and superinfection.
Intrapatient Variation of the Respiratory Syncytial Virus Attachment Protein Gene
Authors: Agoti Charles N. , Mbisa Jean L. , Bett Ann , Medley Graham F. , Nokes D. James , Cane Patricia A. 
Published: July 2010

ABSTRACT
Intrapatient variability of the attachment (G) protein gene of respiratory syncytial virus (RSV) was examined using both population and single-genome sequencing. Samples from three patients infected with a group B virus variant which has a 60-nucleotide duplication in the G protein gene were examined. These samples were chosen because occasional mixed sequence bases were observed. In a minority of RSV genomes from these patients considerable variability was found, including point mutations, insertions, and deletions. Of particular note, the deletion of the exact portion of the gene which had been duplicated in some isolates was observed in viral RNAs from two patients.
An Interaction between the Nucleocapsid Protein and a Component of the Replicase-Transcriptase Complex Is Crucial for the Infectivity of Coronavirus Genomic RNA
Authors: Hurst Kelley R. , Ye Rong , Goebel Scott J. , Jayaraman Priya , Masters Paul S. 
Published: July 2010

ABSTRACTThe coronavirus nucleocapsid (N) protein plays an essential role in virion assembly via interactions with the large, positive-strand RNA viral genome and the carboxy-terminal endodomain of the membrane protein (M). To learn about the functions of N protein domains in the coronavirus mouse hepatitis virus (MHV), we replaced the MHV N gene with its counterpart from the closely related bovine coronavirus (BCoV). The resulting viral mutant was severely defective, even though individual domains of the N protein responsible for N-RNA, N-M, or N-N interactions were completely interchangeable between BCoV and MHV. The lesion in the BCoV N substitution mutant could be compensated for by reverting mutations in the central, serine- and arginine-rich (SR) domain of the N protein. Surprisingly, a second class of reverting mutations were mapped to the amino terminus of a replicase subunit, nonstructural protein 3 (nsp3). A similarly defective MHV N mutant bearing an insertion of the SR region from the severe acute respiratory syndrome coronavirus N protein was rescued by the same two classes of reverting mutations. Our genetic results were corroborated by the demonstration that the expressed amino-terminal segment of nsp3 bound selectively to N protein from infected cells, and this interaction was RNA independent. Moreover, we found a direct correlation between the N-nsp3 interaction and the ability of N protein to stimulate the infectivity of transfected MHV genomic RNA (gRNA). Our results suggest a role for this previously unknown N-nsp3 interaction in the localization of genomic RNA to the replicase complex at an early stage of infection.
Évaluation de l’incertitude due au modèle de représentation du réservoir dans les analyses de rupture de barrageLe présent ouvrage fait partie d’une série d’articles publiés dans ce numéro spécial consacré au génie hydrotechnique.
Authors: Tchamen Georges Williams , Gaucher Jérémie 
Published: July 2010

Le présent article analyse l’impact du modèle de représentation de la vidange du réservoir sur les résultats de modélisation numérique de rupture de barrage. Le modèle à représentation statique à l’aide de la courbe d’emmagasinement est comparé à celui à représentation dynamique à l’aide d’un modèle de Saint-Venant utilisant la bathymétrie du réservoir. La comparaison est basée sur l’hydrogramme à la brèche, les niveaux maximaux, les surfaces inondées et les temps d’arrivée de l’onde à l’aval pour trois cas de réservoir de tailles différentes. Il ressort que la différence entre les deux modèles de représentation est maximale à la brèche et à l’aval immédiat du barrage, notamment pour le niveau maximal et la surface inondée, et qu’elle s’estompe plus loin à l’aval. L’analyse des résultats de simulation des cas étudiés montre que le modèle statique surestime les rehaussements atteints ainsi que la surface inondée à l’aval du barrage dans une proportion qui peut atteindre 20 %. L’utilisation d’un modèle dynamique de représentation du réservoir peut permettre de réduire de 30 % à 40 % ces surestimations. En l’absence de données bathymétriques du réservoir, la reconstitution de données synthétiques reproduisant la courbe d’emmagasinement pour servir de base à un modèle dynamique du réservoir est examinée. Il apparaît que cette solution peut réduire de façon appréciable l’incertitude due à la représentation statique.
Role of insulin on jejunal PepT1 expression and function regulation in diabetic male and female rats
Authors: Der-Boghossian Asdghig H. , Saad Sara R. , Perreault Claudine , Provost Chantale , Jacques Danielle , Kadi Lina N. , Issa Nahla G. , Sibai Abla M. , El-Majzoub Nadim W. , Bikhazi Anwar B. 
Published: July 2010

The aim of this study was to determine whether the jejunal oligopeptide transporter PepT1 is regulated by insulin and whether this regulation is sex-dependent in type 1 diabetic rats. PepT1 expression, real-time polymerase chain reaction, and Western blots were performed using jejunal segments from 4 groups of male and female rats: normal (nondiabetic), insulin-treated nondiabetic, streptozotocin (STZ)-induced diabetic (type 1 diabetes), and insulin-treated diabetic models. Furthermore, the same segments from all groups underwent perfusion to assess uptake of the dipeptide glycylsarcosine through PepT1. Our results showed that insulin treatment of nondiabetic female rats decreased blood glucose level but did not affect nondiabetic male rats. In both male and female diabetic rats, insulin did not completely decrease blood glucose level. Insulin treatment decreased PepT1 mRNA level in nondiabetic male rats and increased mRNA level in nondiabetic female rats without affecting the PepT1 protein level in either sex. Inducing diabetes with STZ increased PepT1 mRNA and protein levels in female rats; however, in diabetic male rats, the increase in mRNA level was accompanied by a decrease in PepT1 protein level. Treatment of diabetic male rats with insulin partially reversed the effect of diabetes on PepT1 mRNA and protein levels, whereas the same treatment completely restored both PepT1 mRNA and protein to control levels in insulin-treated diabetic female rats. In both nondiabetic male and female rats, insulin treatment had no effect on PepT1 influx rate, and STZ treatment decreased the transporter influx rate. Treatment of diabetic male and female rats with insulin significantly increased PepT1 influx rate; however, complete recovery was found only in diabetic female rats. These results clearly show that insulin and diabetes affected blood glucose level as well as PepT1 activity, expression, and protein levels in a sex-dependent manner. These results suggest that a factor, probably estrogen, could be responsible for the sex-dependent effects of diabetes and insulin in PepT1 level and activity.
Peroxisome proliferator-activated receptor γ promotes neuroprotection by modulating cyclic D1 expression after focal cerebral ischemia
Authors: Pei Lichun , Zhang Yanqiao , Zhang Yina , Chu Xiaojie , Zhang Jingyuan , Wang Ruitao , Liu Meiling , Zhu Xiuying , Yu Weigang 
Published: July 2010

Peroxisome proliferator-activated receptor γ (PPARγ) has been shown to protect against stroke and improve neurological outcome after cerebral ischemia. This study investigated whether activation of cerebral PPARγ improves recovery from focal cerebral ischemia by reducing expression of cyclin D1, which is associated with programmed neuron death. Focal cerebral ischemia was induced by 90 min of middle cerebral artery occlusion (MCAO), followed by reperfusion. Intracerebroventricular (i.c.v.) infusion of the PPARγ agonist ciglitazone, beginning 5 days before and continuing through 1 day after MCAO, reduced infarct size and cyclin D1 expression in the peri-infarct cortical region. Furthermore, primary cortical neurons treated with ciglitazone showed suppressed expression of cyclin D1 in response to hypoxia–reoxygenation. This protective effect was reversed after cotreatment with the selective PPAR-γ antagonist GW 9662 (2-chloro-5-nitrobenzanilide), clearly demonstrating the involvement of a PPARγ-dependent mechanism. Our data provide evidence that activation of neuronal PPARγ makes a substantial contribution to neuroprotection by preventing cyclin D1 up-regulation in vitro and in vivo.
Shear strength of soils derived from the weathering of granite and gneiss in Brazil
Authors: Lacerda Willy A. 
Published: July 2010

Abstract
Research on the properties of residual soils has been continuing in Brazil since the pioneering work by Vargas in 1953. A great number of earth dams built since then and the initiation of graduate courses since 1960 have increased the rate of in-depth studies on this theme. This contribution considers the more recent research on the properties of these soils, mainly shear strength parameters.
Male territoriality in a social sciurid, Cynomys gunnisoni: what do patterns of paternity tell us?
Authors: Verdolin  , Slobodchikoff  
Published: July 2010

AbstractIn many social sciurids, male territoriality confers significant mating advantages. We evaluated resident male paternity in Gunnison's prairie dogs (Cynomys gunnisoni), a colonial ground-dwelling sciurid, where males and females cooperatively defend territories. Contrary to findings reported for other social sciurids, our results show that territorial resident males do not gain significant reproductive advantages. Resident males sired the majority of offspring from their respective territories only 10.5% of the time. A single non-resident male sired equal or greater number of offspring than any single resident male 71.2% of the time. While adult males were more likely to sire a greater number of offspring, standard heterozygosity, body mass, and territory size were not significant predictors of how many offspring a male sired. In addition, the number of other males present did not influence the number of offspring sired by any given resident male. However, territory size was significantly correlated with overall offspring number and mean litter size per female, suggesting a potential reproductive advantage for females that occupy larger, better quality territories. Previous work has demonstrated that the cooperative defence of territories by both males and females permits enhanced access to food resources critical to overwinter survival. Our results have important implications for studies that do not distinguish between social and mating systems, because they suggest that individual mating strategies may be different from the social strategies that emerge in response to resource availability.
Four new species of Heth Cobb, 1898 (Rhigonematida: Hethidae) from Vietnamese diplopods
Authors: Malysheva Svetlana V. , Spiridonov Sergei E. 
Published: July 2010

Abstract
Four new species of Heth are described from diplopods collected in different parts of Viet Nam: Heth vietnamensis sp. n. and H. tonkinensis sp. n. in Ba Vi National Park, Ha Tay Province; H. taybaci sp. n. in Lai Chau Province and H. taynguyeni sp. n. in Chu Yang Sin National Park, Dak Lak Province. The new species are morphologically related to those described from Papua New Guinea, but are differentiated by the form of the female cuticular armature. Heth vietnamensis sp. n. is characterised by the posterior end of the lappets overhanging the anterior pair of the lateral spines, the similar size of spines in both pairs and the presence of two pairs of small papillae on the anterior lip of the cloacal aperture. Heth tonkinensis sp. n. can be differentiated from the other species by having the longest lappets, lateral spines with fused bases and the unequal-sized spicule heads. Heth taybaci sp. n. has the shortest lappets of the described Vietnamese species, has gaps between the lateral spines that are wider than the spine base and the presence of a bursa-like cuticular fold at cloacal aperture level. Heth taynguyeni sp. n. males also have a bursa-like cuticular fold but, unlike H. taybaci sp. n., this species is characterised by the bifurcate distal tips of the spicule and the undulating inner margin of the lappets.
Chemopreventive effects of Coltect, a novel dietary supplement, alone and in combination with 5-aminosalicylic acid in 1,2-dimethylhydrazine-induced colon cancer in rats
Authors: Aroch Ilan , Kraus Sarah , Naumov Inna , Ron Ehud , Shapira Shiran , Kazanov Dina , Giladi Nis , Litvak Alex , Lev-Ari Shahar , Hallak Aharon , Dotan Iris , Shpitz Baruch , Arber Nadir 
Published: July 2010

Objectives: Coltect is a novel dietary supplement containing curcumin, green tea and selenomethionine. Previous reports have suggested that these agents can prevent colorectal cancer (CRC). The present study examined the chemopreventive effect of Coltect alone or combined with 5-aminosalicylic acid (5-ASA) using the 1,2-dimethylhydrazine (DMH) model in rats. Methods: The effect of Coltect was examined on HT-29 CRC cells by growth inhibition assay. Apoptosis was determined by annexin V-FITC/PI staining. Male rats were injected with DMH in vivo and treated with Coltect 150 mg/kg, 5-ASA 50 mg/kg or their combination, by oral gavage. Aberrant crypt foci (ACF) were identified by methylene blue staining. Results: HT-29 cells exhibited a dose-dependent response to Coltect. Part of the growth inhibition can be explained by the induction of mild-moderate apoptosis in cancer cells (28%) compared with the untreated cells (10%). In the in vivo model, the average number of ACF was divided into small (1-3 crypts) or large (≥4 crypts). The Coltect compound reduced the number of small and large ACF similarly to 5-ASA (40% reduction). This reduction was amplified by combining the two agents (70% reduction). Conclusion: Coltect inhibits the growth of colon cancer cells, induces apoptosis and inhibits ACF development. Furthermore, it augments the growth inhibitory effect of 5-ASA in vivo. This may be clinically important since this safe dietary supplement-drug combination can be administered as a chemopreventive regimen for the treatment of CRC.
Chemistry, morphology and structural characteristics of synthetic Al-lizardite
Authors: Bentabol M. , Ruiz Cruz M. D. , Sobrados I. 
Published: July 2010

AbstractAl-lizardite has been synthesized under hydrothermal conditions (200ºC). Morphologically, Al-lizardite consists of thin platy particles ~400 Å wide and ~150 Å thick. Structurally, the X-ray diffraction patterns indicate that the 2H2 polytype is dominant, with cell parameters: a = 5.311(0.006) Å; c = 14.333 (0.013) Å and space group P63. High-resolution transmission electron microscopy images revealed, however, the presence of other polytypes and abundant stacking disorder. Chemically, Al-lizardite consists of a single population with average tetrahedral composition Si1.74Al0.26. In contrast to previously described Al-rich serpentines (amesite and Al-lizardite), this Al-lizardite is characterized by an asymmetrical Al distribution, with VIAl ≈0.70 and IVAl ≈0.25 atoms per formula unit.
XRF and nitrogen adsorption studies of acid-activated palygorskite
Authors: Zhang Junping , Wang Qin , Chen Hao , Wang Aiqin 
Published: July 2010

AbstractThe effects of acid activation on the chemical composition, surface area and pore structure of palygorskite from Xuyi (Jiangsu, P.R. China) were investigated systematically using X-ray fluorescence (XRF) and BET techniques. The palygorskite samples were activated with HCl, H2SO4 and H3PO4 of various concentrations at 80ºC for 4 h. The influences of acid concentration and acid type on the chemical composition, adsorption-desorption isotherms at 77 K, pore-size distribution, surface area and pore volume were studied in detail. The contents of most components of palygorskite decrease with increasing acid concentration except for Si and Ti. HCl shows a greater activation activity and its effect on the dissolution of components of palygorskite is greater than that of H2SO4 and H3PO4. It was found that 3 mol l–1 H3PO4 is a more efficient activator for increasing the number of micropores in palygorskite, whereas 12 mol l–1 HCl is more suitable for use in enhancing the number of meso- and macropores. The acid concentration and acid type have a great influence on the surface area and pore volume. HCl is the most effective at enhancing the external surface area and mesopore volume of palygorskite, whereas, H3PO4 is more suitable for use in improving the micropore surface and volume.
Statistical analysis of geochemical data: a tool for discriminating between kaolin deposits of hypogene and supergene origin, Patagonia, Argentina
Authors: Cravero F. , Marfil S. A. , Maiza P. J. 
Published: July 2010

AbstractThe numerous kaolin deposits located in Patagonia, Argentina, have been formed by hypogene or supergene processes. The primary origin has been established from O18 and D isotopic composition of the main minerals, kaolinite and/or dickite, and from the behaviour of certain elements during the alteration. The aim of this paper was to find if there is a tool, other than oxygen-deuterium data, to establish the origin of the Patagonian kaolin deposits. To handle the large number of variables per sample, a statistical multivariate study was used. The Principal Component method defines, on one hand the variables that better characterize each deposit and, on the other hand, the correlation between them. Fifty seven elements were considered and those that were not explained using these two components (which represent 75% of the total variance of the model) were discarded. As a result, the contents of Fe2O3, P2O5, LOI, Sr, Y, Zr, V, Pb, Hf, Rb, S and REE were used and the results show that the two components separate the deposits into two fields that are consistent with the process of formation. The first component indicates that Fe2O3, Y, Rb, U and HREE are more abundant in the supergene deposits, whereas, Sr, Pb, S and V are more abundant in the hypogene deposits. The second component shows that S, P2O5 and the LREE are enriched in the hydrothermal deposits, whereas Zr is more abundant in those formed under weathering conditions.
Bendadaite, a new iron arsenate mineral of the arthurite group
Authors: Kolitsch U. , Atencio D. , Chukanov N. V. , Zubkova N. V. , Menezes Filho L. A. D. , Coutinho J. M. V. , Birch W. D. , Schlüter J. , Pohl D. , Kampf A. R. , Steele I. M. , Favreau G. , Nasdala L. , Möckel S. , Giester G. , Pushcharovsky D. Yu. 
Published: July 2010

AbstractBendadaite, ideally Fe2+Fe23+ (AsO4)2(OH)2·4H2O, is a new member of the arthurite group. It was found as a weathering product of arsenopyrite on a single hand specimen from the phosphate pegmatite Bendada, central Portugal (type locality). Co-type locality is the granite pegmatite of Lavra do Almerindo (Almerindo mine), Linópolis, Divino das Laranjeiras county, Minas Gerais, Brazil. Further localities are the Veta Negra mine, Copiapó province, Chile; Oumlil-East, Bou Azzer district, Morocco; and Pira Inferida yard, Fenugu Sibiri mine, Gonnosfanadiga, Medio Campidano Province, Sardinia, Italy.Type bendadaite occurs as blackish green to dark brownish tufts (<0.1 mm long) and flattened radiating aggregates, in intimate association with an intermediate member of the scorodite–mansfieldite series. It is monoclinic, space group P21/c, with a = 10.239(3) Å, b = 9.713(2) Å, c = 5.552(2) Å, β = 94.11(2)°, V = 550.7(2) Å3, Z = 2. Electron-microprobe analysis yielded (wt.%): CaO 0.04, MnO 0.03, CuO 0.06, ZnO 0.04, Fe2O3 (total) 43.92, Al2O3 1.15, SnO2 0.10, As2O5 43.27, P2O5 1.86, SO3 0.03. The empirical formula is (Fe2+0.52Fe3+0.32☐0.16)Σ1.00(Fe3+1.89Al0.11)Σ2.00(As1.87P0.13)Σ2.00O8(OH)2.00·4H2O based on 2(As,P) and assuming ideal 8O, 2(OH), 4H2O and complete occupancy of the ferric iron site by Fe3+ and Al. Optically, bendadaite is biaxial, positive, 2Vest. = 85±4°, 2Vcalc. = 88°, with α 1.734(3), β 1.759(3), γ 1.787(4). Pleochroism is medium strong: X pale reddish brown, Y yellowish brown, Z dark yellowish brown; absorption Z > Y > X, optical dispersion weak, r > v. Optical axis plane is parallel to (010), with X approximately parallel to a and Z nearly parallel to c. Bendadaite has vitreous to sub-adamantine luster, is translucent and non-fluorescent. It is brittle, shows irregular fracture and a good cleavage parallel to {010}. Dmeas. 3.15±0.10 g/cm3, Dcalc. 3.193 g/cm3 (for the empirical formula). The five strongest powder diffraction lines [d in Å (I)(hkl)] are 10.22 (10)(100), 7.036 (8)(110), 4.250 (5)(111), 2.865 (4)(), 4.833 (3)(020,011). The d spacings are very similar to those of its Zn analogue, ojuelaite. The crystal structure of bendadaite was solved and refined using a crystal from the co-type locality with the composition (Fe2+0.95☐0.05)Σ1.00(Fe3+1.80Al0.20)Σ2.00(As1.48P0.52)Σ2.00O8(OH)2·4H2O (R = 1.6%), and confirms an arthurite-type atomic arrangement.
The structure of H3O+-exchanged pharmacosiderite
Authors: Mills S. J. , Hager S. L. , Leverett P. , Williams P. A. , Raudsepp M. 
Published: July 2010

AbstractThe crystal structure of H3O+-exchanged pharmacosiderite (pharmacosiderite is KFe4(AsO4)3(OH)4·nH2O, sensu stricto) has been determined by single-crystal X-ray diffraction and refined to R1 = 0.0418. H3O+-exchanged pharmacosiderite, (H3O+)Fe4(AsO4)3(OH)4·4.5H2O, is cubic, space group Pm, with a = 7.982(9) Å, V = 508.5(9) Å3 and Z = 1. The structure broadly conforms to that of the general pharmacosiderite structure type, with the hydronium ion generated by partial protonation of a site corresponding to a molecule of water of crystallization and its symmetry-related equivalents. In addition, the structure of a “pharmacosiderite” from Cornwall, United Kingdom, in which no alkali metals could be detected, has been re-evaluated and found to be consistent with that of the H3O+- exchanged structure. Its composition is (H3O+)Fe4(AsO4)3(OH)4·4H2O, with the partially occupied water found for the exchanged structure at (½, ½, ½) being absent in this case.