bluuebunny/crossref_metadata_2025 huggingface dataset:
The formate channel FocA exports the products of mixed-acid fermentation
Authors: Lü Wei , Du Juan , Schwarzer Nikola J. , Gerbig-Smentek Elke , Einsle Oliver , Andrade Susana L. A.
Published: July 2012

Formate is a major metabolite in the anaerobic fermentation of glucose by many enterobacteria. It is translocated across cellular membranes by the pentameric ion channel/transporter FocA that, together with the nitrite channel NirC, forms the formate/nitrite transporter (FNT) family of membrane transport proteins. Here we have carried out an electrophysiological analysis of FocA from
Salmonella typhimurium
to characterize the channel properties and assess its specificity toward formate and other possible permeating ions. Single-channel currents for formate, hypophosphite and nitrite revealed two mechanistically distinct modes of gating that reflect different types of structural rearrangements in the transport channel of each FocA protomer. Moreover, FocA did not conduct cations or divalent anions, but the chloride anion was identified as further transported species, along with acetate, lactate and pyruvate. Formate, acetate and lactate are major end products of anaerobic mixed-acid fermentation, the pathway where FocA is predominantly required, so that this channel is ideally adapted to act as a multifunctional export protein to prevent their intracellular accumulation. Because of the high degree of conservation in the residues forming the transport channel among FNT family members, the flexibility in conducting multiple molecules is most likely a general feature of these proteins.
Early evidence of San material culture represented by organic artifacts from Border Cave, South Africa
Authors: d’Errico Francesco , Backwell Lucinda , Villa Paola , Degano Ilaria , Lucejko Jeannette J. , Bamford Marion K. , Higham Thomas F. G. , Colombini Maria Perla , Beaumont Peter B.
Published: July 2012

Recent archaeological discoveries have revealed that pigment use, beads, engravings, and sophisticated stone and bone tools were already present in southern Africa 75,000 y ago. Many of these artifacts disappeared by 60,000 y ago, suggesting that modern behavior appeared in the past and was subsequently lost before becoming firmly established. Most archaeologists think that San hunter–gatherer cultural adaptation emerged 20,000 y ago. However, reanalysis of organic artifacts from Border Cave, South Africa, shows that the Early Later Stone Age inhabitants of this cave used notched bones for notational purposes, wooden digging sticks, bone awls, and bone points similar to those used by San as arrowheads. A point is decorated with a spiral groove filled with red ochre, which closely parallels similar marks that San make to identify their arrowheads when hunting. A mixture of beeswax,
Euphorbia
resin, and possibly egg, wrapped in vegetal fibers, dated to ∼40,000 BP, may have been used for hafting. Ornaments include marine shell beads and ostrich eggshell beads, directly dated to ∼42,000 BP. A digging stick, dated to ∼39,000 BP, is made of
Flueggea virosa
. A wooden poison applicator, dated to ∼24,000 BP, retains residues with ricinoleic acid, derived from poisonous castor beans. Reappraisal of radiocarbon age estimates through Bayesian modeling, and the identification of key elements of San material culture at Border Cave, places the emergence of modern hunter–gatherer adaptation, as we know it, to ∼44,000 y ago.
Images reveal that atmospheric particles can undergo liquid–liquid phase separations
Authors: You Yuan , Renbaum-Wolff Lindsay , Carreras-Sospedra Marc , Hanna Sarah J. , Hiranuma Naruki , Kamal Saeid , Smith Mackenzie L. , Zhang Xiaolu , Weber Rodney J. , Shilling John E. , Dabdub Donald , Martin Scot T. , Bertram Allan K.
Published: July 2012

A large fraction of submicron atmospheric aerosol particles contains both organic material and inorganic salts. As the relative humidity cycles in the atmosphere and the water content of the particles correspondingly changes, these mixed particles can undergo a range of phase transitions, possibly including liquid–liquid phase separation. If liquid–liquid phase separation occurs, the gas-particle partitioning of atmospheric semivolatile organic compounds, the scattering and absorption of solar radiation, and the reactive uptake of gas species on atmospheric particles may be affected, with important implications for climate predictions. The actual occurrence of liquid–liquid phase separation within individual atmospheric particles has been considered uncertain, in large part because of the absence of observations for real-world samples. Here, using optical and fluorescence microscopy, we present images that show the coexistence of two noncrystalline phases for real-world samples collected on multiple days in Atlanta, GA as well as for laboratory-generated samples under simulated atmospheric conditions. These results reveal that atmospheric particles can undergo liquid–liquid phase separations. To explore the implications of these findings, we carried out simulations of the Atlanta urban environment and found that liquid–liquid phase separation can result in increased concentrations of gas-phase NO3and N2O5due to decreased particle uptake of N2O5.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) induces cancer cell senescence by interacting with telomerase RNA component
Authors: Nicholls Craig , Pinto Alexander Ruvantha , Li He , Li Ling , Wang Lihui , Simpson Richard , Liu Jun-Ping
Published: July 2012

Oxidative stress regulates telomere homeostasis and cellular aging by unclear mechanisms. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a key mediator of many oxidative stress responses, involving GAPDH nuclear translocation and induction of cell death. We report here that GAPDH interacts with the telomerase RNA component (TERC), inhibits telomerase activity, and induces telomere shortening and breast cancer cell senescence. The Rossmann fold containing NAD
+
binding region on GAPDH is responsible for the interaction with TERC, whereas a lysine residue in the GAPDH catalytic domain is required for inhibiting telomerase activity and disrupting telomere maintenance. Furthermore, the GAPDH substrate glyceraldehyde-3-phosphate (G3P) and the nitric oxide donor
S
-nitrosoglutathione (GSNO) both negatively regulate GAPDH inhibition of telomerase activity. Thus, we demonstrate that GAPDH is regulated to target the telomerase complex, resulting in an arrest of telomere maintenance and cancer cell proliferation.
Role of social wasps in
Saccharomyces cerevisiae
ecology and evolution
Authors: Stefanini Irene , Dapporto Leonardo , Legras Jean-Luc , Calabretta Antonio , Di Paola Monica , De Filippo Carlotta , Viola Roberto , Capretti Paolo , Polsinelli Mario , Turillazzi Stefano , Cavalieri Duccio
Published: July 2012

S
accharomyces cerevisiae
is one of the most important model organisms and has been a valuable asset to human civilization. However, despite its extensive use in the last 9,000 y, the existence of a seasonal cycle outside human-made environments has not yet been described. We demonstrate the role of social wasps as vector and natural reservoir of
S. cerevisiae
during all seasons. We provide experimental evidence that queens of social wasps overwintering as adults (
Vespa crabro
and
Polistes
spp
.
) can harbor yeast cells from autumn to spring and transmit them to their progeny. This result is mirrored by field surveys of the genetic variability of natural strains of yeast. Microsatellites and sequences of a selected set of loci able to recapitulate the yeast strain’s evolutionary history were used to compare 17 environmental wasp isolates with a collection of strains from grapes from the same region and more than 230 strains representing worldwide yeast variation. The wasp isolates fall into subclusters representing the overall ecological and industrial yeast diversity of their geographic origin. Our findings indicate that wasps are a key environmental niche for the evolution of natural
S. cerevisiae
populations, the dispersion of yeast cells in the environment, and the maintenance of their diversity. The close relatedness of several wasp isolates with grape and wine isolates reflects the crucial role of human activities on yeast population structure, through clonal expansion and selection of specific strains during the biotransformation of fermented foods, followed by dispersal mediated by insects and other animals.
Twin-arginine translocase mutations that suppress folding quality control and permit export of misfolded substrate proteins
Authors: Rocco Mark A. , Waraho-Zhmayev Dujduan , DeLisa Matthew P.
Published: July 2012

The bacterial twin-arginine translocation (Tat) pathway facilitates the transport of correctly folded proteins across the tightly sealed cytoplasmic membrane. Here, we report the isolation and characterization of suppressor mutations in the Tat translocase that allow export of misfolded proteins, which form structures that are not normally tolerated by the wild-type translocase. Selection of suppressors was enabled by a genetic assay that effectively linked in vivo folding and stability of a test protein with Tat export efficiency of a selectable marker protein, namely TEM-1 β-lactamase. By using a test protein named α
3
B—a designed three-helix-bundle protein that forms collapsed, stable molten globules but lacks a uniquely folded structure—translocase mutants that rescued export of this protein were readily identified. Each mutant translocase still efficiently exported folded substrate proteins, indicating that the substrate specificity of suppressors was relaxed but not strictly altered. A subset of the suppressors could also export other misfolded proteins, such as the aggregation-prone α
3
A protein and reduced alkaline phosphatase. Importantly, the isolation of genetic suppressors that inactivate the Tat quality-control mechanism provides direct evidence for the participation of the Tat translocase in structural proofreading of substrate proteins and reveals epitopes in the translocase that are important for this process.
Gyrotropic response in the absence of a bias field
Authors: Wang Zhiyu , Wang Zheng , Wang Jingyu , Zhang Bin , Huangfu Jiangtao , Joannopoulos John D. , Soljačić Marin , Ran Lixin
Published: July 2012

Electromagnetic materials lacking local time-reversal symmetry, such as gyrotropic materials, are of keen interest and importance both scientifically and technologically. Scientifically, topologically nontrivial phenomena, such as photonic chiral edge states, allow for reflection-free transport even in the presence of large disorder. Technologically, nonreciprocal photonic devices, such as optical isolators and circulators, play critical roles in optical communication and computing technologies because of their ability to eliminate cross-talk and feedback. Nevertheless, most known natural materials that lack local time-reversal symmetry require strong external fields and function only in a limited range of the electromagnetic spectrum. By taking advantage of metamaterials capable of translating the property of unidirectional active electronic circuits into effective dielectric response, we introduce a microwave gyrotropic metamaterial that does not require an external magnetic bias. Strong bulk Faraday-like effects, observed in both simulations and experiments, confirm nonreciprocity of the effective medium. This approach is scalable to many other wavelengths, and it also illustrates an opportunity to synthesize exotic electromagnetic materials.
Designed guanidinium-rich amphipathic oligocarbonate molecular transporters complex, deliver and release siRNA in cells
Authors: Geihe Erika I. , Cooley Christina B. , Simon Jeff R. , Kiesewetter Matthew K. , Edward Justin A. , Hickerson Robyn P. , Kaspar Roger L. , Hedrick James L. , Waymouth Robert M. , Wender Paul A.
Published: July 2012

The polyanionic nature of oligonucleotides and their enzymatic degradation present challenges for the use of siRNA in research and therapy; among the most notable of these is clinically relevant delivery into cells. To address this problem, we designed and synthesized the first members of a new class of guanidinium-rich amphipathic oligocarbonates that noncovalently complex, deliver, and release siRNA in cells, resulting in robust knockdown of target protein synthesis in vitro as determined using a dual-reporter system. The organocatalytic oligomerization used to synthesize these co-oligomers is step-economical and broadly tunable, affording an exceptionally quick strategy to explore chemical space for optimal siRNA delivery in varied applications. The speed and versatility of this approach and the biodegradability of the designed agents make this an attractive strategy for biological tool development, imaging, diagnostics, and therapeutic applications.
Conformational changes in tubulin in GMPCPP and GDP-taxol microtubules observed by cryoelectron microscopy
Authors: Yajima Hiroaki , Ogura Toshihiko , Nitta Ryo , Okada Yasushi , Sato Chikara , Hirokawa Nobutaka
Published: July 2012

Microtubules are dynamic polymers that stochastically switch between growing and shrinking phases. Microtubule dynamics are regulated by guanosine triphosphate (GTP) hydrolysis by β-tubulin, but the mechanism of this regulation remains elusive because high-resolution microtubule structures have only been revealed for the guanosine diphosphate (GDP) state. In this paper, we solved the cryoelectron microscopy (cryo-EM) structure of microtubule stabilized with a GTP analogue, guanylyl 5′-α,β-methylenediphosphonate (GMPCPP), at 8.8-Å resolution by developing a novel cryo-EM image reconstruction algorithm. In contrast to the crystal structures of GTP-bound tubulin relatives such as γ-tubulin and bacterial tubulins, significant changes were detected between GMPCPP and GDP-taxol microtubules at the contacts between tubulins both along the protofilament and between neighboring protofilaments, contributing to the stability of the microtubule. These findings are consistent with the structural plasticity or lattice model and suggest the structural basis not only for the regulatory mechanism of microtubule dynamics but also for the recognition of the nucleotide state of the microtubule by several microtubule-binding proteins, such as EB1 or kinesin.
Heterozygous TBK1 mutations impair TLR3 immunity and underlie herpes simplex encephalitis of childhood
Authors: Herman Melina , Ciancanelli Michael , Ou Yi-Hung , Lorenzo Lazaro , Klaudel-Dreszler Maja , Pauwels Elodie , Sancho-Shimizu Vanessa , Pérez de Diego Rebeca , Abhyankar Avinash , Israelsson Elisabeth , Guo Yiqi , Cardon Annabelle , Rozenberg Flore , Lebon Pierre , Tardieu Marc , Heropolitańska-Pliszka Edyta , Chaussabel Damien , White Michael A. , Abel Laurent , Zhang Shen-Ying , Casanova Jean-Laurent
Published: July 2012

Childhood herpes simplex virus-1 (HSV-1) encephalitis (HSE) may result from single-gene inborn errors of TLR3 immunity. TLR3-dependent induction of IFN-α/β or IFN-λ is crucial for protective immunity against primary HSV-1 infection in the central nervous system (CNS). We describe here two unrelated children with HSE carrying different heterozygous mutations (D50A and G159A) in TBK1, the gene encoding TANK-binding kinase 1, a kinase at the crossroads of multiple IFN-inducing signaling pathways. Both mutant TBK1 alleles are loss-of-function but through different mechanisms: protein instability (D50A) or a loss of kinase activity (G159A). Both are also associated with an autosomal-dominant (AD) trait but by different mechanisms: haplotype insufficiency (D50A) or negative dominance (G159A). A defect in polyinosinic-polycytidylic acid–induced TLR3 responses can be detected in fibroblasts heterozygous for G159A but not for D50A TBK1. Nevertheless, viral replication and cell death rates caused by two TLR3-dependent viruses (HSV-1 and vesicular stomatitis virus) were high in fibroblasts from both patients, and particularly so in G159A TBK1 fibroblasts. These phenotypes were rescued equally well by IFN-α2b. Moreover, the IFN responses to the TLR3-independent agonists and viruses tested were maintained in both patients’ peripheral blood mononuclear cells and fibroblasts. The narrow, partial cellular phenotype thus accounts for the clinical phenotype of these patients being limited to HSE. These data identify AD partial TBK1 deficiency as a new genetic etiology of childhood HSE, indicating that TBK1 is essential for the TLR3- and IFN-dependent control of HSV-1 in the CNS.
Zinc finger transcription factor zDC is a negative regulator required to prevent activation of classical dendritic cells in the steady state
Authors: Meredith Matthew M. , Liu Kang , Kamphorst Alice O. , Idoyaga Juliana , Yamane Arito , Guermonprez Pierre , Rihn Suzannah , Yao Kai-Hui , Silva Israel T. , Oliveira Thiago Y. , Skokos Dimitris , Casellas Rafael , Nussenzweig Michel C.
Published: July 2012

Classical dendritic cells (cDCs) process and present antigens to T cells. Under steady-state conditions, antigen presentation by cDCs induces tolerance. In contrast, during infection or inflammation, cDCs become activated, express higher levels of cell surface MHC molecules, and induce strong adaptive immune responses. We recently identified a cDC-restricted zinc finger transcription factor, zDC (also known as Zbtb46 or Btbd4), that is not expressed by other immune cell populations, including plasmacytoid DCs, monocytes, or macrophages. We define the zDC consensus DNA binding motif and the genes regulated by zDC using chromatin immunoprecipitation and deep sequencing. By deleting zDC from the mouse genome, we show that zDC is primarily a negative regulator of cDC gene expression. zDC deficiency alters the cDC subset composition in the spleen in favor of CD8+ DCs, up-regulates activation pathways in steady-state cDCs, including elevated MHC II expression, and enhances cDC production of vascular endothelial growth factor leading to increased vascularization of skin-draining lymph nodes. Consistent with these observations, zDC protein expression is rapidly down-regulated after TLR stimulation. Thus, zDC is a TLR-responsive, cDC-specific transcriptional repressor that is in part responsible for preventing cDC maturation in the steady state.
In VitroEvaluation of Antiprotozoal and Antiviral Activities of Extracts from ArgentineanMikaniaSpecies
Authors: Laurella Laura C. , Frank Fernanda M. , Sarquiz Andrea , Alonso María R. , Giberti Gustavo , Cavallaro Lucia , Catalán Cesar A. , Cazorla Silvia I. , Malchiodi Emilio , Martino Virginia S. , Sülsen Valeria P.
Published: July 2012

The aim of this study was to investigate the antiprotozoal and antiviral activities of four ArgentineanMikaniaspecies. The organic and aqueous extracts ofMikania micrantha, M. parodii, M. periplocifolia,andM. cordifoliawere tested onTrypanosoma cruziepimastigotes,Leishmania braziliensispromastigotes, and dengue virus type 2. The organic extract ofM. micranthawas the most active againstT. cruziandL. braziliensisexhibiting a growth inhibition of77.6±4.5% and84.9±6.1%, respectively, at a concentration of 10 μg/ml. The bioguided fractionation ofM. micranthaorganic extract led to the identification of two active fractions. The chromatographic profile and infrared analysis of these fractions revealed the presence of sesquiterpene lactones. None of the tested extracts were active against dengue virus type 2.
Isolation and Identification of Sodium Fluoroacetate Degrading Bacteria from Caprine Rumen in Brazil
Authors: Camboim Expedito K. A. , Almeida Arthur P. , Tadra-Sfeir Michelle Z. , Junior Felício G. , Andrade Paulo P. , McSweeney Chris S. , Melo Marcia A. , Riet-Correa Franklin
Published: July 2012

The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L−1sodium fluoroacetate (SF), incubated at 39°C in an orbital shaker.Pseudomonas fluorescens(strain DSM 8341) was used as positive control for fluoroacetate dehalogenase activity. Two isolates were identified by 16S rRNA gene sequencing asPigmentiphaga kullae(ECPB08) andAncylobacter dichloromethanicus(ECPB09). These bacteria degraded sodium fluoroacetate, releasing 20 mmol L−1of fluoride ion after 32 hours of incubation in Brunner medium containing 20 mmol L−1of SF. There are no previous reports of fluoroacetate dehalogenase activity forP. kullaeandA. dichloromethanicus. Control measures to prevent plant intoxication, including use of fences, herbicides, or other methods of eliminating poisonous plants, have been unsuccessful to avoid poisoning by fluoroacetate containing plants in Brazil. In this way,P. kullaeandA. dichloromethanicusmay be used to colonize the rumen of susceptible animals to avoid intoxication by fluoroacetate containing plants.
Differential Responses of Two Broccoli (Brassica oleraceaL. var Italica) Cultivars to Salinity and Nutritional Quality Improvement
Authors: Zaghdoud Chokri , Alcaraz-López Carlos , Mota-Cadenas César , Martínez-Ballesta María del Carmen , Moreno Diego A. , Ferchichi Ali , Carvajal Micaela
Published: July 2012

The comparative responses of two broccoli cultivars (Brassica oleraceavar. Italica, cv. Parthenon and cv. Naxos) to a 15 d exposure to different NaCl levels were investigated. Salinity led to increased concentrations of Na+and Cl−ions in both cultivars, a disruption of the endogenous minerals levels in the shoots and roots—that varied with the cultivar and salt concentration—and decreases in the osmotic potential (Ψπ), root hydraulic conductance (L0), and stomatal conductance (Gs). The reduced biomass of Naxos at moderate NaCl indicates greater sensitivity to salinity, compared with Parthenon. Parthenon accumulated more soluble sugars, for osmotic adjustment, whereas Naxos accumulated proline, which gave the two cultivars differing nutritional characteristics. The total glucosinolates (GSLs) content was not affected by salinity in Parthenon while it decreased significantly in Naxos as a consequence of the decrease in the indole GSL. However, Naxos accumulated more aliphatic GSLs under salt stress than Parthenon, which confers on this cultivar a greater nutritional value when cultivated under salinity.These results suggest that, at distinct salinity levels, each broccoli cultivar adopts a specific strategy, indicating the crucial role of the genetic background on the organoleptic and nutritional properties that each cultivar acquires.
Effect and Removal Mechanisms of 6 Different Washing Agents for Building Wastes Containing Chromium
Authors: Xing-run Wang , Yan-xia Zhang , Qi Wang , Jian-min Shu
Published: July 2012

With the building wastes contaminated by chromium in Haibei Chemical Plan in China as objects, we studied the contents of total Cr and Cr (VI) of different sizes, analyzed the effect of 6 different washing agents, discussed the removal mechanisms of 6 different washing agents for Cr in various forms, and finally selected applicable washing agent. As per the results, particle size had little impact on the contents of total Cr and Cr (VI); after one washing with water, the removal rate of total Cr and Cr (VI) was 75% and 78%, respectively, and after the second washing with 6 agents, the removal rate of citric acid was the highest, above 90% for total Cr and above 99% for hexavalent chromium; the pH of building wastes were reduced by citric acid, and under acid condition, hexavalent chromium was reduced to trivalent chromium spontaneously by organic acid, which led to better removal rate of acid soluble Cr and reducible Cr; due to the complexing action, citric acid had best removal rate for oxidizable trivalent chromium. In conclusion, citric acid is the most applicable second washing agent for building wastes.
Ipsilateral Testicular Catch-Up Growth Rate Following Microsurgical Inguinal Adolescent Varicocelectomy
Authors: Sinanoglu Orhun , Eyyupoglu Seyit Erkan , Ekici Sinan
Published: July 2012

Objective. To evaluate the ipsilateral catch-up growth rates compared to contralateral testicular growth in adolescents with varicocele undergoing microsurgical inguinal varicocelectomy.Materials and Methods. Between December 2005 and May 2007, 39 adolescent patients with grade 2-3 varicocele admitted to our clinic with complaints of pain and/or testicular asymmetry were operated. Preoperative mean age was 14.5 ± 1.96 (9–17). Testicular volumes were assessed with ultrasound every 3 months. The available followup was 39 months.Results. In our series, mean testicular preoperative volumes were9.07±3.19 mL for the right and5.90±1.74 mL for the left. Mean testicular volumes at the end of follow up were13.97±3.42 mL for the right and12.20±4.05 mL for the left. The testicular catch-up growth approximately begins after the 9th month and significant catch-up occurred in the 12–24 months (P<0.05).Conclusion. Since testicular volume is the primary method of assessing testicular function in adolescents, testicular size can predict future fertility status significantly 9 months after surgical varicocele correction.
Effects of Elevated Ambient Temperature on Reproductive Outcomes and Offspring Growth Depend on Exposure Time
Authors: Hamid Huda Yahia , Abu Bakar Zakaria Md Zuki , Yong Meng Goh , Haron Abd. Wahid , Mohamed Mustapha Noordin
Published: July 2012

Reproductive performance has been shown to be greatly affected by changes in environmental factors, such as temperature. However, it is also crucial to identify the particular stage of pregnancy that is most adversely affected by elevated ambient temperature. The aims of this study were to determine the effect on reproductive outcomes of exposure to elevated ambient temperature during different stages of pregnancy and to determine the effect of prenatal heat stress on offspring growth. Sixty pregnant rats were used in this study. The rats were divided equally into four groups as group 1 (control), group 2 (exposed to elevated temperature following implantation), group 3 (exposed to elevated temperature during pre- and periimplantation), and group 4 (exposed to elevated temperature during pre- and periimplantation and following implantation). Groups 3 and 4 had prolonged gestation periods, reduced litter sizes, and male-biased sex ratios. Moreover, the growth patterns of group 3 and 4 pups were adversely affected by prenatal exposure to elevated temperature. The differences between group 1 and group 3 and between group 1 and group 4 were highly significant. However, no significant differences were observed between groups 1 and 2 in the gestation length, sex ratios, and growth patterns. Thus, it can be concluded that exposure to elevated ambient temperature during pre- and periimplantation has stronger adverse effects on reproductive outcomes and offspring growth than postimplantation exposure.
Classroom Misbehavior in the Eyes of Students: A Qualitative Study
Authors: Sun Rachel C. F. , Shek Daniel T. L.
Published: July 2012

Using individual interviews, this study investigated perceptions of classroom misbehaviors among secondary school students in Hong Kong(N=18). Nineteen categories of classroom misbehaviors were identified, with talking out of turn, disrespecting teacher, and doing something in private being most frequently mentioned. Findings revealed that students tended to perceive misbehaviors as those actions inappropriate in the classroom settings and even disrupting teachers' teaching and other students' learning. Among various misbehaviors, talking out of turn and disrespecting teacher were seen as the most disruptive and unacceptable. These misbehaviors were unacceptable because they disturbed teaching and learning, and violated the values of respect, conformity, and obedience in the teacher-student relationship within the classroom. The frequency and intensity of misbehaviors would escalate if students found it fun, no punishment for such misbehaviors, or teachers were not authoritative enough in controlling the situations. Implications for further research and classroom management are discussed.
Virulence Genes and Antimicrobial Resistance Profiles ofPasteurella multocidaStrains Isolated from Rabbits in Brazil
Authors: Ferreira Thais Sebastiana Porfida , Felizardo Maria Roberta , Sena de Gobbi Débora Dirani , Gomes Cleise Ribeiro , Nogueira Filsner Pedro Henrique de Lima , Moreno Marina , Paixão Renata , Pereira Jucélia de Jesus , Micke Moreno Andrea
Published: July 2012

Pasteurella multocidais responsible for a wide range of diseases in domestic animals. In rabbits, the agent is related to nasal discharge, pneumonia, otitis media, pyometra, orchitis, abscess, and septicemia. One hundred and forty rabbits with respiratory diseases from four rabbitries in São Paulo State, Brazil were evaluated for the detection ofP. multocidain their nasal cavities. A total of twenty-nine animals were positive toP. multocidaisolation, and 46 strains were selected and characterized by means of biochemical tests and PCR.P. multocidastrains were tested for capsular type, virulence genes, and resistance profile. A total of 45.6% (21/46) of isolates belonged to capsular type A, and 54.34% (25/46) of the isolates were untypeable. None of the strains harbouredtoxAorpfhAgenes. The frequency of the other twenty genes tested was variable, and the data generated was used to build a dendrogram, showing the relatedness of strains, which were clustered according to origin. Resistance revealed to be more common against sulfonamides and cotrimoxazole, followed by erythromycin, penicillin, and amoxicillin.
Reinstitution of Mechanical Ventilation within 14 Days as a Poor Predictor in Prolonged Mechanical Ventilation Patients following Successful Weaning
Authors: Tu Mei-Lien , Tseng Ching-Wan , Tsai Yuh Chyn , Wang Chin-Chou , Tseng Chia-Cheng , Lin Meng-Chih , Fang Wen-Feng , Chen Yung-Che , Liu Shih-Feng
Published: July 2012

Although many parameters were investigated about weaning and mortality in critical patients in intensive units, no studies have yet investigated predictors in prolonged mechanical ventilation (PMV) patients following successful weaning. A cohort of 142 consecutive PMV patients with successful weaning in our respiratory care center was enrolled in this study. Successful weaning is defined as a patient having smooth respiration for more than 5 days after weaning. The results showed as follows: twenty-seven patients (19%) had the reinstitution within 14 days, and 115 patients (81%) had the reinstitution beyond 14 days. Renal disease RIFLE-LE was associated with the reinstitution within 14 days (P=0.006). One year mortality rates showed significant difference between the two groups (85.2% in the reinstitution within 14 days group versus 53.1% in the reinstitution beyond 14 days;P<0.001). Kaplan-Meier analysis showed that age ≥70 years (P=0.04), ESRD (P=0.02), and the reinstitution within 14 days (P<0.001) were associated with one-year mortality. Cox proportional hazards regression model showed that only the reinstitution within 14 days was the independent predictor for mortality (P<0.001). In conclusion, the reinstitution within 14 days was a poor predictor for PMV patients after successful weaning.
Roles of DICER-LIKE and ARGONAUTE Proteins in TAS-Derived Small Interfering RNA-Triggered DNA Methylation
Authors: Wu Liang , Mao Long , Qi Yijun
Published: July 2012

Trans-acting small interfering RNAs (ta-siRNAs; TAS) emerge as a class of plant-specific small RNAs that are initiated from microRNA-mediated cleavage of TAS gene transcripts. It has been revealed that ta-siRNAs are generated by the sequential activities of SUPPRESSOR OF GENE SILENCING3 (SGS3), RNA-DEPENDENT RNA POLYMERASE6 (RDR6), and DICER-LIKE4 (DCL4), and loaded into ARGONAUTE1 (AGO1) proteins to posttranscriptionally regulate several target genes by messenger RNA cleavage in trans. Here, we showed a high cytosine DNA methylation status at ta-siRNA-generating loci in Arabidopsis (Arabidopsis thaliana), which is dependent on RDR6, SGS3, and DNA-DIRECTED RNA POLYMERASE V (PolV). More important, we found that DCL1 is the only DCL protein that is required for TAS3 loci DNA methylation, and all four DCLs exert combinatory functions in the methylation of TAS1 loci, suggesting a previously unknown role for DCL1 in directly processing TAS gene transcripts. Furthermore, we demonstrated that AGO4/6 complexes rather than AGO1 are responsible for TAS  siRNA-guided DNA methylation. Based upon these findings, we propose a novel ta-siRNA pathway that acts at both the messenger RNA and chromatin level.
3,4,6-Tri-O-acetyl-1,2-O-[1-(exo-ethoxy)ethylidene]-β-D-mannopyranose 0.11-hydrate
Authors: Liu Ya-Ling , Zou Pei , Wu Hao , Xie Min-Hao , Luo Shi-Neng
Published: July 2012

The title compound, C16H24O10·0.11H2O, is a key intermediate in the synthesis of 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG), which is the most widely used molecular-imaging probe for positron emission tomography (PET). The crystal structure has two independent molecules (AandB) in the asymmetric unit, with closely comparable geometries. The pyranose ring adopts a4C1conformation [Cremer–Pople puckering parameters:Q= 0.553 (2) Å, θ = 16.2 (2)° and ϕ = 290.4 (8)° for moleculeA, andQ= 0.529 (2) Å, θ =15.3 (3)° and ϕ = 268.2 (9)° for moleculeB], and the dioxolane ring adopts an envelope conformation. The chiral centre in the dioxolane ring, introduced during the synthesis of the compound, has anRconfiguration, with the ethoxy groupexoto the mannopyranose ring. The asymmetric unit also contains one water molecule with a refined site-occupancy factor of 0.222 (8), which bridges between moleculesAandB viaO—H...O hydrogen bonds.
rac-1-[(2-Methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene and its PdCl2complex
Authors: Traeger J. , Kelling A. , Schilde U. , Holdt H.-J.
Published: July 2012

As an extension of recent findings on the recovery of palladium with dithioether extractants, single crystals of the chelating vicinal thioether sulfoxide ligandrac-1-[(2-methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene, C12H18O3S2, (I), and its square-planar dichloridopalladium complex,rac-dichlorido{1-[(2-methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene-κ2S,S′}palladium(II), [PdCl2(C12H18O3S2)], (II), have been synthesized and their structures analysed. The molecular structure of (II) is the first ever characterized involving a dihalogenide–PdIIcomplex in which the palladium is bonded to both a thioether and a sulfoxide functional group. The structural and stereochemical characteristics of the ligand are compared with those of the analogous dithioether compound [Traegeret al.(2012).Eur. J. Inorg. Chem.pp. 2341–2352]. The sulfinyl O atom suppresses the electron-pushing and mesomeric effect of the S—C...;C—S unit in ligand (I), resulting in bond lengths significantly different than in the dithioether reference compound. In contrast, in complex (II), those bond lengths are nearly the same as in the analogous dithioether complex. As observed previously, there is an interaction between the central PdIIatom and the O atom that is situated above the plane.
Now Being Social: The Barrier of Designing Outdoor Play Spaces for Disabled Children
Authors: Woolley Helen
Published: July 2012

The design of outdoor public play spaces such that disabled children can make use of them is set in the three constructs of play, childhood and disability, drawing upon academic learning, international policy and national policy in England. The suggestion is made that one of the main barriers to the adequate provision of such spaces is that providers and designers do not know how to design such spaces. The paper explores the knowledge which is available to overcome this barrier and which might lead to the provision and design of appropriate outdoor play spaces that disabled children can more fully use.
Hepatitis B virus surface antigen can activate human monocyte‐derived dendritic cells by nuclear factor kappa B and p38 mitogen‐activated protein kinase mediated signaling
Authors: Jan Rong‐Hwa , Lin Yu‐Li , Chen Chia‐Jung , Lin Teng‐Yi , Hsu Ya‐Chun , Chen Li‐Kuang , Chiang Bor‐Luen
Published: July 2012

Hepatitis B virus Ag (HBsAg), a major antigen of hepatitis B virus (HBV), is also a vaccine component for prevention of HBV infection. Dendritic cells (DCs) of HBV carriers reportedly exhibit functional impairment. In this study, the aim was to investigate the effect of HBsAg on activation of human monocyte‐derived dendritic cells (MD‐DCs), and the subsequent signal transduction pathway. Treatment of MD‐DCs with HBsAg resulted in enhanced cell surface expression of cluster of differentiation 80, CD83, CD86 and major histocompatibility complex class II, and increased interleukin (IL)‐12 p40, IL‐12p70, and IL‐10 production. Furthermore, HBsAg treatment of MD‐DCs with HBsAg resulted in enhanced T cell‐stimulatory capacity and increased T cell secretion of interferon and IL‐10. The pathway of MD‐DCs activation by HBsAg was further investigated in the present study. Inhibition of nuclear factor (NF)‐kappa B (κB) by helenalin and p38 mitogen‐activated protein kinase (MAPK) by SB203580 prevented production of IL‐12 p40, IL‐12 p70, and IL‐10. HBsAg also augmented MAPK phosphorylation. Thus, cytokine secretion of human MD‐DCs by HBsAg is blocked by inhibition of the NF‐κB and p38 MAPK pathways. Likewise, decreased inhibition of kappa B alpha concentrations and MAPK phosphorylation are critical for MD‐DC maturation by HBsAg. These findings may provide a strategy for improving the prophylactic and therapeutic efficacy of vaccines and tumor therapies that utilize these pathways.
Impact of central nervous system (CNS) prophylaxis on the incidence and risk factors for CNS relapse in patients with diffuse large B‐cell lymphoma treated in the rituximab era: a single centre experience and review of the literature
Authors: Guirguis Hany R. , Cheung Matthew C. , Mahrous Mervat , Piliotis Eugenia , Berinstein Neil , Imrie Kevin R. , Zhang Liying , Buckstein Rena
Published: July 2012

Central nervous system (CNS) prophylaxis for diffuse large B‐cell lymphoma (DLBCL) is controversial with even less evidence in the era of R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy. We reviewed the impact of CNS prophylaxis in DLBCL patients treated with R‐CHOP at a tertiary care centre over a 7‐year period. CNS prophylaxis was recommended for ‘higher risk’ patients and consisted of intrathecal methotrexate and/or high‐dose methotrexate. Of 214 patients 12·6% received CNS prophylaxis. With a median follow‐up of 27 months, eight patients (3·7%) developed CNS relapse (75% isolated to the CNS and 62·5% as parenchymal brain disease) at a median time of 17 months. Patients who did not receive CNS prophylaxis had lower events (2·7%) than those who did (11·1%). Half of the CNS relapses occurred in testicular lymphoma patients, 75% of whom had received CNS prophylaxis. In multivariate analysis, testicular involvement was the only significant prognostic factor for CNS relapse (hazard ratio 33·5, P < 0·001). In conclusion, CNS relapse in DLBCL appears to present as a later, more isolated parenchymal event and at a lower rate in the rituximab era compared with historical data. R‐CHOP may negate the need for CNS prophylaxis with the exception of testicular lymphoma.
Epidemiology, mortality rate and survival in a homogeneous population of hypopituitary patients
Authors: Fernandez‐Rodriguez E. , Lopez‐Raton M. , Andujar P. , Martinez‐Silva I. M. , Cadarso‐Suarez C. , Casanueva F. F. , Bernabeu I.
Published: July 2012

Introduction

Hypopituitarism is associated with higher prevalence of cardiovascular risk factors and premature death. Furthermore, some clinical and therapeutic features of hypopituitarism have been associated with a worse prognosis.

Objective

We reviewed, retrospectively, a large series of adult patients with hypopituitarism using stringent epidemiological criteria. Prevalence, association with cardiovascular risk factors, mortality and survival have been analysed.

Design and Methods

Two hundred and nine adult hypopituitary patients (56·9% females) from a population of 405 218 inhabitants, followed for 10 years.

Results

Prevalence of hypopituitarism at the end of the study was 37·5 cases/100 000 inhabitants. Incidence of hypopituitarism was 2·07 cases/100 000 inhabitants and year. Thirty‐two patients died during the period of the study. Standardized mortality rate (SMR) was 8·05, higher in males (8·92vs7·34) and in younger patients (84·93vs5·26). Diagnosis of acromegaly (P = 0·033), previous radiotherapy (P = 0·02), higherBMI(P = 0·04), diabetes mellitus (P = 0·03) and cancer (P < 0·0001) were associated with mortality. A lower survival was associated with older age at diagnosis, nontumoural causes, previous radiotherapy, diabetes mellitus with poor metabolic control and malignant disease.

Conclusions

Prevalence of hypopituitarism was 37·5 cases/100 000 inhabitants, and annual incidence was 2·07 cases/100 000 inhabitants.SMRwas 8 times higher in hypopituitarism than in general population and was also higher in males and younger patients. Reduced survival was significantly related to cancer, nontumoural causes of hypopituitarism, older age at diagnosis, previous radiotherapy and diabetes mellitus with poor metabolic control.
Acoustic radiation force impulse imaging for non‐invasive assessment of liver fibrosis in chronic hepatitis B
Authors: Friedrich‐Rust M. , Buggisch P. , de Knegt R. J. , Dries V. , Shi Y. , Matschenz K. , Schneider M. D. , Herrmann E. , Petersen J. , Schulze F. , Zeuzem S. , Sarrazin C.
Published: July 2012

Acoustic radiation force impulse (ARFI) imaging is a novel ultrasound‐based elastography method that is integrated in a conventional ultrasound machine. It might provide an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. While previous studies have shown comparable diagnostic accuracy of ARFI to transient elastography in chronic hepatitis C, the aim of the present prospective multicenter study was to evaluate ARFI for the assessment of liver fibrosis in chronic hepatitis B. ARFI imaging involves the mechanical excitation of tissue using short‐duration acoustic pulses to generate localized displacements in tissue. The displacements result in shear‐wave propagation which is tracked using ultrasonic, correlation‐based methods and recorded in m/s. In the present international prospective study, patients infected with chronic hepatitis B received ARFI imaging, blood tests and if available transient elastography. The results were compared to liver biopsy as reference method analysed by a central pathologist. In 92 of 114 patients, a comparison of ARFI with transient elastography was possible. ARFI imaging and transient elastography correlated significantly with histological fibrosis stage. The diagnostic accuracy expressed as areas under ROC curves for ARFI imaging and transient elastography was 0.75 and 0.83 for the diagnosis of significant fibrosis (F ≥ 2), 0.93 and 0.94 for the diagnosis of severe fibrosis (F ≥ 3), and 0.97 and 0.93 for the diagnosis of liver cirrhosis, respectively. No significant difference was found between ARFI and transient elastography. ARFI imaging is a reliable ultrasound‐based method for the assessment of advanced stages of liver fibrosis in chronic hepatitis B.
Factors associated with HCV antiviral treatment uptake among participants of a community‐based HCV programme for marginalized patients
Authors: Charlebois A. , Lee L. , Cooper E. , Mason K. , Powis J.
Published: July 2012

While the majority of cases of hepatitis C virus (HCV) in developed countries occur among illicit drug users, HCV antiviral treatment uptake is poor in this population. Several studies have shown that patients can successfully be treated for HCV in the context of methadone maintenance programmes, but little evidence exists evaluating HCV treatment models for substance users where methadone maintenance is not indicated. This retrospective cohort study involved 129 persons participating in psycho‐educational support groups and integrated, interprofessional, community‐based health services focused on the treatment for HCV among marginalized populations with high rates of crack cocaine use and mental health comorbidities. We sought to identify the factors associated with antiviral treatment uptake. Group participation improved access to health care. While 19% had previously seen an HCV specialist prior to group initiation, 59% saw an HCV specialist during the group. Half of the participants were nonimmune to hepatitis A or B at baseline, and 80% of these patients received immunization through the programme. The programme treated 24 patients with pegylated interferon and ribavirin and achieved a sustained virologic response (SVR) rate of 91% for genotype 2 or 3 and 54% for genotype 1. Stable housing was independently associated with initiation of treatment, and there was a nonsignificant trend towards lower rates of treatment initiation among women. SVR rates for those who had used crack or injection drugs in the month prior to joining the programme did not differ significantly from those who had abstained.
A parapatric propensity for breeding precludes the completion of speciation in common teal (Anas crecca, sensu lato)
Authors: PETERS JEFFREY L. , McCRACKEN KEVIN G. , PRUETT CHRISTIN L. , ROHWER SIEVERT , DROVETSKI SERGEI V. , ZHURAVLEV YURIY N. , KULIKOVA IRINA , GIBSON DANIEL D. , WINKER KEVIN
Published: July 2012

Speciation is a process in which genetic drift and selection cause divergence over time. However, there is no rule dictating the time required for speciation, and even low levels of gene flow hinder divergence, so that taxa may be poised at the threshold of speciation for long periods of evolutionary time. We sequenced mitochondrial DNA (mtDNA) and eight nuclear introns (nuDNA) to estimate genomic levels of differentiation and gene flow between the Eurasian common teal (Anas crecca crecca) and the North American green‐winged teal (Anas crecca carolinensis). These ducks come into contact in Beringia (north‐eastern Asia and north‐western North America) and have probably done so, perhaps cyclically, since the Pliocene–Pleistocene transition, ∼2.6 Ma, when they apparently began diverging. They have diagnosable differences in male plumage and are 6.9% divergent in the mtDNA control region, with only 1 of 58 crecca and 2 of 86 carolinensis having haplotypes grouping with the other. Two nuclear loci were likewise strongly structured between these teal (Φst ≥ 0.35), but six loci were undifferentiated or only weakly structured (Φst = 0.0–0.06). Gene flow between crecca and carolinensis was ∼1 individual per generation in both directions in mtDNA, but was asymmetrical in nuDNA, with ∼1 and ∼20 individuals per generation immigrating into crecca and carolinensis, respectively. This study illustrates that species delimitation using a single marker oversimplifies the complexity of the speciation process, and it suggests that even with divergent selection, moderate levels of gene flow may stall the speciation process short of completion.