bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal variability of the NPP-GPP ratio at seasonal and interannual time scales in a temperate beech forest
Authors: Campioli M. , Gielen B. , Göckede M. , Papale D. , Bouriaud O. , Granier A.
Published: September 2011

Abstract. The allocation of carbon (C) taken up by the tree canopy for respiration and production of tree organs with different construction and maintenance costs, life span and decomposition rate, crucially affects the residence time of C in forests and their C cycling rate. The carbon-use efficiency, or ratio between net primary production (NPP) and gross primary production (GPP), represents a convenient way to analyse the C allocation at the stand level. In this study, we extend the current knowledge on the NPP-GPP ratio in forests by assessing the temporal variability of the NPP-GPP ratio at interannual (for 8 years) and seasonal (for 1 year) scales for a young temperate beech stand, reporting dynamics for both leaves and woody organs, in particular stems. NPP was determined with biometric methods/litter traps, whereas the GPP was estimated via the eddy covariance micrometeorological technique. The interannual variability of the proportion of C allocated to leaf NPP, wood NPP and leaf plus wood NPP (on average 11% yr−1, 29% yr−1 and 39% yr−1, respectively) was significant among years with up to 12% yr−1 variation in NPP-GPP ratio. Studies focusing on the comparison of NPP-GPP ratio among forests and models using fixed allocation schemes should take into account the possibility of such relevant interannual variability. Multiple linear regressions indicated that the NPP-GPP ratio of leaves and wood significantly correlated with environmental conditions. Previous year drought and air temperature explained about half of the NPP-GPP variability of leaves and wood, respectively, whereas the NPP-GPP ratio was not decreased by severe drought, with large NPP-GPP ratio on 2003 due mainly to low GPP. During the period between early May and mid June, the majority of GPP was allocated to leaf and stem NPP, whereas these sinks were of little importance later on. Improved estimation of seasonal GPP and of the contribution of previous-year reserves to stem growth, as well as reduction of data uncertainty, will be of relevance to increase the accuracy of the seasonal assessment of the NPP-GPP ratio in forests.
Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy
Authors: Meijide A. , Manca G. , Goded I. , Magliulo V. , di Tommasi P. , Seufert G. , Cescatti A.
Published: September 2011

Abstract. Rice paddy fields are one of the greatest anthropogenic sources of methane (CH4), the third most important greenhouse gas after water vapour and carbon dioxide. In agricultural fields, CH4 is usually measured with the closed chamber technique, resulting in discontinuous series of measurements performed over a limited area, that generally do not provide sufficient information on the short-term variation of the fluxes. On the contrary, aerodynamic techniques have been rarely applied for the measurement of CH4 fluxes in rice paddy fields. The eddy covariance (EC) technique provides integrated continuous measurements over a large area and may increase our understanding of the underlying processes and diurnal and seasonal pattern of CH4 emissions in this ecosystem. For this purpose a Fast Methane Analyzer (Los Gatos Research Ltd.) was installed in an eddy-covariance field set-up in a rice paddy field in the Po Valley (Northern Italy). Methane fluxes were measured during the rice growing season, both with EC and with manually operated closed chambers. Methane fluxes were strongly influenced by the presence of the water table, with emissions peaking when it was above 10–12 cm. Further studies are required to evaluate if water table management could decrease CH4 emissions. The development of rice plants and soil temperature were also responsible of the seasonal variation on the fluxes. The EC measured showed a diurnal cycle in the emissions, which was more relevant during the vegetative period, and with CH4 emissions being higher in the late evening, possibly associated with higher water temperature. The comparison between both measurement techniques shows that greater fluxes are measured with the chambers, especially when higher fluxes are being produced, resulting in 30 % higher seasonal estimations with the chambers than with the EC (41.1 and 31.8 g CH4 m−2 measured with chambers and EC respectively). The differences may be a result of the combined effect of overestimation with the chambers, the possible underestimation by the EC technique and of not having considered the daily course of the fluxes for the calculation of seasonal emissions from chambers.
Surface mass budget and meltwater discharge from the Kangerlussuaq sector of the Greenland ice sheet during record-warm year 2010
Authors: van As D. , Hubbard A. , Hasholt B. , Mikkelsen A. B. , van den Broeke M. , Fausto R. S.
Published: September 2011

Abstract. The year 2010 has been anomalously warm in most of Greenland, most notably in the south and along the western coast. Our study targets the Kangerlussuaq region around 67° N in Southwest Greenland, where the temperature anomalies were record setting. In 2010, the average temperature was 5 °C (2.7 standard deviations) above the 1974–2010 average in the town of Kangerlussuaq. High temperatures were also observed over the ice sheet, with the positive anomaly increasing with altitude. Also surface albedo, from calibrated MODIS measurements, was anomalously low in 2010, chiefly in the upper ablation zone. The low albedo was caused by the high ablation in 2010, which profited in turn from high temperatures, low albedo, and of low wintertime accumulation. The largest melt excess (166%) was found in the upper ablation zone, where higher temperatures and lower albedo contributed equally to the melt anomaly. In total, we estimate that 6.6 km3 of surface meltwater ran off the ice sheet in the Kangerlussuaq catchment area in 2010, exceeding "normal" year 2009 by 145%. When compared to discharge estimated from discharge measurements in the proglacial river we find good agreement. The time lag between the records is caused by storage within and underneath the ice sheet, and suggests adaption of the subglacial drainage system to meltwater availability, with more efficient drainage occurring after the peak of the melt season.
Percepção de Valor Através da Técnica Laddering: Uma Análise dos Clientes de Caminhonetes Picapes Médias
Authors: Ladeira Wagner Junior , Zancheta Anderson
Published: September 2011

O presente artigo traz como objetivo identificar a percepo de valor nos consumidores de caminhonetes picapes mdias. Para isto, foi realizada uma pesquisa qualitativa exploratria com consumidores localizados na regio da grande Porto Alegre-RS. Para tanto, utilizou-se como tcnica de coleta e anlise dados a laddering. A amostra da pesquisa contou com 13 entrevistados, sendo este nmero determinado aps atingir a saturao terica das respostas, com a identificao de cadeias completas de valor. A anlise dos dados foi divida em quatro etapas centrais: (a) compilao dos dados isolados em atributos, consequncias e valores; (b) elaborao da tabela de ladders, (c) criao da matriz de implicao e mapa hierrquico de valores e (d) definio das percepes dominantes e do relacionamento que gera o valor percebido para os consumidores de caminhonetes picapes mdias. Logo aps, foram feitas as consideraes finais do trabalho. DOI: 10.5585/remark.v10i1.2178
Modelo y Conocimiento del Comportamiento del Consumidor en la Entrega y Recepción Interpersonal de Regalos
Authors: Cruz Cárdenas Jorge Aníbal
Published: September 2011

La entrega y recepcin interpersonal de regalos implica un proceso de compra ms complejo que las compras usuales del consumidor, pues tiene al menos dos actores centrales, el dador y el receptor, cada uno con sus propias caractersticas personales y psicolgicas. Estos actores son influidos por variables externas como la relacin que sostienen, las variables de marketing y otras variables no controlables por las empresas, como la economa, la cultura y la familia. El proceso de compras del regalo comienza con el reconocimiento de una necesidad, se desarrolla muchas veces con un alto involucramiento del dador y del receptor y termina con el impacto del regalo en la relacin que mantienen. Usando como estructura las variables ms usuales del comportamiento del consumidor, el artculo expone y analiza el estado del conocimiento existente, propone una posible agenda de investigacin, plantea un modelo de comportamiento adaptado desde los modelos estmulo-consumidor-respuesta y finalmente discute las implicaciones para la prctica del marketing. DOI: 10.5585/remark.v10i1.2205
Fatores de influência no Consumo “Verde”: um estudo sobre o comportamento de compra no setor supermercadista
Authors: Braga Júnior Sérgio Silva , Silva Dirceu , Moretti Sérgio Luiz Do Amaral
Published: September 2011

Nos últimos anos, as empresas têm incorporado ao seu cotidiano e planejamento estratégico, elementos de gestão social e ambiental visando se adequar às novas tendências dos consumidores que passaram a valorizar tais iniciativas na sua avaliação de produtos e, para se alinhar às novas obrigações legais ligadas às questões ambientais. Com base no contexto apresentado justifica-se, tanto para os estudos do setor varejista supermercadista quanto da sustentabilidade, verificar os principais fatores que influenciam os consumidores a comprar no varejo supermercadista produtos de consumo considerados “verdes”. Para atingir o objetivo proposto foi aplicado um survey junto a uma amostra de 174 alunos de cursos de pós-graduação. As retas de regressão de cada fator foram avaliadas segundo as variáveis categóricas: sexo, renda familiar, faixa de idade e estado civil. Os resultados mostraram diferenças quanto ao sexo e estado civil. Quanto às variáveis, renda familiar e faixa etária há diferenças no terceiro fator (diminuição dos impactos ambientais). Tal análise indica que as opiniões dos sujeitos da amostra são muito homogêneas e que há uma aparente boa preocupação com os produtos verdes.
Identificando Valores de Estudantes de Cursos de Pós-Graduação Lato Sensu a Distância: Uma Abordagem Teórico-Metodológica da Means-End Chain
Authors: Oliveira Alessandro Silva , Silva Matheus Alberto Rodrigues , Vilas Boas Luiz Henrique De Barros
Published: September 2011

A proposta central do conceito de valor em estudos de consumo de que os clientes buscam a satisfao dos seus valores pessoais, que so os verdadeiros determinantes do comportamento de consumo. Nessa perspectiva, o objetivo do trabalho identificar os valores de estudantes de cursos de ps-graduao lato sensu a distncia. Para tanto, utilizou-se a abordagem terico-metodolgica da Means-End Chains e o mtodo de escalonamento Laddering. As anlises dos resultados indicam que os estudantes esto interessados em criar as condies para o estabelecimento de uma famlia ou de assegurar condies dignas de sobrevivncia, como garantir bons estudos para os filhos, acesso a sade de qualidade, possuir casa prpria e ter um excedente financeiro para atividades de lazer. No obstante, valores de cunho individual tambm foram identificados, estudantes que possuem o valor reconhecimento possuem motivaes por sucesso pessoal atravs da demonstrao de competncia e reconhecimento social. O valor aproveitar a vida desperta nos indivduos o desejo de promover a gratificao e o prazer pessoal. Ambos esto relacionados com reconhecimento social, diverso, prazer e auto-realizao, onde as preferncias so os prprios interesses pessoais em detrimento do coletivo. DOI: 10.5585/remark.v10i1.2214
Public house patrons' engagement in hypothetical sexual assault: a test of Alcohol Myopia Theory in a field setting
Authors: Flowe Heather D. , Stewart Jade , Sleath Emma R. , Palmer Francesca T.
Published: September 2011

Previous research has found that drinking establishments are often antecedent to sexual aggression outcomes. In this study, male participants were randomly selected from public houses (i.e., “pubs”) and asked to imagine themselves in a hypothetical intimate encounter in which the female in the scenario stops consenting to sexual contact. Participants were given the option to continue making sexual advances up to and including sexual intercourse against the woman's will. It was hypothesized based on Alcohol Myopia Theory that participant blood alcohol concentration (BAC) levels would be associated with hypothetical sexual aggression when stereotypical cues of a woman's sexual availability (revealing clothing and alcohol use) were present in the scenario. Men's engagement in hypothetical sexual aggression was associated with BAC levels, but only when the woman was wearing revealing clothing. The sobriety of the female actor was not associated with sexual aggression. Results indicate that Alcohol Myopia Theory generalizes to a field setting. Aggr Behav 37:547–558, 2011. © 2011 Wiley Periodicals, Inc.
Aggression in pigtailed macaque (Macaca nemestrina) breeding groups affects pregnancy outcome
Authors: Ha James C. , Alloway Hayley , Sussman Adrienne
Published: September 2011

Past research has shown that aggressive behaviors can affect female reproductive outcome in nonhuman primate captive breeding programs. In this study, aggressive behaviors were recorded in a colony of pigtailed macaque monkeys (Macaca nemestrina) and related to pregnancy outcome. For 22 weeks, behavioral data were collected from nine breeding groups, consisting of zero to one male (some males were removed after a cycle of conceptions for husbandry reasons) and four to eight females. Observations included all occurrences of 11 aggressive behaviors during 15 min observation sessions, 1–3 times a week. Mean weekly aggression levels during the study period were determined for each group as well as for each pregnancy. Aggression data were summarized with Principal Components Analyses. Results indicate that pigtailed macaque aggression falls into five distinctive categories: warn, engage, threaten, pursue, and attack. Breeding groups differed in their levels of aggression, even after controlling for group size, presence of a sire, and group stability. Levels of the five aggression categories were found to affect the probability that a pregnancy ended in either a natural birth of a live infant, a clinical intervention producing a live infant, or a nonviable outcome. The predictive value of aggression was significant when clinical interventions were included as possible reproductive outcomes. Behavioral observation of captive groups could identify “risk” conditions affecting pregnancy outcome and the requirement for clinical intervention. Am. J. Primatol. 73:1169–1175, 2011. © 2011 Wiley Periodicals, Inc.
Sleeping site selection and presleep behavior in wild pigtailed macaques
Authors: Albert Aurélie , Savini Tommaso , Huynen Marie‐Claude
Published: September 2011

Several factors are likely to control sleeping site selection and presleep behavior in nonhuman primates, including predation risk and location of food resources. We examined the effects of these factors on the sleeping behavior of northern pigtailed macaques (Macaca leonina). While following a troop living in the surroundings of the Visitor Center of Khao Yai National Park (Thailand), we recorded the physical characteristics and location of each sleeping site, tree, the individuals' place in the tree, posture, and behavior. We collected data for 154 nights between April 2009 and November 2010. The monkeys preferred tall sleeping trees (20.9 ± SD 4.9 m) and high sleeping places (15.8 ± SD 4.3 m), which may be an antipredator strategy. The choice of sleeping trees close to the last (146.7 ± SD 167.9 m) or to the first (150.4 ± SD 113.0 m) feeding tree of the day may save energy and decrease predation risk when monkeys are searching for food. Similarly, the choice of sleeping sites close to human settlements eases the access to human food during periods of fruit scarcity. Finally, the temporal pattern of use of sleeping sites, with a preference for four of the sleeping sites but few reuses during consecutive nights, may be a trade‐off between the need to have several sleeping sites (decreasing detection by predators and travel costs to feeding sites), and the need to sleep in well‐known sites (guaranteeing a faster escape in case of predator attack). Am. J. Primatol. 73:1222–1230, 2011. © 2011 Wiley Periodicals, Inc.
Therapeutic devices for epilepsy
Authors: Fisher Robert S.
Published: September 2011

Therapeutic devices provide new options for treating drug‐resistant epilepsy. These devices act by a variety of mechanisms to modulate neuronal activity. Only vagus nerve stimulation (VNS), which continues to develop new technology, is approved for use in the United States. Deep brain stimulation of anterior thalamus for partial epilepsy recently was approved in Europe and several other countries. Responsive neurostimulation, which delivers stimuli to 1 or 2 seizure foci in response to a detected seizure, recently completed a successful multicenter trial. Several other trials of brain stimulation are in planning or underway. Transcutaneous magnetic stimulation (TMS) may provide a noninvasive method to stimulate cortex. Controlled studies of TMS are split on efficacy, which may depend on whether a seizure focus is near a possible region for stimulation. Seizure detection devices in the form of shake detectors via portable accelerometers can provide notification of an ongoing tonic–clonic seizure, or peace of mind in the absence of notification. Prediction of seizures from various aspects of electroencephalography (EEG) is in early stages. Prediction appears to be possible in a subpopulation of people with refractory seizures, and a clinical trial of an implantable prediction device is underway. Cooling of neocortex or hippocampus reversibly can attenuate epileptiform EEG activity and seizures, but engineering problems remain in its implementation. Optogenetics is a new technique that can control excitability of specific populations of neurons with light. Inhibition of epileptiform activity has been demonstrated in hippocampal slices, but use in humans will require more work. In general, devices provide useful palliation for otherwise uncontrollable seizures, but with a different risk profile than with most drugs. Optimizing the place of devices in therapy for epilepsy will require further development and clinical experience. Ann Neurol 2012;71:157–168
Preparation and characterizaton of poly(dimethyl amino ethyl methacrylate) modified poly(vinyl alcohol) membrane by UV radiation for the permeation of 5‐fluorouracil
Authors: Yang Jen Ming , Ho Chia Che
Published: September 2011

Poly(vinyl alcohol) was modified by UV radiation with dimethyl amino ethyl methacrylate (DMAEMA) monomer to get poly(dimethyl amino ethyl methacrylate) modified poly(vinyl alcohol) (PVADMAEMA) membrane. The PVADMAEMA membranes were characterized by Fourier transform infrared spectroscopy. The tensile strength and elongation of PVADMAEMA membranes were measured by Universal Testing Machine. The results of X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that (1) the crystalline area in PVADMAEMA decreased with increasing the content of poly(dimethyl amino ethyl methacrylate) in the membrane. (2) Only one glass transition temperature (Tg) was found for the various PVADMAEMA membranes. It means that poly(dimethyl amino ethyl methacrylate) and PVA are compatible in PVADMAEMA membrane. (3)The Tg of the membrane is reduced with increasing the content of poly(dimethyl amino ethyl methacrylate) in the membrane. The water content on the PVADMAEMA membranes was determined. It was found that the water content on the PVADMAEMA membrane increased with increasing the content of poly(dimethyl amino ethyl methacrylate). The changes of properties enhanced the permeability of 5‐Fluorouracil (5‐Fu) through the PVADMAEMA membranes. A linear relationship between the permeability and the weight percent of poly(dimethyl amino ethyl methacrylate) in the PVADMAEMA membrane is found. It is expressed as P (cm/s) = (9.6 ± 0.4) × 10−5 + (8.8 ± 0.6) × 10−5
Wx, where P is the permeability of 5‐Fu through the membrane and Wx is the weight percent of poly(dimethyl amino ethyl methacrylate) in the PVADMAEMA membrane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of particle type on thermal and mechanical properties of polyoxymethylene nanocomposites
Authors: Wacharawichanant Sirirat , Sangkhaphan Angsumon , Sa‐Nguanwong Niramon , Khamnonwat Vitsarut , Thongyai Supakanok , Praserthdam Piyasan
Published: September 2011

The effects of particle size of titanium dioxide (TiO2) on mechanical, thermal, and morphological properties of pure polyoxymethylene (POM) and POM/TiO2 nanocomposites were investigated and compared with the results for nanoparticle ZnO in the same matrix, reported in a previous paper. POM/TiO2 nanocomposites with varying concentration of TiO2 were prepared by the melt mixing technique in a twin screw extruder, the same method that used for blending the homogeneous ZnO nanocomposites. The dispersion of TiO2 particles in POM nanocomposites was studied by scanning electron microscopy (SEM). The agglomeration, as observed by the mechanical properties of TiO2 particles in the polymer matrix, increased with increasing TiO2 content, a result not found for ZnO even at lower particle sizes. Increasing the filler content of POM/TD32.4 and POM/TD130 (130 nm) nanocomposites resulted in a decrease in tensile strength. The Young modulus, stress at break and impact strength of TiO2 nanocomposite did not improve with increasing filler contents, in opposition to the better agglomeration conditions of ZnO nanocomposite even at lower particle sizes. Because of agglomeration, the POM/TD32.4 nanocomposites had lower mechanical properties and lower degradation temperature than the POM/TD130 ones. The sizes of nanoparticles determined the agglomeration, but however, the agglomeration also depended on the type of nanoparticles, even when using the same matrix (POM) and the same mixing method. TiO2 nanoparticles were more difficult to mix and were more agglomerated in the POM matrix as compared to ZnO nanoparticles, regardless of the size of the nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Colloidal Templating Fabrication of Aluminum‐Organophosphonate Films Using High Molecular Weight PS‐b‐PEO
Authors: Kimura Tatsuo
Published: September 2011

High molecular weight polystyrene‐block‐poly(ethylene oxide) diblock copolymer (PS‐b‐PEO) is utilized as colloidal spheres in the presence of water. Adequately thick films with multilayers of spherical macropores are fabricated in one‐pot under highly concentrated conditions of PS‐b‐PEO. The frameworks are constructed using aluminum organophosphonate as a complicated hybrid component. The macropores (30–200 nm) are homogeneously distributed over the entire films and pore windows between the macropores are tunable (up to nearly 10 nm) by changing the relative amount of PS‐b‐PEO in the precursor solutions.
Investigating diproline segments in proteins: Occurrences, conformation and classification
Authors: Saha Indranil , Shamala Narayanaswamy
Published: September 2011

The covalent linkage between the side‐chain and the backbone nitrogen atom of proline leads to the formation of the five‐membered pyrrolidine ring and hence restriction of the backbone torsional angle ϕ to values of −60 °± 30° for the L‐proline. Diproline segments constitute a chain fragment with considerably reduced conformational choices. In the current study, the conformational states for the diproline segment (
LPro‐
LPro) found in proteins has been investigated with an emphasis on the cis and trans states for the Pro‐Pro peptide bond. The occurrence of diproline segments in turns and other secondary structures has been studied and compared to that of Xaa‐Pro‐Yaa segments in proteins which gives us a better understanding on the restriction imposed on other residues by the diproline segment and the single proline residue. The study indicates that PII–PII and PII–α are the most favorable conformational states for the diproline segment. The analysis on Xaa‐Pro‐Yaa sequences reveals that the Xaa‐Pro peptide bond exists preferably as the trans conformer rather than the cis conformer. The present study may lead to a better understanding of the behavior of proline occurring in diproline segments which can facilitate various designed diproline‐based synthetic templates for biological and structural studies. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 54–64, 2012.
Effects of ring contraction on the conformational preferences of α‐substituted proline analogs
Authors: Revilla‐López Guillem , Warren Javier G. , Torras Juan , Jiménez Ana I. , Cativiela Carlos , Alemán Carlos
Published: September 2011

The structural consequences derived from the incorporation of either a methyl or a phenyl group at the α carbon of proline were recently investigated by quantum mechanical calculations (J Org Chem 2008, 73, 3418). In this work, the effect produced by contraction of the pyrrolidine ring on such α‐substituted proline analogs has been explored using the same computational methods. Specifically, the intrinsic conformational preferences of the N‐acetyl‐N′‐methylamide derivatives of the lower proline homolog L‐azetidine‐2‐carboxylic acid (Aze), characterized by a four‐ instead of a five‐membered ring, and its α‐methyl (αMeAze) and α‐phenyl (αPhAze) derivatives have been determined using quantum mechanical calculations and compared to those observed before for the proline counterparts. Replacement of the pyrrolidine ring by an azetidine cycle leads to a reduction of the conformational flexibility, especially for the Aze and αMeAze derivatives, which should be attributed to the quasi‐planar geometry of the four‐membered ring. Furthermore, the azetidine nitrogen shows pyramidalization, which depending on the peptide backbone conformation favors the formation of an attractive N–H···N interaction or alleviates a severe steric hindrance. Calculations on different environments predict that the tendency of αMeAze to adopt γ‐turns is higher than that of unsubstituted Aze and α‐methylproline, this feature being in full agreement with the experimental observations available. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 98–110, 2012.
Salivary peptidome in type 1 diabetes mellitus
Authors: Caseiro Armando , Vitorino Rui , Barros António S. , Ferreira Rita , Calheiros‐Lobo Maria João , Carvalho Davide , Duarte José Alberto , Amado Francisco
Published: September 2011

Diabetic patients show a high susceptibility to oral diseases of inflammatory, catabolic and chronic nature with potential impact on saliva composition. In this study, our purpose was to characterize type 1 diabetes‐induced alterations in the salivary peptidome aiming to find prospective biomarkers for type 1 diabetes oral health evaluation. Peptidomic analysis of saliva from controls (n = 5) and type 1 diabetic patients (n = 5) were performed by liquid chromatography followed by mass spectrometry. The proteolytic activity and metalloproteinases expression was accessed by zymography and slot blot analysis, respectively. Data evidenced a significant increase in the percentage of peptides in diabetic patients paralleled by a higher proteolytic activity, compared with healthy individuals. The nonsalivary gland protein fragments identified in saliva were mainly derived from collagen and extracellular matrix proteins, namely collagen type I. The cleavage site frequency analysis showed significant differences between healthy and type 1 diabetic individuals, highlighting the activity of proteases such as matrix metalloproteinase‐9 and cathepsin D. Our results highlight salivary collagen fragments as potential biomarkers to follow up diabetes‐related oral damage. Copyright © 2011 John Wiley & Sons, Ltd.
Enhancing the enzymatic digestibility of sugarcane bagasse through the application of an ionic liquid in combination with an acid catalyst
Authors: Diedericks Danie , Rensburg Eugéne van , del Prado García‐Aparicio María , Görgens Johann F.
Published: September 2011

Various ionic liquids have been identified as effective pretreatment solvents that can enhance the cellulose digestibility of lignocellulose by removing lignin, one of the main factors contributing to the recalcitrant nature of lignocellulose. 1‐Butyl‐3‐methylimidazolium methylsulfate ([BMiM]MeSO4) is a potential delignification reagent, hence its application as a pretreatment solvent for sugarcane bagasse (SB) was investigated. The study also evaluated the benefit of an acid catalyst (i.e., H2SO4) and the effect of pretreatment conditions, which varied within a time and temperature range of 0–240 min and 50–150°C, respectively. The use of an acid catalyst contributed to a more digestible solid and a higher degree of delignification. However, the [BMiM]MeSO4‐H2SO4 combination failed to produce a fully digestible solid, as a maximum cellulose digestibility of 77% (w/w) was obtained at the optimum pretreatment condition of 125°C for 120 min. Furthermore, up to half of the lignin content could be extracted during pretreatment, while simultaneously extensive, sometimes complete, removal of xylan, the presence of which, also hampers cellulose digestibility. Hence, [BMiM]MeSO4 has been identified an effective pretreatment solvent for SB as the application thereof both significantly improved digestibility, and simultaneously removed two of the main factors contributing to the recalcitrant nature of lignocellulose. As xylan and lignin have potential value as precursor chemicals, the existing process may in future be extended toward substrate fractionation, a biorefinery concept where value is added to all feedstock constituents. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Nutrient improvement using statistical optimization for growth of Schizophyllum commune, and its antifungal activity against wood degrading fungi of rubberwood
Authors: Teoh Yi Peng , Don Mashitah Mat , Ujang Salmiah
Published: September 2011

Two statistical tools, Plackett‐Burman design (PBD) and Box‐Behnken design (BBD) were used to optimize the mycelia growth of Schizophyllum commune with different nutrient components. Results showed that 32.92 g/L of biomass were produced using a medium consisting of 18.74 g/L yeast extract, 38.65 g/L glucose, and 0.59 g/L MgSO4.7H2O. The experimental data fitted well with the model predicted values within 0.09 to 0.77% error. The biomass was also tested for antifungal activity against wood degrading fungi of rubberwood. Results showed that the minimum inhibitory concentration (MIC) values for antifungal activity range from 0.16 to 5.00 μg/μL. The GC‐MS analysis indicated that this fungus produced several compounds, such as glycerin, 2(3H)‐furanone, 5‐heptyldihydro‐, 4H‐pyran‐4‐one, 2,3‐dihydro‐3,5‐dihydroxy‐6‐methyl‐, and triacetin. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Unprecedented Synthesis of 1,3‐Dimethylcyclobutadiene in the Solid State and Aqueous Solution
Authors: Legrand Yves‐Marie , Gilles Arnaud , Petit Eddy , van der Lee Arie , Barboiu Mihail
Published: September 2011

Cyclobutadiene (CBD), the smallest cyclic hydrocarbon bearing conjugated double bonds, has long intrigued chemists because of its chemical characteristics. The question of whether the molecule could be prepared at all has been answered, but the parent compound and its unperturbed derivatives have eluded crystallographic characterization or synthesis “in water”. Different approaches have been used to generate and to trap cyclobutadiene in a variety of confined environments: a) an Ar matrix at cryogenic temperatures, b) a hemicarcerand cage enabling the characterization by NMR spectroscopy in solution, and c) a crystalline guanidinium–sulfonate–calixarene G4C matrix that is stable enough to allow photoreactions in the solid state. In the latter case, the 4,6‐dimethyl‐α‐pyrone precursor, Me21, has been immobilized in a guanidinium–sulfonate–calixarene G4C crystalline network through a combination of non‐covalent interactions. UV irradiation of the crystals transforms the entrapped Me21 into a 4,6‐dimethyl‐Dewar‐β‐lactone intermediate, Me22, and rectangular‐bent 1,3‐dimethylcyclobutadiene, Me2CBDR, which are sufficiently stable under the confined conditions at 175 K to allow a conventional structure determination by X‐ray diffraction. Further irradiation drives the reaction towards Me23&Me2CBDS/CO2 (63.7 %) and Me2CBDR (37.3 %) superposed crystalline architectures and the amplification of Me2CBDR. The crystallographic models are supported by additional FTIR and Raman experiments in the solid state and by 1H NMR spectroscopy and ESI mass spectrometry experiments in aqueous solution. Amazingly, the 4,6‐dimethyl‐Dewar‐β‐lactone, Me22, the cyclobutadiene‐carboxyl zwitterion, Me23, and 1,3‐dimethylcyclobutadiene, Me2CBD, were obtained by ultraviolet irradiation of an aqueous solution of G4C{Me21}. 1,3‐Dimethylcyclobutadiene is stable in water at room temperature for several weeks and even up to 50 °C as demonstrated by 1H NMR spectroscopy.
Halogen Bonding at the Active Sites of Human Cathepsin L and MEK1 Kinase: Efficient Interactions in Different Environments
Authors: Hardegger Leo A. , Kuhn Bernd , Spinnler Beat , Anselm Lilli , Ecabert Robert , Stihle Martine , Gsell Bernard , Thoma Ralf , Diez Joachim , Benz Jörg , Plancher Jean‐Marc , Hartmann Guido , Isshiki Yoshiaki , Morikami Kenji , Shimma Nobuo , Haap Wolfgang , Banner David W. , Diederich François
Published: September 2011

In two series of small‐molecule ligands, one inhibiting human cathepsin L (hcatL) and the other MEK1 kinase, biological affinities were found to strongly increase when an aryl ring of the inhibitors is substituted with the larger halogens Cl, Br, and I, but to decrease upon F substitution. X‐ray co‐crystal structure analyses revealed that the higher halides engage in halogen bonding (XB) with a backbone CO in the S3 pocket of hcatL and in a back pocket of MEK1. While the S3 pocket is located at the surface of the enzyme, which provides a polar environment, the back pocket in MEK1 is deeply buried in the protein and is of pronounced apolar character. This study analyzes environmental effects on XB in protein–ligand complexes. It is hypothesized that energetic gains by XB are predominantly not due to water replacements but originate from direct interactions between the XB donor (CarylX) and the XB acceptor (CO) in the correct geometry. New X‐ray co‐crystal structures in the same crystal form (space group P212121) were obtained for aryl chloride, bromide, and iodide ligands bound to hcatL. These high‐resolution structures reveal that the backbone CO group of Gly61 in most hcatL co‐crystal structures maintains water solvation while engaging in XB. An arylCF3‐substituted ligand of hcatL with an unexpectedly high affinity was found to adopt the same binding geometry as the aryl halides, with the CF3 group pointing to the CO group of Gly61 in the S3 pocket. In this case, a repulsive F2CF⋅⋅⋅OC contact apparently is energetically overcompensated by other favorable protein–ligand contacts established by the CF3 group.
Brain regions that process case: Evidence from basque
Authors: Nieuwland Mante S. , Martin Andrea E. , Carreiras Manuel
Published: September 2011

The aim of this event‐related fMRI study was to investigate the cortical networks involved in case processing, an operation that is crucial to language comprehension yet whose neural underpinnings are not well‐understood. What is the relationship of these networks to those that serve other aspects of syntactic and semantic processing? Participants read Basque sentences that contained case violations, number agreement violations or semantic anomalies, or that were both syntactically and semantically correct. Case violations elicited activity increases, compared to correct control sentences, in a set of parietal regions including the posterior cingulate, the precuneus, and the left and right inferior parietal lobules. Number agreement violations also elicited activity increases in left and right inferior parietal regions, and additional activations in the left and right middle frontal gyrus. Regions‐of‐interest analyses showed that almost all of the clusters that were responsive to case or number agreement violations did not differentiate between these two. In contrast, the left and right anterior inferior frontal gyrus and the dorsomedial prefrontal cortex were only sensitive to semantic violations. Our results suggest that whereas syntactic and semantic anomalies clearly recruit distinct neural circuits, case, and number violations recruit largely overlapping neural circuits and that the distinction between the two rests on the relative contributions of parietal and prefrontal regions, respectively. Furthermore, our results are consistent with recently reported contributions of bilateral parietal and dorsolateral brain regions to syntactic processing, pointing towards potential extensions of current neurocognitive theories of language. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Depression and type 2 diabetes: Cortisol pathway implication and investigational needs
Authors: Gragnoli Claudia
Published: September 2011

Depression and type 2 diabetes (T2D) are clinically associated and the causes of the association are still under investigation. We aimed at identifying what is known about the stress response and cortisol pathway and the clinical association of depression and T2D, and at hypothesizing the link of the association. In this review, we report independent studies on stress response, cortisol pathway, depression, T2D, and independent studies on stress and cortisol pathway in depression, and in T2D. We focus and integrate the stress and cortisol pathway hypothesis to explain the clinical association of depression and T2D. We hypothesize that the corticotropin‐releasing hormone receptors are one of the missing linking factor of the cortisol pathway underlying the clinical association of depression and T2D. We state what studies are still needed to confirm or rule out our hypothesis. J. Cell. Physiol. 227: 2318–2322, 2012. © 2011 Wiley Periodicals, Inc.
Modulation of functional responses of endothelial cells linked to angiogenesis and inflammation by shear stress: Differential effects of the mechanotransducer CD31
Authors: Glen Katie , Luu N. Thin , Ross Ewan , Buckley Chris D. , Rainger G. Ed , Egginton Stuart , Nash Gerard B.
Published: September 2011

We investigated the roles of the “mechanotransducer” CD31 in the effects of shear stress on endothelial gene expression and functional responses relevant to angiogenesis and inflammation. Human or murine endothelial cells (hEC or mEC) were exposed to different levels of shear stress, while expression of CD31 was modified using siRNA in the hEC, or mEC from CD31−/− mice. Quantitation of expression of genes linked to inflammation or angiogenesis showed several were sensitive to shear. In a “wound” assay, exposure of endothelial cells (EC) to shear stress tended to align migration with the direction of flow and decrease the rate of closure compared to static cultures. When EC were cultured on filters, shear stress promoted migration away from the luminal surface. EC conditioned by shear stress recruited fewer flowing neutrophils, and showed reduced up‐regulation of E‐selectin after stimulation with tumor necrosis factor‐α (TNF). Use of siRNA against CD31 in the hEC, or testing of mEC from mice lacking CD31, indicated that expression of CD31 was not required for the shear‐induced modification of wound closure. However, shear modulation of response to TNF was less effective in the absence of CD31, while reduction of CD31 reduced shear‐sensitivity in some genes (e.g., eNOS), but not others (e.g., KLF‐2). Thus, CD31 played a role in shear‐sensitivity of some genes and of neutrophil recruitment, but not in modulation of endothelial migration. Different mechanotransducers may mediate different functional effects of shear stress. Hence, identification of the specific pathways may provide targets for therapeutic manipulation of angiogenesis or inflammation. J. Cell. Physiol. 227: 2710–2721, 2012. © 2011 Wiley Periodicals, Inc.
The effect of different types of micro‐bubbles on the performance of the coagulation flotation process for coke waste‐water
Authors: Liu Shu , Wang Qunhui , Sun Tichang , Wu Chuanfu , Shi Yang
Published: September 2011

BACKGROUND: Comparison experiments were carried out with three kinds of micro‐bubbles on the coagulation flotation process treatment of coke waste‐water under optimum coagulation conditions obtained from zeta potential measurement.

RESULTS: Micro‐bubble flotation with ozone showed the best performance. The ozone micro‐bubbles exhibited high absolute zeta potential values, creating repulsion forces thus avoiding the coalescence of bubbles as well as creating attractive interaction between bubbles and particles in the waste‐water. Moreover, the fluorescence intensity of three micro‐bubble samples showed that the ozone micro‐bubble system produced the most hydroxyl radicals, which contributed to the degradation of organic material in the coke waste‐water. Compared with either air micro‐bubble flotation and oxygen micro‐bubble flotation processes, pyridine removal efficiency of the ozone micro‐bubble flotation process was, respectively, 4.5 and 1.7 times higher, and benzene removal efficiency 3.6 and 1.5 times higher. Finally, drainage models and oxygen diffusion models of the three kinds of micro‐bubble water samples verified the long persistence of the three kinds of micro‐bubbles in the water.

CONCLUSION: The application of ozone micro‐bubble technology in coagulation processes may provide an efficient and cost‐effective approach to the treatment of waste‐water containing refractory organic compounds. Copyright © 2011 Society of Chemical Industry
Chorioallantoic and yolk sac placentation in Thrichomys laurentinus (Echimyidae) and the evolution of hystricognath rodents
Authors: Franco de Oliveira Moacir , Favaron Phelipe Oliveira , Ambrósio Carlos Eduardo , Miglino Maria Angélica , Mess Andrea Maria
Published: September 2011

The evolutionary history of Hystricognathi is associated with major transformations in their placental system. Data so far indicate that key characters are independent from size dimensions in medium to very large species. To better understand the situation in smaller species, we analyzed placental development in a spiny rat, Thrichomys laurentinus. Fourteen individuals ranging from early implantation to near term were investigated by histology, immunohistochemistry, proliferation activity and electron microscopy. Placentation in Thrichomys revealed major parallels to the guinea pig and other hystricognath rodents with respect to the early and invasive implantation, the process of trophoblast invasion, the internal organization of the labyrinth and the trophospongium as well as the establishment of the complete inverted yolk sac placenta. In contrast to systematically related small‐sized species, the placental regionalization in Thrichomys was characterized by a remarkable lobulated structure and associated growing processes. Reverse to former perspectives, these conditions represented ancient character states of hystricognaths. The subplacenta was temporarily supplied by both the maternal and fetal blood systems, a rare condition among hystricognaths. The extraplacental trophoblast originating from the subplacenta was partly proliferative in mid gestation. In conclusion, the presented results indicated that only minor variations occurred in small‐sized hystricognath species, independent of their systematic interrelationships. Previous views were supported that placentation in hystricognaths followed an extraordinary stable pattern, although the group had distinct habitats in South America and Africa that were separated 30–40 million years ago. J. Exp. Zool. (Mol. Dev. Evol.) 318:13–25, 2012. © 2011 Wiley Periodicals, Inc.
Linking the molecular evolution of avian beta (β) keratins to the evolution of feathers
Authors: Greenwold Matthew J. , Sawyer Roger H.
Published: September 2011

Feathers of today's birds are constructed of beta (β)‐keratins, structural proteins of the epidermis that are found solely in reptiles and birds. Discoveries of “feathered dinosaurs” continue to stimulate interest in the evolutionary origin of feathers, but few studies have attempted to link the molecular evolution of their major structural proteins (β‐keratins) to the appearance of feathers in the fossil record. Using molecular dating methods, we show that before the appearance of Anchiornis (∼155 Million years ago (Ma)) the basal β‐keratins of birds began diverging from their archosaurian ancestor ∼216 Ma. However, the subfamily of feather β‐keratins, as found in living birds, did not begin diverging until ∼143 Ma. Thus, the pennaceous feathers on Anchiornis, while being constructed of avian β‐keratins, most likely did not contain the feather β‐keratins found in the feathers of modern birds. Our results demonstrate that the evolutionary origin of feathers does not coincide with the molecular evolution of the feather β‐keratins found in modern birds. More likely, during the Late Jurassic, the epidermal structures that appeared on organisms in the lineage leading to birds, including early forms of feathers, were constructed of avian β‐keratins other than those found in the feathers of modern birds. Recent biophysical studies of the β‐keratins in feathers support the view that the appearance of the subfamily of feather β‐keratins altered the biophysical nature of the feather establishing its role in powered flight. J. Exp. Zool. (Mol. Dev. Evol.) 316:609–616, 2011. © 2011 Wiley Periodicals, Inc.
Ventral nerve cord in Phoronopsis harmeri larvae
Authors: Temereva Elena N.
Published: September 2011

The nervous system organization is considered a phylogenetically important character among metazoans. The phylum Phoronida is included in a supraphyletic taxon known as Lophotrochozoa. Many lophotrochozoans possess a metameric ventral nerve cord as adults or larvae. Phoronids do not exhibit external metamery either as larvae or as adults. The current study describes the ventral nerve cord in the young larva of Phoronopsis harmeri. This structure is apparent both in the serotonergic and FMRF‐amidergic nervous system in young larvae. The ventral nerve cord extends from the mouth to the tentacular ridge. Both serotonergic and FMRF‐amidergic components consist of two ventrolateral nerves, each with several unipolar neurons. The ventrolateral nerves connect to each other by means of thin repetitive transversal nerves (“commissures”). The abundance of neurons and nerves in the epidermis of the oral field of actinotrocha larva likely reflects the importance of this area in collection of food particles. The ventral nerve cords of the actinotrocha and the metatrochophore differ in their positions with respect to ciliated bands: the cord is located between the preoral and postoral ciliated bands in the actinotrocha but between the postoral ciliated band and telotroch in the metatrochophore. The presence of the ventral nerve cord, which contains repetitive elements (neurons and “commissures”), in the early development of P. harmeri may recapitulate some stages of nervous system development during phoronid phylogeny. The larval nervous system does not contain nervous centers under the tentacular ridge that can correlate with the catastrophic metamorphosis and unique body plan of phoronids. J. Exp. Zool. (Mol. Dev. Evol.) 318:26–34, 2012. © 2011 Wiley Periodicals, Inc.