bluuebunny/crossref_metadata_2025 huggingface dataset:
Oncogenic BRAF signalling increases Mcl‐1 expression in cutaneous metastatic melanoma
Authors: McKee Christopher S. , Hill David S. , Redfern Christopher P. F. , Armstrong Jane L. , Lovat Penny E.
Published: October 2013

The Bcl‐2 family member Mcl‐1 is essential for melanoma survival; however, the influence of oncogenic BRAF signalling remains elusive. In this study, Mcl‐1 splice variant expression was determined in a panel of melanoma cell lines in relation to BRAF mutational status. Mcl‐1L mRNA expression was increased in melanoma cells compared with primary melanocytes with significantly increased mRNA and protein expression observed in BRAFV600E mutant melanoma cells. Although no change in Mcl‐1S mRNA was observed, Mcl‐1S protein expression also increased in BRAF mutant melanoma cells. Additionally, while over‐expression of mutant BRAFV600E increased both Mcl‐1L and Mcl‐1S expression, inhibition of hyperactive BRAF signalling resulted in decreased Mcl‐1L expression. These studies suggest that the regulation of Mcl‐1 expression by BRAF signalling is increased by oncogenic activation of BRAF, revealing a mechanism of apoptotic resistance which may be overcome by the use of more specifically targeted Mcl‐1 inhibitors.
Deranged epidermal differentiation in kl/kl mouse and the effects of βKlotho siRNA on the differentiation of HaCaT cells
Authors: Nakai Kozo , Yoneda Kozo , Haba Reiji , Kushida Yoshio , Katsuki Naomi , Moriue Tetsuya , Kosaka Hiroaki , Kubota Yasuo , Inoue Shigeaki
Published: October 2013

Mice deficient in the klotho gene (kl/kl mice) display the phenotypes of human ageing. We found that the expression of epidermal differentiation‐associated factors (keratin 1, keratin 10, filaggrin and loricrin) was lower in the skin of kl/kl mice than that of wild‐type mice. In vitro experiments showed that the expression of βKlotho, a family of klotho gene‐encoded protein, was induced concomitantly with the differentiation of an immortalized human epidermal keratinocyte cell line (HaCaT cells) when they were cultured in an air–liquid interface. βKlotho knockdown by small interfering ribonucleic acid suppressed the expression of the above differentiation‐associated factors in HaCaT cells. βKlotho small interfering ribonucleic acid increased the expression of keratin 14, which is expressed in mitotically active basal layer cells, and activated p44/p42 mitogen‐activated protein kinase in the HaCaT cells grown in the air–liquid interface. These findings suggest that the epidermal differentiation is deranged in kl/kl mice, and βKlotho is required for the differentiation of human epidermal keratinocytes.
The seascape nursery: a novel spatial approach to identify and manage nurseries for coastal marine fauna
Authors: Nagelkerken Ivan , Sheaves Marcus , Baker Ronald , Connolly Rod M
Published: October 2013

Coastal marine and estuarine ecosystems are highly productive and serve a nursery function for important fisheries species. They also suffer some of the highest rates of degradation from human impacts of any ecosystems. Identifying and valuing nursery habitats is a critical part of their conservation, but current assessment practices typically take a static approach by considering habitats as individual and homogeneous entities. Here, we review current definitions of nursery habitat and propose a novel approach for assigning nursery areas for mobile fauna that incorporates critical ecological habitat linkages. We introduce the term ‘seascape nurseries’, which conceptualizes a nursery as a spatially explicit seascape consisting of multiple mosaics of habitat patches that are functionally connected. Hotspots of animal abundances/productivity identify the core area of a habitat mosaic, which is spatially constrained by the home ranges of its occupants. Migration pathways connecting such hotspots at larger spatial and temporal scales, through ontogenetic habitat shifts or inshore–offshore migrations, should be identified and incorporated. The proposed approach provides a realistic step forward in the identification and management of critical coastal areas, especially in situations where large habitat units or entire water bodies cannot be protected as a whole due to socio‐economic, practical or other considerations.
Cannabidiol reverses the mCPP‐induced increase in marble‐burying behavior
Authors: Nardo Mirella , Casarotto Plinio C. , Gomes Felipe V. , Guimarães Francisco S.
Published: October 2013

Cannabidiol (CBD), one of the main components of Cannabis sp., presents clinical and preclinical anxiolytic properties. Recent results using the marble‐burying test (MBT) suggest that CBD can also induce anticompulsive‐like effects. Meta‐chloro‐phenyl‐piperazine (mCPP) is a nonspecific serotonergic agonist (acting mainly at 5HT1A, 5HT2C and 5HT1D receptors) reported to increase symptoms in OCD patients and block the anticompulsive‐like effect of serotonin reuptake inhibitors (SRIs) in animal models. The aim of this study was to investigate the interference of CBD on mCPP effects in repetitive burying. Administration of mCPP showed dual effects in the MBT, increasing the number of buried marbles at lower (0.1 mg/kg) while decreasing it at higher doses (1 mg/kg), an effect not related to a general increase in anxiety‐like behavior. As found previously, CBD (30 mg/kg) and the positive control fluoxetine (FLX; 10 mg/kg) decreased burying behavior without changing general exploratory activity. A similar effect was found when subeffective doses of CBD (15 mg/kg) and FLX (3 mg/kg) were administered together. These subeffective doses alone were also able to block mCPP‐induced repetitive burying. The results, in addition to reinforcing a possible anticompulsive effect of CBD, also suggest that mCPP‐induced repetitive burying could be a useful test for the screening of compounds with presumed anticompulsive properties.
Antihepatitis B therapy: a review of current medications and novel small molecule inhibitors
Authors: Qiu Li‐Peng , Chen Liang , Chen Ke‐Ping
Published: October 2013

There are approximately 350 million hepatitis B virus (HBV) carriers worldwide. Chronic HBV infection increases the risk of liver cirrhosis and hepatocellular carcinoma. To date, two classes of antiviral drugs have been approved by the Food and Drug Administration for the treatment of hepatitis B, immunomodulators (interferon [IFN]‐α and pegylated‐interferon [PEG‐IFN]‐α) and nucleos(t)ide analogs (lamivudine, telbivudine, adefovir, tenofovir [TDF], and entecavir [ETV]). Of these, ETV, TDF, and PEG‐IFN‐α are the most effective and are currently recommended for anti‐HBV therapy. However, these therapies are less than optimal because of their low rate of viral DNA and surface antigen clearance; thus, there exists a significant unmet medical need for safe and efficacious new anti‐HBV drugs. Covering diverse chemical structures and mechanisms of action, non‐nucleos(t)ide compounds offer great promise in the search for new anti‐HBV drugs. This review summarizes the currently approved anti‐HBV drugs and highlights advances in the identification and characterization of novel small molecule HBV inhibitors. We discuss the sources, structures, anti‐HBV effects, mechanisms of action, and potential toxicities of these novel inhibitors.
Erythromycin‐induced genotoxicity and hepatotoxicity in mice pups treated during prenatal and postnatal period
Authors: Singh Preeti , Singh Lubhan , Mondal Sambhu Charan , Kumar Sokindra , Singh Ishwari Narayan
Published: October 2013

The main aim of this study was to investigate the oxidative stress, genotoxicity and cytotoxicity of erythromycin (EMC) in pups of treated dams in gestation as well as the lactation period (LP). The two doses of EMC were compared using intraperitoneal (i.p.) route in two different periods, that is, in gestation period and in the LP. The rationale behind selection of i.p. route is because of the fact that EMC gets degrades in acidic pH of the stomach. The doses of EMC used were clinically equivalent dose (CED; EMC 14.2 mg/kg, i.p.) and a lower dose (EMC 10 mg/kg, i.p.) than CED. EMC toxicities in mice pups were evaluated using various parameters such as micronucleus (MN) test in peripheral blood and bone marrow, malondialdehyde (MDA) assay, glutathione (GSH reduced) assay and histopathological assessment in liver tissue. The CED of EMC led to a significant increase in MDA and decreased in GSH concentration in pups' liver tissue in both gestation and LPs and also to a significant increase in MN frequency in both peripheral blood and bone marrow cells of pups. There were no significant toxicities at a lower dose than CED. There were also some chronic findings with liver histopathological examination at CED. It is thus concluded that EMC accentuates the oxidative stress, cytotoxicity and DNA damage in pups of their postnatal life; hence, EMC should be avoided in the pregnancy and also in the LP.
Expression of a type 2 diacylglycerol acyltransferase from Thalassiosira pseudonana in yeast leads to incorporation of docosahexaenoic acid β‐oxidation intermediates into triacylglycerol
Authors: Xu Jingyu , Kazachkov Michael , Jia Yunhua , Zheng Zhifu , Zou Jitao
Published: October 2013

Glycerolipids of the marine diatom Thalassiosira pseudonana are enriched particularly with eicosapentaenoic acid (EPA), and also with an appreciable level of docosahexaenoic acid (DHA). The present study describes the functional characterization of a type 2 diacylglycerol acyltransferase (DGAT2, EC 2.3.1.20) from T. pseudonana, designated TpDGAT2, which catalyzes the final step of triacylglycerol (TAG) synthesis. Heterologous expression of this gene restored TAG formation in a yeast mutant devoid of TAG biosynthesis. TpDGAT2 was also shown to exert a large impact on the fatty acid profile of TAG. Its expression caused a 10–12% increase of 18:1 and a concomitant decrease of 16:0 relative to that of AtDGAT1(Arabidopsis thaliana). Furthermore, in the presence of the very‐long‐chain polyunsaturated fatty acids (VLCPUFA) EPA and DHA, TAG formed by TpDGAT2 displayed three‐ to six‐fold increases in the percentage of VLCPUFA relative to that of AtDGAT1 even though TpDGAT2 conferred much lower TAG‐synthetic activities than Arabidopsis DGAT1. Strikingly, when fed DHA, the yeast mutant expressing TpDGAT2 incorporated high levels of EPA and DHA isomers derived from DHA β‐oxidation. In contrast, no such phenomenon occurred in the cells expressing AtDGAT1. These results suggested that, in addition to the role in breaking down storage lipids, yeast peroxisomes also contribute to lipid synthesis by recycling acyl‐CoAs when a fatty acyl assembly system is available to capture and utilize the fatty acyl pools generated via β‐oxidation. Our study hence illustrated a case where the efficiency and substrate preference of an acyltransferase can elicit far reaching metabolic adjustments that affect TAG composition.
Experimental and numerical analysis of low‐velocity impact of plastic laminates
Authors: Ramakrishnan K. R. , Shankar K.
Published: October 2013

Acrylic is extensively used in transparent laminate systems with glass, polycarbonate, polyurethane and other polymers. Impact response of laminated structures is a subject of critical interest because of the high probability of impacts occurring during the manufacture, service or maintenance of structures. The impact loading induces a complex interaction between structural and material behaviour. Impact tests have proven inherently difficult to characterize because of the large number of parameters that play a key role in structural behaviour. Evaluation of impact in the case of ballistic tests is usually in terms of the minimum energy required to cause complete penetration or the maximum energy before penetration. So, metrics like V100 ballistic limit and V50 ballistic limit are determined from a series of experiments. However, in low‐velocity impacts, these statistical estimates are not appropriate. Furthermore, they do not indicate the failure mechanisms involved, the understanding of which is necessary to select materials for improved impact resistance. Different parameters are required to indicate the severity of the event and provide an understanding of the low‐velocity impact behaviour. This paper deals with applying a multi‐parameter approach to evaluate the low‐velocity impact on circular plates of acrylic. The work presented herein focuses on developing a numerical model to simulate the impact deformation and failure behaviour of brittle polymeric materials such as acrylic. The numerical model was developed using the commercial finite element analysis software ls‐dyna, and the results of the simulation is compared with the experimental results obtained from drop tower tests. The dynamic force histories and damage patterns obtained from the finite element simulation show good agreement with the experimental data from drop tower impact tests.
Surface cracks in fatigued structural components: a review
Authors: Brighenti Roberto , Carpinteri Andrea
Published: October 2013

Surface cracks are a common occurrence in structural components due to the frequently highest values of the stress at the outer boundary of the body and to the presence of defects. Such flaws can heavily reduce the service life of structural components leading to their premature failure, especially under repeated loading. During last decades, many research works based on theoretical, numerical and experimental techniques have been performed, mainly devoted to the determination of the stress‐intensity factors for recurrent surface crack shapes, different loading types and boundary conditions. Further, fatigue behaviour of surface cracks has been examined through numerical analyses or by simplifying the expected crack growth process. In the present paper, a literature survey is carried out by discussing the main topics related to the safety assessment of structural components with surface cracks under static or fatigue loading.
Development of the positive mean stress diagrams using genetic algorithm approach
Authors: Sekercioglu T. , Canyurt O. E.
Published: October 2013

In this numerical study, a new optimum positive mean stress fatigue failure equation is developed using previous experimental data and genetic algorithm. Two independent curve fitting coefficients are implemented in the equation to supply better correlations with experimental data of the failure strength envelope. In the literature, Gerber, Goodman, Soderberg, Morrow, Bagci, ASME (elliptic line), Clemson, Sekercioglu and so on suggested different equations for estimating fatigue strength envelope under mean stress condition. In these models, the effect of the materials was not considered in details. Some of these mean stress linear expressions are very conservative or have stress area bigger than the yield limit. The yield strength and the effect of materials are considered in the proposed model. The values of the positive mean stress, which correspond to fatigue failure, are obtained, and a minimum average absolute error among the models presented in the literature is remarked. The proposed model, which has less conservative structure, can be effectively used in the mechanical design process.
Genetic analyses of European minnow, Phoxinus phoxinus, in a river system outside its native range indicate multiple invasions from different sources
Authors: Thaulow J. , Borgstrøm R. , Heun M.
Published: October 2013

European minnow Phoxinus phoxinus (L.) from four different water bodies (the lakes Eivindbuvatn and Grungevatn, and the hydroelectric reservoirs Ståvatn and Totak) in the upper part of the Tokke drainage system, outside the native range of this species, and from one possible source population (River Hunnselva), were analysed to identify the origin of a newly established population in Ståvatn Reservoir. Amplified fragment length polymorphism analyses identified three genetically different populations in the Tokke drainage system, well separated from the purported source population. Thus, the River Hunnselva population connected to a brown trout, Salmo trutta L., hatchery from which European minnow theoretically could have ‘hitchhiked’ was not the source. As such, the dispersal of European minnow in Norway, even in a restricted area within one drainage system, appears to occur from multiple sources and possibly involves the illegal use of the species as live bait.
Metals and altitude drive genetic diversity of chironomids in Andean streams
Authors: Loayza‐Muro Raúl A. , de Baat Milo L. , Palomino Edwin J. , Kuperus Peter , Kraak Michiel H. S. , Admiraal Wim , Breeuwer Johannes A. J.
Published: October 2013

Andean streams cover steep altitude gradients and locally leach metal‐rich bedrock, creating highly selective habitat conditions. Chironomids are among the few dominant insect taxa present under the harshest conditions in Andean high altitude streams, but it remains unclear whether their dominance is due to the adaptive capacity of a few species (population differentiation) or to a diversity of species with different capacities to cope with environmental extremes (species composition). Therefore, the aim of this study was to assess whether metals and altitude drive the genetic diversity of chironomids in Andean streams.

We measured metal concentrations and altitude‐related conditions, such as UV‐B radiation, water temperature and oxygen, in reference and metal‐rich streams located at both 3000 and 4000 m a.s.l. The genetic composition of the chironomid communities from these streams was determined by mitochondrial cytochrome oxidase I (COI) gene sequencing, and a phylogenetic tree was constructed.

The concentrations of all metals were higher in the metal‐rich streams than in the references streams. The UV‐B radiation level at 4000 m was notably higher than at 3000 m, while the water temperature followed the opposite trend. At 3000 m, the reference site was inhabited by six putative species, completely different from the three present at 4000 m. Only one putative species, which did not occur at the reference sites, was present at both the metal‐rich sites at 3000 and 4000 m.

The differences in putative species composition between 3000 and 4000 m indicated a strong sorting of species according to altitude. However, the unique putative species present at the metal‐rich sites at both 3000 and 4000 m indicated that altitude‐driven selection was overridden by the extreme selection pressure exerted by metal exposure. We conclude that altitude limits the distribution of chironomid taxa, but metal selection leads to predominance of a unique metal‐tolerant taxon.
Differences in feeding behaviour amongChironomusspecies revealed by measurements of sulphur stable isotopes and cadmium in larvae
Authors: Proulx Isabelle , Hare Landis
Published: October 2013

We set out to determine the feeding behaviours of 15Chironomusspecies collected from 16 boreal forest lakes by measuring cadmium (Cd) and stable isotopes of carbon (C), nitrogen (N) and sulphur (S) in larvae.

Measurements of S stable isotopes and Cd discriminated betweenChironomusspecies that feed mainly on oxic particles from those that feed mainly on anoxic particles. Our results suggest thatC. dilutus,C. entis,C. plumosusandC. staegerifeed mainly on oxic particles (in the water column, in sediment or both), whereasC. anthracinus,C. bifurcatus,C. cucini,C. decorus‐group sp. 2,C. harpi,C. nr. atroviridis(sp. 2i),C. ochreatus,C. spp.NAI‐NAIIIandC. ‘tigris’feed mainly on anoxic sediments.

In our study lakes, larval C isotopic signatures were relatively high, which suggests that they feed little on methanotrophic bacteria. Although larval C and N signatures differed between some sympatricChironomusspecies, these differences were not consistent among lakes. The absence of a trend among lakes suggests that lake‐specific factors determine larval C and N signatures.

Differences in feeding habits and Cd concentrations among sympatric (cohabiting)Chironomusspecies suggest that pooling them in ecological, palaeolimnological or ecotoxicological studies could obscure trends in nature, thereby limiting their use as monitors of climate change or pollution.
Identification and biochemical characterization of the novel mutation m.8839G>C in the mitochondrial ATP6 gene associated with NARP syndrome
Authors: Blanco‐Grau A. , Bonaventura‐Ibars I. , Coll‐Cantí J. , Melià M. J. , Martinez R. , Martínez‐Gallo M. , Andreu A. L. , Pinós T. , García‐Arumí E.
Published: October 2013

Mutations in the ATP6 gene are reported to be associated with Leber hereditary optic neuropathy, bilateral striatal necrosis, coronary atherosclerosis risk and neuropathy, ataxia and retinitis pigmentosa (NARP)/maternally inherited Leigh syndromes. Here, we present a patient with NARP syndrome, in whom a previously undescribed mutation was detected in the ATP6 gene: m.8839G>C. Several observations support the concept that m.8839G>C is pathogenically involved in the clinical phenotype of this patient: (1) the mutation was heteroplasmic in muscle; (2) mutation load was higher in the symptomatic patient than in the asymptomatic carriers; (3) cybrids carrying this mutation presented lower cell proliferation, increased mitochondrial DNA (mtDNA) copy number, increased steady‐state OxPhos protein levels and decreased mitochondrial membrane potential with respect to isogenic wild‐type cybrids; (4) this change was not observed in 2959 human mtDNAs from different mitochondrial haplogroups; (5) the affected amino acid was conserved in all the ATP6 sequences analyzed; and (6) using in silico prediction, the mutation was classified as ‘probably damaging’. However, measurement of ATP synthesis showed no differences between wild‐type and mutated cybrids. Thus, we suggest that m.8839G>C may lower the efficiency between proton translocation within F0 and F1 rotation, required for ATP synthesis. Further experiments are needed to fully characterize the molecular mechanisms involved in m.8839G>C pathogenicity.
The interaction of early life experiences with COMT val158met affects anxiety sensitivity
Authors: Baumann C. , Klauke B. , Weber H. , Domschke K. , Zwanzger P. , Pauli P. , Deckert J. , Reif A.
Published: October 2013

The pathogenesis of anxiety disorders is considered to be multifactorial with a complex interaction of genetic factors and individual environmental factors. Therefore, the aim of this study was to examine gene‐by‐environment interactions of the genes coding for catechol‐O‐methyltransferase (COMT) and monoamine oxidase A (MAOA) with life events on measures related to anxiety. A sample of healthy subjects (N = 782; thereof 531 women; mean age M = 24.79, SD = 6.02) was genotyped for COMT rs4680 and MAOA‐uVNTR (upstream variable number of tandem repeats), and was assessed for childhood adversities [Childhood Trauma Questionnaire (CTQ)], anxiety sensitivity [Anxiety Sensitivity Index (ASI)] and anxious apprehension [Penn State Worry Questionnaire (PSWQ)]. Main and interaction effects of genotype, environment and gender on measures related to anxiety were assessed by means of regression analyses. Association analysis showed no main gene effect on either questionnaire score. A significant interactive effect of childhood adversities and COMT genotype was observed: Homozygosity for the low‐active met allele and high CTQ scores was associated with a significant increment of explained ASI variance [R2 = 0.040, false discovery rate (FDR) corrected P = 0.04]. A borderline interactive effect with respect to MAOA‐uVNTR was restricted to the male subgroup. Carriers of the low‐active MAOA allele who reported more aversive experiences in childhood exhibited a trend for enhanced anxious apprehension (R2 = 0.077, FDR corrected P = 0.10). Early aversive life experiences therefore might increase the vulnerability to anxiety disorders in the presence of homozygosity for the COMT 158met allele or low‐active MAOA‐uVNTR alleles.
A behavioral comparison of the common laboratory rat strains Lister Hooded, Lewis, Fischer 344 and Wistar in an automated homecage system
Authors: Clemens L. E. , Jansson E. K. H. , Portal E. , Riess O. , Nguyen H. P.
Published: October 2013

Behavioral characterization is an important part of establishing novel animal models, but classical behavioral tests struggle to reveal conclusive results due to problems with both reproducibility and validity. On the contrary, automated homecage observations are believed to produce robust outcomes that relate more to natural animal behavior. However, information on the behavior of background strains from such observations, which could provide important reference material, is rare. For this reason, we compared the behavior of the commonly used Lister Hooded, Lewis, Fischer 344 and Wistar rats during 70 h of exposure to an automated homecage system at 2, 4 and 6 months of age. We found considerable strain differences in metabolic parameters, novelty‐induced and baseline activity‐related behavior as well as differences in the development of these parameters with age. The results are discussed in terms of advantages and disadvantages of the system compared to classical behavioral tests, as well as the system's ability to recreate common findings in literature.
Higher temperature sensitivity for stable than for labile soil organic carbon – Evidence from incubations of long‐term bare fallow soils
Authors: Lefèvre Romain , Barré Pierre , Moyano Fernando E. , Christensen Bent T. , Bardoux Gérard , Eglin Thomas , Girardin Cyril , Houot Sabine , Kätterer Thomas , van Oort Folkert , Chenu Claire
Published: October 2013

The impact of climate change on the stability of soil organic carbon (SOC) remains a major source of uncertainty in predicting future changes in atmospheric CO2 levels. One unsettled issue is whether the mineralization response to temperature depends on SOC mineralization rate. Long‐term (>25 years) bare fallow experiments (LTBF) in which the soil is kept free of any vegetation and organic inputs, and their associated archives of soil samples represent a unique research platform to examine this issue as with increasing duration of fallow, the lability of remaining total SOC decreases. We retrieved soils from LTBF experiments situated at Askov (Denmark), Grignon (France), Ultuna (Sweden), and Versailles (France) and sampled at the start of the experiments and after 25, 50, 52, and 79 years of bare fallow, respectively. Soils were incubated at 4, 12, 20, and 35 °C and the evolved CO2 monitored. The apparent activation energy (Ea) of SOC was then calculated for similar loss of CO2 at the different temperatures. The Ea was always higher for samples taken at the end of the bare‐fallow period, implying a higher temperature sensitivity of stable C than of labile C. Our results provide strong evidence for a general relationship between temperature sensitivity and SOC stability upon which significant improvements in predictive models could be based.
Nesting and acoustic ecology, but not phylogeny, influence passerine urban tolerance
Authors: Cardoso Gonçalo C.
Published: October 2013

Urbanization is one of the most extensive and ecologically significant changes happening to terrestrial environments, as it strongly affects the distribution of biodiversity. It is well established that native species richness is reduced in urban and suburban areas, but the species traits that predict tolerance to urbanization are yet little understood. In birds, one of the most studied groups in this respect, evidence is appearing that acoustic traits influence urban living, but it remains unknown how this compares to the effects of more obvious ecological traits that facilitate urban living. Therefore, it remains unclear whether acoustic communication is an important predictor of urban tolerance among species. Here, with a comparative study across 140 European and North American passerines, I show that high song frequency, which is less masked by the low‐frequency anthropogenic noise, is associated with urban tolerance, with an effect size over half that of the most important ecological trait studied: off‐ground nesting. Other nesting and foraging traits accepted to facilitate urban living did not differ for species occurring in urban environments. Thus, the contribution of acoustic traits for passerine urban tolerance approximates that of more obvious ecological traits. Nonetheless, effect sizes of the biological predictors of urban tolerance were low and the phylogenetic signal for urban tolerance was null, both of which suggest that factors other than phenotypic traits have major effects on urban tolerance. A simple possibility is exposure to urbanization, as there was a higher proportion of urban‐tolerant species in Europe, which is more urbanized than North America.
Carbon–Temperature–Water change analysis for peanut production under climate change: a prototype for the AgMIP Coordinated Climate‐Crop Modeling Project (C3MP)
Authors: Ruane Alex C. , McDermid Sonali , Rosenzweig Cynthia , Baigorria Guillermo A. , Jones James W. , Romero Consuelo C. , DeWayne Cecil L.
Published: October 2013

Climate change is projected to push the limits of cropping systems and has the potential to disrupt the agricultural sector from local to global scales. This article introduces the Coordinated Climate‐Crop Modeling Project (C3MP), an initiative of the Agricultural Model Intercomparison and Improvement Project (AgMIP) to engage a global network of crop modelers to explore the impacts of climate change via an investigation of crop responses to changes in carbon dioxide concentration ([CO2]), temperature, and water. As a demonstration of the C3MP protocols and enabled analyses, we apply the Decision Support System for Agrotechnology Transfer (DSSAT) CROPGRO‐Peanut crop model for Henry County, Alabama, to evaluate responses to the range of plausible [CO2], temperature changes, and precipitation changes projected by climate models out to the end of the 21st century. These sensitivity tests are used to derive crop model emulators that estimate changes in mean yield and the coefficient of variation for seasonal yields across a broad range of climate conditions, reproducing mean yields from sensitivity test simulations with deviations of ca. 2% for rain‐fed conditions. We apply these statistical emulators to investigate how peanuts respond to projections from various global climate models, time periods, and emissions scenarios, finding a robust projection of modest (<10%) median yield losses in the middle of the 21st century accelerating to more severe (>20%) losses and larger uncertainty at the end of the century under the more severe representative concentration pathway (RCP8.5). This projection is not substantially altered by the selection of the AgMERRA global gridded climate dataset rather than the local historical observations, differences between the Third and Fifth Coupled Model Intercomparison Project (CMIP3 and CMIP5), or the use of the delta method of climate impacts analysis rather than the C3MP impacts response surface and emulator approach.
Sustained effects of atmospheric [CO2] and nitrogen availability on forest soilCO2efflux
Authors: Oishi A. Christopher , Palmroth Sari , Johnsen Kurt H. , McCarthy Heather R. , Oren Ram
Published: October 2013

SoilCO2efflux (Fsoil) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity, but the long‐term effects of these factors onFsoilare less clear. Expanding on previous studies at the Duke Free‐AirCO2Enrichment (FACE) site, we quantified the effects of elevated [CO2] and N fertilization onFsoilusing daily measurements from automated chambers over 10 years. Consistent with previous results, compared to ambient unfertilized plots, annualFsoilincreased under elevated [CO2] (ca. 17%) and decreased with N (ca. 21%). N fertilization under elevated [CO2] reducedFsoilto values similar to untreated plots. Over the study period, base respiration rates increased with leaf productivity, but declined after productivity saturated. Despite treatment‐induced differences in aboveground biomass, soil temperature and water content were similar among treatments. Interannually, low soil water content decreased annualFsoilfrom potential values – estimated based on temperature alone assuming nonlimiting soil water content – by ca. 0.7% per 1.0% reduction in relative extractable water. This effect was only slightly ameliorated by elevated [CO2]. Variability in soil N availability among plots accounted for the spatial variability inFsoil, showing a decrease of ca. 114 g C m−2 yr−1per 1 g m−2increase in soil N availability, with consistently higherFsoilin elevated [CO2] plots ca. 127 g C per 100 ppm [CO2] over the +200 ppm enrichment. Altogether, reflecting increased belowground carbon partitioning in response to greater plant nutritional needs, the effects of elevated [CO2] and N fertilization onFsoilin this stand are sustained beyond the early stages of stand development and through stabilization of annual foliage production.
Evidence for key enzymatic controls on metabolism of Arctic river organic matter
Authors: Mann Paul J. , Sobczak William V. , LaRue Madeleine M. , Bulygina Ekaterina , Davydova Anna , Vonk Jorien E. , Schade John , Davydov Sergei , Zimov Nikita , Holmes Robert M. , Spencer Robert G. M.
Published: October 2013

Permafrost thaw in the Arctic driven by climate change is mobilizing ancient terrigenous organic carbon (OC) into fluvial networks. Understanding the controls on metabolism of this OC is imperative for assessing its role with respect to climate feedbacks. In this study, we examined the effect of inorganic nutrient supply and dissolved organic matter (DOM) composition on aquatic extracellular enzyme activities (EEAs) in waters draining the Kolyma River Basin (Siberia), including permafrost‐derived OC. Reducing the phenolic content of the DOM pool resulted in dramatic increases in hydrolase EEAs (e.g., phosphatase activity increased >28‐fold) supporting the idea that high concentrations of polyphenolic compounds in DOM (e.g., plant structural tissues) inhibit enzyme synthesis or activity, limiting OC degradation. EEAs were significantly more responsive to inorganic nutrient additions only after phenolic inhibition was experimentally removed. In controlled mixtures of modern OC and thawed permafrost endmember OC sources, respiration rates per unit dissolved OC were 1.3–1.6 times higher in waters containing ancient carbon, suggesting that permafrost‐derived OC was more available for microbial mineralization. In addition, waters containing ancient permafrost‐derived OC supported elevated phosphatase and glucosidase activities. Based on these combined results, we propose that both composition and nutrient availability regulate DOM metabolism in Arctic aquatic ecosystems. Our empirical findings are incorporated into a mechanistic conceptual model highlighting two key enzymatic processes in the mineralization of riverine OM: (i) the role of phenol oxidase activity in reducing inhibitory phenolic compounds and (ii) the role of phosphatase in mobilizing organic P. Permafrost‐derived DOM degradation was less constrained by this initial ‘phenolic‐OM’ inhibition; thus, informing reports of high biological availability of ancient, permafrost‐derived DOM with clear ramifications for its metabolism in fluvial networks and feedbacks to climate.
Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle
Authors: Gundale Michael J. , From Fredrik , Bach Lisbet H. , Nordin Annika
Published: October 2013

It is proposed that increases in anthropogenic reactive nitrogen (Nr) deposition may cause temperate and boreal forests to sequester a globally significant quantity of carbon (C); however, long‐term data from boreal forests describing how C sequestration responds to realistic levels of chronic Nr deposition are scarce. Using a long‐term (14‐year) stand‐scale (0.1 ha) N addition experiment (three levels: 0, 12.5, and 50 kg N ha−1 yr−1) in the boreal zone of northern Sweden, we evaluated how chronic N additions altered N uptake and biomass of understory communities, and whether changes in understory communities explained N uptake and C sequestration by trees. We hypothesized that understory communities (i.e. mosses and shrubs) serve as important sinks for low‐level N additions, with the strength of these sinks weakening as chronic N addition rates increase, due to shifts in species composition. We further hypothesized that trees would exhibit nonlinear increases in N acquisition, and subsequent C sequestration as N addition rates increased, due to a weakening understory N sink. Our data showed that understory biomass was reduced by 50% in response to the high N addition treatment, mainly due to reduced moss biomass. A 15N labeling experiment showed that feather mosses acquired the largest fraction of applied label, with this fraction decreasing as the chronic N addition level increased. Contrary to our hypothesis, the proportion of label taken up by trees was equal (ca. 8%) across all three N addition treatments. The relationship between N addition and C sequestration in all vegetation pools combined was linear, and had a slope of 16 kg C kg−1 N. While canopy retention of Nr deposition may cause C sequestration rates to be slightly different than this estimate, our data suggest that a minor quantity of annual anthropogenic CO2 emissions are sequestered into boreal forests as a result of Nr deposition.
Future no‐analogue vegetation produced by no‐analogue combinations of temperature and insolation
Authors: Reu Björn , Zaehle Sönke , Bohn Kristin , Pavlick Ryan , Schmidtlein Sebastian , Williams John W. , Kleidon Axel
Published: October 2013

Aim

Projections of future climate change suggest that regional climates may evolve to states that are unlike any climate regime found on Earth today. These climates will impose novel constraints on plant species, and are likely to give rise to plant associations that are compositionally unlike any found on Earth today. Here, we explore whether the geographical distribution of previously mapped no‐analogue climates corresponds to the geographical distribution of simulated no‐analogue vegetation under scenarios of global warming.

Location

Global landmasses.

Methods

We used JeDi, a process‐based vegetation model that accounts for ecophysiological trade‐offs in plant growth and survival, to identify the assembly of plant functional types into no‐analogue associations under scenarios of global warming. We compared the geographical distribution of these no‐analogue vegetation types with those of no‐analogue climates derived from seasonal temperature and precipitation. To better understand the climatic causes that lead to no‐analogue vegetation, we performed a set of JeDi simulation experiments and compared them, as well as selected climate indices, with the geographical distribution of no‐analogue vegetation. Finally, we explored the changes in plant characteristics leading to no‐analogue vegetation composition.

Results

In our model simulations, a no‐analogue vegetation type emerged in Northern Eurasia due to the interacting effects of rising temperatures and the prolongation of the growing season, combined with stable patterns in the seasonal insolation cycle. Future tropical biomes experiencing novel temperature and precipitation regimes however, resemble contemporary vegetation despite significant losses of plant diversity.

Main conclusions

Our modelling study shows how no‐analogue vegetation can emerge in response to novel climates produced by rising temperatures and stable insolation, while also suggesting that no‐analogue climates do not necessarily lead to no‐analogue vegetation types. This result underlines the importance of considering plant diversity and the need to integrate ecophysiological knowledge through process‐orientated models when projecting future vegetation.
Candida albicans adherence and proliferation on the surface of denture base materials
Authors: Koch Carola , Bürgers Ralf , Hahnel Sebastian
Published: October 2013

Objective

This study aimed to evaluate the adhesion and proliferation of Candida albicans on denture base materials with different resin chemistries.

Materials and methods

Standardised specimens were prepared from different denture base materials (i.e. Palapress vario, Paladon 65, Castdon, Sherapress, Eclipse and Mucopren) and subjected to thermal cycling to simulate an artificial ageing process. After the determination of surface roughness and surface free energy, Candida albicans adherence and proliferation on the surface of denture base materials were simulated by subsequent incubation with Candida albicans ATCC 10231 for either 24 h or 196 h with and without prior simulation of salivary pellicle formation.

Results

Regardless of the presence of a salivary pellicle or the incubation time, the results indicate that the proliferation of Candida albicans is significantly dependent on the material that is used for the fabrication of denture bases (p < 0.001). A significantly higher proliferation of Candida albicans was observed on the surface of denture base materials with the highest polar contribution to surface free energy (i.e. Eclipse, Mucopren), and this result supports the assumption that there might be a relationship between the polar contribution to surface free energy of the substratum material and Candida albicans proliferation.

Conclusion

The results obtained from this study indicate that Candida albicans proliferation in particular is not necessarily increased on denture base materials that are subjected to thermal cycling.
Multiple hydrocarbon charging events in Kuh‐e‐Mond oil field, Coastal Fars: evidence from biomarkers in oil inclusions
Authors: Shariatinia Z. , Feiznia S. , Shafiei A. , Haghighi M. , Mousavi Dehghani A. , Memariani M. , Farhadian N.
Published: October 2013

Oil inclusions were retrieved from dolomite and calcite fracture fills in upper, middle and lower reservoir zones in Kuh‐e‐Mond Field, Zagros Basin, Iran. They are assumed to be persevered samples of primary oil; hence, their biomarkers were analysed to determine the maturity gradient and source facies of petroleum at the time of migration. A variety of specific parameters were obtained including n‐alkanes, hopanes, steranes from aromatic hydrocarbons in oil inclusions and reservoir hydrocarbons petroleum. The Pr/Ph ratio varies from 0.5 to 1, which is indicative of dominant reducing conditions during source rock deposition. The fluid inclusion oils with dibenzothiophene/phenanthrene ratios ranging from 0.68 to 1.4, Pr/Ph ratios from 0.8 to 1.2 and with C34/C35 ratios of homohopanes in the range from 1.1 to 1.76, suggest regional variations of organic facies in their source rocks. Biomarker parameters obtained from fluid inclusion oils differ slightly from those of reservoired oil. The biomarker data indicate that the reservoir oil in the Kuh‐e‐Mond Field was generated and expelled predominantly from carbonate–marly sources deposited in anoxic environments. A terrestrial material source seems plausible here, and the presence of C29/C27 ααα 20R steranes supports this finding. The maturity levels of fluid inclusion oils inferred from C12+ parameters are slightly higher in the dolomite and calcite cements from the upper reservoir zone, which may be due to continuous reservoir filling.
Accumulation of geriatric conditions is associated with poor nutritional status in dependent older people living in the community and in nursing homes
Authors: Hirose Takahisa , Hasegawa Jun , Izawa Sachiko , Enoki Hiromi , Suzuki Yuske , Kuzuya Masafumi
Published: October 2013

Aim

To clarify the association between nutritional status and the prevalence of geriatric conditions in dependent older adults.

Methods

A cross‐sectional observational study of dependent older adults aged 65years or older who were living either in the community (n = 511, mean age 81.2years) or in nursing homes (n = 587, mean age 85.2years) was carried out. Data included the participants' demographic characteristics, basic activities of daily living, Charlson Comorbidity Index and the prevalence of eight geriatric conditions (visual impairment, hearing impairment, falls, bladder control problems, cognitive impairment, impaired mobility, swallowing disturbance and loss of appetite). Nutritional status was assessed by the Mini Nutritional Assessment short form (MNA‐SF).

Results

Of 1098 participants, 21.4% (n = 235) were categorized as “malnourished”, according to the MNA‐SF classification. Participants in the “malnourished” group had a greater number of geriatric conditions than those in the other two groups. A higher prevalence of all the geriatric conditions except for falls was detected in the group with poorer nutritional status. Multivariate logistic regression analysis showed that malnutrition was associated with the number of geriatric conditions, but not with that of comorbidities, even after controlling for confounders.

Conclusions

Malnutrition was confirmed to have significant associations with geriatric conditions in dependent older adults. Geriatr Gerontol Int 2014; 14: 198–205.
Carotid ultrasound examination as an aging and disability marker
Authors: Barrera Gladys , Bunout Daniel , de la Maza María Pía , Leiva Laura , Hirsch Sandra
Published: October 2013

Aim

To explore the usefulness of carotid ultrasound examination as a marker of aging and predictor of disability among older people.

Methods

Carotid ultrasound, measuring carotid intima media thickness (CIMT) and recording the presence of plaques, was carried out in 152 adults aged 29–59 years (47 women) and in 107 older adults aged 61–88 years (86 women). In all, clinical routine laboratory parameters and lymphocyte telomere length as T/S ratio were measured. Among older adults, 12‐min walk, timed up and go, hand grip and quadriceps strength were determined.

Results

CIMT was significantly higher among older people and T/S ratio was significantly higher in young women. Carotid plaques were found in one adult and 17 older people. A multiple regression analysis accepted age, systolic blood pressure and T/S ratios as independent predictors of CIMT (R2 = 0.51). Among older people, a logistic regression accepted age and the presence of carotid plaques as significant predictors of a 12‐min walk speed below 1 m/s.

Conclusions

An abnormal 12‐min walk as an indicator of functional decline among older people is associated with the presence of carotid artery plaques. CIMT is independently associated with age. Geriatr Gerontol Int 2014; 14: 710–715.