bluuebunny/crossref_metadata_2025 huggingface dataset:
Red‐Light‐Induced Resistance to Brown Spot Disease Caused by Bipolaris oryzae in Rice
Authors: Parada Roxana Y. , Mon‐nai Wataru , Ueno Makoto , Kihara Junichi , Arase Sakae
Published: July 2014

In this study, the protective effect of red light against the brown spot disease caused by the fungus Bipolaris oryzae in rice was investigated. Lesion formation was significantly inhibited on detached leaves that were inoculated with B. oryzae and kept under red for 48 h, but it was not inhibited when the leaves were kept under natural light or in the dark. The protective effect was also observed in intact rice plants inoculated with B. oryzae; the plants survived under red light, but most of them were killed by infection under natural light or dark condition. Red light did not affect fungal infection in onion epidermis cells or heat‐shocked leaves of rice, and it did not affect cellulose digestion ability; this suggested that the protective effect is due to red‐light‐induced resistance. In addition, the degree of protection increased as the red light dosage increased, regardless of the order of the red light and natural light period, indicating that red‐light‐induced resistance is time dependent. Feeding of detached leaves with a tryptophan decarboxylase inhibitor, s‐α‐fluoromethyltryptophan (0.1 mm), for 24 h inhibited the development of resistance in response to red light irradiation. Suppression of resistance was also observed in leaves treated with a phenylalanine ammonia‐lyase inhibitor, α‐aminooxy acetic acid (0.5 mm). These results suggest that the tryptophan and phenylpropanoid pathways are involved in the red‐light‐induced resistance of rice to B. oryzae.
High environmental salinity reduces the reproductive potential of the spider crab Maja brachydactyla (Decapoda, Majidae)
Authors: Rotllant Guiomar , Simeó Carles G. , Macià Glòria , Estévez Alicia
Published: July 2014

The spider crab Maja brachydactyla is an important fisheries species in Europe. Adults were sampled in Ría de A Coruña (NW Spain) and transported to IRTA rearing facilities. Salinity and photoperiod changes and their effect on reproduction were tested in the laboratory. The number of newly hatched larvae per batch (presence of actively swimming newly hatched larvae in a broodstock tank) was counted and sampled to estimate dry weight and proximal composition. Keeping spider crab broodstock in a high salinity environment (38 ppt) significantly reduced the number of newly hatched larvae, reaching up to fivefold difference in winter. The number of newly hatched larvae produced under a natural photoperiod was 10‐fold higher than those produced using a fixed photoperiod at 34 ppt salinity during winter. No clear pattern of changes in larval dry weight, protein, lipid or carbohydrate composition was observed under the environmental conditions tested. The results show that the salinity used for broodstock maintenance, especially during the embryonic development, is an important factor causing changes in larval production of M. brachydactyla and with potential implications for recruitment success.
Spatio‐temporal variations in demersal fish assemblages and diversity in the northern Gulf of St. Lawrence (Canada)
Authors: Tamdrari Hacène , Brêthes Jean‐Claude , Archambault Diane
Published: July 2014

Species diversity is generally considered one of the key factors of ecosystem resilience in response to anthropogenic pressures, including fishing. In this context, the spatial and temporal changes in demersal fish assemblages and species diversity were investigated in the northern Gulf of St. Lawrence (Canada), over a 20‐year period (1990–2010). Data were obtained from the summer research survey conducted by the Department of Fisheries and Oceans, and include commercial and non‐commercial species. The study covers the period of groundfish fishery collapse, the moratorium period, and the post‐moratorium period, and reflects various modifications in management. Multivariate statistical methods revealed two communities. A coastal community corresponds to strata located above 200 m depth and a deeper community located in the deep channels. Interannual differences in the composition of fish assemblages were observed and are mainly due to the changes in the relative biomass of some dominant species. Three diversity indices (Shannon–Wiener, Simpson's Index of Diversity and Motomura's constant) indicate a slight but significant increase of the diversity over time. This trend is due to the increase of the relative biomass of low‐rank species, which may have been favoured by the prohibition of groundfish trawling after 1997 in that region. The geographical distribution of the Shannon–Wiener index also shows temporal dynamics reflecting the biomass distribution of dominant demersal species.
Spatio‐temporal variability of zooplankton biomass and environmental control in the Northern Benguela Upwelling System: field investigations and model simulation
Authors: Martin Bettina , Eggert Anja , Koppelmann Rolf , Diekmann Rabea , Mohrholz Volker , Schmidt Martin
Published: July 2014

Spatial and temporal distribution patterns of zooplankton are highly variable in the Northern Benguela Upwelling System. We studied the distribution of zooplankton (size class ≥ 0.33 mm) and used field data from four cruises that took place between March 2008 and February 2011, as well as simulation results of a regional ecosystem model. Remotely sensed sea surface temperatures (SST) and surface chlorophyll concentrations were analysed to investigate environmental influences on zooplankton biomass. The Intense Benguela Upwelling Index showed a distinct seasonal signal throughout the years and the highest upwelling peaks in August/September. Even though surface chlorophyll concentrations were very variable throughout the year, the highest concentrations were always detected in September, following the upwelling of nutrient‐rich water. In field catches, zooplankton biomass concentration in the upper 200 m was highest above the outer shelf and shelf‐break in December 2010 and February 2011, i.e. 6 months after the upwelling peaks. In contrast, zooplankton biomass simulated by the model in the surface water was highest in September. In March/April, biomass maxima were typically measured in the field at intermediate water depths, but the vertical distribution was also affected by extensive oxygen minimum zones. The ecosystem model reproduced this vertical pattern. Although general trends were similar, simulation data of zooplankton standing stocks overestimated the field data by a factor of 3. In upwelling systems, food webs are generally considered to be short and dominated by large cells. However, our field data indicate more small‐sized zooplankton organisms above the shelf than offshore.
QTL mapping of freezing tolerance: links to fitness and adaptive trade‐offs
Authors: Oakley Christopher G. , Ågren Jon , Atchison Rachel A. , Schemske Douglas W.
Published: July 2014

Local adaptation, defined as higher fitness of local vs. nonlocal genotypes, is commonly identified in reciprocal transplant experiments. Reciprocally adapted populations display fitness trade‐offs across environments, but little is known about the traits and genes underlying fitness trade‐offs in reciprocally adapted populations. We investigated the genetic basis and adaptive significance of freezing tolerance using locally adapted populations of Arabidopsis thaliana from Italy and Sweden. Previous reciprocal transplant studies of these populations indicated that subfreezing temperature is a major selective agent in Sweden. We used quantitative trait locus (QTL) mapping to identify the contribution of freezing tolerance to previously demonstrated local adaptation and genetic trade‐offs. First, we compared the genomic locations of freezing tolerance QTL to those for previously published QTL for survival in Sweden, and overall fitness in the field. Then, we estimated the contributions to survival and fitness across both field sites of genotypes at locally adaptive freezing tolerance QTL. In growth chamber studies, we found seven QTL for freezing tolerance, and the Swedish genotype increased freezing tolerance for five of these QTL. Three of these colocalized with locally adaptive survival QTL in Sweden and with trade‐off QTL for overall fitness. Two freezing tolerance QTL contribute to genetic trade‐offs across environments for both survival and overall fitness. A major regulator of freezing tolerance, CBF2, is implicated as a candidate gene for one of the trade‐off freezing tolerance QTL. Our study provides some of the first evidence of a trait and gene that mediate a fitness trade‐off in nature.
Molecular epidemiology of cassava mosaic disease in Madagascar
Authors: Harimalala M. , Chiroleu F. , Giraud‐Carrier C. , Hoareau M. , Zinga I. , Randriamampianina J. A. , Velombola S. , Ranomenjanahary S. , Andrianjaka A. , Reynaud B. , Lefeuvre P. , Lett J.‐M.
Published: July 2014

Cassava is the staple food for hundreds of millions of people in Africa but its cultivation is seriously constrained by cassava mosaic disease (CMD) in Madagascar, and in Africa in general. This study identified the cassava mosaic geminiviruses (CMGs) involved in CMD in Madagascar and their associated epidemiological characteristics from countrywide surveys. Molecular characterization of CMGs in Madagascar revealed an unprecedented diversity and co‐occurrence of six viruses: African cassava mosaic virus (ACMV), East African cassava mosaic Cameroon virus (EACMCV), East African cassava mosaic Kenya virus (EACMKV), East African cassava mosaic virus (EACMV), South African cassava mosaic virus (SACMV) and the recently described Cassava mosaic Madagascar virus (CMMGV). Distinct geographical distributions were observed for the six viruses. While ACMV was more prevalent in the central highlands, EACMV and EACMKV were prevalent in lowlands and coastal regions. Both EACMCV and SACMV occurred in almost all the localities visited. PCR diagnosis revealed that mixed infection (up to four co‐infected viruses) occurred in 21% of the samples and were associated with higher symptom severity scores. Pairwise comparisons of virus associations showed that EACMCV was found in mixed infections more often than expected while ACMV and SACMV were mostly found in single infections. A greater abundance of whiteflies was observed in lowland and coastal areas. Nevertheless, infected cuttings remain the primary source of CMD propagation (95%) in Madagascar.
Evaluation of strawberry (Fragaria L.) genetic resources for resistance to Botrytis cinerea
Authors: Bestfleisch M. , Luderer‐Pflimpfl M. , Höfer M. , Schulte E. , Wünsche J. N. , Hanke M.‐V. , Flachowsky H.
Published: July 2014

The grey mould disease caused by Botrytis cinerea leads to substantial economic losses in strawberry production all over the world. Control of the disease requires an extensive amount of fungicide that is applied in varying complexes because the pathogen easily develops resistance against the active compounds. Planting of resistant cultivars seems to be a promising alternative for fruit growers, but there are currently no cultivars available combining resistance to B. cinerea with attractive horticultural traits. Breeding of new cultivars requires the effective identification of resistant strawberry genotypes; therefore the current study was aimed at the evaluation of strawberry genetic resources under controlled conditions by establishing an artificial inoculation assay. The method presented in this study is an artificial inoculation of ripe fruits with a defined spore suspension under laboratory conditions. The results show that this assay is fast and simple and leads to reproducible results that correlate with field observations. Over 3 years a total of 107 strawberry genotypes of the German National Fruit Genebank at the JKI in Dresden‐Pillnitz were evaluated. Five partly resistant genotypes, cultivars Diana, Joerica and Kimberly, and Fragaria virginiana ‘Wildmare Creek’ and F. vesca subsp. bracteata, were identified with mean disease levels of <20% at 6 days post‐inoculation. The obtained results are discussed with regard to future breeding activities.
The Suppressive Function of Human CD8+ iTregs is Inhibited by IL‐1β and TNFα
Authors: Bjarnadottir U. , Lemarquis A. L. , Halldorsdottir S. , Freysdottir J. , Ludviksson B. R.
Published: July 2014

CD8+ Tregs display an immunoregulatory activity and may play an essential role in the immunopathology of several diseases. Therefore, their therapeutic potential is exquisite and further studies on their differentiation and function are essential. The aim of this study was to evaluate the role of the innate immune system in CD8+ iTreg differentiation and function. Naive human CD8+CD25−CD45RA+ T cells were cultured in Treg‐inducing conditions with or without IL‐1β, TNFα or monocyte‐derived dendritic cells (DCs). The differentiation of CD8+CD127−CD25hiFoxP3hi‐induced Tregs (CD8+ iTregs) is dependent on TGF‐β1 and IL‐2, which had synergistic effect upon their differentiation. CD8+ iTregs were also induced in a coculture with allogeneic mature DCs (mDCs). The CD8+ iTregs suppressive function was confirmed, which was diminished in the presence of IL‐1β and TNFα. The IL‐1β‐prevented suppressive function was associated with reduced secretion of IL‐10 and IFNγ, whereas the presence of TNFα did not affect their secretion. Furthermore, the presence of TNFα reduced IL‐10 and TGF‐β1 secretion by CD8+ iTregs, whereas only IL‐10 secretion was decreased by IL‐1β. Together, these results suggest that IL‐1β and TNFα prevent IL‐2‐ and TGF‐β1‐driven CD8+ iTregs suppressive function in human T cells. Such pro‐inflammatory innate immune response possibly mediates its negative tolerogenic effect through reduced IFNγ‐, IL‐10‐ and TGF‐β1‐driven mechanism.
Identification of two novel alleles HLA‐A*11:133 and A*11:02:05 by polymerase chain reaction sequence‐based typing
Authors: He J.‐J. , Chen N.‐Y. , Zhang W. , He J. , Zhu F.‐M. , Lv H.‐J.
Published: July 2014

HLA‐A*11:113 shows one nucleotide difference from HLA‐A*11:01:01: HLA‐A*11:02:05 shows a single nucleotide difference from HLA‐A*11:02:01.
Identification of a novel HLA‐B*51 allele, HLA‐B*51:144, in a Chinese individual
Authors: Jin S.‐Z. , Li Z. , Zou H.‐Y.
Published: July 2014

The novel HLA‐B*51:144 allele shows one nucleotide difference from B*51:02:02 in exon 3.
A key general stress response motif is regulated non‐uniformly by CAMTA transcription factors
Authors: Benn Geoffrey , Wang Chang‐Quan , Hicks Derrick R. , Stein Jeffrey , Guthrie Cade , Dehesh Katayoon
Published: July 2014

Plants cope with environmental challenges by rapidly triggering and synchronizing mechanisms governing stress‐specific and general stress response (GSR) networks. The GSR acts rapidly and transiently in response to various stresses, but the underpinning mechanisms have remained elusive. To define GSR regulatory components we have exploited the Rapid Stress Response Element (RSRE), a previously established functional GSR motif, using Arabidopsis plants expressing a 4xRSRE::Luciferase (RSRE::LUC) reporter. Initially, we searched public microarray datasets and found an enrichment of RSRE in promoter sequences of stress genes. Next, we treated RSRE::LUC plants with wounding and a range of rapidly stress‐inducible hormones and detected a robust LUC activity solely in response to wounding. Application of two Ca2+ burst inducers, flagellin22 (flg22) and oligogalacturonic acid, activated RSRE strongly and systemically, while the Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) significantly reduced wound induction of RSRE::LUC. In line with the signaling function of Ca2+ in transduction events leading to activation of RSRE, we examined the role of CALMODULIN‐BINDING TRANSCRIPTIONAL ACTIVATORs (CAMTAs) in RSRE induction. Transient expression assays displayed CAMTA3 induction of RSRE and not that of the mutated element mRSRE. Treatment of selected camta mutant lines integrated into RSRE::LUC parent plant, with wounding, flg22, and freezing, established a differential function of these CAMTAs in potentiating the activity of RSRE. Wound response studies using camta double mutants revealed a cooperative function of CAMTAs2 and 4 with CAMTA 3 in the RSRE regulation. These studies provide insights into governing components of transduction events and reveal transcriptional modules that tune the expression of a key GSR motif.
Double disruption of α2A‐ and α2C‐adrenoceptors induces endothelial dysfunction in mouse small arteries: role of nitric oxide synthase uncoupling
Authors: Couto Gisele K. , Davel Ana P. , Brum Patrícia C. , Rossoni Luciana V.
Published: July 2014

New Findings

What is the central question of this study?

Knockout mice lacking both α2A‐ and α2C‐adrenergic receptors (α2A/α2C‐ARKO) provide a model for understanding the mechanisms underlying the deleterious effects of sympathetic hyperactivity on the cardiovascular system. The purpose of this study was to compare the effects of sympathetic hyperactivity on the vascular reactivity of large and small arteries from α2A/α2C‐ARKO mice and to evaluate the role of nitric oxide and oxidative stress.

What is the main finding and its importance?

We show that sympathetic hyperactivity alters vascular reactivity only in small arteries. Uncoupling endothelial nitric oxide synthase may be a significant source of superoxide anion and reduced NO bioavailability in small arteries from α2A/α2C‐ARKO mice, increasing the contractile tone.

Knockout mice lacking both α2A‐ and α2C‐adrenergic receptors (α2A/α2C‐ARKO) provide a model for understanding the mechanisms underlying the deleterious effects of sympathetic hyperactivity on the cardiovascular system. Thus, in the present study we investigated the vascular reactivity of large and small arteries of α2A/α2C‐ARKO mice. Aorta and mesenteric small arteries (MSAs) from 7‐month‐old male α2A/α2C‐ARKO mice and congenic C57BL6/J mice (wild‐type, WT) were studied. In the aorta, noradrenaline‐ and serotonin‐induced contraction was similar between groups, but in MSAs there was an increase in agonist‐induced contraction in α2A/α2C‐ARKO compared with WT. The l‐NAME effect was reduced in MSAs of α2A/α2C‐ARKO mice compared with WT mice, as was basal NO evaluated by a 4,5‐diaminofluorescein diacetate probe. Increased total endothelial nitric oxide synthase (eNOS) protein expression was observed in MSAs from α2A/α2C‐ARKO mice, while the dimer/monomer ratio of eNOS was decreased. Mesenteric small arteries from α2A/α2C‐ARKO mice showed an increase in ethidium bromide‐positive nuclei, indicating oxidative stress, which was attenuated by incubation with l‐NAME. The sympathetic hyperactivity present in α2A/α2C‐ARKO mice alters vascular reactivity only in certain types of arteries. Moreover, after chronic sympathetic hyperactivity, uncoupling eNOS may be a significant source of superoxide anion and reduced NO bioavailability in small vessels, increasing the contractile tone.
Association beween resting heart rate, shear and flow‐mediated dilation in healthy adults
Authors: Fox Brandon M. , Brantley Lucy , White Claire , Seigler Nichole , Harris Ryan A.
Published: July 2014

New Findings

What is the central question of this study?

The aim was to explore the relationships among resting heart rate, shear and endothelial function in humans.

What is the main finding and its importance?

The main finding is that resting heart rate is associated with shear and endothelial function in humans. This finding could have implications when studying endothelial function in humans with varying heart rates.

Preclinical data have demonstrated that heart rate (HR) can directly impact vascular endothelial function, in part, through a shear‐stress mechanism. This study sought to explore, in humans, the associations between resting heart rate and both shear and endothelial function assessed by flow‐mediated dilation (FMD). The brachial artery FMD test was performed in 31 apparently healthy volunteers. Basal (B) and hyperaemic (H) shear were quantified in the following two ways using data from the FMD test: the traditional cumulative shear area under the curve up to peak dilation (Shearcum) method; and our novel method of shear summation (Shearsum), which accounts for HR by summing each individual cardiac cycle shear up to peak dilation. Data were grouped by tertiles based on resting HR as follows: low (LHR = 43–56 beats min−1; n = 10); middle (MHR = 58–68 beats min−1; n = 11); and high (HHR = 69–77 beats min−1; n = 10). Within the LHR group, both B‐Shearcum and H‐Shearcum were significantly higher (P < 0.001) than B‐Shearsum and H‐Shearsum, respectively, whereas in the HHR group B‐Shearcum and H‐Shearcum were significantly lower (P < 0.001) than B‐Shearsum and H‐Shearsum, respectively. The FMD in the LHR group (8.8 ± 0.8%) was significantly greater than that in both the MHR group (5.5 ± 0.8%; P = 0.009) and the HHR group (5.9 ± 0.8%; P = 0.024). These findings demonstrate the existence of a relationship between heart rate and both shear and endothelial function in humans. Moreover, these findings have implications for considering heart rate as an important physiological variable when quantifying shear and performing the FMD test.
Silencing of Kir2 channels by caveolin‐1: cross‐talk with cholesterol
Authors: Han Huazhi , Rosenhouse‐Dantsker Avia , Gnanasambandam Radhakrishnan , Epshtein Yulia , Chen Zhenlong , Sachs Frederick , Minshall Richard D. , Levitan Irena
Published: July 2014

Key points

Inwardly rectifying potassium channels (Kir) play key roles in regulating membrane excitability and K+ homeostasis in multiple cell types. Our earlier studies showed that Kir2 channels, one of the major subfamilies of Kir, are suppressed by membrane cholesterol and that cholesterol stabilizes these channels in a closed ‘silent’ state.

This paper addresses a fundamental question of how Kir2 channels are regulated by caveolins, the major structural proteins of caveolae, and the relationship between the sensitivity of the channels to caveolin and to cholesterol.

In this study, we present direct evidence that caveolin‐1 is a negative regulator of Kir2 function and that cholesterol and caveolin‐1 regulate the channels by a common mechanism.

This study also challenges a general notion that cholesterol depletion alters ion channel function by disrupting caveolae, demonstrating that neither caveolin‐1 nor intact caveolae are required for cholesterol sensitivity of Kir2 channels.

Furthermore, we present first insights into the structural determinants of the cross‐talk between the sensitivity of Kir2 channels to caveolin and to cholesterol.

A growing number of studies show that different types of ion channels localize in caveolae and are regulated by the level of membrane cholesterol. Furthermore, it has been proposed that cholesterol‐induced regulation of ion channels might be attributed to partitioning into caveolae and association with caveolin‐1 (Cav‐1). We tested, therefore, whether Cav‐1 regulates the function of inwardly rectifying potassium channels Kir2.1 that play major roles in the regulation of membrane potentials of numerous mammalian cells. Our earlier studies demonstrated that Kir2.1 channels are cholesterol sensitive. In this study, we show that Kir2.1 channels co‐immunoprecipitate with Cav‐1 and that co‐expression of Kir2.1 channels with Cav‐1 in HEK293 cells results in suppression of Kir2 current indicating that Cav‐1 is a negative regulator of Kir2 function. These observations are confirmed by comparing Kir currents in bone marrow‐derived macrophages isolated from Cav‐1−/− and wild‐type animals. We also show, however, that Kir2 channels maintain their sensitivity to cholesterol in HEK293 cells that have very low levels of endogenous Cav‐1 and in bone marrow‐derived macrophages isolated from Cav‐1−/− knockout mice. Thus, these studies indicate that Cav‐1 and/or intact caveolae are not required for cholesterol sensitivity of Kir channels. Moreover, a single point mutation of Kir2.1, L222I that abrogates the sensitivity of the channels to cholesterol also abolishes their sensitivity to Cav‐1 suggesting that the two modulators regulate Kir2 channels via a common mechanism.
Nanoceria based electrochemical sensor for hydrogen peroxide detection
Authors: Ujjain Sanjeev Kumar , Das Anubhav , Srivastava Gaurav , Ahuja Preety , Roy Manas , Arya Aditya , Bhargava Kalpana , Sethy Niroj , Singh Sushil Kumar , Sharma Raj Kishore , Das Mainak
Published: July 2014

Oxidative stress is a condition when the concentration of free radicals and reactive molecular species rise above certain level in living systems. This condition not only perturbs the normal physiology of the system but also has been implicated in many diseases in humans and other animals. Hydrogen peroxide (H2O2) is known to be involved in induction of oxidative stress and has also been linked to a variety of ailments such as inflammation, rheumatoid arthritis, diabetes, and cancer in humans. It is one of the more stable reactive molecular species present in living systems. Because of its stability and links with various diseases, sensing the level of H2O2 can be of great help in diagnosing these diseases, thereby easing disease management and amelioration. Nanoceria is a potent candidate in free radical scavenging as well as sensing because of its unique redox properties. These properties have been exploited, in the reported work, to sense and quantify peroxide levels. Nanoceria has been synthesized using different capping agents: Hexamethylene-tetra-amine (HMTA) and fructose. CeO2-HMTA show rhombohedral and cubic 6.4 nm particles whereas CeO2-fructose are found to be spherical with average particle diameter size 5.8 nm. CeO2-HMTA, due to the better exposure of the active (200) and (220) planes relative to (111) plane, exhibits superior electrocatalytic activity toward H2O2 reduction. Amperometric responses were measured by increasing H2O2 concentration. The authors observed a sensitivity of 21.13 and 9.6 μA cm−2 mM−1 for CeO2-HMTA and CeO2-fructose, respectively. The response time of 4.8 and 6.5 s was observed for CeO2-HMTA and CeO2-fructose, respectively. The limit of detection is as low as 0.6 and 2.0 μM at S/N ratio 3 for CeO2-HMTA and CeO2-fructose, respectively. Ceria-HMTA was further tested for its antioxidant activity in an animal cell line in vitro and the results confirmed its activity.
A new and fast image feature selection method for developing an optimal mammographic mass detection scheme
Authors: Tan Maxine , Pu Jiantao , Zheng Bin
Published: July 2014

Purpose:

Selecting optimal features from a large image feature pool remains a major challenge in developing computer‐aided detection (CAD) schemes of medical images. The objective of this study is to investigate a new approach to significantly improve efficacy of image feature selection and classifier optimization in developing a CAD scheme of mammographic masses.

Methods:

An image dataset including 1600 regions of interest (ROIs) in which 800 are positive (depicting malignant masses) and 800 are negative (depicting CAD‐generated false positive regions) was used in this study. After segmentation of each suspicious lesion by a multilayer topographic region growth algorithm, 271 features were computed in different feature categories including shape, texture, contrast, isodensity, spiculation, local topological features, as well as the features related to the presence and location of fat and calcifications. Besides computing features from the original images, the authors also computed new texture features from the dilated lesion segments. In order to select optimal features from this initial feature pool and build a highly performing classifier, the authors examined and compared four feature selection methods to optimize an artificial neural network (ANN) based classifier, namely: (1) Phased Searching with NEAT in a Time‐Scaled Framework, (2) A sequential floating forward selection (SFFS) method, (3) A genetic algorithm (GA), and (4) A sequential forward selection (SFS) method. Performances of the four approaches were assessed using a tenfold cross validation method.

Results:

Among these four methods, SFFS has highest efficacy, which takes 3%–5% of computational time as compared to GA approach, and yields the highest performance level with the area under a receiver operating characteristic curve (AUC) = 0.864 ± 0.034. The results also demonstrated that except using GA, including the new texture features computed from the dilated mass segments improved the AUC results of the ANNs optimized using other three feature selection methods. In addition, among 271 features, the shape, local morphological features, fat and calcification based features were the most frequently selected features to build ANNs.

Conclusions:

Although conventional GA is a powerful tool in optimizing classifiers used in CAD schemes of medical images, it is very computationally intensive. This study demonstrated that using a new SFFS based approach enabled to significantly improve efficacy of image feature selection for developing CAD schemes.
Asymmetry in perceived duration between up-ramp and down-ramp sounds as a function of duration
Authors: Meunier Sabine , Vannier Michaël , Chatron Jacques , Susini Patrick
Published: July 2014

The perceived duration of 1-kHz pure tones with increasing or decreasing intensity profiles was measured. The ratio between the down- and up-ramp durations at equal subjective durations was examined as a function of the sound duration (50, 100, 200, 500, 1000, 2000 ms). At 50 and 100 ms, the ratio was constant and equaled about 1.7, then it logarithmically decreased from 100 to 1000 ms to reach a constant value of 1 at 1 and 2 s. The different mechanisms proposed in the literature to explain the perceived duration asymmetry between up-ramp and down-ramp were discussed in the light of the dependence of this ratio on duration.
Enhanced auditory temporal gap detection in listeners with musical training
Authors: Mishra Srikanta K. , Panda Manas R. , Herbert Carolyn
Published: July 2014

Many features of auditory perception are positively altered in musicians. Traditionally auditory mechanisms in musicians are investigated using the Western-classical musician model. The objective of the present study was to adopt an alternative model—Indian-classical music—to further investigate auditory temporal processing in musicians. This study presents that musicians have significantly lower across-channel gap detection thresholds compared to nonmusicians. Use of the South Indian musician model provides an increased external validity for the prediction, from studies on Western-classical musicians, that auditory temporal coding is enhanced in musicians.
Microcystin Production and Regulation under Nutrient Stress Conditions in Toxic Microcystis Strains
Authors: Pimentel Juliana S. M. , Giani Alessandra
Published: July 2014

Microcystin is a common and well-known cyanobacterial toxin whose intracellular role is still under investigation. Increasing knowledge on microcystin gene expression and regulation can contribute to the understanding of its putative cellular function. In this work, reverse transcription-quantitative PCR (RT-qPCR) was used to investigate the transcriptional response of the
mcyD
gene to nitrogen (nitrate and ammonium) and phosphorus limitation in two toxic
Microcystis
strains. The existence of a direct correlation between transcripts of
mcyD
and
ntcA
genes was also identified. In previous studies, NtcA (global nitrogen regulator) has been described as a potential component in the control of microcystin biosynthesis. This research showed that stress agents linked to nutrient deprivation could lead to a significant increase of microcystin production in both strains studied. The more toxic strain proved to be more resistant to nutrient limitation. The similar outcomes of
mcyD
regulation observed for all nutrients suggest that this response can be linked to oxidative stress of cells undergoing adverse growth conditions.
Evidence of Environmental and Vertical Transmission of Burkholderia Symbionts in the Oriental Chinch Bug, Cavelerius saccharivorus (Heteroptera: Blissidae)
Authors: Itoh Hideomi , Aita Manabu , Nagayama Atsushi , Meng Xian-Ying , Kamagata Yoichi , Navarro Ronald , Hori Tomoyuki , Ohgiya Satoru , Kikuchi Yoshitomo
Published: July 2014

The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. The oriental chinch bug,
Cavelerius saccharivorus
(Heteroptera: Blissidae), is a serious sugarcane pest, in which symbiotic bacteria densely populate the lumen of the numerous tubule-like midgut crypts that the chinch bug develops. Cloning and sequence analyses of the 16S rRNA genes revealed that the crypts were dominated by a specific group of bacteria belonging to the genus
Burkholderia
of the
Betaproteobacteria
. The
Burkholderia
sequences were distributed into three distinct clades: the
Burkholderia cepacia
complex (BCC), the plant-associated beneficial and environmental (PBE) group, and the stinkbug-associated beneficial and environmental group (SBE). Diagnostic PCR revealed that only one of the three groups of
Burkholderia
was present in ∼89% of the chinch bug field populations tested, while infections with multiple
Burkholderia
groups within one insect were observed in only ∼10%. Deep sequencing of the 16S rRNA gene confirmed that the
Burkholderia
bacteria specifically colonized the crypts and were dominated by one of three
Burkholderia
groups. The lack of phylogenetic congruence between the symbiont and the host population strongly suggested host-symbiont promiscuity, which is probably caused by environmental acquisition of the symbionts by some hosts. Meanwhile, inspections of eggs and hatchlings by diagnostic PCR and egg surface sterilization demonstrated that almost 30% of the hatchlings vertically acquire symbiotic
Burkholderia
via symbiont-contaminated egg surfaces. The mixed strategy of symbiont transmission found in the oriental chinch bug might be an intermediate stage in evolution from environmental acquisition to strict vertical transmission in insects.
Vitamin B
6
Generated by Obligate Symbionts Is Critical for Maintaining Proline Homeostasis and Fecundity in Tsetse Flies
Authors: Michalkova Veronika , Benoit Joshua B. , Weiss Brian L. , Attardo Geoffrey M. , Aksoy Serap
Published: July 2014

The viviparous tsetse fly utilizes proline as a hemolymph-borne energy source. In tsetse, biosynthesis of proline from alanine involves the enzyme alanine-glyoxylate aminotransferase (AGAT), which requires pyridoxal phosphate (vitamin B
6
) as a cofactor. This vitamin can be synthesized by tsetse's obligate symbiont,
Wigglesworthia glossinidia
. In this study, we examined the role of
Wigglesworthia
-produced vitamin B
6
for maintenance of proline homeostasis, specifically during the energetically expensive lactation period of the tsetse's reproductive cycle. We found that expression of
agat
, as well as genes involved in vitamin B
6
metabolism in both host and symbiont, increases in lactating flies. Removal of symbionts via antibiotic treatment of flies (aposymbiotic) led to hypoprolinemia, reduced levels of vitamin B
6
in lactating females, and decreased fecundity. Proline homeostasis and fecundity recovered partially when aposymbiotic tsetse were fed a diet supplemented with either yeast or
Wigglesworthia
extracts. RNA interference-mediated knockdown of
agat
in wild-type flies reduced hemolymph proline levels to that of aposymbiotic females. Aposymbiotic flies treated with
agat
short interfering RNA (siRNA) remained hypoprolinemic even upon dietary supplementation with microbial extracts or B vitamins. Flies infected with parasitic African trypanosomes display lower hemolymph proline levels, suggesting that the reduced fecundity observed in parasitized flies could result from parasite interference with proline homeostasis. This interference could be manifested by competition between tsetse and trypanosomes for vitamins, proline, or other factors involved in their synthesis. Collectively, these results indicate that the presence of
Wigglesworthia
in tsetse is critical for the maintenance of proline homeostasis through vitamin B
6
production.
Polyhydroxyfullerene Binds Cadmium Ions and Alleviates Metal-Induced Oxidative Stress in Saccharomyces cerevisiae
Authors: Pradhan Arunava , Pinheiro José Paulo , Seena Sahadevan , Pascoal Cláudia , Cássio Fernanda
Published: July 2014

The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast
Saccharomyces cerevisiae
by exposing cells to Cd (≤5 mg liter
−1
) in the absence or presence of PHF (≤500 mg liter
−1
) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.
Effect of Metformin on Metabolic Improvement and Gut Microbiota
Authors: Lee Heetae , Ko GwangPyo
Published: July 2014

Metformin is commonly used as the first line of medication for the treatment of metabolic syndromes, such as obesity and type 2 diabetes (T2D). Recently, metformin-induced changes in the gut microbiota have been reported; however, the relationship between metformin treatment and the gut microbiota remains unclear. In this study, the composition of the gut microbiota was investigated using a mouse model of high-fat-diet (HFD)-induced obesity with and without metformin treatment. As expected, metformin treatment improved markers of metabolic disorders, including serum glucose levels, body weight, and total cholesterol levels. Moreover,
Akkermansia muciniphila
(12.44% ± 5.26%) and
Clostridium cocleatum
(0.10% ± 0.09%) abundances increased significantly after metformin treatment of mice on the HFD. The relative abundance of
A. muciniphila
in the fecal microbiota was also found to increase in brain heart infusion (BHI) medium supplemented with metformin
in vitro
. In addition to the changes in the microbiota associated with metformin treatment, when other influences were controlled for, a total of 18 KEGG metabolic pathways (including those for sphingolipid and fatty acid metabolism) were significantly upregulated in the gut microbiota during metformin treatment of mice on an HFD. Our results demonstrate that the gut microbiota and their metabolic pathways are influenced by metformin treatment.
Carbohydrate Coating Reduces Adhesion of Biofilm-Forming Bacillus subtilis to Gold Surfaces
Authors: Kesel S. , Mader A. , Seeberger P. H. , Lieleg O. , Opitz M.
Published: July 2014

The growth of bacterial biofilms in pipes and food tanks causes severe problems in industry. Biofilms growing on medical implants or catheters are of great concern, as they can cause serious infections and decrease the functionality of the medical device. The prevention of bacterial adhesion—the first step in colonization and biofilm formation—is therefore very important. Current research comprises alterations in surface properties, the prevention of adhesin biosynthesis, inhibition with receptor analogs, or the development of anti-adhesive vaccines. We present a new approach that allows us to study bacterial adhesion with high sensitivity in real-time while testing several different surfaces in parallel. Using the cantilever-array technique we demonstrate that coating of gold surfaces with mono- or disaccharides results in a reduction of the bacterial adhesion of the biofilm-forming bacterium
Bacillus subtilis
NCIB 3610 to these gold surfaces. This reduction in bacterial adhesion is independent of the studied carbohydrate. Using several mutant strains, we investigate the underlying molecular interactions, and our results suggest that adhesion to gold surfaces is mediated by thiol groups present in proteins of the bacterial cell membrane or biofilm matrix proteins expressed at low levels by the wild-type strain. Furthermore, our data indicate that the adhesion of
B. subtilis
NCIB 3610 to carbohydrate-coated gold surfaces is facilitated by interactions between carbohydrates installed on the cantilever gold surface and an exopolysaccharide expressed by this strain. Understanding general and specific contributions of molecular interactions mediating bacterial adhesion will enable its prevention in the future.
Decoration of Outer Membrane Vesicles with Multiple Antigens by Using an Autotransporter Approach
Authors: Daleke-Schermerhorn Maria H. , Felix Tristan , Soprova Zora , ten Hagen-Jongman Corinne M. , Vikström David , Majlessi Laleh , Beskers Joep , Follmann Frank , de Punder Karin , van der Wel Nicole N. , Baumgarten Thomas , Pham Thang V. , Piersma Sander R. , Jiménez Connie R. , van Ulsen Peter , de Gier Jan-Willem , Leclerc Claude , Jong Wouter S. P. , Luirink Joen
Published: July 2014

Outer membrane vesicles (OMVs) are spherical nanoparticles that naturally shed from Gram-negative bacteria. They are rich in immunostimulatory proteins and lipopolysaccharide but do not replicate, which increases their safety profile and renders them attractive vaccine vectors. By packaging foreign polypeptides in OMVs, specific immune responses can be raised toward heterologous antigens in the context of an intrinsic adjuvant. Antigens exposed at the vesicle surface have been suggested to elicit protection superior to that from antigens concealed inside OMVs, but hitherto robust methods for targeting heterologous proteins to the OMV surface have been lacking. We have exploited our previously developed hemoglobin protease (Hbp) autotransporter platform for display of heterologous polypeptides at the OMV surface. One, two, or three of theMycobacterium tuberculosisantigens ESAT6, Ag85B, and Rv2660c were targeted to the surface ofEscherichia coliOMVs upon fusion to Hbp. Furthermore, a hypervesiculating ΔtolRΔtolAderivative of attenuatedSalmonella entericaserovar Typhimurium SL3261 was generated, enabling efficient release and purification of OMVs decorated with multiple heterologous antigens, exemplified by theM. tuberculosisantigens and epitopes fromChlamydia trachomatismajor outer membrane protein (MOMP). Also, we showed that delivery ofSalmonellaOMVs displaying Ag85B to antigen-presenting cellsin vitroresults in processing and presentation of an epitope that is functionally recognized by Ag85B-specific T cell hybridomas. In conclusion, the Hbp platform mediates efficient display of (multiple) heterologous antigens, individually or combined within one molecule, at the surface of OMVs. Detection of antigen-specific immune responses upon vesicle-mediated delivery demonstrated the potential of our system for vaccine development.
Estimating daily salt intake based on 24 h urinary sodium excretion in adults aged 18–69 years in Shandong, China
Authors: Zhang Ji-yu , Yan Liu-xia , Tang Jun-li , Ma Ji-xiang , Guo Xiao-lei , Zhao Wen-hua , Zhang Xiao-fei , Li Jian-hong , Chu Jie , Bi Zhen-qiang
Published: July 2014

Objective

24 h urinary sodium extretion was used to estimate the daily salt intake of shandong residents aged from 18 to 69 years in China.

Setting

20 selected counties/districts in Shandong stratified by geographic region (Eastern, Central Southern and North Western) and residence type (urban vs rural).

Participants

Among 2184 randomly selected adults, 2061 provided usable 24 h urine samples. Urine volume <500 mL or male creatinine <3.81 (female creatinine <4.57) are not included in the analysis.

Results

The mean sodium level excreted over 24 h was 237.61 mmol (95% CI 224.77 to 250.44) mmol. Overall, the estimated mean salt intake was 13.90 g/day (95% CI 13.15 to 14.65). The mean salt intake among rural residents was higher than that among urban residents (14.00 vs 13.68 g; p<0.01). Salt intake in men was higher than that in women (14.40 vs 13.37 g; p<0.01). Approximately 96% of the survey participants had a dietary salt intake of ≥6 g/day.

Conclusions

The salt intake in Shandong is alarmingly higher than the current recommended amount (6 g/day). Thus, effective interventions to reduce salt intake levels to combat the increasing burden of non-communicable diseases need to be developed and implemented.
Pop, heavy metal and the blues: secondary analysis of persistent organic pollutants (POP), heavy metals and depressive symptoms in the NHANES National Epidemiological Survey
Authors: Berk Michael , Williams Lana J , Andreazza Ana C , Pasco Julie A , Dodd Seetal , Jacka Felice N , Moylan Steven , Reiner Eric J , Magalhaes Pedro V S
Published: July 2014

Objectives

Persistent environmental pollutants, including heavy metals and persistent organic pollutants (POPs), have a ubiquitous presence. Many of these pollutants affect neurobiological processes, either accidentally or by design. The aim of this study was to explore the associations between assayed measures of POPs and heavy metals and depressive symptoms. We hypothesised that higher levels of pollutants and metals would be associated with depressive symptoms.

Setting

National Health and Nutrition Examination Survey (NHANES).

Participants

A total of 15 140 eligible people were included across the three examined waves of NHANES.

Primary and secondary outcome measures

Depressive symptoms were assessed using the nine-item version of the Patient Health Questionnaire (PHQ-9), using a cut-off point of 9/10 as likely depression cases. Organic pollutants and heavy metals, including cadmium, lead and mercury, as well as polyfluorinated compounds (PFCs), pesticides, phenols and phthalates, were measured in blood or urine.

Results

Higher cadmium was positively associated with depression (adjusted Prevalence Ratios (PR)=1.48, 95% CI 1.16 to 1.90). Higher levels of mercury were negatively associated with depression (adjusted PR=0.62, 95% CI 0.50 to 0.78), and mercury was associated with increased fish consumption (n=5500, r=0.366, p<0.001). In addition, several PFCs (perfluorooctanoic acid, perfluorohexane sulfonic acid, perfluorodecanoic acid and perfluorononanoic acid) were negatively associated with the prevalence of depression.

Conclusions

Cadmium was associated with an increased likelihood of depression. Contrary to hypotheses, many of persistent environmental pollutants were not associated or negatively associated with depression. While the inverse association between mercury and depressive symptoms may be explained by a protective role for fish consumption, the negative associations with other pollutants remains unclear. This exploratory study suggests the need for further investigation of the role of various agents and classes of agents in the pathophysiology of depression.