bluuebunny/crossref_metadata_2025_split huggingface dataset:
Why have no new herbicide modes of action appeared in recent years?
Authors: Duke Stephen O 
Published: December 2011

AbstractHerbicides with new modes of action are badly needed to manage the evolution of resistance of weeds to existing herbicides. Yet no major new mode of action has been introduced to the market place for about 20 years. There are probably several reasons for this. New potential products may have remained dormant owing to concerns that glyphosate‐resistant (GR) crops have reduced the market for a new herbicide. The capture of a large fraction of the herbicide market by glyphosate with GR crops led to significantly diminished herbicide discovery efforts. Some of the reduced herbicide discovery research was also due to company consolidations and the availability of more generic herbicides. Another problem might be that the best herbicide molecular target sites may have already been discovered. However, target sites that are not utilized, for which there are inhibitors that are highly effective at killing plants, suggests that this is not true. Results of modern methods of target site discovery (e.g. gene knockout methods) are mostly not public, but there is no evidence of good herbicides with new target sites coming from these approaches. In summary, there are several reasons for a long dry period for new herbicide target sites; however, the relative magnitude of each is unclear. The economic stimulus to the herbicide industry caused by the evolution of herbicide‐resistant weeds, especially GR weeds, may result in one or more new modes of action becoming available in the not too distant future. Copyright © 2011 Society of Chemical Industry
Time series predictor of Ku band rain attenuation over an Earth–space path at a tropical location
Authors: Das Dalia , Maitra Animesh 
Published: December 2011

SUMMARYA channel model is proposed to predict the time series of Ku band rain attenuation during a rain event at a tropical location. The model is based on considering the Gaussian distribution of the conditional occurrence of rain attenuation with a particular value of the attenuation occurring before. The mean (μ) and standard deviation (σ) for the distribution are modeled with the experimental data. The measured attenuation at a particular time instant is used to obtain μ and σ and to predict the attenuation after certain interval. The channel model has tested well giving the predicted attenuation that agrees with the measured value with a mean error within 15% higher than 1 dB. Validity of the model is also tested with the first‐order and second‐order statistics of attenuation occurrence, on a long‐term basis. The method can also be applied even if attenuation measurements are missing for certain period of time with increased error. Copyright © 2011 John Wiley & Sons, Ltd.
A context‐aware approach to defend against unauthorized reading and relay attacks in RFID systems
Authors: Ma Di , Saxena Nitesh 
Published: December 2011

ABSTRACTRadio frequency identification (RFID) systems are becoming increasingly ubiquitous in both public and private domains. However, because of the inherent weaknesses of underlying wireless radio communications, RFID systems are plagued with a wide variety of security and privacy threats. A large number of these threats arise because of the tag's promiscuous response to any reader requests. This renders sensitive tag information easily subject to unauthorized reading. Promiscuous tag response also incites different forms of relay attacks whereby a malicious colluding pair, relaying messages between a tag and a reader, can successfully impersonate the tag without actually possessing it. Because of the increasing ubiquity of RFID devices, there is a pressing need for the development of security primitives and protocols to defeat unauthorized reading and relay attacks. However, currently deployed or proposed solutions often fail to satisfy the constraints and requirements of the underlying RFID applications in terms of (one or more of) efficiency, security, and usability. This paper proposes a novel research direction, one that utilizes sensing technologies, to tackle the problems of unauthorized reading and relay attacks with a goal of reconciling the requirements of efficiency, security, and usability. The premise of the proposed work is based on a current technological advancement that enables many RFID tags with low‐cost sensing capabilities. The on‐board tag sensors will be used to acquire useful contextual information about the tag's environment (or its owner, or the tag itself). For defense against unauthorized reading and relay attacks, such context information can be leveraged in two ways. First, contextual information can be used to design context‐aware selective unlocking mechanisms so that tags can selectively respond to reader interrogations and thus minimize the likelihood of unauthorized reading and “ghost‐and‐leech” relay attacks. Second, contextual information can be used as a basis for context‐aware secure transaction verification to defend against special types of relay attacks involving malicious readers. Copyright © 2011 John Wiley & Sons, Ltd.
Chinese High School Students' Academic Stress and Depressive Symptoms: Gender and School Climate as Moderators
Authors: Liu Yangyang , Lu Zuhong 
Published: December 2011

AbstractIn a sample of 368 Chinese high school students, the present study examined the different effects of Chinese high school students' academic stress on their depressive symptoms and the moderating effects of gender and students' perceptions of school climate on the relationships between their academic stress and depressive symptoms. Regression mixture model identified two different kinds of subgroups in the effects of students' academic stress on their depressive symptoms. One subgroup contained 90% of the students. In this subgroup, the students' perceptions of academic stress from lack of achievement positively predicted their depressive symptoms. For the other 10% of the students, academic stress did not significantly predict their depressive symptoms. Next, multinomial regression analysis revealed that girls or students who had high levels of achievement orientation were more likely to be in the first subgroup. The findings suggested that gender and students' perceptions of school climate could moderate the relationships between Chinese high school students' academic stress and their depressive symptoms. Copyright © 2011 John Wiley & Sons, Ltd.
Optimization of ethanol, citric acid, and α-amylase production from date wastes by strains of Saccharomyces cerevisiae, Aspergillus niger, and Candida guilliermondii
Authors: Acourene S , Ammouche A 
Published: December 2011

Abstract
The present study deals with submerged ethanol, citric acid, and α-amylase fermentation by Saccharomyces cerevisiae SDB, Aspergillus niger ANSS-B5, and Candida guilliermondii CGL-A10, using date wastes as the basal fermentation medium. The physical and chemical parameters influencing the production of these metabolites were optimized. As for the ethanol production, the optimum yield obtained was 136.00 ± 0.66 g/l under optimum conditions of an incubation period of 72 h, inoculum content of 4% (w/v), sugars concentration of 180.0 g/l, and ammonium phosphate concentration of 1.0 g/l. Concerning citric acid production, the cumulative effect of temperature (30°C), sugars concentration of 150.0 g/l, methanol concentration of 3.0%, initial pH of 3.5, ammonium nitrate concentration of 2.5 g/l, and potassium phosphate concentration of 2.5 g/l during the fermentation process of date wastes syrup did increase the citric acid production to 98.42 ± 1.41 g/l. For the production of α-amylase, the obtained result shows that the presence of starch strongly induces the production of α-amylase with a maximum at 5.0 g/l. Among the various nitrogen sources tested, urea at 5.0 g/l gave the maximum biomass and α-amylase estimated at 5.76 ± 0.56 g/l and 2,304.19 ± 31.08 μmol/l/min, respectively after 72 h incubation at 30°C, with an initial pH of 6.0 and potassium phosphate concentration of 6.0 g/l.
Fine tuning genomic evaluations in dairy cattle through SNP pre-selection with the Elastic-Net algorithm
Authors: CROISEAU PASCAL , LEGARRA ANDRÉS , GUILLAUME FRANÇOIS , FRITZ SÉBASTIEN , BAUR AURÉLIA , COLOMBANI CARINE , ROBERT-GRANIÉ CHRISTÈLE , BOICHARD DIDIER , DUCROCQ VINCENT 
Published: December 2011

SummaryFor genomic selection methods, the statistical challenge is to estimate the effect of each of the available single-nucleotide polymorphism (SNP). In a context where the number of SNPs (p) is much higher than the number of bulls (n), this task may lead to a poor estimation of these SNP effects if, as for genomic BLUP (gBLUP), all SNPs have a non-null effect. An alternative is to use approaches that have been developed specifically to solve the ‘p>>n’ problem. This is the case of variable selection methods and among them, we focus on the Elastic-Net (EN) algorithm that is a penalized regression approach. Performances of EN, gBLUP and pedigree-based BLUP were compared with data from three French dairy cattle breeds, giving very encouraging results for EN. We tried to push further the idea of improving SNP effect estimates by considering fewer of them. This variable selection strategy was considered both in the case of gBLUP and EN by adding an SNP pre-selection step based on quantitative trait locus (QTL) detection. Similar results were observed with or without a pre-selection step, in terms of correlations between direct genomic value (DGV) and observed daughter yield deviation in a validation data set. However, when applied to the EN algorithm, this strategy led to a substantial reduction of the number of SNPs included in the prediction equation. In a context where the number of genotyped animals and the number of SNPs gets larger and larger, SNP pre-selection strongly alleviates computing requirements and ensures that national evaluations can be completed within a reasonable time frame.
A multivariate approach to structural heterogeneity of retinal ganglion cells
Authors: PUSHCHIN I.I. , PODUGOLNIKOVA T.A. , KONDRASHEV S.L. 
Published: December 2011

AbstractKnowing neuronal types is essential for understanding the structural and functional organization of the nervous system. It has long been recognized that neuronal types should be discovered and not defined. This can be done using cluster analysis (CA). Despite there being many studies using CA to classify neurons, only a few of them meet its formal prerequisites. In the present study, we provide an example of using CA in combination with other multivariate techniques for examining neuronal diversity. A special emphasis is put on formal prerequisites to the data and procedure. The data under scrutiny are a sample of ganglion cells projecting to the basal optic nucleus [accessory optic system-projecting ganglion cells (AOS GCs)] in the common frog. There is physiological evidence that these cells comprise at least two functional types but their structural heterogeneity has not been addressed. Cells were labeled with horseradish peroxidasein vivoand examined in whole-mounted retinae using light microscopy. A sample of well-stained cells was obtained and used to estimate 18 structural parameters. A variety of clustering algorithms were used to classify the cells. The joint polar distribution of dendrite mass was monomodal. CA did not reveal a statistically reliable cluster structure in the sample. The clusters were not cohesive and well isolated. ANOVA-on-Ranks revealed no significant between-cluster differences. Our formal conclusion is that functionally distinct frog AOS GCs do not differ in morphology or dendritic arbor orientation. The advantages and limitations of the adopted approach are discussed.
Geographic delineations of yeast communities and populations associated with vines and wines in New Zealand
Authors: Gayevskiy Velimir , Goddard Matthew R 
Published: December 2011

Abstract
Yeasts are a diverse seemingly ubiquitous group of eukaryotic microbes, and many are naturally associated with fruits. Humans have harnessed yeasts since the dawn of civilisation to make wine, and thus it is surprising that we know little of the distribution of yeast communities naturally associated with fruits. Previous reports of yeast community diversity have been descriptive only. Here we present, we believe, the first robust test for the geographic delineation of yeast communities. Humans have relatively recently employed Saccharomyces cerevisiae as a model research organism, and have long harnessed its ancient adaption to ferment even in the presence of oxygen. However, as far as we are aware, there has not been a rigorous test for the presence of regional differences in natural S. cerevisiae populations before. We combined these community- and population-level questions and surveyed replicate vineyards and corresponding spontaneous ferments from different regions on New Zealand's (NZ's) North Island and analysed the resulting data with community ecology and population genetic tests. We show that there are distinct regional delineations of yeast communities, but the picture for S. cerevisiae is more complex: there is evidence for region-specific sub-populations but there are also reasonable levels of gene flow among these regions in NZ. We believe this is the first demonstration of regional delineations of yeast populations and communities worldwide.
Recent change of vegetation growth trend in China
Authors: Peng Shushi , Chen Anping , Xu Liang , Cao Chunxiang , Fang Jingyun , Myneni Ranga B , Pinzon Jorge E , Tucker Compton J , Piao Shilong 
Published: December 2011

Abstract
Using satellite-derived normalized difference vegetation index (NDVI) data, several previous studies have indicated that vegetation growth significantly increased in most areas of China during the period 1982–99. In this letter, we extended the study period to 2010. We found that at the national scale the growing season (April–October) NDVI significantly increased by 0.0007 yr−1 from 1982 to 2010, but the increasing trend in NDVI over the last decade decreased in comparison to that of the 1982–99 period. The trends in NDVI show significant seasonal and spatial variances. The increasing trend in April and May (AM) NDVI (0.0013 yr−1) is larger than those in June, July and August (JJA) (0.0003 yr−1) and September and October (SO) (0.0008 yr−1). This relatively small increasing trend of JJA NDVI during 1982–2010 compared with that during 1982–99 (0.0012 yr−1) (Piao et al 2003 J. Geophys. Res.—Atmos.
108 4401) implies a change in the JJA vegetation growth trend, which significantly turned from increasing (0.0039 yr−1) to slightly decreasing ( − 0.0002 yr−1) in 1988. Regarding the spatial pattern of changes in NDVI, the growing season NDVI increased (over 0.0020 yr−1) from 1982 to 2010 in southern China, while its change was close to zero in northern China, as a result of a significant changing trend reversal that occurred in the 1990s and early 2000s. In northern China, the growing season NDVI significantly increased before the 1990s as a result of warming and enhanced precipitation, but decreased after the 1990s due to drought stress strengthened by warming and reduced precipitation. Our results also show that the responses of vegetation growth to climate change vary across different seasons and ecosystems.
RooTrak: Automated Recovery of Three-Dimensional Plant Root Architecture in Soil from X-Ray Microcomputed Tomography Images Using Visual Tracking
Authors: Mairhofer Stefan , Zappala Susan , Tracy Saoirse R. , Sturrock Craig , Bennett Malcolm , Mooney Sacha J. , Pridmore Tony 
Published: December 2011

Abstract
X-ray microcomputed tomography (μCT) is an invaluable tool for visualizing plant root systems within their natural soil environment noninvasively. However, variations in the x-ray attenuation values of root material and the overlap in attenuation values between roots and soil caused by water and organic materials represent major challenges to data recovery. We report the development of automatic root segmentation methods and software that view μCT data as a sequence of images through which root objects appear to move as the x-y cross sections are traversed along the z axis of the image stack. Previous approaches have employed significant levels of user interaction and/or fixed criteria to distinguish root and nonroot material. RooTrak exploits multiple, local models of root appearance, each built while tracking a specific segment, to identify new root material. It requires minimal user interaction and is able to adapt to changing root density estimates. The model-guided search for root material arising from the adoption of a visual-tracking framework makes RooTrak less sensitive to the natural ambiguity of x-ray attenuation data. We demonstrate the utility of RooTrak using μCT scans of maize (Zea mays), wheat (Triticum aestivum), and tomato (Solanum lycopersicum) grown in a range of contrasting soil textures. Our results demonstrate that RooTrak can successfully extract a range of root architectures from the surrounding soil and promises to facilitate future root phenotyping efforts.
Management of multidrug‐resistant viruses in the immunocompromised host
Authors: Sellar Rob S. , Peggs Karl S. 
Published: December 2011

SummaryMultidrug‐resistant viruses remain a clinically challenging complication in the immunocompromised host. This review discusses mechanisms of viral resistance and treatment options in this context with particular emphasis on the immunocompromised haematology patient. We also outline some of the newer agents and treatment strategies being developed to treat multidrug‐resistant viruses.
Lung damage and airway remodelling in severe asthma
Authors: Brightling C. E. , Gupta S. , Gonem S. , Siddiqui S. 
Published: December 2011

SummarySevere asthma is a heterogeneous disease with substantial unmet clinical need. Airway damage and remodelling is a consequence of complex host–environment interactions and is considered to be the cardinal feature leading onto the development and persistence of airflow obstruction. In this review, we shall bring together recent insights into the causes of airway damage and remodelling that propose key roles for pathogens and mechanical damage in addition to allergens, underlying genetic susceptibility, inflammatory and structural cell interactions, and impaired resolution of damage. We shall consider the consequences of airway remodelling in terms of airway geometry, mechanics and clinical expression of disease. Understanding the causes and consequences of airway damage and remodelling will shed light upon the structure–function relationships required to begin to unravel the complexity of severe asthma and will enable us to target current and novel therapies as we begin to move towards realizing personalized medicine.
Hard‐tissue debris accumulation created by conventional rotary versus self‐adjusting file instrumentation in mesial root canal systems of mandibular molars
Authors: Paqué F. , Al‐Jadaa A. , Kfir A. 
Published: December 2011

Paqué F, Al‐Jadaa A, Kfir A. Hard‐tissue debris accumulation created by conventional rotary versus self‐adjusting file instrumentation in mesial root canal systems of mandibular molars. International Endodontic Journal, 45, 413–418, 2012.AbstractAim  To evaluate the accumulation of hard‐tissue debris when using the Self‐adjusting File (SAF) system in mesial roots of mandibular molars with isthmuses and to compare it with that occurring when the ProTaper file system was used.Methodology  Forty extracted human mandibular molars with joining mesial root canals and an isthmus between the two canals were randomly assigned to two experimental groups and scanned using micro‐computed tomography. Root canals in the control group (N = 20) were instrumented using the ProTaper rotary system until F3. Irrigation with 1 mL of 3% NaOCl solution was applied after each instrument. Root canals in the experimental group (N = 20) were prepared using the SAF for 4 min, with continuous irrigation (3% NaOCl, 4 mL min−1). After rescanning, canals in both groups were further irrigated with 5 mL of 17% EDTA for 2 min. After final scanning, the per cent value of total canal system volume filled with hard‐tissue debris was calculated. Statistical analysis was performed using Mann–Whitney U‐test; the alpha‐type error was set at 1%.Results  Instrumentation of the root canals with ProTaper left 10.1% (IQR 5.2) of the total canal system volume filled with hard‐tissue debris while preparation with the SAF left 1.7% (IQR 1.6). This difference was highly significant (P < 0.0001). After subsequent EDTA irrigation, these values were significantly reduced (P < 0.01) to 7.9% (IQR 4.1) and 1.3% (IQR 0.8) in the ProTaper and SAF groups, respectively.Conclusion  Preparation with the SAF system resulted in less hard‐tissue debris accumulation in isthmus‐containing root canal systems compared with instrumentation with ProTaper rotary files.
Shaping ability and cleaning effectiveness of two single‐file systems in severely curved root canals of extracted teeth: Reciproc and WaveOne versus Mtwo and ProTaper
Authors: Bürklein S. , Hinschitza K. , Dammaschke T. , Schäfer E. 
Published: December 2011

Bürklein S, Hinschitza K, Dammaschke T, Schäfer E. Shaping ability and cleaning effectiveness of two single‐file systems in severely curved root canals of extracted teeth: Reciproc and WaveOne versus Mtwo and ProTaper. International Endodontic Journal, 45, 449–461, 2012.AbstractAim  To compare shaping ability and cleaning effectiveness of two reciprocating single‐file systems with Mtwo and ProTaper rotary instruments during the preparation of curved root canals in extracted teeth.Methodology  A total of 80 root canals with curvatures ranging between 25° and 39° were divided into four groups of 20 canals. Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature. Canals were prepared to the following apical sizes: Mtwo: size 35 using the single‐length technique; ProTaper: F3, instruments were used in a modified crown‐down manner; Reciproc and WaveOne: size 25. Using pre‐ and post‐instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Preparation time and instrument failures were also recorded. These data were analysed statistically using anova and Student–Newman–Keuls test. The amounts of debris and smear layer were quantified on the basis of a numerical evaluation scale and were analysed statistically using the Kruskal–Wallis test.Results  During preparation no file fractured. All instruments maintained the original canal curvature well with no significant differences between the different files (P = 0.382). Instrumentation with Reciproc was significantly faster than with all other instruments (P < 0.05), while WaveOne was significantly faster than Mtwo and ProTaper (P < 0.05). For debris removal, Mtwo and Reciproc instruments achieved significantly better results (P < 0.05) than the other instruments in the apical third of the canals. In the middle and coronal parts, no significant differences were obtained between Mtwo, Reciproc and WaveOne (P > 0.05), while ProTaper showed significantly more residual debris (P < 0.05). The results for remaining smear layer were similar and not significantly different for the different parts of the canals (P > 0.05).Conclusions  Under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. The use of Mtwo and Reciproc instruments resulted in better canal cleanliness in the apical part compared with ProTaper and WaveOne.