bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refining understanding of hydrological connectivity in a boreal catchment
Authors: Spence Christopher , Phillips Ross W. 
Published: June 2014

AbstractLiterature has long documented how streamflow response in boreal hillslopes and catchments is influenced by storage capacities, thresholds, and landscape and runoff pathway heterogeneity. More recently, the influence these traits have on streamflow has been interpreted through the concept of hydrological connectivity. However, the nature of hydrological connectivity in boreal catchments has only begun to be described. The focus of hydrological connectivity studies at the catchment scale has been on discerning from which areas does runoff originate and when, but not necessarily discovering the source waters of this streamflow. This has been the realm of studies investigating residence time and runoff pathways. This article summarizes an investigation in a 155‐km2 catchment in Canada's Northwest Territories that applied both hydrometric and geochemical methods to measure streamflow response, storage state, connectivity and source waters. The goal of this research was to determine if a catchment scale metric of connectivity could be sensitive to changes in source waters and runoff pathways in a boreal landscape, so as to improve the predictive role of connectivity metrics. Nine runoff events from three water years were evaluated. There were distinct patterns of hydrological connectivity, which included, among others, a non‐linear relationship with the runoff ratio and hysteresis with streamflow. The results indicate that one metric of connectivity alone could not encapsulate connectivity extent and quality, identify water sources and be used successfully to predict runoff response. Multiple metrics were needed that further encapsulated the role of precipitation and hydrological processes on both structural and dynamic connectivity. © 2014 Her Majesty the Queen in Right of Canada. Hydrological Processes. © 2014 John Wiley & Sons, Ltd.
Destination Stakeholders' Perceptions of Volunteer Tourism: An Equity Theory Approach
Authors: Burrai Elisa , Font Xavier , Cochrane Janet 
Published: June 2014

AbstractThis study explores destination stakeholders' perceptions of volunteer tourism (VT) using equity theory. In this paper, 26 semi‐structured interviews were conducted to understand individuals' needs, motivations, expectations and their assessments of inputs and outcomes. Equity theory sheds light on the micro‐level of interaction between residents and volunteers and demonstrates why and how residents of Cusco (Peru) with an active role in VT develop certain perceptions in direct encounters with volunteer tourists. The data reveal how perceptions differ according to the respondents' social roles within VT. Heterogeneity, dynamism and a fluctuation between materialities and affection are discussed as important outcomes of these interactions. Copyright © 2014 John Wiley & Sons, Ltd.
Belowground Bud Bank Responses to Grazing Intensity in the Inner‐Mongolia Steppe, China
Authors: Qian Jianqiang , Wang Zhengwen , Liu Zhimin , Busso Carlos A. 
Published: June 2014

AbstractDespite the predominant role of bud banks in population regeneration and community dynamics, they have received far less attention than deserved. In particular, it remains unexplored how bud bank size and composition respond to different grazing intensities in grasslands. We investigated the size and composition of bud banks under different grazing intensities and regimes on a typical steppe in Inner Mongolia, China. Our results showed that (i) the total bud density in the traditional grazing regime (grazing and haymaking within the same year in the same paddock; 2,444 ± 141 buds m−2) was 30 ± 11% higher (mean ± standard error; p < 0·05) than that in the mixed grazing regime (grazing and haymaking alternate annually in the same paddock; 1,872 ± 109 buds m−2), but they did not change with increasing grazing intensity, (ii) rhizome buds and bulb buds decreased sharply (p < 0·05) because of grazing in the mixed grazing regime, (iii) bud banks of rhizomatous grasses showed species‐specific responses to the increasing grazing intensity: decreasing in Leymus chinensis (Trin.) Tzvel., increasing in Agropyron cristatum (L.) Gaertn. and unresponsive in Carex duriuscula C. A. Mey. Data indicated that (i) the studied grazing intensities had no significant effects on the total bud bank, suggesting that belowground bud bank seems to be tolerant of grazing and (ii) the responses of bud bank to grazing differed with the bud bank type and species, indicating that bud banks could be used for explaining and predicting the dynamics of a natural grassland plant community. Copyright © 2014 John Wiley & Sons, Ltd.
Highly directional spaser array for the red wavelength region
Authors: Meng Xiangeng , Liu Jingjing , Kildishev Alexander V. , Shalaev Vladimir M. 
Published: June 2014

AbstractThe spaser offers an opportunity to achieve coherent optical sources at nanometer scales due to the extreme confinement of optical fields. However, achievement of spasers with directional propagation in the visible wavelength region remains a challenge thus far, owing to the unique optical feedback mechanism and large dissipative losses of the metal cavity. Here, we experimentally demonstrate for the first time a spaser showing highly directional emission in the visible by using a periodic subwavelength hole array perforated in a metal film, which function as plasmonic nanocavities, along with an organic laser dye to supply gain. The lasing occurs in the red wavelength region and shows a single mode. It is suggested that the optical feedback for spasing is provided by the SPP–Bloch wave, which is supported by the fact that no spasing was attained in aperiodic holes as well as in periodic holes that do not support the SPP–Bloch wave at the spasing wavelength.
σN‐dependent control of acid resistance and the locus of enterocyte effacement in enterohemorrhagic Escherichia coli is activated by acetyl phosphate in a manner requiring flagellar regulator FlhDC and the σS antagonist FliZ
Authors: Mitra Avishek , Fay Pamela A. , Vendura Khoury W. , Alla Zimrisha , Carroll Ronan K. , Shaw Lindsey N. , Riordan James T. 
Published: June 2014

AbstractIn enterohemorrhagic Escherichia coli (EHEC), sigma factor N (σN) regulates glutamate‐dependent acid resistance (GDAR) and the locus of enterocyte effacement (LEE); discrete genetic systems that are required for transmission and virulence of this intestinal pathogen. Regulation of these systems requires nitrogen regulatory protein C, NtrC, and is a consequence of NtrC‐σN‐dependent reduction in the activity of sigma factor S (σS). This study elucidates pathway components and stimuli for σN‐directed regulation of GDAR and the LEE in EHEC. Deletion of fliZ, the product of which reduces σS activity, phenocopied rpoN (σN) and ntrC null strains for GDAR and LEE control, acid resistance, and adherence. Upregulation of fliZ by NtrC‐σN was shown to be indirect and required an intact flagellar regulator flhDC. Activation of flhDC by NtrC‐σN and FlhDC‐dependent regulation of GDAR and the LEE was dependent on σN‐promoter flhDP2, and a newly described NtrC upstream activator sequence. Addition of ammonium chloride significantly altered expression of GDAR and LEE, acid resistance, and adherence, independently of rpoN, ntrC, and the NtrC sensor kinase, ntrB. Altering the availability of NtrC phosphodonor acetyl phosphate by growth without glucose, with acetate addition, or by deletion of acetate kinase ackA, abrogated NtrC‐σN‐dependent control of flhDC, fliZ, GDAR, and the LEE.
The burglar problem with multiple options
Authors: Chen Kai , Ross Sheldon M. 
Published: June 2014

AbstractWe consider the burglar problem in which a burglar can either retire or choose among different types of burglaries, with each type having its own success probability and reward distribution. Some general structural results are established and, in the case of exponentially distributed reward distributions, a solution technique is presented. The burglar problem's relationship to a stochastic knapsack problem with a random exponentially distributed knapsack capacity is shown. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 359–364, 2014
New Equations for the Size Reconstruction of Sturgeon from Isolated Cranial and Pectoral Girdle Bones
Authors: Thieren E. , Van Neer W. 
Published: June 2014

AbstractMeasurements on cranial and pectoral girdle bones of 56 museum specimens of modern sturgeon (Acipenser sturio and A. oxyrinchus) were used for the establishment of regression equations allowing back‐calculation of size from isolated sturgeon remains. Different curve fittings (power, linear, logarithmic and exponential fit) were modeled to retain the most accurate regression. These were then applied to archaeological sturgeon remains (A. sturio/A. oxyrinchus) from Vlaardingen, a Dutch late Neolithic settlement. The back‐calculated lengths obtained on the archaeological remains all stayed within the known size ranges of the two species and allowed making inferences on the possible place of capture of the fish. Copyright © 2014 John Wiley & Sons, Ltd.
KPNA2 is overexpressed in human and mouse endometrial cancers and promotes cellular proliferation
Authors: Ikenberg Kristian , Valtcheva Nadejda , Brandt Simone , Zhong Qing , Wong Christine E , Noske Aurelia , Rechsteiner Markus , Rueschoff Jan H , Caduff Rosmarie , Dellas Athanassios , Obermann Ellen , Fink Daniel , Fuchs Thomas , Krek Wilhelm , Moch Holger , Frew Ian J , Wild Peter J 
Published: June 2014

AbstractEndometrial cancer is the most frequently occurring malignancy of the female genital tract in Western countries. Although in many cases surgically curable, about 30% of the tumours represent an aggressive and untreatable disease. In an attempt to establish a reliable prognostic marker for endometrial carcinomas disregarding their histological diversity, we investigated the expression of KPNA2, a mediator of nucleocytoplasmic transport, and other cell proliferation‐associated proteins and their correlation with cancer progression. We analysed patient tissue microarrays (TMAs) assembled from 527 endometrial cancer tissue specimens and uterus samples from a Trp53 knockout mouse model of endometrial cancer. Our data show that KPNA2 expression was significantly up‐regulated in human endometrial carcinomas and associated with higher tumour grade (p = 0.026), higher FIGO stage (p = 0.027), p53 overexpression (p < 0.001), activation of the PI3K/AKT pathway, and epithelial–mesenchymal transition. Increased nuclear KPNA2 immunoreactivity was identified as a novel predictor of overall survival, independent of well‐established prognostic factors in Cox regression analyses (hazard ratio 1.7, 95% CI 1.13–2.56, p = 0.01). No significant association between KPNA2 expression and endometrial cancer subtype was detected. In the mouse model, KPNA2 showed increased expression levels from precancerous (EmgD, EIC) to far‐advanced invasive lesions. We further investigated the cell proliferation capacity after siRNA‐mediated KPNA2 knockdown in the human endometrial cancer cell line MFE‐296. KPNA2 silencing led to decreased proliferation of the cancer cells, suggesting interplay of the protein with the cell cycle. Taken together, increased expression of KPNA2 is an independent prognostic marker for poor survival. The mechanism of enhanced nucleocytoplasmic transport by KPNA2 overexpression seems a common event in aggressive cancers since we have shown a significant correlation of KPNA2 expression and tumour aggressiveness in a large variety of other solid tumour entities. Introducing KPNA2 immunohistochemistry in routine diagnostics may allow for the identification of patients who need more aggressive treatment regimens. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
Parental acceptance of minimally invasive fetal and neonatal autopsy compared with conventional autopsy
Authors: Kang Xin , Cos Teresa , Guizani Meriem , Cannie Mieke M. , Segers Valérie , Jani Jacques C. 
Published: June 2014

ABSTRACTObjectiveTo determine parental acceptance of minimally invasive autopsy (MIA) involving postmortem imaging and organ tissue sampling compared with conventional autopsy and to compare the acceptability of percutaneous versus laparoscopic‐guided biopsy.MethodsFollowing termination of pregnancy parents were offered the option of traditional autopsy and subsequently interviewed about their acceptance of MIA. The McNemar test for paired samples was used to assess the difference in acceptance of MIA and conventional autopsy. The Wilcoxon signed‐rank test for paired samples was used to compare the acceptance score for percutaneous versus laparoscopic‐guided biopsy. Logistic regression was selected to study the association of parental acceptance of conventional autopsy and MIA with different variables.ResultsConventional autopsy was accepted by 42 (60.0%) of the 70 parents. Regression analysis showed that non‐Muslim faith was the only factor significantly associated with acceptance of conventional autopsy (p = 0.030). Of 28 parents who initially refused conventional autopsy, 13(46.4%) subsequently accepted MIA, increasing acceptance to 78.6% (p < 0.001). Regression analysis showed that none of the factors significantly affected MIA acceptance. Parents expressed no preference between postmortem percutaneous versus laparoscopic‐guided biopsy (p = 0.061).ConclusionPost‐mortem imaging combined with systematic organ biopsies is highly acceptable among all parents independent of their religion and the method used for organ biopsy. © 2014 John Wiley & Sons, Ltd.
Conserved evolutionary units in the heme‐copper oxidase superfamily revealed by novel homologous protein families
Authors: Pei Jimin , Li Wenlin , Kinch Lisa N. , Grishin Nick V. 
Published: June 2014

AbstractThe heme‐copper oxidase (HCO) superfamily includes HCOs in aerobic respiratory chains and nitric oxide reductases (NORs) in the denitrification pathway. The HCO/NOR catalytic subunit has a core structure consisting of 12 transmembrane helices (TMHs) arranged in three‐fold rotational pseudosymmetry, with six conserved histidines for heme and metal binding. Using sensitive sequence similarity searches, we detected a number of novel HCO/NOR homologs and named them HCO Homology (HCOH) proteins. Several HCOH families possess only four TMHs that exhibit the most pronounced similarity to the last four TMHs (TMHs 9–12) of HCOs/NORs. Encoded by independent genes, four‐TMH HCOH proteins represent a single evolutionary unit (EU) that relates to each of the three homologous EUs of HCOs/NORs comprising TMHs 1–4, TMHs 5–8, and TMHs 9–12. Single‐EU HCOH proteins could form homotrimers or heterotrimers to maintain the general structure and ligand‐binding sites defined by the HCO/NOR catalytic subunit fold. The remaining HCOH families, including NnrS, have 12‐TMHs and three EUs. Most three‐EU HCOH proteins possess two conserved histidines and could bind a single heme. Limited experimental studies and genomic context analysis suggest that many HCOH proteins could function in the denitrification pathway and in detoxification of reactive molecules such as nitric oxide. HCO/NOR catalytic subunits exhibit remarkable structural similarity to the homotrimers of MAPEG (membrane‐associated proteins in eicosanoid and glutathione metabolism) proteins. Gene duplication, fusion, and fission likely play important roles in the evolution of HCOs/NORs and HCOH proteins.
Missing data sensitivity analysis for recurrent event data using controlled imputation
Authors: Keene Oliver N. , Roger James H. , Hartley Benjamin F. , Kenward Michael G. 
Published: June 2014

AbstractStatistical analyses of recurrent event data have typically been based on the missing at random assumption. One implication of this is that, if data are collected only when patients are on their randomized treatment, the resulting de jure estimator of treatment effect corresponds to the situation in which the patients adhere to this regime throughout the study. For confirmatory analysis of clinical trials, sensitivity analyses are required to investigate alternative de facto estimands that depart from this assumption. Recent publications have described the use of multiple imputation methods based on pattern mixture models for continuous outcomes, where imputation for the missing data for one treatment arm (e.g. the active arm) is based on the statistical behaviour of outcomes in another arm (e.g. the placebo arm). This has been referred to as controlled imputation or reference‐based imputation. In this paper, we use the negative multinomial distribution to apply this approach to analyses of recurrent events and other similar outcomes. The methods are illustrated by a trial in severe asthma where the primary endpoint was rate of exacerbations and the primary analysis was based on the negative binomial model. Copyright © 2014 John Wiley & Sons, Ltd.
Reversible data embedding for vector quantization compressed images using search‐order coding and index parity matching
Authors: Qin Chuan , Chang Chin‐Chen , Horng Gwoboa , Huang Ying‐Hsuan , Chen Yen‐Chang 
Published: June 2014

AbstractEmbedding secret data in vector quantization (VQ) compressed images with reversibility has been studied extensively in recent years. However, to date, the reported methods have not achieved satisfactory performances of hiding capacity and image compression ratio simultaneously. In this paper, we propose a reversible embedding method based on search‐order coding (SOC) and index parity matching that can hide secret data into the compressed VQ index, that is, SOC index. If the parity of the candidate SOC index matches the current embedding bit and the error caused by SOC encoding is smaller than a pre‐determined threshold, the length of the stego SOC index after embedding is significantly shorter than the original VQ index. On the receiver side, the embedded secret bits can be easily extracted by checking the parity of stego SOC indices, and all original VQ indices can be recovered correctly. Experimental results demonstrate that our method can achieve greater hiding capacity than the recently reported methods for the same image decompression quality. Copyright © 2014 John Wiley & Sons, Ltd.
Elliptic‐curve scalar multiplication algorithm using ZOT structure
Authors: Almimi Hani , Samsudin Azman , Jahani Shahram 
Published: June 2014

AbstractThe computation of kP over elliptic curves is the dominant operation. It depends on the representation of the scalar k. The binary method is the standard unsigned method that is used to compute the elliptic‐curve (EC) point Q = kP. Researchers found that it is not the most efficient way for implementing EC computations. Other recoding methods such as complementary recoding (CR), nonadjacent form (NAF), and mutual opposite form (MOF) were presented in order to enhance the efficiency of EC computations. Our ZOTEC method that is based on ZOT recoding method was proposed to accelerate the EC computations. ZOTEC can be computed right‐to‐left or left‐to‐right. The recoding process is also faster than NAF and as fast as CR and MOF if the binary conversion is included or excluded. ZOTEC method is more efficient than BIN, CR, MOF, and NAF methods in terms of field complexity and time complexity whenever a field inversion is more expensive than six multiplications for BIN, CR, and MOF, and 8.3 for NAF. Copyright © 2014 John Wiley & Sons, Ltd.
Data privacy breach prevention framework for the cloud service
Authors: Dhasarathan Chandramohan , Thirumal Vengattaraman , Ponnurangam Dhavachelvan 
Published: June 2014

AbstractThis paper examines the privacy awareness and importance of user's secrecy preserving in current ubiquitous cloud computing world. Data stored in the cloud have highly sensitive information. Once the private information gets misused, the probability of privacy breaching increases, which thereby reduces user's trust on cloud providers. In the emerging cloud service‐based internet world, user's information management is a most decisive task. Information stored in the cloud by the finance, healthcare and government sectors makes it all the more challenging because such tasks are to be handled globally. The present scenario therefore demands a new Petri net privacy preserving framework for safeguarding user's privacy and providing consistent and breachless services from the cloud. This is carried out by designing Petri net privacy preserving framework and mitigating privacy using proposed synchronization, sequential, concurrency and conflicts technique. Synchronization, sequential, concurrency and conflicts technique adopts the Petri net model in which employs multi‐agent‐based privacy preserving cohesion technique for handling multiple tasks to prevent the user private information. The proposed technique conveys and collaborates with leading cloud providers to develop, validate, promote, adapt and also increase the need for privacy, flexibility and availability without affecting the performance of cloud service providers and consumers. It acts as an information preserving guard for high secrecy data storage areas. This paper summarizes with few directives towards future research. Copyright © 2014 John Wiley & Sons, Ltd.
Weighted hurdle regression method for joint modeling of cardiovascular events likelihood and rate in the US dialysis population
Authors: Şentürk Damla , Dalrymple Lorien S. , Mu Yi , Nguyen Danh V. 
Published: June 2014

AbstractWe propose a new weighted hurdle regression method for modeling count data, with particular interest in modeling cardiovascular events in patients on dialysis. Cardiovascular disease remains one of the leading causes of hospitalization and death in this population. Our aim is to jointly model the relationship/association between covariates and (i) the probability of cardiovascular events, a binary process, and (ii) the rate of events once the realization is positive—when the ‘hurdle’ is crossed—using a zero‐truncated Poisson distribution. When the observation period or follow‐up time, from the start of dialysis, varies among individuals, the estimated probability of positive cardiovascular events during the study period will be biased. Furthermore, when the model contains covariates, then the estimated relationship between the covariates and the probability of cardiovascular events will also be biased. These challenges are addressed with the proposed weighted hurdle regression method. Estimation for the weighted hurdle regression model is a weighted likelihood approach, where standard maximum likelihood estimation can be utilized. The method is illustrated with data from the United States Renal Data System. Simulation studies show the ability of proposed method to successfully adjust for differential follow‐up times and incorporate the effects of covariates in the weighting. Copyright © 2014 John Wiley & Sons, Ltd.