bluuebunny/crossref_metadata_2025_split huggingface dataset:
Group and hierarchical key management for secure communications in internet of things
Authors: Karrothu Aravind , Norman Jasmine 
Published: November 2018

SummaryDifferent devices with different characteristics form a network to communicate among themselves in Internet of Things (IoT). Thus, IoT is of heterogeneous in nature. Also, Internet plays a major role in IoT. So, issues related to security in Internet become issues of IoT also. Hence, the group and hierarchical management scheme for solving security issues in Internet of Things is proposed in this paper. The devices in the network are formed into groups. One of the devices is selected as a leader of each group. The communication of the devices from each group takes place with the help of the leader of the corresponding group using encrypted key to enhance the security in the network. Blom's key predistribution technique is used to establish secure communication among any nodes of group. The hierarchy is maintained such that the security can be increased further, but the delay is increased as it takes time to encrypt at every level of hierarchy. Hence, the numbers of levels of hierarchy need to be optimized such that delay is balanced. Hence, this algorithm is more suitable for delay‐tolerant applications. The performance of the proposed Algorithm is evaluated and is proved to perform better when compared with the legacy systems like Decentralized Batch‐based Group Key Management Protocol for Mobile Internet of Things (DBGK).
Application of Bayesian network modeling to pathology informatics
Authors: Onisko Agnieszka , Druzdzel Marek J. , Austin R. Marshall 
Published: November 2018

BackgroundIn the era of extensive data collection, there is a growing need for a large scale data analysis with tools that can handle many variables in one modeling framework. In this article, we present our recent applications of Bayesian network modeling to pathology informatics.MethodsBayesian networks (BNs) are probabilistic graphical models that represent domain knowledge and allow investigators to process this knowledge following sound rules of probability theory. BNs can be built based on expert opinion as well as learned from accumulating data sets. BN modeling is now recognized as a suitable approach for knowledge representation and reasoning under uncertainty. Over the last two decades BN have been successfully applied to many studies on medical prognosis and diagnosis.ResultsBased on data and expert knowledge, we have constructed several BN models to assess patient risk for subsequent specific histopathologic diagnoses and their related prognosis in gynecological cytopathology and breast pathology. These models include the Pittsburgh Cervical Cancer Screening Model assessing risk for histopathologic diagnoses of cervical precancer and cervical cancer, modeling of the significance of benign‐appearing endometrial cells in Pap tests, diagnostic modeling to determine whether adenocarcinoma in tissue specimens is of endometrial or endocervical origin, and models to assess risk for recurrence of invasive breast carcinoma and ductal carcinoma in situ.ConclusionsBayesian network models can be used as powerful and flexible risk assessment tools on large clinical datasets and can quantitatively identify variables that are of greatest significance in predicting specific histopathologic diagnoses and their related prognosis. Resulting BN models are able to provide individualized quantitative risk assessments and prognostication for specific abnormal findings commonly reported in gynecological cytopathology and breast pathology.
Disease and climate effects on individuals drive post‐reintroduction population dynamics of an endangered amphibian
Authors: Joseph Maxwell B. , Knapp Roland A. 
Published: November 2018

AbstractThe emergence of novel pathogens often has dramatic negative effects on previously unexposed host populations. Subsequent disease can drive populations and even species to extinction. After establishment in populations, pathogens can continue to affect host dynamics, influencing the success or failure of species recovery efforts. However, quantifying the effect of pathogens on host populations in the wild is challenging because individual hosts and their pathogens are difficult to observe. Here, we use long‐term mark–recapture data to describe the dynamics of reintroduced populations of an endangered amphibian (Rana sierrae) and evaluate the success of these recovery efforts in the presence of a recently emerged pathogen, the amphibian chytrid fungusBatrachochytrium dendrobatidis. We find that highB. dendrobatidisinfection intensities are associated with increases in frog detectability and reductions in survival. When average infection intensities are high, adults are more likely to gain infections and less likely to lose infections. We also find evidence for intensity‐dependent survival, with heavily infected individuals suffering higher mortality. These results highlight the need in disease ecology for probabilistic approaches that account for uncertainty in infection intensity using imperfect observational data. Such approaches can advance the understanding of disease impacts on host population dynamics, and in the current study will improve the effectiveness of species conservation actions.
Reduced adsorption of polyacrylamide‐based fracturing fluid on shale rock using urea
Authors: Li Yang , Wang Shibin , Guo Jianchun , Gou Xinghao , Jiang Zujun , Pan Baofeng 
Published: November 2018

AbstractHydraulic fracturing is generally necessary to achieve economically viable production rates during exploitation of shale reservoirs. Polyacrylamide‐based fracturing fluid is commonly used in shale fracturing. Polyacrylamide (PAM) becomes adsorbed in the shale micro‐fractures, decreasing the permeability of the reservoir. For improving the production of shale after being stimulated, the adsorption behavior and adsorption mechanism between thePAMand shale are studied. An ultraviolet spectrophotometer is used to obtain the amount of adsorption. To observe the adsorption morphology, a scanning electron microscope is employed. The action force between thePAMand shale rock is analyzed through Fourier transform infrared spectroscopy, zeta potential instrument, and X‐ray photoelectron spectroscopy. The results indicate that hydrogen bonding is the key force between thePAMand shale. A kind of shale micro‐fractures model is designed to determine the recovery of permeability. Urea breaks the hydrogen bonding and keeps the molecular ofHPGstretch which can decrease the amount of adsorption on the shale surface and effectively recover the permeability of shale micro‐fractures up to 72.46% after being damaged. In conclusion, it is believed that the competitive adsorption is a new approach for remediation of the permeability damage by PAM‐based fracturing fluid and has great potential in oil field application.
The guanine nucleotide exchange factor Vav3 modulates oligodendrocyte precursor differentiation and supports remyelination in white matter lesions
Authors: Ulc Annika , Zeug Andre , Bauch Juliane , van Leeuwen Simon , Kuhlmann Tanja , ffrench‐Constant Charles , Ponimaskin Evgeni , Faissner Andreas 
Published: November 2018

AbstractThe tightly controlled processes of myelination and remyelination require the participation of the cytoskeleton. The reorganization of the cytoskeleton is controlled by small GTPases of the RhoA family. Here, we report that Vav3, a Rho GTPase regulating guanine nucleotide exchange factor (GEF) is involved in oligodendrocyte maturation, myelination and remyelination. When Vav3 was eliminated by genetic recombination, oligodendrocyte precursor cell (OPC) differentiation toward mature oligodendrocytes was accelerated. In contrast, Vav3‐deficient oligodendrocytes displayed a reduced capacity to myelinate synthetic microfibers in vitro. Furthermore, remyelination was impaired in Vav3 knockout cerebellar slice cultures that were demyelinated by the addition of lysolecithin. In agreement with these observations, remyelination was compromised when the cuprizone model of myelin lesion was performed in Vav3‐deficient mice. When Vav3‐deficient oligodendrocytes were examined with Förster resonance energy transfer (FRET)‐based biosensors, an altered activation profile of RhoA GTPases was revealed on the cellular level, which could be responsible for an impaired remyelination. Taken together, this study highlights Vav3 as a novel regulator of oligodendrocyte maturation and remyelination, suggesting that manipulation of the Vav3‐dependent signaling pathway could help to improve myelin repair.
Prenatal exposures and infant brain: Review of magnetic resonance imaging studies and a population description analysis
Authors: Pulli Elmo P. , Kumpulainen Venla , Kasurinen Jussi H. , Korja Riikka , Merisaari Harri , Karlsson Linnea , Parkkola Riitta , Saunavaara Jani , Lähdesmäki Tuire , Scheinin Noora M. , Karlsson Hasse , Tuulari Jetro J. 
Published: November 2018

AbstractBrain development is most rapid during the fetal period and the first years of life. This process can be affected by many in utero factors, such as chemical exposures and maternal health characteristics. The goal of this review is twofold: to review the most recent findings on the effects of these prenatal factors on the developing brain and to qualitatively assess how those factors were generally reported in studies on infants up to 2 years of age. To capture the latest findings in the field, we searched articles from PubMed 2012 onward with search terms referring to magnetic resonance imaging (MRI), brain development, and infancy. We identified 19 MRI studies focusing on the effects of prenatal environment and summarized them to highlight the recent advances in the field. We assessed population descriptions in a representative sample of 67 studies and conclude that prenatal factors that have been shown to affect brain metrics are not generally reported comprehensively. Based on our findings, we propose some improvements for population descriptions to account for plausible confounders and in time enable reliable meta‐analyses to be performed. This could help the pediatric neuroimaging field move toward more reliable identification of biomarkers for developmental outcomes and to better decipher the nuances of normal and abnormal brain development.
Regional prevalence of health worker absenteeism in Tanzania
Authors: Fujii Tomoki 
Published: November 2018

AbstractAbsenteeism of health workers in developing countries is common and can severely undermine the reliability of the health system. Therefore, it is important to understand where the prevalence of absenteeism is high. We develop a simple imputation method that combines a Service Delivery Indicators survey and a Service Provision Assessment survey to estimate the prevalence of absenteeism of health workers at the level of regions in Tanzania. The resulting estimates allow one to identify the regions in which the prevalence of absenteeism is significantly higher or lower than the national average and help policymakers determine priority areas for intervention.
Controls on fluvial carbon efflux from eroding peatland catchments
Authors: Brown Sarah L. , Goulsbra Claire S. , Evans Martin G. 
Published: November 2018

AbstractGlobal peatlands store an unparalleled proportion of total global organic carbon but it is vulnerable to erosion into fluvial systems. Fluvial networks are being recognized as areas of carbon transformation, with eroded particulate organic carbon processed to dissolved organic carbon and CO2. Existing studies indicate biodegradation and photodegradation as key processes controlling the transformation of organic carbon in fluvial systems, with initial concentrations of dissolved organic carbon (DOC) identified as a control on the rate of carbon mineralization. This study manipulates temperature and incident light intensity to investigate carbon mineralization rates in laboratory simulations of peatland sediment transport into fluvial systems. By directly measuring gaseous CO2 emissions from sampled stream water, the relationship of temperature and light intensity with carbon efflux is identified. In simulations where sediment (as particulate organic matter, POM) is absent, temperature is consistently the dominant factor influencing carbon efflux rates. This influence is independent of the initial DOC concentration of the water sample. In simulations where POM was added, representing a peatland river receiving eroded terrestrial sediment, initial DOC concentration predicts 79% of the variation in total gaseous carbon efflux whereas temperature and light intensity predict 12% and 3%, respectively. When sampled stream water's mineralization rates in the presence of added POM are analysed independently, removing DOC as a model variable, the dominant variable affecting CO2 efflux is opposite for each sample. This study presents novel data suggesting peatland erosion introduces further complexity to dynamic stream systems where rates of carbon transformation processes and the influence of specific environmental variables are interdependent. Anthropogenic climate change is identified as a leading risk factor perpetuating peatland erosion; therefore, understanding the fate of terrestrial sediment in rivers and further quantifying the benefits of protecting peatland soils will be of increasing importance to carbon budgeting and ecosystem function studies.
Localized primary malignant pericardial mesothelioma
Authors: Song Guang , Bi Wenjing , Zhang Xintong , Huang Wanying , Zhou Ke , Ren Weidong 
Published: November 2018

AbstractPrimary malignant pericardial mesothelioma (PMPM) is an extremely rare tumor, which may appear as a localized or a diffuse mass encasing the heart. Diffuse PMPMs have a poor prognosis due to the difficulty of surgical excision, whereas localized PMPMs have clear margins, thus facilitating surgical excision. Timely diagnosis and proper treatment are crucial for a favorable prognosis. Eight cases of localized PMPMs have been reported so far, but their characteristics have not been fully described. Herein, we present a patient with localized PMPM and describe the diagnosis methods, treatment, and outcomes of these tumors.
Analysis of axial scanning range and magnification variation in wide‐field microscope for measurement using an electrically tunable lens
Authors: Qu Yufu , Hu Yongbo 
Published: November 2018

AbstractInserting an electrically tunable lens (ETL), such as liquid lens or tunable acoustic gradient lens, into a microscope can enable fast axial scanning, autofocusing, and extended depth of field. However, placing the ETL at different positions has different influences on image quality. Specially, in a wide‐field microscope for measurement, the magnification has to be constant when introducing an ETL, otherwise it will affect measurement accuracy. To determine the best position of ETL, axial scanning range and magnification variation are quantitatively analyzed and discussed in finite and infinite microscopes through theoretical analysis, optical simulation, and experiment for four configurations: when ETL is placed at the back focal plane of objective, at the conjugate plane of objective's back focal plane between two relay lenses, or behind two relay lenses, and at imaging detector plane. The obtained results are as follows. When ETL is placed at the back focal plane, the system has a large scanning range, but the magnification varies because the back focal plane is inside the objective. When ETL is placed between two relay lenses, the magnification stays constant, but the scanning range is small. When ETL is placed behind two relay lenses, the magnification keeps invariant and the scanning range is large, but ETL and two relay lenses are inside the microscope and the system has to be customized. Finally, when ETL is placed at imaging detector plane, the magnification stays constant, but the scanning range is 0, which means the system has no axial scanning capability.Research highlights

An electrically tunable lens (ETL) is introduced into a wide‐field microscope for measurement.
Axial scanning range and magnification variation are analyzed and discussed.
Theoretical analysis, ZEMAX optical simulation and experiments are performed.
Taxonomic significance of macro and micro‐morphology of Geranium L. species Using Scanning Electron Microscopy
Authors: Esfandani‐Bozchaloyi Somayeh , Zaman Wajid 
Published: November 2018

AbstractMacro and micromorphology of different parts that is, sepals, petals, flowers, indumentum, and leaf shape of 22 Geranium L. taxa from Iran were studied. These taxa representing the eight sections of the genus as sect. Dissecta, sect. Geranium, and sect. Tuberosa (of subgen. Geranium); sect. Batrachioidea, sect. Divaricata, sect. Lucida, sect. Ruberta and sect. Trilopha (of subgen. Robertium), that were collected from different geographical habitats of Iran. The biometric study involved 27 quantitative and 33 qualitative characters which were studied by use of stereomicroscopy and scanning electron microscopy (SEM). Statistical analyses were done by use of PAST software. Principal Component Analysis defined the most variable characters. Results showed that the diagnostic features were; length, width, apex of sepals, petals, trichomes type in pedicles and sepals along with their density, the shape length and width of leaves. In general, the present study revealed that the species could be differentiated by macro and micro‐morphological characters. Taxa of two subgenera were clearly separated based on selected characters. These characters were found useful for the taxonomic identification and species delimitation in almost all taxa studied at the sub generic level, although some species of section Geranium and section Dissecta are mixed and nested in both subgenea.
Quantitative imaging biomarkers alliance (QIBA) recommendations for improved precision of DWI and DCE‐MRI derived biomarkers in multicenter oncology trials
Authors: Shukla‐Dave Amita , Obuchowski Nancy A. , Chenevert Thomas L. , Jambawalikar Sachin , Schwartz Lawrence H. , Malyarenko Dariya , Huang Wei , Noworolski Susan M. , Young Robert J. , Shiroishi Mark S. , Kim Harrison , Coolens Catherine , Laue Hendrik , Chung Caroline , Rosen Mark , Boss Michael , Jackson Edward F. 
Published: November 2018

Physiological properties of tumors can be measured both in vivo and noninvasively by diffusion‐weighted imaging and dynamic contrast‐enhanced magnetic resonance imaging. Although these techniques have been used for more than two decades to study tumor diffusion, perfusion, and/or permeability, the methods and studies on how to reduce measurement error and bias in the derived imaging metrics is still lacking in the literature. This is of paramount importance because the objective is to translate these quantitative imaging biomarkers (QIBs) into clinical trials, and ultimately in clinical practice. Standardization of the image acquisition using appropriate phantoms is the first step from a technical performance standpoint. The next step is to assess whether the imaging metrics have clinical value and meet the requirements for being a QIB as defined by the Radiological Society of North America's Quantitative Imaging Biomarkers Alliance (QIBA). The goal and mission of QIBA and the National Cancer Institute Quantitative Imaging Network (QIN) initiatives are to provide technical performance standards (QIBA profiles) and QIN tools for producing reliable QIBs for use in the clinical imaging community. Some of QIBA's development of quantitative diffusion‐weighted imaging and dynamic contrast‐enhanced QIB profiles has been hampered by the lack of literature for repeatability and reproducibility of the derived QIBs. The available research on this topic is scant and is not in sync with improvements or upgrades in MRI technology over the years. This review focuses on the need for QIBs in oncology applications and emphasizes the importance of the assessment of their reproducibility and repeatability.Level of Evidence: 5Technical Efficacy Stage: 1J. Magn. Reson. Imaging 2019;49:e101–e121.
Vitamin C Administration to the Critically Ill: A Systematic Review and Meta‐Analysis
Authors: Langlois Pascal L. , Manzanares William , Adhikari Neill K. J. , Lamontagne François , Stoppe Christian , Hill Aileen , Heyland Daren K. 
Published: November 2018

AbstractVitamin C, an enzyme cofactor and antioxidant, could hasten the resolution of inflammation, oxidative stress, and microvascular dysfunction. While observational studies have demonstrated that critical illness is associated with low levels of vitamin C, randomized controlled trials (RCTs) of vitamin C, alone or in combination with other antioxidants, have yielded contradicting results. We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials (inception to December 2017) for RCTs comparing vitamin C, by enteral or parenteral routes, with placebo or none, in intensive care unit (ICU) patients. Two independent reviewers assessed study eligibility without language restrictions and abstracted data. Overall mortality was the primary outcome; secondary outcomes were incident infections, ICU length of stay (LOS), hospital LOS, and duration of mechanical ventilation (MV). We prespecified 5 subgroups hypothesized to benefit more from vitamin C. Eleven randomized trials were included. When 9 RCTs (n = 1322) reporting mortality were pooled, vitamin C was not associated with reduced risk of mortality (risk ratio [RR] 0.72, 95% confidence interval [CI]: 0.43–1.20, P = .21). No effect was found on infections, ICU or hospital LOS, or duration of MV. In multiple subgroup comparison, no statistically significant subgroup effects were observed. However, we did observe a tendency towards a mortality reduction (RR 0.21; 95% CI: 0.04–1.05; P = .06) when intravenous high‐dose vitamin C monotherapy was administered. Current evidence does not support supplementing critically ill patients with vitamin C. A moderately large treatment effect may exist, but further studies, particularly of monotherapy administration, are warranted.
Nitrogen isotope (δ15N) patterns for amino acids in lemur bones are inconsistent with aridity driving megafaunal extinction in south‐western Madagascar
Authors: Hixon Sean W. , Elliott Smith Emma A. , Crowley Brooke E. , Perry George H. , Randrianasy Jeannot , Ranaivoarisoa Jean Freddy , Kennett Douglas J. , Newsome Seth D. 
Published: November 2018

ABSTRACTMost endemic species with body masses >10 kg on Madagascar went extinct within the past 1000 years. The extent to which human predation, anthropogenic landscape transformation and aridification may separately or together explain this extinction pattern remains controversial. We present nitrogen isotope (δ15N) values of individual amino acids preserved in bones from now‐extinct Pachylemur insignis and extant Propithecus verreauxi from two subfossil sites in south‐western Madagascar: Tsirave and Taolambiby. The amino acid‐specific approach allows us to identify environmental signals that are otherwise difficult to recognize in bulk collagen δ15N values. Specifically, we use the δ15N values of source amino acids (phenylalanine and lysine) as a proxy for habitat aridity between ca. 4000 years ago and present and the spacing of δ15N values between trophic and source amino acids to quantify trophic levels for these two lemur species. Despite paleoenvironmental evidence for lowering water tables and the expansion of relatively arid savanna between 4000 and 1000 years ago, our isotope data suggest that these lemurs did not live in increasingly arid habitats and did not change their trophic level. Together, our results support the hypothesis that aridity alone did not play a major role in late Holocene megafaunal extinctions in south‐western Madagascar.