bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties and applications of β‐glycosidase from Bacteroides thetaiotaomicron that specifically hydrolyses isoflavone glycosides
Authors: Byun Da‐Hye , Choi Hye‐Jeong , Lee Hye‐Won , Jeon Hye‐Yeon , Choung Woo‐Jae , Shim Jae‐Hoon
Published: March 2015

To modify the glycan part of glycosides, the gene encoding β‐glycosidase was cloned from Bacteroides thetaiotaomicron VPI‐5482. The cloned gene, bt_1780, was expressed in Escherichia coli MC1061 and the expressed enzyme was purified using Ni‐NTA affinity chromatography. The purified enzyme, BTBG, showed optimal activity at 50 °C and pH 5.5. Interestingly, this enzyme did not have any hydrolysing activity on ordinary β‐linkage–containing substrates such as xylobiose, lactose and cello‐oligosaccharide, but specifically hydrolysed isoflavone glycosides such as daidzin, genistin and glycitin. Compared to a commercial beta glucosidase, BTBG selectively hydrolysed isoflavone glycosides in soybean extract mixture solution. These results suggest that BTBG may be a specialized enzyme for the hydrolysis of glycosides and that the substrate specificity of BTBG is applicable for the bioconversion of isoflavone glycosides in the food industry.
A New Experimental Approach for In Situ Damage Assessment in Fibrous Ceramic Matrix Composites at High Temperature
Authors: Tracy Jared , Waas Anthony , Daly Samantha
Published: March 2015

High‐temperature applications of ceramic matrix composites necessitate a rigorous understanding of the fracture and damage mechanisms that occur under thermomechanical loading, requiring the development of advanced small‐scale characterization approaches. In this work, fiber‐reinforced SiC/SiC tensile specimens were loaded in a scanning electron microscope at 800°C, and full‐field deformation maps at the constituent length scale were generated using digital image correlation (DIC). A colloidal system containing mechanically milled titanium nanopowder, bicine, and water was developed for use as a DIC tracking pattern that is stable at 795°C. The resultant full‐field strain maps provide a constituent level characterization of damage evolution from crack initiation through final fracture. An analysis of strain along fiber lengths indicated that fiber mean strain and standard deviation reached a minimum at fiber fracture. In addition, multiple matrix cracks in the process zone ahead of a notch/crack tip were apparent and could falsely appear as a continuous region of high strain in DIC fields. Relatively large displacement (strain) error was attributed to noise and bias at these small length scales and small strain values, and approaches for mitigating this error are discussed.
A novel biphenyl urea derivate inhibits the invasion of breast cancer through the modulation of CXCR4
Authors: Zhan Yingzhuan , Zhang Han , Li Jing , Zhang Yanmin , Zhang Jie , He Langchong
Published: March 2015

The increased migration and invasion of breast carcinoma cells are key events in the development of metastasis to the lymph nodes and distant organs. CXCR4, the receptor for stromal‐derived factor‐1, is reportedly involved in breast carcinogenesis and invasion. In this study, we investigated a novel biphenyl urea derivate, TPD7 for its ability to affect CXCR4 expression as well as function in breast cancer cells. We demonstrated that TPD7 inhibited the breast cancer proliferation and down‐regulated the CXCR4 expression on breast cancer cells both over‐expressing and low‐expressing HER2, an oncogene known to induce the chemokine receptor. Treatments with pharmacological proteasome inhibitors partial suppressed TPD7‐induced decrease in CXCR4 expression. Real‐time PCR analysis revealed that down‐regulation of CXCR4 by TPD7 also occurred at the translational level. Inhibition of CXCR4 expression by TPD7 further correlated with the suppression of SDF‐1α‐induced migration and invasion in breast tumour cells, knockdown of CXCR4 attenuated TPD7‐inhibitory effects. In addition, TPD7 treatment significantly suppressed matrix metalloproteinase (MMP)‐2 and MMP‐9 expression, the downstream targets of CXCR4, perhaps via inactivation of the ERK signaling pathway. Overall, our results showed that TPD7 exerted its anti‐invasive effect through the down‐regulation of CXCR4 expression and thus had the potential for the treatment of breast cancer.
Seasonal Plasticity in the Peptide Neuronal Systems: Potential Roles of Gonadotrophin‐Releasing Hormone, Gonadotrophin‐Inhibiting Hormone, Neuropeptide Y and Vasoactive Intestinal Peptide in the Regulation of the Reproductive Axis in Subtropical Indian Weaver Birds
Authors: Surbhi  , Rastogi A. , Rani S. , Kumar V.
Published: March 2015

Two experiments examined the expression of gonadotrophin‐releasing and inhibiting hormones (GnRH‐I, GnRH‐II and GnIH), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) in subtropical Indian weaver birds, which demonstrate relative photorefractoriness. Experiment 1 measured peptide expression levels in the form of immunoreactive (‐IR) cells, percentage cell area and cell optical density in the preoptic area (GnRH‐I), midbrain (GnRH‐II), paraventricular nucleus (GnIH), mediobasal hypothalamus [dorsomedial hypothalamus (DMH), infundibular complex (INc), NPY and VIP] and lateral septal organ (VIP) during the progressive, breeding, regressive and nonbreeding phases of the annual reproductive cycle. GnRH‐I was decreased in the nonbreeding and VIP was increased in INc in the breeding and regressive states. GnRH‐II and NPY levels did not differ between the testicular phases. Double‐labelled immunohistochemistry (IHC) revealed a close association between the GnRH/GnIH, GnRH/NPY, GnRH/VIP and GnIH/NPY peptide systems, implicating them interacting and playing roles in the reproductive regulation in weaver birds. Experiment 2 further measured these peptide levels in the middle of day and night in weaver birds that were maintained under short days (8 : 16 h light /dark cycle; photosensitive), exposed to ten long days (16 : 8 h light /dark cycle; photostimulated) or maintained for approximately 2 years on a 16 : 8 h light /dark cycle (photorefractory). Reproductively immature testes in these groups precluded the possible effect of an enhanced gonadal feedback on the hypothalamic peptide expression. There were group differences in the GnRH‐I (not GnRH‐II), GnIH, NPY and VIP immunoreactivity, albeit with variations in immunoreactivity measures in the present study. These results, which are consistent with those reported in birds with relative photorefractoriness, show the distribution and possibly a complex interaction of key neuropeptides in the regulation of the annual reproductive cycle in Indian weaver birds.
Do Prices Reveal the Presence of Informed Trading?
Authors: COLLIN‐DUFRESNE PIERRE , FOS VYACHESLAV
Published: March 2015

Using a comprehensive sample of trades from Schedule 13D filings by activist investors, we study how measures of adverse selection respond to informed trading. We find that on days when activists accumulate shares, measures of adverse selection and of stock illiquidity are lower, even though prices are positively impacted. Two channels help explain this phenomenon: (1) activists select times of higher liquidity when they trade, and (2) activists use limit orders. We conclude that, when informed traders can select when and how to trade, standard measures of adverse selection may fail to capture the presence of informed trading.
Informational Frictions and Commodity Markets
Authors: SOCKIN MICHAEL , XIONG WEI
Published: March 2015

This paper develops a model with a tractable log‐linear equilibrium to analyze the effects of informational frictions in commodity markets. By aggregating dispersed information about the strength of the global economy among goods producers whose production has complementarity, commodity prices serve as price signals to guide producers' production decisions and commodity demand. Our model highlights important feedback effects of informational noise originating from supply shocks and futures market trading on commodity demand and spot prices. Our analysis illustrates the weakness common in empirical studies on commodity markets of assuming that different types of shocks are publicly observable to market participants.
Measures of atherosclerotic burden are associated with clinically manifest cardiovascular disease in type 2 diabetes: a European cross‐sectional study
Authors: Shore A. C. , Colhoun H. M. , Natali A. , Palombo C. , Östling G. , Aizawa K. , Kennbäck C. , Casanova F. , Persson M. , Gooding K. , Gates P. E. , Khan F. , Looker H. C. , Adams F. , Belch J. , Pinnoli S. , Venturi E. , Morizzo C. , Goncalves I. , Ladenvall C. , Nilsson J. ,   the SUMMIT consortium
Published: March 2015

Background

There is a need to develop and validate surrogate markers of cardiovascular disease (CVD) in subjects with diabetes. The macrovascular changes associated with diabetes include aggravated atherosclerosis, increased arterial stiffness and endothelial dysfunction. The aim of this study was to determine which of these factors is most strongly associated with clinically manifest cardiovascular events.

Methods

Vascular changes were measured in a cohort of 458 subjects with type 2 diabetes (T2D) and CVD (myocardial infarction, stroke or lower extremity arterial disease), 527 subjects with T2D but without clinically manifest CVD and 515 subjects without T2D and with or without CVD.

Results

Carotid intima–media thickness (IMT) and ankle–brachial pressure index were independently associated with the presence of CVD in subjects with T2D, whereas pulse wave velocity and endothelial function provided limited independent additive information. Measurement of IMT in the carotid bulb provided better discrimination of the presence of CVD in subjects with T2D than measurement of IMT in the common carotid artery. The factors most significantly associated with increased carotid IMT in T2D were age, disease duration, systolic blood pressure, impaired renal function and increased arterial stiffness, whereas there were no or weak independent associations with metabolic factors and endothelial dysfunction.

Conclusions

Measures of atherosclerotic burden are associated with clinically manifest CVD in subjects with T2D. In addition, vascular changes that are not directly related to known metabolic risk factors are important in the development of both atherosclerosis and CVD in T2D. A better understanding of the mechanisms involved is crucial for enabling better identification of CVD risk in T2D.
Assessment of the progression of tooth wear on dental casts
Authors: Vervoorn‐Vis G. M. G. J. , Wetselaar P. , Koutris M. , Visscher C. M. , Evälahti M. , Ahlberg J. , Lobbezoo F.
Published: March 2015

Many methods are available for the grading of tooth wear, but their ability to assess the progression of wear over time has not been studied frequently. The aim was to assess whether the occlusal/incisal grading scale of the Tooth Wear Evaluation System (TWES) was sensitive enough for the detection of tooth wear progression from 14 to 23 years of age. A total of 120 sets of dental casts were gathered from 40 people, of whom impressions were made at 14, 18 and 23 years. The TWES was used to assess loss of clinical crown height throughout the entire dentition. There was a significant difference in the TWES scores between the three age groups on all teeth (Friedman tests; P < 0·005 in all cases). Post hoc Wilcoxon tests revealed that the difference between the scores between 14 and 18 years and between 18 and 23 was significant for most teeth. It was concluded that the TWES is sensitive enough to detect changes in tooth wear over time.
Let's go outside: using photography to explore values and culture in mental health nursing
Authors: Aranda K. , de Goeas S. , Davies S. , Radcliffe M. , Christoforou A.
Published: March 2015

Accessible summary

Creative and imaginative approaches to mental healthcare education are known to help students explore emotions, empathy and others' experiences, as well as address ambivalence and ambiguity.

Very few studies in mental health nursing education specifically utilise photography as a participatory pedagogic tool, with even fewer utilising photography to explore understandings of culture, values and diversity.

Photography makes visible complex, collaborative forms of learning and previously unidentified, unarticulated ideas about culture and values.

Photography as a critical pedagogic method helps develop critical, politicized understandings of culture and values.

Increasing culturally diverse populations means complex and conflicting values have become a common feature in mental health nursing. In education the need to critically examine such topics necessitates creative and engaging pedagogy, and visual methods are readily acknowledged as such. Yet while many studies advocate and demonstrate the value of art‐based methods in student learning, very few studies in mental health nursing specifically utilize photography as a participatory pedagogic tool, and fewer still use photography to explore understandings of culture, values and diversity. In this paper, we discuss a qualitative study where mental health nursing students used photography to create images in order to explore their own and often dominant culture and attendant values. Findings suggest that photography makes visible situated, relational and collaborative learning, and surfaces previously unidentified, unarticulated ideas about culture and values. These practices mimic important processes central to mental health nursing practice and contemporaneous understandings of diverse cultures. We argue that photography provides an important resource with which to unearth subjugated knowledge, promote critical understandings of culture and values, and thereby help address inequalities in mental health care.
The interaction between maternal and post‐hatch n‐3 fatty acid supplementation in broiler diets
Authors: Koppenol A. , Delezie E. , Buyse J. , Everaert N.
Published: March 2015

This study investigated whether offspring from n‐3‐supplemented breeders have an enhanced performance and immune organ weight when fed a post‐hatch n‐3‐enriched diet in comparison with their control‐fed counterparts and the importance of timing of omega‐3 supplementation. Therefore, 480 Ross‐308 broiler breeder hens were fed one of four different diets (120/treatment). The control diet (CON) was a basal diet, rich in n‐6 fatty acids (FA). The three other diets were enriched in n‐3 FA, formulated to obtain a different EPA/DHA ratio of 1/1 (EPA = DHA), 1/2 (DHA) or 2/1 (EPA). At 33 weeks of age, eggs were incubated to obtain 1440 offspring. They were set up according to their maternal diet and sex in 48 pens of 30 chicks each (12 pens per maternal treatment: six male and six female). Half of the offspring were given a post‐hatch control diet, whereas to other half received an n‐3‐supplemented diet. Zootechnical performance was followed for starter, grower and finisher phase, and at the end of each phase two, chicks per pen were sacrificed to determine the weight of the immune organs. No interaction was found between maternal and post‐hatch n‐3 treatment for zootechnical performance. An interaction arose between the maternal and post‐hatch n‐3 supplementation for proportional bursa weight at day 1 and day 14 and proportional liver weight at day 14, but effects on immune organ weight were rather limited. Offspring post‐hatch n‐3 supplementation did not enhance maternal n‐3 supplementation.
Health Status, Behavior, and Care of Lesbian and Bisexual Women in Israel
Authors: Mor Zohar , Eick U.r.i. , Wagner Kolasko G.a.l. , Zviely-Efrat Irit , Makadon Harvey , Davidovitch Nadav
Published: March 2015

Introduction

Lesbian and bisexual women (LBs) have unique health needs compared with heterosexual women (HW).

Aim

This study aimed to associate the health status of LB, their health behavior, disclosure of sexual orientation (SO), and avoidance of health care with that of HW.

Methods

Participants in this cross-sectional study completed anonymous questionnaires, which were distributed in Internet sites and public venues in Israel, comparing health behaviors and outcomes between LB and HW.

Main Outcome Measures

Health outcomes included subjective health status, general practitioner or gynecologist visit in the last 6 months, and satisfaction from the Israeli healthcare system.

Results

In 2012, 681 (34.4%) lesbians, 242 (13.5%) bisexual women, and 937 (52.1%) HW completed the questionnaire. In comparison with HW, LBs were more commonly single, used drugs/alcohol, smoked, experienced eating disorders, and reported an earlier sexual debut. In comparison with all women, lesbians performed less physical activities and were more satisfied with their body weight, whereas bisexuals had riskier sexual behavior and reported more verbal/physical abuse. LB reported more emergency room visits, more visits to psychiatrists, yet underwent Pap smears less frequently compared with HW. In a multivariate analysis, lesbians had fewer gynecologists' visits and were less satisfied with the healthcare system than HW, whereas bisexuals visited their general practitioner or gynecologist less frequently and were less satisfied with the primary healthcare system. Lesbians were more likely to disclose their SO with their doctors than bisexuals and were satisfied with the disclosure. Nondisclosure of SO was correlated with poor subjective health status. The interaction between being bisexual and nondisclosure of SO was strong.

Conclusions

LB utilized health care less frequently than HW, resulting in unmet medical needs. SO disclosure was associated with better healthcare utilization and health outcomes, especially among bisexuals. Providers should be trained about LB's unique health needs and improve their communication skills to encourage SO disclosure.
Validating of a Novel Method for Electronically Recording Overactive Bladder Symptoms in Men
Authors: KRHUT Jan , GÄRTNER Marcel , ZVAROVÁ Katarína , DESARNO Michael , ZVARA Peter
Published: March 2015

Objective

The goal of this study was to compare a novel wireless phone and web based technology to record and store overactive bladder symptoms (OAB‐S) to a traditional pen and paper micturition chart.

Methods

Overactive bladder symptoms were recorded over a period of 3 days using both an electronic micturition chart (EMC) and the standard pen and paper micturition chart (MC). Twenty‐nine men, with lower urinary tract symptoms (LUTS), were included in the study. Dropout rate, patient's preference, and correlation between the quality of life measures (QoL) and symptoms recorded with EMC versus MC, were assessed and compared.

Results

Of the total number of 29 patients enrolled into the study, 24 completed the full 3‐day trial using MC and 27 using EMC. MC was preferred by 50%, while EMC was preferred by 50% of participants. Using MC, 21% of patients forgot to record at least one episode of urgency, versus 17% using EMC, 17% forgot to record at least one micturition using MC versus 8% using EMC. A statistically significant correlation was found between lower severity of OAB‐S and higher QoL, using both recording methods.

Conclusions

In this study population, recording symptoms with EMC did not prove to be preferable compared to MC; however, EMC provided the same level of accuracy with the same or better adherence to the study protocol.
Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100
Authors: Alter S. Elizabeth , Meyer Matthias , Post Klaas , Czechowski Paul , Gravlund Peter , Gaines Cork , Rosenbaum Howard C. , Kaschner Kristin , Turvey Samuel T. , van der Plicht Johannes , Shapiro Beth , Hofreiter Michael
Published: March 2015

Arctic animals face dramatic habitat alteration due to ongoing climate change. Understanding how such species have responded to past glacial cycles can help us forecast their response to today's changing climate. Gray whales are among those marine species likely to be strongly affected by Arctic climate change, but a thorough analysis of past climate impacts on this species has been complicated by lack of information about an extinct population in the Atlantic. While little is known about the history of Atlantic gray whales or their relationship to the extant Pacific population, the extirpation of the Atlantic population during historical times has been attributed to whaling. We used a combination of ancient and modern DNA, radiocarbon dating and predictive habitat modelling to better understand the distribution of gray whales during the Pleistocene and Holocene. Our results reveal that dispersal between the Pacific and Atlantic was climate dependent and occurred both during the Pleistocene prior to the last glacial period and the early Holocene immediately following the opening of the Bering Strait. Genetic diversity in the Atlantic declined over an extended interval that predates the period of intensive commercial whaling, indicating this decline may have been precipitated by Holocene climate or other ecological causes. These first genetic data for Atlantic gray whales, particularly when combined with predictive habitat models for the year 2100, suggest that two recent sightings of gray whales in the Atlantic may represent the beginning of the expansion of this species' habitat beyond its currently realized range.
Financial Intermediaries, Credit Shocks and Business Cycles
Authors: Mimir Yasin
Published: March 2015

We document the cyclical properties of aggregate balance sheet variables of the US commercial banks: (i) Bank credits and deposits are less volatile than output, while net worth and leverage ratio are several times more volatile, (ii) bank credits and net worth are procyclical, while deposits, leverage ratio and loan spread are countercyclical. We then present a real business cycle model with a financial sector to investigate how the dynamics of macroeconomic aggregates and balance sheet variables of the US banks are influenced by empirically disciplined shocks to bank net worth. Both calibrated and estimated versions of the model show that these financial shocks are important not only for explaining the dynamics of financial flows but also for the dynamics of macroeconomic variables. We find that the recent deterioration in aggregate net worth of the US banking sector contributed significantly to the 2007–09 recession.
Linkage between root systems of three pioneer plant species and soil nitrogen during early reclamation of a mine site in Lusatia, Germany
Authors: Boldt‐Burisch Katja , Naeth M. Anne , Schneider Bernd Uwe , Hüttl Reinhard F.
Published: March 2015

In 2005, a 7‐ha artificial watershed (Chicken Creek) was built on a post mined landscape in Lusatia, Germany from sandy substrates of Pleistocene origin, commonly used in reclamation. The watershed was developed to investigate the initial phase of soil and ecosystem development under natural conditions. At this early stage, mineral nitrogen in young sandy soils is primarily limited and nitrogen fixing legumes become key components of natural succession. Local abundant pioneering legumes Lotus corniculatus and Trifolium arvense and one pioneer grass species Calamagrostis epigeios were investigated 5 years after watershed construction. In this study, we investigated the influence of spatial root and nodule distribution of these species on soil nitrogen accumulation. Soil, including roots, was sampled from field monoliths covered with the aforementioned plant species. Root systems of both legumes were mainly restricted to the upper 20 cm of soil, whereas roots of C. epigeios also developed strongly at greater depths. A positive relationship was found, with higher plant densities associated with higher root densities which were associated with higher nodule densities for legumes and which were all associated with significantly higher soil nitrogen content relative to non‐vegetated areas. This research provides rare information on the role root systems of pioneer legumes play in soil nitrogen input in the early stage of soil and ecosystem development during revegetation by natural succession.
Mantle degassing on a near shore volcano, SE Tyrrhenian Sea
Authors: Loreto Maria F. , Italiano Francesco , Deponte Davide , Facchin Lorenzo , Zgur Fabrizio
Published: March 2015

The presence of a seamount‐like structure, located a few nautical miles offshore the Capo Vaticano Promontory (western Calabria, S Italy), was revealed by combined geophysical and geochemical investigation. The edifice covers ~55 km2, with a top located at a depth of about 70 m below sea level, and consists mainly of a NW‐trending structure orthogonally interrupted by minor ridges, the largest of which is affected by extensional faults. The top of the edifice hosts active vents, injected fluids that have been investigated for dissolved volatiles. Gas analyses revealed high CO2 and CH4 contents, several orders of magnitude above the atmospheric‐type values expected for shallow, coastal marine waters, and a noteworthy enrichment in mantle‐derived 3He, which is an unambiguous indicator of the mantle origin of the fluids. Our results, combined with available data from the literature, suggest that the edifice is a tectonically controlled volcanic system, which presence near the Calabria region changes the role played by faults in the frame of the subduction process.
Algae after dark: mechanisms to cope with anoxic/hypoxic conditions
Authors: Yang Wenqiang , Catalanotti Claudia , Wittkopp Tyler M. , Posewitz Matthew C. , Grossman Arthur R.
Published: March 2015

Chlamydomonas reinhardtii is a unicellular, soil‐dwelling (and aquatic) green alga that has significant metabolic flexibility for balancing redox equivalents and generating ATP when it experiences hypoxic/anoxic conditions. The diversity of pathways available to ferment sugars is often revealed in mutants in which the activities of specific branches of fermentative metabolism have been eliminated; compensatory pathways that have little activity in parental strains under standard laboratory fermentative conditions are often activated. The ways in which these pathways are regulated and integrated have not been extensively explored. In this review, we primarily discuss the intricacies of dark anoxic metabolism in Chlamydomonas, but also discuss aspects of dark oxic metabolism, the utilization of acetate, and the relatively uncharacterized but critical interactions that link chloroplastic and mitochondrial metabolic networks.
An Experimental Study of the Post-CHOPS Cyclic Solvent Injection Process
Authors: Du Zhongwei , Zeng Fanhua , Chan Christine
Published: March 2015

Cold heavy oil production with sand (CHOPS) has been applied successfully in many oil fields in Canada. However, typically only 5–15% of the original oil in place (OOIP) is recovered during cold production. Therefore, effective follow-up techniques are of great importance. Cyclic solvent injection (CSI), as a post-CHOPS process, has greater potential than continuous solvent injection to enhance heavy oil recovery. Continuous solvent injection results in early breakthrough due to the existence of wormholes; while in CSI process, the existence of wormholes can increase the contact area of solvent and heavy oil and the wormholes also provide channels that allow diluted oil to flow back to the wellbore. In this study, the effects of wormhole and sandpack model properties on the performance of the CSI process are experimentally investigated using three different cylindrical sandpack models. The length and diameter of the base model are 30.48 cm and 3.81 cm, respectively. The other two models, one with a larger length (i.e., 60.96 cm) and the other with a larger diameter (i.e., 15.24 cm), are used for up-scaling study in the directions parallel and perpendicular to the wormhole, respectively. The porosity and permeability of these models are about 35% and 5.5 Darcy typically. A typical western Canadian oil sample with a viscosity of 4330 mPa·s at 15 °C is used. And pure propane is selected as the solvent. The experimental results suggest that the existence of wormhole can significantly increase the oil production rate. The larger the wormhole coverage is, the better the CSI performance obtained. In terms of the effect of wormhole's location, a reservoir or well with wormholes developed at bottom is more favorable for post-CHOPS CSI process due to the gravity effect. The production of the CSI process can be divided into two phases: early time chamber rising and late time chamber spreading phases. The oil recovery factor in the chamber rising phase is almost independent of the sandpack model diameter; and the oil relative production rates (the oil production rate divided by the OOIP) in two models with different diameters are close during the chamber spreading phase due to similar solvent dispersion rate. It is also found that if the wormhole length is the same, the sandpack model length hardly affects the oil production rate in the earlier stage. In terms of the effects of the wormhole orientation, the well with a horizontal wormhole is inclined to get a good CSI performance. Through analyzing the experimental data, a relationship of oil production rate to drainage height is also obtained and verified.
Comparison of Hybrid-III and Postmortem Human Surrogate Response to Simulated Underbody Blast Loading
Authors: Marie Bailey Ann , Christopher John J. , Salzar Robert S. , Brozoski Frederick
Published: March 2015

Response of the human body to high-rate vertical loading, such as military vehicle underbody blast (UBB), is not well understood because of the chaotic nature of such events. The purpose of this research was to compare the response of postmortem human surrogates (PMHS) and the Hybrid-III anthropomorphic test device (ATD) to simulated UBB loading ranging from 100 to 860 g seat and floor acceleration. Data from 13 whole body PMHS tests were used to create response corridors for vertical loading conditions for the pelvis, T1, head, femur, and tibia; these responses were compared to Hybrid-III responses under matched loading conditions.
Impact Force Based Model for Bearing Local Fault Identification
Authors: Khanam Sidra , Dutt J. K. , Tandon N.
Published: March 2015

Local faults, like spalls in rolling element bearings, give rise to periodic impulsive excitation to the supporting structure. So, an impact based force evaluation, the resulting response analysis of the structure, and experiments are reported in this paper to identify local bearing fault as well as its size. Magnitude and duration of such excitation force are functions of bearing geometry, load, speed, and size of defect. An approach based on the principles of engineering mechanics is followed to obtain a time function of the impact force which is used next to simulate the response of the bearing housing. This response is analyzed in time and frequency domains to get an idea about the bearing fault and its size. Experiments conducted on deep groove ball bearing for different defect sizes and different speeds show acceptable correlation with the theoretical simulation. Hence, the impact based model has laid a theoretical platform to gain insight into the physical phenomena, which is not measured in practice, through impact excitation mechanism and may hold sufficient potential for bearing fault identification.
Ground-Based Response of a Spinning, Cyclic Symmetric Rotor Assembled to a Flexible Stationary Housing Via Multiple Bearings
Authors: Tai W. C. , Shen I. Y.
Published: March 2015

This paper is to study ground-based response of a spinning, cyclic symmetric rotor assembled to a flexible housing via multiple bearings. In particular, interaction of the spinning rotor and the flexible housing is manifested theoretically, numerically, and experimentally. In the theoretical analysis, we show that the interaction primarily appears in coupled rotor–bearing–housing modes whose response is dominated by the housing. Specifically, let a housing-dominant mode have natural frequency ω(H) and the spin speed of the rotor to be ω3. In rotor-based coordinates, response of the spinning rotor for the housing-dominant mode will possess frequency splits ω(H)±ω3. In ground-based coordinates, response of the spinning rotor will possess alternative frequency splits ω(H)-(k+1)ω3 and ω(H)-(k-1)ω3, where k is an integer determined by the cyclic symmetry of the rotor and the housing-dominant mode of interest. In the numerical analysis, we study a benchmark model consisting of a spinning slotted disk mounted on a stationary square plate via two ball bearings. The numerical model successfully confirms the frequency splits both in the rotor-based and ground-based coordinates. In the experimental analysis, we conduct vibration testing on a rotor–bearing–housing system that mimics the numerical benchmark model. Test results reveal two housing-dominant modes. As the rotor spins at various speed, measured waterfall plots confirm that the housing-dominant modes split according to ω(H)-(k+1)ω3 and ω(H)-(k-1)ω3 as predicted.
Theoretical and Numerical Determination of Low-Frequency Reverberant Characteristics of Coupled Rooms
Authors: Meissner Mirosław
Published: March 2015

The main aim of room acoustics is to predict reverberant properties of enclosures from measured or numerically simulated room responses. In this paper, this issue was examined in low-frequency range where acoustic characteristics of rooms are strongly frequency dependent due to differences in a modal damping. A theoretical description of a decaying sound field was based on a modal expansion of the sound pressure, and a reverberant response of the room was initiated by emission of Dirac delta time impulse or by switching off a time-harmonic source. Theoretical findings were employed to determine reverberant characteristics of a coupled-room system containing two connected rectangular subrooms. Simulation results have shown that a sound decay after steady-state harmonic excitation is strongly influenced by the sound frequency and due to large fluctuations in a decaying pressure; numerical techniques for smoothing decay curves are needed. Calculations also revealed that in some one-third octave bands, the decay function found via backward integration of squared room impulse response (RIR) changes very irregularly impeding a proper qualifying of nature of sound decay.
Some Improvements on a General Particle Filter Based Bayesian Approach for Extracting Bearing Fault Features
Authors: Wang Dong , Miao Qiang
Published: March 2015

In our previous work, a general particle filter based Bayesian method was proposed to derive the graphical relationship between wavelet parameters, including center frequency and bandwidth, and to posteriorly find optimal wavelet parameters so as to extract bearing fault features. In this work, some improvements on the previous Bayesian method are proposed. First, the previous Bayesian method strongly depended on an initial uniform distribution to generate random particles. Here, a random particle represented a potential solution to optimize wavelet parameters. Once the random particles were obtained, the previous Bayesian method could not generate new random particles. To solve this problem, this paper introduces Gaussian random walk to joint posterior probability density functions of wavelet parameters so that new random particles can be generated from Gaussian random walk to improve optimization of wavelet parameters. Besides, Gaussian random walk is automatically initialized by the famous fast kurtogram. Second, the previous work used the random particles generated from the initial uniform distribution to generate measurements. Because the random particles used in the previous work were fixed, the measurements were also fixed. To solve this problem, the first measurement used in this paper is provided by the fast kurtogram, and its linear extrapolations are used to generate monotonically increasing measurements. With the monotonically increasing measurements, optimization of wavelet parameters is further improved. At last, because Gaussian random walk is able to generate new random particles from joint posterior probability density functions of wavelet parameters, the number of the random particles is not necessarily set to a high value that was used in the previous work. Two instance studies were investigated to illustrate how the Gaussian random walk based Bayesian method works. Comparisons with the famous fast kurtogram were conducted to demonstrate that the Gaussian random walk based Bayesian method can better extract bearing fault features.
Three-Dimensional Numerical Modeling of Pier Scour Under Current and Waves Using Level-Set Method
Authors: Saud Afzal Mohammad , Bihs Hans , Kamath Arun , Arntsen Øivind A.
Published: March 2015

A three-dimensional (3D) computational fluid dynamics (CFD) model is used to calculate the scour and the deposition pattern around a pier for two different boundary conditions: constant discharge and regular waves. The CFD model solves Reynolds-Averaged Navier–Stokes (RANS) equations in all three dimensions. The location of the free-surface is represented using the level-set method (LSM), which calculates the complex motion of the free-surface in a very realistic manner. For the implementation of waves, the CFD code is used as a numerical wave tank. For the geometric representation of the moveable sediment bed, the LSM is used. The numerical results for the local scour prediction are compared with physical experiments. The decoupling of the hydrodynamic and the morphodynamic time step is tested and found to be a reasonable assumption. For the two situations of local pier scour under current and wave conditions, the numerical model predicts the general evolution (geometry, location, and maximum scour depth) and time development of the scour hole accurately.
An unusual cause of neonatal cyanosis…
Authors: Carreira Raquel , Palaré Maria João , Prior Ana Rita , Garcia Paula , Abrantes Margarida
Published: March 2015

We report a case of a female neonate whose pulse oximetry screening for congenital heart disease at 40 h of life was positive. The pregnancy was uneventful with no relevant family history. The neonate presented with bluish discolouration of the skin lasting until day 15. Cardiovascular examination and chest radiography were normal. Septic screening was negative. Oxygen therapy was started with poor response; investigations revealed a methaemoglobinaemia of 7.4%. The methaemoglobin level reached a peak of 15% on day 10, falling thereafter. The infant was discharged by day 20 with a normal physical examination and a methaemoglobinaemia of 11.4%. By 2 months of age this had fallen to 2.4%. Further investigation revealed a haemoglobin M variant: a heterozygous mutation of the γ globin gene known as Hb F-M Viseu. The mutation occurs in the γ chain, therefore the methaemoglobinaemia is transitory, resolving with the transition from fetal to adult haemoglobin.
A difficult diagnosis: severe Graves’ ophthalmolopathy
Authors: Yip Ivan Yeu Ming , Mushtaq Fizza , Reuser Tristan
Published: March 2015

An 81-year-old woman with atrial fibrillation, on warfarin, with known hyperthyroidism, was admitted to hospital following a fall with proptosis and severely restricted movements in her left eye. Medics initially thought the presentation was related to an intracranial pathology but through subsequent tests and examination, ophthalmologists diagnosed a severe case of thyroid eye disease with intense inflammation. The patient responded well to systemic steroid treatment. This case report highlights a severe rapidly progressing case of thyroid eye disease with diagnostic difficulties arising from multiple comorbidities in an elderly patient.
Identification of a potential metabolic marker, inositol, for the inherently fast growth trait by stems of Pinus densiflora via a retrospective approach
Authors: Kang Jun Won , Kim Hyun-Tae , Lee Wi Young , Choi Mi Na , Park Eung-Jun
Published: March 2015

A retrospective metabolomics approach was utilized as a tool in genomics-assisted selection for forest tree improvement. Key metabolic components were thus correlated with the inherently rapid stem growth of Pinus densiflora Siebold & Zucc. trees, including water soluble metabolites and amino acids found in the inner bark (phloem) of cambial region tissues that were harvested in midsummer (July) from 34-year-old trees. Metabolites were assessed in individual genotypes from seven open-pollinated, half-sibling families. Four of the families were classed as fast growing, and three of the families were significantly slower growing. This metabolomics approach was also used to assess metabolite profiles in similar cambium–phloem region tissues from 4-year-old trees representing 12 unrelated families. Initially by Pearson’s correlation analysis, and subsequently by stepwise linear modeling, we assessed the interactions between stem growth parameters (stem diameters and a stem volume index) and metabolite contents, and we did this via a retrospective approach. Among the metabolites identified, inositol was a consistent, positive, and highly significant correlate with the stem growth of P. densiflora trees at two developmental stages (ages 4 and 34 years). Inositol also exhibited these significant correlations in an environment-independent manner, i.e., on two very different field progeny test sites. We conclude that inositol may be a useful metabolic biomarker for early selection of rapid tree stem growth traits of this conifer species. In so doing, it could appreciably enhance the breeding and selection of inherently rapid-growing families of P. densiflora.
Topological insulator in tellurium-based perovskites
Authors: Yang Ming , Wang Rui-Ning
Published: March 2015

Perovskites have a cubic structure with general formula of ABO 3. The meritorious features such as colossal magnetoresistance, ferroelectricity, superconductivity and charge ordering are observed in this class of materials and make perovskites a hot-spot which receive considerable research interest in recent years. Here, we predict a new topological insulator in tellurium-based perovskites and calculate its band structures, electronic density of states (DOS) and Z2 quantum number. By orbital-projected band structure analysis we find that the orbitals involved in the topological band-inversion process are s- and p-orbitals. The topological surface state is also given. This new material can provide dissipationless signal current for devices and is expected to be applied in spintronics devices.
Discovering Perceptions in Online Social Media: A Probabilistic Approach
Authors: Doran Derek , Gokhale Swapna S. , Dagnino Aldo
Published: March 2015

People across the world habitually turn to online social media to share their experiences, thoughts, ideas, and opinions as they go about their daily lives. These posts collectively contain a wealth of insights into how masses perceive their surroundings. Therefore, extracting people's perceptions from social media posts can provide valuable information about pertinent issues such as public transportation, emergency conditions, and even reactions to political actions or other activities. This paper proposes a novel approach to extract such perceptions from a corpus of social media posts originating from a given broad geographical region. The approach divides the broad region into a number of sub-regions, and trains language models over social media conversations within these sub-regions. Using Bayesian and geo-smoothing methods, the ensemble of language models can be queried with phrases embodying a perception. Discrete and continuous visualization methods represent the extent to which social media posts within the sub-regions express the query. The capabilities of the perception mining approach are illustrated using transportation-themed scenarios.
A Generic Process for the Design and Generation of Software Product Line Skeleton Architectures
Authors: Cabello Maria Eugenia , Ramos Isidro , Santana Oscar Alberto , Beristain Saúl Iván
Published: March 2015

This paper presents a process, a method and a framework for developing families of software systems in a domain. The process is generic (domain-independent) and produces skeleton software architectures as Software Product Lines. The genericity is supported by the metamodels (abstract languages) that are defined in order to describe the Reference Architecture (structure view, behavior view and variability view) of the system domain. A standardized Production Plan takes the Reference Architecture as input and produces the equivalent Skeleton Software Architecture (component-connector view) using a Feature Model configuration (describing the system to be) as output. This Skeleton Software Architecture includes the structure and behavior of the target software product. A framework has been implemented to support the approach. The process is applied, as an example, to the Diagnostic Expert Systems domain.

Our approach is based on Model-Driven Engineering techniques and the Software Product Line paradigm. A domain analysis must be done in order to build the Reference Architecture.
Activity-Based Software Process Lines Tailoring
Authors: Lorenz Wagner Gadêa , Brasil Miguel Bauermann , Fontoura Lisandra Manzoni , Vaz Pereira Guilherme
Published: March 2015

Software process definition requires choosing the process elements that appropriately fulfil the tailoring requirements, such as to prevent risks or to satisfy quality goals. The selection of appropriate process elements is usually done manually, making this process complex, time-consuming and error-prone. Our main objective is to define a systematic approach to tailor software process and a support tool to simplify and to support the tailoring process by improving the selection process of reusable process elements. We developed a systematic approach to tailor software process based on software process architectures and lines. This approach selects the process elements that appropriately match the tailoring requirements. A web tool was developed to support the use of the proposed approach. We concluded that the approach aids process engineer to make decisions for selecting a set of process elements suitable to the tailoring requirements and to the project context.
GPU-Powered Coherent Beamforming
Authors: Magro A. , Adami K. Zarb , Hickish J.
Published: March 2015

Graphics processing units (GPU)-based beamforming is a relatively unexplored area in radio astronomy, possibly due to the assumption that any such system will be severely limited by the PCIe bandwidth required to transfer data to the GPU. We have developed a CUDA-based GPU implementation of a coherent beamformer, specifically designed and optimized for deployment at the BEST-2 array which can generate an arbitrary number of synthesized beams for a wide range of parameters. It achieves [Formula: see text] TFLOPs on an NVIDIA Tesla K20, approximately 10x faster than an optimized, multithreaded CPU implementation. This kernel has been integrated into two real-time, GPU-based time-domain software pipelines deployed at the BEST-2 array in Medicina: a standalone beamforming pipeline and a transient detection pipeline. We present performance benchmarks for the beamforming kernel as well as the transient detection pipeline with beamforming capabilities as well as results of test observation.