bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical exchange–sensitive spin‐lock (CESL) MRI of glucose and analogs in brain tumors
Authors: Jin Tao , Iordanova Bistra , Hitchens T. Kevin , Modo Michel , Wang Ping , Mehrens Hunter , Kim Seong‐Gi 
Published: March 2018

PurposeGlucose uptake and metabolism can be measured by chemical exchange–sensitive spin‐lock (CESL) MRI with an administration of glucose or its analogs. This study investigates the sensitivity, the spatiotemporal characteristics, and the signal source of glucoCESL with a 9L rat brain tumor model.MethodsDynamic CESL MRI with intravenous injection of D‐glucose, 2‐deoxy‐D‐glucose (2DG), and L‐glucose were measured and compared with gadolinium‐based dynamic contrast‐enhanced (DCE) MRI.ResultsThe CESL signals with an injection of glucose or analogs have faster and larger changes in tumors than normal brain tissue. In tumors, the CESL signal with 2DG injection has larger and slower peak response than that with D‐glucose due to the accumulation of 2DG and 2DG‐6‐phosphate in the intracellular compartment, whereas L‐glucose, which cannot be transported intracellularly by glucose transporters, only induces a small change. The initial glucoCESL maps (< 4 minutes) are qualitatively similar to DCE maps, whereas later maps (> 4 minutes) show more widespread responses. The rise times of D‐glucose‐CESL and 2DG‐CESL signals in the tumor are slower than that of DCE. Our data suggest that the initial CESL contrast primarily reflects a passive increase of glucose content in the extracellular space of tumors due to a higher vascular permeability, whereas the later period may have a significant contribution from the uptake/metabolism of glucose in the intracellular compartment.ConclusionsOur results demonstrate that glucoCESL MRI has both extracellular and intracellular contributions, and can be a useful tool for measurements of both vascular permeability and glucose uptake in tumors.
Survival of Juvenile Fall-Run Chinook Salmon through the San Joaquin River Delta, California, 2010–2015
Authors: Buchanan Rebecca A. , Brandes Patricia L. , Skalski John R. 
Published: March 2018

Abstract
Survival of juvenile fall-run Chinook Salmon Oncorhynchus tshawytscha through the San Joaquin River Delta of California (hereafter, “Delta”) has been low for most estimates since 2002 and has been consistently low since 2010. From 2010 through 2015, annual estimates of the probability of surviving through the Delta (from Mossdale to Chipps Island, approximately 92 river kilometers) ranged from 0 to 0.05, based on acoustic-telemetry data from smolt-sized hatchery Chinook Salmon. River conditions were poor in most of these years; average daily river discharge into the Delta from the San Joaquin River was &lt;40 m3/s in four of the six study years. In the high flow year of 2011 (average daily river discharge = 278–308 m3/s), the juvenile survival probability through the Delta was estimated at only 0.02 (SE &lt; 0.01), suggesting increased flows alone will not be sufficient to resolve the low survival through the Delta. The low survival in this short portion of the salmon's life history makes achieving a minimal smolt-to-adult ratio of ≥2% nearly impossible for this fish stock. Over half of the fish surviving through the Delta during 6 years of study were salvaged at the Central Valley Project's water export facility and transported for release just upstream of Chipps Island.
5‐Phenyl‐1,3,4‐oxadiazole‐2‐thiol/polyamide‐montmorillonite microbicides nanocomposites as drug delivery system
Authors: Salahuddin Nehal , Elbarbary Ahmed , Allam Nanis G. , Hashim Ayat F. 
Published: March 2018

AbstractThe preparation and structural characterization of polymeric microbicides consisting of 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol covalently bound to polyamide based on diethyl‐2,3‐dihydroxysuccinate and polyoxypropylenetriamine Jeffamine (T403) are described. Two different mole ratios of 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol was reacted with chloroacetylated diethyl‐2,3‐dihydroxysuccinate followed by polycondensation with Jeffamine (T403). The nanocomposites were prepared by modification of microbicide polyamides to yield polymers with phosphonium salt or amine hydrochloride salt followed by ion exchange process between the phosphonium salt or amine hydrochloride of the polyamides and the intermellar sodium cation of the clay mineral montmorillonite. The monomers were characterized by mass spectrum, proton nuclear magnetic resonance. The polymers showed good or moderate antimicrobial activities. Nanocomposites were characterized by Fourier transformed infrared spectroscopy, X‐ray diffraction, thermal gravimetric analysis, and transmission electron microscope. The swelling behavior and release of 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol in different pH values (2.3, 5.8, and 7.4) were studied. A slow release, ranging from 12% to 28% after 50 hours was recorded from nanocomposites. However, the release profile reached almost 70% from polyamides. The antimicrobial activity of the polyamides was studied against gram‐negative bacteria, gram‐positive bacteria, yeast, and the filamentous fungi by well diffusion method. The polyamides showed better antimicrobial activities than 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol.
A 15‐year hail streak climatology for the Alpine region
Authors: Nisi Luca , Hering Alessandro , Germann Urs , Martius Olivia 
Published: March 2018

In this study, we present a unique 15‐year hail streak climatology for Switzerland based on volumetric radar reflectivity. Two radar‐based hail detection products and an automatic thunderstorm‐tracking algorithm were reprocessed for the extended convective season (April–September) between 2002 and 2016. More than 1.1 million convective cells were automatically tracked over the full radar domain, and over 191,000 storms and 31,000 hail streaks in the considered subdomain were selected for analysis following consistency and robustness tests.The year‐to‐year variability in the number of hailstorms reveals two types of convective seasons: (a) a few seasons with hail frequency far above the average, and (b) all other years with an average number of hailstorms. A high number of hailstorms in a particular year is not correlated with a higher number of convective storms in general, but is related to a greater fraction of severe storms.Convection initiation, hail initiation, and hail frequency maxima are located along the southern and northern foothills over the pre‐Alpine area and over the Jura mountains. Few hail streaks are present over the Alpine main ridge. Hail streak frequency and location is found to be strongly dependent on the synoptic‐scale weather regimes. This is important for monthly and seasonal outlooks, as well as for climate modelling.Analysis of storm life cycles shows that: (a) the majority of hail swaths contain only a single hail streak, (b) severe storms follow a more rapid evolution during their initial stages than do less severe storms, and (c) severe storms produce more spatially extended hail streaks.Finally, significant seasonal and diurnal cycles are present in most of the considered storm characteristics.
Prediction of pregnancy after frozen‐thawed embryo transfer via in vivo intrauterine oxidation‐reduction potential measurements: a pilot study
Authors: Nakamura Hitomi , Hosono Takayoshi , Taniguchi Takeshi , Kumasawa Keiichi , Goa Satoko , Ono Masaaki , Kimura Tadashi 
Published: March 2018

AbstractPurposeDuring the implantation period, the uterus goes through many complex, orchestrated changes, including alterations of the glycocalyx that are due to sialylation, sulfation, and fucosylation. A previous mouse study showed that the in vivo intrauterine oxidation‐reduction potential (ORP) aided in determining the alterations in the uterine endometrium that are suitable for implantation and for evaluating prospective uterine receptivity, while the in vivo intrauterine pH did not. It was assessed if the in vivo intrauterine ORP could be a useful parameter to predict pregnancy in women.MethodsA prospective cohort study was conducted for patients who had received a frozen‐thawed single embryo transfer in a programmed, hormonally controlled cycle. The in vivo intrauterine ORP was measured 3 times during the treatment cycle, at cycle days 9‐10, 1 day before progesterone administration and immediately before the embryo transfer.ResultsThe amount of in vivo intrauterine ORP at 9‐10 days after the start of menstrual bleeding was significantly lower in the pregnant group than in the non‐pregnant group. A receiver‐operator characteristic curve analysis of the intrauterine ORP as a predictor of non‐conception showed an area under the curve of 0.80.ConclusionThe in vivo intrauterine ORP could be a useful parameter to predict pregnancy for the frozen‐thawed embryo transfer treatment cycle.
Robust approximation‐based adaptive control of multiple state delayed nonlinear systems with unmodeled dynamics
Authors: Shi Xiaocheng , Lim Cheng‐Chew , Xu Shengyuan , Shi Peng 
Published: March 2018

SummaryThis paper addresses the problem of tracking control for a class of uncertain nonstrict‐feedback nonlinear systems subject to multiple state time‐varying delays and unmodeled dynamics. To overcome the design difficulty in system dynamical uncertainties, radial basis function neural networks are employed to approximate the black‐box functions. Novel continuous functions that deal with whole states uncertainties are introduced in each step of the adaptive backstepping to make the controller design feasible. The robust problem caused by unmodeled dynamics when constructing a stable controller is solved by employing an auxiliary signal to regulate its boundedness. A novel Lyapunov‐Krasovskii functional is developed to compensate for the delayed nonlinearity without requiring the priori knowledge of its upper bound functions. On the basis of the proposed robust adaptive neural controller, all the closed‐loop signals are semiglobal uniformly ultimately bounded with good tracking performance.
Chemical structure and surface morphology evolution of glow discharge polymer films by Ar‐ions intermittent etching
Authors: Zhang Ling , Chen Guo , He Xiaoshan , Ai Xing , Huang Jinglin , Liu Lei , Tang Yongjian , He Zhibing 
Published: March 2018

The Ar‐ions intermittent‐etching technique was successfully incorporated during the deposition of glow discharge polymer (GDP) films. The ionic components and ion energy distributions (IEDs) of C4H8/H2 and C4H8/H2/Ar plasma were diagnosed by an energy‐resolved mass spectrometer, respectively. The Fourier transform infrared spectroscopy, scanning electron microscope, and white‐light interferometer were used to studying the chemical structure, surface morphology, and roughness of the GDP films, which are deposited with the various time of Ar‐ions intermittent etching. With the introduction of Ar into the chamber, the intensity of the CH absorption peaks becomes weak and the large‐mass CH species were ionized and dissociated from the mass spectrometer results. The surface roughness of GDP films are decreased with Ar‐ions intermittent etching, the lowest surface roughness (Rq) is only 33.6 nm when the intermittent cycle is 60 minutes/15 minutes. The highest sp3CH3 (sym) absorption peaks are attributed to samples also with 60‐minute/15‐minute intermittent cycle, which shortens the length of the carbon chain and reduces the probability of the cluster formations.
Communities of practice as a framework to explain teachers' experiences within the community of science
Authors: Davidson Shannon G. , Hughes Roxanne 
Published: March 2018

AbstractIn this study, we argue that current conceptual frameworks used to understand how novices make sense of science ignore K‐12 teachers' understanding to a detriment. If teachers are supposed to translate the content, context, and culture of science to their students, then it is important for researchers and policymakers to understand how this happens. Communities of science practice (COSP) research identify the ways in which novices make sense of the practices of science within a space where they interact with, observe, and are affected by other members at varying levels of legitimacy. In brief, K‐12 students are rarely exposed to the COSP; therefore, teachers must translate these cultural pieces to their students while simultaneously teaching the content and practices of sciences. We chose to focus on teachers who participated in a Research Experience for Teachers (RET) program. The RET program served as a brief exposure to a COSP for these teachers. The goal for our study was to develop a conceptual framework to study teachers' experiences as spectator novices within a RET program. Spectator novice was the term we used to define teachers' roles as novices moving toward legitimacy within the COSP but with a different goal—that of observing the culture and translating it to their students—from science undergraduate and graduate students who are attempting to become full legitimate participants within the community. Through interviews with teachers, we developed a conceptual framework that can guide future research on the unique experiences of teachers asspectator noviceswithin the COSP.
Immediate effects and outcome of in‐utero pulmonary valvuloplasty in fetuses with pulmonary atresia with intact ventricular septum or critical pulmonary stenosis
Authors: Tulzer A. , Arzt W. , Gitter R. , Prandstetter C. , Grohmann E. , Mair R. , Tulzer G. 
Published: March 2018

ABSTRACTObjectiveTo assess the immediate effects of fetal pulmonary valvuloplasty on right ventricular (RV) size and function as well as in‐utero RV growth and postnatal outcome.MethodsPatients with pulmonary atresia with intact ventricular septum (PAIVS) or critical pulmonary stenosis (CPS) who underwent fetal pulmonary valvuloplasty at our center between October 2000 and July 2017 were included. Echocardiographic data obtained before and after the procedure were analyzed retrospectively (median interval after intervention, 1 (range, 1–3) days) for ventricular and valvular dimensions and ratios, RV filling time (duration of tricuspid valve (TV) inflow/cardiac cycle length), TV velocity time integral (TV‐VTI) × heart rate (HR) and tricuspid regurgitation (TR) velocity. Longitudinal data were collected from only those fetuses followed up in our center. Outcome was assessed using the scoring system as described by Roman et al. for non‐biventricular outcome.ResultsThirty‐five pulmonary valvuloplasties were performed in our institution on 23 fetuses with PAIVS (n = 15) or CPS (n = 8). Median gestational age at intervention was 28 + 4 (range, 23 + 6 to 32 + 1) weeks. No fetal death occurred. Immediately after successful intervention, RV/left ventricular length (RV/LV) ratio (P ≤ 0.0001), TV/mitral valve annular diameter (TV/MV) ratio (P ≤ 0.001), RV filling time (P ≤ 0.00001) and TV‐VTI × HR (P ≤ 0.001) increased significantly and TR velocity (P ≤ 0.001) decreased significantly. In fetuses followed longitudinally to delivery (n = 5), RV/LV and TV/MV ratios improved further or remained constant until birth. Fetuses with unsuccessful intervention (n = 2) became univentricular, all others had either a biventricular (n = 15), one‐and‐a‐half ventricular (n = 3) or still undetermined (n = 3) outcome. Five of nine fetuses with a predicted non‐biventricular outcome, in which the procedure was successful, became biventricular, while two of nine had an undetermined circulation.ConclusionIn selected fetuses with PAIVS or CPS, in‐utero pulmonary valvuloplasty led immediately to larger RV caused by reduced afterload and increased filling, thus improving the likelihood of biventricular outcome even in fetuses with a predicted non‐biventricular circulation. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.
Amyloid β peptides are differentially vulnerable to preanalytical surface exposure, an effect incompletely mitigated by the use of ratios
Authors: Toombs Jamie , Foiani Martha S. , Wellington Henrietta , Paterson Ross W. , Arber Charles , Heslegrave Amanda , Lunn Michael P. , Schott Jonathan M. , Wray Selina , Zetterberg Henrik 
Published: March 2018

AbstractIntroductionWe tested the hypothesis that the amyloid β (Aβ) peptide ratios are more stable than Aβ42 alone when biofluids are exposed to two preanalytical conditions known to modify measurable Aβ concentration.MethodsHuman cerebrospinal fluid (CSF) and culture media (CM) from human cortical neurons were exposed to a series of volumes and polypropylene surfaces. Aβ42, Aβ40, and Aβ38 peptide concentrations were measured using a multiplexed electrochemiluminescence immunoassay. Data were analyzed using mixed models in R.ResultsDecrease of measurable Aβ peptide concentrations was exaggerated in longer peptides, affecting the Aβ42:Aβ40 and Aβ42:Aβ38 ratios. However, the effect size of surface treatment was reduced in Aβ peptide ratios versus Aβ42 alone. For Aβ42:Aβ40, the effect was reduced by approximately 50% (volume) and 75% (transfer) as compared to Aβ42 alone.DiscussionUse of Aβ ratios, in conjunction with concentrations, may mitigate confounding factors and assist the clinical diagnostic process for Alzheimer's disease.
Gridlocked in the city: kinship and witchcraft among Wayao street vendors in Dar es Salaam, Tanzania
Authors: Malefakis Alexis 
Published: March 2018

AbstractFor a group of Wayao street vendors in Dar es Salaam, Tanzania, kinship relations were simultaneously an advantage and a hindrance. Their migration to the city and entry into the urban economy had occurred along ethnic and kinship lines. But, as they perceived the socially heterogeneous environment of the city that potentially offered them opportunities to cooperate with people from different social or ethnic backgrounds, they experienced their continuing dependency on their relatives as a form of confinement. Against the backdrop of the city, the Wayao perceived their social relations as being burdened with an inescapable sameness that made it impossible to trust one another. Mistrust, contempt and mutual suspicion were the flip side of close social relations and culminated in accusations ofuchawi(Swahili: witchcraft). However, these accusations did not have a disintegrative effect; paradoxically, their impact on social relations among the vendors was integrative. On the one hand,uchawiallegations expressed the claustrophobic feeling of stifling relations; on the other, they compelled the accused to adhere to a shared morality of egalitarian relations and exposed the feeling that the accused individual was worthy of scrutiny, indicating that relationships with him were of particular importance to others.
Reconfiguring the culture of kinship: poor people's tactics during South Africa's transition from apartheid
Authors: Spiegel Andrew D. 
Published: March 2018

AbstractOne product of the vicissitudes of apartheid-era labour migration, of persistent constraints on urban settlement and of continuing post-apartheid oscillating migration between South Africa's cities and countryside has been extensive domestic fluidity for many South African working people. As a consequence, they have repeatedly created new social networks across the urban–rural social field. In making sense of those networks by reconfiguring their notions of kinship and clanship, they have demonstrated the significance of kinship as an identity idiom. Based on research in Cape Town's largest African township during the early 1990s period of transition from apartheid, the article shows how, through people's use of notions of clanship, they have recursively reconstructed their idiom of kinship in a context of systemic instability. This article uses ethnographic data from that time and context to argue that we need to understand kinship as a cultural resource, pragmatically used and reinvented over and over again, each time emerging anew. In doing so, the article shows that kinship is not a fixed, recordable structure and that, like so many aspects of culture, it is repeatedly reinvented and reconstituted in order to address pragmatic circumstances.
Closed circles of mistrust: envy, aspirations and urban sociality in coastal Madagascar
Authors: Desplat Patrick 
Published: March 2018

AbstractIn this article, I examine the fear of others’ envy among young students and graduates in the port city of Mahajanga, Madagascar. Although the city provides a favourable environment in relation to the economy, employment and general well-being, many young people from middle-class milieus worry that their aspirations will remain unfulfilled because of envious peers who resent them for any advantage they might have gained. While malicious envy is most expected within close social relations in which social comparison and competition are prevalent, most social actors respond to this threat with tactical practices of secrecy that arguably help to secure an individual's well-being and shield them from unsocial behaviour. I scrutinize these micro-politics of life projects, social comparison, increasing inequalities and a rising sense of mutual mistrust. Yet, I depart from approaches that frame envy as a human condition that socially produces either a prosocial levelling mechanism or a destructive force that bulldozes social bonds. Instead, I understand envy as an assemblage that points to intertwined and often ambivalent social aspects. For many young individuals, overcoming their fear of envy is part of becoming a complete person, a sign of being successful and a responsible adult.
Energy efficiency of digestible protein, fat and carbohydrate utilisation for growth in rainbow trout and Nile tilapia
Authors: Schrama Johan W. , Haidar Mahmoud N. , Geurden Inge , Heinsbroek Leon T. N. , Kaushik Sachi J. 
Published: March 2018

AbstractCurrently, energy evaluation of fish feeds is performed on a digestible energy basis. In contrast to net energy (NE) evaluation systems, digestible energy evaluation systems do not differentiate between the different types of digested nutrients regarding their potential for growth. The aim was to develop an NE evaluation for fish by estimating the energy efficiency of digestible nutrients (protein, fat and carbohydrates) and to assess whether these efficiencies differed between Nile tilapia and rainbow trout. Two data sets were constructed. The tilapia and rainbow data set contained, respectively, eight and nine experiments in which the digestibility of protein, fat and energy and the complete energy balances for twenty-three and forty-five diets was measured. The digestible protein (dCP), digestible fat (dFat) and digestible carbohydrate intakes (dCarb) were calculated. By multiple regression analysis, retained energy (RE) was related to dCP, dFat and dCarb. In tilapia, all digestible nutrients were linearly related to RE (P<0·001). In trout, RE was quadratically related to dCarb (P<0·01) and linearly to dCP and dFat (P<0·001). The NE formula was NE=11·5×dCP+35·8×dFAT+11·3×dCarb for tilapia and NE=13·5×dCP+33·0×dFAT+34·0×dCarb–3·64×(dCarb)2 for trout (NE in kJ/(kg0·8×d); dCP, dFat and dCarb in g/(kg0·8×d)). In tilapia, the energetic efficiency of dCP, dFat and dCarb was 49, 91 and 66 %, respectively, showing large similarity with pigs. Tilapia and trout had similar energy efficiencies of dCP (49 v. 57 %) and dFat (91 v. 84 %), but differed regarding dCarb.