bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk Factor Analysis May Provide Clues to Diarrhea Prevention in Outdoor‐Housed Rhesus Macaques (Macaca mulatta)
Authors: PRONGAY KAMM , PARK BYUNG , MURPHY STEPHANIE J. 
Published: April 2013

AbstractSeventy‐five percent of rhesus macaques at national primate research centers are housed outside. Annually, 15–39% of these animals experience diarrhea and require veterinary treatment for dehydration, electrolyte imbalance, or weight loss. An estimated 21–33% of these patients will die or be euthanized. Many studies have explored the various infectious etiologies of non‐human primate diarrhea. However, there is little published information on diarrhea incidence rates and risk factors in outdoor‐housed rhesus macaques. Without this information, it is challenging to determine endemic and epidemic diarrhea levels, or to develop and evaluate mitigation strategies. Using electronic medical records, we conducted a retrospective cohort study to calculate diarrhea incidence rates for rhesus macaques (N = 3,181) housed in three different outdoor housing types (corrals, shelters, and temporary housing) at the Oregon National Primate Research Center between November 1, 2009 and October 31, 2010. With multiple logistic regression analysis, we determined the relative risk of housing type, sex, and age on development of diarrhea. Diarrhea incidence and mortality in our population was lower than many published ranges. Type of outdoor housing, age, and previous diarrhea episode were positively correlated with diarrhea risk. Younger animals in smaller shelters and temporary housing had a greater risk of acquiring diarrhea, with juvenile animals (0.7–3.9 years) having the highest mortality rate. Sex was not a risk factor, but adult females with diarrhea were more likely to develop life‐threatening complications than adult males. We also constructed a predictive model for diarrhea‐associated mortality using Classification and Regression Tree. Findings from this study will be used to develop and evaluate mitigation strategies in our outdoor‐housed population and to provide a foundation for genetic susceptibility and immune function testing. Am. J. Primatol. 75:872–882, 2013. © 2013 Wiley Periodicals, Inc.
Square‐Root Cubature‐Quadrature Kalman Filter
Authors: Bhaumik Shovan ,   Swati
Published: April 2013

AbstractIn this paper, an on‐going work introducing square‐root extension of cubature‐quadrature based Kalman filter is reported. The proposed method is named square‐root cubature‐quadrature Kalman filter (SR‐CQKF). Unlike ordinary cubature‐quadrature Kalman filter (CQKF), the proposed method propagates and updates square‐root of the error covariance without performing Cholesky decomposition at each step. Moreover SR‐CQKF ensures positive semi‐definiteness of the state covariance matrix. With the help of two examples we show the superior performance of SR‐CQKF compared to EKF and square root cubature Kalman filter.
Analysis and comparison of oxygen consumption of HepG2 cells in a monolayer and three‐dimensional high density cell culture by use of a matrigrid®
Authors: Weise Frank , Fernekorn Uta , Hampl Jörg , Klett Maren , Schober Andreas 
Published: April 2013

ABSTRACTBy the use of a MatriGrid® we have established a three‐dimensional high density cell culture. The MatriGrid® is a culture medium permeable, polymeric scaffold with 187 microcavities. In these cavities (300 μm diameter and 207 μm deep) the cells can growth three‐dimensionally. For these experiments we measured the oxygen consumption of HepG2 cell cultures in order to optimize cultivation conditions. We measured and compared the oxygen consumption, growth rate and vitality under three different cultivation conditions: monolayer, three‐dimensional static and three‐dimensional actively perfused. The results show that the cells in a three‐dimensional cell culture consume less oxygen as in a monolayer cell culture and that the actively perfused three‐dimensional cell culture in the MatriGrid® has a similar growth rate and vitality as the monolayer culture. Biotechnol. Bioeng. 2013; 110:2504–2512. © 2013 Wiley Periodicals, Inc.
Testing alternative kinetic models for utilization of crystalline cellulose (Avicel) by batch cultures of Clostridium thermocellum
Authors: Holwerda Evert K. , Lynd Lee R. 
Published: April 2013

ABSTRACTDescriptive kinetics of batch cellulose (Avicel) and cellobiose fermentation by Clostridium thermocellum were examined with residual substrate and biosynthate concentrations inferred based on elemental analysis. Biosynthate was formed in constant proportion to substrate consumption until substrate was exhausted for cellobiose fermentation, and until near the point of substrate exhaustion for cellulose fermentation. Cell yields (g pellet biosynthate carbon/g substrate carbon) of 0.214 and 0.200 were obtained for cellulose and cellobiose, respectively. For cellulose fermentation a sigmoidal curve fit was applied to substrate and biosynthate concentrations over time, which was then differentiated to calculate instantaneous rates of growth and substrate consumption. Three models were tested to describe the kinetics of Avicel utilization by C. thermocellum: (A) first order in cells, (B) first order in substrate, and (C) first order in cells and substrate, and second order overall. Models (A) and (B) have been proposed in the literature to describe cultures of cellulolytic microorganisms, whereas model (C) has not. Of the three models tested, model (c) provided by far the best fit to batch culture data. A second order rate constant equal to 0.735 L g C−1 h−1 was found for utilization of Avicel by C. thermocellum. Adding an endogenous metabolism term improved the descriptive quality of the model as substrate exhaustion was approached. Such rate constants may in the future find utility for describing and comparing cellulose fermentation involving other microbes and other substrates. Biotechnol. Bioeng. 2013; 110:2389–2394. © 2013 Wiley Periodicals, Inc.
Development and evaluation of methods to infer biosynthesis and substrate consumption in cultures of cellulolytic microorganisms
Authors: Holwerda Evert K. , Ellis Lucas D. , Lynd Lee R. 
Published: April 2013

ABSTRACTConcentrations of biosynthate (microbial biomass plus extracellular proteins) and residual substrate were inferred using elemental analysis for batch cultures of Clostridium thermocellum. Inferring residual substrate based on elemental analysis for a cellulose (Avicel)‐grown culture shows similar results to residual substrate determined by quantitative saccharification using acid hydrolysis. Inference based on elemental analysis is also compared to different on‐line measurements: base addition, CO2 production, and Near Infra Red optical density (OD850). Of these three on‐line techniques, NIR OD850 has the best correlation with residual substrate concentration and is the most practical to use. Both biosynthate and residual substrate concentration demonstrate typical sigmoidal trends that can easily be fitted with a five‐parameter Richards curve. The sigmoidal character of the inferred concentrations and on‐line data, especially the CO2 production rate, suggest that there is a maximum in cell‐specific rates of growth and substrate utilization during batch fermentations of crystalline cellulose, which is not observed during grown on cellobiose. Using a sigmoidal fit curve, the instantaneous specific growth rate was determined. While soluble substrate grown cultures show a constant growth rate, cultures grown on solid substrate do not. Features of various approaches are compared, with some more appropriate for rapid general indication of metabolic activity and some more appropriate for quantitative physiological studies. Biotechnol. Bioeng. 2013; 110:2380–2388. © 2013 Wiley Periodicals, Inc.
Oxygen control of intracellular distribution of mitochondria in muscle fibers
Authors: Pathi B. , Kinsey S. T. , Locke B. R. 
Published: April 2013

ABSTRACTMitochondrial density in skeletal muscle fibers is governed by the demand for aerobic ATP production, but the heterogeneous distribution of these mitochondria appears to be governed by constraints associated with oxygen diffusion. We propose that each muscle fiber has an optimal mitochondrial distribution at which it attains a near maximal rate of ATP consumption (RATPase) while mitochondria are exposed to a minimal oxygen concentration, thus minimizing reactive oxygen species (ROS) production. We developed a coupled reaction–diffusion/cellular automata (CA) mathematical model of mitochondrial function and considered four fiber types in mouse extensor digitorum longus (EDL) and soleus (SOL) muscle. The developed mathematical model uses a reaction–diffusion analysis of metabolites including oxygen, ATP, ADP, phosphate, and phosphocreatine (PCr) involved in energy metabolism and mitochondrial function. A CA approach governing mitochondrial life cycles in response to the metabolic state of the fiber was superimposed and coupled to the reaction–diffusion approach. The model results show the sensitivity of important model outputs such as the RATPase, effectiveness factor (η) and average oxygen concentration available at each mitochondrion to local oxygen concentration in the fibers through variation in the CA model parameter θdet, which defines the sensitivity of mitochondrial death to the oxygen concentration. The predicted optimal mitochondrial distributions matched previous experimental findings. Deviations from this optimal distribution corresponding to higher CA model parameter values (a more uniform mitochondrial distribution) lead to lower aerobic rates. In contrast, distributions corresponding to lower CA model parameter values (a more asymmetric distribution) lead to an increased exposure of mitochondria to oxygen, usually without substantial increases in aerobic rates, which would presumably result in increased ROS production and thus increased risks of cytotoxicity. Biotechnol. Bioeng. 2013; 110:2513–2524. © 2013 Wiley Periodicals, Inc.
Regiospecific modifications of naringenin for astragalin production in Escherichia coli
Authors: Malla Sailesh , Pandey Ramesh Prasad , Kim Byung‐Gee , Sohng Jae Kyung 
Published: April 2013

ABSTRACTWe report the production of astragalin (AST) from regiospecific modifications of naringenin (NRN) in Escherichia coli BL21(DE3). The exogenously supplied NRN was converted into dihydrokaempferol (DHK) and then kaempferol (KMF) in the presence of flavanone‐3‐hydroxylase (f3h) and flavonone synthase (fls1) from Arabidopsis thaliana, respectively. KMF was further modified to produce AST by 3‐O‐glucosylation utilizing the endogeneous UDP‐glucose in presence of UGT78K1 from Glycine max. To increase the intracellular UDP‐glucose concentration by channeling the carbon flux toward UDP‐glucose at the branch point of glucose‐6‐phosphate (G6P), the chromosomal glucose phosphate isomerase (pgi) and D‐glucose‐6‐phosphate dehydrogenase (zwf) were knocked‐out in E. coli BL21(DE3). The two enzymes directly involved in the synthesis of UDP‐glucose from G6P, phosphoglucomutase (nfa44530) from Nocardia farcinia and glucose‐1‐phosphate uridylyltransferase (galU) from E. coli K12 were overexpressed, which successfully diverted the carbon flow from glycolysis to the synthesis of UDP‐glucose. Furthermore, to prevent the dissociation of UDP‐glucose into UDP and glucose, the UDP‐glucose hydrolase (ushA) was deleted. The E. coli ΔpgiΔzwfΔushA mutant harboring the UDP‐glucose biosynthetic pathway and the aforementioned genes for the regiospecific glucosylation produced 109.3 mg/L (244 µM) of AST representing 48.8% conversion from 500 µM of NRN in 60 h without any supplementation of extracellular UDP‐glucose. Biotechnol. Bioeng. 2013; 110:2525–2535. © 2013 Wiley Periodicals, Inc.
Cell spreading and proliferation in response to the composition and mechanics of engineered fibrillar extracellular matrices
Authors: Chen Antony K. , Delrio Frank W. , Peterson Alexander W. , Chung Koo‐Hyun , Bhadiraju Kiran , Plant Anne L. 
Published: April 2013

ABSTRACTThe extracellular matrix (ECM) consists of a complex mixture of biochemical and physical stimuli that together regulate cell behavior. In this study, we engineer a model ECM consisting of fibrillar Type‐1 collagen plus fibronectin that allows systematic examination of the effects of matrix composition and mechanics on cells. On this combined protein matrix, cells exhibit intermediate degrees of spreading and proliferation compared to their responses on collagen or fibronectin alone. Adhesion to the combination matrix could be blocked by peptides containing the sequence arginine‐glycine‐aspartic acid (RGD) and by antibodies against α1 integrin, suggesting cell–matrix engagement was mediated by a combination of integrin receptors that recognize fibronectin and collagen. Regardless of integrin engagement, cells were sensitive to the mechanical properties of the combination ECM, suggesting that cells could process biochemical and mechanical cues simultaneously and independently. Biotechnol. Bioeng. 2013;110: 2731–2741. © 2013 Wiley Periodicals, Inc.
Butyrate production in engineered Escherichia coli with synthetic scaffolds
Authors: Baek Jang‐Mi , Mazumdar Suman , Lee Sang‐Woo , Jung Moo‐Young , Lim Jae‐Hyung , Seo Sang‐Woo , Jung Gyoo‐Yeol , Oh Min‐Kyu 
Published: April 2013

ABSTRACTButyrate pathway was constructed in recombinant Escherichia coli using the genes from Clostridium acetobutylicum and Treponema denticola. However, the pathway constructed from exogenous enzymes did not efficiently convert carbon flux to butyrate. Three steps of the productivity enhancement were attempted in this study. First, pathway engineering to delete metabolic pathways to by‐products successfully improved the butyrate production. Second, synthetic scaffold protein that spatially co‐localizes enzymes was introduced to improve the efficiency of the heterologous pathway enzymes, resulting in threefold improvement in butyrate production. Finally, further optimizations of inducer concentrations and pH adjustment were tried. The final titer of butyrate was 4.3 and 7.2 g/L under batch and fed‐batch cultivation, respectively. This study demonstrated the importance of synthetic scaffold protein as a useful tool for optimization of heterologous butyrate pathway in E. coli. Biotechnol. Bioeng. 2013;110: 2790–2794. © 2013 Wiley Periodicals, Inc.
Dithiazolo[5,4‐b:4′,5′‐d]phosphole: A Highly Luminescent Electron‐Accepting Building Block
Authors: He Xiaoming , Woo Alva Y. Y. , Borau‐Garcia Javier , Baumgartner Thomas 
Published: April 2013

AbstractA family of highly emissive dithiazolo[5,4‐b:4′,5′‐d]phospholes has been designed and synthesized. The structures of two trivalent P species, as well as their corresponding P oxides, have been confirmed by X‐ray crystallography. The parent dithiazolo[5,4‐b:4′,5′‐d]phosphole oxide exhibits strong blue photoluminescence at λem=442 nm, with an excellent quantum yield efficiency of ϕPL=0.81. The photophysical properties of these compounds can be easily tuned by extension of the conjugation and modification of the phosphorus center. Compared with the established dithieno[3,2‐b:2′,3′‐d]phosphole system, the incorporation of electronegative nitrogen atoms leads to significantly lowered frontier orbital energy levels, as validated by both electrochemistry and theoretical calculations, thus suggesting that the dithiazolo[5,4‐b:4′,5′‐d]phospholes are valuable, air‐stable, n‐type conjugated materials. These new building blocks have been further applied to the construction of an extended oligomer with fluorene. Extension of the dithiazolophosphole core with triazole units through click reactions also provides a suitable N,N‐chelating moiety for metal binding and a representative molecular species was successfully used as a selective colorimetric and fluorescent sensor for CuII ions.
Monoester Copillar[5]arenes: Synthesis, Unusual Self‐Inclusion Behavior, and Molecular Recognition
Authors: Chen Yu , Cao Derong , Wang Lingyun , He Minqing , Zhou Lixia , Schollmeyer Dieter , Meier Herbert 
Published: April 2013

AbstractThe self‐inclusion behavior of monoester copillar[5]arenes depends on the position of the ester group, which causes different guest selectivities. Monoester copillar[5]arenes bearing an acetate chain can form stable self‐inclusion complexes in low‐ and high‐concentration solution and exhibit high guest selectivity. However, a monoester copillar[5]arene bearing a butyrate chain can not form a self‐inclusion complex and exhibits low guest selectivity. Thus, a new class of stable self‐inclusion complexes of copillar[5]arenes was explored to improve the selectivity of molecular recognition.
Quantitative Stratification and the Regularity of Harmonic Maps and Minimal Currents
Authors: Cheeger Jeff , Naber Aaron 
Published: April 2013

AbstractWe provide techniques for turning estimates on the infinitesimal behavior of solutions to nonlinear equations (statements concerning tangent cones and their consequences) into more effective control. In the present paper, we focus on proving regularity theorems for minimizing harmonic maps and minimal currents. There are several aspects to our improvements of known estimates. First, we replace known estimates on the Hausdorff dimension of singular sets by estimates on the volumes of their r‐tubular neighborhoods. Second, we give improved regularity control with respect to the number of derivatives bounded and/or on the norm in which the derivatives are bounded. As an example of the former, our results for minimizing harmonic maps
$f: M^n \rightarrow N^m $
between Riemannian manifolds include a priori bounds in $ W^{1,p} \cap W^{2,{p}/{2}} $
for all p < 3. These are the first such bounds involving second derivatives in general dimensions. Finally, the quantity we control actually provides much stronger information than that which follows from a bound on the Lp norm of derivatives. Namely, we obtain Lp bounds for the reciprocal of the regularity scale
$r_f(x):= \max\{r: \sup_{B_r(x)}r|\nabla f|+r^2|\nabla^2 f|\leq 1\}$. Applications to minimal hypersufaces include a priori Lp bounds for the second fundamental form A for all p < 7. Previously known bounds were for $ p < 4+ \sqrt{{8}/{n}} $
in the smooth immersed stable case. Again, the full theorem is much stronger and yields Lp bounds for the reciprocal of the corresponding regularity scale $r_{|A|}(x):= \max\{r: \sup_{B_r(x)}r|A|\leq 1\}$. In outline, our discussion follows that of an earlier paper in which we proved analogous estimates in the context of noncollapsed Riemannian manifolds with a lower bound on Ricci curvature. These were applied to Einstein manifolds. A key role in each of these arguments is played by the relevant quantitative differentiation theorem. © 2013 Wiley Periodicals, Inc.
Homogenization and Enhancement of the G‐Equation in Random Environments
Authors: Cardaliaguet Pierre , Souganidis Panagiotis E. 
Published: April 2013

AbstractWe study the homogenization of a G‐equation that is advected by a divergence free “small mean” stationary vector field in a general ergodic random environment. We prove that the averaged equation is an anisotropic deterministic G‐equation, and we give necessary and sufficient conditions for enhancement. Since the problem is not assumed to be coercive, it is not possible to have uniform bounds for the solutions. In addition, as we show, the associated minimal (first passage) time function does not satisfy, in general, the uniform integrability condition that is necessary to apply the subadditive ergodic theorem. We overcome these obstacles by (i) establishing a new reachability (controllability) estimate for the minimal function and (ii) constructing, for each direction and almost surely, a random sequence that has both a long‐time averaged limit (due to the subadditive ergodic theorem) and stays asymptotically close to the minimal time. © 2013 Wiley Periodicals, Inc.
Plasma enhanced growth of GaN single crystalline layers from Ga vapour
Authors: Zwierz R. , Golka S. , Kachel K. , Siche D. , Fornari R. , Sennikov P. , Vodopyanov A. , Pipa A. V. 
Published: April 2013

AbstractWe present an alternative approach to grow thick GaN single crystalline layers from Ga vapour, transported by an N2 carrier gas flow, and from nitrogen, excited very near the substrate by 2.45 GHz microwaves at pressure in the 200–800 mbar range. Crystal growth requires high stability of process parameters, especially of plasma operation. A major challenge arose from temperature dependent changes in cavity resonance. Optical emission spectroscopy (OES) was used for plasma characterization while the grown layers were characterized by scanning electron microscopy (SEM) and X‐ray diffraction (XRD).
Changes in healthcare use across the transition from civilian to military life
Authors: McWhorter Stephanie K. , Stander Valerie A. , Thomsen Cynthia J. , Merrill Lex L. , Milner Joel S. 
Published: April 2013

SUMMARYPatterns of healthcare use in a sample of young adults entering the US Navy (N = 1137) were examined in a longitudinal survey study. Baseline data provided information about healthcare use as a civilian, whereas follow‐up data were used to examine changes in patterns of use over time following entry into the Military Health System (MHS). Entrance into the MHS was marked by increased use of preventive care. Although few systematic differences were noted with respect to socioeconomic status or race/ethnicity, women consistently used more healthcare than did men, and women's use increased more over time; however, this increase was largely driven by pregnancy during military service. Findings suggest that individuals with access to universal healthcare are likely to increase their overall use of services. However, these effects were quite small in absolute terms, and they were strongest for preventive care rather than more intensive and expensive services. Published 2013. This article is a US Government work and is in the public domain in the USA.
An Examination of the Impact of Minority Status Stress and Impostor Feelings on the Mental Health of Diverse Ethnic Minority College Students
Authors: Cokley Kevin , McClain Shannon , Enciso Alicia , Martinez Mercedes 
Published: April 2013

This study examined differences in minority status stress, impostor feelings, and mental health in a sample of 240 ethnic minority college students. African Americans reported higher minority status stress than Asian Americans and Latino/a Americans, whereas Asian Americans reported higher impostor feelings. Minority status stress and impostor feelings were examined as predictors of mental health. Impostor feelings were stronger predictors of mental health than minority status stress. Counseling implications for ethnic minority students are discussed.Este estudio examinó las diferencias en estrés por estatus de minoría, sentimientos de impostor, y salud mental en una muestra de 240 estudiantes universitarios pertenecientes a minorías étnicas. Los afroamericanos comunicaroun un estrés por estatus de minoría más alto que los asiático‐americanos y los latinoamericanos, mientras que los asiático‐americanos comunicaron sentimientos de impostor más elevados. Se examinaron el estrés por estatus de minoría y los sentimientos de impostor como predictores de salud mental. Los sentimientos de impostor fueron predictores más fuertes de salud mental que el estrés por estatus de minoría. Se discuten las implicaciones en consejería para estudiantes de minorías étnicas.