bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oral Health of Early Head Start Children: A Qualitative Study of Staff, Parents, and Pregnant Women
Authors: Mofidi Mahyar , Zeldin Leslie P. , Rozier R. Gary 
Published: December 2008

Objectives.We explored the oral health knowledge, attitudes, and activities of Early Head Start (EHS) staff members, parents, and pregnant women, along with their suggestions related to future oral health educational interventions targeting EHS children. Methods. Nine focus groups were conducted with EHS staff, parents, and pregnant women. Audiotapes of sessions were transcribed and entered into ATLAS.ti 5.0 for coding and analysis. Results. Attitudes about the importance of children's oral health among parents and pregnant women were mixed. Staff members voiced responsibility for children's oral health but frustration in their inability to communicate effectively with parents. Parents in turn perceived staff criticism regarding how they cared for their children's oral health. Gaps were noted in the oral health activities of EHS programs. Participants expressed confusion regarding the application of Head Start oral health performance standards to EHS. The need for culturally sensitive, hands-on oral health education was highlighted. Conclusions. Tailored, theory-based interventions are needed to improve communication between EHS staff and families. Clear policies on the application of Head Start oral health performance standards to EHS are warranted. Educational activities should address the needs and suggestions of EHS participants.
Using Community Arts Events to Enhance Collective Efficacy and Community Engagement toAddress Depression in an African American Community
Authors: Chung Bowen , Jones Loretta , Jones Andrea , Corbett Charles E. , Booker Theodore , Wells Kenneth B. , Collins Barry 
Published: December 2008

Objectives. We used community-partnered participatory research (CPPR) to measure collective efficacy and its role as a precursor of community engagement to improve depression care in the African American community of South Los Angeles. Methods. We collected survey data from participants at arts events sponsored by a CPPR workgroup. Both exploratory (photography exhibit; n = 747) and confirmatory (spoken word presentations; n = 104) structural equation models were developed to examine how knowledge and attitudes toward depression influenced community engagement. Results. In all models, collective efficacy to improve depression care independently predicted community engagement in terms of addressing depression (B = 0.64–0.97; P < .001). Social stigma was not significantly associated with collective efficacy or community engagement. In confirmatory analyses, exposure to spoken word presentations and previous exposure to CPPR initiatives increased perceived collective efficacy to improve depression care (B = 0.19–0.24; P < .05). Conclusions. Enhancing collective efficacy to improve depression care may be a key component of increasing community engagement to address depression. CPPR events may also increase collective efficacy. Both collective efficacy and community engagement are relevant constructs in the South Los Angeles African American community.
Violence During Pregnancy Among Women With or at Risk for HIV Infection
Authors: Koenig Linda J. , Whitaker Daniel J. , Royce Rachel A. , Wilson Tracey E. , Callahan Michelle R. , Fernandez M. Isabel 
Published: December 2008

Objectives. This study estimated the prevalence of violence during pregnancy in relation to HIV infection. Methods. Violence, current partnerships, and HIV risk behaviors were assessed among 336 HIV-seropositive and 298 HIV-seronegative at-risk pregnant women. Results. Overall, 8.9% of women experienced recent violence; 21.5% currently had abusive partners. Violence was experienced by women in all partnership categories (range = 3.8% with nonabusive partners to 53.6% with physically abusive partners). Neither experiencing violence nor having an abusive partner differed by serostatus. Receiving an HIV diagnosis prenatally did not increase risk. Disclosure-related violence occurred, but was rare. Conclusions. Many HIV-infected pregnant women experience violence, but it is not typically attributable to their serostatus. Prenatal services should incorporate screening and counseling for all women at risk for violence. (Am J Public Health. 2002;92:367–370)
Chronic Illness Among Poor Children Enrolled in the Temporary Assistance for Needy Families Program
Authors: Wise Paul H. , Wampler Nina S. , Chavkin Wendy , Romero Diana 
Published: December 2008

Objectives. This study assessed chronic child illness among recipients of Temporary Assistance for Needy Families (TANF) benefits and poor families not receiving benefits. Methods. Data from the 1998 National Health Interview Survey were used to examine chronic child illness, enrollment in TANF, health insurance status, and selected access indicators. Results. One quarter of TANF-enrolled children had chronic illnesses. Unenrolled children were 3 times as likely as TANF-enrolled children to be uninsured. Among the chronically ill, 31.7% of unenrolled and 14.3% of enrolled children experienced gaps in insurance coverage that were associated with access barriers. Conclusions. Welfare policies should consider the effects of chronic illness and gaps in insurance coverage on the health of poor children.
Synthesis and characterization of monomer‐casting polyamide 6/polymethacrylic ionomer blends
Authors: Wu Tongfei , Yang Guisheng 
Published: December 2008

AbstractMonomer‐casting polyamide 6 (MCPA6)/polymethacrylic ionomer blends were synthesized by the in situ anionic ring‐opening polymerization of ϵ‐caprolactam. The polymethacrylic ionomer used in this study was a copolymer of methyl methacrylate and sodium or zinc methacrylate. Because the polymethacrylic ionomer strongly interacted with polyamide 6 (PA6) chains, it influenced the alignment of the polyamide chains. The change in the degree of the order of hydrogen bonding in MCPA6 caused by the addition of the polymethacrylic ionomer was studied with Fourier transform infrared. The change in the interaction between PA6 chains was studied with rheological measurements. The influence of the polymethacrylic ionomer on the crystallization behavior of MCPA6 was also studied with differential scanning calorimetry. The isothermal crystallization and subsequent melting behavior were investigated at the designated temperature. The commonly used Avrami equation was used to fit the primary stage of the isothermal crystallization. The Avrami exponent (n) values were evaluated to be 2 < n < 3 for the neat MCPA6 and MCPA6/polymethacrylic ionomer blends. The polymethacrylic ionomer, acting as a stumbling‐block agent in the blends, decelerated the crystallization rate with the half‐time of crystallization increasing. The polymethacrylic ionomer made the molecular chains of MCPA6 more difficult to crystallize during the isothermal crystallization process. More less perfect crystals formed in the MCPA6/polymethacrylic ionomer blends because of the interaction between the MCPA6 molecular chains and polymethacrylic ionomer. The crystallinity of the blends was depressed by the addition of the polymethacrylic ionomer. The thermal stability was also studied with thermogravimetric analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Behavior of sulfonated poly(ether ether ketone) in ethanol–water systems
Authors: Roelofs Kimball S. , Kampa Andreas , Hirth Thomas , Schiestel Thomas 
Published: December 2008

AbstractThe behavior of sulfonated poly(ether ether ketone) (sPEEK) membranes in ethanol–water systems was studied for possible application in direct ethanol fuel cells (DEFCs). Polymer membranes with different degrees of sulfonation were tested by means of uptake, swelling, and ethanol transport with dynamic measurements (liquid–liquid and liquid–gas systems). Ethanol permeability was determined in an liquid–liquid diffusion cell. For membranes with an ion‐exchange capacity (IEC) between 1.15 and 1.75 mmol/g, the ethanol permeability varied between 5 × 10−8 and 1 × 10−6 cm2/s, being dependent on the measuring temperature. Ethanol and water transport in liquid–gas systems was tested with pervaporation as a function of IEC and temperature. Higher IEC accounted for higher fluxes and lower water/ethanol selectivity. The temperature had a large effect on the fluxes, but the selectivity remained constant. Furthermore, the membranes were characterized with proton conductivity measurements. The proton diffusion coefficient was calculated, and a transition in the proton transfer mechanism was found at a water number of 12. Membranes with high IEC (>1.6 mmol/g) exhibited larger proton diffusion coefficients in ethanol–water systems than in water systems. The membrane with the lowest IEC exhibited the best proton transport to ethanol permeability selectivity. The use of sPEEK membranes in DEFC systems depends on possible modifications to stabilize the membranes in the higher conductive region rather than on modifications to increase the proton conductivity in the stable region. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Dynamic Gravimetry in Studying The Adsorption of Proteins Onto Metal Surfaces: Analysis and Limitations
Authors: Sandu Constantine , Lund Daryl , Almas Karl , Walling David 
Published: December 2008

AbstractThe paper describes the physical and mathematical fundamentals of dynamic gravimetry in liquid phase. First, a relation is developed to calculate the apparent weight of a vertical thin cylinder partially immersed Into a liquid. It emphasizes the magnitude of buoyancy forces and surface‐tension forces (which act upon fine threads used to suspend a solid object completely immersed into a liquid). Next, the basic relation of dynamic gravimetry is derived to estimate the absolute mass of adsorbed material onto the surface of a submerged solid object. This relation encompasses, apart from the term related to the measured output signal of the balance, three correction terms which originate from the surface tension effects, buoyancy effect of the submerged object, and buoyancy effect due to the adsorbed material.The following sections address adsorption at the air‐liquid interface as well as the molecular diffusion process (both being intermingled with concentration and density gradients in the system). Special attention is given to the errors connected with a series of relaxation processes in which the external menisci, the plate‐beam system, and the surface tension are involved once their equilibrium conditions are disturbed. The time constants of these relaxation processes can not be exactly predicted. The paper concludes with an experimental illustration of dynamic gravimetry, with the adsorption of β‐lactoglobulin onto stainless steel plates. The validity of predictions based upon the physico‐mathematical fundamentals is reconciled with the analytical and technical aspects and difficulties specific to dynamic gravimetry.
Modeling and Measurement of Yeast Flocculation
Authors: Davis Robert H. , Hunt Thomas P. 
Published: December 2008

AbstractA sedimentation/light extinction technique has been developed to quantitatively measure the state of flocculation of a suspension of yeast cells. This experimental method is based upon sedimentation theory with a modified light extinction theory that accounts for the dependence of the extinction coefficient on the floc size distribution, and the loosely‐branched fractal structure of yeast aggregates. As demonstrated by comparisons with direct microscopic observations, this technique is capable of accurately determining the steady‐state of floc sizes as well as floc settling velocities of a variety of yeast cultures.
An Engineering Analysis of the Production of Xylose by Dilute Acid Hydrolysis of Hardwood Hemicellulose
Authors: Maloney Mark T. , Chapman Thomas W. , Baker Andrew J. 
Published: December 2008

AbstractNumerical simulations of various reactors for the production of xylose from hardwood hemicellulose by dilute sulfuric acid hydrolysis have been developed to analyze the effects on reactor performance of heat and mass transfer as well as reaction kinetics. An economic objective function representing the incremental cost of producing a 10% xylose solution for fermentation to ethanol was calculated from the results of the reactor simulations to identify the operating conditions that minimize production costs for each reactor type. Lower production costs were estimated for percolation and continuous counter‐current reactors; the cost for xylose production in a continuous co‐current reactor is significantly higher. Production of ethanol from hardwood hemicellulose is not economical with any of the reactors considered, but the models developed here may be used to analyze other process alternatives for use of hemicellulose via production of xylose.
Deposition of Dairy Protein‐Containing Fluids on Heat Exchange Surfaces
Authors: Rakes P. A. , Swartzel K. R. , Jones V. A. 
Published: December 2008

AbstractThe deposition behavior of milk and dairy protein model systems under turbulent flow conditions (Re > 66,700) was observed in the heating sections of a tubular ultra‐high temperature processing unit. This phenomenon was monitored via thermal resistance of the deposit in four segments in each of two shell‐and‐tube heat exchangers. Model systems were comprised of mixtures of sodium caseinate, whey proteins, salts, lactose, and fat. Fouling rates varied with type of milk protein, heater wall temperature, and location in the heat exchangers. The relationship between deposition rate in the heat exchanger and protein denaturation kinetics was also examined.
Secretion of Heterologous Proteins from Saccharomyces Cerevisiae
Authors: Das Rathin C. , Shultz Janice L. 
Published: December 2008

AbstractIn recent years considerable progress has been achieved on the heterologous gene expression and protein secretion in the yeast Saccharomyces cerevisiae. The variety of natural yeast secretory signal sequences being utilized for heterologous protein secretion are reviewed. The usefulness of the yeast pheromone, α‐factor leader sequence on the secretion of foreign proteins is emphasized.
Intercompartmental Fluid Shifts in Hemodialysis Patients
Authors: Heineken F. G. , Evans M. C. , Keen M. L. , Gotch F. A. 
Published: December 2008

AbstractHemodialysis is a therapeutic procedure for replacing some functions of the natural kidney. As such, it is capable of allowing people with little or no residual kidney function to survive and in some cases to lead productive lives. There are, unfortunately, a number of side effects associated with this procedure (shock, muscle cramps, fatigue, etc.). In order to minimize these side effects, we have undertaken to model shifts of fluid between the intracellular and extracellular fluid spaces in hemodialysis patients. Fluid shifts are primarily a function of osmolality differences between these fluid spaces. Changes in osmolality are caused mainly by changes in urea and salt concentrations. Least squares analysis of patient data has been used to estimate the appropriate ultrafiltration and urea mass transfer coefficients for each patient. The model has then been used to find a dialysate sodium concentration profile that will minimize fluid shifts into and out of the intracellular fluid space.
Enhanced Nutrient Transport in Hollow Fiber Perfusion Bioreactors: A Theoretical Analysis
Authors: Schonberg Jeffrey A. , Belfort Georges 
Published: December 2008

AbstractEntrapped cells (or enzyme) in hollow fiber perfusion reactors is an attractive method for producing concentrated biologicals. Inherent in densely packed‐cell masses are possible mass transfer limitations due to rate limiting transport processes resulting in loss of cell viability. To overcome this limitation, convective fluxes superimposed on diffusion have recently been proposed for entrapped animal cell perfusion bioreactors. We assessed whether radial fluid convection would enhance performance. In an asymptotic analysis using singular perturbation, we show that for large axial Peclet number, Pe−1/3 «« 1, it is permissible to ignore the mass transfer resistance in the lumen. Data from the literature appear to support this assumption. Radial convection of the feed in a shell and tube hollow fiber perfusion reactor is shown to be useful in increasing catalyst efficiency and production rates per unit volume. A series solution to the governing equation is presented assuming Darcy flow, first order kinetics, steady state transport, and irreversible reaction. The effect of convection is studied for many Thiele moduli, for each of two cases; catalyst activity being spatially uniform in one case and distributed in the second. Performance is essentially the same in each case.
Acid Fermentation in Water‐Organic Solvent Two‐Liquid Phase Systems
Authors: Bar Raphael , Gainer John L. 
Published: December 2008

AbstractIn search of an optimal system for extractive fermentation of an organic acid, fermentations of lactic, citric, and acetic acids were studied in a broth saturated with an organic solvent and in a broth‐organic solvent two‐liquid phase system. Among the 13 solvents tested, only long‐chain hydrocarbons, perfluorodecalin, and methyl oleate were found to be nontoxic to the cells of L. delbrueckii in two‐liquid phase systems. However, a distinction was made between toxicity due to dissolved solvent molecules and that due to a separate solvent phase. Thus, cells of L. delbrueckii, which were not inhibited in n‐dodecanol‐saturated broth, but inhibited in a two‐phase system, were successfully protected by immobilization in carrageenan beads. The same solvent however, partially inhibited the growth of A. niger and A. aceti when present at saturated levels in the broth. The effect of tridodecylamine on lactic acid fermentation in a two‐liquid phase system was investigated in view of enhancing the acid extraction. Since extraction of an acid is favored by low pH, an extractive fermentation of an acid is practical for microorganisms that can grow at pH < pKa, such as A. aceti and A. niger. The amine was found to be toxic to L. delbrueckii above a concentration of 222 mM, and at a level of 50%v, it was deleterious to all cell microorganisms tested, either free or gel entrapped.
A Comparative Study of Models to Predict Protein Adsorption
Authors: Graham E. Earl , Pucciani Albert , Pinto Neville G. 
Published: December 2008

AbstractTwo different models for preducing the adsorption of protein on packed beds of resins are examined. The models are compared by predicting the experimental breakthrough curve of Bovine Serum Albumin on two different resins at different flow rates. The first model fits the experimental breakthrough curves better, but the second one fits them reasonably well and requires no separate measurements of an effective particle diffusivity.
Correlation of Aqueous Two‐Phase Partitioning of Proteins with Changes in Free Volume
Authors: Grossman Paul D. , Gainer John L. 
Published: December 2008

AbstractPhase separation and protein partitioning in polymer‐salt aqueous two‐phase systems have been correlated with changes in free volume. Both solute partitioning and phase stability are proposed to be related to those changes in liquid structure that can be described by measurements of the free volume of the mixture upon phase splitting.
Average Convective Heat Transfer Coefficients in Single Screw Extrusion of Non‐Newtonian Food Materials
Authors: Mohamed I. O. , Morgan R. G. , Ofoli R. Y. 
Published: December 2008

AbstractThis study deals with solving the Graetz‐Nusselt problem for single‐screw extrusion of power law fluids with viscous dissipation along the channel. The momentum and energy equations were solved numerically for the temperature and velocity profiles, which were then used for determining the Nusselt number. Results are presented in terms of the Nusselt, Brinkman, and reciprocal Graetz numbers.The results indicate that the Nusselt number is relatively unaffected by the Brinkman number, for both heating and cooling. However, the Brinkman number significantly affects the bulk temperature. For Brinkman numbers less than ‐40, the rate of viscous heat generation is greater than the convective cooling capacity of the extruder. Increasing the screw compression ratio produced significant increase in bulk temperature and Nusselt number for the case of heating. The Nusselt number is less sensitive to the flow behavior index for the case of cooling, while somewhat sensitive for the case of heating. Data from the literature were compared to results from this analysis.
Application of Gibbs' Rule and a Simple Pathway Method to Microbial Stoichiometry
Authors: Tsai S. P. , Lee Y. H. 
Published: December 2008

AbstractThe power of metabolic pathway stoichiometry for applications in bioreactor monitoring and control, in terms of the degrees of freedom, the calculation of reaction rates, and the validity of pathway models, is analyzed by using Gibbs' rule of stoichiometry. The pathway stoichiometry has significant advantages over the macroscopic balance methods when the number of independent reactions is not at its maximum. When the number of reactions is at the maximum, the power of the pathway stoichiometry is very much limited, and it should be used with caution. A simple method is also proposed to derive all possible independent stoichiometric constraints from the metabolic pathways. For most practical fermentations, the proposed method is much easier to use than the existing methods in the literature.
Recovery of an Extracellular Alkaline Protease From Whole Fermentation Broth Using Reversed Micelles
Authors: Rahaman R. S. , Chee J. Y. , Cabral J. M. S. , Hatton T. A. 
Published: December 2008

AbstractThe liquid‐liquid extraction of an extracellular alkaline protease from its fermentation broth was carried out, using a reversed micellar organic solvent. Optimum process parameters were determined for extraction using a 250 mM AOT in isooctane micellar solution. With unequal phase volume ratios, purification factors as high as 6 have been obtained from completely untreated broth. Yields up to 56% were achieved from the same broth using a three‐stage cascade.
The Influence of Shear Stress on Cultured Vascular Endothelial Cells: The Stress Response of an Anchorage‐Dependent Mammalian Cell
Authors: Levesque M. J. , Sprague E. A. , Schwartz C. J. , Nerem R. M. 
Published: December 2008

AbstractThe influence of hydrodynamic forces on anchorage‐dependent mammalian cells is of interest both in biomedical research and in the development of scaled‐up mammalian cell bioreactor systems. Our own studies, reviewed here, have demonstrated that, in response to a fluid‐imposed laminar shear stress, cultured vascular endothelial cells undergo a dramatic alteration in structure and function. From these and related studies, it may be possible to obtain some insight into the general response of anchorage‐dependent mammalian cells to hydrodynamic forces. An unanswered question is: how does such a cell recognize and then transduce a fluid mechanic signal?