RESUMO
In most of the medical therapies, electromagnetic field plays important role to modulate the blood flow and to reduce the pain of human body. With this fact, this paper presents a mathematical model to study the peristaltic blood flow through porous microvessels in the presence of electrohydrodynamics. The effects of Joule heating and different zeta potential are also considered. Darcy law is employed for porous medium. The mathematical analysis is carried out in the form of electroosmosis, flow analysis and heat transfer analysis. Velocity slip conditions are imposed to solve momentum equation and thermal energy equation. Time dependent volumetric flow rate is considered which varies exponentially. Closed form solutions for potential function is obtained under Debye-Hückel approximation and velocity and temperature fields are obtained under low Reynolds number and large wavelength approximations. The influence of Hartmann number, electroosmotic parameter, slip parameters, Zeta potential, and couple stress parameter on flow characteristics, pumping characteristics and trapping phenomenon is computed. The effects of thermal slip parameters, Joule heating parameter, and Brinkman number on heat transfer characteristics are also presented graphically. Finally, the effect of Brinkman number on a graph between Nusselt number and Joule heating parameter is examined.
Assuntos
Simulação por Computador , Campos Eletromagnéticos , Microcirculação , Microvasos/fisiologia , Modelos Cardiovasculares , Fluxo Pulsátil , Velocidade do Fluxo Sanguíneo , Eletro-Osmose , Transferência de Energia , Temperatura Alta , Humanos , Hidrodinâmica , Porosidade , Fluxo Sanguíneo RegionalRESUMO
BACKGROUND: Coordinated, multi-component school-based interventions can improve health behaviors in children, as well as parents, and impact the weight status of students. By leveraging a unique collaboration between Texas AgriLife Extension (a federal, state and county funded educational outreach organization) and the University of Texas School of Public Health, the Texas Grow! Eat! Go! Study (TGEG) modeled the effectiveness of utilizing existing programs and volunteer infrastructure to disseminate an enhanced Coordinated School Health program. The five-year TGEG study was developed to assess the independent and combined impact of gardening, nutrition and physical activity intervention(s) on the prevalence of healthy eating, physical activity and weight status among low-income elementary students. The purpose of this paper is to report on study design, baseline characteristics, intervention approaches, data collection and baseline data. METHODS: The study design for the TGEG study consisted of a factorial group randomized controlled trial (RCT) in which 28 schools were randomly assigned to one of 4 treatment groups: (1) Coordinated Approach to Child Health (CATCH) only (Comparison), (2) CATCH plus school garden intervention [Learn, Grow, Eat & Go! (LGEG)], (3) CATCH plus physical activity intervention [Walk Across Texas (WAT)], and (4) CATCH plus LGEG plus WAT (Combined). The outcome variables include student's weight status, vegetable and sugar sweetened beverage consumption, physical activity, and sedentary behavior. Parents were assessed for home environmental variables including availability of certain foods, social support of student health behaviors, parent engagement and behavior modeling. RESULTS: Descriptive data are presented for students (n = 1369) and parents (n = 1206) at baseline. The sample consisted primarily of Hispanic and African American (53 % and 18 %, respectively) and low-income (i.e., 78 % eligible for Free and Reduced Price School Meals program and 43 % food insecure) students. On average, students did not meet national guidelines for vegetable consumption or physical activity. At baseline, no statistical differences for demographic or key outcome variables among the 4 treatment groups were observed. CONCLUSIONS: The TGEG study targets a population of students and parents at high risk of obesity and related chronic conditions, utilizing a novel and collaborative approach to program formulation and delivery, and a rigorous, randomized study design.
Assuntos
Jardinagem/métodos , Promoção da Saúde/métodos , Pobreza/psicologia , Serviços de Saúde Escolar , Estudantes/psicologia , Peso Corporal , Criança , Análise por Conglomerados , Etnicidade , Exercício Físico/psicologia , Feminino , Jardins , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Instituições Acadêmicas , Texas , VerdurasRESUMO
Alpha-carboxy-4-nitrobenzyl phosphate 4 and its derived monomethyl phosphate ester 5 were synthesized and purified by anion-exchange chromatography. A gradient of LiCl was necessary for elution of the anion-exchange column to avoid unexpected thermal decarboxylation that occurred during vacuum evaporation when the volatile triethylammonium bicarbonate buffer was used. Photolysis of each compound was accompanied by decarboxylation, and 4 released inorganic phosphate with near-100% stoichiometry. Time-resolved infrared spectroscopy of the photolysis reaction, coupled with density functional theory calculations of vibrational frequencies, enabled us to infer a mechanism for the photolytic pathway, although there was some evidence for a second pathway also being operative. In contrast to the results for 4, photolysis of 5 appeared to release little or no monomethyl phosphate.
Assuntos
Ácidos Carboxílicos/química , Fenilacetatos/química , Cromatografia por Troca Iônica , Temperatura Alta , FotoquímicaRESUMO
BACKGROUND: The purpose of this study was to expand the School Physical Activity and Nutrition questionnaire to include a greater variety of vegetables and to evaluate the relative validity and reliability of these revised items. OBJECTIVES: This study utilized 2 convenience samples of third to fifth graders for an analysis: validity (n = 70) and reliability (n = 76). Validity was assessed by comparing questionnaire items with vegetable intake reported from a 24-hour dietary recall covering the same reference period. Reliability estimates were assessed via same-day test-retest. RESULTS: Agreement correlations ranged from 0.35 to 0.71. Kappa statistics varied from 0.16 to 0.66. Percentage agreements ranged from 57% to 87%. Test-retest Spearman coefficients were greater than 0.50 for 6 items, weighted Kappa values were greater than 0.40 for all 7 items, and percentage agreement exceeded 75% for 5 items. CONCLUSIONS: Results suggest that the questionnaire is a valid and reliable measure of the previous day's vegetable intake in third- to fifth-grade students. This trial was registered at ClinicalTrials.gov as NCT02668744.
RESUMO
Very few studies have examined if high birth weight and infant feeding practices have implications for the trajectory of body mass index (BMI) growth across the early childhood period. The goal of this study was to assess if large-for-gestational-age (LGA) and infant feeding practices (exclusive breastfeeding for 6 months, and early introduction of complementary food prior to 4 months) are associated with BMI z-score trajectories over the early childhood period. Group-based trajectory modelling (GBTM) methods were employed to describe and classify developmental BMI z-score trajectories (the outcome of interest) in children from 9 months to 4 years of age (n = 4497) born to prenatal non-smoking mothers in the Early Childhood Longitudinal Study, Birth Cohort (2001-2005). Further analyses examined if the identified BMI z-score trajectories varied systematically with the exposures, LGA and specific infant feeding practices, after accounting for sociodemographic and other early-life factors. Two BMI z-score trajectory groups were identified: normal BMI z-score (56.2%) and high BMI z-score (43.8%). Children who were LGA infants had 2.3 times (risk ratio 95% confidence interval: 1.2, 4.5) greater risk of being in high BMI z-score group relative to normal BMI z-score group. BMI z-score trajectory groups did not differ by infant feeding practices, after controlling for LGA at birth. Membership in the high BMI z-score group was associated with LGA, but not with infant feeding practices. Healthcare professionals should provide early obesity counselling to parents of LGA infants so that parents can take appropriate obesity prevention measures for their children.
Assuntos
Peso ao Nascer , Índice de Massa Corporal , Obesidade/fisiopatologia , Pré-Escolar , Estudos de Coortes , Comportamento Alimentar , Feminino , Idade Gestacional , Humanos , Lactente , Estudos Longitudinais , Masculino , Obesidade/embriologia , GravidezRESUMO
The gastrointestinal tracts of multi-cellular blood-feeding parasites are targets for vaccines and drugs. Recently, recombinant vaccines that interrupt the digestion of blood in the hookworm gut have shown efficacy, so we explored the intestinal transcriptomes of the human and canine hookworms, Necator americanus and Ancylostoma caninum, respectively. We used Laser Microdissection Microscopy to dissect gut tissue from the parasites, extracted the RNA and generated cDNA libraries. A total of 480 expressed sequence tags were sequenced from each library and assembled into contigs, accounting for 268 N. americanus genes and 276 A. caninum genes. Only 17% of N. americanus and 36% of A. caninum contigs were assigned Gene Ontology classifications. Twenty-six (9.8%) N. americanus and 18 (6.5%) A. caninum contigs did not have homologues in any databases including dbEST-of these novel clones, seven N. americanus and three A. caninum contigs had Open Reading Frames with predicted secretory signal peptides. The most abundant transcripts corresponded to mRNAs encoding cholesterol-and fatty acid-binding proteins, C-type lectins, Activation-Associated Secretory Proteins, and proteases of different mechanistic classes, particularly astacin-like metallopeptidases. Expressed sequence tags corresponding to known and potential recombinant vaccines were identified and these included homologues of proteases, anti-clotting factors, defensins and integral membrane proteins involved in cell adhesion.
Assuntos
Ancylostoma/genética , Genes de Helmintos , Mucosa Intestinal/metabolismo , Necator americanus/genética , Sequência de Aminoácidos , Ancylostoma/anatomia & histologia , Ancylostoma/imunologia , Ancylostoma/metabolismo , Animais , Antígenos de Helmintos/imunologia , DNA Complementar/genética , DNA de Helmintos/genética , Ingestão de Alimentos/genética , Etiquetas de Sequências Expressas , Biblioteca Gênica , Humanos , Microdissecção , Microscopia Confocal , Dados de Sequência Molecular , Necator americanus/anatomia & histologia , Necator americanus/imunologia , Necator americanus/metabolismo , Fases de Leitura Aberta , RNA de Helmintos/genética , RNA Mensageiro/genética , Alinhamento de SequênciaRESUMO
The objective of this study was to evaluate the effects of adding 9,10 anthraquinone, a known inhibitor of methanogenesis and sulfate reduction, on blood metabolites, digestibility, and distribution of gas in sheep. In all experiments, we fed a complete pelleted diet that contained 17.5% crude protein and 24.5% acid detergent fiber. In an 8-wk study, feeding up to 66 ppm (dry matter basis) of 9,10 anthraquinone had no adverse effects on blood metabolites including indicators of normal enzyme function, mineral concentrations, and hematological measurements. Feeding 9,10 anthraquinone had no effect on average daily gain, although sheep fed a diet containing 66 ppm of 9,10 anthraquinone numerically gained the least weight. The ruminal molar proportions of acetic acid were decreased (P < 0.05) and the molar proportions of propionic acid were increased (P < 0.05) in sheep fed 1.5 and 66 ppm 9,10 anthraquinone when compared to those fed an unsupplemented diet. In a digestion trial, 9,10 anthraquinone (33 and 66 ppm) had no effect on the apparent digestion of nutrients in the total gastrointestinal tract. In a metabolism study, ruminal gasses were collected by rumenocentesis and analyzed for methane and hydrogen concentrations. Feeding 500 ppm of 9,10 anthraquinone to sheep resulted in a decrease (P < 0.07) in the concentration of methane, but an increase (P < 0.05) in hydrogen concentration of ruminal gas throughout the 19 d of feeding. There was no indication of ruminal adaptation throughout this time. These results are the first to show that 9,10 anthraquinone can partially inhibit in vivo rumen methanogenesis, which supports previous in vitro findings. In addition, at the concentrations used in this study, 9,10 anthraquinone was not toxic to ruminants.
Assuntos
Antraquinonas/farmacologia , Digestão , Metano/antagonistas & inibidores , Rúmen/metabolismo , Ovinos/metabolismo , Animais , Digestão/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fermentação/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Masculino , Distribuição Aleatória , Rúmen/química , Rúmen/microbiologia , Ovinos/sangue , Aumento de PesoRESUMO
Racial disparities in pregnancy outcome in the United States are significant, persistent and costly, but the causes are poorly understood. We propose that disproportionate exposure of African-American women to environmental endocrine disrupting compounds (EDCs) may contribute to birth outcome disparities. Marked racial segregation, as well as health behaviors associated with poverty could result in differences in exposure to particular EDCs. One EDC that has aroused concern in recent years is bisphenol-A (BPA), a widely used industrial plasticizer with known estrogenic properties. Published studies indicate that excessive BPA exposure is associated with reduced fetal survival, as well as reductions in maternal weight and fetal body weight. Related findings include adverse effects of BPA exposure on ovarian function, mammary gland development, earlier age of puberty onset and some metabolic parameters. However, these findings are largely limited to experimental animal studies, and need to be validated in human populations. Our review supports the need to move beyond the currently dominant toxicological approach to examining the effects of BPA exposure, and rely more on observational human studies and epidemiological methods. Many of the risk factors for racial disparities in pregnancy outcome are global or difficult to modify, but exposure to BPA is a potentially malleable risk factor. If BPA contributes to racial disparities in pregnancy outcome, there are important implications for prevention. It is our hope that this review will stimulate further research in this important and neglected area.
Assuntos
Negro ou Afro-Americano , Exposição Ambiental/efeitos adversos , Disparidades nos Níveis de Saúde , Fenóis/efeitos adversos , Complicações na Gravidez/induzido quimicamente , Complicações na Gravidez/etnologia , Compostos Benzidrílicos , Disruptores Endócrinos/efeitos adversos , Feminino , Humanos , Gravidez , Resultado da Gravidez , Efeitos Tardios da Exposição Pré-NatalRESUMO
Photolysis of alpha-carboxy-2-nitrobenzyl (CNB) caged compounds, studied here by time-resolved IR and UV spectroscopy, involves at least two pathways. In one, a conventional 2-nitrobenzyl type rearrangement takes place to release the photoprotected species via rapid decay of an aci-nitro intermediate. The alpha-carboxylate moiety of the CNB group is retained and the final by-product from this pathway is 2-nitrosophenylglyoxylate. Direct measurements of product formation confirmed that release via this pathway is faster for CNB-caged compounds than for related caged compounds without an alpha-carboxylate substituent and a rationale for the faster release rate is proposed. In a second pathway, photodecarboxylation of the starting material occurs: this pathway leads only to a slow, minor release of the photoprotected species. The extent to which the latter pathway contributes is affected by the nature of buffer salts in the irradiated solution. It was more prominent in an amine-based buffer (MOPS) than in phosphate buffer.
Assuntos
Ácidos Carboxílicos/química , Nitrobenzenos/química , Fotólise , Dióxido de Carbono/química , Descarboxilação , Concentração de Íons de Hidrogênio , Cinética , Estrutura Molecular , EspectrofotometriaRESUMO
Two fluorescent conjugates of sialic acid have been prepared, with a convenient synthetic route that involves preparation of an unsaturated benzyl ester by cross-metathesis, followed by combined hydrogenation/ hydrogenolysis to provide a sialoside bearing a delta-carboxybutyl group, suitable for coupling with the chosen fluorophores. The fluorescent conjugates bound to bromelain-cleaved hemagglutinin (BHA) with affinities in the low microM range. Binding was accompanied by approximately 4.5-fold fluorescence enhancement for the dansyl conjugate 1 and approximately 3-fold fluorescence quenching for the pyrene conjugate 3.
Assuntos
Corantes Fluorescentes/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/análise , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Vírus da Influenza A/química , Ligantes , Estrutura MolecularRESUMO
Whole-plant barley (39.4% dry matter) was treated with various chemical and biological additives to assess their effects on silage fermentation and aerobic stability. Treatments were untreated forage, forage treated with several amounts of Lactobacillus buchneri and enzymes (L. buchneri at 1 x 10(5), 5 x 10(5), and 1 x 10(6) cfu/g of fresh forage), forage treated with an inoculant containing (Lactobacillus plantarum, Pediococcus pentosaceus, Propionibacterium freudenreichii, and enzymes), or forage treated with a buffered propionic acid-based additive (0.2% of fresh weight). Sixty-nine d after ensiling, silages treated with L. buchneri and enzymes had lower pH, but had higher concentrations of acetic and propionic acids and higher concentrations of ethanol when compared with untreated silage. Silage treated with the multistrain inoculant containing L. plantarum had lower pH and higher concentrations of lactic acid, but lower concentrations of ammonia-N, neutral detergent fiber, and acid detergent fiber than did untreated silage. The addition of the buffered propionic acid additive resulted in silage with higher concentrations of lactic and acetic acid compared with untreated silage. Numbers of yeasts in all silages were low at silo opening (less than 3.0 log cfu/g) and were numerically the lowest in silages treated with L. buchneri but only treatment with the intermediate and high level of L. buchneri improved the aerobic stability of silage. Because of the altered fermentation pattern, inoculation with L. buchneri, when applied at equal to or more than 5 x 10(5) cfu/g, and enzymes improved the aerobic stability of barley silage.
Assuntos
Aerobiose , Lactobacillus/metabolismo , Silagem/análise , Ácido Acético/análise , Contagem de Colônia Microbiana , Fermentação , Conservação de Alimentos/métodos , Hordeum , Concentração de Íons de Hidrogênio , Ácido Láctico/análise , Propionatos/análiseRESUMO
Several microorganisms and one chemical preservative were tested for their effects on the fermentation and aerobic stability of corn silage. Whole-plant corn (one-half milk line, 31.3% dry matter) was ensiled in quadruplicate 20-L laboratory silos untreated or after the following treatments: Lactobacillus buchneri at 1 x 10(5) and 1 x 10(6) cfu/g of fresh forage; two different strains of L. plantarum, each at 1 x 10(6) cfu/g; and a buffered propionic acid-based product at 0.1% of fresh forage weight. After 100 d of ensiling, silage treated with L. buchneri (1 x 10(6) cfu/g) had a lower concentration of lactic acid compared with the untreated silage, but was similar to other treated silages. The silage treated with the high (1 x 10(6) cfu/g), but not the moderate rate (1 x 10(5) cfu/g) of L. buchneri also had a greater concentration of acetic acid (3.60%) and less yeasts (2.01 log cfu/g) when compared with other treatments (average of 1.88% acetic acid and 5.85 log cfu of yeasts/g). Silages treated with L. plantarums, the moderate rate of L. buchneri, and the chemical preservative took longer to heat than untreated silage when exposed to air, but improvements were numerically small (6.3 to 10.5 h). In contrast, silage treated with the high rate of L. buchneri never heated throughout a 900-h period of monitoring. Inoculating corn silage with 1 x 10(6) cfu/g of L. buchneri resulted in a more heterolactic fermentation and dramatically improved the aerobic stability of corn silage.
Assuntos
Fermentação , Conservantes de Alimentos/farmacologia , Lactobacillus/metabolismo , Silagem , Zea mays , Ácido Acético/análise , Aerobiose , Concentração de Íons de Hidrogênio , Ácido Láctico/análise , Silagem/análiseRESUMO
CONTEXT: While differences in levels of contraceptive use across socioeconomic subgroups of women have narrowed greatly over time, large disparities remain in rates of unintended pregnancy. One reason is variations in the effectiveness with which women and their partners use contraceptive methods. METHODS: Data on contraceptive use and accidental pregnancy from the 1988 and 1995 National Surveys of Family Growth were corrected for abortion underreporting and pooled for analysis. Use-failure rates were estimated for reversible methods during the first year, second year and first two years of use, for subgroups of women of various characteristics. RESULTS: The average failure rate for all reversible methods, adjusted for abortion underreporting, declines from 13% to 8% from the first year of method use to the second year. First-year failure rates are highest among women using spermicides, withdrawal and periodic abstinence (on average, 23-28% in the first year), and lowest for women relying on long-acting methods and oral contraceptives (4-8%). On average, they exceed 10% for all users except women aged 30-44, married women and women in the highest poverty-status category. The chance of accidental pregnancy does not differ significantly between method users younger than 18 and those aged 18-19. CONCLUSION: Both user and method characteristics determine whether contraceptive users will be able to avoid unintended pregnancy. Family planning providers should help clients to identify methods that they are most likely to use successfully, and counsel them on how to be consistent users and to avoid behaviors that contribute to method failure.
Assuntos
Anticoncepção/estatística & dados numéricos , Gravidez/estatística & dados numéricos , Fatores Socioeconômicos , Anticoncepção/métodos , Feminino , Humanos , Entrevistas como Assunto , Estados Unidos/epidemiologiaRESUMO
CONTEXT: Unintended pregnancy remains a major public health concern in the United States. Information on pregnancy rates among contraceptive users is needed to guide medical professionals' recommendations and individuals' choices of contraceptive methods. METHODS: Data were taken from the 1995 National Survey of Family Growth (NSFG) and the 1994-1995 Abortion Patient Survey (APS). Hazards models were used to estimate method-specific contraceptive failure rates during the first six months and during the first year of contraceptive use for all U.S. women. In addition, rates were corrected to take into account the underreporting of induced abortion in the NSFG. Corrected 12-month failure rates were also estimated for subgroups of women by age, union status, poverty level, race or ethnicity, and religion. RESULTS: When contraceptive methods are ranked by effectiveness over the first 12 months of use (corrected for abortion underreporting), the implant and injectables have the lowest failure rates (2-3%), followed by the pill (8%), the diaphragm and the cervical cap (12%), the male condom (14%), periodic abstinence (21%), withdrawal (24%) and spermicides (26%). In general, failure rates are highest among cohabiting and other unmarried women, among those with an annual family income below 200% of the federal poverty level, among black and Hispanic women, among adolescents and among women in their 20s. For example, adolescent women who are not married but are cohabiting experience a failure rate of about 31% in the first year of contraceptive use, while the 12-month failure rate among married women aged 30 and older is only 7%. Black women have a contraceptive failure rate of about 19%, and this rate does not vary by family income; in contrast, overall 12-month rates are lower among Hispanic women (15%) and white women (10%), but vary by income, with poorer women having substantially greater failure rates than more affluent women. CONCLUSIONS: Levels of contraceptive failure vary widely by method, as well as by personal and background characteristics. Income's strong influence on contraceptive failure suggests that access barriers and the general disadvantage associated with poverty seriously impede effective contraceptive practice in the United States.
PIP: This study estimated method-specific contraceptive failure rates in the US. Estimates were adjusted for underreporting of induced abortion in the main survey. The correction made a sizeable impact, as 25% of the 2,157,473 conceptions due to contraceptive failure were aborted. Data were obtained from the 1995 National Survey of Family Growth and the 1994-95 Abortion Patient Survey. Analysis was based on hazard models for failure in the first 6 and 12 months. Data include 7276 contraceptive use segments. The mean duration was 9.6 months. The pill and condom had the largest shares of use segments. The lowest failure rates were for implants and injectables (2-3%). Failure rates were as follows: oral pills (8%), diaphragm and cervical cap (12%), male condom (14%), periodic abstinence (21%), withdrawal (24%), and spermicides (26%). Failure rates were highest among cohabiting and other unmarried women; women with an annual family income below 200% of the federal poverty level; among Black and Hispanic women; and among adolescents and women in their 20s. The failure rate among low income women declined during 1988-95. Women above the 200% of poverty level had stable rates. Poverty continued to have a negative impact on effective contraceptive use. Four models were used to examine the effects of socioeconomic factors on contraceptive failure.
Assuntos
Preservativos/estatística & dados numéricos , Comportamento Contraceptivo/estatística & dados numéricos , Anticoncepcionais , Dispositivos Anticoncepcionais/estatística & dados numéricos , Coleta de Dados , Serviços de Planejamento Familiar , Gravidez , Aborto Induzido , Adolescente , Falha de Equipamento , Características da Família , Feminino , Humanos , Masculino , Estado Civil , Pessoa de Meia-Idade , Grupos Minoritários , Comportamento Sexual , Fatores Socioeconômicos , Fatores de Tempo , Estados UnidosRESUMO
Chopped barley forage was ensiled untreated or treated with several doses (1 x 10(5) to 1 x 10(6) cfu/g of fresh forage) of Lactobacillus buchneri 40788 in laboratory silos and untreated or treated (4 x 10(5) cfu/g) in a farm silo. Silage from the farm silos was fed to lactating cows. In the laboratory silo, the effects of inoculation on fermentation and aerobic stability were also compared to silage treated with a commercial inoculant and a buffered propionic acid additive. Inoculation with L. buchneri 40788 decreased the final concentrations of lactic acid but increased concentrations of acetic acid and ethanol in silage from laboratory and farm silos. Silages stored in laboratory silos did not heat after exposure to air for 7 d and were then mixed with alfalfa silage and a concentrate to form total mixed rations (TMR) that were further exposed to air. The TMR containing silages treated with L. buchneri 40788 or a buffered propionic-acid-based additive took longer to heat and spoil than the TMR containing untreated silage or silagetreated with the commercial inoculant. Silage stored in a farm silo and treated with L. buchneri 40788 had fewer yeasts and molds than did untreated silage. Aerobic stability was greater in treated silage alone and in a TMR containing treated silage. Dry matter intake (18.6 kg/d), milk production (25.7 kg/d), and milk composition did not differ between cows fed a TMR containinguntreated or treated silage. These findings show that L. buchneri can improve the aerobic stability of barley silage in laboratory and farm silos and that feeding treated silage had no negative effect on intake or performance.
Assuntos
Bovinos/fisiologia , Conservação de Alimentos/métodos , Hordeum , Lactobacillus/metabolismo , Silagem/microbiologia , Ácido Acético/análise , Aerobiose , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Contagem de Colônia Microbiana , Feminino , Fermentação , Lactação/fisiologia , Valor Nutritivo , Propionatos/análiseRESUMO
CONTEXT: Publicly funded family planning clinics are a vital source of contraceptive and reproductive health care for millions of U.S. women. It is important periodically to assess the number and type of clinics and the number of contraceptive clients they serve. METHODS: Service data were requested for agencies and clinics providing publicly funded family planning services in the United States in 1997. The numbers of agencies, clinics and female contraceptive clients were tabulated according to various characteristics and were compared with similar data for 1994. Finally, county data were tabulated according to the presence of family planning clinics and private physicians likely to provide family planning care and according to the number of female contraceptive clients served compared with the number of women needing publicly funded care. RESULTS: In 1997, 3,117 agencies offered publicly funded contraceptive services at 7,206 clinic sites. Forty percent of clinics were run by health departments, 21% by community health centers, 13% by Planned Parenthood affiliates and 26% by hospitals or other agencies. Overall, 59% of clinics received Title X funding. Agencies operated an average of 2.3 clinics, and clinics served an average of 910 contraceptive clients per year. Altogether, clinics provided contraceptive services to 6.6 million women-approximately two of every five women estimated to need publicly funded contraceptive care. The total number of providers and the total number of women served remained stable between 1994 and 1997; at the local level, however, clinic turnover was high. Some 85% of all US counties had one or more publicly funded family planning clinics; 36% had one or more clinics, but no private obstetrician-gynecologist. CONCLUSIONS: Publicly funded family planning clinics are distributed widely throughout the United States and continue to provide contraceptive care to millions of US women. Clinics are sometimes the only source of specialized family planning care available to women in rural counties. However, the high rate of clinic tumover and the lack of significant growth in clinic numbers suggest that limited funding and rising costs have hindered the further expansion and outreach of the clinic network to new geographic areas and hard-to-reach populations.
Assuntos
Serviços de Planejamento Familiar/legislação & jurisprudência , Serviços de Planejamento Familiar/tendências , Adolescente , Região do Caribe/epidemiologia , Feminino , Administração Financeira/legislação & jurisprudência , Administração Financeira/tendências , Órgãos dos Sistemas de Saúde/legislação & jurisprudência , Órgãos dos Sistemas de Saúde/tendências , Humanos , Ilhas do Pacífico/epidemiologia , Estados Unidos/epidemiologiaRESUMO
We evaluate men's retrospective fertility histories from the British Household Panel Survey and the U.S. Panel Study of Income Dynamics (PSID). Further, we analyze the PSID men's panel-updated fertility histories for their possible superiority over retrospective collection. One third to one half of men's nonmarital births and births within previous marriages are missed in estimates from retrospective histories. Differential survey underrepresentation of previously married men compared with previously married women accounts for a substantial proportion of the deficits in previous-marriage fertility. More recent retrospective histories and panel-updated fertility histories improve reporting completeness, primarily by reducing the proportion of marital births from unions that are no longer intact at the survey date.
Assuntos
Coleta de Dados/métodos , Interpretação Estatística de Dados , Fertilidade , Homens , Viés , Coeficiente de Natalidade , Coleta de Dados/normas , Feminino , Humanos , Estudos Longitudinais , Masculino , Casamento/estatística & dados numéricos , Grupos Raciais , Reprodutibilidade dos Testes , Estudos Retrospectivos , Reino Unido , Estados UnidosRESUMO
We studied the effects of ammonia treatment on microbial populations during the fermentation of corn silage. We also compared the effects of ammonia to a preservative containing buffered propionic acid and other antifungal compounds on the fermentation and aerobic stability of corn silage. In the first experiment, whole-plant corn was ensiled without treatment or treated with ammonia-N to supply an additional 0.3% N (fresh-forage basis). The addition of ammonia immediately increased silage pH and had no effect on numbers of lactic acid bacteria, but delayed their growth compared with untreated silage. Numbers of enterobacteria declined more slowly, but numbers of yeasts and molds declined more quickly in silage treated with ammonia. During the early stages of ensiling, lactic acid increased more rapidly in untreated than in treated silage. The reverse was true for acetic acid concentrations. When exposed to air, growth of yeasts and molds was delayed in ammonia-treated silage. In a second experiment, various levels (0.1 to 0.3%, fresh weight) of ammonium-N or a preservative with buffered propionic acid were added to whole-plant corn and allowed to ensile for 106 d. Silage treated with ammonia had a greater ratio of L- to D-lactic acid than did other silages. Untreated silage was aerobically stable for 32.3 h, whereas the low (42 h) and moderate (52.7 h) concentrations of both additives numerically improved aerobic stability. High concentrations of ammonia-N (0.3%) or a buffered propionic acid preservative (0.3%), markedly improved the aerobic stability of corn silage (82 and 69 h for ammonia and propionic acid-treated silage, respectively).
Assuntos
Amônia/farmacologia , Fermentação , Conservantes de Alimentos/farmacologia , Propionatos/farmacologia , Silagem/microbiologia , Zea mays , Estabilidade de Medicamentos , Enterobacteriaceae , Concentração de Íons de Hidrogênio , Ácido Láctico/análise , Lactococcus , Oxigênio , LevedurasRESUMO
For 3 successive yr, whole-plant corn was ensiled in laboratory silos with low percentages of silage preservatives, the primary active ingredient of which was propionic acid. Preservatives were added to forage just prior to ensiling at rates of 0.1 to 0.2% of the fresh forage weight. In all 3 yr, treatments had minor effects on fermentation end products, except that the concentration of propionic acid was greater because of its addition. The mean low and high percentages of preservatives increased aerobic stability of the treated silages by 19 and 57 h, respectively, in Experiment 1 and by 17 and 38 h, respectively, in Experiment 2. In Experiment 3, aerobic stability was improved by > 90 h by preservatives (0.2% addition). In a lactation study, a total mixed ration (46% dry matter) was mixed without or with (0.2 or 0.3%) a stabilizer that was designed to prevent spoilage in the feed bunk. The high dose resulted in orts with a lower pH and temperature after 24 h in the feed bunk. However, dry matter intake and milk production were unaffected by treatments. Chemical preservatives based on propionic acid added at low rates did not affect fermentation but were effective in the reduction of heating in corn silage and in a total mixed ration.
Assuntos
Fermentação/efeitos dos fármacos , Conservantes de Alimentos/farmacologia , Propionatos/farmacologia , Silagem , Zea mays , Aerobiose , Animais , Bovinos , Ingestão de Alimentos , Feminino , Concentração de Íons de Hidrogênio , Lactação/fisiologia , Silagem/análiseRESUMO
We have synthesized a set of ATP and ADP analogues that have a fluorophore linked to the nucleotide via the 3'-position of the ribose moiety. Combinations of three different coumarins are each attached via different length linkers. A linker based on propylenediamine increases the separation between the nucleotide and fluorophore relative to that of the previously reported ethylenediamine-linked coumarin nucleotides [Webb, M. R., and Corrie, J. E. T. (2001) Biophys. J. 81, 1562-1569]. A synthesis of 3'-amino-3'-deoxyATP is described using a combination of chemical and enzymatic procedures, mostly from published methods for synthesis of this compound but with some modifications that improved the convenience of the experimental procedures. This compound is used as a basis of a series of analogues with effectively a zero-length linker. Fluorescence properties of all these analogues are described, together with the kinetics of their interaction with rabbit skeletal myosin subfragment 1 in the presence and absence of actin. One particular analogue, deac-aminoATP [3'-(7-diethylaminocoumarin-3-carbonylamino)-3'-deoxyadenosine 5'-triphosphate], shows a 17-fold enhancement of fluorescence upon binding to this (skeletal) myosin II. As the diphosphate, it exhibits a large signal change upon dissociation from the actomyosin, with kinetics similar to those of natural ADP. The ability of this set of analogues to produce large signals indicated potential uses when scarce proteins are studied in small amounts.