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Non-labile plant C contributes to long-lasting macroaggregation of an Oxisol

Martins, Márcio R.; Angers, Denis A.; Corá, José E.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 153-158
Português
Relevância na Pesquisa
25.93%
Decomposition of plant material influences soil aggregation dynamics in ways that are still poorly understood, especially for Oxisols, in which oxides are believed to play a dominant role. In an incubation experiment, we investigated (i) the effect of plant material addition from selected monocot and dicot species on soil organic C (SOC), carbohydrate composition, fungal and total microbial biomass, and aggregation of an Oxisol; and (ii) the relationship among these properties and C mineralization patterns. The experiment was carried out at 25 °C for 180 d after addition of 11 plant materials (4 g C kg-1 soil) and a control (no plant material added). Mineralization of C during the incubation was described considering two pools of C (labile and non-labile) using a first-order plus linear fitting. Compared to the control, corn materials showed larger pentose input, greater mineralization rates for the non-labile C pool (k), greater soil pentose content (xylose + arabinose) and larger mean weight diameter of soil water-stable aggregates at 180 d of incubation. These effects were independent of changes in SOC content, suggesting that total C accrual and macroaggregation may be decoupled processes in this Oxisol. Our results support the hypothesis that the non-labile plant C pool contributes to the long-lasting stability of macroaggregates of this Oxisol and that this effect is mediated by plant and soil pentoses. We propose that plant pentose content and the decomposition rate of the slow pool (k) are useful parameters for the prediction of plant effects on aggregation dynamics of Oxisols and the selection of soil conservation practices. © 2012.

Markers of insulin resistance and sedentary lifestyle are predictors of preeclampsia in women with adverse obstetric results

Hoirisch-Clapauch,S.; Benchimol-Barbosa,P.R.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 Português
Relevância na Pesquisa
66.14%
Some thrombophilias and severe preeclampsia may increase the risk for preterm deliveries and fetal death due to placental insufficiency. Our objective was to evaluate clinical and laboratory data as predictors of preeclampsia in a population of mothers with 3rd trimester fetal losses or preterm deliveries. In a longitudinal retrospective study, 54 consecutive women (age range: 16 to 39 years) with normotensive pregnancies were compared to 79 consecutive women with preeclampsia (age range: 16 to 43 years). Weight accrual rate (WAR) was arbitrarily defined as weight gain from age 18 years to the beginning of pregnancy divided by elapsed years. Independent predictors of preeclampsia were past history of oligomenorrhea, WAR >0.8 kg/years, pre-pregnancy or 1st trimester triglyceridemia >150 mg/dL, and elevated acanthosis nigricans in the neck. In a multivariate logistic regression model, two or more predictors conferred an odds ratio of 15 (95%CI [5.9-37]; P < 0.001) to develop preeclampsia (85% specificity, 73% sensitivity, c-statistic of 81 ± 4%; P < 0.0001). Clinical markers related to insulin resistance and sedentary lifestyles are strong independent predictors of preeclampsia in mothers with 3rd trimester fetal losses or preterm deliveries due to placental insufficiency. Women at risk for preeclampsia in this particular population might benefit from measures focused on overcoming insulin resistance.

Regulation of Lean Mass, Bone Mass, and Exercise Tolerance by the Central Melanocortin System

Braun, Theodore P.; Orwoll, Benjamin; Zhu, Xinxia; Levasseur, Peter R.; Szumowski, Marek; Nguyen, My Linh T.; Bouxsein, Mary L.; Klein, Robert F.; Marks, Daniel L.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 27/07/2012 Português
Relevância na Pesquisa
15.87%
Signaling via the type 4-melanocortin receptor (MC4R) is an important determinant of body weight in mice and humans, where loss of function mutations lead to significant obesity. Humans with mutations in the MC4R experience an increase in lean mass. However, the simultaneous accrual of fat mass in such individuals may contribute to this effect via mechanical loading. We therefore examined the relationship of fat mass and lean mass in mice lacking the type-4 melanocortin receptor (MC4RKO). We demonstrate that MC4RKO mice display increased lean body mass. Further, this is not dependent on changes in adipose mass, as MC4RKO mice possess more lean body mass than diet-induced obese (DIO) wild type mice with equivalent fat mass. To examine potential sources of the increased lean mass in MC4RKO mice, bone mass and strength were examined in MC4RKO mice. Both parameters increase with age in MC4RKO mice, which likely contributes to increases in lean body mass. We functionally characterized the increased lean mass in MC4RKO mice by examining their capacity for treadmill running. MC4R deficiency results in a decrease in exercise performance. No changes in the ratio of oxidative to glycolytic fibers were seen, however MC4RKO mice demonstrate a significantly reduced heart rate...

Barriers to the enrollment of children in the Children’s Oncology Group study of very low risk Wilms tumor. A report from the Children’s Oncology Group

Fernandez, Conrad V; Li, Ning; Mullen, Elizabeth A; Grundy, Paul; Perman, Elizabeth; Shamberger, Robert C; Ehrlich, Peter; Dome, Jeffrey S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/2011 Português
Relevância na Pesquisa
25.96%
Very low risk (VLR) Wilms tumor is defined by favorable histology, age less than 2 years, tumor weight less than 550 grams and stage I. The Children’s Oncology Group is currently studying a nephrectomy only strategy for these patients but the accrual rate is slightly below expected. 25 of 31 institutions responded with reasons by physicians and/or parents for electing not to participate. Parents were primarily concerned with the experimental nature of the study, whereas physicians were concerned about accurate staging, with some overlap. We point out the necessity of assessing these concerns in predicting feasibility of and accrual to a therapy reduction study.

Exercise and Bone Mineral Accrual in Children and Adolescents

Burrows, Melonie
Fonte: Asist Group Publicador: Asist Group
Tipo: Artigo de Revista Científica
Publicado em 01/09/2007 Português
Relevância na Pesquisa
25.87%
Osteoporosis is a serious skeletal disease causing an increase in morbidity and mortality through its association with age-related fractures. Although most effort in fracture prevention has been directed at retarding the rate of age-related bone loss and reducing the frequency and severity of trauma among elderly people, evidence is growing that peak bone mass is an important contributor to bone strength during later life. Indeed, there has been a large emphasis on the prevention of osteoporosis through the optimization of peak bone mass during childhood and adolescence. The prepubertal human skeleton is sensitive to the mechanical stimulation elicited by exercise and there is increasing evidence that regular weight-bearing exercise is an effective strategy for enhancing bone mineral throughout growth. Physical activity or participation in sports needs to start at prepubertal ages and be maintained through pubertal development to obtain the maximal peak bone mass achievable. High strain eliciting sports like gymnastics, or participation in sports or weight bearing physical activity like soccer, are strongly recommended to increase peak bone mass. Many other factors also influence the accumulation of bone mineral during childhood and adolescence...

Regulation of Lean Mass, Bone Mass, and Exercise Tolerance by the Central Melanocortin System

Braun, Theodore P.; Orwoll, Benjamin; Zhu, Xinxia; Levasseur, Peter R.; Szumowski, Marek; Nguyen, My Linh T.; Klein, Robert F.; Marks, Daniel L.; Bouxsein, Mary Larsen
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
15.87%
Signaling via the type 4-melanocortin receptor (MC4R) is an important determinant of body weight in mice and humans, where loss of function mutations lead to significant obesity. Humans with mutations in the MC4R experience an increase in lean mass. However, the simultaneous accrual of fat mass in such individuals may contribute to this effect via mechanical loading. We therefore examined the relationship of fat mass and lean mass in mice lacking the type-4 melanocortin receptor (MC4RKO). We demonstrate that MC4RKO mice display increased lean body mass. Further, this is not dependent on changes in adipose mass, as MC4RKO mice possess more lean body mass than diet-induced obese (DIO) wild type mice with equivalent fat mass. To examine potential sources of the increased lean mass in MC4RKO mice, bone mass and strength were examined in MC4RKO mice. Both parameters increase with age in MC4RKO mice, which likely contributes to increases in lean body mass. We functionally characterized the increased lean mass in MC4RKO mice by examining their capacity for treadmill running. MC4R deficiency results in a decrease in exercise performance. No changes in the ratio of oxidative to glycolytic fibers were seen, however MC4RKO mice demonstrate a significantly reduced heart rate...

The Market Value Implications of Pension Asset Allocation

Turner, Elizabeth H.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
Relevância na Pesquisa
15.8%
Pension funds have been part of the private sector since the 1850’s. Defined Benefit pension plans [DB], where a company promises to make regular contributions to investment accounts held for participating employees in order to pay a promised lifelong annuity, are significant capital markets participants, amounting to 2.3 trillion dollars in 2010 (Federal Reserve Board, 2013). In 2006, Statement of Financial Accounting Standards No.158 (SFAS 158), Employers’ Accounting for Defined Benefit Pension and Other Postemployment Plans, shifted information concerning funding status and pension asset/liability composition from disclosure in the footnotes to recognition in the financial statements. I add to the literature by being the first to examine the effect of recent pension reform during the financial crisis of 2008-09. This dissertation is comprised of three related essays. In my first essay, I investigate whether investors assign different pricing multiples to the various classes of pension assets when valuing firms. The pricing multiples on all classes of assets are significantly different from each other, but only investments in bonds and equities were value-relevant during the recent financial crisis. Consistent with investors viewing pension liabilities as liabilities of the firm...

The market value implications of pension asset allocation

Hendrix Turner, Diane Elizabeth
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
15.8%
Pension funds have been part of the private sector since the 1850's. Defined Benefit pension plans [DB], where a company promises to make regular contributions to investment accounts held for participating employees in order to pay a promised lifelong annuity, are significant capital markets participants, amounting to 2.3 trillion dollars in 2010 (Federal Reserve Board, 2013). In 2006, Statement of Financial Accounting Standards No.158 (SFAS 158), Employers' Accounting for Defined Benefit Pension and Other Postemployment Plans, shifted information concerning funding status and pension asset/liability composition from disclosure in the footnotes to recognition in the financial statements. I add to the literature by being the first to examine the effect of recent pension reform during the financial crisis of 2008-09. ^ This dissertation is comprised of three related essays. In my first essay, I investigate whether investors assign different pricing multiples to the various classes of pension assets when valuing firms. The pricing multiples on all classes of assets are significantly different from each other, but only investments in bonds and equities were value-relevant during the recent financial crisis. Consistent with investors viewing pension liabilities as liabilities of the firm...