Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Nutrients ; 9(8)2017 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-28805670

RESUMO

Animal studies indicate Salacia reduces body weight, possibly due to its α-glucosidase inhibitor (α-GI) properties, but this has not been examined previously. In this study, a randomized, placebo-controlled, three-way cross-over design was used to evaluate whether Salacia Chinensis (SC) reduces appetite in healthy overweight/obese individuals (body mass index 28.8 ±3.6 kg/m²; 32 ± 12 years). Forty-eight participants were fasted overnight and consumed a dose of SC (300 or 500 mg) or placebo with a fixed breakfast meal at each visit. Appetite sensations, glycemic indices and gastrointestinal peptides were measured. Results indicated that SC had no effect on postprandial appetite. However, in women, hunger was reduced by SC compared to placebo at multiple time points (300 mg; p < 0.05), but not in men. Area under the curve (AUC) for serum glucose, insulin and amylin was attenuated with SC compared to placebo (p < 0.05). Glucagon like peptide-1 had two peaks after the meal, but the AUC did not differ between groups. The AUC of peak areas for peptide YY and ghrelin were greater for SC than placebo (p < 0.05). These findings indicate that Salacia decreases glycemic indices supporting its role as an α-GI, and affects certain gastrointestinal peptides suggesting it may be an appetite modulator.


Assuntos
Apetite/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Inibidores de Glicosídeo Hidrolases/farmacologia , Obesidade/tratamento farmacológico , Extratos Vegetais/farmacologia , Salacia/química , Adulto , Estudos Cross-Over , Método Duplo-Cego , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Extratos Vegetais/química
2.
Am J Clin Nutr ; 101(3): 659-67, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25733651

RESUMO

BACKGROUND: Weight loss (WL) negatively affects bone mineral density (BMD) in older populations and has specifically been shown in women. OBJECTIVE: In this prospective controlled trial, we examined variables of bone quality and endocrine changes after intentional WL in men. DESIGN: Thirty-eight overweight and obese [mean ± SD body mass index (in kg/m²): 31.9 ± 4.4; age: 58 ± 6 y] men were recruited to either WL through caloric restriction or weight maintenance (WM) for 6 mo. RESULTS: There was a -7.9 ± 4.4% and +0.2 ± 1.6% change in body weight in the WL and WM groups, respectively. There was a greater increase in femoral neck and total body BMD and bone mineral content (BMC) in the WM group than in the WL group (P-interaction effect < 0.05). In contrast, there was a trend for the tibia cortical thickness and area to decrease more in the WM group than in the WL group (P ≤ 0.08). There was a decrease in the periosteal circumference in both groups over time (P < 0.01) and no statistically significant changes in trabecular bone. Circulating total, free, and bioavailable estradiol decreased in the WL group compared with the WM group, and changes were different between groups (P < 0.05). Serum total and bioavailable testosterone increased in both groups (P < 0.01). Serum 25-hydroxyvitamin D increased to a similar extent in both groups (P < 0.05). CONCLUSIONS: Moderate WL in overweight and obese men did not decrease BMD at any anatomical site or alter cortical and trabecular bone and geometry. Also, despite increased BMD at some sites when maintaining excess body weight, cortical bone showed a trend in the opposite direction.


Assuntos
Reabsorção Óssea/prevenção & controle , Restrição Calórica , Dieta Redutora , Obesidade/dietoterapia , Sobrepeso/dietoterapia , Absorciometria de Fóton , Idoso , Terapia Comportamental , Índice de Massa Corporal , Densidade Óssea , Reabsorção Óssea/diagnóstico por imagem , Reabsorção Óssea/epidemiologia , Reabsorção Óssea/etiologia , Restrição Calórica/efeitos adversos , Terapia Combinada/efeitos adversos , Dieta Redutora/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , New Jersey/epidemiologia , Ciências da Nutrição/educação , Obesidade/fisiopatologia , Obesidade/terapia , Sobrepeso/fisiopatologia , Sobrepeso/terapia , Educação de Pacientes como Assunto , Risco , Tíbia/diagnóstico por imagem , Redução de Peso
3.
J Clin Endocrinol Metab ; 98(5): E886-90, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23509103

RESUMO

CONTEXT: Obesity is associated with lower serum concentrations of 25-hydroxyvitamin D (25OHD) and higher intact PTH. The threshold of 25OHD needed to maximally suppress intact PTH has been suggested as a marker of optimal vitamin D status. OBJECTIVE: In this study, we hypothesized that whereas the obese have a higher serum PTH and lower 25OHD, suppression of serum PTH by 25OHD would be independent of body weight. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis on 383 women (ages 24-75 y) with a wide range of body weights (43-185 kg) who were stabilized to 1-1.2 g calcium/d for 1 month before blood draw. Body composition, serum PTH, 25OHD, calcium, and creatinine were measured. Locally weighted regression and smoothing scatterplots were used to depict the association between serum PTH and 25OHD. A nonlinear exponential model determined the point for near maximal suppression of PTH by 25OHD. RESULTS: The point for near maximal suppression of PTH by 25OHD for all women (body mass index, 31.4 ± 7.7 kg/m²) occurred at a 25OHD concentration of 21.7 ng/mL (95% confidence interval, 28-48 ng/mL). No point of maximal suppression was found for nonobese women, yet in the obese women (n = 207; body mass index, >30 kg/m²) suppression of PTH occurred at a 25OHD concentration of 11.1 ng/mL (95% confidence interval, 4.7-17.5 ng/mL). CONCLUSIONS: These results suggest that if PTH is suppressed at a lower serum 25OHD in the obese compared to the entire population, the lower average 25OHD concentrations in the obese may not have the same physiological significance as in the general population.


Assuntos
25-Hidroxivitamina D 2/sangue , Calcifediol/sangue , Modelos Biológicos , Obesidade/sangue , Hormônio Paratireóideo/sangue , Deficiência de Vitamina D/complicações , Adulto , Idoso , Algoritmos , Biomarcadores/sangue , Índice de Massa Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Estado Nutricional , Obesidade/complicações , Estudos Retrospectivos , Adulto Jovem
4.
Am J Clin Nutr ; 97(3): 637-45, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23364004

RESUMO

BACKGROUND: Weight loss (WL) is associated with a decrease in calcium absorption and may be one mechanism that induces bone loss with weight reduction. OBJECTIVE: Because vitamin D supplementation has been shown to increase true fractional calcium absorption (TFCA), the goal of this study was to examine the effect of vitamin D during WL or weight maintenance (WM). DESIGN: A randomized, placebo-controlled, double-blind 6-wk study was conducted in 82 postmenopausal women [BMI (in kg/m(2); ±SD): 30.2 ± 3.7] with 25-hydroxyvitamin D [25(OH)D] concentrations <70 nmol/L during either WL or WM. All women were given 10 µg vitamin D(3)/d and 1.2 g Ca/d and either weekly vitamin D(3) (375 µg) or a placebo equivalent to 63 µg (2500 IU)/d and 10 µg (400 IU)/d, respectively. We measured TFCA with the use of dual-stable isotopes, 25(OH)D, parathyroid hormone, estradiol, calcitriol, and urinary calcium at baseline and 6 wk in weight loss and vitamin D(3)-supplementation (WL-D; n = 19), weight maintenance and vitamin D(3)-supplementation (WM-D; n = 20), weight loss and placebo (n = 22), and weight maintenance and placebo (n = 21) groups. RESULTS: WL groups lost 3.8 ± 1.1% of weight with no difference between vitamin D(3) supplementation and the placebo. The rise in serum 25(OH)D was greatest in the WL-D group (19.8 ± 14.5 nmol/L) compared with in WM-D (9.1 ± 10.3 nmol/L) and placebo groups (1.5 ± 10.9 nmol/L). TFCA increased with vitamin D(3) supplementation compared with placebo treatment (P < 0.01) and decreased during WL compared with WM. Serum 25(OH)D or 1,25-dihyroxyvitamin D did not correlate with TFCA. CONCLUSION: These data show that vitamin D supplementation increases TFCA and that WL decreases TFCA and suggest that, when calcium intake is 1.2 g/d, either 10 or 63 µg vitamin D/d is sufficient to maintain the calcium balance. This trial was registered at clinicaltrials.gov as NCT00473031.


Assuntos
Cálcio da Dieta/farmacocinética , Restrição Calórica , Colecalciferol/administração & dosagem , Suplementos Nutricionais , Redução de Peso/efeitos dos fármacos , Composição Corporal , Colecalciferol/sangue , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Análise de Regressão
5.
Pituitary ; 15 Suppl 1: S68-71, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22618955

RESUMO

Octreotide is widely used as medical therapy for acromegaly. It is known to markedly reduce growth hormone levels, improve symptoms and reduce tumor size. Common side effects include gastrointestinal symptoms, hepatobiliary disorders, dizziness, headaches, bradycardia, hyperglycemia or hypoglycemia and thyroid dysfunction. Although urticaria, allergy/hypersensitivity reactions and anaphylaxis have been noted as possible adverse reactions, there is a lack of data showing a causal relationship between octreotide and hypersensitivity reactions and there is no information on management when continued use of this medication is essential. We now report a case of a 60 year old male with acromegaly who had presented with a cutaneous hypersensitivity reaction to octreotide. In addition he failed treatment with surgery, radiation, and dopamine agonist and could no longer afford to continue treatment with pegvisomant. The patient underwent desensitization treatment for his octreotide allergy and was able to resume treatment without any further side effects. We believe this case represents the first report of successful desensitization treatment for octreotide allergy in an acromegalic patient.


Assuntos
Acromegalia/tratamento farmacológico , Octreotida/uso terapêutico , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade
6.
Expert Opin Pharmacother ; 12(12): 1967-73, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21679097

RESUMO

INTRODUCTION: Inhibition of dipeptidyl peptidase IV (DPP-4) augments glucose-dependent insulin release and is a new approach to the treatment of type 2 diabetes (T2DM). Vildagliptin is a new DPP-4 inhibitor approved in many countries for the treatment of T2DM. This review provides an overview of vildagliptin with emphasis on its pharmacology and clinical effectiveness. AREAS COVERED: Results of preclinical and several Phase II and III studies from 2004 - 2010 are discussed. EXPERT OPINION: Vildagliptin acts to inhibit the breakdown of glucagon-like peptide (GLP)-1, which in turn enhances the beta-cell response to glucose and inhibits glucagon secretion. It is an effective agent alone or in combination in patients with T2DM, resulting in modest improvements in HbA1c usually in the 0.5 - 1% range. Advantages include weight neutrality and a lesser incidence of hypoglycemia. Concerns remain regarding its use in renal disease and potential complications seen in animal models.


Assuntos
Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Nitrilas/uso terapêutico , Pirrolidinas/uso terapêutico , Adamantano/efeitos adversos , Adamantano/farmacocinética , Adamantano/uso terapêutico , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/farmacocinética , Quimioterapia Combinada , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hemoglobinas Glicadas/análise , Humanos , Hiperglicemia/prevenção & controle , Hipoglicemia/prevenção & controle , Nitrilas/efeitos adversos , Nitrilas/farmacocinética , Pirrolidinas/efeitos adversos , Pirrolidinas/farmacocinética , Vildagliptina
7.
Proc Natl Acad Sci U S A ; 107(27): 12107-9, 2010 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-20566872

RESUMO

Although preliminary estimates from published literature and expert surveys suggest striking agreement among climate scientists on the tenets of anthropogenic climate change (ACC), the American public expresses substantial doubt about both the anthropogenic cause and the level of scientific agreement underpinning ACC. A broad analysis of the climate scientist community itself, the distribution of credibility of dissenting researchers relative to agreeing researchers, and the level of agreement among top climate experts has not been conducted and would inform future ACC discussions. Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97-98% of the climate researchers most actively publishing in the field surveyed here support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.


Assuntos
Mudança Climática/estatística & dados numéricos , Clima , Efeito Estufa , Bases de Dados Factuais , Ecologia/estatística & dados numéricos , Ecologia/tendências , Previsões , Humanos , Opinião Pública , Pesquisadores/estatística & dados numéricos
9.
J Sex Med ; 7(1 Pt 1): 156-65, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19694925

RESUMO

INTRODUCTION: Overweight men with diabetes often report erectile dysfunction (ED), but few studies have examined effects of weight loss on this problem. AIM: This study examined 1-year changes in erectile function (EF) in overweight/obese men with type 2 diabetes participating in the Look AHEAD (Action for Health in Diabetes) trial. METHODS: Participants in Look AHEAD were randomly assigned to a control condition involving diabetes support and education (DSE) or to intensive lifestyle intervention (ILI) involving group and individual sessions to reduce weight and increase physical activity. Men from five of the clinical sites in Look AHEAD completed the International Index of Erectile Function (IIEF) at baseline (N = 372) and at 1 year (N = 306) (82%). MAIN OUTCOME MEASURES: Changes in EF as reported on the EF subscale of the IIEF. RESULTS: At 1 year, the ILI group lost a greater percent of initial body weight (9.9% vs. 0.6 %) and had greater improvements in fitness (22.7% vs. 4.6%) than DSE. EF improved more in ILI (17.3 +/- 7.6 at baseline; 18.6 +/- 8.1 at 1 year) than in DSE (18.3 +/- 7.6 at baseline; 18.4 +/- 8.0 at 1 year); P = 0.04 and P = 0.06 after adjusting for baseline differences. Using established norms for none (i.e., normal EF), and three grades (i.e., mild, moderate, and severe) ED, 8% of men in ILI reported a worsening of EF from baseline to 1 year, 70% stayed in the same category, and 22% reported improvements. In contrast, 20% of DSE reported worsening, 57% stayed in the same category, and 23% improved (P = 0.006). CONCLUSION: In this sample of older overweight/obese diabetic men, weight loss intervention was mildly helpful in maintaining EF.


Assuntos
Diabetes Mellitus Tipo 2/reabilitação , Disfunção Erétil/reabilitação , Comportamentos Relacionados com a Saúde , Estilo de Vida , Obesidade/reabilitação , Sobrepeso/reabilitação , Redução de Peso , Idoso , Índice de Massa Corporal , Terapia Combinada , Diabetes Mellitus Tipo 2/mortalidade , Neuropatias Diabéticas/mortalidade , Neuropatias Diabéticas/reabilitação , Dieta Redutora , Ingestão de Energia , Disfunção Erétil/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Obesidade/mortalidade , Sobrepeso/mortalidade , Educação de Pacientes como Assunto , Aptidão Física
10.
Proc Natl Acad Sci U S A ; 106(24): 9721-4, 2009 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-19509337

RESUMO

Managed relocation (MR) has rapidly emerged as a potential intervention strategy in the toolbox of biodiversity management under climate change. Previous authors have suggested that MR (also referred to as assisted colonization, assisted migration, or assisted translocation) could be a last-alternative option after interrogating a linear decision tree. We argue that numerous interacting and value-laden considerations demand a more inclusive strategy for evaluating MR. The pace of modern climate change demands decision making with imperfect information, and tools that elucidate this uncertainty and integrate scientific information and social values are urgently needed. We present a heuristic tool that incorporates both ecological and social criteria in a multidimensional decision-making framework. For visualization purposes, we collapse these criteria into 4 classes that can be depicted in graphical 2-D space. This framework offers a pragmatic approach for summarizing key dimensions of MR: capturing uncertainty in the evaluation criteria, creating transparency in the evaluation process, and recognizing the inherent tradeoffs that different stakeholders bring to evaluation of MR and its alternatives.


Assuntos
Biodiversidade , Animais , Incerteza
11.
Proc Natl Acad Sci U S A ; 106(11): 4133-7, 2009 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-19251662

RESUMO

Article 2 of the United Nations Framework Convention on Climate Change [United Nations (1992) http://unfccc.int/resource/docs/convkp/conveng.pdf. Accessed February 9, 2009] commits signatory nations to stabilizing greenhouse gas concentrations in the atmosphere at a level that "would prevent dangerous anthropogenic interference (DAI) with the climate system." In an effort to provide some insight into impacts of climate change that might be considered DAI, authors of the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) identified 5 "reasons for concern" (RFCs). Relationships between various impacts reflected in each RFC and increases in global mean temperature (GMT) were portrayed in what has come to be called the "burning embers diagram." In presenting the "embers" in the TAR, IPCC authors did not assess whether any single RFC was more important than any other; nor did they conclude what level of impacts or what atmospheric concentrations of greenhouse gases would constitute DAI, a value judgment that would be policy prescriptive. Here, we describe revisions of the sensitivities of the RFCs to increases in GMT and a more thorough understanding of the concept of vulnerability that has evolved over the past 8 years. This is based on our expert judgment about new findings in the growing literature since the publication of the TAR in 2001, including literature that was assessed in the IPCC Fourth Assessment Report (AR4), as well as additional research published since AR4. Compared with results reported in the TAR, smaller increases in GMT are now estimated to lead to significant or substantial consequences in the framework of the 5 "reasons for concern."


Assuntos
Poluição do Ar/prevenção & controle , Efeito Estufa , Cooperação Internacional , Poluição do Ar/legislação & jurisprudência , Atmosfera , Clima , Comportamento Perigoso , Previsões , Humanos , Nações Unidas
12.
Philos Trans A Math Phys Eng Sci ; 366(1882): 3843-62, 2008 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-18757279

RESUMO

Schemes to modify large-scale environment systems or control climate have been proposed for over 50 years to (i) increase temperatures in high latitudes, (ii) increase precipitation, (iii) decrease sea ice, (iv) create irrigation opportunities, or (v) offset potential global warming by injecting iron in the oceans or sea-salt aerosol in the marine boundary layer or spreading dust in the stratosphere to reflect away an amount of solar energy equivalent to the amount of heat trapped by increased greenhouse gases from human activities. These and other proposed geoengineering schemes are briefly reviewed. Recent schemes to intentionally modify climate have been proposed as either cheaper methods to counteract inadvertent climatic modifications than conventional mitigation techniques such as carbon taxes or pollutant emissions regulations or as a counter to rising emissions as governments delay policy action. Whereas proponents argue cost-effectiveness or the need to be prepared if mitigation and adaptation policies are not strong enough or enacted quickly enough to avoid the worst widespread impacts, critics point to the uncertainty that (i) any geoengineering scheme would work as planned or (ii) that the many centuries of international political stability and cooperation needed for the continuous maintenance of such schemes to offset century-long inadvertent effects is socially feasible. Moreover, the potential exists for transboundary conflicts should negative climatic events occur during geoengineering activities.


Assuntos
Conservação dos Recursos Naturais/métodos , Desastres/prevenção & controle , Ecossistema , Engenharia/tendências , Efeito Estufa
13.
Clin J Sport Med ; 18(5): 473-4, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18806561
14.
J Gen Intern Med ; 23(8): 1194-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18452046

RESUMO

BACKGROUND: Although patients with diabetes may benefit from physical activity, few studies have examined sustained walking in this population. OBJECTIVE: To examine the factors associated with sustained walking among managed care patients with diabetes. DESIGN: Longitudinal, observational cohort study with questionnaires administered 2.5 years apart. PARTICIPANTS: Five thousand nine hundred thirty-five patients with diabetes walking at least 20 minutes/day at baseline. MEASUREMENTS: The primary outcome was the likelihood of sustained walking, defined as walking at least 20 minutes/day at follow-up. We evaluated a logistic regression model that included demographic, clinical, and neighborhood variables as independent predictors of sustained walking, and expressed the results as predicted percentages. RESULTS: The absence of pain was linked to walking behavior, as 62% of patients with new pain, 67% with ongoing pain, and 70% without pain were still walking at follow-up (p = .03). Obese patients were less likely (65%) to sustain walking than overweight (71%) or normal weight (70%) patients (p = .03). Patients > or =65 years (63%) were less likely to sustain walking than patients between 45 and 64 (70%) or < or =44 (73%) years (p = .04). Only 62% of patients with a new comorbidity sustained walking compared with 68% of those who did not (p < .001). We found no association between any neighborhood variables and sustained walking in this cohort of active walkers. CONCLUSIONS: Pain, obesity, and new comorbidities were moderately associated with decreases in sustained walking. Whereas controlled intervention studies are needed, prevention, or treatment of these adverse conditions may help patients with diabetes sustain walking behavior.


Assuntos
Diabetes Mellitus/fisiopatologia , Programas de Assistência Gerenciada , Caminhada/fisiologia , Idoso , Comorbidade , Diabetes Mellitus/terapia , Feminino , Humanos , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Medição da Dor , Características de Residência , Fatores de Risco , Inquéritos e Questionários
15.
J Diabetes Complications ; 22(5): 329-30, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18413180

RESUMO

Glycogenic hepatopathy is an underrecognized complication of long-standing poorly controlled diabetes mellitus. It is characterized by abnormal glycogen accumulation in hepatocytes, elevated liver enzymes and hepatomegaly. This is a distinct entity from other causes of hepatomegaly and elevated liver enzymes in diabetics such as nonalcoholic fatty liver disease. It is important to distinguish this entity as it has the potential for resolution following improved glycemic control as described by this case report.


Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Doença de Depósito de Glicogênio/tratamento farmacológico , Insulina/uso terapêutico , Hepatopatias/tratamento farmacológico , Adulto , Biópsia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/patologia , Feminino , Doença de Depósito de Glicogênio/etiologia , Doença de Depósito de Glicogênio/patologia , Humanos , Hipoglicemiantes/uso terapêutico , Hepatopatias/etiologia , Hepatopatias/patologia , Resultado do Tratamento
16.
Conserv Biol ; 22(1): 140-50, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18254859

RESUMO

Limitations imposed on species ranges by the climatic, ecological, and physiological effects of elevation are important determinants of extinction risk. We modeled the effects of elevational limits on the extinction risk of landbirds, 87% of all bird species. Elevational limitation of range size explained 97% of the variation in the probability of being in a World Conservation Union category of extinction risk. Our model that combined elevational ranges, four Millennium Assessment habitat-loss scenarios, and an intermediate estimate of surface warming of 2.8 degrees C, projected a best guess of 400-550 landbird extinctions, and that approximately 2150 additional species would be at risk of extinction by 2100. For Western Hemisphere landbirds, intermediate extinction estimates based on climate-induced changes in actual distributions ranged from 1.3% (1.1 degrees C warming) to 30.0% (6.4 degrees C warming) of these species. Worldwide, every degree of warming projected a nonlinear increase in bird extinctions of about 100-500 species. Only 21% of the species predicted to become extinct in our scenarios are currently considered threatened with extinction. Different habitat-loss and surface-warming scenarios predicted substantially different futures for landbird species. To improve the precision of climate-induced extinction estimates, there is an urgent need for high-resolution measurements of shifts in the elevational ranges of species. Given the accelerating influence of climate change on species distributions and conservation, using elevational limits in a tested, standardized, and robust manner can improve conservation assessments of terrestrial species and will help identify species that are most vulnerable to global climate change. Our climate-induced extinction estimates are broadly similar to those of bird species at risk from other factors, but these estimates largely involve different sets of species.


Assuntos
Aves/fisiologia , Ecossistema , Extinção Biológica , Altitude , Animais , Demografia , Efeito Estufa , Modelos Biológicos
17.
Diabetes Educ ; 33(6): 991-1011; discussion 1012-3, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18057267

RESUMO

OBJECTIVE: The purpose of this systematic review was 2-fold: first, to perform a comprehensive review of relevant studies on the impact of self-monitoring of blood glucose (SMBG) on HbA1c levels for patients with type 2 diabetes mellitus and, second, to explore mediators and moderators within a self-regulation framework. DATA SOURCES: Five databases-Medline, PsychInfo, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing & Allied Health Literature (CINAHL)-were searched. STUDY SELECTION: Cross-sectional, longitudinal, and randomized control trials from 1990 to 2006, which included patients with type 2 diabetes not on insulin, were reviewed. In total, 6,769 studies were screened for inclusion, 89 were retrieved for detailed analysis, and 29 met criteria for inclusion in the review. DATA EXTRACTION: Data on the impact of SMBG on HbA1c, potential mediators and moderators, study design and participants, and limitations of each study were retrieved. DATA SYNTHESIS: Twenty-nine studies were included in this review: 9 cross-sectional studies, 9 longitudinal studies, and 11 randomized controlled trials. Evidence from the cross-sectional and longitudinal studies was inconclusive. Evidence from randomized controlled trials suggests that SMBG may lead to improvements in glucose control. Very few studies examined potential mediators or moderators of SMBG on HbA1c levels. CONCLUSIONS: SMBG may be effective in controlling blood glucose for patients with type 2 diabetes. There is a need for studies that implement all the components of the process for self-regulation of SMBG to assess whether patient use of SMBG will improve HbA1c levels.


Assuntos
Automonitorização da Glicemia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/reabilitação , Autocuidado , Humanos
18.
Science ; 317(5844): 1513-6, 2007 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-17872436

RESUMO

Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Meio Ambiente , Atividades Humanas , Animais , Biodiversidade , Brasil , China , Ecologia , Humanos , Fatores Socioeconômicos , Sociologia , Suécia , Estados Unidos
20.
Ambio ; 36(8): 639-49, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18240679

RESUMO

Humans have continuously interacted with natural systems, resulting in the formation and development of coupled human and natural systems (CHANS). Recent studies reveal the complexity of organizational, spatial, and temporal couplings of CHANS. These couplings have evolved from direct to more indirect interactions, from adjacent to more distant linkages, from local to global scales, and from simple to complex patterns and processes. Untangling complexities, such as reciprocal effects and emergent properties, can lead to novel scientific discoveries and is essential to developing effective policies for ecological and socioeconomic sustainability. Opportunities for truly integrating various disciplines are emerging to address fundamental questions about CHANS and meet society's unprecedented challenges.


Assuntos
Ecossistema , Meio Ambiente , Humanos , Política Pública
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...