661 research outputs found
Building construction cycles in the United States and selected cities.
Thesis (M.B.A.)--Boston University
N.B.: Pages 65 & 66 are mislabeled. No content is missing
Jack of all trades : the metamorphosis of armored cavalry in Vietnam.
This thesis is a chronological historical examination of armored cavalry doctrine and execution during the Vietnam War, with a focus on comparison of the armored cavalry\u27s doctrinal missions of reconnaissance, security, and economy of force with the reality of execution on the ground. In Vietnam, a metamorphosis occurred between these doctrinal missions and actual execution due to a series of factors, such as the nature of area warfare and a relative lack of doctrinal preparedness, the latter largely due to the doctrinal flux of the early 1960s, myths about warfare in Vietnam, and institutional resistance. The metamorphosis also occurred because it had to, and could, because of the many positive attributes of the cavalry, and because a series of other new enablers supplanted and masked the loss of cavalry in performing their doctrinal missions. The enablers ranged from new reconnaissance concepts and units, to the rise of technologies and increased surveillance abilities. Despite all the changes in execution from doctrine due to the demands of an extremely complex and multi-faceted war, cavalry and armor doctrine returned to its conventional focus following the war, while most of the adapted doctrine was relegated to peripheral manuals
EL PAPEL DEL BOSQUE MESÓFILO DE MONTAÑA EN LOS PROGRAMAS “PAGOS POR SERVICIOS AMBIENTALES HIDROLÓGICOS” EN MÉXICO
The arguments and national context that motivated the creation of several types of hydrological services payment programs (programas de pago por servicios hidrológicos, PSAH) in México were reviewed, as well as their performance. The role that the mountain mesophyll forest (MMF) has played in these programs is described, highlighting several important studies about the local climate, determining the capacity ofthe MMF to contribute to the annual expenditure in basins with PSAHs. In particular, it is noted that in the basins of central Veracruz there are not apt conditions for the MMF as an important source of water at annual scales. However, there is evidence of its importance in the regulation of the base flow and water quality. The way in which these benefits could interest many government instances, which are yet to finance these programs, is shown, highlighting a call to support more hydrological studies and constant monitoring of the basins with PSAHs.Se revisaron los argumentos y contexto nacional que motivaron la creación de varios tipos de programas de pago por servicios hidrológicos (PSAH) en México, así como su desempeño. Se describe el papel que ha jugado el bosque de mesófilo de montaña (BMM) en estos programas, resaltando varios estudios de importancia sobre el clima local, determinando la capacidad del BMM para contribuir al gasto anual en cuencas con PSAH. En particular, se anota que en las cuencas del centro de Veracruz no existen condiciones aptas para el BMM como fuente de agua importante a escalas anuales. Sin embargo, hay evidencia de su importancia en la regulación de flujo base y calidad del agua. Se indica cómo estos beneficios podrían interesar a varias instancias de gobierno que aún no están financiando estos programas, resaltando un llamado para apoyar más estudios hidrológicos y monitoreo constante en las cuencas con PSAH
Spatial analysis of ecosystem service relationships to improve targeting of payments for hydrological services
Payment for hydrological services (PHS) are popular tools for conserving ecosystems and their water-related services. However, improving the spatial targeting and impacts of PHS, as well as their ability to foster synergies with other ecosystem services (ES), remain challenging. We aimed at using spatial analyses to evaluate the targeting performance of Mexico\u27s National PHS program in central Veracruz. We quantified the effectiveness of areas targeted for PHS in actually covering areas of high HS provision and social priority during 2003-2013. First, we quantified provisioning and spatial distributions of two target (water yield and soil retention), and one non-target ES (carbon storage) using InVEST. Subsequently, pairwise relationships among ES were quantified by using spatial correlation and overlap analyses. Finally, we evaluated targeting by: (i) prioritizing areas of individual and overlapping ES; (ii) quantifying spatial co-occurrences of these priority areas with those targeted by PHS; (iii) evaluating the extent to which PHS directly contribute to HS delivery; and (iv), testing if PHS targeted areas disproportionately covered areas with high ecological and social priority. We found that modelled priority areas exhibited non-random distributions and distinct spatial patterns. Our results show significant pairwise correlations between all ES suggesting synergistic relationships. However, our analysis showed a significantly lower overlap than expected and thus significant mismatches between PHS targeted areas and all types of priority areas. These findings suggest that the targeting of areas with high HS provisioning and social priority by Mexico\u27s PHS program could be improved significantly. This study underscores: (1) the importance of using maps of HS provisioning as main targeting criteria in PHS design to channel payments towards areas that require future conservation, and (2) the need for future research that helps balance ecological and socioeconomic targeting criteria
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Human stem cell-derived astrocytes replicate human prions in a PRNP genotype-dependent manner.
Prions are infectious agents that cause neurodegenerative diseases such as Creutzfeldt-Jakob disease (CJD). The absence of a human cell culture model that replicates human prions has hampered prion disease research for decades. In this paper, we show that astrocytes derived from human induced pluripotent stem cells (iPSCs) support the replication of prions from brain samples of CJD patients. For experimental exposure of astrocytes to variant CJD (vCJD), the kinetics of prion replication occur in a prion protein codon 129 genotype-dependent manner, reflecting the genotype-dependent susceptibility to clinical vCJD found in patients. Furthermore, iPSC-derived astrocytes can replicate prions associated with the major sporadic CJD strains found in human patients. Lastly, we demonstrate the subpassage of prions from infected to naive astrocyte cultures, indicating the generation of prion infectivity in vitro. Our study addresses a long-standing gap in the repertoire of human prion disease research, providing a new in vitro system for accelerated mechanistic studies and drug discovery
Ultrasound-detected subclinical inflammation was better reflected by the disease activity score (DAS-28) in patients with suspicion of inflammatory arthritis compared to established rheumatoid arthritis
Limited data are available about the ultrasound (US)-detected inflammatory features in patients with suspicion of inflammatory arthritis (S-IA) vs. established rheumatoid arthritis (RA). Our study aimed to assess if the presence of power Doppler (PD) can be predicted by a combination of clinical, laboratory and US parameters. We conducted a real-life, retrospective cohort study comparing clinical, laboratory and US parameters of 108 patients with established RA and 93 patients with S-IA. We propose a PD signal prediction model based on a beta-binomial distribution for PD variable using a mix of outcome measures. Patients with RA in clinical remission had significantly more active inflammation and erosions on US when compared with patients with S-IA with similar disease scores (p = 0.03 and p = 0.01, respectively); however, RA patients with different disease activity score (DAS-28) scores had similar PD scores (p = 0.058). The PD scores did not correlate with erosions (p = 0.38) or DAS-28 scores (p = 0.28) in RA patients, but they correlated with high disease activity in S-IA patients (p = 0.048). Subclinical inflammation is more common in patients with RA in clinical remission or with low disease activity than in patients with S-IA; therefore, US was more useful in assessing for true remission in RA rather than diagnosing IA in patients with low disease activity scores. This is the first study to propose a PD prediction model integrating several outcome measures in the two different groups of patients. Further research into validating this model can minimise the risk of underdiagnosing subclinical inflammation
Impact of cyclooxygenase inhibitors in the Women's Health Initiative hormone trials: secondary analysis of a randomized trial.
OBJECTIVES: We evaluated the hypothesis that cyclooxygenase (COX) inhibitor use might have counteracted a beneficial effect of postmenopausal hormone therapy, and account for the absence of cardioprotection in the Women's Health Initiative hormone trials. Estrogen increases COX expression, and inhibitors of COX such as nonsteroidal anti-inflammatory agents appear to increase coronary risk, raising the possibility of a clinically important interaction in the trials. DESIGN: The hormone trials were randomized, double-blind, and placebo-controlled. Use of nonsteroidal anti-inflammatory drugs was assessed at baseline and at years 1, 3, and 6. SETTING: The Women's Health Initiative hormone trials were conducted at 40 clinical sites in the United States. PARTICIPANTS: The trials enrolled 27,347 postmenopausal women, aged 50-79 y. INTERVENTIONS: We randomized 16,608 women with intact uterus to conjugated estrogens 0.625 mg with medroxyprogesterone acetate 2.5 mg daily or to placebo, and 10,739 women with prior hysterectomy to conjugated estrogens 0.625 mg daily or placebo. OUTCOME MEASURES: Myocardial infarction, coronary death, and coronary revascularization were ascertained during 5.6 y of follow-up in the estrogen plus progestin trial and 6.8 y of follow-up in the estrogen alone trial. RESULTS: Hazard ratios with 95% confidence intervals were calculated from Cox proportional hazard models stratified by COX inhibitor use. The hazard ratio for myocardial infarction/coronary death with estrogen plus progestin was 1.13 (95% confidence interval 0.68-1.89) among non-users of COX inhibitors, and 1.35 (95% confidence interval 0.86-2.10) among continuous users. The hazard ratio with estrogen alone was 0.92 (95% confidence interval 0.57-1.48) among non-users of COX inhibitors, and 1.08 (95% confidence interval 0.69-1.70) among continuous users. In a second analytic approach, hazard ratios were calculated from Cox models that included hormone trial assignment as well as a time-dependent covariate for medication use, and an interaction term. No significant interaction was identified. CONCLUSIONS: Use of COX inhibitors did not significantly affect the Women's Health Initiative hormone trial results
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Eating Pattern Response to a Low-Fat Diet Intervention and Cardiovascular Outcomes in Normotensive Women: The Women's Health Initiative.
BackgroundWomen without cardiovascular disease (CVD) or hypertension at baseline assigned to intervention in the Women's Health Initiative Dietary Modification (DM) trial experienced 30% lower risk of coronary heart disease (CHD), whereas results in women with hypertension or prior CVD could have been confounded by postrandomization use of statins.ObjectivesIntervention participants reported various self-selected changes to achieve the 20% total fat goals. Reviewed are intervention compared with comparison group HRs for CHD, stroke, and total CVD in relation to specific dietary changes in normotensive participants.MethodsDietary change was assessed by comparing baseline with year 1 FFQ data in women (n = 10,371) without hypertension or CVD at baseline with intake of total fat above the median to minimize biases due to use of the FFQ in trial eligibility screening.ResultsIntervention participants self-reported compensating reduced energy intake from total fat by increasing carbohydrate and protein. Specifically they increased plant protein, with those in the upper quartile (increased total protein by ≥3.3% of energy) having a CHD HR of 0.39 (95% CI: 0.22, 0.71), compared with 0.92 (95% CI: 0.57, 1.48) for those in the lower quartile of change (decreased total protein ≥0.6% of energy), with P-trend of 0.04. CHD HR did not vary significantly with change in percentage energy from carbohydrate, and stroke HR did not vary significantly with any macronutrient changes. Scores reflecting adherence to recommended dietary patterns including the Dietary Approaches to Stop Hypertension Trial and the Healthy Eating Index showed favorable changes in the intervention group.ConclusionsIntervention group total fat reduction replaced with increased carbohydrate and some protein, especially plant-based protein, was related to lower CHD risk in normotensive women without CVD who reported high baseline total fat intake. This trial was registered at clinicaltrials.gov as NCT00000611. Link to the WHI trial protocol: https://www.whi.org/about/SitePages/Dietary%20Trial.aspx
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