223 research outputs found
Collaborative and competitive strategies in the variability and resiliency of large-scale societies in Mesoamerica
Examinations of the variation and duration of past large-scale societies have long involved a conceptual struggle between efforts at generalization and the unraveling of specific trajectories. Although historical particulars are critical to understanding individual cases, there exist both scientific and policy rationales for drawing broader implications regarding the growing corpus of cross-cultural data germane to understanding variability in the constitution of human societies, past and present. Archaeologists have recently paid increased attention to successes and failures in communal-resource management over the long term, as articulated by the transdisciplinary theory on cooperation and collective action. In this article, we consider frameworks that have been traditionally employed in studies of the rise, diversity, and fall of large-scale preindustrial aggregations. We suggest that a comparative theoretical perspective that foregrounds collective-action problems, unaligned individual and group interests, and the social mechanisms that promote or hamper cooperation advances our understanding of variability in these early cooperative arrangements. We apply such a perspective to an examination of cities from pre-Columbian Mesoamerica to demonstrate tendencies for more collective systems to be larger and longer lasting than less collective ones, likely reflecting greater resiliency in the face of the ecological and cultural perturbations specific to the region and era
Abordaxe fisioterápico no asma infantil
[Resumen] Objetivo: analizar qué intervenciones se están llevando a cabo por parte de la fisioterapia en la patología del asma.
Material y métodos: revisión de artículos en los cuales se lleven a cabo intervenciones de fisioterapia en niños asmáticos. La búsqueda se efectuó en las bases de datos Pubmed, PEDro, Web of Science y Scopus, seleccionando artículos publicados entre 2013 y 2017 en lengua inglesa, portuguesa y española.
Resultados: se seleccionaron 6 artículos, la mayoría de calidad intermedia, con variabilidad en el número de sujetos en cada estudio. La población que se seleccionó comprende desde el nacimiento hasta los 18 años. Las terapias fisioterápicas empleadas son variables. Se realiza en todos los casos un tratamiento enfocado al abordaje de las capacidades físicas por medio de diferentes programas de entrenamiento que cada estudio enfocó de forma diferente. Los aspectos más evaluados han sido la función pulmonar, la calidad de vida y la disnea, medidos a través de diferentes test y pruebas funcionales. Se obtienen resultados positivos en el manejo del asma con cada uno de estos programas de entrenamiento físico.
Conclusiones: existen múltiples programas de intervención fisioterápica sobre el asma. Se llevan a cabo programas de entrenamiento de la musculatura inspiratoria, entrenamiento aeróbico, anaeróbico, de fuerza y equilibrio por parte de la fisioterapia en el abordaje de esta patología y todos presentan beneficio sobre ella. Asimismo, se objetivó que el programa de tratamiento que engloba un entrenamiento basado en ejercicio aeróbico y ejercicios respiratorios presenta una mayor eficacia.[Abstract] Objective: to analyze what interventions are being carried out by physiotherapy in the pathology of asthma.
Material and methods: review of articles in which physiotherapy interventions are carried out in asthmatic children. The search was carried out in the Pubmed, PEDro, Web of Science and Scopus databases, selecting articles published between 2013 and 2017 in English, Portuguese and Spanish.
Results: Six articles were selected, most of intermediate quality, with variability in the number of subjects in each study. The population that was selected comprises from birth to 18 years. The physiotherapeutic therapies used are variable. In all cases, a treatment focused on addressing physical abilities is carried out through different training programs that each study focused on differently. The most evaluated aspects have been pulmonary function, quality of life and dyspnea, measured through different tests and functional tests. Positive results are obtained in the management of asthma with each of these physical training programs.
Conclusions: There are multiple programs of physiotherapy intervention on asthma. Training programs for inspiratory musculature, aerobic, anaerobic, strength and balance training are carried out by physiotherapy in the approach to this pathology and all have benefit over it. Likewise, it was found that the treatment program that includes a training based on aerobic exercise and breathing exercises is more effective.[Resumo] Obxectivo: analizar que intervencións se están a facer por parte da fisioterapia na patoloxía da asma.
Material e metodoloxía: revisión de artículos nos que se fagan intervencións de fisioterapia en nenos asmáticos. A búsqueda efectuouse nas bases de datos Pubmed, PEDro, Web of Science y Scopus, seleccionando artículos publicados entre 2013 y 2017 en lingua inglesa, portuguesa e española.
Resultados: seleccionáronse 6 artigos, a maioría de calidade intermedia, con variabilidade no número de suxeitos en cada estudo. A poboación que se seleccionou comprende dende o nacemento ata os 18 anos. As terapias fisioterápicas empregadas son variables. Realizouse en todos os casos un tratamento enfocado á abordaxe das capacidades físicas por medio de diferentes programas de entrenamento que cada estudo enfocou de forma diferente. Os aspectos máis avaliados foron a función pulmonar, a calidade da vida e a disnea, medidos a través de diferentes test e probas funcionais. Obtéñense resultados positivos no manexo do asma con cada un destes programas de entrenamento físico.
Conclusións: existen múltiples programas de intervención fisioterápica sobre a asma infantil. Lévanse a cabo programas de entrenamento da musculatura inspiratoria, entrenamiento aeróbico, anaeróbico, de forza e equilibrio por parte da fisioterapia no abordaxe desta patoloxía e todos presentan beneficio sobre ela. Así mesmo obxectivouse que o programa de tratamento que engloba un entrenamento baseado no exercicio aeróbico e exercicios respiratorios presenta unha maior eficacia.Traballo fin de grao (UDC.FCS). Fisioterapia. Curso 2017/201
The scale, governance, and sustainability of central places in pre-Hispanic Mesoamerica
Examinations of the variation and relative successes or failures of past large-scale societies have long involved attempts to reconcile efforts at generalization and the identification of specific factors with explanatory value for regional trajectories. Although historical particulars are critical to understanding individual cases, there are both scholarly and policy rationales for drawing broader implications regarding the growing corpus of cross-cultural data germane to understanding variability in the constitution of human societies, past and present. Archaeologists have recently highlighted how successes and failures in communal-resource management can be studied over the long term through the material record to both engage and enhance transdisciplinary research on cooperation and collective action. In this article we consider frameworks that have been traditionally employed in studies of the rise, diversity, and fall of preindustrial urban aggregations. We suggest that a comparative theoretical perspective that foregrounds collective-action problems, unaligned individual and group interests, and the social mechanisms that promote or hamper cooperation advances our understanding of variability in these early cooperative arrangements. We apply such a perspective to an examination of pre-Hispanic Mesoamerican urban centers to demonstrate tendencies for more collective systems to be larger and longer lasting than less collective ones, likely reflecting greater sustainability in the face of the ecological and cultural perturbations specific to the region and era.Accepted manuscrip
Cell cycle regulation in hematopoietic stem cells
Hematopoietic stem cells (HSCs) give rise to all lineages of blood cells. Because HSCs must persist for a lifetime, the balance between their proliferation and quiescence is carefully regulated to ensure blood homeostasis while limiting cellular damage. Cell cycle regulation therefore plays a critical role in controlling HSC function during both fetal life and in the adult. The cell cycle activity of HSCs is carefully modulated by a complex interplay between cell-intrinsic mechanisms and cell-extrinsic factors produced by the microenvironment. This fine-tuned regulatory network may become altered with age, leading to aberrant HSC cell cycle regulation, degraded HSC function, and hematological malignancy
Colorectal Cancer Stem Cells Are Enriched in Xenogeneic Tumors Following Chemotherapy
Patients generally die of cancer after the failure of current therapies to eliminate residual disease. A subpopulation of tumor cells, termed cancer stem cells (CSC), appears uniquely able to fuel the growth of phenotypically and histologically diverse tumors. It has been proposed, therefore, that failure to effectively treat cancer may in part be due to preferential resistance of these CSC to chemotherapeutic agents. The subpopulation of human colorectal tumor cells with an ESA(+)CD44(+) phenotype are uniquely responsible for tumorigenesis and have the capacity to generate heterogeneous tumors in a xenograft setting (i.e. CoCSC). We hypothesized that if non-tumorigenic cells are more susceptible to chemotherapeutic agents, then residual tumors might be expected to contain a higher frequency of CoCSC.Xenogeneic tumors initiated with CoCSC were allowed to reach approximately 400 mm(3), at which point mice were randomized and chemotherapeutic regimens involving cyclophosphamide or Irinotecan were initiated. Data from individual tumor phenotypic analysis and serial transplants performed in limiting dilution show that residual tumors are enriched for cells with the CoCSC phenotype and have increased tumorigenic cell frequency. Moreover, the inherent ability of residual CoCSC to generate tumors appears preserved. Aldehyde dehydrogenase 1 gene expression and enzymatic activity are elevated in CoCSC and using an in vitro culture system that maintains CoCSC as demonstrated by serial transplants and lentiviral marking of single cell-derived clones, we further show that ALDH1 enzymatic activity is a major mediator of resistance to cyclophosphamide: a classical chemotherapeutic agent.CoCSC are enriched in colon tumors following chemotherapy and remain capable of rapidly regenerating tumors from which they originated. By focusing on the biology of CoCSC, major resistance mechanisms to specific chemotherapeutic agents can be attributed to specific genes, thereby suggesting avenues for improving cancer therapy
Integrating syntactic theory and variationist analysis : The structure of negative indefinites in regional dialects of British English
This paper integrates syntactic theory and variationist analysis in an investigation of the variation between English 'not'-negation ('I don’t have any money'), 'no'-negation ('I have no money') and negative concord ('I don’t have no money'). Using corpora of three varieties of UK English spoken in Glasgow, Tyneside and Salford respectively, I test two theoretical accounts of the variation. Account 1 applies Zeijlstra’s (2004) agreement-based theory of negative concord to all three variants, such that n-words (e.g. 'nobody') which feature in 'no'-negation and negative concord are not inherently negative but agree with a negative operator in a higher NegP. Under Account 2, 'no'-negation is instead derived via negative-marking within the DP followed by movement to the higher NegP for sentential scope (Kayne 1998; Svenonius 2002; Zeijlstra 2011). These accounts, together with observations about the raising properties of functional versus lexical verbs, lead to the formulation of different hypotheses about the distribution of variants in speech according to verb type, verb phrase complexity, and the discourse status of the propositions expressed. Results of distributional analysis and mixed-effects modelling support Account 2 of the variation over Account 1, suggesting structural identity between 'not'-negation and negative concord (in contrast to 'no'-negation). This supports Tubau’s (2016) proposal that English negative indefinites have two distinct structures: one in which negation is marked syntactically in the DP and one in which they agree with a syntactically-higher NegP
Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial
Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402
Acute and endothelial-specific Robo4 deletion affect hematopoietic stem cell trafficking independent of VCAM1
EL SISTEMA MUNDIAL MESOAMERICANO POSTCLÁSICO
En el periodo Postclásico medio y tardío (1200-1520 d.C.), las diversas regiones de Mesoamérica estaban más fuertemente integradas que en cualquier otro tiempo. Esta integración fue creada y mantenida por el intercambio comercial, el imperialismo y la extensión de estilos artísticos e iconográficos. Presentamos un modelo teórico para explicar estos procesos. Es un ejemplo de la aplicación de la perspectiva del sistema mundial. Aunque en el fondo se deriva de la teoría del sistema mundial de Wallerstein, nuestro modelo es modificado extensamente por su aplicación a las sociedades no-capitalistas de la antigua Mesoamérica.
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