1,107 research outputs found
Maroon Archaeology Beyond the Americas: A View From Kenya
Archaeological research on Maroons—that is, runaway slaves—has been largely confined to the Americas. This essay advocates a more global approach. It specifically uses two runaway slave communities in 19th-century coastal Kenya to rethink prominent interpretive themes in the field, including “Africanisms,” Maroons’ connections to indigenous groups, and Maroon group cohesion and identity. This article’s analysis demonstrates that the comparisons enabled by a more globalized perspective benefit the field. Instead of eliding historical and cultural context, these comparisons support the development of more localized and historically specific understandings of individual runaway slave communities both in Kenya and throughout the New World
Adaptive pairs trading strategy performance in Turkish derivatives exchange with the companies listed on Istanbul stock exchange
Due to copyright restrictions, the access to the full text of this article is only available via subscription.We implemented model-driven statistical arbitrage strategies in Turkish equities market. Trading signals are generated by optimized parameters of distance method. When the trade in signal is triggered by the model, market-neutral portfolio is created by long in the synthetic ETF, which is based on constrained least squares regression of selected Istanbul Stock Exchange stocks and short in Turkish Derivatives Exchange (Turkdex) index futures contract. We performed pairs trading strategy based on a comparative mean reversion of asset prices with daily data over the period February 2005 through July 2011 in Istanbul Stock Exchange (ISE) and Turkdex. We constructed a hypothetical ISE30 ETF Index on a daily basis in order to originate pairs trading strategy with Turkdex. Because of the leverage rule of (1–10) index futures contracts, we had to evaluate spot stock pairs formation with futures contracts pairs strategy. The results indicate that applied pairs strategy produced overall returns of 901 per cent during the investment period, whereas naive strategy (buy and hold ISE-30 index) return for the same period was 111 per cent. Similar outperformance was observed in the Sharpe and Sortino ratios
Adaptation and validation of the Inventory of family protective factors for the portuguese culture
Aim: Describe the process of cultural adaptation and validation of Inventory of Family Protective Factors (IFPF) for portuguese culture. This instrument assesses the protective factors that contribute to family resilience. Studies of resilience fall the salutogenic paradigm, which focuses on protective factors of individuals or groups, without minimizing the risk factors and vulnerability. Methods: We applied this instrument to 85 families of children with special needs and, after linguistic and conceptual equivalence, used an exploratory factor analysis with principal components analysis (with varimax rotation) and calculated the Cronbach's alpha coefficient for each dimension. Results: adequate psychometric properties to be used in Portuguese population (Cronbach´s alpha =.90). Conclusion: IFPF is an useful instrument for studies which propose assess the protective factors of family resilience, however we suggest further studies of revalidation.Objetivo: Describir el proceso de adaptación cultural y validación para la cultura portuguesa de Inventory of Family Protective Factors (IFPF). Este instrumento evalúa los factores de protección que contribuyan a la resiliencia familiar. Estudios de resiliência familiar se apoyan en el paradigma salutogénico, que se centra en los factores de protección de individuos o grupos, sin subestimar los factores de riesgo y vulnerabilidad. Metodologia: Aplicamos este instrumento a 85 familias de niños con necesidades especiales y, después de la equivalencia lingüística y conceptual, hemos llevado a cabo un análisis factorial exploratorio de componentes principales con rotación varimax y calculamos el coeficiente alfa de Cronbach. Resultados: la IFPF tiene adecuadas propiedades psicométricas para la población portuguesa (alfa de Cronbach = .90). Conclusion: Esta es una herramienta útil para evaluar los factores protectores de la resiliencia familiar, sin embargo sugerimos estudios futuros de revalidación.Objetivos: adaptar e validar o Inventory of Family Protective Factors (IFPF) para a cultura portuguesa. Este instrumento avalia os fatores protetores que contribuem para a resiliência familiar. Os estudos sobre resiliência inserem-se no paradigma salutogénico, abordando os fatores protetores dos indivíduos ou grupos, sem subestimar os fatores de risco ou vulnerabilidade. Método: para avaliar a equivalência linguística e conceitual do IFPF realizamos a tradução, retroversão e reflexão falada; para aferir as características psicométricas do instrumento verificamos a sensibilidade, confiabilidade e a validade dos resultados. Realizamos uma análise fatorial de componentes principais com rotação varimax dos itens da escala e calculamos o coeficiente Alpha de Cronbach para cada dimensão. Através de uma amostragem aleatória simples, aplicamos este instrumento a 85 famílias de crianças com necessidades especiais que o auto-preencheram. Resultados: o IFPF apresenta características psicométricas adequadas para a população portuguesa (alfa de Cronbach de .90). Conclusão: o IFPF foi adaptado e validado para a cultura portuguesa. Consideramos tratar-se de um instrumento útil para estudos que se proponham avaliar os fatores protetores da resiliência familiar
Directed acyclic graph kernels for structural RNA analysis
<p>Abstract</p> <p>Background</p> <p>Recent discoveries of a large variety of important roles for non-coding RNAs (ncRNAs) have been reported by numerous researchers. In order to analyze ncRNAs by kernel methods including support vector machines, we propose stem kernels as an extension of string kernels for measuring the similarities between two RNA sequences from the viewpoint of secondary structures. However, applying stem kernels directly to large data sets of ncRNAs is impractical due to their computational complexity.</p> <p>Results</p> <p>We have developed a new technique based on directed acyclic graphs (DAGs) derived from base-pairing probability matrices of RNA sequences that significantly increases the computation speed of stem kernels. Furthermore, we propose profile-profile stem kernels for multiple alignments of RNA sequences which utilize base-pairing probability matrices for multiple alignments instead of those for individual sequences. Our kernels outperformed the existing methods with respect to the detection of known ncRNAs and kernel hierarchical clustering.</p> <p>Conclusion</p> <p>Stem kernels can be utilized as a reliable similarity measure of structural RNAs, and can be used in various kernel-based applications.</p
Association of nutritional status and serum albumin levels with development of toxicity in patients with advanced non-small cell lung cancer treated with paclitaxel-cisplatin chemotherapy: a prospective study
<p>Abstract</p> <p>Background</p> <p>A frequent manifestation of advanced NSCLC is malnutrition, even though there are many studies which relate it with a poor survival, its relation with toxicity has not yet been consistently reported. The aim of this study was to associate malnutrition and albumin serum levels with the occurrence of chemotherapy-induced toxicity in cisplatin plus paclitaxel chemotherapy-treated NSCLC.</p> <p>Methods</p> <p>We prospectively evaluated 100 stage IV NSCLC patients treated with paclitaxel (175 mg/m<sup>2</sup>) and cisplatin (80 mg/m<sup>2</sup>). Malnutrition was assessed using SGA prior treatment. Neutrophil Lymphocyte Ratio (NLR) and the Platelet Lymphocyte Ratio (PLR) were used to determine the presence of systemic inflammatory response (SIR) and were related to the development of toxicity. Toxicity was graded according to NCI CTCAE version 3.0 after two chemotherapy cycles.</p> <p>Results</p> <p>Median age was 58 ± 10 years, 51% of patients were malnourished, 50% had albumin ≤3.0 mg/mL. NLR ≥ 5 was associated with basal hypoalbuminemia (mean ranks, 55.7 vs. 39 p = 0.006), ECOG = 2 (47.2 vs. 55.4 p = 0.026) and PLR ≥ 150 were significantly related with a basal body mass index ≤20 (56.6 vs. 43.5; p = 0.02) and hypoalbuminemia (58.9 vs. 41.3; p = 0.02). Main toxicities observed after 2 cycles of chemotherapy were alopecia (84%), nausea (49%), neuropathy (46%), anemia (33%), lymphopenia (31%), and leukopenia (30%). Patients malnourished and with hypoalbuminemia developed more chemotherapy-induced toxicity overall when compared with those without malnutrition (31 vs 22; <it>p </it>= 0.02) and normal albumin (mean ranks, 62 vs 43; <it>p </it>= 0.002), respectively. Hypoalbuminemia was associated with anemia (56 vs 47; <it>p </it>= 0.05), fatigue (58 vs 46; <it>p </it>= 0.01), and appetite loss (57.1 vs 46.7; <it>p </it>= 0.004) compared with normal albumin. PLR ≥ 150 was related with the development of toxicity grade III/IV (59.27 vs. 47.03 p = 0.008) and anemia (37.9 vs 53.8 p = 0.004).</p> <p>Conclusion</p> <p>SIR parameters were associated with malnutrition, weight loss and hypoalbuminemia. Chemotherapy-induced toxicity in NSCLC patients treated with paclitaxel and cisplatin was associated with malnutrition and hypoalbuminemia. Early nutritional assessment and support might confer beneficial effects.</p
Autoimmunity in CD73/Ecto-5′-Nucleotidase Deficient Mice Induces Renal Injury
Extracellular adenosine formed by 5′-ectonucleotidase (CD73) is involved in tubulo-glomerular feedback in the kidney but is also known to be an important immune modulator. Since CD73−/−mutant mice exhibit a vascular proinflammatory phenotype, we asked whether long term lack of CD73 causes inflammation related kidney pathologies. CD73−/−mice (13 weeks old) showed significantly increased low molecule proteinuria compared to C57BL6 wild type controls (4.8≥0.52 vs. 2.9±0.54 mg/24 h, p<0.03). Total proteinuria increased to 5.97±0.78 vs. 2.55±0.35 mg/24 h at 30 weeks (p<0.01) whereas creatinine clearance decreased (0.161±0.02 vs. 0.224±0.02 ml/min). We observed autoimmune inflammation in CD73−/−mice with glomerulitis and peritubular capillaritis, showing glomerular deposition of IgG and C3 and enhanced presence of CD11b, CD8, CD25 as well as GR-1-positive cells in the interstitium. Vascular inflammation was associated with enhanced serum levels of the cytokines IL-18 and TNF-α as well as VEGF and the chemokine MIP-2 (CXCL-2) in CD73−/−mice, whereas chemokines and cytokines in the kidney tissue were unaltered or reduced. In CD73−/−mice glomeruli, we found a reduced number of podocytes and endothelial fenestrations, increased capillaries per glomeruli, endotheliosis and enhanced tubular fibrosis. Our results show that adult CD73−/−mice exhibit spontaneous proteinuria and renal functional deterioration even without exogenous stress factors. We have identified an autoimmune inflammatory phenotype comprising the glomerular endothelium, leading to glomeruli inflammation and injury and to a cellular infiltrate of the renal interstitium. Thus, long term lack of CD73 reduced renal function and is associated with autoimmune inflammation
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