¿Qué está pasando en Nigeria?

Un gran número de personas del noreste de Nigeria se han visto afectadas por la pobreza, la degradación ambiental y, sobre todo, por la violencia de Boko Haram. La necesidad de llevar allí nuestro conocimiento y nuestros recursos colectivos resulta evidente. Entonces, ¿por qué tomar cartas en el asunto sigue siendo difícil y qué podemos hacer para enderezar las cosas

LIMITING IMPACTS OF INVASIVE GLOSSY BUCKTHORN IN SOUTHEASTERN NEW HAMPSHIRE WOODLANDS: STUDIES OF INTENSIVE CONTROL AND FOREST DYNAMICS

Invasive glossy buckthorn (Frangula alnus P. Mill) threatens forest communities in southeastern New Hampshire both ecologically and economically by outcompeting native regeneration and hampering forest management. Seventy-five white pine (Pinus strobus L.) seedlings surrounded mainly by buckthorn were identified at the MacDonald Lot property in Durham, NH. In spring 2015, fifty of these pines were encouraged to emerge from and overtop surrounding buckthorn by cutting all neighboring plants within 1 m; targeted herbicide was applied to cut stumps at 25 of these. Pine response was assessed after one growing season. Released pines showed increased diameter growth, foliar biomass, and stem non-structural carbohydrate content. No growth differences between pines treated with herbicide and those not treated were observed; however buckthorn did recover more strongly in untreated plots. Buckthorn’s response to forest succession is not known, nor is the status of the regional invasion. To determine a) if the invasion is continuing to invade new stands, and b) what successional factors predict buckthorn presence and abundance in forests, I resampled 20 of 22 sites in an old-field chronosequence in Durham, NH initially sampled 17 years prior. Site characteristics such as age since abandonment, overall shade tolerance, and degree of occupation by various vegetation were analyzed. Site age and shade tolerance were the strongest predictors of buckthorn presence and abundance. In these unmanaged old-field sites, the buckthorn invasion seems to have stabilized with no net gain in stands invaded

From Mouse Models to Patients: A Comparative Bioinformatic Analysis of HFpEF and HFrEF

Heart failure (HF) represents an immense health burden with currently no curative therapeutic strategies. Study of HF patient heterogeneity has led to the recognition of HF with preserved (HFpEF) and reduced ejection fraction (HFrEF) as distinct syndromes regarding molecular characteristics and clinical presentation. Until the recent past, HFrEF represented the focus of research, reflected in the development of a number of therapeutic strategies. However, the pathophysiological concepts applicable to HFrEF may not be necessarily applicable to HFpEF. HF induces a series of ventricular modeling processes that involve, among others, hallmarks of hypertrophy, fibrosis, inflammation, all of which can be observed to some extent in HFpEF and HFrEF. Thus, by direct comparative analysis between HFpEF and HFrEF, distinctive features can be uncovered, possibly leading to improved pathophysiological understanding and opportunities for therapeutic intervention. Moreover, recent advances in biotechnologies, animal models, and digital infrastructure have enabled large-scale collection of molecular and clinical data, making it possible to conduct a bioinformatic comparative analysis of HFpEF and HFrEF. Here, I first evaluated the field of HF transcriptome research by revisiting published studies and data sets to provide a consensus gene expression reference. I discussed the patient clientele that was captured, revealing that HFpEF patients were not represented. Thus, I applied alternative approaches to study HFpEF. I utilized a mouse surrogate model of HFpEF and analyzed single cell transcriptomics to gain insights into the interstitial tissue remodeling. I contrasted this analysis by comparison of fibroblast activation patterns found in mouse models resembling HFrEF. The human reference was used to further demonstrate similarities between models and patients and a novel possible biomarker for HFpEF was introduced. Mouse models only capture selected aspects of HFpEF but largely fail to imitate the complex multi-factor and multi-organ syndrome present in humans. To account for this complexity, I performed a top-down analysis in HF patients by analyzing phenome-wide comorbidity patterns. I derived clinical insights by contrasting HFpEF and HFrEF patients and their comorbidity profiles. These profiles were then used to predict associated genetic profiles, which could be also recovered in the HFpEF mouse model, providing hypotheses about the molecular links of comorbidity profiles. My work provided novel insights into HFpEF and HFrEF syndromes and exemplified an interdisciplinary bioinformatic approach for a comparative analysis of both syndromes using different data modalities

DEA investment strategy in the Brazilian stock market

This paper presents a multi-period investment strategy using Data Envelopment Analysis (DEA) in the Brazilian stock market. Results show that the returns based on the DEA strategy were superior to the returns of a Brazilian stock index in most of the 22 quarters analyzed, presenting a significant Jensen's alpha.

Abordagem do Marketing de Relacionamento no Ensino Superior: Um Estudo Exploratório

A presente dissertação é um estudo exploratório sobre a viabilidade de implementação de uma abordagem de marketing de relacionamento nas universidades privadas e comunitárias. Apresenta uma análise do atual cenário competitivo do ensino superior brasileiro, com o objetivo de demonstrar que a utilização de estratégias de marketing é um fator crítico de sucesso para essas organizações. O trabalho trata da existência de barreiras contra uma abordagem de marketing nas universidades, fruto de um modelo de gestão acadêmica desenvolvido tendo como base um mercado sem competição, comprovando que há uma resistência contra o uso de estratégias mercadológicas nas instituições de ensino superior. No entanto, a rápida mudança no ambiente competitivo, ocasionada pela queda da demanda associada à multiplicação de novos concorrentes, tem feito com que algumas universidades passem a utilizar estratégias de marketing identificadas como marketing de massa. Neste trabalho são analisadas as estratégias de marketing utilizadas e são discutidos a sua importância e os seus resultados sob um enfoque transacional para, imediatamente, ser feito um confronto dessas estratégias com uma abordagem de marketing de relacionamento. É feita uma revisão teórica sobre o marketing relacional, sempre em paralelo com as teorias do marketing transacional e com imediata contextualização para organizações universitárias. Finalmente, são apresentados estudos sobre a aderência da abordagem do marketing de relacionamento na captação e retenção de alunos, com o objetivo de completar, apoiar ou substituir as estratégias de marketing de massa

Profiling of the anti-malarial drug candidate SC83288 against artemisinins in Plasmodium falciparum

Background: The increased resistance of the human malaria parasite Plasmodium falciparum to currently employed drugs creates an urgent call for novel anti-malarial drugs. Particularly, efforts should be devoted to developing fast-acting anti-malarial compounds in case clinical resistance increases to the first-line artemisinin-based combination therapy. SC83288, an amicarbalide derivative, is a clinical development candidate for the treatment of severe malaria. SC83288 is fast-acting and able to clear P. falciparum parasites at low nanomolar concentrations in vitro, as well as in a humanized SCID mouse model system in vivo. In this study, the antiplasmodial activity of SC83288 against artemisinins was profiled in order to assess its potential to replace, or be combined with, artemisinin derivatives. Results: Based on growth inhibition and ring survival assays, no cross-resistance was observed between artemisinins and SC83288, using parasite lines that were resistant to either one of these drugs. In addition, no synergistic or antagonistic interaction was observed between the two drugs. This study further confirmed that SC83288 is a fast acting drug in several independent assays. Combinations of SC83288 and artesunate maintained the rapid parasite killing activities of both components. Conclusion: The results obtained in this study are consistent with artemisinins and SC83288 having distinct modes of action and different mechanisms of resistance. This study further supports efforts to continue the clinical development of SC83288 against severe malaria as an alternative to artemisinins in areas critically affected by artemisinin-resistance. Considering its fast antiplasmodial activity, SC83288 could be combined with a slow-acting anti-malarial drug

Improving Performance of an Existing Heat Pump: A Case Study

Improving Performance of an Existing Heat Pump: A Case Study Vijay Bahel, Scott Lanzer and Suresh Shivashankar Emerson Climate Technologies Sidney, Ohio 45365, USA Phone: 937-498-3643, Fax: 937-498-3203 Email: [email protected] Abstract This paper presents the findings of a case study used to identify the design options for upgrading the performance of an Air Source Heat Pump with minimum design changes to the system chassis. We used Emerson’s Steady-State System Model to identify opportunities for improving the baseline SEER. Our starting point was a nominal Fixed Capacity 5 ton, 14 SEER Heat Pump using Refrigerant R-410a. In this exercise we identified opportunities to improve SEER by selecting a Variable Speed: (i) Compressor, and (i) Indoor and Outdoor Fans. These changes are relatively easy to implement and don’t require changes in the indoor and outdoor heat exchanger surfaces, circuiting etc. Additional improvements opportunities were found by optimizing Refrigerant Charge. SEER changed from 14.0 Btu/Wh to 16.6 Btu/Wh a gain of about 19%. We ended with a HSPF value of 10.6 Btu/Wh. As a first step, several Scroll Variable Speed Compressors models with different rated capacities and efficiencies were evaluated. Once the system model identified the best compressor candidate, we performed a validation run in the laboratory to confirm the findings of the system model before determining the other design options. Our findings show that the model provides excellent correlation between measured and simulated results. Next, we simulated several cases with different combinations of Compressor Speeds and Indoor and Outdoor Air Flow Rates for maximizing Cooling and Heating Performances. An additional benefit of the Indoor Fan Strategy is improved dehumidification with a lower Sensible Heat Ratio for cooling mode and higher delivered temperature for heating mode operation. We next performed simulations to find the best refrigerant charge for various combinations of Subcooling and Compressor Superheat settings. Once the design options were identified we proceeded to validate the simulated results with experimental data per guidelines listed in AHRI Standard 210/240 for both cooling and heating mode operation. Our findings show, the model’s accuarcy is within 5% for a variety of operating conditions. Using the simulation tool to model the system and analyze numerous design changes can eliminate several weeks of expensive laboratory testing and evaluation. While, the real cost of engineering time will vary by organization, it can safely be shown that there is a significant cost benefit associated in using the model to rapidly identify design options. It also offers opportunity to streamline the product development process and speed of the time it takes to get new products to market