Ecological niche modeling and geographical distribution of pollinator and plants: A case study of Peponapis fervens (Smith, 1879) (Eucerini: Apidae) and Cucurbita species (Cucurbitaceae)

The bees of the Peponapes genus (Eucerini, Apidae) have a Neotropical distribution with the center of species diversity located in Mexico and are specialized in Cucurbita plants. which have many species of economic importance. such as squashes and pumpkins Peponapis fervens is the only species of the genus known from southern South America The Cucurbita species occurring in the same area as P fervens Include four domesticated species (C ficifolia, C maxima maxima, C moschata and C pepo) and one non-domesticated species (Cucurbita maxima andreana) It was suggested that C. in andreana was the original pollen source to P fervens, and this bee expanded its geographical range due to the domestication of Cucurbita The potential geographical areas of these species were determined and compared using ecological niche modeling that was performed with the computational system openModeller and GARP with best subsets algorithm The climatic variables obtained through modeling were compared using Cluster Analysis Results show that the potential areas of domesticated species practically spread all over South America The potential area of P fervens Includes the areas of C m andreana but reaches a larger area, where the domesticated species of Cucurbita also Occur The Cluster Analysis shows a high climatic similarity between P fervens and C. m. andreana Nevertheless. P fervens presents the ability to occupy areas with wider ranges of climatic variables and to exploit resources provided by domesticated species (C) 2009 Elsevier B V All rights reserved

Ecological niche modeling and principal component analysis of Krameria Loefl. (Krameriaceae)

Krameria plants are found in arid regions of the Americas and present a floral system that attracts oil-collecting bees. Niche modeling and multivariate tools were applied to examine ecological and geographical aspects of the 18 species of this genus, using occurrence data obtained from herbaria and literature. Niche modeling showed the potential areas of occurrence for each species and the analysis of climatic variables suggested that North American species occur mostly in deserted or xeric ecoregions with monthly precipitation below 140 mm and large temperature ranges. South American species are mainly found in deserted ecoregions and subtropical savannas where monthly precipitation often exceeds 150 mm and temperature ranges are smaller. Principal Component Analysis (PCA) performed with values of temperature and precipitation showed that the distribution limits of Krameria species are primarily associated with maximum and minimum temperatures. Modeling of Krameria species proved to be a useful tool for analyzing the influence of the ecological niche variables in the geographical distribution of species, providing new information to guide future investigations. (C) 2011 Elsevier Ltd. All rights reserved.

Epidemiology and control of frontier malaria in Brazil: lessons from community-based studies in rural Amazonia

We describe the epidemiology of malaria in a frontier agricultural settlement in Brazilian Amazonia. We analysed the incidence of slide-confirmed symptomatic infections diagnosed between 2001 and 2006 in a cohort of 531 individuals (2281.53 person-years of follow-up) and parasite prevalence data derived from four cross-sectional surveys. Overall, the incidence rates of Plasmodium vivax and P. falciparaum were 20.6/100 and 6.8/100 person-years at risk, respectively, with a marked decline in the incidence of both species (81.4 and 56.8%, respectively) observed between 2001 and 2006. PCR revealed 5.4-fold more infections than conventional microscopy in population-wide cross-sectional surveys carried out between 2004 and 2006 (average prevalence, 11.3 vs. 2.0%). Only 27.2% of PCR-positive (but 73.3% of slide-positive) individuals had symptoms when enrolled, indicating that asymptomatic carriage of low-grade parasitaemias is a common phenomenon in frontier settlements. A circular cluster comprising 22.3% of the households, all situated in the area of most recent occupation, comprised 69.1% of all malaria infections diagnosed during the follow-up, with malaria incidence decreasing exponentially with distance from the cluster centre. By targeting one-quarter of the households, with selective indoor spraying or other house-protection measures, malaria incidence could be reduced by more than two-thirds in this community. (C) 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

On modeling and evaluating multicomputer transcoding architectures for live-video streams

The pervasive and ubiquitous computing has motivated researches on multimedia adaptation which aims at matching the video quality to the user needs and device restrictions. This technique has a high computational cost which needs to be studied and estimated when designing architectures and applications. This paper presents an analytical model to quantify these video transcoding costs in a hardware independent way. The model was used to analyze the impact of transcoding delays in end-to-end live-video transmissions over LANs, MANs and WANs. Experiments confirm that the proposed model helps to define the best transcoding architecture for different scenarios.

On the efficiency of data representation on the modeling and characterization of complex networks

Specific choices about how to represent complex networks can have a substantial impact on the execution time required for the respective construction and analysis of those structures. In this work we report a comparison of the effects of representing complex networks statically by adjacency matrices or dynamically by adjacency lists. Three theoretical models of complex networks are considered: two types of Erdos-Renyi as well as the Barabasi-Albert model. We investigated the effect of the different representations with respect to the construction and measurement of several topological properties (i.e. degree, clustering coefficient, shortest path length, and betweenness centrality). We found that different forms of representation generally have a substantial effect on the execution time, with the sparse representation frequently resulting in remarkably superior performance. (C) 2011 Elsevier B.V. All rights reserved.

Structural modeling and mutational analysis of yeast eukaryotic translation initiation factor 5A reveal new critical residues and reinforce its involvement in protein synthesis

Eukaryotic translation initiation factor 5A (eIF5A) is a protein that is highly conserved and essential for cell viability. This factor is the only protein known to contain the unique and essential amino acid residue hypusine. This work focused on the structural and functional characterization of Saccharomyces cerevisiae eIF5A. The tertiary structure of yeast eIF5A was modeled based on the structure of its Leishmania mexicana homologue and this model was used to predict the structural localization of new site-directed and randomly generated mutations. Most of the 40 new mutants exhibited phenotypes that resulted from eIF-5A protein-folding defects. Our data provided evidence that the C-terminal alpha-helix present in yeast eIF5A is an essential structural element, whereas the eIF5A N-terminal 10 amino acid extension not present in archaeal eIF5A homologs, is not. Moreover, the mutants containing substitutions at or in the vicinity of the hypusine modification site displayed nonviable or temperature-sensitive phenotypes and were defective in hypusine modification. Interestingly, two of the temperature-sensitive strains produced stable mutant eIF5A proteins - eIF5A(K56A) and eIF5A(Q22H,L93F)- and showed defects in protein synthesis at the restrictive temperature. Our data revealed important structural features of eIF5A that are required for its vital role in cell viability and underscored an essential function of eIF5A in the translation step of gene expression.

Molecular modeling and UV-vis spectroscopic studies on the mechanism of action of reversed chloroquine (RCQ)

Reversed chloroquine (RCQ) is a multiple ligand compound active against chloroquine-sensitive and resistant falciparum malaria. It is composed by a 4-aminoquinoline moiety (like that present in chloroquine (CQ)) joined to imipramine (IMP), a modulating agent that also showed intrinsic antiplasmodial activity against Brazilian Plasmodium falciparum isolates resistant to CQ. Molecular modeling and ultraviolet-visible spectroscopy (UV-vis) studies strongly suggest that the interaction between RCQ and heme is predominant through the quinoline moiety in a mechanism of action similar to that observed for CQ. (C) 2010 Elsevier Ltd. All rights reserved.

Modeling and simulation of the anode in direct ethanol fuels cells

Mathematical modeling has been extensively applied to the study and development of fuel cells. In this work, the objective is to characterize a mechanistic model for the anode of a direct ethanol fuel cell and perform appropriate simulations. The software Comsol Multiphysics (R) (and the Chemical Engineering Module) was used in this work. The software Comsol Multiphysics (R) is an interactive environment for modeling scientific and engineering applications using partial differential equations (PDEs). Based on the finite element method, it provides speed and accuracy for several applications. The mechanistic model developed here can supply details of the physical system, such as the concentration profiles of the components within the anode and the coverage of the adsorbed species on the electrode surface. Also, the anode overpotential-current relationship can be obtained. To validate the anode model presented in this paper, experimental data obtained with a single fuel cell operating with an ethanol solution at the anode were used. (C) 2008 Elsevier B.V. All rights reserved.

Open Circuit Interaction of Formic Acid with Oxidized Pt Surfaces: Experiments, Modeling, and Simulations

We report in this work the study of the interaction between formic acid and an oxidized platinum surface under open circuit conditions. The investigation was carried out with the aid of in situ infrared spectroscopy, and results analyzed in terms of a mathematical model and numerical simulations. It has been found that during the first seconds of the interaction a small amount of CO(2) is produced and absolutely no adsorbed CO was observed. A sudden drop in potential then follows, which is accompanied by a steep increase first of CO(2) production and then by adsorbed CO. The steep transient was rationalized in terms of an autocatalytic production of free platinum sites which enhances the overall rate of reaction. Modeling and simulation showed nearly quantitative agreement with the experimental observations and provided further insight into some experimentally inaccessible variables such as surface free sites. Finally, based on the understanding provided from the combined experimental and theoretical approach, we discuss the general aspects influencing the open circuit transient.

Manoeuvring between anxiety and control : Patients experience of learning to live with diabetes: a lifeworld phenomenological study

Research shows that people with diabetes want their lives to proceed as normally as possible, but some patients experience difficulty in reaching their desired goals with treatment. The learning process is a complex phenomenon interwoven into every facet of life. Patients and healthcare providers often have different perspectives in care which gives different expectations on what the patients need to learn and cope with. The aim of this study, therefore, is to describe the experience of learning to live with diabetes. Interviews were conducted with 12 patients afflicted with type 1 or type 2 diabetes. The interviews were then analysed with reference to the reflective lifeworld research approach. The analysis shows that when the afflicted realize that their bodies undergo changes and that blood sugar levels are not always balanced as earlier in life, they can adjust to their new conditions early. The afflicted must take responsibility for balancing their blood sugar levels and incorporating the illness into their lives. Achieving such goals necessitates knowledge. The search for knowledge and sensitivity to changes are constant requirements for people with diabetes. Learning is driven by the tension caused by the need for and dependence on safe blood sugar control, the fear of losing such control, and the fear of future complications. The most important responsibilities for these patients are aspiring to understand their bodies as lived bodies, ensuring safety and security, and acquiring the knowledge essential to making conscious choices.

Modeling and illustrating requirement prioritization in public e-service development from a value-based perspective

A major problem in e-service development is the prioritization of the requirements of different stakeholders. The main stakeholders are governments and their citizens, all of whom have different and sometimes conflicting requirements. In this paper, the prioritization problem is addressed by combining a value-based approach with an illustration technique. This paper examines the following research question: How can multiple stakeholder requirements be illustrated from a value-based perspective in order to be prioritizable? We used an e-service development case taken from a Swedish municipality to elaborate on our approach. Our contributions are: 1) a model of the relevant domains for requirement prioritization for government, citizens, technology, finances and laws and regulations; and 2) a requirement fulfillment analysis tool (RFA) that consists of a requirement-goal-value matrix (RGV), and a calculation and illustration module (CIM). The model reduces cognitive load, helps developers to focus on value fulfillment in e-service development and supports them in the formulation of requirements. It also offers an input to public policy makers, should they aim to target values in the design of e-services.

Final report on heat pump developments in WP 4 - MacSheep Deliverable 4.4 : MacSheep -New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance

FP7- MacSheep

Influence of hydraulics and control of thermal storage in solar assisted heat pump combisystems

This paper studies the influence of hydraulics and control of thermal storage in systems combined with solar thermal and heat pump for the production of warm water and space heating in dwellings. A reference air source heat pump system with flat plate collectors connected to a combistore was defined and modeled together with the IEA SHC Task 44 / HPP Annex 38 (T44A38) “Solar and Heat Pump Systems” boundary conditions of Strasbourg climate and SFH45 building. Three and four pipe connections as well as use of internal and external heat exchangers for DHW preparation were investigated as well as sensor height for charging of the DHW zone in the store. The temperature in this zone was varied to ensure the same DHW comfort was achieved in all cases. The results show that the four pipe connection results in 9% improvement in SPF compared to three pipe and that the external heat exchanger for DHW preparation leads to a 2% improvement compared to the reference case. Additionally the sensor height for charging the DHW zone of the store should not be too low, otherwise system performance is adversely affected

Modeling and forecasting long-term natural gas (NG) consumption in Iran, using particle swarm optimization (PSO)

The gradual changes in the world development have brought energy issues back into high profile. An ongoing challenge for countries around the world is to balance the development gains against its effects on the environment. The energy management is the key factor of any sustainable development program. All the aspects of development in agriculture, power generation, social welfare and industry in Iran are crucially related to the energy and its revenue. Forecasting end-use natural gas consumption is an important Factor for efficient system operation and a basis for planning decisions. In this thesis, particle swarm optimization (PSO) used to forecast long run natural gas consumption in Iran. Gas consumption data in Iran for the previous 34 years is used to predict the consumption for the coming years. Four linear and nonlinear models proposed and six factors such as Gross Domestic Product (GDP), Population, National Income (NI), Temperature, Consumer Price Index (CPI) and yearly Natural Gas (NG) demand investigated.