78 research outputs found
A Model for Accomplishing and Managing Dynamic Cloud Federations
Cloud computing is not just a promising approach to the service provisioning: nowadays it represents the reference model in such field. Several cloud service providers have emerged as de facto standards and an increasing number of companies are choosing to migrate their business in the Cloud "ecosystem". Nevertheless, each provider adopts a particular interface to manage its services and uses a proprietary technology. In this paper we present a cloud federation model which is able to provide scalability and flexibility to small clouds. The idea is to benefit of renting seamless resources according to federation agreements among operators. The challenge here is to overcome all the problems raising trying to merge small clouds with heterogeneous administrative domains
Creating and Managing Dynamic Cloud Federations
Cloud computing has evolved from a promising approach to the service provisioning to the reference model for all new data centres to build. Additionally, an increasing number of companies are choosing to migrate their business in the cloud "ecosystem" adopting the solutions developed by the biggest public Cloud Service Providers (CSPs). Smaller CSPs build their infrastructure on technologies available and to better support user activities and provide enough resources to their users, the federation could be a possible solution. In this work, we present different federation models, showing their strengths and weakness together with our considerations. Beside the highlighted existing federation we show the design of a new implementations under development at INFN aiming at maximising the scalability and flexibility of small and/or hybrid clouds by the introduction of a federation manager. This new component will support a seamless resources renting on the base of acceptance of federation agreements among operators. Additionally, we will discuss how the implementation of this model inside research institutes could help in the field of High Energy Physics with explicit reference at LHC experiments, digital humanities, life sciences and others
Studying GGDEF Domain in the Act: Minimize Conformational Frustration to Prevent Artefacts
GGDEF-containing proteins respond to different environmental cues to finely modulate cyclic diguanylate (c-di-GMP) levels in time and space, making the allosteric control a distinctive trait of the corresponding proteins. The diguanylate cyclase mechanism is emblematic of this control: two GGDEF domains, each binding one GTP molecule, must dimerize to enter catalysis and yield c-di-GMP. The need for dimerization makes the GGDEF domain an ideal conformational switch in multidomain proteins. A re-evaluation of the kinetic profile of previously characterized GGDEF domains indicated that they are also able to convert GTP to GMP: this unexpected reactivity occurs when conformational issues hamper the cyclase activity. These results create new questions regarding the characterization and engineering of these proteins for in solution or structural studies
The Atlas of human African trypanosomiasis: a contribution to global mapping of neglected tropical diseases
<p>Abstract</p> <p>Background</p> <p>Following World Health Assembly resolutions 50.36 in 1997 and 56.7 in 2003, the World Health Organization (WHO) committed itself to supporting human African trypanosomiasis (HAT)-endemic countries in their efforts to remove the disease as a public health problem. Mapping the distribution of HAT in time and space has a pivotal role to play if this objective is to be met. For this reason WHO launched the HAT Atlas initiative, jointly implemented with the Food and Agriculture Organization of the United Nations, in the framework of the Programme Against African Trypanosomosis.</p> <p>Results</p> <p>The distribution of HAT is presented for 23 out of 25 sub-Saharan countries having reported on the status of sleeping sickness in the period 2000 - 2009. For the two remaining countries, i.e. Angola and the Democratic Republic of the Congo, data processing is ongoing. Reports by National Sleeping Sickness Control Programmes (NSSCPs), Non-Governmental Organizations (NGOs) and Research Institutes were collated and the relevant epidemiological data were entered in a database, thus incorporating (i) the results of active screening of over 2.2 million people, and (ii) cases detected in health care facilities engaged in passive surveillance. A total of over 42 000 cases of HAT and 6 000 different localities were included in the database. Various sources of geographic coordinates were used to locate the villages of epidemiological interest. The resulting average mapping accuracy is estimated at 900 m.</p> <p>Conclusions</p> <p>Full involvement of NSSCPs, NGOs and Research Institutes in building the Atlas of HAT contributes to the efficiency of the mapping process and it assures both the quality of the collated information and the accuracy of the outputs. Although efforts are still needed to reduce the number of undetected and unreported cases, the comprehensive, village-level mapping of HAT control activities over a ten-year period ensures a detailed and reliable representation of the known geographic distribution of the disease. Not only does the Atlas serve research and advocacy, but, more importantly, it provides crucial evidence and a valuable tool for making informed decisions to plan and monitor the control of sleeping sickness.</p
The sequential aerosol technique : a major component in an Iitegrated strategy of intervention against riverine Tsetse in Ghana
An integrated strategy of intervention against tsetse flies was implemented in the Upper West Region of
Ghana (9.62u–11.00u N, 1.40u–2.76u W), covering an area of <18,000 km2 within the framework of the Pan-African Tsetse
and Trypanosomosis Eradication Campaign. Two species were targeted: Glossina tachinoides and Glossina palpalis
gambiensis.
METHODOLOGY/PRINCIPAL FINDINGS: The objectives were to test the potentiality of the sequential aerosol technique (SAT) to
eliminate riverine tsetse species in a challenging subsection (dense tree canopy and high tsetse densities) of the total
sprayed area (6,745 km2) and the subsequent efficacy of an integrated strategy including ground spraying (<100 km2),
insecticide treated targets (20,000) and insecticide treated cattle (45,000) in sustaining the results of tsetse suppression in
the whole intervention area. The aerial application of low-dosage deltamethrin aerosols (0.33–0.35 g a.i/ha) was conducted
along the three main rivers using five custom designed fixed-wings Turbo thrush aircraft. The impact of SAT on tsetse
densities was monitored using 30 biconical traps deployed from two weeks before until two weeks after the operations.
Results of the SAT monitoring indicated an overall reduction rate of 98% (from a pre-intervention mean apparent density
per trap per day (ADT) of 16.7 to 0.3 at the end of the fourth and last cycle). One year after the SAT operations, a second
survey using 200 biconical traps set in 20 sites during 3 weeks was conducted throughout the intervention area to measure
the impact of the integrated control strategy. Both target species were still detected, albeit at very low densities (ADT of
0.27 inside sprayed blocks and 0.10 outside sprayed blocks).
CONCLUSIONS/SIGNIFICANCE: The SAT operations failed to achieve elimination in the monitored section, but the subsequent
integrated strategy maintained high levels of suppression throughout the intervention area, which will contribute to
improving animal health, increasing animal production and fostering food security.The work was funded by the Pan-African Tsetse and Trypanosomosis Eradication Campaign/Ghana and the International Fund for Agricultural
Development (IFAD) (project GCP/RAF/442/IFA).http://www.plosntds.org /home.actionam2013ab201
MicroRNA-135b promotes cancer progression by acting as a downstream effector of oncogenic pathways in colon cancer
MicroRNA deregulation is frequent in human colorectal cancers (CRCs), but little is known as to whether it represents a bystander event or actually drives tumor progression in vivo. We show that miR-135b overexpression is triggered in mice and humans by APC loss, PTEN/PI3K pathway deregulation, and SRC overexpression and promotes tumor transformation and progression. We show that miR-135b upregulation is common in sporadic and inflammatory bowel disease-associated human CRCs and correlates with tumor stage and poor clinical outcome. Inhibition of miR-135b in CRC mouse models reduces tumor growth by controlling genes involved in proliferation, invasion, and apoptosis. We identify miR-135b as a key downsteam effector of oncogenic pathways and a potential target for CRC treatment
Human African trypanosomiasis in the Democratic Republic of the Congo: disease distribution and risk
Developing a continental atlas of the distribution and trypanosomal infection of tsetse flies (Glossina species)
Abstract Background Tsetse flies (Genus: Glossina) are the sole cyclical vectors of African trypanosomoses. Despite their economic and public health impacts in sub-Saharan Africa, it has been decades since the latest distribution maps at the continental level were produced. The Food and Agriculture Organization of the United Nations is trying to address this shortcoming through the Atlas of tsetse and African animal trypanosomosis. Methods For the tsetse component of the Atlas, a geospatial database is being assembled which comprises information on the distribution and trypanosomal infection of Glossina species. Data are identified through a systematic literature review. Field data collected since January 1990 are included, with a focus on occurrence, apparent density and infection rates of tsetse flies. Mapping is carried out at the level of site/location. For tsetse distribution, the database includes such ancillary information items as survey period, trap type, attractant (if any), number of traps deployed in the site and the duration of trapping (in days). For tsetse infection, the sampling and diagnostic methods are also recorded. Results As a proof of concept, tsetse distribution data for three pilot countries (Ethiopia, Kenya and Uganda) were compiled from 130 peer-reviewed publications, which enabled tsetse occurrence to be mapped in 1266 geographic locations. Maps were generated for eight tsetse species (i.e. G. brevipalpis, G. longipennis, G. fuscipes fuscipes, G. tachinoides, G. pallidipes, G. morsitans submorsitans, G. austeni and G. swynnertoni). For tsetse infection rates, data were identified in 25 papers, corresponding to 91 sites. Conclusions A methodology was developed to assemble a geo-spatial database on the occurrence, apparent density and trypanosomal infection of Glossina species, which will enable continental maps to be generated. The methodology is suitable for broad brush mapping of all tsetse species of medical and veterinary public health importance. For a few tsetse species, especially those having limited economic importance and circumscribed geographic distribution (e.g. fusca group), recently published information is scanty or non-existent. Tsetse-infested countries can adopt and adapt this approach to compile national Atlases, which ought to draw also on the vast amount of unpublished information
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