113 research outputs found
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Mathematical relationships between scoring parameters in capped tendering
[EN] Mathematical relationships between Scoring Parameters can be used in Economic Scoring Formulas (ESF) in tendering to distribute the score among bidders in the economic part of a proposal.Each contracting authority must set an ESF when publishing tender specifications and the strategy of each bidder will differ depending on the ESF selected and the weight of the overall proposal scoring.This paper introduces the various mathematical relationships and density distributions that describe and inter-relate not only the main Scoring Parameters but the main Forecasting Parameters in any capped tender (those whose price is upper-limited).Forecasting Parameters, as variables that can be known in advance before the deadline of a tender is reached, together with Scoring Parameters constitute the basis of a future Bid Tender Forecasting Model. © 2012 Elsevier Ltd. APM and IPMA.Ballesteros Pérez, P.; González-Cruz, M.; Cañavate-Grimal, A. (2012). Mathematical relationships between scoring parameters in capped tendering. International Journal of Project Management. 30(7):850-862. https://doi.org/10.1016/j.ijproman.2012.01.008S85086230
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On competitive bidding: scoring and position probability graphs
Iso-score curves graph (iSCG) and mathematical relationships between Scoring Parameters (SP) and Forecasting Parameters (FP) can be used in Economic Scoring Formulas (ESF) used in tendering to distribute the score among bidders in the economic part of a proposal.
Each contracting authority must set an ESF when publishing tender specifications and the strategy of each bidder will differ depending on the ESF selected and the weight of the overall proposal scoring.
The various mathematical relationships and density distributions that describe the main SPs and FPs, and the representation of tendering data by means of iSCGs, enable the generation of two new types of graphs that can be very useful for bidders who want to be more competitive: the scoring and position probability graphs
Sequence analysis of the 3-untranslated region of HSP70 (type I) genes in the genus Leishmania: Its usefulness as a molecular marker for species identification
Background: The Leishmaniases are a group of clinically diverse diseases caused by parasites of the genus Leishmania. To distinguish between species is crucial for correct diagnosis and prognosis as well as for treatment decisions. Recently, sequencing of the HSP70 coding region has been applied in phylogenetic studies and for identifying of Leishmania species with excellent results. Methods: In the present study, we analyzed the 3-untranslated region (UTR) of Leishmania HSP70-type I gene from 24 strains representing eleven Leishmania species in the belief that this non-coding region would have a better discriminatory capacity for species typing than coding regions. Results: It was observed that there was a remarkable degree of sequence conservation in this region, evenbetween species of the subgenus Leishmania and Viannia. In addition, the presence of many microsatellites was a common feature of the 3-UTR of HSP70-I genes in the Leishmania genus. Finally, we constructed dendrograms based on global sequence alignments of the analyzed Leishmania species and strains, the results indicated that this particular region of HSP70 genes might be useful for species (or species complex) typing, improving for particular species the discrimination capacity of phylogenetic trees based on HSP70 coding sequences. Given the large size variation of the analyzed region between the Leishmania and Viannia subgenera, direct visualization of the PCR amplification product would allow discrimination between subgenera, and a HaeIII-PCR-RFLP analysis might be used for differentiating some species within each subgenera. Conclusions: Sequence and hylogenetic analyses indicated that this region, which is readily amplified using a single pair of primers from both Old and New World Leishmania species, might be useful as a molecular marker for species discrimination. © 2012 Requena et al.; licensee BioMed Central Ltd.Ministerio de Ciencia y Tecnología (BFU2009-08986); Fondo de Investigaciones Sanitarias (ISCIII-RETIC RD06/0021/0008-FEDER and ISCIII-RETIC RD06/0021/0009-FEDER); Agencia Española de Cooperación Internacional para el Desarrollo (AECID, A/024740/09); Fundación Ramón ArecesPeer Reviewe
Risk factors for visceral leishmaniasis in a new epidemic site in Amhara Region, Ethiopia
We conducted a case-control study to evaluate risk factors for visceral leishmaniasis during an epidemic in a previously unaffected district of Ethiopia. We also collected blood and bone marrow specimens from dogs in the outbreak villages. In multivariable analyses of 171 matched case-control pairs, dog ownership, sleeping under an acacia tree during the day, and habitually sleeping outside at night were associated with significantly increased risk. Specimens from 7 (3.8%) dogs were positive by immunofluorescent antibody test (IFAT) and both enzyme-linked immunosorbent assays (ELISAs), whereas Leishmania DNA was detected in 5 (2.8%) bone marrow aspirates (from 3 seropositive and 2 seronegative dogs). Insecticide-treated nets may only protect a portion of those at risk. Further research on the vectors, the role of the dog in the transmission cycle, and the effect of candidate interventions are needed to design the best strategy for control
Effects of the disruption of the HSP70-II gene on the growth, morphology, and virulence of Leishmania infantum promastigotes
The 70-kDa heat shock protein (HSP70) is highly conserved among both prokaryotes and eukaryotes and plays essential roles in diverse cellular functions not only under stress but also under normal conditions. In the protozoan Leishmania infantum, the causative agent of visceral leishmaniasis, HSP70 is encoded by two HSP70 genes. Here, we describe the phenotypic alterations of HSP70-II-deficient (Deltahsp70-II) promastigotes. The absence of HSP70-II caused a major alteration in growth as the promastigotes reached stationary phase. In addition, aberrant forms were frequently observed in Deltahsp70-II mutant cultures. An accumulation of cells in the G2/M phase in cultures of the Deltahsp70-II mutant was determined by flow cytometry. Furthermore, Deltahsp70-II promastigotes showed a limited capacity of multiplication within macrophages, even though attachment to and uptake by macrophages did not differ significantly from the wild-type. Moreover, Deltahsp70-II was highly attenuated in BALB/c mouse experimental infections. In mutants re-expressing HSP70-II, the growth rate was restored, the normal morphology was recovered, and interactions with macrophages increased. However, promastigotes re-expressing HSP70-II did not recover their virulence. Overall, these data highlight the essential role played by HSP70-II expression in Leishmania virulence, pointing to this gene as a promising target for therapeutic interventions
The Leishmania HSP20 Is Antigenic during Natural Infections, but, as DNA Vaccine, It does not Protect BALB/c Mice against Experimental L. amazonensis Infection
Protozoa of the genus Leishmania are causative agents
of leishmaniasis, an important health problem in both human and veterinary medicine. Here,
we describe a new heat shock protein (HSP) in Leishmania, belonging to
the small HSP (sHSP) family in kinetoplastids. The protein is highly conserved in
different Leishmania species, showing instead significant divergence
with sHSP's from other organisms. The humoral response elicited against this protein
during Leishmania infection has been investigated in natural infected
humans and dogs, and in experimentally infected hamsters. Leishmania
HSP20 is a prominent antigen for canine hosts; on the contrary, the protein seems to
be a poor antigen for human immune system. Time-course analysis of appearance of
anti-HSP20 antibodies in golden hamsters indicated that these antibodies are produced
at late stages of the infection, when clinical symptoms of disease are patent. Finally, the
protective efficacy of HSP20 was assessed in mice using a DNA vaccine approach prior to
challenge with Leishmania amazonensis
Fatal congenital Chagas' disease in a non-endemic area: a case report
The early diagnosis of congenital Chagas' disease is very important if infected newborns, whether symptomatic or not, are to receive adequate treatment. This paper describes the complications arising in the diagnosis of a newborn with fatal congenital Chagas' disease in Spain, a non-endemic area where visceral leishmaniasis is present
Beneficial effect of shikonin on experimental colitis induced by dextran sulfate sodium in Balb/C mice.
The naphthoquinone shikonin, a major component of the root of Lithospermum erythrorhizon, now is studied as an antiinflammatory agent in the treatment of ulcerative colitis (UC). Acute UC was induced in Balb/Cmice by oral administration of 5% dextran sodium sulfate (DSS). The disease activity index was evaluated, and a histologic study was carried out. Orally administered shikonin reduces induced UC in a dose-dependent manner, preventing the shortening of the colorectum and decreasing weight loss by 5% while improving the appearance of feces and preventing bloody stools. The disease activity index score was much lower in shikonin-treated mice than in the colitic group, as well as the myeloperoxidase activity. The expression of cyclooxygenase-2 was reduced by 75%, activation of NF-κB was reduced by 44%, and that of pSTAT-3 by 47%, as well as TNF-α, IL-1β, and IL-6 production. Similar results were obtained in primary macrophages culture. This is the first report of shikonin¿s ability to attenuate acute UC induced by DSS. Shikonin acts by blocking the activation of two major targets: NF-κB and STAT-3, and thus constitutes a promising potential therapeutic agent for the management of the inflammatory bowel disease
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