115 research outputs found

    LOCALLY AND COLOCALLY FACTORABLE BANACH SPACES

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    We generalize the concept of locality (resp. colocality) to the concept of locally factorable (resp. colocally factorable) such that Theorem 2 of [2] and Theorems 1.7 and 1.16 of [11] are still valid for the new concepts. In addition we show that locally factorable and colocally factorable are inherited by complemented subspace, then we present some examples and establish relations between locally factorable and colocally factorable. We prove some relations between being finitely (resp. cofinitely) represented in a Banach space and being locally factorable (resp. colocally factorable) some family of finite dimensional Banach spaces.</p

    Colocality and twisted sums of Banach spaces

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    Using the relation between subspaces of Banach spaces and quotients of their duals, we introduce the concept of colocality to give a new method that guarantees the existence of nontrivial twisted sums in which finite quotients play a major role (Theorem 1.7). An interesting point is that no restrictions are imposed on the quotients, only on the various subspaces. New examples of nontrivial twisted sums are given.C

    Rituximab efficacy in pediatric patients with refractory nephrotic syndrome

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    Background: Nephrotic syndrome (NS) in children is a disease of glomerular filtration barrier failure, manifesting with severe proteinuria leading to hypoalbuminemia, hypercholesterolemia, and generalized edema. it could be primary or secondary. In primary NS, also known as idiopathic NS, the histological findings of Primary NS include minimal change disease which mainly respond to steroids (steroid sensitive NS), focal segmental glomerulosclerosis which are usually steroid resistant or membranous nephropathy. Rituximab has been shown to be effective for patients with complicated FRNS/SDNS and refractory SRNS. While the incidence of nephrotic syndrome (NS) is increasing, the morbidity of difficult-to-treat NS is significant.Methods: This is a retrospective cohort study that took place in King Abdulaziz University Hospital from 2012 to 2016. Patients included: Any patient under 18 years, and diagnosed with steroid resistant and dependent nephrotic syndrome. Patients excluded: Any patient above 18 years, and known to have secondary Nephrotic Syndrome.Results: Present study consists of 24 children with nephrotic syndrome (NS) were recruited in the study. In the population 8 patients (33.33 %) were diagnosed with SDNS, while the other 16 patients (66.67%) were diagnosed SRNS. Also, patients who were treated with Rituximab we found that (the mean) number of relapses per year before rituximab was about 2.67±1.49 (standard deviation 1.49), while patient who relapsed after rituximab was about 1.09±1.38 (standard deviation 1.38).Conclusions: Rituximab is a biological agent that started to be widely used in difficult nephrotic syndrome cases. The effectiveness of rituximab is most observed in steroid depended nephrotic syndrome patients since it decreases the frequency of relapses and steroid dependency. However, it has been shown that it is less effective in steroid resistant nephrotic syndrome cases and was associated with significant numbers of relapses

    Challenges of one-year longitudinal follow-up of a prospective, observational cohort study using an anonymised database:Recommendations for trainee research collaboratives

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    Background: trainee research collaboratives (TRCs) have pioneered high quality, prospective ‘snap-shot’ surgical cohort studies in the UK. Outcomes After Kidney injury in Surgery (OAKS) was the first TRC cohort study to attempt to collect one-year follow-up data. The aims of this study were to evaluate one-year follow-up and data completion rates, and to identify factors associated with improved follow-up rates. Methods: in this multicentre study, patients undergoing major gastrointestinal surgery were prospectively identified and followed up at one-year following surgery for six clinical outcomes. The primary outcome for this report was the follow-up rate for mortality at 1 year. The secondary outcome was the data completeness rate in those patients who were followed-up. An electronic survey was disseminated to investigators to identify strategies associated with improved follow-up. Results: of the 173 centres that collected baseline data, 126 centres registered to participate in one-year follow-up. Overall 62.3% (3482/5585) of patients were followed-up at 1 year; in centres registered to collect one-year outcomes, the follow-up rate was 82.6% (3482/4213). There were no differences in sex, comorbidity, operative urgency, or 7-day postoperative AKI rate between patients who were lost to follow-up and those who were successfully followed-up. In centres registered to collect one-year follow-up outcomes, overall data completeness was 83.1%, with 57.9% (73/126) of centres having ≥95% data completeness. Factors associated with increased likelihood of achieving ≥95% data completeness were total number of patients to be followed-up (77.4% in centres with &lt; 15 patients, 59.0% with 15–29 patients, 51.4% with 30–59 patients, and 36.8% with &gt; 60 patients, p = 0.030), and central versus local storage of patient identifiers (72.5% vs 48.0%, respectively, p = 0.006). Conclusions: TRC methodology can be used to follow-up patients identified in prospective cohort studies at one-year. Follow-up rates are maximized by central storage of patient identifiers

    Multifaceted Population Structure and Reproductive Strategy in Leishmania donovani Complex in One Sudanese Village

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    Leishmania species of the subgenus Leishmania and especially L. donovani are responsible for a large proportion of visceral leishmaniasis cases. The debate on the mode of reproduction and population structure of Leishmania parasites remains opened. It has been suggested that Leishmania parasites could alternate different modes of reproduction, more particularly clonality and frequent recombinations either between related individuals (endogamy) or between unrelated individuals (outcrossing) within strongly isolated subpopulations. To determine whether this assumption is generalized to other species, a population genetics analysis within Leishmania donovani complex strains was conducted within a single village. The results suggest that a mixed-mating reproduction system exists, an important heterogeneity of subsamples and the coexistence of several genetic entities in Sudanese L. donovani. Indeed, results showed significant genetic differentiation between the three taxa (L. donovani, L. infantum and L. archibaldi) and between the human or canine strains of such taxa, suggesting that there may be different imbricated transmission cycles involving either dogs or humans. Results also are in agreement with an almost strict specificity of L. donovani stricto sensu to human hosts. This empirical study demonstrates the complexity of population structure in the genus Leishmania and the need to pursue such kind of analyses at the smallest possible spatio-temporal and ecological scales

    The role of Allee effect in modelling post resection recurrence of glioblastoma

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    Resection of the bulk of a tumour often cannot eliminate all cancer cells, due to their infiltration into the surrounding healthy tissue. This may lead to recurrence of the tumour at a later time. We use a reaction-diffusion equation based model of tumour growth to investigate how the invasion front is delayed by resection, and how this depends on the density and behaviour of the remaining cancer cells. We show that the delay time is highly sensitive to qualitative details of the proliferation dynamics of the cancer cell population. The typically assumed logistic type proliferation leads to unrealistic results, predicting immediate recurrence. We find that in glioblastoma cell cultures the cell proliferation rate is an increasing function of the density at small cell densities. Our analysis suggests that cooperative behaviour of cancer cells, analogous to the Allee effect in ecology, can play a critical role in determining the time until tumour recurrence

    Multilocus Microsatellite Typing (MLMT) of Strains from Turkey and Cyprus Reveals a Novel Monophyletic L. donovani Sensu Lato Group

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    In eastern Mediterranean, leishmaniasis represents a major public health problem with considerable impact on morbidity and potential to spread. Cutaneous leishmaniasis (CL) caused by L. major or L. tropica accounts for most cases in this region although visceral leishmaniasis (VL) caused by L. infantum is also common. New foci of human CL caused by L. donovani complex strains were recently described in Cyprus and Turkey. Herein we analyzed Turkish strains from human CL foci in Çukurova region (north of Cyprus) and a human VL case in Kuşadasi. These were compared to Cypriot strains that were previously typed by Multilocus Enzyme Electrophoresis (MLEE) as L. donovani MON-37. Nevertheless, they were found genetically distinct from MON-37 strains of other regions and therefore their origin remained enigmatic. A population study was performed by Multilocus Microsatellite Typing (MLMT) and the profile of the Turkish strains was compared to previously analyzed L. donovani complex strains. Our results revealed close genetic relationship between Turkish and Cypriot strains, which form a genetically distinct L. infantum monophyletic group, suggesting that Cypriot strains may originate from Turkey. Our analysis indicates that the epidemiology of leishmaniasis in this region is more complicated than originally thought

    A prospective cohort study to assess seroprevalence, incidence, knowledge, attitudes and practices, willingness to pay for vaccine and related risk factors in dengue in a high incidence setting

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    Abstract Background Dengue is one of the most important vector-borne diseases in the world, causing significant morbidity and economic impact. In Colombia, dengue is a major public health problem. Departments of La Guajira, Cesar and Magdalena are dengue endemic areas. The objective of this research is to determine the seroprevalence and the incidence of dengue virus infection in the participating municipalities from these Departments, and also establish the association between individual and housing factors and vector indices with seroprevalence and incidence. We will also assess knowledge, attitudes and practices, and willingness-to-pay for dengue vaccine. Methods A cohort study will be assembled with a clustered multistage sampling in 11 endemic municipalities. Approximately 1000 homes will be visited to enroll people older than one year who living in these areas, who will be followed for 1 year. Dengue virus infections will be evaluated using IgG indirect ELISA and IgM and IgG capture ELISA. Additionally, vector indices will be measured, and adult mosquitoes will be captured with aspirators. Ovitraps will be used for continuous estimation of vector density. Discussion This research will generate necessary knowledge to design and implement strategies with a multidimensional approach that reduce dengue morbidity and mortality in La Guajira and other departments from Colombian Caribbean
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