162 research outputs found
Generalized Mittag-Leffler Distributions and Processes for Applications in Astrophysics and Time Series Modeling
Geometric generalized Mittag-Leffler distributions having the Laplace
transform is
introduced and its properties are discussed. Autoregressive processes with
Mittag-Leffler and geometric generalized Mittag-Leffler marginal distributions
are developed. Haubold and Mathai (2000) derived a closed form representation
of the fractional kinetic equation and thermonuclear function in terms of
Mittag-Leffler function. Saxena et al (2002, 2004a,b) extended the result and
derived the solutions of a number of fractional kinetic equations in terms of
generalized Mittag-Leffler functions. These results are useful in explaining
various fundamental laws of physics. Here we develop first-order autoregressive
time series models and the properties are explored. The results have
applications in various areas like astrophysics, space sciences, meteorology,
financial modeling and reliability modeling.Comment: 12 pages, LaTe
Temporal fossa arachnoid cyst presenting with bilateral subdural hematoma following trauma: two case reports
<p>Abstract</p> <p>Introduction</p> <p>Intracranial arachnoid cysts are considered to be congenital malformations with a predilection for the temporal fossa. They are often asymptomatic but can sometimes be symptomatic due to enlargement or hemorrhage. There are multiple case reports of arachnoid cysts becoming symptomatic with hemorrhagic complications following head trauma. In such cases, the bleeding is often confined to the side ipsilateral to the arachnoid cyst. Occurrence of contralateral subdural hematomas in patients with temporal fossa arachnoid cysts has rarely been observed and is reported less frequently in the medical literature.</p> <p>Case presentation</p> <p>We report two cases of people (a 23-year-old man and a 41-year-old man) with temporal fossa arachnoid cysts complicated by a subdural hematoma following head injury. Both patients developed a subdural hematoma contralateral to the side of a temporal fossa arachnoid cyst. It is likely that lack of adequate intracranial cushioning in the presence of an intracranial arachnoid cyst may result in injury not only to ipsilateral but also to contralateral bridging veins, following head trauma.</p> <p>Conclusion</p> <p>It is important to identify and report such rare complications with intracranial arachnoid cysts, so that asymptomatic patients with an intracranial arachnoid cyst can be counseled about such possibilities following head trauma.</p
Mean population salt consumption in India: a systematic review
Background: Member states of the WHO, including India, have adopted a target 30% reduction in mean population salt consumption by 2025 to prevent noncommunicable diseases. Our aim was to support this initiative by summarizing existing data that describe mean salt consumption in India. Method: Electronic databases – MEDLINE via Ovid, EMBASE, CINAHL and the Cochrane Database of Systematic Reviews – were searched up to November 2015 for studies that reported mean or median dietary salt intake in Indian adults aged 19 years and older. Random effects meta-analysis was used to obtain summary estimates of salt intake. Results: Of 1201 abstracts identified, 90 were reviewed in full text and 21 were included: 18 cross-sectional surveys (n = 225 024), two randomized trials (n = 255) and one case–control study (n = 270). Data were collected between 1986 and 2014, and reported mean salt consumption levels were between 5.22 and 42.30 g/day. With an extreme outlier excluded, overall mean weighted salt intake was 10.98 g/day (95% confidence interval 8.57–13.40). There was significant heterogeneity between the estimates for contributing studies (I2 = 99.97%) (P homogeneity ≤0.001), which was likely attributable to the different measurement methods used and the different populations studied. There was no evidence of a change in intake over time (P trend = 0.08). Conclusion: The available data leave some uncertainty about exact mean salt consumption in India but there is little doubt that population salt consumption far exceeds the WHO-recommended maximum of 5 g per person per day
In vitro activity of daptomycin, linezolid and rifampicin on Staphylococcus epidermidis biofilms
Owing to their massive use, Staphylococcus
epidermidis has recently developed significant resistance to
several antibiotics, and became one of the leading causes of
hospital-acquired infections. Current antibiotics are typically
ineffective in the eradication of bacteria in biofilmassociated
persistent infections. Accordingly, the paucity
of effective treatment against cells in this mode of growth
is a key factor that potentiates the need for new agents
active in the prevention or eradication of biofilms. Daptomycin
and linezolid belong to the novel antibiotic therapies
that are active against gram-positive cocci. On the other
hand, rifampicin has been shown to be one of the most
potent, prevalent antibiotics against S. epidermidis biofilms.
Therefore, the main aim of this study was to study
the susceptibility of S. epidermidis biofilm cells to the two
newer antimicrobial agents previously mentioned, and
compare the results obtained with the antimicrobial effect
of rifampicin, widely used in the prevention/treatment of
indwelling medical device infections. To this end the in
vitro activities of daptomycin, linezolid, and rifampicin on
S. epidermidis biofilms were accessed, using these antibiotics
at MIC and peak serum concentrations. The results
demonstrated that at MIC concentration, rifampicin was the
most effective antibiotic tested. At peak serum concentration,
both strains demonstrated similar susceptibility to
rifampicin and daptomycin, with colony-forming units
(CFUs) reductions of approximately 3–4 log10, with a
slightly lower response to linezolid, which was also more
strain dependent. However, considering all the parameters
studied, daptomycin was considered the most effective
antibiotic tested, demonstrating an excellent in vitro
activity against S. epidermidis biofilm cells. In conclusion,
this antibiotic can be strongly considered as an acceptable
therapeutic option for S. epidermidis biofilm-associated
infections and can represent a potential alternative to rifampicin
in serious infections where rifampicin resistance
becomes prevalent.Bruna Leite acknowledges the financial support from ISAC/Program Erasmus Munds External Cooperation and the IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus of Gualtar. Fernanda Gomes and Pilar Teixeira fully acknowledge the financial support from Fundacao para a Ciencia e Tecnologia (FCT) through the grants SFRH/BD/32126/2006 and SFRH/BPD/26803/2006, respectively
The Infection of Chicken Tracheal Epithelial Cells with a H6N1 Avian Influenza Virus
Sialic acids (SAs) linked to galactose (Gal) in α2,3- and α2,6-configurations are the receptors for avian and human influenza viruses, respectively. We demonstrate that chicken tracheal ciliated cells express α2,3-linked SA, while goblet cells mainly express α2,6-linked SA. In addition, the plant lectin MAL-II, but not MAA/MAL-I, is bound to the surface of goblet cells, suggesting that SA2,3-linked oligosaccharides with Galβ1–3GalNAc subterminal residues are specifically present on the goblet cells. Moreover, both α2,3- and α2,6-linked SAs are detected on single tracheal basal cells. At a low multiplicity of infection (MOI) avian influenza virus H6N1 is exclusively detected in the ciliated cells, suggesting that the ciliated cell is the major target cell of the H6N1 virus. At a MOI of 1, ciliated, goblet and basal cells are all permissive to the AIV infection. This result clearly elucidates the receptor distribution for the avian influenza virus among chicken tracheal epithelial cells and illustrates a primary cell model for evaluating the cell tropisms of respiratory viruses in poultry
Resistance to HSP90 inhibition involving loss of MCL1 addiction
YesInhibition of the chaperone heat-shock protein 90 (HSP90) induces apoptosis, and it is a promising anti-cancer strategy. The mechanisms underpinning apoptosis activation following HSP90 inhibition and how they are modified during acquired drug resistance are unknown. We show for the first time that, to induce apoptosis, HSP90 inhibition requires the cooperation of multi BH3-only proteins (BID, BIK, PUMA) and the reciprocal suppression of the pro-survival BCL-2 family member MCL1, which occurs via inhibition of STAT5A. A subset of tumour cell lines exhibit dependence on MCL1 expression for survival and this dependence is also associated with tumour response to HSP90 inhibition. In the acquired resistance setting, MCL1 suppression in response to HSP90 inhibitors is maintained; however, a switch in MCL1 dependence occurs. This can be exploited by the BH3 peptidomimetic ABT737, through non-BCL-2-dependent synthetic lethality
A systematic review and meta-analysis of evidence for correlation between molecular markers of parasite resistance and treatment outcome in falciparum malaria
<p>Abstract</p> <p>Background</p> <p>An assessment of the correlation between anti-malarial treatment outcome and molecular markers would improve the early detection and monitoring of drug resistance by <it>Plasmodium falciparum</it>. The purpose of this systematic review was to determine the risk of treatment failure associated with specific polymorphisms in the parasite genome or gene copy number.</p> <p>Methods</p> <p>Clinical studies of non-severe malaria reporting on target genetic markers (SNPs for <it>pfmdr1</it>, <it>pfcrt</it>, <it>dhfr</it>, <it>dhps</it>, gene copy number for <it>pfmdr1</it>) providing complete information on inclusion criteria, outcome, follow up and genotyping, were included. Three investigators independently extracted data from articles. Results were stratified by gene, codon, drug and duration of follow-up. For each study and aggregate data the random effect odds ratio (OR) with 95%CIs was estimated and presented as Forest plots. An OR with a lower 95<sup>th </sup>confidence interval > 1 was considered consistent with a failure being associated to a given gene mutation.</p> <p>Results</p> <p>92 studies were eligible among the selection from computerized search, with information on <it>pfcrt </it>(25/159 studies), <it>pfmdr1 </it>(29/236 studies), <it>dhfr </it>(18/373 studies), <it>dhps </it>(20/195 studies). The risk of therapeutic failure after chloroquine was increased by the presence of <it>pfcrt </it>K76T (Day 28, OR = 7.2 [95%CI: 4.5–11.5]), <it>pfmdr1 </it>N86Y was associated with both chloroquine (Day 28, OR = 1.8 [95%CI: 1.3–2.4]) and amodiaquine failures (OR = 5.4 [95%CI: 2.6–11.3, p < 0.001]). For sulphadoxine-pyrimethamine the <it>dhfr </it>single (S108N) (Day 28, OR = 3.5 [95%CI: 1.9–6.3]) and triple mutants (S108N, N51I, C59R) (Day 28, OR = 3.1 [95%CI: 2.0–4.9]) and <it>dhfr</it>-<it>dhps </it>quintuple mutants (Day 28, OR = 5.2 [95%CI: 3.2–8.8]) also increased the risk of treatment failure. Increased <it>pfmdr1 </it>copy number was correlated with treatment failure following mefloquine (OR = 8.6 [95%CI: 3.3–22.9]).</p> <p>Conclusion</p> <p>When applying the selection procedure for comparative analysis, few studies fulfilled all inclusion criteria compared to the large number of papers identified, but heterogeneity was limited. Genetic molecular markers were related to an increased risk of therapeutic failure. Guidelines are discussed and a checklist for further studies is proposed.</p
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