656 research outputs found

    IVY Plot: Enhancing a Dot Plot by Representing Observations as Leaflets

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    For a large data set, a dot plot poses a challenge—albeit unintended—in counting the dots. To overcome this shortcoming Sarkar and Rashid (2021) proposed an IVY plot, which represents tied data in batches of five by depicting an IVY leaf with five leaflets. These leaves are bottom-justified and stacked vertically, with the topmost leaf possibly having fewer than five leaflets, until the number of leaflets equals the frequency at each valu

    Increased use of malaria rapid diagnostic tests improves targeting of anti-malarial treatment in rural Tanzania: implications for nationwide rollout of malaria rapid diagnostic tests.

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    ABSTRACT: BACKGROUND: The World Health Organization recommends parasitological confirmation of all malaria cases. Tanzania is implementing a phased rollout of malaria rapid diagnostic tests (RDTs) for routine use in all levels of care as one strategy to increase parasitological confirmation of malaria diagnosis. This study was carried out to evaluated artemisinin combination therapy (ACT) prescribing patterns in febrile patients with and without uncomplicated malaria in one pre-RDT implementation and one post-RDT implementation area. METHODS: A cross-sectional health facility surveys was conducted during high and low malaria transmission seasons in 2010 in both areas. Clinical information and a reference blood film on all patients presenting for an initial illness consultation were collected. Malaria was defined as a history of fever in the past 48 hours and microscopically confirmed parasitaemia. Routine diagnostic testing was defined as RDT or microscopy ordered by the health worker and performed at the health facility as part of the health worker-patient consultation. Correct diagnostic testing was defined as febrile patient tested with RDT or microscopy. Over-testing was defined as a febrile patient tested with RDT or microscopy. Correct treatment was defined as patient with malaria prescribed ACT. Over-treatment was defined as patient without malaria prescribed ACT. RESULTS: A total of 1,247 febrile patients (627 from pre-implementation area and 620 from post-implementation area) were included in the analysis. In the post-RDT implementation area, 80.9% (95% CI, 68.2-89.3) of patients with malaria received recommended treatment with ACT compared to 70.3% (95% CI, 54.7-82.2) of patients in the pre-RDT implementation area. Correct treatment was significantly higher in the post-implementation area during high transmission season (85.9% (95%CI, 72.0-93.6) compared to 58.3% (95%CI, 39.4-75.1) in pre-implementation area (p=0.01). Over-treatment with ACT of patients without malaria was less common in the post-RDT implementation area (20.9%; 95% CI, 14.7-28.8) compared to the pre-RDT implementation area (45.8%; 95% CI, 37.2-54.6) (p<0.01) in high transmission. The odds of overtreatment was significantly lower in post- RDT area (adjusted Odds Ratio (OR: 95%CI) 0.57(0.36-0.89); and much higher with clinical diagnosis adjusted OR (95%CI) 2.24(1.37-3.67) CONCLUSION: Implementation of RDTs increased use of RDTs for parasitological confirmation and reduced over-treatment with ACT during high malaria transmission season in one area in Tanzania. Continued monitoring of the national RDT rollout will be needed to assess whether these changes in case management practices will be replicated in other areas and sustained over time. Additional measures (such as refresher trainings, closer supervisions, etc) may be needed to improve ACT targeting during low transmission seasons

    TsHKT1;2, a HKT1 homolog from the extremophile arabidopsis relative Thellungiella salsuginea, shows K \u3csup\u3e+\u3c/sup\u3e specificity in the presence of NaCl

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    Cellular Na +/K + ratio is a crucial parameter determining plant salinity stress resistance. We tested the function of plasma membrane Na +/K + cotransporters in the High-affinity K + Transporter (HKT) family from the halophytic Arabidopsis (Arabidopsis thaliana) relative Thellungiella salsuginea. T. salsuginea contains at least two HKT genes. TsHKT1;1 is expressed at very low levels, while the abundant TsHKT1;2 is transcriptionally strongly up-regulated by salt stress. TsHKT-based RNA interference in T. salsuginea resulted in Na + sensitivity and K + deficiency. The athkt1 mutant lines overexpressing TsHKT1;2 proved less sensitive to Na + and showed less K + deficiency than lines overexpressing AtHKT1. TsHKT1;2 ectopically expressed in yeast mutants lacking Na + or K + transporters revealed strong K + transporter activity and selectivity for K + over Na +. Altering two amino acid residues in TsHKT1;2 to mimic the AtHKT1 sequence resulted in enhanced sodium uptake and loss of the TsHKT1;2 intrinsic K + transporter activity. We consider the maintenance of K + uptake through TsHKT1;2 under salt stress an important component supporting the halophytic lifestyle of T. salsuginea. © 2012 American Society of Plant Biologists

    A single amino-acid substitution in the sodium transporter HKT1 associated with plant salt tolerance

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    © 2016 American Society of Plant Biologists. All rights reserved. A crucial prerequisite for plant growth and survival is the maintenance of potassium uptake, especially when high sodium surrounds the root zone. The Arabidopsis HIGH-AFFINITY K+ TRANSPORTER1 (HKT1), and its homologs in other salt-sensitive dicots, contributes to salinity tolerance by removing Na+ from the transpiration stream. However, TsHKT1;2, one of three HKT1 copies in Thellungiella salsuginea, a halophytic Arabidopsis relative, acts as a K+transporter in the presence of Na+ in yeast (Saccharomyces cerevisiae). Amino-acid sequence comparisons indicated differences between TsHKT1;2 and most other published HKT1 sequences with respect to an Asp residue (D207) in the second pore-loop domain. Two additional T. salsuginea and most other HKT1 sequences contain Asn (N) in this position. Wild-type TsHKT1;2 and altered AtHKT1 (AtHKT1N-D) complemented K+-uptake deficiency of yeast cells. Mutanthkt1-1 plants complemented with both AtHKT1N-D and TsHKT1;2 showed higher tolerance to salt stress than lines complemented by the wild-type AtHKT1. Electrophysiological analysis in Xenopus laevis oocytes confirmed the functional properties of these transporters and the differential selectivity for Na+ and K+based on the N/D variance in the pore region. This change also dictated inward-rectification for Na+ transport. Thus, the introduction of Asp, replacing Asn, in HKT1-type transporters established altered cation selectivity and uptake dynamics. We describe one way, based on a single change in a crucial protein that enabled some crucifer species to acquire improved salt tolerance, which over evolutionary time may have resulted in further changes that ultimately facilitated colonization of saline habitats

    Recent Advances on The Applications of Phase Change Materials in Cold Thermal Energy Storage: A Critical Review

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    Cold thermal energy storage (CTES) based on phase change materials (PCMs) has shown great promise in numerous energy-related applications. Due to its high energy storage density, CTES is able to balance the existing energy supply and demand imbalance. Given the rapidly growing demand for cold energy, the storage of hot and cold energy is emerging as a particularly attractive option. The main purpose of this study is to provide a comprehensive overview of the current research progress on the utilisation of PCMs in CTES. The greatest difficulties associated with using PCMs for CTES are also examined in this overview. In this regard, a critical evaluation of experimental and numerical studies of the heat transfer properties of various fundamental fluids using PCMs is conducted. Specifically, several aspects that affect the thermal conductivity of PCMs are investigated. These factors include nanoparticle-rich PCM, a form of encapsulated PCM, solids volume percentage, and particle size. Discussions focus on observations and conclusions are drawn from conducted studies on PCMs used in CTES. Based on the findings of this study, a set of plausible recommendations are made for future research initiatives

    Age-Related Patterns in Clinical Presentations and Gluten-Related Issues Among Children and Adolescents With Celiac Disease

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    OBJECTIVES: Celiac disease (CD) is common and often cited as an “iceberg” phenomenon (i.e., an assumed large number of undiagnosed cases). Recently, atypical or asymptomatic manifestations are becoming more commonly described in older children and adolescents. Moreover, CD diagnosis in children can be complicated by several factors, including its diverse clinical presentations, delay in recognizing CD signs and symptoms, and premature dietary gluten avoidance before the formal diagnosis of CD. To date, few studies have directly examined age-related differences in clinical characteristics and gluten-related issues among children with CD. The aim of this study was to determine age-related patterns in clinical characteristics and gluten-related issues among children with confirmed CD. METHODS: We performed a structured medical record review of biopsy-proven CD patients, aged 0–19 years, between 2000 and 2010 at a large Boston teaching hospital. Data collection included demographics, medical history, gluten-related issues, and diagnostic investigations (CD-specific serology, upper gastrointestinal endoscopy, and small intestinal biopsy). The first positive duodenal biopsy with Marsh III classification defined age of diagnosis. Patients were divided into three age groups for comparisons of the aforementioned characteristics: infant-preschool group (0–5 years), school-aged group (6–11 years), and adolescence group (12–19 years). RESULTS: Among 411 children with biopsy-proven CD, the mean age was 9.5 (s.d. 5.1) years. Most were female (63%) and white (96%). All children had positive CD-specific serology. Most children presented with either abdominal complaints or bowel movement changes. Overall, boys were more common among infant-preschool group compared with the other age groups. More distinct clinical manifestations (vomiting, bowel movement changes, and weight issues) were apparent in the youngest group, whereas school-aged children had more subjective abdominal complaints at the initial presentation. Conversely, the adolescents were most likely to present without any gastrointestinal (GI) symptoms, but not when this was combined with absence of weight issues. Age of diagnosis was not associated with atypical extraintestinal CD presentations. Regarding the gluten-related issues, 10% of school-aged children avoided dietary gluten before the formal CD diagnosis, and 27% of the adolescents reported dietary gluten transgression within the first 12 months of diagnosis, significantly higher than the other age groups. Age differences in histopathology were also found. Whereas the infant-preschool group had a higher proportion of total villous atrophy, the older children were more likely to have gross duodenal abnormalities and chronic duodenitis suggestive of CD at the time of diagnosis. CONCLUSIONS: Children and adolescents with CD have age-related patterns in both the clinical presentations and gluten-related issues. More pronounced clinical and histological features were determined in younger children, whereas older children more commonly presented with solely subjective abdominal complaints or even without any GI symptoms. However, silent and atypical extraintestinal CD presentations were comparable between age groups. In addition to the aforementioned presentations, the higher rates of dietary gluten avoidance and transgression in older children make CD diagnosis and management particularly challenging. These age-related patterns may further increase awareness, facilitate early diagnosis, and improve patient care of pediatric CD

    A genotypic analysis of five P. aeruginosa strains after biofilm infection by phages targeting different cell surface receptors

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    The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fmicb. 2017.01229/full#supplementary-materialAntibiotic resistance constitutes one of the most serious threats to the global public health and urgently requires new and effective solutions. Bacteriophages are bacterial viruses increasingly recognized as being good alternatives to traditional antibiotic therapies. In this study, the efficacy of phages, targeting different cell receptors, against Pseudomonas aeruginosa PAO1 biofilm and planktonic cell cultures was evaluated over the course of 48h. Although significant reductions in the number of viable cells were achieved for both cases, the high level of adaptability of the bacteria in response to the selective pressure caused by phage treatment resulted in the emergence of phage-resistant variants. To further investigate the genetic makeup of phage-resistant variants isolated from biofilm infection experiments, some of these bacteria were selected for phenotypic and genotypic characterization. Whole genome sequencing was performed on five phage-resistant variants and all of them carried mutations affecting the galU gene as well as one of pil genes. The sequencing analysis further revealed that three of the P. aeruginosa PAO1 variants carry large deletions (> 200 kbp) in their genomes. Complementation of the galU mutants with wild-type galU in trans restored LPS expression on the bacterial cell surface of these bacterial strains and rendered the complemented strains to be sensitive to phages. This provides unequivocal evidence that inactivation of galU function was associated with resistance to the phages that uses LPS as primary receptors. Overall, this work demonstrates that P. aeruginosa biofilms can survive phage attack and develop phage-resistant variants exhibiting defective LPS production and loss of type IV pili that are well adapted to the biofilm mode of growth.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the project PTDC/BBB-BSS/6471/2014; the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER006684) and BioTecNorte operation (NORTE-01-0145-FEDER000004)funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. SS is an FCT investigator (IF/01413/2013). Work done in the lab of JL is supported by Canadian Institutes of Health Research (Grant MOP-14687). YH was a recipient of a postdoctoral fellowship award from Cystic Fibrosis, and JL holds a Canada Research Chair in Cystic Fibrosis and Microbial Glycobiology funded by the Canadian Foundation of Innovation. Work done in the lab of CK is supported by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada(#371639).info:eu-repo/semantics/publishedVersio

    Malaria control under the Taliban regime: insecticide-treated net purchasing, coverage, and usage among men and women in eastern Afghanistan

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    BACKGROUND: Scaling up insecticide-treated mosquito net (ITN) coverage is a key malaria control strategy even in conflict-affected countries 12. Socio-economic factors influence access to ITNs whether subsidized or provided free to users. This study examines reported ITN purchasing, coverage, and usage in eastern Afghanistan and explores women's access to health information during the Taliban regime (1996-2001). This strengthens the knowledge base on household-level health choices in complex-emergency settings. METHODS: Fifteen focus group discussions (FGDs) and thirty in-depth interviews were conducted with men and women from ITN-owning and non-owning households. FGDs included rank ordering, pile sorting and focused discussion of malaria knowledge and ITN purchasing. Interviews explored general health issues, prevention and treatment practices, and women's malaria knowledge and concerns. Seven key informant interviews with health-related workers and a concurrent survey of 200 ITN-owning and 214 non-owning households were used to clarify or quantify findings. RESULTS: Malaria knowledge was similar among men and women and ITN owners and non-owners. Women reported obtaining health information through a variety of sources including clinic staff, their husbands who had easier access to information, and particularly female peers. Most participants considered ITNs very desirable, though not usually household necessities. ITN owners reported more household assets than non-owners. Male ITN owners and non-owners ranked rugs and ITNs as most desired, while women ranked personal assets such as jewellery highest. While men were primarily responsible for household decision-making and purchasing, older women exerted considerable influence. Widow-led and landless households reported most difficulties purchasing ITNs. Most participants wanted to buy ITNs only if they could cover all household members. When not possible, preferential usage was given to women and children. CONCLUSIONS: Despite restricted access to health facilities and formal education, Afghan women were surprisingly knowledgeable about the causes of malaria and the value of ITNs in prevention. Inequities in ITN usage were noted between rather than within households, with some unable to afford even one ITN and others not wanting ITNs unless all household members could be protected. Malaria knowledge thus appears a lesser barrier to ITN purchasing and coverage in eastern Afghanistan than are pricing and distribution strategies
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