254 research outputs found
A Functional Kinase Is Necessary for Cyclin-Dependent Kinase G1 (CDKG1) to Maintain Fertility at High Ambient Temperature in Arabidopsis
Maintaining fertility in a fluctuating environment is key to the reproductive success of flowering plants. Meiosis and pollen formation are particularly sensitive to changes in growing conditions, especially temperature. We have previously identified cyclin-dependent kinase G1 (CDKG1) as a master regulator of temperature-dependent meiosis and this may involve the regulation of alternative splicing (AS), including of its own transcript. CDKG1 mRNA can undergo several AS events, potentially producing two protein variants: CDKG1L and CDKG1S, differing in their N-terminal domain which may be involved in co-factor interaction. In leaves, both isoforms have distinct temperature-dependent functions on target mRNA processing, but their role in pollen development is unknown. In the present study, we characterize the role of CDKG1L and CDKG1S in maintaining Arabidopsis fertility. We show that the long (L) form is necessary and sufficient to rescue the fertility defects of the cdkg1-1 mutant, while the short (S) form is unable to rescue fertility. On the other hand, an extra copy of CDKG1L reduces fertility. In addition, mutation of the ATP binding pocket of the kinase indicates that kinase activity is necessary for the function of CDKG1. Kinase mutants of CDKG1L and CDKG1S correctly localize to the cell nucleus and nucleus and cytoplasm, respectively, but are unable to rescue either the fertility or the splicing defects of the cdkg1-1 mutant. Furthermore, we show that there is partial functional overlap between CDKG1 and its paralog CDKG2 that could in part be explained by overlapping gene expression
Making grooves with needles: Using e-textiles to encourage gender diversity in embedded audio systems design
Historically, women have been excluded from engineering and computer science disciplines, and interactive audio is no exception. Relatively few women are involved with the designing and building of embedded audio systems with traditional tools such as microprocessors, but when embedded audio systems are built using e-textiles, much larger proportions of women become engaged with technology. In this paper we review theories for this gender disparity and the barriers women face in working with audio technology, and then present a comparison of survey data between an e-textile audio workshop and an audio platform user group. Extrapolating from the case study and the surveyed literature, we propose that flexibility in learning, communal dissemination of knowledge, and gendering of tools are prominent reasons why women engage with technology via e-textiles
PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons
An experiment demonstrating a new method for producing polarized positrons has been performed at the CEBAF accelerator at Jefferson Laboratory. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e+/e− pairs originating from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a 1.0 mm tungsten pair-production target. This paper describes preliminary results of measurements using an 8.2 MeV/c electron beam with polarization 84% to generate positrons in the range of 3.1 to 6.2 MeV/c with polarization as high as ∼80%
Production of highly-polarized positrons using polarized electrons at MeV energies
The Polarized Electrons for Polarized Positrons experiment at the injector of
the Continuous Electron Beam Accelerator Facility has demonstrated for the
first time the efficient transfer of polarization from electrons to positrons
produced by the polarized bremsstrahlung radiation induced by a polarized
electron beam in a high- target. Positron polarization up to 82\% have been
measured for an initial electron beam momentum of 8.19~MeV/, limited only by
the electron beam polarization. This technique extends polarized positron
capabilities from GeV to MeV electron beams, and opens access to polarized
positron beam physics to a wide community.Comment: 5 pages, 4 figure
Teenage Visitor Experience: Classification of Behavioral Dynamics in Museums
Teenagers' engagement in museums is much talked about but little research has been done to understand their behavior and inform design. Findings from co-design sessions with teenagers suggested they value games and stories when thinking about enjoyable museum tours. Informed by these findings and working with a natural history museum, we designed: a story-based tour (Turning Point) and a game-based tour (Haunted Encounters), informed by similar content. The two strategies were evaluated with 78 teenagers (15-19 years old) visiting the museum as part of an educational school trip. We assessed teenagers' personality in class; qualitative and quantitative data on their engagement, experience, and usability of the apps were collected at the museum. The triangulation of quantitative and qualitative data show personality traits mapping into different behaviors. We offer implications for the design of museum apps targeted to teenagers, a group known as difficult to reach
Comparative efficacy and complications of long-acting and intermediate-acting insulin regimens for adults with type 1 diabetes: an individual patient data network meta-analysis.
ObjectiveTo examine the comparative efficacy and complications of long-acting and intermediate-acting insulin for different patient characteristics for type 1 diabetes mellitus (T1DM).DesignSystematic review and individual patient data (IPD) network meta-analysis (NMA).Data sourcesMEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched through June 2015.Eligibility criteriaRandomised controlled trials (RCTs) on adults with T1DM assessing glycosylated haemoglobin (A1c) and severe hypoglycaemia in long-acting and intermediate-acting insulin regimens.Data extraction and synthesisWe requested IPD from authors and funders. When IPD were not available, we used aggregate data. We conducted a random-effects model, and specifically a one-stage IPD-NMA for those studies providing IPD and a two-stage IPD-NMA to incorporate those studies not providing IPD.ResultsWe included 28 RCTs plus one companion report, after screening 6680 titles/abstracts and 205 full-text articles. Of the 28 RCTs, 27 studies provided data for the NMA with 7394 participants, of which 12 RCTs had IPD on 4943 participants. The IPD-NMA for A1c suggested that glargine once daily (mean difference [MD]=-0.31, 95% confidence interval [CI]: -0.48 to -0.14) and detemir once daily (MD=-0.25, 95% CI: -0.41 to -0.09) were superior to neutral protamine Hagedorn (NPH) once daily. NPH once/two times per day improved A1c compared with NPH once daily (MD=-0.30, 95% CI: -0.50 to -0.11). Results regarding complications in severe hypoglycaemia should be considered with great caution due to inconsistency in the evidence network. Accounting for missing data, there was no evidence of inconsistency and long-acting insulin regimens ranked higher regarding reducing severe hypoglycaemia compared with intermediate-acting insulin regimens (two-stage NMA: glargine two times per day SUCRA (Surface Under the Cumulative Ranking curve)=89%, detemir once daily SUCRA=77%; one-stage NMA: detemir once daily/two times per day SUCRA=85%). Using multiple imputations and IPD only, complications in severe hypoglycaemia increased with diabetes-related comorbidities (regression coefficient: 1.03, 95% CI: 1.02 to 1.03).ConclusionsLong-acting insulin regimens reduced A1c compared with intermediate-acting insulin regimens and were associated with lower severe hypoglycaemia. Of the observed differences, only glargine once daily achieved a clinically significant reduction of 0.30%. Results should be interpreted with caution due to very low quality of evidence.Prospero registration numberCRD42015023511
Treatment seeking behaviours, antibiotic use and relationships to multi-drug resistance : a study of urinary tract infection patients in Kenya, Tanzania and Uganda
Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviour, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Using data from 6,388 patients, we analysed patterns of self-reported treatment seeking behaviours (‘patient pathways’) using process mining and single-channel sequence analysis. Among those with microbiologically confirmed UTI (n = 1,946), we used logistic regression to assess the relationship between treatment seeking behaviour, AB use, and the likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathway for UTI-like symptoms in this sample involved attending health facilities, rather than other providers like drug sellers. Patients from sites in Tanzania and Uganda, where over 50% of patients had an MDR UTI, were more likely to report treatment failures, and have repeat visits to providers than those from Kenyan sites, where MDR UTI proportions were lower (33%). There was no strong or consistent relationship between individual AB use and likelihood of MDR UTI, after accounting for country context. The results highlight the hurdles East African patients face in accessing effective UTI care. These challenges are exacerbated by high rates of MDR UTI, suggesting a vicious cycle of failed treatment attempts and sustained selection for drug resistance. Whilst individual AB use may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of variations in ABR.Peer reviewe
The Association between Peptic Ulcer Disease and Gastric Cancer: Results from the Stomach Cancer Pooling (StoP) Project Consortium
Simple Summary Gastric cancer (GC) is the fifth most common type of cancer and the fourth most common cause of cancer-related mortality. In this meta-analysis, we utilized SToP consortium data to investigate the association between gastric ulcer (GU) and duodenal ulcer (DU) and development of GC. Among 4106 GC cases and 6922 controls, we detected a positive association between GU and GC (OR = 3.04, 95% CI: 2.07-4.49). On the other hand, no significant association between DU and GC was detected (OR = 1.03, 95% CI: 0.77-1.39). In the pooled analysis, incorporating 11 case-control studies revealed positive association between the gastric ulcer and risk of gastric cancer. Background. Gastric cancer (GC) is the fifth most common type of cancer and the fourth most common cause of cancer-related mortality. Although the risk of GC and peptic ulcer disease (PUD) is known to be increased by H. pylori infection, evidence regarding the direct relationship between PUD and GC across ethnicities is inconclusive. Therefore, we investigated the association between PUD and GC in the Stomach cancer Pooling (StoP) consortium. Methods. History of peptic ulcer disease was collected using a structured questionnaire in 11 studies in the StoP consortium, including 4106 GC cases and 6922 controls. The two-stage individual-participant data meta-analysis approach was adopted to generate a priori. Unconditional logistic regression and Firth's penalized maximum likelihood estimator were used to calculate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between gastric ulcer (GU)/duodenal ulcer (DU) and risk of GC. Results. History of GU and DU was thoroughly reported and used in association analysis, respectively, by 487 cases (12.5%) and 276 controls (4.1%), and 253 cases (7.8%) and 318 controls (6.0%). We found that GU was associated with an increased risk of GC (OR = 3.04, 95% CI: 2.07-4.49). No association between DU and GC risk was observed (OR = 1.03, 95% CI: 0.77-1.39). Conclusions. In the pooled analysis of 11 case-control studies in a large consortium (i.e., the Stomach cancer Pooling (StoP) consortium), we found a positive association between GU and risk of GC and no association between DU and GC risk
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