86 research outputs found

    A literature-based comparison of nutrient and contaminant contents between organic and conventional vegetables and potatoes

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    Purpose - The increasing demand for organic foods is explained mainly by consumers' concerns about the quality and safety of foods and their perception that organically produced foods are healthier and safer than conventional foods. Based on internationally available concentration data of organic and conventional vegetables (carrots, tomatoes, lettuce and spinach) and potatoes, the paper aims to investigate the scientific validity of nutrition claims as "no vegetable/potato has higher amounts of nutrient X than organic vegetables/potatoes" and "no vegetable/potato has lower amounts of contaminant Y than organic vegetables/potatoes". Design/methodology/approach - Detailed nutrient and contaminant databases were developed for organic and conventional vegetables separately. Non-parametric (Mann-Whitney test) methods were used to detect significant differences between both types of vegetables. A chi-square test was used to compare the incidence of pesticide residues in organic and conventional vegetables. Findings - From a nutritional and toxicological point of view, organic vegetables and potato in general are not significantly better than conventional vegetables and potatoes. For some nutrients and contaminants organic vegetables and potatoes score significantly better but for others they score significantly worse. Therefore, it becomes difficult to justify general claims indicating a surplus value of organic over conventional vegetables and potatoes. More data from controlled paired studies are needed to reconsider the use of claims for these organic plant foods in the future. Research limitations/implications - Only a limited number of studies comparing the nutrient and/or contaminant concentration of organic and conventional vegetables are available ("paired studies"). Additionally, the majority of the studies are of moderate or poor quality. The implication is that more of those paired studies are heavily needed. Another limitation of the study is the fact that most pesticide residue data originated from the USA, the EU and Australia. Originality/value - So far only few studies compared both nutrient and contaminant contents between organic and conventional plant foods. This paper covers therefore an important, not well-explored research sub area

    Entrepreneurship Education and Training in a Small Business Context: Insights from the Competence-based Approach

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    The concept of competence, as it is brought into play in current research, is a potentially powerful construct for entrepreneurship education research and practice. Although the concept has been the subject of strong debate in educational research in general, critical analysis of how it has been used, applied and experienced in entrepreneurship education practice is scarce. This article contributes specifically to the discussion of entrepreneurial competence by theoretically unfolding and discussing the concept. Subsequently, the implications of applying a competence-based approach in entrepreneurship education are illustrated and discussed based on analysis of two cases t

    Quality assurance of rectal cancer diagnosis and treatment - phase 3 : statistical methods to benchmark centres on a set of quality indicators

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    In 2004, the Belgian Section for Colorectal Surgery, a section of the Royal Belgian Society for Surgery, decided to start PROCARE (PROject on CAncer of the REctum), a multidisciplinary, profession-driven and decentralized project with as main objectives the reduction of diagnostic and therapeutic variability and improvement of outcome in patients with rectal cancer. All medical specialties involved in the care of rectal cancer established a multidisciplinary steering group in 2005. They agreed to approach the stated goal by means of treatment standardization through guidelines, implementation of these guidelines and quality assurance through registration and feedback. In 2007, the PROCARE guidelines were updated (Procare Phase I, KCE report 69). In 2008, a set of 40 process and outcome quality of care indicators (QCI) was developed and organized into 8 domains of care: general, diagnosis/staging, neoadjuvant treatment, surgery, adjuvant treatment, palliative treatment, follow-up and histopathologic examination. These QCIs were tested on the prospective PROCARE database and on an administrative (claims) database (Procare Phase II, KCE report 81). Afterwards, 4 QCIs were added by the PROCARE group. Centres have been receiving feedback from the PROCARE registry on these QCIs with a description of the distribution of the unadjusted centre-averaged observed measures and the centre’s position therein. To optimize this feedback, centres should ideally be informed of their risk-adjusted outcomes and be given some benchmarks. The PROCARE Phase III study is devoted to developing a methodology to achieve this feedback

    Rer1p competes with APH-1 for binding to nicastrin and regulates γ-secretase complex assembly in the early secretory pathway

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    The γ-secretase complex, consisting of presenilin, nicastrin, presenilin enhancer-2 (PEN-2), and anterior pharynx defective-1 (APH-1) cleaves type I integral membrane proteins like amyloid precursor protein and Notch in a process of regulated intramembrane proteolysis. The regulatory mechanisms governing the multistep assembly of this “proteasome of the membrane” are unknown. We characterize a new interaction partner of nicastrin, the retrieval receptor Rer1p. Rer1p binds preferentially immature nicastrin via polar residues within its transmembrane domain that are also critical for interaction with APH-1. Absence of APH-1 substantially increased binding of nicastrin to Rer1p, demonstrating the competitive nature of these interactions. Moreover, Rer1p expression levels control the formation of γ-secretase subcomplexes and, concomitantly, total cellular γ-secretase activity. We identify Rer1p as a novel limiting factor that negatively regulates γ-secretase complex assembly by competing with APH-1 during active recycling between the endoplasmic reticulum (ER) and Golgi. We conclude that total cellular γ-secretase activity is restrained by a secondary ER control system that provides a potential therapeutic value

    Evaluation of relative quantification of alternatively spliced transcripts using droplet digital PCR

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    Introduction: For the relative quantification of isoform expression, RT-qPCR has been the gold standard for over a decade. More recently, digital PCR is becoming widely implemented, as it is promised to be more accurate, sensitive and less affected by inhibitors, without the need for standard curves. In this study we evaluated RT-qPCR versus RT-droplet digital PCR (ddPCR) for the relative quantification of isoforms in controls and carriers of the splice site mutation BRCA1 c.212+3A>G, associated with increased expression of several isoforms. Materials and methods: RNA was extracted from EBV cell lines of controls and heterozygous BRCA1 c.212+3A>G carriers. Transcript-specific plasmids were available to determine the efficiency, precision, reproducibility and accuracy of each method. Results: Both ddPCR and RT-qPCR were able to accurately quantify all targets and showed the same LOB, LOD and LOQ; also precision and reproducibility were similar. Both techniques have the same dynamic range and linearity at biologically relevant template concentrations. However, a significantly higher cost and workload was required for ddPCR experiments. Conclusions: Our study recognizes the potential and validity of digital PCR but shows the value of a highly optimized qPCR for the relative quantification of isoforms. Cost efficiency and simplicity turned out to be better for RT-qPCR. Keywords: Reverse transcriptase polymerase chain reaction, Alternative splicing, Droplet digital PC

    Presenilin 1 mediates the turnover of telencephalin in hippocampal neurons via an autophagic degradative pathway

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    Presenilin 1 (PS1) interacts with telencephalin (TLN) and the amyloid precursor protein via their transmembrane domain (Annaert, W.G., C. Esselens, V. Baert, C. Boeve, G. Snellings, P. Cupers, K. Craessaerts, and B. De Strooper. 2001. Neuron. 32:579–589). Here, we demonstrate that TLN is not a substrate for γ-secretase cleavage, but displays a prolonged half-life in PS1−/− hippocampal neurons. TLN accumulates in intracellular structures bearing characteristics of autophagic vacuoles including the presence of Apg12p and LC3. Importantly, the TLN accumulations are suppressed by adenoviral expression of wild-type, FAD-linked and D257A mutant PS1, indicating that this phenotype is independent from γ-secretase activity. Cathepsin D deficiency also results in the localization of TLN to autophagic vacuoles. TLN mediates the uptake of microbeads concomitant with actin and PIP2 recruitment, indicating a phagocytic origin of TLN accumulations. Absence of endosomal/lysosomal proteins suggests that the TLN-positive vacuoles fail to fuse with endosomes/lysosomes, preventing their acidification and further degradation. Collectively, PS1 deficiency affects in a γ-secretase–independent fashion the turnover of TLN through autophagic vacuoles, most likely by an impaired capability to fuse with lysosomes

    The uncertain future of lay counsellors : continuation of HIV services in Lesotho under pressure

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    Between 2006 and 2011, when antiretroviral therapy (ART) was scaled up in a context of severe human resources shortages, transferring responsibility for elements in human immunodeficiency virus (HIV) care from conventional health workers to lay counsellors (LCs) contributed to increased uptake of HIV services in Lesotho. HIV tests rose from 79 394 in 2006 to 274 240 in 2011 and, in that same period, the number of people on ART increased from 17 352 to 83 624. However, since 2012, the jobs of LCs have been at risk because of financial and organizational challenges. We studied the role of LCs in HIV care in Lesotho between 2006 and 2013, and discuss potential consequences of losing this cadre. Methods included a case study of LCs in Lesotho based on: (1) review of LC-related health policy and planning documents, (2) HIV programme review and (3) workload analysis of LCs. LCs are trained to provide HIV testing and counselling (HTC) and ART adherence support. Funded by international donors, 487 LCs were deployed between 2006 and 2011. However, in 2012, the number of LCs decreased to 165 due to a decreasing donor funds, while administrative and fiscal barriers hampered absorption of LCs into the public health system. That same year, ART coverage decreased from 61% to 51% and facility-based HTC decreased by 15%, from 253 994 in 2011 to 215 042 tests in 2012. The workload analysis indicated that LCs work averagely 77 h per month, bringing considerable relief to the scarce professional health workforce. HIV statistics in Lesotho worsened dramatically in the recent era of reduced support to LCs. This suggests that in order to ensure access to HIV care in an under-resourced setting like Lesotho, a recognized and well-supported counsellor cadre is essential. The continued presence of LCs requires improved prioritization, with national and international support
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