45 research outputs found

    A quantitative model to characterize granular flow behavior – A measure of grain layer mixing in storage facilities

    Get PDF
    Food quality and safety concerns have led to many nations implementing regulation and legislation around acceptable food and feed practices. Traceability systems are one component of food and feed practices that have been a topic of much research in recent years. Traceability tools are useful for ensuring regulations are met and offering metrics for improving company processes. Companies that implement traceability systems reap economic benefits, gain market advantage, and decrease losses from costly food recalls through the ability to more efficiently remove contaminated food from the value chain. Bulk commodities, such as grain, greatly increase the difficulty inherent in designing and implementing a traceability system. Comingling grain from various sources is a common practice to transform grain of various quality attributes to achieve an overall higher quality grain for sale to processors. Comingling complicates traceability as granular flow combines all grain sources together with no clear separation point. Previous granular flow research shows that there are two main flow regimes present in a granular material flowing in this manner: 1) Mass flow, where all of the material is in motion and the grain is removed in a mostly first-in-first-out (FIFO) behavior, and 2) Core flow, where the grain forms a natural hopper with some of the grain forced into stagnation and providing a mostly last-in-first-out (LIFO) behavior. The amount of mixing that occurs due to the layering of grain and the flow regimes present as grain is removed has not been previously quantified. Assumptions are made based on the FIFO and LIFO flow regimes but result in a lack of certainty about shipping container composition after the grain is removed from the bin. This lack of certainty leads to costly and inefficient recalls. This experiment is a first step in the development of understanding how much mixing is occurring in grain storage bins. It consisted of the design and development of a small model similar in structure to a flat-floored cylindrical grain bin. The experimental model presented flow behavior that aligned with expected regimes for flat-floored structures and provided consistent data. These outcomes signify that the model and the method are not causing significant changes in flow behavior and indicate that further testing and scaling should be possible. Outcomes from this quantification of granular mixing will provide a useful tool in the area of traceability. Given enough data on the mixing between layers of various types of grain probability models can be developed to provide a more precise prediction of what the composition of each shipment consists of on a percent basis

    Distressed family caregivers of lung cancer patients: an examination of psychosocial and practical challenges

    Get PDF
    Purpose: Lung cancer and its treatment impose many demands on family caregivers, which may increase their risk for distress. However, little research has documented aspects of the caregiving experience that are especially challenging for distressed caregivers of lung cancer patients. This study aimed to explore caregivers' key challenges in coping with their family member's lung cancer. Methods: Single, semi-structured qualitative interviews were conducted with 21 distressed family caregivers of lung cancer patients. Results: Caregivers described three key challenges in coping with their family member's lung cancer. The most common challenge, identified by 38 % of caregivers, was a profound sense of uncertainty regarding the future as they attempted to understand the patient's prognosis and potential for functional decline. Another key challenge, identified by 33 % of caregivers, involved time-consuming efforts to manage the patient's emotional reactions to the illness. Other caregivers (14 %) characterized practical tasks, such as coordinating the patient's medical care, as their greatest challenge. Conclusions: Results suggest that clinical efforts are needed to assist distressed caregivers in providing practical and emotional support to the patient and attending to their own emotional needs

    Severe neurocognitive and growth disorders due to variation in THOC2, an essential component of nuclear mRNA export machinery

    Get PDF
    Highly conserved TREX-mediated mRNA export is emerging as a key pathway in neuronal development and differentiation. TREX subunit variants cause neurodevelopmental disorders (NDDs) by interfering with mRNA export from the cell nucleus to the cytoplasm. Previously we implicated four missense variants in the X-linked THOC2 gene in intellectual disability (ID). We now report an additional six affected individuals from five unrelated families with two de novo and threematernally inherited pathogenic or likely pathogenic variants in THOC2 extending the genotypic and phenotypic spectrum. These comprise three rare missense THOC2 variants that affect evolutionarily conserved amino acid residues and reduce protein stability and two with canonical splice-site THOC2 variants that result in C-terminally truncated THOC2 proteins.We present detailed clinical assessment and functional studies on a de novo variant in a female with an epileptic encephalopathy and discuss an additional four families with rare variants in THOC2 with supportive evidence for pathogenicity. Severe neurocognitive features, including movement and seizure disorders, were observed in this cohort. Taken together our data show that even subtle alterations to the canonical molecular pathways such asmRNAexport, otherwise essential for cellular life, can be compatible with life, but lead to NDDs in human

    Human neural crest cells display molecular and phenotypic hallmarks of stem cells

    Get PDF
    The fields of both developmental and stem cell biology explore how functionally distinct cell types arise from a self-renewing founder population. Multipotent, proliferative human neural crest cells (hNCC) develop toward the end of the first month of pregnancy. It is assumed that most differentiate after migrating throughout the organism, although in animal models neural crest stem cells reportedly persist in postnatal tissues. Molecular pathways leading over time from an invasive mesenchyme to differentiated progeny such as the dorsal root ganglion, the maxillary bone or the adrenal medulla are altered in many congenital diseases. To identify additional components of such pathways, we derived and maintained self-renewing hNCC lines from pharyngulas. We show that, unlike their animal counterparts, hNCC are able to self-renew ex vivo under feeder-free conditions. While cross species comparisons showed extensive overlap between human, mouse and avian NCC transcriptomes, some molecular cascades are only active in the human cells, correlating with phenotypic differences. Furthermore, we found that the global hNCC molecular profile is highly similar to that of pluripotent embryonic stem cells when compared with other stem cell populations or hNCC derivatives. The pluripotency markers NANOG, POU5F1 and SOX2 are also expressed by hNCC, and a small subset of transcripts can unambiguously identify hNCC among other cell types. The hNCC molecular profile is thus both unique and globally characteristic of uncommitted stem cells

    Characteristics and management of HIV-1-infected pregnant women enrolled in a randomised trial: differences between Europe and the USA

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Rates of mother-to-child transmission of HIV-1 (MTCT) have historically been lower in European than in American cohort studies, possibly due to differences in population characteristics. The Pediatric AIDS Clinical Trials Group Protocol (PACTG) 316 trial evaluated the effectiveness of the addition of intrapartum/neonatal nevirapine in reducing MTCT in women already receiving antiretroviral prophylaxis. Participation of large numbers of pregnant HIV-infected women from the US and Western Europe enrolling in the same clinical trial provided the opportunity to identify and explore differences in their characteristics and in the use of non-study interventions to reduce MTCT.</p> <p>Methods</p> <p>In this secondary analysis, 1350 women were categorized according to enrollment in centres in the USA (n = 978) or in Europe (n = 372). Factors associated with receipt of highly active antiretroviral therapy and with elective caesarean delivery were identified with logistic regression.</p> <p>Results</p> <p>In Europe, women enrolled were more likely to be white and those of black race were mainly born in Sub-Saharan Africa. Women in the US were younger and more likely to have previous pregnancies and miscarriages and a history of sexually transmitted infections.</p> <p>More than 90% of women did not report symptoms of their HIV infection; however, more women from the US had symptoms (8%), compared to women from Europe (4%). Women in the US were less likely to have HIV RNA levels <400 copies/ml at delivery than women enrolling in Europe, and more likely to receive highly active antiretroviral therapy, and to start therapy earlier in pregnancy. The elective caesarean delivery rate in Europe was 61%, significantly higher than that in the US (22%). Overall, 1.48% of infants were infected and there was no significant difference in the rate of transmission between Europe and the US despite the different approaches to treatment and delivery.</p> <p>Conclusion</p> <p>These findings confirm that there are important historical differences between the HIV-infected pregnant populations in Western Europe and the USA, both in terms of the characteristics of the women and their obstetric and therapeutic management. Although highly active antiretroviral therapy predominates in pregnancy in both settings now, population differences are likely to remain.</p> <p>Trial registration</p> <p>NCT00000869</p

    Tailored Print Communication and Telephone Motivational Interviewing Are Equally Successful in Improving Multiple Lifestyle Behaviors in a Randomized Controlled Trial

    Get PDF
    Background: Computer tailoring and motivational interviewing show promise in promoting lifestyle change, despite few head-to-head comparative studies. Purpose: Vitalum is a randomized controlled trial in which the efficacy of these methods was compared in changing physical activity and fruit and vegetable consumption in middle-aged Dutch adults. Methods: Participants (n?=?1,629) were recruited via 23 general practices and randomly received either four tailored print letters, four motivational telephone calls, two of each type of intervention, or no information. The primary outcomes were absolute change in self-reported physical activity and fruit and vegetable consumption. Results: All three intervention groups (i.e., the tailored letters, the motivational calls, and the combined version) were equally and significantly more effective than the control group in increasing physical activity (hours/day), intake of fruit (servings/day), and consumption of vegetables (grams/day) from baseline to the intermediate measurement (week 25), follow-up 1 (week 47) and 2 (week 73). Effect sizes (Cohen's d) ranged from 0.15 to 0.18. Participants rated the interventions positively; interviews were more positively evaluated than letters. Conclusions: Tailored print communication and telephone motivational interviewing or their combination are equally successful in changing multiple behaviors. © 2010 The Author(s)

    The CI-FLOW Project: A System for Total Water Level Prediction from the Summit to the Sea

    Get PDF
    Kildow et al. (2009) reported that coastal states support 81% of the U.S. population and generate 83 percent [$11.4 trillion (U.S. dollars) in 2007] of U.S. gross domestic product. Population trends show that a majority of coastal communities have transitioned from a seasonal, predominantly weekend, tourist-based economy to a year-round, permanently based, business economy where industry expands along shorelines and the workforce commutes from inland locations. As a result of this transition, costs associated with damage to the civil infrastructure and disruptions to local and regional economies due to coastal flooding events are escalating, pushing requirements for a new generation of flood prediction technologies and hydrologic decision support tools
    corecore