134 research outputs found

    Probing CP Violation with and without Momentum Reconstruction at the LHC

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    We study the potential to observe CP-violating effects in SUSY cascade decay chains at the LHC. We consider squark and gluino production followed by subsequent decays into neutralinos with a three-body leptonic decay in the final step. Asymmetries composed by triple products of momenta of the final state particles are sensitive to CP-violating effects. Due to large boosts these asymmetries can be difficult to observe at a hadron collider. We show that using all available kinematic information one can reconstruct the decay chains on an event-by-event basis even in the case of 3-body decays, neutrinos and LSPs in the final state. We also discuss the most important experimental effects like major backgrounds and momentum smearing due to finite detector resolution. We show that with 300 fb1^{-1} of collected data, CP violation may be discovered at the LHC for a wide range of the phase of the bino mass parameter M1M_1.Comment: Version accepted for publication in JHEP. Clarifications added on the assumptions used for plots. New references adde

    Self-care coping strategies in people with diabetes: a qualitative exploratory study

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    <p>Abstract</p> <p>Background</p> <p>The management of diabetes self-care is largely the responsibility of the patient. With more emphasis on the prevention of complications, adherence to diabetes self-care regimens can be difficult. Diabetes self-care requires the patient to make many dietary and lifestyle changes. This study will explore patient perceptions of diabetes self-care, with particular reference to the burden of self-care and coping strategies among patients.</p> <p>Methods</p> <p>A maximum variation sample of 17 patients was selected from GP practices and diabetes clinics in Ireland to include patients with types 1 and 2 diabetes, various self-care regimens, and a range of diabetes complications. Data were collected by in-depth interviews; which were tape-recorded and transcribed. The transcripts were analysed using open and axial coding procedures to identify main categories, and were reviewed by an independent corroborator. Discussion of the results is made in the theoretical context of the health belief, health value, self-efficacy, and locus of control frameworks.</p> <p>Results</p> <p>Patients' perceptions of their self-care varied on a spectrum, displaying differences in self-care responsibilities such as competence with dietary planning, testing blood sugar and regular exercise. Three patient types could be distinguished, which were labeled: "proactive manager," a patient who independently monitors blood glucose and adjusts his/her self-care regime to maintain metabolic control; "passive follower," a patient who follows his/her prescribed self-care regime, but does not react autonomously to changes in metabolic control; and "nonconformist," a patient who does not follow most of his/her prescribed self-care regimen.</p> <p>Conclusion</p> <p>Patients have different diabetes self-care coping strategies which are influenced by their self-care health value and consequently may affect their diet and exercise choices, frequency of blood glucose monitoring, and compliance with prescribed medication regimens. Particular attention should be paid to the patient's self-care coping strategy, and self-care protocols should be tailored to complement the different patient types.</p

    Induction of cancer-specific cytotoxicity towards human prostate and skin cells using quercetin and ultrasound

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    Bioflavonoids, such as quercetin, have recently emerged as a new class of chemotherapeutic drugs for the treatment of various cancer types, but are marred by their low potency and poor selectivity. We report that a short application of low-frequency ultrasound selectively sensitises prostate and skin cancer cells against quercetin. Pretreatment of cells with ultrasound (20 kHz, 2 W cm−2, 60 s) selectively induced cytotoxicity in skin and prostate cancer cells, while having minimal effect on corresponding normal cell lines. About 90% of the viable skin cancer cell population was lost within 48 h after ultrasound-quercetin (50 μM) treatment. Ultrasound reduced the LC50 of quercetin for skin cancer cells by almost 80-fold, while showing no effect on LC50 for nonmalignant skin cells

    High mutation rates explain low population genetic divergence at copy-number-variable loci in Homo sapiens

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    Copy-number-variable (CNV) loci differ from single nucleotide polymorphic (SNP) sites in size, mutation rate, and mechanisms of maintenance in natural populations. It is therefore hypothesized that population genetic divergence at CNV loci will differ from that found at SNP sites. Here, we test this hypothesis by analysing 856 CNV loci from the genomes of 1184 healthy individuals from 11 HapMap populations with a wide range of ancestry. The results show that population genetic divergence at the CNV loci is generally more than three times lower than at genome-wide SNP sites. Populations generally exhibit very small genetic divergence (G(st) = 0.05 ± 0.049). The smallest divergence is among African populations (G(st) = 0.0081 ± 0.0025), with increased divergence among non-African populations (G(st) = 0.0217 ± 0.0109) and then among African and non-African populations (G(st) = 0.0324 ± 0.0064). Genetic diversity is high in African populations (~0.13), low in Asian populations (~0.11), and intermediate in the remaining 11 populations. Few significant linkage disequilibria (LDs) occur between the genome-wide CNV loci. Patterns of gametic and zygotic LDs indicate the absence of epistasis among CNV loci. Mutation rate is about twice as large as the migration rate in the non-African populations, suggesting that the high mutation rates play dominant roles in producing the low population genetic divergence at CNV loci

    What are the current barriers to effective cancer care coordination? A qualitative study

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    <p>Abstract</p> <p>Background</p> <p>National cancer policies identify the improvement of care coordination as a priority to improve the delivery of health services for people with cancer. Identification of the current barriers to effective cancer care coordination is needed to drive service improvement.</p> <p>Methods</p> <p>A qualitative study was undertaken in which semi-structured individual interviews and focus groups were conducted with those best placed to identify issues; patients who had been treated for a range of cancers and their carers as well as health professionals involved in providing cancer care. Data collection continued until saturation of concepts was reached. A grounded theory influenced approach was used to explore the participants' experiences and views of cancer care coordination.</p> <p>Results</p> <p>Overall, 20 patients, four carers and 29 health professionals participated. Barriers to cancer care coordination related to six aspects of care namely, recognising health professional roles and responsibilities, implementing comprehensive multidisciplinary team meetings, transitioning of care: falling through the cracks, inadequate communication between specialist and primary care, inequitable access to health services and managing scarce resources.</p> <p>Conclusions</p> <p>This study has identified a number of barriers to coordination of cancer care. Development and evaluation of interventions based on these findings is now required.</p

    Living with myotonic dystrophy; what can be learned from couples? a qualitative study

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    Contains fulltext : 96062.pdf (publisher's version ) (Open Access)BACKGROUND: Myotonic dystrophy type 1 (MD1) is one of the most prevalent neuromuscular diseases, yet very little is known about how MD1 affects the lives of couples and how they themselves manage individually and together. To better match health care to their problems, concerns and needs, it is important to understand their perspective of living with this hereditary, systemic disease. METHODS: A qualitative study was carried out with a purposive sample of five middle-aged couples, including three men and two women with MD1 and their partners. Fifteen in-depth interviews with persons with MD1, with their partners and with both of them as a couple took place in the homes of the couples in two cities and three villages in the Netherlands in 2009. Results : People with MD1 associate this progressive, neuromuscular condition with decreasing abilities, describing physical, cognitive and psychosocial barriers to everyday activities and social participation. Partners highlighted the increasing care giving burden, giving directions and using reminders to compensate for the lack of initiative and avoidant behaviour due to MD1. Couples portrayed the dilemmas and frustrations of renegotiating roles and responsibilities; stressing the importance of achieving a balance between individual and shared activities. All participants experienced a lack of understanding from relatives, friends, and society, including health care, leading to withdrawal and isolation. Health care was perceived as fragmentary, with specialists focusing on specific aspects of the disease rather than seeking to understand the implications of the systemic disorder on daily life. CONCLUSIONS: Learning from these couples has resulted in recommendations that challenge the tendency to treat MD1 as a condition with primarily physical impairments. It is vital to listen to couples, to elicit the impact of MD1, as a multisystem disorder that influences every aspect of their life together. Couple management, supporting the self-management skills of both partners is proposed as a way of reducing the mismatch between health services and health needs

    Natural History of Tuberculosis: Duration and Fatality of Untreated Pulmonary Tuberculosis in HIV Negative Patients: A Systematic Review

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    Background The prognosis, specifically the case fatality and duration, of untreated tuberculosis is important as many patients are not correctly diagnosed and therefore receive inadequate or no treatment. Furthermore, duration and case fatality of tuberculosis are key parameters in interpreting epidemiological data. Methodology and Principal Findings To estimate the duration and case fatality of untreated pulmonary tuberculosis in HIV negative patients we reviewed studies from the pre-chemotherapy era. Untreated smear-positive tuberculosis among HIV negative individuals has a 10-year case fatality variously reported between 53% and 86%, with a weighted mean of 70%. Ten-year case fatality of culture-positive smear-negative tuberculosis was nowhere reported directly but can be indirectly estimated to be approximately 20%. The duration of tuberculosis from onset to cure or death is approximately 3 years and appears to be similar for smear-positive and smear-negative tuberculosis. Conclusions Current models of untreated tuberculosis that assume a total duration of 2 years until self-cure or death underestimate the duration of disease by about one year, but their case fatality estimates of 70% for smear-positive and 20% for culture-positive smear-negative tuberculosis appear to be satisfactory

    Abrasive, Silica Phytoliths and the Evolution of Thick Molar Enamel in Primates, with Implications for the Diet of Paranthropus boisei

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    Background: Primates—including fossil species of apes and hominins—show variation in their degree of molar enamel thickness, a trait long thought to reflect a diet of hard or tough foods. The early hominins demonstrated molar enamel thickness of moderate to extreme degrees, which suggested to most researchers that they ate hard foods obtained on or near the ground, such as nuts, seeds, tubers, and roots. We propose an alternative hypothesis—that the amount of phytoliths in foods correlates with the evolution of thick molar enamel in primates, although this effect is constrained by a species ’ degree of folivory. Methodology/Principal Findings: From a combination of dietary data and evidence for the levels of phytoliths in plant families in the literature, we calculated the percentage of plant foods rich in phytoliths in the diets of twelve extant primates with wide variation in their molar enamel thickness. Additional dietary data from the literature provided the percentage of each primate’s diet made up of plants and of leaves. A statistical analysis of these variables showed that the amount of abrasive silica phytoliths in the diets of our sample primates correlated positively with the thickness of their molar enamel, constrained by the amount of leaves in their diet (R 2 = 0.875; p,.0006). Conclusions/Significance: The need to resist abrasion from phytoliths appears to be a key selective force behind the evolution of thick molar enamel in primates. The extreme molar enamel thickness of the teeth of the East African homini

    Transcriptomic analysis of the late stages of grapevine (Vitis vinifera cv. Cabernet Sauvignon) berry ripening reveals significant induction of ethylene signaling and flavor pathways in the skin

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    Background: Grapevine berry, a nonclimacteric fruit, has three developmental stages; the last one is when berrycolor and sugar increase. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of thisripening stage. The transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the late stages ofripening between 22 and 37 \ub0Brix was assessed using whole-genome micorarrays.Results: The transcript abundance of approximately 18,000 genes changed with \ub0Brix and tissue type. There were alarge number of changes in many gene ontology (GO) categories involving metabolism, signaling and abioticstress. GO categories reflecting tissue differences were overrepresented in photosynthesis, isoprenoid metabolismand pigment biosynthesis. Detailed analysis of the interaction of the skin and pulp with \ub0Brix revealed that therewere statistically significantly higher abundances of transcripts changing with \ub0Brix in the skin that were involved inethylene signaling, isoprenoid and fatty acid metabolism. Many transcripts were peaking around known optimalfruit stages for flavor production. The transcript abundance of approximately two-thirds of the AP2/ERF superfamilyof transcription factors changed during these developmental stages. The transcript abundance of a unique clade ofERF6-type transcription factors had the largest changes in the skin and clustered with genes involved in ethylene,senescence, and fruit flavor production including ACC oxidase, terpene synthases, and lipoxygenases. The transcriptabundance of important transcription factors involved in fruit ripening was also higher in the skin.Conclusions: A detailed analysis of the transcriptome dynamics during late stages of ripening of grapevine berriesrevealed that these berries went through massive transcriptional changes in gene ontology categories involvingchemical signaling and metabolism in both the pulp and skin, particularly in the skin. Changes in the transcriptabundance of genes involved in the ethylene signaling pathway of this nonclimacteric fruit were statisticallysignificant in the late stages of ripening when the production of transcripts for important flavor and aroma compoundswere at their highest. Ethylene transcription factors known to play a role in leaf senescence also appear to play a role infruit senescence. Ethylene may play a bigger role than previously thought in this non-climacteric fruit
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