71 research outputs found
Harmonic sets and the harmonic prime number theorem
We restrict primes and prime powers to sets H(x)= Uān=1 (x/2n, x/(2n-1)). Let ĪøH(x)= ā pĪµH(x)log p. Then the error in ĪøH(x) has, unconditionally, the expected order of magnitude ĪøH (x)= xlog2 + O(āx). However, if ĻH(x)= āpmĪµ H(x) log p then ĻH(x)= xlog2+ O(log x). Some reasons for and consequences of these sharp results are explored. A proof is given of the āharmonic prime number theoremā Ļ H(x)/ Ļ(x) ā log2
Motivation, Justiļ¬cation, Normalization: Talk Strategies Used by Canadian Medical Tourists Regarding Their Choices to Go Abroad for Hip and Knee Surgeries
Contributing to health geography scholarship on the topic, the objective of this paper is to reveal Canadian medical touristsā perspectives regarding their choices to seek knee replacement or hip replacement or resurfacing (KRHRR) at medical tourism facilities abroad rather than domestically. We address this objective by examining the ātalk strategiesā used by these patients in discussing their choices and the ways in which such talk is co-constructed by others. Fourteen interviews were conducted with Canadians aged 42-77 who had gone abroad for KRHRR. Three types of talk strategies emerged through thematic analysis of their narratives: motivation, justiļ¬cation, and normalization talk. Motivation talk referenced participantsā desires to maintain or resume physical activity, employment, and participation in daily life. Justiļ¬cation talk emerged when participants described how limitations in the domestic system drove them abroad. Finally, being a medical tourist was talked about as being normal on several bases. Among other ļ¬ndings, the use of these three talk strategies in patientsā narratives surrounding medical tourism for KRHRR offers new insight into the language-health-place interconnection. Speciļ¬cally, they reveal the complex ways in which medical tourists use talk strategies to assert the soundness of their choice to shift the site of their own medical care on a global scale while also anticipating, if not even guarding against, criticism of what ultimately is their own patient mobility. These talk strategies provide valuable insight into why international patients are opting to engage in the spatially explicit practice of medical tourism and who and what are informing their choices
Nanofiltration-induced cell death: An integral perspective of early stage biofouling under permeate flux conditions
The performance of pressure-driven membrane filtration processes for water treatment is hampered by biofouling. A relevant, but often overlooked aspect of this phenomenon concerns the localized microenvironment at the membrane interface. A key question is the level of stress on adhering cells and how this impacts on the developing biofilm. In this study, Pseudomonas fluorescens biofilms were monitored after 1, 2 and 7-day cross-flow nanofiltration experiments using confocal microscopy with live/dead staining which enabled analysis of both biofilm structure and the spatial localization of dead versus live cells. A significant increased level of biomass at low- compared to high-flux conditions (2-day experiments) suggested hindrance of bacterial proliferation at higher fluxes. An increase in live cell fractions was generally observed between 24- and 48-h at low flux conditions (3Ā bar), while the fraction of dead/injured cells remained constant during that same period. At higher flux conditions (15Ā bar), the volume of live cell fractions remained constant over 24- and 48-h experiments. The implications of these findings point to the need to reevaluate classical contact-killing strategy for controlling membrane fouling; initial membrane fouling events are characterized by an initially-induced cell death stage followed by an adaptation period through which surviving cells are able to acclimatize in their respective environments. This study emphasizes the need to better understand the role of operating parameters and its resulting cell death during early stage fouling. It is in this context that fouling management strategies can be further developed.European Research CouncilScience Foundation IrelandEuropean Commission - Seventh Framework Programme (FP7
Visceral Adipose Tissue Modulates Radiosensitivity in Oesophageal Adenocarcinoma
Oesophageal adenocarcinoma (OAC) is an exemplar model of obesity-associated cancer. Response to neoadjuvant chemoradiotherapy (NA CRT) is a clinical challenge. We examined if visceral adipose tissue and obesity status alter radiosensitivity in OAC. The radioresistant (OE33R) and radioresponsive (OE33P) OAC isogenic model was cultured with adipose tissue conditioned media from three patient cohorts: non-cancer patients, surgery only OAC patients and NA CRT OAC patients. Cell survival was characterised by clonogenic assay, metabolomic profiling by nuclear magnetic resonance spectroscopy and adipokine receptor gene expression by qPCR. A retrospective in vivo study compared tumour response to NA CRT in normal weight (n=53) versus overweight/obese patients (n=148). Adipose conditioned media (ACM) from all patient cohorts significantly increased radiosensitivity in radioresistant OE33R cells. ACM from the NA CRT OAC cohort increased radiosensitivity in OE33P cells. Metabolomic profiling demonstrated separation of the non-cancer and surgery only OAC cohorts and between the non-cancer and NA CRT OAC cohorts. Gene expression profiling of OE33P versus OE33R cells demonstrated differential expression of the adiponectin receptor-1 (AR1), adiponectin receptor-2 (AR2), leptin receptor (LepR) and neuropilin receptor-1 (NRP1) genes. In vivo overweight/obese OAC patients achieved an enhanced tumour response following NA CRT compared to normal weight patients. This study demonstrates that visceral adipose tissue modulates the cellular response to radiation in OA
Modified Whole-Mount In situ Hybridization Protocol for the Detection of Transgene Expression in Electroporated Chick Embryos
hybridization. hybridization (WISH).Here we describe a modification to the WISH protocol that is essential to prevent DNA cross-hybridization and to specifically detect transgene mRNA transcripts in electroporated embryos. Our optimized WISH procedure can be applied not only to electroporated chick embryos but also to other embryos or adult tissues that have been transfected with large amounts of reporter- or expression construct DNA
Implementation of Multigene Germline and Parallel Somatic Genetic Testing in Epithelial Ovarian Cancer: SIGNPOST Study
We present findings of a cancer multidisciplinary-team (MDT) coordinated mainstreaming pathway of unselected 5-panel germline BRCA1/BRCA2/RAD51C/RAD51D/BRIP1 and parallel somatic BRCA1/BRCA2 testing in all women with epithelial-OC and highlight the discordance between germline and somatic testing strategies across two cancer centres. Patients were counselled and consented by a cancer MDT member. The uptake of parallel multi-gene germline and somatic testing was 97.7%. Counselling by clinical-nurse-specialist more frequently needed >1 consultation (53.6% (30/56)) compared to a medical (15.0% (21/137)) or surgical oncologist (15.3% (17/110)) (p 0.001). The median age was 54 (IQR = 51ā62) years in germline pathogenic-variant (PV) versus 61 (IQR = 51ā71) in BRCA wild-type (p = 0.001). There was no significant difference in distribution of PVs by ethnicity, stage, surgery timing or resection status. A total of 15.5% germline and 7.8% somatic BRCA1/BRCA2 PVs were identified. A total of 2.3% patients had RAD51C/RAD51D/BRIP1 PVs. A total of 11% germline PVs were large-genomic-rearrangements and missed by somatic testing. A total of 20% germline PVs are missed by somatic first BRCA-testing approach and 55.6% germline PVs missed by family history ascertainment. The somatic testing failure rate is higher (23%) for patients undergoing diagnostic biopsies. Our findings favour a prospective parallel somatic and germline panel testing approach as a clinically efficient strategy to maximise variant identification. UK Genomics test-directory criteria should be expanded to include a panel of OC genes.Peer reviewe
Understanding particle deposition kinetics on NF membranes:A focus on micro-beads and membrane interactions at different environmental conditions
Ā© 2014 Elsevier B.V.The significance of nanofiltration membrane surface properties when interacting with microbeads with and without permeate flux was investigated. This was achieved by characterising the surface tension and zeta potential of micro-beads and NF90 membranes to determine the colloid-membrane interaction forces. Dynamic adhesion assays under different ionic strengths (0.1M and 0.01M) and pH (5, 7, and 9) were conducted. Experimental results showed that at high ionic strength, pH does not have a significant effect on adhesion rates, while at low ionic strength the adhesion rate increased at pH 7 (4.56s-1cm-2) compared to pH 5 and pH 9, with rates of 2.69 and 3.66s-1cm-2 respectively. A model was devised to predict colloidal adhesion onto membranes under increasing permeate flux conditions, taking into account all interaction forces. Model predictions indicate that drag force overwhelms all other colloid-membrane interaction forces when the permeate flux increases to 7.2Lh-1m-2. This study suggests that altering membrane surface properties for the prevention of fouling may be limited in its success as an antifouling strategy.Link_to_subscribed_fulltex
Use Of Medical Tourism For Hip And Knee Surgery In Osteoarthritis: A Qualitative Examination Of Distinctive Attitudinal Characteristics Among Canadian Patients
Background
Medical tourism is the term that describes patientsā international travel with the intention of seeking medical treatment. Some medical tourists go abroad for orthopaedic surgeries, including hip and knee resurfacing and replacement. In this article we examine the findings of interviews with Canadian medical tourists who went abroad for such surgeries to determine what is distinctive about their attitudes when compared to existing qualitative research findings about patientsā decision-making in and experiences of these same procedures in their home countries.
Methods
Fourteen Canadian medical tourists participated in semi-structured phone interviews, all of whom had gone abroad for hip or knee surgery to treat osteoarthritis. Transcripts were coded and thematically analysed, which involved comparing emerging findings to those in the existing qualitative literature on hip and knee surgery.
Results
Three distinctive attitudinal characteristics among participants were identified when interview themes were compared to findings in the existing qualitative research on hip and knee surgery in osteoarthritis. These attitudinal characteristics were that the medical tourists we spoke with were: (1) comfortable health-related decision-makers; (2) unwavering in their views about procedure necessity and urgency; and (3) firm in their desires to maintain active lives.
Conclusions
Compared to other patients reported on in the existing qualitative hip and knee surgery literature, medical tourists are less likely to question their need for surgery and are particularly active in their pursuit of surgical intervention. They are also comfortable with taking control of health-related decisions. Future research is needed to identify motivators behind patientsā pursuit of care abroad, determine if the attitudinal characteristics identified here hold true for other patient groups, and ascertain the impact of these attitudinal characteristics on surgical outcomes. Arthritis care providers can use the attitudinal characteristics identified here to better advise osteoarthritis patients who are considering seeking care abroad
āDo your homeworkā¦and then hope for the bestā: the challenges that medical tourism poses to Canadian family physiciansā support of patientsā informed decision-making
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