Szemer\'edi's theorem in the primes

Green and Tao famously proved in 2005 that any subset of the primes of fixed positive density contains arbitrarily long arithmetic progressions. Green had previously shown that in fact any subset of the primes of relative density tending to zero sufficiently slowly contains a 3-term term progression. This was followed by work of Helfgott and de Roton, and Naslund, who improved the bounds on the relative density in the case of 3-term progressions. The aim of this note is to present an analogous result for longer progressions by combining a quantified version of the relative Szemer\'edi theorem given by Conlon, Fox and Zhao with Henriot's estimates of the enveloping sieve weights.Comment: 11 page

Re:Generation – A Model For Age-Inclusive Care

The Canadian population is aging. Seniors are becoming the fastest growing age group as a result of the aging of the baby boom generation, and a lowered fertility rate and an increase in life expectancy in the millennial generation. Currently, the population of Canada is approximately 35 million people, of which five million are aged 65 and over. It is estimated that by 2051, about one in four Canadians will be aged 65 and over. At the rate our population is aging, it is foreseeable that the cost of services for the elderly will escalate rapidly as a result of an increased demand for services but a lack of caregivers and facilities to support them. As such, there is a growing demand for new models of living and care for seniors with a shift towards a more economically sustainable, community-oriented schema, where the collaboration and mutual support between the residents could ease the economic and social burden for society. The author has developed a new approach with regards to designing for an aging population – a conceptual kit of parts known as the Model For Age-Inclusive Care. The thesis proposes the development of an age-inclusive multi-service and care hub to reintegrate the elderly into the social fabric of the city by using underperforming, under-utilized commercial developments as an activator. In essence, this thesis will attempt to connect between the more disparate parts of society through the incorporation of places with potential for development in an attempt to present a model of symbiotic community space aging

Social Psychological Analysis of the Women's Movement

Sociolog

Evaluation of a peer counselling programme to sustain breastfeeding practice in Hong Kong

<p>Abstract</p> <p>Background</p> <p>Peer counselling is reported to increase breastfeeding rates. We evaluated an intervention consisting of mainly telephone contact peer counselling programme on breastfeeding duration and exclusivity.</p> <p>Methods</p> <p>Peer counsellors (PCs) were mothers who had successfully breastfed and had received formal training. Following a postnatal visit, they provided scheduled telephone consultations (Days 1, 4, 7, Weeks 2, 4, 8, and Month 4) to PC group mothers (n = 100) who continued breastfeeding their infants after discharge. Control group mothers (n = 100) received routine care.</p> <p>Results</p> <p>After adjusting for mothers' previous breastfeeding experiences, mothers' working status and breastfeeding problems, no statistical differences in mothers' feeding methods (exclusive, almost exclusive or predominant breastfeeding) were noted at the three follow-up times for intervention and control mothers respectively (Day 5: 37%/38%, 46%/53%, 57%/63%; Month 3: 10%/9%, 17%/23%, 20%/26%; Month 6: 2%/1%, 18%/18%, 18%/19%). All differences between the groups were not significant. Also, there was no evidence to suggest that PC intervention prolonged breastfeeding duration.</p> <p>Conclusion</p> <p>The lack of effect of our PC intervention may reflect the low baseline breastfeeding rate and low value placed on breastfeeding in our population, the type of PC intervention or group allocation biases.</p> <p>Trial registration</p> <p>ISRCTN93605280.</p

Neonatal-Onset Chronic Intestinal Pseudo-Obstruction Syndrome with In Utero Urological Manifestation as Megacystis

SummaryObjectiveWe describe a case of neonatal-onset chronic intestinal pseudo-obstruction syndrome (CIPS) with in utero urological manifestation as congenital megacystis. Pitfalls in the interpretation of prenatal sonographic appearance, genetic counseling, and differential diagnosis are discussed.Case ReportA 28-year-old Taiwanese woman, gravida 6, para 3, was referred for further sonographic examination because of a suspected fetal abdominal cyst. Targeted ultrasound at 28 weeks' gestation showed megacystis filling the abdominal cavity. The renal parenchyma appeared normal, and there was no evidence of reflux hydroureteronephrosis. At 38 weeks of gestation, the patient spontaneously delivered a female infant weighing 3,350 g with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. At the age of 12 days, the infant still required Foley catheterization because of voiding difficulty, so reduction cystoplasty was performed. The infant presented with recurrent episodes of intestinal obstruction thereafter and underwent ileostomy and resections of segmental intestine loops (3 times) in the ensuing years. At the age of 6 years, she is orally fed with partial parenteral infusion support, and the voiding act is satisfactory.ConclusionAttention should be given to the prenatal diagnosis of neonatal-onset CIPS when fetal congenital megacystis with unknown etiology is first detected. Whether there is any relationship between the megacystismicrocolon-intestinal-hypoperistalsis syndrome, CIPS, and pure congenital megacystis requires further study

Disruption of the Abdominal-B Promoter Tethering Element Results in a Loss of Long-Range Enhancer-Directed Hox Gene Expression in Drosophila

There are many examples within gene complexes of transcriptional enhancers interacting with only a subset of target promoters. A number of molecular mechanisms including promoter competition, insulators and chromatin looping are thought to play a role in regulating these interactions. At the Drosophila bithorax complex (BX-C), the IAB5 enhancer specifically drives gene expression only from the Abdominal-B (Abd-B) promoter, even though the enhancer and promoter are 55 kb apart and are separated by at least three insulators. In previous studies, we discovered that a 255 bp cis-regulatory module, the promoter tethering element (PTE), located 5′ of the Abd-B transcriptional start site is able to tether IAB5 to the Abd-B promoter in transgenic embryo assays. In this study we examine the functional role of the PTE at the endogenous BX-C using transposon-mediated mutagenesis. Disruption of the PTE by P element insertion results in a loss of enhancer-directed Abd-B expression during embryonic development and a homeotic transformation of abdominal segments. A partial deletion of the PTE and neighboring upstream genomic sequences by imprecise excision of the P element also results in a similar loss of Abd-B expression in embryos. These results demonstrate that the PTE is an essential component of the regulatory network at the BX-C and is required in vivo to mediate specific long-range enhancer-promoter interactions

Minimally invasive versus transcatheter closure of secundum atrial septal defects:a systematic review and meta-analysis

BACKGROUND: Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to transcatheter (TC) closure of atrial septal defects (ASD). This systematic review and meta-analysis aims to compare post-operative outcomes of MIS versus TC repair in ASD closure. METHODS: PubMed, Medline and EMBASE were searched from inception until June 2018 for randomised and observational studies comparing post-operative outcomes for MIS and TC repair. The studies were reviewed for bias using the ROBINS-I Score and pooled in a meta-analysis using STATA (version 15). RESULTS: Six observational studies, involving 1524 patients assessing three primary and five secondary outcomes were included. Evidence suggests TC repair yielded shorter hospital stay (MD = 3.32, 95% CI 1.04–5.60) and lower rates of transient atrial fibrillation (AF) (RR = 0.48, 95% CI 0.20–1.15). TC repair patients also had fewer pericardial effusions (RR = 0.27, 95% CI 0.05–1.54, I(2) = 0.0%) and pneumothoraxes (RR = 0.18, 95% CI 0.04–0.80, I(2) = 0.0%). However, TC repair results in more minor residual shunts (RR = 6.04, 95% CI 1.69–21.63 in favour of MIS, I(2) = 39.0%). No differences were found for incidences of strokes (RR = 1.58, 95% CI 0.23–10.91, I(2) = 19.3%), unexpected bleeding (RR = 0.44, 95% CI 0.19–1.04, I(2) = 0.0%) and blood transfusion (RR = 0.39, 95% CI 0.09–1.59, I(2) = 0.0%). CONCLUSIONS: MIS closure for ASD has similar outcomes compared to TC repair. However, the lack of randomised literature related to MIS versus TC repair for ASD closure warrants further evidence in the form of RCTs to further support these findings

Association of Genetic Variants Related to Combined Exposure to Higher Body Mass Index and Waist-to-Hip Ratio on Lifelong Cardiovascular Risk in UK Biobank

OBJECTIVE: This study examines the individual and combined association of body mass index (BMI) and 7 waist-to-hip ratio (WHR) with cardiovascular diseases (CVD) risk using genetic scores of the 8 obesity measurements as proxies. DESIGN: A 2×2 factorial analysis approach was applied, with participants divided into four groups of lifetime exposure to low BMI and WHR, high BMI, high WHR, and high BMI and WHR based on weighted genetic risk scores. The difference in CVD risk across groups was evaluated using multivariable logistic regression. SETTING: Cohort study. PARTICIPANTS: A total of 408,003 participants were included from the prospective observational UK Biobank study. RESULTS: A total of 58,429 of CVD events were recorded. Compared to the low BMI and WHR genetic scores group, higher BMI or higher WHR genetic scores were associated with an increase in CVD risk (high BMI: odds ratio (OR), 1.07; 95%CI, 1.04-1.10; high WHR: OR, 1.12; 95%CI, 1.09-1.16). A weak additive effect on CVD risk was found between BMI and WHR (high BMI and WHR: OR, 1.16; 95%CI, 1.12-1.19). Subgroup analysis showed similar patterns between different sex, age (<65, ≥65 years old), smoking status, Townsend deprivation index, fasting glucose level and medication uses, but lower systolic blood pressure was associated with higher CVD risk in obese participants. CONCLUSIONS: High BMI or WHR were associated with increased CVD risk, and their effects are weakly additive. Even though there were overlapping of effect, both BMI and WHR are important in assessing the CVD risk in the general population

Differential Requirement for Satellite Cells During Overload-Induced Muscle Hypertrophy in Growing Versus Mature Mice

Background: Pax7+ satellite cells are required for skeletal muscle fiber growth during post-natal development in mice. Satellite cell-mediated myonuclear accretion also appears to persist into early adulthood. Given the important role of satellite cells during muscle development, we hypothesized that the necessity of satellite cells for adaptation to an imposed hypertrophic stimulus depends on maturational age. Methods: Pax7CreER-R26RDTA mice were treated for 5 days with vehicle (satellite cell-replete, SC+) or tamoxifen (satellite cell-depleted, SC-) at 2 months (young) and 4 months (mature) of age. Following a 2-week washout, mice were subjected to sham surgery or 10 day synergist ablation overload of the plantaris (n = 6–9 per group). The surgical approach minimized regeneration, de novo fiber formation, and fiber splitting while promoting muscle fiber growth. Satellite cell density (Pax7+ cells/fiber), embryonic myosin heavy chain expression (eMyHC), and muscle fiber cross sectional area (CSA) were evaluated via immunohistochemistry. Myonuclei (myonuclei/100 mm) were counted on isolated single muscle fibers. Results: Tamoxifen treatment depleted satellite cells by ≥90% and prevented myonuclear accretion with overload in young and mature mice (p \u3c 0.05). Satellite cells did not recover in SC- mice after overload. Average muscle fiber CSA increased ~20% in young SC+ (p = 0.07), mature SC+ (p \u3c 0.05), and mature SC- mice (p \u3c 0.05). In contrast, muscle fiber hypertrophy was prevented in young SC- mice. Muscle fiber number increased only in mature mice after overload (p \u3c 0.05), and eMyHC expression was variable, specifically in mature SC+ mice. Conclusions: Reliance on satellite cells for overload-induced hypertrophy is dependent on maturational age, and global responses to overload differ in young versus mature mice

Bioactivity in silica/poly(γ-glutamic acid) sol–gel hybrids through calcium chelation

Bioactive glasses and inorganic/organic hybrids have great potential as biomedical implant materials. Sol–gel hybrids with interpenetrating networks of silica and biodegradable polymers can combine the bioactive properties of a glass with the toughness of a polymer. However, traditional calcium sources such as calcium nitrate and calcium chloride are unsuitable for hybrids. In this study calcium was incorporated by chelation to the polymer component. The calcium salt form of poly(γ-glutamic acid) (γCaPGA) was synthesized for use as both a calcium source and as the biodegradable toughening component of the hybrids. Hybrids of 40 wt.% γCaPGA were successfully formed and had fine scale integration of Ca and Si ions, according to secondary ion mass spectrometry imaging, indicating a homogeneous distribution of organic and inorganic components. 29Si magic angle spinning nuclear magnetic resonance data demonstrated that the network connectivity was unaltered with changing polymer molecular weight, as there was no perturbation to the overall Si speciation and silica network formation. Upon immersion in simulated body fluid a hydroxycarbonate apatite surface layer formed on the hybrids within 1 week. The polymer molecular weight (Mw 30–120 kDa) affected the mechanical properties of the resulting hybrids, but all hybrids had large strains to failure, >26%, and compressive strengths, in excess of 300 MPa. The large strain to failure values showed that γCaPGA hybrids exhibited non-brittle behaviour whilst also incorporating calcium. Thus calcium incorporation by chelation to the polymer component is justified as a novel approach in hybrids for biomedical materials