Probing the Neutron Star Interior with Glitches

With the aim of constraining the structural properties of neutron stars and the equation of state of dense matter, we study sudden spin-ups, glitches, occurring in the Vela pulsar and in six other pulsars. We present evidence that glitches represent a self-regulating instability for which the star prepares over a waiting time. The angular momentum requirements of glitches in Vela indicate that at least 1.4% of the star's moment of inertia drives these events. If glitches originate in the liquid of the inner crust, Vela's `radiation radius' $R_\infty$ must exceed ~12 km for a mass of 1.4 solar masses. The isolated neutron star RX J18563-3754 is a promising candidate for a definitive radius measurement, and offers to further our understanding of dense matter and the origin of glitches.Comment: Invited talk at the Pacific Rim Conference on Stellar Astrophysics, Hong Kong, Aug. 1999. 9 pages, 5 figure

Physical (in)activity, nutritional status and muscle status in older adults:Towards objective assessments in clinical practice

Older age is characterised by the increase of morbidities, such as cardiovascular diseases, diabetes and more complex geriatric syndromes. A health domain of specific interest in older adults is muscle status, which can be defined by the assessment of muscle mass, muscle strength, and physical performance. Poor muscle status, defined as limitations or deficits in muscle quality and quantity, may manifest before actual disabilities are present. Therefore, the assessment of muscle status could be used as a ‘signalling assessment’ to detect those individuals at risk for declining functional performance and losing independence. These morbidities and geriatric syndromes could be partly prevented, delayed or even treated by a healthy lifestyle, e.g., by minimising sedentary behaviour (SB), participating in physical activity (PA) and maintaining a healthy diet to preserve nutritional status. The aim of this thesis was to address aspects of the relationships between objectively assessed (instrumented) SB (i-SB) and PA (i-PA), nutritional status and muscle status in different older adult populations: first, in relatively healthy older adults, and second in geriatric rehabilitation inpatients. Understanding these interrelations could inform future intervention studies on how to successfully preserve muscle status in older adults, which could be considered a prerequisite for maintaining functional performance, independent living, and thus actively participating in society

The role of urban agriculture towards livelihood and food security

Urban agriculture plays a major role in providing food and income in cities. It also serves as a tool for poverty alleviation. Any agricultural activities including crop and vegetable growing, animal rearing, beekeeping, dairy and poultry farms practiced at backyards, open spaces, river banks and small farm lands in peri-urban areas are considered as urban agriculture. This study quantifies cultivated land size in Addis Ababa city and explores the contribution of urban agriculture to livelihood and food security of the actors in the city. The study primarily uses ArcMap and Google Earth software to quantify Addis Ababa’s land used for urban agriculture. Questionnaire interview, Key Informants Interview (KII), Focus Group Discussion (FGD), and observation are employed as primary data collection methods complemented by secondary data obtained by reviewing documents related literature. This study finds that 22% of Addis Ababa’s land is covered with cultivated land whereas water, one of agricultural activities major inputs, constitutes only 1% of the city’s land. The study also finds that urban agriculture is the main source of food and income for the sample households of the study. Furthermore, urbanization, unskilled agricultural practices, lack of collaborative action and networking, as well as inadequate water and irrigation schemes have been identified as main determinants of urban agriculture in the city

Risk factors for unfavourable postoperative outcome in patients with Crohn's disease undergoing right hemicolectomy or ileocaecal resection An international audit by ESCP and S-ECCO

Background Patient and disease-related factors, as well as operation technique all have the potential to impact on postoperative outcome in Crohn's disease. The available evidence is based on small series and often displays conflicting results. Aim To investigate the effect of pre- and intra-operative risk factors on 30-day postoperative outcome in patients undergoing surgery for Crohn's disease. Method International prospective snapshot audit including consecutive patients undergoing right hemicolectomy or ileocaecal resection. This study analysed a subset of patients who underwent surgery for Crohn's disease. The primary outcome measure was the overall Clavien-Dindo postoperative complication rate. The key secondary outcomes were anastomotic leak, re-operation, surgical site infection and length of stay at hospital. Multivariable binary logistic regression analyses were used to produce odds ratios (OR) and 95% confidence intervals (CI). Results Three hundred and seventy five resections in 375 patients were included. The median age was 37 and 57.1% were female. In multivariate analyses, postoperative complications were associated with preoperative parenteral nutrition (OR 2.36 95% CI 1.10-4.97)], urgent/expedited surgical intervention (OR 2.00, 95% CI 1.13-3.55) and unplanned intraoperative adverse events (OR 2.30, 95% CI 1.20-4.45). The postoperative length of stay in hospital was prolonged in patients who received preoperative parenteral nutrition (OR 31, CI [1.08-1.61]) and those who had urgent/expedited operations (OR 1.21, CI [1.07-1.37]). Conclusion Preoperative parenteral nutritional support, urgent/expedited operation and unplanned intraoperative adverse events were associated with unfavourable postoperative outcome. Enhanced preoperative optimization and improved planning of operation pathways and timings may improve outcomes for patients

Quantile regression with interval-censored data in questionnaire-based studies

Interval-censored data can arise in questionnaire-based studies when the respondent gives an answer in the form of an interval without having pre-specified ranges. Such data are called self-selected interval data. In this case, the assumption of independent censoring is not fulfilled, and therefore the ordinary methods for interval-censored data are not suitable. This paper explores a quantile regression model for self-selected interval data and suggests an estimator based on estimating equations. The consistency of the estimator is shown. Bootstrap procedures for constructing confidence intervals are considered. A simulation study indicates satisfactory performance of the proposed methods. An application to data concerning price estimates is presented

Localized tachyon mass and a g-theorem analogue

We study the localized tachyon condensation (LTC) of non-supersymmetric orbifold backgrounds in their mirror Landau-Ginzburg picture. Using he existence of four copies of (2,2) worldsheet supersymmetry, we show at the CFT level, that the minimal tachyon mass in twisted sectors shows somewhat analogous properties of c- or g-function. Namely, $m := |\alpha' M^2_{min}|$ satisfies $m(M) \geq m(D_1\oplus D_2)={\rm max} \{m(D_1),m(D_2)\}$. $c$- $g$- $m$- functions share the common property $f(M)\geq f(D_1\oplus D_2)$ for $f=c,g,m$, although they have different behavior in detail.Comment: 15 pages, no figure, to appear in NP

Why is leptospirosis hard to avoid for the impoverished? Deconstructing leptospirosis transmission risk and the drivers of knowledge, attitudes, and practices in a disadvantaged community in Salvador, Brazil

Several studies have identified socioeconomic and environmental risk factors for infectious disease, but the relationship between these and knowledge, attitudes, and practices (KAP), and more importantly their web of effects on individual infection risk, have not previously been evaluated. We conducted a cross-sectional KAP survey in an urban disadvantaged community in Salvador, Brazil, leveraging on simultaneously collected fine-scale environmental and epidemiological data on leptospirosis transmission. Residents’ knowledge influenced their attitudes which influenced their practices. However, different KAP variables were driven by different socioeconomic and environmental factors; and while improved KAP variables reduced risk, there were additional effects of socioeconomic and environmental factors on risk. For example, males and those of lower socioeconomic status were at greater risk, but once we controlled for KAP, male gender and lower socioeconomic status themselves were not direct drivers of seropositivity. Employment was linked to better knowledge and a less contaminated environment, and hence lower risk, but being employed was independently associated with a higher, not lower risk of leptospirosis transmission, suggesting travel to work as a high risk activity. Our results show how such complex webs of influence can be disentangled. They indicate that public health messaging and interventions should take into account this complexity and prioritize factors that limit exposure and support appropriate prevention practices