Strong singularity of singular masas in II₁ factors

A singular masa A in a II1 factor N is defined by the property that any unitary w ∈ N for which A=wAw* must lie in A. A strongly singular masa A is one that satisfies the inequality ||EA- EwAw*||∞,2 ≥||w- EA(w)||2 for all unitaries w ∈ N where EA is the conditional expectation of N onto A, and ||⋅||∞,2 is defined for bounded maps Φ : N → N by sup{||Φ (x)||2:x ∈ N,||x||≤1}. Strong singularity easily implies singularity, and the main result of this paper shows the reverse implication

Development of a new diagnostic device for extracorporeal shock-wave lithotripsy

Extracorporeal Shock-Wave Lithotripsy (ESWL) is the leading technique for the non-invasive treatment of urinary stones. Thousands of ultrasound shocks are focused on the stones in order to break them into fragments small enough to be passed naturally by the body. The procedure is well established, though the re-treatment rate is around 50%. One of the limits of the procedure is that there is no capability for on-line monitoring of the degree of fragmentation of the stone. The output of the treatments could probably be improved if this facility was made available. The underlying physical mechanisms responsible for the break-up of the stone are still subject to investigation. However both direct stress damage and indirect cavitation erosion seem to be necessary to obtain eliminable fragments. In previous studies, Coleman et al. monitored cavitation in-vivo through the associated acoustic emissions. The objective of this research was to design a new diagnostic device for lithotripsy, exploiting the information carried by these acoustic emissions. After preliminary laboratory experiments some clinical prototypes were developed in collaboration with Precision Acoustic Ltd., UK. The prototypes are currently been tested in the clinic

Quasiballistic correction to the density of states in three-dimensional metal

We study the exchange correction to the density of states in the three-dimensional metal near the Fermi energy. In the ballistic limit, when the distance to the Fermi level exceeds the inverse transport relaxation time $1/\tau$, we find the correction linear in the distance from the Fermi level. By a large parameter $\epsilon_{\rm F} \tau$ this ballistic correction exceeds the diffusive correction obtained earlier.Comment: 2 pages, 1 figur

Dairy intake-related intentions, attitudes, subjective norms and perceived behavioural control of South African nutrition professionals

Background: Intake of dairy-related nutrients of South Africans is low. Nutrition professionals may influence dietary behaviour. Their own disposition related to dairy is unknown, yet important in promoting the “have milk, maas or yoghurt every day” guideline.Aim: Guided by the Theory of Planned Behaviour (TPB), this study aimed to describe determinants of target behaviour of consumption of 2–3 servings of dairy daily among nutrition professionals.Methods: An electronic survey (Qualtrics Online Survey Software) of conveniently sampled Association for Dietetics in South Africa (ADSA) and Nutrition Society of South Africa (NSSA) members determined their dairy-related behaviour, intentions, attitudes, subjective norms and perceived behavioural control regarding dairy in general, and of milk, maas, yoghurt and cheese.Results: Three hundred and six (306) responses (aged 36.4 ± 10.5 years) were received. A third of nutrition professionals reported that their daily dairy intake was 2–3 servings 4–6 times per week, yet over 40% met the target once per week or less often. Intake differed across products. Intention to consume the target was high (5.2 ± 0.12; scale 1–7). Attitudinal evaluations revealed highest belief scores related to nutritional quality and bone health. Associations with cancer development, diabetes and the environment were believed to be least likely. Professional training and scientific evidence emerged as the strongest subjective norms. Nutrition professionals perceived themselves to be in control of the target behaviour, yet their clients significantly less so (p < 0.0001).Conclusion: Nutrition professionals’ attitudes, subjective norms and behavioural control can aid responsive empowerment to support dairy-related nutrition education of South Africans.Keywords: dairy intake, nutrition professionals, Theory of Planned Behaviou

Dietary intakes in adult patients with cystic fibrosis–do they achieve guidelines?

AbstractBackground: Most patients with cystic fibrosis (CF) require a higher energy and protein intake than their healthy peer group. There are few data on dietary intakes of adult patients. The aim of this study was to determine nutritional intakes in an adult population with CF. The impact of nutritional intervention and disease on macronutrient intake was examined. Methods: Retrospective cross-sectional analysis of 94 unweighed food diaries at annual review (1995–2000). Energy and protein intakes were compared to the estimated average requirement (EAR) for energy and reference nutrient intake (RNI) for protein. The effect of diet alone, oral supplements, enteral tube feeding, and cystic fibrosis related diabetes (CFRD), on macronutrient intake was examined and impact of pancreatic sufficency (PS) and lung transplantation. Results: Mean energy and protein intakes approached recommended CF guidelines, but in 72% of assessments these values were not achieved. Mean energy and protein intakes for patients on diet alone and protein intake for those with CFRD failed to meet recommendations. Oral supplementation and enteral tube feeding regimens increased energy and protein intake above recommended levels. No group achieved 40% total energy from fat. Patients receiving enteral tube feeds had the highest mean energy and protein intakes but lowest body mass index (BMI) and lung function. Conclusion: Adequate mean energy and protein intakes in adult patients with CF mask subgroups of patients who fail to meet recommendations ie. diet alone, diabetic. Oral supplementation and enteral tube feeding increase energy and protein intake but fail to achieve an adequate BMI level in subjects with a decreased clinical status. Individual nutritional assessment remains essential

Quantum spin chains in a magnetic field

We demonstrate that the ``worm'' algorithm allows very effective and precise quantum Monte Carlo (QMC) simulations of spin systems in a magnetic field, and its auto-correlation time is rather insensitive to the value of H at low temperature. Magnetization curves for the $s=1/2$ and $s=1$ chains are presented and compared with existing Bethe ansatz and exact diagonalization results. From the Green function analysis we deduce the magnon spectra in the s=1 system, and directly establish the "relativistic" form E(p)=(\Delta ^2 +v^2 p^2)^{1/2} of the dispersion law.Comment: 6 pages, 8 figures; removed discussion of spin-2 case - will be published later in a separate pape

Proximity effect in ultrathin Pb/Ag multilayers within the Cooper limit

We report on transport and tunneling measurements performed on ultra-thin Pb/Ag (strong coupled superconductor/normal metal) multilayers evaporated by quench condensation. The critical temperature and energy gap of the heterostructures oscillate with addition of each layer, demonstrating the validity of the Cooper limit model in the case of multilayers. We observe excellent agreement with a simple theory for samples with layer thickness larger than 30\AA . Samples with single layers thinner than 30\AA deviate from the Cooper limit theory. We suggest that this is due to the "inverse proximity effect" where the normal metal electrons improve screening in the superconducting ultrathin layer and thus enhance the critical temperature.Comment: 4 pages, 4 figure

High fat diet attenuates the anticontractile activity of aortic PVAT via a mechanism involving AMPK and reduced adiponectin secretion

Background and aim: Perivascular adipose tissue (PVAT) positively regulates vascular function through production of factors such as adiponectin but this effect is attenuated in obesity. The enzyme AMP-activated protein kinase (AMPK) is present in PVAT and is implicated in mediating the vascular effects of adiponectin. In this study, we investigated the effect of an obesogenic high fat diet (HFD) on aortic PVAT and whether any changes involved AMPK. Methods: Wild type Sv129 (WT) and AMPKα1 knockout (KO) mice aged 8 weeks were fed normal diet (ND) or HFD (42% kcal fat) for 12 weeks. Adiponectin production by PVAT was assessed by ELISA and AMPK expression studied using immunoblotting. Macrophages in PVAT were identified using immunohistochemistry and markers of M1 and M2 macrophage subtypes evaluated using real time-qPCR. Vascular responses were measured in endothelium-denuded aortic rings with or without attached PVAT. Carotid wire injury was performed and PVAT inflammation studied 7 days later. Key results: Aortic PVAT from KO and WT mice was morphologically indistinct but KO PVAT had more infiltrating macrophages. HFD caused an increased infiltration of macrophages in WT mice with increased expression of the M1 macrophage markers Nos2 and Il1b and the M2 marker Chil3. In WT mice, HFD reduced the anticontractile effect of PVAT as well as reducing adiponectin secretion and AMPK phosphorylation. PVAT from KO mice on ND had significantly reduced adiponectin secretion and no anticontractile effect and feeding HFD did not alter this. Wire injury induced macrophage infiltration of PVAT but did not cause further infiltration in KO mice. Conclusions: High-fat diet causes an inflammatory infiltrate, reduced AMPK phosphorylation and attenuates the anticontractile effect of murine aortic PVAT. Mice lacking AMPKα1 phenocopy many of the changes in wild-type aortic PVAT after HFD, suggesting that AMPK may protect the vessel against deleterious changes in response to HFD

Spin-1 Antiferromagnetic Heisenberg Chains in an External Staggered Field

We present in this paper a nonlinear sigma-model analysis of a spin-1 antiferromagnetic Heisenberg chain in an external commensurate staggered magnetic field. After rediscussing briefly and extending previous results for the staggered magnetization curve, the core of the paper is a novel calculation, at the tree level, of the Green functions of the model. We obtain precise results for the elementary excitation spectrum and in particular for the spin gaps in the transverse and longitudinal channels. It is shown that, while the spectral weight in the transverse channel is exhausted by a single magnon pole, in the longitudinal one, besides a magnon pole a two-magnon continuum appears as well whose weight is a stedily increasing function of the applied field, while the weight of the magnon decreases correspondingly. The balance between the two is governed by a sum rule that is derived and discussed. A detailed comparison with the present experimental and numerical (DMRG) status of the art as well as with previous analytical approaches is also made.Comment: 23 pages, 3 figures, LaTe