Motivated by the recent experimental success in realizing synthetic spin-orbit coupling in ultracold atomic systems, we consider N-component atoms coupled to a non-Abelian SU(N) gauge field. More ...specifically, we focus on the case, referred to here as "SU(3) spin-orbit-coupling," where the internal states of three-component atoms are coupled to their momenta via a matrix structure that involves the Gell-Mann matrices (in contrast to the Pauli matrices in conventional SU(2) spin-orbit-coupled systems). It is shown that the SU(3) spin-orbit-coupling gives rise to qualitatively different phenomena and in particular we find that even a homogeneous SU(3) field on a simple square lattice enables a topologically nontrivial state to exist, while such SU(2) systems always have trivial topology. In deriving this result, we first establish an equivalence between the Hofstadter model with a 1/N Abelian flux per plaquette and a homogeneous SU(N) non-Abelian model. The former is known to have a topological spectrum for N>2, which is thus inherited by the latter. It is explicitly verified by an exact calculation for N=3, where we develop and use a new algebraic method to calculate topological indices in the SU(3) case. Finally, we consider a strip geometry and establish the existence of three gapless edge states-the hallmark feature of such an SU(3) topological insulator.
We have carried out the largest randomised trial to date of newly diagnosed myeloma patients, in which lenalidomide has been used as an induction and maintenance treatment option and here report its ...impact on second primary malignancy (SPM) incidence and pathology. After review, 104 SPMs were confirmed in 96 of 2732 trial patients. The cumulative incidence of SPM was 0.7% (95% confidence interval (CI) 0.4-1.0%), 2.3% (95% CI 1.6-2.7%) and 3.8% (95% CI 2.9-4.6%) at 1, 2 and 3 years, respectively. Patients receiving maintenance lenalidomide had a significantly higher SPM incidence overall (P=0.011). Age is a risk factor with the highest SPM incidence observed in transplant non-eligible patients aged >74 years receiving lenalidomide maintenance. The 3-year cumulative incidence in this group was 17.3% (95% CI 8.2-26.4%), compared with 6.5% (95% CI 0.2-12.9%) in observation only patients (P=0.049). There was a low overall incidence of haematological SPM (0.5%). The higher SPM incidence in patients receiving lenalidomide maintenance therapy, especially in advanced age, warrants ongoing monitoring although the benefit on survival is likely to outweigh risk.
Robust minimum variance beamforming Lorenz, R.G.; Boyd, S.P.
IEEE transactions on signal processing,
05/2005, Letnik:
53, Številka:
5
Journal Article
Recenzirano
Odprti dostop
This paper introduces an extension of minimum variance beamforming that explicitly takes into account variation or uncertainty in the array response. Sources of this uncertainty include imprecise ...knowledge of the angle of arrival and uncertainty in the array manifold. In our method, uncertainty in the array manifold is explicitly modeled via an ellipsoid that gives the possible values of the array for a particular look direction. We choose weights that minimize the total weighted power output of the array, subject to the constraint that the gain should exceed unity for all array responses in this ellipsoid. The robust weight selection process can be cast as a second-order cone program that can be solved efficiently using Lagrange multiplier techniques. If the ellipsoid reduces to a single point, the method coincides with Capon's method. We describe in detail several methods that can be used to derive an appropriate uncertainty ellipsoid for the array response. We form separate uncertainty ellipsoids for each component in the signal path (e.g., antenna, electronics) and then determine an aggregate uncertainty ellipsoid from these. We give new results for modeling the element-wise products of ellipsoids. We demonstrate the robust beamforming and the ellipsoidal modeling methods with several numerical examples.
A newly developed analytical method was used to measure concentrations of nine pharmaceuticals and personal care products (PPCPs) in samples from two surface water bodies, a sewage treatment plant ...effluent and various stages of a drinking water treatment plant in Louisiana, USA, and from one surface water body, a drinking water treatment plant and a pilot plant in Ontario, Canada. The analytical method provides for simultaneous extraction and quantification of the following broad range of PPCPs and endocrine-disrupting chemicals: naproxen; ibuprofen; estrone; 17β-estradiol; bisphenol A; clorophene; triclosan; fluoxetine; and clofibric acid. Naproxen was detected in Louisiana sewage treatment plant effluent at 81–106 ng/l and Louisiana and Ontario surface waters at 22–107 ng/l. Triclosan was detected in Louisiana sewage treatment plant effluent at 10–21 ng/l. Of the three surface waters sampled, clofibric acid was detected in Detroit River water at 103 ng/l, but not in Mississippi River or Lake Pontchartrain waters. None of the other target analytes were detected above their method detection limits. Based on results at various stages of treatment, conventional drinking-water treatment processes (coagulation, flocculation and sedimentation) plus continuous addition of powdered activated carbon at a dosage of 2 mg/l did not remove naproxen from Mississippi River waters. However, chlorination, ozonation and dual media filtration processes reduced the concentration of naproxen below detection in Mississippi River and Detroit River waters and reduced clofibric acid in Detroit River waters. Results of this study demonstrate that existing water treatment technologies can effectively remove certain PPCPs. In addition, our study demonstrates the importance of obtaining data on removal mechanisms and byproducts associated with PPCPs and other endocrine-disrupting chemicals in drinking water and sewage treatment processes.
Identifying important sites for biodiversity is vital for conservation and management. However, there is a lack of accessible, easily applied tools that enable practitioners to delineate important ...sites for highly mobile species using established criteria.
We introduce the R package ‘track2KBA’, a tool to identify important sites at the population level using tracking data from individual animals based on three key steps: (a) identifying individual core areas, (b) assessing population‐level representativeness of the sample and (c) quantifying spatial overlap among individuals and scaling up to the population.
We describe package functionality and exemplify its application using tracking data from three taxa in contrasting environments: a seal, a marine turtle and a migratory land bird.
This tool facilitates the delineation of sites of ecological relevance for diverse taxa and provides output useful for assessing their importance to a population or species, as in the Key Biodiversity Area (KBA) Standard. As such, ‘track2KBA’ can contribute directly to conservation planning at global and regional levels.
Resumo
A identificação de áreas importantes para a biodiversidade é essencial para a sua conservação. No entanto, são escassas as ferramentas acessíveis e de fácil aplicação que permitam o delineamento de áreas importantes para espécies altamente móveis usando critérios estabelecidos.
Neste estudo, apresentamos o pacote de R 'track2KBA', uma ferramenta para identificar áreas importantes ao nível populacional usando dados de seguimento de animais com base em três passos principais: (1) identificação de áreas vitais dos indivíduos, (2) avaliação da representatividade da amostra ao nível da população, (3) e quantificação da sobreposição espacial entre indivíduos e extrapolação para a populacão.
Descrevemos a funcionalidade do pacote e exemplificamos a sua aplicação usando dados de seguimento de três éspecies ‐ lobo‐marinho, tartaruga marinha e uma ave terrestre migradora‐ em ambientes contrastantes.
Esta ferramenta facilita o delineamento de áreas com relevância ecológica para diversos taxa e fornece resultados importantes para avaliar a sua importância para uma população ou espécie, utilizando por exemplo o Key Biodiversity Area (KBA) Standard. Como tal, o ‘track2KBA’ pode contribuir directamente para o planeamento da conservação a nível global e regional.
Aims: To investigate the lagged effects of cold temperature on cardiorespiratory mortality and to determine whether “wind chill” is a better predictor of these effects than “dry bulb” temperature. ...Methods: Generalised linear Poisson regression models were used to investigate the relation between mortality and “dry bulb” and “wind chill” temperatures in the three largest Scottish cities (Glasgow, Edinburgh, and Aberdeen) between January 1981 and December 2001. Effects of temperature on mortality (lags up to one month) were quantified. Analyses were conducted for the whole year and by season (cool and warm seasons). Main results: Temperature was a significant predictor of mortality with the strongest association observed between temperature and respiratory mortality. There was a non-linear association between mortality and temperature. Mortality increased as temperatures fell throughout the range, but the rate of increase was steeper at temperatures below 11°C. The association between temperature and mortality persisted at lag periods beyond two weeks but the effect size generally decreased with increasing lag. For temperatures below 11°C, a 1°C drop in the daytime mean temperature on any one day was associated with an increase in mortality of 2.9% (95% CI 2.5 to 3.4), 3.4% (95% CI 2.6 to 4.1), 4.8% (95% CI 3.5 to 6.2) and 1.7% (95% CI 1.0 to 2.4) over the following month for all cause, cardiovascular, respiratory, and “other” cause mortality respectively. The effect of temperature on mortality was not observed to be significantly modified by season. There was little indication that “wind chill” temperature was a better predictor of mortality than “dry bulb” temperature. Conclusions: Exposure to cold temperature is an important public health problem in Scotland, particularly for those dying from respiratory disease.
Purpose
Seizures are common in comatose children, but may be clinically subtle or only manifest on continuous electroencephalographic monitoring (cEEG); any association with outcome remains ...uncertain.
Methods
cEEG (one to three channels) was performed for a median 42 h (range 2–630 h) in 204 unventilated and ventilated children aged ≤15 years (18 neonates, 61 infants) in coma with different aetiologies. Outcome at 1 month was independently determined and dichotomized for survivors into favourable (normal or moderate neurological handicap) and unfavourable (severe handicap or vegetative state).
Results
Of the 204 patients, 110 had clinical seizures (CS) before cEEG commenced. During cEEG, 74 patients (36 %, 95 % confidence interval, 95 % CI, 32–41 %) had electroencephalographic seizures (ES), the majority without clinical accompaniment (non-convulsive seizures, NCS). CS occurred before NCS in 69 of the 204 patients; 5 ventilated with NCS had no CS observed. Death (93/204; 46 %) was independently predicted by admission Paediatric Index of Mortality (PIM; adjusted odds ratio, aOR, 1.027, 95 % CI 1.012–1.042;
p
< 0.0005), Adelaide coma score (aOR 0.813, 95 % CI 0.700–0.943;
p
= 0.006), and EEG grade on admission (excess slow with >3 % fast, aOR 5.43, 95 % CI 1.90–15.6; excess slow with <3 % fast, aOR 8.71, 95 % CI 2.58–29.4; low amplitude, 10th centile <9 µV, aOR 3.78, 95 % CI 1.23–11.7; and burst suppression, aOR 10.68, 95 % CI 2.31–49.4) compared with normal cEEG, as well as absence of CS at any time (aOR 2.38, 95 % CI 1.18–4.81). Unfavourable outcome (29/111 survivors; 26 %) was independently predicted by the presence of ES (aOR 15.4, 95 % CI 4.7–49.7) and PIM (aOR 1.036, 95 % CI 1.013–1.059).
Conclusion
Seizures are common in comatose children, and are associated with an unfavourable outcome in survivors. cEEG allows the detection of subtle CS and NCS and is a prognostic tool.
Summary
Benign epilepsy with centrotemporal spikes (BECTS) is associated with language disturbances during the active phase of the seizure disorder. However, it is not yet known whether these ...deficits are reversible or have long‐term impact on the development of language skills. We report on a study conducted in 13 patients in remission from BECTS and 13 age‐matched controls, who underwent neuropsychological assessments. We also recorded event‐related potentials (ERPs) during a verb generation task, to determine cortical lateralization of language. The BECTS group showed significant language deficits compared to controls as well as a pattern of atypical ERP lateralization in frontal regions. These findings support the view that BECTS in childhood may lead to enduring effects on brain maturation and language development.
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