Characterizing CDMA downlink feasibility via effective interference

This paper models and analyses downlink power assignment feasibility in Code Division Multiple Access (CDMA) mobile networks. By discretizing the area into small segments, the power requirements are characterized via a matrix representation that separates user and system characteristics. We obtain a closed-form analytical expression of the so-called Perron-Frobenius eigenvalue of that matrix, which provides a quick assessment of the feasibility of the power assignment for each distribution of calls over the segments. Although the obtained relation is non-linear, it basically provides an effective interference characterisation of downlink feasibility. Our results allow for a fast evaluation of outage and blocking probabilities, and enable a quick evaluation of feasibility that may be used for Call Acceptance Control. \u

The signature of dissipation in the mass-size relation: are bulges simply spheroids wrapped in a disc?

The relation between the stellar mass and size of a galaxy's structural subcomponents, such as discs and spheroids, is a powerful way to understand the processes involved in their formation. Using very large catalogues of photometric bulge+disc structural decompositions and stellar masses from the Sloan Digital Sky Survey Data Release Seven, we carefully define two large subsamples of spheroids in a quantitative manner such that both samples share similar characteristics with one important exception: the 'bulges' are embedded in a disc and the 'pure spheroids' are galaxies with a single structural component. Our bulge and pure spheroid subsample sizes are 76,012 and 171,243 respectively. Above a stellar mass of ~$10^{10}$ M$_{\odot}$, the mass-size relations of both subsamples are parallel to one another and are close to lines of constant surface mass density. However, the relations are offset by a factor of 1.4, which may be explained by the dominance of dissipation in their formation processes. Whereas the size-mass relation of bulges in discs is consistent with gas-rich mergers, pure spheroids appear to have been formed via a combination of 'dry' and 'wet' mergers.Comment: Accepted for publication in MNRAS, 6 pages, 3 figure

Pest-predator spatial relationships in winter rape: implications for integrated crop management

Douglas Warner, Les J Allen-Williams, Andrew W Ferguson, and Ingrid H Williams, 'Pest–predator spatial relationships in winter rape: implications for integrated crop management', Pest Management Science, Vol. 56 (11): 977-982, November 2000, doi: 10.1002/1526-4998(200011)56:113.0.CO;2-U. Copyright © 2000 Society of Chemical IndustryThe brassica pod midge (Dasineura brassicae) is an important and widespread pest of winter and spring oilseed rape throughout Europe. Pods infested by D brassicae larvae split prematurely, releasing seeds, and the larvae drop to the soil into which they burrow to pupate. At this stage in its lifecycle D brassicae is potentially vulnerable to predation by carabid beetles foraging on the soil surface. This is the first study in the UK to focus on carabid beetles as predators of D brassicae in the oilseed rape crop. The spatio-temporal distributions of larvae of D brassicae dropping to the soil from the crop canopy and of adult carabid beetles active on the soil surface were analysed in two consecutive years. Insect samples were collected from spatially referenced sampling points across each crop. Counts of insects were mapped and analysed, and the degree of spatial association between predator and prey determined using Spatial Analysis by Distance Indices (SADIE). Carabid species abundant and active during peak drop of first generation D brassicae larvae included Agonum dorsale, Amara similata, Harpalus rufipes and Nebria brevicollis. The larvae of D brassicae had a marked edge distribution within the crop. SADIE analysis revealed significant spatial association between larvae of D brassicae and adult H rufipes (P <0.05) in 1998, but not with adults of A dorsale, A similata or N brevicollis. In 1999, there was strong spatial association only between larvae of D brassicae and adult A dorsale (P <0.01). Aggregation of N brevicollis adults occurred in some areas of greatest D brassicae larval counts in 1999, but overall spatial association was not signi®cant. The distributions are discussed in terms of their relevance to integrated crop management (ICM) strategies and spatial targeting of insecticides.Peer reviewe

Constructing the personal narratives of Lesbian, gay and bisexual asylum claimants

This article draws upon psychological and sociological literature to explore the issues that arise in eliciting and presenting a refugee narrative when the claim is based upon sexual orientation. Rigid notions of homosexual identity may consciously or subconsciously shape decision-makers' approaches in this field. First, we identify psycho-social issues of particular significance to lesbian, gay and bisexual claimants which may act as barriers to eliciting their narrative of self-identity, including: a reluctance to reveal group membership as the basis of a claim, the experience of passing or concealment strategies, the impact of shame and depression on memory, common experience of sexual assault, and sexualization of the identity narrative in the legal process. Secondly, we explore factors which inhibit the reception of such narratives in the legal process. In particular we explore the psychological 'stage model' of sexual identity development and examine the pervasive impact this model has had upon decision-makers' 'pre-understanding' of sexual identity development as a uniform and linear trajectory. © The Author [2009]. Published by Oxford University Press. All rights reserved

A supersymmetric multicritical point in a model of lattice fermions

We study a model of spinless fermions with infinite nearest-neighbor repulsion on the square ladder which has microscopic supersymmetry. It has been conjectured that in the continuum the model is described by the superconformal minimal model with central charge c=3/2. Thus far it has not been possible to confirm this conjecture due to strong finite-size corrections in numerical data. We trace the origin of these corrections to the presence of unusual marginal operators that break Lorentz invariance, but preserve part of the supersymmetry. By relying mostly on entanglement entropy calculations with the density-matrix renormalization group, we are able to reduce finite-size effects significantly. This allows us to unambiguously determine the continuum theory of the model. We also study perturbations of the model and establish that the supersymmetric model is a multicritical point. Our work underlines the power of entanglement entropy as a probe of the phases of quantum many-body systems.Comment: 16 pages, 8 figure

Large-scale Monte Carlo simulations of the isotropic three-dimensional Heisenberg spin glass

We study the Heisenberg spin glass by large-scale Monte Carlo simulations for sizes up to 32^3, down to temperatures below the transition temperature claimed in earlier work. The data for the larger sizes show more marginal behavior than that for the smaller sizes, indicating the lower critical dimension is close to, and possibly equal to three. We find that the spins and chiralities behave in a quite similar manner.Comment: 8 pages, 8 figures. Replaced with published versio

Point-of-sale marketing and context of marijuana retailers: Assessing reliability and generalizability of the marijuana retail surveillance tool

As recreational marijuana expands, standardized surveillance measures examining the retail environment are critical for informing policy and enforcement. We conducted a reliability and generalizability study using a previously developed tool involving assessment of a sample of 25 randomly selected Seattle recreational marijuana retailers (20 recreational; 5 recreational/medical) in 2017. The tool assessed: 1) contextual/neighborhood features (i.e., facilities nearby); 2) compliance/security (e.g., age-of-sale signage, age verification); and 3) marketing (i.e., promotions, product availability, price). We found that retailers were commonly within two blocks of restaurants (n = 23), grocery stores (n = 17), liquor stores (n = 13), and bars/clubs (n = 11). Additionally, two were within two blocks of schools, and four were within two blocks of parks. Almost all (n = 23) had exterior signage indicating the minimum age requirement, and 23 verified age. Two retailers had exterior ads for marijuana, and 24 had interior ads. Overall, there were 76 interior ads (M = 3.04; SD = 1.84), most commonly for edibles (n = 28). At least one price promotion/discount was recorded in 17 retailers, most commonly in the form of loyalty membership programs (n = 10) or daily/weekly deals (n = 10). One retailer displayed potential health harms/warnings, while three posted some health claim. Products available across product categories were similar; we also noted instances of selling retailer-branded apparel/ paraphernalia (which is prohibited). Lowest price/unit across product categories demonstrated low variability across retailers. This study documented high inter-rater reliability of the surveillance tool (Kappas = 0.73 to 1.00). In conclusion, this tool can be used in future research and practice aimed at examining retailers marketing practices and regulatory compliance. Keywords: Marijuana use, Retail environment, Marketing, Recreational marijuana, Measure developmen

Social work in movement: marketisation, differentiation and managerial performativity in Sweden and England

This article considers the changing nature of social work in England and Sweden in the context of neoliberal reforms, and the consequences of the ongoing shifts to marketisation and differentiation, managerialism and performativity. Drawing on secondary sources and some interview data from English and Swedish social workers, the article argues that social workers in England and Sweden face similar shifts as marketisation, differentiation, managerialism and its related performativity reshape the occupation, all related to the influence of the macro-context of neoliberalism. ‘Evidence based practice’ has become elevated as an important approach in line with increasing managerialism and performativity, affecting micro processes of everyday working life. Differences between the two countries lie largely in the timing of reforms and how social workers respond to them in organised ways – through mobilisation within the profession in England and through trades unions and local authorities in Sweden. The changes create uncertainty for social workers; while they are not merely passive victims of change they face difficult conditions in which to forge alternative models of professional practice. Contrary to what might have been expected, given the different social, political and historical legacies in Sweden and England of social democracy and liberalism respectively, comparing the social work occupation in these two countries finds many more similarities than differences in how marketisation, differentiation, managerialism and performativity impact on the occupation