Adsorbed self-avoiding walks subject to a force

We consider a self-avoiding walk model of polymer adsorption where the adsorbed polymer can be desorbed by the application of a force. In this paper the force is applied normal to the surface at the last vertex of the walk. We prove that the appropriate limiting free energy exists where there is an applied force and a surface potential term, and prove that this free energy is convex in appropriate variables. We then derive an expression for the limiting free energy in terms of the free energy without a force and the free energy with no surface interaction. Finally we show that there is a phase boundary between the adsorbed phase and the desorbed phase in the presence of a force, prove some qualitative properties of this boundary and derive bounds on the location of the boundary

‘Going implicit’: using implicit measures in organizations

Implicit tests are increasingly being used and discussed in the field of Industrial-Organizational psychology. Despite their growing popularity, little is known about the types of implicit tests that exist, how they operationalize constructs, and how to improve their usefulness to predict relevant organizational behavior. We provide a timely contribution to practitioners and scholars who are considering adopting implicit measures in their organizations. By drawing on dual-processing theory, we reviewed the most prevalent implicit tests (Implicit Association Test, Picture Story Exercise, and Conditional Reasoning Test), and evaluated each against the following criteria: how they work, application areas, psychometric properties, perceptions of fairness, and faking potential. Based on prior empirical evidence, we provide ideas to improve these measures, how they may be applied in practice, and which avenues deserve future research. Together, these recommendations may enhance the value of implicit measures in organizations

A comprehensive programme addressing HIV/AIDS and gender based violence

A survey was administered to 304 respondents participating from three areas near Welkom, South Africa. Face-toface interviews were conducted with women from randomly selected households to evaluate the impact of a service provision programme targeting women living with HIV/AIDS and gender based violence. Gender based violence (GBV) awareness and knowledge was high. Respondents had high perceived levels of risk.They reported making various behavioural changes to avoid GBV.The respondents were aware of their legal rights pertaining to GBV. HIV/AIDS knowledge levels and attitudes were acceptable. Behavioural changes included condom use, abstinence and being faithful to one partner. Disclosure of HIV was lower than disclosure of GBV.Awareness and knowledge of female condoms were high, yet usage low. Participants reported that they would be able to introduce condoms to a relationship and negotiate usage with relative ease. Perceived levels of GBV and HIV were high, and stigma levels towards the affected women were also relatively high.The awareness and knowledge levels of GBV and HIV of older respondents were lower than younger respondents.The key findings of this study support the notion of using a holistic approach, targeting more than one issue.There is lower stigma levels associated with combined conditions, which might allow easier access to vulnerable groups. Coordination and collaboration of services are however needed to enable this benefit. Une étude a été faite auprès de 304 participantes venant de trois quartiers près de Welkom, en Afrique du Sud. Des chercheurs de terrain, bien formés, ont mené des entretiens en tête-à-tête avec des femmes de foyers sélectionnés au hasard avec le but d'évaluer l'impact du programme de service visant des femmes qui vivent avec le VIH/SIDA et la violence contre les femmes. La prise de conscience et la connaissance de la violence contre les femmes étaient élevées. Les participantes montraient des niveaux élevés du risque perçu. Elles avouent avoir changé leur comportement afin d'éviter la violence contre les femmes, ainsi que dénoncer le malfaiteur. Elles connaissaient leurs droits par rapport à la violence contre les femmes. Les niveaux de connaissance du VIH/SIDA et des attitudes étaient satisfaisants. Le changement de comportement inclut entre autres, l'utilisation du préservatif (même si cela n'était pas fait régulièrement), l'abstinence et être fidèle à un seul partenaire. La divulgation de sa séropositivité était plus basse que celle de la violence. La prise de conscience et la connaissance du préservatif féminin était élevé. Cependant, son usage était très bas car il n'est pas facilement disponible. Les participantes ont signalé qu'elles pourraient proposer un préservatif et négocier son usage sans beaucoup de difficulté. Les niveaux perçus de la violence contre les femmes et le VIH étaient élevés. Le niveau de stigmatisation envers des femmes infectées était relativement élevé. Le niveau de conscience et de connaissance de la violence contre les femmes et du SIDA chez les participantes plus âgées était plus bas par rapport à celui de participantes plus jeunes.Tandis que tous les trois quartiers ont montré une évidence de valeur des activités de “LifeLine”, la valeur des interventions à Odendaalsrus était moins importante. Il y a un besoin de réorganiser des activités prioritaires par le biais de “LifeLine”. Les résultats de cette étude soutien la notion de l'utilisation d'une approche holistique visant plus d'un sujet. Le niveau de stigmatisation liée aux conditions complexes est moins élevé. Cela peut permettre l'accès plus facile aux groupes vulnérables. La coordination et la collaboration des services sont toutefois nécessaires afin de permettre la rentabilité. Les résultats des interventions de GBV et de VIH confirment d'autres études. Le manque des documents et davantage d'études sur la rentabilité des interventions compréhensives est abordé dans cette description d'une approche qui a pour but d'aborder la violence contre les femmes et le VIH en se servant d'une approche holistique. Keywords: HIV/AIDS and GBV, holistic, comprehensive programme.SAHARA J Vol. 4 (3) 2007: pp. 695-70

The aims of initiation ceremonies at universities: Comparisons in time and space1

In this article initiation practices at South African universities are analysed and compared with initiation ceremonies described in anthropological literature. It is argued that any initiation ceremony has at least the partial aim of preparing initiates for the roles and functions in society or specific organizations. Naturally a reasonable degree of harmony between the intent of initiation on the one hand and the values of an institution on the other hand can be expected. The intention of initiation usually is to prepare one for a position or rote by means of the expression of certain values. On the question whether this harmony between ideas and actions is found in the case of existent initiation ceremonies at South African universities, the answer is negative. These ceremonies do not aim to convey and develop attitudes and values essential to a university and in fact do not prepare first-year students for their new environment and a community of scholars. The way in which universities transcend their authority by condoning and officially allowing the demeaning initiation practices is also questioned

Anthropology, social change and the reconstruction of South African society1

In this article it is argued that, since the abuse of anthropology in the colonial and apartheid eras, the responsive relationship between anthropology and society has been re-emphasised. In the reconstruction of South African society, therefore, anthropologists will not be allowed the luxury of evading their social responsibility. In their re-invention of anthropology as a humane science, and the reiteration of their commitment to accountability and relevance, these scientists ought to build their discipline upon the investigation of the major consequences of differential power and inequality. This could be helpful in creating new forms of co-existence in South Afric

A simple model of a vesicle drop in a confined geometry

We present the exact solution of a two-dimensional directed walk model of a drop, or half vesicle, confined between two walls, and attached to one wall. This model is also a generalisation of a polymer model of steric stabilisation recently investigated. We explore the competition between a sticky potential on the two walls and the effect of a pressure-like term in the system. We show that a negative pressure ensures the drop/polymer is unaffected by confinement when the walls are a macroscopic distance apart

Partially directed paths in a wedge

The enumeration of lattice paths in wedges poses unique mathematical challenges. These models are not translationally invariant, and the absence of this symmetry complicates both the derivation of a functional recurrence for the generating function, and solving for it. In this paper we consider a model of partially directed walks from the origin in the square lattice confined to both a symmetric wedge defined by $Y = \pm pX$, and an asymmetric wedge defined by the lines $Y= pX$ and Y=0, where $p > 0$ is an integer. We prove that the growth constant for all these models is equal to $1+\sqrt{2}$, independent of the angle of the wedge. We derive functional recursions for both models, and obtain explicit expressions for the generating functions when $p=1$. From these we find asymptotic formulas for the number of partially directed paths of length $n$ in a wedge when $p=1$. The functional recurrences are solved by a variation of the kernel method, which we call the ``iterated kernel method''. This method appears to be similar to the obstinate kernel method used by Bousquet-Melou. This method requires us to consider iterated compositions of the roots of the kernel. These compositions turn out to be surprisingly tractable, and we are able to find simple explicit expressions for them. However, in spite of this, the generating functions turn out to be similar in form to Jacobi $\theta$-functions, and have natural boundaries on the unit circle.Comment: 26 pages, 5 figures. Submitted to JCT

Diagnosis and treatment of schizophrenia in a general hospital based acute psychiatric ward

Objectives: To review and describe the clinical profile and acute in-patient treatment of patients diagnosed with schizophrenia over a four-year period; to review and describe the documented evidence for the diagnosis of schizophrenia; and to identify possible associated or predictive factors in the acute in-patient treatment outcome of patients at an acute (designated for 72-hour assessments) ward – within a general hospital, Helen Joseph Hospital (HJH). Method: Routine discharge summaries were used in a retrospective clinical review of patients with schizophrenia. The demographic, clinical and treatment profile of these patients were described and the documented evidence for the diagnosis of schizophrenia was reviewed using descriptive and comparative statistics. Factors were evaluated to assess their association with the length of stay (LOS) as outcome variable, using “Generalized Linear Latent and Mixed Models” (GLLAMM). Results: A total of 436 patients were diagnosed with schizophrenia, constituting on average about 20% of the total numbers of admissions. The overall mean LOS was 19.5 days. Considering DSM IV-TR criteria for schizophrenia, behavior problems were confirmed in 71.8% (n=313), perceptual disturbances in 29% (n=126) and thought disorders in 83.5% (n=364). The duration of symptoms were specified in 68% (n=298) patients. Age (