"Hidden" Social Networks in Behavior Change Interventions

We investigated whether “hidden” (or unobserved) social networks were evident in a 2011 physical activity behavior change intervention in Belfast, Northern Ireland. Results showed evidence of unobserved social networks in the intervention and illustrated how the network evolved over short periods and affected behavior. Behavior change interventions should account for the interaction among participants (i.e., social networks) and how such interactions affect intervention outcome.

Algorithms for Hidden Markov Models With Imprecisely Specified Parameters

Hidden Markov models (HMMs) are widely used models for sequential data. As with other probabilistic graphical models, they require the specification of precise probability values, which can be too restrictive for some domains, especially when data are scarce or costly to acquire. We present a generalized version of HMMs, whose quantification can be done by sets of, instead of single, probability distributions. Our models have the ability to suspend judgment when there is not enough statistical evidence, and can serve as a sensitivity analysis tool for standard non-stationary HMMs. Efficient inference algorithms are developed to address standard HMM usage such as the computation of likelihoods and most probable explanations. Experiments with real data show that the use of imprecise probabilities leads to more reliable inferences without compromising efficiency.

From Substance Use to Homelessness or Vice Versa?

Homelessness is associated with substance use, but whether substance use precedes or follows homelessness is unclear. We investigate the nature of the relationship between homelessness and substance use using data from the unique Australian panel dataset Journeys Home collected in 4 surveys over the period from October 2011 to May 2013. Our data refer to 1325 individuals who were homeless or at risk of becoming homeless. We investigate dynamics in homelessness and substance use over the survey period. We find that the two are closely related: homeless individuals are more likely to be substance users and substance users are more likely to be homeless. These relationships, however, are predominantly driven by observed and unobserved individual characteristics which cause individuals to be both more likely to be homeless and to be substance users. Once we take these personal characteristics into account it seems that homelessness does not affect substance use, although we cannot rule out that alcohol use increases the probability that an individual becomes homeless. These overall relationships also hide some interesting heterogeneity by ‘type’ of homelessness

Homeless young people, families and change.:Family support as a facilitator to exiting homelessness.

The families of homeless young people are most often portrayed as a precipitating factor in their homelessness. However, recent studies, particularly those taking a longitudinal approach, have drawn attention to the enabling role of family members and their positive influence on the housing trajectories of homeless youth. Drawing on selected findings from an ongoing longitudinal qualitative study of homeless young people in Dublin, Ireland, this paper aims to build on this relatively fertile area of research. We demonstrate the supportive role of the families of young people who experience homelessness (often as a consequence of difficult family environments) and specifically examine how family re-engagement is negotiated and achieved. The findings highlight a number of dimensions of transition and change. Prominent among these is the importance of renewed trust and communication. Young people and their parents also had to accept responsibility for areas of life that previously served to undermine their relationships and were implicated in the circumstances surrounding a young person's premature home-leaving. Tensions and resistances on the part of young people are highlighted, demonstrating the adaptive mechanisms at work as they attempt to re-engage with family members. The implications of the findings for social work intervention with homeless youth are discussed.

Young people exiting homelessness: An exploration of process, meaning and definition

In the past decade in particular, research attention has shifted from an almost exclusive focus on routes or pathways into homelessness towards the investigation of exits from homelessness. As well as demonstrating the multiple paths possible for young people who become homeless, recent research, and longitudinal studies in particular, has contributed to a more nuanced understanding of the complexity of the homeless pathways of young people. Nonetheless, knowledge and understanding of the nature of homeless exits, and of the mechanisms that facilitate the transition out of homelessness, is far from complete. This paper explores the processes surrounding the exit routes taken by young people out of homelessness and the meanings attached by them to these housing transitions based on selected findings from an ongoing qualitative longitudinal study of homeless youth in Dublin, Ireland. More broadly, the paper considers the utility of distinguishing between the types of routes that young people take out of homelessness, with particular attention to the notions of ‘independent’ and ‘dependent’ exits. The paper aims to further the discussion and debate on the conceptualisation of homeless exits and also discusses a number of policy implications arising from the study's findings.

Deciphering the performance hints hidden in J. S. Bach’s quaver beams

Bach often beamed his quavers beyond the beat-unit indicated by the time-signature, as if to indicate the way he perceived, phrased or articulated a musical line. In my previous study in 2011 I demonstrated the significance for both performers and editors of critical editions of quaver beaming against a broader background of Bach’s notational practice. In this article, I go one step further and demonstrate that Bach’s quaver beams reflect how Bach responded to his pieces in composition and performance, which sheds light on how he engaged with and perceived his music from motivic to structural levels. This enquiry has never before been pursued thoroughly and it promises to uncover the ideas that guided his notational practice as well as his spontaneous responses to the challenges he faced while writing out his music on paper

Using the hidden Markov model to capture quality of care in Lombardy geriatric wards

Quality of care is an important aspect of healthcare monitoring, which is used to ensure that the healthcare system is delivering care of the highest standard. With populations growing older there is an increased urgency in making sure that the healthcare delivered is of the highest standard. Healthcare providers are under increased pressure to ensure that this is the case with public and government demand expecting a healthcare system of the highest quality. Modelling quality of care is difficult to measure due to the many ways of defining it. This paper introduces a potential model which could be used to take quality of care into account when modelling length of stay. The Coxian phase-type distribution is used to model length of stay and the associated quality of care incorporated into the Coxian using a Hidden Markov model. Covariates are also introduced to determine their impact on the hidden level to find out what potentially can affect quality of care. This model is applied to geriatic patient data from the Lombardy region of Italy. The results obtained highlighted that bed numbers and the type of hospital (public or private) can have an effect on the quality of care delivered.

Hidden Markov Models With Set-Valued Parameters

Hidden Markov models (HMMs) are widely used probabilistic models of sequential data. As with other probabilistic models, they require the specification of local conditional probability distributions, whose assessment can be too difficult and error-prone, especially when data are scarce or costly to acquire. The imprecise HMM (iHMM) generalizes HMMs by allowing the quantification to be done by sets of, instead of single, probability distributions. iHMMs have the ability to suspend judgment when there is not enough statistical evidence, and can serve as a sensitivity analysis tool for standard non-stationary HMMs. In this paper, we consider iHMMs under the strong independence interpretation, for which we develop efficient inference algorithms to address standard HMM usage such as the computation of likelihoods and most probable explanations, as well as performing filtering and predictive inference. Experiments with real data show that iHMMs produce more reliable inferences without compromising the computational efficiency.

Using a Discrete Hidden Markov Model Kernel for lip-based biometric identification

In this paper, a novel and effective lip-based biometric identification approach with the Discrete Hidden Markov Model Kernel (DHMMK) is developed. Lips are described by shape features (both geometrical and sequential) on two different grid layouts: rectangular and polar. These features are then specifically modeled by a DHMMK, and learnt by a support vector machine classifier. Our experiments are carried out in a ten-fold cross validation fashion on three different datasets, GPDS-ULPGC Face Dataset, PIE Face Dataset and RaFD Face Dataset. Results show that our approach has achieved an average classification accuracy of 99.8%, 97.13%, and 98.10%, using only two training images per class, on these three datasets, respectively. Our comparative studies further show that the DHMMK achieved a 53% improvement against the baseline HMM approach. The comparative ROC curves also confirm the efficacy of the proposed lip contour based biometrics learned by DHMMK. We also show that the performance of linear and RBF SVM is comparable under the frame work of DHMMK.

Diabetes Distress: Understanding the Hidden Struggles of Living with Diabetes and Exploring Intervention Strategies

Diabetes Distress is a rational emotional response to the threat of a life-changing illness. Distinct from depression, it is rooted in the demands of diabetes management and is a product of psychological adjustment. Diabetes distress has been found to be significantly associated with HbA1c and self-care, which demonstrates its clinical use in treatment outcomes. Interpersonal factors such as perceived support and protectiveness of partners significantly contribute to elevated distress, suggesting that these are valued areas of focus for interventions. Pioneering large-scale research, DAWN2, gives voices to the families of those with diabetes and reaffirms the need to consider psychosocial factors in routine diabetes care. Structured diabetes education programmes are the most widely used in helping individuals cope with diabetes, but they fail to consider the psychological or interpersonal aspects of diabetes management. Psycho-educational approaches are found to be effective in reducing diabetes distress while also improving HbA1c. Certain limitations in the current literature are discussed, along with future directions. Of utmost importance is the need for health practitioners, irrespective of background, to demonstrate an understanding of diabetes distress and actively engage in discussion with individuals struggling to cope with diabetes; to normalize this and integrate it into routine diabetes practice.

Lysosome-associated membrane glycoprotein (LAMP)--preliminary study on a hidden antigen target for vaccination against schistosomiasis

Our previously reported gene atlasing of schistosome tissues revealed transcripts that were highly enriched in the digestive tract of Schistosoma mansoni. From these, we selected two candidates, Sm-LAMP and Sm-NPC2 for testing as vaccine targets. The two molecules were selected on the basis of relatively high expression in the gastrodermis, their potentially important biological function, divergence from homologous molecules of the host and possible apical membrane expression in the gastrodermis. Bacterially expressed recombinant peptides corresponding to regions excluding trans-membrane domains of the selected vaccine targets were used in blinded vaccine trials in CBA mice using alum-CpG as adjuvant. Vaccine trials using the recombinant insoluble Sm-LAMP protein showed 16-25% significant reduction in total worm burden. Faecal egg count reduction was 52% and 60% in two trials, respectively, with similar results for the solubly expressed protein. Liver egg burden was reduced significantly (20% and 38%) with an insoluble recombinant Sm-LAMP in two trials, but not with the soluble recombinant form. Parasite fecundity was not affected by either Sm-LAMP protein preparations in the trials. It is concluded that Sm-LAMP may provide limited protection towards S. mansoni infections but could be used in combination with other vaccine candidates, to provide more comprehensive protection.