On some new approaches to practical Slepian-Wolf compression inspired by channel coding

This paper considers the problem, first introduced by Ahlswede and Körner in 1975, of lossless source coding with coded side information. Specifically, let X and Y be two random variables such that X is desired losslessly at the decoder while Y serves as side information. The random variables are encoded independently, and both descriptions are used by the decoder to reconstruct X. Ahlswede and Körner describe the achievable rate region in terms of an auxiliary random variable. This paper gives a partial solution for the optimal auxiliary random variable, thereby describing part of the rate region explicitly in terms of the distribution of X and Y

Ecological factors and adolescent marijuana use: results of a prospective study in Santiago, Chile

PURPOSE: Despite the growing evidence that ecological factors contribute to substance use, the relationship of ecological factors and illicit drugs such as marijuana use is not well understood, particularly among adolescents in Latin America. Guided by social disorganization and social stress theories, we prospectively examined the association of disaggregated neighborhood characteristics with marijuana use among adolescents in Santiago, Chile, and tested if these relationships varied by sex. METHODS: Data for this study are from 725 community-dwelling adolescents participating in the Santiago Longitudinal Study, a study of substance using behaviors among urban adolescents in Santiago, Chile. Adolescents completed a two-hour interviewer administered questionnaire with questions about drug use and factors related to drug using behaviors. RESULTS: As the neighborhood levels of drug availability at baseline increased, but not crime or noxious environment, adolescents had higher odds of occasions of marijuana use at follow up, approximately 2 years later (odds ratio [OR] = 1.39; 95% CI = 1.16–1.66), even after controlling for the study’s covariates. No interactions by sex were significant. DISCUSSION: The findings suggest that “poverty”, “crime”, and “drug problems” may not be synonyms and thus can be understood discretely. As Latin American countries re-examine their drug policies, especially those concerning decriminalizing marijuana use, the findings suggest that attempts to reduce adolescent marijuana use in disadvantaged neighborhoods may do best if efforts are concentrated on specific features of the “substance abuse environment”.We are extremely grateful to the families in Chile for their participation in this study. This study received support from the U.S. National Institute on Drug Abuse (R01 DA021181; T32 DA007267) and the Vivian A. and James L. Curtis School of Social Work Research and Training Center. (R01 DA021181 - U.S. National Institute on Drug Abuse; T32 DA007267 - U.S. National Institute on Drug Abuse; Vivian A. and James L. Curtis School of Social Work Research and Training Center

Low-Complexity Approaches to Slepian–Wolf Near-Lossless Distributed Data Compression

This paper discusses the Slepian–Wolf problem of distributed near-lossless compression of correlated sources. We introduce practical new tools for communicating at all rates in the achievable region. The technique employs a simple “source-splitting” strategy that does not require common sources of randomness at the encoders and decoders. This approach allows for pipelined encoding and decoding so that the system operates with the complexity of a single user encoder and decoder. Moreover, when this splitting approach is used in conjunction with iterative decoding methods, it produces a significant simplification of the decoding process. We demonstrate this approach for synthetically generated data. Finally, we consider the Slepian–Wolf problem when linear codes are used as syndrome-formers and consider a linear programming relaxation to maximum-likelihood (ML) sequence decoding. We note that the fractional vertices of the relaxed polytope compete with the optimal solution in a manner analogous to that observed when the “min-sum” iterative decoding algorithm is applied. This relaxation exhibits the ML-certificate property: if an integral solution is found, it is the ML solution. For symmetric binary joint distributions, we show that selecting easily constructable “expander”-style low-density parity check codes (LDPCs) as syndrome-formers admits a positive error exponent and therefore provably good performance

A Call for a Humanistic Stance Toward K–12 Data Science Education

There is growing interest in how to better prepare K–12 students to work with data. In this article, we assert that these discussions of teaching and learning must attend to the human dimensions of data work. Specifically, we draw from several established lines of research to argue that practices involving the creation and manipulation of data are shaped by a combination of personal experiences, cultural tools and practices, and political concerns. We demonstrate through two examples how our proposed humanistic stance highlights ways that efforts to make data personally relevant for youth also necessarily implicate cultural and sociopolitical dimensions that affect the design and learning opportunities in data-rich learning environments. We offer an interdisciplinary framework based on literature from multiple bodies of educational research to inform design, teaching and research for more effective, responsible, and inclusive student learning experiences with and about data

Families that fire together smile together: Resting state connectome similarity and daily emotional synchrony in parent-child dyads

Despite emerging evidence suggesting a biological basis to our social tiles, our understanding of the neural processes which link two minds is unknown. We implemented a novel approach, which included connectome similarity analysis using resting state intrinsic networks of parent-child dyads as well as daily diaries measured across 14 days. Intrinsic resting-state networks for both parents and their adolescent child were identified using independent component analysis (ICA). Results indicate that parents and children who had more similar RSN connectome also had more similar day-to-day emotional synchrony. Furthermore, dyadic RSN connectome similarity was associated with children's emotional competence, suggesting that being neurally in-tune with their parents confers emotional benefits. We provide the first evidence that dyadic RSN similarity is associated with emotional synchrony in what is often our first and most essential social bond, the parent-child relationship

Nurse Practitioner Autonomy in Georgia: Exploring Barriers to Full Practice Authority

Background: There is a significant shortage of primary care physicians in Georgia, with the greatest needs in rural communities. The evidence suggests that nurse practitioners (NPs) improve the quality of care for patients with chronic diseases and may be the solution to the physician shortage. However, the scope of practice for Georgia NPs is among the most restricted in the United States. Purpose: This policy review project explored the barriers to full practice authority for nurse practitioners in the state of Georgia and assessed the impact of current policy on NPs opening independent practices in rural Georgia. The goal of the project was to build a consensus for legislative change to current NP scope of practice. Methodology: A quantitative design was used to collect data from a large nursing organization in Georgia via convenience sampling. One hundred and seventy-nine NPs responded. However, only 135 participants (N=135) consented. Participants completed an online survey in thirty minutes or less. Some questions required free text responses. One-way ANOVA and correlational analysis were used to determine differences between variables. There were no significant differences between NP characteristics (such as race, age, education level, etc) and the likelihood of opening an independent practice. Results: Most NPs (77%) reported a desire for full scope of practice, 80% believed removal of practice barriers would be an advantage to Georgia NPs, and a significant number said if autonomous practice was granted, they were likely or very likely to open an independent practice in rural Georgia

Racial differences in prediabetes prevalence by test type for the US pediatric and adult population: NHANES 1999‐2016

BackgroundPrevious studies have shown that US estimates of prediabetes or diabetes differ depending on test type, fasting plasma glucose (FPG) vs hemoglobin A1c (HbA1c). Given age, race, and test differences reported in the literature, we sought to further examine these differences in prediabetes detection using a nationally representative sample.MethodsUsing the National Health and Nutrition Examination Survey (NHANES) 1999‐2016, individuals were identified as having prediabetes with an HbA1c of 5.7% to 6.4% or a FPG of 100 to 125 mg/dL. We excluded individuals with measurements in the diabetic range. We ran generalized estimating equation logistic regressions to examine the relationship between age, race, and test type with interactions, controlling for sex and body mass index. We compared the difference in predicted prediabetes prevalence detected by impaired fasting glycemia (IFG) vs HbA1c by race/ethnicity among children and adults separately using adjusted Wald tests.ResultsThe absolute difference in predicted prediabetes detected by IFG vs HbA1c was 19.9% for white adolescents, 0% for black adolescents, and 20.1% for Hispanic adolescents; 21.4% for white adults, −1.2% for black adults, and 19.2% for Hispanic adults. Using adjusted Wald tests, we found the absolute differences between black vs white and black vs Hispanic individuals to be significant, but, not between Hispanic and white individuals among children and adults separately.ConclusionsThese observations highlight differences in test performance among racial/ethnic groups. Our findings corroborate the need for further studies to determine appropriate HbA1c cutoff levels for diagnosis of prediabetes by age group and race.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163459/2/pedi13083_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163459/1/pedi13083.pd

Two interdependent mechanisms of antimicrobial activity allow for efficient killing in nylon-3-based polymeric mimics of innate immunity peptides

AbstractNovel synthetic mimics of antimicrobial peptides have been developed to exhibit structural properties and antimicrobial activity similar to those of natural antimicrobial peptides (AMPs) of the innate immune system. These molecules have a number of potential advantages over conventional antibiotics, including reduced bacterial resistance, cost-effective preparation, and customizable designs. In this study, we investigate a family of nylon-3 polymer-based antimicrobials. By combining vesicle dye leakage, bacterial permeation, and bactericidal assays with small-angle X-ray scattering (SAXS), we find that these polymers are capable of two interdependent mechanisms of action: permeation of bacterial membranes and binding to intracellular targets such as DNA, with the latter necessarily dependent on the former. We systemically examine polymer-induced membrane deformation modes across a range of lipid compositions that mimic both bacteria and mammalian cell membranes. The results show that the polymers' ability to generate negative Gaussian curvature (NGC), a topological requirement for membrane permeation and cellular entry, in model Escherichia coli membranes correlates with their ability to permeate membranes without complete membrane disruption and kill E. coli cells. Our findings suggest that these polymers operate with a concentration-dependent mechanism of action: at low concentrations permeation and DNA binding occur without membrane disruption, while at high concentrations complete disruption of the membrane occurs. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova

Modular video endoscopy for in vivo cross-polarized and vital-dye fluorescence imaging of Barrett's-associated neoplasia

A modular video endoscope is developed and tested to allow imaging in different modalities. This system incorporates white light imaging (WLI), cross-polarized imaging (CPI), and vital-dye fluorescence imaging (VFI), using interchangeable filter modules. CPI and VFI are novel endoscopic modalities that probe mucosal features associated with Barrett's neoplasia. CPI enhances vasculature, while VFI enhances glandular architecture. In this pilot study, we demonstrate the integration of these modalities by imaging areas of Barrett's metaplasia and neoplasia in an esophagectomy specimen. We verify that those key image features are also observed during an in vivo surveillance procedure. CPI images demonstrate improved visualization of branching blood vessels associated with neoplasia. VFI images show glandular architecture with increased glandular effacement associated with neoplasia. Results suggests that important pathologic features seen in CPI and VFI are not visible during standard endoscopic white light imaging, and thus the modalities may be useful in future in vivo studies for discriminating neoplasia from Barrett's metaplasia. We further demonstrate that the integrated WLI/CPI/VFI endoscope is compatible with complementary high-resolution endomicroscopy techniques such as the high-resolution microendoscope, potentially enabling two-step (“red-flag” widefield plus confirmatory high-resolution imaging) protocols to be enhanced

A survey of the workplace experiences of police force employees who are autistic and/or have attention deficit hyperactivity disorder

Background There has been little focus on autism and attention-deficit hyperactivity disorder (ADHD) in occupational groups, particularly in high-demand roles such as the police. Aims To describe the characteristics and experiences of UK-based police force employees who are autistic and/or have ADHD, including the benefits and challenges their conditions bring to their occupation, their need for reasonable adjustments, and their co-occurring mental illnesses. Method An online survey was developed, containing both quantitative and qualitative elements. Survey invitations were disseminated through the National Police Autism Association. The survey was open from 23 April to 23 July 2022. Results A total of 117 participants participated in the survey, including 66 who were autistic and 51 with ADHD. Participants who were autistic and/or had ADHD widely reported both benefits and challenges related to their condition(s) in policing work. Both the autistic and ADHD groups widely reported having requested workplace adjustments related to their condition(s), although these were frequently not made. Anxiety (n = 57; 49%) and depression (n = 40; 36%) were both highly prevalent among the participants. The qualitative findings identified four themes: (a) motivations for taking on this career, (b) rewards of the role, (c) challenges of the job and (d) challenges regarding career progression. Conclusions Police force employees who are autistic and/or have ADHD reported that their conditions provided both benefits and challenges with respect to policing work, and that they had requested related workplace adjustments, although such adjustments frequently do not take place. Healthcare professionals need to recognise the importance of workplace considerations and advocacy for people who are autistic and/or have ADHD