98 research outputs found
Low-Floor Tanner Codes via Hamming-Node or RSCC-Node Doping
We study the design of structured Tanner codes with low error-rate floors on the AWGN channel. The design technique involves the âdopingâ of standard LDPC (proto-)graphs, by which we mean Hamming or recursive systematic convolutional (RSC) code constraints are used together with single-parity-check (SPC) constraints to construct a codeâs protograph. We show that the doping of a âgoodâ graph with Hamming or RSC codes is a pragmatic approach that frequently results in a code with a good threshold and very low error-rate floor. We focus on low-rate Tanner codes, in part because the design of low-rate, low-floor LDPC codes is particularly difficult. Lastly, we perform a simple complexity analysis of our Tanner codes and examine the performance of lower-complexity, suboptimal Hamming-node decoders
Conditional KCa3.1-transgene induction in murine skin produces pruritic eczematous dermatitis with severe epidermal hyperplasia and hyperkeratosis
Ion channels have recently attracted attention as potential mediators of skin disease. Here, we explored the consequences of genetically encoded induction of the cell volume-regulating Ca2+-activated KCa3.1 channel (Kcnn4) for murine epidermal homeostasis. Doxycycline-treated mice harboring the KCa3.1+-transgene under the control of the reverse tetracycline-sensitive transactivator (rtTA) showed 800-fold channel overexpression above basal levels in the skin and solid KCa3.1-currents in keratinocytes. This overexpression resulted in epidermal spongiosis, progressive epidermal hyperplasia and hyperkeratosis, itch and ulcers. The condition was accompanied by production of the pro-proliferative and pro-inflammatory cytokines, IL-Ă1 (60-fold), IL-6 (33-fold), and TNFa (26-fold) in the skin. Treatment of mice with the KCa3.1-selective blocker, Senicapoc, significantly suppressed spongiosis and hyperplasia, as well as induction of IL-Ă1 (-88%) and IL-6 (-90%). In conclusion, KCa3.1-induction in the epidermis caused expression of pro-proliferative cytokines leading to spongiosis, hyperplasia and hyperkeratosis. This skin condition resembles pathological features of eczematous dermatitis and identifies KCa3.1 as a regulator of epidermal homeostasis and spongiosis, and as a potential therapeutic target
Machine learning uncovers the most robust self-report predictors of relationship quality across 43 longitudinal couples studies
Given the powerful implications of relationship quality for health and well-being, a central mission of relationship science is explaining why some romantic relationships thrive more than others. This large-scale project used machine learning (i.e., Random Forests) to 1) quantify the extent to which relationship quality is predictable and 2) identify which constructs reliably predict relationship quality. Across 43 dyadic longitudinal datasets from 29 laboratories, the top relationship-specific predictors of relationship quality were perceived-partner commitment, appreciation, sexual satisfaction, perceived-partner satisfaction, and conflict. The top individual-difference predictors were life satisfaction, negative affect, depression, attachment avoidance, and attachment anxiety. Overall, relationship-specific variables predicted up to 45% of variance at baseline, and up to 18% of variance at the end of each study. Individual differences also performed well (21% and 12%, respectively). Actor-reported variables (i.e., own relationship-specific and individual-difference variables) predicted two to four times more variance than partner-reported variables (i.e., the partnerâs ratings on those variables). Importantly, individual differences and partner reports had no predictive effects beyond actor-reported relationship-specific variables alone. These findings imply that the sum of all individual differences and partner experiences exert their influence on relationship quality via a personâs own relationship-specific experiences, and effects due to moderation by individual differences and moderation by partner-reports may be quite small. Finally, relationship-quality change (i.e., increases or decreases in relationship quality over the course of a study) was largely unpredictable from any combination of self-report variables. This collective effort should guide future models of relationships
âIn Sickness and in Healthâ? Disclosures of Genetic Risks in Dating
Individuals who have, or are at risk for, various genetic disorders face many challenges concerning disclosures of genetic information in dating situations. We conducted a qualitative interview study of 64 individuals confronting Huntington's disease, breast cancer, or Alphaâ1 antitrypsin deficiency, examining what issues these individuals encountered, and how they viewed and addressed theseâincluding issues of understandings, privacy, and disclosures of genetic information to various groups (e.g., family members). Incidental to the primary research questions addressed, participants also often described a series of dilemmas in dating situations that they and/or family members, friends, and fellow patients faced of whether to date, and if so, whether, what, how, why, and when to disclose their genetic risk or illness. At times, these individuals feared and experienced rejection, and hence delayed, avoided, or opposed disclosure, or disclosed indirectly or inadvertently. These data are reported in this paper and highlight the importance of patients, their loved ones, genetic counselors, and other health care providers being aware of these issues, and appreciating the complex factors involved, which can affect patientsâ coping and social support. This paper, the first to explore several key aspects of disclosures of genetic information in dating, thus suggests needs for public and professional education, and future research in this area
The challenges of insider research in educational institutions: wielding a doubleâedged sword and resolving delicate dilemmas
Deliberate self-harm and attachment: mediating and moderating roles of depression, anxiety, social support and interpersonal problems among Pakistani school going adolescents
Introduction: In Pakistan there is dearth of research on deliberate self-harm (DSH) and
its predictors among adolescents. While the lack of research in Pakistan can be partly
attributed to the sacrilegious status, criminalization and stigmatization attached to DSH, it
is also an attribute of paucity of Urdu versions of the standardized psychological
instruments. Previous research in developed countries has indicated that attachment theory
can be used as a useful framework to understand the development of austere
psychopathologies like DSH, as well as for studying pathways of interaction of
interpersonal and intrapersonal factors of psychopathologies. In this study, standardized
psychological instruments are translated into Urdu language as a first step. These
instruments are then used to study pathways of interaction of interpersonal and
intrapersonal factors of DSH, conceptualized within attachment framework.
Method: The study was conducted in two steps. In step 1, Youth Health Risk Behavior
Survey (YHRB), Inventory of Interpersonal Problems-32 (IIP-32) and Significant Others
Scale (SOS), were translated into Urdu language. Along with these scales, Urdu translated
versions of Hospital Anxiety and Depression Scale (HADS), Adolescent Relationship
Scales Questionnaire (ARSQ), Life Events scale (LES) from CASE questionnaire and
Family Affluence Scale-II (FAS-II) were reviewed for accuracy of translation through
expert judgement and psychometric evaluation. Secondly, a cross sectional survey was
conducted with 1290 adolescents (10 - 19 years age) using the translated Urdu versions of
the instruments and demographic pro forma. Structural equation modelling was used to
study the pathways of associations between predictors of DSH.
Results: The extensive process of translation resulted in establishment of semantic,
content, technical and construct equivalence of the translated instruments with the original
English versions. Multiple imputation was performed to account for missing values in
SPSS 20. Important structural adaptations were made in the scales based on factor analyses
conducted in M plus. After modifications, all scales showed satisfactory CFI (â„ 0.90) and
RMSEA (†0.06). Results of the survey indicated that the prevalence of DSH (with, without
and ambivalent suicidal intentions) was 7%. Two SEM models were constructed involving
both mediation and moderation pathways. Results of Model 1 showed association of
attachment with DSH was double mediated by social support, depression and anxiety.
Model 2 also confirmed association of attachment with DSH with double mediation
through relationship style problems, depression and anxiety. In order to understand the
contextual picture of the concepts studied in this research both SEM models were also
constructed by controlling for demographic factors. This resulted in confirming age,
gender and family affluence as significant contributors but with very small effects.
Discussion and conclusion: In the present study translation of the instruments helped in
building a reservoir for future research. The results of translation and validation of
instruments indicated that cultural differences, language needs and age must be accounted
for while using standardized psychological instruments. Taking into consideration specific
cultural and demographic background of Pakistan, this study also confirms the key role of
attachment in influencing interaction of predictors of DSH. It is suggested that
intrapersonal and interpersonal factors are influential points of intervention for designing
clinical, school and community based awareness and prevention programs for DSH. The
thesis also discusses the implications for policy guidelines along with recommendations
for future research and other applications of the study
Ensemble Weight Enumerators for Protograph-Based Generalized LDPC Codes
Protograph-based LDPC codes have the advantages of a simple design (or search) procedure and highly structured encoders and decoders. These advantages have also been exploited in the design of protograph-based generalized LDPC (G-LDPC) codes. Recently, a technique for computing ensemble weight enumerators for protograph-based LDPC codes has been published. In the current paper, we extend those results to protograph-based G-LDPC codes. That is, we first derive ensemble weight enumerators for finite-length G-LDPC codes based on protographs, and then we consider the asymptotic case. The asymptotic results allow us to determine whether or not the typical minimum distance in the ensemble grows linearly with codeword length
- âŠ