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Character Levels and Character Bounds
No full textWe develop the concept of character level for the complex irreducible characters of finite, general or special, linear and unitary groups. We give characterizations of the level of a character in terms of its Lusztig label and in terms of its degree. Then we prove explicit upper bounds for character values at elements with not-too-large centralizers and derive upper bounds on the covering number and mixing time of random walks corresponding to these conjugacy classes. We also characterize the level of the character in terms of certain dual pairs and prove explicit exponential character bounds for the character values, provided that the level is not too large. Several further applications are also provided. Related results for other finite classical groups are obtained in the sequel [Guralnick et al. ‘Character levels and character bounds for finite classical groups’, Preprint, 2019, arXiv:1904.08070] by different methods
The relationships between cognitive function, literacy and HIV status knowledge among older adults in rural South Africa
No full textIntroduction: Although HIV prevalence is exceptionally high in South Africa, HIV testing rates remain below targeted guidelines. Older adults living with HIV are substantially more likely to remain undiagnosed than younger people. Cognitive function and literacy could play key roles in HIV status knowledge due to the decision‐making processes required around weighing the costs and benefits of testing, navigating testing logistics and processing results. We aimed to assess the independent relationships among each of cognitive function, literacy and education with HIV status knowledge in a population‐based sample of older adults living in a rural South African community with high HIV prevalence. Methods: We analyzed data from a population‐based study of 5059 men and women aged 40 years and older in rural South Africa (Health and Aging in Africa: A Longitudinal Study of an INDEPTH community (HAALSI)). HAALSI surveys, conducted between 2014 and 2015, queried self‐reported literacy, educational attainment and HIV status knowledge. Laboratory tests were conducted to assess true HIV sero‐status. Cognitive function was assessed with a battery of cognitive tests measuring time orientation, immediate and delayed recall, and numeracy and coded using confirmatory factor analysis as a z‐standardized latent variable. We estimated the relationship between the outcome of HIV status knowledge and each of three exposures: (1) latent cognitive z‐score, (2) literacy and (3) education, using confounder‐adjusted modified Poisson regression models in the study population overall and stratified by HIV sero‐status. Results: We found that HIV status knowledge was higher among those with higher cognitive z‐scores (adjusted Prevalence Ratio (aPR) (95% CI): 1.18 (1.14, 1.21) per standard deviation unit), and among literate participants (aPR (95% CI): 1.24 (1.16, 1.32) vs. non‐literate participants). Taken together, the associations with literacy and cognitive function completely attenuated the otherwise positive association between educational attainment and HIV status knowledge. The magnitudes of effect were generally similar among laboratory‐confirmed HIV‐negative and HIV‐positive participants. Conclusions: Campaigns that target older adults in rural South Africa with HIV testing messages should carefully consider the cognitive and literacy levels of the intended audience. Innovations to ease the cognitive load associated with HIV testing could prove fruitful to increase HIV status knowledge
The Relationship Between Perception of HIV Susceptibility and Willingness to Discuss PrEP With a Health Care Provider: A Pilot Study
No full textHIV continues to be a significant public health concern and despite recent reductions in new HIV diagnoses, certain demographics continue to be disproportionality affected. Men who have sex with other men (MSM) account for the largest percentage of new HIV diagnoses; however, 24% of new diagnoses can be attributed to male-to-female sex, highlighting the need to explore the HIV epidemic beyond the narrow scope of MSM. A multivariate linear regression model was used to explore the perception of HIV susceptibility and level of comfort discussing pre-exposure prophylaxis (PrEP) with a health care provider among a sample of men living in the United States (n = 377). Men who had an increased perception of HIV susceptibility were significantly more likely to feel comfortable discussing PrEP with a health care provider. Men who distinguish themselves to be at increased risk of acquiring HIV were significantly more likely to report having either insertive or receptive condomless anal intercourse within the previous 3 months, while men who reported condomless vaginal intercourse perceived low HIV susceptibility. Never being screened for HIV was significantly associated with a perception of low HIV susceptibility compared to those men who had been screened in the previous year. Understanding how men perceive HIV susceptibility and engage with HIV prevention may help to improve HIV prevention efforts such as PrEP
Feasibility of Mass-Spectrometry to Lower Cost and Blood Volume Requirements for Assessment of B Vitamins in Patients Undergoing Bariatric Surgery
No full textBariatric surgery induces deficiencies in a combination of B vitamins. However, high costs and a large blood volume requirement are barriers to routine screening. We adapted and validated a method coupling tandem mass spectrometry (MS/MS) with high-performance liquid chromatography (HPLC) to facilitate cost-effective analysis for simultaneous detection of B vitamins in low volumes of plasma. Based on existing methods, pooled plasma was extracted using hexane and acetonitrile and seven B vitamin analytes were separated using HPLC. Detection was performed with an Agilent 6460 triple quadrupole tandem mass spectrometer (MS/MS) using electrospray ionization in the positive ion mode. We evaluated linearity, recovery, precision, and limit of detection, as well as costs of the assay. We evaluated seven B vitamins from plasma; five (riboflavin, nicotinamide, pantothenic acid, pyridoxine, and biotin) were detected and quantified with precision and linearity. Recovery ranged from 63 to 81% for each of the vitamins, except for nicotinamide—the recovery of which was suppressed to 40%, due to plasma matrix effects. We demonstrated the feasibility of the HPLC–MS/MS method for use in patients who undergo bariatric surgery by analyzing pooled plasma from patients with a lower cost and blood volume than had we sent the samples to a commercial laboratory. It is advantageous and feasible, in terms of low cost and blood volume requirement, to simultaneously measure plasma concentrations of B vitamins using HPLC–MS/MS. With further improvements, the method may enable personalized nutritional assessment for the nutritionally compromised, bariatric surgery population
Predicting smartphone location-sharing decisions through self-reflection on past privacy behavior
No full textSmartphone location sharing is a particularly sensitive type of information disclosure that has implications for users’ digital privacy and security as well as their physical safety. To understand and predict location disclosure behavior, we developed an Android app that scraped metadata from users’ phones, asked them to grant the location-sharing permission to the app, and administered a survey. We compared the effectiveness of using self-report measures commonly used in the social sciences, behavioral data collected from users’ mobile phones, and a new type of measure that we developed, representing a hybrid of self-report and behavioral data to contextualize users’ attitudes toward their past location-sharing behaviors. This new type of measure is based on a reflective learning paradigm where individuals reflect on past behavior to inform future behavior. Based on data from 380 Android smartphone users, we found that the best predictors of whether participants granted the location-sharing permission to our app were: behavioral intention to share information with apps, the “FYI” communication style, and one of our new hybrid measures asking users whether they were comfortable sharing location with apps currently installed on their smartphones. Our novel, hybrid construct of self-reflection on past behavior significantly improves predictive power and shows the importance of combining social science and computational science approaches for improving the prediction of users’ privacy behaviors. Further, when assessing the construct validity of the Behavioral Intention construct drawn from previous location-sharing research, our data showed a clear distinction between two different types of Behavioral Intention: self-reported intention to use mobile apps versus the intention to share information with these apps. This finding suggests that users desire the ability to use mobile apps without being required to share sensitive information, such as their location. These results have important implications for cybersecurity research and system design to meet users’ location-sharing privacy needs
Critical Folkloristics, Free Speech, and the “War on Terror”
Full text linkIn 2008, five affiliates of the Holy Land Foundation for Relief and Development (HLF) were convicted of conspiring to supply “material support” to the terrorist organization Hamas. One of the convicted was a folksinger, included in the indictment due to a series of music performances given at HLF fundraisers. In this article, I critically interrogate the history and development of the HLF trial, arguing for the development of an activist-oriented critical folkloristics as a powerful tool with which to respond to Islamophobic discourses at the heart of the American “War on Terror.
Unethical Numbers? A Meta-analysis of Library Learning Analytics Studies
Full text linkFollowing trends in higher education that emphasize quantitative analytical approaches to learn about educational outcomes, academic libraries are increasingly attempting to quantify their impacts on student learning and demonstrate their value to the university’s educational mission. By applying learning analytics techniques to library use and instructional data, libraries have especially focused on attempting to measure the impact of the library on student GPA, retention and attainment measures. Because learning analytics studies typically require large datasets of personally identifiable information (PII), they present inherent risks to the privacy, confidentiality, and autonomy of research subjects, who often are unaware and uniformed of the data collected. To support this critique, this paper presents the results of a meta-analysis of learning analytics studies in libraries that examine the effects of library use on measures of student success. Based on the aggregate results, we argue that outcomes of these studies have not produced findings that justify the loss of privacy and risk borne by students. Moreover, we argue that basing highimpact decisions on studies with no, or low, effect sizes, and weak correlation or regression values, has the potential to harm students, particularly those in already vulnerable populations. Finally, we believe that these studies also have the potential to harm institutions that rely on these particular analytical approaches to make crucial business and educational decisions
Gene-environment interactions in antisocial behavior are mediated by early-life 5-HT receptor activation
No full textThe ontogeny of antisocial behavior (ASB) is rooted in complex gene-environment (G×E) interactions. The best-characterized of these interplays occurs between: a) low-activity alleles of the gene encoding monoamine oxidase A (MAOA), the main serotonin-degrading enzyme; and b) child maltreatment. The purpose of this study was to develop the first animal model of this G×E interaction, to help understand the neurobiological mechanisms of ASB and identify novel targets for its therapy. Maoa hypomorphic transgenic mice were exposed to an early-life stress regimen consisting of maternal separation and daily intraperitoneal saline injections and were then compared with their wild-type and non-stressed controls for ASB-related neurobehavioral phenotypes. Maoa hypomorphic mice subjected to stress from postnatal day (PND) 1 through 7 – but not during the second postnatal week - developed overt aggression, social deficits and abnormal stress responses from the fourth week onwards. On PND 8, these mice exhibited low resting heart rate - a well-established premorbid sign of ASB – and a significant and selective up-regulation of serotonin 5-HT2A receptors in the prefrontal cortex. Notably, both aggression and neonatal bradycardia were rescued by the 5-HT2 receptor antagonist ketanserin (1–3 mg kg−1, IP), as well as the selective 5-HT2A receptor blocker MDL-100,907 (volinanserin, 0.1–0.3 mg kg−1, IP) throughout the first postnatal week. These findings provide the first evidence of a molecular basis of G×E interactions in ASB and point to early-life 5-HT2A receptor activation as a key mechanism for the ontogeny of this condition
The Dependability of the Updated NSSE: A Generalizability Study
Full text linkThis study utilized generalizability theory to assess the context where the National Survey of Student Engagement’s (NSSE) summary measures, the Engagement Indicators, produce dependable group-level means. The dependability of NSSE group means is an important topic for the higher education assessment community given its wide utilization and usage in institutional assessment and accreditation. We found that the Engagement Indicators produced dependable group means for an institution derived from samples as small as 25 to 50 students. Furthermore, we discuss how the assessment community should use NSSE data
Learning by Teaching: Co-teaching to Enhance Nature of Science Pedagogy
No full textThis study aimed to give insights of in-service teachers’ experiences of nature of science (NOS) learning and NOS teaching through a co-teaching professional learning context. For this purpose, the co-teachers were encouraged to share and discuss ideas and improve NOS science teaching through reflection and collaborative interaction in the context of Saturday Science Teaching program. The Saturday Science Program provided local students in grade K-2 with hands on activities covering various science topics over 5 weekly 2.5-hour sessions. One of the cooperating teachers was an experienced university teacher while the other cooperating teacher was an experienced primary teacher without experience teaching NOS. Data were collected by use of pre- and post -instruction of Views of Nature of Science questionnaire, follow-up interviews, written artifacts, and videotapes of teaching sessions. Results showed that co-teaching contributed to the teacher’s NOS learning as well as NOS teaching. The teacher recognized subjective NOS, creative NOS, empirical NOS and socio-cultural NOS. Regarding improvement of NOS teaching the teacher started to use NOS vocabulary more comfortably such as use of words observation and inferences. She developed NOS teaching strategies such as creating observation/inference table to address observation and inference, developing examples for socio- cultural NOS