Are network planning guidelines based on equal access equitable?

Public transport network planning principles include simplicity, legibility, frequency and spatial coverage. These principles are normally translated into a series of “Guidelines” setting out the specific standards for network design within a jurisdiction. In practice such guidelines usually concentrate on creating a bus network or on the role of buses within a multimodal network as rail-based routes are regarded as fixed in location and separate planning processes are typically used to design rail frequencies and stopping patterns. The outcome of the network planning gives rise to trade-offs between the economic and institutional environments and is conditioned by historical legacy. Bus routes often continue because historically this is where they operated. This paper offers a case study based on Sydney, Australia where the network planning guidelines still place emphasis on equality of spatial coverage despite moving towards a more ‘integrated’ approach to network planning. This paper identifies that guidelines focusing on equal spatial coverage may inadvertently promote inequity through not taking account of the difficulties (and therefore higher cost) of serving challenging topographical areas. This paper therefore examines the equity impacts of the implementation of service planning guidelines based on equal spatial coverage using Sydney as a case study. Criteria relating to equity will be established which are then measured using bus supply data, journey to work and socio-economic data. The conclusions of the paper are a contribution to network planning implementation with many cities both in Australia and elsewhere implementing similar guidelines to Sydney

Signatures of a Pressure-Induced Topological Quantum Phase Transition in BiTeI

We report the observation of two signatures of a pressure-induced topological quantum phase transition in the polar semiconductor BiTeI using x-ray powder diffraction and infrared spectroscopy. The x-ray data confirm that BiTeI remains in its ambient-pressure structure up to 8 GPa. The lattice parameter ratio c/a shows a minimum between 2.0-2.9 GPa, indicating an enhanced c-axis bonding through pz band crossing as expected during the transition. Over the same pressure range, the infrared spectra reveal a maximum in the optical spectral weight of the charge carriers, reflecting the closing and reopening of the semiconducting band gap. Both of these features are characteristics of a topological quantum phase transition, and are consistent with a recent theoretical proposal.Comment: revised final versio

How early can myocardial iron overload occur in Beta thalassemia major?

BACKGROUND: Myocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM. METHODS AND RESULTS: We analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload. CONCLUSIONS: The TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old

Factors Influencing Health Care Access Perceptions and Care-seeking Behaviors of Immigrant Latino Sexual Minority Men and Transgender Individuals: Baseline Findings from the HOLA Intervention Study

Little is known about immigrant Latino sexual minorities’ health seeking behaviors. This study examined factors associated with perceptions of access and actual care behaviors among this population in North Carolina. Methods: A community-based participatory research partnership recruited 180 Latino sexual minority men and transgender individuals within preexisting social networks to participate in a sexual health intervention. Mixed-effects logistic regression models and GIS mapping examined factors influencing health care access perceptions and use of services (HIV testing and routine check-ups). Results: Results indicate that perceptions of access and actual care behaviors are low and affected by individual and structural factors, including: years living in NC, reported poor general health, perceptions of discrimination, micro-, meso-, and macro-level barriers, and residence in a Medically Underserved Area. Discussion: To improve Latino sexual minority health, focus must be placed on multiple levels, including: individual characteristics (e.g., demographics), clinic factors (e.g., provider competence and clinic environment), and structural factors (e.g., discrimination)

The “kaleidoscope” of factors influencing urban adolescent pregnancy in Baltimore, Maryland

Existing intervention and prevention efforts for adolescent pregnancy focus primarily on individual-level approaches; however, there is an emerging expectation to include a more contextually based social-ecological approach. This approach is salient in urban communities like Baltimore, Maryland, with one of the nation’s highest adolescent pregnancy and birth rates. Poverty, community violence, and compromised school systems further complicate the precursors and consequences of adolescent pregnancy. In this mixed methods study, we conducted interviews with key informants (n = 16) from community-based organizations, health departments, foundations, the public school system, clinics, and the faith community who worked with youth in Baltimore to gain a more comprehensive perspective on factors affecting adolescent pregnancy. Interviews were digitally recorded, transcribed verbatim, and analyzed using the constant comparative method. Geographic maps of select socio-demographic variables were created to examine the community context. Results highlighted contributing multi-level factors that emerged across the social-ecological model. Key informants described community- (e.g., environment, community norms, public policy; “Teen pregnancy is norm in many communities”), interpersonal- (e.g., peer social norms; “If you don’t perceive that you have a whole lot of options, you might just kind-of do what everybody else does”), and intrapersonal-level (e.g., specific developmental phase, self-esteem; “You need somebody to love and somebody to love you back”) influences on adolescent pregnancy and birth. GIS maps further illustrated disparities in adolescent birth rates, poverty level, and available community resources. Key informants recommended institutional and structural changes in the community, such as improving sexuality education and school-based health centers and increasing inter-organizational collaboration. These findings underscore the importance of considering creative community partnerships that address key social determinants of reproductive health in developing interventions to address adolescent pregnancy

Individual and structural factors influencing HIV care linkage and engagement: Perceived barriers and solutions among HIV-positive persons

To meet the National HIV/AIDS Strategy’s goals of reducing and preventing HIV transmission, understanding factors that shape HIV-positive persons’ care-seeking behaviors is critical. Accordingly, this study examined factors that affect HIV care linkage and engagement. Six focus groups were conducted with 33 HIV-positive persons living in North Carolina. A variety of factors influenced care behaviors, including: structural and policy factors, relationship with HIV care systems, and individuals’ personal characteristics. Participants also provided solutions for addressing specific factors to care. Improving clinical services and utilizing context-specific strategies can help facilitate greater care linkage and engagement

Ambivalent messages: Adolescents’ perspectives on pregnancy and birth

Purpose To examine, from a youth’s perspective, adolescent pregnancy and parenting in Baltimore, Maryland, a city with high rates of adolescent pregnancy. Methods Six gender-stratified focus groups with 13- to 19-year-olds (4 female and 2 male groups; n = 47). We recorded focus groups, transcribed them verbatim, and analyzed them using the constant comparison method. Participants completed questionnaires to collect demographic and behavioral information. Results Results fit into a social-ecological framework. Individual (e.g., contraceptive use behaviors, religion), interpersonal (e.g., peer norms, maintaining male partners), and community (e.g., clinic factors, perceptions of community) level influences on adolescent pregnancy emerged. Participants discussed contradictory messages that were often gendered in their expectations; for instance, women were responsible for not getting pregnant and raising children. Adolescents expressed beliefs both against (e.g., challenging to complete school) and supporting early childrearing (e.g., religion). Recommendations for addressing the different influences included mentors, education, and community resources. Conclusions Adolescents’ perspectives and values regarding pregnancy and parenting may not mirror traditional and expected norms for pregnancy and requirements for raising a child. These findings challenge the framing of existing interventions as they may not accurately reflect adolescents' values regarding pregnancy and parenting, and thus may need to be modified to highlight positive attitudes toward contraception and postponing pregnancy

Revisiting protein aggregation as pathogenic in sporadic Parkinson and Alzheimer diseases.

The gold standard for a definitive diagnosis of Parkinson disease (PD) is the pathologic finding of aggregated α-synuclein into Lewy bodies and for Alzheimer disease (AD) aggregated amyloid into plaques and hyperphosphorylated tau into tangles. Implicit in this clinicopathologic-based nosology is the assumption that pathologic protein aggregation at autopsy reflects pathogenesis at disease onset. While these aggregates may in exceptional cases be on a causal pathway in humans (e.g., aggregated α-synuclein in SNCA gene multiplication or aggregated β-amyloid in APP mutations), their near universality at postmortem in sporadic PD and AD suggests they may alternatively represent common outcomes from upstream mechanisms or compensatory responses to cellular stress in order to delay cell death. These 3 conceptual frameworks of protein aggregation (pathogenic, epiphenomenon, protective) are difficult to resolve because of the inability to probe brain tissue in real time. Whereas animal models, in which neither PD nor AD occur in natural states, consistently support a pathogenic role of protein aggregation, indirect evidence from human studies does not. We hypothesize that (1) current biomarkers of protein aggregates may be relevant to common pathology but not to subgroup pathogenesis and (2) disease-modifying treatments targeting oligomers or fibrils might be futile or deleterious because these proteins are epiphenomena or protective in the human brain under molecular stress. Future precision medicine efforts for molecular targeting of neurodegenerative diseases may require analyses not anchored on current clinicopathologic criteria but instead on biological signals generated from large deeply phenotyped aging populations or from smaller but well-defined genetic-molecular cohorts

Doping dependence of charge dynamics in electron-doped cuprates

Within the t-t'-J model, the doping dependence of charge dynamics in electron-doped cuprates is studied. The conductivity spectrum shows a pseudogap structure with a low-energy peak appearing at $\omega\sim 0$ and an rather sharp midinfrared peak appearing around $\omega\sim 0.3\mid t\mid$, and the resistivity exhibits a crossover from the high temperature metallic-like to low temperature insulating-like behavior in the relatively low doped regime, and a metallic-like behavior in the relatively high doped regime, in qualitative agreement with experiments. Our results also show that these unusual behaviors of the charge dynamics is intriguingly related to the magnetic correlation in the system.Comment: 5 pages, 3 figures, discussions are added, accepted for publication in Phys. Lett.

Health Vulnerability Model for Latinx Sexual and Gender Minorities: Typologies with Socioeconomic Stability, Health Care Access, and Social Characteristics Indicators

Vulnerability can undermine positive health outcomes and challenge healthcare services access. However, to date, vulnerable populations research has been limited by overly broad definitions, lack of clear indicators, and failure to explore subtypes of vulnerability. Informed by literature and theory, this analysis used a specific operationalization of health vulnerability to identify typologies among a sample of Latinx sexual and gender minorities. We analyzed baseline data from Latinx sexual and gender minorities (N = 186) recruited for a community-based HIV intervention. We performed latent class analysis to operationalize vulnerability using eight socioeconomic stability, health care access, and social characteristics indicators. We identified three typologies of vulnerability from our sample: Low Education and High Social Support (63.4% of sample), High Education and Year-round Employment (18.8%), and High Education and High Discrimination (17.7%). Using specific indicators produced more nuanced vulnerability typologies which, after further testing, can assist in informing tailored health promotion interventions