The site and stoichiometry of the N-phenylmaleimide reaction with myosin when weakly-binding crossbridges are formed in skinned rabbit psoas fibers

AbstractTreatment of relaxed skinned rabbit psoas muscle fibers with 0.1 mM N-phenylmaleimide (NPM) for 1 h locks all of the crossbridges in a weakly-binding state resembling that of the myosin ATP crossbridge. Under these conditions, NPM reacts mainly with myosin heavy chain (Barnett et al. (1992) Biophys. J. 61, 358–367). Here the specific sites for that reaction are explored. Small bundles of rabbit psoas muscle fibers were treated with Triton X-100 to make the fiber sarcolemmas permeable. The bundles were treated with 0.1 mM [14C]NPM for 1 h, and homogenized for SDS-PAGE. 43 ± 2.2% of the muscle fiber protein ran in the myosin heavy chain band, the same as for untreated fibers. An alkylating stoichiometry of 2.2 ± 0.33 moles NPM per mole myosin heavy chain was determined. Exhaustive trypsin digestion followed by two-dimensional thin-layer chromatography and reverse-phase HPLC revealed two major sites on myosin heavy chain for NPM binding. The sites contained about the same amount of linked NPM, suggesting that the reaction stoichiometry of each site under the conditions studied is approx. 1 mol NPM/mol myosin heavy chain. Comparison of the labeled tryptic peptides with NPM-reacted synthetic SH1 and SH2 tryptic peptides and analysis of the treated fiber bundles' ATPase activity suggested that the sites for NPM reaction on myosin heavy chain when it locks crossbridges in a weakly-binding state are Cys-697 (SH2) and Cys-707 (SH1)

Digital Storytelling: A Tool for Health Promotion and Cancer Awareness in Rural Alaskan Communities

BACKGROUND: The purpose of this study was to learn community members\u27 perspectives about digital storytelling after viewing a digital story created by a Community Health Aide/Practitioner (CHA/P). METHODS: Using a qualitative research design, we explored digital storytelling likeability as a health-messaging tool, health information viewers reported learning and, if viewing, cancer-related digital stories facilitated increased comfort in talking about cancer. In addition, we enquired if the digital stories affected how viewers felt about cancer, as well as if viewing the digital stories resulted in health behaviour change or intent to change health behaviour. FINDINGS: A total of 15 adult community members participated in a 30-45 minute interview, 1-5 months post-viewing of a CHA/P digital story. The majority (13) of viewers interviewed were female, all were Alaska Native and they ranged in age from 25 to 54 years with the average age being 40 years. Due to the small size of communities, which ranged in population from 160 to 2,639 people, all viewers knew the story creator or knew of the story creator. Viewers reported digital stories as an acceptable, emotionally engaging way to increase their cancer awareness and begin conversations. These conversations often served as a springboard for reflection, insight, and cancer-prevention and risk-reduction activities

The Relationship between Neighborhood Food Environment and Food Store Choice on Purchasing Habits among SNAP and Lower Income Households, USDA FoodAPS Data

The objective of the study was to determine relationship between neighborhood food store availability, store choice and food purchasing habits among Supplemental Nutrition Assistance Program (SNAP) participating households. The study sample consisted of SNAP households (n=1581) and low income households participating in the USDA\u27s National Household Food Acquisition and Purchase Survey (FoodAPS) a nationally representative cross-sectional survey of American households with household food purchases and acquisitions data. Main Outcomes: 1) Food purchasing choices (sugar-sweetened beverages, fruits and vegetables, snacks, water, and milk) obtained from store receipts over a one-week period; 2) food shopping activities was obtained from a log book of where food was purchased over a one-week period. Key findings indicated those SNAP households within 1 mile of a supermarket had higher odds of shopping at a supermarket (2.05 OR [95% CI 1.34, 3.15]) compared to those without a supermarket. Shopping at a supermarket was associated with greater odds of purchasing water and low-calorie beverages (OR 1.69 [95% CI 1.12, 2.54]) and fruits and vegetables (OR 2.50 (95% CI 1.52, 4.11]) compared to not shopping at supermarket among SNAP households. Additionally, a fractional multinomial logit analysis (n=4,664) similarly found that close proximity to superstores or supermarkets increases the share of weekly food purchases made there, and that car access increases purchases made at restaurants while decreasing purchases made at other food shopping venues. Findings suggest that policies aiming to improve food purchasing habits among SNAP need to consider how to situate stores where SNAP households will choose to shop

Promoting Culturally Respectful Cancer Education Through Digital Storytelling

Cancer is the leading cause of mortality among Alaska Native people. Over half of Alaska Native people live in rural communities where specially trained community members called Community Health Aides/Practitioners (CHA/Ps) provide health care. In response to CHA/Ps’ expressed desire to learn more about cancer, four 5-day cancer education and digital storytelling courses were provided in 2014. Throughout each course, participants explored cancer information, reflected on their personal experiences, and envisioned how they might apply their knowledge within their communities. Each course participant also created a personal and authentic digital story, a methodology increasingly embraced by Indigenous communities as a way to combine storytelling traditions with modern technology to promote both individual and community health. Opportunities to learn of CHA/Ps’ experiences with cancer and digital storytelling included a 3-page end-of-course written evaluation, a weekly story-showing log kept for 4 weeks post-course, a group teleconference held 1–2 weeks post-course, and a survey administered 6 months post-course. Participants described digital storytelling as a culturally respectful way to support cancer awareness and education. Participants described the process of creating digital stories as supporting knowledge acquisition, encouraging personal reflection, and sparking a desire to engage in cancer risk reduction activities for themselves and with their families and patients. As a result of creating a personalized digital story, CHA/Ps reported feeling differently about cancer, noting an increase in cancer knowledge and comfort to talk about cancer with clients and family. Indigenous digital stories have potential for broad use as a culturally appropriate health messaging tool

Depth-dependent δ13 C trends in platform and slope settings of the Campbellrand-Malmani carbonate platform and possible implications for Early Earth oxygenation

Highlights • Carbon cycle of Neoarchean carbonate platform and potential oxygen oasis. • Carbon isotopes reveal a shift to aerobic biosphere and increasing oxidation state. • Rare earth element patterns reveal decrease in open ocean water influx. • Rimmed margin architecture was crucial for evolution of aerobic ecosystems. Abstract The evolution of oxygenic photosynthesis is widely seen as the major biological factor for the profound shift from reducing to slightly oxidizing conditions in Earth’s atmosphere during the Archean-Proterozoic transition period. The delay from the first biogenic production of oxygen and the permanent oxidation of Earth’s atmosphere during the early Paleoproteorozoic Great Oxidation Event (GOE) indicates that significant environmental modifications were necessary for an effective accumulation of metabolically produced oxygen. Here we report a distinct temporal shift to heavier carbon isotope signatures in lagoonal and intertidal carbonates (δ13Ccarb from -1.6 to +0.2 ‰, relative to VPDB) and organic matter (δ13Corg from about -40 to -25 ‰, relative to VPDB) from the 2.58–2.50 Gy old shallow–marine Campbellrand-Malmani carbonate platform (South Africa). This indicates an increase in the burial rate of organic matter caused by enhanced primary production as well as a change from an anaerobic to an aerobic ecosystem. Trace element data indicate limited influx of reducing species from deep open ocean water into the platform and an increased supply of nutrients from the continent, both supporting primary production and an increasing oxidation state of the platform interior. These restricted conditions allowed that the dissolved inorganic carbon (DIC) pool in the platform interior developed differently than the open ocean. This is supported by coeval carbonates from the marginal slope setting, which had a higher interaction with open ocean water and do not record a comparable shift in δ13Ccarb throughout the sequence. We propose that the emergence of stable shallow-water carbonate platforms in the Neoarchean provided ideal conditions for the evolution of early aerobic ecosystems, which finally led to the full oxidation of Earth’s atmosphere during the GOE

Distributed Cognition in Cancer Treatment Decision Making: An Application of the DECIDE Decision-Making Styles Typology

Distributed cognition occurs when cognitive and affective schemas are shared between two or more people during interpersonal discussion. Although extant research focuses on distributed cognition in decision making between health care providers and patients, studies show that caregivers are also highly influential in the treatment decisions of patients. However, there are little empirical data describing how and when families exert influence. The current article addresses this gap by examining decisional support in the context of cancer randomized clinical trial (RCT) decision making. Data are drawn from in-depth interviews with rural, Appalachian cancer patients (N = 46). Analysis of transcript data yielded empirical support for four distinct models of health decision making. The implications of these findings for developing interventions to improve the quality of treatment decision making and overall well-being are discussed

Distributed Cognition in Cancer Treatment Decision Making: An Application of the DECIDE Decision-Making Styles Typology

Distributed cognition occurs when cognitive and affective schemas are shared between two or more people during interpersonal discussion. Although extant research focuses on distributed cognition in decision making between health care providers and patients, studies show that caregivers are also highly influential in the treatment decisions of patients. However, there are little empirical data describing how and when families exert influence. The current article addresses this gap by examining decisional support in the context of cancer randomized clinical trial (RCT) decision making. Data are drawn from in-depth interviews with rural, Appalachian cancer patients (N = 46). Analysis of transcript data yielded empirical support for four distinct models of health decision making. The implications of these findings for developing interventions to improve the quality of treatment decision making and overall well-being are discussed