Complex Microbial Communities Drive Iron and Sulfur Cycling in Arctic Fjord Sediments.

Glacial retreat is changing biogeochemical cycling in the Arctic, where glacial runoff contributes iron for oceanic shelf primary production. We hypothesize that in Svalbard fjords, microbes catalyze intense iron and sulfur cycling in low-organic-matter sediments. This is because low organic matter limits sulfide generation, allowing iron mobility to the water column instead of precipitation as iron monosulfides. In this study, we tested this with high-depth-resolution 16S rRNA gene libraries in the upper 20 cm at two sites in Van Keulenfjorden, Svalbard. At the site closer to the glaciers, iron-reducing Desulfuromonadales, iron-oxidizing Gallionella and Mariprofundus, and sulfur-oxidizing Thiotrichales and Epsilonproteobacteria were abundant above a 12-cm depth. Below this depth, the relative abundances of sequences for sulfate-reducing Desulfobacteraceae and Desulfobulbaceae increased. At the outer station, the switch from iron-cycling clades to sulfate reducers occurred at shallower depths (∼5 cm), corresponding to higher sulfate reduction rates. Relatively labile organic matter (shown by δ13C and C/N ratios) was more abundant at this outer site, and ordination analysis suggested that this affected microbial community structure in surface sediments. Network analysis revealed more correlations between predicted iron- and sulfur-cycling taxa and with uncultured clades proximal to the glacier. Together, these results suggest that complex microbial communities catalyze redox cycling of iron and sulfur, especially closer to the glacier, where sulfate reduction is limited due to low availability of organic matter. Diminished sulfate reduction in upper sediments enables iron to flux into the overlying water, where it may be transported to the shelf.IMPORTANCE Glacial runoff is a key source of iron for primary production in the Arctic. In the fjords of the Svalbard archipelago, glacial retreat is predicted to stimulate phytoplankton blooms that were previously restricted to outer margins. Decreased sediment delivery and enhanced primary production have been hypothesized to alter sediment biogeochemistry, wherein any free reduced iron that could potentially be delivered to the shelf will instead become buried with sulfide generated through microbial sulfate reduction. We support this hypothesis with sequencing data that showed increases in the relative abundance of sulfate reducing taxa and sulfate reduction rates with increasing distance from the glaciers in Van Keulenfjorden, Svalbard. Community structure was driven by organic geochemistry, suggesting that enhanced input of organic material will stimulate sulfate reduction in interior fjord sediments as glaciers continue to recede.

Sediment accumulation and mixing in the Penobscot River and estuary, Maine.

Mercury (Hg) was discharged in the late 1960s into the Penobscot River by the Holtra-Chem chlor-alkali production facility, which was in operation from 1967 to 2000. To assess the transport and distribution of total Hg, and recovery of the river and estuary system from Hg pollution, physical and radiochemical data were assembled from sediment cores collected from 58 of 72 coring stations sampled in 2009. These stations were located throughout the lower Penobscot River, and included four principal study regions, the Penobscot River (PBR), Mendall Marsh (MM), the Orland River (OR), and the Penobscot estuary (ES). To provide the geochronology required to evaluate sedimentary total Hg profiles, 58 of 72 sediment cores were dated using the atmospheric radionuclide tracers 137Cs, 210Pb, and 239,240Pu. Sediment cores were assessed for depths of mixing, and for the determination of sediment accumulation rates using both geochemical (total Hg) and radiochemical data. At most stations, evidence for significant vertical mixing, derived from profiles of 7Be (where possible) and porosity, was restricted to the upper ~1-3cm. Thus, historic profiles of both total Hg and radionuclides were only minimally distorted, allowing a reconstruction of their depositional history. The pulse input tracers 137Cs and 239,240Pu used to assess sediment accumulation rates agreed well, while the steady state tracer 210Pb exhibited weaker agreement, likely due to irregular lateral sediment inputs.

Mercury inputs and redistribution in the Penobscot River and estuary, Maine.

We examined total mercury (Hg) distributions in sediments from the Penobscot River and estuary, Maine, a site of extensive Hg releases from HoltraChem (1967-2000). Our objectives were to quantify: (1) bottom sediment Hg inventories (upper ~1m; 50-100 y); (2) sediment accumulation rates; and (3) contemporary Hg fluxes to bottom sediments; by sampling the Penobscot River (PBR), Mendall Marsh (MM), the Orland River (OR) and the Penobscot estuary (ES). Hg was rapidly distributed here, and the cumulative total (9.28 metric tons) associated with sediments system-wide was within the range released (6-12 metric tons). Evidence of sediment/Hg remobilization was observed in cores primarily from the PBR, and to a lesser extent the ES, whereas cores from MM, most of the OR, the ES, and half from the PBR exhibited sharp peaks in Hg concentrations at depth, followed by gradual decreases towards the surface. Based on background PBR sediment Hg concentrations (100ngg-1), "elevated" (300ngg-1), or "highly elevated" (600ngg-1) Hg concentrations in sediments, and resulting inventories, we assessed impact levels ("elevated"≥270, or "highly elevated"≥540mgm-2). 71% of PBR stations had "elevated", and 29% had "highly elevated" Hg inventories; 45% of MM stations had "elevated", and 27% had "highly elevated" inventories; 80% of OR stations had "elevated" inventories only; and 17% of ES stations had "elevated" inventories only. Most "highly elevated" stations were located within 8km of HoltraChem, in MM, in the PBR, and in the OR. Near-surface sediments in the OR, PBR and MM were all "highly elevated", while those in the ES were "elevated", on average. Mean Hg fluxes to bottom sediments were greatest in the OR (554), followed by the PBR (469), then MM (452), and finally the ES (204ngcm-2y-1).

Mimicking biophysical stimuli within bone tumor microenvironment.

In vivo, cells reside in a complex environment regulating their fate and function. Most of this complexity is lacking in standard in vitro models, leading to readouts falling short of predicting the actual in vivo situation. The use of engineering tools, combined with deep biological knowledge, leads to the development and use of bioreactors providing biologically sound niches. Such bioreactors offer new tools for biological research, and are now also entering the field of cancer research. Here we present the development and validation of a modular bioreactor system providing: (i) high throughput analyses, (ii) a range of biological conditions, (iii) high degree of control, and (iv) application of physiological stimuli to the cultured samples. The bioreactor was used to engineer a three-dimensional (3D) tissue model of cancer, where the effects of mechanical stimulation on the tumor phenotype were evaluated. Mechanical stimuli applied to the engineered tumor model activated the mechanotransduction machinery and resulted in measurable changes of mRNA levels towards a more aggressive tumor phenotype.

Examining the relationships of depressive symptoms, stigma, social support and regimen-specific support on quality of life in adult patients with epilepsy.

Epilepsy research efforts have primarily focused on medical treatment and physical management of epilepsy; however, to provide comprehensive care, efforts cannot focus solely on physical manifestations of epilepsy. Research findings show that people with epilepsy face many challenges that can negatively affect quality of life (QOL). In this descriptive study, we examined the individual relationships between depressive symptoms, stigma, social support and regimen-specific support and QOL in adults with epilepsy. Study data were obtained from a subset of patients (N = 147) who participated in a longitudinal study of adult patients with epilepsy. Measures of QOL, depressive symptoms, stigma, social support and regimen-specific support were analyzed to answer the research questions. The results of correlational analyses revealed statistically significant negative correlations between depressive symptoms, stigma and sometimes regimen-specific support and QOL and statistically significant positive correlations between social support and QOL. A hierarchical multiple linear regression model revealed that depressive symptoms accounted for the most variance in QOL. Psychosocial variables measured 3 months prior to QOL were entered into a hierarchical multiple linear regression model, revealing that depressive symptoms, stigma and social support can be used to predict QOL at a later time.

Does vegetation prevent wave erosion of salt marsh edges?

This study challenges the paradigm that salt marsh plants prevent lateral wave-induced erosion along wetland edges by binding soil with live roots and clarifies the role of vegetation in protecting the coast. In both laboratory flume studies and controlled field experiments, we show that common salt marsh plants do not significantly mitigate the total amount of erosion along a wetland edge. We found that the soil type is the primary variable that influences the lateral erosion rate and although plants do not directly reduce wetland edge erosion, they may do so indirectly via modification of soil parameters. We conclude that coastal vegetation is best-suited to modify and control sedimentary dynamics in response to gradual phenomena like sea-level rise or tidal forces, but is less well-suited to resist punctuated disturbances at the seaward margin of salt marshes, specifically breaking waves.

Using motivational interviewing to promote adherence to antiretroviral medications: a randomized controlled study.

The primary aim of this study was to test an intervention to support antiretroviral medication adherence among primarily low-income men and women with HIV. The study was a randomized controlled trial (Get Busy Living) with participants assigned to treatment (Motivational Interviewing [MI]) and control groups. Participants were recruited from an HIV/AIDS clinic in Atlanta, Georgia, US. Of those referred to the study, 247 completed a baseline assessment and were enrolled with 125 randomized to the intervention group and 122 to the control group. Participants were patients beginning antiretroviral therapy or changing to a new drug regimen. The intervention consisted of five MI sessions delivered by registered nurses in individual counselling sessions. Participants were paid for each session attended. The intervention sought to build confidence, reduce ambivalence and increase motivation for ART medication-taking. Medication adherence was measured by the Medication Event Monitoring System (MEMS) from the time of screening until the final follow-up conducted approximately 12 months following the baseline assessment. Participants in the intervention condition showed a trend towards having a higher mean percent of prescribed doses taken and a greater percent of doses taken on schedule when compared to the control group during the months following the intervention period. This effect was noted beginning at about the eighth month of the study period and was maintained until the final study month. Although the finding was weaker for overall percent of prescribed doses taken, the results for the percent of doses taken on schedule suggests that the MI intervention may be a useful approach for addressing specific aspects of medication adherence, such as adherrence to a specified dosing schedule.

Invariance of isotope ratios of lithogenic radionuclides: more evidence for their use as sediment source tracers.

Activities of radionuclides in the 238U (230Th, 226Ra, 210Pb) and 232Th (232Th, 228Th, 228Ra) decay series were determined in sediments from an east Texas watershed and examined with isotope ratios and compared to particulate organic carbon (POC), % fines (<63 microm) and total concentrations of Al, Fe and Mn. The objective was to elucidate the presence or absence of relationships affecting the effectiveness of these radionuclides in modeling sediment transport. Strong positive correlations were observed between radionuclides and Mn (Th) and % fines (Ra and Th). Isotope ratios effectively reduce these influences, supporting the contention that isotope ratios offset extrinsic variability in terrestrial sediments. Strong associations of 210Pbxs (excess 210Pb) and 226Ra/230Th with POC agree with data from marine and terrestrial settings, indicating that the role of POC in isotope fractionation, transport and sequestration merits further investigation.

Maintaining study validity in a changing clinical environment.

BACKGROUND: Nurse scientists who conduct intervention research in a variety of clinical settings find themselves facing numerous challenges posed by today's changing and sometimes complex health care environment. Maintaining study validity thus becomes a major focus of interventional research, but existing literature does not fully address challenges to study validity nor offer potential solutions. OBJECTIVES: The purposes of this paper are to 1) discuss methodologic challenges to maintaining study validity of intervention research that is conducted in a changing clinical environment, and 2) share strategies for maximizing study validity. METHODS: A recently completed intervention study is used as an example to discuss two specific areas that affected study validity, provide examples of selected threats to validity, and outline strategies used to minimize these threats. RESULTS: Careful definition of goals, thoughtful decision making, and implementation of specific strategies to maintain study validity helped increased the rigor of the research. CONCLUSIONS: Investigators conducting intervention research in changing clinical settings can reduce threats to study validity and increase design rigor by considering clinical realities (e.g., clinician-researcher role conflict) when making methodologic decisions, becoming familiar with the setting, and involving clinicians in the research.

Implementation of an oral care standard for leukemia and transplantation patients.

The purpose of this project was to develop an oral care standard on two nursing units in a university hospital where care was given to patients undergoing bone marrow or stem cell transplantation (BMSCT) and other treatments for leukemia. Strategies used in this interdisciplinary effort included collaboration, consultation, education, and evaluation. In the collaboration phase, a core group of nurses talked with staff about current practices, reviewed literature and published standards, examined protocols from other institutions, decided on goals, and developed the standard. Consultation with a dentist, pharmacist, and physician occurred before completion of the standard. The education phase included in-service sessions for nurses and technicians. The evaluation phase, which occurred in two phases, focused on checking to see if the goals had been met, including tolerability and adherence. The first phase allowed identification of problem areas and subsequent revisions, whereas the second phase evaluated adherence at a later time point. Overall, most of the patients adhered to the standard. Future implications include specific recommendations such as an emphasis on oral care, documentation, and patient and staff education. This project is an example of how nurses addressed the challenge of implementing an acceptable oral care standard to decrease patients' oral complications and distress.

Acute oral pain and mucositis in bone marrow transplant and leukemia patients: data from a pilot study.

The purposes of this prospective, repeated-measures descriptive pilot study were to describe patterns of acute oral pain and mucositis in patients receiving a bone marrow transplant or high-dose chemotherapy for leukemia, and to test procedures and instruments before initiating a larger intervention study. A nonprobability, purposive selection process was used to enroll 18 patients admitted to two acute care inpatient hospital units for bone marrow transplantation or leukemia therapy at a university health sciences center in the southeastern United States. Data were collected at baseline, then daily through patient interviews, oral examination, and chart review for at least 3 weeks or until discharge. Research variables were pain intensity, intolerable pain, verbal descriptors of pain, pain relief, and use of pain relief strategies (Pain Assessment Form), mucositis (erythema and ulceration) in eight anatomic locations of the oral cavity (Oral Mucositis Index), voice/talking (Oral Assessment Guide), and mood states (11-item Brief Profile of Mood States). Mild to moderate pain occurred in nearly 70% of patients and was described as "tender," "irritating," and "sore." Patients used pain medicines, mouth care, and mental and physical activities to relieve pain, and reported partial overall relief of pain. Mucositis was mild, with the tongue and buccal and labial mucosa most commonly affected with erythema and the buccal mucosa with ulceration. Voice/talking were only mildly impaired, and mood disturbance was mild. Patterns of pain, mucositis, and mood disturbance were consistent with each other and followed the trajectory described in previous research. Results suggest that nurses should continue to assess these symptoms vigorously and assist patients in selecting multiple management strategies. Research using repeated-measures designs in this acutely ill inpatient population is challenging and needs careful attention by researchers. The results have been used to improve the ongoing larger intervention study.

Patients' perspectives of fatigue while undergoing chemotherapy.

PURPOSE/OBJECTIVES: To explore the experience of fatigue from the perspective of patients undergoing chemotherapy. DESIGN: Qualitative research and secondary analysis of data from a larger study. SETTING: Participants were recruited from 18 sites, including large outpatient chemotherapy clinics and private medical oncologists' offices. SAMPLE: 127 adult patients who were beginning their first protocol of chemotherapy. METHODS: Data were collected through individual and open-ended interviews and a qualitative, thematic analysis of the participants' responses using grounded theory techniques. MAIN RESEARCH VARIABLE: The experience of fatigue as perceived by patients undergoing chemotherapy. FINDINGS: The analysis resulted in eight major thematic categories: (a) experiencing fatigue, (b) effects on well-being, (c) attribution of origin, (d) awareness and expectations, (e) emotional reactions, (f) activity, (g) the "biggest" concern, and (h) strategies and plans. CONCLUSIONS: This study demonstrates the variation, extent, duration, and temporality of fatigue among patients receiving chemotherapy and the dynamic, changing aspects of the experience. IMPLICATIONS FOR NURSING PRACTICE: Fatigue must be considered within the context of patients' daily lives and environments, disease processes, and treatment modalities. Nurses must listen carefully to patients' own descriptions of being tired. Further research examining patients' perspectives of and experiences related to fatigue is necessary to increase the theoretical understanding of fatigue and to improve therapeutic nursing interventions.

Differences in pain knowledge in cancer patients with and without pain.

PURPOSE: The authors determined: 1) whether there were differences in knowledge about pain between oncology outpatients with and without cancer-related pain and 2) whether there were relationships between selected patient characteristics (age, gender, education, Karnofsky performance status, pain intensity, and pain duration) and the knowledge about pain of oncology outpatients with cancer-related pain. DESCRIPTION OF STUDY: Three hundred sixty-nine oncology outpatients completed several self-report questionnaires including a demographic questionnaire, a pain experience scale that measured knowledge about pain and pain management, the Karnofsky performance scale, and descriptive numeric rating scales that measured pain intensity and pain duration. RESULTS: Patients with cancer-related pain knew significantly more about pain and its management than pain-free patients (P < 0.004). However, in both groups, mean knowledge scores were below 60%. Older patients with cancer-related pain had less knowledge about pain than younger patients (P < 0.0001). In addition, patients with cancer pain who had more education and those with higher reported pain intensity scores had more knowledge about pain and pain management. Finally, women with cancer pain had more knowledge than men about pain and pain management. CLINICAL IMPLICATIONS: Results of this study suggest that oncology patients with and without pain need more education about pain and effective pain management strategies.

Health promotion practices among physicians.

Personal belief concerning both the validity of health promotion and the physician's ability to influence patient behavior may affect how much effort a physician spends on health promotion strategies. We assessed these beliefs through a mail survey to physicians practicing in a predominantly rural southern state in 1987 (n = 83) and 1991 (n = 96). Response rates in both studies exceeded 75%. The instrument was obtained from similar studies conducted in Massachusetts in 1981 and Maryland in 1983. Between 1987 and 1991 we found slight improvements in the perceived importance of many health behaviors, but significant improvement was observed in the importance of reducing intake of dietary saturated fat (66% in 1987 to 80% in 1991; P < .05). Less than 10% of the physicians thought they could be "very successful" in modifying patients' behaviors. However, in 1991 physicians perceived that their ability to be "very successful" in helping patients to modify their behavior would increase threefold (8%-24% for exercise; 4%-18% for smoking) if given appropriate support. Although the type of appropriate support was not identified, the credibility of physician's advice in promoting health changes is important. These results suggest that efforts should be made to provide support to physicians who are inclined to discuss health behavior changes with their patients. Medical Subject Headings (MeSH): dietary fats, exercise, patient education, physician's practice patterns, smoking.

A model immunization demonstration for preschoolers in an inner-city barrio, San Diego, California, 1992-1994.

An immunization demonstration project was conducted in an inner-city Latino neighborhood in San Diego to address underimmunization of children of preschool age. The project attempted interventions on consumer, provider, and system levels to reduce barriers to immunization and raise immunization rates. Free walk-in immunization clinics with emphasis on cultural sensitivity and that incorporated computerized reminder/recall were established. An educational series was offered to community health center (CHC) providers, and extensive community-based outreach and education took place in schools, churches, a WIC site, etc. Evaluation activities included preintervention and postintervention provider knowledge, attitudes, and practice surveys, CHC chart audits, and household surveys in the intervention ZIP code area and a control ZIP code area. Immunization coverage for 4DPT, 3OPV, and 1MMR (4:3:1) among two-year-olds increased significantly from 37% to 50% overall, and to 59% in the 1991 birth cohort in the intervention area compared to a one percentage point overall increase in the control area. Coverage improved significantly and missed opportunities decreased in one intervention CHC that participated most actively in educational inservices. While the Year 2000 U.S. Public Health Service objective of 90% 4:3:1 coverage for two-year-olds was not achieved over the 21-month course of the project, the results approached the 1996 single-antigen objectives. This demonstration underscores the importance of multilevel interventions including low cost, no appointment, and culturally appropriate immunization services for the indigent; the use of computerized reminder systems; and provider assessment, education, and feedback in the effort to raise preschool immunization levels. Medical Subject Headings (MeSH): immunization, preschool-age children, health promotion, provider education, immunization monitoring and follow-up systems, pediatric immunization standards, household surveys.

Differences in pain knowledge and perception of the pain experience between outpatients with cancer and their family caregivers.

PURPOSE/OBJECTIVES: To determine if knowledge about pain and the perception of the pain experience differ when comparing outpatients experiencing cancer-related pain with their family caregivers. DESIGN: Quantitative, descriptive. SETTING: Sixteen oncology outpatient settings that are part of the Oncology Nursing Research Network. SAMPLE: Eighty-six outpatients with cancer-related pain and their family caregivers. METHODS: Patients and their family caregivers were recruited in the outpatient setting and asked to complete a demographic questionnaire and the Pain Experience Scale. The patients also were asked to complete the Karnofsky Performance Scale. MAIN RESEARCH VARIABLES: Patients' and their family caregivers' knowledge about pain and their perception of the pain experience. FINDINGS: No significant differences in knowledge scores were found between the patients and their family caregivers. A significant difference in the perception of the pain experience was found, with the family caregivers viewing the experience more negatively than the patients did. Family caregivers reported that (a) patients had significantly higher levels of pain compared to patient reports, (b) patients experienced significantly greater distress from their pain than the patients reported for themselves, and (c) family caregivers experienced significantly greater distress from the patients' pain than the patients reported for their caregiver. CONCLUSIONS: Outpatients with cancer and their family caregivers possess limited knowledge about pain and pain management and perceive the pain experience differently. IMPLICATIONS FOR NURSING PRACTICE: Outpatients and their family caregivers need to be better educated about how to manage cancer-related pain. In addition, to reduce patient and caregiver distress, oncology nurses need to facilitate communication between patients and family caregivers about the pain experience.

Direct determination of deuterium in untreated water and urine by NMR: application to DLW analysis.

Determination of deuterium (D) concentration in tap water and urine is demonstrated to average error approximately 0.5% (coefficient of variation) using a 400-MHz nuclear magnetic resonance (NMR) instrument. Time domain data are obtained using 0.75-ml samples in a broadband probe. Peak areas derived from absorption and magnitude mode Fourier transforms and least-squares fitting of the time domain free induction decays (FIDs) are all investigated as means to derive D concentrations from raw data. Least-squares fits using a sum of exponentially damped sinusoids, which yields estimates for the amplitude, damping constant (relaxation time), wavelength (resulting from mixing of precession and reference frequencies), and phase for each of the two components, are shown to provide the best precision for unfiltered FID. Amplitudes are proportional to the number of spins at each frequency, as analysis of untreated urine from doubly labeled water experiments yield highly linear washout data (r2 > 0.99998) for baseline-corrected log-transformed data. The procedure is general and should extend to other body fluids with minimal modifications. These data show that least-squares curve fitting is the most precise method of quantitative NMR data reduction for a wide range of experimental conditions.

Continuing education needs assessment: a brief report.

A needs assessment was conducted to quantify the need for, and the capacity to provide, public health continuing education in San Diego County, California. The study was conducted with the objective of developing public health continuing education courses to be offered by the San Diego State University Graduate School of Public Health (SDSU-GSPH) to address the unmet demands of local practitioners. Survey instruments were developed to separately assess the continuing education needs of public health practitioners and the capacity of SDSU-GSPH faculty to provide courses in San Diego County. The faculty survey was distributed to all full-time SDSU-GSPH faculty. Practitioner surveys were distributed to a systematic sample of divisions and subdivisions in the County of San Diego Department of Health Services. The overall survey response rates were 71% for faculty (22/31) and 40% for practitioners (190/470). Practitioners indicated a strong interest in several of the 64 specific course topics they were asked to rate. Reported faculty interest and capacity to teach continuing education courses appears to be limited. The analysis confirms a need to improve and increase SDSU-GSPH public health continuing education offerings. Further, our results suggest that external instructional resources will be needed to meet this educational demand.

Sedentary lifestyle and state variation in coronary heart disease mortality.

Using linear regression, the authors demonstrated a strong association between State-specific coronary heart disease mortality rates and State prevalence of sedentary lifestyle (r2 = 0.34; P = 0.0002) that remained significant after controlling for the prevalence of diagnosed hypertension, smoking, and overweight among the State's population. This ecologic analysis suggests that sedentary lifestyle may explain State variation in coronary heart disease mortality and reinforces the need to include physical activity promotion as a part of programs in the States to prevent heart disease.