Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

The site of breast cancer metastases dictates their clonal composition and reversible transcriptomic profile

Intratumoral heterogeneity is a driver of breast cancer progression, but the nature of the clonal interactive network involved in this process remains unclear. Here, we optimized the use of optical barcoding to visualize and characterize 31 cancer subclones in vivo. By mapping the clonal composition of thousands of metastases in two clinically relevant sites, the lungs and liver, we found that metastases were highly polyclonal in lungs but not in the liver. Furthermore, the transcriptome of the subclones varied according to their metastatic niche. We also identified a reversible niche-driven signature that was conserved in lung and liver metastases collected during patient autopsies. Among this signature, we found that the tumor necrosis factor-α pathway was up-regulated in lung compared to liver metastases, and inhibition of this pathway affected metastasis diversity. These results highlight that the cellular and molecular heterogeneity observed in metastases is largely dictated by the tumor microenvironment.

Church leaders' barriers and facilitators before and after implementing a physical activity and nutrition intervention

Faith-based health promotion programs have been effective in increasing healthy eating (HE) and physical activity (PA). Very few reports exist regarding church leaders' anticipated and experienced barriers and facilitators to program implementation. Pastors (n = 38, 70%) and program coordinators (n = 54, 100%) from churches (N = 54) who attended a program training answered open-ended questions about anticipated barriers and facilitators to implementing the HE and PA parts of the Faith, Activity, and Nutrition (FAN) program. Twelve months later, pastors (n = 49, 92%) and coordinators (n = 53, 98%) answered analogous questions about their experienced barriers and facilitators to implementing the HE and PA parts of the FAN program. Responses were coded using thematic analysis. Similar themes appeared at baseline and follow-up for anticipated and experienced barriers and facilitators. The most common barriers were no anticipated barriers, resistance to change, church characteristics, and lack of participation/motivation. The most common facilitators were internal support, leadership, and communication. Few differences were found between anticipated and experienced barriers and facilitators. Understanding these perspectives, particularly overcoming resistance to change and church characteristics through strong leadership and internal support from church leaders, will improve future program development, resources, and technical assistance in faith-based and non-faith-based communities alike.

Excess Mortality, Hospital Stay, and Cost Due to Candidemia: A Case-Control Study Using Data From Population-Based Candidemia Surveillance

Objective:

To determine the mortality, hospital stay, and total hospital charges and cost of hospitalization attributable to candidemia by comparing patients with candidemia with control-patients who have otherwise similar illnesses. Prior studies lack broad patient and hospital representation or cost-related information that accurately reflects current medical practices.

Design:

Our case-control study included case-patients with candidemia and their cost-related data, ascertained from laboratory-based candidemia surveillance conducted among all residents of Connecticut and Baltimore and Baltimore County, Maryland, during 1998 to 2000. Control-patients were matched on age, hospital type, admission year, discharge diagnoses, and duration of hospitalization prior to candidemia onset.

Results:

We identified 214 and 529 sets of matched case-patients and control-patients from the two locations, respectively. Mortality attributable to candidemia ranged between 19% and 24%. On multivariable analysis, candidemia was associated with mortality (OR, 5.3 for Connecticut and 8.5 for Baltimore and Baltimore County;P< .05), whereas receiving adequate treatment was protective (OR, 0.5 and 0.4 for the two locations, respectively;P< .05). Candidemia itself did not increase the total hospital charges and cost of hospitalization; when treatment status was accounted for, having received adequate treatment for candidemia significantly increased the total hospital charges and cost of hospitalization ($6,000 to $29,000 and $3,000 to $22,000, respectively) and the length of stay (3 to 13 days).

Conclusion:

Our findings underscore the burden of candidemia, particularly regarding the risk of death, length of hospitalization, and cost associated with treatment (Infect Control Hosp Epidemiol2005;26:540-547).

Clinically meaningful changes in functional performance resulting from self-directed interventions in individuals with arthritis

OBJECTIVES

To examine the clinical meaningfulness of changes observed in functional performance from two self-directed interventions targeting adults with arthritis.

STUDY DESIGN

Randomized controlled trial.

METHODS

Participants (n = 312) were randomized to a 12-week self-directed exercise or nutrition intervention. Objective measures of functional performance (6-minute walk, seated reach, grip strength, 30-second chair stand, gait speed, balance) were obtained at baseline, 12 weeks, and nine months. Minimally (≥0.20 standard deviation) and substantially (≥0.50) meaningful changes in functional performance were examined. Changes in the percent 'impaired' and at risk for losing independence using established standards, and associations between physical activity and impairment/risk status were also examined. Group × Time interactions were not significant; therefore groups were combined in all analyses.

RESULTS

Minimally (31-71%) and substantially (13-54%) meaningful changes in function were shown. There was a significant decrease in the percentage of participants 'impaired' on the 30-second chair stand (both time points) and gait speed (nine months). The percentage of participants at risk for losing independence significantly decreased for the 30-second chair stand (both time points) and the 6-minute walk (nine months). Those engaging in ≥2 h of leisure-time physical activity were significantly less likely to be impaired on the 6-minute walk, 30-second chair stand, and gait speed at 12 weeks, and the 6-minute walk at nine months.

CONCLUSIONS

Interventions that can slow functional declines, and ideally result in clinically meaningful improvements in functional performance among adults with arthritis are needed. Meaningful improvements in various indicators of functional performance can result from self-directed exercise and nutrition programs. These types of programs have the potential for wide-spread dissemination, and thus broad reach.

Physical activity mediates the relationship between program participation and improved mental health in older adults

OBJECTIVES

There is an implicit assumption that increased physical activity (PA) levels are responsible for the mental health benefits resulting from participation in PA programs. Other factors associated with participation may in fact be responsible. The purpose of this study was to examine whether changes in PA mediated the effects of two PA programs (Active Choices [AC] and Active Living Every Day [ALED]) on mental health outcomes.

STUDY DESIGN

Secondary data analyses of quasi-experimental study.

METHODS

A sub-sample of older adults who participated in AC (n = 744) and ALED (n = 853) were included in the current analyses. MacKinnon's product of coefficients was used to test change in PA as a mediator of the relationship between program dose and change in mental health outcomes (depressive symptoms, stress, and number of days with poor mental health).

RESULTS

Change in PA explained 19% (AC) and 13% (ALED) of the absolute effects of program dose on depressive symptoms, 18% (AC) and 14% (ALED) of the effects on stress, and 37% (ALED) of the effects on days with poor mental health.

CONCLUSIONS

Mounting evidence from both epidemiological studies and controlled trials suggests that PA can improve mental health. This study adds that increasing PA levels may improve mental health in older adults in 'real-world' settings.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Baseline predictors of physical activity in a sample of adults with arthritis participating in a self-directed exercise program

OBJECTIVES

To examine baseline predictors of moderate-to-vigorous intensity physical activity (MVPA) at the 12-week follow-up in a sample of adults with arthritis participating in a self-directed, multicomponent exercise program.

STUDY DESIGN

Pretest-posttest. Analyses were limited to those randomized to the exercise intervention.

METHODS

Participants (n = 152) completed a survey assessing demographic, health-related, and arthritis-related factors, and completed anthropometric and functional measurements at baseline. Self-reported MVPA was assessed at baseline and 12 weeks. Participants were classified as engaging in ≥2.5 or <2.5 h/week of MVPA at the 12-week follow-up. Baseline demographic, health-related, arthritis-related, and functional factors were examined as predictors of engaging in ≥2.5 h of MVPA.

RESULTS

At the 12-week follow-up, 66.5% (n = 101) of participants engaged in ≥2.5 h/week of MVPA. Those with a higher body mass index, more days with poor physical health, a greater number of health conditions, self-reported hypertension, self-reported high cholesterol, and greater pain and stiffness were less likely to engage in ≥2.5 h of MVPA at the 12-week follow-up; those with greater arthritis self-efficacy and better performance on the 6 minute walk test were more likely. None of the other factors examined were associated with MVPA.

CONCLUSIONS

This study uncovered health-related, arthritis-related, and functional factors associated with MVPA that may help guide intervention strategies. Participants with less severe symptoms, better functional performance and fewer comorbidities at baseline were more likely to achieve the recommended MVPA level at 12 weeks; therefore self-directed PA interventions may be best suited for those with relatively good health status despite arthritis, while those with worse symptoms and health status may benefit more from other intervention delivery modalities such as structured, individualized programs where additional support for managing arthritis symptoms and comorbidity can be addressed.

Development and validation of a portable platform for deploying decision-support algorithms in prehospital settings

BACKGROUND

Advanced decision-support capabilities for prehospital trauma care may prove effective at improving patient care. Such functionality would be possible if an analysis platform were connected to a transport vital-signs monitor. In practice, there are technical challenges to implementing such a system. Not only must each individual component be reliable, but, in addition, the connectivity between components must be reliable.

OBJECTIVE

We describe the development, validation, and deployment of the Automated Processing of Physiologic Registry for Assessment of Injury Severity (APPRAISE) platform, intended to serve as a test bed to help evaluate the performance of decision-support algorithms in a prehospital environment.

METHODS

We describe the hardware selected and the software implemented, and the procedures used for laboratory and field testing.

RESULTS

The APPRAISE platform met performance goals in both laboratory testing (using a vital-sign data simulator) and initial field testing. After its field testing, the platform has been in use on Boston MedFlight air ambulances since February of 2010.

CONCLUSION

These experiences may prove informative to other technology developers and to healthcare stakeholders seeking to invest in connected electronic systems for prehospital as well as in-hospital use. Our experiences illustrate two sets of important questions: are the individual components reliable (e.g., physical integrity, power, core functionality, and end-user interaction) and is the connectivity between components reliable (e.g., communication protocols and the metadata necessary for data interpretation)? While all potential operational issues cannot be fully anticipated and eliminated during development, thoughtful design and phased testing steps can reduce, if not eliminate, technical surprises.

Anger expression and natural killer cell activity in family caregivers participating in a physical activity trial

Associations between psychological functioning and natural killer cell activity (NKA) were examined in 23 older (62.2 ± 7.5 years) family caregivers randomized to a moderate intensity four-month exercise program or to a wait-list control condition. At baseline, although NKA was related to anger-control (r = -.42; trend p < .06) and anger-out (r = .50; p < .03), it was not related to depression, anxiety, perceived stress, or caregiver burden. After controlling for baseline NKA, changes in anger-control explained 14 percent of the variance in NKA four months later. Decreases in anger-control predicted increases in NKA. Group assignment (exercise vs control) was unrelated to changes in NKA over the four-month period; however, the study was not powered to detect this effect. These results are consistent with reported relationships of anger expression with other physiological measures, and extend the importance of anger expression to immune functioning in older family caregivers.

Modeling of defect modes in photonic crystals using the fictitious source superposition method

We present an exact theory for modeling defect modes in two-dimensional photonic crystals having an infinite cladding. The method is based on three key concepts, namely, the use of fictitious sources to modify response fields that allow defects to be introduced, the representation of the defect mode field as a superposition of solutions of quasiperiodic field problems, and the simplification of the two-dimensional superposition to a more efficient, one-dimensional average using Bloch mode methods. We demonstrate the accuracy and efficiency of the method, comparing results obtained using alternative techniques, and then concentrate on its strengths, particularly in handling difficult problems, such as where a mode is highly extended near cutoff, that cannot be dealt with in other ways.

Long wavelength behavior of the fundamental mode in microstructured optical fibers

Using a novel computational method, the fundamental mode in index-guided microstructured optical fibers with genuinely infinite cladding is studied. It is shown that this mode has no cut-off, although its area grows rapidly when the wavelength crosses a transition region. The results are compared with those for w-fibers, for which qualitatively similar results are obtained.

Disruption of a novel member of a sodium/hydrogen exchanger family and DOCK3 is associated with an attention deficit hyperactivity disorder-like phenotype

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a complex condition with high heritability. However, both biochemical investigations and association and linkage studies have failed to define fully the underlying genetic factors associated with ADHD. We have identified a family co-segregating an early onset behavioural/developmental condition, with features of ADHD and intellectual disability, with a pericentric inversion of chromosome 3, 46N inv(3)(p14:q21).

METHODS

We hypothesised that the inversion breakpoints affect a gene or genes that cause the observed phenotype. Large genomic clones (P1 derived/yeast/bacterial artificial chromosomes) were assembled into contigs across the two inversion breakpoints using molecular and bioinformatic technologies. Restriction fragments crossing the junctions were identified by Southern analysis and these fragments were amplified using inverse PCR.

RESULTS

The amplification products were subsequently sequenced to reveal that the breakpoints lay within an intron of the dedicator of cytokinesis 3 (DOCK3) gene at the p arm breakpoint, and an intron of a novel member of the solute carrier family 9 (sodium/hydrogen exchanger) isoform 9 (SLC9A9) at the q arm. Both genes are expressed in the brain, but neither of the genes has previously been implicated in developmental or behavioural disorders.

CONCLUSION

These two disrupted genes are candidates for involvement in the pathway leading to the neuropsychological condition in this family.

Agreement between participant-rated and compendium-coded intensity of daily activities in a triethnic sample of women ages 40 years and older

Participant-rated and compendium-coded intensity of daily physical activities were compared in 148 African American, 144 Native American, 51 non-Hispanic White women ages 40 to 91 years who completed 4 days of activity records. For compendium-coded intensity, reported activities were classified as light (< 3 metabolic equivalents [METS]), moderate (3-6 METS), or vigorous (> 6 METS) using the Compendium of Physical Activities (1), whereas these categories were self-assigned for participant-rated intensity. Minutes per day (min/d) spent in activities at each intensity level were computed. Relative to compendium-coded min/d, participants reported significantly greater time spent in light (+10 min/d; p < .01) and vigorous (+17 min/d; p < .001) activities, and less time spent in moderate activities (-27 min/d; p <.001). Similarly, compendium-coded estimates yielded higher rates ofparticipants meeting Centersfor Disease Control and Prevention-American College of Sports Medicine and Surgeon General recommendations than participant-rated estimates (11-18% differences) but substantially lower rates meeting American College of Sports Medicine vigorous recommendations (22% difference). Further, 247 greater kilocalories per day were estimated based on compendium-coded intensity. Kilocalories per day estimates based on compendium codings were more highly associated with pedometer counts than those based on participant ratings (p < .05). Studypatterns were generally seen across all sample subgroups. Discrepancies between participant and compendium estimates are likely to be most meaningful in studies estimating energy expenditure as it relates to health outcomes and in studies estimating vigorous activities.

Prevalence and nature of connexin 26 mutations in children with non-syndromic deafness

OBJECTIVE

To determine (1) the prevalence and nature of connexin 26 mutations in a cohort of Australian children with non-syndromic hearing loss, and (2) the carrier frequency of the common connexin 26 mutation (35delG) in the general population.

DESIGN

A cohort, case-finding study. Mutation analysis was performed on DNA extracted from white blood cells, buccal cells, or Guthrie blood spots.

SETTING

A hearing loss investigation clinic and a deafness centre in two Australian capital cities, 1 January 1998 to 31 October 2000.

PARTICIPANTS

(1) 243 children (age range, 4 weeks to 16 years; median, 4 years), attending hearing loss clinics in Sydney and Melbourne; (2) 1000 blood samples obtained from anonymous Guthrie card blood spots collected in 1984 [corrected] by the Victorian Clinical Genetics Service as part of the newborn screening program.

MAIN OUTCOME MEASURES

(1) The prevalence and types of connexin 26 mutations in a cohort of children with prelingual deafness; (2) the carrier frequency of the common connexin 26 mutation, 35delG, in the general population.

RESULTS

Connexin 26 mutations were identified and characterised in 52 (21%) of the 243 children; 14 different mutations, including four previously unreported mutations (135S, C53R, T123N and R127C), were identified. The common 35delG mutation was found in 56 of the 104 alleles (ie, 86 of the connexin 26 alleles in which a mutation was positively identified). The mutations V371 and M34T were also relatively common. The carrier frequency of connexin 26 mutations and of the common 35delG connexin 26 mutation in the Victorian population was estimated to be 1 in 54 and 1 in 100, respectively.

CONCLUSIONS

Mutations in the connexin 26 gene (especially the 35delG mutation) are a common cause of prelingual hearing loss in Australia.

Gender differences in cardiovascular response to dementia caregiving

PURPOSE

This study examined gender differences in cardiovascular responses to laboratory-based stress, as well as in ambulatory hemodynamic (i.e., blood pressure and heart rate) functioning among caregivers of persons with dementia.

DESIGN & METHODS

Participants were 25 men and 25 women caregivers, matched on age, type of care recipient's dementia, and relationship to the care recipient. After cardiovascular reactivity to a laboratory-based caregiving stressor was assessed, the ambulatory hemodynamic functioning levels of caregivers were measured in caregivers' natural environments.

RESULTS

Female caregivers displayed greater systolic and diastolic blood pressure reactivity to a laboratory-based stress task (i.e., discussing caregiving difficulties) compared with male caregivers (p < or =.01). In contrast, no gender differences were found for ambulatory hemodynamic functioning when aggregated overall or when in the presence of the care recipient.

IMPLICATIONS

Laboratory-based findings suggest that female caregivers experience greater blood pressure reactivity to caregiving-related stress than do male caregivers. However, these laboratory-based gender differences may not generalize to differences in hemodynamic functioning in caregivers' daily lives.

Nutrition and physical activity interventions to reduce cardiovascular disease risk in health care settings: a quantitative review with a focus on women

The authors conducted a quantitative literature review of the impact of 32 diet and physical activity (PA) interventions delivered in health care settings on cardiovascular disease risk factors. Intervention effects were relatively modest but statistically significant for PA, body mass index or weight, dietary fat, blood pressure, and total and low-density lipoprotein serum cholesterol. Intervention effects were generally larger for samples with a mean age >50 years and for studies with <6 months follow-up. Type of comparison group, type of intervention, and use of a behavior theory did not have a consistent impact on intervention effects. Few studies focused on persons of color, although the results from these studies are promising.

Ypel1: a novel nuclear protein that induces an epithelial-like morphology in fibroblasts

BACKGROUND

Embryonic development depends on the regulation of cell morphology and behaviour to carry out morphogenesis. One example of this is the development of the face, which is constructed from independent blocks of tissue that must grow in a coordinated way and then fuse to form a continuous tissue.

RESULTS

We have isolated a novel gene of unknown function from mouse and quail embryos in a search for genes involved in craniofacial development. Sequence analysis of this gene, known as Ypel1, demonstrates a striking level of amino acid conservation between vertebrates and invertebrates but no significant homology with any other characterized genes. Ypel1 is expressed in the ventral half of early embryos including the branchial arches from which the face derives. Ypel1 localizes to the nucleus, and transfection into fibroblasts induces an epithelial-like transition, which is accompanied by alterations to the cytoskeleton and cell adhesion machinery. In addition, human YPEL1 localizes to chromosome 22q11.2, a region associated with a number of syndromes involving malformation of the craniofacial complex.

CONCLUSION

These data suggest a role in regulation of cellular morphology and behaviour that is important for development of the craniofacial complex.

Promoting adherence and retention to clinical trials in special populations: a women's health initiative workshop

This paper describes a Women's Health Initiative workshop on promoting adherence and retention in randomized clinical trials among ethnic minority women, participants of lower socioeconomic status, and older women. Workshop objectives were: (1) to increase knowledge of demographic and cultural characteristics of diverse groups, (2) to increase awareness of how diversity can affect interactions in clinical research, (3) to explore how research staff behavior can influence adherence and retention, and (4) to increase knowledge of strategies to enhance adherence and retention in special populations. The workshop emphasized the importance of understanding beliefs, values, and experiences that are common in diverse groups of individuals, while at the same time recognizing and respecting individual differences that result from varying life circumstances and experiences. We discuss strategies to increase cultural competence, reduce stereotypes and discrimination, and create a culturally relevant and sensitive research environment.

Lifestyle interventions influence relative errors in self-reported diet intake of sodium and potassium

PURPOSE

To characterize the distribution of errors in self-reported sodium and potassium dietary intakes relative to more objective urine measures among participants receiving lifestyle interventions.

METHODS

We analyzed longitudinal data from 900 individuals with hypertension who had been enrolled in a randomized controlled clinical trial to establish whether usual care or three lifestyle interventions (weight loss, sodium reduction, and combined weight loss and sodium reduction) could effectively substitute for phamacotherapy. Repeated standardized 24-hour diet recalls and 24-hour urine collections were collected over up to three years of follow-up to estimate sodium and potassium intakes. By contrasting self-reported and urine-based sodium and potassium data collected before and during interventions, we examined the relative impact of intervention assignment on estimated intakes, repeatability, and multivariate measurement error.

RESULTS

Relative to urine-based measures, mean self-reported sodium intakes were biased about 10% lower among participants assigned to combined weight loss and sodium reduction, but were unaffected by the other interventions. The repeatability of self-report measures increased slightly with time, particularly among participants assigned to sodium interventions. Errors in self-reported sodium and potassium intakes were correlated before the start of the intervention, but became uncorrelated among individuals assigned to sodium restriction interventions.

CONCLUSIONS

Lifestyle interventions may influence not only diet intake, but also the measurement of diet intake.

Improving the number of mothers breastfeeding in the postpartum period

The objective of this study was to review an experience at Jackson Memorial Hospital, Miami, Florida that has resulted in an increase in the percentage of mothers breastfeeding at postpartum discharge. Data was obtained from postpartum interviews in 1993, which provided the percentage of mothers breastfeeding at discharge. Staff members and personnel involved in the care of postpartum mothers and babies were educated about breastfeeding, and rounds were made to problem solve and reinforce. Patients who elected to breastfeed from April to September 1994 were followed for a duration of 3 months. These early efforts led to the implementation of a Baby-Friendly initiative and intent in 1996 and the formation of a mother-baby unit in 1997. Ten percent of mothers were breastfeeding at postpartum discharge. After implementing a program in 1994, 41% were breastfeeding at discharge. There was a decline in the number of mothers breastfeeding during the postpartum period from discharge. At 3 days postpartum, 80% of patients were breastfeeding followed by 64%, 37%, and 17% at 2 weeks, 6 weeks, and 3 months from discharge, respectively. The percentage of mothers opting not to breastfeed at 3 days after discharge was 20%, followed by 12% from 3 days to 2 weeks postdischarge, by 21% 2 weeks to 6 weeks postdischarge, and finally by 16% from 6 weeks to 3 months postdischarge. In 1998, 70% of patients were breastfeeding, and in 1999, 71% of patients were breastfeeding upon postpartum discharge. The data show that by implementing programs to promote breastfeeding, through education, encouragement, and reinforcement, one can increase the number of mothers who breastfeed at postpartum discharge. However, there is an inverse relationship between the duration of the postdischarge period and the number of mothers breastfeeding.

Personal and environmental factors associated with physical inactivity among different racial-ethnic groups of U.S. middle-aged and older-aged women

Personal, program-based, and environmental barriers to physical activity were explored among a U.S. population-derived sample of 2,912 women 40 years of age and older. Factors significantly associated with inactivity included American Indian ethnicity, older age, less education, lack of energy, lack of hills in one's neighborhood, absence of enjoyable scenery, and infrequent observation of others exercising in one's neighborhood. For all ethnic subgroups, caregiving duties and lacking energy to exercise ranked among the top 4 most frequently reported barriers. Approximately 62% of respondents rated exercise on one's own with instruction as more appealing than undertaking exercise in an instructor-led group, regardless of ethnicity or current physical activity levels. The results underscore the importance of a multifaceted approach to understanding physical activity determinants in this understudied, high-risk population segment.

Factors related to sleep disturbance in older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis

OBJECTIVES

To describe the types and frequencies of sleep complaints and the biopsychosocial factors associated with sleep disturbance in a large community sample of older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis (OA).

DESIGN

Baseline analyses of an observational prospective study.

SETTING AND PARTICIPANTS

Participants were 429 men and women aged 65 years and older experiencing knee pain or knee pain with radiographic evidence of OA enrolled in the Observational Arthritis Study in Seniors (OASIS).

MEASUREMENTS

Demographic variables (age, gender, ethnicity, education), health (X-rays of knee rated for OA severity, medical conditions, medication use, smoking status, body mass index, self-rated health), physical functioning (self-rated physical functioning, physical performance), knee pain, and psychosocial functioning (social support, depression) were measured.

RESULTS

Problems with sleep onset, sleep maintenance, and early morning awakenings occurred at least weekly among 31%, 81%, and 51% of participants, respectively. Bivariate correlates of greater sleep disturbance in those with OA were less education, cardiovascular disease, more arthritic joints, poorer self-rated health, poorer physical functioning, poorer physical performance, knee pain, depression, and less social support. In regression analyses, each set of variables representing the domains of health, physical functioning, pain, and psychosocial functioning contributed to the prediction of sleep disturbance beyond the demographic set. Finally, in a simultaneous model, white race (trend, P = .06), poorer self-rated health, poorer physical functioning, and depressive symptoms were predictive of sleep disturbance.

CONCLUSIONS

Sleep disturbance is common in older adults experiencing knee pain or knee pain with radiographic evidence of OA and is best understood through the consideration of demographic, physical health, physical functioning, pain, and psychosocial variables. Interventions that take into account the multidetermined nature of sleep disturbance in knee pain or knee OA are most likely to be successful.

Determinants of leisure time physical activity in rural compared with urban older and ethnically diverse women in the United States

STUDY OBJECTIVE

Determinants of leisure time physical activity (LTPA) in rural middle aged and older women of diverse racial and ethnic groups are not well understood. This study examined: (1) urban-rural differences in LTPA by sociodemographic factors, (2) urban-rural differences in LTPA determinants, and (3) the pattern of relations between LTPA determinants and LTPA.

DESIGN

A modified version of the sampling plan of the Behavioral Risk Factor Surveillance Survey (BRFSS) was used. Zip codes were selected with 20% or more of each of the following race/ethnic groups: African American, American Indian/Alaskan Native (AI/AN), and Hispanic. A comparison group of white women were also surveyed using standard BRFSS techniques.

PARTICIPANTS

Rural (n=1242) and urban (n=1096) women aged 40 years and older from the US Women's Determinants Study.

MAIN RESULTS

Rural women, especially Southern and less educated women, were more sedentary than urban women. Rural women reported more personal barriers to LTPA, cited caregiving duties as their top barrier (compared with lack of time for urban women), and had greater body mass indices. Rural women were less likely to report sidewalks, streetlights, high crime, access to facilities, and frequently seeing others exercise in their neighbourhood. Multivariate correlates of sedentary behaviour in rural women were AI/AN and African American race, older age, less education, lack of enjoyable scenery, not frequently seeing others exercise, greater barriers, and less social support (p<0.05); and in urban women, older age, greater barriers, less social support (p<0.05), and less education (p<0.09).

CONCLUSIONS

Rural and urban women seem to face different barriers and enablers to LTPA, and have a different pattern of determinants, thus providing useful information for designing more targeted interventions.

Personal and environmental factors associated with physical inactivity among different racial-ethnic groups of U.S. middle-aged and older-aged women

Personal, program-based, and environmental barriers to physical activity were explored among a U.S. population-derived sample of 2,912 women 40 years of age and older. Factors significantly associated with inactivity included American Indian ethnicity, older age, less education, lack of energy, lack of hills in one's neighborhood, absence of enjoyable scenery, and infrequent observation of others exercising in one's neighborhood. For all ethnic subgroups, caregiving duties and lacking energy to exercise ranked among the top 4 most frequently reported barriers. Approximately 62% of respondents rated exercise on one's own with instruction as more appealing than undertaking exercise in an instructor-led group, regardless of ethnicity or current physical activity levels. The results underscore the importance of a multifaceted approach to understanding physical activity determinants in this understudied, high-risk population segment.

Do changes in physical activity lead to dietary changes in middle and old age?

INTRODUCTION

Research examining the relationship between dietary factors and physical activity patterns has yielded conflicting findings. Few prospective studies have examined whether individuals who change their level of physical activity make corresponding changes in their diet.

METHODS

The current study examined, in two randomized clinical trials of physical activity, whether self-report of dietary factors changed over a 1-year period, whether these changes differed by gender or exercise-intervention group, and whether changes in physical activity led to changes in dietary factors. Participants included 268 men and women aged 50-65 years who participated in the Stanford-Sunnyvale Health Improvement Project I (SSHIP-I) and 103 men and women aged 65-82 years who participated in SSHIP-II. In both trials we recruited participants through random-digit telephone dialing and citywide promotion.

RESULTS

Overall, participants adopted healthier diets over the 1-year period. The SSHIP-I participants decreased their consumption of total calories, total fat, saturated fat, protein, and cholesterol. The SSHIP-II participants decreased their consumption of high-fat, high-cholesterol foods. The SSHIP-I women were more likely than men to decrease their intake of total fat and protein (p < 0.01), as well as total calories, saturated fat, and cholesterol (p < 0.05). However, we found that changes in physical activity were not associated with changes in self-report measures of dietary habits.

CONCLUSIONS

We found no evidence to support the idea that changes in physical activity are a gateway for changes in dietary factors in middle-aged and older adults.

Azo-dye degradation in an anaerobic-aerobic treatment system operating on simulated textile effluent

Decolorisation of azo dyes during biological effluent treatment can involve both adsorption to cell biomass and degradation by azo-bond reduction during anaerobic digestion. Degradation is expected to form aromatic amines, which may be toxic and recalcitrant to anaerobic treatment but degradable aerobically. Methods for the quantitative detection of substituted aromatic amines arising from azo-dye cleavage are complex. A simple qualitative method is suggested as a way in which to investigate whether decolorisation is actually due to degradation, and whether the amines generated are successfully removed by aerobic treatment. Samples from a combined anaerobic-aerobic system used for treating a simulated textile wastewater containing the reactive azo dye Procion Red H-E7B were analysed by high-performance liquid chromatography/ultraviolet (HPLC-UV) methods. Anaerobic treatment gave significant decolorisation, and respiration-inhibition tests showed that the anaerobic effluent had an increased toxicity, suggesting azo-dye degradation. The HPLC method showed that more polar, UV-absorbing compounds had been generated. Aerobically, these compounds were removed or converted to highly polar compounds, as shown by HPLC analysis. Since the total organic nitrogen (TON) decreased aerobically as organic N-containing compounds were mineralised, aromatic amine degradation is suggested. Although only a simple qualitative HPLC method was used, colour removal, toxicity and TON removal all support its usefulness in analysing biotreatment of azo dyes.

Knowledge and perceived risk of major diseases in middle-aged and older women

Women's (N = 200; 41-95 years) knowledge of mortality risks and their perceived general risk, personal risk, control, and preventability of coronary heart disease (CHD) and breast, colon, and lung cancer were examined. Middle-aged (MA) women were more accurate in their mortality knowledge for MA men than for MA women and were more accurate for MA than for older (OA) men and women. OA women, in contrast, were least accurate in their mortality knowledge for OA women compared with all other target groups; only 34% knew that CHD is the leading cause of death in OA women. Participants also overestimated a woman's risk of death from breast cancer and underestimated the risk from lung and colon cancer. Ratings of perceived risk, control, and preventability varied as a function of disease. OA women in particular appear to lack knowledge regarding women's risk of major diseases. Results have implications for women's health behaviors and medical decisions.

Knowledge and perceived risk of major diseases in middle-aged and older women

Women's (N = 200; 41-95 years) knowledge of mortality risks and their perceived general risk, personal risk, control, and preventability of coronary heart disease (CHD) and breast, colon, and lung cancer were examined. Middle-aged (MA) women were more accurate in their mortality knowledge for MA men than for MA women and were more accurate for MA than for older (OA) men and women. OA women, in contrast, were least accurate in their mortality knowledge for OA women compared with all other target groups; only 34% knew that CHD is the leading cause of death in OA women. Participants also overestimated a woman's risk of death from breast cancer and underestimated the risk from lung and colon cancer. Ratings of perceived risk, control, and preventability varied as a function of disease. OA women in particular appear to lack knowledge regarding women's risk of major diseases. Results have implications for women's health behaviors and medical decisions.

Sleep complaints in older women who are family caregivers

Providing care to a family member with dementia has significant psychological and physical consequences. Sleep quality is likely affected by caregiving, yet this domain has received surprisingly little empirical study. In this study, sleep complaints were examined in 90 older women who were family caregivers of adults with dementia. Caregivers reported more sleep complaints than similarly aged healthy adults on all seven components of the Pittsburgh Sleep Quality Index, and a similar level of sleep complaints to those of sleep-impaired women and depressives on 6 and 4 components, respectively. Sleep medication was used by 38% of caregivers in the past month. The most common sleep complaints that occurred at least weekly were waking up in the night or early morning (84%), bathroom needs (83%), and sleep onset difficulties (41%). Sixty percent of the sample reporting nighttime care recipient disruptions stated that these disruptions occurred 3 or more times per week. Caregiver relationship and care recipient diagnosis were unrelated to sleep complaints. Lower levels of education, less internalized anger, care recipient disruptions, and psychological distress were related to poorer overall sleep quality. Sleep complaints are a common yet understudied problem in family caregivers.

The effects of marital transitions on changes in physical activity: results from a 10-year community study

The potential effects of making a marital transition on subsequent physical activity were evaluated across a ten-year period in a population-based sample of 302 women and 256 men ages 25 to 75 years. Subjects completed a structured interview at five timepoints throughout the ten-year period during which they reported on their physical activity level as well as marital status. The transition from a married to a single state did not affect physical activity relative to remaining married when analyses of either slopes or mean values were used. In contrast, the transition from a single to a married state resulted in significant positive changes in physical activity relative to remaining single throughout the study period when physical activity slopes, though not means, were compared. The results suggest that marriage may potentially set the stage for natural changes in physical activity that could be capitalized on through appropriate intervention, but additional research is needed to verify this in light of the inconsistent pattern of findings.

Relations among age, exercise, and psychological variables in a community sample of women

Age, exercise status, and their interaction were examined in relation to self-motivation, exercise self-efficacy, and attitudes toward exercise among a community sample of women aged 20 to 85 years. Random digit telephone dialing yielded 121 participants, stratified by age and exercise status. Age was negatively related to attitudes toward exercise and exercise self-efficacy but was unrelated to self-motivation. Age also interacted with exercise status; the belief that exercise would be enjoyable and beneficial decreased with increasing age only among nonexercisers. Finally, exercisers were significantly more self-motivated, had greater exercise self-efficacy, and had more positive attitudes toward exercise than did nonexercisers.

Relations among age, exercise, and psychological variables in a community sample of women

Age, exercise status, and their interaction were examined in relation to self-motivation, exercise self-efficacy, and attitudes toward exercise among a community sample of women aged 20 to 85 years. Random digit telephone dialing yielded 121 participants, stratified by age and exercise status. Age was negatively related to attitudes toward exercise and exercise self-efficacy but was unrelated to self-motivation. Age also interacted with exercise status; the belief that exercise would be enjoyable and beneficial decreased with increasing age only among nonexercisers. Finally, exercisers were significantly more self-motivated, had greater exercise self-efficacy, and had more positive attitudes toward exercise than did nonexercisers.

Potassium transport in the freshwater bivalve Dreissena polymorpha

Potassium transport and blood ion composition were examined in the freshwater bivalve Dreissena polymorpha. Animals acclimated to artificial pondwater (APW, [K+]=0.05 mmol l-1) for 4 weeks gradually lost Na+ and Cl-, but the blood K+ concentration remained constant near 0.5 mmol l-1. Blood [K+] in D. polymorpha declined by 41 % after 1 week of exposure to K+-free APW. Conversely, blood [K+] rose to 1.52&plusmn;0.05 mmol l-1 (mean &plusmn; s.e.m.) 24 h after exposure to 0.5 mmol l-1 K+ APW. Total tissue K+ content remained stable in animals maintained in APW, but fell significantly in animals exposed to K+-free APW for 2 weeks. The net K+ flux (Jnet) for animals incubated in APW, with an average K+ concentration of 0.07 mmol l-1, was -0.27&plusmn;0.06 &micro;equiv g-1 dry tissue h-1, significantly different from the value of 0.50&plusmn;0.08 &micro;equiv g-1 dry tissue h-1 for animals transferred to 0.30 mmol l-1 K+ APW. A transepithelial membrane potential of -3.6&plusmn;0.7 mV (blood negative compared with the bathing medium) was measured in APW-acclimated mussels. Potassium influx was measured with 42K and displayed Michaelis&shy;Menten saturation kinetics at dilute K+ concentrations. The Km was 0.084&plusmn;0.054 mmol l-1 and the Jmax was 1.74&plusmn;0.39 &micro;equiv g-1 dry tissue h-1. Both the Km and Jmax for animals exposed to K+-free APW for 7 days were unchanged. Using 86Rb, qualitatively similar transport characteristics were observed for animals incubated in K+-free, Rb+ APW, but the 22 day K+ depletion time significantly increased Jmax. D. polymorpha compensated for changes in the ionic composition of the acclimation medium by tolerating alterations in blood solute composition and adjusting ion transport rates.