First Measurement of a Long-Lived π

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike π^{+}π^{-} atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1 µm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n_{A}^{L}=436_{-61}^{+157}|_{tot}, the lifetime of the 2p state is found to be τ_{2p}=(0.45_{-0.30}^{+1.08}|_{tot})×10^{-11} s, not contradicting the corresponding QED 2p state lifetime τ_{2p}^{QED}=1.17×10^{-11} s. This lifetime value is three orders of magnitude larger than our previously measured value of the π^{+}π^{-} atom ground state lifetime τ=(3.15_{-0.26}^{+0.28}|_{tot})×10^{-15} s. Further studies of long-lived π^{+}π^{-} atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor ππ scattering lengths with the aim to check QCD predictions.

Observation of π

The observation of hydrogenlike πK atoms, consisting of π^{-}K^{+} or π^{+}K^{-} mesons, is presented. The atoms are produced by 24 GeV/c protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionization) of πK atoms in the same targets yields characteristic πK pairs, called "atomic pairs," with small relative momenta Q in the pair center-of-mass system. The upgraded DIRAC experiment observed 349±62 such atomic πK pairs, corresponding to a signal of 5.6 standard deviations. This is the first statistically significant observation of the strange dimesonic πK atom.

In-phase millennial-scale glacier changes in the tropics and North Atlantic regions during the Holocene.

Based on new and published cosmic-ray exposure chronologies, we show that glacier extent in the tropical Andes and the north Atlantic regions (TANAR) varied in-phase on millennial timescales during the Holocene, distinct from other regions. Glaciers experienced an early Holocene maximum extent, followed by a strong mid-Holocene retreat and a re-advance in the late Holocene. We further explore the potential forcing of TANAR glacier variations using transient climate simulations. Since the Atlantic Meridional Overturning Circulation (AMOC) evolution is poorly represented in these transient simulations, we develop a semi-empirical model to estimate the "AMOC-corrected" temperature and precipitation footprint at regional scales. We show that variations in the AMOC strength during the Holocene are consistent with the observed glacier changes. Our findings highlight the need to better constrain past AMOC behavior, as it may be an important driver of TANAR glacier variations during the Holocene, superimposed on other forcing mechanisms.

A motivation-focused weight loss maintenance program is an effective alternative to a skill-based approach.

OBJECTIVE: Maintaining weight loss is a major challenge in obesity treatment. Individuals often indicate that waning motivation prompts cessation of effective weight management behaviors. Therefore, a novel weight loss maintenance program that specifically targets motivational factors was evaluated. DESIGN: Overweight women (N=338; 19% African American) with urinary incontinence were randomized to lifestyle obesity treatment or control and followed for 18 months. All participants in lifestyle (N=226) received the same initial 6-month group behavioral obesity treatment and were then randomized to (1) a novel motivation-focused maintenance program (N=113) or (2) a standard skill-based maintenance approach (N=113). MAIN OUTCOME MEASURE: Weight assessed at baseline, 6 and 18 months. RESULTS: Both treatment groups (motivation-focused and skill-based) achieved comparable 18-month weight losses (-5.48% for motivation-focused vs -5.55% in skill-based, P=0.98), and both groups lost significantly more than controls (-1.51%; P=0.0012 in motivation-focused and P=0.0021 in skill-based). CONCLUSIONS: A motivation-focused maintenance program offers an alternative, effective approach to weight maintenance expanding available evidence-based interventions beyond traditional skill-based programs.

[About the microbiological criteria for air quality barracks in the far north].

A comparative study of air quality in terms of microbiological indicators in the barracks room personnel a number of units of the Northern Fleet is perfomed. The direct dependence of the degree of microbial contamination of air and the frequency of respimratory diseases from the specific volume of space per person is showed. Criteria for assessing air quality in terms of microbiological indicators and a set of measures to improve it are suggested.

MEG signatures of long-term effects of agreement and disagreement with the majority.

People often change their beliefs by succumbing to an opinion of others. Such changes are often referred to as effects of social influence. While some previous studies have focused on the reinforcement learning mechanisms of social influence or on its internalization, others have reported evidence of changes in sensory processing evoked by social influence of peer groups. In this study, we used magnetoencephalographic (MEG) source imaging to further investigate the long-term effects of agreement and disagreement with the peer group. The study was composed of two sessions. During the first session, participants rated the trustworthiness of faces and subsequently learned group rating of each face. In the first session, a neural marker of an immediate mismatch between individual and group opinions was found in the posterior cingulate cortex, an area involved in conflict-monitoring and reinforcement learning. To identify the neural correlates of the long-lasting effect of the group opinion, we analysed MEG activity while participants rated faces during the second session. We found MEG traces of past disagreement or agreement with the peers at the parietal cortices 230 ms after the face onset. The neural activity of the superior parietal lobule, intraparietal sulcus, and precuneus was significantly stronger when the participant's rating had previously differed from the ratings of the peers. The early MEG correlates of disagreement with the majority were followed by activity in the orbitofrontal cortex 320 ms after the face onset. Altogether, the results reveal the temporal dynamics of the neural mechanism of long-term effects of disagreement with the peer group: early signatures of modified face processing were followed by later markers of long-term social influence on the valuation process at the ventromedial prefrontal cortex.

Are standard behavioral weight loss programs effective for young adults?

OBJECTIVE: To compare the enrollment, attendance, retention and weight losses of young adults in behavioral weight loss (BWL) programs with older participants in the same trials. METHODS: Data were pooled from three NIH-funded adult BWL trials from two clinical centers in different regions of the country (total N=298); young adults were defined as those aged 18-35 years. Both young adults and adults were compared on session attendance, retention at the 6-month assessment, weight loss and physical activity at 6 months. RESULTS: Young adults represented 7% of the sample, attended significantly fewer sessions than did adults (52 vs 74%, respectively; P<0.001) and were less likely to be retained for the 6-month assessment (67 vs 95%, respectively; P<0.05). Controlling for demographic variables, study and baseline weight, the mean weight losses achieved were significantly less for young adults compared with adults (-4.3 kg (6.3) vs -7.7 kg (7.0), respectively; P<0.05); fewer young adults achieved > or =5% weight loss at 6 months compared with older participants (8/21 (38%) vs 171/277 (62%); P<0.05). After controlling for session attendance, differences in the mean weight loss were not significant (P=0.81). Controlling for baseline values, study and demographics, changes in total physical activity over the initial 6 months of treatment were less for young adults compared with adults, but these differences only approached statistical significance (P=0.07). CONCLUSION: These data indicate that standard programs do not meet the weight control needs of young adults. Research is urgently required to improve recruitment and retention efforts with this high-risk group.

Sustaining eHealth engagement in a multi-year weight gain prevention intervention.

INTRODUCTION: Digital tools are widely used and effective in weight management interventions; however, usage declines over time. Strategies to promote continued engagement should be explored. We examined the effects of offering additional modes of weight reporting as well as periodic online campaigns to promote engagement, assessed by frequency of weight reporting, in a weight gain prevention study for young adults. METHODS: Using an observational design, self-reported weights obtained through digital tools were pooled across participants assigned to two interventions (n = 312). Analysis examined the effects before during and after introduction of an additional reporting modality (email) and for three time-limited refresher campaigns over 2 years. RESULTS: Adding a new modality to the three existing modes (SMS, web, and mobile web) increased weight reporting as well as the number of modalities participants used to report weights. The use of several modes of reporting was associated with more weights submitted (p < 0.01). Refresher campaigns did not increase the proportion of participants reporting; however, the number of weights submitted during the 4-week campaigns increased compared with the 4 weeks before the campaign (p's ≥ 0.45, <0.001, respectively). CONCLUSION: Using multiple digital modalities and periodic campaigns shows promise for sustaining engagement with weight reporting in a young adult population, and incorporating such strategies may mitigate typical declines in eHealth and mHealth interventions.

Weight loss treatment influences untreated spouses and the home environment: evidence of a ripple effect.

OBJECTIVES: To examine whether a weight loss program delivered to one spouse has beneficial effects on the untreated spouse and the home environment. METHODS: We assessed untreated spouses of participants in three sites of Look AHEAD, a multicenter randomized controlled trial evaluating the impact of intentional weight loss on cardiovascular outcomes in overweight individuals with type 2 diabetes. Participants and spouses (n=357 pairs) were weighed and completed measures of diet and physical activity at 0 and 12 months. Spouses completed household food and exercise environment inventories. We examined differences between spouses of participants assigned to the intensive lifestyle intervention (ILI) or to the enhanced usual care (DSE; diabetes support and education). RESULTS: Spouses of ILI participants lost -2.2+/-4.5 kg vs -0.2+/-3.3 kg in spouses of DSE participants (P<0.001). In addition, more ILI spouses lost > or =5% of their body weight than DSE spouses (26 vs 9%, P<0.001). Spouses of ILI participants also had greater reductions in reported energy intake (P=0.007) and percent of energy from fat (P=0.012) than DSE spouses. Spouse weight loss was associated with participant weight loss (P<0.001) and decreases in high-fat foods in the home (P=0.05). CONCLUSION: The reach of behavioral weight loss treatment can extend to a spouse, suggesting that social networks can be utilized to promote the spread of weight loss, thus creating a ripple effect.

Fabrication of silicon nitride waveguides for visible-light using PECVD: a study of the effect of plasma frequency on optical properties.

This paper presents work aimed at optimizing the fabrication of silicon nitride Si(x)N(y) thin-film visible-light planar waveguides using plasma-enhanced chemical vapour deposition (PECVD). The effects of plasma frequency, precursor gas ratio, and thermal annealing in relation to waveguide optical properties (refractive index, propagation losses) are studied. Experimental results over a wide range of precursor gas ratios show convincingly that waveguides fabricated using low-frequency PECVD have lower propagation losses in the visible range compared to waveguides of equal refractive index fabricated with high-frequency PECVD.

Outcomes of an early childhood obesity prevention program in a low-income community: a pilot, randomized trial.

BACKGROUND: Obesity is a major and worldwide health problem in children. OBJECTIVES: The Early Childhood Obesity Prevention Program is a multi-component, randomized, controlled trial of a pilot community-focused obesity prevention program for mother/newborn dyads. METHODS: Underserved, mother/newborn dyads were recruited to receive a standard home visitation program (Nurturing Families Network, NFN) or an enhanced program (NFN+) that incorporated behavioural change strategies (e.g., goal-setting, problem-solving) and focused on six obesity-associated behaviours (breastfeeding, juice/sugar-sweetened beverages, solids, infant sleep, TV/screen time and soothability) with linkages to community resources. Weight-for-length (WFL) z-score and maternal diet were secondary outcomes. RESULTS: Fifty-seven dyads were recruited and 47 fully eligible dyads were enrolled (NFN = 21, NFN+ = 26). Forty-one (87.2%) were assessed at 6 months and 34 (72.3%) at 12 months. Retention at 12 months was higher for NFN+ dyads (84.6% vs. 56.1%, p = 0.04). NFN+ mothers were more likely to continue breastfeeding at 6 and 12 months vs. NFN mothers (p = 0.03 and 0.003, respectively), and at 12 months, NFN+ infants had fewer nocturnal awakenings (p = 0.04). There were no differences in other primary outcome measures or in WFL z-score at 6 or 12 months. CONCLUSIONS: A multi-component behavioural intervention increased breastfeeding duration and decreased nocturnal awakenings in infants of low-income families.

Noninvasive measurement of pulmonary transvascular protein flux in normal man.

Onset of lung edema is usually associated with increase in the pulmonary transvascular flux of water and proteins. Clinical measurement of these parameters may aid in early diagnosis of pulmonary edema, and allow differentiation between "cardiogenic" and "noncardiogenic" types base on the magnitude of the detected changes. We have previously described a noninvasive method for estimating transvascular protein flux in lung (Gorin, A. B., W. J. Weidner, R. H. Demling, and N. C. Staub, 1978. Noninvasive measurement of pulmonary transvascular protein flux in sheep. J. Appl. Physiol. 45: 225-233). Using this method we measured the net transvascular flux of [113mIn]transferrin (mol wt, 76,000 in lungs of nine normal human volunteers. Plasma clearance of [113In]transferrin occurred with a T1/2 = 7.0 +/- 2.6 h (mean +/- SD). The pulmonary transvascular flux coefficient, alpha, was 2.9 +/- 1.4 X 10(-3) ml/s (mean +/- SD) in man, slightly greater than that previously measured in sheep (2.7 +/- 0.7 X 10(-3) ml/s; mean +/- SD). The pulmonary transcapillary escape rate is twofold greater than the transcapillary escape rate for the vascular bed as a whole, indicating a greater "porosity" of exchanging vessels in the lung than exists for the "average" microvessel in the body. Time taken to reach half-equilibrium concentration of tracer protein in the lung interstitium was quite short, 52 +/- 13 min (mean +/- SD). We have shown that measurement of pulmonary transvascular protein flux in man is practical. The coefficient of variation of measurements of alpha (between subjects) was 0.48, and of measurements of pulmonary transcapillary escape rates was 0.39. In animals, endothelial injury commonly results in a two- to threefold increase in transvascular protein flux. Thus, external radioflux detection should be a suitable means of quantitating lung vascular injury in human disease states.

Continuous negative external chest pressure decreases transvascular lung water transport in sheep after Pseudomonas bacteremia.

We studied the effects of continuous negative external chest pressure (CNECP) produced by a cuirass appliance on lung water and protein transport in sheep with chronic lung lymphatic fistulas. We compared data obtained during periods of mechanical ventilation (base line) to period of CNECP, using identical ventilatory support. Three groups were studied: six sheep were studied before and after application of CNECP for 1 h (control) and again after induction of a pulmonary vascular permeability defect (PVPD) by infusing live Pseudomonas bacteria (group I); another six sheep were studied under control conditions before and after prolonged application of CNECP for over 4 h (group II); 10 sheep were studied 24 h after a Pseudomonas infusion (PVPD), before and after 4 h of CNECP (group III). Compared to base-line data, CNECP produced significant increases in functional residual capacity and decreases in pulmonary blood volume, pulmonary artery pressure, and left atrial pressure in all groups. Lung lymph flow (Q(L)) was unchanged during the 1st h of CNECP and therefore was not significantly different from base line in group I, but after prolonged CNECP a steady-state decrease in Q(L) as well as a decrease in lung albumin transport was found in groups II and III (P < 0.05 by paired t test). We postulate that decreased pleural pressure during CNECP produces decreased hydrostatic filtration pressures, thereby decreasing Q(L). Reduction of both convective forces as well as microvascular surface area available for solute exchange account for decreases in lung albumin transport. Histologic examination and gravimetric studies on four sheep failed to demonstrate increase in lung water accumulation after 4 h of CNECP. We conclude that CNECP mechanically reversed the PVPD in our group III sheep. These physiologic effects of CNECP may be of benefit in the management of patients with adult respiratory distress syndrome.

Release of angiotensin converting enzyme by the lung after Pseudomonas bacteremia in sheep.

We studied release of angiotensin-converting enzyme (ACE) by the lung after acute injury associated with an increase in pulmonary vascular permeability. In eight adult sheep with chronic lung lymph fistulas, we measured lymph flow (QL), and both ACE activity and total protein content in lymph and plasma under base-line conditions and during 24 h after an infusion of live pseudomonas organism. Under base-line conditions, ACE activity in plasma was 4.93 +/- 0.43 U/ml (mean +/- SEM). The [lymph]/[plasma] ([L]/[P]) ratio for ACE was 0.93 +/- 0.18, compared with a ratio of 0.79 +/- 0.08 for albumin (mean +/- SD). We estimated the molecular weight of ovine ACE to be 145,000 by gel chromatography. Predicted [L]/[P] ratio for a molecule this size is 0.51. Thus, a substantial fraction of ACE activity detected lung lymph under base-line conditions (11.1 +/- 6.2 U/h; mean +/- SD) originated in the lung, and did not diffuse passively from plasma. After pseudomonas infusion, endothelial injury was demonstrated by a rise in pulmonary vascular clearance for total protein (Crp = QL X [L]/[P]). Crp = 3.1 +/- 0.6 ml/h before pseudomonas bacteremia, and rose to 6.7 +/- 1.2 ml/h by 2 h after onset of the infusion (means +/- SEM, p less than 0.05). Crp remained significantly elevated for at least 10 h after the infusion. Release of ACE into lung lymph doubled after acute lung injury and equaled 22.3 +/- 13.8 U/h at 4 h after onset of the infusion. ACE secretion into lung lymph had returned to baseline levels by 24 h after bacteremia. We did not observe a significant rise in plasma ACE activity after acute lung injury. Pseudomonas bacteremia in sheep results in acute, reversible lung injury associated with increased pulmonary vascular permeability, and increased release of ACE by the lung. Failure to detect a rise in plasma ACE content might result from dilution in the large vascular pool or rapid catabolism of the enzyme at some site distant from the lung.

Missing the target: including perspectives of women with overweight and obesity to inform stigma-reduction strategies.

OBJECTIVE: Pervasive weight stigma and discrimination have led to ongoing calls for efforts to reduce this bias. Despite increasing research on stigma-reduction strategies, perspectives of individuals who have experienced weight stigma have rarely been included to inform this research. The present study conducted a systematic examination of women with high body weight to assess their perspectives about a broad range of strategies to reduce weight-based stigma. METHODS: Women with overweight or obesity (N = 461) completed an online survey in which they evaluated the importance, feasibility and potential impact of 35 stigma-reduction strategies in diverse settings. Participants (91.5% who reported experiencing weight stigma) also completed self-report measures assessing experienced and internalized weight stigma. RESULTS: Most participants assigned high importance to all stigma-reduction strategies, with school-based and healthcare approaches accruing the highest ratings. Adding weight stigma to existing anti-harassment workplace training was rated as the most impactful and feasible strategy. The family environment was viewed as an important intervention target, regardless of participants' experienced or internalized stigma. CONCLUSION: These findings underscore the importance of including people with stigmatized identities in stigma-reduction research; their insights provide a necessary and valuable contribution that can inform ways to reduce weight-based inequities and prioritize such efforts.

Anchoring an extended HTLV-1 Rex peptide within an RNA major groove containing junctional base triples.

BACKGROUND: The Rex protein of the human T cell leukemia virus type 1 (HTLV-1) belongs to a family of proteins that use arginine-rich motifs (ARMs) to recognize their RNA targets. Previously, an in vitro selected RNA aptamer sequence was identified that mediates mRNA transport in vivo when placed in the primary binding site on stem-loop IID of the Rex response element. We present the solution structure of the HTLV-1 arginine-rich Rex peptide bound to its RNA aptamer target determined by multidimensional heteronuclear NMR spectroscopy. RESULTS: The Rex peptide in a predominantly extended conformation threads through a channel formed by the shallow and widened RNA major groove and a looped out guanine. The RNA aptamer contains three stems separated by a pair of two-base bulges, and adopts an unanticipated fold in which both junctional sites are anchored through base triple formation. Binding specificity is associated with intermolecular hydrogen bonding between guanidinium groups of three non-adjacent arginines and the guanine base edges of three adjacent G.C pairs. CONCLUSIONS: The extended S-shaped conformation of the Rex peptide, together with previous demonstrations of a beta-hairpin conformation for the bovine immunodeficiency virus (BIV) Tat peptide and an alpha-helical conformation for the human immunodeficiency virus (HIV) Rev peptide in complex with their respective RNA targets, expands our understanding of the strategies employed by ARMs for adaptive recognition and highlights the importance of RNA tertiary structure in accommodating minimalist elements of protein secondary structure.

Super-enhancement of 1.54 µm emission from erbium codoped with oxygen in silicon-on-insulator.

We report on the super enhancement of the 1.54 µm Er emission in erbium doped silicon-on-insulator when codoped with oxygen at a ratio of 1:1. This is attributed to a more favourable crystal field splitting in the substitutional tetrahedral site favoured for the singly coordinated case. The results on these carefully matched implant profiles show that optical response is highly determined by the amount and ratio of erbium and oxygen present in the sample and ratios of O:Er greater than unity are severely detrimental to the Er emission. The most efficient luminescence is forty times higher than in silicon-on-insulator implanted with Er only. This super enhancement now offers a realistic route not only for optical communication applications but also for the implementation of silicon photonic integrated circuits for sensing, biomedical instrumentation and quantum communication.

B-DNA twisting correlates with base-pair morphology.

The observed sequence dependence of the mean twist angles in 38 B-DNA crystal structures can be understood in terms of simple geometrical features of the constituent base-pairs. Structures with low twist appear to unwind in response to severe steric clashes of large exocyclic groups (such as NH2-NH2) in the major and minor grooves, while those with high twist are subjected to lesser contacts (H-O and H-H). We offer a simple clash function that depends on base-pair morphology (i.e. the chemical constitution of base-pairs) and satisfactorily accounts for the twist angles of the ten common Watson-Crick dimer steps both in the solid state and in solution. The twist-clash correlation that we find here still holds when extended to modified bases. In addition to Calladine's purine-purine clashes, we add other close contacts between bases in the grooves, and consider the conformational restrictions on the geometry of the sugar-phosphate backbone (namely, we emphasize the tendency of DNA to conserve virtual backbone length). The significance of this finding is threefold: (1) sequence-dependent DNA twisting is directly involved in protein-DNA interactions; (2) strong correlation between Twist and Roll helps to elucidate the bending of the double helix as a function of base sequence; (3) it is possible to anticipate the effects of chemical modifications on twisting and bending. The mutual correlations of other structural parameters with the twist make this angle a primary determinant of DNA conformational heterogeneity.

A two-stranded template-based approach to G.(C-A) triad formation: designing novel structural elements into an existing DNA framework.

We have designed a DNA sequence, d(G-G-G-T-T-C-A-G-G), which dimerizes to form a 2-fold symmetric G-quadruplex in which G(syn). G(anti).G(syn).G(anti) tetrads are sandwiched between all trans G. (C-A) triads. The NMR-based solution structural analysis was greatly aided by monitoring hydrogen bond alignments across N-H...N and N-H...O==C hydrogen bonds within the triad and tetrad, in a uniformly ((13)C,(15)N)-labeled sample of the d(G-G-G-T-T-C-A-G-G) sequence. The solution structure establishes that the guanine base-pairs with the cytosine through Watson-Crick G.C pair formation and with adenine through sheared G.A mismatch formation within the G.(C-A) triad. A model of triad DNA was constructed that contains the experimentally determined G.(C-A) triad alignment as the repeating stacked unit.