On latency of multiple zonal jets in the oceans

Author Posting. © Cambridge University Press, 2011. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 686 (2011): 534-567, doi:10.1017/jfm.2011.345.Most of the nearly zonal, multiple, alternating jets observed in the oceans are latent, that is, their amplitudes are weak relative to the ambient mesoscale eddies. Yet, relatively strong jets are often observed in dynamical simulations. To explore mechanisms controlling the degree of latency, we analyse solutions of an idealized, eddy-resolving and flat-bottom quasigeostrophic model, in which dynamically generated mesoscale eddies maintain and interact with a set of multiple zonal jets. We find that the degree of the latency is controlled primarily by the bottom friction: the larger the friction parameter, the more latent are the jets; and the degree of the latency is substantial for a realistic range of the oceanic bottom friction coefficient. This result not only provides a plausible explanation for the latency of the oceanic jets, but it may also be relevant to the prominent atmospheric multiple jets observed on giant gas planets, such as Jupiter. We hypothesize that these jets can be so strong because of the relative absence of the bottom friction. The mechanism controlling the latency in our solutions is understood in terms of the changes induced in the linear eigenmodes of the time–mean flow by varying the bottom friction coefficient; these changes, in turn, affect and modify the jets. Effects of large Reynolds numbers on the eddies, jets, and the latency are also discussed.Funding was provided: for P.B. by NSF grants OCE 0725796 and OCE 0845150, for J.T.F. by NSF grant OCE 0845150, for I.K. by NSF grant OCE 0842834, and for S.K. by the University Research Fellowship from the Royal Society. S.K. also acknowledges support from the Mary Sears Grant from the Woods Hole Oceanographic Institution.2012-09-2

Air-Sea Interaction in the Bay of Bengal

Recent observations of surface meteorology and exchanges of heat, freshwater, and momentum between the ocean and the atmosphere in the Bay of Bengal are presented. These observations characterize air-sea interaction at 18°N, 89.5°E from December 2014 to January 2016 and also at other locations in the northern Bay of Bengal. Monsoonal variability dominated the records, with winds to the northeast in summer and to the southwest in winter. This variability included a strong annual cycle in the atmospheric forcing of the ocean in the Bay of Bengal, with the winter monsoon marked by sustained ocean heat loss resulting in ocean cooling, and the summer monsoon marked by strong storm events with dark skies and rain that also resulted in ocean cooling. The spring intermonsoon was a period of clear skies and low winds, when strong solar heating and weak wind-driven mixing led to ocean warming. The fall intermonsoon was a transitional period, with some storm events but also with enough clear skies and sunlight that ocean surface temperature rose again. Mooring and shipboard observations are used to examine the ability of model-based surface fluxes to represent air-sea interaction in the Bay of Bengal; the model-based fluxes have significant errors. The surface forcing observed at 18°N is also used together with a one-dimensional ocean model to illustrate the potential for local air-sea interaction to drive upper-ocean variability in the Bay of Bengal

A multicentre, randomised, double-blind, single-dose study assessing the efficacy of AMC/DCBA Warm lozenge or AMC/DCBA Cool lozenge in the relief of acute sore throat

<p>Abstract</p> <p>Background</p> <p>Clinically proven over-the-counter (OTC) treatment options are becoming increasingly important in the self-management of acute sore throat. The aim of this study was to determine the analgesic and sensorial benefits of two different amylmetacresol/2,4-dichlorobenzyl alcohol (AMC/DCBA) throat lozenge formulation variants, AMC/DCBA Warm lozenge and AMC/DCBA Cool lozenge, compared with an unflavoured, non-medicated placebo lozenge in the relief of acute sore throat due to upper respiratory tract infections.</p> <p>Methods</p> <p>In this multicentre, randomised, double-blind, single-dose study, 225 adult patients with acute sore throat were randomly assigned to receive either one AMC/DCBA Warm lozenge (n = 77), one AMC/DCBA Cool lozenge (n = 74) or one unflavoured, non-medicated lozenge (matched for size, shape and demulcency; n = 74). After baseline assessments, patients received their assigned lozenge and completed four rating assessments at 11 timepoints from 1 to 120 minutes post dose. Analgesic properties were assessed by comparing severity of throat soreness and sore throat relief ratings. Difficulty in swallowing, throat numbness, functional, sensorial and emotional benefits were also assessed.</p> <p>Results</p> <p>Both the AMC/DCBA Warm and AMC/DCBA Cool lozenge induced significant analgesic, functional, sensorial and emotional effects compared with the unflavoured, non-medicated lozenge. Sore throat relief, improvements in throat soreness and difficulty in swallowing, and throat numbness were observed as early as 1-5 minutes, and lasted up to 2 hours post dose. Sensorial benefits of warming and cooling associated with the AMC/DCBA Warm and AMC/DCBA Cool lozenge, respectively, were experienced soon after first dose, and in the case of the latter, it lasted long after the lozenge had dissolved. Emotional benefits of feeling better, happier, less distracted and less frustrated were reported in those taking either of the AMC/DCBA throat lozenge variants, with no differences in adverse events compared with the unflavoured, non-medicated lozenge.</p> <p>Conclusions</p> <p>AMC/DCBA Warm and AMC/DCBA Cool lozenges are well-tolerated and effective OTC treatment options, offering functional, sensorial and emotional benefits to patients with acute sore throat, over and above that of the rapid efficacy effects provided.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN00003567">ISRCTN00003567</a></p

The effect of Neuragen PN® on Neuropathic pain: A randomized, double blind, placebo controlled clinical trial

<p>Abstract</p> <p>Background</p> <p>A double blind, randomized, placebo controlled study to evaluate the safety and efficacy of the naturally derived topical oil, "Neuragen PN^®" for the treatment of neuropathic pain.</p> <p>Methods</p> <p>Sixty participants with plantar cutaneous (foot sole) pain due to all cause peripheral neuropathy were recruited from the community. Each subject was randomly assigned to receive one of two treatments (Neuragen PN^®or placebo) per week in a crossover design. The primary outcome measure was acute spontaneous pain level as reported on a visual analog scale.</p> <p>Results</p> <p>There was an overall pain reduction for both treatments from pre to post application. As compared to the placebo, Neuragen PN^®led to significantly (p < .05) greater pain reduction. Fifty six of sixty subjects (93.3%) receiving Neuragen PN^®reported pain reduction within 30 minutes. This reduction within 30 minutes occurred in only twenty one of sixty (35.0%) subjects receiving the placebo. In a break out analysis of the diabetic only subgroup, 94% of subjects in the Neuragen PN^®group achieved pain reduction within 30 minutes vs 11.0% of the placebo group. No adverse events were observed.</p> <p>Conclusions</p> <p>This randomized, placebo controlled, clinical trial with crossover design revealed that the naturally derived oil, Neuragen PN^®, provided significant relief from neuropathic pain in an all cause neuropathy group. Participants with diabetes within this group experienced similar pain relief.</p> <p>Trial registration</p> <p><b>ISRCTN registered: </b>ISRCTN13226601</p

Mixing to monsoons: Air-sea interactions in the bay of Bengal

More than 1 billion people depend on rainfall from the South Asian monsoon for their livelihoods. Summertime monsoonal precipitation is highly variable on intraseasonal time scales, with alternating "active" and "break" periods. These intraseasonal oscillations in large-scale atmospheric convection and winds are closely tied to 1°C-2°C variations of sea surface temperature in the Bay of Bengal

How Do Bone Marrow Lesions Cause Osteoarthritis Pain? a Structural and Functional Tissue-Based Study

Background/Purpose: Susceptibility to ankylosing spondylitis (AS) is primarily genetic; thus far 113 susceptibility variants for AS have been identified. However, most of the AS associated SNPs do not directly affect protein-coding genes. Studies of disease- and trait-associated SNPs suggest they may act by affecting gene regulatory regions in specific cell types or tissues. Therefore, identifying the AS relevant cell types is crucial for further mechanistic studies. Methods: We applied several bioinformatics methods to utilize epigenetic, gene and protein expression information to identify the primary relevant cell types through which genetic variants associated with AS operate. In total, there are 113 AS associated loci; 39 of them show genome-wide significance in AS-only analyses, whereas the remainder are genome-wide significant in analyses leveraging pleiotrophy with other related diseases (Crohn’s disease (CD), psoriasis, primary sclerosing cholangitis (PSC) and ulcerative colitis (UC))1. Results: AS-associated SNPs are disproportionately found in regions bearing epigenetic marks indicating transcriptional activity found in immune cell types including monocytes, CD4+ and CD8+ T cells, NK cells, regulatory T cells, and B cells. Gene expression studies showed enrichment of AS associated loci in genes specifically expressed in monocytes and NK cells while protein expression study shows protein products of AS associated loci were significantly enriched in CD8+ T cells. Epigenetic analyses also showed evidence that AS-associated signals operate in gut cell types including in mucosa from the small intestine, sigmoid colon and rectum. These findings particularly relate to pleiotropic loci also associated with IBD, psoriasis, and PSC. Conclusion: These findings highlight the role of key immune cell types in the mechanism by which genetic associations with AS drive the disease, as well as providing further evidence for the involvement of the gut in the pathogenesis of AS. 1Ellinghaus D. at al, Nature Genetics 201

Does inter-vertebral range of motion increase after spinal manipulation? A prospective cohort study.

Background: Spinal manipulation for nonspecific neck pain is thought to work in part by improving inter-vertebral range of motion (IV-RoM), but it is difficult to measure this or determine whether it is related to clinical outcomes. Objectives: This study undertook to determine whether cervical spine flexion and extension IV-RoM increases after a course of spinal manipulation, to explore relationships between any IV-RoM increases and clinical outcomes and to compare palpation with objective measurement in the detection of hypo-mobile segments. Method: Thirty patients with nonspecific neck pain and 30 healthy controls matched for age and gender received quantitative fluoroscopy (QF) screenings to measure flexion and extension IV-RoM (C1-C6) at baseline and 4-week follow-up between September 2012-13. Patients received up to 12 neck manipulations and completed NRS, NDI and Euroqol 5D-5L at baseline, plus PGIC and satisfaction questionnaires at follow-up. IV-RoM accuracy, repeatability and hypo-mobility cut-offs were determined. Minimal detectable changes (MDC) over 4 weeks were calculated from controls. Patients and control IV-RoMs were compared at baseline as well as changes in patients over 4 weeks. Correlations between outcomes and the number of manipulations received and the agreement (Kappa) between palpated and QF-detected of hypo-mobile segments were calculated. Results: QF had high accuracy (worst RMS error 0.5o) and repeatability (highest SEM 1.1o, lowest ICC 0.90) for IV-RoM measurement. Hypo-mobility cut offs ranged from 0.8o to 3.5o. No outcome was significantly correlated with increased IV-RoM above MDC and there was no significant difference between the number of hypo-mobile segments in patients and controls at baseline or significant increases in IV-RoMs in patients. However, there was a modest and significant correlation between the number of manipulations received and the number of levels and directions whose IV-RoM increased beyond MDC (Rho=0.39, p=0.043). There was also no agreement between palpation and QF in identifying hypo-mobile segments (Kappa 0.04-0.06). Conclusions: This study found no differences in cervical sagittal IV-RoM between patients with non-specific neck pain and matched controls. There was a modest dose-response relationship between the number of manipulations given and number of levels increasing IV-RoM - providing evidence that neck manipulation has a mechanical effect at segmental levels. However, patient-reported outcomes were not related to this

Estimating the number needed to treat from continuous outcomes in randomised controlled trials: methodological challenges and worked example using data from the UK Back Pain Exercise and Manipulation (BEAM) trial

Background Reporting numbers needed to treat (NNT) improves interpretability of trial results. It is unusual that continuous outcomes are converted to numbers of individual responders to treatment (i.e., those who reach a particular threshold of change); and deteriorations prevented are only rarely considered. We consider how numbers needed to treat can be derived from continuous outcomes; illustrated with a worked example showing the methods and challenges. Methods We used data from the UK BEAM trial (n = 1, 334) of physical treatments for back pain; originally reported as showing, at best, small to moderate benefits. Participants were randomised to receive 'best care' in general practice, the comparator treatment, or one of three manual and/or exercise treatments: 'best care' plus manipulation, exercise, or manipulation followed by exercise. We used established consensus thresholds for improvement in Roland-Morris disability questionnaire scores at three and twelve months to derive NNTs for improvements and for benefits (improvements gained+deteriorations prevented). Results At three months, NNT estimates ranged from 5.1 (95% CI 3.4 to 10.7) to 9.0 (5.0 to 45.5) for exercise, 5.0 (3.4 to 9.8) to 5.4 (3.8 to 9.9) for manipulation, and 3.3 (2.5 to 4.9) to 4.8 (3.5 to 7.8) for manipulation followed by exercise. Corresponding between-group mean differences in the Roland-Morris disability questionnaire were 1.6 (0.8 to 2.3), 1.4 (0.6 to 2.1), and 1.9 (1.2 to 2.6) points. Conclusion In contrast to small mean differences originally reported, NNTs were small and could be attractive to clinicians, patients, and purchasers. NNTs can aid the interpretation of results of trials using continuous outcomes. Where possible, these should be reported alongside mean differences. Challenges remain in calculating NNTs for some continuous outcomes

The effect of initial local anesthetic dose with continuous interscalene analgesia on postoperative pain and diaphragmatic function in patients undergoing arthroscopic shoulder surgery: a double-blind, randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Interscalene block (ISB) is commonly performed using 20-40 mL of local anesthetic. Spread to adjacent structures and consequent adverse effects including paralysis of the ipsilateral hemidiaphragm are frequent. Pain ratings, analgesic requirements, adverse events, satisfaction, function and diaphragmatic excursion were compared following interscalene block (ISB) with reduced initial bolus volumes.</p> <p>Methods</p> <p>Subjects undergoing arthroscopic rotator cuff repair were randomized to receive 5, 10, or 20 mL ropivacaine 0.75% for ISB in a double-blind fashion (N = 36). Continuous infusion with ropivacaine 0.2% was maintained for 48 h. Pain and diaphragmatic excursion were assessed before block and in the recovery unit.</p> <p>Results</p> <p>Pain ratings in the recovery room were generally less than 4 (0-10 NRS) for all treatment groups, but a statistically significant difference was noted between the 5 and 20 mL groups (NRS: 2.67 vs. 0.62 respectively; p = 0.04). Pain ratings and supplemental analgesic use were similar among the groups at 24 h, 48 h and 12 weeks. There were no differences in the quality of block for surgical anesthesia. Dyspnea was significantly greater in the 20 mL group (p = 0.041). Subjects with dyspnea had significant diaphragmatic impairment more frequently (Relative risk: 2.5; 95%CI: 1.3-4.8; p = 0.042). Increased contralateral diaphragmatic motion was measured in 29 of the 36 subjects. Physical shoulder function at 12 weeks improved over baseline in all groups (baseline mean SST: 6.3, SEM: 0.6; 95%CI: 5.1-7.5; 12 week mean SST: 8.2, SEM: 0.46; 95%CI: 7.3-9.2; p = 0.0035).</p> <p>Conclusions</p> <p>ISB provided reliable surgical analgesia with 5 mL, 10 mL or 20 mL ropivacaine (0.75%). The 20 mL volume was associated with increased complaints of dyspnea. The 5 mL volume was associated with statistically higher pain scores in the immediate postoperative period. Lower volumes resulted in a reduced incidence of dyspnea compared to 20 mL, however diaphragmatic impairment was not eliminated. Compensatory increases in contralateral diaphragmatic movement may explain tolerance for ipsilateral paresis.</p> <p>Trial Registration</p> <p>clinicaltrials.gov. identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00672100">NCT00672100</a></p

Can cancer patients assess the influence of pain on functions? A randomised, controlled study of the pain interference items in the Brief Pain Inventory

BACKGROUND: The Brief Pain Inventory (BPI) is recommended as a pain measurement tool by the Expert Working Group of the European Association of Palliative Care. The BPI is designed to assess both pain severity and interference with functions caused by pain. The purpose of this study was to investigate if pain interference items are influenced by other factors than pain. METHODS: We asked adult cancer patients to complete the original and a revised BPI on two study days. In the original version of the BPI the patients were asked how, during the last 24 hours, pain has interfered with functions. In the revised BPI this question was changed to how, during the last 24 hours, these functions are affected in general. Heath related quality of life was assessed at both study days applying the European Organization for Research and Treatment of Cancer quality of life questionnaire. RESULTS: Forty-eight of the 55 included patients completed both assessments. The BPI pain intensities scores and the health related quality of life scores were similar at the two study days. Except for mood this study observed no significant distinctions between the patients' BPI interference items scores in the original (pain influence on function) and the revised BPI (function in general). Seventeen patients reported higher influence from pain on functions than the total influence on function from all causes. CONCLUSION: We observed similar scores in the original BPI interference scores (pain influence on function) compared with the revised BPI interference scores (decreased function in general). This finding might imply that the BPI interference scale measures are partly responded to as more of a global interference measure