Cold Dry Air Research Articles

引发甘肃白银市严重山洪地质灾害的暴雨过程分析

利用常规气象观测资料、自动站逐小时雨量、物理量、NCEP再分析资料和卫星云图等资料，对2011年5月28日发生在甘肃白银市的局地暴雨引发山洪天气过程进行诊断分析。结果表明：1)这次暴雨天气过程发生在西伯利亚冷涡东移的大尺度环流背景下，冷涡底部不断有分裂的冷槽携带干冷空气和西太平洋副热带高压西北侧的西南暖湿气流交汇，大气不稳定度增大，触发对流产生。2)700hpa低涡、切变线和850 hpa鞍形场环流配置，有利于耦合导致上升运动加强，触发不稳定能量的释放，成为暴雨天气的中尺度影响系统。3)散度场、涡度场、垂直速度场等物理量场的高低空配置和时空变化与暴雨过程的时空变化高度吻合。4)地面辐合线或干线是触发强对流天气的因子之一，对流单体一般生成于地面辐合线附近，在地面辐合线与干线结合处易于对流单体或云团的新生和发展。5)引发山洪的暴雨强度大，持续时间短，在卫星云图上表现为一个水平尺度200~400 km，云顶亮温最低为−80℃的中β尺度对流云团。6)山洪发生在地质条件脆弱区，不同的地质状况对应不同的灾害。 Based on the data of routine meteorological observation, hourly precipitation of automatic weather station and NCEP reanalysis data, the local rainstorm in Baiyin of Gansu province on 28 May 2011 was analyzed. The results show that this rainstorm occurred on large scale circulation background of the Siberia cold vortex moved eastward; the dry cold air which constantly split from the bottom of the cold vortex converged with southwest airflow of warm; the atmospheric instability increased that triggered convective weather. The meso-scale influential systems of this rainstorm were vortex and shear line of 700 hPa and saddle type of 850 hPa. This circulation pattern was beneficial to strengthen ascending movement and trigger off instability energy releasing. The allocation at different heights and temporal and spatial variation of physical field was consistent with the rainstorm. Surface convergence line was one of triggering factors contributed to convection. The convection cells were easily formed near the joint of surface convergence line and dry line. The characteristics of rainstorm which caused mountain torrent geology disaster were high intensity and short duration. There was a meso-β-scale convective cloud cluster in satellite cloud image. Its horizontal scale was 200 - 400 km and the minimum of TBB was −80˚C. The mountain torrent occurred in the geological conditions of vulnerable areas, different geological conditions can form different disasters.

An analysis of an extreme rainstorm caused by the interaction of the Tibetan Plateau vortex and the Southwest China vortex from an intensive observation

A rainstorm caused by the coupling of the Tibetan Plateau vortex (TPV) and the Southwest China vortex (SWCV) in eastern Sichuan during 29 June–2 July 2013 is analyzed by using the conventional observed data and its time intensive observed data, the intensive observed data of SWCV scientific experiment during flood season. The results show that under the control of a large transverse trough in Eurasia region at mid-high latitude, the westerly flow in northern China leads TPV eastward movement. And SWCV moves northeastward. Finally, both of them merge to form a combined vortex (CBV) in Sichuan Basin resulting in heavy rainfall. The water vapor from both the Bay of Bengal and the South China Sea provides the sufficient humidity condition. The intensive observation clearly reveals the nascent states of TPV and SWCV, the movements and interactions, especially, the two vortices' merging process, and the effects of cold and warm advection, as well as the rainstorm. When the two vortices merge into CBV, cold tongue and warm flow meet and produce frontogenesis around the center of CBV. A frontogenetical area exists deeply from lower troposphere to upper troposphere with the south-positive and north-negative vertical structure, which is similar to front. The positive PV evidently developed both in the range and in the intensity with the stronger center at upper level, and the positive PV center located at the front of CBV has indicative significance for the vortex’s activities. And CBV has the same distributions of vorticity and temperature with SWCV and TPV, respectively. SWCV and TPV make different key contributions to the dynamic–thermodynamic property of CBV, but both of them have obvious influences on the divergence distribution of CBV. Furthermore, rainfall mainly distributes in the high areas of averaged temperature deviation gradient, and it is closely related to the joint influences of warm-moist air from the south and dry-cold air from the north. But, only using the conventional observed data, it is difficult to obtain the above useful understanding. So, augmenting intensive observation, improving scientific experiment, and focusing on fine study are much conducive for the meso-scale and small-scale weather systems such as SWCV and TPV, as well as its weather influences.

Effectiveness of 5-Pyrrolidone-2-Carboxylic Acid and Copper Sulphate (Pirometaxine) in Cold Dry Air Induced Rhinitis with or without Viral Superinfection

Introduction: Exposure to cold dry air can determine rhinitis-like symptoms. 5-Pyrrolidone- 2-Carboxylic acid (PCA) and Copper Sulphate (CS) showed antiviral and osmoprotectant ef- fect. Aim of this study is evaluation of effectiveness of 5-Pyrrolidone-2-Carboxylic acid (PCA) and Copper Sulphate pentahydrate (CS) (Pirometaxine) association in the treatment of cold dry air rhinitis with or without viral infection. Methods: Fifty consecutive adult patients affected by cold dry air rhinitis with or without viral/ bacterial infection were enrolled in this prospective observational study and treated with pyro- glutamic acid (PCA) plus copper sulphate (CS) (pirometaxine). All patients underwent an ob- jective evaluation with optic fiber endoscopy and symptoms assessment at time of enrolment, after 3 and 7 days of treatment. Results: All symptoms scores decreased at 3 and 7 days with a mean Total Symptoms Score of 5.98±2.22 and 1.30±1.23, respectively. Twenty-seven patients (54%) reached a Total Symp- toms Score of zero after 7 days. Median number of days until healing was 6. Only 18% of cases had turbinate hypertrophy and 10% nasal mucosa hyperaemia after 7 days. Main side effects were nasal itch in 4 cases (8%) and nasal burning in one case (2%). Conclusions: The association of 5-Pyrrolidone-2-carboxylic acid and copper sulphate (piro- metaxine) represent a safe treatment for CDA-induced rhinitis with or without viral infection, with few side effects. Clinical importance of this therapy will be better understood with further studies, comparing results to those observed in a control group.

Whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults.

Recovery strategies are often used with the intention of preventing or minimising muscle soreness after exercise. Whole-body cryotherapy, which involves a single or repeated exposure(s) to extremely cold dry air (below -100 °C) in a specialised chamber or cabin for two to four minutes per exposure, is currently being advocated as an effective intervention to reduce muscle soreness after exercise. To assess the effects (benefits and harms) of whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, the British Nursing Index and the Physiotherapy Evidence Database. We also searched the reference lists of articles, trial registers and conference proceedings, handsearched journals and contacted experts.The searches were run in August 2015. We aimed to include randomised and quasi-randomised trials that compared the use of whole-body cryotherapy (WBC) versus a passive or control intervention (rest, no treatment or placebo treatment) or active interventions including cold or contrast water immersion, active recovery and infrared therapy for preventing or treating muscle soreness after exercise in adults. We also aimed to include randomised trials that compared different durations or dosages of WBC. Our prespecified primary outcomes were muscle soreness, subjective recovery (e.g. tiredness, well-being) and adverse effects. Two review authors independently screened search results, selected studies, assessed risk of bias and extracted and cross-checked data. Where appropriate, we pooled results of comparable trials. The random-effects model was used for pooling where there was substantial heterogeneity. We assessed the quality of the evidence using GRADE. Four laboratory-based randomised controlled trials were included. These reported results for 64 physically active predominantly young adults (mean age 23 years). All but four participants were male. Two trials were parallel group trials (44 participants) and two were cross-over trials (20 participants). The trials were heterogeneous, including the type, temperature, duration and frequency of WBC, and the type of preceding exercise. None of the trials reported active surveillance of predefined adverse events. All four trials had design features that carried a high risk of bias, potentially limiting the reliability of their findings. The evidence for all outcomes was classified as 'very low' quality based on the GRADE criteria.Two comparisons were tested: WBC versus control (rest or no WBC), tested in four studies; and WBC versus far-infrared therapy, also tested in one study. No studies compared WBC with other active interventions, such as cold water immersion, or different types and applications of WBC.All four trials compared WBC with rest or no WBC. There was very low quality evidence for lower self-reported muscle soreness (pain at rest) scores after WBC at 1 hour (standardised mean difference (SMD) -0.77, 95% confidence interval (CI) -1.42 to -0.12; 20 participants, 2 cross-over trials); 24 hours (SMD -0.57, 95% CI -1.48 to 0.33) and 48 hours (SMD -0.58, 95% CI -1.37 to 0.21), both with 38 participants, 2 cross-over studies, 1 parallel group study; and 72 hours (SMD -0.65, 95% CI -2.54 to 1.24; 29 participants, 1 cross-over study, 1 parallel group study). Of note is that the 95% CIs also included either no between-group differences or a benefit in favour of the control group. One small cross-over trial (9 participants) found no difference in tiredness but better well-being after WBC at 24 hours post exercise. There was no report of adverse events.One small cross-over trial involving nine well-trained runners provided very low quality evidence of lower levels of muscle soreness after WBC, when compared with infrared therapy, at 1 hour follow-up, but not at 24 or 48 hours. The same trial found no difference in well-being but less tiredness after WBC at 24 hours post exercise. There was no report of adverse events. There is insufficient evidence to determine whether whole-body cryotherapy (WBC) reduces self-reported muscle soreness, or improves subjective recovery, after exercise compared with passive rest or no WBC in physically active young adult males. There is no evidence on the use of this intervention in females or elite athletes. The lack of evidence on adverse events is important given that the exposure to extreme temperature presents a potential hazard. Further high-quality, well-reported research in this area is required and must provide detailed reporting of adverse events.

Seasonal differences in climate in the Chianti region of Tuscany and the relationship to vintage wine quality.

Climatic factors and weather type frequencies affecting Tuscany are examined to discriminate between vintages ranked into the upper- and lower-quartile years as a consensus from six rating sources of Chianti wine during the period 1980 to 2011. These rankings represent a considerable improvement on any individual publisher ranking, displaying an overall good consensus for the best and worst vintage years. Climate variables are calculated and weather type frequencies are matched between the eight highest and the eight lowest ranked vintages in the main phenological phases of Sangiovese grapevine. Results show that higher heat units; mean, maximum and minimum temperature; and more days with temperature above 35°C were the most important discriminators between good- and poor-quality vintages in the spring and summer growth phases, with heat units important during ripening. Precipitation influences on vintage quality are significant only during veraison where low precipitation amounts and precipitation days are important for better quality vintages. In agreement with these findings, weather type analysis shows good vintages are favoured by weather type 4 (more anticyclones over central Mediterranean Europe (CME)), giving warm dry growing season conditions. Poor vintages all relate to higher frequencies of either weather type 3, which, by producing perturbation crossing CME, favours cooler and wetter conditions, and/or weather type 7 which favours cold dry continental air masses from the east and north east over CME. This approach shows there are important weather type frequency differences between good- and poor-quality vintages. Trend analysis shows that changes in weather type frequencies are more important than any due to global warming.

Bernoulli’s Equation with Acceleration

For steady frictionless flow along a straight line, when a constant acceleration is applied parallel to that line, a term needs to be added to the standard form of Bernoulli’s equation. After so modifying, the equation then predicts that along a streamline, when the speed is high, the pressure is significantly lower than that if there were no acceleration. For example, one might think of a dense fluid falling down through a less dense fluid under gravity. Potential applications to vertical motions of the atmosphere, such as down bursts of cold dry air and warm humid updrafts in the eye of a hurricane, are mentioned.

Analysis of Gale Process Caused by an Explosive Cyclone

An uncommon explosive cyclone as well as the gale process was studies. It is found that: The development of explosive cyclone attribute to the high-level divergence area caused by the upper jet adjustment superimposed on cyclone,the low-level vorticity transport accompanied by dry cold air next to the rear of cyclone,and the latent heat released by the 850 h Pa southwest jet and the warm flows on west side of the cyclone. Meanwhile,high potential vorticity at the high level also promote the rapid development of the cyclone at the initial stage. The third quadrant of the cyclone gale pass by the momentum to trigger strong convection and the formation of the wind speed superimposed resulting in the gale. The low-level northwest air currents with off the water vapor source result in the rainfall decrease. The gale will appear at the area which overlap between shear line on lowlevel and high convective available potential energy( CAPE) in the next 1 ~ 2 h. There has a significant indicating for prediction.

Developing and Emerging Clinical Asthma Phenotypes

For more than a century, clinicians have attempted to subdivide asthma into different phenotypes based on triggers that cause asthma attacks, the course of the disease, or the prognosis. The first phenotypes that were described included allergic asthma, intrinsic or nonallergic asthma, infectious asthma, and aspirin-exacerbated asthma. These phenotypes are being reviewed elsewhere in this issue of the journal. The present article focuses on developing and emerging clinical asthma phenotypes. First, asthma phenotypes that are associated with environmental exposures (occupational agents, cigarette smoke, air pollution, cold dry air); second, asthma phenotypes that are associated with specific symptoms or clinical characteristics (cough, obesity, adult onset of disease); and third, asthma phenotypes that are based on biomarkers. This latter approach is the most promising because it attempts to identify asthma phenotypes with different underlying mechanisms so that therapies can be better targeted toward disease-specific features and disease outcomes can be improved.

Climatological characteristics of fronts in the western North Pacific based on surface weather charts

AbstractComposite front climatology in the western North Pacific is determined using a newly developed 1.0° gridded data set. Here we propose a research strategy for determining the spatiotemporal distribution of fronts using weather chart images published by the Japan Meteorological Agency, one of the major data providers in the region. A preliminarily investigation of the internal data characteristics for the period of 2000–2010 is undertaken, and the final 4 years of data are used for an analysis of front climatology to avoid the effect of any spurious trends. This enables in‐depth analyses to be conducted, which have not previously been possible in the region, including the composites of cross‐sectional patterns for the thermal fields and precipitation near fronts, front length seasonality, and the significance of the thermal gradient near the fronts, in addition to determining the frontal frequency and spatial distribution of frontal precipitation. Pixel‐wise analysis reveals that 56% of the local precipitation maximum is located on the warm side of a cold front caused by less tilted upward motion on the warm side, with the intrusion of the upper level cold dry air into the warm side. This new data set also enables a further analysis of the occluded fronts, which are not correctly distinguished in the existing objective detection method.

TRPV1 inhibition does not prevent cold dry air-elicited symptoms in non-allergic rhinitis

The transient receptor potential vanilloid 1 (TRPV1)-expressing sensory C-fibers may play a role in the development of nasal hyper-responsiveness and symptoms of non-allergic rhinitis (NAR). To evaluate the effects of a TRPV1-antagonist, SB-705498, on cold dry air (CDA)-induced symptoms in patients with NAR. This randomized, double-blind, placebo-controlled, crossover study evaluated 14 days of once daily, topical intranasal SB-705498 12 mg in 40 patients with NAR using a CDA challenge experimental model in an environmental exposure chamber (EEC, Cetero Research, Mississauga, Ontario). The primary endpoint was total symptom score (TSS), expressed as weighted mean over 60 minutes (WM0-60) or maximum TSS at 1 hour and 24 hours postdosing. Treatment with SB-705498, relative to placebo, did not improve WM0-60 or maximum TSS at 1 hour and 24 hours post-dosing on days 1 or 14. Mean (95% CI) treatment differences (SB-705498 - placebo) on day 14 were, for WM0-60 at 1 hour: -0.12 (-0.60, 0.36); for maximum TSS at 1 hour: -0.03 (-0.58, 0.51). SB-705498 had no impact on any other efficacy parameters. SB-705498 was well tolerated and pharmacokinetics analysis supported the dosing regimen. SB-705498 12 mg for 14 days did not alleviate the CDA-induced symptoms of NAR. Despite engagement of the TRPV1 receptor, there was no translation to clinical efficacy, suggesting redundancy in symptom pathways.

Strong Downslope Wind Events in Ammassalik, Southeast Greenland

Abstract Ammassalik in southeast Greenland is known for strong wind events that can reach hurricane intensity and cause severe destruction in the local town. Yet, these winds and their impact on the nearby fjord and shelf region have not been studied in detail. Here, data from two meteorological stations and the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim) are used to identify and characterize these strong downslope wind events, which are especially pronounced at a major east Greenland fjord, Sermilik Fjord, within Ammassalik. Their local and regional characteristics, their dynamics and their impacts on the regional sea ice cover, and air–sea fluxes are described. Based on a composite of the events it is concluded that wind events last for approximately a day, and seven to eight events occur each winter. Downslope wind events are associated with a deep synoptic-scale cyclone between Iceland and Greenland. During the events, cold dry air is advected down the ice sheet. The downslope flow is accelerated by gravitational acceleration, flow convergence inside the Ammassalik valley, and near the coast by an additional thermal and synoptic-scale pressure gradient acceleration. Wind events are associated with a large buoyancy loss over the Irminger Sea, and it is estimated that they drive one-fifth of the net wintertime loss. Also, the extreme winds drive sea ice out of the fjord and away from the shelf.

Capsaicin treatment reduces nasal hyperreactivity and transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) overexpression in patients with idiopathic rhinitis

Idiopathic rhinitis (IR) is a prevalent condition for which capsaicin nasal spray is the most effective treatment. However, the mechanisms underlying IR and the therapeutic action of capsaicin remain unknown. We sought to investigate the molecular and cellular bases of IR and the therapeutic action of capsaicin. Fourteen patients with IR and 12 healthy control subjects (HCs) were treated with intranasal capsaicin. The therapeutic effect was assessed in patients with IR by using visual analog scale and therapeutic response evaluation scores, and nasal hyperreactivity was evaluated by means of cold dry air provocation. Nasal samples served to measure the levels of neuromediators and expression of chemosensory cation channels, protein gene product 9.5 (PGP 9.5), and the mast cell marker c-kit. The effects of capsaicin were also tested in vitro on human nasal epithelial cells and mast cells. Patients with IR had higher baseline transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) expression in the nasal mucosa and higher concentrations of substance P (SP) in nasal secretions than HCs. Symptomatic relief was observed in 11 of 14 patients with IR after capsaicin treatment. Expression of TRPV1; transient receptor potential cation channel subfamily M, receptor 8 (TRPM8); and PGP 9.5 was only reduced in patients with IR after capsaicin treatment. Capsaicin did not alter c-KIT expression or nasal epithelial morphology in patients with IR and HCs nor did it induce apoptosis or necrosis in cultured human nasal epithelial cells and mast cells. IR features an overexpression of TRPV1 in the nasal mucosa and increased SP levels in nasal secretions. Capsaicin exerts its therapeutic action by ablating the TRPV1-SP nociceptive signaling pathway in the nasal mucosa.

Nasal hyper-reactivity is a common feature in both allergic and nonallergic rhinitis

Nasal hyper-reactivity is an increased sensitivity of the nasal mucosa to various nonspecific stimuli. Both allergic rhinitis (AR) and nonallergic rhinitis (NAR) patients can elicit nasal hyper-reactivity symptoms. Differences in the prevalence or type of nasal hyper-reactivity in AR and NAR patients are largely unknown. In this study, we quantitatively and qualitatively assessed nasal hyper-reactivity in AR and NAR. In the first part, an analysis of a prospectively collected database was performed to reveal patient-reported symptoms of hyper-reactivity. In the second part, cold dry air provocation (CDA) was performed as a hyper-reactivity measure in AR and NAR patients and healthy controls, and symptoms scores, nasal secretions and peak nasal inspiratory flow were measured. Comparisons were made between AR and NAR patients in both studies. The database analysis revealed high hyper-reactivity prevalence in AR (63.4%) and NAR (66.9%). There were no differences between AR and NAR in terms of the number or type of hyper-reactivity stimuli. Hyper-reactivity to physical stimuli did not exclude a response to chemical stimuli, or vice versa. CDA provocation resulted in a significant increase in rhinitis symptoms and the amount of nasal secretions in AR and NAR patients, but not in controls. We found no quantitative or qualitative differences in nasal hyper-reactivity between AR and NAR patients. It is not possible to differentiate NAR subpopulations based on physical or chemical stimuli.

Tonic stimulation of the pharyngeal mucosa causes pain and a reversible increase of inflammatory mediators

Objective and design To develop a model of the inflammatory component of non-infectious sore throat using tonic stimulation and quantification of inflammatory mediators in pharyngeal lavage fluid.Material or subjectsForty-five healthy volunteers.TreatmentCold dry air.MethodTonic stimulation of the pharynx was achieved using a constant stream of cold dry air to the back of the throat. Following optimization of stimulation conditions (phase 1), pharyngeal pain, irritation, and swallowing discomfort were assessed using visual analog scales, and the concentration of inflammatory markers were measured in pharyngeal lavage fluid (phase 2).ResultsOptimum conditions for tonic pharyngeal stimulation were cold dry air at 12 °C, relative humidity 20 %, at a flow rate of 12 L/min for 15 min. Analysis of pharyngeal lavage fluid collected 5 min after stimulation showed significant increases in prostaglandin E2 (P = 0.018), thromboxane B2 (P < 0.001), and substance P (P < 0.001), but no increase in peptidoleukotriene. When the stimulus was removed, the level of inflammatory markers in pharyngeal lavage fluid returned to baseline by 30 min post-stimulation. These objective measures mirrored subjective pain ratings.ConclusionsTonic stimulation of the pharyngeal mucosa with cold dry air causes pain and an increase of inflammatory mediators which are reversible.Electronic supplementary materialThe online version of this article (doi:10.1007/s00011-013-0663-7) contains supplementary material, which is available to authorized users.

Transient Non-Suppressible Cough at Altitude Occurring With Cessation of Exercise

The aim of this report is to describe two subjects with an uncontrollable dry cough that occurred at altitude immediately after cessation of intense exercise; the cough occurred at 5 - 15 second intervals and resolved in 20-30 min with rest or a reduced level of exercise. The presence of cough did not foreshadow an increased risk of acute mountain sickness (AMS) or high altitude pulmonary edema (HAPE) and, in a third subject, was observed to occur at sea level. Its etiology is uncertain but it is probably not related to the cold dry air at altitude, bronchoconstriction, respiratory tract infection, AMS, vasomotor rhinitis or water loss from the respiratory tract. A plausible hypothesis is a transient overload of normal physiologic processes resulting from an imbalance between the increased production of transpulmonary filtrate due to elevated pulmonary artery pressures from intense exercise and hypoxia combined with a sudden reduction in the rate of lymph clearance due to the decrease in hyperpnea following the abrupt cessation of intense exercise. Clinical pulmonary edema results from a breakdown of normal homeostatic processes for removal of interstitial fluid; for individuals in this report, normal homeostatic processes were still operative. Regardless of the mechanism, this syndrome appears to be benign and when it occurs at altitude, it does not imply an increased risk of AMS or HAPE, does not require treatment and does not necessitate a restriction in activity or a prohibition against higher ascent. J Med Cases. 2013;4(5):323-326 doi: https://doi.org/10.4021/jmc1250e

Nasal Provocation Test Using Allergen Extract versus Cold Dry Air Provocation Test: Which and When?

Nasal provocation tests (NPTs) are useful for evaluation of patients with allergic rhinitis. The cold dry air (CDA) provocation test is useful for evaluation of patients with nonspecific nasal hyperreactivity (NHR). This study aimed to determine whether the NPT or CDA provocation would be more useful for patients with different clinical pictures. We evaluated changes in nasal symptoms (visual analog scale [VAS]) and acoustic parameters after NPT or CDA provocation in healthy volunteers (group A, n = 27), patients with allergic rhinitis (group B, n = 20), and subjects with nonallergic rhinitis (group C, n = 26). According to their subjective cold hyperresponsiveness (SCH), we compared changes in VAS and acoustic parameters after each protocol. The correlation between results of the skin-prick test (SPT) and changes in VAS after each protocol was analyzed. Finally, we performed an analysis of correlation between NPT and CDA provocation. After NPT, group B showed a larger change in VAS for rhinorrhea, sneezing, and itching (p < 0.01). After CDA challenge, the change in VAS for nasal obstruction was larger in group C (p < 0.05). Changes in acoustic parameters were larger in groups B and C after NPT (p < 0.01). After CDA challenge, the SCH(+) group (n = 49) showed a larger decrease of acoustic parameters than the SCH(-) group (n = 24; p < 0.01). Significant correlation was observed between the size of SPT and degree of change in VAS after NPT. No significant correlation was observed between NPT and CDA. CDA could be an adjunct tool for evaluating NHR in patients with self-reported SCH.

Transient Non-Suppressible Cough at Altitude Occurring With Cessation of Exercise

The aim of this report is to describe two subjects with an uncontrollable dry cough that occurred at altitude immediately after cessation of intense exercise; the cough occurred at 5 - 15 second intervals and resolved in 20-30 min with rest or a reduced level of exercise. The presence of cough did not foreshadow an increased risk of acute mountain sickness (AMS) or high altitude pulmonary edema (HAPE) and, in a third subject, was observed to occur at sea level. Its etiology is uncertain but it is probably not related to the cold dry air at altitude, bronchoconstriction, respiratory tract infection, AMS, vasomotor rhinitis or water loss from the respiratory tract. A plausible hypothesis is a transient overload of normal physiologic processes resulting from an imbalance between the increased production of transpulmonary filtrate due to elevated pulmonary artery pressures from intense exercise and hypoxia combined with a sudden reduction in the rate of lymph clearance due to the decrease in hyperpnea following the abrupt cessation of intense exercise. Clinical pulmonary edema results from a breakdown of normal homeostatic processes for removal of interstitial fluid; for individuals in this report, normal homeostatic processes were still operative. Regardless of the mechanism, this syndrome appears to be benign and when it occurs at altitude, it does not imply an increased risk of AMS or HAPE, does not require treatment and does not necessitate a restriction in activity or a prohibition against higher ascent. J Med Cases. 2013;4(5):323-326 doi: https://doi.org/10.4021/jmc1250e

Fraction of Exhaled Nitric Oxide and Bronchial Responsiveness Are Associated and Continuous Traits in Young Children Independent of Asthma

Elevated fraction of exhaled nitric oxide (FENO) and bronchial hyperresponsiveness are used as surrogate markers of asthma. These traits may be continuous in the population. The objective of this study was to investigate whether FENO and bronchial responsiveness are associated in both children with and children without a history of asthma symptoms. One hundred ninety-six 6-year-old children with no asthma symptoms, intermittent asthma symptoms, and persistent asthma were randomly included from the Copenhagen Prospective Study on Asthma in Childhood prospective clinical birth cohort of mothers with asthma. Bronchial responsiveness was assessed as the relative change in specific airway resistance after cold dry air hyperventilation. FENO measurements were performed prior to the hyperventilation test. The association between FENO and bronchial responsiveness was assessed by generalized linear models. Bronchial responsiveness and FENO exhibited a significant and linear association in the population. A doubling of FENO corresponded to an 8.4% (95% CI, 3.7%-13.1%; P = .0006) increase in airway resistance after challenge testing and remained significant after adjustment for sex, allergic rhinitis, current asthma, inhaled corticosteroid treatment, and upper respiratory tract infections prior to testing. Stratified analyses showed similar associations in children with and without asthma. FENO and bronchial responsiveness are associated and continuous traits in young children regardless of asthma symptoms, suggesting a continuous subclinical to clinical process underlying asthma. The findings also suggest caution against the use of these surrogate markers for a dichotomized approach to asthma diagnosis.

P154 TRPV1 is not a Target for the Treatment of non-allergic Rhinitis: A Clinical Study

BackgroundTRPV1 is a ligand gated ion channel activated by a range of physiological factors such at Temperature, pH, and osmotic stress. In the nose, the TRPV1-expressing sensory c-fibres are thought...

Some aspects of squall over Indira Gandhi International airport, New Delhi

A study is undertaken to analyse the characteristics of squall over Delhi and to find out the potential precursors for its prediction. For this purpose, the squall data of Indira Gandhi International (IGI) airport along with the surface and upper air meteorological parameters recorded by India Meteorological Department have been considered for all individual months over the period of 2001-2010. Apart from the characteristics like period of occurrence, intensity, duration, frequency and nature of squall, the environmental changes due to squall and thermodynamic features and indices leading to squall have been analysed.&#x0D; Higher than normal warming of lower troposphere upto 700 hPa level in March, April &amp; June and at 925 hPa in May accompanied with cold dry air advection leading to lower than normal dew point in middle and upper levels (500-300 hPa in March, May and June, 400-300 hPa in April) are favourable for occurrence of the squall over Delhi. The lower level inversion in March and April only also helps in the occurrence of squall. In monsoon months of July- September, cold and dry air advection in middle and upper tropospheric levels (8- 15° C below normal dew point at 400-300 hPa in July, about 15° C below normal dew point at 300-200 hPa in August and 17- 24° C below normal dew point at 500-300 hPa in September) favours occurrence of squall over Delhi. Unlike pre-monsoon months lower level moisture does not play any role for the occurrence of squall over Delhi in monsoon months. Significantly higher than normal SWEAT index in March to September at 0000 UTC can be used as predictor of squall over Delhi on that day. Total totals index is the next suitable precursor for all the months except June.