bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Antihistamines on Innate Immune Responses to Severe Bacterial Infection in Mice
Authors: Metz Martin , Doyle Elizabeth , Bindslev-Jensen Carsten , Watanabe Takeshi , Zuberbier Torsten , Maurer Marcus
Published: February 2011

Background: Sedating and non-sedating histamine H1 receptor (H1R) antagonists and H2R blockers are widely used drugs which are generally considered to be safe medications. However, recently, these drugs have been shown to possibly impair the outcome of perforating appendicitis in children. Objective: It was the aim of this study to characterize the effects of histamine receptor blockade in severe bacterial infections in more detail. Methods: To obtain information on the safety of histamine receptor blockade in more detail, we used pharmacological and genetic approaches targeting histamine receptors and performed cecal ligation and puncture (CLP), a mouse model of septic peritonitis. After induction of septic peritonitis, morbidity and mortality were monitored closely. Results: Here, we show that oral treatment with first-generation H1R antihistamine diphenhydramine, H2R blocker cimetidine and H3/4R blocker thioperamide impairs optimal innate immune responses in severe murine bacterial sepsis. However, these adverse effects are not mediated by H1R, as mice deficient for H1R show similar rates of morbidity and mortality after CLP as their wild-type controls. Similarly, the second-generation antihistamine desloratadine neither affects morbidity nor mortality after CLP. Conclusion: Our findings indicate that sedating first-generation H1R antihistamines and H2R blockers might impair innate immune responses to bacteria and that these drugs should be used with caution in patients with severe bacterial infections.
Caffeine and Creatine Use in Sport
Authors: Tarnopolsky Mark A.
Published: February 2011

Background/Aims: Caffeine and creatine are 2 of the most widely available and used compounds in sport. Although the use of either is not considered a doping infraction, the evidence does suggest ergogenic potential in certain sports. The purpose of this paper is to review the pharmacology and potential mechanism(s) of action of caffeine and creatine as they pertain to possible use as an ergogenic aid in sport. Methods: Previous review articles on caffeine and creatine use in sport were screened for relevant information and references, and studies for review and recent articles (2007 onwards) were obtained and reviewed using a PUBMED search with the terms ‘caffeine AND exercise’, ‘creatine and creatine monohydrate AND exercise’, and appropriate linked articles were evaluated. Results: Caffeine taken before (3–6 mg/kg) or during (1–2 mg/kg) endurance exercise enhances performance, through central nervous system and direct muscle effects. Creatine monohydrate supplementation at higher (approx. 20 g/day × 3–5 days) or lower (approx. 5 g/day × 30 days) doses increases skeletal muscle total and phosphocreatine by 10–20%. Creatine supplementation appears to minimally but significantly enhance high-intensity sport performance and the mass and possibly strength gains made during resistance exercise training over the first few months. Conclusions: Although caffeine and creatine appear to be ergogenic aids, they do so in a sport-specific context and there is no rationale for their simultaneous use in sport. Higher doses of caffeine can be toxic and appear to be ergolytic. There is no rationale for creatine doses in excess of the recommendations, and some athletes can get stomach upset, especially at higher creatine doses.
Exercise, Appetite and Appetite-Regulating Hormones: Implications for Food Intake and Weight Control
Authors: Stensel David
Published: February 2011

Knowledge about the relationship between exercise and appetite is important both for athletes wishing to optimise performance and for those interested in maintaining a healthy body weight. A variety of hormones are involved in appetite regulation including both episodic hormones, which are responsive to episodes of feeding, and tonic hormones, which are important regulators of energy storage over the longer term (e.g. insulin and leptin). Notable among the episodic appetite-regulating hormones is ghrelin, which plays a unique role in stimulating appetite and energy intake. Many studies have demonstrated that acute bouts of moderately vigorous exercise transiently suppress appetite and this has been termed ‘exercise-induced anorexia’. The mechanisms by which acute exercise suppresses appetite are not fully understood but may involve lowered concentrations of ghrelin and increased concentrations of satiety hormones, notably peptide YY and glucagon-like peptide 1. Evidence suggests that chronic exercise training typically causes a partial but incomplete compensation in energy intake perhaps due to beneficial changes in appetite-regulating hormones. The lack of a full compensatory response of appetite to exercise may facilitate the development of a negative energy balance and weight loss although there is individual variability in the response to exercise. From a practical standpoint athletes should not feel concerned that exercise will cause overeating as there is limited evidence to support this. For those desiring weight loss there may be some merit in performing exercise in the postprandial period as a means of enhancing the satiating effect of a meal but additional evidence is required to confirm the effectiveness of this strategy.
Density of Demodex folliculorum in Patients Receiving Epidermal Growth Factor Receptor Inhibitors
Authors: Gerber Peter A. , Kukova Gabriela , Buhren Bettina A. , Homey Bernhard
Published: February 2011

Background: Rosacea-like papulopustular eruptions (rash) are considered the most frequent toxicities associated with the use of inhibitors of the epidermal growth factor receptor (EGFR). Recently, evidence has been accumulating of infectious complications in patients suffering from these adverse effects. Objective: We sought to analyze the density of Demodex folliculorum (DF) in cutaneous lesions of patients presenting with EGFR-inhibitor (EGFRI)-induced rashes. Methods: This is a retrospective study of 19 adult patients presenting with EGFRI rashes. Patients were reviewed for the density of DF (Demodex density, Dd; mites per square centimeter) by standardized skin surface biopsy. Results: In our patient collective the mean Dd of 4.7/cm2 significantly exceeded the mean Dd reported for the healthy adult population (Dd = 0.7/cm2). Limitations: The retrospective nature of the study. Conclusions: EGFRI patients have an increased susceptibility to DF colonization or infection, respectively. Our results support the recent concept that EGFRI may induce an impairment of antimicrobial defense mechanisms.
The Essen Stroke Risk Score in One-Year Follow-Up Acute Ischemic Stroke Patients
Authors: Fitzek Sabine , Leistritz Lutz , Witte Otto W. , Heuschmann Peter U. , Fitzek Clemens
Published: February 2011

Background and Purpose: We aimed to validate the usefulness of the Essen Stroke Risk Score (ESRS) to predict stroke recurrence in a hospital-based follow-up study. Methods: We followed up 730 consecutive patients admitted to a neurological stroke unit in Berlin, Germany, with ischemic stroke (IS) or transient ischemic attack (TIA). The mean follow-up time was 13.4 months (SD 5.9). We calculated the time of event-free survival by Kaplan-Meier estimates. Results: The cumulative rate of a recurrent stroke was 10.4% (76 of 730). The risk of a recurrent stroke was significantly higher in patients with an ESRS >2 (p = 0.01; log rank). The area under the curve (AUC) was 0.59. The risk of a vascular event (VE), defined as a fatal or nonfatal IS or myocardial infarction, was significantly higher in patients with an ESRS >2 (p = 0.003; log rank). The AUC was 0.58. Stratifying the data at exact 1-year follow-up, 9 of 185 (10.3%) patients with an ESRS ≤2 suffered a recurrent stroke, while 56 of 311 (18%) patients with an ESRS >2 did so (p < 0.02; χ2). Thirty-six of 196 (18.4%) patients with an ESRS ≤2 suffered a VE, while 156 of 353 (35.7%) patients with an ESRS >2 did so (p < 0.001; χ2). Conclusions: The ESRS identifies groups of patients with TIA or IS who are at significantly increased risk for a recurrent stroke and cardiovascular event. Patients with a high ESRS require short-term follow-up and reevaluation of secondary prevention strategies.
Olopatadine Hydrochloride Inhibits Capsaicin-Induced Flare Response in Humans
Authors: Shindo Masahisa , Yoshida Yuichi , Yamamoto Osamu
Published: February 2011

Capsaicin, a vanilloid, has the potential for releasing substance P (SP) from sensory nerves. Topical application of capsaicin induces a flare response in the skin. However, it has not been clarified whether the release of SP is involved in the process of flare response or not. A potent antihistamine drug, olopatadine hydrochloride, is known to have inhibitory action against the release of SP. We examined the effects of olopatadine (at a dose of 5 mg) on skin reaction induced by topical application of capsaicin in 10 healthy subjects. The scores of capsaicin-induced flare responses after olopatadine administration were significantly lower at 30 min than at baseline. Our findings suggest that olopatadine hydrochloride could inhibit capsaicin-induced flare responses.
Effects of N-Acetylcysteine on Renal Hemodynamics in Contrast Media-Induced Nephropathy
Authors: Krzossok Stefan , Braun Claude , Weiss Elizabeth , Hoeger Simone , Schnuelle Peter , Benck Urs , Birck Rainer , Krämer Bernhard K. , Göttmann Uwe
Published: February 2011

Background: N-acetylcysteine (NAC) has been proposed to prevent radiocontrast nephropathy in high-risk patients. Methods: The effect of single-dose and prolonged administration of NAC before application of either the ionic, high-osmolar radiocontrast agent diatrizoate sodium (DTZ) or the nonionic, low-osmolar radiocontrast agent iohexol (IOH) in a rat model combining uninephrectomy, salt depletion, and administration of indomethacin was explored. Arterial blood pressure and total, cortical, and medullary blood flow were continuously recorded in anesthetized Sprague-Dawley rats. Results: NAC had no effect on renal hemodynamics in control rats. Both DTZ and IOH induced biphasic changes in renal blood flow and cortical renal blood flux and persistently reduced medullary blood flux. Neither single-dose nor prolonged administration of NAC prevented the hemodynamic changes following administration of DTZ or IOH, respectively. Acute prophylactic administration of NAC prevented increased urinary ET excretion after injection of IOH and, to a smaller degree, of DTZ. Both an ionic, high-osmolar (DTZ) and a nonionic, low-osmolar (IOH) radiocontrast agent induce marked changes in renal hemodynamics in salt-depleted rats treated with indomethacin. Conclusions: Renal perfusion is not affected by NAC application in a model of experimental contrast nephropathy in rats. Other effects of NAC might thus account for the presumed renoprotective properties.
Study of Ethane Level in Exhaled Breath in Patients with Age-Related Macular Degeneration: Preliminary Study
Authors: Cagini C. , Giordanelli A. , Fiore T. , Giardinieri R. , Malici B. , De Medio G.E. , Pelli M.A. , De Bellis F. , Capodicasa E.
Published: February 2011

Purpose: A variety of factors have been implicated in the pathogenesis of age-related macular degeneration (ARMD), and oxidative stress plays an important role in the onset and progression of the disease. Breath ethane is now considered a specific and non-invasive test for determining and monitoring the trend of lipid peroxidation and free radical-induced damage in vivo. This test provides an index of the patients’ overall oxidative stress level. We evaluated the breath ethane concentration in exhaled air in patients with advanced ARMD. Methods: In this study, we enrolled 13 patients with advanced ARMD and a control group, and a breath analysis was carried out by gas chromatography. Results: The mean ethane level in the ARMD patients was 0.82 ± 0.93 nmol/l (range: 0.01–2.7 nmol/l) and the mean ethane value in the control group was 0.12 ± 0.02 nmol/l (range: 0.08–0.16 nmol/l). The difference between the values of the 2 groups was statistically significant (p < 0.005). Receiver operating characteristic analysis showed an elevated area under the curve (0.831; 95% CI: 0.634–0.948), with a significance level of p < 0.0014 (area = 0.5). Conclusions: These preliminary results seem to indicate that breath ethane levels are higher in most patients with ARMD. The breath ethane test could thus be a useful method for evaluating the level of oxidative stress in patients with ARMD. To our knowledge, there are no data on this type of analysis applied to ARMD.
MicroRNA-100 Regulates Neovascularization by Suppression of Mammalian Target of Rapamycin in Endothelial and Vascular Smooth Muscle Cells
Authors: Grundmann Sebastian , Hans Felix P. , Kinniry Sheena , Heinke Jennifer , Helbing Thomas , Bluhm Franziska , Sluijter Joost P.G. , Hoefer Imo , Pasterkamp Gerard , Bode Christoph , Moser Martin
Published: February 2011

Background—

The adaptive growth of blood vessels is an important protective mechanism in cardiovascular disease. However, the underlying regulatory mechanisms of this process are only partly understood. Recently, small endogenous RNAs (microRNAs [miRNAs]) were found to play an important role in embryonic and postnatal vascular development. Here, we used miRNA transcriptome analysis after induction of hind-limb ischemia in mice to screen for miRNAs involved in adaptive blood vessel growth following arterial occlusion.

Methods and Results—

Using miRNA arrays, we explored the miRNA expression profile during adaptive neovascularization. We describe specific changes in miRNA expression patterns and show that miRNA-100 is significantly downregulated after induction of hind-limb ischemia in mice. Our data demonstrate that miR-100 modulates proliferation, tube formation, and sprouting activity of endothelial cells and migration of vascular smooth muscle cells and functions as an endogenous repressor of the serine/threonine protein kinase mammalian target of rapamycin (mTOR). Whereas miR-100 inhibition increased mTOR levels in endothelial cells, overexpression of miR-100 reduced mTOR expression and consequently attenuated cellular proliferation. Supporting this notion, overexpression of an mTOR construct lacking the miRNA binding site rescued the inhibitory effect of miR-100 on cell proliferation. Accordingly, miR-100 inhibition by specific antagomirs in vivo stimulated angiogenesis and resulted in functional improvement of perfusion after femoral artery occlusion in mice. In contrast, treatment with the mTOR inhibitor rapamycin had the opposite effect.

Conclusions—

Our data demonstrate that miR-100 has an antiangiogenic function and represses mTOR signaling in endothelial and vascular smooth muscle cells. Inhibition of miR-100 could be a novel approach for the modulation of blood vessel growth and other mTOR-dependent processes.
Endogenous Circadian Rhythm in Vasovagal Response to Head-Up Tilt
Authors: Hu Kun , Scheer Frank A.J.L. , Laker Michael , Smales Carolina , Shea Steven A.
Published: February 2011

Background—

The incidence of syncope exhibits a daily pattern with more occurrences in the morning, possibly as a result of influences from the endogenous circadian system and/or the daily pattern of behavioral/emotional stimuli. This study tested the hypothesis that the circadian system modulates cardiovascular responses to postural stress, leading to increased susceptibility to syncope at specific times of day.

Methods and Results—

Twelve subjects underwent a 13-day in-laboratory protocol in which subjects' sleep-wake cycles were adjusted to 20 hours for 12 cycles. A 15-minute tilt-table test (60° head-up) was performed ≈4.5 hours after scheduled awakening in each cycle so that 12 tests in each subject were distributed evenly across the circadian cycle. Of 144 tests, signs/symptoms of presyncope were observed in 21 tests in 6 subjects. These presyncope events displayed a clear circadian rhythm (
P
=0.028) with almost all cases (17/21) occurring in the half of the circadian cycle corresponding to the biological night (10:30
pm
to 10:30
am
). Significant circadian rhythms were also observed in hemodynamic and autonomic function markers (blood pressure, heart rate, epinephrine, norepinephrine, and indices of cardiac vagal tone) that may underlie the circadian rhythm of presyncope susceptibility.

Conclusions—

The circadian system affects cardiovascular responses to postural stress, resulting in greater susceptibility to presyncope during the night. This finding suggests that night-shift workers and people with disrupted sleep at night may have greater risk of syncope as a result of their exposure to postural stress during the biological night.
Missed Opportunities in Cardiovascular Disease Prevention?
Authors: Schmittdiel Julie , Selby Joe V. , Swain Bix , Daugherty Stacie L. , Leong Thomas K. , Ho Michael , Margolis Karen L. , O'Connor Patrick , Magid David J. , Bibbins-Domingo Kirsten
Published: February 2011

Younger women use both internal medicine and obstetrics-gynecology (OBGYN) clinics as primary sources of health care. However, the role of OBGYN clinics in cardiovascular disease prevention is largely unexplored. The objective of this study was to examine rates of hypertension recognition in women <50 years of age who presented with elevated blood pressures in family practice and internal medicine (medicine) OBGYN clinics and to compare these rates across clinic type. The study's population consisted of 34 627 nonpregnant women ages 18 to 49 years with new-onset hypertension (defined as 2 consecutive visits with elevated blood pressures of systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg with no previous hypertension history) from 2002 to 2006. Multivariate logistic regressions predicting the clinical recognition of hypertension (a recorded diagnosis of hypertension and/or an antihypertensive prescription by any provider within 1 year of the second elevated blood pressure) assessed the association between hypertension recognition and the clinic where the second elevated blood pressure was recorded. Analysis showed that hypertension was recognized in <33% of women with new-onset hypertension. Women whose second consecutive elevated blood pressure was recorded in OBGYN clinics were less likely to be recognized as having hypertension within 12 months by any provider compared with women whose second consecutive elevated blood pressure was recorded in a medicine clinic (odds ratio: 0.51 [95% CI: 0.48 to 0.54]). This study suggests that further attention be paid to identifying and treating cardiovascular disease risk factors in women <50 years of age presenting in both medicine and OBGYN clinics and that improved coordination across care settings has the potential to improve cardiovascular disease prevention in young women.
Boundary Layer Characteristics over Homogeneous and Heterogeneous Surfaces Simulated by MM5 and DALES
Authors: Braam Miranda , Vilà-Guerau de Arellano Jordi , Górska Monica
Published: February 2011

The multiple-single-column approach is proposed as a new concept to study the boundary layer parameterization scheme in the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5). The results are compared with the Dutch Atmospheric Large-Eddy Simulation Model (DALES). Numerical experiments were performed over homogeneous and heterogeneous surfaces under clear convective boundary layer conditions. Identical simulations using MM5 and DALES were performed, which enabled an evaluation of the MM5 boundary layer scheme with DALES results. From the experiment with a homogeneous surface, MM5 shows a slightly shallower, colder, and moister boundary layer than DALES. This result is produced by an underestimation of turbulent mixing near the surface and less-vigorous entrainment of heat and dry air in MM5. In the heterogeneous surface experiment, the domain is divided into dry and wet patches, with the result that both models produce a mesoscale circulation. However, relative to the homogeneous case, larger differences were found between the models in the representation of the boundary layer dynamics. In DALES, the surface heterogeneity influenced the turbulent motions, making the mesoscale circulation much stronger (wmax is 6 times as large) than in MM5. Because of this stronger circulation, the boundary layer height, bulk temperature, and humidity also displayed differences in time and spatial patterns. Because of the land–atmosphere coupling in MM5, the mesoscale circulation strengthened the surface flux heterogeneity. Cold and moist air advection close to the surface from the wet patch to the dry patch increased the sensible heat flux above the dry patch and thus the induced mesoscale flow.
Cross Validation of Spaceborne Radar and Ground Polarimetric Radar Aided by Polarimetric Echo Classification of Hydrometeor Types
Authors: Wen Yixin , Hong Yang , Zhang Guifu , Schuur Terry J. , Gourley Jonathan J. , Flamig Zac , Morris K. Robert , Cao Qing
Published: February 2011

Ground-based polarimetric weather radar is arguably the most powerful validation tool that provides physical insight into the development and interpretation of spaceborne weather radar algorithms and observations. This study aims to compare and resolve discrepancies in hydrometeor retrievals and reflectivity observations between the NOAA/National Severe Storm Laboratory “proof of concept” KOUN polarimetric Weather Surveillance Radar-1988 Doppler (WSR-88D) and the spaceborne precipitation radar (PR) on board NASA’s Tropical Rainfall Measuring Mission (TRMM) platform. An intercomparison of PR and KOUN melting-layer heights retrieved from 2 to 5 km MSL shows a high correlation coefficient of 0.88 with relative bias of 5.9%. A resolution volume–matching technique is used to compare simultaneous TRMM PR and KOUN reflectivity observations. The comparisons reveal an overall bias of <0.2% between PR and KOUN. The bias is hypothesized to be from non-Rayleigh scattering effects and/or errors in attenuation correction procedures applied to Ku-band PR measurements. By comparing reflectivity with respect to different hydrometeor types (as determined by KOUN’s hydrometeor classification algorithm), it is found that the bias is from echoes that are classified as rain–hail mixture, wet snow, graupel, and heavy rain. These results agree with expectations from backscattering calculations at Ku and S bands, but with the notable exception of dry snow. Comparison of vertical reflectivity profiles shows that PR suffers significant attenuation at lower altitudes, especially in convective rain and in the melting layer. The attenuation correction performs very well for both stratiform and convective rain, however. In light of the imminent upgrade of the U.S. national weather radar network to include polarimetric capabilities, the findings in this study will potentially serve as the basis for nationwide validation of space-based precipitation products and also invite synergistic development of coordinated space–ground multisensor precipitation products.
A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part I: Project Design and Response Variables
Authors: Manton Michael J. , Warren Loredana , Kenyon Suzanne L. , Peace Andrew D. , Bilish Shane P. , Kemsley Karen
Published: February 2011

The Snowy Precipitation Enhancement Research Project (SPERP) was undertaken from May 2005 to June 2009 in the Snowy Mountains of southeastern Australia with the aim of enhancing snowfall in westerly flows associated with winter cold fronts. Building on earlier field studies in the region, SPERP was developed as a confirmatory experiment of glaciogenic static seeding using a silver-chloroiodide material dispersed from ground-based generators. Seeding of 5-h experimental units (EUs) was randomized with a seeding ratio of 2:1. A total of 107 EUs were undertaken at suitable times, based on surface and upper-air observations. Indium (III) oxide was released during all EUs for comparison of indium and silver concentrations in snow in seeded and unseeded EUs to test the targeting of seeding material. A network of gauges was deployed at 44 sites across the region to detect whether precipitation was enhanced in a fixed target area of 832 km2, using observations from a fixed control area to estimate the natural precipitation in the target. Additional measurements included integrated supercooled liquid water at a site in the target area and upper-air data from a site upwind of the target.
A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part II: Primary and Associated Analyses
Authors: Manton Michael J. , Warren Loredana
Published: February 2011

The Snowy Precipitation Enhancement Research Project (SPERP) was undertaken in winters from May 2005 to June 2009 in the Snowy Mountains region of southeastern Australia. Part I of this paper describes the design and implementation of the project, as well as the characteristics of the key datasets collected during the field phase. The primary analysis in this paper (Part II) shows an unequivocal impact on the targeting of seeding material, with the maximum level of silver in snow samples collected from the primary target area found to be significantly greater in seeded than unseeded experimental units (EUs). A positive but not statistically significant impact on precipitation was found. Further analysis shows that a substantial source of uncertainty in the estimation of the impacts of seeding on precipitation is associated with EUs where the seeding generators operated for relatively few hours. When the analysis is repeated using only EUs with more than 45 generator hours, the increase in precipitation in the primary target area is 14% at the 8% significance level. When applying that analysis to the overall target area, the precipitation increase is 14% at the 3% significance level. A secondary analysis of the ratio of silver to indium in snow supports the hypothesis that seeding material affected the cloud microphysics. Other secondary analyses reveal that seeding had an impact on virtually all of the physical variables examined in a manner consistent with the seeding hypothesis.
The Modified Gamma Size Distribution Applied to Inhomogeneous and Nonspherical Particles: Key Relationships and Conversions
Authors: Petty Grant W. , Huang Wei
Published: February 2011

The four-parameter modified gamma distribution (MGD) is the most general mathematically convenient model for size distributions of particle types ranging from aerosols and cloud droplets or ice particles to liquid and frozen precipitation. The common three-parameter gamma distribution, the exponential distribution (e.g., Marshall–Palmer), and power-law distribution (e.g., Junge) are all special cases. Depending on the context, the particle “size” used in a given formulation may be the actual geometric diameter, the volume- or area-equivalent spherical diameter, the actual or equivalent radius, the projected or surface area, or the mass.

For microphysical and radiative transfer calculations, it is often necessary to convert from one size representation to another, especially when comparing or utilizing distribution parameters obtained from a variety of sources. Furthermore, when the mass scales with Db, with b < 3, as is typical for snow and ice and other particles having a quasi-fractal structure, an exponential or gamma distribution expressed in terms of one size parameter becomes an MGD when expressed in terms of another. The MGD model is therefore more fundamentally relevant to size distributions of nonspherical particles than is often appreciated.

The central purpose of this paper is to serve as a concise single-source reference for the mathematical properties of, and conversions between, atmospheric particle size distributions that can expressed as MGDs, including exponential and gamma distributions as special cases.

For illustrative purposes, snow particle size distributions published by Sekhon and Srivastava, Braham, and Field et al. are converted to a common representation and directly compared for identical snow water content, allowing large differences in their properties to be discerned and quantified in a way that is not as easily achieved without such conversion.
Orogenic Propagating Precipitation Systems over the United States in a Global Climate Model with Embedded Explicit Convection
Authors: Pritchard Michael S. , Moncrieff Mitchell W. , Somerville Richard C. J.
Published: February 2011

In the lee of major mountain chains worldwide, diurnal physics of organized propagating convection project onto seasonal and climate time scales of the hydrologic cycle, but this phenomenon is not represented in conventional global climate models (GCMs). Analysis of an experimental version of the superparameterized (SP) Community Atmosphere Model (CAM) demonstrates that propagating orogenic nocturnal convection in the central U.S. warm season is, however, representable in GCMs that use the embedded explicit convection model approach [i.e., multiscale modeling frameworks (MMFs)]. SP-CAM admits propagating organized convective systems in the lee of the Rockies during synoptic conditions similar to those that generate mesoscale convective systems in nature. The simulated convective systems exhibit spatial scales, phase speeds, and propagation speeds comparable to radar observations, and the genesis mechanism in the model agrees qualitatively with established conceptual models. Convective heating and condensate structures are examined on both resolved scales in SP-CAM, and coherently propagating cloud “metastructures” are shown to transcend individual cloud-resolving model arrays. In reconciling how this new mode of diurnal convective variability is admitted in SP-CAM despite the severe idealizations in the cloud-resolving model configuration, an updated discussion is presented of what physics may transcend the re-engineered scale interface in MMFs. The authors suggest that the improved diurnal propagation physics in SP-CAM are mediated by large-scale first-baroclinic gravity wave interactions with a prognostic organization life cycle, emphasizing the physical importance of preserving “memory” at the inner resolved scale.
A Latent Heat Retrieval and Its Effects on the Intensity and Structure Change of Hurricane Guillermo (1997). Part I: The Algorithm and Observations
Authors: Guimond Stephen R. , Bourassa Mark A. , Reasor Paul D.
Published: February 2011

Despite the fact that latent heating in cloud systems drives many atmospheric circulations, including tropical cyclones, little is known of its magnitude and structure, largely because of inadequate observations. In this work, a reasonably high-resolution (2 km), four-dimensional airborne Doppler radar retrieval of the latent heat of condensation/evaporation is presented for rapidly intensifying Hurricane Guillermo (1997). Several advancements in the basic retrieval algorithm are shown, including 1) analyzing the scheme within the dynamically consistent framework of a numerical model, 2) identifying algorithm sensitivities through the use of ancillary data sources, and 3) developing a precipitation budget storage term parameterization. The determination of the saturation state is shown to be an important part of the algorithm for updrafts of ~5 m s−1 or less.

The uncertainties in the magnitude of the retrieved heating are dominated by errors in the vertical velocity. Using a combination of error propagation and Monte Carlo uncertainty techniques, biases are found to be small, and randomly distributed errors in the heating magnitude are ~16% for updrafts greater than 5 m s−1 and ~156% for updrafts of 1 m s−1. Even though errors in the vertical velocity can lead to large uncertainties in the latent heating field for small updrafts/downdrafts, in an integrated sense the errors are not as drastic.

In Part II, the impact of the retrievals is assessed by inserting the heating into realistic numerical simulations at 2-km resolution and comparing the generated wind structure to the Doppler radar observations of Guillermo.
Regionalization of Present-Day Precipitation in the Greater Monsoon Region of Asia*
Authors: Conroy Jessica L. , Overpeck Jonathan T.
Published: February 2011

The spatial domain of the Asian monsoon has been defined by the intensity, seasonal concentration, and annual range of precipitation. Monsoon subdomains, such as the Indian monsoon, East Asian monsoon, and western North Pacific monsoon, have also been identified based on seasonal wind reversals as well as the timing and source of monsoon moisture. However, precipitation across the Asian monsoon region is heterogeneous and spatially complex and may have influences farther north than commonly assumed, particularly if scientists consider records of past variability spanning the current interglacial period. This paper presents an additional means of identifying the Asian monsoon domain and monsoon subsystems using an empirical orthogonal function (EOF)-based regionalization of gridded precipitation values. Regions of unique precipitation variability for the Asian monsoon region are determined using monthly precipitation anomalies from the Climate Prediction Center Merged Analysis of Precipitation (CMAP) gridded precipitation dataset from 1979 to 2009. From these regions, an area of Asian monsoon influence extending from the Arabian Sea eastward to the western North Pacific Ocean is defined, similar to other studies. One key difference is that this region of monsoon influence penetrates farther north into the Tibetan Plateau and northern China. Thus, paleoclimate observations of wetter conditions in these northern arid regions may suggest an intensification of monsoon moisture, rather than a northward shift in the boundary of the monsoon. In contrast, the Arabian Peninsula, largely removed from monsoon precipitation today, likely saw a shift of monsoon influence inland earlier in the Holocene. Also identified are different subdomains of distinct precipitation variability in southeastern Asia, the western North Pacific, and the East Asian monsoon region of northeastern China that agree with previous studies. Not identified in the paper is a single Indian summer monsoon region. Instead, the Arabian Sea was found to have unique precipitation variability relative to the Indian subcontinent. Summers with enhanced precipitation over the Arabian Sea coincide with decreased summer precipitation in the western North Pacific. This relationship is likely a result of the El Niño–Southern Oscillation (ENSO)-induced development of the Philippine Sea anticyclone. Local and remote sea surface temperatures were generally found to covary with regional precipitation, but not all regions respond similarly to the remote climate variability associated with ENSO. There is some evidence that the EOF-defined regions were stable … through the Holocene, although additional regionalization analyses of paleorecords and model simulations of past precipitation variability are needed to reconstruct past regions of coherent precipitation variability.
Statistics of Cloud Optical Properties from Airborne Lidar Measurements
Authors: Yorks John E. , Hlavka Dennis L. , Hart William D. , McGill Matthew J.
Published: February 2011

Accurate knowledge of cloud optical properties, such as extinction-to-backscatter ratio and depolarization ratio, can have a significant impact on the quality of cloud extinction retrievals from lidar systems because parameterizations of these variables are often used in nonideal conditions to determine cloud phase and optical depth. Statistics and trends of these optical parameters are analyzed for 4 yr (2003–07) of cloud physics lidar data during five projects that occurred in varying geographic locations and meteorological seasons. Extinction-to-backscatter ratios (also called lidar ratios) are derived at 532 nm by calculating the transmission loss through the cloud layer and then applying it to the attenuated backscatter profile in the layer, while volume depolarization ratios are computed using the ratio of the parallel and perpendicular polarized 1064-nm channels. The majority of the cloud layers yields a lidar ratio between 10 and 40 sr, with the lidar ratio frequency distribution centered at 25 sr for ice clouds and 16 sr for altocumulus clouds. On average, for ice clouds the lidar ratio slightly decreases with decreasing temperature, while the volume depolarization ratio increases significantly as temperatures decrease. Trends for liquid water clouds (altocumulus clouds) are also observed. Ultimately, these observed trends in optical properties, as functions of temperature and geographic location, should help to improve current parameterizations of extinction-to-backscatter ratio, which in turn should yield increased accuracy in cloud optical depth and radiative forcing estimates.
Life Cycle Study of a Diabatic Rossby Wave as a Precursor to Rapid Cyclogenesis in the North Atlantic—Dynamics and Forecast Performance
Authors: Boettcher Maxi , Wernli Heini
Published: February 2011

The life cycle of a North Atlantic cyclone in December 2005 that included a rapid propagation phase as a diabatic Rossby wave (DRW) is investigated by means of operational analyses and deterministic forecasts from the ECMWF. A quasigeostrophic omega diagnostic has been applied to assess the impact of upper-level forcing during the genesis, propagation, and intensification phase, respectively. The system was generated in the Gulf of Mexico as a mesoscale convective vortex (MCV) influenced by vertical motion forcing from a nearby upper-level trough. The DRW propagation phase was characterized by a shallow, low-level, diabatically produced potential vorticity (PV) anomaly that rapidly propagated along the southern border of an intense baroclinic zone. No significant upper-level forcing could be identified during this phase of the development. Eventually, explosive intensification occurred as the region of vertical motion forced by an approaching upper-level trough reached the position of the DRW. The rapid intensification of 34 hPa in 24 h led to a mature extratropical cyclone in the central North Atlantic with marked frontal structures associated with a pronounced PV tower.

The performance of four operational deterministic ECMWF forecasts has been investigated for the DRW propagation and cyclone intensification. The forecasts showed a highly variable skill. Despite the fact that the DRW was initially well represented in all forecasts, two of them failed to capture the explosive intensification. By applying a DRW tracking tool, the low-level baroclinicity downstream of the DRW and the moisture supply to the south of the DRW could be identified as the key environmental parameters during DRW propagation. The subsequent cyclone intensification went wrong in two of the forecasts because of the missing interaction of the DRW and the upper-level trough. It is shown that this interaction can fail if the intensity of the DRW and/or the approaching upper-level wave are too weak, or in case of an erroneous structure of the upper-level trough leading to a phasing problem of the vertical interaction with the DRW. Therefore, the DRW intensification bears similar characteristics and forecast challenges as the extratropical reintensification of tropical cyclones.
French Norms and Validation of the Child Development Inventory (CDI): Inventaire du Développement de l’Enfant (IDE)
Authors: Duyme Michel , Zorman Michel , Tervo Raymond , Capron Christiane
Published: February 2011

The aim of this study was to determine the French norms and examine the validity of a parent-report inventory: the Child Development Inventory (CDI), called “Inventaire du Développement de l’Enfant (IDE)” in French. This assesses the general level of a child’s development in 8 developmental domains. The norms were determined for a community sample of 1287 children, aged 15 to 72 months. The score for the CDI general development scale correlates closely with chronological age ( r = .89). The intra- and interobserver (mother vs teacher) agreements were .97 and .76. The 1-year stability coefficient between the developmental quotient (DQ) values was .81. Correlation between the DQ (CDI) and the IQ of psychometric individual test was high ( r = .84). The sensitivity and specificity for detecting borderline children (IQ < 86) were 84% (95% CI = 72% to 92%) and 92% (95% CI = 84% to 97%), respectively. Therefore, the French version of the CDI, like the English one, provides a useful tool for measuring children’s development.
Biclustering
Authors: Dolnicar Sara , Kaiser Sebastian , Lazarevski Katie , Leisch Friedrich
Published: February 2011

Data-driven market segmentation is a popular and widely used segmentation method in tourism. It aims to identify market segments among tourists who are similar to each other, thus allowing a targeted marketing mix to be developed. Typically data used to segment tourists are characterized by small numbers of respondents and large numbers of survey questions. Small samples and numerous questions cause serious methodological problems that have typically been addressed by using factor-cluster analysis to reduce the dimensionality of data. Recently, factor-cluster analysis has been shown as an unacceptable solution to the problem of high data dimensionality in segmentation. In this article, the authors introduce biclustering, a novel approach to address the problem of high dimensionality in tourism segmentation studies. We discuss the circumstances in which biclustering should be used rather than parametric or nonparametric grouping techniques. An illustrative example of how biclustering is computed is also provided.
The Cuban Revolution
Authors: López Segrera Francisco
Published: February 2011

The new stage of the Cuban Revolution that began with the presidency of Raúl Castro has seen consultation with the masses about what kind of socialism they want to build, a return to some aspects of the economic reform abandoned in 2000, a key role in the economy for the armed forces, the dismantling of certain programs of the Battle of Ideas that have proved economically unsound, the elimination of certain subsidies and free food for workers, and the reduction of the state through the fusion of ministries and the reduction of the labor force. The success of these policies will condition what scenarios will prevail in Cuba in the future. Possible scenarios include (1) transformation toward a twenty-first-century socialism consistent with the historical roots of the Cuban Revolution, (2) immobility, (3) a socialist market economy such as those of China and Vietnam, (4) collapse and implosion in the style of the Soviet Union and the countries of the Eastern Bloc and/or internal revolt, and (5) overthrow of the government because of a military invasion by the United States. Scenarios 1, 2, and 3 are most probable, but 5 cannot be ruled out. A series of policy alternatives is suggested here that might make the first scenario possible.
A composite pulsating controller for achieving high-performance positioning
Authors: Tufekci C.S. , Craig K.C.
Published: February 2011

A non-linear robust control algorithm called a composite pulsating controller (CPC), which attains high-performance positioning specifications, is presented. The CPC is designed specifically for real product applications that have certain limitations such as friction, motor sizing, amplifier saturation, computational power and like. The CPC is composed of a bang-bang controller, a nominal proportional-integral-derivative (PID) controller, a high-gain PID controller and a pulsating controller in accomplishing the high-performance requirements. The mathematical structure of each component of the CPC is conceptualized, modelled and analysed in order to achieve superior positioning requirements for high performance. A bounded stability of the CPC is achieved and computer simulations are performed to demonstrate its practical applicability. Experimental digital implementation of the CPC with promising results is realized in the laboratory on a test bed equipped with a friction application apparatus.
Examining private and public provision in Canada’s provincial health care systems: comparing Ontario and Quebec
Authors: Palley Howard A. , Pomey Marie-Pascale , Forest Pierre-Gerlier
Published: February 2011

Globally, the mix of private- and public-sector involvement in health care delivery is a focus of political concern. This concern in Canada takes place within the parameters of the federal Canada Health Act. Private for-profit activities in the health care sector in Canadian provinces have moderately shrunk the definition of ‘necessary medical and hospital services’ that must be provided by the public administration system under the federal Canada Health Act. In this article, we argue that the development of new technologies, pharmaceutical innovations, competing (non-health) demands on the federal dollar, and an aging population together create an environment where pressures for economic and political sustainability have led to some erosion of necessary health services in the provinces. Such pressures have, in turn, led to the growth of private commercial-sector health services. Within Canada’s federal system, provincial negotiation of the role of commercial health care organizations has developed in different ways in Ontario and Quebec. Such subnational developments are a significant focus for comparative health policy analysis.
Playing-related musculoskeletal problems in child instrumentalists: The influence of gender, age and instrument exposure
Authors: Ranelli Sonia , Smith Anne , Straker Leon
Published: February 2011

Playing-related musculoskeletal problems (PRMP) are common in adult musicians. The limited available evidence suggests PRMP are common in children and adolescents and that risk factors may be similar. The aim of this study was to determine the prevalence of PRMP in children and adolescents and their associations with female gender, age and instrument exposure. The study surveyed 731 children learning musical instruments (460 females) ranging in age from 7—17 years. Lifetime symptoms, monthly symptoms and monthly disorders (the inability to play an instrument as usual) were examined. Logistic regression evaluated the independent association of these potential risk factors with PRMP prevalences. A total of 67% students reported PRM symptoms at some point, 56% reported PRM symptoms within the last month and 30% reported an inability to play as usual within the last month. Female gender was significantly associated with PRMP (OR 1.38—1.56, p = 0.004—0.046), as was age (OR 1.19—0.23, p < 0.001). After adjustment for gender and age, type of instrument (upper and lower strings, woodwind and brass) were significantly associated with all PRMP ( p < 0.005) and playing three instruments was protective against monthly symptoms (OR 0.43, p = 0.05).

The study concludes that the high prevalence and disabling impact of playing-related musculoskeletal problems is clearly an important issue for child and adolescent health with gender, age and instrument exposure important factors for risk management.