We present a feasibility study for an object-based method to characterise thunderstorm properties in simulation data from convection-permitting weather models. An existing thunderstorm tracker, the ...Thunderstorm Identification, Tracking, Analysis and Nowcasting (TITAN) algorithm, was applied to thunderstorms simulated by the Advanced Research Weather Research and Forecasting (AR-WRF) weather model at convection-permitting resolution for a domain centred on Switzerland. Three WRF microphysics parameterisations were tested. The results are compared to independent radar-based observations of thunderstorms derived using the MeteoSwiss Thunderstorms Radar Tracking (TRT) algorithm. TRT was specifically designed to track thunderstorms over the complex Alpine topography of Switzerland. The object-based approach produces statistics on the simulated thunderstorms that can be compared to object-based observation data. The results indicate that the simulations underestimated the occurrence of severe and very large hail compared to the observations. Other properties, including the number of storm cells per day, geographical storm hotspots, thunderstorm diurnal cycles, and storm movement directions and velocities, provide a reasonable match to the observations, which shows the feasibility of the technique for characterisation of simulated thunderstorms over complex terrain.
The lower-order moments of the drop size distribution (DSD) have generally been considered difficult to retrieve accurately from polarimetric radar data because these data are related to higher-order ...moments. For example, the 4.6th moment is associated with a specific differential phase and the 6th moment with reflectivity and ratio of high-order moments with differential reflectivity. Thus, conventionally, the emphasis has been to estimate rain rate (3.67th moment) or parameters of the exponential or gamma distribution for the DSD. Many double-moment “bulk” microphysical schemes predict the total number concentration (the 0th moment of the DSD, or M0) and the mixing ratio (or equivalently, the 3rd moment M3). Thus, it is difficult to compare the model outputs directly with polarimetric radar observations or, given the model outputs, forward model the radar observables. This article describes the use of double-moment normalization of DSDs and the resulting stable intrinsic shape that can be fitted by the generalized gamma (G-G) distribution. The two reference moments are M3 and M6, which are shown to be retrievable using the X-band radar reflectivity, differential reflectivity, and specific attenuation (from the iterative correction of measured reflectivity Zh using the total Φdp constraint, i.e., the iterative ZPHI method). Along with the climatological shape parameters of the G-G fit to the scaled/normalized DSDs, the lower-order moments are then retrieved more accurately than possible hitherto. The importance of measuring the complete DSD from 0.1 mm onwards is emphasized using, in our case, an optical array probe with 50 µm resolution collocated with a two-dimensional video disdrometer with about 170 µm resolution. This avoids small drop truncation and hence the accurate calculation of lower-order moments. A case study of a complex multi-cell storm which traversed an instrumented site near the CSU-CHILL radar is described for which the moments were retrieved from radar and compared with directly computed moments from the complete spectrum measurements using the aforementioned two disdrometers. Our detailed validation analysis of the radar-retrieved moments showed relative bias of the moments M0 through M2 was <15 % in magnitude, with Pearson’s correlation coefficient >0.9. Both radar measurement and parameterization errors were estimated rigorously. We show that the temporal variation of the radar-retrieved mass-weighted mean diameter with M0 resulted in coherent “time tracks” that can potentially lead to studies of precipitation evolution that have not been possible so far.
Intracellular pH (pH(i)) is an important factor for understanding cellular processes associated with the response of central neurons to metabolic disturbances such as anoxia or ischemia. In the ...present study, pH(i) was fluorometrically measured in 2'7'-bis(carboxyethyl)-5(6)-carboxyfluorescin (BCECF)-filled, voltage-clamped dorsal vagal neurons (DVN) of brainstem slices from rats during metabolic disturbances activating ATP-sensitive K(+) (K(ATP)) channels. Chemical anoxia induced by cyanide, rotenone or p-trifluoromethoxy-phenylhydrazone (FCCP) decreased pH(i) by >0.4 pH units. Untreated neurons with normal pH(i) baseline (7.2) responded to glucose-free superfusate after a delay of 7-16 min with a progressive fall of pH(i). In contrast, pH(i) increased by >0.2 pH units after approximately 10 min in cells that had a mean pH(i) of 6.8 due to incomplete recovery from a CN(-)induced acid load prior to glucose depletion. Metabolic arrest, induced by cyanide in glucose-free solution after 30 min preincubation in glucose-free saline, caused a progressive glutamate-mediated inward current with no change of pH(i). Upon metabolic arrest, depolarization-evoked pH(i) decreases ( approximately 0.2 pH units) were abolished, whereas glucose-free superfusate slightly delayed their recovery without major effects on amplitude. The glucose-dependent pH(i) fall coincided with activation of the K(ATP) channel-mediated outward current, while K(ATP) currents due to anoxia or metabolic arrest could reach their maximum in the absence of a major pH(i) change. The results indicate that the anoxic pH(i) decrease is due to enhanced glycolysis and lactate formation with often no obvious effect on K(ATP) channel activity. The origin of glucose-dependent acidosis and its relation to K(ATP) channel activity remain to be determined.
Background/Aims: A minority of German medical students believe they know how to support smokers willing to quit. This paper examined whether the same would be true for treating alcohol use disorder ...(AUD), and individual factors associated with incorrect beliefs about the effectiveness of methods to treat AUD. Methods: In this cross-sectional study, 19,526 undergraduate students from 27 German medical schools completed a survey addressing beliefs about the effectiveness of different methods of overcoming AUD. Beliefs about AUD treatment effectiveness were compared across the 5 years of undergraduate education and predictors identified by means of multiple linear regression. Results: Even in the fifth year, 28.1% (95% CI: 26.5–29.7) of students believed that willpower alone was more effective for overcoming AUD than a comprehensive treatment program. The only significant predictor of this belief was a similar belief for stopping smoking. Conclusion: Our results indicate that a considerable proportion of German medical students overestimate the effectiveness of willpower to treat smoking and AUD. The addictive nature of these disorders needs to be stressed during undergraduate medical education to ensure that future physicians will be able and motivated to support patients in their quit attempts.
Intracellular pH (pH
i) is an important factor for understanding cellular processes associated with the response of central neurons to metabolic disturbances such as anoxia or ischemia. In the ...present study, pH
i was fluorometrically measured in 2′7′-bis(carboxyethyl)-5(6)-carboxyfluorescin (BCECF)-filled, voltage-clamped dorsal vagal neurons (DVN) of brainstem slices from rats during metabolic disturbances activating ATP-sensitive K
+ (K
ATP) channels. Chemical anoxia induced by cyanide, rotenone or
p-trifluoromethoxy-phenylhydrazone (FCCP) decreased pH
i by >0.4 pH units. Untreated neurons with normal pH
i baseline (7.2) responded to glucose-free superfusate after a delay of 7–16 min with a progressive fall of pH
i. In contrast, pH
i increased by >0.2 pH units after ∼10 min in cells that had a mean pH
i of 6.8 due to incomplete recovery from a CN
–induced acid load prior to glucose depletion. Metabolic arrest, induced by cyanide in glucose-free solution after 30 min preincubation in glucose-free saline, caused a progressive glutamate-mediated inward current with no change of pH
i. Upon metabolic arrest, depolarization-evoked pH
i decreases (∼0.2 pH units) were abolished, whereas glucose-free superfusate slightly delayed their recovery without major effects on amplitude. The glucose-dependent pH
i fall coincided with activation of the K
ATP channel-mediated outward current, while K
ATP currents due to anoxia or metabolic arrest could reach their maximum in the absence of a major pH
i change. The results indicate that the anoxic pH
i decrease is due to enhanced glycolysis and lactate formation with often no obvious effect on K
ATP channel activity. The origin of glucose-dependent acidosis and its relation to K
ATP channel activity remain to be determined.
Einleitung:
Auch bei optimaler Nutzung der verfügbaren Maßnahmen zur Tabakentwöhnung liegt die langfristige Abstinenzquote in publizierten Studien nur um 30%. Eine Impfung gegen Nikotin soll zur ...Bildung von Antikörpern führen, die den Suchtstoff vor Erreichen des Gehirns binden und damit seine Wirkung am Effektororgan verhindern. Die Nikotin-Impfung stellt ein neuartiges Therapiekonzept dar, das sich mittlerweile in der klinischen Erprobung befindet.
Methoden:
Es wurde eine systematische Literatur-Recherche (PubMed) mit den Suchbegriffen „nicotine“, „vaccination“ und „immunization“ durchgeführt. Die identifizierten Artikel wurden auf weiterführende Zitierungen geprüft und relevante Volltexte analysiert.
Ergebnisse:
Es wurden 28 tierexperimentelle und 5 klinische Studien (Gesamt-n: 763 Patienten) zur Immunisierung gegen Nikotin identifiziert. In Tierstudien wurden sowohl Aktiv- als auch Passivimpfungen getestet; am Menschen wurde bislang nur die Aktivimpfung eingesetzt. Während die tierexperimentellen Studien deutliche positive Effekte der Impfung auf die Pharmakokinetik des Nikotins sowie auf Surrogatparameter der Sucht nachwiesen, konnte in zwei klinischen Dosisfindungsstudien kein genereller Effektivitätsnachweis erbracht werden. In einer Studie ergab sich bei Patienten mit besonders hohen Antikörper-Titern jedoch eine kontinuierliche 12-Monats-Abstinenzquote von 42%. Schwerwiegende unerwünschte Ereignisse wurden nicht beobachtet.
Schlussfolgerung:
Die fehlende Übertragbarkeit der Ergebnisse aus tierexperimentellen Studien auf die Anwendung beim Menschen liegt teilweise in den methodischen Limitationen der Tiermodelle begründet. Moderne Behandlungsstrategien (evtl. unter Einschluss einer weiterentwickelten Nikotinimpfung) müssen dem komplexen Zusammenspiel pathophysiologischer und psychologischer Faktoren bei der Entstehung und Aufrechterhaltung der Tabakabhängigkeit Rechnung tragen.
Successful smoking cessation is associated with a survival benefit for patients with lung cancer. However, smokers newly diagnosed with non-small cell lung cancer and scheduled for curative resection ...are frequently discouraged from stopping smoking in the immediate preoperative period. This recommendation is based on the results of one single prospective cohort study published in 1998 which reported an increased risk of perioperative pulmonary complications in patients undergoing non-thoracic surgery who had reduced their tobacco consumption within the two months leading up to the operation. During the past 12 years, numerous observational studies have investigated the impact of preoperative smoking cessation on perioperative risk for thoracic and non-thoracic surgery. However, no more than six studies included patients with pulmonary neoplasms. Owing to methodological limitations and considerable heterogeneity of the included patient groups, the existing data are insufficient to support or refuse any recommendation regarding cessation advice for patients during the immediate preoperative phase. In view of the post-cessation recovery time-course of pathophysiological alterations relevant to the occurrence of perioperative complications, a smoke-free preoperative interval of 2 - 6 weeks appears most favourable. However, this is difficult to achieve as a curative resection should not be postponed. Since there is no scientific evidence demonstrating a negative impact of preoperative smoking cessation on prognosis, patients newly diagnosed with lung cancer should be encouraged to make an attempt to quit while waiting for thoracic surgery.
Zusammenfassung
Zur Todeszeitdiagnostik im frühen postmortalen Intervall wird die sog. Komplexmethode angewandt, die sowohl temperaturbasierte als auch nichttemperaturbasierte Faktoren ...berücksichtigt. Die nichttemperaturbasierten Komponenten der Komplexmethode und ihre Zeitgrenzen wurden im Wesentlichen aus empirischen Daten älterer Literaturquellen abgeleitet; neuere systematische Studien fehlten bislang. Die vorgestellten Untersuchungen über die Auslösbarkeit mehrerer nichttemperaturbasierter Faktoren führten zur Verifizierung (idiomuskuläre Kontraktion und Wegdrückbarkeit von Leichenflecken) sowie zur Falsifizierung (Neubildung der Leichenstarre, pharmakologische Beeinflussbarkeit der Pupillomotorik) bisher mitgeteilter forensisch relevanter Post-Mortem-Zeitgrenzen. Sie tragen damit zur erhöhten Sicherheit der forensischen Beurteilung bei.
Health-related apps can provide helpful resources for both doctors and patients. The selection of potentially useful apps and the appraisal of their quality are particularly important in the context ...of medicine as false or confusing app content may put patients at risk.
In this article a brief overview of the topic is provided and the results of a pilot study, in which medical students tested and evaluated the quality of 143 health-related apps on the topics of cardiology and pulmonology are presented.
Using the semiautomated retrospective app store analysis (SARASA) method, a group of apps concerned with cardiology and pulmonology were identified from a pool of over 2,000,000 apps available in the Apple Store. As part of a practical exercise, 138 4th year medical students tested a total of 143 of these apps, subsequently evaluating them using a specially devised questionnaire.
The most frequent target population among the tested apps was identified as patients and their carers and the primary purpose in the majority of cases was the provision of information. Despite this, at least one quarter of all apps tested required users to enter sensitive health-related information. The evaluations by the students portrayed a large range in terms of the quality of the apps tested.
Health-related apps play a growing role in the management of illnesses in the field of internal medicine. Doctors must be aware of the benefits and limitations of using such apps and should be prepared during their medical studies for the challenge of advising patients on this topic.
Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. Cigarette smoking is the main cause of COPD. Quitting smoking is thus the most effective treatment strategy and ...central in COPD prevention. A number of guidelines on prevention, diagnosis, therapy and rehabilitation of COPD have been published. To help implementing and standardizing smoking cessation in COPD a guideline was published 2008 in Germany focusing on this complex issue. The present guideline is an update of the 2008 guideline and has a high grade of evidence (S3 according to the AWMF; Arbeitsgemeinschaft wissenschaftlicher medizinischer Fachgesellschaften). The guideline gives comprehensive and practical information on how to integrate smoking cessation as an central part of COPD therapy.
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