Thermal imaging of cucumber leaves affected by downy mildew and environmental conditions.

Pathogenesis of Pseudoperonospora cubensis causing downy mildew of cucumber resulted in changes in the metabolic processes within cucumber leaves including the transpiration rate. Due to the negative correlation between transpiration rate and leaf temperature, digital infrared thermography permitted a non-invasive monitoring and an indirect visualization of downy mildew development. Depending on the stage of pathogenesis and the topology of chloroses and necroses, infection resulted in a typical temperature pattern. Spatial heterogeneity of the leaf temperature could be quantified by the maximum temperature difference (MTD) within a leaf. The MTD increased during pathogenesis with the formation of necrotic tissue and was related to disease severity as described by linear and quadratic regression curves. Under controlled conditions, changes in temperature of infected leaves allowed the discrimination between healthy and infected areas in thermograms, even before visible symptoms of downy mildew appeared. Environmental conditions during thermographic measurement, in particular air temperature and humidity, as well as water content and age of the leaf influenced the temperature of its surface. Conditions enhancing the transpiration rate facilitated the detection of changes in leaf temperature of infected leaves at early stages of infection. As modified by environmental conditions, MTD alone is not suitable for the quantification of downy mildew severity in the field.

Distributing entanglement and single photons through an intra-city, free-space quantum channel.

We have distributed entangled photons directly through the atmosphere to a receiver station 7.8 km away over the city of Vienna, Austria at night. Detection of one photon from our entangled pairs constitutes a triggered single photon source from the sender. With no direct time-stable connection, the two stations found coincidence counts in the detection events by calculating the cross-correlation of locally-recorded time stamps shared over a public internet channel. For this experiment, our quantum channel was maintained for a total of 40 minutes during which time a coincidence lock found approximately 60000 coincident detection events. The polarization correlations in those events yielded a Bell parameter, S=2.27+/-0.019, which violates the CHSH-Bell inequality by 14 standard deviations. This result is promising for entanglement-based freespace quantum communication in high-density urban areas. It is also encouraging for optical quantum communication between ground stations and satellites since the length of our free-space link exceeds the atmospheric equivalent.

[Dolasetron, droperidol and a combination of both in prevention of postoperative nausea and vomiting after extracapsular cataract extraction under general anesthesia]. / Dolasetron, Droperidol und die Kombination beider Substanzen zur Prophylaxe von Ubelkeit und Erbrechen nach extrakapsulären Kataraktextraktionen in Allgemeinanästhesie.

BACKGROUND: Both, droperidol and the new 5-HT3-antagonist (e.g. dolasetron) are effective drugs in the prevention of postoperative nausea and vomiting (PONV). It was the aim of this prospective double blind placebo controlled study to determine the efficacy of low-dose droperidol, dolasetron, and a combination of both drugs in the prevention of PONV after extracapsular cataract extraction. METHODS: 148 inpatients undergoing cataract surgery were stratified according to gender and then randomised to receive one of four antiemetic regimens: placebo, droperiodol (10 micrograms x kg-1), dolasetron (12.5 mg), or the combination of both drugs (10 micrograms x kg-1 + 12.5 mg). The drugs were administered intravenously 5-10 minutes before the end of anaesthesia. General anaesthesia and the perioperative management of the patients were standardised: benzodiazepine premedication, induction with etomidate, alfentanil and mivacurium. Maintenance using desflurane in N2O/O2, and a continuous infusion of mivacurium was used. Postoperative analgesia (diclofenac or paracetamol) and antiemetic rescue medication (dimenhydrinate and metoclopramide) was standardised. Nausea, episodes of vomiting, retching and the need for additional antiemetics were recorded for 24-hours. The severity of PONV was categorised using a standardised scoring algorithm. The main aim of the study was the number of patients who stayed completely free from PONV. RESULTS: There were no differences between the two groups with regard to biometric data, type of surgery, and distribution of risk factors for developing PONV. In all three treatment groups significantly less patients suffered from PONV (placebo: 66%; droperidol: 89%, dolasetron: 92%, combination: 89%; p = 0.011). Furthermore, the severity of PONV was reduced (p = 0.012). CONCLUSION: Low-dose droperidol and dolasetron are equally effective to reduce the incidence of PONV after cataract surgery under general anaesthesia. The combination of both drugs revealed no additional effect.

Role of cholecystokinin in cholestyramine-induced changes of the exocrine pancreas.

This study was an investigation of the role of cholecystokinin (CCK) in the stimulatory action of cholestyramine on rat exocrine pancreas. Postprandial CCK release was significantly enhanced by acute administration of cholestyramine (12.7 +/- 1.8 vs 3.7 +/- 0.5 pmol/L in controls). Over four weeks, rats were fed either regular diet or diet containing 6% cholestyramine, and were treated with the specific CCK receptor antagonist L-364,718 (2 x 0.5 mg/kg body weight/day s.c.) or DMSO (vehicle for the antagonist). Cholestyramine significantly increased pancreatic weight and trypsin and chymotrypsin contents. L-364,718 abolished these effects. Concomitant administration of antagonist and cholestyramine elevated amylase content, compared to controls. CCK levels in fasted animals did not differ between the four groups. The effect of the same dose of L-364,718 on pancreatic enzyme depletion, induced by the protease inhibitor camostate, was studied in a control experiment. A single dose of camostate (200 mg/kg) caused a 44-68% decrease in enzyme content. L-364,718 reversed this effect for all enzymes. We conclude that CCK is the mediator of cholestyramine-induced pancreatic hypertrophy and increase in content of proteases. After long-term administration, the CCK receptor antagonist, in combination with cholestyramine revealed an agonistic effect on individual, pancreatic enzyme content.