The Kurosawa-Desmedt key encapsulation is not chosen-ciphertext secure

At CRYPTO 2004, Kurosawa and Desmedt presented a new hybrid encryption scheme that is chosen-ciphertext (CCA2) secure in the standard model. Until now it was unknown if the key encapsulation part of the Kurosawa-Desmedt scheme by itself is still CCA2-secure or not. In this note we answer this question to the negative, namely we present a simple CCA2 attack on the Kurosawa-Desmedt key encapsulation mechanism. Our attack further supports the design paradigm of Kurosawa and Desmedt to build CCA2-secure hybrid encryption from weak key encapsulation.     

Quantitation of estragole by stable isotope dilution assays

Various calibration strategies for the quantitation of the phenylpropane estragole by gas chromatography-mass spectrometry were developed and compared. For application in stable isotope dilution assays, two deuterium labelled estragole isotopologues were synthesized. Of these, [3′,3′-²H₂]estragole was prepared by Wittig reaction of 4-methoxy-phenylacetaldehyde with [²H₃]methyl-triphenyl-phosphonium bromide, whereas [1″,1″,1″-²H₃]estragole was obtained by demethylation of estragole and deuteromethylation of the resulting 4-allylphenole.Besides estragole isotopologues, 1,2,4-trimethoxybenzene and 4-propylanisole were also tested as internal standards (I.S.) for the determination of estragole in fennel tea.[1″,1″,1″-²H₃]Estragole, 1,2,4-trimethoxybenzene, and 4-propylanisole revealed linear calibration functions and, therefore, were suitable for estragole quantitation. In contrast to this, [3′,3′-²H₂]estragole could only be applied as I.S. if it was added to the extracts in stoichiometric deficiency compared to unlabelled estragole. Moreover, due to its different chemical and physical properties, 1,2,4-trimethoxybenzene showed a recovery as low as 77%, whereas the other I.S. revealed recovery rates close to 100%. Considering the “real” values of estragole in fennel tea, the choice of the I.S. obviously is less important than the way of preparing the tea. In contrast to the common method for tea preparation, squeezing of the teabags increased the estragole content significantly by 50%.     

Prozeßidentifikation beim Plasmaspritzen temperatursensitiver Werkstoffe mit Hilfe einer Infrarot-Hochtemperatur-Thermokamera

Process-Identification at Plasma Spraying Thermally Sensitive Materials Using an Infra-red Thermal Imaging System Nowadays so called thermally sensitive materials are deposited by thermal spray techniques. Due to the high temperature process an undesired alteration (evaporation, chemical decomposition) of the material could occur. Therefore, optimisation of the deposition based only on empirical methods may be deremental with respect to the coating properties. This study shows the potential of an IR thermal imaging technique as a process control for evaluation and optimisation of the deposition through better understanding of the thermal spray process. The spray trials presented are based on preliminary examinations carried out with diagnostic tools. Therefore it was possible to achieve defined air plasma sprayed coatings of hydroxyapatite with different coating and component properties. This is particularly of interest, since there exists only a standard for hydroxyapatite as starting material but not for plasma sprayed coatings. Hence the coatings had either high or low contents of undesired phases, different degrees of cristallinity and bond strengths-varying from 5 to 42 MPa. Besides the power levels and the way to obtain the power the carrier gas flow significantly influences the properties of the coatings.     

Schrifttumsberichte

Ohne Zusammenfassung     

Chloride and Indium‐Chloride‐Complex Inorganic Ligands for Efficient Stabilization of Nanocrystals in Solution and Doping of Nanocrystal Solids

Here, the surface functionalization of CdSe and CdSe/CdS core/shell nanocrystals (NCs) with compact chloride and indium‐chloride‐complex ligands is reported. The ligands provide not only short interparticle distances but additionally control doping and passivation of surface trap states, leading to enhanced electronic coupling in NC‐based arrays. The solids based on these NCs show an excellent electronic transport behavior after heat treatment at the relatively low temperature of 190 °C. Indeed, the indium‐chlorido‐capped 4.5 nm CdSe NC based thin‐film field‐effect transistor reaches a saturation mobility of μ = 4.1 cm² (V s)^?1 accompanied by a low hysteresis, while retaining the typical features of strongly quantum confined semiconductor NCs. The capping with chloride ions preserves the high photoluminescence quantum yield ( ≈ 66%) of CdSe/CdS core/shell NCs even when the CdS shell is relatively thin (six monolayers). The simplicity of the chemical incorporation of chlorine and indium species via solution ligand exchange, the efficient electronic passivation of the NC surface, as well as their high stability as dispersions make these materials especially attractive for wide‐area solution‐processable fabrication of NC‐based devices.     

A decomposition theorem for finite persistent transition systems

In this paper, we consider finite labelled transition systems. We show that if such transition systems are deterministic, persistent, and weakly periodic, then they can be decomposed in the following sense. There exists a finite set of label-disjoint cycles such that any other cycle is Parikh-equivalent to a multiset of cycles from this set.     

Alternating current electrical field effects on lettuce (Lactuca sativa) growing in hydroponic culture with and without cadmium contamination

The aim of the present study was to investigate the effect of a 10 Hz alternating current (10 Hz 1 V cm⁻¹) and a 50 Hz alternating current (50 Hz 1 V cm⁻¹) on the lettuce plant (Lactuca sativa) growing in a hydroponic (soil-free) culture. Thirty lettuce plants were pre-germinated, and then 15 of them were treated with cadmium solution (CdCl₂) of 5 mg/L in concentration. Ten plants (five plants with Cd and five plants without Cd) were subjected to a 10 Hz alternating current (AC) electrical field; 10 plants were subjected to a 50 Hz AC field. The rest of the plants were used as a control. The lettuce plants were harvested after a growth of 60 days. The chlorophyll content, biomass and metal content of the lettuce plants were determined. The biomass of the plants growing in non-contaminated medium was 28 and 106% higher under the 10 and the 50 Hz AC fields respectively compared to the control. Although the plant biomass was reduced by the presence of Cd in the growth medium, the biomass of the plants growing in Cd contaminated medium was 40 and 63% higher respectively for 10 and 50 Hz AC field compared to the plant growing in Cd contaminated medium without electrical treatment. Increased uptake of Cd in the plant shoot was found with the 50 Hz AC field. Significant accumulation and uptake of Cu in plant roots and shoots was found under both electrical treatments.     

A prospective 12-year study of subsyndromal and syndromal depressive symptoms in unipolar major depressive disorders

BACKGROUND: Investigations of unipolar major depressive disorder (MDD) have focused primarily on major depressive episode remission/recovery and relapse/recurrence. This is the first prospective, naturalistic, long-term study of the weekly symptomatic course of MDD. METHODS: The weekly depressive symptoms of 431 patients with MDD seeking treatment at 5 academic centers were divided into 4 levels of severity: (1) depressive symptoms at the threshold for MDD; (2) depressive symptoms at the threshold for minor depressive or dysthymic disorder (MinD); (3) subsyndromal or subthreshold depressive symptoms (SSDs), below the thresholds for MinD and MDD; and (4) no depressive symptoms. The percentage of weeks at each level, number of changes in symptom level, and medication status were analyzed overall and for 3 subgroups defined by mood disorder history. RESULTS: Patients were symptomatically ill in 59% of weeks. Symptom levels changed frequently (1.8/y), and 9 of 10 patients spent weeks at 3 or 4 different levels during follow-up. The MinD (27%) and SSD (17%) symptom levels were more common than the MDD (15%) symptom level. Patients with double depression and recurrent depression had more chronic symptoms than patients with their first lifetime major depressive episode (72% and 65%, respectively, vs 46% of follow-up weeks). CONCLUSION: The long-term weekly course of unipolar MDD is dominated by prolonged symptomatic chronicity. Combined MinD and SSD level symptoms were about 3 times more common (43%) than MDD level symptoms (15%). The symptomatic course is dynamic and changeable, and MDD, MinD, and SSD symptom levels commonly alternate over time in the same patients as a symptomatic continuum of illness activity of a single clinical disease.     

Regulatory strategies to reduce tobacco addiction in youth

Preventing tobacco addiction and achieving cessation in established users are the cornerstones of efforts to reduce tobacco use and disease. It has been increasingly recognised that reducing tobacco toxin exposure has theoretical potential to reduce disease in continuing tobacco users. This has been controversial because such approaches also carry the potential to undermine prevention and cessation. As complicated as harm reduction issues are for adults, they are still more complicated for youth. Harm reduction is not a singular approach, but rather a concept that encompasses an extremely diverse array of potential approaches. These carry equally diverse potential risks and benefits. The regulatory framework (for example, whether or not the Food and Drug Administration regulates the approach) is also predicted to be a major factor in determining the consequences of harm reduction approaches. This paper examines the various issues and potential approaches concerning the application of harm reduction to youth. We conclude that although some carry great risk, others may actually support broader tobacco control efforts to prevent tobacco use and foster cessation in youth and adults.     

Parallelisation of the Lagrangian atmospheric dispersion model NAME

The NAME  Atmospheric Dispersion Model is a Lagrangian particle model used by the Met Office to predict the propagation and spread of pollutants in the atmosphere. The model is routinely used in emergency response applications, where it is important to obtain results as quickly as possible. This requirement for a short runtime and the increase in core number of commonly available CPUs, such as the Intel Xeon series, has motivated the parallelisation of NAME  in the OpenMP  shared memory framework. In this work we describe the implementation of this parallelisation strategy in NAME  and discuss the performance of the model for different setups. Due to the independence of the model particles, the parallelisation of the main compute intensive loops is relatively straightforward. The random number generator for modelling sub-grid scale turbulent motion needs to be adapted to ensure that different particles use independent sets of random numbers. We find that on Intel Xeon X5680 CPUs the model shows very good strong scaling up to 12 cores in a realistic emergency response application for predicting the dispersion of volcanic ash in the North Atlantic airspace. We implemented a mechanism for asynchronous reading of meteorological data from disk and demonstrate how this can reduce the runtime if disk access plays a significant role in a model run. To explore the performance on different chip architectures we also ported the part of the code which is used for calculating the gamma dose from a cloud of radioactive particles to a graphics processing unit (GPU) using CUDA-C. We were able to demonstrate a significant speedup of around one order of magnitude relative to the serial CPU version.