Unmasking Optical Chaotic Cryptosystems Based on Delayed Optoelectronic Feedback

29 páginas, 22 figuras, 3 tablas.The authors analyze the security of optical chaotic communication systems. The chaotic carrier is generated by a laser diode subject to delayed optoelectronic feedback. Transmitters with one and two fixed delay times are considered. A new type of neural networks, modular neural networks, is used to reconstruct the nonlinear dynamics of the transmitter from experimental time series in the single-delay case, and from numerical simulations in single and two-delay cases. The authors show that the complexity of the model does not increase when the delay time is increased, in spite of the very high dimension of the chaotic attractor. However, it is found that nonlinear dynamics reconstruction is more difficult when the feedback strength is increased. The extracted model is used as an unauthorized receiver to recover the message. Therefore, the authors conclude that optical chaotic cryptosystems based on optoelectronic feedback systems with several fixed time delays are vulnerable.This work was supported by CICYT (Spain) under Project TEC2009-14581-C02-02.Peer reviewe

Global climate change, widening health inequalities, and epidemiology

4 pages, 2 figures, 1 table.-- PMID: 16488897 [PubMed].The most recent report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC) provided compelling evidence on the effect of human release of greenhouse gases from fossil fuels and deforestation on the global climate change.1 The IPCC estimate that since the mid-19th century there has been an increase in average temperature of 0.6ºC, most of this increase occurring at the end of 20th century. In addition, it provides evidence of changes in the patterns of precipitation, ridification, and humidity. Events occurring since the publication of the IPCC report in 2001 have added substantial new evidence. The average concentration of carbon dioxide has reached 375 p.p.m. (almost 100 p.p.m. above the interglacial levels) (Figure 1); polar and alpine ice is melting at faster rates than expected2 and mean sea level has been observed to rise by ~30 cm during the 20th century.3 Circumpolar winds are accelerating, probably intensifying the El Nin˜ o/Southern oscillation with increasing flows in Southern Asia, South-east Africa, South-east USA, or Central America and a large increase in the number of hurricanes reaching categories 4–5 on the Saffir–Simpson scale has occurred in the last 15 years.4 The IPCC projections forecast rises in temperature between 1.4 and 5.8ºC by 2100, elevation in mean sea level of 9–88 cm,1 and increases in heatwave frequency of 25–31%.Peer reviewe

Histochemie / Immunhistochemische Charakterisierung von Verhornungsstörungen:Untersuchungen unter besonderer Berücksichtigung von Transglutaminase 3, Calpain und Osteonectin

Bei klinisch definierten Verhornungsstörungen wurden die o.g. Kandidatenproteine untersucht, weil sie zum einen in der ätiologisch relevanten, histologischen Zielregion (Str. gran.) exprimiert werden und des Weiteren in Kopplungsstudien chrom. Regionen für aut. rez. lamelläre Ichthyose /Selbstheilendes Kollodiumbaby, Harlekinichthyose, Netherton-Syndrom gezeigt wurden, in denen Genorte für die hier untersuchten Proteine platziert werden konnten. Wir konnten in der Arbeit erstmals ein Fehlen oder eine starke Reduktion zweier für die epidermale Biologie relevanter Proteine, TGase3 und CalpainI nachweisen. Die Befunde unterstreichen, dass diese Proteine, bzw. die für sie kodierenden Gene als Kandidatengene für ARLI/SHCB und HI in Frage kommen. Die Bedeutung von TGase3 Defizienz bei NTS kann derzeit als sekundäre Folge des Mangels von LEKTI angesehen werden, einem Serinproteaseinhibitor für den SPINK5 kodiert

A time-resolved fluorescence immunoassay for the measurement of testosterone in saliva: Monitoring of testosterone replacement therapy with testosterone buciclate

Monitoring of testosterone replacement therapy requires a reliable method for testosterone measurement. Determination of salivary testosterone, which reflects the hormone's biologically active plasma fraction, is a superior technique for this purpose. The aim of the present study was to establish a new sensitive time-resolved fluorescence immunoassay for the accurate measurement of testosterone levels in saliva and to validate it by monitoring testosterone replacement therapy in eight hypogonadal men. A clinical phase I- study with the new ester testosterone buciclate was performed to search for new testosterone preparations to produce constant serum levels in the therapy of male hypogonadism. After two control examinations eight male patients with primary hypogonadism were randomly assigned to two treatment groups (n = 2x4) and given single doses of either 200 mg (group I) or 600 mg (group II) testosterone buciclate intramuscularly. Saliva and blood samples were obtained 1, 2, 3, 5 and 7 days post injection and then weekly for three months. The time-resolved fluorescence immunoassay for salivary testosterone shows a detection limit of 16 pmol/l, an intra-assay CV of 8.9% (at a testosterone concentration of 302 pmol/l), an inter-assay CV of 8.7% (at a testosterone concentration of 305 pmol/l) and a good correlation with an established radioimmunsassay of r = 0.89. The sample volume required by this method is only 180 mu l for extraction and duplicate determination. The assay procedure requires no more than three hours. In group I (200 mg) testosterone did not increase to normal levels either in saliva or in serum. However, in group II, androgen levels increased significantly and were maintained in the normal range for up to 12 weeks with maximal salivary testosterone levels of 303 +/- 18 pmol/l (mean+/-SE) and maximal testosterone levels of 13.1 +/- 0.9 nmol/l (mean+/-SE) in serum in study week 6 and 7. The time-resolved fluorescence immunoassay for salivary testosterone provides a useful tool for monitoring androgen status in men and women and is well suited for the follow-up of testosterone replacement therapy on an outpatient basis. The long-acting ester testosterone buciclate is a promising agent for substitution therapy of male hypogonadism and in combination with testosterone monitoring in saliva offers an interesting new perspective for male contraception

Requirements for an IoT-lock enabling asynchronous physical handovers of temi-trailers in road freight relay-transport

In long-distance road freight transport, capacity utilization of semi-trailers is less than 30 % due to mandatory steering and rest periods. Truck parking spaces are overcrowded while resulting parking search traffic leads to additional emissions. At the same time, the acute driver shortage and customers' expectations of ever faster functioning supply chains force the highest efficiency in transport means and personnel. Multi-carrier relay-transport represents an approach to solving these problems and exploiting untapped efficiency potentials: Via a digital platform, long distances are intelligently divided into short route sections which are distributed among different carriers. At predefined switching points, the asynchronous handover of semi-trailers to rested drivers takes place. To enable a secure cross-company physical handover, IoT-locking mechanisms play a crucial role. This paper details the asynchronous handover process and introduces the technical design of an IoT-lock which provides effective theft protection while the trailer is parked and reliably connects tractor and semi-trailer during transport. Based on an analysis of stakeholder requirements, software functionalities and mechanical properties of the IoT-lock are derived, which ensure effective theft protection as well as real-time data transmission for relay transports. In addition, legal requirements for asynchronous transfers are investigated to determine liability in case of damage or loss. These form the basis for digital handover protocols that record the condition of the freight and trailer during the handover process

Ageing, physical function, and the diurnal rhythms of cortisol and dehydroepiandrosterone

The present study examined the relationship between ageing, physical function and the diurnal rhythms of cortisol and dehydroepiandrosterone (DHEA). Participants were 36 community dwelling older adults aged between 65-86 years old. Salivary cortisol and DHEA were measured over the course of one day: immediately upon awakening, 30 min later, and then 3 h, 6 h, 9 h and 12 h post-awakening. Participants completed the Nottingham extended activities of daily living index, the Berg Balance Scale and their handgrip strength was assessed. Older participants had a significantly higher cortisol area under the curve (AUC), lower overall DHEA levels, lower DHEA AUC, a decreased diurnal slope of decline and increased cortisol:DHEA ratio. Lower diurnal cortisol levels were associated with poorer performance on the Berg Balance Scale and lower handgrip strength, and those with a flattened DHEA diurnal profile reported less independence in carrying out daily tasks. These associations withstood adjustment for age. In conclusion, this study suggests an association between cortisol, DHEA, ageing and physical function

Позиционный электропривод механизма перемещения

Объектом исследования является позиционный асинхронный электропривод механизма горизонтального перемещения груза. Цель работы – исследовать основные характеристики асинхронного электропривода с трехконтурной системой управления положением вала двигателя. В процессе исследования проводились выбор асинхронного двигателя для механизма перемещения, расчет параметров двигателя, его статических и динамических характеристик, выбор преобразователя частоты, синтез трехконтурной системы управления следящим электроприводом на базе регулируемого с векторным управлением.The object of the study is a positional asynchronous electric drive mechanism for the horizontal movement of cargo. The purpose of the work is to investigate the basic characteristics of an asynchronous electric drive with a three-circuit control system for positioning the motor shaft. In the process of research, the choice of an asynchronous motor for the displacement mechanism, calculation of the engine parameters, its static and dynamic characteristics, choice of a frequency converter, synthesis of a three-circuit control system for a servomotor drive based on an adjustable vector control were made