Envelope Factorization with Partial Elimination and Recombination, EF-PER, a New Linear RF Architecture

In this paper, a new architecture for efficient linear radio frequency transmitters is proposed; it includes envelope-tracking (ET) and envelope-elimination-and-restoration (EER) architectures as special instances. The proposed technique is referred to as Envelope Factorization with Partial Elimination and Recombination (EF-PER). It relies on a decomposition of the RF signal before power amplification as a product of two signals, one of them being the envelope signal elevated to an exponent “α”. Compared to ET or EER architectures, the parameter “α” constitutes a new degree of freedom. This allows one to realize good tradeoffs between different performance criteria such as spectrum use, power efficiency, and transmitter linearity. An intuitive aggregate cost function is introduced to capture the desired tradeoff and turns out to be maximized in α=0.5. The full relevance of EF-PER is sustained both by analytical results and realistic simulations performed for OFDM signals. The EF-PER architecture (with α=0.5) has been simulated under Agilent-ADS with a non-linear transistor model from Avago (E-PHEMT) and compared with ET and EER

Safety Critical Systems Analysis

Abstract - A brief overview of the fields that must be considered when designing, implementing safety-critical systems is presented. The notion of safety is most likely to come to mind when we drive a car, fly on an airliner, or take an elevator ride. In each case, we are concerned with the threat of a mishap, which defined as an unplanned event or series of events that result in death, injury, occupational illness, damage to or loss of equipment or property or damage to the environment

20 Years of Progress in Malaria Research

U.S. Naval Medical Research Unit No. 2 Detachment (NAMRU), in collaboration with National Institute of Health Research and Development (NIHRD) and many other Indonesian government agencies and universities, has conducted studies of malaria throughout Java, Sumatra, Sulawesi, Kalimantan, Flores, Timor, and Irian Jaya. Most studies have characterized the disease epidemiologically by defining the parasitologic distribution of the disease in the population, and by defining the entomologic parameters of local transmission. Studies of patterns of resistance to antimalarials have also been done at many field sites. Several studies on the clinical management of malaria occurred in Rumah Sakit Umum Propinsi in Jayapura. In addition to these studies which impact upon local public health planning policy, immunologic studies routinely occurred in support of the global effort to develop a vaccine against malaria. This report summarizes the progress made in these areas of research during the first 20 years of NAMRU in Indonesia

UWB Vivaldi Antenna Array Lower Band Improvement for Ground Penetrating Radar Applications

This paper concerns a ground penetrating radar system (GPR) presenting beam forming ability. This ability is due to a great flexibility in the emission of wavefronts. The innovative concept is to use an array of antennas which can reconfigure itself dynamically, in order to focus on a desired target. This antennas system can act as a new microwave sensor to detect and characterize buried targets in an inhomogeneous medium which is the case study in various application fields such as geophysics, medical, planetology… Its electronics are in development with the DORT (Time reversal technique) method integration for optimizing the localization of buried target. This paper aims are to present the antenna optimization used in the GPR applications. Typical antennas used in GPR are generally Vivaldi ones directly on the ground. Especially, in the context of the space mission ExoMars 2020, the radar antenna is set on a mobile station at a distance of about 30 cm from the ground to avoid any contact. However, they are limited by their important size, due to the lowest frequency of their bandwidth. Results of this work concern an increase of the antenna bandwidth by shifting the lower-band limit, making it a UWB type [500 MHz - 4 GHz] without changing its size. As low frequency waves can spread deeper into probed medium, this optimization can improve the radar data inversion performances

A mathematical model for the burden of diabetes and its complications

BACKGROUND: The incidence and prevalence of diabetes are increasing all over the world. Complications of diabetes constitute a burden for the individuals and the whole society. METHODS: In the present paper, ordinary differential equations and numerical approximations are used to monitor the size of populations of diabetes with and without complications. RESULTS: Different scenarios are discussed according to a set of parameters and the dynamical evolution of the population from the stage of diabetes to the stage of diabetes with complications is clearly illustrated. CONCLUSIONS: The model shows how efficient and cost-effective strategies can be obtained by acting on diabetes incidence and/or controlling the evolution to the stage of complications

Genetic Variants of the Renin Angiotensin System: Effects on Atherosclerosis in Experimental Models and Humans

The renin angiotensin system (RAS) has profound effects on atherosclerosis development in animal models, which is partially complimented by evidence in the human disease. Although angiotensin II was considered to be the principal effector of the RAS, a broader array of bioactive angiotensin peptides have been identified that have increased the scope of enzymes and receptors in the RAS. Genetic interruption of the synthesis of these peptides has not been extensively performed in experimental or human studies. A few studies demonstrate that interruption of a component of the angiotensin peptide synthesis pathway reduces experimental lesion formation. The evidence in human studies has not been consistent. Conversely, genetic manipulation of the RAS receptors has demonstrated that AT1a receptors are profoundly involved in experimental atherosclerosis. Few studies have reported links of genetic variants of angiotensin II receptors to human atherosclerotic diseases. Further genetic studies are needed to define the role of RAS in atherosclerosis

The Female Athlete's Heart: Facts and Fallacies.

Purpose of the review For many years, competitive sport has been dominated by men. Recent times have witnessed a significant increase in women participating in elite sports. As most studies investigated male athletes, with few reports on female counterparts, it is crucial to have a better understanding on physiological cardiac adaptation to exercise in female athletes, to distinguish normal phenotypes from potentially fatal cardiac diseases. This review reports on cardiac adaptation to exercise in females. Recent findings Recent studies show that electrical, structural, and functional cardiac changes due to physiological adaptation to exercise differ in male and female athletes. Women tend to exhibit eccentric hypertrophy, and while concentric hypertrophy or concentric remodeling may be a normal finding in male athletes, it should be evaluated carefully in female athletes as it may be a sign of pathology. Although few studies on veteran female athletes are available, women seem to be affected by atrial fibrillation, coronary atherosclerosis, and myocardial fibrosis less than male counterparts. Summary Males and females exhibit many biological, anatomical, and hormonal differences, and cardiac adaptation to exercise is no exception. The increasing participation of women in sports should stimulate the scientific community to develop large, longitudinal studies aimed at a better understanding of cardiac adaptation to exercise in female athletes

Influences of the G2350A polymorphism in the ACE Gene on cardiac structure and function of ball game players

<p>Abstract</p> <p>Background</p> <p>Except for the I/D polymorphism in the angiotensin I-converting enzyme (ACE) gene, there were few reports about the relationship between other genetic polymorphisms in this gene and the changes in cardiac structure and function of athletes. Thus, we investigated whether the G2350A polymorphism in the <it>ACE </it>gene is associated with the changes in cardiac structure and function of ball game players. Total 85 healthy ball game players were recruited in this study, and they were composed of 35 controls and 50 ball game players, respectively. Cardiac structure and function were measured by 2-D echocardiography, and the G2350A polymorphism in the <it>ACE </it>gene analyzed by the SNaPshot method.</p> <p>Results</p> <p>There were significant differences in left ventricular mass index (LVmassI) value among each sporting discipline studied. Especially in the athletes of basketball disciplines, indicated the highest LVmassI value than those of other sporting disciplines studied (p < 0.05). However, there were no significant association between any echocardiographic data and the G2350A polymorphism in the <it>ACE </it>gene in the both controls and ball game players.</p> <p>Conclusions</p> <p>Our data suggests that the G2350A polymorphism in the <it>ACE </it>gene may not significantly contribute to the changes in cardiac structure and function of ball game players, although sporting disciplines of ball game players may influence the changes in LVmassI value of these athletes. Further studies using a larger sample size and other genetic markers in the <it>ACE </it>gene will be needed.</p

Dietary fruits and vegetables and cardiovascular diseases risk

Diet is likely to be an important determinant of cardiovascular disease (CVD) risk. In this article, we will review the evidence linking the consumption of fruit and vegetables and CVD risk. The initial evidence that fruit and vegetable consumption has a protective effect against CVD came from observational studies. However, uncertainty remains about the magnitude of the benefit of fruit and vegetable intake on the occurrence of CVD and whether the optimal intake is five portions or greater. Results from randomized controlled trials do not show conclusively that fruit and vegetable intake protects against CVD, in part because the dietary interventions have been of limited intensity to enable optimal analysis of their putative effects. The protective mechanisms of fruit and vegetables may not only include some of the known bioactive nutrient effects dependent on their antioxidant, anti-inflammatory, and electrolyte properties, but also include their functional properties, such as low glycemic load and energy density. Taken together, the totality of the evidence accumulated so far does appear to support the notion that increased intake of fruits and vegetables may reduce cardiovascular risk. It is clear that fruit and vegetables should be eaten as part of a balanced diet, as a source of vitamins, fiber, minerals, and phytochemicals. The evidence now suggests that a complicated set of several nutrients may interact with genetic factors to influence CVD risk. Therefore, it may be more important to focus on whole foods and dietary patterns rather than individual nutrients to successfully impact on CVD risk reduction. A clearer understanding of the relationship between fruit and vegetable intake and cardiovascular risk would provide health professionals with significant information in terms of public health and clinical practice

UDP-glucose 4, 6-dehydratase Activity Plays an Important Role in Maintaining Cell Wall Integrity and Virulence of Candida albicans

Candida albicans, a human fungal pathogen, undergoes morphogenetic changes that are associated with virulence. We report here that GAL102 in C. albicans encodes a homolog of dTDP-glucose 4,6-dehydratase, an enzyme that affects cell wall properties as well as virulence of many pathogenic bacteria. We found that GAL102 deletion leads to greater sensitivity to antifungal drugs and cell wall destabilizing agents like Calcofluor white and Congo red. The mutant also formed biofilms consisting mainly of hyphal cells that show less turgor. The NMR analysis of cell wall mannans of gal102 deletion strain revealed that a major constituent of mannan is missing and the phosphomannan component known to affect virulence is greatly reduced. We also observed that there was a substantial reduction in the expression of genes involved in biofilm formation but increase in the expression of genes encoding glycosylphosphatidylinositol-anchored proteins in the mutant. These, along with altered mannosylation of cell wall proteins together might be responsible for multiple phenotypes displayed by the mutant. Finally, the mutant was unable to grow in the presence of resident peritoneal macrophages and elicited a weak pro-inflammatory cytokine response in vitro. Similarly, this mutant elicited a poor serum pro-inflammatory cytokine response as judged by IFNγ and TNFα levels and showed reduced virulence in a mouse model of systemic candidiasis. Importantly, an Ala substitution for a conserved Lys residue in the active site motif YXXXK, that abrogates the enzyme activity also showed reduced virulence and increased filamentation similar to the gal102 deletion strain. Since inactivating the enzyme encoded by GAL102 makes the cells sensitive to antifungal drugs and reduces its virulence, it can serve as a potential drug target in combination therapies for C. albicans and related pathogens