HIV type 1 subtypes in Malaysia, determined with serologic assays: 1992-1996

We investigated the molecular epidemiology of HIV-1 subtypes in Malaysia among injecting drug users (IDUs) and sexual transmission risk groups, using serologic and genetic techniques. Frozen sera collected at a general hospital, a blood bank, several drug treatment centers, and an STD clinic in Kuala Lumpur, between 1992 and 1996, were investigated retrospectively. V3 peptide serotyping and monomeric gp120 capture serotyping were used to study 89 known HIV-1-infected subjects. The methods differentiate subtypes B, E, and C. V3 peptide and gp120 capture results were comparable. No subtype C-specific reactive sera were found; one specimen was dually reactive for subtypes C and B, using the V3 peptide ELISA; and four were durally reactive for subtypes E and C using this assay. Genotypic analysis of HIV-1 gag RNA in serum was done on a subset of subjects and confirmed serologic findings. HIV-1 subtypes differed significantly by risk category: of 53 IDUs, 29 (55%) were infected with subtype B and 19 (36%) were infected with subtype E, 3 (6%) were dually reactive, and 2 (4%) were not typable. Of 36 persons with heterosexual risks, 29 (81%) were infected with subtype E, 5 (14%) were infected with subtype B, and 2 (5%) were not typable. Persons with IDU risks were significantly more likely to be infected with subtype B than were those with sexual risks (OR 5.89; 95% CI, 1.94-18.54; p < 0.001). Subtypes B and E of HIV-1 appear to predominate in Malaysia; subtype B was more prevalent among IDUs; subtype E was more prevalent among all other groups. These results may have important HIV-1 vaccine implications.     

On the development of a biomechatronic system to record tendon sliding movements

The main goal of this paper is to study the feasibility of a novel implantable micro-system able to record information about tendon sliding movements by using contactless measurement devices (magnetic sources and sensors). The system, named "Biomechatronic Position Transducer" (BPT), can be used for the implementation of advanced control strategies in neuroprostheses. After a preliminary analysis based on finite element model simulations, an experimental setup was developed in order to simulate the recording conditions (the sensors fixed to the bones and the magnetic sources placed on the tendons). In order to limit the number of implanted components of the system, a fuzzy Mamdani-like architecture was developed to extract the information from the raw data. The results confirm the possibility of using the presented approach for developing an implantable micro-sensor able to extract kinematic information useful for the control of neuroprostheses. Future works will go in the direction of integrating and testing the sensors and the electronic circuitry (to provide power supply and to record the data) during in vitro and in situ experiments.     

基于猜测供给函数的需求弹性对电力市场运行的影响

影响市场运行的一个重要因素是需求弹性。低需求弹性将导致市场出清价格高,市场运行效率低,经济效益分配不合理。由于电力商品的特殊性,目前电力市场本质上具有寡头竞争的特点。相对较完全的竞争市场,发电商的策略竟标行为将导致市场运行在低效率水平下,这一消极因素在低需求弹性下尤为突出。为此提出了一个能评估需求弹性对发电商策略竞标行为影响的模型。该模型将发电商的博弈行为模拟成猜测供给函数(conjiecture supply function,CSF)竞争,同时将交易市场中的用户需求弹性包含在数学模型中。通过对意大利电力市场的单时段交易的模拟,运用一系列指标来量化评估需求弹性对具有寡头竞争性质的市场运行的影响。     

Dolichol levels in younger and older rat hearts heterotopically transplanted in younger recipients

Dolichol (D) levels increase dramatically in older tissue. An understanding of the exchangeability of D between tissues may be essential in order to understand the mechanism of the abnormal accumulation associated with aging. The question was investigated by the use of organ transplantation. D-poor hearts donated by 3-mon-old and D-rich by 22-mon-old male Lewis rats were transplanted heterotopically in 3-mon-old syngenic recipients, whose peripheral tissues and liver were poor in D. Native and transplanted hearts were taken 7 and 21 d after surgery. Native hearts of 3-mon- and 22-mon-old male Lewis rats served as control. D concentration and quantity were higher in older than in younger native hearts as expected. In the transplanted hearts, the quantity of D was unchanged, irrespective of the age of the donor and of the time of transplantation, whereas D concentration increased because of the remarkable disuse atrophy. No changes in D were observed in recipients’ tissues. It is concluded that dolichol is not redistributed via circulation from the transplanted heart to the tissues and liver of the younger recipient.     

Contamination of vegetable oils marketed in Italy by phthalic acid esters

More than 90% of the phthalic acid esters (PAEs) produced in Europe is used to plasticize polyvinyl chloride (PVC). Animal studies have shown that some PAEs can damage the liver and interfere with the endocrine system, whereas data on the toxic effects on humans are inconsistent. For the general population, the diet is believed to be the main source of PAEs. Food can be contaminated from environmental pollution, industrial food processing (PVC tubing) and certain storage containers. The present study evaluates the contamination levels of the four main PAEs named Di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), diisononyl phthalate (DINP), in 172 samples of vegetable oils marketed in Italy. Diluted oils were directly analysed by GC–MS. PAEs concentrations in vegetable oils were lower than those reported in other studies. Olive-derived oils showed the highest levels. Considering their high consumption in Italy, this finding is significant and some hypotheses on environmental or technological causes have been made. In the case of extravirgin olive oil, the higher levels of PAEs can be ascribed to the absence of the refining process since it has been verified that this technological treatment partially decontaminates the final product while for olive and olive pomace oils, both refined oils, the reasons for a higher contamination are less clear. Probably, a different plant uptake of PAEs from the air, water and soil could give account of this finding. Finally, the percentage Italian intake of PAEs due to the various types of vegetable oils analysed has been calculated.     

A fast object-oriented Matlab implementation of the Reproducing Kernel Particle Method

Novel numerical methods, known as Meshless Methods or Meshfree Methods and, in a wider perspective, Partition of Unity Methods, promise to overcome most of disadvantages of the traditional finite element techniques. The absence of a mesh makes meshfree methods very attractive for those problems involving large deformations, moving boundaries and crack propagation. However, meshfree methods still have significant limitations that prevent their acceptance among researchers and engineers, namely the computational costs. This paper presents an in-depth analysis of computational techniques to speed-up the computation of the shape functions in the Reproducing Kernel Particle Method and Moving Least Squares, with particular focus on their bottlenecks, like the neighbour search, the inversion of the moment matrix and the assembly of the stiffness matrix. The paper presents numerous computational solutions aimed at a considerable reduction of the computational times: the use of kd-trees for the neighbour search, sparse indexing of the nodes-points connectivity and, most importantly, the explicit and vectorized inversion of the moment matrix without using loops and numerical routines.     

Congestion management impacts on bilateral electricity markets under strategic negotiation

Congestion management design is key to a fair and efficient use of transmission facilities and an improvement of market efficiency. Emergence of bilateral electricity markets provides a more flexible, private and decentralized decision-making scenario, in which the self-interested players autonomously search for counterparts to negotiate profitable transactions. In competitive bilateral markets of imperfect and incomplete information and explicit consideration of the network constraints, which make the markets significantly complex, more sophisticated bargaining strategies and market evaluation tools are imperative to both players and regulators.In this paper, under an assumption of imperfect and incomplete information, evolutionary bipartite complex network theory is employed to develop quantities bidding strategies through a dynamic game, in which the players drive the evolution of the network while maximizing their own utilities with explicitly considering the congestion management results. Resorting to adjustment bids, two congestion management schemes, with and without balancing bilateral transactions, are considered.The approach is illustrated with an application to the IEEE30 test system, assessing the impact of different congestion management schemes on the negotiations, market equilibria, market performance and gaming opportunities for the market participants in congestion managements.     

Monte Carlo analysis of a lateral IBIC experiment on a 4H-SiC Schottky diode

The transport properties of a 4H-SiC Schottky diode have been investigated by the ion beam induced charge (IBIC) technique in lateral geometry through the analysis of the charge collection efficiency (CCE) profile at a fixed applied reverse bias voltage.The cross section of the sample orthogonal to the electrodes was irradiated by a rarefied 4 MeV proton microbeam and the charge pulses have been recorded as function of incident proton position with a spatial resolution of 2 μm.The CCE profile shows a broad plateau with CCE values close to 100% occurring at the depletion layer, whereas in the neutral region, the exponentially decreasing profile indicates the dominant role played by the diffusion transport mechanism.Mapping of charge pulses was accomplished by a novel computational approach, which consists in mapping the Gunn’s weighting potential by solving the electrostatic problem by finite element method and hence evaluating the induced charge at the sensing electrode by a Monte Carlo method. The combination of these two computational methods enabled an exhaustive interpretation of the experimental profiles and allowed an accurate evaluation both of the electrical characteristics of the active region (e.g. electric field profiles) and of basic transport parameters (i.e. diffusion length and minority carrier lifetime).