A prospective review on New Economic Geography

This paper serves as an orientation towards the understanding of some of the contributions and theoretical limitations in New Economic Geography and seeks to provide a prospective assessment of new avenues of research along which the field could improve and develop. We identify many of the persistent features and assumptions which have thwarted the evolution of New Economic Geography and led to a sprawl of criticism within the field. This criticism has opened a discussion towards the identification of new possible directions, some of which are being progressively undertaken, while others raise issues that are difficult to overcome both analytically and empirically.     

A mathematical model describing the two stages of low-pressure-vaporization of free water

This paper reports the development and application of a mathematical model for the prediction of the low-pressure-vaporization (LPV) process of free water. The study is focused on defining clearly the two stages of the LPV process (before and after the so-called flash point) and on evaluating their contribution for the overall transient evolution of the relevant parameters.     

Dendrimer‐Encapsulated Ruthenium Oxide Nanoparticles as Catalysts in Lithium‐Oxygen Batteries

Dendrimer‐encapsulated ruthenium oxide nanoparticles (DEN‐RuO₂) have been used as catalysts in lithium‐oxygen (Li‐O₂) batteries for the first time. The results obtained from ultraviolet‐visible spectroscopy, electron microscopy and X‐ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide, not metallic ruthenium as reported by other groups. The DEN‐RuO₂ significantly improves the cycling stability of Li‐O₂ batteries with carbon electrodes and decreases the charging potential even at ten times less catalyst loading than those reported previously. The monodispersity, porosity, and large number of surface functionalities of the dendrimer template prevent the aggregation of the RuO₂ nanoparticles, making their entire surface area available for catalysis. The potential of using DEN‐RuO₂ as a standalone cathode material for Li‐O₂ batteries is also explored.     

Quantification and molecular characterization of enteric viruses detected in effluents from two hospital wastewater treatment plants

Hospital wastewater has been described as an important source of spreading pathogenic microorganisms in the environment. However, there are few studies reporting the presence and concentrations of gastroenteric viruses and hepatitis A viruses in these environmental matrices. The aim of this study was to assess the contamination by viruses responsible for acute gastroenteritis and hepatitis derived from hospital wastewater treatment plants (WWTPs). Rotavirus A (RV-A), human adenoviruses (HAdV), norovirus genogroup I and II (NoV GI/GII) and hepatitis A viruses (HAV) were detected and quantified in sewage samples from two WWTPs located in Rio de Janeiro (Brazil) that operates different sewage treatments. WWTP-1 uses an Upflow Anaerobic Sludge Blanket (UASB reactor) and three serial anaerobic filters while WWTP-2 uses aerobic processes, activated sludge with extended aeration and final chlorination of the effluents. Viruses’ detection was investigated by using conventional PCR/RT-PCR, quantitative real-time PCR (qPCR) and partial sequencing of the genome of the viruses detected. Rate of viruses detection ranged from 7% (NoV GI in WWTP-1) to 95% (RV-A in WWTP-2) and genome from all viruses were detected. The most prevalent genotypes were RV-A SG I, HAdV species D and F, NoV GII/4 and HAV subgenotype IA. Mean values of viral loads (genome copies (GC)/ml) obtained in filtered effluents from anaerobic process was 1.9 × 10³ (RV-A), 2.8 × 10³ (HAdV) and 2.4 × 10³ (NoV GII). For chlorinated effluents from activated sludge process, the mean values of viral loads (GC/ml) was 1.2 × 10⁵ (RV-A), 1.4 × 10³ (HAdV), 8.1 × 10² (NoV GII) and 2.8 × 10⁴ (HAV). Data on viral detection in treated effluents of hospital WWTPs confirmed the potential for environmental contamination by viruses and could be useful to establish standards for policies on wastewater management.     

Formulation of chitosan-TPP-pDNA nanocapsules for gene therapy applications

The encapsulation of DNA inside nanoparticles meant for gene delivery applications is a challenging process where several parameters need to be modulated in order to design nanocapsules with specific tailored characteristics. The purpose of this study was to investigate and improve the formulation parameters of plasmid DNA (pDNA) loaded in chitosan nanocapsules using tripolyphosphate (TPP) as polyanionic crosslinker. Nanocapsule morphology and encapsulation efficiency were analyzed as a function of chitosan degree of deacetylation and chitosan-TPP ratio. The manipulation of these parameters influenced not only the particle size but also the encapsulation and release of pDNA. Consequently the transfection efficiency of the nanoparticulated systems was also enhanced with the optimization of the particle characteristics. Overall, the differently formulated nanoparticulated systems possess singular properties that can be employed according to the desired gene delivery application.     

Defining the configuration of co‐rotating twin‐screw extruders with multiobjective evolutionary algorithms

Multiobjective evolutionary algorithms have already been used for the optimization of the processing conditions of a co‐rotating twin screw extruder. In the present paper, we develop this approach for the optimization of the screw geometry, in terms of the most adequate location of a pre‐selected set of screw elements, in order to maximize a prescribed performance. Experimental validation shows the pertinence of this approach, which is computationally more rapid and less expensive than the classical trial and error procedure. An application to the complex case of reactive extrusion is also presented. POLYM. ENG. SCI., 45:1159–1173, 2005. © 2005 Society of Plastics Engineers     

Relationship between the number of daily meals and the energy and nutrient intake in the elderly. Effect on various cardiovascular risk factors]

The research literature on the psychiatric consequences of the Vietnam War focuses primarily on the construct of Posttraumatic Stress Disorder (PTSD), after an initial focus in the 1970s on depression and alcohol and substance abuse. The present paper examines the hypothesis that among men without current PTSD, those with higher combat in Vietnam will be more likely to have current DSM-III-R illnesses. The Australian Vietnam Veterans' Health Study (AVVHS) collected a broad range of interview data on 641 Vietnam veterans throughout 1990-1993. Measures of combat exposure, age at embarkation to Vietnam, enlistment IQ and pre-Army personality problems were drawn from Army records of the era. Retrospective measures of combat were obtained at interview. The interview also involved the administration by trained lay interviewers of the DSM-III-R based Diagnostic Interview Schedule (DIS). This epidemiological instrument provides current psychiatric diagnoses as well as temporal (retrospective) symptom and diagnosis onset data. The results of this study show that current disorders (without PTSD comorbidity) with onsets within 5 years of embarkation to Vietnam are more likely among men who saw higher combat, as indexed by combat-exposure measures drawn from Army records of the era as well as retrospective self-report. This combat relatedness remains when age at embarkation. IQ at enlistment and pre-Army personality measures are used as covariates. No more than 11.4% of sampled Vietnam veterans currently meet DSM-III-R diagnostic criteria for PTSD, while a further 7.8% do not have current PTSD but do have some other current DIS diagnosis with onset in the 5-year period following (first) emabarkation to Vietnam. Our data support the hypothesis that the current illnesses of many of these men without PTSD are combat-related DSM-III-R illnesses.     

Clinical experience with AVE Micro Stent. Results of the implantation of 204 stents

To assess the efficacy and safety of the AVE Micro Stent, we deployed 204 stents in 144 consecutive patients during a one year period. Indications for stenting were acute closure in 3.4%, dissection in 5.4%, post balloon pTCA restenosis in 3.4%, non-favorable result in 16.7% and de novo in 71.1%. Patient population included 39 (27%) patients with stable angina, 86 (59.7%) with unstable angina, 16 (11.1%) with acute MI and 3 (2.1%) with cardiogenic shock. Angiographic lesion morphology were as follows: type A, 17.7%, type B1, 42.1%; type B2, 16.2%; type C, 24%. Procedural success was obtained in 204 of 205 attempted stents (99.5%) and clinical success was 93.1%. Oral anticoagulation was not routinely used. Enzymatic elevation consistent with myocardial necrosis occurred in 3.2% with Q wave MI in 0.7%. Three patients (2.1%) had bleeding at site of femoral puncture with one requiring transfusion and surgery. Mortality was 0.8% in the angina group, 6.25% in the MI group and one of the 3 patients with cardiogenic shock died and represents the only apparent stent thrombosis as she experienced sudden death one week after successful left main stenting. We conclude that high success rates can be obtained with the AVE Micro Stent due to it's excellent trackability, adequate radio-opacity and relative flexibility.     

Development of enzyme-loaded nanoparticles: effect of pH

Enzyme superoxide dismutase (SOD) incorporation parameters were evaluated after immobilization in polyisobutylcyanoaclylate (PIBCA) nanoparticles. After initialization of the anionic mechanism of polymerization, pH was increased and its effect on the characteristics of PIBCA nanoparticles analysed. Our goal included optimization of enzyme activity during incorporation into nanoparticles and the influence on size distribution. Unloaded nanoparticles were not significantly affected by the pH increase. At pH 3 the size distribution indicates a bimodal distribution: 58 nm (63%) and 146 nm (37%). When pH was increased to 5 after 1 h of polymerization the size distribution is: 57 nm (70%) and 125 nm (30%). When pH was increased to 5, after 2 h of polymerization, the size distribution is 67 nm (56%) and 160 nm (44%). Meanwhile, the retention of activity of SOD in polymerization medium is 49% at pH 3, and 98% at pH 5. The effect of pH increase from 3 to 5, after 1 h of polymerization, on the characteristics of loaded nanoparticles is an increase of retention of enzyme activity (18 to 30%); and the evidence of a pH-dependent smaller size population of loaded nanoparticles. In fact at pH 3 the size distribution is 83 nm (15%), 195 nm (15%), 440 nm (70%) and when pH is increased from 3 to 5 the size distribution becomes 55 nm (30%); 170 nm (30%); 430 nm (40%).This paper was accepted for publication after the 1995 Conference of the European Society of Biomaterials, Oporto, Portugal, 10–13 September.