Air services on thin routes: Regional versus low-cost airlines

An examination of the impact in the US and EU markets of two major innovations in the provision of air services on thin routes - regional jet technology and the low-cost business model - reveals significant differences. In the US, regional airlines monopolize a high proportion of thin routes, whereas low-cost carriers are dominant on these routes in Europe. Our results have different implications for business and leisure travelers, given that regional services provide a higher frequency of flights (at the expense of higher fares), while low-cost services offer lower fares (at the expense of lower flight frequencies). Keywords: air transportation; regional jet technology; low-cost business model; thin markets. JEL Classification Numbers: L13; L2; L93.

Creació i transmissió de coneixement als clústers empresarials: un model de simulació

Projecte de recerca elaborat a partir d’una estada a l’Snider Entrepreneurial Research Center de la Wharton School de la University of Pennsilvanya y, EUA entre juliol i desembre del 2007. L’objectiu d’aquest projecte és estudiar la relació entre les estratègies de gestió del coneixement i les tecnologies de la informació i la comunicació (TIC) en l’evolució de les poblacions d’organitzacions i els seus efectes en els patrons industrials d’aglomeració espacial. Per a això s’adopta una aproximació fonamentada en la utilització d'un model basats en agents per a obtenir hipòtesis significatives i provables sobre l’evolució de les poblacions d’organitzacions al si de clústers geogràfics. El model de simulació incorpora les perspectives i supòsits d’un marc conceptual, l’Espai de la Informació o I-Space. Això permet una conceptualització basada en la informació de l’entorn econòmic que té en compte les seves dimensions espacials i temporals. Mitjançant els paràmetres del model es dóna la possibilitat d’assignar estratègies específiques de gestió del coneixement als diversos agents i de localitzar-los en una posició de l’espai físic. La simulació mostra com l'adopció d'estratègies diverses pel que fa a la gestió del coneixement influeix en l'evolució de les organitzacions i de la seva localització espacial, i que aquesta evolució es veu modificada pel desenvolupament de les TIC. A través de la modelització de dos casos ben coneguts de clústers geogràfics d’alta tecnologia, com són Silicon Valley a Califòrnia i la Route 128 als voltants de Boston, s’estudia la interrelació entre les estratègies de gestió del coneixement adoptades per les empreses i la seva tria de localització espacial, i també com això és afectat per l’evolució de les tecnologies de la informació i de la comunicació (TIC). Els resultats obtinguts generen una sèrie d’hipòtesis de rica potencialitat sobre l’impacte del desenvolupament de les TIC en la dinàmica d’aquests clusters geogràfics. Concretament, es troba que la estructuració del coneixement i l’aglomeració espacial co-evolucionen i que aquesta coevolució es veu significativament alterada pel desenvolupament de les TIC.

Occupational exposure of truck drivers to dust and polynuclear aromatic hydrocarbons: a pilot study in Geneva, Switzerland.

The exposure to dust and polynuclear aromatic hydrocarbons (PAH) of 15 truck drivers from Geneva, Switzerland, was measured. The drivers were divided between "long-distance" drivers and "local" drivers and between smokers and nonsmokers and were compared with a control group of 6 office workers who were also divided into smokers and nonsmokers. Dust was measured on 1 workday both by a direct-reading instrument and by sampling. The local drivers showed higher exposure to dust (0.3 mg/m3) and PAH than the long-distance drivers (0.1 mg/m3), who showed no difference with the control group. This observation may be due to the fact that the local drivers spend more time in more polluted areas, such as streets with heavy traffic and construction sites, than do the long-distance drivers. Smoking does not influence exposure to dust and PAH of professional truck drivers, as measured in this study, probably because the ventilation rate of the truck cabins is relatively high even during cold days (11-15 r/h). The distribution of dust concentrations was shown in some cases to be quite different from the expected log-normal distribution. The contribution of diesel exhaust to these exposures could not be estimated since no specific tracer was used. However, the relatively low level of dust exposure dose not support the hypothesis that present day levels of diesel exhaust particulates play a significant role in the excess occurrence of lung cancer observed in professional truck drivers.

Exposure to tobacco smoke before and after a partial smoking ban in prison: indoors air quality measures

Although exposure to secondhand smoke (SHS) is reportedly high in prison, few studies have measured this in the prison environment, and none have done so in Europe. We measured two indicators of SHS exposure (particulate matter PM10 and nicotine) in fixed locations before (2009) and after (2010) introduction of a partial smoking ban in a Swiss prison. Access to smoking cessation support was available to detainees throughout the study. Objectives To measure SHS before and after the introduction of a partial smoking ban. Methods Assessment of particulate matter PM10 (suspended microparticles of 10 μm) and nicotine in ambient air, collected by real-time aerosol monitor and nicotine monitoring devices. Results The authors observed a significant improvement of nicotine concentrations in the air after the introduction of the smoking ban (before: 7.0 μg/m(3), after: 2.1 μg/m(3), difference 4.9 μg/m(3), 95% CI for difference: 0.52 to 9.8, p=0.03) but not in particulate matter PM10 (before: 0.11 mg/m(3), after: 0.06 mg/m(3), difference 0.06 mg/m(3), 95% CI for difference of means: -0.07 to 0.19, p=0.30). Conclusions The partial smoking ban was followed by a decrease in nicotine concentrations in ambient air. These improvements can be attributed to the introduction of the smoking ban since no other policy change occurred during this period. Although this shows that concentrations of SHS decreased significantly, protection was still incomplete and further action is necessary to improve indoor air quality.

2006 National Drug Control Strategy launched in US

The Bush administration announced its 2006 National Drug Control Strategy in the first city to legalize marijuana, a decision that wasn't entirely coincidental. John P. Walters, director of the Office of National Drug Control Policy, who selected a youth drug treatment center here as the site for the announcement, said Denver represented 'a model of what we see and what we're trying to face'. The 2006 strategy calls for a continuation of the Bush administration's balance of reducing demand through, among other things, drug-prevention campaigns, and reducing supply by securing the Mexican border. Mr. Walters described the strategy, implemented in 2001, as a success, pointing to studies showing that overall teenage drug use has dropped since then by 19 per cent. Use of methamphetamine, LSD and steroids also have declined, he said.This resource was contributed by The National Documentation Centre on Drug Use.

Web de control de tráfico marítimo

El proyecto Web de Control de Tráfico Marítimo (WCTM) un proyecto Web que va a gestionar información útil para el Control del Tráfico Marítimo de una determinada zona del mundo. Usa el concepto de arquitectura SOA, una arquitectura que se basa en los servicios Web, proporciona en tiempo real información sobre los buques usando los mapas de Google.

Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations:a nested case-control study

Objective. To examine the association between pre-diagnostic circulating vitamin D concentration, dietary intake of vitamin D and calcium, and the risk of colorectal cancer in European populations. Design Nested case-control study. Setting. The study was conducted within the EPIC study, a cohort of more than 520 000 participants from 10 western European countries. Participants: 1248 cases of incident colorectal cancer, which developed after enrolment into the cohort, were matched to 1248 controls. Main outcome measures. Circulating vitamin D concentration (25-hydroxy-vitamin-D, 25-(OH)D) was measured by enzyme immunoassay. Dietary and lifestyle data were obtained from questionnaires. Incidence rate ratios and 95% confidence intervals for the risk of colorectal cancer by 25-(OH)D concentration and levels of dietary calcium and vitamin D intake were estimated from multivariate conditional logistic regression models, with adjustment for potential dietary and other confounders. Results. 25-(OH)D concentration showed a strong inverse linear dose-response association with risk of colorectal cancer (P for trend <0.001). Compared with a pre-defined mid-level concentration of 25-(OH)D (50.0-75.0 nmol/l), lower levels were associated with higher colorectal cancer risk (<25.0 nmol/l: incidence rate ratio 1.32 (95% confidence interval 0.87 to 2.01); 25.0-49.9 nmol/l: 1.28 (1.05 to 1.56), and higher concentrations associated with lower risk (75.0-99.9 nmol/l: 0.88 (0.68 to 1.13); ≥100.0 nmol/l: 0.77 (0.56 to 1.06)). In analyses by quintile of 25-(OH)D concentration, patients in the highest quintile had a 40% lower risk of colorectal cancer than did those in the lowest quintile (P<0.001). Subgroup analyses showed a strong association for colon but not rectal cancer (P for heterogeneity=0.048). Greater dietary intake of calcium was associated with a lower colorectal cancer risk. Dietary vitamin D was not associated with disease risk. Findings did not vary by sex and were not altered by corrections for season or month of blood donation. Conclusions The results of this large observational study indicate a strong inverse association between levels of pre-diagnostic 25-(OH)D concentration and risk of colorectal cancer in western European populations. Further randomised trials are needed to assess whether increases in circulating 25-(OH)D concentration can effectively decrease the risk of colorectal cancer.

Air pollution exposure during pregnancy and reduced birth size: a prospective birth cohort study in Valencia, Spain

Background Maternal exposure to air pollution has been related to fetal growth in a number of recent scientific studies. The objective of this study was to assess the association between exposure to air pollution during pregnancy and anthropometric measures at birth in a cohort in Valencia, Spain. Methods Seven hundred and eighty-five pregnant women and their singleton newborns participated in the study. Exposure to ambient nitrogen dioxide (NO2) was estimated by means of land use regression. NO2 spatial estimations were adjusted to correspond to relevant pregnancy periods (whole pregnancy and trimesters) for each woman. Outcome variables were birth weight, length, and head circumference (HC), along with being small for gestational age (SGA). The association between exposure to residential outdoor NO2 and outcomes was assessed controlling for potential confounders and examining the shape of the relationship using generalized additive models (GAM). Results For continuous anthropometric measures, GAM indicated a change in slope at NO2 concentrations of around 40 μg/m3. NO2 exposure >40 μg/m3 during the first trimester was associated with a change in birth length of -0.27 cm (95% CI: -0.51 to -0.03) and with a change in birth weight of -40.3 grams (-96.3 to 15.6); the same exposure throughout the whole pregnancy was associated with a change in birth HC of -0.17 cm (-0.34 to -0.003). The shape of the relation was seen to be roughly linear for the risk of being SGA. A 10 μg/m3 increase in NO2 during the second trimester was associated with being SGA-weight, odds ratio (OR): 1.37 (1.01-1.85). For SGA-length the estimate for the same comparison was OR: 1.42 (0.89-2.25). Conclusions Prenatal exposure to traffic-related air pollution may reduce fetal growth. Findings from this study provide further evidence of the need for developing strategies to reduce air pollution in order to prevent risks to fetal health and development.

Clinical and molecular epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli as a cause of nosocomial infection or colonization: implications for control.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing members of the Enterobacteriaceae family are important nosocomial pathogens. Escherichia coli producing a specific family of ESBL (the CTX-M enzymes) are emerging worldwide. The epidemiology of these organisms as causes of nosocomial infection is poorly understood. The aims of this study were to investigate the clinical and molecular epidemiology of nosocomial infection or colonization due to ESBL-producing E. coli in hospitalized patients, consider the specific types of ESBLs produced, and identify the risk factors for infection and colonization with these organisms. METHODS: All patients with nosocomial colonization and/or infection due to ESBL-producing E. coli in 2 centers (a tertiary care hospital and a geriatric care center) identified between January 2001 and May 2002 were included. A double case-control study was performed. The clonal relatedness of the isolates was studied by repetitive extragenic palindromic-polymerase chain reaction and pulsed-field gel electrophoresis. ESBLs were characterized by isoelectric focusing, polymerase chain reaction, and sequencing. RESULTS: Forty-seven case patients were included. CTX-M-producing E. coli were clonally unrelated and more frequently susceptible to nonoxyimino-beta-lactams. Alternately, isolates producing SHV- and TEM-type ESBL were epidemic and multidrug resistant. Urinary catheterization was a risk factor for both CTX-M-producing and SHV-TEM-producing isolates. Previous oxyimino-beta-lactam use, diabetes, and ultimately fatal or nonfatal underlying diseases were independent risk factors for infection or colonization with CTX-M-producing isolates, whereas previous fluoroquinolone use was associated with infection or colonization with SHV-TEM-producing isolates. CONCLUSIONS: The epidemiology of ESBL-producing E. coli as a cause of nosocomial infection is complex. Sporadic CTX-M-producing isolates coexisted with epidemic multidrug-resistant SHV-TEM-producing isolates. These data should be taken into account for the design of control measures.

Admission Control for TCP Flows Using Packet Classes and Edge-to-edge Measurements of Aggregates

TCP flows from applications such as the web or ftp are well supported by a Guaranteed Minimum Throughput Service (GMTS), which provides a minimum network throughput to the flow and, if possible, an extra throughput. We propose a scheme for a GMTS using Admission Control (AC) that is able to provide different minimum throughput to different users and that is suitable for "standard" TCP flows. Moreover, we consider a multidomain scenario where the scheme is used in one of the domains, and we propose some mechanisms for the interconnection with neighbor domains. The whole scheme uses a small set of packet classes in a core-stateless network where each class has a different discarding priority in queues assigned to it. The AC method involves only edge nodes and uses a special probing packet flow (marked as the highest discarding priority class) that is sent continuously from ingress to egress through a path. The available throughput in the path is obtained at the egress using measurements of flow aggregates, and then it is sent back to the ingress. At the ingress each flow is detected using an implicit way and then it is admission controlled. If it is accepted, it receives the GMTS and its packets are marked as the lowest discarding priority classes; otherwise, it receives a best-effort service. The scheme is evaluated through simulation in a simple "bottleneck" topology using different traffic loads consisting of "standard" TCP flows that carry files of varying sizes

Conceiving Comparative Policy Analysis : Implementing Air Quality Improvement Programs

The comparative analysis of air quality control policies provides an interesting field for studies of comparative policy analysis including program formulation and implementation processes. In European countries, the problem is comparable, whereas implementation structures, programs and policy impacts vary to a considerable extent. Analysis testing possibilities and constraints of air control policies under varying conditions are likely to contribute to a further development of a theory of policy analysis. This paper presents the analytical framework applied in a continuing empirical study explaining program formulation and implementation processes with respect to the different actors involved. Concrete emitter behavior can be explained by interaction processes at the very local level, by program elements of national legislation, and by structural constraints under which such programs are produced.

Genome-wide mRNA expression correlates of viral control in CD4+ T-cells from HIV-1-infected individuals.

There is great interindividual variability in HIV-1 viral setpoint after seroconversion, some of which is known to be due to genetic differences among infected individuals. Here, our focus is on determining, genome-wide, the contribution of variable gene expression to viral control, and to relate it to genomic DNA polymorphism. RNA was extracted from purified CD4+ T-cells from 137 HIV-1 seroconverters, 16 elite controllers, and 3 healthy blood donors. Expression levels of more than 48,000 mRNA transcripts were assessed by the Human-6 v3 Expression BeadChips (Illumina). Genome-wide SNP data was generated from genomic DNA using the HumanHap550 Genotyping BeadChip (Illumina). We observed two distinct profiles with 260 genes differentially expressed depending on HIV-1 viral load. There was significant upregulation of expression of interferon stimulated genes with increasing viral load, including genes of the intrinsic antiretroviral defense. Upon successful antiretroviral treatment, the transcriptome profile of previously viremic individuals reverted to a pattern comparable to that of elite controllers and of uninfected individuals. Genome-wide evaluation of cis-acting SNPs identified genetic variants modulating expression of 190 genes. Those were compared to the genes whose expression was found associated with viral load: expression of one interferon stimulated gene, OAS1, was found to be regulated by a SNP (rs3177979, p = 4.9E-12); however, we could not detect an independent association of the SNP with viral setpoint. Thus, this study represents an attempt to integrate genome-wide SNP signals with genome-wide expression profiles in the search for biological correlates of HIV-1 control. It underscores the paradox of the association between increasing levels of viral load and greater expression of antiviral defense pathways. It also shows that elite controllers do not have a fully distinctive mRNA expression pattern in CD4+ T cells. Overall, changes in global RNA expression reflect responses to viral replication rather than a mechanism that might explain viral control.

Surveillance, health promotion and control of Chagas disease in the Amazon Region - Medical attention in the Brazilian Amazon Region: a proposal

We refer to Oswaldo Cruz’s reports dating from 1913 about the necessities of a healthcare system for the Brazilian Amazon Region and about the journey of Carlos Chagas to 27 locations in this region and the measures that would need to be adopted. We discuss the risks of endemicity of Chagas disease in the Amazon Region. We recommend that epidemiological surveillance of Chagas disease in the Brazilian Amazon Region and Pan-Amazon region should be implemented through continuous monitoring of the human population that lives in the area, their housing, the environment and the presence of triatomines. The monitoring should be performed with periodic seroepidemiological surveys, semi-annual visits to homes by health agents and the training of malaria microscopists and healthcare technicians to identify Trypanosoma cruzi from patients’ samples and T. cruzi infection rates among the triatomines caught. We recommend health promotion and control of Chagas disease through public health policies, especially through sanitary education regarding the risk factors for Chagas disease. Finally, we propose a healthcare system through base hospitals, intermediate-level units in the areas of the Brazilian Amazon Region and air transportation, considering the distances to be covered for medical care.

Health effects of occupational exposure to traffic particles and noise

Exposure to fine particles and noise has been linked to cardiovascular diseases and elevated cardiovascular mortality affecting the worldwide population. Residence and/or work in proximity to emission sources as for example road traffic leads to an elevated exposure and a higher risk for adverse health effects. Highway maintenance workers spend most of their work time in traffic and are exposed regularly to particles and noise. The aims of this thesis were to provide a better understanding of the workers' mixed exposure to particles and noise and to assess cardiopulmonary short term health effects in relation to this exposure. Exposure and health data were collected in collaboration with 8 maintenance centers of the Swiss Road Maintenance Services located in the cantons Bern, Fribourg and Vaud in western Switzerland. Repeated measurements with 18 subjects were conducted during 50 non-consecutive work shifts between Mai 2010 and February 2012, equally distributed over all seasons. In the first part of this thesis we tested and validated measurements of ultrafine particles with a miniature diffusion size classifier (miniDiSC) - a novel particle counting device that was used for the exposure assessment during highway maintenance work. We found that particle numbers and average particle size measured by the miniDiSC were highly correlated with data from the P-TRAK, a condensation particle counter (CPC), as well as from a scanning mobility particle sizer (SMPS). However, the miniDiSC measured significantly more particles than the P-TRAK and significantly less than the SMPS in its full size range. Our data suggests that the instrument specific cutoffs were the main reason for the different particle counts. The first main objective of this thesis was to investigate the exposure of highway maintenance workers to air pollutants and noise, in relation to the different maintenance activities. We have seen that the workers are regularly exposed to high particle and noise levels. This was a consequence of close proximity to highway traffic and the use of motorized working equipment such as brush cutters, chain saws, generators and pneumatic hammers during which the highest exposure levels occurred. Although exposure to air pollutants were not critical if compared to occupational exposure limits, the elevated exposure to particles and noise may lead to a higher risk for cardiovascular diseases in this worker population. The second main objective was to investigate cardiopulmonary short-term health effects in relation to the particle and noise exposure during highway maintenance work. We observed a PM2.5 related increase of the acute-phase inflammation markers C-reactive protein and serum amyloid A and a decrease of TNFa. Heart rate variability increased as a consequence of particle as well as noise exposure. Increased high frequency power indicated a stronger parasympathetic influence on the heart. Elevated noise levels during recreational time, after work, were related to increased blood pressure. Our data confirmed that highway maintenance workers are exposed to elevated levels of particles and noise as compared to the average population. This exposure poses a cardiovascular health risk and it is therefore important to make efforts to better protect the workers health. The use of cleaner machines during maintenance work would be a major step to improve the workers' situation. Furthermore, regulatory policies with the aim of reducing combustion and non-combustion emissions from road traffic are important for the protection of workers in traffic environments and the entire population.

RFID per al control de vehicles en àrees de trànsit restringit

En aquest projecte s'ha dissenyat un sistema informàtic per controlar els esdeveniments produïts per vehicles en zones de trànsit restringit i zones de càrrega i descàrrega. La tecnologia utilitzada és RFID (Radio Frequency Identification Vehicles). Pel que fa al maquinari del projecte, s'ha desenvolupat un sistema a partir d'una placa amb un microcontrolador. Amb aquesta placa es simulen els esdeveniments i s'envien a una màquina amb estructura PC via port Sèrie. Finalment, aquesta màquina processa els esdeveniments rebuts, i els envia a través de la xarxa Ethernet a un servidor central. Pel que fa al programari del projecte, s'ha dissenyat una aplicació web amb llenguatge PHP que processarà les dades rebudes des de la màquina via Ethernet. Un cop l'aplicació rep les dades dels esdeveniments, aquesta s'encarrega d'introduir-les a la base de dades, de manera que aquesta es mantingui actualitzada en tot moment. A més, aquesta aplicació ha de permetre consultar totes les dades sobre els esdeveniments produïts, de manera que es guardi un historial d'aquests