Narrow-band variable center frequency single-loop and multistage sigma-delta modulators for bandpass signals

Oversampled narrow-band single-loop and multistage resonator-based bandpass sigma-delta (Σ-Δ) modulators that can accommodate different passband center to sampling frequency ratios are reported. These tunable bandpass configurations are designed by analytically determining and subsequently verifying through detailed empirical simulations the required compensation hardware to deliver enhanced noise-shaping. It is demonstrated that comparatively superior in-band signal-to-noise ratios and dynamic ranges are attributed to the inclusion of appropriate digital feedforward and feedback compensators within these structures.

Sex-specific disruption of murine midbrain astrocytic and dopaminergic developmental trajectories following antenatal GC treatment

The mammalian midbrain dopaminergic systems arising in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) are critical for coping behaviours and are implicated in neuropsychiatric disorders where early life challenges comprise significant risk factors. Here, we aimed to advance our hypothesis that glucocorticoids (GCs), recognised key players in neurobiological programming, target development within these systems, with a novel focus on the astrocytic population. Mice received antenatal GC treatment (AGT) by including the synthetic GC, dexamethasone, in the mothers' drinking water on gestational days 16-19; controls received normal drinking water. Analyses of regional shapes and volumes of the adult SNc and VTA demonstrated that AGT induced long-term, dose-dependent, structural changes that were accompanied by profound effects on astrocytes (doubling/tripling of numbers and/or density). Additionally, AGT induced long-term changes in the population size and distribution of SNc/VTA dopaminergic neurons, confirming and extending our previous observations made in rats. Furthermore, glial/neuronal structural remodelling was sexually dimorphic and depended on the AGT dose and sub-region of the SNc/VTA. Investigations within the neonatal brain revealed that these long-term organisational effects of AGT depend, at least in part, on targeting perinatal processes that determine astrocyte density and programmed cell death in dopaminergic neurons. Collectively, our characterisation of enduring, AGT-induced, sex-specific cytoarchitectural disturbances suggests novel mechanistic links for the strong association between early environmental challenge (inappropriate exposure to excess GCs) and vulnerability to developing aberrant behaviours in later life, with translational implications for dopamine-associated disorders (such as schizophrenia, ADHD, autism, depression), which typically show a sex bias

Developmental switch in the kinase dependency of long-term potentiation depends on expression of GluA4 subunit-containing AMPA receptors

The AMPA-receptor subunit GluA4 is expressed transiently in CA1 pyramidal neurons at the time synaptic connectivity is forming, but its physiological significance is unknown. Here we show that GluA4 expression is sufficient to alter the signaling requirements of long-term potentiation (LTP) and can fully explain the switch in the LTP kinase dependency from PKA to Ca2(+)/calmodulin-dependent protein kinase II during synapse maturation. At immature synapses, activation of PKA leads to a robust potentiation of AMPA-receptor function via the mobilization of GluA4. Analysis of GluA4-deficient mice indicates that this mechanism is critical for neonatal PKA-dependent LTP. Furthermore, lentiviral expression of GluA4 in CA1 neurons conferred a PKA-dependent synaptic potentiation and LTP regardless of the developmental stage. Thus, GluA4 defines the signaling requirements for LTP and silent synapse activation during a critical period of synapse development.

Intelligent behavior in a Cyber-Ambient training system for control center operators

This paper deals with the application of an intelligent tutoring approach to delivery training in diagnosis procedures of a Power System. In particular, the mechanisms implemented by the training tool to support the trainees are detailed. This tool is part of an architecture conceived to integrate Power Systems tools in a Power System Control Centre, based on an Ambient Intelligent paradigm. The present work is integrated in the CITOPSY project which main goal is to achieve a better integration between operators and control room applications, considering the needs of people, customizing requirements and forecasting behaviors.

Do outro lado da linha: impacto dos horários de trabalho de trabalhadores de call center nas necessidades de recuperação – engagement e esforço compensatório

Dissertação apresentada ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Gestão das Organizações, Ramo Gestão de Empresas Orientada por: Profª Doutora Maria Alexandra Pacheco Ribeiro da Costa Esta dissertação inclui as críticas e sugestões feitas pelo Júri.

Lupus and Pregnancy. 15 Years of Experience in a Tertiary Center

This retrospective study was designed to evaluate the outcome of pregnancies in women diagnosed with systemic lupus erythematosus (SLE) followed in a tertiary fetal–maternal center. Data were collected from clinical charts between January 1993 and December 2007, with a total of 136 pregnancies (107 patients). Mean maternal age was 29 years, with the vast majority of patients being Caucasian. Most patients were in remission 6 months prior to pregnancy (93%) and the most frequently affected organs were the skin and joints. Renal lupus accounted for 14% of all cases. Twenty-nine percent of patients were positive for at least one antiphospholid antibody (aPL) and nearly 50% had positive SSa/SSb antibodies. All patients with positive aPL received low-dosage aspirin and low molecular- weight heparin (LMWH). There were no pregnancy complications in more than 50% of cases and hypertensive disease and intrauterine growth restriction were the most common adverse events. There were 125 live births, one neonatal death, eight miscarriages, and three medical terminations of pregnancy. Preterm delivery occurred in 25% of pregnancies. Our results are probably the conjoined result of a multidisciplinary approach together with a systematic management of SLE pregnancies, with most patients keeping their prior SLE medication combined with low-dosage aspirin and LMWH in the presence of aPL.

Nós callcentristas somos o novo proletariado. Identidades e resistências do trabalho em call center

Dissertação de mestrado em Antropologia - Direitos Humanos e Movimentos Sociais

The Hybrid Approach for Palliation of Hypoplastic Left Heart Syndrome: Intermediate Results of a Single-Center Experience

INTRODUCTION: Hypoplastic left heart syndrome (HLHS) is a major cause of cardiac death during the first week of life. The hybrid approach is a reliable, reproducible treatment option for patients with HLHS. Herein we report our results using this approach, focusing on its efficacy, safety and late outcome. METHODS: We reviewed prospectively collected data on patients treated for HLHS using a hybrid approach between July 2007 and September 2014. RESULTS: Nine patients had a stage 1 hybrid procedure, with seven undergoing a comprehensive stage 2 procedure. One patient completed the Fontan procedure. Five patients underwent balloon atrial septostomy after the hybrid procedure; in three patients, a stent was placed across the atrial septum. There were three deaths: two early after the hybrid procedure and one early after stage two palliation. Overall survival was 66%. CONCLUSIONS: In our single-center series, the hybrid approach for HLHS yields intermediate results comparable to those of the Norwood strategy. The existence of dedicated teams for the diagnosis and management of these patients, preferably in high-volume centers, is of major importance in this condition.

Liver Depurative Techniques: A Single Liver Transplantation Center Experience

In a liver transplant (LT) center, treatments with Prometheus were evaluated. The main outcome considered was 1 and 6 months survival. Methods. During the study period, 74 patients underwent treatment with Prometheus; 64 were enrolled,with a mean age of 51 13 years; 47men underwent 212 treatments (mean, 3.02 per patient). The parameters evaluated were age, sex, laboratorial (liver enzymes, ammonia) and clinical (model for end-stage liver disease and Child-Turcotte-Pugh score) data. Results. Death was verified in 23 patients (35.9%) during the hospitalization period, 20 patients (31.3%) were submitted to liver transplantation, and 21 were discharged. LT was performed in 4 patients with acute liver failure (ALF, 23.7%), in 7 patients with acute on chronic liver failure (AoCLF, 43.7%), and in 6 patients with liver disease after LT (30%). Seven patients who underwent LT died (35%). In the multivariate analysis, older age (P ¼ .015), higher international normalized ratio (INR) (P ¼ .019), and acute liver failure (P ¼ .039) were independently associated with an adverse 1-month clinical outcome. On the other hand, older age (P ¼ .011) and acute kidney injury (P ¼ .031) at presentation were both related to worse 6-month outcome. For patients with ALF and AoCLF we did not observe the same differences. Conclusions. In this cohort, older age was the most important parameter defining 1- and 6-month survival, although higher INR and presence of ALF were important for 1-month survival and AKI for 6-month survival. No difference was observed between patients who underwent LT or did not have LT.

Infections After Liver Transplantation: A Retrospective, Single-Center Study

Objective. To access the incidence of infectious problems after liver transplantation (LT). Design. A retrospective, single-center study. Materials and Methods. Patients undergoing LT from January 2008 to December 2011 were considered. Exclusion criterion was death occurring in the first 48 hours after LT. We determined the site of infection and the bacterial isolates and collected and compared recipient’s variables, graft variables, surgical data, post-LT clinical data. Results. Of the 492 patients who underwent LT and the 463 considered for this study, 190 (Group 1, 41%) developed at least 1 infection, with 298 infections detected. Of these, 189 microorganisms were isolated, 81 (51%) gram-positive bacteria (most frequently Staphylococcus spp). Biliary infections were more frequent (mean time of 160.4 167.7 days after LT); from 3 months after LT, gram-negative bacteria were observed (57%). Patients with infections after LT presented lower aminotransferase levels, but higher requirements in blood transfusions, intraoperative vasopressors, hemodialysis, and hospital stay. Operative and cold ischemia times were similar. Conclusion. We found a 41% incidence of all infections in a 2-year follow-up after LT. Gram-positive bacteria were more frequent isolated; however, negative bacteria were commonly isolated later. Clinical data after LT were more relevant for the development of infections. Donors’ variables should be considered in future analyses.

Validation of Two US Risk Scores for Percutaneous Coronary Intervention in a Single-Center Portuguese Population of Patients with Acute Coronary Syndrome

INTRODUCTION: New scores have been developed and validated in the US for in-hospital mortality risk stratification in patients undergoing coronary angioplasty: the National Cardiovascular Data Registry (NCDR) risk score and the Mayo Clinic Risk Score (MCRS). We sought to validate these scores in a European population with acute coronary syndrome (ACS) and to compare their predictive accuracy with that of the GRACE risk score. METHODS: In a single-center ACS registry of patients undergoing coronary angioplasty, we used the area under the receiver operating characteristic curve (AUC), a graphical representation of observed vs. expected mortality, and net reclassification improvement (NRI)/integrated discrimination improvement (IDI) analysis to compare the scores. RESULTS: A total of 2148 consecutive patients were included, mean age 63 years (SD 13), 74% male and 71% with ST-segment elevation ACS. In-hospital mortality was 4.5%. The GRACE score showed the best AUC (0.94, 95% CI 0.91-0.96) compared with NCDR (0.87, 95% CI 0.83-0.91, p=0.0003) and MCRS (0.85, 95% CI 0.81-0.90, p=0.0003). In model calibration analysis, GRACE showed the best predictive power. With GRACE, patients were more often correctly classified than with MCRS (NRI 78.7, 95% CI 59.6-97.7; IDI 0.136, 95% CI 0.073-0.199) or NCDR (NRI 79.2, 95% CI 60.2-98.2; IDI 0.148, 95% CI 0.087-0.209). CONCLUSION: The NCDR and Mayo Clinic risk scores are useful for risk stratification of in-hospital mortality in a European population of patients with ACS undergoing coronary angioplasty. However, the GRACE score is still to be preferred.

How to attract central and Northeneuropeans to a rural tourism establishment in the center of Portugal

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Business development in Siemens global shared services delivery center Portugal

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Morphological diversification through the evolution of developmental hierarchies

Changes in development impact the final form of organisms and compose the natural variation that is the raw material for evolution. Development is hierarchically structured in progressive series of cell fate determination and differentiation. How does variation in different stages of development contribute to morphological diversification?

Managing talent through developmental job experiences (DJE): The mediating role of DJE between HPWS and employees' outcomes

In the competitive landscape of the 21st century, effectively managing human capital in firms is considered to be a potential source of sustainable performance. Therefore, in this study, we tested the influence of high-performance work systems, as a talent management tool, on employees’ experience of developmental jobs. Then, we tested the mediating effect of such experiences on employees’ engagement, exhaustion, performance and turnover intention. With a sample of 254 employees of a diversity of companies and sectors of activity, our findings demonstrated that high-performance practices increase engagement, via the promotion of developmental experiences of fit, which improves performance and decreases turnover intention. Besides, those practices do not control for the pressure dimension of the developmental job experiences that increases exhaustion and turnover intention despite not worsening performance.