Mapping multi-species habitat use for marine conservation planning

Tese de Doutoramento, Ciências do Mar (Biologia Marinha)

Optimization of multi-stage amplifiers in deep-submicron CMOS using a distributed/parallel genetic algorithm

IEEE International Symposium on Circuits and Systems, pp. 724 – 727, Seattle, EUA

Rainwater harvesting case study: FCT/UNL campus

Dissertação apresentada para a obtenção do grau de Mestre em Engenharia do Ambiente, Perfil Engenharia Sanitária

The hyperaccumulator Sedum plumbizincicola harbors metal-resistant endophytic bacteria that improve its phytoextraction capacity in multi-metal contaminated soil

Endophyte-assisted phytoremediation has recently been suggested as a successful approach for ecological restoration of metal contaminated soils, however little information is available on the influence of endophytic bacteria on the phytoextraction capacity of metal hyperaccumulating plants in multi-metal polluted soils. The aims of our study were to isolate and characterize metal-resistant and 1-aminocyclopropane-1-carboxylate (ACC) utilizing endophytic bacteria from tissues of the newly discovered Zn/Cd hyperaccumulator Sedum plumbizincicola and to examine if these endophytic bacterial strains could improve the efficiency of phytoextraction of multi-metal contaminated soils. Among a collection of 42 metal resistant bacterial strains isolated from the tissues of S. plumbizincicola grown on Pb/Zn mine tailings, five plant growth promoting endophytic bacterial strains (PGPE) were selected due to their ability to promote plant growth and to utilize ACC as the sole nitrogen source. The five isolates were identified as Bacillus pumilus E2S2, Bacillus sp. E1S2, Bacillus sp. E4S1, Achromobacter sp. E4L5 and Stenotrophomonas sp. E1L and subsequent testing revealed that they all exhibited traits associated with plant growth promotion, such as production of indole-3-acetic acid and siderophores and solubilization of phosphorus. These five strains showed high resistance to heavy metals (Cd, Zn and Pb) and various antibiotics. Further, inoculation of these ACC utilizing strains significantly increased the concentrations of water extractable Cd and Zn in soil. Moreover, a pot experiment was conducted to elucidate the effects of inoculating metal-resistant ACC utilizing strains on the growth of S. plumbizincicola and its uptake of Cd, Zn and Pb in multi-metal contaminated soils. Out of the five strains, B. pumilus E2S2 significantly increased root (146%) and shoot (17%) length, fresh (37%) and dry biomass (32%) of S. plumbizincicola as well as plant Cd uptake (43%), whereas Bacillus sp. E1S2 significantly enhanced the accumulation of Zn (18%) in plants compared with non-inoculated controls. The inoculated strains also showed high levels of colonization in rhizosphere and plant tissues. Results demonstrate the potential to improve phytoextraction of soils contaminated with multiple heavy metals by inoculating metal hyperaccumulating plants with their own selected functional endophytic bacterial strains.

Design of a low-voltage CMOS RF receiver for energy harvesting sensor node

In this thesis a CMOS low-power and low-voltage RF receiver front-end is presented. The main objective is to design this RF receiver so that it can be powered by a piezoelectric energy harvesting power source, included in a Wireless Sensor Node application. For this type of applications the major requirements are: the low-power and low-voltage operation, the reduced area and cost and the simplicity of the architecture. The system key blocks are the LNA and the mixer, which are studied and optimized with greater detail, achieving a good linearity, a wideband operation and a reduced introduction of noise. A wideband balun LNA with noise and distortion cancelling is designed to work at a 0.6 V supply voltage, in conjunction with a double-balanced passive mixer and subsequent TIA block. The passive mixer operates in current mode, allowing a minimal introduction of voltage noise and a good linearity. The receiver analog front-end has a total voltage conversion gain of 31.5 dB, a 0.1 - 4.3 GHz bandwidth, an IIP3 value of -1.35 dBm, and a noise figure lower than 9 dB. The total power consumption is 1.9 mW and the die area is 305x134.5 m2, using a standard 130 nm CMOS technology.

Use of multi-sensory marketing techniques and its influence on brand experience in retail and HORECA sector

Double degree. 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 and Warsaw School of Economics

Analysis and implementation of a multi-ratio switched capacitor DC-DC converter for a supercapacitor power supply

An energy harvesting system requires an energy storing device to store the energy retrieved from the surrounding environment. This can either be a rechargeable battery or a supercapcitor. Due to the limited lifetime of rechargeable batteries, they need to be periodically replaced. Therefore, a supercapacitor, which has ideally a limitless number of charge/discharge cycles can be used to store the energy; however, a voltage regulator is required to obtain a constant output voltage as the supercapacitor discharges. This can be implemented by a Switched-Capacitor DC-DC converter which allows a complete integration in CMOS technology, although it requires several topologies in order to obtain a high efficiency. This thesis presents the complete analysis of four different topologies in order to determine expressions that allow to design and determine the optimum input voltage ranges for each topology. To better understand the parasitic effects, the implementation of the capacitors and the non-ideal effect of the switches, in 130 nm technology, were carefully studied. With these two analysis a multi-ratio SC DC-DC converter was designed with an output power of 2 mW, maximum efficiency of 77%, and a maximum output ripple, in the steady state, of 23 mV; for an input voltage swing of 2.3 V to 0.85 V. This proposed converter has four operation states that perform the conversion ratios of 1/2, 2/3, 1/1 and 3/2 and its clock frequency is automatically adjusted to produce a stable output voltage of 1 V. These features are implemented through two distinct controller circuits that use asynchronous time machines (ASM) to dynamically adjust the clock frequency and to select the active state of the converter. All the theoretical expressions as well as the behaviour of the whole system was verified using electrical simulations.

Light harvesting in solar cells using natural pigments from red fruits adsorbed to mesoporous TiO2

Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.

Towards high performance and multi-functional structural membranes using advanced fibrous and textile materials

Scientific and technological advancements in the area of fibrous and textile materials have greatly enhanced their application potential in several high-end technical and industrial sectors including construction, transportation, medical, sports, aerospace engineering, electronics and so on. Excellent performance accompanied by light-weight, mechanical flexibility, tailor-ability, design flexibility, easy fabrication and relatively lower cost are the driving forces towards wide applications of these materials. Cost-effective fabrication of various advanced and functional materials for structural parts, medical devices, sensors, energy harvesting devices, capacitors, batteries, and many others has been possible using fibrous and textile materials. Structural membranes are one of the innovative applications of textile structures and these novel building skins are becoming very popular due to flexible design aesthetics, durability, lightweight and cost benefits. Current demand on high performance and multi-functional materials in structural applications has motivated to go beyond the basic textile structures used for structural membranes and to use innovative textile materials. Structural membranes with self-cleaning, thermoregulation and energy harvesting capability (using solar cells) are examples of such recently developed multi-functional membranes. Besides these, there exist enormous opportunities to develop wide varieties of multi-functional membranes using functional textile materials. Additionally, it is also possible to further enhance the performance and functionalities of structural membranes using advanced fibrous architectures such as 2D, 3D, hybrid, multi-layer and so on. In this context, the present paper gives an overview of various advanced and functional fibrous and textile materials which have enormous application potential in structural membranes.

Extent of Hypoattenuation On CT Angiography Source Images In Basilar Artery Occlusion: Prognostic Accuracy Of Posterior Circulation ASPECTS And The Pons-midbrain Score In The Basilar Artery International Cooperation Study

Background: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) and the combined Pons-midbrain score quantify the extent of early ischemic changes in the posterior circulation. We compared the prognostic accuracy of both scores if applied to CT angiography (CTA) source images (CTA-SI) of patients in the Basilar Artery International Cooperation Study (BASICS).Methods: BASICS was a prospective, observational, multi-centre, registry of consecutive patients who presented with acute symptomatic basilar artery occlusion (BAO). Functional outcome was assessed at 1 month. We applied pc-ASPECTS and the combined Pons-midbrain score to CTA-SI by 3-reader-consensus. Readers were blinded to clinical data. We performed multivariable logistic regression analysis, adjusting for thrombolysis, baseline NIHSS score and age, and used the output to derive ROC curves to compare the ability of both scores to discriminate patients with favourable (modified Rankin Scale [mRS] scores 0-3) from patients with unfavourable (mRS scores 4-6) functional outcome.Results: We reviewed CTAs of 158 patients (64% men, mean age 65 _ 15 years, median NIHSS score 25 [0-38], median GCS score 7 [3-15], median onset-to-CTA time 234 minutes [11-7380]). At 1 month, 40 (25%) patients had a favourable outcome, 49 (31%) had an unfavourable outcome (mRS score 4-5) and 69 (44%) were deceased. Both techniques of assessing CTA-SI hypoattenuation in the posterior circulation showed equally good discriminative value in predicting final outcome (C-statistics; area under ROC curve 0.74 versus 0.75, respectively; p_0.37). Pc-ASPECTS dichotomized at _6 versus _6 was an independent predictor of favourable functional outcome (RR _ 2.2; CI95 1.1-4.7; p _ 0.034).Conclusion: Compared to the combined Pons-midbrain score, the pc-ASPECTS score has similar prognostic accuracy to identify patients with a favourable functional outcome in BASICS. Dichotomized pc-ASPECTS (_6 versus _6) is an independent predictor of favourable functional outcome in this population. Author Disclosures: V. Puetz: None. A. Khomenko: None. M.D. Hill: None. I. Dzialowski: None. P. Michel: None. C. Weimar: None. C.A.C. Wijman: None. H. Mattle: None. K. Muir: None. T. Pfefferkorn: None. D. Tanne: None. S. Engelter: None. K. Szabo: None. A. Algra: None. A.M. Demchuk: None. W.J. Schonewille: None.

Quantifying network properties in multi-electrode recordings: spatiotemporal characterization and inter-trial variation of evoked gamma oscillations in mouse somatosensory cortex in vitro.

Linking the structural connectivity of brain circuits to their cooperative dynamics and emergent functions is a central aim of neuroscience research. Graph theory has recently been applied to study the structure-function relationship of networks, where dynamical similarity of different nodes has been turned into a "static" functional connection. However, the capability of the brain to adapt, learn and process external stimuli requires a constant dynamical functional rewiring between circuitries and cell assemblies. Hence, we must capture the changes of network functional connectivity over time. Multi-electrode array data present a unique challenge within this framework. We study the dynamics of gamma oscillations in acute slices of the somatosensory cortex from juvenile mice recorded by planar multi-electrode arrays. Bursts of gamma oscillatory activity lasting a few hundred milliseconds could be initiated only by brief trains of electrical stimulations applied at the deepest cortical layers and simultaneously delivered at multiple locations. Local field potentials were used to study the spatio-temporal properties and the instantaneous synchronization profile of the gamma oscillatory activity, combined with current source density (CSD) analysis. Pair-wise differences in the oscillation phase were used to determine the presence of instantaneous synchronization between the different sites of the circuitry during the oscillatory period. Despite variation in the duration of the oscillatory response over successive trials, they showed a constant average power, suggesting that the rate of expenditure of energy during the gamma bursts is consistent across repeated stimulations. Within each gamma burst, the functional connectivity map reflected the columnar organization of the neocortex. Over successive trials, an apparently random rearrangement of the functional connectivity was observed, with a more stable columnar than horizontal organization. This work reveals new features of evoked gamma oscillations in developing cortex.

Dried blood spots as a practical and inexpensive source for human immunodeficiency virus and hepatitis C virus surveillance

Passive surveillance of infectious diseases with a high percentage of asymptomatic cases or long incubation periods, such as acquired immunodeficiency syndrome (AIDS), does not reflect the current transmission dynamics. Thus, a multi-strategic surveillance, such as the human immunodeficiency virus (HIV) sentinel surveillance proposed by the World Health Organization (WHO), is necessary. The Brazilian HIV sentinel surveillance was started in May 1992 with this purpose. The objectives of this study were to evaluate the feasibility and costs of HIV and hepatitis C virus (HCV) surveillance using dried blood spots (DBS) collected for neonatal screening of metabolic diseases in the state of Minas Gerais, Brazil. This was accomplished through the comparison of HIV and HCV seroprevalence with previous Brazilian studies. From December 2001 to June 2002, 24,905 newborns were tested for HIV and 4211 for HCV. HIV seroprevalence was 0.25% and the 95% confidence interval (CI) was 0.18, 0.31%; and HCV seroprevalence was 0.71% and the 95% CI was 0.46, 0.97%. These numbers are similar to previous Brazilian studies. Cost in this study was approximately US$ 3.10 per sample, which was roughly one third of the cost of the same exam at the Brazilian HIV sentinel surveillance. We conclude that it is possible and more cost-effective to use DBS for infectious diseases surveillance, albeit it is still necessary to compare these results with the usual sentinel methodology in a concomitant trial.

Entrained macrocryst minerals as a key to the source region of olivine nephelinites: Humberg, Kaiserstuhl, Germany

Olivine nephelinites commonly contain macrocrysts of olivine and clinopyroxene. Some of these macrocrysts might represent fragments of the source region of the host magma transported to the Earth surface. If this hypothesis is correct these fragments can be used to characterize the composition of the source region and to put constraints on the magma generation process. In this study, we investigate the origin of macrocrysts and mineral aggregates from an olivine nephelinite from the Kaiserstuhl, Germany. We focus on clinopyroxenes (Cpx), which can be divided into three groups. Cpx I is relict Cpx from aggregates with deformed olivine that is depleted in Ca and characterized by strong light rare earth element (LREE) fractionation, low Ti/Eu and negative high field strength element (HFSE) anomalies. Its geochemical signature is consistent with formation by carbonatite metasomatism and with equilibration in the Presence of orthopyroxene. Cpx II is Ca-rich Cpx, forming both aggregates with deformed olivine and individual macrocrysts. The LREE, as for Cpx I, are strongly fractionated. Convex REE patterns may be present. The depletion in HFSE is less pronounced. Cpx III is oscillatory zoned Cpx phenociysis showing enrichment in Ca, convex REE patterns and no HFSE anomalies. The transition in the trace element abundances between the Cpx of the three groups is gradual. However, Cpx I and H did not crystallize from the host magma, as demonstrated by the presence of kink-bands and undulose extinction in the associated olivine and by the composition of alkali aluminosilicate glass inclusions in Cpx H. Based on the Cpx relationships, we interpret the studied suite of macrocrysts and mineral aggregates as a mixture of disintegrated fragments of the source region of the host olivine nephelinite. The process of melt generation was multi-stage. A primary carbonatite melt ascending from deeper levels in the mantle, probably from the dolomite-garnet peridotite stability field, reacted with mantle peridotite along the solidus ledge in the system lherzolite-CO2 (< 20-22 kbar) and started to crystallize carbonate minerals. Because of its low solidus temperature, the resulting carbonate-wehrlite assemblage melted incongruently with the formation of additional clinopyroxene. The carbonatite melt evolved during crystallization of carbonate minerals and concomitant incongruent melting of the carbonate-wehrlite, accompanied by the segregation of incipient alkali aluminosilicate melts. As a consequence of fast reaction rates in the presence of a carbonatite melt, this process probably took place under disequilibrium conditions. Further melting of the assemblage wehrlite + alkali aluminosilicate melt led to the generation of the olivine nephelinite magma. It entrained fragments of the wehrlite and brought them to the surface.

Metastatic tumors to the colon and rectum: a multi-institutional study.

Context.-Unlike the small bowel, the colorectal mucosa is seldom the site of metastatic disease. Objective.-To determine the incidence of truly colorectal metastases, and subsequent clinicopathologic findings, in a substantial colorectal cancer population collected from 7 European centers. Design.-During the last decade, 10 365 patients were identified as having colorectal malignant tumors, other than systemic diseases. Data collected included patient demographics, clinical symptoms, treatment, the presence of metastases in other sites, disease-free interval, follow-up, and overall survival. All secondary tumors resulting from direct invasion from malignant tumors of the contiguous organs were excluded, as well as those resulting from lymph node metastases or peritoneal seeding. Results.-Only 35 patients were included (10 men) with a median age of 59 years. They presented with obstruction, bleeding, abdominal pain, or perforation. The leading source of metastases was the breast, followed by melanoma. Metastases were synchronous in 3 cases. The mean disease-free interval for the remaining cases was 6.61 years. Surgical resection was performed in 28 cases. Follow-up was available for 26 patients; all had died, with a mean survival time of 10.67 months (range, 1-41 months). Conclusions.-Colorectal metastases are exceptional (0.338%) with the breast as a leading source of metastases; they still represent a late stage of disease and reflect a poor prognosis. Therefore, the pathologist should be alert for the possibility of secondary tumors when studying large bowel biopsies. Any therapy is usually palliative, but our results suggest that prolonged survival after surgery and complementary therapy can be obtained in some patients.

Spirituality and religion in outpatients with schizophrenia: A multi-site comparative study of Switzerland, Canada, and the United States

Objective: To assess the importance of spirituality and religious coping among outpatients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder living in three countries. Method: A total of 276 outpatients (92 from Geneva, Switzerland, 121 from Trois-Rivières, Canada, and 63 from Durham, North Carolina), aged 18-65, were administered a semi-structured interview on the role of spirituality and religiousness in their lives and to cope with their illness. Results: Religion is important for outpatients in each of the three country sites, and religious involvement is higher than in the general population. Religion was helpful (i.e., provided a positive sense of self and positive coping with the illness) among 87% of the participants and harmful (a source of despair and suffering) among 13%. Helpful religion was associated with better social, clinical and psychological status. The opposite was observed for the harmful aspects of religion. In addition, religion sometimes conflicted with psychiatric treatment. Conclusions: These results indicate that outpatients with schizophrenia or schizoaffective disorder often use spirituality and religion to cope with their illness, basically positively, yet sometimes negatively. These results underscore the importance of clinicians taking into account the spiritual and religious lives of patients with schizophrenia.