Zigbee over tinyos: Implementation and experimental challenges

The IEEE 802.15.4/Zigbee protocols are a promising technology for Wireless Sensor Networks (WSNs). This paper shares our experience on the implementation and use of these protocols and related technologies in WSNs. We present problems and challenges we have been facing in implementing an IEEE 802.15.4/ZigBee stack for TinyOS in a two-folded perspective: IEEE 802.15.4/ZigBee protocol standards limitations (ambiguities and open issues) and technological limitations (hardware and software). Concerning the former, we address challenges for building scalable and synchronized multi-cluster ZigBee networks, providing a trade-off between timeliness and energy-efficiency. On the latter issue, we highlight implementation problems in terms of hardware, timer handling and operating system limitations. We also report on our experience from experimental test-beds, namely on physical layer aspects such as coexistence problems between IEEE 802.15.4 and 802.11 radio channels.

Renewable Power Sources

Of all of the sources of renewable energies available one can argue that the most abundant and accessible are solar power, radiation, and the energy of the tides (70 % of the earth surface is covered by water). The tidal wave energy hasn’t seen a widespread distribution yet, mainly due to the lack of interest of the governments, most of the coastal areas of the world are exclusive responsibility of the governments, thus not easily open for private venture. Considering solar power, there exist two main fields of application, land based systems and space based systems. The former systems are still in a very embryonic phase, with Japan being the lead researcher in the field, with an experimental satellite-power station to be launched before 2010. Land based systems, on the other hand, are well studied, with major research and application programs in all known forms of solar power production. Given a minimum value of incident radiation, and applying the appropriate system, (i.e. power plant type), for any given area the solar power becomes an income-producing industry.

Chiroptical and emissive properties of a calix[4]arene-containing chiral poly (P-phenylene ethynylene) with enantioselective recognition ability

Supramolecular chirality was achieved in solutions and thin films of a calixarene-containing chiral aryleneethynylene copolymer. The observed chiroptical activity, which is primarily allied with the formation of aggregates of high molecular weight polymer chains, is the result of a combination of intrachain and interchain effects. The former arises by the adoption of an induced helix-sense by the polymer main-chain while the latter comes from the exciton coupling of aromatic backbone transitions. The co-existence of bulky bis-calixKlarene units and chiral side-chains on the polymer skeleton prevents efficient pi-stacking of neighbouring chains, keeping the chiral assembly highly emissive. In contrast, for a model polymer lacking calixarene moieties, the chiroptical activity is dominated by strong interchain exciton couplings as a result of more favourable packing of polymer chains, leading to a marked decrease of photoluminescence in the aggregate state. The enantiomeric recognition abilities of both polymers towards (R)- and (S)-alpha-methylbenzylamine were examined. It was found that a significant enantiodiscrimination is exhibited by the calixarene-based polymer in the aggregate state.

New RuII(arene) complexes with halogen-substituted bis- and tris(pyrazol-1-YL)borate ligands

[RuCl(arene)(-Cl)](2) dimers were treated in a 1:2 molar ratio with sodium or thallium salts of bis- and tris(pyrazolyl)borate ligands [Na(BpBr3)], [Tl(TpBr3)], and [Tl(Tp(iPr,4Br))]. Mononuclear neutral complexes [RuCl(arene)((2)-BpBr3)] (1: arene=p-cymene (cym); 2: arene=hexamethylbenzene (hmb); 3: arene=benzene (bz)), [RuCl(arene)((2)-TpBr3)] (4: arene=cym; 6: arene=bz), and [RuCl(arene)((2)-Tp(iPr,4Br))] (7: arene=cym, 8: arene=hmb, 9: arene=bz) have been always obtained with the exception of the ionic [Ru-2(hmb)(2)(-Cl)(3)][TpBr3] (5), which formed independently of the ratio of reactants and reaction conditions employed. The ionic [Ru(CH3OH)(cym)((2)-BpBr3)][X] (10: X=PF6, 12: X=O3SCF3) and the neutral [Ru(O2CCF3)(cym)((2)-BpBr3)] (11) have been obtained by a metathesis reaction with corresponding silver salts. All complexes 1-12 have been characterized by analytical and spectroscopic data (IR, ESI-MS, H-1 and (CNMR)-C-13 spectroscopy). The structures of the thallium and calcium derivatives of ligand TpBr3, [Tl(TpBr3)] and [Ca(dmso)(6)][TpBr3](2)2DMSO, of the complexes 1, 4, 5, 6, 11, and of the decomposition product [RuCl(cym)(Hpz(iPr,4Br))(2)][Cl] (7) have been confirmed by using single-crystal X-ray diffraction. Electrochemical studies showed that 1-9 and 11 undergo a single-electron (RuRuIII)-Ru-II oxidation at a potential, measured by cyclic voltammetry, which allows comparison of the electron-donor characters of the bis- and tris(pyrazol-1-yl)borate and arene ligands, and to estimate, for the first time, the values of the Lever E-L ligand parameter for BpBr3, TpBr3, and Tp(iPr,4Br). Theoretical calculations at the DFT level indicated that both oxidation and reduction of the Ru complexes under study are mostly metal-centered with some involvement of the chloride ligand in the former case, and also demonstrated that the experimental isolation of the (3)-binuclear complex 5 (instead of the mononuclear 5) is accounted for by the low thermodynamic stability of the latter species due to steric reasons.

The 1998 Faial earthquake, Azores: Evidence for a transform fault associated with the Nubia-Eurasia plate boundary?

With very few exceptions, M > 4 tectonic earthquakes in the Azores show normal fault solution and occur away from the islands. Exceptionally, the 1998 shock was pure strike-slip and occurred within the northern edge of the Pico-Faial Ridge. Fault plane solutions show two possible planes of rupture striking ENE-WSW (dextral) and NNW-SSE (sinistral). The former has not been recognised in the Azores, but is parallel to the transform direction related to the relative motion between the Eurasia and Nubia plates. Therefore, the main question we address in the present study is: do transform faults related to the Eurasia/Nubia plate boundary exist in the Azores? Knowing that the main source of strain is related to plate kinematics, we conclude that the sinistral strike-slip NNW-SSE fault plane solution is not consistent with either the fault dip (ca. 65, which is typical of a normal fault) or the ca. ENE-WSW direction of maximum extension; both are consistent with a normal fault, as observed in most major earthquakes on faults striking around NNW-SSE in the Azores. In contrast, the dextral strike-slip ENE-WSW fault plane solution is consistent with the transform direction related to the anticlockwise rotation of Nubia relative to Eurasia. Altogether, tectonic data, measured ground motion, observed destruction, and modelling are consistent with a dextral strike-slip source fault striking ENE-WSW. Furthermore, the bulk clockwise rotation measured by GPS is typical of bookshelf block rotations observed at the termination of such master strike-slip faults. Therefore, we suggest that the 1998 earthquake can be related to the WSW termination of a transform (ENE-WSW fault plane solution) associated with the Nubia-Eurasia diffuse plate boundary. (C) 2014 Elsevier B.V. All rights reserved.

The effect of superplasticizers on the mechanical performance of concrete made with fine recycled concrete aggregates

It is considered that using crushed recycled concrete as aggregate for concrete production is a viable alternative to dumping and would help to conserve abiotic resources. This use has fundamentally been based on the coarse fraction because the fine fraction is likely to degrade the performance of the resulting concrete. This paper presents results from a research work undertaken at Institut Superior Tecnico (IST), Lisbon, Portugal, in which the effects of incorporating two types of superplasticizer on the mechanical performance of concrete containing fine recycled aggregate were evaluated. The purpose was to see if the addition of superplasticizer would offset the detrimental effects associated with the use of fine recycled concrete aggregate. The experimental programme is described and the results of tests for splitting tensile strength, modulus of elasticity and abrasion resistance are presented. The relative performance of concrete made with recycled aggregate was found to decrease. However, the same concrete with admixtures in general exhibited a better mechanical performance than the reference mixes without admixtures or with a less active superplasticizer. Therefore, it is argued that the mechanical performance of concrete made with fine recycled concrete aggregates can be as good as that of conventional concrete, if superplasticizers are used to reduce the water-cement ratio of the former concrete.

Study on the growth promoting capacity of calf and fetal bovine serum for animal cells "in vitro" II: electrophoretic study and survey on the antiproteolytic activity of pools of calf and fetal bovine serum

Calf serum and fetal bovine serum present great variability as to its growth promoting efficiency (GPE). As supplement of culture media to cultivate cells of animal origin they stimulate the "in vitro" multiplication and maintain cell viability. When fourteen lots of calf sera of variable GPE had the total protein contents as well as the percentages of serum fractions determined, no significant differences that could possibly explain the variability of the GPE were observed. Evaluation of the antiproteolytic activity of nineteen lots of calf serum and eighteen serum lots of younger calves showed that the former exhibited lower antiproteolytic titers (1:40 to 1:80) than the latter (1:80 to 1:160). Twelve lots of fetal bovine serum studied in parallel, showed the highest concentration of antiproteolytic factors, with titers equal to 1:320. Sera of bovine origin, but not fetal sera, are usually heat-inactivated, what was demonstrated to be responsible for the decrease of the antiproteolytic activity of 75% of the lots tested. This could explain the inability of certain heat-inactivated sera in promoting multiplication of some cells "in vitro", as verified with primary monkey kidney cells. The results obtained in this study indicated the convenience of submiting each lot of serum to be introduced in cell culture to previous determination of its characteristics, such as growth promoting efficiency, antiproteolytic activity and also toxicity, absence of extraneous agents, etc., in order to minimize the possibility of using serum lots of questionable quality, thus preventing not only the loss of cell lines, but also undesirable and sometimes expensive delays.

Transnational Migrants and Transnational Spirits: An African Religion in Lisbon

Journal of Ethnic and Migration Studies, Vol.34, n.2,pp. 253 — 269

Survey on the clinical trial results achieved in Brazil comparing praziquantel and oxamniquine in the treatment of mansoni schistosomiasis

A random, double-blind, parallel group clinical trial program was carried out to compare praziquantel, a recently developed anti-helmintic drug, and oxamniquine, an already established agent for treating mansoni schistosomiasis. Both drugs were administered orally as a single dose, on the average, praziquantel 55 mg/kg and oxamniquine 16 mg/kg BWT. The diagnosis and the parasitological follow-up lasting for a minimum of six months, were based on stool examinations according to Kato/Katz technique. A patient was considered cured if all results were negative and if he had performed at least three post-treatment controls, each one comprising three stool examinations. The finding of a single S. mansoni egg in any stool examination indicated, a therapeutical failure. A total of 267, cases were treated with praziquantel and 272 with oxamniquine. The two groups were homogeneous in regard to patients, age, clinical form of the disease, risk of reinfection and worm burden, relevant factors in the therapeutical response. The incidence and severity of untoward, effects were similar in both groups but abdominal distress and diarrhoea were more frequently reported under praziquantel and dizzines under oxamniquine (p < 0.05). In the former group a marked urticariform reaction was observed whereas in the latter one patient presented convulsion. The laboratory work-up. failed to disclose any significant alteration although the AST, ALT and y-GT mean values revealed a tendence to increase on the 7th day after oxamniquine intake. The overall parasitological cure rates were 75.5% (139/ 184) with praziquantel and 69.8% (134/192) with oxamniquine (p > 0.05). Amongst the noncured aptients a reduction of 88.6% and 74.6% in the mean number of eggs/g of feces Was seen following the treatment with praziquantel and oxamniquine, respectively (p < 0.05). In conclusion, in spite of their different chemical, pharmacological and toxicological profiles as well as mechanisms-of-action, inclusively praziquantel already had proved to be 100% active against S. mansoni strains resistant to oxamniquine, both drugs showed comparable tolerance and therapeutical efficacy.

Perspetivas dos professores do ensino básico e secundário face ao desempenho da profissão: perplexidades e desafios

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ciências da Educação, especialidade Supervisão em Educação

A influência dos jogos matemáticos na predisposição dos alunos para a matemática e na sua aprendizagem

Relatório de estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1.º e do 2.º Ciclo do Ensino Básico

Natural populations of saccharomyces kudriavzevii in Portugal are associated with oak bark and are sympatric with s. cerevisiae and s. paradoxus

Applied Environmental Microbiology, Vol. 74, nº7

Treatment of patients with Schistosomiasis mansoni: a double blind clinical trial comparing praziquantel with oxamniquine

A double-blind clinical trial involving 120 patients with chronic schistosomiasis was carried out to compare the tolerability and efficacy of praziquantel and oxamniquine. The patients were randomly allocated into two groups. One was treated with praziquantel, 55 mg/kg of body weight CBWT), and the other one with oxamniquine, 15mg/kg bwt, administered in a single oral dose. The diagnosis and the parasitological follow-up was based on stool examinations by quantitative Kato-Katz method and on rectal biopsies. Side-effects — mainly dizziness, sleepness, abdominal distress, headache, nausea and diarrhea — were observed in 87% of the cases. Their incidence, intensity and duration were similar for both drugs but abdominal pain was significantly more frequent after praziquantel intake and severe dizziness was more commonly reported after oxamniquine. A significant increase of alanine-aminotransferase and y-glutamyltransferase was found with the latter drug and of total bilirubin with the former one. A total of 48 patients treated with praziquantel and 46 with oxamniquine completed with negative findings the required three post-treatment parasitological controls — three slides of each stool sample on the first, third and sixth month. The achieved cure rates were 79.2% and 84.8%, respectively, a difference without statistical significance. The non-cured cases showed a mean reduction in the number of eggs per gram of feces of 93.5% after praziquantel and of 84.1% after oxamniquine. This diference also was not significant. Five patients retreated with praziquantel were cured but only one out of three treated a second time with oxamniquine. These findings show that both drugs — despite their different chemical structures, pharmacological properties and mechanisms-of-action — induce similar side-effects as well as a comparable therapeutical efficacy, in agreement with the results reported from analogous investigations.

Serologic studies on the behaviour of influenza virus type A in persons of greater São Paulo during 1976, 1978 and 1979

Sera of persons of different age groups collected in 1976, 1978 and 1979 were tested for the presence of HI antibodies against various strains of the H3N2 and H1N1 subtypes of influenza virus. The occurrence of infection by H3N2 subtype was recorded during the 1976-1978 period but in 1979, circulation of this subtype of virus was limited. The prevalence of antibody against A/São Paulo/1/78 (H1N1) was significantly higher than that of antibody to A/USSB/90/77 (HIND in 1978. However in 1979 the predominant strain was A/USSR/90/77 (HIND. Persons under 20 years of age were the most affected by H1N1 subtype. Antibodies to H1N1 subtype were detected in sera of individuals older than 20 years in 1976, before the re-emergence of this strain. Serological results indicate that infections by H3N2 subtype in 1978 occurred in 65.4% of young children (0-4 year group). About 47.0% of children from the 0-4 year group had antibodies to H1N1 subtype in 1979. Antibodies to swine influenza virus were detected in 60% of 60+ year old people.

Optimising the energy consumption on pultrusion process

This study is based on a previous experimental work in which embedded cylindrical heaters were applied to a pultrusion machine die, and resultant energetic performance compared with that achieved with the former heating system based on planar resistances. The previous work allowed to conclude that the use of embedded resistances enhances significantly the energetic performance of pultrusion process, leading to 57% decrease of energy consumption. However, the aforementioned study was developed with basis on an existing pultrusion die, which only allowed a single relative position for the heaters. In the present work, new relative positions for the heaters were investigated in order to optimise heat distribution process and energy consumption. Finite Elements Analysis was applied as an efficient tool to identify the best relative position of the heaters into the die, taking into account the usual parameters involved in the process and the control system already tested in the previous study. The analysis was firstly developed based on eight cylindrical heaters located in four different location plans. In a second phase, in order to refine the results, a new approach was adopted using sixteen heaters with the same total power. Final results allow to conclude that the correct positioning of the heaters can contribute to about 10% of energy consumption reduction, decreasing the production costs and leading to a better eco-efficiency of pultrusion process.