Conception of an E-learning scheme at the University of Algarve

With the proliferation of the Internet use, a growth of e-learning courses has been verified. We arrived to the moment where it is not enough for Universities to have standard courses to offer to the students, because there is an increasing population which tends to choose his formation according to their objectives, styles, needs and learning preferences (the student profile). This way, the universities are faced with a new challenge, which is to offer, together with the standard courses, modules specially tailored to the user desires, based on the identification of the customers needs. In this paper, a model for the distance formation through Internet is discussed, that is being developed in the University of Algarve, which makes possible each individual to learn in agreement with his/her profile

Thermal Stability of Self-Assembled Monolayers of n-Hexanethiol on Au(111)-(1 × 1) and Au(001)-(1 × 1)

Thermal desorption in an ultrahigh vacuum of n-hexanethiol (C6T) self-assembled monolayers (SAMs) prepared from ethanolic solutions on Au(111) and Au(001) unreconstructed surfaces was investigated by X-ray photoelectron spectroscopy. The SAMs desorption was performed from room temperature (RT) to 380 K. We report that the hexanethiolate surface saturation coverage is bigger (∼0.4 ML) for the SAM on Au(001) than on Au(111) (∼0.33 ML). We identified a greater stability for C6T SAMs on Au(001). Large amounts of physisorbed species were found on preferred oriented (111) polycrystalline Au at the low coverage regime at RT, while the SAM on the Au(001) single crystal at this conditions desorbs at a steady pace. At 340 K, both SAMs remain stable at the coverage expected for the lying-down phases that maximizes the van der Waals interactions. We observe that at higher temperatures the carbon alpha-sulfur bond breaks, producing free S on both gold surfaces.Fil: Cristina, Lucila Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Ruano Sandoval, Gustavo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Salvarezza, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Ferron, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Materiales; Argentin

Decoding of Matrix-Product Codes

We propose a decoding algorithm for the $(u\mid u+v)$-construction that decodes up to half of the minimum distance of the linear code. We extend this algorithm for a class of matrix-product codes in two different ways. In some cases, one can decode beyond the error correction capability of the code

MACROSCOPIC LESIONS ON THE GREY TRIGGERFISH, BALISTES CAPRISCUS (PISCES) ASSOCIATED WITH THE PRESENCE OF THE PEDUNCULATE BARNACLE, CONCHODERMA VIRGATUM (CIRRIPEDIA, THORACICA)

Fifteen live specimens of Conchoderma virgatum were attached to a grey triggerfish (Balistes capriscus) caught in S.W. Portugal. The barnacles were distributed in three groups (right abdominal external face, anterior side of the insertion of the pelvic spine, and close to (5 mm) the left eye (on the lacrymal bone)). The specimens were very different in size, ranging from 2 mm to 18.9 mm (maximum capitular length, CL). The four largest barnacles (CL 16.4 mm) had egg lamellae. Signs of potential predation on the barnacles (rests of barnacles and half-cut cirri in a barnacle) were detected. The left-eye blindness of the grey trigger fish could have been caused by traumatic action performed by the barnacles that settled close to the eye. The skin surrounding the barnacle cluster attached to the right abdominal external face was inflamed. Skin lesions were of sub-acute or chronic nature and the gall-bladder dilatation was consistent with a prolonged status of injury. Both traumatic and inflammatory lesions could have contributed to the loss of body condition of the grey triggerfish. This study is the first report of C. virgatum in S.W. Portugal and the first record of attachment to a grey triggerfish

Large Nc scaling of meson masses and decay constants

We perform an ab initio calculation of the Nc scaling of the low-energy couplings of the chiral Lagrangian of low-energy strong interactions, extracted from the mass dependence of meson masses and decay constants. We compute these observables on the lattice with four degenerate fermions, Nf= 4 , and varying number of colours, Nc= 3 –6, at a lattice spacing of a≃ 0.075 fm. We find good agreement with the expected Nc scaling and measure the coefficients of the leading and subleading terms in the large Nc expansion. From the subleading Nc corrections, we can also infer the Nf dependence, that we use to extract the value of the low-energy couplings for different values of Nf. We find agreement with previous determinations at Nc= 3 and Nf= 2 , 3 and also, our results support a strong paramagnetic suppression of the chiral condensate in moving from Nf= 2 to Nf=

Effects of no tillage on the abundance and diversity of soil and olive tree canopy arthropods.

Soil tillage is a traditional practice in the olive groves of Trás-os-Montes region (Northeast of Portugal) where the soil is maintained without any vegetal cover. However, this agronomic practice may have dangerous environmental effects of several orders. In this way, with the present work we aimed to contribute for the knowledge about the effect of two soil management practices in the olive grove (traditional tillage in comparison to no tillage) on the arthropods abundance and diversity of the olive grove soil and the olive tree canopy with special reference to Formicidae family. The work was developed between April and October of 2004, in two continuous plots submitted to the following agronomical practices: one plot submitted to frequent tillage to control weeds, and the other plot was no tilled. Monthly, the soil fauna was evaluated by 30 pitfall traps and olive canopy fauna was monitored by the beating technique of 25 trees per plot. The recovered material was sorted and identified. The results showed the existence of a diverse and rich fauna associated to the soil of olive grove and olive tree canopy. The olive soil arthropods are constituted mainly by Formicidae and Collembola

Antibiotic prophylaxis and its appropriate timing for urological surgical procedures in patients with asymptomatic bacteriuria: a systematic review

Objective To review the existing literature on when and how to treat patients with asymptomatic bacteriuria (AB) who undergo urological surgery, as uncertainty about this issue persists. Methods A systematic review was conducted to compare the different timing of administration of antibiotic prophylaxis in patients with AB undergoing urological surgery. We used predefined inclusion and exclusion criteria, and we also developed a specific quality scale to assess the quality of the papers included. Results Nine studies met the inclusion criteria. Of the nine studies included, eight evaluated antibiotic prophylaxis regardless of the presence of AB, as their purpose was to evaluate the effectiveness of antibiotic prophylaxis for urological procedures. Of these, four studies showed a significant reduction in the rate of infections in the intervention group compared with placebo, or with the same antibiotic therapy but using different durations of therapy. Four studies found no significant differences in infectious complications between the intervention and comparison arms. Only one study assessed the duration of antibiotic prophylaxis in patients with AB. Conclusions With the available evidence, antibiotic therapy should be considered only for procedures in which studies have shown a clinical benefit in the prevention of infection. It is important to establish the duration and type of treatment for antimicrobial therapy for surgical prophylaxis in patients with AB who are going to receive urological invasive procedures.Open Access funded by Arab Association of UrologyS

Influence of the thermomechanical processing on the superplastic forming of Mg-Al alloys

The aim of this paper is to study the influence of the initial microstructure of several Mg–Al alloys on their superplastic formability and on their post-forming microstructure and mechanical properties. Various thermomechanical processing routes, such as annealing, conventional rolling, severe rolling and cross rolling, were used in order to fabricate AZ31 and AZ61 alloys with different grain sizes. These materials were then blow formed into a hat shaped die. It was found that the processing route has only a small effect in the formability of Mg–Al alloys or on the postforming microstructures and properties due to rapid dynamic grain growth taking place at the forming temperatures. Nevertheless, good formability is achieved as a result of the simultaneous operation of grain boundary sliding and crystallographic slip during forming.The authors are thankful to Comunidad de Madrid for funding this work under grant GR-MAT-0715-2004. FS is grateful to CSIC for a postgraduate grant. JAV acknowledges support from a Ramón y Cajal contract awarded by the Spanish Ministry of Education and Science.Peer reviewe

Iron sulphides at the epithermal gold-copper deposit of Palai-Islica (Almería, SE of Spain)

El artículo original ha sido publicado por la Mineralogical Society disponible en: http://www.minersoc.org/pages/e_journals/minmag.htmlAu-Cu mineralisation at Palai-Islica occurs as disseminations in massive silicification and, more abundantly, in sulphide-bearing quartz veins. The major ore minerals in the deposit are pyrite ± chalcopyrite, sphalerite and galena and there are a great variety of accessory minerals, including Au-Ag alloys and native gold. Pyrite, the most abundant sulphide, is closely associated with gold. Seven different types of pyrite have been distinguished with a variable concentration of different trace elements. Among them only free of trace elements (type IV) is related to Au-Ag alloys. Pyrites associated with these Au-Ag alloys have a cubic and pentagonal dodecahedral habits whereas those with only the pentagonal dodecahedral habit are from barren zones. In addition, there is no significant invisible gold in pyrite, but there is relatively high Ag in collomorphic pyrite (up to 0.20 wt%) or type III pyrite (up to 1.47 wt%). As is the most abundant trace element in pyrite (up to 6.11 wt%), present as a metastable solid solution or as a non-stoichiometric element. Some kind of marcasite related with gold levels also have considerable amounts of trace elements (As, up to 1.15 wt%, Sb up to 0.40 wt%)Departamento de Mineralogía y Petrología. Grupo de Investigación de la Junta de Andalucía RNM-0131. Proyectos PB-97-1211 y BTE2001-330