208 research outputs found

    Introducing a Regulatory Policy Framework of Bait Fishing in European Coastal Lagoons: The Case of Ria de Aveiro in Portugal

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    The harvesting of bait through digging in coastal mudflats is practiced for recreational and commercial purposes in European coastal systems including the Ria de Aveiro coastal lagoon on the northwest Atlantic coast of Portugal. The scale of harvesting in the Ria de Aveiro has recently increased due to the current economic climate in Portugal, with targeting of the polychaete, Diopatra neapolitana species or “casulo” as it is widely known in the Aveiro region. The national authorities have attempted to control casulo digging by issuing a regulation (Ordinance) in 2014 on the maximum daily catch limit to be caught by each individual. The daily catch limit is intended to represent the Maximum Sustainable Yield (MSY) for casulo beyond which overfishing will occur. The monitoring of the regulatory measures is expected to be conducted through on-site inspections in the digging areas. However, weak law enforcement was noticed, while there is also controversy over the daily catch limit (quota) stipulated by the Ordinance. To this end, the current study attempted to assess digging activities through remote monitoring and random inspections for a better policy enforcement of the national regulation. In addition, different harvesting scenarios were employed through a simplified bioeconomic model to attribute the current and future harvesting trends of bait digging in Aveiro coastal lagoon. The study findings indicate that remote monitoring coupled with some onsite interviews could be a more effective approach for the implementation of the current bait digging policy. Further, the results point to a distinctive discrepancy between the daily catch amount (MSY) introduced by the national legislation and the study findings which should be further scrutinized. The diggers seem to have reached the sustainable harvest identified by the present research. The current economic hardship in Portugal and the low profitability in similar employment sectors will possibly attract more diggers and increase harvesting in the near future. An increased harvest would likely trigger overfishing of D. neapolitana with unknown consequences for the population of the species as well as the aquatic ecosystem. The socio-economic and environmental effects are yet to be further clarified with more detailed data and advanced modeling techniques to ensure the sustainability of the activity

    Generalized Ladder Operators for Shape-invariant Potentials

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    A general form for ladder operators is used to construct a method to solve bound-state Schr\"odinger equations. The characteristics of supersymmetry and shape invariance of the system are the start point of the approach. To show the elegance and the utility of the method we use it to obtain energy spectra and eigenfunctions for the one-dimensional harmonic oscillator and Morse potentials and for the radial harmonic oscillator and Coulomb potentials.Comment: in Revte

    An Algebraic Construction of Generalized Coherent States for Shape-Invariant Potentials

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    Generalized coherent states for shape invariant potentials are constructed using an algebraic approach based on supersymmetric quantum mechanics. We show this generalized formalism is able to: a) supply the essential requirements necessary to establish a connection between classical and quantum formulations of a given system (continuity of labeling, resolution of unity, temporal stability, and action identity); b) reproduce results already known for shape-invariant systems, like harmonic oscillator, double anharmonic, Poschl-Teller and self-similar potentials and; c) point to a formalism that provides an unified description of the different kind of coherent states for quantum systems.Comment: 14 pages of REVTE

    Generalized Swanson models and their solutions

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    We analyze a class of non-Hermitian quadratic Hamiltonians, which are of the form H=AA+αA2+βA2 H = {\cal{A}}^{\dagger} {\cal{A}} + \alpha {\cal{A}} ^2 + \beta {\cal{A}}^{\dagger 2} , where α,β \alpha, \beta are real constants, with αβ \alpha \neq \beta , and A{\cal{A}}^{\dagger} and A{\cal{A}} are generalized creation and annihilation operators. Thus these Hamiltonians may be classified as generalized Swanson models. It is shown that the eigenenergies are real for a certain range of values of the parameters. A similarity transformation ρ\rho, mapping the non-Hermitian Hamiltonian HH to a Hermitian one hh, is also obtained. It is shown that HH and hh share identical energies. As explicit examples, the solutions of a couple of models based on the trigonometric Rosen-Morse I and the hyperbolic Rosen-Morse II type potentials are obtained. We also study the case when the non-Hermitian Hamiltonian is PT{\cal{PT}} symmetric.Comment: 17 page

    Gestational weght gain and body mass index in pre-school children

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    To examine the association between gestational weight gain (GWG) and body mass index (BMI) in pre-school children.info:eu-repo/semantics/publishedVersio

    Fetal stem cells obtained from amniotic fluid and wharton's jelly expanded using platelet lysate for tissue engineering applications

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    Extra-embryonic tissues, such as amniotic fluid (AF) and Wharton´s Jelly (WJ) of umbilical cord, offer many advantages over both embryonic and adult stem cell sources. These tissues are routinely discarded at parturition and the extracorporeal nature of these cell sources facilitates isolation, as well as the comparatively large volume and ease of physical manipulation theoretically increases the number of stem cells that can be isolated. Autologous approaches to use MSCs, namely from bone marrow, have difficulties regarding the limited availability of large amounts of cells from the patient. Fetal stem cells appear to have even more pronounced immunomodulatory properties than adult MSCs (1, 2). This allogeneic escape mechanism may be of therapeutic value, because transplantation of allogeneic human MSCs in stock would be readily available, as opposed to the culture of autologous cells for subsequent transplantation. Cell expansion protocols are based on the use of media supplemented with fetal bovine serum (FBS) as a source of nutrientes and growth factors. The animal serum is not completely safe, once there is a possibility of contamination by animal viroses, prions or others contaminants and it is described that FBS used systematically in MSCs subcultivation induces more humoral immune response (3). Additionally anti-FBS antibodies could be detected in patients after receiving MSCs expanded in FBS (4). Platelet lysate (PL) has enormous possibilities in cell therapy, namely because of the high concentration of growth factors that promotes higher cell expansion, such as tissue regeneration (5). A recent study showed that proliferation of MSCs was much higher on PL gel compared to tissue culture plastic (6). The immunomodulatory properties of MSCs are maintained when expanded in culture medium supplemented with PL (7) Based on these premises we isolated fetal stem cells from AF obtained from amniocentesis and WJ from umbilical cords. These cells were plated and expanded in low density numbers in basal culture medium with FBS or either supplemented with PL. In each passage cells were counted for proliferation kinetics and prepared for flow cytometry analysis. Expanded populations were analysed both population size and complexity and for the MSCs well-known surface markers (CD34, CD45, CD73, CD44, CD106, CD105, CD29, CD90, CD31) and markers related with immune response (HLADR, 80, 83, 86) and embryonic markers SSEA-4 and TRA-1-60

    Coherent states of P{\"o}schl-Teller potential and their revival dynamics

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    A recently developed algebraic approach for constructing coherent states for solvable potentials is used to obtain the displacement operator coherent state of the P\"{o}schl-Teller potential. We establish the connection between this and the annihilation operator coherent state and compare their properties. We study the details of the revival structure arising from different time scales underlying the quadratic energy spectrum of this system.Comment: 13 pages, 6 figure

    Colonic mucinous adenocarcinoma with atypical metastasis

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    Doente do sexo masculino, de 70 anos de idade, com diagnóstico de neoplasia do cego foi submetido a hemicolectomia direita em 2002. A histologia da peça operatória revelou adenocarcinoma bem diferenciado do cego com componente mucinoso (estádio C de Dukes, pT 3 pN 1 pM x G 1 , margens cirúrgicas sem tecido neoplásico). Posteriormente foi submetido a quimioterapia adjuvante. Em Janeiro de 2007 o paciente foi submetido a cura cirúrgica de hidrocelo, tendo sido identificada intra-operatoriamente uma massa testicular volu- mosa de consistência dura, o que determinou a realização de orquidectomia direita. A histologia da peça operatória revelou tratar-se de uma metástase de adenocarcinoma mucinoso com provável origem gastro-intestinal. Em Março do mesmo ano procedeu-se a excisão do cordão espermático e linfadenectomia, tendo o exame anatomo-patológico revelado múltiplos focos de adenocarcinoma mucinoso com provável origem cólica e margens cirúrgicas sem neoplasia. Foi realizada laparoscopia exploradora que não evidenciou implantes peritoneais ou lesões intra-abdominais suspeitas. Em 2008 e novamente em 2009 foi submetido a excisão de metástases cutâneas ingui- nais à direita. Iniciou radioterapia em 2009 após surgirem metástases paratesticular direita e na rafe perineal

    Intermediate energy Coulomb excitation as a probe of nuclear structure at radioactive beam facilities

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    The effects of retardation in the Coulomb excitation of radioactive nuclei in intermediate energy collisions (Elab ~100 MeV/nucleon) are investigated. We show that the excitation cross sections of low-lying states in 11Be, {38,40,42}S and {44,46}Ar projectiles incident on gold and lead targets are modified by as much as 20% due to these effects. The angular distributions of decaying gamma-rays are also appreciably modified.Comment: 21 pages, 3 figures, Phys. Rev. C, in pres

    Synergistic impact of endurance training and intermittent hypobaric hypoxia on cardiac function and mitochondrial energetic and signaling

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    Background Intermittent hypobaric-hypoxia (IHH) and endurance-training (ET) are cardioprotective strategies against stress-stimuli. Mitochondrial modulation appears to be an important step of the process. This study aimed to analyze whether a combination of these approaches provides additive or synergistic effects improving heart-mitochondrial and cardiac-function. Methods Two-sets of rats were divided into normoxic-sedentary (NS), normoxic-exercised (NE, 1 h/day/5 weeks treadmill-running), hypoxic-sedentary (HS, 6000 m, 5 h/day/5 weeks) and hypoxic-exercised (HE) to study overall cardiac and mitochondrial function. In vitro cardiac mitochondrial oxygen consumption and transmembrane potential were evaluated. OXPHOS subunits and ANT protein content were semi-quantified by Western blotting. HIF-1α, VEGF, VEGF-R1 VEGF-R2, BNP, SERCA2a and PLB expressions were measured by qRT-PCR and cardiac function was characterized by echocardiography and hemodynamic parameters. Results Respiratory control ratio (RCR) increased in NE, HS and HE vs. NS. Susceptibility to anoxia/reoxygenation-induced dysfunction decreased in NE, HS and HE vs. NS. HS decreased mitochondrial complex-I and -II subunits; however HE completely reverted the decreased content in complex-II subunits. ANT increased in HE. HE presented normalized ventricular–arterial coupling (Ea) and BNP myocardial levels and significantly improved myocardial performance as evaluated by increased cardiac output and normalization of the Tei index vs. HS. Conclusion Data demonstrates that IHH and ET confer cardiac mitochondria with a more resistant phenotype although without visible addictive effects at least under basal conditions. It is suggested that the combination of both strategies, although not additive, results into improved cardiac function
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