Effect of shellfish culture on phytodetritus vertical fluxes in tropical waters: southern Brazil

Mussel culture is an expanding activity in shallow and sheltered bays along the coast of Santa Catarina, southern Brazil. Although mussel culture generates benefits, several environmental impacts are associated with this kind of activity. Its success depends on. factors which inc1ude the environmental impact and the carrying capacity of the system. One conspicuous effect of mussel culture is the enhancement of vertical particle flux to the bottom sediment and depletion of water column phytoplankton biomass. Phytodetritus vertical fluxes was evaluated in a mussel culture area by collecting partic1es with sediment traps and analysing plant pigment by high performance liquid chromatography (RF-HPLC). Results showed that mussel culture, in average, enhances almost 5 times the vertical phytodetritus flux as compared to the reference site. Pheophorbide like pigments were the main chlorophyll-a degradation products collected by the traps. Given the high phytodetritus production, compared to the low water column phytoplankton biomass observed, it is suggested that allocthonous phytoplankton advected to the cultured area is an important process to sustain the mussel growth in the area.O cultivo de moluscos ao longo da costa de Santa Catarina tem crescido de forma acelerada nos últimos anos. Embora os benefícios sejam muitos, vários tipos de impactos ambientais podem ser decorrentes do cultivo de moluscos. Desta forma, o sucesso da atividade depende de fatores que envolvem a capacidade suporte do meio e do grau que o ambiente é impactado. Um dos mais evidentes impactos associados ao cultivo de moluscos marinhos é o aumento da taxa de fluxo vertical de partículas associado a redução da biomassa fitoplanctônica na coluna de água. O fluxo vertical de fitodetritos produzidos em uma área de cultivo foi avaliado por meio de análise por cromatografia líquida de alta eficiência (CLAE) de pigmentos fotossintéticos e produtos de degradação do material coletado por armadilhas de sedimento. Os resultados indicam que o cultivo de moluscos aumenta em média 5 vezes o fluxo vertical de fitodetritos, sendo que a maior parte da degradação da c1orofila-a ocorre na forma de feoforbideos. Dado o expressivo fluxo vertical de fitodetritos, comparado a pequena biomassa na coluna de água, sugere-se que o fitopl ncton a1OOono, trazido por processos advectivos, é importante para a manutenção do crescimento dos moluscos na área estudada

The quantum-classical transition in thermally seeded parametric downconversion

We address the pair of conjugated field modes obtained from parametric-downconversion as a convenient system to analyze the quantum-classical transition in the continuous variable regime. We explicitly evaluate intensity correlations, negativity and entanglement for the system in a thermal state and show that a hierarchy of nonclassicality thresholds naturally emerges in terms of thermal and downconversion photon number. We show that the transition from quantum to classical regime may be tuned by controlling the intensities of the seeds and detected by intensity measurements. Besides, we show that the thresholds are not affected by losses, which only modify the amount of nonclassicality. The multimode case is also analyzed in some detail.Comment: 12 pages, 3 figure

The quantum-classical transition in thermally seeded parametric downconversion

We address the pair of conjugated field modes obtained from parametric-downconversion as a convenient system to analyze the quantum-classical transition in the continuous variable regime. We explicitly evaluate intensity correlations, negativity and entanglement for the system in a thermal state and show that a hierarchy of nonclassicality thresholds naturally emerges in terms of thermal and downconversion photon number. We show that the transition from quantum to classical regime may be tuned by controlling the intensities of the seeds and detected by intensity measurements. Besides, we show that the thresholds are not affected by losses, which only modify the amount of nonclassicality. The multimode case is also analyzed in some detail.Comment: 12 pages, 3 figure

Calzado y Logística: entre la formalidad y la informalidad. Un estudio en el municipio de La Matanza

La investigación reflexiona sobre las tensiones que se generan entre las mejoras de los indicadores de empleo, por un lado, y, por otro, la subsistencia de rasgos que suelen caracterizarse como "heredados" del contexto anterior (1990-2002), tales como empleo no registrado, modalidades precarias de contratación, heterogeneidad en el empleo, entre algunos otros de los rasgos de informalidad (Gallart, 2007). Nuestra pregunta gira en torno a si esa "herencia" no implicaría una necesaria reproducción y readaptación de las relaciones laborales en orden a articular los aspectos productivos que sostienen la economía en el contexto de la Argentina actual. A su vez, analizamos cómo las estrategias empresarias de flexibilización afectan la cohesión sindical y los conflictos laborales en un escenario donde el crecimiento económico y el fortalecimiento institucional de las relaciones laborales parecieran posibilitar la implementación de estrategias de revitalización sindical.Fil: Schettini, Patricia. Universidad Nacional de La Plata; Argentina.Fil: Pontoni, Gabriela A. Universidad Nacional de La Matanza; Argentina.Fil: Radiciotti, Luisina. Universidad Nacional de La Matanza; Argentina

Attentional processes during P3-based Brain Computer Interface task in amyotrophic lateral sclerosis patients

To be available for a wide range of end-users a brain-computer interface (BCI) should be flexible and adaptable to end-users’ cognitive strengths and weaknesses. People’s cognitive abilities change according to the disease they are affected by, and people suffering from the same disease could have different cognitive capacities. We aimed at investigating how the amyotrophic lateral sclerosis (ALS) disease, and two different cognitive attentional aspects [1] influenced the usage of a P3-based BC

Patients With Psychoactive Substance Use Disorders Treated In A Psychiatric Emergency Unit

Study type: Prevalence study. Objective: To describe the socio demographic and clinical profile of patients with mental and behavioral disorders due to psychoactive substance (PAS) use, evaluated by the Psychiatric team of the Referenced Emergency Unit (REU) at the State University Clinical Hospital of Campinas (UNICAMP-HC). Methods and casuistic: This is a descriptive and quantitative study, which analyzed patients with mental and behavioral disorders due to PAS use, evaluated by the Psychiatric team of the REU-HC-UNICAMP during a period of 12 months, starting on May 2010. Results: There were evaluated 350 patients with PAS related disorders, representing 23.8% of those who sought psychiatric care. Most were males and younger than other patients of the emergency unit. The main reason for seeking help was psychiatric complaint other than PAS related disorders (23.1%), followed by desire to be treated oneself/being admitted to inpatient psychiatric treatment (20.8%) and intoxication (12.5%); 38.5% had a diagnosis of multiple PAS dependence and 34.8% were diagnosed with isolated alcohol dependence; 36% had psychiatric comorbidities and, when compared to other patients, they received more medications during attendance and were less directed to primary care units. Conclusion: There is a high rate of consultations of patients with PAS related problems in the psychiatric emergency unit. Data on the profile of the evaluated these patients can contribute to the improvement of care to this population.49214315

Optimizing single-photon-source heralding efficiency at 1550 nm using periodically poled lithium niobate

We explore the feasibility of using high conversion-efficiency periodically-poled crystals to produce photon pairs for photon-counting detector calibrations at 1550 nm. The goal is the development of an appropriate parametric down-conversion (PDC) source at telecom wavelengths meeting the requirements of high-efficiency pair production and collection in single spectral and spatial modes (single-mode fibers). We propose a protocol to optimize the photon collection, noise levels and the uncertainty evaluation. This study ties together the results of our efforts to model the single-mode heralding efficiency of a two-photon PDC source and to estimate the heralding uncertainty of such a source.Comment: 14 pages, 2 tables and 3 figures, final version accepted by Metrologi

Nonacceptability criteria and closure properties for the class of languages accepted by binary systolic tree automata

AbstractIn this paper a contribution is given to the solution of the problem of finding an inductive characterization of the class of languages accepted by binary systolic tree automata, L(BSTA), in terms of the closure of a class of languages with respect to certain operations. It is shown that L(BSTA) is closed with respect to some new operations: selective concatenation, restricted concatenation and restricted iteration. The known nonclosure of L(BSTA) with respect to classical language operations, like concatenation and Kleene iteration is proved here by using a new nonacceptability criterion

Hidrologia do Saco da Fazenda, Itajaí, SC

The Saco da Fazenda (SF) is a semi-enclosed coastal water body artificially made and inserted in the urban scenario of Itajaí city. The SF was created from the enterprise of retification of the access channel to the Port of Itajaí. The last curvature of the lower estuary was isolated from the main channel, and then creating the SF. Nowadays it is a depositional basin for the sediments from the Itajaí-Açu River and from small streams which drains the Itajaí City downtown. These small streams flow to the SF with no treatment at all, and, consequently, the water quality is low. Applying basic morphological data and hydrographic data from the SF and the lower Itajaí-Açu estuary, it was estimated the flushing time of the SF and the exchange level between the SF and the lower estuary. The flushing time is basically function of the tidal prism exchange, and the half-live was estimated as of the order of ‘few days’, or specifically 0,8 to 2,6 days varying the tidal height of neap and spring tide, respectivelly. The salinity of the SF the same of the upper layer of the lower estuary, and varies inversely and non-linearly related to the Itajaí-Açu river discharge, indicating higher level of eschange between them.The Saco da Fazenda (SF) is a semi-enclosed coastal water body artificially made and inserted in the urban scenario of Itajaí city. The SF was created from the enterprise of retification of the access channel to the Port of Itajaí. The last curvature of the lower estuary was isolated from the main channel, and then creating the SF. Nowadays it is a depositional basin for the sediments from the Itajaí-Açu River and from small streams which drains the Itajaí City downtown. These small streams flow to the SF with no treatment at all, and, consequently, the water quality is low. Applying basic morphological data and hydrographic data from the SF and the lower Itajaí-Açu estuary, it was estimated the flushing time of the SF and the exchange level between the SF and the lower estuary. The flushing time is basically function of the tidal prism exchange, and the half-live was estimated as of the order of ‘few days’, or specifically 0,8 to 2,6 days varying the tidal height of neap and spring tide, respectivelly. The salinity of the SF the same of the upper layer of the lower estuary, and varies inversely and non-linearly related to the Itajaí-Açu river discharge, indicating higher level of eschange between them