Infrared Constraints on AGN Tori Models

This work focuses on the properties of dusty tori in active galactic nuclei (AGN) derived from the comparison of SDSS type 1 quasars with mid-Infrared (MIR) counterparts and a new, detailed torus model. The infrared data were taken by the Spitzer Wide-area InfraRed Extragalactic (SWIRE) Survey. Basic model parameters are constraint, such as the density law of the graphite and silicate grains, the torus size and its opening angle. A whole variety of optical depths is supported. The favoured models are those with decreasing density with distance from the centre, while there is no clear tendency as to the covering factor, ie small, medium and large covering factors are almost equally distributed. Based on the models that better describe the observed SEDs, properties such as the accretion luminosity, the mass of dust, the inner to outer radius ratio and the hydrogen column density are computed.Comment: 4 pages, 4 figures, to appear in "Infrared Diagnostics of Galaxy Evolution", ASP Conference Series, Pasadena, 14-16 November 200

Serum levels and removal by haemodialysis and haemodiafiltration of tryptophan-derived uremic toxins in ESKD patients

Tryptophan is an essential dietary amino acid that originates uremic toxins that contribute to end-stage kidney disease (ESKD) patient outcomes. We evaluated serum levels and removal during haemodialysis and haemodiafiltration of tryptophan and tryptophan-derived uremic toxins, indoxyl sulfate (IS) and indole acetic acid (IAA), in ESKD patients in different dialysis treatment settings. This prospective multicentre study in four European dialysis centres enrolled 78 patients with ESKD. Blood and spent dialysate samples obtained during dialysis were analysed with high-performance liquid chromatography to assess uremic solutes, their reduction ratio (RR) and total removed solute (TRS). Mean free serum tryptophan and IS concentrations increased, and concentration of IAA decreased over pre-dialysis levels (67%, 49%, -0.8%, respectively) during the first hour of dialysis. While mean serum total urea, IS and IAA concentrations decreased during dialysis (-72%, -39%, -43%, respectively), serum tryptophan levels increased, resulting in negative RR (-8%) towards the end of the dialysis session (p < 0.001), despite remarkable Trp losses in dialysate. RR and TRS values based on serum (total, free) and dialysate solute concentrations were lower for conventional low-flux dialysis (p < 0.001). High-efficiency haemodiafiltration resulted in 80% higher Trp losses than conventional low-flux dialysis, despite similar neutral Trp RR values. In conclusion, serum Trp concentrations and RR behave differently from uremic solutes IS, IAA and urea and Trp RR did not reflect dialysis Trp losses. Conventional low-flux dialysis may not adequately clear Trp-related uremic toxins while high efficiency haemodiafiltration increased Trp losses

Observations of the Hubble Deep Field with the Infrared Space Observatory. I. Data reduction, maps and sky coverage

We present deep imaging at 6.7 micron and 15 micron from the CAM instrument on the Infrared Space Observatory (ISO), centred on the Hubble Deep Field (HDF). These are the deepest integrations published to date at these wavelengths in any region of sky. We discuss the observation strategy and the data reduction. The observed source density appears to approach the CAM confusion limit at 15 micron, and fluctuations in the 6.7 micron sky background may be identifiable with similar spatial fluctuations in the HDF galaxy counts. ISO appears to be detecting comparable field galaxy populations to the HDF, and our data yields strong evidence that future IR missions (such as SIRTF, FIRST and WIRE) as well as SCUBA and millimetre arrays will easily detect field galaxies out to comparably high redshifts.Comment: 7 pages, LaTeX (using mn.sty), 9 figures included as GIFs. Gzipped Postscipt version available from http://artemis.ph.ic.ac.uk/hdf/papers/ps/. Further information on ISO-HDF project can be found at http://artemis.ph.ic.ac.uk/hdf

Economic incentives and comparative advantage in Indonesian food crop production:

In Indonesia production of food crops grew an impressive 4.3 percent a year between 1978 and 1988, largely as a result of favorable government pricing, research, and investment policies toward rice and other crops. In recent years, however, the high costs of subsidies to the government and the increasing competition for scarce resources among commodities have caused Indonesian policymakers to take a fresh look at these policies in order to determine what is needed in a changing economic environment. What policies should the government pursue for rice and other major food crops? Should the government provide incentives or investments to promote rice as an export crop? What have been the effects of government policies on the international competitiveness of other commodities such as corn or cassava? Is there a continuing role for large input subsidies, or should these subsidies be eliminated? What investments are appropriate in the food crop sector? The report examines trends in the government policies and production of five major food crops (rice, corn, soybeans, sugar, and cassava) in Indonesia; analyzes the effects of government input-output pricing policies on domestic production incentives for these food crops; and assesses their relative comparative advantage under the three trade regimes of import substitution, interregional trade, and export promotion.Agricultural policy Indonesia., Produce trade Government policy Indonesia., Food crops Economic aspects Indonesia., Food production Economic aspects Indonesia.,

'Dreamers’, (un)deserving immigrants and generational interdependence

Undocumented young people known as the ‘Dreamers’ have become the embodiment of the ‘deserving immigrant’ in US public debates on immigration. Through exploring the narratives of undocumented young organisers in California, this article examines how they came to be framed in this way and the limitations of this as a pathway to social justice. It explores their accounts of organising in the undocumented youth movement to examine how their relationships with their families have influenced their engagement with the Dreamer narrative and its contestation. It was found that the figure of the deserving Dreamer represented an overly individualised account of migrant youth experiences and trajectories. Drawing on a relational understanding of migration and life course pathways, it is argued that undocumented youth are embedded in interdependent intergenerational relationships which affect their experiences and outcomes and therefore need to be recognised in any pathway to social justice

Semiconducting Monolayer Materials as a Tunable Platform for Excitonic Solar Cells

The recent advent of two-dimensional monolayer materials with tunable optoelectronic properties and high carrier mobility offers renewed opportunities for efficient, ultra-thin excitonic solar cells alternative to those based on conjugated polymer and small molecule donors. Using first-principles density functional theory and many-body calculations, we demonstrate that monolayers of hexagonal BN and graphene (CBN) combined with commonly used acceptors such as PCBM fullerene or semiconducting carbon nanotubes can provide excitonic solar cells with tunable absorber gap, donor-acceptor interface band alignment, and power conversion efficiency, as well as novel device architectures. For the case of CBN-PCBM devices, we predict the limit of power conversion efficiencies to be in the 10 - 20% range depending on the CBN monolayer structure. Our results demonstrate the possibility of using monolayer materials in tunable, efficient, polymer-free thin-film solar cells in which unexplored exciton and carrier transport regimes are at play.Comment: 7 pages, 5 figure

Theory of Type-II Superconductors with Finite London Penetration Depth

Previous continuum theory of type-II superconductors of various shapes with and without vortex pinning in an applied magnetic field and with transport current, is generalized to account for a finite London penetration depth lambda. This extension is particularly important at low inductions B, where the transition to the Meissner state is now described correctly, and for films with thickness comparable to or smaller than lambda. The finite width of the surface layer with screening currents and the correct dc and ac responses in various geometries follow naturally from an equation of motion for the current density in which the integral kernel now accounts for finite lambda. New geometries considered here are thick and thin strips with applied current, and `washers', i.e. thin film squares with a slot and central hole as used for SQUIDs.Comment: 14 pages, including 15 high-resolution figure

Experiencia subjetiva del empleado en colaboradores de establecimientos hoteleros de la región Junín

Objective: To determine the characteristics of the employee experience in employees of hotel establishments in the Junín region. Methods. The type of research was basic, descriptive level, simple descriptive design and non-experimental-transectional. The methods used were observation, analysis and synthesis and inductive-deductive, while the instrument applied was the questionnaire and the technique was the survey. The sample consisted of 320 employees of hotel establishments in the Junín region and the sample selection criterion was non-probabilistic by convenience. Results. The main results were that the levels of employee experience at the subjective level were regular in its physical and technological dimensions, and high in its cultural dimension; which reflects that, despite the adverse conditions due to the covid-19 pandemic, the collaborators performed their tasks with appropriateness and assertiveness. Conclusion. Companies in the hotel sector should implement programs that reinforce and establish the objective conditions of their work environment in order to generate profitable and positive subjective experiences in favor of their employees and the productivity of the organization.Objetivo. Determinar las características del employee experience en colaboradores de establecimientos hoteleros de la región Junín. Métodos. El tipo de investigación fue básica, de nivel descriptivo, diseño descriptivo simple y no experimental-transeccional. Los métodos fueron la observación, el análisis y síntesis y el inductivo-deductivo, mientras que el instrumento aplicado fue el cuestionario y la técnica la encuesta. La muestra estuvo conformada por 320 colaboradores de establecimientos hoteleros de la región Junín y el criterio de selección de la muestra fue no probabilístico por conveniencia. Resultados. Los principales resultados fueron que los niveles de experiencia del empleado a nivel subjetivo fueron regulares en sus dimensiones física y tecnológica, y de nivel alto en su dimensión cultural; lo que refleja que, pese a las condiciones adversas por pandemia de la covid-19, los colaboradores desarrollaron labores con propiedad y asertividad. Conclusión. Las empresas del sector hotelero deben implementar programas que refuercen y establezcan las condiciones objetivas de su entorno laboral a fin de generar experiencias subjetivas redituables y positivas en favor de sus colaboradores y la productividad de la organización