Is the transition redshift a new cosmological number?

Observations from Supernovae Type Ia (SNe Ia) provided strong evidence for an expanding accelerating Universe at intermediate redshifts. This means that the Universe underwent a transition from deceleration to acceleration phases at a transition redshift $z_t$ of the order unity whose value in principle depends on the cosmology as well as on the assumed gravitational theory. Since cosmological accelerating models endowed with a transition redshift are extremely degenerated, in principle, it is interesting to know whether the value of $z_t$ itself can be observationally used as a new cosmic discriminator. After a brief discussion of the potential dynamic role played by the transition redshift, it is argued that future observations combining SNe Ia, the line-of-sight (or "radial") baryon acoustic oscillations, the differential age of galaxies, as well as the redshift drift of the spectral lines may tightly constrain $z_t$, thereby helping to narrow the parameter space for the most realistic models describing the accelerating Universe.Comment: 12 pages, 5 figures. Some discussions about how to estimate the transition redshift have been added. New data by Planck and H(z) data have been mentioned. New references have been adde

New coupled quintessence cosmology

A component of dark energy has been recently proposed to explain the current acceleration of the Universe. Unless some unknown symmetry in Nature prevents or suppresses it, such a field may interact with the pressureless component of dark matter, giving rise to the so-called models of coupled quintessence. In this paper we propose a new cosmological scenario where radiation and baryons are conserved, while the dark energy component is decaying into cold dark matter (CDM). The dilution of CDM particles, attenuated with respect to the usual $a^{-3}$ scaling due to the interacting process, is characterized by a positive parameter $\epsilon$, whereas the dark energy satisfies the equation of state $p_x=\omega \rho_x$ ($\omega < 0$). We carry out a joint statistical analysis involving recent observations from type Ia supernovae, baryon acoustic oscillation peak, and Cosmic Microwave Background shift parameter to check the observational viability of the coupled quintessence scenario here proposed.Comment: 7 pages, 7 figures. Minor corrections to match published versio

Why Do Firms Engage in Selective Hedging?

Surveys of corporate risk management document that selective hedging, where managers incorporate their market views into firms’ hedging programs, is widespread in the U.S. and other countries. Stulz (1996) argues that selective hedging could enhance the value of firms that possess an information advantage relative to the market and have the financial strength to withstand the additional risk from market timing. We study the practice of selective hedging in a 10-year sample of North American gold mining firms and find that selective hedging is most prevalent among firms that are least likely to meet these valuemaximizing criteria -- (a) smaller firms, i.e., firms that are least likely to have private information about future gold prices; and (b) firms that are closest to financial distress. The latter finding provides support for the alternative possibility suggested by Stulz that selective hedging may also be driven by asset substitution motives. We detect weak relationships between selective hedging and some corporate governance measures, especially board size, but find no evidence of a link between selective hedging and managerial compensation.Corporate risk management, selective hedging, speculation, financial distress, corporate governance, managerial compensation

Drying of α-amylase by spray drying and freeze-drying - a comparative study

This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen) and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique313625631FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP99/12379-5; 01/00571-

Caracterização da comunidade de borboletas frugívoras do Parque Zoobotânico de Macapá, AP.

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Budgetary balances adjustments from governmental accounting to national accounts in EU countries: can deficits be prone to management?

European Union (EU) countries are required to achieve deficit targets and are thus incentivized to use tools to keep within budgetary limits. This paper argues that accounting discretion might be used to manage some adjustments made during the translation of data from Governmental Accounting (GA) into National Accounts (NA), to window‐dress the final deficit/surplus reported to EUROSTAT. The empirical research shows there are certain circumstances that might facilitate the use of GA–NA “adjustment discretion.” EU authorities must pay special attention to these conditions to ensure the reliability of reported deficits. The main findings of this paper could also assist in future efforts to improve the integrity of the adjustment process.info:eu-repo/semantics/acceptedVersio

Distribuição temporal e espacial do besouro-verde-do-açaizeiro [Macraspis pseudochrysis (Coleoptera: Scarabaeidae: Rutelini)] em açaizeiros de várzea em Mazagão, Amapá.

Em diferentes regiões do Estado do Amapá, foi verificada recentemente a ocorrência do besouro-verde-do-açaizeiro (Macraspis pseudochrysis Landin), derrubando as inflorescências de açaizeiro (Euterpe oleracea) em várzeas, provocando preocupação aos produtores, uma vez que a ação deste inseto poderia influenciar na formação de frutos. Com o objetivo de avaliar a distribuição temporal e espacial de M. pseudochrysis, foram realizadas amostragens mensais em inflorescências de E. oleracea em várzea no Campo Experimental da Embrapa Amapá em Mazagão, Amapá. Os açaizeiros eram provenientes de duas regiões do estuário amazônico que apresentam produção de frutos em épocas distintas do ano. A população 1 foi representada por açaizeiros que têm a produção de frutos no período chuvoso do ano (abril a agosto) e a população 2 foi composta por açaizeiros do tipo açaí de verão tendo sua produção de frutos no período de estiagem (agosto a dezembro). No período de maio a outubro de 2011 foram registrados 271 indivíduos de M. pseudochrysis em toda a área experimental. Na população 1 a maior densidade foi obtida em maio, apresentando 3 indivíduos/inflorescência. A população 2 apresentou densidade mais alta em julho com 4 indivíduos/inflorescência. Na maioria das ocasiões de amostragem o padrão de distribuição espacial foi agregado em ambas as populações.bitstream/item/100960/1/CPAF-AP-2014-BPD-82-Besouro-acai-DG3comCGPE.pd