Trade disclosure and price dispersion

This paper determines the effects of post-trade opaqueness on market performance. We find that the degree of market transparency has important effects on market equilibria. In particular, we show that dealers operating in a transparent structure set regret-free prices at each period making zero expected profits in each of the two trading rounds, whereas in the opaque market dealers invest in acquiring information at the beginning of the trading day. Moreover, we obtain that if there is no trading activity in the first period, then market makers only change their quotes in the opaque market. Additionally, we show that trade disclosure increases the informational efficiency of transaction prices and reduces volatility. Finally, concerning welfare of market participants, we obtain ambiguous results

Risk Aversion, Transparency, and Market Performance

Using a model of market making with inventories based on Biais (1993), we find that investors obtain more favorable execution prices, and they hence invest more, when markets are fragmented. In our model, risk-averse dealers use less aggressive price strategies in more transparent markets (centralized) because quote dissemination alleviates uncertainty about the prices quoted by other dealers and, hence, reduces the need to compete aggressively for order flow. Further, we show that the move toward greater transparency (centralization) may have detrimental effects on liquidity and welfare.Publicad

Trade disclosure and price dispersion

This paper studies the implications of trade reporting in a two-stage trade model similar to Journal of Financial Economics 14, 71–100. We find that the degree of market transparency has important effects on market equilibria. In particular, we show that dealers operating in a transparent structure set regret-free prices at each period. In contrast, dealers in an opaque market invest in acquiring information at the beginning of the trading day. Moreover, we show that in equilibrium there is price dispersion in the opaque market, whereas this is not the case if orders are reported. Additionally, we show that trade disclosure increases the informational efficiency of transaction prices and reduces volatility. Finally, concerning the welfare of market participants, we obtain ambiguous results.Publicad

Hybrid type theory: a quartet in four movements

This paper sings a song -a song created by bringing together the work of four great names in the history of logic: Hans Reichenbach, Arthur Prior, Richard Montague, and Leon Henkin. Although the work of the first three of these authors have previously been combined, adding the ideas of Leon Henkin is the addition required to make the combination work at the logical level. But the present paper does not focus on the underlying technicalities (these can be found in Areces, Blackburn, Huertas, and Manzano [to appear]) rather it focusses on the underlying instruments, and the way they work together. We hope the reader will be tempted to sing along

Desprendimiento de retina regmatógeno. Actuación de Enfermería

El objetivo principal de este trabajo es, la realización y presentación con la recopilación e información actualizada en el desprendimiento de retina regmatógeno, para preparar los conocimientos teóricos y prácticos necesarios y poder realizar el trabajo diario con la mayor calidad posible. Los principales objetivos secundarios planteados son: 1. Conocer en qué consiste la patología del desprendimiento de retina y definir la etiología, patogenia, evolución, tratamiento y posibles complicaciones. 2. Describir las funciones del personal de enfermería en los pacientes que acuden a la consulta de oftalmología afectos por esta patología. 3. Definir los cuidados que un profesional de enfermería ha de poner en práctica ante la persona con un DR antes, durante y después de la intervención quirúrgica, encaminados a prestar educación para la salud.Máster en Enfermería Oftalmológic

Worldwide Research on Plant Defense against Biotic Stresses as Improvement for Sustainable Agriculture

Agriculture is the basis for food production on a global scale. Sustainable agriculture tries to improve or maintain the quality of food without compromising the environment. As sessile organisms, plants cannot avoid adverse environmental conditions and contact with other living organisms. The damage caused to plants by other living organisms such as parasites and pathogens (virus, bacteria, fungi, nematodes or insects) brings about what is known as biotic stress. Plants are constantly exposed to biotic stress, which causes changes in plant metabolism involving physiological damages that lead to a reduction of their productivity. To fight biotic stress, plants have developed sophisticated defense mechanisms. Thus, understanding plant defense mechanisms might prevent important crop and economic losses. In this article, a bibliometric analysis of biotic stress is carried out. Different aspects of the publications are analyzed, such as publication type, research field, journal type, countries and their institutions, as well as the keyword occurrence frequency, and finally special attention is paid to the plant studied by the leading countries and institutions. As expected, journals selected by authors to publish their relevant findings are plant-specific journals. However, it should be noted that the fourth position, in terms of the number of publications per journal, is occupied by BMC Genomics journal. Such a journal considers mainly articles on genomics, which indicates the involvement of genetic factors in the control of biotic stress. Analysis of the keywords used in publications about biotic stress shows the great interest in the biotic–abiotic stress interaction, in the gene expression regulation in plants as well as phytohormones in the current research. In short, the great effort made by the scientific community in the biotic and abiotic stresses field with the aim to understand, regulate and control plant damages caused by biotic stress agents will help in the development of sustainable agriculture

Auditoria das redes sociais no sector do azeite

From the analysis of data collected in a survey conducted by 13 February to 13 March 2021 in the social media of both Castillo de Canena and its competitors has already been carried out in the field of social media, in order to be able to compare them and detect the weaknesses of the main company. All the companies studied have a profile created on Facebook, Instagram and YouTube, however, on Twitter not all of them have a profile, especially Maestros Hojiblanca, which is positioned at a very low level compared to Castillo de Canena. The order of use of these RRSS by organizations is respectively Facebook, Instagram, Twitter and YouTube, with Facebook being the RRSS most used both at an organizational level and by users of all ages, followed by Instagram. Castillo de Canena must correct its weaknesses detected in the field of social media in order to position itself at least at the same level as its competition. For this, a series of strategies and tactics or actions are proposed that will help to achieve the objectives that are proposed below. In addition, the actions proposed will be monitored or controlled to verify that they are being carried out correctly and that they are being effective and efficient. Interest to know how the olive sector is working on social networks and to know first-hand what the engagement is in each of the social networks they use.A partir da análise de dados recolhidos num inquérito realizado de 13 de fevereiro a 13 de março de 2021 nas redes sociais da empresa Castillo de Canena e dos seus concorrentes, procedeu-se à comparação para detetar as fraquezas da empresa principal. Todas as empresas estudadas têm um perfil criado no Facebook, Instagram e YouTube, no entanto, no Twitter nem todas têm esse perfil, especialmente a Maestros Hojiblanca, que se posiciona a um nível muito baixo em comparação com Castillo de Canena. A ordem de utilização destas RRSS por organizações é respectivamente Facebook, Instagram, Twitter e YouTube, sendo o Facebook o RRSS mais utilizado tanto a nível organizacional como por outros utilizadores, seguido pela Instagram. O Castillo de Canena deve corrigir as suas fraquezas detetadas no campo das redes sociais, a fim de se posicionar pelo menos ao mesmo nível da sua concorrência. Para tal, é proposta uma série de estratégias e ações que ajudarão a alcançar os objetivos que são propostos. Além disso, as ações propostas serão monitorizadas ou controladas para verificar se estão a ser levadas a cabo corretamente e se estão a ser eficazes. Considera-se de interesse, saber como o setor olivícola está a trabalhar nas redes sociais e em saber qual é o seu envolvimento em cada uma das redes sociais que utilizam

Data hidding in color images using perceptual models

One of the problems arising from the use of digital media is the ease of identical copies of digital images or audio files, allowing manipulation and unauthorized use. Copyright is an effective tool for preserving intellectual property of those documents but authors and publishers need effective techniques that prevent from copyright modification, due to the straightforward access to multimedia applications and the wider use of digital publications through the www. These techniques are generally called watermarking and allow the introduction of side information (i.e. author identification, copyrights, dates, etc.). This work concentrates on the problem embedding and optimum blind detection of data in color images through the use of spread spectrum techniques, both in space (Direct Sequence Spread Spectrum or DSSS) and frequency (Frequency Hopping). It is applied to RGB and opponent color component representations. Perceptive information is considered in both color systems. Some tests are performed in order to ensure imperceptibility and to assess detection quality of the optimum color detectors.Peer ReviewedPostprint (published version