Advocating better habitat use and selection models in bird ecology

Studies on habitat use and habitat selection represent a basic aspect of bird ecology, due to its importance in natural history, distribution, response to environmental changes, management and conservation. Basically, a statistical model that identifies environmental variables linked to a species presence is searched for. In this sense, there is a wide array of analytical methods that identify important explanatory variables within a model, with higher explanatory and predictive power than classical regression approaches. However, some of these powerful models are not widespread in ornithological studies, partly because of their complex theory, and in some cases, difficulties on their implementation and interpretation. Here, I describe generalized linear models and other five statistical models for the analysis of bird habitat use and selection outperforming classical approaches: generalized additive models, mixed effects models, occupancy models, binomial N-mixture models and decision trees (classification and regression trees, bagging, random forests and boosting). Each of these models has its benefits and drawbacks, but major advantages include dealing with non-normal distributions (presence-absence and abundance data typically found in habitat use and selection studies), heterogeneous variances, non-linear and complex relationships among variables, lack of statistical independence and imperfect detection. To aid ornithologists in making use of the methods described, a readable description of each method is provided, as well as a flowchart along with some recommendations to help them decide the most appropriate analysis. The use of these models in ornithological studies is encouraged, given their huge potential as statistical tools in bird ecology.Fil: Palacio, Facundo Xavier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentin

EVEREST IST - 2002 - 00185 : D23 : final report

Deliverable públic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version

"On Lower-bound Traps: A Framework for the Analysis of Monetary Policy in the ÒAgeÓ of Central Banks"

We present a simple theoretical framework that integrates the notion of the natural or neutral interest rate, liquidity preference theory, and the monetary policy practice by modern central banks. We claim that this theory explains the conditions under which an economy will experience an aggregate demand deficiency problem within a modern institutional setting. Contrary to the predictions of the New Consensus View in macroeconomics, the model suggests that ÒstructuralÓ factors such as a high saving rate and, especially, a low ÒnaturalÓ rate of growth increase the chances that an economy experiences an aggregate demand deficiency. Contrary to conventional wisdom, the model predicts that a fall in the NAIRU may lead to a rise in the natural interest rate, and vice versa.

Capital accumulation, technical progress and wage flexibility: Keynes´approach to aggregate supply and demand analysis revisited

The aggregate supply and demand model (AS-AD) posited by Keynes in the General Theory and elaborated by Weintraub and Davidson is analysed by inserting a CES production function. We perform a comparative statics analysis where the effects on the equilibrium level of employment and the price level of changes in a wide range of variables and parameters are worked out. The effect of changes in the money wage rate on the level of employment and the price level are found to be ambiguous. Finally, we argue that this approach provides a more consistent approach than conventional AS-AD analysis does.

Money wage rigidity, monopoly power and hysteresis

The literature that addresses the effects on the level of aggregate demand of changes in the degree of monopoly typically assumes away the existence of an “inflation barrier” and an inflationtargeting central bank. The presence of these two institutional factors entails that any aggregate demand change brought about by changes in the functional distribution of income will tend to be offset by changes in real interest rates. We postulate a simple macroeconomic model for a closed economy with a government sector and hypothesize that a change in the average mark up affects the inflation rate, the “inflation-barrier” and aggregate demand. The model allows for the analysis of the effects on the employment rate of demand and supply shocks when the economy exhibits asymmetric inflation dynamics (AID) and hysteresis effects. Among other results we find that, if the economy exhibits AID and hysteresis, the effect on the employment rate of a change in the mark up is likely to be either ineffectual or counterproductive even if the associated demand shock is expansionary. We also show that an inadequate functional distribution of income may lead to the occurrence of an aggregate demand deficiency problem.Neutral interest rate, degree of monopoly, asymmetric inflation dynamics, zero lower bound, hysteresis, reversibility

Financing Problems as a Pretext for a Change in the Spanish Social Security System Model: The Role of Financial Institutions and Their Media

This study summarizes the traditional characteristics of the Spanish Social Security System (generally taken from the European model), the different legal reforms that have come into force in recent years and the degree of penetration of important financial groups in the mass media which increased with the last financial crisis as well as the role developed by the insurance and financial entities benefiting from the change of model. The conclusion is that we are at the beginning of an interesting change in the Social Security model, aimed at the capitalization of social contributions by the private sector, which will obtain significant economic benefits in the management of old-age risk

G-Bikes: Gettysburg Bike Share

The focus of this paper was to asses Gettysburg as possible location to implement a bike share program and ultimately to propose a framework for a successful program. We evaluated bike share programs across North America and created a list of criteria of successful programs. The second part of our data collection included a Google Forms survey which targeted three demographics, students, locals and tourists. We targeted our focus groups by posting on Facebook pages frequented by each demographic, as well as administering the survey in person with smart phones in Lincoln Square in Gettysburg. Our survey generated 134 responses, 86 of which were students, 27 locals, and 21 tourists. Our research showed that, demographically, successful programs occur in areas with high traffic from college students and tourists, as well as support from the local population. On the technical side, successful programs have 10-30 bikes per 10,000 residents with bike stations that range from 1-2 miles apart, averaging 4-8 trips per day, per bike. Our survey showed that a bike share program in Gettysburg would receive heavy support from our three demographics. It also showed that the largest concern from each demographic was bike related travel during the winter months which is consistent with the other programs we studied. Based on our research, we propose that the G-Bikes program should have 5 stations located at the top five intended locations of visitation, Gettysburg Town Center, Gettysburg College, Little Round Top, The Observation Tower, and on Steinwehr Avenue near the National Cemetery. Based off the overall population we recommend that the program start with a minimum of 20 bikes. We also recommend that the bike models follow the oBike specs from European bike share programs to maximize user convenience and minimize the threat of theft and vandalism. Through our study we determined Gettysburg\u27s unique niche as a small college town and tourist hub to be a possible location to implement a successful bike share program that implements many of the similar characteristics of other tourist destinations we studied

"Can Portugal Escape Stagnation without Opting Out from the Eurozone?"

The creation of the Economic and Monetary Union (EMU) has not brought significant gains to the Portuguese economy in terms of real convergence with wealthier eurozone countries. We analyze the causes of the underperformance of the Portuguese economy in the last decade, discuss its growth prospects within the EMU, and make two proposals for urgent institutional reform of the EMU. We argue that, under the prevailing institutional framework, Portugal faces a long period of stagnation, high unemployment, and painful structural reform, and conclude that, in the absence of institutional reform of the EMU, getting out of the eurozone represents a serious political option for Portugal.Nominal Wage Cuts; Eurozone; Relative Unit Labor Costs; Zero-sum Game

Literatura y otras artes - Hip Hop, Eminem and his multiple identities

Además del lado perverso que muestra Eminem en muchas de sus canciones, también existe un lado personal en él que queda prácticamente desconocido. Por ello, nosotros en este trabajo proponemos un análisis de estos distintos “yo”, precedido por la descripción de los cuatro elementos que componen esta tribu urbana, los que consideramos los eventos clave en la historia del hip-hop y un panorama de los principales países y sus MCs para detallar su importancia.Besides the evil self Eminem shows in many of his songs, there is a personal side in him which may remain practically unknown. Therefore, in this work we propose an analysis of these different selves, preceded by a description of the 4 elements which conform this urban culture, what we consider the key events in hip-hop history and a tour over the main countries and its MCs to detail their relevance