Shirking, Commuting and Labor Market Outcomes

Recent theoretical work has examined the spatial distribution of unemployment using the efficiency wage model as the mechanism by which unemployment arises in the urban economy. This paper extends the standard efficiency wage model in order to allow for behavioral substitution between leisure time at home and effort at work. In equilibrium, residing at a location with a long commute affects the time available for leisure at home and therefore affects the trade-off between effort at work and risk of unemployment. This model implies an empirical relationship between expected commutes and labor market outcomes, which is tested using the metropolitan sample of the American Housing Survey. No evidence is found to suggest a consistent impact of efficiency wages on the spatial pattern of unemployment or earnings.

Application of a building cost estimation model to the appraisal of the churches damaged by earthquakes in Lorca (Spain)

The objective of this paper is the development of a building cost estimation model whose purpose is to quickly and precisely evaluate rebuilding costs for historic heritage buildings affected by catastrophic events. Specifically, this study will be applied to the monumental buildings owned by the Catholic Church that were affected by two earthquakes on May 11, 2011 in the town of Lorca. To estimate the initial total replacement cost new, calculation model will be applied which, on the one hand, will use two-dimensional metric exterior parameters and, on the other, three-dimensional interior cubic parameters. Based on the total of the analyzed buildings, and considering damage caused by the seismic event, the final reconstruction cost for the building units ruined by the earthquakes can be estimated. The proposed calculation model can also be applied to other emergency scenarios and situations for the quick estimation of construction costs necessary for rebuilding historic heritage buildings which have been affected by catastrophic events that deteriorate or ruin their structural or constructive configuration.

Auditorium: una tipología del siglo XX

Se recoge en esta tesis doctoral la definición y clasificación de los edificios cuya finalidad es proporcionar espacios para escuchar y producir música. Se centra en aquellos construidos a lo largo del siglo XX, en el área geográfica y cultural que forman Europa occidental y Estados Unidos. Se analizan edificios construidos en el pasado, en una serie que se origina a mediados del siglo XIX y que se culmina terciado el propio siglo XX. Son edificios que contienen espacios pensados para músicas que, sin embargo, en su mayoría fueron creadas en un periodo anterior, desde mediados del siglo XVIII hasta las primeras décadas del siglo pasado. Un auditorium es un edificio cuya idea conlleva la compleja herencia de los múltiples lugares, abiertos y cerrados, que han alojado la música a lo largo del tiempo. Es un edificio que es útil a la sociedad y que ocupa un lugar significativo dentro de la ciudad, y es consecuencia del campo de fuerzas que constituyen los avances técnicos, el progreso de las sociedades urbanas y la evolución del arte, al compartir estrechamente, música y arquitectura, el interés por hallar la expresión de una nueva relación con la naturaleza. Se parte de la hipótesis de que el auditorium puede constituir un tipo arquitectónico con entidad suficiente para generar una tipología. Entendida ésta como una herramienta que dota de conocimientos útiles a quien va a proyectar un edificio para la música y también que permita abrir el campo de pensamiento sobre el espacio musical, sin necesidad de recurrir a modelos previos, aunque se hayan manifestado útiles y precisos. Se comienza con una aproximación a una definición del término «auditorium » y se analizan a qué funciones responde y en qué es distinto de otros edificios, a través de determinar las características formales propias. Para ello se articula la tesis en varios bloques de análisis. I Elementos para una tipología Se indaga en los atributos que determinan la naturaleza de los auditorios para definir cómo son estos edificios y qué características y condiciones tienen, no sólo las salas sino también los edificios que las contienen, buscando el origen de los espacios musicales y su relación con las personas que allí se han reunido para celebrar, a través de la música, acontecimientos colectivos. Relación que ha comportado desplazamientos por los distintos espacios que ha compartido, supeditada a otras actividades, hasta que finalmente, la música ha reclamado espacios propios. Pero también se establece otra relación física entre las distintas posiciones que ocupan en el espacio cuantos intervienen en la celebración del hecho musical, músicos y público. De otra parte se analiza cómo son sus espacios interiores, salas y vestíbulos, y los volúmenes y formas de los edificios en relación con la ciudad. Su conexión con la idea del paisaje abierto y con el carácter originario de la cueva. II Cinco tiempos Los edificios sobre los que se van explorar estas capacidades son en muchos casos arquitecturas divulgadas y conocidas. Sin embargo no todas han tenido desde su aparición el mismo grado de aprecio ni reconocimiento, y sólo el paso del tiempo ha confirmado su excelencia. El estudio se estructura en los periodos marcados por los acontecimientos bélicos y las grandes crisis que sacudieron Europa y Norte América desde comienzos del siglo XX. La identificación de los elementos significativos de la tipología se hace a través del análisis de distintos tiempos que agrupan casos heterogéneos, tiempos entendidos unas veces como la relación entre edificios coetáneos y otra como proyectos pensados por un mismo arquitecto y se detiene, entre otros, en cuatro excepcionales edificios que condensan la experiencia de varias décadas y demuestran su plenitud arquitectónica, por haber evolucionado de modelos precedentes o por su novedosas aportaciones. El Royal Festival Hall (1951), el Kresge Auditorium (1954), el Kulttuuritalo (1958) y la Philharmonie de Berlín (1963), sirven de base para una clasificación del auditorium. III Cronología gráfica Este apartado es fundamentalmente gráfico y consta un inventario de más de 100 archivos correspondientes a otros tantos auditorios y sus salas, en orden cronológico. Cada archivo cuenta con una imagen del exterior del edificio y otra del interior de la sala. Se han incorporado en cada uno de los archivos, dos dibujos a la misma escala. El primero muestra la planta de la sala con tres parámetros: la ocupación del público en referencia al lugar que ocupa la orquesta, la relación de tamaño entre la sala y las de los cuatro auditorios de referencia y la distancia al foco de sonido, la orquesta, mediante una escala en metros. Estos tres parámetros están superpuestos al que he considerado espacio audible, un rectángulo de 60 por 90 metros, en el que el foco está desplazado, por considerar que el sonido de una orquesta tiene una componente directional y que en esas dimensiones la energía sonora no decae. En el friso bajo el dibujo, aparecen cuatro iconos que informan de la relación formal de la sala con la del auditorium. Puede ser una sala dentro de un edificio sin correspondencia formal, un edificio en el que se manifiesta exteriormente el volumen de la sala, un edificio que tiene la forma de la sala y resuelve el resto del programa funcional sin manifestarlo exteriormente o, finalmente un edificio complejo cuya forma absorbe dos o más salas de música. El segundo dibujo es la sección longitudinal de la sala, recortada sobre un fondo negro para destacar su forma y proporción, todas están a la misma escala y en la misma dirección respecto del escenario para facilitar su lectura y comparación. En el parte inferior de la sección, aparecen cuatro esquemas de la forma y distribución en planta sobre el que destaca la de cada caso de estudio. La forma del techo de las salas de música de los auditorios, expresada a través de la sección longitudinal, es uno de los elementos que caracteriza el espacio musical. El perímetro de la sección, determina su superficie y por tanto, el volumen total interior. Es una herramienta técnica que permite dirigir el sonido reflejado en él, hasta cualquier lugar del interior de la sala, garantizando una distribución homogénea y evitando concentraciones perjudiciales o «sombras acústicas», lugares donde no llegan las primeras reflexiones. IV Geometría de las salas El análisis efectuado permite la elaboración de paralelos de tres de los elementos fundamentales de la tipología de las salas de los auditorium y que definen el espacio musical. El perímetro de la sección y su superficie que establecen el volumen total interior, que es un factor determinante en la reverberación de una sala. La forma y superficie del techo, que interviene directamente en el cálculo de la absorción del sonido, en función de la cualidad reflejante o absorbente del material con el que está construido, y por otra parte en la distribución del sonido en el espacio. Y por último, la forma del suelo de las salas también expresada a través de la sección longitudinal, es otro de los elementos que caracteriza el espacio musical. El modelado del suelo permite mediante distintas pendientes garantizar la correcta visión del escenario y por tanto permite también una buena audición, puesto que la llegada directa del sonido está asegurada. La otra limitación dimensional es el ancho de la grada. Cuando se ha buscado incrementar al máximo la capacidad de una sala, se han establecido graderíos en balcones en voladizo para no penalizar la distancia al escenario, de manera que algunas partes del graderío quedan cubiertas, en detrimento de su calidad acústica al privarlas de las primeras reflexiones que proceden del techo. V Auditórium y ciudad El auditorium es un edificio singular que establece con la ciudad una relación particular y que contiene en su interior una o varias salas especiales destinadas a oír y ejecutar música, a las que se accede a través de otros espacios de carácter social. Han ido evolucionando y modificándose de manera ininterrumpida, dando lugar a edificios de diversa complejidad en su programa y a salas cada vez mas especificas para cumplir mejor su cometido, perfeccionando su sonido y buscando la más elevada musicalidad. Estos edificios disponen de otros ámbitos de relación, son los espacios interiores, vestíbulos y escaleras, generalmente generosos en superficie y espacialidad, previos al espacio musical, corazón del auditorium donde suena la música en condiciones acústicas precisas. También el lugar donde se construyen los auditoriums en las ciudades tiene un especial significado, porque generalmente han buscado interponer espacios abiertos o ajardinados que suavicen el contacto directo con la ciudad y que implican, por otra parte, una preparación de las personas que asisten para escuchar los conciertos. Con el paso del tiempo, la aceptación generalizada de formas afianzadas en la ciudad, será uno de los vehículos que permita contaminar a otros tipos de edificios y alcanzar una libertad formal renovadora de los paisajes urbanos. Conclusiones La disolución del espacio musical convencional pregonado por el pabellón Philips del año 1958, no ha impedido que hoy siga vivo para el arquitecto el reto del proyecto y construcción del auditorium. Hoy conviven experiencias musicales totales; imagen, luz y movimiento, ocupando todo tipo de espacios públicos, cerrados o al aire libre, con la voluntad de conseguir espacios capaces de crear la intimidad y las precisas condiciones ambientales que hagan posible la recreación de las músicas del pasado en una especie de emocionante museo sonoro vivo. Como edificios urbanos, los auditoriums han conseguido un lugar destacado en la iconografía urbana después de un largo camino hasta conseguir el reconocimiento social. Se puede, así, establecer que estos edificios han introducido en la ciudad una nueva manera de expresarse la arquitectura. Que lo inesperado de sus formas y volúmenes en el espacio urbano, o la sorpresa de sus interiores altamente técnicos, justificados para satisfacer las nuevas necesidades impuestas por una audiencia cada vez más y más experta, obtienen la aceptación urbana por su utilidad social y por su capacidad de establecer una relación distinta entre las personas, la ciudad y la naturaleza. Coda Finalmente, el epílogo habla de la metamorfosis del espacio musical y de la convivencia de distintos espacios musicales en la actualidad. Desde la creación de las primeras y sencillas salas de música hasta las grandes salas filarmónicas que se construyen en las últimas décadas, la arquitectura ha proporcionado lugares adecuados para contener y disfrutar la música, espacios que se han modificado según cambiaban las formas musicales. Sin embargo el sonido parece mostrarse reticente a ser encerrado en el espacio y busca aliarse con el tiempo para conseguir un desplazamiento permanente. Seguramente es en el pabellón Philips de Bruselas en 1958 donde se presenta el último intento de la arquitectura de contener la música, que impulsada por tecnologías absolutamente nuevas, se mueve como dardos que atraviesan el espacio en todos los lugares y en todas las direcciones. Desde aquellas décadas centrales del pasado siglo, y superando los mas optimistas intentos de distribuir masivamente la música a través de incipientes tecnologías, se puede afirmar que vivimos en una inmersión sonora universal. Anexos Incluyen, una colección de mapas de la geografía de los auditorios europeos y norte-americanos, referenciados a los periodos de su construcción, y una relación de los auditorios estudiados con referencias bibliográficas. ABSTRACT This doctoral thesis does not only look at the ways in which architecture and music relate with one another; it also seeks to be an exact, scientific study of auditoriums, a building type that first appeared in the 20th century as a place in which to produce and listen to music. It studies concert halls, raised in Europe and the United Stated in the 20th century, for the purpose of recreating older music, that were the result of the evolution of various ancient building types. Auditoriums have a complex heritage of architecture of all times, openair and covered alike, and occupy important spots in cities. They incorporate the technical innovations of their times, and are reflections not only of the music played within them, but also of the societies that built them. Music and architecture share an interest in connecting with nature. Auditorium, a 20th-century Typology tries to define this building typology, and with that, be a practical tool in designing and constructing spaces for music, besides exploring the relationship between the two disciplines, architecture and music, and establishing the foundations for an entire school of thought. It is organized in five chapters, each focusing on a particular aspect of auditoriums, all towards defining a possible typology: I Typology elements. A study of the origin of auditoriums, and of how the different parts of these buildings —the actual concert hall, the foyer, the open spaces— relate with the city and with nature, which is ever present in music and in the origin of auditoriums. II Five sequences. A chronological journey through the 20th century, in periods marked by the two world wars and the consequent crises, with case studies of four exceptional buildings: the Royal Festival Hall (1951), the Kresge Auditorium (1954), the Kulttuuritalo (1958), and the Berlin Philharmonie (1963). III Graphic chronology. A methodical sequence looking at a hundred auditoriums, with each entry presenting images of the concert hall and the building as a whole, and two drawings on the same scale. Each concert hall floor plan shows how the orchestra relates with the audience, and it is compared to the floor plans of the four case-study examples named above. We also see how the hall is set into the building. The second drawing is the longitudinal section of the hall. Ceiling shape much determines the character of concert hall spaces, while technical data like air volume and the amount of absorbent and reflecting materials used have a direct bearing on the reflection of sound and on the overall musical quality of the auditorium. IV Geometry of concert halls. Graphic analysis of the key elements of a music space: the ceiling and the floor plan. The section is a necessary tool for determining the reverberation time of a concert hall, and is closely linked to the shape of the floor plan. In concert halls, there is a strong connection between the ceiling, the walls, and the floor, as there is between different musical instruments. It also includes maps showing where these European and American buildings are located geographically as well as in time. V The auditorium in the city. This chapter presents a series of maps showing the location of auditoriums in the city. They are often located in squares and gardens, open public spaces that serve to emotionally prepare the listener for an imminent musical experience. Time has shown that concert halls have changed the urban landscape and city life. Conclusions As a building type, auditoriums —though «dissolved» by the Philips Pavilion in 1958— remain valid spaces for listening to music. As intimate and unique spaces for social gathering and musical creation, they have done their part in transforming cities. Acoustics play a key role in these technical interiors, but just as important is the rapport that is struck between the musicians and the audience, and between musical works of the past, present, and future. Auditoriums are urban buildings that have been very successful throughout history. They have enriched our cities with surprising shapes and volumes, introduced new interiors in architecture, and struck new relationships between people, the city, and nature. As such, they are necessary. Coda Finally, the epilogue presents the evolution of the music space, from the early simple music halls to the highly complex philharmonic halls of recent years. Architecture has produced spaces for the enjoyment of music that have been modified for new musical creations, while remaining useful for the historical repertoire. Sound, and thus music, has as complex a relationship with space as it does with time. The coda of this thesis is the Philips Pavilion of 1958, perhaps the last attempt to propose a new kind of architecture for music with the latest technology. Annexes The thesis includes a collection of site maps of European and American auditoriums, complete with completion dates and descriptions.

Current housing reports.

Description based on: 1981.

Current housing reports.

Description based on: 1979.

Current housing reports.

Description based on: 1981.

Bulletin.

Mode of access: Internet.

Housing conditions and housing options for older residents : a question of need, a question of acceptable alternatives : final report /

The primary goal of this project is to learn more about the housing conditions of the rural elderly in Illinois. By using questions similar to those included in the American Housing Survey (AHS) used by the Bureau of the Census, comparisons can be made between Illinois residents and a national sample. The questions used in this Housing Conditions and Housing Options for Older Residents Survey (2002) (Appendix B) focus specifically on issues related to the availability and condition of plumbing, heating, electricity, and upkeep using guidelines extablished by the AHS. ... There are three objectives for this study (1) to determine the type and condition of housing occupied by older residents in three regions of Illinois, (2) to determine the types of housing elderly residents would choose from a list of options and what conditions would cause them to choose that type of housing, and (3) to examine whether regional variations exist in housing conditions and housing options among rural residents of Illinois.

The Elizabeth River Story: A Case Study in Evolutionary Toxicology.

The Elizabeth River system is an estuary in southeastern Virginia, surrounded by the towns of Chesapeake, Norfolk, Portsmouth, and Virginia Beach. The river has played important roles in U.S. history and has been the location of various military and industrial activities. These activities have been the source of chemical contamination in this aquatic system. Important industries, until the 1990s, included wood treatment plants that used creosote, an oil-derived product that is rich in polycyclic aromatic hydrocarbons (PAH). These plants left a legacy of PAH pollution in the river, and in particular Atlantic Wood Industries is a designated Superfund site now undergoing remediation. Numerous studies examined the distribution of PAH in the river and impacts on resident fauna. This review focuses on how a small estuarine fish with a limited home range, Fundulus heteroclitus (Atlantic killifish or mummichog), has responded to this pollution. While in certain areas of the river this species has clearly been impacted, as evidenced by elevated rates of liver cancer, some subpopulations, notably the one associated with the Atlantic Wood Industries site, displayed a remarkable ability to resist the marked effects PAH have on the embryonic development of fish. This review provides evidence of how pollutants have acted as evolutionary agents, causing changes in ecosystems potentially lasting longer than the pollutants themselves. Mechanisms underlying this evolved resistance, as well as mechanisms underlying the effects of PAH on embryonic development, are also described. The review concludes with a description of ongoing and promising efforts to restore this historic American river.

Combining Information from Multiple Sources in Bayesian Modeling

Surveys can collect important data that inform policy decisions and drive social science research. Large government surveys collect information from the U.S. population on a wide range of topics, including demographics, education, employment, and lifestyle. Analysis of survey data presents unique challenges. In particular, one needs to account for missing data, for complex sampling designs, and for measurement error. Conceptually, a survey organization could spend lots of resources getting high-quality responses from a simple random sample, resulting in survey data that are easy to analyze. However, this scenario often is not realistic. To address these practical issues, survey organizations can leverage the information available from other sources of data. For example, in longitudinal studies that suffer from attrition, they can use the information from refreshment samples to correct for potential attrition bias. They can use information from known marginal distributions or survey design to improve inferences. They can use information from gold standard sources to correct for measurement error.

This thesis presents novel approaches to combining information from multiple sources that address the three problems described above.

The first method addresses nonignorable unit nonresponse and attrition in a panel survey with a refreshment sample. Panel surveys typically suffer from attrition, which can lead to biased inference when basing analysis only on cases that complete all waves of the panel. Unfortunately, the panel data alone cannot inform the extent of the bias due to attrition, so analysts must make strong and untestable assumptions about the missing data mechanism. Many panel studies also include refreshment samples, which are data collected from a random sample of new

individuals during some later wave of the panel. Refreshment samples offer information that can be utilized to correct for biases induced by nonignorable attrition while reducing reliance on strong assumptions about the attrition process. To date, these bias correction methods have not dealt with two key practical issues in panel studies: unit nonresponse in the initial wave of the panel and in the

refreshment sample itself. As we illustrate, nonignorable unit nonresponse

can significantly compromise the analyst's ability to use the refreshment samples for attrition bias correction. Thus, it is crucial for analysts to assess how sensitive their inferences---corrected for panel attrition---are to different assumptions about the nature of the unit nonresponse. We present an approach that facilitates such sensitivity analyses, both for suspected nonignorable unit nonresponse

in the initial wave and in the refreshment sample. We illustrate the approach using simulation studies and an analysis of data from the 2007-2008 Associated Press/Yahoo News election panel study.

The second method incorporates informative prior beliefs about

marginal probabilities into Bayesian latent class models for categorical data.

The basic idea is to append synthetic observations to the original data such that

(i) the empirical distributions of the desired margins match those of the prior beliefs, and (ii) the values of the remaining variables are left missing. The degree of prior uncertainty is controlled by the number of augmented records. Posterior inferences can be obtained via typical MCMC algorithms for latent class models, tailored to deal efficiently with the missing values in the concatenated data.

We illustrate the approach using a variety of simulations based on data from the American Community Survey, including an example of how augmented records can be used to fit latent class models to data from stratified samples.

The third method leverages the information from a gold standard survey to model reporting error. Survey data are subject to reporting error when respondents misunderstand the question or accidentally select the wrong response. Sometimes survey respondents knowingly select the wrong response, for example, by reporting a higher level of education than they actually have attained. We present an approach that allows an analyst to model reporting error by incorporating information from a gold standard survey. The analyst can specify various reporting error models and assess how sensitive their conclusions are to different assumptions about the reporting error process. We illustrate the approach using simulations based on data from the 1993 National Survey of College Graduates. We use the method to impute error-corrected educational attainments in the 2010 American Community Survey using the 2010 National Survey of College Graduates as the gold standard survey.

Methods for Imputing Missing Values and Synthesizing Confidential Values for Continuous and Magnitude Data

Abstract

Continuous variable is one of the major data types collected by the survey organizations. It can be incomplete such that the data collectors need to fill in the missingness. Or, it can contain sensitive information which needs protection from re-identification. One of the approaches to protect continuous microdata is to sum them up according to different cells of features. In this thesis, I represents novel methods of multiple imputation (MI) that can be applied to impute missing values and synthesize confidential values for continuous and magnitude data.

The first method is for limiting the disclosure risk of the continuous microdata whose marginal sums are fixed. The motivation for developing such a method comes from the magnitude tables of non-negative integer values in economic surveys. I present approaches based on a mixture of Poisson distributions to describe the multivariate distribution so that the marginals of the synthetic data are guaranteed to sum to the original totals. At the same time, I present methods for assessing disclosure risks in releasing such synthetic magnitude microdata. The illustration on a survey of manufacturing establishments shows that the disclosure risks are low while the information loss is acceptable.

The second method is for releasing synthetic continuous micro data by a nonstandard MI method. Traditionally, MI fits a model on the confidential values and then generates multiple synthetic datasets from this model. Its disclosure risk tends to be high, especially when the original data contain extreme values. I present a nonstandard MI approach conditioned on the protective intervals. Its basic idea is to estimate the model parameters from these intervals rather than the confidential values. The encouraging results of simple simulation studies suggest the potential of this new approach in limiting the posterior disclosure risk.

The third method is for imputing missing values in continuous and categorical variables. It is extended from a hierarchically coupled mixture model with local dependence. However, the new method separates the variables into non-focused (e.g., almost-fully-observed) and focused (e.g., missing-a-lot) ones. The sub-model structure of focused variables is more complex than that of non-focused ones. At the same time, their cluster indicators are linked together by tensor factorization and the focused continuous variables depend locally on non-focused values. The model properties suggest that moving the strongly associated non-focused variables to the side of focused ones can help to improve estimation accuracy, which is examined by several simulation studies. And this method is applied to data from the American Community Survey.

Camoens and his epic; a historic, geographic, and cultural survey.

Mode of access: Internet.

Linking the American Time Use Survey (ATUS) and the Compendium of Physical Activities : methods and rationale

Background: The 2003 Bureau of Labor Statistics American Time Use Survey (ATUS) contains 438 distinct primary activity variables that can be analyzed with regard to how time is spent by Americans. The Compendium of Physical Activities is used to code physical activities derived from various surveys, logs, diaries, etc to facilitate comparison of coded intensity levels across studies. ------ ----- Methods: This paper describes the methods, challenges, and rationale for linking Compendium estimates of physical activity intensity (METs, metabolic equivalents) with all activities reported in the 2003 ATUS. ----- ----- Results: The assigned ATUS intensity levels are not intended to compute the energy costs of physical activity in individuals. Instead, they are intended to be used to identify time spent in activities broadly classified by type and intensity. This function will complement public health surveillance systems and aid in policy and health-promotion activities. For example, at least one of the future projects of this process is the descriptive epidemiology of time spent in common physical activity intensity categories. ----- ----- Conclusions: The process of metabolic coding of the ATUS by linking it with the Compendium of Physical Activities can make important contributions to our understanding of Americans’ time spent in health-related physical activity.

The distribution and size composition of finfish, American lobster, and long-finned squid in Long Island Sound based on the Connecticut Fisheries Division Bottom Trawl Survey, 1984–1994

The distribution, abundance, and length composition of marine finfish, lobster, and squid in Long Island Sound were examined relative to season and physical features of the Sound, using Connecticut Department of Environmental Protection trawl survey data collected from 1984 to 1994. The following are presented: seasonal distribution maps for 59 species, abundance indices for 41 species, and length frequencies for 26 species. In addition, a broader view of habitat utilization in the Sound was examined by mapping aggregated catches (total catch per tow, demersal catch per tow, and pelagic catch per tow) and by comparing species richness and mean aggregate catch/tow by analysis of variance (ANOVA) among eight habitat types defined by depth interval and bottom type. For many individual species, seasonal migration patterns and preference for particular areas within Long Island Sound were evident. The aggregate distribution maps show that overall abundance was lower in the eastern Sound than the central and western portions. Demersal and pelagic temporal abundance show opposite trends—demersals were abundant in spring and declined through summer and fall, whereas pelagic abundance was low in spring and increased into fall. The analysis of habitat types revealed significant differences for both species richness and mean catch per tow. Generally, species richness was highest in habitats within the central area of the Sound and lowest in eastern habitats. The aggregate mean catch was highest in the western and central habitats, and declined eastward. (PDF file contains 199 pages.)

Estimating Sighting Proportions of American Alligator Nests during Helicopter Survey

Proportions of American alligator (Alligator mississippiensis) nests sighted during aerial survey in Florida were estimated based upon multiple surveys by different observers. We compared sighting proportions across habitats, nesting seasons, and observer experience levels. The mean sighting proportion across all habitats and years was 0.736 (SE=0.024). Survey counts corrected by the mean sighting proportion reliably predicted total nest counts (R2=0.933). Sighting proportions did not differ by habitat type (P=0.668) or year P=0.328). Experienced observers detected a greater proportion of nests (P