Informe de la Cuarta sesión del panel de expertos de la evaluación del stock de anchoveta peruana

Se presenta una revisión de los sucesos de las pesquerías en el lapso desde la anterior reunión del Panel en Julio, 1972 y de lo que se piensa ha tenido lugar en el recurso y en su medio ambiente; se indican diversas líneas de investigación del stock. Se resume la evidencia colateral acerca de los stocks y de su medio ambiente; ésta se relaciona con el fenómeno de El Niño, con las aves guaneras, el aumento de las capturas de sardinas, el contenido graso de la anchoveta y los estadios de maduración de la misma. Cada una de estas entidades indican que recientemente han prevalecido condiciones especiales en el ambiente de la anchoveta, en la biota asociada y en ciertos aspectos de su fisiología. Se ha hecho una detallada revisión de varios tipos de investigación de las poblaciones de anchoveta y de las evidencias que, acerca del estado del recurso, pueden derivarse de tales investigaciones. Se examinó la evidencia obtenida del uso de equipo acústico en el estudio de la distribución de stocks y en la estimación de su abundancia; el trabajo se realizó mediante exploraciones de varias embarcaciones (exploraciones Eureka) y de exploraciones especiales con el barco de investigación SNP-1; también se hizo uso de equipo eco-integrador. Se discuten las fuentes de errores sistemáticos existentes en ese trabajo. Se llega a la conclusión que lo que ese trabajo indicó fue que en Febrero de 1973 existía alrededor de 4 millones de toneladas de anchoveta.

Segundo panel de expertos:informe sobre los efectos económicos de diferentes medidas regulatorias de la pesquería de la Anchoveta peruana

En el informe de su cuarta reunión el Panel de Expertos en Dinámica revisó los datos proporcionados por el Instituto del Mar del Perú sobre el presente estado del stock de la anchoveta. Estos datos mostraron, evidentemente, que el stock de ancho veta se encontraba en una crítica situación a comienzos de 1973. Los mejores cálculos indicaban que la mayor captura que podría obtenerse en 1973 sería alrededor de a millones de toneladas pero que sería conveniente mantencrla muy por debajo de este nivel, especialmente antes de la mayor temporada de desove en Agosto-Setiembre. En 1974 el reclutamiento podía ser muy bajo especialmente si el stock desovante seguía siendo agotado por la pesca, de modo que las capturas en 1974 podrían ser mucho más bajas del promedio aún en el caso de que no hubiera restricciones para la pesca.

Informe de la primera sesión del panel internacional de expertos para evaluación de la población de la merluza peruana. Marzo 2003

Presentan los resultados del trabajo del panel siguiendo la secuencia establecida en los términos de referencia: estimar el estatus del stock de la merluza peruana, Proveer proyecciones del rendimiento y desarrollo del stock, bajo un escenario pesquero apropiado para el stock de la merluza peruana, comentar sobre medidas administrativas apropiadas de corto y mediano plazo, para la merluza peruana.

Informe de la segunda sesión del panel internacional de expertos para evaluación de la población de la merluza peruana. Marzo 2004

Evalua los resultados del trabajo del Panel de acuerdo con los términos de referencia: actualizar la evaluación y estimar el estatus del stock de la merluza peruana, evaluar el stock desovante y la ojiva de madurez, proponer una cuota para el año 2004, revisar los datos de los cruceros para determinar si existe merluza fuera del área geográfica muestreada, proveer proyecciones del rendimiento y desarrollo del stock bajo esquemas pesqueros apropiados para la merluza peruana.

V panel internacional de expertos en evaluación de la Anchoveta Peruana (Engraulis ringens Jenyns)

Estudia la información sobre los procesos biológicos de la anchoveta y su dinámica poblacional frente a la variabilidad ambiental, en el marco de un enfoque ecosistémico, que permita caracterizar el rol actual de la anchoveta en el Ecosistema de Afloramiento frente al Perú, proporcionando mayores elementos para el desarrollo sustentable de su pesquería.

Convergence in panel data: Evidence from the skipping estimation

This paper demonstrates that, unlike what the conventional wisdom says, measurement error biases in panel data estimation of convergence using OLS with fixed effects are huge, not trivial. It does so by way of the "skipping estimation"': taking data from every m years of the sample (where m is an integer greater than or equal to 2), as opposed to every single year. It is shown that the estimated speed of convergence from the OLS with fixed effects is biased upwards by as much as 7 to 15%.

Financing constraints and fixed-term employment contracts

This paper studies the interactions between financing constraints and theemployment decisions of firms when both fixed-term and permanent employmentcontracts are available. We first develop a dynamic model that shows theeffects of financing constraints and firing costs on employment decisions. Oncecalibrated, the model shows that financially constrained firms tend to use moreintensely fixed term workers, and to make them absorb a larger fraction of thetotal employment volatility than financially unconstrained firms do. We testand confirm the predictions of the model on a unique panel data of Italian manufacturingfirms with detailed information about the type of workers employedby the firms and about firm financing constraints.

Notas sobre el estado actual del stock de anchoveta a base del informe del panel de expertos realizado en julio de 1972 y de los últimos estudios y prospecciones bio-oceanológicas efectuados por el Instituto del Mar

Revisa los acontecimientos recientes de la pesquería de anchoveta a la luz de las investigaciones contínuas realizadas y de las conclusiones del terce informe del Panel de Expertos en dinámica de poblaciones.

Italian kansalliskirjasto Firenzessä

Marjo Kuusela

Comparison of organ doses and image quality between CT and flat panel XperCT scans in wrist and inner ear examinations.

The aim of this study was to evaluate and compare organ doses delivered to patients in wrist and petrous bone examinations using a multislice spiral computed tomography (CT) and a C-arm cone-beam CT equipped with a flat-panel detector (XperCT). For this purpose, doses to the target organ, i.e. wrist or petrous bone, together with those to the most radiosensitive nearby organs, i.e. thyroid and eye lens, were measured and compared. Furthermore, image quality was compared for both imaging systems and different acquisition modes using a Catphan phantom. Results show that both systems guarantee adequate accuracy for diagnostic purposes for wrist and petrous bone examinations. Compared with the CT scanner, the XperCT system slightly reduces the dose to target organs and shortens the overall duration of the wrist examination. In addition, using the XperCT enables a reduction of the dose to the eye lens during head scans (skull base and ear examinations).

A reflection about the social and technological aspects in flood risk management - the case of the Italian Civil Protection

The right of a person to be protected from natural hazards is a characteristic of the social and economical development of the society. This paper is a contribution to the reflection about the role of Civil Protection organizations in a modern society. The paper is based in the inaugural conference made by the authors on the 9th Plinius Conference on Mediterranean Storms. Two major issues are considered. The first one is sociological; the Civil Protection organizations and the responsible administration of the land use planning should be perceived as reliable as possible, in order to get consensus on the restrictions they pose, temporary or definitely, on the individual free use of the territory as well as in the entire warning system. The second one is technological: in order to be reliable they have to issue timely alert and warning to the population at large, but such alarms should be as "true" as possible. With this aim, the paper summarizes the historical evolution of the risk assessment, starting from the original concept of "hazard", introducing the concepts of "scenario of event" and "scenario of risk" and ending with a discussion about the uncertainties and limits of the most advanced and efficient tools to predict, to forecast and to observe the ground effects affecting people and their properties. The discussion is centred in the case of heavy rains and flood events in the North-West of Mediterranean Region.

Biases of the ordinary least squares and instrumental variables estimators of the intergenerational earnings elasticity : revisited in the light of panel data

The OLS estimator of the intergenerational earnings correlation is biased towards zero, while the instrumental variables estimator is biased upwards. The first of these results arises because of measurement error, while the latter rests on the presumption that the education of the parent family is an invalid instrument. We propose a panel data framework for quantifying the asymptotic biases of these estimators, as well as a mis-specification test for the IV estimator. [Author]

The central Sesia-Lanzo zone (Western Italian Alps) - New field observations and lithostratigraphic subdivisions

An extensive study of the central part of the Sesia Lanzo Zone has been undertaken to identify pre-Alpine protoliths and to reconstruct the lithologic and tectonic setting of this part of the Western Alps. Three main complexes have been defined: 1) the Polymetamorphic Basement Complex, corresponding to the lower unit of the Sesia Lanzo Zone after COMPAGNONI et al. (1977), is further subdivided into the three following units: a) an Internal Unit characterized by eo-Alpine high pressure (HP) assemblages (DAL PIAZ et al., 1972) (Eclogitic Micaschists); b) an Intermediate Unit where HP parageneses are partially re-equilibrated under greenschist conditions and c) an External Unit where the main foliation is defined by a greenschist paragenesis (Gneiss Minuti auct.). 2) the Monometamorphic Cover Complex, subdivided into the followings: a) the Bonze Unit, composed of sheared metagabbros, eclogitized metabasalts with MORB geochemical affinity and related metasediments (micaschists, quartzites and Mn-cherts) and b) the Scalaro Unit, containing predominantly metasediments of supposed Permo-Triassic age (yellow dolomitic marbles, calcschists and conglomeratic limestones, micaschists and quartzites with thin levels of basic rocks with within plate basalts [WPB] geochimical affinity). Multiple lithostratigraphic sequences for the Monometamorphic Cover Complex are proposed. The contact between the Bonze and Scalaro Units is defined by repetitions of dolomitic marbles and metabasalts; the ages of the metasediments have been assigned solely by analogy with other sediments of the Western Alps, due to the absence of fossils. The Monometamorphic Cover Complex can be considered as the autochthonous cover of the Sesia Lanzo Zone because of the primary contacts with the basement and because of the presence of preAlpine HT basement blocks in the cover sequences. 3) The pre-Alpine high temperature (HT) Basement Complex (or `'Seconda Zona Diorito-Kinzigitica''), comprises HT Hercynian rocks like kinzigites, amphibolites, granulites and calcite marbles; this Complex is always located between the Internal and the External Units and can be followed continuously for several kilometers south of the Gressoney Valley to the Orco Valley. A schematic evolution for the Sesia Lanzo Zone is proposed; based on available data together with new geochronological data, this study shows that the internal and external parts of the polymetamorphic basement of the Sesia Zone experienced different cooling histories .