Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon

Rockfishes (Sebastes spp.) support one of the most economically important f isheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon (14C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated 14C signal by emphasizing the utility of the time-specific marker created by the initial rise of bomb-14C. Second, the bomb-generated 14C signal retained in fish otoliths was used to validate the age and age estimation method of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year’s growth of quillback rockfish otoliths were plotted against estimated birth year to produce a 14C time series spanning 1950 to 1985. The initial rise in bomb-14C from prebomb levels (~ –90‰) occurred in 1959 [±1 year] and 14C levels rose relatively rapidly to peak Δ14C values in 1967 (+105.4‰) and subsequently declined through the end of the time series in 1985 (+15.4‰). The agreement between the year of initial rise of 14C levels from the quillback rockfish time series and the chronology determined for the waters of southeast Alaska from yelloweye rockfish (S. ruberrimus) otoliths validated the aging method for the quillback rockfish. The concordance of the entire quillback rockfish 14C time series with the yelloweye rockfish time series demonstrated the effectiveness of this age validation technique, confirmed the longevity of the quillback rockfish up to a minimum of 43 years, and strongly confirms higher age estimates of u

AGRICULTURAL COOPERATION AND PRODUCE MARKETING IN SOUTHWEST VIRGINIA

Growers and community leaders have expressed interest in establishing a horticultural shipping-point market in Southwest Virginia. This paper reports on a study that assessed whether horticultural production would be profitable in the region and, if so, the physical and organizational requirements for a successful shipping-point market. It appears that tomatoes, peppers, and pumpkins can be produced and marketed profitably to large-volume wholesale buyers if growers meet the exacting requirements of the retailers. A cooperative association is the organizational structure with the greatest chance of success. At the conclusion of this study, a shipping-point market in the recommended form was established in Southwest Virginia.Agribusiness, Marketing,

Use of Annual Phosphorus Loss Estimator (APLE) Model to Evaluate a Phosphorus Index

The Phosphorus (P) Index was developed to provide a relative ranking of agricultural fields according to their potential for P loss to surface water. Recent efforts have focused on updating and evaluating P Indices against measured or modeled P loss data to ensure agreement in magnitude and direction. Following a recently published method, we modified the Maryland P Site Index (MD-PSI) from a multiplicative to a component index structure and evaluated the MD-PSI outputs against P loss data estimated by the Annual P Loss Estimator (APLE) model, a validated, field-scale, annual P loss model. We created a theoretical dataset of fields to represent Maryland conditions and scenarios and created an empirical dataset of soil samples and management characteristics from across the state. Through the evaluation process, we modified a number of variables within the MD-PSI and calculated weighting coefficients for each P loss component. We have demonstrated that our methods can be used to modify a P Index and increase correlation between P Index output and modeled P loss data. The methods presented here can be easily applied in other states where there is motivation to update an existing P Index

Iron, silicate, and light co-limitation of three Southern Ocean diatom species

The effect of combined iron, silicate, and light co-limitation was investigated in the three diatom species Actinocyclus sp. Ehrenberg, Chaetoceros dichaeta Ehrenberg, and Chaetoceros debilis Cleve, isolated from the Southern Ocean (SO). Growth of all species was co-limited by iron and silicate, reflected in a significant increase in the number of cell divisions compared to the control. Lowest relative Si uptake and drastic frustule malformation was found under iron and silicate co-limitation in C. dichaeta, while Si limitation in general caused cell elongation in both Chaetoceros species. Higher light intensities similar to SO surface conditions showed a negative impact on growth of C. dichaeta and Actinocyclus sp. and no effect on C. debilis. This is in contrast to the assumed light limitation of SO diatoms due to deep wind driven mixing. Our results suggest that growth and species composition of Southern Ocean diatoms is influenced by a sensitive interaction of the abiotic factors, iron, silicate, and light

Cohabitation : the Pan-America View

In this concluding chapter we reflect on a series of issues of both a methodological and substantive nature encountered in this research project. Firstly, we must realize that the use of individual census records not only opened vast possibilities, but also entails a number of limitations. Secondly, the very large sample sizes allowed for the disaggregation of national trends into far more detailed spatial, ethnic and educational patterns. This, in its turn, allowed us to adopt a "geo-historical" view of the rise of cohabitation for almost the entire American continent, from Alaska to Tierra del Fuego. Furthermore, statistical analyses could be performed at the individual and contextual levels simultaneously. Results show that the effects of social stratification, religion and ethnicity are continuing to be of major importance. This not only holds at the individual level, but at the contextual level as well. Nevertheless, an entirely new wave of change started rolling over the pre-existing patterns from the 1970s onward. These trends are following a firm course, irrespective of the economic ups and downs. The Americas, as opposed to many Asian societies and Africa, are now following in the European footsteps, be it with their own distinct and path-dependent characteristics associated with regionally varying historical antecedents

Investigations of (Delta)14C, (delta)13C, and (delta)15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean

The white shark (Carcharodon carcharias) has a complex life history that is characterized by large scale movements and a highly variable diet. Estimates of age and growth for the white shark from the eastern North Pacific Ocean indicate they have a slow growth rate and a relatively high longevity. Age, growth, and longevity estimates useful for stock assessment and fishery models, however, require some form of validation. By counting vertebral growth band pairs, ages can be estimated, but because not all sharks deposit annual growth bands and many are not easily discernable, it is necessary to validate growth band periodicity with an independent method. Radiocarbon ({sup 14}C) age validation uses the discrete {sup 14}C signal produced from thermonuclear testing in the 1950s and 1960s that is retained in skeletal structures as a time-specific marker. Growth band pairs in vertebrae, estimated as annual and spanning the 1930s to 1990s, were analyzed for {Delta}{sup 14}C and stable carbon and nitrogen isotopes ({delta}{sup 13}C and {delta}{sup 15}N). The aim of this study was to evaluate the utility of {sup 14}C age validation for a wide-ranging species with a complex life history and to use stable isotope measurements in vertebrae as a means of resolving complexity introduced into the {sup 14}C chronology by ontogenetic shifts in diet and habitat. Stable isotopes provided useful trophic position information; however, validation of age estimates was confounded by what may have been some combination of the dietary source of carbon to the vertebrae, large-scale movement patterns, and steep {sup 14}C gradients with depth in the eastern North Pacific Ocean

Growth and Diversity of the Population of the Soviet Union

The most remarkable feature of the Soviet Union's demography is its ethnic diversity. More than 90 ethnic groups are indigenous to the territory of the Soviet Union. Ethnic Russians composed only 50.8 percent of the population according to preliminary 1989 census results. The article examines official Soviet statistics for the period 1959 to 1989 to illustrate some of the risks in describing Soviet demographic behavior. Is fertility in the Soviet Union high or low? Answer: both. Is the Soviet population growing rapidly or slowly? Answer: both. The changing ethnic composition of the population of the USSR as a whole reflects large differences in growth rates of ethnic groups; the changing composition of the USSR by region also reflects differences in migration by ethnic group. Differences in growth rates are reshaping the ethnic composition of the Soviet labor force. For the USSR as a whole between 1979 and 1989, three-fourths of the net increment to the working ages was contributed by the one-sixth of the population in 1979 that was traditionally Muslim in religion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67141/2/10.1177_000271629051000112.pd

The Decline of Remarriage: Evidence From German Village Populations in the Eighteenth and Nineteenth Centuries

Family reconstitution data for fourteen German village populations permit the examination of remarriage during the eighteenth and nineteenth cen turies. The results provide compelling evidence for a secular decline in the tenden cy to remarry. Pronounced age and sex differentials in the likelihood of remar riage were evident: widows were far less likely to remarry than widowers, and the probability of remarriage declined rapidly with age, particularly for women. The probability of remarriage was also inversely associated with the number and age of children. There were, however, no clear differences in either the probability of remarriage or its tendency to decline over time among major occupational groups. The decline in remarriage probabilities was caused in part by declines in adult mortality, which gradually raised the ages of surviving spouses to levels at which remarriage has historically been rather unlikely. However, age-specific marriage probabilities also declined, affecting both men and women and all oc cupational groups, suggesting the presence of a social change of wide scope. Some comments on possible factors contributing to the decline of remarriage are presented. The need for a comprehensive explanation of remarriage trends and differentials remains an important challenge for family historians.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68212/2/10.1177_036319908501000103.pd

Pricing reverse mortgages in Spain

[EN] In Spain, as in other European countries, the continuous ageing of the population creates a need for long-term care services and their financing. However, in Spain the development of this kind of services is still embryonic. The aim of this article is to obtain a calculation method for reverse mortgages in Spain based on the fit and projection of dynamic tables for Spanish mortality, using the Lee and Carter model. Mortality and life expectancy for the next 20 years are predicted using the fitted model, and confidence intervals are obtained from the prediction errors of parameters for the mortality index of the model. The last part of the article illustrates an application of the results to calculate the reverse mortgage model promoted by the Spanish Instituto de Crédito Oficial (Spanish State Financial Agency), for which the authors have developed a computer application.The authors are indebted to Jose Garrido, whose suggestions improved the original manuscript, and to the anonymous referee for his/her valuable comments. This work was partially supported by grants from the MEyC (Ministerio de Educacio´n y Ciencia, Spain), projects MTM2010- 14961 and MTM2008-05152.Debón Aucejo, AM.; Montes, F.; Sala, R. (2013). Pricing reverse mortgages in Spain. European Actuarial Journal. 3:23-43. https://doi.org/10.1007/s13385-013-0071-yS23433Blay-Berrueta D (2007) Sistemas de cofinaciaciación de la dependencia: seguro privado frente a hipoteca inversa. Cuadernos de la Fundación, Fundación Mapfre Estudios, Madrid.Booth H (2006) Demographic forecasting: 1980 to 2005 in review. Int J Forecast 22(3):547–582Booth H, Hyndman R, Tickle L, de Jong P (2006) Lee–Carter mortality forecasting: a multi-country comparison of variants and extensions. Demogr Res 15(9):289–310Booth H, Maindonald J, Smith L (2002) Applying Lee–Carter under conditions of variable mortality decline. Popul Stud 56(3):325–336Booth H, Tickle L (2003) The future aged: new projections of Australia’s ederly population. Popul Stud 22(4):38–44Brouhns N, Denuit M, Keilegom IV (2005) Bootstrapping Poisson log-bilinear model for mortality forecasting. Scand Actuar J 2005(3):212–224Brouhns N, Denuit M, Vermunt J (2002) A Poisson log-bilinear regression approach to the construction of projected lifetables. Insur Math Econ 31(3):373–393Carter L, Lee R (1992) Modeling and forecasting US sex differentials in mortality. Int J Forecast 8(3):393–411Carter L, Prkawetz A (2001) Examining structural shifs in mortality using the Lee–Carter method. Mpidr wp 2001–2007, Center for Demography and Ecology Information, University of Wisconsin-Madison.Chinloy P, Megbolugbe I (1994) Reverse mortgages: contracting and crossover. J Am Real Estate Urban Econ Assoc 22(2):367–386Coale A, Guo G (1989) Revisited regional model life tables at very low levels of mortality. Popul Index 55:613–643Coale A, Kisker E (1990) Defects in data old age mortality in the United States: New procedures for calculating approximately accurate mortality schedules and lifes tables at the highest ages. Asian Pac Popul Forum 4:1–31Cossette H, Delwarde A, Denuit M, Guillot F, Étienne M (2007) Pension plan valuation and mortality projection: a case study with mortality data. N Am Actuar J 11(2):1–34.Costa-Font J (2009) Ageing in place? exploring elderly people’s housing preferences in Spain. Urban Stud 46(2):295–316Costa-Font J (2013) Housing-related well-being in older people: the impact of environmental and financial influences. Urban Stud 50(4):657–673Currie I, Kirkby J, Durban M, Eilers P (2004) Smooth Lee–Carter models and beyond. In: Workshop on Lee–Carter Methods, http://www.ma.hw.ac.uk/~iain/workshop/workshop.html . Accessed 4 Mar 2005Czado C, Delwarde A, Denuit M (2005) Bayesian Poisson log-bilinear mortality projections. Insur Math Econ 36(3):260–284D’Amato V, Haberman S, Piscopo G, Russolillo M (2012) Modelling dependent data for longevity projections. Insur Math Econ 51(3):694–701Davidoff T (2012) Can ‘high costs’ justify weak demand for the home equity conversion mortgage? Technical report, available at SSRNDavidoff T, Welke G (2007) Selection and moral hazard in the reverse mortgage market. Technical report, Haas School of Business, UC BerkeleyDebón A, Montes F, Mateu J, Porcu E, Bevilacqua M (2008) Modelling residuals dependence in dymanic life tables. Comput Stat Data Anal 52(3):3128–3147Debón A, Montes F, Puig F (2008) Modelling and forecasting mortality in Spain. Eur J Oper Res 189(3):624–637Debón A, Montes F, Sala R (2009) Tablas de mortalidad dinámicas. Una aplicación a la hipoteca inversa en España. Fundación ICO. Publicaciones de la Universitat de Valéncia, ValenciaDebón A, Montes F, Martínez-Ruiz F (2011) Statistical methods to compare mortality for a group with non-divergent populations: an application to Spanish regions. Eur Actuar J 1:291–308Delwarde A, Denuit M, Eilers P (2007) Smoothing the Lee–Carter and poisson log-bilinear models for mortality forecasting: a penalized log-likelihood approach. Stat Modell 7(1):29–48Denuit M (2007) Distribution of the random future life expectancies in log-bilinear mortality projections models. Lifetime Data Anal 13(3):381–397Denuit M, Goderniaux A (2004) Closing and projecting lifetables using log-linear models. Mitteilungen. der Schweizerischen Aktuarvereingung 1:29–49Felipe A, Guillén M, Pérez-Marín A (2002) Recent mortality trends in the Spanish population. Br Actuar J 8(4):757–786.Forfar D, McCutcheon J, Wilkie A (1988) On graduation by mathematical formula. J Inst Actuar 115(459):1–149Guillen M, Vidiella-i-Anguera A (2005) Forecasting Spanish natural life expectancy. Risk Anal 25(5):1161–1170Heligman L, Pollard J (1980) The age pattern of mortality. J Inst Actuar 107:49–80Herranz-Gonzalez R (2006) Hipoteca inversa y figuras afines. Informes Portal Mayores 49, IMSERSO, Madrid, http://www.imsersomayores.csic.es/documentos/documentos/herranz-hipoteca-01.pdfHoriuchi S, Wilmoth J (1998) Decelaration in the age pattern of mortality at older ages. Demography 35:391–412Hyndman RJ (2008) Forecast: forecasting functions for time series. R package version 1.11Koissi M, Shapiro A, Hgns G (2006) Evaluating and extending the Lee–Carter model for mortality forecasting confidence interval. Insur Math Econ 38(1):1–20Kutty N (1998) The scope for poverty alleviation among elderly home-owners in the United States through reverse mortgages. Urban Stud 35(1):113–129Lee R (2000) The Lee–Carter method for forecasting mortality, with various extensions and applications. N Am Actuar J 4(1):80–91Lee R, Carter L (1992) Modelling and forecasting US mortality. J Am Stat Assoc 87(419):659–671Lee R, Nault F (1993) Modeling and forecasting provincial mortality in Canada. Montreal world congress of the International Union for Scientific Study of PopulationLee R, Rofman R (1994) Modelación y Proyección de la mortalidad en Chile. Notas Poblacin 22(59):182–213Li N, Lee R (2005) Coherent mortality forecast for a group of populations: an extension of the Lee–Carter method. Demography 42(3):575–593Li S-H, Hardy M, Tan K (2009) Uncertainty in mortality forecasting: an extensin to the classical Lee–Carter approach. Astin Bull 31:137–164Lindbergson M (2001) Mortality among the elderly in Sweden. Scan Actuar J 1:79–94Liu X, Braun WJ (2010) Investigating mortality uncertainty using the block bootstrap. J Probab Stat 2010:385–399McNown R, Rogers A (1989) Forecasting mortality: a parametrized time series aproach. Demography 26(4):645–660McNown R, Rogers A (1992) Forecasting cause-specific mortality using time series methods. Int J Forecast 8(3):413–432Miceli T, Sirmans C (1994) Reverse mortgages and borrower maintenance risk. J Am Real Estate Urban Econ Assoc 22(2):433–450Pedroza C (2006) A bayesian forecasting model: predicting US male mortality. Biostatistics 7(4):530–550Renshaw A, Haberman S (2003) Lee–Carter mortality forecasting: a parallel generalized linear modelling aproach for England and Wales mortality projections. J R Stat Soc C 52(1):119–137Renshaw A, Haberman S (2003) Lee–Carter mortality forecasting with age specific enhancement. Insur Math Econ 33(2):255–272Renshaw A, Haberman S (2003) On the forecasting of mortality reduction factors. Insur Math Econ 32(3):379–401Renshaw A, Haberman S (2006) A cohort-based extension to the Lee–Carter model for mortality reduction factors. Insur Math Econ 38(3):556–570Renshaw A, Haberman S (2008) On simulation-based approaches to risk measurement in mortality with specific reference to poisson Lee–Carter modelling. Insur Math Econ 42(2):797–816Shiller R, Weiss A (2000) Moral hazard in home equity conversion. Real Estate Econ 28(1):1–31Skarr D (2008) Financial planner’s guide to the FHA insured home equity conversion mortgage. J Financ Plan 21(5):68–75Sánchez-Álvarez I, Lpez-Ares S, Quiroga-García R (2007) Diseño de hipotecas inversas en el mercado español. Proyecto 205/05 3, Instituto de Mayores y Servicios SocialesTaffin C (2006) La hipoteca inversa o vitalicia. Informes externos, Asociación Hipotecaria EspañolaThatcher A, Kannisto V, Andreev K (2002) The survivor ratio method for estimating numbers at high ages. Demogr Res 6(1):1–18Thatcher A, Kannisto V, Vaupel J (1998) The force of mortality at ages 80 to 120. Odense University Press, OdenseTuljapurkar S, Li N, Boe C (2000) A universal pattern of mortality decline in the G7 countries. Nature 405(6788):789–792Wang L, Valdez E, Piggott J (2008) Securization of longevity risk in reverse mortgages. N Am Actuar J 12(4):345–370Wilmoth J (1993) Computational methods for fitting and extrapolating the Lee–Carter model of mortality change. Technical report, Departament of Demography, University of California, BerkeleyWilmoth J (1996) Health and mortality among elderly populations, chapter mortality projections for Japan: a comparison of four methods. Oxford University Press, Oxford, pp 266–28