Another look at a good approximation of data for the distribution of COVID-19 in Cuba / Otra mirada hacia una correcta aproximación de datos para la distribución de la COVID-19 en Cuba

In the article "Adjustment of population growth curve applied to Covid-19 in Cuba", the authors propose six types of models to approximate data from the distribution of COVID-19 in Cuba, while giving a clear answer to the possible advantages of some considerations. In this paper, we study intrinsic properties of some models of growth with polynomial variable transfer that give a very good approximation of the specific data on the pandemics in Cuba by June 5, 2020. The models have the right to exist in the treatment of issues from different fields of scientific knowledge. Numerical examples are presented using CAS MATHEMATICA(AU)

En el artículo "Ajuste de curvas de crecimiento poblacional aplicadas a la COVID-19 en Cuba", los autores proponen y seriamente analizan seis tipos de modelos (logísticos y otros modelos de crecimiento) para aproximar los datos sobre la distribución de la COVID-19 en Cuba mientras plantean una clara respuesta a las posibles ventajas de algunas consideraciones. En este trabajo estudiamos las propiedades intrínsecas de algunos modelos de creciemiento con transferencia de variables polinómicas que proporcionan una muy buena aproximación de los datos específicos sobre la pandemia en Cuba antes del 5 de junio de 2020. Los modelos tienen el derecho a existir en el tratamiento de cuestiones de diferentes campos del conocimiento científico. Los ejemplos numéricos se presentan utilizando un modelo matemático para calcular los casos(AU)

Study of number of children preferred and knowledge, attitude, practice regarding birth spacing and contraception among primigravida in urban setting

Background: Overpopulation is a major problem in 21st century India. 2012 census shows birth rate of 20.97/1000 people and death rate of 7.48/1000 people. Fertility rate in 2019 was 2.28 children per women. Many states implemented 2 child norms. Purpose of study is to understand the number of children preferred.Methods: A Cross sectional study was done amongst 200 primigravida women who attended antenatal clinic at SMC, Shimoga. A predesigned and pretested standard Questionnaire was used to know the number of children preferred, KAP about birth spacing, contraceptive use and unsafe abortions using objective questions.Results: Most women preferred 2 child norms across most subclasses. Most Muslims (85.7%) preferred ?3 children. Though 100% were aware of family planning, only 46% chose to space their next pregnancy. 56.5% were in support of 2-child norm. Family pressure plays crucial role in 83.5% cases and 65.5% still opted sterilization as the first choice for contraception.Conclusions: India with high population density is staring at demographic disaster due to limited life resources. Right attitude towards birth spacing, contraceptive use, avoidance unwanted pregnancies and unsafe abortions is needed. Better female literacy, societal awareness and good medical facility at last mile is crucial. Male partner's involvement in every step is vital.

Ajuste de curvas de crecimiento poblacional aplicadas a la COVID-19 en Cuba / Adjustment of population growth curve applied to COVID-19 in Cuba

Introducción: Cuba ha sido afectada por la COVID-19. Todas las provincias del país han presentado casos confirmados de la enfermedad. Se han llevado a cabo medidas por parte del gobierno y el sistema de salud, para contrarrestar el contagio de persona a persona. Es de gran ayuda contar con estimaciones de casos confirmados para las decisiones. Objetivos: Obtener predicciones para los picos de casos confirmados y cantidad total de estos para algunas provincias de Cuba y para todo el país. Material y Métodos: Estudio de tipo predictivo de curvas de crecimiento poblacional. Se analizan los datos correspondientes a los primeros 52 días de afectación de la enfermedad en el país para estimar los modelos y aplicar el método de los mínimos cuadrados para modelos no lineales con respecto a los parámetros. Se utilizan el coeficiente de determinación ajustado, el criterio de información de Akaike y el error estándar de los residuos para medir la bondad del ajuste de los modelos. Se estudian las provincias del país que presentan una tasa de infectados por cien mil habitantes mayor que 14,71 y el país en su conjunto. Resultados: La bondad de ajuste de los modelos utilizados en las localidades estudiadas y en el país es alta, lo cual permite su confiabilidad para los pronósticos efectuados. Conclusiones: Las predicciones plantean que las cinco localidades analizadas presentan su pico de contagio en abril al igual que Cuba (AU)

Introduction: Cuba and all its provinces have been affected by COVID-19 disease. The government and the health system have taken measures to avoid contagion from person to person. To take these measures it is important to have estimates of the rate of infection. Objectives: To obtain predictions for the peak of infected cases and the total number for some Cuban provinces and the whole country. Material and Methods: Predictive study of population growth curves. Data from the first 52 days of the disease in the country are processed to estimate the models and to apply the method of least squares estimation of nonlinear parameters. The adjusted coefficient of determination, the Akaike information criterion and the standard error of the residuals are used to measure the goodness of fit of the models. The provinces that present a rate of infection per 100,000 inhabitants greater than 14,71 and the country as a whole are studied. Results: The goodness of fit of the models used in the provinces studied and the country is high, which allows them to be reliable for predictions. Conclusions: The predictions suggest that the five provinces analyzed and Cuba show their peak of contagion in April (AU)

Influencing factors on single-cell protein production by submerged fermentation: a review

Since more than twenty years ago, some species of bacteria and fungi have been used to produce protein biomass or single-cell protein (SCP), with inexpensive feedstock and wastes being used as their sources of carbon and energy. The role of SCP as a safe food and feed is being highlighted more because of the worldwide protein scarcity. Even though SCP has been successfully commercialized in the UK for decades, study of optimal fermentation conditions, various potential substrates, and a broad range of microorganisms is still being pursued by many researchers. In this article, commonly used methods for the production of SCP and different fermentation systems are briefly reviewed, with submerged fermentation being highlighted as a more commonly used method. Emphasis is given to the effect of influencing factors on the biomass yield and productivity in an effort to provide a comprehensive review for researchers in related fields of interest.

Influencia de la proporción sexual y del ambiente en la tasa de crecimiento poblacional de Callinectes bellicosus (Decapoda: Portunidae) del Golfo de California / Sex ratio and environmental influence on population growth rate of Callinectes bellicosus (Decapoda: Portunidae) in the Gulf of California

ResumenPara la jaiba café (Callinectes bellicosus) capturada en Sonora, México dentro del Golfo de California desde 1986, durante 20 años se ha observado una tendencia decreciente en la biomasa. Se estimaron las tasas de crecimiento poblacional (r) y proporción de sexos de C. bellicosus además de tres parámetros que describen su hábitat: temperatura del mar, extensión de humedales y tamaño del hábitat en cuatro zonas a lo largo de la costa de Sonora. La proporción de sexos se estimó de 25 556 jaibas muestreadas de las capturas comerciales en los años 19982002 y 2012; la temperatura media en el período de desove (mayo-agosto) se generó a partir de sensores remotos en los mismos años; la cobertura de humedales se obtuvo de reportes publicados; y el tamaño del hábitat se estimó como la superficie de pesca. Para cada zona se estimó r mediante un método desarrollado para situaciones de escasa información utilizando las capturas comerciales (t) de 1986 a 2013. Con los datos de las cuatro zonas se desarrollaron modelos de regresión lineal simple y múltiple para evaluar las sensibilidades teóricas de r a variaciones en la proporción de sexos y en los parámetros ambientales. Los machos dominaron (68.8 %) sobre las hembras en el período de estudio en las cuatro zonas; un análisis de conglomerados identificó dos grupos de acuerdo a la proporción de sexos: un grupo norteño con las zonas 1 y 2, y otro sureño con las zonas 3 y 4. Los valores de r fueron diferentes en las cuatro zonas (P<0.001) igual que la proporción de sexos (P=0.037); no se encontraron diferencias en la temperatura entre los años considerados en el estudio (P>0.995). Tanto los datos estimados como los análisis de sensibilidad sugieren que r dependen directa y positivamente de la proporción de hembras de jaiba y el tamaño de los humedales. Por lo anterior planteamos la hipótesis de que la pesca excesiva de hembras es la causa del descenso de la biomasa de jaiba café en Sonora, y concluimos que es conveniente implementar refugios pesqueros dentro de humedales costeros para proteger las hembras en el período de desove.

Abstract:The brown swimming crab (Callinectesbellicosus) is an economically important species in the Gulf of California, and its fishing activity, held in Sonora from 1986, has been affected by a 20-year declining trend in its biomass. With the aim to understand the possible reasons of this species population changes along time, we estimated population growth rate (r) and sex ratio of C. bellicosus, and combined them with three parameters describing its habitat: sea temperature, wetland extension and habitat size in four areas along the coast of Sonora. For this, monthly mean sex ratio was estimated from crabs samples obtained from commercial catches during 1998-2002 and 2012; mean sea surface temperature for the spawning period (May-August) were derived from remote sensors for the same years; while wetland coverages were obtained from published reports, and habitat size was estimated as the fishing surface. For each area, r was estimated using a method developed for limited data situations using commercial landings (t) from 1986-2013. With data from the four areas, simple and multiple linear regression models were developed to ascertain theoretical sensitivities of r to variations in sex ratio and environmental parameters. A total of 24 556 crabs were sampled; males dominated (68.8 %) over females during the study period and in all areas; a cluster analysis identified two groups according to sex ratio: a Northern group with zones 1 and 2, and a Southern group with zones 3 and 4. r values were different in all zones (P<0.001) as was sex ratio (P=0.037); no differences in temperature were identified within the study years (P>0.995). Both the estimated data and sensitivity analyses suggest the existence of a direct and positive dependence of r on the proportion of female crabs and wetland size. We hypothesize that excess fishing of females caused the declining biomass trend of the brown swimming crab in Sonora, and concluded on the convenience of implementing harvest refugia inside coastal wetlands to protect females during the spawning season. Rev. Biol. Trop. 64 (3): 1259-1271. Epub 2016 September 01.

As migrações nas cidades médias de Minas Gerais e seus impactos no crescimento e na composição por sexo e idade da população no período 1980-2010 / Migration in the intermediate cities of Minas Gerais and its effects on population growth and sex and age composition in the period 1980-2010 / Las migraciones en las ciudades intermedias de Minas Gerais y sus impactos en el crecimiento y la composición por sexo y edad de la población en el período 1980-2010

O principal objetivo deste artigo é investigar as migrações nas cidades médias de Minas Gerais e os seus efeitos no crescimento e na composição por sexo e idade da população, no período 1980-2010. Para isso, foram utilizados os dados dos Censos Demográficos de 1980, 1991, 2000 e 2010 e os dados referentes ao quesito de migrante "data fixa" dos três últimos censos (desagregados por sexo e idade). Os resultados revelaram um quadro heterogêneo no que diz respeito aos impactos das migrações no volume e na composição das populações estudadas. Apesar de a maioria das cidades médias de Minas Gerais ter apresentado saldos migratórios positivos e relativamente altos em todos os períodos analisados, algumas exceções marcantes foram observadas na porção leste do Estado. Enquanto os efeitos das migrações na composição por sexo mostraram-se pouco significativos, os efeitos na estrutura etária foram substanciais, indicando uma forte tendência de os ganhos populacionais decorrentes da migração atuarem no sentido de reduzir o ritmo de envelhecimento populacional, em função da seletividade etária dos migrantes

The main objective of this paper is to investigate migration in the intermediate cities of Minas Gerais state in Brazil and its effects on growth and composition by age and sex of the population in the period 1980-2010. The data used came from the Demographic Censuses of 1980, 1991, 2000 and 2010 and from the question related to a previous place of residence at a fixed date over the last three censuses (disaggregated by sex and age). The results revealed a mixed picture regarding the impacts of migration on the volume and composition of the studied populations. Although most of the intermediate cities of Minas Gerais have shown positive and relatively high net migration in all analyzed periods, some striking exceptions were observed in the eastern portion of the state. While the effects of migration on the gender composition proved to be insignificant, effects on age structure were substantial, indicating a strong tendency for population gains from migration to slow population aging because of migrant age selectivity

El objetivo principal de este artículo es investigar las migraciones en las ciudades intermedias de Minas Gerais y sus efectos sobre el crecimiento y la composición por edad y sexo de la población en el período 1980-2010. Para ello se utilizaron datos de los censos demográficos de 1980, 1991, 2000 y 2010 y los relativos a la cuestión de los migrantes "de fecha fija anterior" de los tres últimos censos, desagregados por sexo y edad. Los resultados revelaron un panorama heterogéneo respecto de los impactos de las migraciones sobre el volumen y la composición de las poblaciones estudiadas. Aunque la mayoría de las ciudades intermedias de Minas Gerais han registrado saldos migratorios positivos y relativamente altos en todos los períodos analizados, se observaron algunas excepciones notables en la región oriental del estado. Mientras los efectos de las migraciones en la composición por sexo resultaron ser poco significativos, aquellos que incidieron sobre la estructura etaria fueron sustanciales, indicando una fuerte tendencia a que las ganancias de población resultantes de la migración actúen reduciendo el ritmo de envejecimiento poblacional debido a la selectividad por edad de los migrantes

Demografía de Caulerpa paspaloides var. Wudermannii (Bryopsidales: Caulerpaceae) en la zona costera de Campeche, México / Demography of Caulerpa paspaloides var. wudermanni (Bryopsidales: Caulerpaceae) in the coastal zone of Campeche, México

The subaquatic vegetation of Los Petenes, Campeche, Mexico, stands out due to its considerable floristic diversity, composed of a great variety of sea grasses and several species of the genus Caulerpa sp. This is a genus of ecological relevance, with the invasive species in the Mediterranean, with negative impact on several native sub-aquatic plants; nevertheless, little is known about the demography and population dynamics of Caulerpa species and their contribution to food webs. Thus the main objective of this study was to describe the demographics of Caulerpa paspaloides var. wudermanni, using the number of stolons, complete and incomplete fronds, the diameter of the stolons and the biomass. The information was used to determine the growth rate (λ) of this species. The study was conducted in the Biosphere Reserve of Los Petenes, which is located in the Northwest of the state of Campeche. The submerged aquatic vegetation (SAV) in the Petenes Biosphere consists of monospecific and mixed populations of seagrass species (Thalassia testudinum, Halodule wrightii and Syringodium filiforme). Although chlorophytes, brown algae and red algae, are fundamental elements in the specific composition of the SAV in Petenes, several species of Caulerpa are prominent because of their coverage and abundance. In May and June of 2010, significant differences in the quantity of stolons, their diameter, incomplete and complete fronds, and the size of the stolons and rhizomes, were observed. In 2010, the finite population growth rate (λ) was 2.38±0.1571 for individuals and 1.20±0.1356 for the population, and in 2011 the values of λ were 1.80±0.3608 and 1.35±0.1571, respectively. From these results it can be concluded that the population is growing; however, growth is controlled by biotic and abiotic factors. Despite there was no apparent threat, we suggest continuing the demographic studies of C. paspaloides var. wurdemannii, as well as of other species of the same genus, not only to detect invasion or explosive growth, but also their presence indicated low oxygen levels and high sulphates. Rev. Biol. Trop. 62 (2): 729-741. Epub 2014 June 01.

La vegetación subacuática de Los Petenes, Campeche, México, se destaca por su gran diversidad florística, compuesto por una gran variedad de pastos marinos y varias especies del género Caulerpa sp. Caulerpa es un género de relevancia ecológica, con especies como la Caulerpa taxifolia, que es invasiva en el Mediterráneo, con un impacto negativo en varias plantas sub-acuáticas nativas, pero poco se sabe acerca de la demografía y la dinámica poblacional de las especies de Caulerpa y su contribución a las redes alimenticias. El objetivo general es conocer la demografía de Caulerpa sp., por medio del número de estolones, frondas completas e incompletas, el diámetro de los estolones y la biomasa. El estudio se realizó en la Reserva de la Biosfera de Los Petenes, en Campeche, México. La Vegetación Acuática Sumergida (VAS) en la Biosfera de los Petenes está constituida por poblaciones tanto monoespecíficas como mixtas de las especies de pastos marinos Thalassia testudinum, Halodule wrightii y Syringodium filiforme. Aunque las especies de algas clorófitas, feofitas y rodófitas son elementos fundamentales de la VAS, destacan por su cobertura y abundancia las especies de Caulerpa. En mayo y junio del 2010, hubo diferencias significativas de la cantidad de estolones, su diámetro, frondas completas e incompletas y el tamaño de los estolones como el de los ejes erectos. En el 2010 el valor de la tasa finita de crecimiento poblacional (l) fue de 2.38±0.15 con el método de las marcas y con el de la biomasa 1.20±0.13 y en el 2011 los valores fueron de 1.80±0.36 con las marcas y de 1.35±0.15 con la biomasa. Los resultados indican que la población está creciendo, pero es controlada por factores bióticos y abióticos. A pesar de que no se detecta la especie como una amenaza aparente, sugerimos que se continúen estos estudios demográficos sobre C. paspaloides var. wurdemannii e incluso de otras especies del mismo género. No solo para detectar una invasión o un crecimiento explosivo, sino porque la presencia de estas especies no indican condiciones bajas en oxígeno y altas en sulfatos.

“Population Growth in Himachal Pradesh 2001-2011: A Spatial Analysis”.

Population growth is one of the important indicators of the level of socio-economic development because it is the level of socio-economic development that determines the rate of population at any given time. The analysis of population growth is an important element to the understanding not only of a region’s problems but potentials (providing food, schooling, employment, health facilities, housing etc.) and for future planning. Therefore, it is useful to study the pattern of population growth of any region. The present study attempts to study the growth of population in Himachal Pradesh at tehsils/sub-tehsils level during 2001 to 2011. The study is mainly based on the secondary data collected from Directorate of Census Operations. The simple percentage method and choropleth technique have been used to highlight spatio-temporal variations in growth of population. The peculiar topographical characteristics of the state resulted into great spatial variation in growth pattern. The study reveals that about one-third of the tehsils/sub-tehsils witnessed a decadal growth rate, higher than the state average. There is an equal number of tehsils/sub-tehsils, where the decadal growth rate was below the state average.

Effective Population Size of Korean Populations

Recently, new methods have been developed for estimating the current and recent changes in effective population sizes. Based on the methods, the effective population sizes of Korean populations were estimated using data from the Korean Association Resource (KARE) project. The overall changes in the population sizes of the total populations were similar to CHB (Han Chinese in Beijing, China) and JPT (Japanese in Tokyo, Japan) of the HapMap project. There were no differences in past changes in population sizes with a comparison between an urban area and a rural area. Age-dependent current and recent effective population sizes represent the modern history of Korean populations, including the effects of World War II, the Korean War, and urbanization. The oldest age group showed that the population growth of Koreans had already been substantial at least since the end of the 19th century.

Efectos de la migración sobre el crecimiento poblacional a largo plazo de las provincias cubanas / Efeitos da migração sobre o crescimento populacional de longo prazo das províncias cubanas / Effects of migration on long-term population growth in the provinces of Cuba

Cuba es un país que, además de presentar niveles de fecundidad inferiores al nivel de reemplazo, ha registrado un significativo saldo migratorio negativo. Se observa también un intenso flujo migratorio interno cuyo patrón es muy diferente entre las provincias. Debido a la magnitud de estos flujos migratorios, la migración se presenta como un componente demográfico importante en la dinámica poblacional cubana. De esta forma, el objetivo de este trabajo es estimar el efecto de la migración interna e internacional sobre el potencial de crecimiento a largo plazo de Cuba y de sus provincias. Para esto, calculamos medidas de reproducción y de crecimiento poblacional a partir de los métodos demográficos convencionales y de la metodología propuesta por Preston y Wang (2007), que se basa en los métodos de variable r. Considerando el patrón demográfico corriente, en la mayoría de los territorios de Cuba se observa una reducción substantiva en la capacidad de reposición de las generaciones y en tamaño futuro de la población cuando se consideran los efectos de la migración.

Cuba é um país que, além de apresentar níveis de fecundidade inferiores ao nível de reposição, tem registrado um saldo migratório líquido negativo significativo. Observa-se também um intenso fluxo migratório interno, cujo padrão é bastante diferente nas diversas províncias do país. Devido à magnitude destes fluxos migratórios, a migração apresenta-se como um componente demográfico importante na dinâmica populacional cubana. Assim, o objetivo deste trabalho é estimar o efeito das migrações interna e internacional sobre o potencial de crescimento de longo prazo de Cuba e de suas províncias. Para tanto, foram calculadas medidas de reprodução e de crescimento populacional a partir dos métodos demográficos convencionais e da metodologia proposta por Preston e Wang (2007), que se baseia nos métodos da variável-r. Levando em conta o padrão demográfico atual, observa-se, na maioria dos territórios de Cuba, uma redução substantiva na capacidade de reposição das gerações e no tamanho futuro da população quando se consideram os efeitos da migração.

Cuba has shown very low fertility levels, even below replacement level, in addition to significant negative net migration flows. In the country's interior there is intense population mobility, characterized by different migration patterns from one province to another. In this article the effects of both internal and international migration flows on long-term population growth in Cuba and in its provinces are discussed. We estimate reproduction and population growth measures using conventional demographic methods, together with the methodology developed by Preston and Wang (2007), based on variable-r methods. Given current demographic patterns in the majority of Cuban provinces, and when migration effects are accounted for, our analysis shows significant negative consequences for the future maintenance of the Cuban population.

Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa) fed Chlorella vulgaris and Scenedesmus acutus cultured on different media

Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold’s basal) medium or the commercial liquid fertilizer (Bayfolan). Experiments were conducted at one algal concentration 1.0x10(6)cells/mL of C. vulgaris or its equivalent dry weight of 0.5x10(6)cells/mL of S. acutus. The population dynamics were tested at 23±1ºC in 100mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates). For the life table experiments with M. macrocopa, we introduced 10 neonates (<24h old) into each test jar containing the specific algal type and concentration. For the rotifer experiments, we set 5mL tubes with one neonate each and 10 replicates for each algal species and culture medium. We found that the average rotifer life span was not influenced by the diet, but for M. macrocopa fed S. acutus cultured in Bold’s medium, the average lifespan was significantly lower than with the other diets. The gross and net reproductive rates of A. fissa (ranging from 18-36 offspring per female) were significantly higher for C. vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens, ranged from 0.1-0.25/d and were significantly higher on C. vulgaris cultured in liquid fertilizer as compared to the other diets. The growth rates of M. macrocopa ranged from 0.1 to 0.38/d, and were highest with diets of C. vulgaris cultured in Bold medium and S. acutus cultured in fertilizer. Thus, regardless of the culture medium used, the growth rates of the evaluated zooplankton species were higher with Chlorella than with Scenedesmus. The peak population density was highest (2 800ind/mL) for A. fissa fed Chlorella that was cultured on liquid fertilizers, while B. rubens and M. macrocopa had peak abundances of 480 and 12ind/mL, respectively under similar conditions.

Generalmente el crecimiento del zooplancton está a menudo limitado por la calidad de su dieta de algas. La demografía del zooplancton durante la alimentación con algas no ha sido estudiada, a pesar de que el cultivo de algas con fertilizantes es una práctica económica común en acuacultura. Se analizó la demografía de Anuraeopsis fissa y Brachionus rubens (rotíferos) y Moina macrocopa (cladóceros), alimentados con las algas verdes Scenedesmus acutus o Chlorella vulgaris cultivadas en medio Bold o fertilizante líquido comercial (Bayfolan, de Bayer). En los rotíferos no se observaron diferencias significativas en el promedio de vida, sin embargo, este parámetro en M. macrocopa con S. acutus cultivada en Medio Bold, fue significativamente menor que en otras dietas. Las tasas de reproducción bruta y neta de A. fissa fueron significativamente mayores con C. vulgaris cultivada en medio Bold, que con el fertilizante; estas tasas en B. rubens, independientemente del medio de cultivo, resultaron significativamente mayores con Chlorella que S. acutus. La tasa de reproducción de M. macrocopa fue significativamente mayor en todas, a excepción de S. acutus en Bold. En el crecimiento poblacional con A. fissa y B. rubens la tasa de crecimiento poblacional varió de 0.1 hasta 0.25/d, significativamente mayores en C. vulgaris cultivadas con fertilizante, en comparación con las otras dietas; en M. macrocopa la tasa de crecimiento varió desde 0.1 hasta 0.38/d, las más altas fueron: con C. vulgaris cultivadas en medio Bold y S. acutus cultivadas con fertilizante. Así, en todas las especies, la tasa de crecimiento fue más alta con Chlorella que con Scenedesmus.

Experimental culture of Cyclopina sp with differents microalgae’s species / Cultivo experimental de Cyclopina sp con diferentes especies de microalgas / Cultura experimental de Cyclopina sp com diferentes espécies de microalgas

Copepods are the main natural prey for most marine fish and other marine crustaceans and their nauplius, thus playing a fundamental role in aquatic food webs. There is a need to investigate the potential of copepods species found in Colombian coasts for the development of marine aquaculture. Objective: evaluate the performance of the marine copepod Cyclopina sp fed with different microalgae species. Methods: experimental cultures were conducted in 10 L aquariums with an initial density of 2 copepods/ mL, constant aeration and 24 h light. Treatments consisted of feeding the copepods with a combination of two microalgae species in a 70:30 ratio, at concentrations of 4x10(5) cells/mL, as follows: T1 = Tetraselmis suecica + Isochrysis galbana, T2 = I. galbana. + Nannochloropsis oculata, T3 = N. oculata. + T. suecica, T4 = Yeast (Saccharomyces cerevisiae). Temperature (ºC), salinity (%), dissolved oxygen (mg/L), pH, were registered daily, and the growth and population dynamics were evaluated every 48 hours for 15 days. Results: the greater density of total copepods (10± 3 copepods/ml) and number of nauplii (6 ± 2 nauplii/ mL), were registered on day 15 in T1, being significantly different (p<0.05) from any other treatments. Conclusions: the best growth and reproduction were attained in copepod populations fed with the combination of microalgae T. suecica + I. galbana (T1).

Los copépodos son la principal presa natural para la mayoría de larvas de peces y crustáceos marinos y sus nauplios como alimento vivo representan un papel fundamental en la sobrevivencia de las larvas. Objetivo: establecer el potencial de especies de copépodos presentes en las costas colombianas para el desarrollo de la piscicultura marina, siendo objetivo de esta investigación, evaluar el desempeño del copépodo marino Cyclopina sp alimentado con diferentes especies de microalgas. Métodos: cultivos experimentales se realizaron en acuarios con volumen útil de 10 litros, a densidad inicial de 2 copépodos/ ml, con aireación y luz constante. Combinaciones de microalgas (proporción 70:30) en concentración 4x10(5) cel/ml. Se usaron como tratamientos: T1 = Tetraselmis suecica + Isochrysis galbana, T2 = I. galbana + Nannochloropsis oculata, T3 = N. oculata + T. suecica, T4 = Levadura (Saccharomyces cerevisiae). Diariamente se registró la temperatura (ºC), salinidad (‰), oxígeno disuelto (mg/L), pH y se evaluaron cada 2 días el crecimiento y la composición poblacional durante el tiempo de cultivo. Resultados: la mayor densidad de copépodos totales (10 ± 3 copépodos/ml) y el mayor número de nauplios (6 ± 2 nauplios/ ml), se registraron el día 15 en T1, mostrando diferencias significativas (p<0.05) respecto a los demás tratamientos. Conclusión: los mejores crecimiento y composición poblacional, se registraron en las poblaciones alimentadas con la combinación de las microalgas T. suecica e I. galbana (T1).

Os copépodos são a principal presa natural para a maioria de larvas de peixes e crustáceos marinhos e seus náuplios como alimento vivo desempenhan um papel fundamental na sobrevivência das larvas. Objetivo: estabelecer o potencial de espécies de copépodos presentes nas costas colombianas para o desenvolvimento da piscicultura marinha, sendo o objetivo desta pesquisa avaliar o desempenho do copépodo marinho Cyclopina sp alimentado com diferentes espécies de microalgas. Métodos: culturas experimentais foram realizadas em aquarios com volume útil de 10 litros, densidade inicial de 2 copépodos/ ml, com aeração e luz constante. Combinações de microalgas (proporção 70:30) em concentração 4x10(5) cel/ml, foram usadas como tratamentos: T1 = Tetraselmis suecica + Isochrysis galbana, T2 = I. galbana + Nannochloropsis oculata, T3 = N. oculata + T. suecica, T4 = Levadura (Saccharomyces cerevisiae). Foi registrada diariamente a temperatura (°C), salinidade (‰), oxigênio dissolvido (mg/L) e pH. A cada dois días foram avaliados o crescimento e composição populacional durante o tempo de cultivo. Resultados: a maior densidade de copépodos totais (10 ± 3 copépodos/ml) e o maior número de náuplios (6 ± 2 náuplios/ ml), foram registrados no día 15 do T1, apresentando diferença estatística significativa (p<0.05) em comparação com os outros tratamentos. Conclusõe: o maior crescimento e composição populacional foi registrado na população alimentada com a combinação de microalgas T. suecica e I. galbana (T1).

Perfil demográfico do município de Goiania Pernambuco: 1940-2010 / Demographic profile of Goiana's town, Pernambuco: 1940-2010

O município de Goiana, Pernambuco, vem recebendo grandes investimentos para instalação de grandes empresas em seu território. Nesta perspectiva, percebe-se que o município poderá passar por uma grande variação no seu quantitativo populacional. Desta forma, este trabalho se propõe a apresentar uma descrição da estrutura populacional do município com base nos censos demográficos de 1940 a 2010. Para realização deste trabalho foram construídas pirâmides etárias do município com as informações apresentadas nos censos demográficos, bem como, foram calculados indicadores considerando sexo, faixa etária e situação do domicílio. A partir destes dados é possível perceber que Goiana apresentou um crescimento populacional constante até a década de 60. Em 1970 ocorreu uma grande queda no total da população e a partir de então manteve o seu crescimento continuo. Em relação à urbanização o município apresentou um aumento do número de pessoas morando nas cidades, porém no censo de 1991 apresentou uma proporção constante comparada à década anterior e em 2000 ocorreu um declínio da proporção de pessoas que moram na zona urbana do município e posteriormente um brusco crescimento da taxa de urbanização. Outro aspecto fundamental a ser considerado é mostrado através das pirâmides etárias, mostrando o processo de transição demográfica que o município está vivenciando, com a redução nas taxas de fecundidade e o aumento da população idosa, principalmente do sexo feminino. Tais achados mostram que o município esta passando por constantes transformações que em alguns casos diferem dos apresentados pelo estado de Pernambuco e pelo país. Assim, sugere-se que novos estudossejam realizados em busca das principais causas para os acontecimentos destes eventos neste município.

The Goiana’s town, Pernambuco, had been receiving a lot of investments to installing big companies in his territory. In this perspective, it is perceived that the town can pass by a wide variation in his quantitative population...

Fertility tables of two populations of the parthenogenetic species Poratia salvator (Diplopoda, Polydesmida, Pyrgodesmidae) / Tabela de fertilidade de duas populações da espécie partenogenética P. salvator (Diplopoda, Polydesmida, Pyrgodesmidae)

Diplopods are very susceptible to various degrees of environmental disturbance, particularly climate, altitude and diet. In order to increase our understanding of millipede ecological plasticity, we used fertility tables to access and to compare the fertility and survival of two populations of the parthenogenetic species Poratia salvator from two areas with distinct characteristics. Collecting was conducted in two localities within the state of Mato Grosso, in the Pantanal of Mato Grosso, municipality of Nossa Senhora do Livramento, and in the municipality of Várzea Grande. The specimens were maintained at room temperature. In the first generation, individuals from the Pantanal of Mato Grosso population reproduced early and also died earlier when compared with individuals from the Várzea Grande population. Furthermore, the population from the Pantanal had a lower net reproduction rate and a higher intrinsic growth rate than the population from the Várzea Grande. The generation time was lower for the Pantanal population than for the Várzea Grande population. In the second generation, the net reproduction rate observed for both populations was higher than that observed in the first generation, suggesting an increase in the reproductive potential of the females throughout their lives. The intrinsic growth rate of both populations decreased as a function of an increase in generation time observed in the second generation. As a result, the population growth rate in the second generation was slower when compared with the first generation, probably a result of the longer life expectancy of the second generation, which may have become adapted to the artificial conditions of the experiment.

Os Diplopoda demonstram forte sensibilidade às mudanças ambientais em diferentes escalas, sendo que fatores como clima, altitude e disponibilidade de alimento são os que mais influenciam o seu desenvolvimento biológico. Dessa maneira, este estudo objetivou estimar as taxas de sobrevivência e fertilidade da espécie partenogenética Poratia salvator através da elaboração de tabelas de fertilidade, a fim de caracterizar o crescimento populacional desta espécie, oriunda de diferentes ambientes. As coletas foram realizadas em duas localidades, uma no Pantanal de Mato Grosso, município de Nossa Senhora do Livramento, e outra no município de Várzea Grande-MT. Os indivíduos foram mantidos sob temperatura ambiente. Como resultado observou-se que a população proveniente do Pantanal apresentou aceleração da reprodução, na primeira geração, com mortalidade prematura das progenitoras. Para a população oriunda de Várzea Grande, a reprodução ocorreu em idades mais avançadas do período reprodutivo, e as fêmeas viveram por um maior período. Na primeira geração, a população do Pantanal teve menor taxa líquida de reprodução e maior taxa intrínseca de crescimento que a população de Várzea Grande. O tempo de geração da população do Pantanal foi menor que a de Várzea Grande. Na segunda geração, observou-se que a taxa líquida de reprodução das duas populações foi maior que a observada na primeira geração, evidenciando um incremento no potencial reprodutivo de cada uma das fêmeas ao longo da vida. A taxa intrínseca de crescimento diminuiu devido ao aumento no tempo de geração da segunda geração estudada. Com isso, a taxa de crescimento das populações, na segunda geração, foi mais lenta que a primeira, visto que houve um prolongamento na vida das progenitoras, aparentemente, devido à adaptação dos animais às condições artificiais.

Understanding Below-replacement Fertility in Kerala, India.

Kerala is well-known globally for the unprecedented fertility transition in the Indian subcontinent towards the end of the last century. The state has already reached below-replacement fertility level in the 1990s while the rest of India was experiencing high or mid-level fertility. With this backdrop, an attempt was made in this paper (a) to explore the plausible factors associated with sub-replacement fertility and consequent population momentum in Kerala and (b) to trace their socioeconomic and health policy implications. The underlying factors that led to the fertility transition was explored and discussed in some detail. An enhanced level of human development achieved during the last quarter of the 20th century, mainly through developments in social and health sectors, is likely to be the main contributor. Unlike other states in India, there were historical factors as well that functioned as a catalyst for this, such as widespread education and women’s empowerment. As an inevitable demographic impact, population growth due to momentum is expected to be very strong in Kerala with an age-structural transition favouring the old. The so-called ‘demographic dividend’ invoked by the increase of labour-force derived from the youth bulge in the age-structure is being lost in the state due to very limited capital investments and political will. Again, as a direct consequence of population growth, population density in Kerala will take a staggering level of 1,101 persons per sq km in 2026. The ill effects of environmental deterioration and consequent changes in morbidity patterns will have to be dealt with seriously. The very foundations of health policy needs revamping in the light of demographic changes associated with sub-replacement fertility. The tempo of population-ageing is very high in Kerala. The proportion of population aged 60+ years is likely to be 20% in 2026 whereas it will be around 12% only in India. The current level of social and health infrastructure in the state may not be sufficient to cope with the emerging demands of population-ageing since the financial and morbidity burdens of the elderly are already quite high. To conclude, Kerala portrays a typical case of the vagaries of the onset of sub-replacement fertility level in the absence of reasonable structural changes in the economic and health fronts.

Anticonceptivos en el Sur, Seguridad Nacional en el Norte / Southern Contraceptives, Northern National Security

En este ensayo se presentan los principales argumentos del National Security Study Memorandum 200 (NSSM 200), elaborado en 1974 por la oficina del Secretario de Estado de los Estados Unidos. Este documento, titulado Implications of worldwide population growth for U.S. security and overseas interests, revela las acciones de planificación familiar que este gobierno tomaría para disminuir las tasas de crecimiento poblacional en países menos desarrollados, particularmente aquellos que recibían apoyo de la Agencia de los Estados Unidos para el Desarrollo Internacional (USAID). Aunque originalmente de naturaleza confidencial, el NSSM 200 se hizo público en la década del '90, y es una de las pocas fuentes que existen para entender cómo el gobierno de los EE.UU. interpretaba el crecimiento demográfico en los años '60 y '70 del siglo XX, su relación con la pobreza en los países en vías de desarrollo, y la seguridad nacional de los EE.UU.

This essay presents the main arguments of the National Security Study Memorandum 200, developed in 1974 by the Office of the Secretary of State of the United States. This document, entitled Implications of Worldwide Population Growth for U.S. Security and Overseas Interests, reveals the steps in family planning that the U.S. government would take to reduce population growth rates in less developed countries, particularly those that received aid from the U.S. Agency for International Development (USAID). Though originally confidential, the NSSM 200 became public in the 1990s, and is one of the few sources that help us understand how the U.S. government interpreted demographic growth in the 1960s and 1970s, its relation to poverty in developing countries, and the national security of the U.S.

Reproduction and survival of Muscina stabulans under laboratory conditions / Reprodução e sobrevivência de Muscina stabulans em condições de laboratório

This is the first published report concerning reproduction and survival using life table analyses of fertility and survival for Muscina stabulans maintained under laboratory conditions with artificial diets. The intrinsic rate of growth, reproduction rate and average generational time were obtained, suggesting a rapid population growth under these rearing conditions. These findings permitted the creation of time models of survival and oviposition, as well as a quantitative estimate of the adaptation capacity of this species.

Com o objetivo de apresentar um primeiro delineamento para a reprodução e sobrevivência da Muscina stabulans em condições de laboratório, foram desenvolvidas tabelas de vida em dieta artificial. A taxa intrínseca de crescimento natural, a taxa reprodutiva líquida e o tempo médio de uma geração foram estimados, além da análise do tempo de oviposição e da sobrevivência dos adultos dessa espécie. Os dados sugerem uma alta taxa de crescimento da população nas condições de criação. Esses resultados permitem a criação de modelos de sobrevivência e oviposição, bem como estimativas quantitativas da adaptabilidade dessa espécie.

Examining Perceptions of Rapid Population Growth in North and South Gondar Zones, Northwest Ethiopia.

Ethiopia is one of the most populous countries in Africa and ranks second only to Nigeria. Rapid population growth has hampered the country’s development, making the eradication of extreme poverty and hunger difficult. This study which had two components—quantitative and qualitative—was aimed at exploring the perceptions of women and other social groups on the prevailing population pressures. The quantitative study involved 3,512 women aged 15-49 years. The qualitative study consisted of five focus-group discussions and six key-informant interviews. Over 90% of women (n=3,512) who participated in the quantitative study and nearly all the focus-group discussants and interviewees (n=39) felt that something should be done to keep the population from growing too fast. Most (over 90%) participants approved of the Government passing a law regarding the maximum number of children that a couple should have. It is, therefore, timely for the responsible bodies to exert maximum effort and commitment in responding to the emerging attitudes of the people by making the population problem a priority.

Tasa de crecimiento poblacional del rotífero Brachionus rotundiformis (Rotifera: Brachionidae) en un quimiostato de dos cámaras

Population growth rate of the rotifer Brachionus rotundiformis (Rotifera: Brachionidae) in two-stage chemostat. The population growth rates of Brachionus rotundiformis were estimated in two-stage chemostat cultures. Chlorella sorokiniana was supplied continuously from a steady state culture growing with constant illumination on limiting nitrate. Rotifer growth in the second stage was limited by the rate of algal supply. The algal supply rate and rotifer population growth rate were determined by the second-stage dilution rate. The maximum population growth rate in the transient state of B. rotundiformis (1.96 day-1) was observed at 2.5 x 106 cel/ml of the algae whereas in the steady state the maximum population growth rate (1.09 day-1) was similar to the point Hopf’s bifurcation predicted by Fussmann and was observed at 1 x 106 cel/ml of the algae. In the transient state, the rotifer’s growth rate increased and the duplication time decreased at higher algal concentrations, until reaching a peak where the population growth rate begins to decrease. In the steady state, the opposite was true. The growth rates observed in this work are among the highest recorded for this rotifer in continuous cultures. Rev. Biol. Trop. 56 (3): 1149-1157. Epub 2008 September 30.

Se estimaron las tasas de crecimiento poblacionales de Brachionus rotundiformis en un quimiostato de dos cámaras. Suministramos Chlorella sorokiniana continuamente a partir de un cultivo en estado estacionario con iluminación constante y nitrato como nutriente limitante. El crecimiento del rotífero en la segunda cámara estuvo limitado por la tasa de suministro del alga. La tasa de suministro del alga y la tasa de crecimiento poblacional del rotífero fueron determinadas a partir de la tasa de dilución en la segunda cámara. La tasa máxima poblacional de crecimiento en estado de transición de B. rotundiformis (1.96 día-1) se obtuvo a 2.5 x106 cel/ml del alga, mientras que en estado estacionario la tasa máxima (1.09 día-1) fue similar al punto de bifurcación de Hopf predicho en Fussmann et al., (2000) y se obtuvo a 1 x106 cel/ml del alga. En la fase de transición se observó que a mayor concentración del alga, mayor era la tasa de crecimiento del rotífero y menor su tiempo de duplicación, hasta alcanzar un pico donde comienza a decrecer. En la fase estacionaria se observó lo contrario. Los valores obtenidos se encuentran entre los más altos reportados hasta ahora para este rotífero en cultivos continuos.