Too young to have sex: conversations with very young adolescents about sex, dating and related decision-making

Background. Very young adolescents receive little research and pragmatic attention regarding their sexual and reproductive health (SRH) needs. As a result, their experiences are often overlooked. Furthermore, when this age group is included in SRH education, the dominant public health lens tends to focus on health risks associated with sex, with less emphasis on a holistic approach that considers the socio-cultural and relational contexts in which adolescents' decision-making about sex and dating occurs. Objectives. To explore the beliefs, perceptions and decision-making pathways of adolescents about heterosexual sex, dating and relationships. Methods. The sample included 33 girls and 30 boys aged 10 - 14 years attending schools in rural Mpumalanga Province, South Africa. Data collection entailed participatory methodologies of group-based activities and individual interviews. Data were recorded and transcribed verbatim. Transcripts were coded and analysed using thematic analysis. Results. The findings focused on three themes: timing of dating, relationships and sex; gendered depictions of first sex; and agency in sexual decision-making. These themes shed light on the relational context in which adolescents' decision-making takes place and highlight the pervasive influence of wider gendered norms. Conclusion. Very young adolescents are not sexually naive and instead are faced with complex decisions regarding sex and dating. This age group is not, however, fully supported in developing a healthy, positive sexuality when emphasis is on the negative outcomes of sex. The paper concludes with recommendations for adolescent SRH programmes to provide a supportive environment for younger adolescents to make informed choices and develop positive, healthy sexualities

Comportamiento del semen bovino sexado congelado-descongelado en fertilización in vitro (FIV) capacitado mediante BO en dos concentraciones versus percoll / Behavior of sexed frozen-thawed bovine semen on in vitro fertilization (IVF) capacitated with two concentrations of BO versus percoll

RESUMEN: El objetivo fue comparar la tasa de división (TD) y desarrollo embrionario (DE) con semen sexado X (SX) en FIV capacitado con Percoll vs. BO, y evaluar el efecto de dos concentraciones (5x106 vs. 10x106 espermatozoides/ml), capacitado con BO, comparado con el semen no-sexado (NS). Un avance importante es predeterminar el sexo en bovinos, es posible obtener mayor proporción de terneras a partir del citómetro de flujo con la capacidad de seleccionar los espermatozoides X por la diferencia del ADN (4 %, bovinos), con confiabilidad del 90 %. El SX aumenta la eficiencia reproductiva, permite la selección de hembras e incrementa la ganancia genética. Se obtuvieron complejos ovocito cúmulus (COC), de ovarios de matadero, se cultivaron para maduración en gotas de 100 µl de TCM-199 + 5 % de suero fetal bovino + 0.005 U/ml de (FSH-p) + 10 IU hCG/ml + 1µg Estradiol (E2)/ml, 15 COC/gota, cubiertas con aceite mineral, en incubadora (38,5 ºC, 5 % de CO2 y 95 % de humedad), 22 h. Posmaduración se dividieron en 4 grupos (G1, G2, G3, G4) y se realizaron dos experimentos simultáneamente: I) G1: NS a 5x106, G2: SX a 5x106, G3: SX a 10x106 espermatozoides/ml capacitados con BO. II) G2: SX a 4,5x106 espermatozoides/ml capacitados con BO y G4: SX capacitado con Percoll a 5x106 espermatozoides/ ml. Se colocaron 15 COC/gota de semen cubiertas con aceite mineral, en incubadora, 18 h. Para el desarrollo se colocaron en gotas de CR1aa, en incubadora. Se aplicó el test de χ2. La TD a las 48 h entre G1 y G3 no presentó diferencias significativas (p<0,05), sin embargo, en ambos grupos fue significativamente mayor al G2. En el DE al día 7 hubo diferencias significativas (p<0,05) a favor del G4. Se obtuvo mayor DE con el SX capacitado con Percoll respecto al BO y no hubo diferencias entre ambas concentraciones de semen.

SUMMARY: The objective of this study was to evaluate the in vitro fertility of bovine sexed semen (SX) capacitated with Percoll vs. BO. The division rate (DR), embryo development (ED) were evaluated in two concentrations 5x106 vs. 10x106 sperm/ml, capacitated with BO and compared with non-sexed semen (NS). Offspring sexing represents an important advance for livestock production. Flow cytometry separates X and Y spermatozoa by difference in DNA content (4 % greater in X) with 90 % effectiveness. The SX increases the reproductive efficiency, allows the selection of females and increases the genetic gain. Cumulusoocytes complexes (COC) were obtained from slaughterhouse ovaries. They were then cultured 22 hours for maturation in TCM199 + 5 % fetal calf serum + 0.005 IU/ml (FSH-p) + 10 IU hCG/ml + 1 mg Estradiol (E2)/ml, in 100 µl drops with mineral oil, in incubator (38.5 ºC, 5 % CO and 95 % humidity). Post maturation, 4 groups were randomly assigned (G1, G2, G3, G4) and were performed two experiments simultaneously: I) G1 was inseminated with NS at 5x106 sperm/ml, G2: SX at 5x106, G3: SX at 10x106 sperm/ml capacitated with BO. II) G2: SX at 5x106 sperm/ml capacitated with BO and G4: SX capacitated with Percoll at 5x106 sperm/ml. 15 COC/drop of capacitated semen covered with mineral oil and placed in an incubator for 18 hours. For development, they were placed in drops of CR1aa, in an incubator. Results were analyzed with the c square test. At 48 hours, there were no significant differences (p<0.05) in DR between G1 and G3, however, in both groups it was significantly greater than G2. At day 7 there were significant differences (p <0.05) in ED, greater in G4. At 48 hours, there were no significant differences (p<0.05) in DR between G1 and G3, however, in both groups it was significantly greater than G2. At day 7 there were significant differences (p <0.05) in ED, greater in G4. A higher ED was obtained with the SX capacitated with Percoll, with respect to BO and there was no difference between the two semen concentrations.

Semen bovino sexado congelado-descongelado en producción de embriones in vitro / In vitro embryo production with frozen-thawed bovine semen sexed

El objetivo de este trabajo fue evaluar la fertilidad in vitro del semen bovino sexado (SX) vs. no sexado (NS) congelado-descongelado de dos toros Holstein, cada uno de la misma partida. Determinar el sexo de las crías significa un avance importante para la producción. El citómetro de flujo separa los espermatozoides X e Y por diferencia de ADN (4 % mayor en X), con 90 % de efectividad. Los complejos ovocito-cúmulus (COC) se obtuvieron de folículos de 2 a 8 mm de ovarios de frigorífico, se cultivaron para maduración 22 h en TCM-199 + 5 % de SFB + 10 % licor folicular bovino (LFB), en gotas de 100 µl, cubiertos con aceite mineral, en incubadora (38,5 C, 5 % CO2 y 95 % de humedad). Posmaduración, se formaron al azar 4 grupos de COC los cuales fueron inseminados con NS y SX de los toros 1 y 2. Los COC se incluyeron en gotas de 100 ml a razón de 10 COC por gota de semen capacitado a una concentración de 2x106 espermatozoides/ml en todos los grupos, incubados durante 6 h. Posteriormente se cultivaron en CR1aa + 5 % SFB, en incubadora. A las 48 h se evaluó el clivaje y al día 7 el desarrollo embrionario. Los resultados fueron analizados con el Test de c2. Se encontró diferencias significativas en el toro 1 en el desarrollo embrionario a favor del NS (p<0,05). En el toro 2 no se encontró diferencias significativas en el clivaje ni en el desarrollo (p<0,05).

The objective of this study was to evaluate the in vitro fertility of sexed (SX) vs. non-sexed (NS), frozen-thawed bovine semen from two Holstein bull, from the same batch each one. Offspring sexing represents an important advance for livestock production. Flow cytometry separates X and Y spermatozoa by difference in DNA (4 % greater in X) with 90 % effectiveness. Cumulus-oocytes complexes (COC) were obtained from follicles measuring between 2 and 8 mm collected from slaughterhouse ovaries; they were then cultured 22 h for maturation in TCM-199 + 5 % BFS + 10 % bovine follicular fluid (BFF) in 100 µl drops with mineral oil, in incubator (38.5 C, 5% CO2 and 95 % humidity). Postmaturation, 4 groups were randomly formed and inseminated with NS and SX of the 1 and 2 bulls, including them in 100 µl drops at 10 COC per drop of capacitated semen diluted to a concentration of 2x106 sperms/ml in all groups, incubated during 6 h. They were then cultured in CR1aa + 5% BFS in an incubator. At 48 h cleavage and at day 7 embryonic development, were assessed. Results were analyzed with c2 square Test. There were significant differences (P<0.05) in the embryonic development in bull 1, grater in NS. In bull 2 there were not significant differences in cleavage neither in embryo development.

Citometría de flujo y sexaje de espermatozoides en animales / Flow cytometry and sperm sexing in animals

Actualmente, cientos de crías se han gestado a través de inseminación artificial conespermatozoides sexados en producción animal. Desde 1992 se utiliza la citometría de flujo, técnica que permite diferenciar espermatozoides X e Y según su contenido de ADN. No existe, hasta el momento, ninguna otra técnica práctica para sexar espermatozoides manteniendo la capacidad fecundante. Los objetivos de esta revisión son explicar: (1) por qué los espermatozoides que contienen el cromosoma X o Y son similaresfenotípicamente, pero a la vez mantienen diferencias entre ellos, (2) los principios y procedimientos utiliza-dos para sexar espermatozoides mediante citometría de flujo y sorting (3) la precisión, velocidad y la eficiencia de los procedimientos actuales de sexaje espermático, (4) el daño espermático ocurrido durante el sexaje espermático y consecuentemente los efectos sobre la fecundidad.

Flow cytometry is a useful technology in the sexed sperm, which measures and analyzes simultaneously, multiple physical characteristics of the cell, as they flow in a stream flow, through a lightbeam. The measured properties are the size of a particle, relative internal granularity, relative complexity and relative fluorescence intensity. Currently, hundreds of calves have been gestated through artificial insemination with sexed sperm in animal production. Since 1992, flow cytometry has been used, a technique that allows spermatozoa X and Y differentiation by DNA content. There is no other practical technique forsperm sexing to keep sperm functionality. The objectives of this review are to explain: (1) why the sperm containing the X or Y chromosome are phenotypically similar, but differ among themselves, (2) the principlesand procedures used for sexing sperm by flow cytometry and sorting ( 3) accuracy, speed and efficiency ofcurrent procedure sperm sexing, (4) sperm damage occurred during sperm sexing and consequently the effects on fertility.

Spatial and temporal length distribution of Zungaro zungaro caught in the Orinoco River Basin of Colombia / Distribución espacial y temporal de tallas de captura de Zungaro zungaro en la Orinoquia colombiana

Objective. To determine the effect of fishing on capture size of both male and female Zungaro zungaro catfish, historical records of size and spatial distribution of the species were analyzed from the Orinoco Basin in Colombian. Materials and methods. Information was collected by sampling fishing port landings in the region between 1979 and 2011. Each specimen was measured, weighed and sexed. With 5411 records, the average size at capture were compared in time and among the different ports. Size at 50% maturity was estimated by quinquennium. Results. The average commercial capture sizes of Z. zungaro ranged from 35 to 161 cm standard length, with differences between males and females. From 1979 to 2011, in Puerto Lopez, the size at sexual maturity decreased from 123.8 to 83.4 cm in females and from 93.3 to 61 in males. In the annual cycle the greater average capture size in females was from April to July and for males from May to June. Average annual length is higher in the higher parts of the Meta and Guaviare river drainages. In the last quinquennium the size at 50% maturity had fallen 10 cm in females and 5 cm in males and it is higher than the average capture size. Conclusions. Populations of Z. zungaro in the Colombian Orinoco River Basin have been affected by overfishing and selective fishing of females.

Objetivo. Determinar el grado de afección en la población de Zungaro zungaro a partir del análisis del comportamiento histórico y espacial de las tallas de captura de hembras y machos de la especie en la Orinoquia colombiana. Materiales y métodos. La información fue colectada mediante muestreos a los desembarcos en puertos pesqueros de la región entre 1979 y 2011. Cada ejemplar fue medido, pesado y sexado. Con 5411 registros, se estableció la distribución de las tallas medias de captura, que se compararon en el tiempo y entre los diferentes puertos. Se estimó la talla de madurez gonadal (TMG) por quinquenios. Resultados. El rango de las tallas de captura comercial Z. zungaro fue de 35 a 161 cm longitud estándar (LS), con diferencia entre machos y hembras. Entre los años 1979 a 2011, en Puerto López, la talla promedio de captura anual (LS) disminuyó de 123.8 a 83.4 cm en hembras y de 93.3 a 61 cm en machos. En el ciclo anual la mayor talla promedio de captura de hembras se presenta en abril a julio y de machos en mayo y junio. La talla promedio de captura anual (TPCA) es superior en las partes altas de los ríos Meta y Guaviare. En el último quinquenio la TMG ha disminuido 10 cm en las hembras y cinco cm en los machos y es superior a la TPCA. Conclusiones. Hay afectación sobre la población explotada de Z. zungaro por sobrepesca por crecimiento y pesca selectiva de hembras en la Orinoquia colombiana.

Sensibilidade da PCR na amplificação do DNA bovino em diluição seriada e mistura de amostra macho e fêmea / Sensitivity of PCR to amplify sex-specific bovine DNA in diluted samples

A mixture of bovine DNA from a male and a female Jersey (Bos taurus taurus) bred in different proportions was used to determine the sensitivity of PCR to amplify and discriminate the bovine DNA samples. Samples were obtained from the peripheral blood of a bull and a heifer and DNA was isolated using a commercial kit for extraction and purification of nucleic acids. Two primers sets were designed to flank genomic regions: one autosomal and one Y-specific. DNA samples were diluted in water to a final concentration of 4x10-14 ng. The results showed positive amplification of the samples diluted to a concentration of 4x10-10ng and 4x10-4ng for the autosomal and Y-specific regions, respectively. PCR was able to discriminate the male DNA in a mixture of 99:1 (DNA ♀: DNA ♂) heifer to bull ratio. Therefore, the PCR was successful in amplifying the bovine genome in samples containing low concentrations of DNA. Thus, PCR can be used as a sensitive and efficient tool to determine the sex of the fetus in pregnant cows, helping to promote correct and efficient animal management, sex selection, and breeding in commercial herds.

Successful sex pre-selection using natural family planning

The objective of the study was to test the hypothesis that gender can be preselected by timing coitus in relation to ovulation, the marker of ovulation being the Peak symptom according to the Billings Method. A blind prospective study of 99 couples wishing to preselect the sex of their child was conducted in Nigeria, using the Post-Peak approach of Billings Method for males and Pre-Peak for females. Research co-ordinators examined the 'post-conception' form within four months of conception. This form recorded the timing of coitus prior to conception, and from this, the sex of child was predicted. 94 of the couples had a child of pre-selected sex showing a method success of 94.9%. 78 of 81 predicting a male were successful (96.3%) and 16 of the 18 predicting a female (88.9%). There was one user-failure, a couple who wanted a girl, timed coitus as for a boy, which they had. The study indicates that where comprehensive instruction is provided, the sex of a child can be preselected with a high degree of confidence by timing coitus, using the Post-Peak approach of Billings Method for males and Pre-Peak for females (Afr J Reprod Health 2011; 15[1]: 79-84)

Knowledge and attitudes of a number of Iranian policy-makers towards abortion

Unsafe and illegal abortions are the third leading cause of maternal death. It affects physical, emotional and social health of women and their families. Abortion is a multi-dimensional phenomenon with several social, legal, and religious implications. The views of policy-makers affect the approach to abortion in every society. Understanding the attitudes and knowledge of high-ranking decision makers towards abortion was the purpose of this study. A qualitative research was implemented by carrying out individual interviews with 29 out of a selection of 80 presidents of medical sciences universities, senior executive managers in the legal system, forensic medicine and decision-makers in the health system and a number of top Muslim clerics, using a semi-structured questionnaire for data gathering. Content analysis revealed the results. There were considerable unwillingness and reluctance among the interviewees to participate in the study. The majority of participants fairly knew about the prevalence of illegal abortions and their complications. There was strong agreement on abortion when health of the mother or the fetus was at risk. Abortion for reproductive health reasons was supported by a minority of the respondents. The majority of them disagreed with abortion when pregnancy was the result of a rape, temporary marriage or out of wedlock affairs. Making decision for abortion by the pregnant mother, as a matter of her right, did not gain too much approval. It seemed that physical health of the mother or the fetus was of more importance to the respondents than their mental or social health. The mother's hardship was not any indication for induced abortion in the viewpoints of the interviewed policy-makers. Strengthening family planning programs, making appropriate laws in lines with religious orders and advocacy programs targeting decision makers are determined as strategies for improving women's health rights

A preliminary study on chromosome aneuploidy & mosaicism in early pre-implantation human embryo by fluorescence in situ hybridization.

BACKGROUND & OBJECTIVE: Chromosome aneuploidy plays an important role in infertility, early pregnancy wastage and perinatal mortality. Cytogenetic & fluorescent in situ hybridization (FISH) studies on developmentally arrested and morphologically poor embryo have shown high frequency of chromosomal abnormality and mosaicism. In this study, we attempted to evaluate chromosome aneuploidy and mosaicism on human embryos through the use of FISH. METHODS: Sixty one grade IV un-transferable embryos were obtained from 25 patients undergoing in vitro fertilization (IVF). Forty six embryos were studied by FISH; 15 were lost during transport and handling. FISH probes (non-commercial) for centromeres of chromosome X, Y, 1 and 18 were used for the study. Zona of embryos were dissolved in 0.01N HCl containing 0.1 per cent Tween 20 for 2-3 min. RESULTS: Interpretable FISH results were obtained in 24 embryos. Nineteen embryos (79.2%) were disomic (normal) for chromosome X/Y or 1/18 and five (20.8%) were abnormal. Among five abnormal embryos two were triploidy (from same patient), one was double mosaic aneuploidy, one was mosaic aneuploidy and one was trisomy for sex chromosome (XXY). There was eleven embryos with presence of Y chromosome i.e., male and three embryos were female. INTERPRETATION & CONCLUSION: Skewing of sex ratio (11M vs. 3F) and low chromosome aneuploidy were observed in this preliminary study, however, it will be premature to conclude as the numbers of embryos studied were limited and so were the numbers of FISH probes used.

Nacimiento de la primera niña en Venezuela con selección de sexo en espermatozoides / Birth of the first baby girl in Venezuela with sperm separation for gender selection

El objetivo del presente trabajo es realizar la selección de sexo de espermatozoides portadores del cromosoma sexual femenino, para lograr el embarazo y nacimiento de una niña. Paciente de 36 años, III gesta, dos embarazos simples y en gemelar, acude con su esposo a sonsultar por deseos de tener una hija. Se seleccionaron los espermatozoides portadores del cromosoma X y fueron teñidos con bisbenzimida y seleccionados por citometría de flujo con tecnología Microsort. La fracción enriquecida fue congelada. Se realizó a la paciente una inducción de la ovulación con agonista de GnRH y FSH. Se realizó la inyección intracitoplasmática de espermatozoides (ICSI) con los espermatozoides sexados a 9 ovocitos maduros. Se transfirieron dos embriones de 8 células. Se confirmó el embarazo y el sexo femenino diagnosticado por US y amniocentesis, con el nacimiento de una niña normal. Esta es la primera vez, que se aplica con éxito la selección de sexo de espermatozoides en Venezuela, lo que abre caminos para lograr tener un hijo del sexo deseado.

Prejuicios, estereotipos y discriminación: reflexión ética y psicodinámica sobre la selección de sexo embrionario / Prejudice, stereotypes and discrimination: ethical and psychodynamic reflection on embryonic sex selection / Preconceitos, estereótipos e discriminação: reflexão ética e psicodinâmica sobre a seleção do sexo embrionário

La elección de sexo embrionario es una posibilidad biotecnológica que por ser realizada sobre gametos no causa daño al cigoto. La elección del sexo de los hijos podría ser inocua pero, para que fuera libre, debería estar exenta de presiones psicológicas, específicamente de sentimientos de discriminación como síntoma neurótico. El artículo señala las bases de este síntoma y sus manifestaciones. Existe una gran responsabilidad cuando se toman decisiones que afectan a terceros y es necesario que se realicen con el más alto grado posible de libertad. En este trabajo también se analizan las alternativas, prevención y manejo de la discriminación neurótica.

The selection of embryonic sex is a biotechnological possibility that, because it is done on gametes, does not cause damage to the zygote. Selecting the sex of a child can be innocuous, but for that choice to be freely made there should be no psychological pressure, specifically from feelings of discrimination as a neurotic symptom. The article outlines the bases of this symptom and its manifestations. A great responsibility exists when decisions are taken that affect third parties, and it is necessary that they are realized with the highest possible level of freedom. This work also analyzes the alternatives, prevention and management of neurotic discrimination.

A escolha do sexo embrionário é uma possibilidade biotecnológica que por ser realizada sobre gametas não causa dano ao zigoto. A escolha do sexo dos filhos poderá ser inócua, porém, para ser livre, deverá estar isenta de pressões psicológicas, especificamente de sentimentos de discriminação como sintoma neurótico. O artigo assinala as bases deste sintoma e suas manifestações. Existe uma grande responsabilidade quando se tomam decisões que afetam a terceiros é necessário que sejam realizadas com o mais alto grau possível de liberdade. Neste trabalho também se analisam as alternativas, prevenção e manejo da discriminação neurótica.

Determinants and causes of son preference among women delivering in Mansoura, Egypt

This study in Egypt, measured the son preference index, its determinants, and impact on reproductive behaviour and intention of 400 mothers attending for delivery. Overall son preference index was 1.4. The causes of sex preference were mainly psychological and social. Mothers with only girls were 496 times more likely to prefer a son as compared to those with boys only. Mothers with illiterate husbands were nearly 10 times more likely to prefer a son than those married to highly educated husbands. Achievement of the desired sex, whether son or daughter, was associated with less desire for more children, intention to prolong pregnancy spacing and intention to use contraceptives

Efectos de la experiencia social temprana en las preferencias sexuales de la codorniz japonesa (coturnix japonica) / Effects of early social experiences on mating preferences of coturnix japonica

Las teorías clásicas propuestas para explicar las preferencias sexuales han hecho énfasis en los determinantes genéticos; consideran que las preferencias de las hembras y los rasgos sexuales de los machos coevolucionan, porque los rasgos son un indicador confiable de "buenos genes" que favorecen la supervivencia de los hijos. Una hipótesis alternativa explica las preferencias sexuales mediante un mecanismo de aprendizaje; un ejemplo de este enfoque es el aprendizaje por impronta propuesto por Konrad Lorenz. El presente experimento se propuso evaluar los efectos de diferentes prácticas de crianza temprana sobre las preferencias de pareja. Para este propósito, se seleccionaron 35 pollitos de codorniz, de 15 días de nacidos, y se dividieron en cuatro grupos: (1) un grupo de 9 pollitos machos criados cada uno en compañía de una hembra adulta de tres meses;(2) un grupo de 9 pollitos hembras criadas cada una en compañía de un macho adulto de tres meses; (3) un grupo de 9 pollitos machos criados en jaulas individuales y sin contacto visual con otros de su especie, y (4) un grupo de 8 pollitos hembras criadas en jaulas individuales y sin contacto visual con otros de su especie. Estas condiciones se mantuvieron por tres meses, al cabo de los cuales cada uno de los animales fue sometido a una prueba de preferencia de pareja y se midió el tiempo que el animal dedicaba a observar a una pareja potencial (la pareja con la que se había criado y una pareja distinta) en ensayos de 10 minutos, durante 10 días. Los resultados muestran que el 50 por ciento de los 18 pollitos que conformaron los grupos de machos y hembras criados en pareja, presentaron diferencias significativas (23 por ciento a favor de la pareja de crianza y 27 por ciento a favor de una pareja distinta); y de los 17 pollitos que conformaron los grupos de crianza individualizada, sólo el 12 por ciento del grupo de machos mostró diferencias significativas en sus preferencias de pareja. Al ...

Current theories that attempt to explain mating preferences have placed particular emphasis on genetic determinants. They state that sexual preferences of females and sexual features of males evolve concurrently given the fact that male features are a reliable indicator of the presence of "good genes" which favor offspring survival. An alternative hypothesis explains mating preferences by means of a learning mechanism. An example of this approach is the theory of learning by imprinting proposed by Konrad Lorenz. This experiment aimed to evaluate the effects of different types of early breeding practices on later mating preferences. For this purpose, 35 quail chicks, 15 days old, were selected and split into four groups: (1) a group of 9 male chicks which were individually raised in the company of a mature three months old female; (2) a group of 9 female chicks which were individually raised in the company of a mature three months old male; (3) a group of 9 male chicks, which were raised alone in individual cages and without visual contact with other members of their species; and (4) a group of 8 female chicks which were raised alone in individual cages and without visual contact with others of their species. Subjects were exposed to these conditions for a period of three months. Later, each one of the animals underwent a mating preference test where the time that an animal spent observing a potential partner (the partner the chick had been raised with and a different partner) was measured during a 10minutes trial for10 days. Results show that 50 percent of the18 chicks that formed the groups of males and females raised in a pair fashion, presented significant differences in mating preferences (23 percent in favor of the breeding partner and 27 percent in favor of a different partner). But in the group of 17 chicks that were placed in the condition of individualized breeding, only 12 percent of the male chicks showed significant differences in their preference for a specific partner. When comparing the various rearing conditions by means of an ANOVA, significant differences were obtained between them: F (7, 663) = 2,072, P <0, 05. The results of this experiment suggest that rearing conditions have a differential effect on males and females in terms of mating preferences and seem to have a greater impact on females.

Vanishing female foetuses and its consequences in India.

The article deals with the declining sex ratio, reasons for it and the resulting consequences. Authors have concluded that not only the strict enforcement of PNDT act but also realisation of the value of the daughters by their own families is the need of the hour.

Selección del sexo: algunas reflexiones desde la ética / Sex selection: Some reflections based on ethics

Las iniquidades y diferencias de género latentes en muchas sociedades, han potenciado la preferencia de los padres por tener descendencias de uno u otro sexo. Tal es el caso, que desde tiempos remotos la selección del sexo de los hijos se ha convertido en una práctica regular, pasando desde el infanticidio, hasta la propia selección de gametos masculinos; donde –indudablemente– el desarrollo tecnológico ha tenido un papel protagónico en dicha evolución. Lo cierto es, que como mismo las personas tienen derecho a escoger su descendencia, de igual manera no existen razones que sustenten la discriminación de las mujeres frente a los varones, por la razón que fuere. En este artículo pretendemos llamar la atención y reflexionar sobre la selección del sexo y el papel de la tecnología en este evento, desde una mirada ética y social