The influence of eutrophication on sexual selection in sticklebacks

Jordens ekologiska system undergår för tillfället stora förändringar pga. människans aktiviteter. Ett växande antal studier visar att dessa förändringar påverkar naturliga och sexuella urvalet och därmed evolutiva processer. Målet med detta arbete var att undersöka effekterna av omgivningsförändringar på sexuella urvalet genom att använda den ökade övergödningen inom storpiggen Gasterosteus aculeatus lekområden som modell system. Sexuella urvalet är en viktig evolutiv kraft med följder på populations- och artnivå (Kapitel 1). Avhandlingens olika delar fokuserar på övergödningens effekter på upptäckandet av partners, användningen av visuella- och doftsignaler i partnersval, och fördelningen av parningsframgången mellan bobyggande hanar. I Kapitel II och III simuleras hur grumlighet orsakad av fytoplankton påverkar hastigheten med vilken potentiella partners påträffas, genom effekter på synligheten. Resultaten visar att normala algblomningar i Östersjön har en måttlig effekt på finnandet av potentiella partners. Detta tyder på att algblomningarna troligen inte kommer att minska på selektiva parningen pga. ökade sökkostnader. I Kapitel IV visas att storspiggen ändrar relativa användningen av olika signaler när vattnets grumlighet ökar; visuella signaler minskar i betydelse medan doftsignaler ökar i betydelse. Samtidigt underlättas användandet av doftsignaler av ändringar i vattnets kemiska sammansättning då fotosyntesen intensifieras (Kapitel V). Lek i övergödda vatten kan ändå vara kostsamt både på individ- och populationsnivån, då parasiterade hanar, som troligen är dåligt genetiskt anpassade till sin miljö, lyckas få mer ägg i sina bon än friskare hanar som troligen är av högre genetisk kvalitet (Kapitel VI). Övergödningen påverkar således partnersval och konkurrensen om partners genom att påverka upptäckandet av potentiella partners, evalueringen av partners och fördelningen av partners inom lekområdena. De följder detta kan ha för evolutionen av sexuellt selekterad egenskaper och för populationers dynamik och livskraft är dock oklara. Avhandlingen visar på svårigheten att förutse följderna av omgivningsförändringar för sexuella urvalet och effekterna på individ och populationsnivå.

Studies of the age, growth, sexual maturity and spawning of populations of anchoveta (Cetengraulis mysticetus) of the coast of the Eastern Tropical Pacific Ocean

ENGLISH: Three hundred and twenty-six collections of anchoveta (Cetengraulis mysticetus), an important tuna bait species, taken between April 1951 and April 1960 from seven major baiting areas in the Eastern Tropical Pacific Ocean (Almejas Bay, Guaymas, Ahome Point, Banderas Bay, Gulf of Fonseca, coast of Colombia and Ecuador-Peru) are the basis of this study of age, growth, sexual maturity and spawning. The study of the temporal progression of modal size groups from plots of monthly length-frequency distributions provided estimates of age and rate of growth. The study of sexual maturity and time of spawning was based on gross examination of ovaries, and application of the gonad index. SPANISH: Trescientas veintiseis recolecciones de anchovetas (Cetengraulis mysticetus), una importante especie de carnada para la pesca del atún, cogidas entre abril de 1951 y abril de 1960 en siete de las mayores áreas de pesca de peces de carnada en el Océano Pacífico Oriental Tropical (Bahía de Almejas, Guaymas, Punta Ahome, Bahía Banderas, Golfo de Fonseca, y las costas de Colombia y de Ecuador- Perú), sirven de base a este estudio de la edad, crecimiento, madurez sexual y desove de dicha especie. El estudio de la progresión temporal de los grupos de tamaños modales según los gráficos de las distribuciones de la frecuencia de las longitudes proporcionó estimaciones de la edad y de la tasa de crecimiento. La investigación de la madurez sexual y la época de desove se basó en el examen macroscópico de los ovarios y en la aplicación del índice de gónadas.

A study of the age, growth, sexual maturity, and spawning of the anchoveta, Cetengraulis mysticetus, in the Gulf of Panama

ENGLISH: Crew members of tuna clippers and Commission personnel are collecting specimens of anchovetas (Cetengraulis mysticetus) for studies of the biology of this important tuna-bait species. More than 27,000 fish from 231 collections captured in the Gulf of Panama between June 1951 and January 1956 are the basis of this study of the age, growth, sexual maturity, and spawning season of this species in that area. Estimates of age and rate of growth were made by studying the temporal progression of modal size groups from monthly length frequency distributions. Sexual development and time of spawning were determined from gross examination of ovaries and measurements of ovarian eggs. SPANISH: Con el fin de estudiar la biología de la anchoveta (Cetengraulis mysticetus) los tripulantes de los barcos atuneros y el personal de la Comisión están recolectando especimenes de esta importante especie de carnada para capturar el atún. Mas de 27,000 ejemplares de las 231 colecciones hechas en el Golfo de Panamá entre junio de 1951 y enero de 1956, sirven de material al presente estudio sobre la edad, el crecimiento, la madurez sexual y las épocas de desove de esta especie en el área indicada. Las estimaciones de la edad y de la proporción del crecimiento fueron hechas a base del estudio de la progresión temporal de los grupos modales de tamaño en las distribuciones mensuales de frecuencias de longitud. El desarrollo sexual y el periodo de desove fueron determinados mediante el examen microscópico de los ovarios y las mediciones de los huevos ováricos. (PDF contains 79 pages.)

Age, size, and sexual maturity of channeled whelk (Busycotypus canaliculatus) in Buzzards Bay, Massachusetts

With the southern New England lobster fishery in distress, lobster fishermen have focused more effort toward harvesting channeled whelk (Busycotypus canaliculatus). However, minimal research has been conducted on the life history and growth rates of channeled whelk. Melongenid whelks generally grow slowly and mature late in life, a characteristic that can make them vulnerable to overfishing as fishing pressure increases. We sampled channeled whelk from Buzzards Bay, Massachusetts, in August 2010 and in July 2011, studied their gonad development by histology, and aged them by examining opercula. Males had a slower growth rate and a lower maximum size than females. Male whelk reached 50% maturity (SM50) at 115.5 mm shell length (SL) and at the age of 6.9 years. Female whelk reached SM50 at 155.3 mm SL and at the age of 8.6 years. With a minimum size limit of 69.9 mm (2.75 in) in shell width, males entered the fishery at 7.5 years, a few months after SM50, but females entered the fishery at 6.3 years, approximately 2 years before SM50. Increased fishing pressure combined with slow growth rates and the inability to reproduce before being harvested can easily constrain the long-term viability of the channeled whelk fishery in Massachusetts.

Sexual differences in vigilance of paired Ruddy Shelduck in winter

The effect of distance between members of pairs of the Ruddy Shelduck (Tadorna ferruginea) during vigilance behavior was studied during winter at Lijiang Lashihai Lake Reserve, southwest China. The distance between the paired birds while feeding was grouped into three categories: <1 m, 1-3 to and >3 m. Nearly 90% of the distances recorded between paired males and females were within three meters. The degree of vigilance increased with distance apart for females, but not for males. The scanning rate of males was significantly, higher than that of females at <1 m and at 1-3 m respectively, but no significant difference occurred when the distance between them was >3 m. These results are discussed in relation to mate competition and wintering strategy; it is suggested that staving close together is the optimal strategy for members of Ruddy Shelduck pairs.

Determination of sexual hormones in liquid cosmetics by polymer monolith microextraction coupled with high performance liquid chromatography

A method was presented for the determination of testosterone, methyltestosterone and progesterone in liquid cosmetics by coupling polymer monolith microextraction (PMME) to high performance liquid chromatography with UV detection. A poly (methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column was selected as the extraction medium, which showed high extraction capacity towards these compounds. To achieve optimum extraction performance, several parameters relating to PMME were investigated, including extraction flow rate and pH value, inorganic salt and organic phase concentration of the sample matrix. By simple dilution with phosphate solution and filtering, the sample solution then could be directly injected into the device for extraction. The limits of detection of testosterone, methyltestosterone and progesterone were calculated to be 2, 3, 2, 8 and 4.6 mu g/L. Good linearity was achieved in the range of 10 to 1000 mu g/L with a linear coefficient. r value above 0. 996. Excellent method reproducibility was found by intra- and inter-day precisions, yielding the relative standard deviations of < 7. 7 % and < 7. 5 %, respectively. Recovery for them in the real samples was between 83% and 119%.

The precocious Chinese mitten crab: Changes of gonad, survival rate, and life span in a freshwater lake

Changes of the gonad. survival rate, and life span of the precocious (i.e., sexually mature in their first October-November, at the age of 5 or 6 months) Chinese mitten crab (Eriocheir sinensis) were studied in a small, shallow, macrophytic, freshwater lake along the middle reaches of the Changjiang River, China. The gonosomatic index (GSI) reached peak during the next March when the female GSI was 12.32 +/- 1.75 SD% and the male GSI A as 4.24 +/- 0.19%. The sexual glands degraded from then on. In the first ten-day period of the following July, there was no complete ovum in the ovary. and the sperm became thin and lost adhesion. The population declined sharply from November to July, and the last one (a female) died in the middle of July, which indicated that the life span of the precocious crab was about 12 months (from larval hatching in June to death in July of next year). The survival curve might be expressed as Y = 1.09exp(-0.018x) (Y survival rate; x: days) for the precocious crabs stocked in experimental cages.

Workplace violence and intentions to quit: results from a survey of London nurses

Study Objective: Work-place violence, harassment and abuse is an increasing feature of nurses’ experience of work in many countries. There is some evidence that the experience of workplace violence affects levels of job satisfaction (Hesketh et al 2003) and career decisions (e.g. Mayer et al 1999, Fernandes et al 1999). This paper reports on verbal and physical abuse by patients, relatives and carers, as well as racial and sexual harassment in Acute Hospitals in London and investigates whether workplace violence affects nurses’ intentions to leave either their current job or the nursing profession, controlling for a number of other factors that are known to affect career decisions, such as workload, pay and own health. Method: A questionnaire designed by two of the authors (Reeves and West) to assess many different aspects of nurses work life was used in a postal survey of nurses grades A to I practising in twenty London acute trusts in 2002. A total of 6,160 clinical nurses were mailed the questionnaires and 2,880 returned completed questionnaires, resulting in an overall response rate of 47%, discounting undelivered questionnaires. Respondents worked in a wide variety of clinical settings but mainly in acute medical and surgical wards. In addition to descriptive statistics, results were analysed using logistic regression with robust standard errors: the appropriate test when the dependent variable is dichotomous and the individual respondents clustered within units (nurses working within hospitals are not statistically independent). Results: Our results show high levels of racial (%), sexual (%) and other, unspecified forms of harassment (%), as well as verbal and physical abuse (14% had been physically assaulted with 5% being assaulted more than once), over the previous 6 months. A very small number (1%) reported experiencing all three forms of harassment; 12% two forms and 29% one form. Only 45% of this sample intended to stay in nursing for at least 3 years; 40% were undecided and 15% intended to leave. Logistic regression estimates showed that reported levels of abuse and harassment had a significant impact on respondents’ career intentions, even in models that controlled for known factors affecting career decisions. About 70% of our respondents reported that they had had too little training in dealing with aggressive behaviour—or none at all—but there was no statistical relationship between lack of training and reported assaults. Conclusions: The international shortage of health care workers is due at least in part to low retention rates. It is crucial to investigate nurses’ experiences of work to identify the factors that shape their career decisions. Workplace violence is increasingly acknowledged as an international, service-wide, health care problem. This paper adds to the literature that shows that workplace violence has an impact on nurses’ career decisions. The implications for managers and policy makers are that strengthening systems of security and providing nurses with training in interpersonal relationships including dealing with aggressive patients could slow nurse turnover.

The energy costs of sexual dimorphism in mole-rats are morphological not behavioural.

Different reproductive strategies of males and females may lead to the evolution of differences in their energetic costs of reproduction, overall energetic requirements and physiological performances. Sexual dimorphism is often associated with costly behaviours (e.g. large males might have a competitive advantage in fighting, which is energetically expensive). However, few studies of mammals have directly compared the energy costs of reproductive activities between sexes. We compared the daily energy expenditure (DEE) and resting metabolic rate (RMR) of males and females of two species of mole-rat, Bathyergus janetta and Georychus capensis (the former is sexually dimorphic in body size and the latter is not) during a period of intense digging when males seek females. We hypothesized that large body size might be indicative of greater digging or fighting capabilities, and hence greater mass-independent DEE values in males of the sexually dimorphic species. In contrast to this prediction, although absolute values of DEE were greater in B. janetta males, mass-independent values were not. No differences were apparent between sexes in G. capensis. By comparison, although RMR values were greater in B. janetta than G. capensis, no differences were apparent between the sexes for either species. The energy cost of dimorphism is most likely to be the cost of maintenance of a large body size, and not the cost of behaviours performed when an individual is large.

Sexual offences against children: An exploration of attrition in the Northern Ireland criminal justice system

Objective: This paper uses data provided by the Police Service for Northern Ireland (PSNI) to compare the characteristics and outcomes of reported sexual offences involving child and adult victims and explore the factors associated with case outcomes.
Method: PSNI provided data on 8,789 sexual offences recorded between April 2001 and March 2006. Case outcomes were based on whether a case was recorded by police as having sufficient evidence to summons, charge, or caution an offender (detected). Where an offender was summonsed, charged, or cautioned, this is classified as detection with a formal sanction. A case can also be classified as "detected" without a formal sanction. The analysis focused on two key categories of detection without formal sanction: cases in which the police deem there to be sufficient evidence to charge an offender but took no further action because the victim did not wish to prosecute, or because the police or the Public Prosecution Service (PPS) decided that no useful purpose would be served by proceeding.
Results: The analysis confirmed that the characteristics of recorded sexual offences involving adult and child victims vary significantly according to gender, offence type, the timing of report and victim-offender relationship. Almost half of child sex abuse cases are not detected by police and a quarter do not proceed through the criminal justice system because either the victim declines to prosecute or the Police/PPS decide not to proceed. Only one in five child cases involved detection with a formal sanction. Child groups with lower detection with formal sanction rates included children under 5, teenagers, those who do not report when the abuse occurs but disclose at a later date; and those who experience abuse at the hands of peers and adults known to them but not related. The analysis also highlighted variation in formal sanction rates depending on where the offence was reported.
Conclusions: Consideration needs to be given to improving the criminal justice response to specific child groups as well as monitoring detection rates in different police areas in order to address potential practice variation.
Practice implications: Consideration needs to be given to improving the professional response in relation to with particularly lower detection with formal sanction rates. There is also a need to monitor case outcomes to ensure that child victims in different areas receive a similar service.

Evaluation of a partnership between primary and secondary care providing an accessible Level 1 sexual health service in the community

Comprehensive testing for asymptomatic sexually transmitted infections in Northern Ireland has traditionally been provided by genitourinary medicine clinics. As patient demand for services has increased while budgets have remained limited, there has been increasing difficulty in accommodating this demand. In May 2013, the newly commissioned specialist Sexual Health service in the South Eastern Trust sought to pilot a new model of care working alongside a GP partnership of 12 practices. A training programme to enable GPs and practice nurses to deliver Level 1 sexual health care to heterosexual patients aged >16 years, in accordance with the standards of BASHH, was developed. A comprehensive care pathway and dedicated community health advisor supported this new model with close liaison between primary and secondary care. Testing for Chlamydia, gonorrhoea, HIV and syphilis was offered. The aims of the pilot were achieved, namely to provide accessible, cost-effective sexual health care within a framework of robust clinical governance. Furthermore, it uncovered a high positivity rate for Chlamydia, especially in young men attending their general practice, and demonstrated a high level of patient satisfaction. Moreover the capacity of secondary care to deliver Levels 2 and 3 services was increased.

Howard Barker’s ‘monstrous assaults’: eroticism, death and the antique text

Howard Barker is a writer who has made several notable excursions into what he calls ‘the charnel house…of European drama.’ David Ian Rabey has observed that a compelling property of these classical works lies in what he calls ‘the incompleteness of [their] prescriptions’, and Barker’s Women Beware Women (1986), Seven Lears (1990) and Gertrude: The Cry (2002), are in turn based around the gaps and interstices found in Thomas Middleton’s Women Beware Women (c1627), Shakespeare’s King Lear (c1604) and Hamlet (c1601) respectively. This extends from representing the missing queen from King Lear, who Barker observes, ‘is barely quoted even in the depths of rage or pity’, to his new ending for Middleton’s Jacobean tragedy and the erotic revivification of Hamlet’s mother. This paper will argue that each modern reappropriation accentuates a hidden but powerful feature in these Elizabethan and Jacobean plays – namely their clash between obsessive desire, sexual transgression and death against the imposed restitution of a prescribed morality. This contradiction acts as the basis for Barker’s own explorations of eroticism, death and tragedy. The paper will also discuss Barker’s project for these ‘antique texts’, one that goes beyond what he derisively calls ‘relevance’, but attempts instead to recover ‘smothered genius’, whereby the transgressive is ‘concealed within structures that lend an artificial elegance.’ Together with Barker’s own rediscovery of tragedy, the paper will assert that these rewritings of Elizabethan and Jacobean drama expose their hidden, yet unsettling and provocative ideologies concerning the relationship between political corruption / justice through the power of sexuality (notably through the allure and danger of the mature woman), and an erotics of death that produces tragedy for the contemporary age.

Effects of competition on sexual and clonal reproduction of a tunicate: the importance of competitor identity

Individual fitness and the structure of marine communities are strongly affected by spatial competition. Among the most common space holders are the colonial ascidians, which have the ability to monopolize large areas of hard substrate, overgrowing most other competitors. The effects of competition on colony growth and on gonad production of the ascidian Didemnum perlucidum were studied in southeastern Brazil by experimentally removing surrounding competitors. Colonies of D, perlucidum competing for space exhibited a growth rate 9 times less than that of colonies that were competitor free. Among the colonies subject to competition, growth rates were unrelated to the percentage of colony border that was free of competitors. However, the identity of the competitor was important in the outcome of border contacts. At the beginning of the experiment, most border encounters of D. perlucidum were with solitary organisms, which in most cases were overgrown. These were progressively replaced by colonial ascidians and bryozoans, resulting mostly in stand-off interactions. Besides reducing asexual growth, spatial competition also affected female gonad production. Colonies free of competitors had a significantly higher proportion of zooids with ovaries. Thus, our findings show that spatial competition reduces both ascidian colony size and gonad production.

A quasispecies approach to the evolution of sexual replication in unicellular organisms

This study develops a simplified model describing the evolutionary dynamics of a population composed of obligate sexually and asexually reproducing, unicellular organisms. The model assumes that the organisms have diploid genomes consisting of two chromosomes, and that the sexual organisms replicate by first dividing into haploid intermediates, which then combine with other haploids, followed by the normal mitotic division of the resulting diploid into two new daughter cells. We assume that the fitness landscape of the diploids is analogous to the single-fitness-peak approach often used in single-chromosome studies. That is, we assume a master chromosome that becomes defective with just one point mutation. The diploid fitness then depends on whether the genome has zero, one, or two copies of the master chromosome. We also assume that only pairs of haploids with a master chromosome are capable of combining so as to produce sexual diploid cells, and that this process is described by second-order kinetics. We find that, in a range of intermediate values of the replication fidelity, sexually reproducing cells can outcompete asexual ones, provided the initial abundance of sexual cells is above some threshold value. The range of values where sexual reproduction outcompetes asexual reproduction increases with decreasing replication rate and increasing population density. We critically evaluate a common approach, based on a group selection perspective, used to study the competition between populations and show its flaws in addressing the evolution of sex problem.

Blaming the target of sexual harrassment: impact of gender role, sexist attitudes and work role.

This study was conducted to examine factors associated with blaming the target of sexual harassment. Participants' experiences of sexual harassment, sexist attitudes, gender, gender role identity, age, worker or student status, and belief in a just world were included as independent variables. Level of blame was evaluated using a series of 12 vignettes that manipulated the gender of the target and harasser as well as the seriousness of the harassing behavior. The sample comprised 30 female and 32 male workers from two workplaces, whose ages ranged from 18 to 65 (M = 35) years, and 102 female and 18 male university students whose ages ranged from 17 to 40 (M = 21) years. Approximately 70% of the sample were from Anglo Australian background, and 30% from European, Middle Eastern or Asian background. Females experienced more sexual harassment than males did, although the male rate was higher than expected. Although the majority of subjects attributed little blame to the target, males blamed the target of sexual harassment more than females did, and workers blamed the target of harassment more than university students did. Worker status, sexist attitudes, and gender significantly predicted blame for the total sample. Gender-typing increased the blame of the target by males but not by females. Attribution of blame was significantly influenced by worker versus student status, which supports the social psychological perspective that gender-related behavior is context dependent. The findings from this study suggest that organisational culture and environment influence respondents' attitudes to sexually harassing behavior.