Who has a vasectomy reversal?

A comparatively small proportion of sterilized men request vasectomy reversals, and the size of the proportion (which UK estimates place between 1% and 1.5%) depends on awareness of the availability of reversal. In this study, the characteristics of 200 cases of vasectomy reversal (the 1st 200 such operations performed in the UK) were analyzed. All 200 had been completed by 1981, the mean time from vasectomy to reversal being 4.8 years. The time figure varied according to the reason for requesting reversal, and was particularly short when the operation had been performed at the time of the partner's pregnancy. General practitioners and friends were particularly important sources of referral. 30% of the men were with the same partner and 70% a new partner. Vasectomy reversal cases tended to be younger than vasectomy patients as a whole but did not differ significantly in social class. Most requesting reversal wanted to have another child. Scattered cases requested the reversal after a partner's pregnancy termination. 12 men requested it for psychosexual reasons. In this series of reversals, spermatozoa were present in the ejaculate throughout the 20-week follow-up time in 80% of the men; the pregnancy rate was 44%. The study demonstrates the need for counselling prior to a vasectomy, especially with regard to the posibility of marital breakdown or pregnancy termination.     

Identifying predators clarifies predictors of nest success in a temperate passerine

1.  Nest predation negatively affects most avian populations. Studies of nest predation usually group all nest failures when attempting to determine temporal and parental activities, habitat or landscape predictors of success. Often these studies find few significant predictors and interpret patterns as essentially random.
2.  Relatively little is known about the importance of individual predator species or groups on observed patterns of nest success, and how the ecology of these predators may influence patterns of success and failure.
3.  In 2006 and 2007, time-lapse, infrared video systems were deployed at nests of Swainson's warblers ( Limnothlypis swainsonii Audubon) in east-central Arkansas to identify dominant nest predators and determine whether factors predicting predation differed among these predators.
4.  Analysis of pooled data yielded few predictors of predation risk, whereas separate analyses for the three major predator groups revealed clear, but often conflicting, patterns.
5.  Predation by ratsnakes ( Elaphe obsoleta ) and raptors was more common during the nestling period, whereas predation by brown-headed cowbirds ( Molothrus ater ) occurred more during incubation. Additionally, the risk of predation by raptors and cowbirds decreased throughout the breeding season, whereas ratsnake predation risk increased.
6.  Contrary to expectations, predation by ratsnakes and cowbirds was more common far from edges, whereas raptor predation was more common close to agricultural edges.
7.  Collectively, our results suggest that associating specific predators with the nests they prey on is necessary to understand underlying mechanisms.     

Display behaviour and dewlap colour as predictors of contest success in brown anoles

Many animals display visual signals in male contests for access to females and territories. These visual signals can be multimodal and stimulate different aspects of a signal receiver's visual system. Over two summers, we tested whether aspects of behaviour and dewlap colour might function as signals that predict contest success when males compete for access to either mates or territories in male brown anole lizards. We found that behaviour (PC1, a correlated composite of head‐bob, push‐up, and dewlap extension frequency) and an aspect of dewlap colour (PC3, the relative amounts of ultraviolet, yellow, orange, and red of the dewlap margin) were retained in the minimum adequate model predicting contest success across years and social contexts. Winners showed significant differences in behaviour (winners displayed more) and dewlap margin PC3 (winners had lower PC3 scores) compared to contest losers. These findings suggest that display behaviour and dewlap colour might serve as signals indicating a male's ability to win contests for access to females and territories. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 646–655.     

Behavioral predictors of pairing success in rhesus macaques (Macaca mulatta)

Pair housing is one of the most important components of behavioral management for caged macaques; however, it can result in aggression and injury if partners are incompatible. Knowing when to proceed and when to stop social introductions can be challenging, and can have consequences for the partners. We examined whether behavior early in social introductions predicted success (i.e., partners remained cohoused with full contact for at least 28 days) in 724 female–female and 477 male–male rhesus macaque pairs. We took cage side one–zero focal observations on pairs during the first 2 days of full contact, recording social and aggressive behaviors. The majority of pairs (79.6% of female and 83.0% of male) were successful. The most common behaviors exhibited by pairs during these observations were maintaining proximity, tandem threats, and anxiety. Mounting was also relatively common in male pairs. Grooming and close social contact (e.g., touching) were not common in our study. Several behaviors observed on Day 1 significantly predicted pairing success. For females, these included proximity, tandem threat, rump present, mount, and groom. Day 1 predictors of success for male pairs included proximity, tandem threat, rump present, mount, and social contact. Fewer behaviors predicted success on Day 2. Maintaining proximity on Day 2 predicted success for both sexes, but tandem threat predicted success only for females. Behaviors that predicted incompatibility for females on Day 1 included displace, grimace, threat, bite, and other aggressive contacts. Day 1 predictors of separation for male pairs were displaced, grimace, and abnormal behavior. The only Day 2 behavior that correlated with incompatibility was grimace, which was predictive for males. Interestingly, aggression did not predict incompatibility for male pairs. Identifying behaviors exhibited by monkeys early in the pair introduction that are predictive of long-term compatibility can shape pairing decisions, reducing later stress and potential injury.     

Genomic pedigree reconstruction identifies predictors of mating and reproductive success in an invasive vertebrate

The persistence of an invasive species is influenced by its reproductive ecology, and a successful control program must operate on this premise. However, the reproductive ecology of invasive species may be enigmatic due to factors that also limit their management, such as cryptic coloration and behavior. We explored the mating and reproductive ecology of the invasive Brown Treesnake (BTS: Boiga irregularis) by reconstructing a multigenerational genomic pedigree based on 654 single nucleotide polymorphisms for a geographically closed population established in 2004 on Guam (N = 426). The pedigree allowed annual estimates of individual mating and reproductive success to be inferred for snakes in the study population over a 14‐year period. We then employed generalized linear mixed models to gauge how well phenotypic and genomic data could predict sex‐specific annual mating and reproductive success. Average snout–vent length (SVL), average body condition index (BCI), and trappability were significantly related to annual mating success for males, with average SVL also related to annual mating success for females. Male and female annual reproductive success was positively affected by SVL, BCI, and trappability. Surprisingly, the degree to which individuals were inbred had no effect on annual mating or reproductive success. When juxtaposed with current control methods, these results indicate that baited traps, a common interdiction tool, may target fecund BTS in some regards but not others. Our study emphasizes the importance of reproductive ecology as a focus for improving BTS control and promotes genomic pedigree reconstruction for such an endeavor in this invasive species and others.     

Field estimates of reproductive success in a model insect: behavioural surrogates are poor predictors of fitness

Understanding, and therefore measuring, factors that determine fitness is a central problem in evolutionary biology. We studied a natural population of Coenagrion puella (Odonata: Zygoptera) over two entire breeding seasons, with over a thousand individuals uniquely marked and genotyped, and all mating events at the rendezvous site recorded. Using a parentage analysis, fitness of individuals in the first generation was quantified as the numbers of offspring that survived to maturity. Although mating behaviour can be predicted by environmental and demographical variables, the numbers of mature offspring produced (fitness) cannot, and crucially, are poorly correlated with behavioural observations of mating. While fitness of both sexes was positively related to mating behaviour and to female's ectoparasite burden, these behavioural observations explained little more variance in offspring production than environmental and demographical variables. Thus, we demonstrate that behavioural measures of reproductive success are not necessarily reliable estimates of fitness in natural populations.     

Ways of coping as predictors of satisfaction with curriculum and academic success in medical school

The purpose of the present study was to determine the coping strategies of medical students and to investigate the effects of coping strategies on student satisfaction and academic achievement with different instruction methods. A total of 152 medical students was followed throughout the first 2 yr of medical education between 2008 and 2010. Students completed a sociodemographic questionnaire and revised form of the Ways of Coping questionnaire both at the beginning of the first year and at the end of the second year. These forms provided data about the characteristics and main coping strategies (problem focused or emotion focused) of the students and revealed the change over time. At the end of the second year, participants also completed a satisfaction questionnaire asking their satisfaction with lectures, problem-based learning, and practicals. The authors used block, problem-based learning, and practical exam scores of the students attained in the past 2 yr as academic achievement indicators. No sociodemographic variable was related to coping strategy. The majority of students (80.9%) adopted problem-focused coping. A shift occurred in the main coping strategies of some students in both sides. Problem-focused coping scores decreased over time. Problem-focused coping positively correlated with satisfaction with practicals and practical exam scores, whereas emotion-focused coping showed the same correlation negatively. The main coping strategy also predicted satisfaction and exam success in practicals. In conclusion, a main coping strategy may be helpful to predict student satisfaction and academic achievement with some student-centered instruction methods. Determining undesired coping strategies may provide an opportunity for intervention to prevent relevant dissatisfaction and failure.     

Mating systems and predictors of relative reproductive success in a Cutthroat Trout subspecies of conservation concern

Mating systems and patterns of reproductive success in fishes play an important role in ecology and evolution. While information on the reproductive ecology of many anadromous salmonids (Oncorhynchus spp.) is well detailed, there is less information for nonanadromous species including the Yellowstone Cutthroat Trout (O. clarkii bouvieri), a subspecies of recreational angling importance and conservation concern. Using data from a parentage‐based tagging study, we described the genetic mating system of a migratory population of Yellowstone Cutthroat Trout, tested for evidence of sexual selection, and identified predictors of mating and reproductive success. The standardized variance in mating success (i.e., opportunity for sexual selection) was significantly greater for males relative to females, and while the relationship between mating success and reproductive success (i.e., Bateman gradient) was significantly positive for both sexes, a greater proportion of reproductive success was explained by mating success for males (r ² = 0.80) than females (r ² = 0.59). Overall, the population displayed a polygynandrous mating system, whereby both sexes experienced variation in mating success due to multiple mating, and sexual selection was variable across sexes. Tests for evidence of sexual selection indicated the interaction between mating success and total length best‐predicted relative reproductive success. We failed to detect a signal of inbreeding avoidance among breeding adults, but the group of parents that produced progeny were on average slightly less related than adults that did not produce progeny. Lastly, we estimated the effective number of breeders (N _b) and effective population size (N _e) and identified while N _b was lower than N _e, both are sufficiently high to suggest Yellowstone Cutthroat Trout in Burns Creek represent a genetically stable and diverse population.     

Primates: Their use in research on vasectomy

Studies based on experimental vasectomies clearly reveal marked species differences in response to vasectomy. In rats, vasectomy invariably results in granuloma formation at the surgical site. In rabbits, immune-complex orchitis develops. Allergic orchitis may also develop in guinea pigs, and the morphological lesions can be adoptively transferred. My co-workers and I have been able to study systematically, biochemically, hormonally, pathologically, and immunologically, primates vasectomized up to 14 years earlier and to compare them with age-matched controls. We have monitored antibody levels in vasectomized rhesus and cynomolgus macaques by sperm-agglutination, sperm-immobilization, and indirect immunofluorescence techniques. Antibodies develop in almost every monkey, in some as early as 10 days after vasectomy. About 50% retain such circulating antisperm antibodies. In men, antibody development is less rapid, and about half of vasectomized men reveal detectable levels. Testicular histopathological studies have revealed detectable levels. Testicular histopathological studies have revealed orchitis, aspermatogenesis, or both, resembling allergic orchitis in most of the vasectomized monkeys and in about one-fourth of the controls. Limited studies of human material reveal some testicular changes. Epididymitis and epididymal granuloma occur exclusively in the vasectomized animals. Use of immunofluorescence has revealed significantly more granular deposits of IgA, IgG, and/or C3 in the basal lamina of the ductus efferens and the caput epididymidis of the vasectomized monkeys. Similar studies on human material have not been done. Both cynomolgus and rhesus macaques have proved to be excellent models for research in atherosclerosis and so have been used to determine whether constant sperm antigen leakage causes immune-complex formation that might result in arteritis and atherosclerosis. Evaluation of the cardiovascular systems from such animals has revealed that vasectomized monkeys have more frequent, more extensive, and more severe arteriosclerosis than age-matched controls. Epidemiological studies are currently under way to determine whether such an effect also occurs in men after vasectomy.     

Introduction pathway and climate trump ecology and life history as predictors of establishment success in alien frogs and toads

A major goal for ecology and evolution is to understand how abiotic and biotic factors shape patterns of biological diversity. Here, we show that variation in establishment success of nonnative frogs and toads is primarily explained by variation in introduction pathways and climatic similarity between the native range and introduction locality, with minor contributions from phylogeny, species ecology, and life history. This finding contrasts with recent evidence that particular species characteristics promote evolutionary range expansion and reduce the probability of extinction in native populations of amphibians, emphasizing how different mechanisms may shape species distributions on different temporal and spatial scales. We suggest that contemporary changes in the distribution of amphibians will be primarily determined by human-mediated extinctions and movement of species within climatic envelopes, and less by species-typical traits.     

Psychological aspects of vasectomy in Malaysia

246 men, aged 21-59, living on rubber estates on the outskirts of Kuala Lumpur, Malaysia, were interviewed 1-4 years after vasectomy in a study conducted by the International Institute for the Study of Human Reproduction of Columbia University and the National Family Planning Board of Malaysia. Most of the men were of Indian origin; 223 were Hindus. The incidence and nature of psychological and medical complications were investigated, but this article treats only the psychological effects. The basic interviews consisted of verbal questionnaires; care was taken to avoid drawing attention to the researchers' interest in psychosexual effects. Men claiming regrets, fears, ill effects, and problems in married life after the operation were 9%, 11%, 54%, and 4%, respectively, of the total population. 11.8% of the men claimed to have a loss of libido. The percentages of men expressing regrets and fears decreased with increasing age, parity, and pregnancies of wife; age here is probably the overriding variable. When the vasectomy decision was joint, rather than the individual decision of either husband or wife, regrets and fears were significantly less (p.05 for both regrets and fears). No couple in the sample was without at least 1 living son, this suggesting that men without heirs will refrain from vasectomy in Malaysia. Higher proportions of men who had lost children reported anxiety. Men reporting psychosexual complications were reinterviewed in depth. In these depth interviews a variety of fantasies associated with the operation was revealed.     

The effects of vasectomy on health

The study of possible adverse effects of vasectomy have been mainly focussed on hormonal balance, spermatogenesis, the induction. of auto-immune reactions and cardiovascular changes including the non-fatal myocardial infarction. The review of literature, including our own work on the immunological sequelae of vasectomy, indicates that there is no health hazard following vasectomy. The presence of antibodies to spermatozoa in some individuals, however, may effect future fertility, if reversal is requested.     

Screening the vasectomy applicant: reassessing the importance of eligibility criteria

All family planning clinics and a random sample of private physicians throughout the US were surveyed in 1972 and 1984 by questionnaire to discern the importance of eligibility criteria in the process of screening vasectomy applicants. In general, age and parity expectations have become significantly more flexible and liberal over a decade of waning vasectomy popularity. Physicians in the 2 surveys tend to ascribe greater importance than clinical staff to marital status, religious conflicts, marital stability, and spousal consent. Both groups currently place less emphasis on eligibility criteria than they did 12 years ago. A common measure has been age of the applicant; in 1972 nearly 20% of clinics expected applicants to be between 27-34 years old, but in 1984 this expectation had declined to 5% of clinic services. In the 1984 survey significantly more clinics than physicians reported acceptance of younger men. More clinic respondents (27% compared to 13%) noted that age-parity criteria were not specifically appropriate to or compatible with overall eligibility criteria; unsolicited remarks indicate that eligibility decisions rested more on other criteria than age or parity.     

A review of epidemiologic studies of vasectomy

A number of epidemiologic studies of vasectomy have been published in recent years. These studies have been methodologically diverse and have involved several groups of investigators in several countries. The studies are consistent in finding no long-term effects of vasectomy on the risk of cardiovascular disease, cancer, impotence, prostatic disease, or disease related to immune function and dysfunction. Continued follow-up of vasectomized men to evaluate further the possibility of adverse effects of vasectomy is recommended. At this time, epidemiologic studies of vasectomy in man are strongly reassuring. Vasectomy decreases prostatic secretory function. In a study conducted by Sidney, no association was found between vasectomy and benign prostatic hypertrophy or prostatic cancer. Massey et al. found that the incidence of impotence was 1.9/1000 man-years of observation in men with vasectomy and 1.7/1000 man-years in non-vasectomized men, a difference that was not statistically significant. 3 studies examining the risk of malignant and nonmalignant neoplasms in vasectomized and nonvasectomized men revealed that vasectomy was not associated with an increased risk of malignant or nonmalignant neoplasms.