The Effect of Female Quality on Male Ejaculatory Expenditure and Reproductive Success in a Praying Mantid

PubMed Central

Jayaweera, Anuradhi; Barry, Katherine L.

2015-01-01

Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality) or poor condition with few eggs (i.e. low quality). Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario. PMID:25970459

Mating Disruption of Planococcus ficus (Hemiptera: Pseudococcidae) in Vineyards Using Reservoir Pheromone Dispensers

PubMed Central

Cocco, Arturo; Lentini, Andrea; Serra, Giuseppe

2014-01-01

Abstract Mating disruption field experiments to control the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), were carried out in 2008 and 2009 in two commercial vineyards in Sardinia (Italy). The effectiveness of mating disruption was evaluated by testing reservoir dispensers loaded with 100 mg (62.5 g/ha) and 150 mg (93.8 g/ha) of the sex pheromone in 2008 and 2009, respectively. The number of males captured in pheromone traps, the P. ficus population density and age structure, the parasitism rate, the percentage of ovipositing females, and the crop damage were compared between disrupted and untreated plots. In both field trials, the number of males captured in mating disruption plots was significantly reduced by 86% and 95%, respectively. Mating disruption at the initial dose of 62.5 g/ha of active ingredient gave inconclusive results, whereas the dose of 93.8 g/ha significantly lowered the mealybug density and modified the age structure, which showed a lower percentage of ovipositing females and a higher proportion of preovipositing females. Mating disruption did not affect negatively the parasitism rate, which was higher in the disrupted than in the control plots (>1.5-fold). Crop damage at harvest was very low in both field trials and did not differ between treatments. Mating disruption was effective in wide plots protected with dispensers loaded with 150 mg of the sex pheromone, showing its potential to be included in the overall integrated control programs in Mediterranean wine-growing regions. PMID:25347835

Addressing the Lack of Measurement Invariance for the Measure of Acceptance of the Theory of Evolution

NASA Astrophysics Data System (ADS)

Wagler, Amy; Wagler, Ron

2013-09-01

The Measure of Acceptance of the Theory of Evolution (MATE) was constructed to be a single-factor instrument that assesses an individual's overall acceptance of evolutionary theory. The MATE was validated and the scores resulting from the MATE were found to be reliable for the population of inservice high school biology teachers. However, many studies have utilized the MATE for different populations, such as university students enrolled in a biology or genetics course, high school students, and preservice teachers. This is problematic because the dimensionality and reliability of the MATE may not be consistent across populations. It is not uncommon in science education research to find examples where scales are applied to novel populations without proper assessment of the validity and reliability. In order to illustrate this issue, a case study is presented where the dimensionality of the MATE is evaluated for a population of non-science major preservice elementary teachers. With this objective in mind, factor analytic and item response models are fit to the observed data to provide evidence for or against a one-dimensional latent structure and to detect which items do not conform to the theoretical construct for this population. The results of this study call into question any findings and conclusions made using the MATE for a Hispanic population of preservice teachers and point out the error of assuming invariance across substantively different populations.

PARTIAL REPRODUCTIVE ISOLATION OF A RECENTLY DERIVED RESIDENT-FRESHWATER POPULATION OF THREESPINE STICKLEBACK (GASTEROSTEUS ACULEATUS) FROM ITS PUTATIVE ANADROMOUS ANCESTOR

PubMed Central

Furin, Christoff G.; Von Hippel, Frank A.; Bell, Michael A.

2012-01-01

We used no-choice mating trials to test for assortative mating between a newly derived resident-freshwater population (8 – 22 generations since founding) of threespine stickleback (Gasterosteus aculeatus) in Loberg Lake, Alaska and its putative anadromous ancestor as well as a morphologically convergent but distantly related resident-freshwater population. Partial reproductive isolation has evolved between the Loberg Lake population and its ancestor within a remarkably short time period. However, Loberg stickleback readily mate with morphologically similar, but distantly related resident-freshwater stickleback. Partial pre-mating isolation is asymmetrical; anadromous females and smaller, resident-freshwater males from Loberg Lake readily mate, but the anadromous males and smaller Loberg females do not. Our results indicate that pre-mating isolation can begin to evolve in allopatry within a few generations after isolation as a correlated effect of evolution of reduced body size. PMID:23025615

Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus).

PubMed

Wright, Daniel Shane; Pierotti, Michele E R; Rundle, Howard D; McKinnon, Jeffrey S

2015-01-01

Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.

Conspicuous Female Ornamentation and Tests of Male Mate Preference in Threespine Sticklebacks (Gasterosteus aculeatus)

PubMed Central

Wright, Daniel Shane; Pierotti, Michele E. R.; Rundle, Howard D.; McKinnon, Jeffrey S.

2015-01-01

Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks. PMID:25806520

Managing the rate of increase in average co-ancestry in a rolling front tree breeding strategy.

PubMed

Kerr, R J; McRae, T A; Dutkowski, G W; Tier, B

2015-04-01

In breeding forest trees, as for livestock, the goal is to capture as much genetic gain as possible for the breeding objective, while limiting long- and short-term inbreeding. The Southern Tree Breeding Association (STBA) is responsible for breeding Australia's two main commercial forest tree species and has adopted algorithms and methods commonly used in animal breeding to achieve this balance. Discrete generation breeding is the norm for most tree breeding programmes. However, the STBA uses an overlapping generation strategy, with a new stream of breeding initiated each year. A feature of the species bred by the STBA (Pinus radiata and Eucalyptus globulus) is the long interval (up to 7 years) between when an individual is mated and when its progeny is first assessed in field trials and performance data included in the national performance database. Mate selection methods must therefore recognize the large pool of unmeasured progeny generated over recent years of crossing. In addition, the substantial delay between when an individual is selected in a field trial and when it is clonally copied into a mating facility (breeding arboretum) means that selection and mating must occur as a two-step process. In this article, we describe modifications to preselection and mate selection algorithms that allow unmeasured progeny (juveniles) to be recognized. We also demonstrate that the addition of hypothetical new progeny to the juvenile pool is important for computing the increase in average co-ancestry in the population. Methods outlined in this article may have relevance to animal breeding programmes where between mating and progeny measurement, new rounds of mating are initiated. © 2015 Blackwell Verlag GmbH.

Using computerised decision support to improve compliance of cancer multidisciplinary meetings with evidence-based guidance

PubMed Central

Patkar, Vivek; Acosta, Dionisio; Davidson, Tim; Jones, Alison; Fox, John

2012-01-01

Objectives The cancer multidisciplinary team (MDT) meeting (MDM) is regarded as the best platform to reduce unwarranted variation in cancer care through evidence-compliant management. However, MDMs are often overburdened with many different agendas and hence struggle to achieve their full potential. The authors developed an interactive clinical decision support system called MATE (Multidisciplinary meeting Assistant and Treatment sElector) to facilitate explicit evidence-based decision making in the breast MDMs. Design Audit study and a questionnaire survey. Setting Breast multidisciplinary unit in a large secondary care teaching hospital. Participants All members of the breast MDT at the Royal Free Hospital, London, were consulted during the process of MATE development and implementation. The emphasis was on acknowledging the clinical needs and practical constraints of the MDT and fitting the system around the team's workflow rather than the other way around. Delegates, who attended MATE workshop at the England Cancer Networks' Development Programme conference in March 2010, participated in the questionnaire survey. Outcome measures The measures included evidence-compliant care, measured by adherence to clinical practice guidelines, and promoting research, measured by the patient identification rate for ongoing clinical trials. Results MATE identified 61% more patients who were potentially eligible for recruitment into clinical trials than the MDT, and MATE recommendations demonstrated better concordance with clinical practice guideline than MDT recommendations (97% of MATE vs 93.2% of MDT; N=984). MATE is in routine use in breast MDMs at the Royal Free Hospital, London, and wider evaluations are being considered. Conclusions Sophisticated decision support systems can enhance the conduct of MDMs in a way that is acceptable to and valued by the clinical team. Further rigorous evaluations are required to examine cost-effectiveness and measure the impact on patient outcomes. The decision support technology used in MATE is generic and if found useful can be applied across medicine. PMID:22734113

Drosophila melanogaster virgins are more likely to mate with strangers than familiar flies.

PubMed

Odeen, Anders; Moray, Clea M

2008-03-01

Recent evidence shows that females of many species can discriminate against males and/or male phenotypes they have mated with previously. However, these studies have not tested whether actual mating is necessary to induce the avoidance behaviour. A preference for strangers may have evolved because it avoids multiple matings with similar genotypes. Alternatively, there may be selection against mating with familiar individuals directly. By choosing its first mate among unfamiliar individuals (which are less likely close relatives than are those encountered early in life), a virgin might disentangle some of the potential benefits of avoiding genetic incompatibility and inbreeding in the offspring from the costs of remating. In this study, we test whether Drosophila melanogaster flies bias their mate choice towards strangers according to previous, non-copulatory, experience. Based on 173 trials over 12 weeks, virgin females presented with two virgin males were 59% more likely to mate with a novel male than the one which she had been housed with for 8 h the day before. Hence we present the first report showing that a dipteran can distinguish between previously encountered and not previously encountered conspecifics.

Drosophila melanogaster virgins are more likely to mate with strangers than familiar flies

NASA Astrophysics Data System (ADS)

Ödeen, Anders; Moray, Clea M.

2008-03-01

Recent evidence shows that females of many species can discriminate against males and/or male phenotypes they have mated with previously. However, these studies have not tested whether actual mating is necessary to induce the avoidance behaviour. A preference for strangers may have evolved because it avoids multiple matings with similar genotypes. Alternatively, there may be selection against mating with familiar individuals directly. By choosing its first mate among unfamiliar individuals (which are less likely close relatives than are those encountered early in life), a virgin might disentangle some of the potential benefits of avoiding genetic incompatibility and inbreeding in the offspring from the costs of remating. In this study, we test whether Drosophila melanogaster flies bias their mate choice towards strangers according to previous, non-copulatory, experience. Based on 173 trials over 12 weeks, virgin females presented with two virgin males were 59% more likely to mate with a novel male than the one which she had been housed with for 8 h the day before. Hence we present the first report showing that a dipteran can distinguish between previously encountered and not previously encountered conspecifics.

Pleiotropic Effects of DDT Resistance on Male Size and Behaviour.

PubMed

Rostant, Wayne G; Bowyer, Jemima; Coupland, Jack; Facey, James; Hosken, David J; Wedell, Nina

2017-07-01

Understanding the evolution and spread of insecticide resistance requires knowing the relative fitness of resistant organisms. In the absence of insecticides, resistance is predicted to be costly. The Drosophila melanogaster DDT resistance allele (DDT-R) is associated with a male mating cost. This could be because resistant males are generally smaller, but DDT-R may also alter courtship behaviours. Here we tested for body size and courtship effects of DDT-R on mating success in competitive and non-competitive mating trials respectively. We also assessed relative aggression in resistant and susceptible males because aggression can also influence mating success. While the effect of DDT-R on male size partly contributed to reduced mating success, resistant males also had lower rates of courtship and were less aggressive than susceptible males. These differences contribute to the observed DDT-R mating costs. Additionally, these pleiotropic effects of DDT-R are consistent with the history and spread of resistance alleles in nature.

Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions.

PubMed

Bellini, R; Balestrino, F; Medici, A; Gentile, G; Veronesi, R; Carrieri, M

2013-01-01

Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence.

Mate choice screening in captive solitary carnivores: The role of male behavior and cues on mate preference and paternity in females of a model species, American mink (Neovison vison).

PubMed

Noer, Christina Lehmkuhl; Balsby, Thorsten Johannes Skovbjerg; Anistoroaei, Razvan; Stelvig, Mikkel; Dabelsteen, Torben

2017-12-01

Mate choice studies suggest that choosy females benefit from increased fecundity, litter size, and offspring survival. Thus, providing females with the opportunity to choose among potential mates, deemed genetically suitable based on studbook data, might improve breeding management in production and zoo animals and thereby the sustainability of captive populations. Investigating mate preference via odor from potential mates before animal transfer is a proposed strategy for incorporating mate choice into breeding management. In this study, we test whether olfactory cues and signals from males can be used to assess and measure female mate preference in American mink. Eighteen females were subjected to a 4-day stimulus test in which females showed a preference for one of two males' urine and feces. Subsequently, each female was subjected to a 10-day mate preference test involving the same two males of the first test. Paternity tests revealed that 13 females had offspring, which could be assigned to only one male, suggesting that these females performed a mate choice. In nine of these females preference during the stimulus test was directed toward the male that fathered their offspring. Our results suggest that even though there was a preference difference in scent stimulus trials from potential mates this preference was not predictive of eventual mate preference or paternity. Other factors such as aspects of male behavior seem to play a role, when the mates are introduced. Our study supports that mate preference and mate choice are complex matters influenced by multiple cues and signals. © 2017 Wiley Periodicals, Inc.

Females Choose Mates Based on Genetic Relatedness in a Small Dasyurid Marsupial, the Agile Antechinus (Antechinus agilis)

PubMed Central

Parrott, Marissa L.; Ward, Simon J.; Temple-Smith, Peter D.; Selwood, Lynne

2015-01-01

Females in a variety of taxa mate with more than one male during a single oestrus and exhibit mate preferences for genetically compatible males, but the influence of female mate choice on siring success is not clearly understood. Whether females choose to mate with more than one male or endure forced copulations is also often unknown. Here, we examined the effects of genetic relatedness on female mate choice and siring success in a small semelparous carnivorous marsupial, the agile antechinus (Antechinus agilis), during two consecutive breeding seasons. Experimental trials were conducted in captivity over periods of 72 hours using interconnected enclosures in which female antechinus could choose to access any of four separated males, but males were only able to access females that entered their quarters. Females had access to two genetically similar and two genetically dissimilar males simultaneously and all behavioural interactions were observed and scored from continuous video recordings. Genetic similarity between mates and paternity of young was determined by microsatellite analyses. Some females chose to enter and mate with more than one male during a single oestrus period. Although females investigated all males, they spent significantly more time visiting, and mated more times with, genetically dissimilar males. Males that were genetically dissimilar to the female sired 88% of subsequent offspring. Whilst males mated readily with most females, they rejected the advances of some receptive females, indicating a previously unexpected level of male mate choice. The results show that genetic relatedness between mates has a significant influence on mate choice, breeding and siring success in the agile antechinus. PMID:25923325

Females Choose Mates Based on Genetic Relatedness in a Small Dasyurid Marsupial, the Agile Antechinus (Antechinus agilis).

PubMed

Parrott, Marissa L; Ward, Simon J; Temple-Smith, Peter D; Selwood, Lynne

2015-01-01

Females in a variety of taxa mate with more than one male during a single oestrus and exhibit mate preferences for genetically compatible males, but the influence of female mate choice on siring success is not clearly understood. Whether females choose to mate with more than one male or endure forced copulations is also often unknown. Here, we examined the effects of genetic relatedness on female mate choice and siring success in a small semelparous carnivorous marsupial, the agile antechinus (Antechinus agilis), during two consecutive breeding seasons. Experimental trials were conducted in captivity over periods of 72 hours using interconnected enclosures in which female antechinus could choose to access any of four separated males, but males were only able to access females that entered their quarters. Females had access to two genetically similar and two genetically dissimilar males simultaneously and all behavioural interactions were observed and scored from continuous video recordings. Genetic similarity between mates and paternity of young was determined by microsatellite analyses. Some females chose to enter and mate with more than one male during a single oestrus period. Although females investigated all males, they spent significantly more time visiting, and mated more times with, genetically dissimilar males. Males that were genetically dissimilar to the female sired 88% of subsequent offspring. Whilst males mated readily with most females, they rejected the advances of some receptive females, indicating a previously unexpected level of male mate choice. The results show that genetic relatedness between mates has a significant influence on mate choice, breeding and siring success in the agile antechinus.

Reconstructing the flight kinematics of swarming and mating behavior in wild mosquitoes

USDA-ARS?s Scientific Manuscript database

We describe a tracking system for reconstructing three-dimensional tracks of individual mosquitoes in wild swarms and present the results of validating the system by filming swarms and mating events of the malaria mosquito Anopheles gambiae in Mali. The tracking system is designed to address noisy, ...

The MATE1 rs2289669 polymorphism affects the renal clearance of metformin following ranitidine treatment.

PubMed

Cho, Sung Kweon; Chung, Jae-Yong

2016-04-01

Human multidrug and toxin extrusion member 1 (MATE1, SLC47A1) and Organic Cation Transporter 2 (OCT2, SLC22A2) play important roles in the renal elimination of various pharmacologic agents, including the anti-diabetic drug metformin. The goal of this study was to determine the association between metformin's pharmacokinetics and pharmacodynamics and the genetic variants of MATE1 (rs2289669) and OCT2 (rs316019) before and after treatment with the potential MATE inhibitor, ranitidine. We recruited 26 healthy Koreans balanced across the OCT2 and MATE1 genetic variants, and conducted a prospective clinical trial to investigate their effects on metformin's pharmacokinetics and pharmacodynamics before and after ranitidine treatment. Neither MATE1 rs2289669 nor OCT2 rs316019 affected metformin's pharmacokinetics and pharmacodynamics before ranitidine treatment. However, the renal clearance of metformin was significantly higher (15.2%) after ranitidine treatment in the MATE1 GG group compared with the MATE1 GA + AA group. Only the effect of MATE1 on the renal clearance of metformin after ranitidine treatment was significant (b = -0.465, p ≤ 0.05) after including demographic data and the OCT2 genotype in the model. Our study suggests that MATE1 rs2289669 may be a significant determinant in the renal clearance of metformin in the case of transporter-mediated drug interactions.

Mate choice and genetic monogamy in a biparental, colonial fish.

PubMed

Schaedelin, Franziska C; van Dongen, Wouter F D; Wagner, Richard H

2015-01-01

In socially monogamous species, in which both sexes provide essential parental care, males as well as females are expected to be choosy. Whereas hundreds of studies have examined monogamy in biparental birds, only several such studies exist in fish. We examined mate choice in the biparental, colonial cichlid fish Neolamprologus caudopunctatus in Lake Tanganyika, Zambia. We genotyped more than 350 individuals at 11 microsatellite loci to investigate their mating system. We found no extrapair paternity, identifying this biparental fish as genetically monogamous. Breeders paired randomly according to their genetic similarity, suggesting a lack of selection against inbreeding avoidance. We further found that breeders paired assortatively by body size, a criterion of quality in fish, suggesting mutual mate choice. In a subsequent mate preference test in an aquarium setup, females showed a strong preference for male size by laying eggs near the larger of 2 males in 13 of 14 trials.

Mate choice and genetic monogamy in a biparental, colonial fish

PubMed Central

van Dongen, Wouter F.D.; Wagner, Richard H.

2015-01-01

In socially monogamous species, in which both sexes provide essential parental care, males as well as females are expected to be choosy. Whereas hundreds of studies have examined monogamy in biparental birds, only several such studies exist in fish. We examined mate choice in the biparental, colonial cichlid fish Neolamprologus caudopunctatus in Lake Tanganyika, Zambia. We genotyped more than 350 individuals at 11 microsatellite loci to investigate their mating system. We found no extrapair paternity, identifying this biparental fish as genetically monogamous. Breeders paired randomly according to their genetic similarity, suggesting a lack of selection against inbreeding avoidance. We further found that breeders paired assortatively by body size, a criterion of quality in fish, suggesting mutual mate choice. In a subsequent mate preference test in an aquarium setup, females showed a strong preference for male size by laying eggs near the larger of 2 males in 13 of 14 trials. PMID:26023276

Mate preferences do predict attraction and choices in the early stages of mate selection.

PubMed

Li, Norman P; Yong, Jose C; Tov, William; Sng, Oliver; Fletcher, Garth J O; Valentine, Katherine A; Jiang, Yun F; Balliet, Daniel

2013-11-01

Although mate preference research has firmly established that men value physical attractiveness more than women do and women value social status more than men do, recent speed-dating studies have indicated mixed evidence (at best) for whether people's sex-differentiated mate preferences predict actual mate choices. According to an evolutionary, mate preference priority model (Li, Bailey, Kenrick, & Linsenmeier, 2002; Li & Kenrick, 2006; Li, Valentine, & Patel, 2011), the sexes are largely similar in what they ideally like, but for long-term mates, they should differ on what they most want to avoid in early selection contexts. Following this model, we conducted experiments using online messaging and modified speed-dating platforms. Results indicate that when a mating pool includes people at the low end of social status and physical attractiveness, mate choice criteria are sex-differentiated: Men, more than women, chose mates based on physical attractiveness, whereas women, more than men, chose mates based on social status. In addition, individuals who more greatly valued social status or physical attractiveness on paper valued these traits more in their actual choices. In particular, mate choices were sex-differentiated when considering long-term relationships but not short-term ones, where both sexes shunned partners with low physical attractiveness. The findings validate a large body of mate preferences research and an evolutionary perspective on mating, and they have implications for research using speed-dating and other interactive contexts. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Sexual and romantic jealousy in heterosexual and homosexual adults.

PubMed

Harris, Christine R

2002-01-01

Several theorists have claimed that men are innately more upset by a mate's sexual infidelity and women are more upset by a mate's emotional infidelity because the sexes faced different adaptive problems (for men, cuckoldry; for women, losing a mate's resources). The present work examined this theory of jealousy as a specific innate module in 196 adult men and women of homosexual and heterosexual orientations. As in previous work, heterosexuals' responses to a forced-choice question about hypothetical infidelity yielded a gender difference. However no gender differences were found when participants recalled personal experiences with a mate's actual infidelity. Men and women, regardless of sexual orientation, on average focused more on a mate's emotional infidelity than on a mate's sexual infidelity. Responses to hypothetical infidelity were uncorrelated with reactions to actual infidelity. This finding casts doubt on the validity of the hypothetical measures used in previous research.

Relative Effects of Juvenile and Adult Environmental Factors on Mate Attraction and Recognition in the Cricket, Allonemobius socius

PubMed Central

Olvido, Alexander E.; Fernandes, Pearl R.; Mousseau, Timothy A.

2010-01-01

Finding a mate is a fundamental aspect of sexual reproduction. To this end, specific-mate recognition systems (SMRS) have evolved that facilitate copulation between producers of the mating signal and their opposite-sex responders. Environmental variation, however, may compromise the efficiency with which SMRS operate. In this study, the degree to which seasonal climate experienced during juvenile and adult life-cycle stages affects the SMRS of a cricket, Allonemobius socius (Scudder) (Orthoptera: Gryllidae) was assessed. Results from two-choice behavioral trials suggest that adult ambient temperature, along with population and family origins, mediate variation in male mating call, and to a lesser extent directional response of females for those calls. Restricted maximum-likelihood estimates of heritability for male mating call components and for female response to mating call appeared statistically nonsignificant. However, appreciable “maternal genetic effects” suggest that maternal egg provisioning and other indirect maternal determinants of the embryonic environment significantly contributed to variation in male mating call and female response to mating calls. Thus, environmental factors can generate substantial variation in A. socius mating call, and, more importantly, their marginal effect on female responses to either fast-chirp or long-chirp mating calls suggest negative fitness consequences to males producing alternative types of calls. Future studies of sexual selection and SMRS evolution, particularly those focused on hybrid zone dynamics, should take explicit account of the loose concordance between signal producers and responders suggested by the current findings. PMID:20673114

Polyandry produces sexy sons at the cost of daughters in red flour beetles.

PubMed Central

Pai, Aditi; Yan, Guiyun

2002-01-01

Female mating with multiple males within a single fertile period is a common phenomenon in the animal kingdom. Female insects are particularly promiscuous. It is not clear why females mate with multiple partners despite several potential costs, such as expenditure of time and energy, reduced lifespan, risk of predation and contracting sexually transmitted diseases. Female red flour beetles (Tribolium castaneum) obtain sufficient sperm from a single insemination to retain fertility for several months. Nonetheless they copulate repeatedly within minutes with different males despite no direct fitness benefits from this behaviour. One hypothesis is that females mate with multiple partners to provide indirect benefits via enhanced offspring fitness. To test this hypothesis, we compared the relative fitness of F(1) offspring from females mated with single males and multiple males (2, 4, 8, or 16 partners), under the condition of relatively high intraspecific competition. We found that a female mating with 16 males enhanced the relative fitness of F(1) males (in two out of three trials) but reduced F(1) females' fitness (in two independent trials) in comparison with singly mated females. We also determined whether several important fitness correlates were affected by polyandry. We found that F(1) males from mothers with 16 partners inseminated more females than F(1) males from mothers with a single partner. The viability of the eggs sired or produced by F(1) males and females from highly polyandrous mothers was also increased under conditions of low intra-specific competition. Thus, the effects of polyandry on F(1) offspring fitness depend on environmental conditions. Our results demonstrated a fitness trade-off between male and female offspring from polyandrous mothers in a competitive environment. The mechanisms and biological significance of this unique phenomenon are discussed. PMID:11886623

Polyandry produces sexy sons at the cost of daughters in red flour beetles.

PubMed

Pai, Aditi; Yan, Guiyun

2002-02-22

Female mating with multiple males within a single fertile period is a common phenomenon in the animal kingdom. Female insects are particularly promiscuous. It is not clear why females mate with multiple partners despite several potential costs, such as expenditure of time and energy, reduced lifespan, risk of predation and contracting sexually transmitted diseases. Female red flour beetles (Tribolium castaneum) obtain sufficient sperm from a single insemination to retain fertility for several months. Nonetheless they copulate repeatedly within minutes with different males despite no direct fitness benefits from this behaviour. One hypothesis is that females mate with multiple partners to provide indirect benefits via enhanced offspring fitness. To test this hypothesis, we compared the relative fitness of F(1) offspring from females mated with single males and multiple males (2, 4, 8, or 16 partners), under the condition of relatively high intraspecific competition. We found that a female mating with 16 males enhanced the relative fitness of F(1) males (in two out of three trials) but reduced F(1) females' fitness (in two independent trials) in comparison with singly mated females. We also determined whether several important fitness correlates were affected by polyandry. We found that F(1) males from mothers with 16 partners inseminated more females than F(1) males from mothers with a single partner. The viability of the eggs sired or produced by F(1) males and females from highly polyandrous mothers was also increased under conditions of low intra-specific competition. Thus, the effects of polyandry on F(1) offspring fitness depend on environmental conditions. Our results demonstrated a fitness trade-off between male and female offspring from polyandrous mothers in a competitive environment. The mechanisms and biological significance of this unique phenomenon are discussed.

Evidence for inbreeding depression and pre-copulatory, but not post copulatory inbreeding avoidance in the cabbage beetle Colaphellus bowringi.

PubMed

Liu, XingPing; Tu, XiaoYun; He, HaiMin; Chen, Chao; Xue, FangSen

2014-01-01

Inbreeding is known to have adverse effects on fitness-related traits in a range of insect species. A series of theoretical and experimental studies have suggested that polyandrous insects could avoid the cost of inbreeding via pre-copulatory mate choice and/or post-copulatory mechanisms. We looked for evidence of pre-copulatory inbreeding avoidance using female mate preference trials, in which females were given the choice of mating with either of two males, a sibling and a non-sibling. We also tested for evidence of post-copulatory inbreeding avoidance by conducting double mating experiments, in which four sibling females were mated with two males sequentially, either two siblings, two non-siblings or a sibling and a non-sibling in either order. We identified substantial inbreeding depression: offspring of females mated to full siblings had lower hatching success, slower development time from egg to adult, lower survival of larval and pupal stages, and lower adult body mass than the offspring of females mated to non-sibling males. We also found evidence of pre-copulatory inbreeding avoidance, as females preferred to mate with non-sibling males. However, we did not find any evidence of post-copulatory inbreeding avoidance: egg hatching success of females mating to both sibling and non-sibling males were consistent with sperm being used without bias in relation to mate relatedness. Our results suggest that this cabbage beetle has evolved a pre-copulatory mechanism to avoid matings between close relative, but that polyandry is apparently not an inbreeding avoidance mechanism in C. bowringi.

Evidence for Inbreeding Depression and Pre-Copulatory, but Not Post Copulatory Inbreeding Avoidance in the Cabbage Beetle Colaphellus bowringi

PubMed Central

Liu, XingPing; Tu, XiaoYun; He, HaiMin; Chen, Chao; Xue, FangSen

2014-01-01

Inbreeding is known to have adverse effects on fitness-related traits in a range of insect species. A series of theoretical and experimental studies have suggested that polyandrous insects could avoid the cost of inbreeding via pre-copulatory mate choice and/or post-copulatory mechanisms. We looked for evidence of pre-copulatory inbreeding avoidance using female mate preference trials, in which females were given the choice of mating with either of two males, a sibling and a non-sibling. We also tested for evidence of post-copulatory inbreeding avoidance by conducting double mating experiments, in which four sibling females were mated with two males sequentially, either two siblings, two non-siblings or a sibling and a non-sibling in either order. We identified substantial inbreeding depression: offspring of females mated to full siblings had lower hatching success, slower development time from egg to adult, lower survival of larval and pupal stages, and lower adult body mass than the offspring of females mated to non-sibling males. We also found evidence of pre-copulatory inbreeding avoidance, as females preferred to mate with non-sibling males. However, we did not find any evidence of post-copulatory inbreeding avoidance: egg hatching success of females mating to both sibling and non-sibling males were consistent with sperm being used without bias in relation to mate relatedness. Our results suggest that this cabbage beetle has evolved a pre-copulatory mechanism to avoid matings between close relative, but that polyandry is apparently not an inbreeding avoidance mechanism in C. bowringi. PMID:24718627

Small Cages with Insect Couples Provide a Simple Method for a Preliminary Assessment of Mating Disruption

PubMed Central

Briand, Françoise; Guerin, Patrick M.; Charmillot, Pierre-Joseph; Kehrli, Patrik

2012-01-01

Mating disruption by sex pheromones is a sustainable, effective and widely used pest management scheme. A drawback of this technique is its challenging assessment of effectiveness in the field (e.g., spatial scale, pest density). The aim of this work was to facilitate the evaluation of field-deployed pheromone dispensers. We tested the suitability of small insect field cages for a pre-evaluation of the impact of sex pheromones on mating using the grape moths Eupoecilia ambiguella and Lobesia botrana, two major pests in vineyards. Cages consisted of a cubic metal frame of 35 cm sides, which was covered with a mosquito net of 1500 μm mesh size. Cages were installed in the centre of pheromone-treated and untreated vineyards. In several trials, 1 to 20 couples of grape moths per cage were released for one to three nights. The proportion of mated females was between 15 to 70% lower in pheromone-treated compared to untreated vineyards. Overall, the exposure of eight couples for one night was adequate for comparing different control schemes. Small cages may therefore provide a fast and cheap method to compare the effectiveness of pheromone dispensers under standardised semi-field conditions and may help predict the value of setting-up large-scale field trials. PMID:22645483

Mutual Mate Choice: When it Pays Both Sexes to Avoid Inbreeding

PubMed Central

Lihoreau, Mathieu; Zimmer, Cédric; Rivault, Colette

2008-01-01

Theoretical models of sexual selection predict that both males and females of many species should benefit by selecting their mating partners. However, empirical evidence testing and validating this prediction is scarce. In particular, whereas inbreeding avoidance is expected to induce sexual conflicts, in some cases both partners could benefit by acting in concert and exerting mutual mate choice for non-assortative pairings. We tested this prediction with the gregarious cockroach Blattella germanica (L.). We demonstrated that males and females base their mate choice on different criteria and that choice occurs at different steps during the mating sequence. Males assess their relatedness to females through antennal contacts before deciding to court preferentially non-siblings. Conversely, females biased their choice towards the most vigorously courting males that happened to be non-siblings. This study is the first to demonstrate mutual mate choice leading to close inbreeding avoidance. The fact that outbred pairs were more fertile than inbred pairs strongly supports the adaptive value of this mating system, which includes no “best phenotype” as the quality of two mating partners is primarily linked to their relatedness. We discuss the implications of our results in the light of inbreeding conflict models. PMID:18843373

Mutual mate choice: when it pays both sexes to avoid inbreeding.

PubMed

Lihoreau, Mathieu; Zimmer, Cédric; Rivault, Colette

2008-01-01

Theoretical models of sexual selection predict that both males and females of many species should benefit by selecting their mating partners. However, empirical evidence testing and validating this prediction is scarce. In particular, whereas inbreeding avoidance is expected to induce sexual conflicts, in some cases both partners could benefit by acting in concert and exerting mutual mate choice for non-assortative pairings. We tested this prediction with the gregarious cockroach Blattella germanica (L.). We demonstrated that males and females base their mate choice on different criteria and that choice occurs at different steps during the mating sequence. Males assess their relatedness to females through antennal contacts before deciding to court preferentially non-siblings. Conversely, females biased their choice towards the most vigorously courting males that happened to be non-siblings. This study is the first to demonstrate mutual mate choice leading to close inbreeding avoidance. The fact that outbred pairs were more fertile than inbred pairs strongly supports the adaptive value of this mating system, which includes no "best phenotype" as the quality of two mating partners is primarily linked to their relatedness. We discuss the implications of our results in the light of inbreeding conflict models.

Experimental evidence for asymmetric mate preference and aggression: behavioral interactions in a woodrat (Neotoma) hybrid zone

PubMed Central

2013-01-01

Background Female mate preferences may be under strong selection in zones of contact between closely related species because of greater variation in available mates and the potential costs of hybridization. We studied female mate preferences experimentally in a zone of secondary contact between Desert and Bryant’s Woodrat (Neotoma lepida and N. bryanti) in the southern foothills of the Sierra Nevada of California. We tested female preference for conspecific versus heterospecific males in paired choice trials in which females could interact freely with males, but males could not interact directly with each other. We compared preferences of females from both allopatric and sympatric sites. Results We did not find evidence of the process of reinforcement as assortative preferences were not stronger in sympatry than in allopatry. Mate preferences, however, were asymmetric, with N. lepida females mating preferentially with conspecifics and N. bryanti females showing no preference by species. Sympatric females were less likely to mate than allopatric females, due in part to an increase in aggressive interactions. However, even in the absence of aggression, courtship led to mating less often in sympatric females, suggesting they were choosier or had lower sexual motivation than allopatric females. Conclusions Patterns of mate choice in this woodrat system appear to be strongly impacted by body size and aggressive behavior. In particular, females of the smaller-bodied species rarely interact with the relatively large heterospecific males. In contrast females of the larger-bodied species accept the relatively small heterospecific males. For sympatric animals, rates of aggression were markedly higher than for allopatric animals and reduced affiliative and reproductive behavior in our trials. Sympatric animals are larger and more aggressive, traits that are likely under strong ecological selection across the sharp resource gradient that characterizes the contact zone. However, our results suggest that these traits that are likely favored in competitive interactions between the species also impact reproductive interactions. Combined with our previous findings of post-zygotic isolation in this system, this study suggests that multiple isolating mechanisms contribute to the rate of genetic exchange between these species when they come into contact, and that these mechanisms are the result of selection on traits that are important in a range of ecological and reproductive interactions. PMID:24093823

Secondary compounds from exotic tree plantations change female mating preferences in the palmate newt (Lissotriton helveticus).

PubMed

Iglesias-Carrasco, M; Head, M L; Jennions, M D; Cabido, C

2017-10-01

Selection can favour phenotypic plasticity in mate choice in response to environmental factors that alter the costs and benefits of being choosy, or of choosing specific mates. Human-induced environmental change could alter sexual selection by affecting the costs of mate choice, or by impairing the ability of individuals to identify preferred mates. For example, variation in mate choice could be driven by environmentally induced differences in body condition (e.g. health) that change the cost of choosiness, or by environmental effects on the ability to detect or discriminate sexual signals. We teased apart these possibilities experimentally, by comparing female mate choice in the palmate newt Lissotriton helveticus between environments that mimic water from either native oak forests or exotic eucalypt plantations. In laboratory two-choice mate trials in clean water, females with prolonged exposure (21 days) to waterborne chemicals leached from eucalypt leaves did not preferentially associate with the male with a stronger immune response, but females exposed to water with chemicals from oak leaves did. In contrast, female choice was unaffected by the immediate presence or absence of eucalypt leachates during mate choice (using only females previously held in oak-treated water). The habitat-related change in female choice we observed is likely to be driven by effects of eucalypt leachates on female physiology, rather than immediate inhibition of pheromone transmission or blocking of pheromone reception. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Males of the orb-web spider Argiope bruennichi sacrifice themselves to unrelated females

PubMed Central

Welke, Klaas W.; Schneider, Jutta M.

2010-01-01

Costs of inbreeding can lead to total reproductive failure and inbreeding avoidance is, therefore, common. In classical sex roles with no paternal care, the selective pressure to avoid inbreeding is mostly on the female, which carries the higher costs. In some orb-web spiders, this situation is very different because females are polyandrous and males are monogynous or at most bigynous. Additionally, females of many entelegyne orb weavers are thought to bias paternity post-copulatorily towards a desired mate. This increases the selective pressure on males to adjust their investment in a mating with regard to the compatibility to a female. Here, we examine whether genetic relatedness influences mating behaviour in the orb-web spider Argiope bruennichi. We mated either a sibling or a non-sibling male to a female in single copulation trials and compared copulation duration, cannibalism rate and female fecundity. Our experiment revealed that males prolonged their copulation duration and were cannibalized more frequently when mating with a non-sibling female. Males mating with a sibling female were more likely to escape cannibalism by copulating briefly, thus presumably increasing their chances of re-mating with a more compatible female. This suggests that males can adaptively adjust their investment relating to the compatibility of a female. PMID:20410027

Polyandry as a mediator of sexual selection before and after mating

PubMed Central

Kvarnemo, Charlotta; Simmons, Leigh W.

2013-01-01

The Darwin–Bateman paradigm recognizes competition among males for access to multiple mates as the main driver of sexual selection. Increasingly, however, females are also being found to benefit from multiple mating so that polyandry can generate competition among females for access to multiple males, and impose sexual selection on female traits that influence their mating success. Polyandry can reduce a male's ability to monopolize females, and thus weaken male focused sexual selection. Perhaps the most important effect of polyandry on males arises because of sperm competition and cryptic female choice. Polyandry favours increased male ejaculate expenditure that can affect sexual selection on males by reducing their potential reproductive rate. Moreover, sexual selection after mating can ameliorate or exaggerate sexual selection before mating. Currently, estimates of sexual selection intensity rely heavily on measures of male mating success, but polyandry now raises serious questions over the validity of such approaches. Future work must take into account both pre- and post-copulatory episodes of selection. A change in focus from the products of sexual selection expected in males, to less obvious traits in females, such as sensory perception, is likely to reveal a greater role of sexual selection in female evolution. PMID:23339234

Validation of Bateman's principles: a genetic study of sexual selection and mating patterns in the rough-skinned newt.

PubMed Central

Jones, Adam G; Arguello, J Roman; Arnold, Stevan J

2002-01-01

Few studies have influenced thought on the nature of sexual selection to the extent of the classic paper of A. J. Bateman on mating patterns in Drosophila. However, interpretation of his study remains controversial, and a lack of modern empirical evidence prevents a consensus with respect to the perceived utility of Bateman's principles in the study of sexual selection. Here, we use a genetic study of natural mating patterns in the rough-skinned newt, Taricha granulosa, to investigate the concordance between Bateman's principles and the intensity of sexual selection. We found that males experienced strong sexual selection on tail height and body size, while sexual selection was undetectable in females. This direct quantification of sexual selection agreed perfectly with inferences that are based on Bateman's principles. Specifically, males (in comparison with females) exhibited greater standardized variances in reproductive and mating success, as well as a stronger relationship between mating success and reproductive success. Overall, our results illustrate that Bateman's principles provide the only quantitative measures of the mating system with explicit connections to formal selection theory and should be the central focus of studies of mating patterns in natural populations. PMID:12573067

Polyandry as a mediator of sexual selection before and after mating.

PubMed

Kvarnemo, Charlotta; Simmons, Leigh W

2013-03-05

The Darwin-Bateman paradigm recognizes competition among males for access to multiple mates as the main driver of sexual selection. Increasingly, however, females are also being found to benefit from multiple mating so that polyandry can generate competition among females for access to multiple males, and impose sexual selection on female traits that influence their mating success. Polyandry can reduce a male's ability to monopolize females, and thus weaken male focused sexual selection. Perhaps the most important effect of polyandry on males arises because of sperm competition and cryptic female choice. Polyandry favours increased male ejaculate expenditure that can affect sexual selection on males by reducing their potential reproductive rate. Moreover, sexual selection after mating can ameliorate or exaggerate sexual selection before mating. Currently, estimates of sexual selection intensity rely heavily on measures of male mating success, but polyandry now raises serious questions over the validity of such approaches. Future work must take into account both pre- and post-copulatory episodes of selection. A change in focus from the products of sexual selection expected in males, to less obvious traits in females, such as sensory perception, is likely to reveal a greater role of sexual selection in female evolution.

The Development and Validation of the Measure of Acceptance of the Theory of Evolution Instrument.

ERIC Educational Resources Information Center

Rutledge, Michael L.; Warden, Melissa A.

1999-01-01

Describes the development and validation of the Measure of Acceptance of the Theory of Evolution (MATE), a 20-item, Likert-scaled instrument that assesses teachers' overall acceptance of evolutionary theory. (Author/CCM)

Short-term exposure to a synthetic estrogen disrupts mating dynamics in a pipefish.

PubMed

Partridge, Charlyn; Boettcher, Anne; Jones, Adam G

2010-11-01

Sexual selection is responsible for the evolution of some of the most elaborate traits occurring in nature, many of which play a vital role in competition over access to mates and individual reproductive fitness. Because expression of these traits is typically regulated by sex-steroids there is a significant potential for their expression to be affected by the presence of certain pollutants, such as endocrine disrupting compounds. Endocrine disruptors have been shown to alter primary sexual traits and impact reproduction, but few studies have investigated how these compounds affect secondary sexual trait expression and how that may, in turn, impact mating dynamics. In this study we examine how short-term exposure to a synthetic estrogen impacts secondary sexual trait expression and mating dynamics in the Gulf pipefish, a species displaying sex-role reversal. Our results show that only 10days of exposure to 17α-ethinylestradiol results in adult male pipefish developing female-like secondary sexual traits. While these males are capable of reproduction, females discriminate against exposed males in mate choice trials. In natural populations, this type of discrimination would reduce male mating opportunities, thus potentially reducing their long-term reproductive success. Importantly, the effects of these compounds on mating dynamics and mating opportunity would not be observed using the current standard methods of assessing environmental contamination. However, disrupting these processes could have profound effects on the viability of exposed populations. Copyright © 2010 Elsevier Inc. All rights reserved.

Frequency of micronucleus in oral epithelial cells after exposure to mate-tea in healthy humans

PubMed Central

Campagnoli, Eduardo B.; Milan, José R.; Reinheimer, Angélica; Masson, Maicon; Capella, Diogo L.

2014-01-01

Objectives: The aim of this study was to evaluate the possibility of technique simplification for cytology slides in order to evaluate the frequency of micronuclei (FMic) and conduct a experiment looking to know the FMic of oral epithelial cells of healthy volunteers exposed to mate tea (Ilex paraguarariensis). Material and Methods: This is a laboratorial and nonrandomized trial (quasi-experiment), where the nonusers subjects were exposed to mate-tea, consumed in the traditional way, two drinks, two times a day for a single week. Two cytology of exfoliated epithelial cells were obtained before and after the mate tea exposition. Results: The sample was composed by 10 volunteers. The age ranged from 18 to 33 years (Mean 23; SD5.5). The use of mate tea did not showed significant variation in the FMic (Wilcoxon Signed Ranks Test p= .24). Conclusions: The proposed technique simplification showed to be reliable, without losses when compared to the conventional technique and with the advantage of eliminate toxic substances, becoming simple and practical tool for research in dentistry. The acute exposure to mate tea did not induce an increase of FMic in exfoliated buccal cells of healthy nondrinkers and nonsmokers subjects and may not have genotoxic effect. More human studies are needed before a conclusion can be made on the oral carcinogenic risk of mate tea to humans. Key words:Micronucleus, Oral Cancer, Cytology, Mate tea, Ilex paraguariensis. PMID:24608213

Dopamine neurons modulate pheromone responses in Drosophila courtship learning.

PubMed

Keleman, Krystyna; Vrontou, Eleftheria; Krüttner, Sebastian; Yu, Jai Y; Kurtovic-Kozaric, Amina; Dickson, Barry J

2012-09-06

Learning through trial-and-error interactions allows animals to adapt innate behavioural ‘rules of thumb’ to the local environment, improving their prospects for survival and reproduction. Naive Drosophila melanogaster males, for example, court both virgin and mated females, but learn through experience to selectively suppress futile courtship towards females that have already mated. Here we show that courtship learning reflects an enhanced response to the male pheromone cis-vaccenyl acetate (cVA), which is deposited on females during mating and thus distinguishes mated females from virgins. Dissociation experiments suggest a simple learning rule in which unsuccessful courtship enhances sensitivity to cVA. The learning experience can be mimicked by artificial activation of dopaminergic neurons, and we identify a specific class of dopaminergic neuron that is critical for courtship learning. These neurons provide input to the mushroom body (MB) γ lobe, and the DopR1 dopamine receptor is required in MBγ neurons for both natural and artificial courtship learning. Our work thus reveals critical behavioural, cellular and molecular components of the learning rule by which Drosophila adjusts its innate mating strategy according to experience.

Multicentre clinical trial experience with the HeartMate 3 left ventricular assist device: 30-day outcomes.

PubMed

Zimpfer, Daniel; Netuka, Ivan; Schmitto, Jan D; Pya, Yuriy; Garbade, Jens; Morshuis, Michiel; Beyersdorf, Friedhelm; Marasco, Silvana; Rao, Vivek; Damme, Laura; Sood, Poornima; Krabatsch, Thomas

2016-09-01

The objective of this study was to describe the operative experience and 30-day outcomes of patients implanted with the HeartMate 3 Left Ventricular Assist System (LVAS) during the Conformité Européenne (CE) Mark clinical trial. Adult patients met inclusion and exclusion criteria defining advanced-stage heart failure and included the indications of bridge to transplant and destination therapy. Operative parameters, outcomes, adverse events, physical status and quality-of-life parameters were assessed in the first 30 days after LVAS implant. Fifty patients were implanted with the HeartMate 3 at 10 centres in 6 countries. The 30-day survival rate was 98%. The median operative and cardiopulmonary bypass times were 200 (range: 95-585) min and 84 (range: 47-250) min, respectively. Patients required transfusion with packed red blood cells (3.6 ± 2.3 units), fresh frozen plasma (6.5 ± 5 units) and platelets (2 ± 1 units). Six patients (12%) required reoperation for postoperative bleeding and 10 patients (20%) did not require blood transfusion. The median intensive care time was 6 days (range: 1-112 days) and the total hospital stay was 28 days (range: 14-116 days). The most common adverse events were bleeding (15, 30%), arrhythmia (14, 28%) and infection (10, 20%). There were 2 (4%) strokes. The 30-day outcomes following implantation of the HeartMate 3 demonstrates excellent survival with low adverse event rates. The LVAD performed as intended with no haemolysis or device failure. NCT02170363. HeartMate 3™ CE Mark Clinical Investigation Plan (HM3 CE Mark). © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Effect of chocolate and mate tea on the lipid profile of individuals with HIV/AIDS on antiretroviral therapy: A clinical trial.

PubMed

Souza, Suelen J; Petrilli, Aline A; Teixeira, Andrea M; Pontilho, Patricia M; Carioca, Antonio A; Luzia, Liania A; Souza, José M; Damasceno, Nágila R; Segurado, Aluisio A; Rondó, Patricia H

HIV/AIDS is generally associated with dyslipidemia and oxidative imbalance, which are caused by the infection itself and by antiretroviral therapy (ART). The flavonoids, found in cocoa and yerba mate, have antioxidant and hypolipidemic properties. The aim of this study was to evaluate the effects of the consumption of dark chocolate and mate tea on the lipid profiles of individuals with HIV/AIDS who are undergoing ART. A randomized, double-blind, placebo-controlled crossover clinical trial was conducted with 92 patients receiving ART for ≥6 mo and with viral suppression. The participants were randomized to receive either 65 g of chocolate (with 2148 mg polyphenols) or placebo chocolate (without polyphenols) or 3 g of mate tea (with 107 mg total phenols and 84.24 mg chlorogenic acid) or placebo mate (without polyphenols) for 15 d each, separated by a washout period of 15 d. The lipid profile, including determination of electronegative low-density lipoprotein, was determined after each intervention. The data were analyzed by analysis of variance using the pkcross procedure of the Stata 11.0 software. Analysis of variance revealed a significant overall difference in mean high-density lipoprotein cholesterol (HDL-C) between all supplements (P = 0.047). Using the paired t test, the effect was attributed to the consumption of dark chocolate (P = 0.046). The other parameters investigated were not improved. The consumption of dark chocolate for 15 d improved HDL-C concentrations of individuals with HIV/AIDS undergoing ART, possibly due to the presence of fatty acids (stearic acid), polyphenols, and theobromine. This fact is important for the cardiovascular protection of these individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Interpersonal Interaction on Festinating Gait Rehabilitation in Patients with Parkinson’s Disease

PubMed Central

Uchitomi, Hirotaka; Ogawa, Ken-ichiro; Orimo, Satoshi; Wada, Yoshiaki; Miyake, Yoshihiro

2016-01-01

Although human walking gait rhythms are generated by native individual gait dynamics, these gait dynamics change during interactions between humans. A typical phenomenon is synchronization of gait rhythms during cooperative walking. Our previous research revealed that fluctuation characteristics in stride interval of subjects with Parkinson’s disease changed from random to 1/f fluctuation as fractal characteristics during cooperative walking with the gait assist system Walk-Mate, which emulates a human interaction using interactive rhythmic cues. Moreover, gait dynamics were relearned through Walk-Mate gait training. However, the system’s clinical efficacy was unclear because the previous studies did not focus on specific gait rhythm disorder symptoms. Therefore, this study aimed to evaluate the effect of Walk-Mate on festinating gait among subjects with Parkinson’s disease. Three within-subject experimental conditions were used: (1) preinteraction condition, (2) interaction condition, and (3) postinteraction condition. The only difference between conditions was the interactive rhythmic cues generated by Walk-Mate. Because subjects with festinating gait gradually and involuntarily decreased their stride interval, the regression slope of stride interval as an index of severity of preinteraction festinating gait was elevated. The regression slope in the interaction condition was more gradual than during the preinteraction condition, indicating that the interactive rhythmic cues contributed to relieving festinating gait and stabilizing gait dynamics. Moreover, the gradual regression slope was carried over to the postinteraction condition, indicating that subjects with festinating gait have the potential to relearn stable gait dynamics. These results suggest that disordered gait dynamics are clinically restored through interactive rhythmic cues and that Walk-Mate may have the potential to assist therapists in more effective rehabilitation. Trial Registration: UMIN Clinical Trials Registry UMIN000012591 PMID:27253376

Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals.

PubMed

Petrilli, Aline A; Souza, Suelen J; Teixeira, Andrea M; Pontilho, Patricia M; Souza, José M P; Luzia, Liania A; Rondó, Patricia H C

2016-05-23

Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders. Their effect on HIV individuals has not been studied yet, despite the high cardiovascular risk of this population. This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals. A cross-over, placebo-controlled, double-blind, randomized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six months and at viral suppression. Participants were randomized to receive either 65 g of chocolate or chocolate-placebo or 3 g of yerba mate or mate-placebo for 15 days each, alternating by a washout period of 15 days. At baseline, and at the end of each intervention regimen, data regarding anthropometry, inflammatory, oxidative and immunological parameters were collected. High-sensitivity C-reactive protein, fibrinogen, lipid profile, white blood cell profile and thiobarbituric acid reactive substances were assessed. There was a difference between mean concentrations of HDL-c (ANOVA; p ≤ 0.05) among the different regimens: dark chocolate, chocolate-placebo, yerba mate and mate-placebo. When a paired Student t-test was used for comparisons between mean HDL-c at baseline and after each regimen, the mean concentration of HDL-c was higher after supplementation with dark chocolate (p = 0.008).

Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals

PubMed Central

Petrilli, Aline A.; Souza, Suelen J.; Teixeira, Andrea M.; Pontilho, Patricia M.; Souza, José M. P.; Luzia, Liania A.; Rondó, Patricia H. C.

2016-01-01

Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders. Their effect on HIV individuals has not been studied yet, despite the high cardiovascular risk of this population. This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals. A cross-over, placebo-controlled, double-blind, randomized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six months and at viral suppression. Participants were randomized to receive either 65 g of chocolate or chocolate-placebo or 3 g of yerba mate or mate-placebo for 15 days each, alternating by a washout period of 15 days. At baseline, and at the end of each intervention regimen, data regarding anthropometry, inflammatory, oxidative and immunological parameters were collected. High-sensitivity C-reactive protein, fibrinogen, lipid profile, white blood cell profile and thiobarbituric acid reactive substances were assessed. There was a difference between mean concentrations of HDL-c (ANOVA; p ≤ 0.05) among the different regimens: dark chocolate, chocolate-placebo, yerba mate and mate-placebo. When a paired Student t-test was used for comparisons between mean HDL-c at baseline and after each regimen, the mean concentration of HDL-c was higher after supplementation with dark chocolate (p = 0.008). PMID:27223302

On the Psychometric Study of Human Life History Strategies.

PubMed

Richardson, George B; Sanning, Blair K; Lai, Mark H C; Copping, Lee T; Hardesty, Patrick H; Kruger, Daniel J

2017-01-01

This article attends to recent discussions of validity in psychometric research on human life history strategy (LHS), provides a constructive critique of the extant literature, and describes strategies for improving construct validity. To place the psychometric study of human LHS on more solid ground, our review indicates that researchers should (a) use approaches to psychometric modeling that are consistent with their philosophies of measurement, (b) confirm the dimensionality of life history indicators, and (c) establish measurement invariance for at least a subset of indicators. Because we see confirming the dimensionality of life history indicators as the next step toward placing the psychometrics of human LHS on more solid ground, we use nationally representative data and structural equation modeling to test the structure of middle adult life history indicators. We found statistically independent mating competition and Super-K dimensions and the effects of parental harshness and childhood unpredictability on Super-K were consistent with past research. However, childhood socioeconomic status had a moderate positive effect on mating competition and no effect on Super-K, while unpredictability did not predict mating competition. We conclude that human LHS is more complex than previously suggested-there does not seem to be a single dimension of human LHS among Western adults and the effects of environmental components seem to vary between mating competition and Super-K.

TrackMate: An open and extensible platform for single-particle tracking.

PubMed

Tinevez, Jean-Yves; Perry, Nick; Schindelin, Johannes; Hoopes, Genevieve M; Reynolds, Gregory D; Laplantine, Emmanuel; Bednarek, Sebastian Y; Shorte, Spencer L; Eliceiri, Kevin W

2017-02-15

We present TrackMate, an open source Fiji plugin for the automated, semi-automated, and manual tracking of single-particles. It offers a versatile and modular solution that works out of the box for end users, through a simple and intuitive user interface. It is also easily scriptable and adaptable, operating equally well on 1D over time, 2D over time, 3D over time, or other single and multi-channel image variants. TrackMate provides several visualization and analysis tools that aid in assessing the relevance of results. The utility of TrackMate is further enhanced through its ability to be readily customized to meet specific tracking problems. TrackMate is an extensible platform where developers can easily write their own detection, particle linking, visualization or analysis algorithms within the TrackMate environment. This evolving framework provides researchers with the opportunity to quickly develop and optimize new algorithms based on existing TrackMate modules without the need of having to write de novo user interfaces, including visualization, analysis and exporting tools. The current capabilities of TrackMate are presented in the context of three different biological problems. First, we perform Caenorhabditis-elegans lineage analysis to assess how light-induced damage during imaging impairs its early development. Our TrackMate-based lineage analysis indicates the lack of a cell-specific light-sensitive mechanism. Second, we investigate the recruitment of NEMO (NF-κB essential modulator) clusters in fibroblasts after stimulation by the cytokine IL-1 and show that photodamage can generate artifacts in the shape of TrackMate characterized movements that confuse motility analysis. Finally, we validate the use of TrackMate for quantitative lifetime analysis of clathrin-mediated endocytosis in plant cells. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Mate competition and evolutionary outcomes in genetically modified zebrafish (Danio rerio).

PubMed

Howard, Richard D; Rohrer, Karl; Liu, Yiyang; Muir, William M

2015-05-01

Demonstrating relationships between sexual selection mechanisms and trait evolution is central to testing evolutionary theory. Using zebrafish, we found that wild-type males possessed a significant advantage in mate competition over transgenic RFP Glofish® males. In mating trials, wild-type males were aggressively superior to transgenic males in male-male chases and male-female chases; as a result, wild-type males sired 2.5× as many young as did transgenic males. In contrast, an earlier study demonstrated that female zebrafish preferred transgenic males as mates when mate competition was excluded experimentally. We tested the evolutionary consequence of this conflict between sexual selection mechanisms in a long-term study. The predicted loss of the transgenic phenotype was confirmed. More than 18,500 adults collected from 18 populations across 15 generations revealed that the frequency of the transgenic phenotype declined rapidly and was eliminated entirely in all but one population. Fitness component data for both sexes indicated that only male mating success differed between wild-type and transgenic individuals. Our predictive demographic model based on fitness components closely matched the rate of transgenic phenotype loss observed in the long-term study, thereby supporting its utility for studies assessing evolutionary outcomes of escaped or released genetically modified animals. © 2015 The Author(s).

Social biases determine spatiotemporal sparseness of ciliate mating heuristics.

PubMed

Clark, Kevin B

2012-01-01

Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate's initial subjective bias, responsiveness, or preparedness, as defined by Stevens' Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present findings indicate sparseness performs a similar function in single aneural cells by tuning the size and density of encoded computational architectures useful for decision making in social contexts.

Social biases determine spatiotemporal sparseness of ciliate mating heuristics

PubMed Central

2012-01-01

Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate’s initial subjective bias, responsiveness, or preparedness, as defined by Stevens’ Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present findings indicate sparseness performs a similar function in single aneural cells by tuning the size and density of encoded computational architectures useful for decision making in social contexts. PMID:22482001

REINFORCEMENT OF STICKLEBACK MATE PREFERENCES: SYMPATRY BREEDS CONTEMPT.

PubMed

Rundle, Howard D; Schluter, Dolph

1998-02-01

Detailed studies of reproductive isolation and how it varies among populations can provide valuable insight into the mechanisms of speciation. Here we investigate how the strength of premating isolation varies between sympatric and allopatric populations of threespine sticklebacks to test a prediction of the hypothesis of reinforcement: that interspecific mate discrimination should be stronger in sympatry than in allopatry. In conducting such tests, it is important to control for ecological character displacement between sympatric species because ecological character divergence may strengthen prezygotic isolation as a by-product. We control for ecological character displacement by comparing mate preferences of females from a sympatric population (benthics) with mate preferences of females from two allopatric populations that most closely resemble the sympatric benthic females in ecology and morphology. No-choice mating trials indicate that sympatric benthic females mate less readily with heterospecific (limnetic) than conspecific (benthic) males, whereas two different populations of allopatric females resembling benthics show no such discrimination. These differences demonstrate reproductive character displacement of benthic female mate choice. Previous studies have established that hybridization between sympatric species occurred in the past in the wild and that hybrid offspring have lower fitness than either parental species, thus providing conditions under which natural selection would favor individuals that do not hybridize. Results are therefore consistent with the hypothesis that female mate preferences have evolved as a response to reduced hybrid fitness (reinforcement), although direct effects of sympatry or a biased extinction process could also produce the pattern. Males of the other sympatric species (limnetics) showed a preference for smaller females, in contrast to the inferred ancestral preference for larger females, suggesting reproductive character displacement of limnetic male mate preferences as well. © 1998 The Society for the Study of Evolution.

The Effect of Yerba Mate (Ilex paraguarensis) Supplementation on the Productive Performance of Dorper Ewes and Their Progeny

PubMed Central

Po, Eleonora; Xu, Ziqian; Celi, Pietro

2012-01-01

Yerba Mate (Ilex paraguariensis), a tea known for its high antioxidant content, was supplemented to 30 of 60 ewes for 13 wks to assess its effect on their productive performance. A 2.5% inclusion rate of Yerba Mate (YM) in a pelleted concentrate diet decreased feed intake and live weight (LW) during the first few weeks post partum (p<0.001). Overall, the YM group ate less (2,092±78 g/d) pellet than the control (CTRL) one (2,434±83 g/d); similarly, LW was lower in the YM group compared to the CTRL one, 64.9±1.6 kg and 67.3±1.4 kg, respectively. Lambs’ birth weight and growth rates were not affected. At birth, lambs’ LW were similar between the Yerba Mate and control groups (4.2±0.5 kg and 4.1±0.4 kg, respectively. At the end of the trial, Yerba Mate lambs weighed 15.7±0.4 kg while CTRL lambs weighed 16.1±0.4 kg. Average daily growth rate was similar between the two groups and ranged from 176±19 to 234 ±24 g/d. The inclusion of Yerba Mate in a pelleted diet increased milk fat, protein and total solids content while it decreased milk lactose content. Further work is required to investigate the mechanisms by which Yerba Mate supplementation affects feed intake and milk composition. PMID:25049648

Higher male educational hypergamy: evidence from Portugal.

PubMed

Correia, Hamilton R

2003-04-01

Studies of human mate choice have been based almost exclusively on stated preferences and personal advertisements, and the external validity of such studies has therefore been questioned. In the present study, real-life matings based on a large representative sample of newly wed couples in 1998 (n=66,598) were analysed according to educational assortative mating. The results demonstrate a strong educational homogamy in this national Portuguese sample. However, men tend to marry women who are slightly more educated than themselves. The results are compared with those of a modern society (US, 1940-87) and a traditional society (Kipsigis, 1952-91). Since educational attainment is strongly associated with social status and intelligence, these results are discussed in an evolutionary perspective.

Disruptive ecological selection on a mating cue.

PubMed

Merrill, Richard M; Wallbank, Richard W R; Bull, Vanessa; Salazar, Patricio C A; Mallet, James; Stevens, Martin; Jiggins, Chris D

2012-12-22

Adaptation to divergent ecological niches can result in speciation. Traits subject to disruptive selection that also contribute to non-random mating will facilitate speciation with gene flow. Such 'magic' or 'multiple-effect' traits may be widespread and important for generating biodiversity, but strong empirical evidence is still lacking. Although there is evidence that putative ecological traits are indeed involved in assortative mating, evidence that these same traits are under divergent selection is considerably weaker. Heliconius butterfly wing patterns are subject to positive frequency-dependent selection by predators, owing to aposematism and Müllerian mimicry, and divergent colour patterns are used by closely related species to recognize potential mates. The amenability of colour patterns to experimental manipulation, independent of other traits, presents an excellent opportunity to test their role during speciation. We conducted field experiments with artificial butterflies, designed to match natural butterflies with respect to avian vision. These were complemented with enclosure trials with live birds and real butterflies. Our experiments showed that hybrid colour-pattern phenotypes are attacked more frequently than parental forms. For the first time, we demonstrate disruptive ecological selection on a trait that also acts as a mating cue.

Variation in pre- and post-copulatory sexual selection on male genital size in two species of lygaeid bug.

PubMed

Dougherty, Liam R; Shuker, David M

Sexual selection has been shown to be the driving force behind the evolution of the sometimes extreme and elaborate genitalia of many species. Sexual selection may arise before and/or after mating, or vary according to other factors such as the social environment. However, bouts of selection are typically considered in isolation. We measured the strength and pattern of selection acting on the length of the male intromittent organ (or processus) in two closely related species of lygaeid seed bug: Lygaeus equestris and Lygaeus simulans . In both species, we measured both pre- and post-copulatory selection. For L. equestris , we also varied the experimental choice design used in mating trials. We found contrasting pre- and post-copulatory selection on processus length in L. equestris . Furthermore, significant pre-copulatory selection was only seen in mating trials in which two males were present. This selection likely arises indirectly due to selection on a correlated trait, as the processus does not interact with the female prior to copulation. In contrast, we were unable to detect significant pre- or post-copulatory selection on processus length in L. simulans . However, a formal meta-analysis of previous estimates of post-copulatory selection on processus length in L. simulans suggests that there is significant stabilising selection across studies, but the strength of selection varies between experiments. Our results emphasise that the strength and direction of sexual selection on genital traits may be multifaceted and can vary across studies, social contexts and different stages of reproduction. Animal genitalia vary greatly in size and complexity across species, and selection acting on genital size and shape can be complex. In this study, we show that the length of the penis in two species of seed bug is subject to complex patterns of selection, varying depending on the social context and whether selection is measured before or after mating. In one of the species, we show unexpectedly that penis length is correlated with male mating success, despite the fact that the penis does not interact with the female prior to mating. Our results highlight the fact that genitalia may be subject to both direct and indirect selection at different stages of mating and that to fully understand the evolution of such traits we should combine estimates of selection arising from these multiple episodes.

Exploitation of insect vibrational signals reveals a new method of pest management.

PubMed

Eriksson, Anna; Anfora, Gianfranco; Lucchi, Andrea; Lanzo, Francesco; Virant-Doberlet, Meta; Mazzoni, Valerio

2012-01-01

Food production is considered to be the main source of human impact on the environment and the concerns about detrimental effects of pesticides on biodiversity and human health are likely to lead to an increasingly restricted use of chemicals in agriculture. Since the first successful field trial, pheromone based mating disruption enabled sustainable insect control, which resulted in reduced levels of pesticide use. Organic farming is one of the fastest growing segments of agriculture and with the continuously growing public concern about use of pesticides, the main remaining challenge in increasing the safety of the global food production is to identify appropriate alternative mating disruption approaches for the numerous insect pests that do not rely on chemical communication. In the present study, we show for the first time that effective mating disruption based on substrate-borne vibrational signals can be achieved in the field. When disruptive vibrational signals were applied to grapevine plants through a supporting wire, mating frequency of the leafhopper pest Scaphoideus titanus dropped to 9 % in semi-field conditions and to 4 % in a mature vineyard. The underlying mechanism of this environmentally friendly pest-control tactic is a masking of the vibrational signals used in mate recognition and location. Because vibrational communication is widespread in insects, mating disruption using substrate vibrations can transform many open field and greenhouse based farming systems.

A Randomized Controlled Trial Evaluation of an After-School Prosocial Behavior Program in an Area of Socioeconomic Disadvantage

ERIC Educational Resources Information Center

O'Hare, Liam; Biggart, Andy; Kerr, Karen; Connolly, Paul

2015-01-01

A randomized controlled trial was used to evaluate the effects of a prosocial behavior after-school program called Mate-Tricks for 9- and 10-year-old children and their parents living in an area of significant socioeconomic disadvantage. The children were randomly assigned to an intervention (n = 220) or a control group (n = 198). Children were…

Does large body size in males evolve to facilitate forcible insemination? A study on garter snakes.

PubMed

Shine, Richard; Mason, Robert T

2005-11-01

A trend for larger males to obtain a disproportionately high number of matings, as occurs in many animal populations, typically is attributed either to female choice or success in male-male rivalry; an alternative mechanism, that larger males are better able to coercively inseminate females, has received much less attention. For example, previous studies on garter snakes (Thamnophis sirtalis parietalis) at communal dens in Manitoba have shown that the mating benefit to larger body size in males is due to size-dependent advantages in male-male rivalry. However, this previous work ignored the possibility that larger males may obtain more matings because of male-female interactions. In staged trials within outdoor arenas, larger body size enhanced male mating success regardless of whether a rival male was present. The mechanism involved was coercion rather than female choice, because mating occurred most often (and soonest) in females that were least able to resist courtship-induced hypoxic stress. Males do physically displace rivals from optimal positions in the mating ball, and larger males are better able to resist such displacement. Nonetheless, larger body size enhances male mating success even in the absence of such male-male interactions. Thus, even in mating systems where males compete physically and where larger body size confers a significant advantage in male-male competition, the actual selective force for larger body size in males may relate to forcible insemination of unreceptive females. Experimental studies are needed to determine whether the same situation occurs in other organisms in which body-size advantages have been attributed to male-male rather than male-female interactions.

HeartMate II left ventricular assist system: from concept to first clinical use.

PubMed

Griffith, B P; Kormos, R L; Borovetz, H S; Litwak, K; Antaki, J F; Poirier, V L; Butler, K C

2001-03-01

The HeartMate II left ventricular assist device (LVAD) (ThermoCardiosystems, Inc, Woburn, MA) has evolved from 1991 when a partnership was struck between the McGowan Center of the University of Pittsburgh and Nimbus Company. Early iterations were conceptually based on axial-flow mini-pumps (Hemopump) and began with purge bearings. As the project developed, so did the understanding of new bearings, computational fluid design and flow visualization, and speed control algorithms. The acquisition of Nimbus by ThermoCardiosystems, Inc (TCI) sped developments of cannulas, controller, and power/monitor units. The system has been successfully tested in more than 40 calves since 1997 and the first human implant occurred in July 2000. Multicenter safety and feasibility trials are planned for Europe and soon thereafter a trial will be started in the United States to test 6-month survival in end-stage heart failure.

The truthful signalling hypothesis: an explicit general equilibrium model.

PubMed

Hausken, Kjell; Hirshleifer, Jack

2004-06-21

In mating competition, the truthful signalling hypothesis (TSH), sometimes known as the handicap principle, asserts that higher-quality males signal while lower-quality males do not (or else emit smaller signals). Also, the signals are "believed", that is, females mate preferentially with higher-signalling males. Our analysis employs specific functional forms to generate analytic solutions and numerical simulations that illuminate the conditions needed to validate the TSH. Analytic innovations include: (1) A Mating Success Function indicates how female mating choices respond to higher and lower signalling levels. (2) A congestion function rules out corner solutions in which females would mate exclusively with higher-quality males. (3) A Malthusian condition determines equilibrium population size as related to per-capita resource availability. Equilibria validating the TSH are achieved over a wide range of parameters, though not universally. For TSH equilibria it is not strictly necessary that the high-quality males have an advantage in terms of lower per-unit signalling costs, but a cost difference in favor of the low-quality males cannot be too great if a TSH equilibrium is to persist. And although the literature has paid less attention to these points, TSH equilibria may also fail if: the quality disparity among males is too great, or the proportion of high-quality males in the population is too large, or if the congestion effect is too weak. Signalling being unprofitable in aggregate, it can take off from a no-signalling equilibrium only if the trait used for signalling is not initially a handicap, but instead is functionally useful at low levels. Selection for this trait sets in motion a bandwagon, whereby the initially useful indicator is pushed by male-male competition into the domain where it does indeed become a handicap.

A Novel Quantitative Approach to Women’s Reproductive Strategies

PubMed Central

Milne, Fritha H.; Judge, Debra S.

2012-01-01

The patterned way in which individuals allocate finite resources to various components of reproduction (e.g. mating effort, reproductive timing and parental investment) is described as a reproductive strategy. As energy is limited, trade-offs between and within aspects of reproductive strategies are expected. The first aim of this study was to derive aspects of reproductive strategies using complete reproductive histories from 718 parous Western Australian women. Factor analysis using a subset of these participants resulted in six factors that represented ‘short-term mating strategy’, ‘early onset of sexual activity’, ‘reproductive output’, ‘timing of childbearing’, ‘breastfeeding’, and ‘child spacing’. This factor structure was internally validated by replication using a second independent subset of the data. The second aim of this study examined trade-offs between aspects of reproductive strategies derived from aim one. Factor scores calculated for each woman were incorporated in generalised linear models and interaction terms were employed to examine the effect of mating behaviour on the relationships between reproductive timing, parental investment and overall reproductive success. Early sexual activity correlates with early reproductive onset for women displaying more long-term mating strategies. Women with more short-term mating strategies exhibit a trade-off between child quantity and child quality not observed in women with a long-term mating strategy. However, women with a short-term mating strategy who delay reproductive timing exhibit levels of parental investment (measured as breastfeeding duration per child) similar to that of women with long-term mating strategies. Reproductive delay has fitness costs (fewer births) for women displaying more short-term mating strategies. We provide empirical evidence that reproductive histories of contemporary women reflect aspects of reproductive strategies, and associations between these strategic elements, as predicted from life history theory. PMID:23056440

No evidence for female discrimination against male house mice carrying a selfish genetic element

PubMed Central

Lindholm, Anna K.

2016-01-01

Meiotic drivers distort transmission to the next generation in their favor, with detrimental effects on the fitness of their homologues and the rest of the genome. Male carriers of meiotic drivers commonly inflict costs on their mates through genetic incompatibility, reduced fecundity, or biased brood sex ratios. Given these costs, evidence for female discrimination against male carriers is surprisingly rare. One of few examples is the t haplotype in house mice, a meiotic driver that shows strong transmission distortion in males and is typically homozygote lethal. As a consequence, mating between 2 t heterozygous (+/t) mice leads to high embryo mortality. Previous experiments showing that +/t females avoid this incompatibility cost by preferring +/+ versus +/t males have inferred preference based on olfactory cues or brief social interactions. Evidence from mating contexts in laboratory settings and semi-natural populations has been inconclusive. Here, we investigated female choice from a large number of no-choice mating trials. We found no evidence for discrimination against +/t males based on mating, remating, and copulatory behavior. Further, we found no evidence for avoidance of incompatibility through selective interactions between gametes. The likelihood of mating showed significant effects of female weight and genotype, suggesting that our test paradigm enabled females to exhibit mate choice. We discuss the strengths and limitations of our approach. By explicitly considering selection at both the individual and gene level, we argue why precopulatory female discrimination by +/t females may be less evolutionarily stable than discrimination by all females based on postcopulatory mechanisms. PMID:29491955

Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3

PubMed Central

Zhou, Gaofeng; Ryan, Peter R.

2014-01-01

Malate and citrate efflux from root apices is a mechanism of Al3+ tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al3+-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approach to increase the Al3+ tolerance of barley by transforming it with two MATE genes that encode citrate transporters: SbMATE is the major Al3+-tolerance gene from sorghum whereas FRD3 is involved with Fe nutrition in Arabidopsis. Independent transgenic and null T3 lines were generated for both transgenes. Lines expressing SbMATE showed Al3+-activated citrate efflux from root apices and greater tolerance to Al3+ toxicity than nulls in hydroponic and short-term soil trials. Transgenic lines expressing FRD3 exhibited similar phenotypes except citrate release from roots occurred constitutively. The Al3+ tolerance of these lines was compared with previously generated transgenic barley lines overexpressing the endogenous HvAACT1 gene and the TaALMT1 gene from wheat. Barley lines expressing TaALMT1 showed significantly greater Al3+ tolerance than all lines expressing MATE genes. This study highlights the relative efficacy of different organic anion transport proteins for increasing the Al3+ tolerance of an important crop species. PMID:24692647

No evidence for female discrimination against male house mice carrying a selfish genetic element.

PubMed

Sutter, Andreas; Lindholm, Anna K

2016-12-01

Meiotic drivers distort transmission to the next generation in their favor, with detrimental effects on the fitness of their homologues and the rest of the genome. Male carriers of meiotic drivers commonly inflict costs on their mates through genetic incompatibility, reduced fecundity, or biased brood sex ratios. Given these costs, evidence for female discrimination against male carriers is surprisingly rare. One of few examples is the t haplotype in house mice, a meiotic driver that shows strong transmission distortion in males and is typically homozygote lethal. As a consequence, mating between 2 t heterozygous (+/ t ) mice leads to high embryo mortality. Previous experiments showing that +/ t females avoid this incompatibility cost by preferring +/+ versus +/ t males have inferred preference based on olfactory cues or brief social interactions. Evidence from mating contexts in laboratory settings and semi-natural populations has been inconclusive. Here, we investigated female choice from a large number of no-choice mating trials. We found no evidence for discrimination against +/ t males based on mating, remating, and copulatory behavior. Further, we found no evidence for avoidance of incompatibility through selective interactions between gametes. The likelihood of mating showed significant effects of female weight and genotype, suggesting that our test paradigm enabled females to exhibit mate choice. We discuss the strengths and limitations of our approach. By explicitly considering selection at both the individual and gene level, we argue why precopulatory female discrimination by +/ t females may be less evolutionarily stable than discrimination by all females based on postcopulatory mechanisms.

An experimental test for indirect benefits in Drosophila melanogaster

PubMed Central

Rundle, Howard D; Ödeen, Anders; Mooers, Arne Ø

2007-01-01

Background Despite much empirical attention, tests for indirect benefits of mate choice have rarely considered the major components of sexual and nonsexual offspring fitness relevant to a population. Here we use a novel experimental design to test for the existence of any indirect benefits in a laboratory adapted population of D. melanogaster. Our experiment compared the fitness (mating success, longevity, and productivity) of individuals possessing genomes that derived two generations previously from males that were either entirely successful (studs) or wholly unsuccessful (duds) at achieving mates in three subsequent rounds of mating trials. Results Males from the stud treatment were 30% more successful on average at securing mates than males from the dud treatment. In contrast, we found no difference between treatments in measures of productivity or of longevity when measured in a mixed-sex environment. In the absence of females, however, males in the stud treatment outlived males in the dud treatment. Conclusion Our results suggest that mating with successful males in this population provides an indirect benefit to females and that, at least in this environment, the benefit arises primarily through the production of more attractive male offspring. However, it is unclear whether this represents solely a traditional sexy sons benefit or whether there is an additional good genes component (with male offspring simply allocating their surplus condition to traits that enhance their mating success). The lack of any detectable differences in female fitness between the two treatments suggests the former, although the longevity advantage of males in the stud treatment when females were absent is consistent with the latter. Determining the effect of this indirect benefit on the evolution of female mate preferences (or resistance) will require comparable data on the direct costs of mating with various males, and an understanding of how these costs and benefits integrate across generations and vary among environments. PMID:17349042

Sex in murky waters: algal-induced turbidity increases sexual selection in pipefish.

PubMed

Sundin, Josefin; Aronsen, Tonje; Rosenqvist, Gunilla; Berglund, Anders

2017-01-01

Algal-induced turbidity has been shown to alter several important aspects of reproduction and sexual selection. However, while turbidity has been shown to negatively affect reproduction and sexually selected traits in some species, it may instead enhance reproductive success in others, implying that the impact of eutrophication is far more complex than originally believed. In this study, we aimed to provide more insight into these inconsistent findings. We used molecular tools to investigate the impact of algal turbidity on reproductive success and sexual selection on males in controlled laboratory experiments, allowing mate choice, mating competition, and mate encounter rates to affect reproduction. As study species, we used the broad-nosed pipefish, Syngnathus typhle , a species practicing male pregnancy and where we have previously shown that male mate choice is impaired by turbidity. Here, turbidity instead enhanced sexual selection on male size and mating success as well as reproductive success. Effects from mating competition and mate encounter rates may thus override effects from mate choice based on visual cues, producing an overall stronger sexual selection in turbid waters. Hence, seemingly inconsistent effects of turbidity on sexual selection may depend on which mechanisms of sexual selection that have been under study. Algal blooms are becoming increasingly more common due to eutrophication of freshwater and marine environments. The high density of algae lowers water transparency and reduces the possibility for fish and other aquatic animals to perform behaviors dependent on vision. We have previously shown that pipefish are unable to select the best partner in mate choice trials when water transparency was reduced. However, fish might use other senses than vision to compensate for the reduction in water transparency. In this study, we found that when fish were allowed to freely interact, thereby allowing competition between partners and direct contact between the fish, the best partner was indeed chosen. Hence, the negative effects of reduced water visibility due to algal blooms may be counteracted by the use of other senses in fish.

Male antenna morphology and its effect on scramble competition in false garden mantids

NASA Astrophysics Data System (ADS)

Jayaweera, Anuradhi; Barry, Katherine L.

2017-10-01

Well-developed antennae are crucial for many insects, but especially for scramble competitors, who race to find their mates using female sex cues. In these systems, the ability of males to locate females quickly is thought to be under strong selection. A rarely tested assumption is that males with more sensory structures are able to locate females faster. In the present study, we used the false garden mantid Pseudomantis albofimbriata to investigate male antennal morphology and its effect on male efficiency in finding a mate. We used scanning electron microscopy to describe the major sensilla types and their arrangement along the length of male antennae. We also conducted field enclosure trials relating male antennal morphology to scramble competition in this system. We identified six different types of antennal sensilla (cheatic, trichoid, basiconic, grooved peg, ceolocapitular and campaniform) on male P. albofimbriata antennae. As expected, males who had more trichoid sensilla located females quicker than did males with fewer sensilla. Results of the current study suggest that antenna morphology plays a significant role in mate location and hence scramble competition in the P. albofimbriata mating system.

Male antenna morphology and its effect on scramble competition in false garden mantids.

PubMed

Jayaweera, Anuradhi; Barry, Katherine L

2017-08-23

Well-developed antennae are crucial for many insects, but especially for scramble competitors, who race to find their mates using female sex cues. In these systems, the ability of males to locate females quickly is thought to be under strong selection. A rarely tested assumption is that males with more sensory structures are able to locate females faster. In the present study, we used the false garden mantid Pseudomantis albofimbriata to investigate male antennal morphology and its effect on male efficiency in finding a mate. We used scanning electron microscopy to describe the major sensilla types and their arrangement along the length of male antennae. We also conducted field enclosure trials relating male antennal morphology to scramble competition in this system. We identified six different types of antennal sensilla (cheatic, trichoid, basiconic, grooved peg, ceolocapitular and campaniform) on male P. albofimbriata antennae. As expected, males who had more trichoid sensilla located females quicker than did males with fewer sensilla. Results of the current study suggest that antenna morphology plays a significant role in mate location and hence scramble competition in the P. albofimbriata mating system.

Territorial behavior of a green hairstreak Chrysozephyrus smaragdinus (Lepidoptera: Lycaenidae): site tenacity and wars of attrition.

PubMed

Takeuchi, Tsuyoshi; Imafuku, Michio

2005-09-01

Males of Chrysozephyrus smaragdinus were active from late morning to late afternoon, during which they showed territorial behavior, perhaps for mating. The territorial male stayed in a particular area and occasionally flew around it, referred to hereafter as the inspection area. When other male intruded into this area, the territorial male rushed to him. Then, they engaged in a circling flight regarded as a "war of attrition". During this flight, the two males sometimes strayed far away from the territory. After the circling flight, the resident returned to his territory in almost all cases (98%). Despite such intrusions, many residents defended their territory for several successive days. This suggests strongly the "effect of prior residence". We recorded the circling flights with a high-speed video camera, and confirmed that the male that ceased the circling flight first was the loser. This finding gave some validity to consider circling flight as wars of attrition. In a few cases, the territorial male mated with a female that came to the territory. These once mated males held the territory no longer, suggesting that mating experience should restrict the next mating opportunity in this species.

Quantification of mutation-derived bias for alternate mating functionalities of the Saccharomyces cerevisiae Ste2p pheromone receptor.

PubMed

Choudhary, Pooja; Loewen, Michele C

2016-01-01

Although well documented for mammalian G-protein-coupled receptors, alternate functionalities and associated alternate signalling remain to be unequivocally established for the Saccharomyces cerevisiae pheromone Ste2p receptor. Here, evidence supporting alternate functionalities for Ste2p is re-evaluated, extended and quantified. In particular, strong mating and constitutive signalling mutations, focusing on residues S254, P258 and S259 in TM6 of Ste2p, are stacked and investigated in terms of their effects on classical G-protein-mediated signal transduction associated with cell cycle arrest, and alternatively, their impact on downstream mating projection and zygote formation events. In relative dose response experiments, accounting for systemic and observational bias, mutational-derived functional differences were observed, validating the S254L-derived bias for downstream mating responses and highlighting complex relationships between TM6-mutation derived constitutive signalling and ligand-induced functionalities. Mechanistically, localization studies suggest that alterations to receptor trafficking may contribute to mutational bias, in addition to expected receptor conformational stabilization effects. Overall, these results extend previous observations and quantify the contributions of Ste2p variants to mediating cell cycle arrest versus downstream mating functionalities. © Crown copyright 2015.

How a microbial drug transporter became essential for crop cultivation on acid soils: aluminium tolerance conferred by the multidrug and toxic compound extrusion (MATE) family

PubMed Central

Magalhaes, Jurandir V.

2010-01-01

Background Aluminium (Al) toxicity is a major agricultural constraint for crop cultivation on acid soils, which comprise a large portion of the world's arable land. One of the most widely accepted mechanisms of Al tolerance in plants is based on Al-activated organic acid release into the rhizosphere, with organic acids forming stable, non-toxic complexes with Al. This mechanism has recently been validated by the isolation of bona-fide Al-tolerance genes in crop species, which encode membrane transporters that mediate Al-activated organic acid release leading to Al exclusion from root apices. In crop species such as sorghum and barley, members in the multidrug and toxic compound extrusion (MATE) family underlie Al tolerance by a mechanism based on Al-activated citrate release. Scope and Conclusions The study of Al tolerance in plants as conferred by MATE family members is in its infancy. Therefore, much is yet to be discovered about the functional diversity and evolutionary dynamics that led MATE proteins to acquire transport properties conducive to Al tolerance in plants. In this paper we review the major characteristics of transporters in the MATE family and will relate this knowledge to Al tolerance in plants. The MATE family is clearly extremely flexible with respect to substrate specificity, which raises the possibility that Al tolerance as encoded by MATE proteins may not be restricted to Al-activated citrate release in plant species. There are also indications that regulatory loci may be of pivotal importance to fully explore the potential for Al-tolerance improvement based on MATE genes. PMID:20511585

Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3.

PubMed

Zhou, Gaofeng; Pereira, Jorge F; Delhaize, Emmanuel; Zhou, Meixue; Magalhaes, Jurandir V; Ryan, Peter R

2014-06-01

Malate and citrate efflux from root apices is a mechanism of Al(3+) tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al(3+)-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approach to increase the Al(3+) tolerance of barley by transforming it with two MATE genes that encode citrate transporters: SbMATE is the major Al(3+)-tolerance gene from sorghum whereas FRD3 is involved with Fe nutrition in Arabidopsis. Independent transgenic and null T3 lines were generated for both transgenes. Lines expressing SbMATE showed Al(3+)-activated citrate efflux from root apices and greater tolerance to Al(3+) toxicity than nulls in hydroponic and short-term soil trials. Transgenic lines expressing FRD3 exhibited similar phenotypes except citrate release from roots occurred constitutively. The Al(3+) tolerance of these lines was compared with previously generated transgenic barley lines overexpressing the endogenous HvAACT1 gene and the TaALMT1 gene from wheat. Barley lines expressing TaALMT1 showed significantly greater Al(3+) tolerance than all lines expressing MATE genes. This study highlights the relative efficacy of different organic anion transport proteins for increasing the Al(3+) tolerance of an important crop species. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

All or nothing: Area-wide approach frustrates peachtree borers in Georgia

USDA-ARS?s Scientific Manuscript database

Mating disruption research has been done in the southeast against borers attacking peach since the sex pheromones of the peachtree borer, Synanthedon exitiosa (Lepidoptera: Sesiidae) and lesser peachtree borer, S. pictipes (Lepidoptera: Sesiidae) were identified. However, replicated trials over thr...

Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

PubMed Central

Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

2015-01-01

The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

The efficiency of close inbreeding to reduce genetic adaptation to captivity

PubMed Central

Theodorou, K; Couvet, D

2015-01-01

Although ex situ conservation is indispensable for thousands of species, captive breeding is associated with negative genetic changes: loss of genetic variance and genetic adaptation to captivity that is deleterious in the wild. We used quantitative genetic individual-based simulations to model the effect of genetic management on the evolution of a quantitative trait and the associated fitness of wild-born individuals that are brought to captivity. We also examined the feasibility of the breeding strategies under a scenario of a large number of loci subject to deleterious mutations. We compared two breeding strategies: repeated half-sib mating and a method of minimizing mean coancestry (referred to as gc/mc). Our major finding was that half-sib mating is more effective in reducing genetic adaptation to captivity than the gc/mc method. Moreover, half-sib mating retains larger allelic and adaptive genetic variance. Relative to initial standing variation, the additive variance of the quantitative trait increased under half-sib mating during the sojourn in captivity. Although fragmentation into smaller populations improves the efficiency of the gc/mc method, half-sib mating still performs better in the scenarios tested. Half-sib mating shows two caveats that could mitigate its beneficial effects: low heterozygosity and high risk of extinction when populations are of low fecundity and size and one of the following conditions are met: (i) the strength of selection in captivity is comparable with that in the wild, (ii) deleterious mutations are numerous and only slightly deleterious. Experimental validation of half-sib mating is therefore needed for the advancement of captive breeding programs. PMID:25052417

Polyandry: the history of a revolution

PubMed Central

Parker, Geoff A.; Birkhead, Tim R.

2013-01-01

We give a historic overview and critical perspective of polyandry in the context of sexual selection. Early approaches tended to obfuscate the fact that the total matings (copulations) by the two sexes is equal, neglecting female interests and that females often mate with (or receive ejaculates from) more than one male (polyandry). In recent years, we have gained much more insight into adaptive reasons for polyandry, particularly from the female perspective. However, costs and benefits of multiple mating are unlikely to be equal for males and females. These must be assessed for each partner at each potential mating between male i and female j, and will often be highly asymmetric. Interests of i and j may be in conflict, with (typically, ultimately because of primordial sex differences) i benefitting and j losing from mating, although theoretically the reverse can also obtain. Polyandry reduces the sex difference in Bateman gradients, and the probability of sexual conflict over mating by: (i) reducing the potential expected value of each mating to males in inverse proportion to the number of mates per female per clutch, and also often by (ii) increasing ejaculate costs through increased sperm allocation. It can nevertheless create conflict over fertilization and increase conflict over parental investment. The observed mean mating frequency for the population (and hence the degree of polyandry) is likely, at least in part, to reflect a resolution of sexual conflict. Immense diversity exists across and within taxa in the extent of polyandry, and views on its significance have changed radically, as we illustrate using avian polyandry as a case study. Despite recent criticisms, the contribution of the early pioneers of sexual selection, Darwin and Bateman, remains generally valid, and should not, therefore, be negated; as with much in science, pioneering advances are more often amplified and refined, rather than replaced with entirely new paradigms. PMID:23339245

A Rare-Male Advantage in the Housefly Induced by Wing Clipping and Some General Considerations for Drosophila

PubMed Central

Bryant, Edwin H.; Kence, Aykut; Kimball, Kay T.

1980-01-01

Multiple-choice crosses among five geographic strains of the housefly, Musca domestica L., were carried out in equal (10:10) and low-frequency (4:16) ratios. Initially, a low-frequency-male mating advantage was apparent, but further analyses related this minority advantage to a reduction of male mating success during marking by wing clipping. When there are fluctuating differences in the level of sexual vigor between competing male types over replicate trials of a cross, a mating advantage will accrue to the minority type. Even if males from the two competing strains are equally vigorous, such fluctuating differences will occur during sampling of flies. Harming the flies during marking will serve to enhance this effect and make significant departures toward greater mating success of rare males highly likely. This statistical bias in favor of minority males was substantiated in simulations of the Kence-Bryant model of mating success and compared with our results of a minority advantage in the housefly and with published results of a minority advantage in Drosophila. Our evidence, though circumstantial, that an advantage to minority males could have been induced by such an experimental bias suggests that a re-examination of existing data, as well as new experimentation, is necessary to discern whether or not a real rare-male advantage exists. PMID:7262546

Biocontrol of Sugarcane Smut Disease by Interference of Fungal Sexual Mating and Hyphal Growth Using a Bacterial Isolate.

PubMed

Liu, Shiyin; Lin, Nuoqiao; Chen, Yumei; Liang, Zhibin; Liao, Lisheng; Lv, Mingfa; Chen, Yufan; Tang, Yingxin; He, Fei; Chen, Shaohua; Zhou, Jianuan; Zhang, Lianhui

2017-01-01

Sugarcane smut is a fungal disease caused by Sporisorium scitamineum , which can cause severe economic losses in sugarcane industry. The infection depends on the mating of bipolar sporida to form a dikaryon and develops into hyphae to penetrate the meristematic tissue of sugarcane. In this study, we set to isolate bacterial strains capable of blocking the fungal mating and evaluate their potential in control of sugarcane smut disease. A bacterial isolate ST4 from rhizosphere displayed potent inhibitory activity against the mating of S. scitamineum bipolar sporida and was selected for further study. Phylogenetic analyses and biochemical characterization showed that the isolate was most similar to Pseudomonas guariconensis . Methanol extracts from minimum and potato dextrose agar (PDA) agar medium, on which strain ST4 has grown, showed strong inhibitory activity on the sexual mating of S. scitamineum sporida, without killing the haploid cells MAT-1 or MAT-2. Further analysis showed that only glucose, but not sucrose, maltose, and fructose, could support strain ST4 to produce antagonistic chemicals. Consistent with the above findings, greenhouse trials showed that addition of 2% glucose to the bacterial inoculum significantly increased the strain ST4 biocontrol efficiency against sugarcane smut disease by 77% than the inoculum without glucose. The results from this study depict a new strategy to screen for biocontrol agents for control and prevention of the sugarcane smut disease.

Smelling fit: scent marking exposes parasitic infection status in the banded mongoose.

PubMed

Mitchell, Jessica; Cant, Michael A; Vitikainen, Emma I K; Nichols, Hazel J

2017-06-01

Preference for uninfected mates is presumed beneficial as it minimizes one's risk of contracting an infection and infecting one's offspring. In avian systems, visual ornaments are often used to indicate parasite burdens and facilitate mate choice. However, in mammals, olfactory cues have been proposed to act as a mechanism allowing potential mates to be discriminated by infection status. The effect of infection upon mammalian mate choice is mainly studied in captive rodents where experimental trials support preference for the odors of uninfected mates and some data suggest scent marking is reduced in individuals with high infection burdens. Nevertheless, whether such effects occur in nonmodel and wild systems remains poorly understood. Here, we investigate the interplay between parasite load (estimated using fecal egg counts) and scent marking behavior in a wild population of banded mongooses Mungos mungo . Focusing on a costly protozoan parasite of the genus Isospora and the nematode worm Toxocara , we first show that banded mongooses that engage in frequent, intensive scent marking have lower Isospora loads, suggesting marking behavior may be an indicator trait regarding infection status. We then use odor presentations to demonstrate that banded mongooses mark less in response to odors of opposite sexed individuals with high Isospora and Toxocara loads. As both of these parasites are known to have detrimental effects upon the health of preweaned young in other species, they would appear key targets to avoid during mate choice. Results provide support for scent as an important ornament and mechanism for advertising parasitic infection within wild mammals.

Hit or Miss: Fertilization Outcomes of Natural Inseminations by Japanese Quail

PubMed Central

Adkins-Regan, Elizabeth

2015-01-01

Variation in fertilization success underlies sexual selection, yet mating does not guarantee fertilization. The relationship between natural inseminations and fertilization success is essential for understanding sexual selection, yet that relationship and its underlying mechanisms are poorly understood in sperm-storing vertebrates such as birds. Here the relationship is analyzed in mating trials using Japanese quail (Coturnix japonica), which show striking variation in the fertilizing success of inseminations. Failures of males’ inseminations to fertilize eggs were mainly due to failures prior to sperm-egg contact. Fertilization probabilities on any given day were unrelated to whether the female had laid an egg the previous day, arguing against stimulation of sperm release from sperm storage tubules by the events of the daily egg-laying cycle. Instead, an unfertilized egg laid between two fertilized eggs predicted a longer sperm storage interval. Both sexes gained similar numbers of fertilized eggs by mating with a second partner the next day, but males, unlike females in a previous study, did not gain by having two females to mate with at the same time. Instead, they were both behaviorally and sperm limited, whereas females gain by mating twice in quick succession. Even double inseminations often failed to fertilize any eggs, and multiple matings would be needed for an entire clutch to be fertilized with high certainty. Paradoxically, this low and probabilistic fertilization success co-occurs with other notable characteristics of male quail suggestive of past sexual selection for increased success, including vigorous copulatory behavior, forced copulations, foamy secretion aiding in sperm competition, large testes and unusual sperm morphology. PMID:26222780

Predictive Validity and Adjustment of Ideal Partner Preferences Across the Transition Into Romantic Relationships.

PubMed

Gerlach, Tanja M; Arslan, Ruben C; Schultze, Thomas; Reinhard, Selina K; Penke, Lars

2017-09-18

Although empirical research has investigated what we ideally seek in a romantic partner for decades, the crucial question of whether ideal partner preferences actually guide our mating decisions in real life has remained largely unanswered. One reason for this is the lack of designs that assess individuals' ideal partner preferences before entering a relationship and then follow up on them over an extended period. In the Göttingen Mate Choice Study (GMCS), a preregistered, large-scale online study, we used such a naturalistic prospective design. We investigated partner preferences across 4 preference domains in a large sample of predominantly heterosexual singles (N = 763, aged 18-40 years) and tracked these individuals across a period of 5 months upon a possible transition into romantic relationships. Attesting to their predictive validity, partner preferences prospectively predicted the characteristics of later partners. This was equally true for both sexes, except for vitality-attractiveness where men's preferences were more predictive of their later partners' standing on this dimension than women's. Self-perceived mate value did not moderate the preference-partner characteristics relations. Preferences proved to be relatively stable across the 5 months interval, yet were less stable for those who entered a relationship. Subgroup analyses using a newly developed indicator of preference adjustment toward (vs. away from) partner characteristics revealed that participants adjusted their preferences downward when partners fell short of initial preferences, but showed no consistent adjustment when partners exceeded them. Results and implications are discussed against the background of ongoing controversies in mate choice and romantic relationship research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Reproductive isolation and the expansion of an invasive hybrid swarm

USGS Publications Warehouse

Blum, Michael J.; Walters, David M.; Burkhead, Noel M.; Freeman, Byron J.; Porter, Brady A.

2010-01-01

Biological invasions involving hybridization proceed according to prezygotic and postzygotic reproductive isolating mechanisms. Yet few comparisons of reproductive isolation have been carried out to understand how different mechanisms prevent or promote invasions involving hybridization. Here we present a study of prezygotic and postzygotic isolation between non-native red shiner (Cyprinella lutrensis) and native blacktail shiner (C. venusta stigmatura) from the Coosa River basin (USA) to better understand the formation and expansion of invasive hybrid swarms. We conducted spawning trials to measure mating preferences and raised broods from crosses to assay hybrid viability through early juvenile development. Females of both species were more responsive to conspecific mates, although blacktail shiner females responded more often to heterospecific mates than did red shiner females. Fecundity of red shiner females was also higher than blacktail shiner females. Heterospecific crosses resulted in lower fertilization and egg hatching rates, but we found no other evidence of inviability. Rather, we found comparatively low larval mortality of F1 hybrids, which is suggestive of heterosis. These findings support prior inferences of assortative mating from genetic descriptions of hybridization, and that the invasion in the Coosa River is likely proceeding due to interspecific competition and intrinsic hybrid viability.

Eliminating female Anopheles arabiensis by spiking blood meals with toxicants as a sex separation method in the context of the sterile insect technique

PubMed Central

2013-01-01

Background Ivermectin has longevity reducing effects in several insect species, including disease transmitting mosquitoes after feeding on hosts that have received ivermectin treatment. This has important implications in mosquito population control and thus the reduction of disease transmission. In addition, ivermectin could play an enormous role in mosquito control operations by its use in the female elimination process during mass-rearing, enabling the release of only sterile males in the context of the sterile insect technique (SIT). Methods Blood meals were spiked with various toxicants and were then offered to adult Anopheles arabiensis and killing effects were observed. Varying concentrations of the most effective substance were then tested in subsequent trials to obtain an optimal dose for quick and total female elimination. The remaining males were mated with untreated virgin females to assess whether their mating efficiency had been compromised. The most promising substance at the optimal concentration was further tested on a larger number of adults, after they had been irradiated and partially sterilised as pupae with 70 Gy to evaluate the feasibility of the method in a mass-rearing, and SIT context. The males resulting from the latter trial were also checked for mating efficiency post treatments. Results Ivermectin (Virbamec®) at a concentration of 7.5 ppm was chosen from the toxicants tested as sufficiently effective in eliminating all female An. arabiensis in 4 days, the shortest time required for female elimination of all chemicals tested. Mating efficiency of the non-blood feeding male mosquitoes was not compromised significantly compared to controls even when they were kept for a total of 4 days (from emergence) before theoretical release. The irradiation treatment did not affect overall female feeding behaviour in this setting, nor were the sterile males less competitive for mating with virgin females after the treatments than virgin sterile males that had not been in the ivermectin treatment environment. Conclusions Spiking bloodmeals with ivermectin has shown potential as a viable treatment to eliminate female An. arabiensis from laboratory colonies although its practical use in a mass-rearing facility still needs to be tested. PMID:23822117

Judging a man by the width of his face: the role of facial ratios and dominance in mate choice at speed-dating events.

PubMed

Valentine, Katherine A; Li, Norman P; Penke, Lars; Perrett, David I

2014-03-01

Previous research has shown that men with higher facial width-to-height ratios (fWHRs) have higher testosterone and are more aggressive, more powerful, and more financially successful. We tested whether they are also more attractive to women in the ecologically valid mating context of speed dating. Men's fWHR was positively associated with their perceived dominance, likelihood of being chosen for a second date, and attractiveness to women for short-term, but not long-term, relationships. Perceived dominance (by itself and through physical attractiveness) mediated the relationship between fWHR and attractiveness to women for short-term relationships. Furthermore, men's perceptions of their own dominance showed patterns of association with mating desirability similar to those of fWHR. These results support the idea that fWHR is a physical marker of dominance. This is the first study to show that male dominance and higher fWHRs are attractive to women for short-term relationships in a controlled and interactive situation that could actually lead to mating and dating.

Desire and ability: hormones and the regulation of female sexual behavior.

PubMed

Wallen, K

1990-01-01

The distinction between the ability to copulate and the desire to copulate is used to understand species differences in hormonal regulation of female sexual behavior. Evidence is presented demonstrating that ovarian hormones modulate female sexual motivation in both rodent and primate females. The thesis is developed that rodent females differ from primate females primarily in their dependence upon hormones for the ability to mate. Thus, apparent differences between the two groups of females in the extent to which hormones control copulatory behavior does not stem from differences in hormonal regulation of female sexual motivation but from the physical ability of primate, but not rodent, females to mate without hormonal stimulation. This emancipation of the ability to copulate from hormonal influence makes female sexual motivation the primary regulator of mating in primates. Dependence upon female sexual motivation means that the copulatory behavior of primate females is easily influenced by their physical and social environment. Because primate females can mate without hormonal input, female sexual initiation, not copulation, is argued to be the only valid indicator of female sexual motivation.

Reconstructing the flight kinematics of swarming and mating in wild mosquitoes

PubMed Central

Butail, Sachit; Manoukis, Nicholas; Diallo, Moussa; Ribeiro, José M.; Lehmann, Tovi; Paley, Derek A.

2012-01-01

We describe a novel tracking system for reconstructing three-dimensional tracks of individual mosquitoes in wild swarms and present the results of validating the system by filming swarms and mating events of the malaria mosquito Anopheles gambiae in Mali. The tracking system is designed to address noisy, low frame-rate (25 frames per second) video streams from a stereo camera system. Because flying A. gambiae move at 1–4 m s−1, they appear as faded streaks in the images or sometimes do not appear at all. We provide an adaptive algorithm to search for missing streaks and a likelihood function that uses streak endpoints to extract velocity information. A modified multi-hypothesis tracker probabilistically addresses occlusions and a particle filter estimates the trajectories. The output of the tracking algorithm is a set of track segments with an average length of 0.6–1 s. The segments are verified and combined under human supervision to create individual tracks up to the duration of the video (90 s). We evaluate tracking performance using an established metric for multi-target tracking and validate the accuracy using independent stereo measurements of a single swarm. Three-dimensional reconstructions of A. gambiae swarming and mating events are presented. PMID:22628212

Outcomes in advanced heart failure patients with left ventricular assist devices for destination therapy.

PubMed

Park, Soon J; Milano, Carmelo A; Tatooles, Antone J; Rogers, Joseph G; Adamson, Robert M; Steidley, D Eric; Ewald, Gregory A; Sundareswaran, Kartik S; Farrar, David J; Slaughter, Mark S

2012-03-01

The HeartMate II (HMII) destination therapy (DT) trial demonstrated significant improvements in outcomes in continuous-flow left ventricular assist devices compared with patients implanted with the pulsatile-flow HeartMate XVE. The primary hypothesis of the current study is that trial patients enrolled after the initial data cohort would have better clinical outcomes. Two hundred eighty-one patients who underwent HMII for DT from May 2007 to March 2009 (Mid Trial [MT] group) were compared with the initial 133 HMII patients from March 2005 to May 2007 (Early Trial [ET] group). Patient entry criteria were the same during the 2 time periods. Survival, adverse events, and quality of life were compared between the 2 groups. Baseline characteristics were similar between the groups. Compared with the ET group, patients in the MT group had reduced adverse event rates for bleeding requiring transfusions (1.66 versus 1.13 events per patient-year, P<0.001), sepsis (0.38 versus 0.27, P=0.025), device-related infections (0.47 versus 0.27, P<0.001), and hemorrhagic stroke (0.07 versus 0.03, P=0.01). Other event rates were similar between groups including ischemic stroke (0.06 versus 0.05 events per patient-year, P=0.57). Survival at 1 year in the MT group was 73% versus 68% in the ET group (P=0.21). Additionally, there was a significant reduction in deaths caused by hemorrhagic stroke (P=0.01). Quality of life improvements were significant in both the groups (P<0.001). The benefit of DT therapy with the HMII is confirmed in subsequent trial patients, with improved adverse event rates and a strong trend for improvements in survival. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00121485.

Sexual Contests in Aquatic Crustaceans: What's Physiology Got To Do with It?

ERIC Educational Resources Information Center

Keogh, Daniel P.; Sparkes, Timothy C.

2003-01-01

Describes a science laboratory on reproductive behavior and studies the dynamics in Lirceus, an aquatic crustacean of which the females evaluate the males' quality through mating contests. Explains collecting isopods and developing colonies in the lab environment. Investigates food deprivation, locomotor activity, and behavioral trials to…

Shifts in reproductive assurance strategies and inbreeding costs associated with habitat fragmentation in Central American mahogany

PubMed Central

Breed, Martin F; Gardner, Michael G; Ottewell, Kym M; Navarro, Carlos M; Lowe, Andrew J

2012-01-01

The influence of habitat fragmentation on mating patterns and progeny fitness in trees is critical for understanding the long-term impact of contemporary landscape change on the sustainability of biodiversity. We examined the relationship between mating patterns, using microsatellites, and fitness of progeny, in a common garden trial, for the insect-pollinated big-leaf mahogany, Swietenia macrophylla King, sourced from forests and isolated trees in 16 populations across Central America. As expected, isolated trees had disrupted mating patterns and reduced fitness. However, for dry provenances, fitness was negatively related to correlated paternity, while for mesic provenances, fitness was correlated positively with outcrossing rate and negatively with correlated paternity. Poorer performance of mesic provenances is likely because of reduced effective pollen donor density due to poorer environmental suitability and greater disturbance history. Our results demonstrate a differential shift in reproductive assurance and inbreeding costs in mahogany, driven by exploitation history and contemporary landscape context. PMID:22381041

Workers in the VPF observe the lower end of the IUS to be mated to the Chandra X-ray Observatory

NASA Technical Reports Server (NTRS)

1999-01-01

Workers in the Vertical Processing Facility observe the lower end of the Inertial Upper Stage (IUS) that will be mated with the Chandra X-ray Observatory (out of sight above it). After the two components are mated, they will undergo testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93.

Mate familiarity and social learning in a monogamous lizard.

PubMed

Munch, Kirke L; Noble, Daniel W A; Wapstra, Erik; While, Geoffrey M

2018-05-08

Social learning is thought to be advantageous as it allows an animal to gather information quickly without engaging in costly trial-and-error learning. However, animals should be selective about when and whom they learn from. Familiarity is predicted to positively influence an animal's reliance on social learning; yet, few studies have empirically tested this theory. We used a lizard (Liopholis whitii) that forms long-term monogamous pair bonds to examine the effects of partner familiarity on social learning in two novel foraging tasks, an association and a reversal task. We allowed female lizards to observe trained conspecifics that were either familiar (social mate) or unfamiliar execute these tasks and compared these two groups with control females that did not receive social information. Lizards preferentially relied on trial-and-error learning in the association task. In the reversal task, lizards that were demonstrated by familiar partners learnt in fewer trials compared to control lizards and made more correct choices. Our results provide some evidence for context-dependent learning with lizards differentiating between when they utilize social learning, and, to a limited degree, whom they learnt from. Understanding the role of the social context in which learning occurs provides important insights into the benefits of social learning and sociality more generally.

LCP crystallization and X-ray diffraction analysis of VcmN, a MATE transporter from Vibrio cholerae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kusakizako, Tsukasa; Tanaka, Yoshiki; Hipolito, Christopher J.

A V. cholerae MATE transporter was crystallized using the lipidic cubic phase (LCP) method. X-ray diffraction data sets were collected from single crystals obtained in a sandwich plate and a sitting-drop plate to resolutions of 2.5 and 2.2 Å, respectively. Multidrug and toxic compound extrusion (MATE) transporters, one of the multidrug exporter families, efflux xenobiotics towards the extracellular side of the membrane. Since MATE transporters expressed in bacterial pathogens contribute to multidrug resistance, they are important therapeutic targets. Here, a MATE-transporter homologue from Vibrio cholerae, VcmN, was overexpressed in Escherichia coli, purified and crystallized in lipidic cubic phase (LCP). X-raymore » diffraction data were collected to 2.5 Å resolution from a single crystal obtained in a sandwich plate. The crystal belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 52.3, b = 93.7, c = 100.2 Å. As a result of further LCP crystallization trials, crystals of larger size were obtained using sitting-drop plates. X-ray diffraction data were collected to 2.2 Å resolution from a single crystal obtained in a sitting-drop plate. The crystal belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 61.9, b = 91.8, c = 100.9 Å. The present work provides valuable insights into the atomic resolution structure determination of membrane transporters.« less

Is the Combination of Insecticide and Mating Disruption Synergistic or Additive in Lightbrown Apple Moth, Epiphyas postvittana?

PubMed Central

Baker, Greg; Salehi, Latif; Woods, Bill

2016-01-01

Pest suppression from combinations of tactics is fundamental to pest management and eradication. Interactions may occur among tactical combinations and affect suppression. The best case is synergistic, where suppression from a combination is greater than the sum of effects from single tactics (AB >> A+B). We explored how mating disruption and insecticide interacted at field scale, additively or synergistically. Use of a pheromone delivery formulation (SPLAT™) as either a mating disruption treatment (i.e. a two-component pheromone alone) or as a lure and kill treatment (i.e. the two-component pheromone plus a permethrin insecticide) was compared for efficacy against the lightbrown apple moth Epiphyas postvittana. Next, four point-source densities of the SPLAT™ formulations were compared for communication disruption. Finally, the mating disruption and lure and kill treatments were applied with a broadcast insecticide. Population assessment used virgin female traps and synthetic pheromone in replicated 9-ha vineyard plots compared with untreated controls and insecticide-treated plots, to investigate interactions. Lure and kill and mating disruption provided equivalent suppression; no additional benefit accrued from including permethrin with the pheromone suggesting lack of contact. The highest point-source density tested (625/ha) was most effective. The insect growth regulator methoxyfenoxide applied by broadcast application lowered pest prevalence by 70% for the first ten weeks compared to pre-trial. Pheromone addition suppressed the pest further by an estimated 92.5%, for overall suppression of 97.7% from the treatment combination of insecticide plus mating disruption. This was close to that expected for an additive model of interactivity between insecticide and mating disruption (AB = A+B) estimated from plots with single tactics as 98% suppression in a combination. The results indicate the need to examine other tactical combinations to achieve the potential cost-efficiencies of synergistic interactions. PMID:27500834

Is the Combination of Insecticide and Mating Disruption Synergistic or Additive in Lightbrown Apple Moth, Epiphyas postvittana?

PubMed

Suckling, David M; Baker, Greg; Salehi, Latif; Woods, Bill

2016-01-01

Pest suppression from combinations of tactics is fundamental to pest management and eradication. Interactions may occur among tactical combinations and affect suppression. The best case is synergistic, where suppression from a combination is greater than the sum of effects from single tactics (AB > A+B). We explored how mating disruption and insecticide interacted at field scale, additively or synergistically. Use of a pheromone delivery formulation (SPLAT™) as either a mating disruption treatment (i.e. a two-component pheromone alone) or as a lure and kill treatment (i.e. the two-component pheromone plus a permethrin insecticide) was compared for efficacy against the lightbrown apple moth Epiphyas postvittana. Next, four point-source densities of the SPLAT™ formulations were compared for communication disruption. Finally, the mating disruption and lure and kill treatments were applied with a broadcast insecticide. Population assessment used virgin female traps and synthetic pheromone in replicated 9-ha vineyard plots compared with untreated controls and insecticide-treated plots, to investigate interactions. Lure and kill and mating disruption provided equivalent suppression; no additional benefit accrued from including permethrin with the pheromone suggesting lack of contact. The highest point-source density tested (625/ha) was most effective. The insect growth regulator methoxyfenoxide applied by broadcast application lowered pest prevalence by 70% for the first ten weeks compared to pre-trial. Pheromone addition suppressed the pest further by an estimated 92.5%, for overall suppression of 97.7% from the treatment combination of insecticide plus mating disruption. This was close to that expected for an additive model of interactivity between insecticide and mating disruption (AB = A+B) estimated from plots with single tactics as 98% suppression in a combination. The results indicate the need to examine other tactical combinations to achieve the potential cost-efficiencies of synergistic interactions.

Accuracy of a Portable Indirect Calorimeter for Measuring Resting Energy Expenditure in Individuals With Cancer.

PubMed

Purcell, Sarah A; Elliott, Sarah A; Ryan, Aoife M; Sawyer, Michael B; Prado, Carla M

2018-06-05

Determining optimal caloric intake for an individual with cancer is complicated by metabolic changes that occur, namely, alterations in resting energy expenditure (REE). There is currently no validated clinically available equation or tool to measure energy expenditure in these patients. Patients with newly diagnosed solid tumors underwent REE assessments using the FitMate GS portable indirect calorimeter and reference VMax metabolic cart; both used canopy hoods. REE was also estimated from the Harris-Benedict, Mifflin St. Jeor, and Henry equations for comparison. Data were analyzed using paired samples t-test and the Bland-Altman approach to assess group-level and individual-level agreement compared with the metabolic cart. A total 26 patients (19 males; body mass index: 27.8 ± 5.5 kg/m 2 ; age: 62 ± 10 years) participated in the study. Biases for the FitMate GS and both equations were low (ranging from -44 to -92 kcal or -2.3% to -5.1%), indicating good group-level accuracy. The FitMate GS had low bias, but the widest limits of agreement (-28.0% to 21.2%) compared with the 3 equations (Harris-Benedict: -15.8% to 11.2%; Mifflin St. Jeor: -17.1% to 6.9%; Henry: -15.4% to 11.5%). These differences were not due to volume of oxygen, BMI category, or sex. FitMate GS performed well on a group level, but its accuracy was poor on an individual level. Further research should develop better equations and validate tools to measure energy expenditure for accurate dietary recommendations for patients at nutrition risk. © 2018 American Society for Parenteral and Enteral Nutrition.

An Evaluation of Computerized Tests as Predictors of Job Performance: II. Differential Validity for Global and Job Element Criteria. Final Report.

ERIC Educational Resources Information Center

Cory, Charles H.

This report presents data concerning the validity of a set of experimental computerized and paper-and-pencil tests for measures of on-job performance on global and job elements. It reports on the usefulness of 30 experimental and operational variables for predicting marks on 42 job elements and on a global criterion for Electrician's Mate,…

Trait-specific dependence in romantic relationships.

PubMed

Ellis, Bruce J; Simpson, Jeffry A; Campbell, Lorne

2002-10-01

Informed by three theoretical frameworks--trait psychology, evolutionary psychology, and interdependence theory--we report four investigations designed to develop and test the reliability and validity of a new construct and accompanying multiscale inventory, the Trait-Specific Dependence Inventory (TSDI). The TSDI assesses comparisons between present and alternative romantic partners on major dimensions of mate value. In Study 1, principal components analyses revealed that the provisional pool of theory-generated TSDI items were represented by six factors: Agreeable/Committed, Resource Accruing Potential, Physical Prowess, Emotional Stability, Surgency, and Physical Attractiveness. In Study 2, confirmatory factor analysis replicated these results on a different sample and tested how well different structural models fit the data. Study 3 provided evidence for the convergent and discriminant validity of the six TSDI scales by correlating each one with a matched personality trait scale that did not explicitly incorporate comparisons between partners. Study 4 provided further validation evidence, revealing that the six TSDI scales successfully predicted three relationship outcome measures--love, time investment, and anger/upset--above and beyond matched sets of traditional personality trait measures. These results suggest that the TSDI is a reliable, valid, and unique construct that represents a new trait-specific method of assessing dependence in romantic relationships. The construct of trait-specific dependence is introduced and linked with other theories of mate value.

Sociosexuality from Argentina to Zimbabwe: a 48-nation study of sex, culture, and strategies of human mating.

PubMed

Schmitt, David P

2005-04-01

The Sociosexual Orientation Inventory (SOI; Simpson & Gangestad 1991) is a self-report measure of individual differences in human mating strategies. Low SOI scores signify that a person is sociosexually restricted, or follows a more monogamous mating strategy. High SOI scores indicate that an individual is unrestricted, or has a more promiscuous mating strategy. As part of the International Sexuality Description Project (ISDP), the SOI was translated from English into 25 additional languages and administered to a total sample of 14,059 people across 48 nations. Responses to the SOI were used to address four main issues. First, the psychometric properties of the SOI were examined in cross-cultural perspective. The SOI possessed adequate reliability and validity both within and across a diverse range of modem cultures. Second, theories concerning the systematic distribution of sociosexuality across cultures were evaluated. Both operational sex ratios and reproductively demanding environments related in evolutionary-predicted ways to national levels of sociosexuality. Third, sex differences in sociosexuality were generally large and demonstrated cross-cultural universality across the 48 nations of the ISDP, confirming several evolutionary theories of human mating. Fourth, sex differences in sociosexuality were significantly larger when reproductive environments were demanding but were reduced to more moderate levels in cultures with more political and economic gender equality. Implications for evolutionary and social role theories of human sexuality are discussed.

No pain, no gain: Male plasticity in burrow digging according to female rejection in a sand-dwelling wolf spider.

PubMed

Carballo, Matilde; Baldenegro, Fabiana; Bollatti, Fedra; Peretti, Alfredo V; Aisenberg, Anita

2017-07-01

Behavioral plasticity allows individuals to reversibly respond to short-term variations in their ecological and social environment in order to maximize their fitness. Allocosa senex is a burrow-digging spider that inhabits the sandy coasts of South America. This species shows a reversal in typical sex roles expected in spiders: females are wanderers that visit males at their burrows and initiate courtship. They prefer males with long burrows for mating, and males prefer virgin over mated females. We tested whether female sexual rejection induced males to enlarge their burrows and if female reproductive status affected males' responses. We exposed males who had constructed burrows to: a) virgin females or b) mated females, (n=16 for each category). If female rejection occurred, we repeated the trial 48h later with the same female. As control, we maintained a group of males without female exposure (unexposed group, n=32). Rejected males enlarged their burrows more frequently and burrows were longer compared to unexposed males. However, frequency and length of enlargement did not differ according to female reproductive status. Males of A. senex showed plasticity in digging behavior in response to the availability of females, as a way to maximize the possibilities of future mating. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid evolution of cuticular hydrocarbons in a species radiation of acoustically diverse Hawaiian crickets (Gryllidae: trigonidiinae: Laupala).

PubMed

Mullen, Sean P; Mendelson, Tamra C; Schal, Coby; Shaw, Kerry L

2007-01-01

Understanding the origin and maintenance of barriers to gene exchange is a central goal of speciation research. Hawaiian swordtail crickets (genus Laupala) represent one of the most rapidly speciating animal groups yet identified. Extensive acoustic diversity, strong premating isolation, and female preference for conspecific acoustic signals in laboratory phonotaxis trials have strongly supported divergence in mate recognition as the driving force behind the explosive speciation seen in this system. However, recent work has shown that female preference for conspecific male calling song does not extend to mate choice at close range among these crickets, leading to the hypothesis that additional sexual signals are involved in mate recognition and premating isolation. Here we examine patterns of variation in cuticular lipids among several species of Laupala from Maui and the Big Island of Hawaii. Results demonstrate (1) a rapid and dramatic evolution of cuticular lipid composition among species in this genus, (2) significant differences among males and females in cuticular lipid composition, and (3) a significant reduction in the complexity of cuticular lipid profiles in species from the Big Island of Hawaii as compared to two outgroup species from Maui. These results suggest that behavioral barriers to gene exchange in Laupala may be composed of multiple mate recognition signals, a pattern common in other cricket species.

Improved monitoring of oriental fruit moth (Lepidoptera: Tortricidae) with terpinyl acetate plus acetic acid membrane lures

USDA-ARS?s Scientific Manuscript database

Male and female moth catches of Grapholita molesta (Busck) in traps were evaluated in stone and pome fruit orchards untreated or treated with sex pheromones for mating disruption in Uruguay, Argentina, Chile, USA, and Italy from 2015 - 2017. Trials evaluated various blends loaded into either membran...

The Impeachment of Andrew Johnson. Web Lesson.

ERIC Educational Resources Information Center

Constitutional Rights Foundation, Los Angeles, CA.

This lesson presents the historical background of Abraham Lincoln's selection of Andrew Johnson as his running mate in the election of 1864. The lesson considers the climate in the U.S. Congress after President Lincoln's assassination. The details of the impeachment and trial of President Andrew Johnson are given. The lesson presents three…

Widespread evidence for interspecific mating between Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in nature.

PubMed

Bargielowski, I E; Lounibos, L P; Shin, D; Smartt, C T; Carrasquilla, M C; Henry, A; Navarro, J C; Paupy, C; Dennett, J A

2015-12-01

Aedes aegypti and Aedes albopictus, two important vectors of the dengue and chikungunya viruses to humans, often come in contact in their invasive ranges. In these circumstances, a number of factors are thought to influence their population dynamics, including resource competition among the larval stages, prevailing environmental conditions and reproductive interference in the form of satyrization. As the distribution and abundance of Ae. aegypti and Ae. albopictus have profound epidemiological implications, understanding the competitive interactions that influence these patterns in nature is important. While evidence for resource competition and environmental factors had been gathered from the field, the evidence for reproductive interference, though strongly inferred through laboratory trials, remained sparse (one small-scale field trial). In this paper we demonstrate that low rates (1.12-3.73%) of interspecific mating occur in nature among populations of these species that have co-existed sympatrically from 3 to 150yrs. Finally this report contributes a new species-specific primer set for identifying the paternity of sperm extracted from field collected specimens. Copyright © 2015 Elsevier B.V. All rights reserved.

Detection of Gene Flow from Sexual to Asexual Lineages in Thrips tabaci (Thysanoptera: Thripidae)

PubMed Central

Li, Xiao-Wei; Wang, Ping; Fail, Jozsef; Shelton, Anthony M.

2015-01-01

Populations of Thrips tabaci are known to have two sympatric but genetically isolated reproductive modes, arrhenotoky (sexual reproduction) and thelytoky (asexual reproduction). Herein, we report behavioral, ecological and genetic studies to determine whether there is gene flow between arrhenotokous and thelytokous T. tabaci. We did not detect significant preference by arrhenotokous males to mate with females of a particular reproductive mode, nor did we detect significant behavioral differences between arrhenotokous males mated with arrhenotokous or thelytokous females in their pre-copulation, copulation duration and mating frequency. Productive gene transfer resulting from the mating between the two modes was experimentally confirmed. Gene transfer from arrhenotokous T. tabaci to thelytokous T. tabaci was further validated by confirmation of the passage of the arrhenotokous male-originated nuclear gene (histone H3 gene) allele to the F2 generation. These behavioral, ecological and genetic studies confirmed gene transfer from the sexual arrhenotokous mode to the asexual thelytokous mode of T. tabaci in the laboratory. These results demonstrate that asexual T. tabaci populations may acquire genetic variability from sexual populations, which could offset the long-term disadvantage of asexual reproduction. PMID:26375283

Pheromone communication in amphibians and reptiles.

PubMed

Houck, Lynne D

2009-01-01

This selective review considers herpetological papers that feature the use of chemical cues, particularly pheromones involved in reproductive interactions between potential mates. Primary examples include garter snake females that attract males, lacertid lizards and the effects of their femoral gland secretions, aquatic male newts that chemically attract females, and terrestrial salamander males that chemically persuade a female to mate. Each case study spans a number of research approaches (molecular, biochemical, behavioral) and is related to sensory processing and the physiological effects of pheromone delivery. These and related studies show that natural pheromones can be identified, validated with behavioral tests, and incorporated in research on vomeronasal functional response.

Sexual Competitiveness of Anastrepha ludens (Diptera: Tephritidae) Males Exposed to Citrus aurantium and Citrus paradisi Essential Oils.

PubMed

Morató, Santiago; Shelly, Todd; Rull, Juan; Aluja, Martin

2015-04-01

Males of the Mediterranean fruit fly (Ceratitis capitata (Wiedemann)) display increased mating competitiveness following exposure to the odor of certain host and nonhost plants, and this phenomenon has been used in the sterile insect technique to boost the mating success of released, sterile males. Here, we aimed to establish whether males of the Mexican fruit fly (Anastrepha ludens (Loew)) gain a mating advantage when exposed to the aroma of two preferred hosts, grapefruit (Citrus paradisi Macfadyen) and bitter orange (Citrus aurantium L.). Under seminatural conditions, we observed that, in trials using wildish males (from a young laboratory colony started with wild flies) exclusively, exposure to the aroma of bitter orange had no effect on male mating success but exposure to the odor grapefruit oil increased male mating success significantly. In a separate test involving both exposed and nonexposed wildish and mass-reared, sterile males, although wildish males were clearly more competitive than sterile males, exposure to grapefruit oil had no detectable effect on either male type. Exposure to oils had no effect on copulation duration in any of the experiments. We discuss the possibility that the positive effect of grapefruit essential oils on wildish male competitiveness may have been linked to exposure of females to grapefruit as a larval food, which may have imprinted them with grapefruit odors during pupal eclosion and biased their response as adults to odors of their maternal host. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

New targeted treatments for non-small-cell lung cancer - role of nivolumab.

PubMed

Zago, Giulia; Muller, Mirte; van den Heuvel, Michel; Baas, Paul

2016-01-01

Non-small-cell lung cancer (NSCLC) is often diagnosed at an advanced stage of disease, where it is no longer amenable to curative treatment. During the last decades, the survival has only improved significantly for lung cancer patients who have tumors harboring a driver mutation. Therefore, there is a clear unmet need for effective therapies for patients with no mutation. Immunotherapy has emerged as an effective treatment for different cancer types. Nivolumab, a monoclonal inhibitory antibody against PD-1 receptor, can prolong survival of NSCLC patients, with a manageable toxicity profile. In two Phase III trials, nivolumab was compared to docetaxel in patients with, respectively, squamous (CheckMate 017) and non-squamous NSCLC (CheckMate 057). In both trials, nivolumab significantly reduced the risk of death compared to docetaxel (41% and 27% lower risk of death for squamous and non-squamous NSCLC, respectively). Therefore, nivolumab has been approved in the US and in Europe as second-line treatment for advanced NSCLC. Unfortunately, accurate predictive factors for patient selection are lacking, making it difficult to decide who will benefit and who will not. Currently, there are many ongoing trials that evaluate the efficacy of nivolumab in different settings and in combination with other agents. This paper reviews the present literature about the role of nivolumab in the treatment of NSCLC. Particular attention has been given to efficacy studies, toxicity profile, and current and emerging predictive factors.

Negative Effects of Makeup Use on Perceptions of Leadership Ability Across Two Ethnicities.

PubMed

James, Esther A; Jenkins, Shauny; Watkins, Christopher D

2018-01-01

Cosmetics alter social perceptions, and prior work suggests that cosmetic use may aid female intrasexual competition, making women appear more dominant to other women but more prestigious to other men. It is unclear whether these findings reflect general improvements in perceptions of traits related to women's dominance or if they are specific to mating contexts only. Here, across two ethnicities, we examined effects of cosmetics used for a social night out on perceptions of women's leadership ability, a trait that denotes competence/high status outside of mating contexts. Participants of African and Caucasian ethnicity judged faces for leadership ability where half of the trials differed in ethnicity (own- vs. other-ethnicity face pairs) and the subtlety of the color manipulation (50% vs. 100%). Regardless of the participant's sex or ethnicity, makeup used for a social night out had a negative effect on perceptions of women's leadership ability. Our findings suggest that, in prior work, women are afforded traits related to dominance, as makeup enhances perceptions of traits that are important for successful female mating competition but not other components of social dominance such as leadership.

Computational Ranking of Yerba Mate Small Molecules Based on Their Predicted Contribution to Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus

DOE PAGES

Rempe, Caroline S.; Burris, Kellie P.; Woo, Hannah L.; ...

2015-05-08

We report that the aqueous extract of yerba mate, a South American tea beverage made from Ilex paraguariensis leaves, has demonstrated bactericidal and inhibitory activity against bacterial pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). The gas chromatography-mass spectrometry (GC-MS) analysis of two unique fractions of yerba mate aqueous extract revealed 8 identifiable small molecules in those fractions with antimicrobial activity. For a more comprehensive analysis, a data analysis pipeline was assembled to prioritize compounds for antimicrobial testing against both MRSA and methicillin-sensitive S. aureus using forty-two unique fractions of the tea extract that were generated in duplicate, assayed for activity, andmore » analyzed with GC-MS. As validation of our automated analysis, we checked our predicted active compounds for activity in literature references and used authentic standards to test for antimicrobial activity. 3,4-dihydroxybenzaldehyde showed the most antibacterial activity against MRSA at low concentrations in our bioassays. In addition, quinic acid and quercetin were identified using random forests analysis and 5-hydroxy pipecolic acid was identified using linear discriminant analysis. We also generated a ranked list of unidentified compounds that may contribute to the antimicrobial activity of yerba mate against MRSA. Here we utilized GC-MS data to implement an automated analysis that resulted in a ranked list of compounds that likely contribute to the antimicrobial activity of aqueous yerba mate extract against MRSA.« less

Computational Ranking of Yerba Mate Small Molecules Based on Their Predicted Contribution to Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rempe, Caroline S.; Burris, Kellie P.; Woo, Hannah L.

We report that the aqueous extract of yerba mate, a South American tea beverage made from Ilex paraguariensis leaves, has demonstrated bactericidal and inhibitory activity against bacterial pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). The gas chromatography-mass spectrometry (GC-MS) analysis of two unique fractions of yerba mate aqueous extract revealed 8 identifiable small molecules in those fractions with antimicrobial activity. For a more comprehensive analysis, a data analysis pipeline was assembled to prioritize compounds for antimicrobial testing against both MRSA and methicillin-sensitive S. aureus using forty-two unique fractions of the tea extract that were generated in duplicate, assayed for activity, andmore » analyzed with GC-MS. As validation of our automated analysis, we checked our predicted active compounds for activity in literature references and used authentic standards to test for antimicrobial activity. 3,4-dihydroxybenzaldehyde showed the most antibacterial activity against MRSA at low concentrations in our bioassays. In addition, quinic acid and quercetin were identified using random forests analysis and 5-hydroxy pipecolic acid was identified using linear discriminant analysis. We also generated a ranked list of unidentified compounds that may contribute to the antimicrobial activity of yerba mate against MRSA. Here we utilized GC-MS data to implement an automated analysis that resulted in a ranked list of compounds that likely contribute to the antimicrobial activity of aqueous yerba mate extract against MRSA.« less

Evolution of premating reproductive isolation among conspecific populations of the sea rock-pool beetle Ochthebius urbanelliae driven by reinforcing natural selection.

PubMed

Porretta, Daniele; Urbanelli, Sandra

2012-04-01

How natural selection might be involved in speciation remains a fundamental question in evolutionary biology. When two or more species co-occur in the same areas, natural selection may favor divergence in mating traits. By acting in sympatric but not allopatric populations, natural selection can also affect mate choice within species and ultimately initiate speciation among conspecific populations. Here, we address this potential effect in the sea rock-pool beetles Ochthebius quadricollis and O. urbanelliae. The two species, which inhabit the Mediterranean coasts, co-occurr syntopically in an area along the Italian Tyrrhenian coast and completed reproductive isolation by reinforcement. In this article, through mating trials under laboratory conditions between conspecific populations, we found in O. quadricollis no deviations from random mating. Conversely, in O. urbanelliae, we found a clear pattern of premating isolation between the reinforced populations sympatric with O. quadricollis and those nonreinforced allopatric. This pattern is consistent with the view that natural selection, which completed the reproductive isolation between the two species in sympatry, led incidentally also to partial premating reproductive isolation (I(PSI) estimator from 0.683 to 0.792) between conspecific populations of O. urbanelliae. This case study supports an until recently underappreciated role of natural selection resulting from species interactions in initiating speciation. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Facial attractiveness, symmetry, and physical fitness in young women.

PubMed

Hönekopp, Johannes; Bartholomé, Tobias; Jansen, Gregor

2004-06-01

This study explores the evolutionary-based hypothesis that facial attractiveness (a guiding force in mate selection) is a cue for physical fitness (presumably an important contributor to mate value in ancestral times). Since fluctuating asymmetry, a measure of developmental stability, is known to be a valid cue for fitness in several biological domains, we scrutinized facial asymmetry as a potential mediator between attractiveness and fitness. In our sample of young women, facial beauty indeed indicated physical fitness. The relationships that pertained to asymmetry were in the expected direction. However, a closer analysis revealed that facial asymmetry did not mediate the relationship between fitness and attractiveness. Unexpected problems regarding the measurement of facial asymmetry are discussed.

Mating Disruption of the Navel Orangeworm (Lepidoptera: Pyralidae) Using Widely Spaced, Aerosol Dispensers: Is the Pheromone Blend the Most Efficacious Disruptant?

PubMed

Higbee, Bradley S; Burks, Charles S; Cardé, Ring T

2017-10-01

The navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is a key pest of almonds and pistachios and is sometimes controlled using mating disruption as part of a program of integrated management. The formulation used has a single, nonattractive compound [(11Z,13Z)-hexadecadienal] as the active ingredient that is emitted from timed aerosol dispensers. This study compared this nonattractive, single-compound formulation with two aerosol formulations also containing two additional compounds [(11Z,13Z)-hexadecadien-1-ol and (3Z,6Z,9Z,12Z,15Z)-tricosapentaene] that are found in the pheromone glands, and that in combination with the aldehyde are attractive in wind-tunnel and field-attraction trials. An experiment in pistachios found 97% to 99% suppression of males captured in female-baited traps and 82-93% suppression of mating in sentinel females. Both assays revealed a trend to greater suppression by the more complete pheromone formulations. In almonds, where the abundance of navel orangeworm was lower, all three formulations suppressed males captured in traps and mating in sentinel females by >99%. Each of the formulations significantly reduced damage to Nonpareil almonds. In almonds, there were no significant differences among the formulations in disruption of sexual communication or in damage. These findings suggest that it may be possible to make mating disruption more cost-effective and to achieve higher levels of mating disruption by using attractive aerosol formulations to reduce the number of dispenser per ha. Such a formulation, however, would be more expensive to register in the United States than pheromones meeting the definition of straight-chain lepidopteran pheromone, including the currently used aldehyde-only formulation. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Association of mate tea (Ilex paraguariensis) intake and dietary intervention and effects on oxidative stress biomarkers of dyslipidemic subjects.

PubMed

Boaventura, Brunna Cristina Bremer; Di Pietro, Patrícia Faria; Stefanuto, Aliny; Klein, Graziela Alessandra; de Morais, Elayne Cristina; de Andrade, Fernanda; Wazlawik, Elisabeth; da Silva, Edson Luiz

2012-06-01

To evaluate the effect of long-term ingestion of mate tea, with or without dietary intervention, on the markers of oxidative stress in dyslipidemic individuals. Seventy-four dyslipidemic volunteers participated in this randomized clinical trial. Subjects were divided into three treatment groups: mate tea (MT), dietary intervention (DI), and mate tea with dietary intervention (MD). Biochemical and dietary variables were assessed at the beginning of the study (baseline) and after 20, 40, 60, and 90 d of treatment. Participants in the MT and MD groups consumed 1 L/d of mate tea. Those in the DI and MD groups were instructed to increase their intake of fruit, legumes and vegetables and decrease their consumption of foods rich in cholesterol and saturated and trans-fatty acids. Biomarkers of oxidative stress such as antioxidant capacity of serum (ferric reducing antioxidant potential assay), uric acid, reduced glutathione, paraoxonase-1 enzyme, lipid hydroperoxide (LOOH), and protein carbonyl were analyzed. Participants in the DI group showed a significant decrease in total fat and saturated fatty acid intakes. Those in the DI and MD groups presented a significant increase in vitamin C consumption. For all groups, there was a significant increase in ferric reducing antioxidant potential and reduced glutathione concentrations but no significant changes in LOOH, protein carbonyl, and paraoxonase-1 values. The reduced glutathione concentration was positively correlated with the consumption of monounsaturated fatty acids, fiber, and vitamin C, whereas levels of LOOH were inversely correlated with intakes of vitamin C and fiber. In addition, LOOH correlated positively with low-density lipoprotein cholesterol and inversely with high-density lipoprotein cholesterol, which had a positive association with paraoxonase-1. The ingestion of mate tea independently of the dietary intervention increased plasma and blood antioxidant protection in patients with dyslipidemia. Copyright © 2012 Elsevier Inc. All rights reserved.

NGSCheckMate: software for validating sample identity in next-generation sequencing studies within and across data types.

PubMed

Lee, Sejoon; Lee, Soohyun; Ouellette, Scott; Park, Woong-Yang; Lee, Eunjung A; Park, Peter J

2017-06-20

In many next-generation sequencing (NGS) studies, multiple samples or data types are profiled for each individual. An important quality control (QC) step in these studies is to ensure that datasets from the same subject are properly paired. Given the heterogeneity of data types, file types and sequencing depths in a multi-dimensional study, a robust program that provides a standardized metric for genotype comparisons would be useful. Here, we describe NGSCheckMate, a user-friendly software package for verifying sample identities from FASTQ, BAM or VCF files. This tool uses a model-based method to compare allele read fractions at known single-nucleotide polymorphisms, considering depth-dependent behavior of similarity metrics for identical and unrelated samples. Our evaluation shows that NGSCheckMate is effective for a variety of data types, including exome sequencing, whole-genome sequencing, RNA-seq, ChIP-seq, targeted sequencing and single-cell whole-genome sequencing, with a minimal requirement for sequencing depth (>0.5X). An alignment-free module can be run directly on FASTQ files for a quick initial check. We recommend using this software as a QC step in NGS studies. https://github.com/parklab/NGSCheckMate. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Population Biology of Schistosoma Mating, Aggregation, and Transmission Breakpoints: More Reliable Model Analysis for the End-Game in Communities at Risk

PubMed Central

Gurarie, David; King, Charles H.

2014-01-01

Mathematical modeling is widely used for predictive analysis of control options for infectious agents. Challenging problems arise for modeling host-parasite systems having complex life-cycles and transmission environments. Macroparasites, like Schistosoma, inhabit highly fragmented habitats that shape their reproductive success and distribution. Overdispersion and mating success are important factors to consider in modeling control options for such systems. Simpler models based on mean worm burden (MWB) formulations do not take these into account and overestimate transmission. Proposed MWB revisions have employed prescribed distributions and mating factor corrections to derive modified MWB models that have qualitatively different equilibria, including ‘breakpoints’ below which the parasite goes to extinction, suggesting the possibility of elimination via long-term mass-treatment control. Despite common use, no one has attempted to validate the scope and hypotheses underlying such MWB approaches. We conducted a systematic analysis of both the classical MWB and more recent “stratified worm burden” (SWB) modeling that accounts for mating and reproductive hurdles (Allee effect). Our analysis reveals some similarities, including breakpoints, between MWB and SWB, but also significant differences between the two types of model. We show the classic MWB has inherent inconsistencies, and propose SWB as a reliable alternative for projection of long-term control outcomes. PMID:25549362

Pharmacokinetic Evaluation of a Drug Transporter Cocktail Consisting of Digoxin, Furosemide, Metformin, and Rosuvastatin

PubMed Central

Giessmann, T; Hohl, K; Sharma, A; Ishiguro, N; Taub, ME; Zimdahl‐Gelling, H; Gansser, D; Wein, M; Ebner, T; Müller, F

2016-01-01

This article reports the clinical investigation of a probe drug cocktail containing substrates of key drug transporters. Single oral doses of 0.25 mg digoxin (P‐gp), 5 mg furosemide (OAT1 and OAT3), 500 mg metformin (OCT2, MATE1, and MATE2‐K), and 10 mg rosuvastatin (OATP1B1, OATP1B3, and BCRP) were administered separately or as a cocktail in a randomized six‐period crossover trial in 24 healthy male volunteers. As a cocktail, relative bioavailabilities of digoxin and metformin and furosemide AUC0‐tz were similar to separate dosing. However, when administered as a cocktail the Cmax of furosemide was 19.1% lower and the Cmax and AUC0‐tz of rosuvastatin were 38.6% and 43.4% higher, respectively. In addition, the effects of increased doses of metformin or furosemide on the cocktail were investigated in 11 and 12 subjects, respectively. The cocktail explored in this trial has the potential to be used for the in vivo screening of transporter‐mediated drug–drug interactions. © 2016 American Society for Clinical Pharmacology and Therapeutics PMID:27256812

[Immunotherapy for renal cell carcinoma - current status].

PubMed

Grimm, Marc-Oliver; Foller, Susan

2018-04-01

Systemic treatment of metastatic renal cell carcinoma (mRCC) has substantially changed during the last 2 years due to approval of the immune-checkpoint inhibitor Nivolumab (Opdivo ® ) and new multikinase inhibitors (Cabozantinib, Lenvatinib, Tivozanib). The german kidney tumor guideline strongly recommends Nivolumab and Cabozantinib as 2nd line treatments after prior VEGF targeted therapy. CheckMate 025, the prospective randomized trial which led to approval of Nivolumab demonstrated improved overall survival (26 month vs. 19.7 month; hazard ratio 0.73; p = 0.0006) and response rate (26 % vs. 5 %) as well as a favorable toxicity profile compared with Everolimus. Currently, numerous combinations with PD-1/PD-L1 inhibitors are compared to Sunitinib as first line treatment of mRCC. Out of these CheckMate 214, a randomized phase-3 trial is the first to demonstrate a significant higher objective response rate (42 % vs. 27 %, p < 0.0001) and overall survival (Sunitinib 26.0 month, median for Nivo + Ipi has been not yet reached (28.2 - NR); Hazard ratio 0.63) for the combination of Nivolumab and the CTLA-4 antibody Ipilimumab in IMDC intermediate and high risk patients. Furthermore, CheckMate 214 shows better side effect profile and quality of life in patients receiving Nivolumab and Ipilimumab compared with Sunitinib. However, a considerable increase of immune related adverse events is associated with the immune combination therapy. Another randomized trial demonstrates improved progression-free survival for the combination of the PD-L1 inhibitor Atezolizumab and the VEGF antibody Bevacizumab in patients with PD-L1 positive tumors; this was found in all IMDC risk groups. Further phase-3 trials with "new" VEGFR-TKIs (Axitinib, Cabozantinib, Lenvatinib) and PD-1/PD-L1 inhibitor combinations are ongoing.In conclusion, the PD-1 immune checkpoint inhibitor Nivolumab will remain a standard treatment for patients with metastatic renal cell carcinoma after prior VEGF targeted therapy. Nivolumab in combination with Ipilimumab will become a standard 1st line option for patients with intermediate and high risk profile according to IMDC. Further data are required regarding PD-1/PD-L1 inhibitors in combination with Bevacizumab and VEGFR-TKIs, respectively, including overall survival and side effect profile. © Georg Thieme Verlag KG Stuttgart · New York.

Multi-Species Mating Disruption in Cranberries (Ericales: Ericaceae): Early Evidence Using a Flowable Emulsion.

PubMed

Steffan, Shawn A; Chasen, Elissa M; Deutsch, Annie E; Mafra-Neto, Agenor

2017-01-01

Pheromone-based mating disruption has proven to be a powerful pest management tactic in many cropping systems. However, in the cranberry system, a viable mating disruption program does not yet exist. There are commercially available pheromones for several of the major pests of cranberries, including the cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae) and blackheaded fireworm, Rhopobota naevana (Hübner) (Lepidoptera: Tortricidae). Previous studies have shown that mating disruption represents a promising approach for R. naevana management although carrier and delivery technologies have remained unresolved. The present study examined the suitability of Specialized Pheromone & Lure Application Technology (SPLAT; ISCA Technologies, Inc., Riverside, CA), a proprietary wax and oil blend, to serve as a pheromone carrier in the cranberry system. In 2013 and 2014, we tested a blend of pheromones targeting A. vaccinii and R. naevana in field-scale, replicated trials. Pheromones were loaded into SPLAT and the resulting "SPLAT BFW CFW" formulation was deployed in commercial cranberry marshes. We compared moth trap-catch counts within SPLAT-treated blocks to those of conventionally managed blocks. In 2013, applications of SPLAT BFW CFW resulted in highly successful disruption of R. naevana and promising, though inconsistent, disruption of A. vaccinii. To improve disruption of A. vaccinii, the pheromone load was increased in 2014, providing 92% and 74% reductions in trap-catch for R. naevana and A. vaccinii, respectively. Importantly, larval infestation rates in SPLAT-treated blocks were lower than those of conventionally managed blocks. These results suggest that a multispecies mating disruption system (SPLAT BFW CFW) may represent an effective pesticide-alternative for serious pests of cranberries. Published by Oxford University Press on behalf of the Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Rapid adaptation to mammalian sociality via sexually selected traits

PubMed Central

2013-01-01

Background Laboratory studies show that the components of sexual selection (e.g., mate choice and intrasexual competition) can profoundly affect the development and fitness of offspring. Less is known, however, about the total effects of sexual selection on offspring in normal social conditions. Complex social networks, such as dominance hierarchies, regulate the opportunity for mating success, and are often missing from laboratory studies. Social selection is an extended view of sexual selection that incorporates competition during sexual and nonsexual interactions, and predicts complex evolutionary dynamics. Whether social selection improves or constrains offspring fitness is controversial. Results To identify fitness consequences of social selection, wild-derived mice that had bred under laboratory conditions for eight generations were re-introduced to naturalistic competition in enclosures for three consecutive generations (promiscuous line). In parallel, a control lineage bred in cages under random mate assignment (monogamous line). A direct competition experiment using second-generation animals revealed that promiscuous line males had greater reproductive success than monogamous line males (particularly during extra-territorial matings), in spite of higher mortality and equivalent success in social dominance and sperm competition. There were no major female fitness effects (though promiscuous line females had fewer litters than monogamous line females). This result suggested that selection primarily acted upon a sexually attractive male phenotype in the promiscuous line, a hypothesis we confirmed in female odor and mating preference trials. Conclusions We present novel evidence for the strength of sexual selection under normal social conditions, and show rapid male adaptation driven largely by sexual trait expression, with tradeoffs in survivorship and female fecundity. Re-introducing wild-derived mice to competition quickly uncovers sexually selected phenotypes otherwise lost in normal colony breeding. PMID:23577674

Effect of Interpersonal Interaction on Festinating Gait Rehabilitation in Patients with Parkinson's Disease.

PubMed

Uchitomi, Hirotaka; Ogawa, Ken-Ichiro; Orimo, Satoshi; Wada, Yoshiaki; Miyake, Yoshihiro

2016-01-01

Although human walking gait rhythms are generated by native individual gait dynamics, these gait dynamics change during interactions between humans. A typical phenomenon is synchronization of gait rhythms during cooperative walking. Our previous research revealed that fluctuation characteristics in stride interval of subjects with Parkinson's disease changed from random to 1/f fluctuation as fractal characteristics during cooperative walking with the gait assist system Walk-Mate, which emulates a human interaction using interactive rhythmic cues. Moreover, gait dynamics were relearned through Walk-Mate gait training. However, the system's clinical efficacy was unclear because the previous studies did not focus on specific gait rhythm disorder symptoms. Therefore, this study aimed to evaluate the effect of Walk-Mate on festinating gait among subjects with Parkinson's disease. Three within-subject experimental conditions were used: (1) preinteraction condition, (2) interaction condition, and (3) postinteraction condition. The only difference between conditions was the interactive rhythmic cues generated by Walk-Mate. Because subjects with festinating gait gradually and involuntarily decreased their stride interval, the regression slope of stride interval as an index of severity of preinteraction festinating gait was elevated. The regression slope in the interaction condition was more gradual than during the preinteraction condition, indicating that the interactive rhythmic cues contributed to relieving festinating gait and stabilizing gait dynamics. Moreover, the gradual regression slope was carried over to the postinteraction condition, indicating that subjects with festinating gait have the potential to relearn stable gait dynamics. These results suggest that disordered gait dynamics are clinically restored through interactive rhythmic cues and that Walk-Mate may have the potential to assist therapists in more effective rehabilitation. UMIN Clinical Trials Registry UMIN000012591.

Non-lethal assessment of the reproductive status of broadnose sevengill sharks (Notorynchus cepedianus) to determine the significance of habitat use in coastal areas

PubMed Central

Awruch, Cynthia A.; Jones, Susan M.; Asorey, Martin García; Barnett, Adam

2014-01-01

Identification of the importance of habitats that are frequently used by any species is essential to a complete understanding of the species' biology and to incorporate their ecological role into conservation and management programmes. In this context, the present study investigated whether Tasmanian coastal waters have any reproductive relevance for the broadnose sevengill shark (Notorynchus cepedianus). Although this species is a large coast-associated apex predator in these areas, there is a complete gap in understanding the role that these coastal systems could play in its reproduction. Reproductive hormones were used as a non-lethal method to address the reproductive biology of this species. Females seemed to have at least a bi-annual reproductive cycle, being pregnant for ∼1 year and spending at least 1 year non-pregnant, with the ovulatory cycle separated from gestation. Mature females were found to be ovulating, in the initial stages of pregnancy, resting or starting a new vitellogenic cycle. Notorynchus cepedianus did not use these coastal habitats for mating or as a pupping ground. Although the mating season was distinguished between September to April, only 22% of males showed mating scars during the peak of the mating period and no near-term pregnant females were observed. Thus, despite these coastal waters being an important foraging ground for this species, these areas did not have any reproductive relevance. In consequence, future management and conservation planning programmes need to identify whether there are other areas in Tasmania that play a critical role for reproductive purposes in this species. Finally, although previous studies have linked reproductive hormones with external examination of the gonads to validate the use of steroids as a non-lethal tool to address reproduction, the present study used this methodology without killing any animals. This has important implications for conservation programmes of threatened and endangered species worldwide where the methodology cannot be validated. PMID:27293634

Behaviour of Arctic charr Salvelinus alpinus during an induced mating season in captivity: how male relative size influences male behavioural investment and female preference over time.

PubMed

Bolgan, M; O'Brien, J; Picciulin, M; Manning, L; Gammell, M

2017-04-01

The behaviour of sexually mature Arctic charr Salvelinus alpinus specimens (fifth farm generation) was observed in captivity for four consecutive days. Only agonistic interactions between males of different size were facilitated on the first 2 days, while both agonistic and courtship interactions were possible from the third day up to the end of the experiment. The reliability of behavioural analysis was assessed in order to reduce the possibility of observer errors within the generated datasets. The behavioural investment of big males, small males and females was analysed using general linear models (two-way repeated measures ANOVAs with time and male size as factors). A peak in the agonistic interactions between males occurred during the first day of interactions, where the agonistic investment of big males was significantly higher than that of small males. This resulted in an increased investment in submissive behaviour by the small males, who consistently performed submissive behaviours from the second day of interactions up to the end of the trial. Big males were found to invest significantly more than small males in courtship behaviours for the duration of the trial. Even though females performed inter-sexual behaviours towards both big and small males for the entire observation period, female interaction rate towards big males was higher than towards small males. This study suggests that both male investment in mating behaviour and female preference might be related to male characteristics such as body length and that S. alpinus behavioural patterns and mate choice cues might be strongly context-related and characterized by high levels of behavioural plasticity (i.e. presence-absence of certain behavioural units or potential reversal of a mate choice cue) within the same species. Finally, in light of this, some conservation measures are discussed. In particular, effective management plans should take into account the high level of behavioural plasticity likely to be occurring in this species. © 2016 The Fisheries Society of the British Isles.

Pollen Competition as a Reproductive Isolation Barrier Represses Transgene Flow between Compatible and Co-Flowering Citrus Genotypes

PubMed Central

Pons, Elsa; Navarro, Antonio; Ollitrault, Patrick; Peña, Leandro

2011-01-01

Background/Objective Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. Methodology/Principal Findings Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17–2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. Conclusions/Significance Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species. PMID:21991359

Low reproductive isolation and highly variable levels of gene flow reveal limited progress towards speciation between European river and brook lampreys.

PubMed

Rougemont, Q; Gaigher, A; Lasne, E; Côte, J; Coke, M; Besnard, A-L; Launey, S; Evanno, G

2015-12-01

Ecologically based divergent selection is a factor that could drive reproductive isolation even in the presence of gene flow. Population pairs arrayed along a continuum of divergence provide a good opportunity to address this issue. Here, we used a combination of mating trials, experimental crosses and population genetic analyses to investigate the evolution of reproductive isolation between two closely related species of lampreys with distinct life histories. We used microsatellite markers to genotype over 1000 individuals of the migratory parasitic river lamprey (Lampetra fluviatilis) and freshwater-resident nonparasitic brook lamprey (Lampetra planeri) distributed in 10 sympatric and parapatric population pairs in France. Mating trials, parentage analyses and artificial fertilizations demonstrated a low level of reproductive isolation between species even though size-assortative mating may contribute to isolation. Most parapatric population pairs were strongly differentiated due to the joint effects of geographic distance and barriers to migration. In contrast, we found variable levels of gene flow between sympatric populations ranging from panmixia to moderate differentiation, which indicates a gradient of divergence with some population pairs that may correspond to alternative morphs or ecotypes of a single species and others that remain partially isolated. Ecologically based divergent selection may explain these variable levels of divergence among sympatric population pairs, but incomplete genome swamping following secondary contact could have also played a role. Overall, this study illustrates how highly differentiated phenotypes can be maintained despite high levels of gene flow that limit the progress towards speciation. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Arrhenius-kinetics evidence for quantum tunneling in microbial "social" decision rates.

PubMed

Clark, Kevin B

2010-11-01

Social-like bacteria, fungi and protozoa communicate chemical and behavioral signals to coordinate their specializations into an ordered group of individuals capable of fitter ecological performance. Examples of microbial "social" behaviors include sporulation and dispersion, kin recognition and nonclonal or paired reproduction. Paired reproduction by ciliates is believed to involve intra- and intermate selection through pheromone-stimulated "courting" rituals. Such social maneuvering minimizes survival-reproduction tradeoffs while sorting superior mates from inferior ones, lowering the vertical spread of deleterious genes in geographically constricted populations and possibly promoting advantageous genetic innovations. In a previous article, I reported findings that the heterotrich Spirostomum ambiguum can out-complete mating rivals in simulated social trials by learning behavioral heuristics which it then employs to store and select sets of altruistic and deceptive signaling strategies. Frequencies of strategy use typically follow Maxwell-Boltzmann (MB), Fermi-Dirac (FD) or Bose-Einstein (BE) statistical distributions. For ciliates most adept at social decision making, a brief classical MB computational phase drives signaling behavior into a later quantum BE computational phase that condenses or favors the selection of a single fittest strategy. Appearance of the network analogue of BE condensation coincides with Hebbian-like trial-and-error learning and is consistent with the idea that cells behave as heat engines, where loss of energy associated with specific cellular machinery critical for mating decisions effectively reduces the temperature of intracellular enzymes cohering into weak Fröhlich superposition. I extend these findings by showing the rates at which ciliates switch serial behavioral strategies agree with principles of chemical reactions exhibiting linear and nonlinear Arrhenius kinetics during respective classical and quantum computations. Nonlinear Arrhenius kinetics in ciliate decision making suggest transitions from one signaling strategy to another result from a computational analogue of quantum tunneling in social information processing.

Pollen competition as a reproductive isolation barrier represses transgene flow between compatible and co-flowering citrus genotypes.

PubMed

Pons, Elsa; Navarro, Antonio; Ollitrault, Patrick; Peña, Leandro

2011-01-01

Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17-2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species.

Plant-like mating in an animal: sexual compatibility and allocation trade-offs in a simultaneous hermaphrodite with remote transfer of sperm.

PubMed

Pemberton, A J; Sommerfeldt, A D; Wood, C A; Flint, H C; Noble, L R; Clarke, K R; Bishop, J D D

2004-05-01

The importance of sexual compatibility between mates has only recently been realized in zoological research into sexual selection, yet its study has been central to botanical research for many decades. The reproductive characteristics of remote mating, an absence of precopulatory mate screening, internal fertilization and embryonic brooding are shared between passively pollinated plants and a phylogenetically diverse group of sessile aquatic invertebrates. Here, we further characterize the sexual compatibility system of one such invertebrate, the colonial ascidian Diplosoma listerianum. All 66 reciprocal pairings of 12 genetic individuals were carried out. Fecundities of crosses varied widely and suggested a continuous scale of sexual compatibility. Of the 11 animals from the same population c. 40% of crosses were completely incompatible with a further c. 20% having obvious partial compatibility (reduced fecundity). We are unaware of other studies documenting such high levels of sexual incompatibility in unrelated individuals. RAPD fingerprinting was used to estimate relatedness among the 12 individuals after a known pedigree was successfully reconstructed to validate the technique. In contrast to previous results, no correlation between genetic similarity and sexual compatibility was detected. The blocking of many genotypes of sperm is expected to severely modify realized paternity away from 'fair raffle' expectations and probably reduce levels of intra-brood genetic diversity in this obligatorily promiscuous mating system. One adaptive benefit may be to reduce the bombardment of the female reproductive system by outcrossed sperm with conflicting evolutionary interests, so as to maintain female control of somatic : gametic investment.

Incipient speciation driven by hypertrophied lips in Midas cichlid fishes?

PubMed

Machado-Schiaffino, Gonzalo; Kautt, Andreas F; Torres-Dowdall, Julian; Baumgarten, Lukas; Henning, Frederico; Meyer, Axel

2017-04-01

Sympatric speciation has been debated in evolutionary biology for decades. Although it has gained in acceptance recently, still only a handful of empirical examples are seen as valid (e.g. crater lake cichlids). In this study, we disentangle the role of hypertrophied lips in the repeated adaptive radiations of Nicaraguan crater lake cichlid fish. We assessed the role of disruptive selection and assortative mating during the early stages of divergence and found a functional trade-off in feeding behaviour between thick- and thin-lipped ecotypes, suggesting that this trait is a target of disruptive selection. Thick-lipped fish perform better on nonevasive prey at the cost of a poorer performance on evasive prey. Using enclosures in the wild, we found that thick-lipped fish perform significantly better in rocky than in sandy habitats. We found almost no mixed pairs during two breeding seasons and hence significant assortative mating. Genetic differentiation between ecotypes seems to be related to the time since colonization, being subtle in L. Masaya (1600 generations ago) and absent in the younger L. Apoyeque (<600 generations ago). Genome-wide differentiation between ecotypes was higher in the old source lakes than in the young crater lakes. Our results suggest that hypertrophied lips might be promoting incipient sympatric speciation through divergent selection (ecological divergence in feeding performance) and nonrandom mating (assortative mating) in the young Nicaraguan crater lakes. Nonetheless, further manipulative experiments are needed in order to confirm the role of hypertrophied lips as the main cue for assortative mating. © 2017 John Wiley & Sons Ltd.

A disparity between locomotor economy and territory-holding ability in male house mice.

PubMed

Morris, Jeremy S; Ruff, James S; Potts, Wayne K; Carrier, David R

2017-07-15

Both economical locomotion and physical fighting are important performance traits to many species because of their direct influence on components of Darwinian fitness. Locomotion represents a substantial portion of the total daily energy budget of many animals. Fighting performance often determines individual reproductive fitness through the means of resource control, social dominance and access to mates. However, phenotypic traits that improve either locomotor economy or fighting ability may diminish performance in the other. Here, we tested for a predicted disparity between locomotor economy and competitive ability in wild-derived house mice ( Mus musculus ). We used 8 week social competition trials in semi-natural enclosures to directly measure male competitive ability through territorial control and female occupancy within territories. We also measured oxygen consumption during locomotion for each mouse using running trials in an enclosed treadmill and open-flow respirometry. Our results show that territory-holding males have higher absolute and mass-specific oxygen consumption when running (i.e. reduced locomotor economy) compared with males that do not control territories. This relationship was present both before and after 8 week competition trials in semi-natural enclosures. This disparity between physical competitive ability and economical locomotion may impose viability costs on males in species for which competition over mates is common and may constrain the evolution of behavioral and phenotypic diversity, particularly in natural settings with environmental and resource variability. © 2017. Published by The Company of Biologists Ltd.

Placement matching of alcohol-dependent patients based on a standardized intake assessment: rationale and design of a randomized controlled trial.

PubMed

Buchholz, Angela; Friedrichs, Anke; Berner, Michael; König, Hans-Helmut; Konnopka, Alexander; Kraus, Ludwig; Kriston, Levente; Küfner, Heinrich; Piontek, Daniela; Rist, Fred; Röhrig, Jeanette

2014-10-14

Despite considerable research on substance-abuse placement matching, evidence is still inconclusive. The aims of this exploratory trial are to evaluate (a) the effects of following matching guidelines on health-care costs and heavy drinking, and (b) factors affecting the implementation of matching guidelines in the treatment of alcohol-dependent patients. A total of 286 alcohol-dependent patients entering one of four participating detoxification units and having no arrangements for further treatment will be recruited. During the first week of treatment, all patients will be administered Measurements in the Addictions for Triage and Evaluation (MATE), European Quality of Life-Five Dimensions health status questionnaire (EQ-5D), and the Client Socio--Demographic and Service Receipt Inventory-European Version (CSSRI-EU). Patients who are randomly allocated to the intervention group will receive feedback regarding their assessment results, including clear recommendations for subsequent treatment. Patients of the control group will receive treatment as usual and, if requested, global feedback regarding their assessment results, but no recommendations for subsequent treatment. At discharge, treatment outcome and referral decisions will be recorded. Six months after discharge, patients will be administered MATE-Outcome, EQ-5D, and CSSRI-EU during a telephone interview. This trial will provide evidence on the effects and costs of using placement-matching guidelines based on a standardized assessment with structured feedback in the treatment of alcohol-dependent patients. A process evaluation will be conducted to facilitate better understanding of the relationship between the use of guidelines, outcomes, and potential mediating variables. German Clinical Trials Register DRKS00005035. Registered 03 June 2013.

Probability of identification (POI): a statistical model for the validation of qualitative botanical identification methods

USDA-ARS?s Scientific Manuscript database

A qualitative botanical identification method (BIM) is an analytical procedure which returns a binary result (1 = Identified, 0 = Not Identified). A BIM may be used by a buyer, manufacturer, or regulator to determine whether a botanical material being tested is the same as the target (desired) mate...

The predictive validity of ideal partner preferences: a review and meta-analysis.

PubMed

Eastwick, Paul W; Luchies, Laura B; Finkel, Eli J; Hunt, Lucy L

2014-05-01

A central element of interdependence theory is that people have standards against which they compare their current outcomes, and one ubiquitous standard in the mating domain is the preference for particular attributes in a partner (ideal partner preferences). This article reviews research on the predictive validity of ideal partner preferences and presents a new integrative model that highlights when and why ideals succeed or fail to predict relational outcomes. Section 1 examines predictive validity by reviewing research on sex differences in the preference for physical attractiveness and earning prospects. Men and women reliably differ in the extent to which these qualities affect their romantic evaluations of hypothetical targets. Yet a new meta-analysis spanning the attraction and relationships literatures (k = 97) revealed that physical attractiveness predicted romantic evaluations with a moderate-to-strong effect size (r = ∼.40) for both sexes, and earning prospects predicted romantic evaluations with a small effect size (r = ∼.10) for both sexes. Sex differences in the correlations were small (r difference = .03) and uniformly nonsignificant. Section 2 reviews research on individual differences in ideal partner preferences, drawing from several theoretical traditions to explain why ideals predict relational evaluations at different relationship stages. Furthermore, this literature also identifies alternative measures of ideal partner preferences that have stronger predictive validity in certain theoretically sensible contexts. Finally, a discussion highlights a new framework for conceptualizing the appeal of traits, the difference between live and hypothetical interactions, and the productive interplay between mating research and broader psychological theories.

Heat Generation in Axial and Centrifugal Flow Left Ventricular Assist Devices.

PubMed

Yost, Gardner; Joseph, Christine Rachel; Royston, Thomas; Tatooles, Antone; Bhat, Geetha

Despite increasing use of left ventricular assist devices (LVADs) as a surgical treatment for advanced heart failure in an era of improved outcomes with LVAD support, the mechanical interactions between these pumps and the cardiovascular system are not completely understood. We utilized an in vitro mock circulatory loop to analyze the heat production incurred by operation of an axial flow and centrifugal flow LVAD. A HeartMate II and a HeartWare HVAD were connected to an abbreviated flow loop and were implanted in a viscoelastic gel. Temperature was measured at the surface of each LVAD. Device speed and fluid viscosity were altered and, in the HeartMate II, as artificial thrombi were attached to the inflow stator, impeller, and outflow stator. The surface temperatures of both LVADs increased in all trials and reached a plateau within 80 minutes of flow initiation. Rate of heat generation and maximum system temperature were greater when speed was increased, when viscosity was increased, and when artificial thrombi were attached to the HeartMate II impeller. Normal operation of these two widely utilized LVADs results in appreciable heat generation in vitro. Increased pump loading resulted in more rapid heat generation, which was particularly severe when a large thrombus was attached to the impeller of the HeartMate II. While heat accumulation in vivo is likely minimized by greater dissipation in the blood and soft tissues, focal temperature gains with the pump housing of these two devices during long-term operation may have negative hematological consequences.

Intraspecific evidence from guppies for correlated patterns of male and female genital trait diversification

PubMed Central

Evans, Jonathan P.; Gasparini, Clelia; Holwell, Gregory I.; Ramnarine, Indar W.; Pitcher, Trevor E.; Pilastro, Andrea

2011-01-01

The role of sexual selection in fuelling genital evolution is becoming increasingly apparent from comparative studies revealing interspecific divergence in male genitalia and evolutionary associations between male and female genital traits. Despite this, we know little about intraspecific variance in male genital morphology, or how male and female reproductive traits covary among divergent populations. Here we address both topics using natural populations of the guppy, Poecilia reticulata, a livebearing fish that exhibits divergent patterns of male sexual behaviour among populations. Initially, we performed a series of mating trials on a single population to examine the relationship between the morphology of the male's copulatory organ (the gonopodium) and the success of forced matings. Using a combination of linear measurements and geometric morphometrics, we found that variation in the length and shape of the gonopodium predicted the success of forced matings in terms of the rate of genital contacts and insemination success, respectively. We then looked for geographical divergence in these traits, since the relative frequency of forced matings tends to be greater in high-predation populations. We found consistent patterns of variation in male genital size and shape in relation to the level of predation, and corresponding patterns of (co)variation in female genital morphology. Together, these data enable us to draw tentative conclusions about the underlying selective pressures causing correlated patterns of divergence in male and female genital traits, which point to a role for sexually antagonistic selection. PMID:21270040

Heat stress but not inbreeding affects offensive sperm competitiveness in Callosobruchus maculatus

PubMed Central

Lieshout, Emile; Tomkins, Joseph L; Simmons, Leigh W

2013-01-01

Environmental and genetic stress have well-known detrimental effects on ejaculate quality, but their concomitant effect on male fitness remains poorly understood. We used competitive fertilization assays to expose the effects of stress on offensive sperm competitive ability in the beetle Callosobruchus maculatus, a species where ejaculates make up more than 5% of male body mass. To examine the effects of environmental and genetic stress, males derived from outcrosses or sib matings were heat shocked at 50°C for 50 min during the pupal stage, while their siblings were maintained at a standard rearing temperature of 28°C. Heat-shocked males achieved only half the offensive paternity success of their siblings. While this population exhibited inbreeding depression in body size, sperm competitiveness was unaffected by inbreeding, nor did the effect of heat shock stress on sperm competitiveness depend on inbreeding status. In contrast, pupal emergence success was increased by 34% among heat-stressed individuals, regardless of their inbreeding status. Heat-shocked males' ejaculate size was 19% reduced, but they exhibited 25% increased mating duration in single mating trials. Our results highlight both the importance of stress in postcopulatory sexual selection, and the variability among stressors in affecting male fitness. PMID:24101978

Heat stress but not inbreeding affects offensive sperm competitiveness in Callosobruchus maculatus.

PubMed

Lieshout, Emile; Tomkins, Joseph L; Simmons, Leigh W

2013-09-01

Environmental and genetic stress have well-known detrimental effects on ejaculate quality, but their concomitant effect on male fitness remains poorly understood. We used competitive fertilization assays to expose the effects of stress on offensive sperm competitive ability in the beetle Callosobruchus maculatus, a species where ejaculates make up more than 5% of male body mass. To examine the effects of environmental and genetic stress, males derived from outcrosses or sib matings were heat shocked at 50°C for 50 min during the pupal stage, while their siblings were maintained at a standard rearing temperature of 28°C. Heat-shocked males achieved only half the offensive paternity success of their siblings. While this population exhibited inbreeding depression in body size, sperm competitiveness was unaffected by inbreeding, nor did the effect of heat shock stress on sperm competitiveness depend on inbreeding status. In contrast, pupal emergence success was increased by 34% among heat-stressed individuals, regardless of their inbreeding status. Heat-shocked males' ejaculate size was 19% reduced, but they exhibited 25% increased mating duration in single mating trials. Our results highlight both the importance of stress in postcopulatory sexual selection, and the variability among stressors in affecting male fitness.

Systemic Review and Meta-analysis of Randomized Clinical Trials Comparing Primary vs Delayed Primary Skin Closure in Contaminated and Dirty Abdominal Incisions

DTIC Science & Technology

2013-06-26

Chatwiriyacharoen14 Betadine gauze Unclear 5 Unclear Until suitable for suture Purulent dis- charge or mate- rial or surround- ing cellulitis Unclear Reopened and...Opened McGreal et al20 Povidone-io- dine (1%)- soaked wick Subcuticu- lar suture 4 Unclear Steri-Strips on day 4 Cellulitis , cul- ture-positive

Impact of age, sex, therapeutic intent, race and severity of advanced heart failure on short-term principal outcomes in the MOMENTUM 3 trial.

PubMed

Goldstein, Daniel J; Mehra, Mandeep R; Naka, Yoshifumi; Salerno, Christopher; Uriel, Nir; Dean, David; Itoh, Akinobu; Pagani, Francis D; Skipper, Eric R; Bhat, Geetha; Raval, Nirav; Bruckner, Brian A; Estep, Jerry D; Cogswell, Rebecca; Milano, Carmelo; Fendelander, Lahn; O'Connell, John B; Cleveland, Joseph

2018-01-01

Primary outcomes analysis of the Multicenter Study of MagLev Technology in Patients Undergoing MCS Therapy With HeartMate 3 (MOMENTUM 3) trial short-term cohort demonstrated a higher survival rate free of debilitating stroke and reoperation to replace/remove the device (primary end-point) in patients receiving the HeartMate 3 (HM3) compared with the HeartMate (HMII). In this study we sought to evaluate the individual and interactive effects of pre-specified patient subgroups (age, sex, race, therapeutic intent [bridge to transplant/bridge to candidacy/destination therapy] and severity of illness) on primary end-point outcomes in MOMENTUM 3 patients implanted with HM3 and HMII devices. Cox proportional hazard models were used to analyze patients enrolled in the "as-treated cohort" (n = 289) of the MOMENTUM 3 trial to: (1) determine interaction of various subgroups on primary end-point outcomes; and (2) identify independent variables associated with primary end-point success. Baseline characteristics were well balanced among HM3 (n = 151) and HMII (n = 138) cohorts. No significant interaction between the sub-groups on primary end-point outcomes was observed. Cox multivariable modeling identified age (≤65 years vs >65 years, hazard ratio 0.42 [95% confidence interval 0.22 to 0.78], p = 0.006]) and pump type (HM3 vs HMII, hazard ratio 0.53 [95% confidence interval 0.30 to 0.96], p = 0.034) to be independent predictors of primary outcomes success. After adjusting for age, no significant impact of sex, race, therapeutic intent and INTERMACS profiles on primary outcomes were observed. This analysis of MOMENTUM 3 suggests that younger age (≤65 years) at implant and pump choice are associated with a greater likelihood of primary end-point success. These findings further suggest that characterization of therapeutic intent into discrete bridge-to-transplant and destination therapy categories offers no clear clinical advantage, and should ideally be abandoned. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Updating of Attentional and Premotor Allocation Resources as function of previous trial outcome

PubMed Central

Arjona, Antonio; Escudero, Miguel; Gómez, Carlos M.

2014-01-01

The neural bases of the inter-trial validity/invalidity sequential effects in a visuo-auditory modified version of the Central Cue Posner's Paradigm (CCPP) are analyzed by means of Early Directing Attention Negativity (EDAN), Contingent Negative Variation (CNV) and Lateralized Readiness Potential (LRP). ERPs results indicated an increase in CNV and LRP in trials preceded by valid trials compared to trials preceded by invalid trials. The CNV and LRP pattern would be highly related to the behavioral pattern of lower RTs and higher number of anticipations in trials preceded by valid with respect to trials preceded by invalid trials. This effect was not preceded by a modulation of the EDAN as a result of the previous trial condition. The results suggest that there is a trial-by-trial dynamic modulation of the attentional system as a function of the validity assigned to the cue, in which conditional probabilities between cue and target are continuously updated. PMID:24681570

Mobile applications for handheld devices to screen and randomize acute stroke patients in clinical trials.

PubMed

Qureshi, Ai; Connelly, B; Abbott, Ei; Maland, E; Kim, J; Blake, J

2012-08-01

The availability of internet connectivity and mobile application software used by low-power handheld devices makes smart phones of unique value in time-sensitive clinical trials. Trial-specific applications can be downloaded by investigators from various mobile software distribution platforms or web applications delivered over HTTP. The Antihypertensive Treatment in Acute Cerebral Hemorrhage (ATACH) II investigators in collaboration with MentorMate released the ATACH-II Patient Recruitment mobile application available on iPhone, Android, and Blackberry in 2011. The mobile application provides tools for pre-screening, assessment of eligibility, and randomization of patients. Since the release of ATACH-II mobile application, the CLEAR-IVH (Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage) trial investigators have also adopted such a mobile application. The video-conferencing capabilities of the most recent mobile devices open up additional opportunities to involve central coordinating centers in the recruitment process in real time.

Criteria for the validity of clinical trials of treatments of cohorts of cancer patients based on the Hardin Jones principle.

PubMed Central

Pauling, L; Herman, Z S

1989-01-01

With the assumption of the validity of the Hardin Jones principle that the death rate of members of a homogeneous cohort of cancer patients is constant, three criteria for the validity of clinical trials of cancer treatments are formulated. These criteria are satisfied by most published clinical trials, but one trial was found to violate all three, rendering the validity of its reported results uncertain. PMID:2780542

Transitions in Sexuality: Recapitulation of an Ancestral Tri- and Tetrapolar Mating System in Cryptococcus neoformans▿ †

PubMed Central

Hsueh, Yen-Ping; Fraser, James A.; Heitman, Joseph

2008-01-01

Sex is orchestrated by the mating-type locus (MAT) in fungi and by sex chromosomes in plants and animals. In fungi, two patterns of sexuality occur: bipolar with a single, typically biallelic sex determinant that promotes inbreeding, and tetrapolar with two unlinked, often multiallelic sex determinants that restrict inbreeding. Multiallelism in either bipolar or tetrapolar mating systems promotes outcrossing. Cryptococcus neoformans is a pathogenic bipolar yeast with two unusually large MAT alleles (a/α) spanning >100 kb, ∼100-fold larger than many other fungal MAT loci. Based on comparative genomic analysis, this unusual MAT locus is hypothesized to have evolved from an ancestral tetrapolar system. In this model, the unlinked homeodomain (HD) transcription factor and pheromone/receptor tetrapolar loci acquired additional sex-related genes and then fused via chromosomal translocation, forming an intermediate transitional mating system (which we term tripolar), which then underwent recombination and gene conversion to fashion the extant bipolar MAT alleles. To experimentally validate this model, C. neoformans was engineered to have a tetrapolar mating system by relocating the MAT SXI1α and SXI2a HD genes to an unlinked genomic locale. Genetic and molecular analyses revealed that this modified organism could complete a tetrapolar sexual cycle. Analysis of progeny generated from bipolar, tripolar, and tetrapolar crosses provides direct experimental evidence that the tripolar state confers decreased fertility and therefore may represent an unstable evolutionary intermediate. These findings illustrate how transitions between outcrossing and inbreeding preference occur by involving sex determinant linkage and collapse from multiallelic to biallelic sex determination, providing insights into both fungal sex evolution and early steps in sex chromosome evolution. PMID:18723606

Mating competitiveness of sterile male Anopheles coluzzii in large cages.

PubMed

Maïga, Hamidou; Damiens, David; Niang, Abdoulaye; Sawadogo, Simon P; Fatherhaman, Omnia; Lees, Rosemary S; Roux, Olivier; Dabiré, Roch K; Ouédraogo, Georges A; Tripet, Fréderic; Diabaté, Abdoulaye; Gilles, Jeremie R L

2014-11-26

Understanding the factors that account for male mating competitiveness is critical to the development of the sterile insect technique (SIT). Here, the effects of partial sterilization with 90 Gy of radiation on sexual competitiveness of Anopheles coluzzii allowed to mate in different ratios of sterile to untreated males have been assessed. Moreover, competitiveness was compared between males allowed one versus two days of contact with females. Sterile and untreated males four to six days of age were released in large cages (~1.75 sq m) with females of similar age at the following ratios of sterile males: untreated males: untreated virgin females: 100:100:100, 300:100:100, 500:100:100 (three replicates of each) and left for two days. Competitiveness was determined by assessing the egg hatch rate and the insemination rate, determined by dissecting recaptured females. An additional experiment was conducted with a ratio of 500:100:100 and a mating period of either one or two days. Two controls of 0:100:100 (untreated control) and 100:0:100 (sterile control) were used in each experiment. When males and females consort for two days with different ratios, a significant difference in insemination rate was observed between ratio treatments. The competitiveness index (C) of sterile males compared to controls was 0.53. The number of days of exposure to mates significantly increased the insemination rate, as did the increased number of males present in the untreated: sterile male ratio treatments, but the number of days of exposure did not have any effect on the hatch rate. The comparability of the hatch rates between experiments suggest that An. coluzzii mating competitiveness experiments in large cages could be run for one instead of two days, shortening the required length of the experiment. Sterilized males were half as competitive as untreated males, but an effective release ratio of at least five sterile for one untreated male has the potential to impact the fertility of a wild female population. However, further trials in field conditions with wild males and females should be undertaken to estimate the ratio of sterile males to wild males required to produce an effect on wild populations.

The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies-II. Validation

PubMed Central

Müller, Klaus; Smielik, Ievgen; Hütwohl, Jan-Marco; Kuhnert, Klaus-Dieter; Witte, Klaudia

2017-01-01

Abstract The use of computer animation in behavioral research is a state-of-the-art method for designing and presenting animated animals to live test animals. The major advantages of computer animations are: (1) the creation of animated animal stimuli with high variability of morphology and even behavior; (2) animated stimuli provide highly standardized, controlled and repeatable testing procedures; and (3) they allow a reduction in the number of live test animals regarding the 3Rs principle. But the use of animated animals should be attended by a thorough validation for each test species to verify that behavior measured with live animals toward virtual animals can also be expected with natural stimuli. Here we present results on the validation of a custom-made simulation for animated 3D sailfin mollies Poecilia latipinna and show that responses of live test females were as strong to an animated fish as to a video or a live male fish. Movement of an animated stimulus was important but female response was stronger toward a swimming 3D fish stimulus than to a “swimming” box. Moreover, male test fish were able to discriminate between animated male and female stimuli; hence, rendering the animated 3D fish a useful tool in mate-choice experiments with sailfin mollies. PMID:29491964

The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies-II. Validation.

PubMed

Gierszewski, Stefanie; Müller, Klaus; Smielik, Ievgen; Hütwohl, Jan-Marco; Kuhnert, Klaus-Dieter; Witte, Klaudia

2017-02-01

The use of computer animation in behavioral research is a state-of-the-art method for designing and presenting animated animals to live test animals. The major advantages of computer animations are: (1) the creation of animated animal stimuli with high variability of morphology and even behavior; (2) animated stimuli provide highly standardized, controlled and repeatable testing procedures; and (3) they allow a reduction in the number of live test animals regarding the 3Rs principle. But the use of animated animals should be attended by a thorough validation for each test species to verify that behavior measured with live animals toward virtual animals can also be expected with natural stimuli. Here we present results on the validation of a custom-made simulation for animated 3D sailfin mollies Poecilia latipinna and show that responses of live test females were as strong to an animated fish as to a video or a live male fish. Movement of an animated stimulus was important but female response was stronger toward a swimming 3D fish stimulus than to a "swimming" box. Moreover, male test fish were able to discriminate between animated male and female stimuli; hence, rendering the animated 3D fish a useful tool in mate-choice experiments with sailfin mollies.

KSC-99pp0625

NASA Image and Video Library

1999-06-04

Workers in the Vertical Processing Facility observe the lower end of the Inertial Upper Stage (IUS) that will be mated with the Chandra X-ray Observatory (out of sight above it). After the two components are mated, they will undergo testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

ClinicalTrials.gov and Drugs@FDA: A comparison of results reporting for new drug approval trials

PubMed Central

Schwartz, Lisa M.; Woloshin, Steven; Zheng, Eugene; Tse, Tony; Zarin, Deborah A.

2016-01-01

Background Pharmaceutical companies and other trial sponsors must submit certain trial results to ClinicalTrials.gov. The validity of these results is unclear. Purpose To validate results posted on ClinicalTrials.gov against publicly-available FDA reviews on Drugs@FDA. Data sources ClinicalTrials.gov (registry and results database) and Drugs@FDA (medical/statistical reviews). Study selection 100 parallel-group, randomized trials for new drug approvals (1/2013 – 7/2014) with results posted on ClinicalTrials.gov (3/15/2015). Data extraction Two assessors systematically extracted, and another verified, trial design, primary/secondary outcomes, adverse events, and deaths. Results The 100 trials were mostly phase 3 (90%) double-blind (92%), placebo-controlled (73%), representing 32 drugs from 24 companies. Of 137 primary outcomes from ClinicalTrials.gov, 134 (98%) had corresponding data in Drugs@FDA, 130 (95%) had concordant definitions, and 107 (78%) had concordant results; most differences were nominal (i.e. relative difference < 10%). Of 100 trials, primary outcome results in 14 could not be validated . Of 1,927 secondary outcomes from ClinicalTrials.gov, 1,061 (55%) definitions could be validated and 367 (19%) had results. Of 96 trials with ≥ 1 serious adverse event in either source, 14 could be compared and 7 were discordant. Of 62 trials with ≥ 1 death in either source, 25 could be compared and 17 were discordant. Limitations Unknown generalizability to uncontrolled or crossover trial results. Conclusion Primary outcome definitions and results were largely concordant between ClinicalTrials.gov and Drugs@FDA. Half of secondary outcomes could not be validated because Drugs@FDA only includes “key outcomes” for regulatory decision-making; nor could serious adverse events and deaths because Drugs@FDA frequently only includes results aggregated across multiple trials. PMID:27294570

Build-Up Approach to Updating the Mock Quiet Spike Beam Model

NASA Technical Reports Server (NTRS)

Herrera, Claudia Y.; Pak, Chan-gi

2007-01-01

When a new aircraft is designed or a modification is done to an existing aircraft, the aeroelastic properties of the aircraft should be examined to ensure the aircraft is flight worthy. Evaluating the aeroelastic properties of a new or modified aircraft can include performing a variety of analyses, such as modal and flutter analyses. In order to produce accurate results from these analyses, it is imperative to work with finite element models (FEM) that have been validated by or correlated to ground vibration test (GVT) data, Updating an analytical model using measured data is a challenge in the area of structural dynamics. The analytical model update process encompasses a series of optimizations that match analytical frequencies and mode shapes to the measured modal characteristics of structure. In the past, the method used to update a model to test data was "trial and error." This is an inefficient method - running a modal analysis, comparing the analytical results to the GVT data, manually modifying one or more structural parameters (mass, CG, inertia, area, etc.), rerunning the analysis, and comparing the new analytical modal characteristics to the GVT modal data. If the match is close enough (close enough defined by analyst's updating requirements), then the updating process is completed. If the match does not meet updating-requirements, then the parameters are changed again and the process is repeated. Clearly, this manual optimization process is highly inefficient for large FEM's and/or a large number of structural parameters. NASA Dryden Flight Research Center (DFRC) has developed, in-house, a Mode Matching Code that automates the above-mentioned optimization process, DFRC's in-house Mode Matching Code reads mode shapes and frequencies acquired from GVT to create the target model. It also reads the current analytical model, as we11 as the design variables and their upper and lower limits. It performs a modal analysis on this model and modifies it to create an updated model that has similar mode shapes and frequencies as those of the target model. The Mode Matching Code output frequencies and modal assurance criteria (MAC) values that allow for the quantified comparison of the updated model versus the target model. A recent application of this code is the F453 supersonic flight testing platform, NASA DFRC possesses a modified F-15B that is used as a test bed aircraft for supersonic flight experiments. Traditionally, the finite element model of the test article is generated. A GVT is done on the test article ta validate and update its FEM. This FEM is then mated to the F-15B model, which was correlated to GVT data in fall of 2004, A GVT is conducted with the test article mated to the aircraft, and this mated F-15B/ test article FEM is correlated to this final GVT.

Does the decision in a validation process of a surrogate endpoint change with level of significance of treatment effect? A proposal on validation of surrogate endpoints.

PubMed

Sertdemir, Y; Burgut, R

2009-01-01

In recent years the use of surrogate end points (S) has become an interesting issue. In clinical trials, it is important to get treatment outcomes as early as possible. For this reason there is a need for surrogate endpoints (S) which are measured earlier than the true endpoint (T). However, before a surrogate endpoint can be used it must be validated. For a candidate surrogate endpoint, for example time to recurrence, the validation result may change dramatically between clinical trials. The aim of this study is to show how the validation criterion (R(2)(trial)) proposed by Buyse et al. are influenced by the magnitude of treatment effect with an application using real data. The criterion R(2)(trial) proposed by Buyse et al. (2000) is applied to the four data sets from colon cancer clinical trials (C-01, C-02, C-03 and C-04). Each clinical trial is analyzed separately for treatment effect on survival (true endpoint) and recurrence free survival (surrogate endpoint) and this analysis is done also for each center in each trial. Results are used for standard validation analysis. The centers were grouped by the Wald statistic in 3 equal groups. Validation criteria R(2)(trial) were 0.641 95% CI (0.432-0.782), 0.223 95% CI (0.008-0.503), 0.761 95% CI (0.550-0.872) and 0.560 95% CI (0.404-0.687) for C-01, C-02, C-03 and C-04 respectively. The R(2)(trial) criteria changed by the Wald statistics observed for the centers used in the validation process. Higher the Wald statistic groups are higher the R(2)(trial) values observed. The recurrence free survival is not a good surrogate for overall survival in clinical trials with non significant treatment effects and moderate for significant treatment effects. This shows that the level of significance of treatment effect should be taken into account in validation process of surrogate endpoints.

A New MI-Based Visualization Aided Validation Index for Mining Big Longitudinal Web Trial Data

PubMed Central

Zhang, Zhaoyang; Fang, Hua; Wang, Honggang

2016-01-01

Web-delivered clinical trials generate big complex data. To help untangle the heterogeneity of treatment effects, unsupervised learning methods have been widely applied. However, identifying valid patterns is a priority but challenging issue for these methods. This paper, built upon our previous research on multiple imputation (MI)-based fuzzy clustering and validation, proposes a new MI-based Visualization-aided validation index (MIVOOS) to determine the optimal number of clusters for big incomplete longitudinal Web-trial data with inflated zeros. Different from a recently developed fuzzy clustering validation index, MIVOOS uses a more suitable overlap and separation measures for Web-trial data but does not depend on the choice of fuzzifiers as the widely used Xie and Beni (XB) index. Through optimizing the view angles of 3-D projections using Sammon mapping, the optimal 2-D projection-guided MIVOOS is obtained to better visualize and verify the patterns in conjunction with trajectory patterns. Compared with XB and VOS, our newly proposed MIVOOS shows its robustness in validating big Web-trial data under different missing data mechanisms using real and simulated Web-trial data. PMID:27482473

Research on HOPE communication and data processing equipment

NASA Astrophysics Data System (ADS)

Yamamoto, Satoru; Kikuchi, Toshio

1992-08-01

An overview of the research on heat-resisting antenna is presented. Candidate heat-resisting antennas which were selected as the result of review on seven kinds of antenna are the antennas of micro strip, cavity, and horn types. Heat resistance characteristics of electric power supplying section (connectors) of heat-resisting antenna were studied. Heat cycling test and heat shock tests were conducted on the subject plugs and it was confirmed that they can be usable at - 80 C to + 200 C against - 65 C to + 125 C for the existing plugs. Fundamental electric data such as antenna pattern were acquired mating trial produced components simulating electric characteristics of heat-resisting antenna and trial-produced ceramic tiles.

Making clinical trials more relevant: improving and validating the PRECIS tool for matching trial design decisions to trial purpose.

PubMed

Loudon, Kirsty; Zwarenstein, Merrick; Sullivan, Frank; Donnan, Peter; Treweek, Shaun

2013-04-27

If you want to know which of two or more healthcare interventions is most effective, the randomised controlled trial is the design of choice. Randomisation, however, does not itself promote the applicability of the results to situations other than the one in which the trial was done. A tool published in 2009, PRECIS (PRagmatic Explanatory Continuum Indicator Summaries) aimed to help trialists design trials that produced results matched to the aim of the trial, be that supporting clinical decision-making, or increasing knowledge of how an intervention works. Though generally positive, groups evaluating the tool have also found weaknesses, mainly that its inter-rater reliability is not clear, that it needs a scoring system and that some new domains might be needed. The aim of the study is to: Produce an improved and validated version of the PRECIS tool. Use this tool to compare the internal validity of, and effect estimates from, a set of explanatory and pragmatic trials matched by intervention. The study has four phases. Phase 1 involves brainstorming and a two-round Delphi survey of authors who cited PRECIS. In Phase 2, the Delphi results will then be discussed and alternative versions of PRECIS-2 developed and user-tested by experienced trialists. Phase 3 will evaluate the validity and reliability of the most promising PRECIS-2 candidate using a sample of 15 to 20 trials rated by 15 international trialists. We will assess inter-rater reliability, and raters' subjective global ratings of pragmatism compared to PRECIS-2 to assess convergent and face validity. Phase 4, to determine if pragmatic trials sacrifice internal validity in order to achieve applicability, will compare the internal validity and effect estimates of matched explanatory and pragmatic trials of the same intervention, condition and participants. Effect sizes for the trials will then be compared in a meta-regression. The Cochrane Risk of Bias scores will be compared with the PRECIS-2 scores of pragmatism. We have concrete suggestions for improving PRECIS and a growing list of enthusiastic individuals interested in contributing to this work. By early 2014 we expect to have a validated PRECIS-2.

Arrhenius-kinetics evidence for quantum tunneling in microbial “social” decision rates

PubMed Central

2010-01-01

Social-like bacteria, fungi and protozoa communicate chemical and behavioral signals to coordinate their specializations into an ordered group of individuals capable of fitter ecological performance. Examples of microbial “social” behaviors include sporulation and dispersion, kin recognition and nonclonal or paired reproduction. Paired reproduction by ciliates is believed to involve intra- and intermate selection through pheromone-stimulated “courting” rituals. Such social maneuvering minimizes survival-reproduction tradeoffs while sorting superior mates from inferior ones, lowering the vertical spread of deleterious genes in geographically constricted populations and possibly promoting advantageous genetic innovations. In a previous article, I reported findings that the heterotrich Spirostomum ambiguum can out-complete mating rivals in simulated social trials by learning behavioral heuristics which it then employs to store and select sets of altruistic and deceptive signaling strategies. Frequencies of strategy use typically follow Maxwell-Boltzmann (MB), Fermi-Dirac (FD) or Bose-Einstein (BE) statistical distributions. For ciliates most adept at social decision making, a brief classical MB computational phase drives signaling behavior into a later quantum BE computational phase that condenses or favors the selection of a single fittest strategy. Appearance of the network analogue of BE condensation coincides with Hebbian-like trial-and-error learning and is consistent with the idea that cells behave as heat engines, where loss of energy associated with specific cellular machinery critical for mating decisions effectively reduces the temperature of intracellular enzymes cohering into weak Fröhlich superposition. I extend these findings by showing the rates at which ciliates switch serial behavioral strategies agree with principles of chemical reactions exhibiting linear and nonlinear Arrhenius kinetics during respective classical and quantum computations. Nonlinear Arrhenius kinetics in ciliate decision making suggest transitions from one signaling strategy to another result from a computational analogue of quantum tunneling in social information processing. PMID:21331234

GapFiller: a de novo assembly approach to fill the gap within paired reads

PubMed Central

2012-01-01

Background Next Generation Sequencing technologies are able to provide high genome coverages at a relatively low cost. However, due to limited reads' length (from 30 bp up to 200 bp), specific bioinformatics problems have become even more difficult to solve. De novo assembly with short reads, for example, is more complicated at least for two reasons: first, the overall amount of "noisy" data to cope with increased and, second, as the reads' length decreases the number of unsolvable repeats grows. Our work's aim is to go at the root of the problem by providing a pre-processing tool capable to produce (in-silico) longer and highly accurate sequences from a collection of Next Generation Sequencing reads. Results In this paper a seed-and-extend local assembler is presented. The kernel algorithm is a loop that, starting from a read used as seed, keeps extending it using heuristics whose main goal is to produce a collection of error-free and longer sequences. In particular, GapFiller carefully detects reliable overlaps and operates clustering similar reads in order to reconstruct the missing part between the two ends of the same insert. Our tool's output has been validated on 24 experiments using both simulated and real paired reads datasets. The output sequences are declared correct when the seed-mate is found. In the experiments performed, GapFiller was able to extend high percentages of the processed seeds and find their mates, with a false positives rate that turned out to be nearly negligible. Conclusions GapFiller, starting from a sufficiently high short reads coverage, is able to produce high coverages of accurate longer sequences (from 300 bp up to 3500 bp). The procedure to perform safe extensions, together with the mate-found check, turned out to be a powerful criterion to guarantee contigs' correctness. GapFiller has further potential, as it could be applied in a number of different scenarios, including the post-processing validation of insertions/deletions detection pipelines, pre-processing routines on datasets for de novo assembly pipelines, or in any hierarchical approach designed to assemble, analyse or validate pools of sequences. PMID:23095524

Bayesian Adaptive Trial Design for a Newly Validated Surrogate Endpoint

PubMed Central

Renfro, Lindsay A.; Carlin, Bradley P.; Sargent, Daniel J.

2011-01-01

Summary The evaluation of surrogate endpoints for primary use in future clinical trials is an increasingly important research area, due to demands for more efficient trials coupled with recent regulatory acceptance of some surrogates as ‘valid.’ However, little consideration has been given to how a trial which utilizes a newly-validated surrogate endpoint as its primary endpoint might be appropriately designed. We propose a novel Bayesian adaptive trial design that allows the new surrogate endpoint to play a dominant role in assessing the effect of an intervention, while remaining realistically cautious about its use. By incorporating multi-trial historical information on the validated relationship between the surrogate and clinical endpoints, then subsequently evaluating accumulating data against this relationship as the new trial progresses, we adaptively guard against an erroneous assessment of treatment based upon a truly invalid surrogate. When the joint outcomes in the new trial seem plausible given similar historical trials, we proceed with the surrogate endpoint as the primary endpoint, and do so adaptively–perhaps stopping the trial for early success or inferiority of the experimental treatment, or for futility. Otherwise, we discard the surrogate and switch adaptive determinations to the original primary endpoint. We use simulation to test the operating characteristics of this new design compared to a standard O’Brien-Fleming approach, as well as the ability of our design to discriminate trustworthy from untrustworthy surrogates in hypothetical future trials. Furthermore, we investigate possible benefits using patient-level data from 18 adjuvant therapy trials in colon cancer, where disease-free survival is considered a newly-validated surrogate endpoint for overall survival. PMID:21838811

Field cage studies and progressive evaluation of genetically-engineered mosquitoes.

PubMed

Facchinelli, Luca; Valerio, Laura; Ramsey, Janine M; Gould, Fred; Walsh, Rachael K; Bond, Guillermo; Robert, Michael A; Lloyd, Alun L; James, Anthony A; Alphey, Luke; Scott, Thomas W

2013-01-01

A genetically-engineered strain of the dengue mosquito vector Aedes aegypti, designated OX3604C, was evaluated in large outdoor cage trials for its potential to improve dengue prevention efforts by inducing population suppression. OX3604C is engineered with a repressible genetic construct that causes a female-specific flightless phenotype. Wild-type females that mate with homozygous OX3604C males will not produce reproductive female offspring. Weekly introductions of OX3604C males eliminated all three targeted Ae. aegypti populations after 10-20 weeks in a previous laboratory cage experiment. As part of the phased, progressive evaluation of this technology, we carried out an assessment in large outdoor field enclosures in dengue endemic southern Mexico. OX3604C males were introduced weekly into field cages containing stable target populations, initially at 10:1 ratios. Statistically significant target population decreases were detected in 4 of 5 treatment cages after 17 weeks, but none of the treatment populations were eliminated. Mating competitiveness experiments, carried out to explore the discrepancy between lab and field cage results revealed a maximum mating disadvantage of up 59.1% for OX3604C males, which accounted for a significant part of the 97% fitness cost predicted by a mathematical model to be necessary to produce the field cage results. Our results indicate that OX3604C may not be effective in large-scale releases. A strain with the same transgene that is not encumbered by a large mating disadvantage, however, could have improved prospects for dengue prevention. Insights from large outdoor cage experiments may provide an important part of the progressive, stepwise evaluation of genetically-engineered mosquitoes.

Ciliates learn to diagnose and correct classical error syndromes in mating strategies

PubMed Central

Clark, Kevin B.

2013-01-01

Preconjugal ciliates learn classical repetition error-correction codes to safeguard mating messages and replies from corruption by “rivals” and local ambient noise. Because individual cells behave as memory channels with Szilárd engine attributes, these coding schemes also might be used to limit, diagnose, and correct mating-signal errors due to noisy intracellular information processing. The present study, therefore, assessed whether heterotrich ciliates effect fault-tolerant signal planning and execution by modifying engine performance, and consequently entropy content of codes, during mock cell–cell communication. Socially meaningful serial vibrations emitted from an ambiguous artificial source initiated ciliate behavioral signaling performances known to advertise mating fitness with varying courtship strategies. Microbes, employing calcium-dependent Hebbian-like decision making, learned to diagnose then correct error syndromes by recursively matching Boltzmann entropies between signal planning and execution stages via “power” or “refrigeration” cycles. All eight serial contraction and reversal strategies incurred errors in entropy magnitude by the execution stage of processing. Absolute errors, however, subtended expected threshold values for single bit-flip errors in three-bit replies, indicating coding schemes protected information content throughout signal production. Ciliate preparedness for vibrations selectively and significantly affected the magnitude and valence of Szilárd engine performance during modal and non-modal strategy corrective cycles. But entropy fidelity for all replies mainly improved across learning trials as refinements in engine efficiency. Fidelity neared maximum levels for only modal signals coded in resilient three-bit repetition error-correction sequences. Together, these findings demonstrate microbes can elevate survival/reproductive success by learning to implement classical fault-tolerant information processing in social contexts. PMID:23966987

Highly variable sperm precedence in the stalk-eyed fly, Teleopsis dalmanni

PubMed Central

Corley, Laura S; Cotton, Samuel; McConnell, Ellen; Chapman, Tracey; Fowler, Kevin; Pomiankowski, Andrew

2006-01-01

Background When females mate with different males, competition for fertilizations occurs after insemination. Such sperm competition is usually summarized at the level of the population or species by the parameter, P2, defined as the proportion of offspring sired by the second male in double mating trials. However, considerable variation in P2 may occur within populations, and such variation limits the utility of population-wide or species P2 estimates as descriptors of sperm usage. To fully understand the causes and consequences of sperm competition requires estimates of not only mean P2, but also intra-specific variation in P2. Here we investigate within-population quantitative variation in P2 using a controlled mating experiment and microsatellite profiling of progeny in the multiply mating stalk-eyed fly, Teleopsis dalmanni. Results We genotyped 381 offspring from 22 dam-sire pair families at four microsatellite loci. The mean population-wide P2 value of 0.40 was not significantly different from that expected under random sperm mixing (i.e. P2 = 0.5). However, patterns of paternity were highly variable between individual families; almost half of families displayed extreme second male biases resulting in zero or complete paternity, whereas only about one third of families had P2 values of 0.5, the remainder had significant, but moderate, paternity skew. Conclusion Our data suggest that all modes of ejaculate competition, from extreme sperm precedence to complete sperm mixing, occur in T. dalmanni. Thus the population mean P2 value does not reflect the high underlying variance in familial P2. We discuss some of the potential causes and consequences of post-copulatory sexual selection in this important model species. PMID:16800877

Field Cage Studies and Progressive Evaluation of Genetically-Engineered Mosquitoes

PubMed Central

Facchinelli, Luca; Valerio, Laura; Ramsey, Janine M.; Gould, Fred; Walsh, Rachael K.; Bond, Guillermo; Robert, Michael A.; Lloyd, Alun L.; James, Anthony A.; Alphey, Luke; Scott, Thomas W.

2013-01-01

Background A genetically-engineered strain of the dengue mosquito vector Aedes aegypti, designated OX3604C, was evaluated in large outdoor cage trials for its potential to improve dengue prevention efforts by inducing population suppression. OX3604C is engineered with a repressible genetic construct that causes a female-specific flightless phenotype. Wild-type females that mate with homozygous OX3604C males will not produce reproductive female offspring. Weekly introductions of OX3604C males eliminated all three targeted Ae. aegypti populations after 10–20 weeks in a previous laboratory cage experiment. As part of the phased, progressive evaluation of this technology, we carried out an assessment in large outdoor field enclosures in dengue endemic southern Mexico. Methodology/Principal Findings OX3604C males were introduced weekly into field cages containing stable target populations, initially at 10∶1 ratios. Statistically significant target population decreases were detected in 4 of 5 treatment cages after 17 weeks, but none of the treatment populations were eliminated. Mating competitiveness experiments, carried out to explore the discrepancy between lab and field cage results revealed a maximum mating disadvantage of up 59.1% for OX3604C males, which accounted for a significant part of the 97% fitness cost predicted by a mathematical model to be necessary to produce the field cage results. Conclusions/Significance Our results indicate that OX3604C may not be effective in large-scale releases. A strain with the same transgene that is not encumbered by a large mating disadvantage, however, could have improved prospects for dengue prevention. Insights from large outdoor cage experiments may provide an important part of the progressive, stepwise evaluation of genetically-engineered mosquitoes. PMID:23350003

Making clinical trials more relevant: improving and validating the PRECIS tool for matching trial design decisions to trial purpose

PubMed Central

2013-01-01

Background If you want to know which of two or more healthcare interventions is most effective, the randomised controlled trial is the design of choice. Randomisation, however, does not itself promote the applicability of the results to situations other than the one in which the trial was done. A tool published in 2009, PRECIS (PRagmatic Explanatory Continuum Indicator Summaries) aimed to help trialists design trials that produced results matched to the aim of the trial, be that supporting clinical decision-making, or increasing knowledge of how an intervention works. Though generally positive, groups evaluating the tool have also found weaknesses, mainly that its inter-rater reliability is not clear, that it needs a scoring system and that some new domains might be needed. The aim of the study is to: Produce an improved and validated version of the PRECIS tool. Use this tool to compare the internal validity of, and effect estimates from, a set of explanatory and pragmatic trials matched by intervention. Methods The study has four phases. Phase 1 involves brainstorming and a two-round Delphi survey of authors who cited PRECIS. In Phase 2, the Delphi results will then be discussed and alternative versions of PRECIS-2 developed and user-tested by experienced trialists. Phase 3 will evaluate the validity and reliability of the most promising PRECIS-2 candidate using a sample of 15 to 20 trials rated by 15 international trialists. We will assess inter-rater reliability, and raters’ subjective global ratings of pragmatism compared to PRECIS-2 to assess convergent and face validity. Phase 4, to determine if pragmatic trials sacrifice internal validity in order to achieve applicability, will compare the internal validity and effect estimates of matched explanatory and pragmatic trials of the same intervention, condition and participants. Effect sizes for the trials will then be compared in a meta-regression. The Cochrane Risk of Bias scores will be compared with the PRECIS-2 scores of pragmatism. Discussion We have concrete suggestions for improving PRECIS and a growing list of enthusiastic individuals interested in contributing to this work. By early 2014 we expect to have a validated PRECIS-2. PMID:23782862

Identification and expression analysis of MATE genes involved in flavonoid transport in blueberry plants.

PubMed

Chen, Li; Liu, Yushan; Liu, Hongdi; Kang, Limin; Geng, Jinman; Gai, Yuzhuo; Ding, Yunlong; Sun, Haiyue; Li, Yadong

2015-01-01

Multidrug and toxic compound extrusion (MATE) proteins are the most recently identified family of multidrug transporters. In plants, this family is remarkably large compared to the human and bacteria counterpart, highlighting the importance of MATE proteins in this kingdom. Here 33 Unigenes annotated as MATE transporters were found in the blueberry fruit transcriptome, of which eight full-length cDNA sequences were identified and cloned. These proteins are composed of 477-517 residues, with molecular masses ~54 kDa, and theoretical isoelectric points from 5.35 to 8.41. Bioinformatics analysis predicted 10-12 putative transmembrane segments for VcMATEs, and localization to the plasma membrane without an N-terminal signal peptide. All blueberry MATE proteins shared 32.1-84.4% identity, among which VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8, and VcMATE9 were more similar to the MATE-type flavonoid transporters. Phylogenetic analysis showed VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8 and VcMATE9 clustered with MATE-type flavonoid transporters, indicating that they might be involved in flavonoid transport. VcMATE1 and VcMATE4 may be involved in the transport of secondary metabolites, the detoxification of xenobiotics, or the export of toxic cations. Real-time quantitative PCR demonstrated that the expression profile of the eight VcMATE genes varied spatially and temporally. Analysis of expression and anthocyanin accumulation indicated that there were some correlation between the expression profile and the accumulation of anthocyanins. These results showed VcMATEs might be involved in diverse physiological functions, and anthocyanins across the membranes might be mutually maintained by MATE-type flavonoid transporters and other mechanisms. This study will enrich the MATE-based transport mechanisms of secondary metabolite, and provide a new biotechonology strategy to develop better nutritional blueberry cultivars.

Identification and Expression Analysis of MATE Genes Involved in Flavonoid Transport in Blueberry Plants

PubMed Central

Chen, Li; Liu, Yushan; Liu, Hongdi; Kang, Limin; Geng, Jinman; Gai, Yuzhuo; Ding, Yunlong; Sun, Haiyue; Li, Yadong

2015-01-01

Multidrug and toxic compound extrusion (MATE) proteins are the most recently identified family of multidrug transporters. In plants, this family is remarkably large compared to the human and bacteria counterpart, highlighting the importance of MATE proteins in this kingdom. Here 33 Unigenes annotated as MATE transporters were found in the blueberry fruit transcriptome, of which eight full-length cDNA sequences were identified and cloned. These proteins are composed of 477–517 residues, with molecular masses ~54 kDa, and theoretical isoelectric points from 5.35 to 8.41. Bioinformatics analysis predicted 10–12 putative transmembrane segments for VcMATEs, and localization to the plasma membrane without an N-terminal signal peptide. All blueberry MATE proteins shared 32.1–84.4% identity, among which VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8, and VcMATE9 were more similar to the MATE-type flavonoid transporters. Phylogenetic analysis showed VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8 and VcMATE9 clustered with MATE-type flavonoid transporters, indicating that they might be involved in flavonoid transport. VcMATE1 and VcMATE4 may be involved in the transport of secondary metabolites, the detoxification of xenobiotics, or the export of toxic cations. Real-time quantitative PCR demonstrated that the expression profile of the eight VcMATE genes varied spatially and temporally. Analysis of expression and anthocyanin accumulation indicated that there were some correlation between the expression profile and the accumulation of anthocyanins. These results showed VcMATEs might be involved in diverse physiological functions, and anthocyanins across the membranes might be mutually maintained by MATE-type flavonoid transporters and other mechanisms. This study will enrich the MATE-based transport mechanisms of secondary metabolite, and provide a new biotechonology strategy to develop better nutritional blueberry cultivars. PMID:25781331

Spinosad- and Deltamethrin-Induced Impact on Mating and Reproductive Output of the Maize Weevil Sitophilus zeamais.

PubMed

Vélez, Mayra; Botina, Lorena L; Turchen, Leonardo M; Barbosa, Wagner F; Guedes, Raul Narciso C

2018-04-02

Assessments of acute insecticide toxicity frequently focus on the lethal effects on individual arthropod pest species and populations neglecting the impacts and consequences of sublethal exposure. However, the sublethal effects of insecticides may lead to harmful, neutral, or even beneficial responses that may affect (or not) the behavior and sexual fitness of the exposed insects. Intriguingly, little is known about such effects on stored product insect pests in general and the maize weevil in particular. Thus, we assessed the sublethal effects of spinosad and deltamethrin on female mate-searching, mating behavior, progeny emergence, and grain consumption by maize weevils. Insecticide exposure did not affect the resting time, number of stops, and duration of mate-searching by female weevils, but their walking velocity was compromised. Maize weevil couples sublethally exposed to deltamethrin and spinosad exhibited altered reproductive behavior (walking, interacting, mounting, and copulating), but deltamethrin caused greater impairment. Curiously, higher grain consumption and increased progeny emergence were observed in deltamethrin-exposed insects, suggesting that this pyrethroid insecticide elicits hormesis in maize weevils that may compromise control efficacy by this compound. Although spinosad has less of an impact on weevil reproductive behavior than deltamethrin, this bioinsecticide also benefited weevil progeny emergence, but did not affect grain consumption. Therefore, our findings suggest caution using either compound, and particularly deltamethrin, for controlling the maize weevil, as they may actually favor this species population growth when in sublethal exposure requiring further assessments. The same concern may be valid for other insecticides as well, what deserves future attention.

Structures of a Na+-coupled, substrate-bound MATE multidrug transporter

PubMed Central

Lu, Min; Symersky, Jindrich; Radchenko, Martha; Koide, Akiko; Guo, Yi; Nie, Rongxin; Koide, Shohei

2013-01-01

Multidrug transporters belonging to the multidrug and toxic compound extrusion (MATE) family expel dissimilar lipophilic and cationic drugs across cell membranes by dissipating a preexisting Na+ or H+ gradient. Despite its clinical relevance, the transport mechanism of MATE proteins remains poorly understood, largely owing to a lack of structural information on the substrate-bound transporter. Here we report crystal structures of a Na+-coupled MATE transporter NorM from Neisseria gonorrheae in complexes with three distinct translocation substrates (ethidium, rhodamine 6G, and tetraphenylphosphonium), as well as Cs+ (a Na+ congener), all captured in extracellular-facing and drug-bound states. The structures revealed a multidrug-binding cavity festooned with four negatively charged amino acids and surprisingly limited hydrophobic moieties, in stark contrast to the general belief that aromatic amino acids play a prominent role in multidrug recognition. Furthermore, we discovered an uncommon cation–π interaction in the Na+-binding site located outside the drug-binding cavity and validated the biological relevance of both the substrate- and cation-binding sites by conducting drug resistance and transport assays. Additionally, we uncovered potential rearrangement of at least two transmembrane helices upon Na+-induced drug export. Based on our structural and functional analyses, we suggest that Na+ triggers multidrug extrusion by inducing protein conformational changes rather than by directly competing for the substrate-binding amino acids. This scenario is distinct from the canonical antiport mechanism, in which both substrate and counterion compete for a shared binding site in the transporter. Collectively, our findings provide an important step toward a detailed and mechanistic understanding of multidrug transport. PMID:23341609

Estimating Allee dynamics before they can be observed: polar bears as a case study.

PubMed

Molnár, Péter K; Lewis, Mark A; Derocher, Andrew E

2014-01-01

Allee effects are an important component in the population dynamics of numerous species. Accounting for these Allee effects in population viability analyses generally requires estimates of low-density population growth rates, but such data are unavailable for most species and particularly difficult to obtain for large mammals. Here, we present a mechanistic modeling framework that allows estimating the expected low-density growth rates under a mate-finding Allee effect before the Allee effect occurs or can be observed. The approach relies on representing the mechanisms causing the Allee effect in a process-based model, which can be parameterized and validated from data on the mechanisms rather than data on population growth. We illustrate the approach using polar bears (Ursus maritimus), and estimate their expected low-density growth by linking a mating dynamics model to a matrix projection model. The Allee threshold, defined as the population density below which growth becomes negative, is shown to depend on age-structure, sex ratio, and the life history parameters determining reproduction and survival. The Allee threshold is thus both density- and frequency-dependent. Sensitivity analyses of the Allee threshold show that different combinations of the parameters determining reproduction and survival can lead to differing Allee thresholds, even if these differing combinations imply the same stable-stage population growth rate. The approach further shows how mate-limitation can induce long transient dynamics, even in populations that eventually grow to carrying capacity. Applying the models to the overharvested low-density polar bear population of Viscount Melville Sound, Canada, shows that a mate-finding Allee effect is a plausible mechanism for slow recovery of this population. Our approach is generalizable to any mating system and life cycle, and could aid proactive management and conservation strategies, for example, by providing a priori estimates of minimum conservation targets for rare species or minimum eradication targets for pests and invasive species.

Estimating Allee Dynamics before They Can Be Observed: Polar Bears as a Case Study

PubMed Central

Molnár, Péter K.; Lewis, Mark A.; Derocher, Andrew E.

2014-01-01

Allee effects are an important component in the population dynamics of numerous species. Accounting for these Allee effects in population viability analyses generally requires estimates of low-density population growth rates, but such data are unavailable for most species and particularly difficult to obtain for large mammals. Here, we present a mechanistic modeling framework that allows estimating the expected low-density growth rates under a mate-finding Allee effect before the Allee effect occurs or can be observed. The approach relies on representing the mechanisms causing the Allee effect in a process-based model, which can be parameterized and validated from data on the mechanisms rather than data on population growth. We illustrate the approach using polar bears (Ursus maritimus), and estimate their expected low-density growth by linking a mating dynamics model to a matrix projection model. The Allee threshold, defined as the population density below which growth becomes negative, is shown to depend on age-structure, sex ratio, and the life history parameters determining reproduction and survival. The Allee threshold is thus both density- and frequency-dependent. Sensitivity analyses of the Allee threshold show that different combinations of the parameters determining reproduction and survival can lead to differing Allee thresholds, even if these differing combinations imply the same stable-stage population growth rate. The approach further shows how mate-limitation can induce long transient dynamics, even in populations that eventually grow to carrying capacity. Applying the models to the overharvested low-density polar bear population of Viscount Melville Sound, Canada, shows that a mate-finding Allee effect is a plausible mechanism for slow recovery of this population. Our approach is generalizable to any mating system and life cycle, and could aid proactive management and conservation strategies, for example, by providing a priori estimates of minimum conservation targets for rare species or minimum eradication targets for pests and invasive species. PMID:24427306

Potential role of polymorphisms in the transporter genes ENT1 and MATE1/OCT2 in predicting TAS-102 efficacy and toxicity in patients with refractory metastatic colorectal cancer.

PubMed

Suenaga, Mitsukuni; Schirripa, Marta; Cao, Shu; Zhang, Wu; Yang, Dongyun; Dadduzio, Vincenzo; Salvatore, Lisa; Borelli, Beatrice; Pietrantonio, Filippo; Ning, Yan; Okazaki, Satoshi; Berger, Martin D; Miyamoto, Yuji; Gopez, Roel; Barzi, Afsaneh; Yamaguchi, Toshiharu; Loupakis, Fotios; Lenz, Heinz-Josef

2017-11-01

Trifluridine (FTD) is an active cytotoxic component of the metastatic colorectal cancer (mCRC) drug TAS-102, and thymidine phosphorylase inhibitor (TPI) inhibits the rapid degradation of FTD. We tested whether single nucleotide polymorphisms (SNPs) in genes involved in FTD metabolism and TPI excretion could predict outcome in patients with mCRC treated with TAS-102. We investigated three different cohorts: a training cohort (n = 52) and a testing cohort (n = 129) both receiving TAS-102 and a control cohort (n = 52) receiving regorafenib. SNPs of TK1, ENT1, CNT1, MATE1, MATE2 and OCT2 were analysed by polymerase chain reaction-based direct DNA sequencing. In the training cohort, patients with any ENT1 rs760370 G allele had a significantly longer progression-free survival (PFS; 3.5 versus 2.1 months, respectively, hazard ratio [HR] 0.44, P = 0.004) and overall survival (OS; 8.7 versus 5.3 months, respectively, HR 0.27, P = 0.003) than the A/A genotype. These findings were validated in the testing cohort (P = 0.021 and 0.009 for PFS and OS, respectively). In addition, the combination of ENT1 rs760370, MATE1 rs2289669 and OCT2 rs316019 SNPs significantly stratified patients with the risk of PFS and OS in both cohorts (P < 0.001 for PFS and OS in the training cohort; P = 0.053 and 0.025 for PFS and OS, respectively, in the testing cohort). No significant differences were observed in the control group. The combination of ENT1, MATE1 and OCT2 SNPs may serve as a predictive and prognostic marker in mCRC patients treated with TAS-102. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adiposity, compared with masculinity, serves as a more valid cue to immunocompetence in human mate choice.

PubMed

Rantala, Markus J; Coetzee, Vinet; Moore, Fhionna R; Skrinda, Ilona; Kecko, Sanita; Krama, Tatjana; Kivleniece, Inese; Krams, Indrikis

2013-01-22

According to the 'good genes' hypothesis, females choose males based on traits that indicate the male's genetic quality in terms of disease resistance. The 'immunocompetence handicap hypothesis' proposed that secondary sexual traits serve as indicators of male genetic quality, because they indicate that males can contend with the immunosuppressive effects of testosterone. Masculinity is commonly assumed to serve as such a secondary sexual trait. Yet, women do not consistently prefer masculine looking men, nor is masculinity consistently related to health across studies. Here, we show that adiposity, but not masculinity, significantly mediates the relationship between a direct measure of immune response (hepatitis B antibody response) and attractiveness for both body and facial measurements. In addition, we show that circulating testosterone is more closely associated with adiposity than masculinity. These findings indicate that adiposity, compared with masculinity, serves as a more important cue to immunocompetence in female mate choice.

Hemocompatibility-Related Outcomes in the MOMENTUM 3 Trial at 6 Months: A Randomized Controlled Study of a Fully Magnetically Levitated Pump in Advanced Heart Failure.

PubMed

Uriel, Nir; Colombo, Paolo C; Cleveland, Joseph C; Long, James W; Salerno, Christopher; Goldstein, Daniel J; Patel, Chetan B; Ewald, Gregory A; Tatooles, Antone J; Silvestry, Scott C; John, Ranjit; Caldeira, Christiano; Jeevanandam, Valluvan; Boyle, Andrew J; Sundareswaran, Kartik S; Sood, Poornima; Mehra, Mandeep R

2017-05-23

The HeartMate 3 (HM3) Left Ventricular Assist System (LVAS) (Abbott) is a centrifugal, fully magnetically levitated, continuous-flow blood pump engineered to enhance hemocompatibility and reduce shear stress on blood components. The MOMENTUM 3 trial (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) compares the HM3 LVAS with the HeartMate II (HMII) LVAS (Abbott) in advanced heart failure refractory to medical management, irrespective of therapeutic intention (bridge to transplant versus destination therapy). This investigation reported its primary outcome in the short-term cohort (n=294; 6-month follow-up), demonstrating superiority of the HM3 for the trial primary end point (survival free of a disabling stroke or reoperation to replace the pump for malfunction), driven by a reduced need for reoperations. The aim of this analysis was to evaluate the aggregate of hemocompatibility-related clinical adverse events (HRAEs) between the 2 LVAS. We conducted a secondary end point evaluation of HRAE (survival free of any nonsurgical bleeding, thromboembolic event, pump thrombosis, or neurological event) in the short-term cohort (as-treated cohort n=289) at 6 months. The net burden of HRAE was also assessed by using a previously described hemocompatibility score, which uses 4 escalating tiers of hierarchal severity to derive a total score for events encountered during the entire follow-up experience for each patient. In 289 patients in the as-treated group (151 the HM3 and 138 the HMII), survival free of any HRAE was achieved in 69% of the HM3 group and in 55% of the HMII group (hazard ratio, 0.62; confidence interval, 0.42-0.91; P =0.012). Using the hemocompatibility score, the HM3 group demonstrated less pump thrombosis requiring reoperation (0 versus 36 points, P <0.001) or medically managed pump thrombosis (0 versus 5 points, P =0.02), and fewer nondisabling strokes (6 versus 24 points, P =0.026) than the control HMII LVAS. The net hemocompatibility score in the HM3 in comparison with the HMII patients was 101 (0.67±1.50 points/patient) versus 137 (0.99±1.79 points/patient) (odds ratio, 0.64; confidence interval, 0.39-1.03; P =0.065). In this secondary analysis of the MOMENTUM 3 trial, the HM3 LVAS demonstrated greater freedom from HRAEs in comparison with the HMII LVAS at 6 months. URL: http://clinicaltrials.gov. Unique identifier: NCT02224755. © 2017 American Heart Association, Inc.

Bactrocera dorsalis male sterilization by targeted RNA interference of spermatogenesis: empowering sterile insect technique programs

PubMed Central

Dong, Yong-Cheng; Wang, Zhi-Jian; Chen, Zhen-Zhong; Clarke, Anthony R.; Niu, Chang-Ying

2016-01-01

RNA interference (RNAi) is a genetic technique which has novel application for sustainable pest control. The Sterile Insect Technique (SIT) uses releases of mass-produced, sterile male insects to out-compete wild males for mates to reduce pest populations. RNAi sterilization of SIT males would have several advantages over radiation sterilization, but to achieve this appropriate target genes must first be identified and then targeted with interference technology. With this goal, eight spermatogenesis related candidate genes were cloned and tested for potential activity in Bactrocera dorsalis. The knockdown of candidate genes by oral delivery of dsRNAs did not influence the mating of male flies, but significantly affected the daily average number of eggs laid by females, and reduced egg hatching rate by 16–60%. RNAi negatively affected spermatozoa quantitatively and qualitatively. Following the mating of lola-/topi-/rac-/rho-/upd-/magu-silenced males, we recorded a significant decrease in number and length of spermatozoa in female spermatheca compared to gfp-silenced control group. In a greenhouse trial, the number of damaged oranges and B. dorsalis larvae were significantly reduced in a dsrho-treated group compared with the dsgfp group. This study provides strong evidence for the use RNAi in pest management, especially for the improvement of SIT against B. dorsalis and other species. PMID:27767174

Evolution of female multiple mating: A quantitative model of the “sexually selected sperm” hypothesis

PubMed Central

Bocedi, Greta; Reid, Jane M

2015-01-01

Explaining the evolution and maintenance of polyandry remains a key challenge in evolutionary ecology. One appealing explanation is the sexually selected sperm (SSS) hypothesis, which proposes that polyandry evolves due to indirect selection stemming from positive genetic covariance with male fertilization efficiency, and hence with a male's success in postcopulatory competition for paternity. However, the SSS hypothesis relies on verbal analogy with “sexy-son” models explaining coevolution of female preferences for male displays, and explicit models that validate the basic SSS principle are surprisingly lacking. We developed analogous genetically explicit individual-based models describing the SSS and “sexy-son” processes. We show that the analogy between the two is only partly valid, such that the genetic correlation arising between polyandry and fertilization efficiency is generally smaller than that arising between preference and display, resulting in less reliable coevolution. Importantly, indirect selection was too weak to cause polyandry to evolve in the presence of negative direct selection. Negatively biased mutations on fertilization efficiency did not generally rescue runaway evolution of polyandry unless realized fertilization was highly skewed toward a single male, and coevolution was even weaker given random mating order effects on fertilization. Our models suggest that the SSS process is, on its own, unlikely to generally explain the evolution of polyandry. PMID:25330405

Low-impact mating system

NASA Technical Reports Server (NTRS)

Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

2009-01-01

An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

Evaluation of pheromone release from commercial mating disruption dispensers.

PubMed

Tomaszewska, Elizabeth; Hebert, Vincent R; Brunner, Jay F; Jones, Vincent P; Doerr, Mike; Hilton, Richard

2005-04-06

Pome fruit growers and crop consultants have expressed concerns about the seasonal release performance of commercial codling moth mating disruption dispenser products. Because of these concerns, we developed a laboratory flow-through volatile collection system (VCS) for measuring the volatile release of the codling moth sex pheromone, codlemone, from commercially available hand-applied dispensers. Under controlled air-flow and temperature conditions, the released vapor was trapped onto a polyurethane foam adsorbent followed by solvent extraction, solvent reduction, and GC/MS determination. Method recovery and breakthrough validations were performed to demonstrate system reliability before determining codlemone release from commercial dispensers field-aged over 140 days. The volatile collection was carried out in a consistent manner among five dispenser types most commonly used by growers, so that direct comparison of performance could be made. The comparison showed differences in the amount of pheromone released and in the patterns of release throughout the season between dispenser types. The variation in release performance demonstrates the need for routine evaluation of commercially marketed mating disruption dispensers. We believe that the simple and cost-effective volatile collection system can assist pheromone dispenser manufacturers in determining seasonal dispenser performance before new products are introduced into the commercial market and in rapidly verifying dispenser release when field-aged dispenser efficacy is in question.

Mate Value Discrepancy and Mate Retention Behaviors of Self and Partner.

PubMed

Sela, Yael; Mogilski, Justin K; Shackelford, Todd K; Zeigler-Hill, Virgil; Fink, Bernhard

2017-10-01

This study investigated the relationship between perceived mate value discrepancy (i.e., the difference between an individual's mate value and their partner's mate value) and perceived frequency of mate retention performed by an individual relative to his or her partner. In two studies, participants in long-term, exclusive, sexual, heterosexual relationships reported their own, and their partner's, mate value and mate retention. Samples included 899 community members (Study 1) and 941 students and community members (Study 2). In Study 1, we documented that individuals with higher self-perceived short-term mate value, and who perceive their partner to have lower (vs. higher) short-term mate value, perform less frequent Benefit-Provisioning mate retention, controlling for the partner's Benefit-Provisioning mate retention. In Study 2, we documented that individuals who perceive that they could less easily replace their partner, and who perceive their partner could more (vs. less) easily replace them, perform more frequent mate retention (Benefit-Provisioning and Cost-Inflicting), controlling for the partner's mate retention. These results highlight the importance of assessing perceived discrepancies in mate value (notably, regarding the replaceability of self and partner with another long-term mate) and perceived mate retention behaviors of self, relative to partner, between men and women in long-term relationships. © 2016 Wiley Periodicals, Inc.

Evolution of male and female choice in polyandrous systems.

PubMed

Puurtinen, Mikael; Fromhage, Lutz

2017-03-29

We study the evolution of male and female mating strategies and mate choice for female fecundity and male fertilization ability in a system where both sexes can mate with multiple partners, and where there is variation in individual quality (i.e. in the availability of resources individuals can allocate to matings, mate choice and production of gametes). We find that when the cost of mating differs between sexes, the sex with higher cost of mating is reluctant to accept matings and is often also choosy, while the other sex accepts all matings. With equal mating costs, the evolution of mating strategies depends on the strength of female sperm limitation, so that when sperm limitation is strong, males are often reluctant and choosy, whereas females tend to accept available matings. Male reluctance evolves because a male's benefit per mating diminishes rapidly as he mates too often, hence losing out in the process of sperm competition as he spends much of his resources on mating costs rather than ejaculate production. When sperm limitation is weaker, females become more reluctant and males are more eager to mate. The model thus suggests that reversed sex roles are plausible outcomes of polyandry and limited sperm production. Implications for empirical studies of mate choice are discussed. © 2017 The Author(s).

How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples

PubMed Central

Conroy-Beam, Daniel; Buss, David M.

2016-01-01

Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294) we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection. PMID:27276030

How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

PubMed

Conroy-Beam, Daniel; Buss, David M

2016-01-01

Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294) we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

Can Findings from Randomized Controlled Trials of Social Skills Training in Autism Spectrum Disorder Be Generalized? The Neglected Dimension of External Validity

ERIC Educational Resources Information Center

Jonsson, Ulf; Olsson, Nora Choque; Bölte, Sven

2016-01-01

Systematic reviews have traditionally focused on internal validity, while external validity often has been overlooked. In this study, we systematically reviewed determinants of external validity in the accumulated randomized controlled trials of social skills group interventions for children and adolescents with autism spectrum disorder. We…

First-in-human Phase 1 CRISPR Gene Editing Cancer Trials: Are We Ready?

PubMed

Baylis, Francoise; McLeod, Marcus

2017-01-01

A prospective first-in-human Phase 1 CRISPR gene editing trial in the United States for patients with melanoma, synovial sarcoma, and multiple myeloma offers hope that gene editing tools may usefully treat human disease. An overarching ethical challenge with first-in-human Phase 1 clinical trials, however, is knowing when it is ethically acceptable to initiate such trials on the basis of safety and efficacy data obtained from pre-clinical studies. If the pre-clinical studies that inform trial design are themselves poorly designed - as a result of which the quality of pre-clinical evidence is deficient - then the ethical requirement of scientific validity for clinical research may not be satisfied. In turn, this could mean that the Phase 1 clinical trial will be unsafe and that trial participants will be exposed to risk for no potential benefit. To assist sponsors, researchers, clinical investigators and reviewers in deciding when it is ethically acceptable to initiate first-in-human Phase 1 CRISPR gene editing clinical trials, structured processes have been developed to assess and minimize translational distance between pre-clinical and clinical research. These processes draw attention to various features of internal validity, construct validity, and external validity. As well, the credibility of supporting evidence is to be critically assessed with particular attention to optimism bias, financial conflicts of interest and publication bias. We critically examine the pre-clinical evidence used to justify the first-inhuman Phase 1 CRISPR gene editing cancer trial in the United States using these tools. We conclude that the proposed trial cannot satisfy the ethical requirement of scientific validity because the supporting pre-clinical evidence used to inform trial design is deficient. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Contribution of MATE1 to Renal Secretion of the NMDA Receptor Antagonist Memantine.

PubMed

Müller, Fabian; Weitz, Dietmar; Derdau, Volker; Sandvoss, Martin; Mertsch, Katharina; König, Jörg; Fromm, Martin F

2017-09-05

The weak base memantine is actively secreted into urine, however the underlying mechanisms are insufficiently understood. Potential candidates involved in memantine renal secretion are organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATE1, MATE2-K). The aim of this in vitro study was the examination of the interaction of memantine with OCT2 and MATEs. Memantine transporter inhibition and transport were examined in HEK cells expressing human OCT2, MATE1, or MATE2-K. Monolayers of single- (MDCK-OCT2, MDCK-MATE1) and double-transfected MDCK cells (MDCK-OCT2-MATE1) were used for studies on vectorial, basal to apical memantine transport. Memantine inhibited OCT2-, MATE1-, and MATE2-K-mediated metformin transport with IC 50 values of 3.2, 40.9, and 315.3 μM, respectively. In HEK cells, no relevant memantine uptake by OCT2, MATE1, or MATE2-K was detected. Vectorial transport experiments, however, indicated a role of MATE1 for memantine export: After memantine administration to the basal side of the monolayers, memantine cellular accumulation was considerably lower (MDCK-MATE1 vs MDCK control cells, P < 0.01) and memantine transcellular, basal to apical transport was higher in MATE1 expressing cells (MDCK-MATE1 vs MDCK control cells, P < 0.001 at 60 and 180 min). Both effects were abolished upon addition of the MATE inhibitor cimetidine. These experiments suggest a relevant role of MATE1 for renal secretion of memantine. In the clinical setting, renal elimination of memantine could be impaired by coadministration of MATE inhibitors.

Evolution of the Bipolar Mating System of the Mushroom Coprinellus disseminatus From Its Tetrapolar Ancestors Involves Loss of Mating-Type-Specific Pheromone Receptor Function

PubMed Central

James, Timothy Y.; Srivilai, Prayook; Kües, Ursula; Vilgalys, Rytas

2006-01-01

Mating incompatibility in mushroom fungi is controlled by the mating-type loci. In tetrapolar species, two unlinked mating-type loci exist (A and B), whereas in bipolar species there is only one locus. The A and B mating-type loci encode homeodomain transcription factors and pheromones and pheromone receptors, respectively. Most mushroom species have a tetrapolar mating system, but numerous transitions to bipolar mating systems have occurred. Here we determined the genes controlling mating type in the bipolar mushroom Coprinellus disseminatus. Through positional cloning and degenerate PCR, we sequenced both the transcription factor and pheromone receptor mating-type gene homologs from C. disseminatus. Only the transcription factor genes segregate with mating type, discounting the hypothesis of genetic linkage between the A and B mating-type loci as the causal origin of bipolar mating behavior. The mating-type locus of C. disseminatus is similar to the A mating-type locus of the model species Coprinopsis cinerea and encodes two tightly linked pairs of homeodomain transcription factor genes. When transformed into C. cinerea, the C. disseminatus A and B homologs elicited sexual reactions like native mating-type genes. Although mating type in C. disseminatus is controlled by only the transcription factor genes, cellular functions appear to be conserved for both groups of genes. PMID:16461425

Self-Perceived Mate Value, Facial Attractiveness, and Mate Preferences: Do Desirable Men Want It All?

PubMed

Arnocky, Steven

2018-01-01

Ten years ago, Buss and Shackelford demonstrated that high mate value (i.e., physically attractive) women held more discerning mate preferences relative to lower mate value women. Since then, researchers have begun to consider the equally important role of men's sexual selectivity in human mate choice. Yet, little research has focused on whether high mate value men are similarly choosy in their mate preferences. In a sample of 139 undergraduate men, relationships between self-perceived mate value as well as female-rated facial attractiveness were examined in relation to men's expressed mate preferences. Results showed that self-perceived mate value was unrelated to men's facial attractiveness as rated by women. Men who believed they were of high mate value were more likely than lower mate value men to prefer to marry at a younger age; to have a spouse who was younger than them; and to have a partner who was sociable, ambitious, high in social status, with good financial prospects, a desire for children, health, good looks, and mutual attraction. Objective male facial attractiveness was generally unrelated to heightened mate preferences, with the exception of heightened preference for similar religious background and good physical health. Findings suggest that men who perceive themselves as high in overall mate value are selective in their mate choice in a manner similar to high mate value women.

Sex roles and mutual mate choice matter during mate sampling.

PubMed

Myhre, Lise Cats; de Jong, Karen; Forsgren, Elisabet; Amundsen, Trond

2012-06-01

The roles of females and males in mating competition and mate choice have lately proven more variable, between and within species, than previously thought. In nature, mating competition occurs during mate search and is expected to be regulated by the numbers of potential mates and same-sex competitors. Here, we present the first study to test how a temporal change in sex roles affects mating competition and mate choice during mate sampling. Our model system (the marine fish Gobiusculus flavescens) is uniquely suitable because of its change in sex roles, from conventional to reversed, over the breeding season. As predicted from sex role theory, courtship was typically initiated by males and terminated by females early in the breeding season. The opposite pattern was observed late in the season, at which time several females often simultaneously courted the same male. Mate-searching females visited more males early than late in the breeding season. Our study shows that mutual mate choice and mating competition can have profound effects on female and male behavior. Future work needs to consider the dynamic nature of mating competition and mate choice if we aim to fully understand sexual selection in the wild.

Assessing the generalizability of randomized trial results to target populations.

PubMed

Stuart, Elizabeth A; Bradshaw, Catherine P; Leaf, Philip J

2015-04-01

Recent years have seen increasing interest in and attention to evidence-based practices, where the "evidence" generally comes from well-conducted randomized trials. However, while those trials yield accurate estimates of the effect of the intervention for the participants in the trial (known as "internal validity"), they do not always yield relevant information about the effects in a particular target population (known as "external validity"). This may be due to a lack of specification of a target population when designing the trial, difficulties recruiting a sample that is representative of a prespecified target population, or to interest in considering a target population somewhat different from the population directly targeted by the trial. This paper first provides an overview of existing design and analysis methods for assessing and enhancing the ability of a randomized trial to estimate treatment effects in a target population. It then provides a case study using one particular method, which weights the subjects in a randomized trial to match the population on a set of observed characteristics. The case study uses data from a randomized trial of school-wide positive behavioral interventions and supports (PBIS); our interest is in generalizing the results to the state of Maryland. In the case of PBIS, after weighting, estimated effects in the target population were similar to those observed in the randomized trial. The paper illustrates that statistical methods can be used to assess and enhance the external validity of randomized trials, making the results more applicable to policy and clinical questions. However, there are also many open research questions; future research should focus on questions of treatment effect heterogeneity and further developing these methods for enhancing external validity. Researchers should think carefully about the external validity of randomized trials and be cautious about extrapolating results to specific populations unless they are confident of the similarity between the trial sample and that target population.

Polyandry promotes enhanced offspring survival in decorated crickets.

PubMed

Ivy, Tracie M; Sakaluk, Scott K

2005-01-01

Although female multiple mating is ubiquitous in insects, its adaptive significance remains poorly understood. Benefits to multiple mating can accrue via direct material benefits, indirect genetic benefits, or both. We investigated the effects of multiple mating in the decorated cricket, Gryllodes sigillatus, by simultaneously varying the number of times that females mated and the number of different males with which they mated, measuring aspects of female fecundity and elements of offspring performance and viability. Multiple matings resulted in enhanced female fitness relative to single matings when females mated with different partners, but not when females mated repeatedly with the same male. Specifically, polyandrous females produced significantly more offspring surviving to reproductive maturity than did monogamous females mating once or mating repeatedly with the same male. These results suggest that the benefit females gain from multiple mating is influenced primarily by genetic and not material benefits.

Use of LiDAR to Assist in Delineating Waters of the United States, Including Wetlands

DTIC Science & Technology

2014-03-01

investigator’s objective. For example, if the sole objective is to identify geomorphic breaks in slope associated with the OHWM, points representing vegetation... geomorphic position. During the data-gathering stage of wetland delinea- tions, measurements made using LiDAR data should be considered esti- mates...field. Field validation of LiDAR topographic data is essential before using them as evidence of a secondary hydrology indicator, such as geomorphic

Early exposure to 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) affects mating behavior of zebra finches.

PubMed

Eng, Margaret L; Elliott, John E; MacDougall-Shackleton, Scott A; Letcher, Robert J; Williams, Tony D

2012-05-01

2,2',4,4',5-Pentabromodiphenyl ether (BDE-99) is a brominated flame retardant congener that has pervaded global food chains, being reported in avian egg and tissue samples throughout the world. Its effects on birds are not well known, but there is evidence in exposed mammals that it directly mediates and causes neurotoxicity, alters thyroid hormone homeostasis, and lowers sex steroid hormone concentrations. In birds, those processes could disrupt the song-control system and male mating behavior. In this study, the effects of nestling exposure to environmentally relevant levels of BDE-99 were assessed in a model songbird species, the zebra finch (Taeniopygia guttata). A tissue residue study in which zebra finch nestlings were orally exposed to 0, 2.5, 15.8, or 50.7 ng BDE-99/g body weight (bw) per day over the 21-day nesting period validated dosing methods and confirmed dose levels were environmentally relevant (332.7 ± 141.0 to 4450.2 ± 1396.2 ng/g plasma lipid). A full-scale study exposing nestlings to 0, 2.5, 15.8, 50.7, or 173.8 ng BDE-99/g bw/day was carried out to investigate long-term effects of BDE-99 on the adult song-control nuclei volumes, song quality, and male mating behavior. Early exposure to BDE-99 had significant effects on male mating behavior and the response of clean experienced females to exposed males. There was no effect on male song-control nuclei or song quality, and there were nondose-dependent effects on female song-control nuclei. The results demonstrate that early exposure to environmentally relevant levels of BDE-99 affects the behavior of zebra finches.

A temperature rise reduces trial-to-trial variability of locust auditory neuron responses.

PubMed

Eberhard, Monika J B; Schleimer, Jan-Hendrik; Schreiber, Susanne; Ronacher, Bernhard

2015-09-01

The neurophysiology of ectothermic animals, such as insects, is affected by environmental temperature, as their body temperature fluctuates with ambient conditions. Changes in temperature alter properties of neurons and, consequently, have an impact on the processing of information. Nevertheless, nervous system function is often maintained over a broad temperature range, exhibiting a surprising robustness to variations in temperature. A special problem arises for acoustically communicating insects, as in these animals mate recognition and mate localization typically rely on the decoding of fast amplitude modulations in calling and courtship songs. In the auditory periphery, however, temporal resolution is constrained by intrinsic neuronal noise. Such noise predominantly arises from the stochasticity of ion channel gating and potentially impairs the processing of sensory signals. On the basis of intracellular recordings of locust auditory neurons, we show that intrinsic neuronal variability on the level of spikes is reduced with increasing temperature. We use a detailed mathematical model including stochastic ion channel gating to shed light on the underlying biophysical mechanisms in auditory receptor neurons: because of a redistribution of channel-induced current noise toward higher frequencies and specifics of the temperature dependence of the membrane impedance, membrane potential noise is indeed reduced at higher temperatures. This finding holds under generic conditions and physiologically plausible assumptions on the temperature dependence of the channels' kinetics and peak conductances. We demonstrate that the identified mechanism also can explain the experimentally observed reduction of spike timing variability at higher temperatures. Copyright © 2015 the American Physiological Society.

A temperature rise reduces trial-to-trial variability of locust auditory neuron responses

PubMed Central

Schleimer, Jan-Hendrik; Schreiber, Susanne; Ronacher, Bernhard

2015-01-01

The neurophysiology of ectothermic animals, such as insects, is affected by environmental temperature, as their body temperature fluctuates with ambient conditions. Changes in temperature alter properties of neurons and, consequently, have an impact on the processing of information. Nevertheless, nervous system function is often maintained over a broad temperature range, exhibiting a surprising robustness to variations in temperature. A special problem arises for acoustically communicating insects, as in these animals mate recognition and mate localization typically rely on the decoding of fast amplitude modulations in calling and courtship songs. In the auditory periphery, however, temporal resolution is constrained by intrinsic neuronal noise. Such noise predominantly arises from the stochasticity of ion channel gating and potentially impairs the processing of sensory signals. On the basis of intracellular recordings of locust auditory neurons, we show that intrinsic neuronal variability on the level of spikes is reduced with increasing temperature. We use a detailed mathematical model including stochastic ion channel gating to shed light on the underlying biophysical mechanisms in auditory receptor neurons: because of a redistribution of channel-induced current noise toward higher frequencies and specifics of the temperature dependence of the membrane impedance, membrane potential noise is indeed reduced at higher temperatures. This finding holds under generic conditions and physiologically plausible assumptions on the temperature dependence of the channels' kinetics and peak conductances. We demonstrate that the identified mechanism also can explain the experimentally observed reduction of spike timing variability at higher temperatures. PMID:26041833

Post-mating interactions and their effects on fitness of female and male Echinothrips americanus (Thysanoptera: Thripidae), a new insect pest in China.

PubMed

Li, Xiao-Wei; Jiang, Hong-Xue; Zhang, Xiao-Chen; Shelton, Anthony M; Feng, Ji-Nian

2014-01-01

Post-mating, sexual interactions of opposite sexes differ considerably in different organisms. Post-mating interactions such as re-mating behavior and male harassment can affect the fitness of both sexes. Echinothrips americanus is a new insect pest in Mainland China, and little is known about its post-mating interactions. In this study, we observed re-mating frequency and male harassment frequency and their effects on fitness parameters and offspring sex ratios of E. americanus females. Furthermore, we tested the impact of mating and post-mating interactions on fitness parameters of males. Our results revealed that the re-mating frequency in female adults was extremely low during a 30-day period. However, post-mating interactions between females and males, consisting mainly of male harassment and female resistance, did occur and significantly reduced female longevity and fecundity. Interestingly, increased access to males did not affect the ratio of female offspring. For males, mating dramatically reduced their longevity. However, post-mating interactions with females had no effects on the longevity of mated males. These results enrich our basic knowledge about female and male mating and post-mating behaviors in this species and provide important information about factors that may influence population regulation of this important pest species.

Mate-choice copying in single and coupled women: the influence of mate acceptance and mate rejection decisions of other women.

PubMed

Deng, Yan; Zheng, Yong

2015-01-26

Studies of humans and non-human animals indicate that females tend to change the likelihood of choosing a potential mate based on the decisions of other females; this is known as mate-choice copying. In a sample of both single and coupled women, we examined the influence of other women's (model) mate-choice decisions, including mate acceptance and mate rejection, on participants' attractiveness ratings of men (target) and willingness of mate selection. We also examined whether different types of relationships between the target men and the model women affected mate-choice copying. We found that both the single and coupled women showed mate-choice copying, but their response patterns differed. The significant effects for single women were dependent on a decrease in attractiveness ratings when they perceived the models' mate rejection. However, the significant findings for coupled women relied on an increase in attractiveness ratings when they observed the models' mate acceptance. Furthermore, the relationship status between the target men and the model women affected the magnitude of mate-choice copying effects for the single women. Specifically, they showed less mate-choice copying when the targets and models were in a committed romantic relationship than when in a temporary relationship.

Heterozygosity-based assortative mating in blue tits (Cyanistes caeruleus): implications for the evolution of mate choice

PubMed Central

García-Navas, Vicente; Ortego, Joaquín; Sanz, Juan José

2009-01-01

The general hypothesis of mate choice based on non-additive genetic traits suggests that individuals would gain important benefits by choosing genetically dissimilar mates (compatible mate hypothesis) and/or more heterozygous mates (heterozygous mate hypothesis). In this study, we test these hypotheses in a socially monogamous bird, the blue tit (Cyanistes caeruleus). We found no evidence for a relatedness-based mating pattern, but heterozygosity was positively correlated between social mates, suggesting that blue tits may base their mating preferences on partner's heterozygosity. We found evidence that the observed heterozygosity-based assortative mating could be maintained by both direct and indirect benefits. Heterozygosity reflected individual quality in both sexes: egg production and quality increased with female heterozygosity while more heterozygous males showed higher feeding rates during the brood-rearing period. Further, estimated offspring heterozygosity correlated with both paternal and maternal heterozygosity, suggesting that mating with heterozygous individuals can increase offspring genetic quality. Finally, plumage crown coloration was associated with male heterozygosity, and this could explain unanimous mate preferences for highly heterozygous and more ornamented individuals. Overall, this study suggests that non-additive genetic traits may play an important role in the evolution of mating preferences and offers empirical support to the resolution of the lek paradox from the perspective of the heterozygous mate hypothesis. PMID:19474042

ClinicalTrials.gov and Drugs@FDA: A Comparison of Results Reporting for New Drug Approval Trials.

PubMed

Schwartz, Lisa M; Woloshin, Steven; Zheng, Eugene; Tse, Tony; Zarin, Deborah A

2016-09-20

Pharmaceutical companies and other trial sponsors must submit certain trial results to ClinicalTrials.gov. The validity of these results is unclear. To validate results posted on ClinicalTrials.gov against publicly available U.S. Food and Drug Administration (FDA) reviews on Drugs@FDA. ClinicalTrials.gov (registry and results database) and Drugs@FDA (medical and statistical reviews). 100 parallel-group, randomized trials for new drug approvals (January 2013 to July 2014) with results posted on ClinicalTrials.gov (15 March 2015). 2 assessors extracted, and another verified, the trial design, primary and secondary outcomes, adverse events, and deaths. Most trials were phase 3 (90%), double-blind (92%), and placebo-controlled (73%) and involved 32 drugs from 24 companies. Of 137 primary outcomes identified from ClinicalTrials.gov, 134 (98%) had corresponding data at Drugs@FDA, 130 (95%) had concordant definitions, and 107 (78%) had concordant results. Most differences were nominal (that is, relative difference <10%). Primary outcome results in 14 trials could not be validated. Of 1927 secondary outcomes from ClinicalTrials.gov, Drugs@FDA mentioned 1061 (55%) and included results data for 367 (19%). Of 96 trials with 1 or more serious adverse events in either source, 14 could be compared and 7 had discordant numbers of persons experiencing the adverse events. Of 62 trials with 1 or more deaths in either source, 25 could be compared and 17 were discordant. Unknown generalizability to uncontrolled or crossover trial results. Primary outcome definitions and results were largely concordant between ClinicalTrials.gov and Drugs@FDA. Half the secondary outcomes, as well as serious events and deaths, could not be validated because Drugs@FDA includes only "key outcomes" for regulatory decision making and frequently includes only adverse event results aggregated across multiple trials. National Library of Medicine.

Mate value asymmetry and relationship satisfaction in female opinion.

PubMed

Nowak, Natalia; Danel, Dariusz

2014-01-01

A considerable amount of studies highlight positive assortative mating in terms of various aspects of mate value. However, there is a lack of studies that directly show how both partners' mate value and mate value differences are related to the satisfaction in heterosexual relationship. In the present study, the authors focused on women and analyzed how their mate value self-assessment and perception of their partners' mate value are related to female relationship satisfaction. The authors also classified them under 3 categories of couples defined by partners' mate value discrepancy, that is, in which a woman has higher, lower, and equal mate value than does her male partner. Women's relationship satisfaction was positively related to the perception of their partners' mate value but negatively correlated to their mate value self-assessment. Moreover, relationship satisfaction was the lowest in the category where woman has higher self-assessed mate value. The level of women's relationship satisfaction did not differ in 2 other categories of relationships. Our results suggest that women's perception of mate value and mate value asymmetry may significantly affect women's satisfaction from their relationships. The authors provide several possible, evolutionary-based explanatory mechanisms.

Design and validation of a portable, inexpensive and multi-beam timing light system using the Nintendo Wii hand controllers.

PubMed

Clark, Ross A; Paterson, Kade; Ritchie, Callan; Blundell, Simon; Bryant, Adam L

2011-03-01

Commercial timing light systems (CTLS) provide precise measurement of athletes running velocity, however they are often expensive and difficult to transport. In this study an inexpensive, wireless and portable timing light system was created using the infrared camera in Nintendo Wii hand controllers (NWHC). System creation with gold-standard validation. A Windows-based software program using NWHC to replicate a dual-beam timing gate was created. Firstly, data collected during 2m walking and running trials were validated against a 3D kinematic system. Secondly, data recorded during 5m running trials at various intensities from standing or flying starts were compared to a single beam CTLS and the independent and average scores of three handheld stopwatch (HS) operators. Intraclass correlation coefficient and Bland-Altman plots were used to assess validity. Absolute error quartiles and percentage of trials in absolute error threshold ranges were used to determine accuracy. The NWHC system was valid when compared against the 3D kinematic system (ICC=0.99, median absolute error (MAR)=2.95%). For the flying 5m trials the NWHC system possessed excellent validity and precision (ICC=0.97, MAR<3%) when compared with the CTLS. In contrast, the NWHC system and the HS values during standing start trials possessed only modest validity (ICC<0.75) and accuracy (MAR>8%). A NWHC timing light system is inexpensive, portable and valid for assessing running velocity. Errors in the 5m standing start trials may have been due to erroneous event detection by either the commercial or NWHC-based timing light systems. Copyright © 2010 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Update on simulation-based surgical training and assessment in ophthalmology: a systematic review.

PubMed

Thomsen, Ann Sofia S; Subhi, Yousif; Kiilgaard, Jens Folke; la Cour, Morten; Konge, Lars

2015-06-01

This study reviews the evidence behind simulation-based surgical training of ophthalmologists to determine (1) the validity of the reported models and (2) the ability to transfer skills to the operating room. Simulation-based training is established widely within ophthalmology, although it often lacks a scientific basis for implementation. We conducted a systematic review of trials involving simulation-based training or assessment of ophthalmic surgical skills among health professionals. The search included 5 databases (PubMed, EMBASE, PsycINFO, Cochrane Library, and Web of Science) and was completed on March 1, 2014. Overall, the included trials were divided into animal, cadaver, inanimate, and virtual-reality models. Risk of bias was assessed using the Cochrane Collaboration's tool. Validity evidence was evaluated using a modern validity framework (Messick's). We screened 1368 reports for eligibility and included 118 trials. The most common surgery simulated was cataract surgery. Most validity trials investigated only 1 or 2 of 5 sources of validity (87%). Only 2 trials (48 participants) investigated transfer of skills to the operating room; 4 trials (65 participants) evaluated the effect of simulation-based training on patient-related outcomes. Because of heterogeneity of the studies, it was not possible to conduct a quantitative analysis. The methodologic rigor of trials investigating simulation-based surgical training in ophthalmology is inadequate. To ensure effective implementation of training models, evidence-based knowledge of validity and efficacy is needed. We provide a useful tool for implementation and evaluation of research in simulation-based training. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Analysis of the Mating and Reproductive Traits of Plutella xylostella (Lepidoptera: Plutellidae)

PubMed Central

Song, Wen; Liu, Li; Li, Pengyan; Sun, Hui; Qin, Yuchuan

2014-01-01

Abstract The reproductive traits of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) were investigated and analyzed by different analytical methods. Simple statistical analysis showed relatively higher mating rates maintained from 21:00 to 2:00, thereafter dropping to a minimum at about 18:00. Mating rates were affected by female and male age. Mating was most likely to take place between females and males that were 1 d old. Correlation and factor analysis indicated that mating delayed females have a relatively lower and unsuccessful mating rate and relatively shorter copulation duration, with lower egg hatchability and fecundity; in addition, the mating delayed male would reduce female’s fertility. Delay of mating prolonged life of both males and females. A higher and successful mating rate would cause a higher egg hatchability and fecundity. Canonical correlation analysis showed that mating age and successful copulation of female play a decisive role for her fecundity and longevity, and mating age and mating rates of male play a decisive role for his longevity. PMID:25434041

The PRECIS-2 tool has good interrater reliability and modest discriminant validity.

PubMed

Loudon, Kirsty; Zwarenstein, Merrick; Sullivan, Frank M; Donnan, Peter T; Gágyor, Ildikó; Hobbelen, Hans J S M; Althabe, Fernando; Krishnan, Jerry A; Treweek, Shaun

2017-08-01

PRagmatic Explanatory Continuum Indicator Summary (PRECIS)-2 is a tool that could improve design insight for trialists. Our aim was to validate the PRECIS-2 tool, unlike its predecessor, testing the discriminant validity and interrater reliability. Over 80 international trialists, methodologists, clinicians, and policymakers created PRECIS-2 helping to ensure face validity and content validity. The interrater reliability of PRECIS-2 was measured using 19 experienced trialists who used PRECIS-2 to score a diverse sample of 15 randomized controlled trial protocols. Discriminant validity was tested with two raters to independently determine if the trial protocols were more pragmatic or more explanatory, with scores from the 19 raters for the 15 trials as predictors of pragmatism. Interrater reliability was generally good, with seven of nine domains having an intraclass correlation coefficient over 0.65. Flexibility (adherence) and recruitment had wide confidence intervals, but raters found these difficult to rate and wanted more information. Each of the nine PRECIS-2 domains could be used to differentiate between trials taking more pragmatic or more explanatory approaches with better than chance discrimination for all domains. We have assessed the validity and reliability of PRECIS-2. An elaboration study and web site provide guidance to help future users of the tool which is continuing to be tested by trial teams, systematic reviewers, and funders. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Mating Status and Age on the Male Mate Choice and Mating Competency in the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae).

PubMed

Wang, Desen; Wang, Changlu; Singh, Narinderpal; Cooper, Richard; Zha, Chen; Eiden, Amanda L

2016-04-28

We investigated male mate choice and mating competency in the common bed bug, Cimex lectularius L., using video tracking for 10 min per experiment. In the male mate choice experiment, when a male was placed with two females of different mating status, males preferred to initiate copulation with the virgin female more quickly than with the mated female, and the mean total copulation duration with virgin females (38.0 ± 3.0 s) was significantly longer than with mated females (14.6 ± 3.0 s). When a male was placed with two females of different age, males initiated copulation more quickly with the old virgin female (29-34 d adult emergence) than with the young virgin one (<7 d adult emergence), and the mean total copulation duration with old virgin females (38.4 ± 4.0 s) was significantly longer than with young virgin females (24.0 ± 3.0 s). In the male mating competency experiment where a female was placed with two males of different mating status or age, the virgin males were more eager to mate than the mated males, and the old virgin males (29-34 d adult emergence) were more eager than the young virgin males (<7 d adult emergence), with eagerness measured by the percentage of first mate selected (first copulation occurred) and the total copulation duration by each group of males. Male mating competency is related to postmating duration (PMD); males mated 1 d earlier were significantly less likely to mate than virgin males. However, males mated 7 d earlier showed no significant difference in mating competency compared to virgin males. In conclusion, mate choice in C. lectularius is associated with both male and female mating status, age, and PMD. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Multidrug and toxin extrusion proteins mediate cellular transport of cadmium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Hong; Guo, Dong; Obianom, Obinna N.

Cadmium (Cd) is an environmentally prevalent toxicant posing increasing risk to human health worldwide. As compared to the extensive research in Cd tissue accumulation, little was known about the elimination of Cd, particularly its toxic form, Cd ion (Cd{sup 2+}). In this study, we aimed to examine whether Cd{sup 2+} is a substrate of multidrug and toxin extrusion proteins (MATEs) that are important in renal xenobiotic elimination. HEK-293 cells overexpressing the human MATE1 (HEK-hMATE1), human MATE2-K (HEK-hMATE2-K) and mouse Mate1 (HEK-mMate1) were used to study the cellular transport and toxicity of Cd{sup 2+}. The cells overexpressing MATEs showed a 2–4more » fold increase of Cd{sup 2+} uptake that could be blocked by the MATE inhibitor cimetidine. A saturable transport profile was observed with the Michaelis-Menten constant (K{sub m}) of 130 ± 15.8 μM for HEK-hMATE1; 139 ± 21.3 μM for HEK-hMATE2-K; and 88.7 ± 13.5 μM for HEK-mMate1, respectively. Cd{sup 2+} could inhibit the uptake of metformin, a substrate of MATE transporters, with the half maximal inhibitory concentration (IC{sub 50}) of 97.5 ± 6.0 μM, 20.2 ± 2.6 μM, and 49.9 ± 6.9 μM in HEK-hMATE1, HEK-hMATE2-K, and HEK-mMate1 cells, respectively. In addition, hMATE1 could transport preloaded Cd{sup 2+} out of the HEK-hMATE1 cells, thus resulting in a significant decrease of Cd{sup 2+}-induced cytotoxicity. The present study has provided the first evidence supporting that MATEs transport Cd{sup 2+} and may function as cellular elimination machinery in Cd intoxication. - Highlights: • Cadmium is an environmentally prevalent toxicant. • Little was known regarding the elimination and detoxification of cadmium. • Cadmium ion is here demonstrated as a substrate of MATE transporters. • MATEs may function as cellular elimination machinery in cadmium detoxification.« less

Mate-choice copying, social information processing, and the roles of oxytocin.

PubMed

Kavaliers, Martin; Matta, Richard; Choleris, Elena

2017-01-01

Social and sexual behaviors, including that of mate choice, are dependent on social information. Mate choice can be modified by prior and ongoing social factors and experience. The mate choice decisions of one individual can be influenced by either the actual or potential mate choice of another female or male. Such non-independent mate choice, where individuals gain social information and socially learn about and recognizes potential mates by observing the choices of another female or male, has been termed "mate-choice copying". Here we first briefly review how, why, and under what circumstances individuals engage in mate-choice copying. Secondly, we review the neurobiological mechanisms underlying mate-choice copying. In particular, we consider the roles of the nonapeptide, oxytocin, in the processing of social information and the expression of mate-choice copying. Copyright © 2016 Elsevier Ltd. All rights reserved.

Females use self-referent cues to avoid mating with previous mates.

PubMed

Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

2005-12-07

Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that female crickets (Gryllodes sigillatus) mark males with their own unique chemical signatures during mating, enabling females to recognize prior mates in subsequent encounters and to avoid remating with them. Because self-referent chemosensory cues provide females with a simple, but reliable mechanism of identifying individuals with whom they have mated without requiring any special cognitive ability, they may be a widespread means by which females across a broad range of animal mating systems maximize the genetic benefits of polyandry.

Females use self-referent cues to avoid mating with previous mates

PubMed Central

Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

2005-01-01

Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that female crickets (Gryllodes sigillatus) mark males with their own unique chemical signatures during mating, enabling females to recognize prior mates in subsequent encounters and to avoid remating with them. Because self-referent chemosensory cues provide females with a simple, but reliable mechanism of identifying individuals with whom they have mated without requiring any special cognitive ability, they may be a widespread means by which females across a broad range of animal mating systems maximize the genetic benefits of polyandry. PMID:16271971

Same-Sex Gaze Attraction Influences Mate-Choice Copying in Humans

PubMed Central

Yorzinski, Jessica L.; Platt, Michael L.

2010-01-01

Mate-choice copying occurs when animals rely on the mating choices of others to inform their own mating decisions. The proximate mechanisms underlying mate-choice copying remain unknown. To address this question, we tracked the gaze of men and women as they viewed a series of photographs in which a potential mate was pictured beside an opposite-sex partner; the participants then indicated their willingness to engage in a long-term relationship with each potential mate. We found that both men and women expressed more interest in engaging in a relationship with a potential mate if that mate was paired with an attractive partner. Men and women's attention to partners varied with partner attractiveness and this gaze attraction influenced their subsequent mate choices. These results highlight the prevalence of non-independent mate choice in humans and implicate social attention and reward circuitry in these decisions. PMID:20161739

Rearing Temperature Influences Adult Response to Changes in Mating Status

PubMed Central

Westerman, Erica; Monteiro, Antónia

2016-01-01

Rearing environment can have an impact on adult behavior, but it is less clear how rearing environment influences adult behavior plasticity. Here we explore the effect of rearing temperature on adult mating behavior plasticity in the butterfly Bicyclus anynana, a species that has evolved two seasonal forms in response to seasonal changes in temperature. These seasonal forms differ in both morphology and behavior. Females are the choosy sex in cohorts reared at warm temperatures (WS butterflies), and males are the choosy sex in cohorts reared at cooler temperatures (DS butterflies). Rearing temperature also influences mating benefits and costs. In DS butterflies, mated females live longer than virgin females, and mated males live shorter than virgin males. No such benefits or costs to mating are present in WS butterflies. Given that choosiness and mating costs are rearing temperature dependent in B. anynana, we hypothesized that temperature may also impact male and female incentives to remate in the event that benefits and costs of second matings are similar to those of first matings. We first examined whether lifespan was affected by number of matings. We found that two matings did not significantly increase lifespan for either WS or DS butterflies relative to single matings. However, both sexes of WS but not DS butterflies experienced decreased longevity when mated to a non-virgin relative to a virgin. We next observed pairs of WS and DS butterflies and documented changes in mating behavior in response to changes in the mating status of their partner. WS but not DS butterflies changed their mating behavior in response to the mating status of their partner. These results suggest that rearing temperature influences adult mating behavior plasticity in B. anynana. This developmentally controlled behavioral plasticity may be adaptive, as lifespan depends on the partner’s mating status in one seasonal form, but not in the other. PMID:26863319

Multiple Imputation based Clustering Validation (MIV) for Big Longitudinal Trial Data with Missing Values in eHealth.

PubMed

Zhang, Zhaoyang; Fang, Hua; Wang, Honggang

2016-06-01

Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering are more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services.

Multiple Imputation based Clustering Validation (MIV) for Big Longitudinal Trial Data with Missing Values in eHealth

PubMed Central

Zhang, Zhaoyang; Wang, Honggang

2016-01-01

Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering is more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services. PMID:27126063

Physiotherapy for patients with soft tissue shoulder disorders: a systematic review of randomised clinical trials.

PubMed Central

van der Heijden, G. J.; van der Windt, D. A.; de Winter, A. F.

1997-01-01

OBJECTIVE: To assess the effectiveness of physiotherapy for patients with soft tissue shoulder disorders. DESIGN: A systematic computerised literature search of Medline and Embase, supplemented with citation tracking, for relevant trials with random allocation published before 1996. SUBJECTS: Patients treated with physiotherapy for disorders of soft tissue of the shoulder. MAIN OUTCOME MEASURES: Success rates, mobility, pain, functional status. RESULTS: Six of the 20 assessed trials satisfied at least five of eight validity criteria. Assessment of methods was often hampered by insufficient information on various validity criteria, and trials were often flawed by lack of blinding, high proportions of withdrawals from treatment, and high proportions of missing values. Trial sizes were small: only six trials included intervention groups of more than 25 patients. Ultrasound therapy, evaluated in six trials, was not shown to be effective. Four other trials favoured physiotherapy (laser therapy or manipulation), but the validity of their methods was unsatisfactory. CONCLUSIONS: There is evidence that ultrasound therapy is ineffective in the treatment of soft tissue shoulder disorders. Due to small trial sizes and unsatisfactory methods, evidence for the effectiveness of other methods of physiotherapy is inconclusive. For all methods of treatment, trials were too heterogeneous with respect to included patients, index and reference treatments, and follow up to merit valid statistical pooling. Future studies should show whether physiotherapy is superior to treatment with drugs, steroid injections, or a wait and see policy. PMID:9233322

Variation in human mate choice: Simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating

PubMed Central

Zietsch, Brendan P.; Verweij, Karin J. H.; Heath, Andrew C.; Martin, Nicholas G.

2012-01-01

Human mate choice is central to individuals’ lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we look at a large community-based sample of twins and their partners and parents (N > 20,000 individuals) to test for genetic and family environmental influences on mate choice, with and without controlling for the effects of assortative mating. Key traits are analyzed, including height, body mass index, age, education, income, personality, social attitudes, and religiosity. This revealed near-zero genetic influences on male and female mate choice over all traits and no significant genetic influences on mate choice for any specific trait. A significant family environmental influence was found for the age and income of females’ mate choices, possibly reflecting parental influence over mating decisions. We also tested for evidence of sexual imprinting, where individuals acquire mate-choice criteria during development by using their opposite-sex parent as the template of a desirable mate; there was no such effect for any trait. The main discernable pattern to mate choice was assortative mating; we found that partner similarity was due to initial choice rather than convergence and also due at least in part to phenotypic matching. PMID:21508607

Variation in human mate choice: simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating.

PubMed

Zietsch, Brendan P; Verweij, Karin J H; Heath, Andrew C; Martin, Nicholas G

2011-05-01

Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents ([Formula: see text] individuals) to test for genetic and family environmental influences on mate choice, while controlling for and not controlling for the effects of assortative mating. Key traits were analyzed, including height, body mass index, age, education, income, personality, social attitudes, and religiosity. This revealed near-zero genetic influences on male and female mate choice over all traits and no significant genetic influences on mate choice for any specific trait. A significant family environmental influence was found for the age and income of females' mate choices, possibly reflecting parental influence over mating decisions. We also tested for evidence of sexual imprinting, where individuals acquire mate-choice criteria during development by using their opposite-sex parent as the template of a desirable mate; there was no such effect for any trait. The main discernible pattern of mate choice was assortative mating; we found that partner similarity was due to initial choice rather than convergence and also at least in part to phenotypic matching.

Behavioral interactions of penned red and arctic foxes

USGS Publications Warehouse

Rudzinski, D.R.; Graves, H.B.; Sargeant, A.B.; Storm, G.L.

1982-01-01

Expansion of the geographical distribution of red foxes (Vulpes vulpes) into the far north tundra region may lead to competition between arctic (Alopex lagopus) and red foxes for space and resources. Behavioral interactions between red and arctic foxes were evaluated during 9 trials conducted in a 4.05-ha enclosure near Woodworth, North Dakota. Each trial consisted of introducing a male-female pair of arctic foxes into the enclosure and allowing them to acclimate for approximately a week before releasing a female red fox into the enclosure, followed by her mate a few days later. In 8 of 9 trials, red foxes were dominant over arctic foxes during encounters. Activity of the arctic foxes decreased upon addition of red foxes. Arctic foxes tried unsuccessfully to defend preferred den, resting, and feeding areas. Even though the outcome of competition between red and arctic foxes in the Arctic is uncertain, the more aggressive red fox can dominate arctic foxes in direct competition for den sites and other limited resources.

Pharmacokinetic Interactions Between Isavuconazole and the Drug Transporter Substrates Atorvastatin, Digoxin, Metformin, and Methotrexate in Healthy Subjects

PubMed Central

Yamazaki, Takao; Desai, Amit; Goldwater, Ronald; Han, David; Lasseter, Kenneth C.; Howieson, Corrie; Akhtar, Shahzad; Kowalski, Donna; Lademacher, Christopher; Rammelsberg, Diane

2016-01-01

Abstract This article summarizes 4 phase 1 trials that explored interactions between the novel, triazole antifungal isavuconazole and substrates of the drug transporters breast cancer resistance protein (BCRP), multidrug and toxin extrusion protein‐1 (MATE1), organic anion transporters 1/3 (OAT1/OAT3), organic anion‐transporting polypeptide 1B1 (OATP1B1), organic cation transporters 1/2 (OCT1/OCT2), and P‐glycoprotein (P‐gp). Healthy subjects received single doses of atorvastatin (20 mg; OATP1B1 and P‐gp substrate), digoxin (0.5 mg; P‐gp substrate), metformin (850 mg; OCT1, OCT2, and MATE1 substrate), or methotrexate (7.5 mg; BCRP, OAT1, and OAT3 substrate) in the presence and absence of clinical doses of isavuconazole (200 mg 3 times a day for 2 days; 200 mg once daily thereafter). Coadministration with isavuconazole increased mean area under the plasma concentration‐time curves (90% confidence interval) of atorvastatin, digoxin, and metformin to 137% (129, 145), 125% (117, 134),  and 152% (138, 168) and increased mean maximum plasma concentrations to 103% (88, 121), 133% (119, 149), and 123% (109, 140), respectively. Methotrexate parameters were unaffected by isavuconazole. There were no serious adverse events. These findings indicate that isavuconazole is a weak inhibitor of P‐gp, as well as OCT1, OCT2, MATE1, or a combination thereof but not of BCRP, OATP1B1, OAT1, or OAT3. PMID:27273004

Inversion of the chromosomal region between two mating type loci switches the mating type in Hansenula polymorpha.

PubMed

Maekawa, Hiromi; Kaneko, Yoshinobu

2014-11-01

Yeast mating type is determined by the genotype at the mating type locus (MAT). In homothallic (self-fertile) Saccharomycotina such as Saccharomyces cerevisiae and Kluveromyces lactis, high-efficiency switching between a and α mating types enables mating. Two silent mating type cassettes, in addition to an active MAT locus, are essential components of the mating type switching mechanism. In this study, we investigated the structure and functions of mating type genes in H. polymorpha (also designated as Ogataea polymorpha). The H. polymorpha genome was found to harbor two MAT loci, MAT1 and MAT2, that are ∼18 kb apart on the same chromosome. MAT1-encoded α1 specifies α cell identity, whereas none of the mating type genes were required for a identity and mating. MAT1-encoded α2 and MAT2-encoded a1 were, however, essential for meiosis. When present in the location next to SLA2 and SUI1 genes, MAT1 or MAT2 was transcriptionally active, while the other was repressed. An inversion of the MAT intervening region was induced by nutrient limitation, resulting in the swapping of the chromosomal locations of two MAT loci, and hence switching of mating type identity. Inversion-deficient mutants exhibited severe defects only in mating with each other, suggesting that this inversion is the mechanism of mating type switching and homothallism. This chromosomal inversion-based mechanism represents a novel form of mating type switching that requires only two MAT loci.

The Shock and Vibration Digest. Volume 12, Number 5.

DTIC Science & Technology

1980-05-01

response 80-957 This paper presents a way of analyzing the vibration of a The Dynamics of Rotor- Bearing Systems with Axial t rotor shaft system coupled with...Research on the Flutter of Axial Turbomachine To use this stability criteria the loading must be conservative. The numerical results are compared...Stiffness on the Statically radial bearing forces and the load cal-icity are found approxi- Optimum Distance Between the Double Row Rolling mately valid for

Nest-mate recognition in Manuelia postica (Apidae: Xylocopinae): an eusocial trait is present in a solitary bee.

PubMed

Flores-Prado, Luis; Aguilera-Olivares, Daniel; Niemeyer, Hermann M

2008-02-07

In eusocial Hymenoptera, females are more tolerant towards nest-mate than towards non-nest-mate females. In solitary Hymenoptera, females are generally aggressive towards any conspecific female. Field observations of the nest biology of Manuelia postica suggested nest-mate recognition. Experiments were performed involving two live interacting females or one live female interacting with a dead female. Live females from different nests were more intolerant to each other than females from the same nest. Females were more intolerant towards non-nest-mate than towards nest-mate dead females. When dead females were washed with pentane, no differences in tolerant and intolerant behaviours were detected between non-nest-mate and nest-mate females. Females were more intolerant towards nest-mate female carcasses coated with the cuticular extract from a non-nest-mate than towards non-nest-mate female carcasses coated with the cuticular extract from a nest-mate. The compositions of the cuticular extracts was more similar between females from the same nest than between females from different nests. The results demonstrate for the first time nest-mate recognition mediated by cuticular chemicals in a largely solitary species of Apidae. The position of Manuelia at the base of the Apidae phylogeny suggests that nest-mate recognition in eusocial species apical to Manuelia represents the retention of a primitive capacity in Apidae.

Molecular identification and functional characterization of rabbit MATE1 and MATE2-K.

PubMed

Zhang, Xiaohong; Cherrington, Nathan J; Wright, Stephen H

2007-07-01

An electroneutral organic cation (OC)/proton exchanger in the apical membrane of proximal tubules mediates the final step of renal OC excretion. Two members of the multidrug and toxin extrusion family, MATE1 and MATE2-K, were recently identified in human and rodent kidney and proposed to be the molecular basis of renal OC/H(+) exchange. To take advantage of the comparative value of the large database on the kinetic and selectivity characteristics of OC/H(+) exchange that exists for rabbit kidney, we cloned rbMATE1 and rbMATE2-K. The rabbit homologs have 75% (MATE1) and 74% (MATE2-K) amino acid identity to their human counterparts (and 51% identity with each other). rbMATE1 and rbMATE2-K exhibited H(+) gradient-dependent uptake and efflux of tetraethylammonium (TEA) when expressed in Chinese hamster ovary cells. Both transporters displayed similar affinities for selected compounds [IC(50) values within 2-fold for TEA, 1-methyl-4-phenylpyridinium, and quinidine] and very different affinities for others (IC(50) values differing by 8- to 80-fold for choline and cimetidine, respectively). These results indicate that rbMATE1 and rbMATE2-K are multispecific OC/H(+) exchangers with similar, but distinct, functional characteristics. Overall, the selectivity of MATE1 and MATE2-K correlated closely with that observed in rabbit renal brush-border membrane vesicles.

Validating automated kidney stone volumetry in computed tomography and mathematical correlation with estimated stone volume based on diameter.

PubMed

Wilhelm, Konrad; Miernik, Arkadiusz; Hein, Simon; Schlager, Daniel; Adams, Fabian; Benndorf, Matthias; Fritz, Benjamin; Langer, Mathias; Hesse, Albrecht; Schoenthaler, Martin; Neubauer, Jakob

2018-06-02

To validate AutoMated UroLithiasis Evaluation Tool (AMULET) software for kidney stone volumetry and compare its performance to standard clinical practice. Maximum diameter and volume of 96 urinary stones were measured as reference standard by three independent urologists. The same stones were positioned in an anthropomorphic phantom and CT scans acquired in standard settings. Three independent radiologists blinded to the reference values took manual measurements of the maximum diameter and automatic measurements of maximum diameter and volume. An "expected volume" was calculated based on manual diameter measurements using the formula: V=4/3 πr³. 96 stones were analyzed in the study. We had initially aimed to assess 100. Nine were replaced during data acquisition due of crumbling and 4 had to be excluded because the automated measurement did not work. Mean reference maximum diameter was 13.3 mm (5.2-32.1 mm). Correlation coefficients among all measured outcomes were compared. The correlation between the manual and automatic diameter measurements to the reference was 0.98 and 0.91, respectively (p<0.001). Mean reference volume was 1200 mm³ (10-9000 mm³). The correlation between the "expected volume" and automatically measured volume to the reference was 0.95 and 0.99, respectively (p<0.001). Patients' kidney stone burden is usually assessed according to maximum diameter. However, as most stones are not spherical, this entails a potential bias. Automated stone volumetry is possible and significantly more accurate than diameter-based volumetric calculations. To avoid bias in clinical trials, size should be measured as volume. However, automated diameter measurements are not as accurate as manual measurements.

Instruments to Identify Prescription Medication Misuse, Abuse, and Related Events in Clinical Trials: An ACTTION Systematic Review.

PubMed

Smith, Shannon M; Paillard, Florence; McKeown, Andrew; Burke, Laurie B; Edwards, Robert R; Katz, Nathaniel P; Papadopoulos, Elektra J; Rappaport, Bob A; Slagle, Ashley; Strain, Eric C; Wasan, Ajay D; Turk, Dennis C; Dworkin, Robert H

2015-05-01

Measurement of inappropriate medication use events (eg, abuse or misuse) in clinical trials is important in characterizing a medication's abuse potential. However, no gold standard assessment of inappropriate use events in clinical trials has been identified. In this systematic review, we examine the measurement properties (ie, content validity, cross-sectional reliability and construct validity, longitudinal construct validity, ability to detect change, and responder definitions) of instruments assessing inappropriate use of opioid and nonopioid prescription medications to identify any that meet U.S. and European regulatory agencies' rigorous standards for outcome measures in clinical trials. Sixteen published instruments were identified, most of which were not designed for the selected concept of interest and context of use. For this reason, many instruments were found to lack adequate content validity (or documentation of content validity) to evaluate current inappropriate medication use events; for example, evaluating inappropriate use across the life span rather than current use, including items that did not directly assess inappropriate use (eg, questions about anger), or failing to capture information pertinent to inappropriate use events (eg, intention and route of administration). In addition, the psychometric data across all instruments were generally limited in scope. A further limitation is the heterogeneous, nonstandardized use of inappropriate medication use terminology. These observations suggest that available instruments are not well suited for assessing current inappropriate medication use within the specific context of clinical trials. Further effort is needed to develop reliable and valid instruments to measure current inappropriate medication use events in clinical trials. This systematic review evaluates the measurement properties of inappropriate medication use (eg, abuse or misuse) instruments to determine whether any meet regulatory standards for clinical trial outcome measures to assess abuse potential. Copyright © 2015 American Pain Society. All rights reserved.

Heartmate 3 fully magnetically levitated left ventricular assist device for the treatment of advanced heart failure -1 year results from the Ce mark trial.

PubMed

Krabatsch, Thomas; Netuka, Ivan; Schmitto, Jan D; Zimpfer, Daniel; Garbade, Jens; Rao, Vivek; Morshuis, Michiel; Beyersdorf, Friedhelm; Marasco, Silvana; Damme, Laura; Pya, Yuriy

2017-04-04

The HeartMate 3 Left Ventricular Assist System (LVAS) (St. Jude Medical Inc., St Paul, MN) with full magnetic levitation allows for wide and consistent blood flow paths and an artificial pulse designed for enhanced hemocompatibility. The HeartMate 3 received market approval in the European Union in 2015 following completion of a multicenter study. After reaching the 6-month study endpoint, patients continue to be followed for 2 years with the 1-year results presented herein. A prospective, non-randomized study included adults with advanced heart failure and ejection fraction (EF) ≤ 25%, cardiac index (CI) ≤ 2.2 L/min/m2 while not on inotropes, or inotrope dependent, or on optimal medical management for 45/60 days. Fifty patients-54% bridge to transplant (BTT) and 46% destination therapy (DT)-were enrolled and implanted with the HeartMate 3. At baseline, 92% of the patients were INTERMACS profiles 2-4, with cardiac index 1.8 + 0.5 L/min/m 2 and 58% were supported with inotropes. At 1 year, 74% of the patients remain on support, 18% expired, 6% transplanted, and 2% explanted. The adverse events include 12% gastrointestinal bleeding, 16% driveline infections, 18% strokes, and 2% outflow graft thrombosis. There was no hemolysis, pump thrombosis or pump malfunction through 1 year. The six-minute walk test distance increased from a mean of 273 m to 371 m (P <0.0001). EQ-5D quality-of-life score increased from a mean of 52.7 to 70.8 (P = 0.0006). The 1-year HeartMate 3 LVAS results show survival and adverse-event profile are similar to other approved devices, with no pump thrombosis or pump failure. Patient's functional status and quality of life significantly improved over time. Clinicaltrials.gov registration number: NCT02170363 . Registered June 19, 2014.

Tissue remodeling: a mating-induced differentiation program for the Drosophila oviduct.

PubMed

Kapelnikov, Anat; Rivlin, Patricia K; Hoy, Ronald R; Heifetz, Yael

2008-12-08

In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While Drosophila is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in Drosophila have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise. Using electron- and confocal-microscopy we identified tissue-wide post-mating changes in the oviduct including differentiation of cellular junctions, remodeling of extracellular matrix, increased myofibril formation, and increased innervation. Analysis of once- and twice-mated females reveals that some mating-responsive proteins respond only to the first mating, while others respond to both matings. We uncovered ultrastructural changes in the mated oviduct that are consistent with the roles that mating-responsive proteins play in muscle and epithelial differentiation elsewhere. This suggests that mating triggers the late differentiation of the oviduct. Furthermore, we suggest that mating-responsive proteins that respond only to the first mating are involved in the final maturation of the oviduct while proteins that remain responsive to later matings are also involved in maintenance and ongoing function of the oviduct. Taken together, our results establish the oviduct as an attractive system to address mechanisms that regulate the late stages of differentiation and maintenance of a tubular organ.

Tissue remodeling: a mating-induced differentiation program for the Drosophila oviduct

PubMed Central

Kapelnikov, Anat; Rivlin, Patricia K; Hoy, Ronald R; Heifetz, Yael

2008-01-01

Background In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While Drosophila is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in Drosophila have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise. Results Using electron- and confocal-microscopy we identified tissue-wide post-mating changes in the oviduct including differentiation of cellular junctions, remodeling of extracellular matrix, increased myofibril formation, and increased innervation. Analysis of once- and twice-mated females reveals that some mating-responsive proteins respond only to the first mating, while others respond to both matings. Conclusion We uncovered ultrastructural changes in the mated oviduct that are consistent with the roles that mating-responsive proteins play in muscle and epithelial differentiation elsewhere. This suggests that mating triggers the late differentiation of the oviduct. Furthermore, we suggest that mating-responsive proteins that respond only to the first mating are involved in the final maturation of the oviduct while proteins that remain responsive to later matings are also involved in maintenance and ongoing function of the oviduct. Taken together, our results establish the oviduct as an attractive system to address mechanisms that regulate the late stages of differentiation and maintenance of a tubular organ. PMID:19063748

The influence of mare numbers, ejaculation frequency and month on the fertility of Thoroughbred stallions.

PubMed

Allen, W R; Wilsher, S

2012-09-01

Although considerable variation in per cycle pregnancy rates exists between Thoroughbred (TB) stallions, there is little information on factors that may influence this figure. To assess the influence of month, mare numbers and mating frequency on the fertility of TB stallions standing on studfarms in East Anglia, England. The daily breeding records of 31 TB stallions mating 3034 mares on 4851 occasions during the 2010 season were surveyed and related to first scan pregnancy rates. The influences of mare book size, month, number of matings per day and mating frequency or abstinence on per mating pregnancy rates were analysed. The overall per mating pregnancy rate for all the stallions was 59.6%, but for individual stallions the figures ranged from 19.0% to 80.1%. The first mating occurred on 9 February and the last on 24 July and the per mating pregnancy rate per month was significantly reduced in June and July. The number of mares mated by individual stallions ranged from 15 to 161, giving a mean overall workload of 160 matings per 100 mares. The per mating pregnancy rate was not related to book size, the number of matings in the season or the mating frequency per day. However, some stallions showed differences in per mating pregnancy rate related to month or the number of ejaculations in the preceding 3 days. The majority of TB stallions are able to maintain good fertility despite large books of mares. However, 5 of the 31 stallions surveyed showed a per mating pregnancy rate of ≤50%. This survey has identified wide differences between the per mating pregnancy rate in TB stallions. Identification of the factors involved through more comprehensive surveys would provide useful information for mare and stallion owners. © 2011 EVJ Ltd.

Size and competitive mating success in the yeast Saccharomyces cerevisiae.

PubMed

Smith, Carl; Pomiankowski, Andrew; Greig, Duncan

2014-03-01

In unicellular organisms like yeast, mating with the right partner is critical to future fitness because each individual can only mate once. Because cell size is important for viability, mating with a partner of the right size could be a significant advantage. To investigate this idea, we manipulated the size of unmated yeast cells and showed that their viability depended on environmental conditions; large cells do better on rich medium and small cells do better on poor medium. We also found that the fitness of offspring is determined by the size of their parents. Finally, we demonstrated that when a focal cell of one mating type was placed with a large and a small cell of the opposite mating type, it was more likely to mate with the cell that was closer to the optimum size for growth in a given environment. This pattern was not generated by differences in passive mating efficiency of large and small cells across environments but by competitive mating behavior, mate preference, or both. We conclude that the most likely mechanism underlying this interesting behavior is that yeast cells compete for mates by producing pheromone signals advertising their viability, and cells with the opportunity to choose prefer to mate with stronger signalers because such matings produce more viable offspring.

A test of the critical assumption of the sensory bias model for the evolution of female mating preference using neural networks.

PubMed

Fuller, Rebecca C

2009-07-01

The sensory bias model for the evolution of mating preferences states that mating preferences evolve as correlated responses to selection on nonmating behaviors sharing a common sensory system. The critical assumption is that pleiotropy creates genetic correlations that affect the response to selection. I simulated selection on populations of neural networks to test this. First, I selected for various combinations of foraging and mating preferences. Sensory bias predicts that populations with preferences for like-colored objects (red food and red mates) should evolve more readily than preferences for differently colored objects (red food and blue mates). Here, I found no evidence for sensory bias. The responses to selection on foraging and mating preferences were independent of one another. Second, I selected on foraging preferences alone and asked whether there were correlated responses for increased mating preferences for like-colored mates. Here, I found modest evidence for sensory bias. Selection for a particular foraging preference resulted in increased mating preference for similarly colored mates. However, the correlated responses were small and inconsistent. Selection on foraging preferences alone may affect initial levels of mating preferences, but these correlations did not constrain the joint evolution of foraging and mating preferences in these simulations.

Chemical characterization of candy made of Erva-Mate (Ilex paraguariensis A. St. Hil.) residue.

PubMed

Vieira, Manoela A; Rovaris, Angela A; Maraschin, Marcelo; De Simas, Karina N; Pagliosa, Cristiane M; Podestá, Rossana; Amboni, Renata D M C; Barreto, Pedro L M; Amante, Edna R

2008-06-25

The aim of this work was to evaluate the chemical properties of the residues from erva-mate processing and also to determine the candy-making performance with addition of residues from erva-mate on consumers' acceptance and purchase intent of this new product. The candies containing different amounts of mate powder were evaluated through overall acceptability test and purchase intent. Mate powder showed high contents of dietary fiber, total ash, and total polyphenols. The total dietary fiber content of the mate candies ranged from 5.7 to 6.29% on a dry matter basis. Supplementation with mate powder caused significant increases in polyphenol and mineral contents of mate candies. The incorporation of mate powder increased the hardness of the candies and produced desirable results in their nutritional characteristics. The sensory tests indicated that mate candies were acceptable and approved in relation to purchase intent.

Quality of life and functional capacity outcomes in the MOMENTUM 3 trial at 6 months: A call for new metrics for left ventricular assist device patients.

PubMed

Cowger, Jennifer A; Naka, Yoshifumi; Aaronson, Keith D; Horstmanshof, Douglas; Gulati, Sanjeev; Rinde-Hoffman, Debbie; Pinney, Sean; Adatya, Sirtaz; Farrar, David J; Jorde, Ulrich P

2018-01-01

The Multicenter Study of MAGLEV Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) clinical trial demonstrated improved 6-month event-free survival, but a detailed analysis of health-related quality of life (HR-QOL) and functional capacity (FC) was not presented. Further, the effect of early serious adverse events (SAEs) on these metrics and on the general ability to live well while supported with a left ventricular assist system (LVAS) warrants evaluation. FC (New York Heart Association [NYHA] and 6-minute walk test [6MWT]) and HR-QOL (European Quality of Life [EQ-5D-5L] and the Kansas City Cardiomyopathy [KCCQ]) assessments were obtained at baseline and 6 months after HeartMate 3 (HM3, n = 151; Abbott, Abbott Park, IL) or HeartMate II (HMII, n = 138; Abbott) implant as part of the MOMENTUM 3 clinical trial. Metrics were compared between devices and in those with and without events. The proportion of patients "living well on an LVAS" at 6 months, defined as alive with satisfactory FC (NYHA I/II or 6MWT > 300 meters) and HR-QOL (overall KCCQ > 50), was evaluated. Although the median (25th-75th percentile) patient KCCQ (change for HM3: +28 [10-46]; HMII: +29 [9-48]) and EQ-5D-5L (change for HM3: -1 [-5 to 0]; HMII: -2 [-6 to 0]) scores improved from baseline to 6 months (p < 0.05), there were no differences between devices (p > 0.05). Likewise, there was an equivalent improvement in 6MWT distance at 6 months in HM3 (+94 [1-274] meters] and HMII (+188[43-340 meters]) from baseline. In patients with SAEs (n = 188), 6MWTs increased from baseline (p < 0.001), but gains for both devices were less than those without SAE (HM3: +74 [-9 to 183] meters with SAE vs +140 [35-329] meters without SAE; HMII: +177 [47-356] meters with SAE vs +192 [23-337] meters without SAE, both p < 0.003). SAEs did not affect the 6-month HR-QOL scores. The "living well" end point was achieved in 145 HM3 (63%) and 120 HMII (68%) patients (p = 0.44). Gains in HR-QOL and FC were similar early after HM3 and HMII implant. 6MWT improvements were attenuated in patients experiencing SAEs, but HR-QOL metrics did not change. The development of left ventricular assist device-specific HR-QOL tools is needed to better characterize the effect of SAEs on a patient's well-being. MOMENTUM 3 clinical trial #NCT02224755. Copyright © 2018 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Drug designs fulfilling the requirements of clinical trials aiming at personalizing medicine

PubMed Central

Mandrekar, Sumithra J.; Sargent, Daniel J.

2014-01-01

In the current era of stratified medicine and biomarker-driven therapies, the focus has shifted from predictions based on the traditional anatomic staging systems to guide the choice of treatment for an individual patient to an integrated approach using the genetic makeup of the tumor and the genotype of the patient. The clinical trial designs utilized in the developmental pathway for biomarkers and biomarker-directed therapies from discovery to clinical practice are rapidly evolving. While several issues need careful consideration, two critical issues that surround the validation of biomarkers are the choice of the clinical trial design (which is based on the strength of the preliminary evidence and marker prevalence), and biomarker assay related issues surrounding the marker assessment methods such as the reliability and reproducibility of the assay. In this review, we focus on trial designs aiming at personalized medicine in the context of early phase trials for initial marker validation, as well as in the context of larger definitive trials. Designs for biomarker validation are broadly classified as retrospective (i.e., using data from previously well-conducted randomized controlled trials (RCTs) versus prospective (enrichment, all-comers, hybrid or adaptive). We believe that the systematic evaluation and implementation of these design strategies are essential to accelerate the clinical validation of biomarker guided therapy. PMID:25414851

Adiposity, compared with masculinity, serves as a more valid cue to immunocompetence in human mate choice

PubMed Central

Rantala, Markus J.; Coetzee, Vinet; Moore, Fhionna R.; Skrinda, Ilona; Kecko, Sanita; Krama, Tatjana; Kivleniece, Inese; Krams, Indrikis

2013-01-01

According to the ‘good genes’ hypothesis, females choose males based on traits that indicate the male's genetic quality in terms of disease resistance. The ‘immunocompetence handicap hypothesis’ proposed that secondary sexual traits serve as indicators of male genetic quality, because they indicate that males can contend with the immunosuppressive effects of testosterone. Masculinity is commonly assumed to serve as such a secondary sexual trait. Yet, women do not consistently prefer masculine looking men, nor is masculinity consistently related to health across studies. Here, we show that adiposity, but not masculinity, significantly mediates the relationship between a direct measure of immune response (hepatitis B antibody response) and attractiveness for both body and facial measurements. In addition, we show that circulating testosterone is more closely associated with adiposity than masculinity. These findings indicate that adiposity, compared with masculinity, serves as a more important cue to immunocompetence in female mate choice. PMID:23193134

Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation.

PubMed

Blyton, Michaela D J; Banks, Sam C; Peakall, Rod; Lindenmayer, David B

2012-02-01

The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation. © 2011 Blackwell Publishing Ltd.

Drinking High Amounts of Alcohol as a Short-Term Mating Strategy: The Impact of Short-Term Mating Motivations on Young Adults' Drinking Behavior.

PubMed

Vincke, Eveline

2017-01-01

Previous research indicates that drinking large quantities of alcohol could function as a short-term mating strategy for young adults in mating situations. However, no study investigated whether this is actually the case. Therefore, in this article, the link between short-term mating motivations and drinking high amounts of alcohol is tested. First, a survey study ( N = 345) confirmed that young adults who engage in binge drinking are more short-term oriented in their mating strategy than young adults who never engage in binge drinking. Also, the more short-term-oriented young adults were in their mating strategy, the more often binge drinking behavior was conducted. In addition, an experimental study ( N = 229) empirically verified that short-term mating motivations increase young adults' drinking behavior, more so than long-term mating motivations. Results of the experiment clearly showed that young men and young women are triggered to drink more alcoholic beverages in a short-term mating situation compared to a long-term mating situation. Furthermore, the mating situation also affected young adults' perception of drinking behavior. Young adults in a short-term mating context perceived a higher amount of alcoholic beverages as heavy drinking compared to peers in a long-term mating context. These findings confirm that a high alcohol consumption functions as a short-term mating strategy for both young men and young women. Insights gained from this article might be of interest to institutions aimed at targeting youth alcohol (ab)use.

Biomarkers and surrogate endpoints in glaucoma clinical trials

PubMed Central

Medeiros, Felipe A

2015-01-01

Surrogate endpoints are often used as replacements for true clinically relevant endpoints in several areas of medicine, as they enable faster and less expensive clinical trials. However, without proper validation, the use of surrogates may lead to incorrect conclusions about the efficacy and safety of treatments. This article reviews the general requirements for validating surrogate endpoints and provides a critical assessment of the use of intraocular pressure (IOP), visual fields, and structural measurements of the optic nerve as surrogate endpoints in glaucoma clinical trials. A valid surrogate endpoint must be able to predict the clinically relevant endpoint and fully capture the effect of an intervention on that endpoint. Despite its widespread use in clinical trials, no proper validation of IOP as a surrogate endpoint has ever been conducted for any class of IOP-lowering treatments. Evidence has accumulated with regard to the role of imaging measurements of optic nerve damage as surrogate endpoints in glaucoma. These measurements are predictive of functional losses in the disease and may explain, at least in part, treatment effects on clinically relevant endpoints. The use of composite endpoints in glaucoma trials may overcome weaknesses of the use of structural or functional endpoints in isolation. Unless research is dedicated to fully develop and validate suitable endpoints that can be used in glaucoma clinical trials, we run the risk of inappropriate judgments about the value of new therapies. PMID:25034049

The relationship between external and internal validity of randomized controlled trials: A sample of hypertension trials from China.

PubMed

Zhang, Xin; Wu, Yuxia; Ren, Pengwei; Liu, Xueting; Kang, Deying

2015-10-30

To explore the relationship between the external validity and the internal validity of hypertension RCTs conducted in China. Comprehensive literature searches were performed in Medline, Embase, Cochrane Central Register of Controlled Trials (CCTR), CBMdisc (Chinese biomedical literature database), CNKI (China National Knowledge Infrastructure/China Academic Journals Full-text Database) and VIP (Chinese scientific journals database) as well as advanced search strategies were used to locate hypertension RCTs. The risk of bias in RCTs was assessed by a modified scale, Jadad scale respectively, and then studies with 3 or more grading scores were included for the purpose of evaluating of external validity. A data extract form including 4 domains and 25 items was used to explore relationship of the external validity and the internal validity. Statistic analyses were performed by using SPSS software, version 21.0 (SPSS, Chicago, IL). 226 hypertension RCTs were included for final analysis. RCTs conducted in university affiliated hospitals (P < 0.001) or secondary/tertiary hospitals (P < 0.001) were scored at higher internal validity. Multi-center studies (median = 4.0, IQR = 2.0) were scored higher internal validity score than single-center studies (median = 3.0, IQR = 1.0) (P < 0.001). Funding-supported trials had better methodological quality (P < 0.001). In addition, the reporting of inclusion criteria also leads to better internal validity (P = 0.004). Multivariate regression indicated sample size, industry-funding, quality of life (QOL) taken as measure and the university affiliated hospital as trial setting had statistical significance (P < 0.001, P < 0.001, P = 0.001, P = 0.006 respectively). Several components relate to the external validity of RCTs do associate with the internal validity, that do not stand in an easy relationship to each other. Regarding the poor reporting, other possible links between two variables need to trace in the future methodological researches.

Optimal numbers of matings: the conditional balance between benefits and costs of mating for females of a nuptial gift-giving spider.

PubMed

Toft, S; Albo, M J

2015-02-01

In species where females gain a nutritious nuptial gift during mating, the balance between benefits and costs of mating may depend on access to food. This means that there is not one optimal number of matings for the female but a range of optimal mating numbers. With increasing food availability, the optimal number of matings for a female should vary from the number necessary only for fertilization of her eggs to the number needed also for producing these eggs. In three experimental series, the average number of matings for females of the nuptial gift-giving spider Pisaura mirabilis before egg sac construction varied from 2 to 16 with food-limited females generally accepting more matings than well-fed females. Minimal level of optimal mating number for females at satiation feeding conditions was predicted to be 2-3; in an experimental test, the median number was 2 (range 0-4). Multiple mating gave benefits in terms of increased fecundity and increased egg hatching success up to the third mating, and it had costs in terms of reduced fecundity, reduced egg hatching success after the third mating, and lower offspring size. The level of polyandry seems to vary with the female optimum, regulated by a satiation-dependent resistance to mating, potentially leaving satiated females in lifelong virginity. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

How multiple mating by females affects sexual selection

PubMed Central

Shuster, Stephen M.; Briggs, William R.; Dennis, Patricia A.

2013-01-01

Multiple mating by females is widely thought to encourage post-mating sexual selection and enhance female fitness. We show that whether polyandrous mating has these effects depends on two conditions. Condition 1 is the pattern of sperm utilization by females; specifically, whether, among females, male mating number, m (i.e. the number of times a male mates with one or more females) covaries with male offspring number, o. Polyandrous mating enhances sexual selection only when males who are successful at multiple mating also sire most or all of each of their mates' offspring, i.e. only when Cov♂(m,o), is positive. Condition 2 is the pattern of female reproductive life-history; specifically, whether female mating number, m, covaries with female offspring number, o. Only semelparity does not erode sexual selection, whereas iteroparity (i.e. when Cov♀(m,o), is positive) always increases the variance in offspring numbers among females, which always decreases the intensity of sexual selection on males. To document the covariance between mating number and offspring number for each sex, it is necessary to assign progeny to all parents, as well as identify mating and non-mating individuals. To document significant fitness gains by females through iteroparity, it is necessary to determine the relative magnitudes of male as well as female contributions to the total variance in relative fitness. We show how such data can be collected, how often they are collected, and we explain the circumstances in which selection favouring multiple mating by females can be strong or weak. PMID:23339237

Low-Impact Mating System for Docking Spacecraft

NASA Technical Reports Server (NTRS)

Lewis, James L.; Robertson, Brandan; Carroll, Monty B.; Le, Thang; Morales, Ray

2008-01-01

A document describes a low-impact mating system suitable for both docking (mating of two free-flying spacecraft) and berthing (in which a robot arm in one spacecraft positions an object for mating with either spacecraft). The low-impact mating system is fully androgynous: it mates with a copy of itself, i.e., all spacecraft and other objects to be mated are to be equipped with identical copies of the system. This aspect of the design helps to minimize the number of unique parts and to standardize and facilitate mating operations. The system includes a closed-loop feedback control subsystem that actively accommodates misalignments between mating spacecraft, thereby attenuating spacecraft dynamics and mitigating the need for precise advance positioning of the spacecraft. The operational characteristics of the mating system can be easily configured in software, during operation, to enable mating of spacecraft having various masses, center-of-gravity offsets, and closing velocities. The system design provides multi-fault tolerance for critical operations: for example, to ensure unmating at a critical time, a redundant unlatching mechanism and two independent pyrotechnic release subsystems are included.

Efficient Breeding by Genomic Mating.

PubMed

Akdemir, Deniz; Sánchez, Julio I

2016-01-01

Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

Development and feasibility of the misuse, abuse, and diversion drug event reporting system (MADDERS®).

PubMed

Treister, Roi; Trudeau, Jeremiah J; Van Inwegen, Richard; Jones, Judith K; Katz, Nathaniel P

2016-12-01

Inappropriate use of analgesic drugs has become increasingly pervasive over the past decade. Currently, drug abuse potential is primarily assessed post-marketing; no validated tools are available to assess this potential in phase II and III clinical trials. This paper describes the development and feasibility testing of a Misuse, Abuse, and Diversion Drug Event Reporting System (MADDERS), which aims to identify potentially abuse-related events and classify them according to a recently developed classification scheme, allowing the quantification of these events in clinical trials. The system was initially conceived and designed with input from experts and patients, followed by field-testing to assess its feasibility and content validity in both completed and ongoing clinical trials. The results suggest that MADDERS is a feasible system with initial validity. It showed higher rates of the triggering events in subjects taking medications with known abuse potential than in patients taking medications without abuse potential. Additionally, experts agreed on the classification of most abuse-related events in MADDERS. MADDERS is a new systematic approach to collect information on potentially abuse-related events in clinical trials and classify them. The system has demonstrated feasibility for implementation. Additional research is ongoing to further evaluate its validity. Currently, there are no validated tools to assess drug abuse potential during clinical trials. Because of its ease of implementation, its systematic approach, and its preliminary validation results, MADDERS could provide such a tool for clinical trials. (Am J Addict 2016;25:641-651). © 2016 American Academy of Addiction Psychiatry.

Instruments to identify prescription medication misuse, abuse, and related events in clinical trials: an ACTTION systematic review

PubMed Central

Smith, Shannon M.; Paillard, Florence; McKeown, Andrew; Burke, Laurie B.; Edwards, Robert R.; Katz, Nathaniel P.; Papadopoulos, Elektra J.; Rappaport, Bob A.; Slagle, Ashley; Strain, Eric C.; Wasan, Ajay D.; Turk, Dennis C.; Dworkin, Robert H.

2017-01-01

Measurement of inappropriate medication use events (e.g., abuse, misuse) in clinical trials is important in characterizing a medication’s abuse potential. However, no “gold standard” assessment of inappropriate use events in clinical trials has been identified. In this systematic review, we examine the measurement properties (i.e., content validity, cross-sectional reliability and construct validity, longitudinal construct validity, ability to detect change, and responder definitions) of instruments assessing inappropriate use of opioid and non-opioid prescription medications to identify any that meet U.S. and European regulatory agencies’ rigorous standards for outcome measures in clinical trials. Sixteen published instruments were identified, most of which were not designed for the selected concept of interest and context of use. For this reason, many instruments were found to lack adequate content validity (or documentation of content validity) to evaluate current inappropriate medication use events; for example, evaluating inappropriate use across the lifespan rather than current use, including items that did not directly assess inappropriate use (e.g., questions about anger), or failing to capture information pertinent to inappropriate use events (e.g., intention, route of administration). In addition, the psychometric data across all instruments were generally limited in scope. A further limitation is the heterogeneous, non-standardized use of inappropriate medication use terminology. These observations suggest that available instruments are not well suited for assessing current inappropriate medication use within the specific context of clinical trials. Further effort is needed to develop reliable and valid instruments to measure current inappropriate medication use events in clinical trials. PMID:25660826

Knowledge and skills of cancer clinical trials nurses in Australia.

PubMed

Scott, Kathleen; White, Kate; Johnson, Catherine; Roydhouse, Jessica K

2012-05-01

  This paper is a report of the development and testing of a questionnaire measuring knowledge and skills of cancer clinical trials nurse in Australia.   The role of cancer clinical trials nurse, widely acknowledged as an integral member of the clinical research team, has evolved in recent years. Elements of the clinical trials nurse role in cancer have previously been described. To evaluate specific cancer clinical trials nurse educational and training needs, the development of a valid and reliable tool is required.   In 2009, a study was conducted in three stages. Stage I: questionnaire development and pilot testing; stage II: focus group; stage III: national survey. Internal consistency reliability testing and multi-trait analysis of item convergent/divergent validity were employed. Regression analysis was used to identify predictors of clinical trials nurse knowledge and skills.   The national survey was a 48-item questionnaire, measuring six clinical trial knowledge and seven skills sub-scales. Of 61 respondents, 90% were women, with mean age 43 years, 19 years as a Registered Nurse and 5 years as a cancer clinical trials nurse. Self-reported knowledge and skills were satisfactory to good. Internal consistency reliability was high (Cronbach's alpha: knowledge = 0·98; skills = 0·90). Criteria for item convergent/divergent validity were met. Number of years as cancer clinical trials nurse was positively related to self-reported knowledge and skills.   Preliminary data suggest that the national survey is reliable and valid. Data have contributed to better understanding the knowledge and skills of cancer clinical trials nurse in Australia and development of a postgraduate course in clinical trials. © 2011 Blackwell Publishing Ltd.

Out of Lust or Jealousy: The Effects of Mate-Related Motives on Study-Time Allocation to Faces Varying in Attractiveness.

PubMed

Li, Weijian; Zhang, Yuchi; Li, Fengying; Li, Xinyu; Li, Ping; Jia, Xiaoyu; Chen, Haide; Ji, Haojie

2015-01-01

Although a growing number of empirical studies have revealed that activating mate-related motives might exert a specific set of consequences for human cognition and behaviors, such as attention and memory, little is known about whether mate-related motives affect self-regulated learning. The present study examined the effects of mate-related motives (mate-search and mate-guarding) on study-time allocation to faces varying in attractiveness. In two experiments, participants in mate-related priming conditions (Experiment 1: mate-search; Experiment 2: mate-guarding) or control conditions studied 20 female faces (10 highly attractive, 10 less attractive) during a self-paced study task, and then were given a yes/no face recognition task. The finding of Experiment 1 showed that activating a mate-search motive led the male participants to allocate more time to highly attractive female faces (i.e., perceived potential mates) than to less attractive ones. In Experiment 2, female participants in the mate-guarding priming condition spent more time studying highly attractive female faces (i.e., perceived potential rivals) than less attractive ones, compared to participants in the control condition. These findings illustrate the highly specific consequences of mate-related motives on study-time allocation, and highlight the value of exploring human cognition and motivation within evolutionary and self-regulated learning frameworks.

Out of Lust or Jealousy: The Effects of Mate-Related Motives on Study-Time Allocation to Faces Varying in Attractiveness

PubMed Central

Li, Fengying; Li, Xinyu; Li, Ping; Jia, Xiaoyu; Chen, Haide; Ji, Haojie

2015-01-01

Although a growing number of empirical studies have revealed that activating mate-related motives might exert a specific set of consequences for human cognition and behaviors, such as attention and memory, little is known about whether mate-related motives affect self-regulated learning. The present study examined the effects of mate-related motives (mate-search and mate-guarding) on study-time allocation to faces varying in attractiveness. In two experiments, participants in mate-related priming conditions (Experiment 1: mate-search; Experiment 2: mate-guarding) or control conditions studied 20 female faces (10 highly attractive, 10 less attractive) during a self-paced study task, and then were given a yes/no face recognition task. The finding of Experiment 1 showed that activating a mate-search motive led the male participants to allocate more time to highly attractive female faces (i.e., perceived potential mates) than to less attractive ones. In Experiment 2, female participants in the mate-guarding priming condition spent more time studying highly attractive female faces (i.e., perceived potential rivals) than less attractive ones, compared to participants in the control condition. These findings illustrate the highly specific consequences of mate-related motives on study-time allocation, and highlight the value of exploring human cognition and motivation within evolutionary and self-regulated learning frameworks. PMID:26121131

'Good genes as heterozygosity': the major histocompatibility complex and mate choice in Atlantic salmon (Salmo salar).

PubMed

Landry, C; Garant, D; Duchesne, P; Bernatchez, L

2001-06-22

According to the theory of mate choice based on heterozygosity, mates should choose each other in order to increase the heterozygosity of their offspring. In this study, we tested the 'good genes as heterozygosity' hypothesis of mate choice by documenting the mating patterns of wild Atlantic salmon (Salmo salar) using both major histocompatibility complex (MHC) and microsatellite loci. Specifically, we tested the null hypotheses that mate choice in Atlantic salmon is not dependent on the relatedness between potential partners or on the MHC similarity between mates. Three parameters were assessed: (i) the number of shared alleles between partners (x and y) at the MHC (M(xy)), (ii) the MHC amino-acid genotypic distance between mates' genotypes (AA(xy)), and (iii) genetic relatedness between mates (r(xy)). We found that Atlantic salmon choose their mates in order to increase the heterozygosity of their offspring at the MHC and, more specifically, at the peptide-binding region, presumably in order to provide them with better defence against parasites and pathogens. This was supported by a significant difference between the observed and expected AA(xy) (p = 0.0486). Furthermore, mate choice was not a mechanism of overall inbreeding avoidance as genetic relatedness supported a random mating scheme (p = 0.445). This study provides the first evidence that MHC genes influence mate choice in fish.

Fitness consequences of female multiple mating: A direct test of indirect benefits

PubMed Central

2012-01-01

Background The observation that females mate multiply when males provide nothing but sperm - which sexual selection theory suggests is unlikely to be limiting - continues to puzzle evolutionary biologists. Here we test the hypothesis that multiple mating is prevalent under such circumstances because it enhances female fitness. We do this by allowing female Trinidadian guppies to mate with either a single male or with multiple males, and then tracking the consequences of these matings across two generations. Results Overall, multiply mated females produced 67% more F2 grand-offspring than singly mated females. These offspring, however, did not grow or mature faster, nor were they larger at birth, than F2 grand-offspring of singly mated females. Our results, however, show that multiple mating yields benefits to females in the form of an increase in the production of F1. The higher fecundity among multiply mated mothers was driven by greater production of sons but not daughters. However, contrary to expectation, individually, the offspring of multiply mated females do not grow at different rates than offspring of singly mated females, nor do any indirect fitness benefits or costs accrue to second-generation offspring. Conclusions The study provides strong evidence that multiple mating is advantageous to females, even when males contribute only sperm. This benefit is achieved through an increase in fecundity in the first generation, rather than through other fitness correlates such as size at birth, growth rate, time to sexual maturation and survival. Considered alongside previous work that female guppies can choose to mate with multiple partners, our results provide compelling evidence that direct fitness benefits underpin these mating decisions. PMID:22978442

Experimental evolution under hyper-promiscuity in Drosophila melanogaster.

PubMed

Perry, Jennifer C; Joag, Richa; Hosken, David J; Wedell, Nina; Radwan, Jacek; Wigby, Stuart

2016-06-16

The number of partners that individuals mate with over their lifetime is a defining feature of mating systems, and variation in mate number is thought to be a major driver of sexual evolution. Although previous research has investigated the evolutionary consequences of reductions in the number of mates, we know little about the costs and benefits of increased numbers of mates. Here, we use a genetic manipulation of mating frequency in Drosophila melanogaster to create a novel, highly promiscuous mating system. We generated D. melanogaster populations in which flies were deficient for the sex peptide receptor (SPR) gene - resulting in SPR- females that mated more frequently - and genetically-matched control populations, and allowed them to evolve for 55 generations. At several time-points during this experimental evolution, we assayed behavioural, morphological and transcriptional reproductive phenotypes expected to evolve in response to increased population mating frequencies. We found that males from the high mating frequency SPR- populations evolved decreased ability to inhibit the receptivity of their mates and decreased copulation duration, in line with predictions of decreased per-mating investment with increased sperm competition. Unexpectedly, SPR- population males also evolved weakly increased sex peptide (SP) gene expression. Males from SPR- populations initially (i.e., before experimental evolution) exhibited more frequent courtship and faster time until mating relative to controls, but over evolutionary time these differences diminished or reversed. In response to experimentally increased mating frequency, SPR- males evolved behavioural responses consistent with decreased male post-copulatory investment at each mating and decreased overall pre-copulatory performance. The trend towards increased SP gene expression might plausibly relate to functional differences in the two domains of the SP protein. Our study highlights the utility of genetic manipulations of animal social and sexual environments coupled with experimental evolution.

Genetic compatibility, mate choice and patterns of parentage: invited review.

PubMed

Tregenza, T; Wedell, N

2000-08-01

There is growing interest in the possibility that genetic compatibility may drive mate choice, including gamete choice, particularly from the perspective of understanding why females frequently mate with more than one male. Mate choice for compatibility differs from other forms of choice for genetic benefits (such as 'good genes') because individuals are expected to differ in their mate preferences, changing the evolutionary dynamics of sexual selection. Recent experiments designed to investigate genetic benefits of polyandry suggest that mate choice on the basis of genetic compatibility may be widespread. However, in most systems the mechanisms responsible for variation in compatibility are unknown. We review potential sources of variation in genetic compatibility and whether there is any evidence for mate choice driven by these factors. Selfish genetic elements appear to have the potential to drive mate compatibility mate choice, though as yet there is only one convincing example. There is abundant evidence for assortative mating between populations in hybrid zones, but very few examples where this is clearly a result of selection against mating with genetically less compatible individuals. There are also numerous cases of inbreeding avoidance, but little evidence that mate choice or differential fertilization success driven by genetic compatibility occurs between unrelated individuals. The exceptions to this are a handful of situations where both the alleles causing incompatibility and the alleles involved in mate choice are located in a chromosome region where recombination is suppressed. As yet there are only a few potential sources of genetic compatibility which have clearly been shown to drive mate choice. This may reflect limitations in the potential for the evolution of mate choice for genetic compatibility within populations, although the most promising sources of such incompatibilities have received relatively little research.

Learning to speciate: The biased learning of mate preferences promotes adaptive radiation

PubMed Central

Gilman, R. Tucker; Kozak, Genevieve M.

2015-01-01

Bursts of rapid repeated speciation called adaptive radiations have generated much of Earth's biodiversity and fascinated biologists since Darwin, but we still do not know why some lineages radiate and others do not. Understanding what causes assortative mating to evolve rapidly and repeatedly in the same lineage is key to understanding adaptive radiation. Many species that have undergone adaptive radiations exhibit mate preference learning, where individuals acquire mate preferences by observing the phenotypes of other members of their populations. Mate preference learning can be biased if individuals also learn phenotypes to avoid in mates, and shift their preferences away from these avoided phenotypes. We used individual‐based computational simulations to study whether biased and unbiased mate preference learning promotes ecological speciation and adaptive radiation. We found that ecological speciation can be rapid and repeated when mate preferences are biased, but is inhibited when mate preferences are learned without bias. Our results suggest that biased mate preference learning may play an important role in generating animal biodiversity through adaptive radiation. PMID:26459795

Condition-dependent mate choice: A stochastic dynamic programming approach.

PubMed

Frame, Alicia M; Mills, Alex F

2014-09-01

We study how changing female condition during the mating season and condition-dependent search costs impact female mate choice, and what strategies a female could employ in choosing mates to maximize her own fitness. We address this problem via a stochastic dynamic programming model of mate choice. In the model, a female encounters males sequentially and must choose whether to mate or continue searching. As the female searches, her own condition changes stochastically, and she incurs condition-dependent search costs. The female attempts to maximize the quality of the offspring, which is a function of the female's condition at mating and the quality of the male with whom she mates. The mating strategy that maximizes the female's net expected reward is a quality threshold. We compare the optimal policy with other well-known mate choice strategies, and we use simulations to examine how well the optimal policy fares under imperfect information. Copyright © 2014 Elsevier Inc. All rights reserved.

Direct fitness benefits explain mate preference, but not choice, for similarity in heterozygosity levels.

PubMed

Zandberg, Lies; Gort, Gerrit; van Oers, Kees; Hinde, Camilla A

2017-10-01

Under sexual selection, mate preferences can evolve for traits advertising fitness benefits. Observed mating patterns (mate choice) are often assumed to represent preference, even though they result from the interaction between preference, sampling strategy and environmental factors. Correlating fitness with mate choice instead of preference will therefore lead to confounded conclusions about the role of preference in sexual selection. Here we show that direct fitness benefits underlie mate preferences for genetic characteristics in a unique experiment on wild great tits. In repeated mate preference tests, both sexes preferred mates that had similar heterozygosity levels to themselves, and not those with which they would optimise offspring heterozygosity. In a subsequent field experiment where we cross fostered offspring, foster parents with more similar heterozygosity levels had higher reproductive success, despite the absence of assortative mating patterns. These results support the idea that selection for preference persists despite constraints on mate choice. © 2017 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Production benefits from pre- and post-lambing anthelmintic treatment of ewes on commercial farms in the southern North Island of New Zealand.

PubMed

Miller, C M; Ganesh, S; Garland, C B; Leathwick, D M

2015-07-01

To measure the magnitude and variability in production responses to anthelmintic treatments administered to adult ewes around lambing. Ewes carrying twin lambs, from sheep and beef farms (eight in Year 1 and six in Year 2) in the Wairarapa region of New Zealand, were enrolled in 14 trials (part of an experiment carried out on one farm in one year). Experiment 1 compared ewes treated 2-4 weeks pre-lambing with a controlled release capsule (CRC) containing abamectin, albendazole, Se and Co, to ewes injected pre-lambing with a long-acting Se plus vitamin B12 product, and to untreated ewes. Experiment 2 included these treatments, plus a CRC administered at pregnancy scanning. Experiment 3 included the same treatments as Experiment 1, plus administration of a CRC containing albendazole, Se and Co, injectable moxidectin or oral derquantel plus abamectin, all administered pre-lambing, or oral derquantel plus abamectin administered 4-6 weeks after lambing. Variables compared were ewe liveweight at weaning and pre-mating, lamb liveweight at weaning, total weight of lamb weaned per ewe and ewe dag score at weaning. Ewes treated with a CRC pre-lambing were heavier than untreated ewes (mean 3.2 kg) at weaning in 12/14 trials, and pre-mating (mean 2.8 kg) in 9/14 trials (p<0.001). Compared with mineral-treated ewes the mean difference was 2.8 kg pre-lambing (9/14 trials) and 1.7 kg pre-weaning (6/14 trials). Lambs reared by treated ewes were heavier (mean 1.55 kg) at weaning in 6/14 trials (p<0.001), but there was no effect of CRC treatment on total weight of lambs weaned per ewe (p=0.507). Variation in weight of lamb weaned per ewe was largely explained by differences in lamb survival from birth to weaning (p<0.001), with no effect of CRC treatment (p>0.65). Treatment of ewes with a CRC at pregnancy scanning was neither better nor worse than a pre-lambing treatment (p=0.065). There was no difference in the response from treatment with either of the two CRC or moxidectin. Treatment with short-acting oral anthelmintics resulted in no consistent benefit. Anthelmintic treatments administered to ewes around lambing resulted in variable responses between farms and years, which in some trials were negative for some variables, and some of the variability was due to the mineral component of the CRC. The widespread perception amongst farmers and veterinarians that anthelmintic treatment of ewes around lambing will always result in positive benefits is not supported.

Determination of caffeine, theobromine and theophylline in Mate beer and Mate soft drinks by high-performance thin-layer chromatography.

PubMed

Oellig, Claudia; Schunck, Jacob; Schwack, Wolfgang

2018-01-19

Mate beer and Mate soft drinks are beverages produced from the dried leaves of Ilex paraguariensis (Yerba Mate). In Yerba Mate, the xanthine derivatives caffeine, theobromine and theophylline, also known as methylxanthines, are important active components. The presented method for the determination of caffeine, theobromine and theophylline in Mate beer and Mate soft drinks by high-performance thin-layer chromatography with ultraviolet detection (HPTLC-UV) offers a fully automated and sensitive determination of the three methylxanthines. Filtration of the samples was followed by degassing, dilution with acetonitrile in the case of Mate beers for protein precipitation, and centrifugation before the extracts were analyzed by HPTLC-UV on LiChrospher silica gel plates with fluorescence indicator and acetone/toluene/chloroform (4:3:3, v/v/v) as the mobile phase. For quantitation, the absorbance was scanned at 274nm. Limits of detection and quantitation were 1 and 4ng/zone, respectively, for caffeine, theobromine and theophylline. With recoveries close to 100% and low standard deviations reliable results were guaranteed. Experimental Mate beers as well as Mate beers and Mate soft drinks from the market were analyzed for their concentrations of methylxanthines. Copyright © 2017 Elsevier B.V. All rights reserved.

MATE2 Mediates Vacuolar Sequestration of Flavonoid Glycosides and Glycoside Malonates in Medicago truncatula[C][W][OA

PubMed Central

Zhao, Jian; Huhman, David; Shadle, Gail; He, Xian-Zhi; Sumner, Lloyd W.; Tang, Yuhong; Dixon, Richard A.

2011-01-01

The majority of flavonoids, such as anthocyanins, proanthocyanidins, and isoflavones, are stored in the central vacuole, but the molecular basis of flavonoid transport is still poorly understood. Here, we report the functional characterization of a multidrug and toxin extrusion transporter (MATE2), from Medicago truncatula. MATE 2 is expressed primarily in leaves and flowers. Despite its high similarity to the epicatechin 3′-O-glucoside transporter MATE1, MATE2 cannot efficiently transport proanthocyanidin precursors. In contrast, MATE2 shows higher transport capacity for anthocyanins and lower efficiency for other flavonoid glycosides. Three malonyltransferases that are coexpressed with MATE2 were identified. The malonylated flavonoid glucosides generated by these malonyltransferases are more efficiently taken up into MATE2-containing membrane vesicles than are the parent glycosides. Malonylation increases both the affinity and transport efficiency of flavonoid glucosides for uptake by MATE2. Genetic loss of MATE2 function leads to the disappearance of leaf anthocyanin pigmentation and pale flower color as a result of drastic decreases in the levels of various flavonoids. However, some flavonoid glycoside malonates accumulate to higher levels in MATE2 knockouts than in wild-type controls. Deletion of MATE2 increases seed proanthocyanidin biosynthesis, presumably via redirection of metabolic flux from anthocyanin storage. PMID:21467581

Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates

PubMed Central

Lass-Hennemann, Johanna; Deuter, Christian E.; Kuehl, Linn K.; Schulz, André; Blumenthal, Terry D.; Schachinger, Hartmut

2010-01-01

Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters men's preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates. PMID:20219732

Effect of mating stage on water balance, cuticular hydrocarbons and metabolism in the desert harvester ant, Pogonomyrmex barbatus.

PubMed

Johnson, Robert A; Gibbs, Allen G

2004-10-01

Water-loss rates increase after mating in queens of the harvester ant Pogonomyrmex barbatus (Formicidae: Myrmicinae), then increase again after the mated queens excavate an incipient nest. We determined the mechanistic basis for these increased water-loss rates by examining cuticular permeability, respiratory water loss, metabolic rates, and cuticular hydrocarbons for queens at three stages in the mating sequence: unmated alate queens, newly mated dealate queens, and mated queens excavated from their incipient nest. Both total water loss and cuticular transpiration increased significantly following mating, with cuticular transpiration accounting for 97% of the increased water loss. In contrast, metabolic rate and respiratory water loss were unaffected by mating stage. The total quantity of cuticular hydrocarbons did not vary by mating stage. However, relative amounts of four of the most abundant cuticular hydrocarbons did vary by mating stage, as did quantities of n-alkanes and methylalkanes. The general pattern was that percent composition of n-alkanes decreased through the mating sequence, while percent composition of methylalkanes increased over the same sequence. We discuss three mechanisms that might cause these post-mating increases in cuticular permeability. Our data support the hypothesis that part of this increase results from soil particles abrading the cuticle during the process of nest excavation.

Quality of public information matters in mate-choice copying in female zebra finches.

PubMed

Kniel, Nina; Schmitz, Jennifer; Witte, Klaudia

2015-01-01

Mate-choice copying is a form of social learning in which an individual gains information about potential mates by observing conspecifics. However, it is still unknown what kind of information drives the decision of an individual to copy the mate choice of others. Among zebra finches (Taeniopygia guttata castanotis), only females (not males) copy the mate choice of others. We tested female zebra finches in a binary choice test where they, first, could choose between two males of different phenotypes: one unadorned male and one male artificially adorned with a red feather on the forehead. After this mate-choice test, females could observe a single unadorned male and a pair of zebra finches, i.e. a wild-type female and her adorned mate. Pair interactions were either restricted to acoustic and visual communication (clear glass screen between pair mates) or acoustic communication alone (opaque screen between pair mates). After the observation period, females could again choose between new males of the two phenotypes in a second mate-choice test. In experiments with a clear glass screen, time spent with the respective males changed between the two mate-choice tests, and females preferred adorned over unadorned males during the second mate-choice test. In experiments with an opaque screen, time spent with the respective males did not change between the two mate-choice tests, although females lost an initial preference for unadorned males. Our results demonstrate that the quality of the received public information (visual and acoustic interaction of the observed pair) influences mate-choice copying in female zebra finches.

Comparison of sexual compatibility in crosses between the southern and northern populations of the cabbage beetle Colaphellus bowringi.

PubMed

Liu, Xing-Ping; Tu, Xiao-Yun; He, Hai-Min; Chen, Chao; Xue, Fang-Sen

2014-12-01

It is widely accepted that the genetic divergence and reproductive incompatibility between closely related species and/or populations is often viewed as an important step toward speciation. In this study, sexual compatibility in crosses between the southern XS population and the northern TA population of the polyandrous cabbage beetle Colaphellus bowringi was investigated by testing their mating preferences, mating latency, copulation duration, and reproductive performances of post-mating. In choice mating experiments, the percentages of matings were significantly higher in intra-population crosses than in inter-population crosses. Both isolation index (I) and index of pair sexual isolation (IPSI ) indicated partial mating incompatibility or assortative mating in crosses between the two different geographical populations. In single pair mating experiments, XS females in inter-population crosses mated significantly later and copulated significantly shorter than those in intra-population crosses. However, TA females in inter-population crosses mated significantly earlier and copulated longer than those in intra-population crosses, suggesting that larger XS males may enhance heterotypic mating. The lifetime fecundity was highest in XS homotypic matings, lowest in TA homotypic matings, and intermediate in heterotypic matings between their parents. The inter-population crosses resulted in significantly lower egg hatching rate and shorter female longevity than intra-population crosses. These results demonstrated that there exist some incompatibilities in premating, postmating-prezygotic, and postzygotic stages between the southern XS population and northern TA population of the cabbage beetle Colaphellus bowringi. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Honey bee queens do not count mates to assess their mating success

USDA-ARS?s Scientific Manuscript database

The mating system of honey bees (genus Apis) is extremely polyandrous, where reproductive females (queens) typically mate with 12 or more males (drones) during their mating flight(s). The evolutionary implications for hyperpolyandry have been subject to considerable debate and empirical testing beca...

Demonstration/Validation of the TC-60 Controlled Detonation Chamber, Porton Down, UK: Final Demonstration Test Report

DTIC Science & Technology

2007-06-01

Joint At the exit of the expansion tank, a polymeric composition of ethylene-propylene- diene terpolymer ( EPDM ) rubber was used to mate the flange of...The final connection of the detonator was cumbersome for an operator wearing thick butyl rubber gloves. The detonator wire connection was made to a...operators were required to wear PPE, including rubber gloves. The decision was made to transfer the PLC components to outside the VCS. In Phase I, the

The Use of Prototypes in Weapon System Development

DTIC Science & Technology

1981-03-01

engine to minimize flameouts; experience showed that some uses of composite mate- rials were unwarranted, and other uses were proved valid; and a special... composite structure materials. The YF-16 used a single F100, an engine already developed for the F-15 program. By the time of the YF-16 first flight...lessons learned during the prototype tests led to a reduction in the use of composite materials ir the full scale F-16A program. UTTAS. Because of the

MATE standardization

NASA Astrophysics Data System (ADS)

Farmer, R. E.

1982-11-01

The MATE (Modular Automatic Test Equipment) program was developed to combat the proliferation of unique, expensive ATE within the Air Force. MATE incorporates a standard management approach and a standard architecture designed to implement a cradle-to-grave approach to the acquisition of ATE and to significantly reduce the life cycle cost of weapons systems support. These standards are detailed in the MATE Guides. The MATE Guides assist both the Air Force and Industry in implementing the MATE concept, and provide the necessary tools and guidance required for successful acquisition of ATE. The guides also provide the necessary specifications for industry to build MATE-qualifiable equipment. The MATE architecture provides standards for all key interfaces of an ATE system. The MATE approach to the acquisition and management of ATE has been jointly endorsed by the commanders of Air Force Systems Command and Air Force Logistics Command as the way of doing business in the future.

Chinese undergraduates' preferences for altruistic traits in mate selection and personal advertisement: Evidence from Q-sort technique.

PubMed

Guo, Qingke; Feng, Linlin; Wang, Mingming

2017-04-01

Human's preferences for altruistic mates have been confirmed by many researchers. Under the deep influence of Confucianism that authorised more parental control over offspring's mate selection, Chinese people's mating strategies and mate preferences may be different from what the evolutionary psychologists have suggested. This study used the Q-sort technique to assess the roles of altruistic traits in mate selection and personal advertisement. A total of 200 university students participated in the Q-sort procedures and were asked to sort 50 traits (among which altruistic traits were mixed) according to their importance when choosing (or advertising to) a long-term (LT) or a short-term (ST) mate. Our findings were quite different from prior studies. When Chinese participants chose a mate or advertised themselves to a potential mate, kin altruism was considered to be the most important trait; altruistic traits were more preferred by males than by females and females tended to advertise themselves as more altruistic; preferences for altruistic traits showed no difference between LT and ST mate selections (or between personal advertisement to a LT and a ST mate). © 2015 International Union of Psychological Science.

The effects of mating status and time since mating on female sex pheromone levels in the rice leaf bug, Trigonotylus caelestialium

NASA Astrophysics Data System (ADS)

Yamane, Takashi; Yasuda, Tetsuya

2014-02-01

Although mating status affects future mating opportunities, the biochemical changes that occur in response to mating are not well understood. This study investigated the effects of mating status on the quantities of sex pheromone components found in whole-body extracts and volatile emissions of females of the rice leaf bug, Trigonotylus caelestialium. When sampled at one of four time points within a 4-day postmating period, females that had copulated with a male had greater whole-body quantities of sex pheromone components than those of virgin females sampled at the same times. The quantities of sex pheromone components emitted by virgin females over a 24-h period were initially high but then steadily decreased, whereas 24-h emissions were persistently low among mated females when measured at three time points within the 4 days after mating. As a result, soon after mating, the mated females emitted less sex pheromones than virgin females, but there were no significant differences between mated and virgin females at the end of the experiment. Thus, postmating reduction in the rate of emission of sex pheromones could explain previously observed changes in female attractiveness to male T. caelestialium.

Female mating strategy in an enclosed group of Japanese macaques.

PubMed

Soltis, J; Mitsunaga, F; Shimizu, K; Yanagihara, Y; Nozaki, M

1999-01-01

Female Japanese macaques (Macaca fuscata) are noted for mating with multiple males and for their ability to exert mate choice. In a captive group of Japanese macaques housed at the Primate Research Institute of Kyoto University, Japan, behavioral and endocrine data were combined to examine female mating strategies. During one breeding season, daily behavioral observations were conducted on females who exhibited copulatory behavior. Blood was collected from females twice weekly and their ovulatory periods estimated by analyzing hormone profiles. Females began mating shortly before ovulation, peaked at ovulation, and continued receiving ejaculations for up to ten weeks after conception. Females were more responsible than males for inbreeding avoidance with matrilineal kin. Males sometimes approached females from their own matriline, but females avoided such males and expressed mate choice behavior preferentially toward non-matrilineal males. Over the entire mating season, females did not choose non-matrilineal males on the basis of displays, dominance rank, age, weight, or weight change during the mating season. When females were likely to conceive, however, they expressed mate choice behavior toward males who displayed most frequently. Female mating strategy may include both mate choice at ovulation and other, non-procreative functions.

Effects of a parasitic nematode on male mate choice in a livebearing fish with a coercive mating system (western mosquitofish, Gambusia affinis).

PubMed

Deaton, Raelynn

2009-01-01

I examined the effects of the parasitic larval nematode, Eustrongylides ignotus, on male mate choice in the western mosquitofish, Gambusia affinis. I hypothesized that parasite presence influences male mate choice either directly (via reduction in male mating behavior due to presence of parasite in females) or indirectly (via reduction in male mating behavior due to reduced condition of infected females). Specifically, I tested the predictions that (1) males would mate preferentially with uninfected over infected females (scoring both mating attempts and association time with females); (2) parasitized females would be in poorer condition than non-parasitized females (measured as soluble fat stores); and (3) parasitized females would have reduced fecundity (measured as number of developing embryos). Males preferred to mate with non-parasitized over parasitized females, but showed no differences in association time between females. The nematode did not decrease female body condition, but did decrease female mass, and appeared to decrease female fecundity via reduction in broods (# embryos). Results support that parasites affect male mate choice in mosquitofish; however, the mechanisms used by males to differentiate between parasitized and non-parasitized females remain untested. This study provides the first empirical evidence of parasite affects on male mate choice in livebearing fishes, and suggest a potentially important role for parasite-mediated sexual selection in organisms that use coercive mating as the primary mechanism of obtaining mates.

Fungal Sex: The Basidiomycota.

PubMed

Coelho, Marco A; Bakkeren, Guus; Sun, Sheng; Hood, Michael E; Giraud, Tatiana

2017-06-01

Fungi of the Basidiomycota, representing major pathogen lineages and mushroom-forming species, exhibit diverse means to achieve sexual reproduction, with particularly varied mechanisms to determine compatibilities of haploid mating partners. For species that require mating between distinct genotypes, discrimination is usually based on both the reciprocal exchange of diffusible mating pheromones, rather than sexes, and the interactions of homeodomain protein signals after cell fusion. Both compatibility factors must be heterozygous in the product of mating, and genetic linkage relationships of the mating pheromone/receptor and homeodomain genes largely determine the complex patterns of mating-type variation. Independent segregation of the two compatibility factors can create four haploid mating genotypes from meiosis, referred to as tetrapolarity. This condition is thought to be ancestral to the basidiomycetes. Alternatively, cosegregation by linkage of the two mating factors, or in some cases the absence of the pheromone-based discrimination, yields only two mating types from meiosis, referred to as bipolarity. Several species are now known to have large and highly rearranged chromosomal regions linked to mating-type genes. At the population level, polymorphism of the mating-type genes is an exceptional aspect of some basidiomycete fungi, where selection under outcrossing for rare, intercompatible allelic variants is thought to be responsible for numbers of mating types that may reach several thousand. Advances in genome sequencing and assembly are yielding new insights by comparative approaches among and within basidiomycete species, with the promise to resolve the evolutionary origins and dynamics of mating compatibility genetics in this major eukaryotic lineage.

Roles of Female and Male Genotype in Post-Mating Responses in Drosophila melanogaster.

PubMed

Delbare, Sofie Y N; Chow, Clement Y; Wolfner, Mariana F; Clark, Andrew G

2017-10-30

Mating induces a multitude of changes in female behavior, physiology, and gene expression. Interactions between female and male genotype lead to variation in post-mating phenotypes and reproductive success. So far, few female molecules responsible for these interactions have been identified. Here, we used Drosophila melanogaster from 5 geographically dispersed populations to investigate such female × male genotypic interactions at the female transcriptomic and phenotypic levels. Females from each line were singly-mated to males from the same 5 lines, for a total of 25 combinations. Reproductive output and refractoriness to re-mating were assayed in females from the 25 mating combinations. Female × male genotypic interactions resulted in significant differences in these post-mating phenotypes. To assess whether female × male genotypic interactions affect the female post-mating transcriptome, next-generation RNA sequencing was performed on virgin and mated females at 5 to 6 h post-mating. Seventy-seven genes showed strong variation in mating-induced expression changes in a female × male genotype-dependent manner. These genes were enriched for immune response and odorant-binding functions, and for expression exclusively in the head. Strikingly, variation in post-mating transcript levels of a gene encoding a spermathecal endopeptidase was correlated with short-term egg production. The transcriptional variation found in specific functional classes of genes might be a read-out of female × male compatibility at a molecular level. Understanding the roles these genes play in the female post-mating response will be crucial to better understand the evolution of post-mating responses and related conflicts between the sexes. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Costs of mate-guarding in wild male long-tailed macaques (Macaca fascicularis): physiological stress and aggression.

PubMed

Girard-Buttoz, Cédric; Heistermann, Michael; Rahmi, Erdiansyah; Agil, Muhammad; Fauzan, Panji Ahmad; Engelhardt, Antje

2014-09-01

Mate-guarding is an important determinant of male reproductive success in a number of species. However, it is known to potentially incur costs. The aim of the present study was to assess the effect of mate-guarding on male physiological stress and aggression in long-tailed macaques, a species in which males mate-guard females to a lesser extent than predicted by the Priority of Access model (PoA). The study was carried out during two mating periods on three groups of wild long-tailed macaques in Indonesia by combining behavioral observations with non-invasive measurements of fecal glucocorticoid (fGC) levels. Mate-guarding was associated with a general rise in male stress hormone levels but, from a certain threshold of mate-guarding onwards, increased vigilance time was associated with a decrease in stress hormone output. Mate-guarding also increased male-male aggression rate and male vigilance time. Overall, alpha males were more physiologically stressed than other males independently of mating competition. Increased glucocorticoid levels during mate-guarding are most likely adaptive since it may help males to mobilize extra-energy required for mate-guarding and ultimately maintain a balanced energetic status. However, repeated exposure to high levels of stress over an extended period is potentially deleterious to the immune system and thus may carry costs. This potential physiological cost together with the cost of increased aggression mate-guarding male face may limit the male's ability to mate-guard females, explaining the deviance from the PoA model observed in long-tailed macaques. Comparing our results to previous findings we discuss how ecological factors, reproductive seasonality and rank achievement may modulate the extent to which costs of mate-guarding limit male monopolization abilities. Copyright © 2014. Published by Elsevier Inc.

Ondansetron Can Enhance Cisplatin-Induced Nephrotoxicity via Inhibition of Multiple Toxin and Extrusion Proteins (MATEs)

PubMed Central

Li, Qing; Guo, Dong; Dong, Zhongqi; Zhang, Wei; Zhang, Lei K.; Huang, Shiew-Mei; Polli, James E.; Shu, Yan

2013-01-01

The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate for OCTs and MATEs, in wild-type and Mate1−/− mice. The nephrotoxicity was assessed in the wild-type and Mate1−/− mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1−/− mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT3) receptor antagonists, such as ondansetron, should be investigated in patients. PMID:24001450

Why do female Callosobruchus maculatus kick their mates?

PubMed

van Lieshout, Emile; McNamara, Kathryn B; Simmons, Leigh W

2014-01-01

Sexual conflict is now recognised as an important driver of sexual trait evolution. However, due to their variable outcomes and effects on other fitness components, the detection of sexual conflicts on individual traits can be complicated. This difficulty is exemplified in the beetle Callosobruchus maculatus, where longer matings increase the size of nutritious ejaculates but simultaneously reduce female future receptivity. While previous studies show that females gain direct benefits from extended mating duration, females show conspicuous copulatory kicking behaviour, apparently to dislodge mating males prematurely. We explore the potential for sexual conflict by comparing several fitness components and remating propensity in pairs of full sibling females where each female mated with a male from an unrelated pair of full sibling males. For one female, matings were terminated at the onset of kicking, whereas the other's matings remained uninterrupted. While fecundity (number of eggs) was similar between treatments, uninterrupted matings enhanced adult offspring numbers and fractionally also longevity. However, females whose matings were interrupted at the onset of kicking exhibited an increased propensity to remate. Since polyandry can benefit female fitness in this species, we argue that kicking, rather than being maladaptive, may indicate that females prefer remating over increased ejaculate size. It may thus be difficult to assess the presence of sexual conflict over contested traits such as mating duration when females face a trade off between direct benefits gained from one mating and indirect benefits from additional matings.

Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

NASA Astrophysics Data System (ADS)

Fowler-Finn, Kasey D.; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L.

2014-03-01

Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.

Mate retention behavior of men and women in heterosexual and homosexual relationships.

PubMed

Vanderlaan, Doug P; Vasey, Paul L

2008-08-01

Comparing the behavior of heterosexual and homosexual persons can provide insight into the origins of heterosexual sex differences in psychology. Evidence indicates that, aside from sexual partner preference, the mating psychology of homosexual men is sex-typical whereas that of homosexual women tends to be more sex-atypical. The current study examined one aspect of mating psychology, mate retention behavior, and tested whether homosexual men and women were sex-typical or sex-atypical for those mate retention tactics where heterosexual men and women differed. Men and women in heterosexual and homosexual relationships were asked to provide information regarding their partners' mate retention behavior by using the Mate Retention Inventory Questionnaire. Heterosexual men and women differed significantly for six of the 19 mate retention tactics considered. With respect to the six mate retention tactics where heterosexual sex differences existed, homosexual men behaved in a sex-typical manner for five of the tactics, whereas homosexual women behaved in a sex-atypical manner for all six tactics. We discuss the significance of these findings for explaining the origins of the mate retention behavior of heterosexual men and women. In addition, we consider what the pattern of sex-typical and sex-atypical mating psychology among homosexual men and women, respectively, suggests in regard to sex differences in the development of mating psychology and the development of homosexual persons.

Negative-assortative mating for color in wolves.

PubMed

Hedrick, Philip W; Smith, Douglas W; Stahler, Daniel R

2016-04-01

There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Sampling and assessment accuracy in mate choice: a random-walk model of information processing in mating decision.

PubMed

Castellano, Sergio; Cermelli, Paolo

2011-04-07

Mate choice depends on mating preferences and on the manner in which mate-quality information is acquired and used to make decisions. We present a model that describes how these two components of mating decision interact with each other during a comparative evaluation of prospective mates. The model, with its well-explored precedents in psychology and neurophysiology, assumes that decisions are made by the integration over time of noisy information until a stopping-rule criterion is reached. Due to this informational approach, the model builds a coherent theoretical framework for developing an integrated view of functions and mechanisms of mating decisions. From a functional point of view, the model allows us to investigate speed-accuracy tradeoffs in mating decision at both population and individual levels. It shows that, under strong time constraints, decision makers are expected to make fast and frugal decisions and to optimally trade off population-sampling accuracy (i.e. the number of sampled males) against individual-assessment accuracy (i.e. the time spent for evaluating each mate). From the proximate-mechanism point of view, the model makes testable predictions on the interactions of mating preferences and choosiness in different contexts and it might be of compelling empirical utility for a context-independent description of mating preference strength. Copyright © 2011 Elsevier Ltd. All rights reserved.

Coordinate control of initiative mating device for autonomous underwater vehicle based on TDES

NASA Astrophysics Data System (ADS)

Yan, Zhe-Ping; Hou, Shu-Ping

2005-06-01

A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV (autonomons underwater vehicle) and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought foward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES (time discrete event system). After taking into account the time problem, it is a useful method to control mating by simulation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.

Biomarkers and Surrogate Endpoints: Lessons Learned From Glaucoma

PubMed Central

Medeiros, Felipe A.

2017-01-01

With the recent progress in imaging technologies for assessment of structural damage in glaucoma, a debate has emerged on whether these measurements can be used as valid surrogate endpoints in clinical trials evaluating new therapies for the disease. A discussion of surrogates should be grounded on knowledge acquired from their use in other areas of medicine as well as regulatory requirements. This article reviews the conditions for valid surrogacy in the context of glaucoma clinical trials and critically evaluates the role of biomarkers such as IOP and imaging measurements as potential surrogates for clinically relevant outcomes. Valid surrogate endpoints must be able to predict a clinically relevant endpoint, such as loss of vision or decrease in quality of life. In addition, the effect of a proposed treatment on the surrogate must capture the effect of the treatment on the clinically relevant endpoint. Despite its widespread use in clinical trials, no proper validation of IOP as a surrogate endpoint has yet been conducted for any class of IOP-lowering treatments. Although strong evidence has accumulated about imaging measurements as predictors of relevant functional outcomes in glaucoma, there is still insufficient evidence to support their use as valid surrogate endpoints. However, imaging biomarkers could potentially be used as part of composite endpoints in glaucoma trials, overcoming weaknesses of the use of structural or functional endpoints in isolation. Efforts should be taken to properly design and conduct studies that can provide proper validation of potential biomarkers in glaucoma clinical trials. PMID:28475699

Biomarkers and Surrogate Endpoints: Lessons Learned From Glaucoma.

PubMed

Medeiros, Felipe A

2017-05-01

With the recent progress in imaging technologies for assessment of structural damage in glaucoma, a debate has emerged on whether these measurements can be used as valid surrogate endpoints in clinical trials evaluating new therapies for the disease. A discussion of surrogates should be grounded on knowledge acquired from their use in other areas of medicine as well as regulatory requirements. This article reviews the conditions for valid surrogacy in the context of glaucoma clinical trials and critically evaluates the role of biomarkers such as IOP and imaging measurements as potential surrogates for clinically relevant outcomes. Valid surrogate endpoints must be able to predict a clinically relevant endpoint, such as loss of vision or decrease in quality of life. In addition, the effect of a proposed treatment on the surrogate must capture the effect of the treatment on the clinically relevant endpoint. Despite its widespread use in clinical trials, no proper validation of IOP as a surrogate endpoint has yet been conducted for any class of IOP-lowering treatments. Although strong evidence has accumulated about imaging measurements as predictors of relevant functional outcomes in glaucoma, there is still insufficient evidence to support their use as valid surrogate endpoints. However, imaging biomarkers could potentially be used as part of composite endpoints in glaucoma trials, overcoming weaknesses of the use of structural or functional endpoints in isolation. Efforts should be taken to properly design and conduct studies that can provide proper validation of potential biomarkers in glaucoma clinical trials.

Mate preferences and infectious disease: theoretical considerations and evidence in humans

PubMed Central

Tybur, Joshua M.; Gangestad, Steven W.

2011-01-01

Mate preferences may operate in part to mitigate the threats posed by infectious disease. In this paper, we outline various ways in which preferring healthy mates can offer direct benefits in terms of pathogen avoidance and indirect benefits in terms of heritable immunity to offspring, as well as the costs that may constrain mate preferences for health. We then pay special attention to empirical work on mate preferences in humans given the depth and breadth of research on human mating. We review this literature and comment on the degree to which human mate preferences may reflect preferences for health. PMID:22042915

Effects of delayed mating on the reproductive biology of the vine mealybug, Planococcus ficus (Hemiptera: Pseudococcidae).

PubMed

Lentini, A; Mura, A; Muscas, E; Nuvoli, M T; Cocco, A

2018-04-01

The effect of increasing mating delay on the reproductive performance and population growth rates of the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), was investigated under laboratory conditions. Virgin females were mated at 1, 3, 5, 7, 14, 21 and 28 days after emergence and reproductive and life table parameters were estimated. The pre-oviposition period (number of days between mating and the onset of oviposition) significantly decreased in females mated within 7 days, whereas females mated at older ages showed equivalent pre-oviposition periods (7 days, as shorter delays in mating did not reduce the population growth rates.

Playback responses of socially monogamous black-fronted titi monkeys to simulated solitary and paired intruders.

PubMed

Caselli, Christini B; Mennill, Daniel J; Gestich, Carla C; Setz, Eleonore Z F; Bicca-Marques, Júlio César

2015-11-01

Many birds and primates use loud vocalizations to mediate agonistic interactions with conspecifics, either as solos by males or females, or as coordinated duets. The extensive variation in duet complexity, the contribution of each sex, and the context in which duets are produced suggest that duets may serve several functions, including territory and mate defense. Titi monkeys (Callicebus spp.) are believed to defend their home range via solo loud calls or coordinated duets. Yet there are remarkably few experimental studies assessing the function of these calls. Observations of interactions between wild established groups and solitary individuals are rare and, therefore, controlled experiments are required to simulate such situations and evaluate the mate and joint territorial defense hypotheses. We conducted playback experiments with three free-ranging groups of habituated black-fronted titi monkeys (Callicebus nigrifrons) to test these hypotheses. We found that titi monkeys responded to the three conspecific playback treatments (duets, female solos, and male solos) and did not respond to the heterospecific control treatment. The monkeys did not show sex-specific responses to solos (N = 12 trials). Partners started to duet together in 79% of their responses to playback-simulated rivals (N = 14 calls in response to playback). Males started to approach the loudspeaker before females regardless of the type of stimulus. The strength of the response of mated pairs to all three conspecific treatments was similar. Overall, our results are consistent with the idea that black-fronted titi monkeys use their loud calls in intergroup communication as a mechanism of joint territorial defense. © 2015 Wiley Periodicals, Inc.

Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha).

PubMed

Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

2017-05-01

Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm-egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm-egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm-egg interactions.

Internal validation of the prognostic index for spine metastasis (PRISM) for stratifying survival in patients treated with spinal stereotactic radiosurgery.

PubMed

Jensen, Garrett; Tang, Chad; Hess, Kenneth R; Bishop, Andrew J; Pan, Hubert Y; Li, Jing; Yang, James N; Tannir, Nizar M; Amini, Behrang; Tatsui, Claudio; Rhines, Laurence; Brown, Paul D; Ghia, Amol J

2017-01-01

We sought to validate the Prognostic Index for Spinal Metastases (PRISM), a scoring system that stratifies patients into subgroups by overall survival.Methods and materials: The PRISM was previously created from multivariate Cox regression with patients enrolled in prospective single institution trials of stereotactic spine radiosurgery (SSRS) for spinal metastasis. We assess model calibration and discrimination within a validation cohort of patients treated off-trial with SSRS for metastatic disease at the same institution. The training and validation cohorts consisted of 205 and 249 patients respectively. Similar survival trends were shown in the 4 PRISM. Survival was significantly different between PRISM subgroups (P<0.0001). C-index for the validation cohort was 0.68 after stratification into subgroups. We internally validated the PRISM with patients treated off-protocol, demonstrating that it can distinguish subgroups by survival, which will be useful for individualizing treatment of spinal metastases and stratifying patients for clinical trials.

Endeavour and its modified 747 carrier aircraft are illuminated by the morning sun after mating was completed in the Mate-DeMate gantry at NASA DFRC

NASA Image and Video Library

2008-12-09

The Space Shuttle Endeavour and its modified Boeing 747 carrier aircraft are illuminated by the morning sun Tuesday after mating of the pair was completed overnight in the Mate-DeMate gantry at NASA Dryden Flight Research Center. The pair are scheduled to depart Edwards Air Force Base on their ferry flight back to the Kennedy Space Center early Wednesday morning, Dec. 10.

Associations between body morphology, mating success and mate preferences among Slovak males and females.

PubMed

Prokop, Pavol; Fedor, Peter

2013-01-01

Human body morphology is thought to be correlated with sexual behaviour and sociosexuality (defined as an increased willingness to engage in sex without commitment) influences the perception of certain cues of physical attractiveness. Based on a sample of Slovak university students, we investigated relationships between 1) male and female mating success and reported body morphology (body mass index, BMI and waist-to-hip ratio, WHR) and 2) mate preference characteristics and mating success. Both males and females reported a similar number of long-term sexual partners and frequency of engaging in extra-pair copulation (EPC). The mating success of both sexes was positively mediated by self-perceived attractiveness. However, female BMI was inversely associated with mating success whereas increasing BMI was positively associated with male mating success (the total number of lifetime sexual partners) as well as with the likelihood of engaging in EPC. Unrestricted sociosexuality positively correlated with direct and indirect benefits from mating and negatively with the religious/political background of a potential mate and with the desire for a home/ children. These results confirm the hypothesis that human body morphology is associated with sexual behaviour and that cues of direct/indirect benefits in a potential mate positively correlate with sociosexuality.

Mate loss affects survival but not breeding in black brant geese

USGS Publications Warehouse

Nicolai, Christopher A.; Sedinger, James S.; Ward, David H.; Boyd, W. Sean

2012-01-01

For birds maintaining long-term monogamous relationships, mate loss might be expected to reduce fitness, either through reduced survival or reduced future reproductive investment. We used harvest of male brant during regular sport hunting seasons as an experimental removal to examine effects of mate loss on fitness of female black brant (Branta bernicla nigricans; hereafter brant). We used the Barker model in program MARK to examine effects of mate loss on annual survival, reporting rate, and permanent emigration. Survival rates decreased from 0.847 ± 0.004 for females who did not lose their mates to 0.690 ± 0.072 for birds who lost mates. Seber ring reporting rate for females that lost their mates were 2 times higher than those that did not lose mates, 0.12 ± 0.086 and 0.06 ± 0.006, respectively, indicating that mate loss increased vulnerability to harvest and possibly other forms of predation. We found little support for effects of mate loss on fidelity to breeding site and consequently on breeding. Our results indicate substantial fitness costs to females associated with mate loss, but that females who survived and were able to form new pair bonds may have been higher quality than the average female in the population.

Ondansetron can enhance cisplatin-induced nephrotoxicity via inhibition of multiple toxin and extrusion proteins (MATEs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qing; Institute of Clinical Pharmacology, Central South University, Hunan 410078; Guo, Dong

2013-11-15

The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate formore » OCTs and MATEs, in wild-type and Mate1−/− mice. The nephrotoxicity was assessed in the wild-type and Mate1−/− mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1−/− mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT{sub 3}) receptor antagonists, such as ondansetron, should be investigated in patients. - Highlights: • Nephrotoxicity significantly limits clinical use of the chemotherapeutic cisplatin. • The antiemetic ondansetron is frequently co-administrated with cisplatin. • Ondansetron was here demonstrated as a potent inhibitor of MATE transporters. • Ondansetron enhanced cisplatin nephrotoxicity likely via Mate1 inhibition in mice. • Ondansetron may increase patient risk of nephrotoxicity in cisplatin chemotherapy.« less

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

Assessment of generalizability, applicability and predictability (GAP) for evaluating external validity in studies of universal family-based prevention of alcohol misuse in young people: systematic methodological review of randomized controlled trials.

PubMed

Fernandez-Hermida, Jose Ramon; Calafat, Amador; Becoña, Elisardo; Tsertsvadze, Alexander; Foxcroft, David R

2012-09-01

To assess external validity characteristics of studies from two Cochrane Systematic Reviews of the effectiveness of universal family-based prevention of alcohol misuse in young people. Two reviewers used an a priori developed external validity rating form and independently assessed three external validity dimensions of generalizability, applicability and predictability (GAP) in randomized controlled trials. The majority (69%) of the included 29 studies were rated 'unclear' on the reporting of sufficient information for judging generalizability from sample to study population. Ten studies (35%) were rated 'unclear' on the reporting of sufficient information for judging applicability to other populations and settings. No study provided an assessment of the validity of the trial end-point measures for subsequent mortality, morbidity, quality of life or other economic or social outcomes. Similarly, no study reported on the validity of surrogate measures using established criteria for assessing surrogate end-points. Studies evaluating the benefits of family-based prevention of alcohol misuse in young people are generally inadequate at reporting information relevant to generalizability of the findings or implications for health or social outcomes. Researchers, study authors, peer reviewers, journal editors and scientific societies should take steps to improve the reporting of information relevant to external validity in prevention trials. © 2012 The Authors. Addiction © 2012 Society for the Study of Addiction.

Effect of yerba mate (Ilex paraguariensis) extract on the metabolism of diabetic rats.

PubMed

Rocha, Débora Santos; Casagrande, Lucas; Model, Jorge Felipe Argenta; Dos Santos, Jordana Tres; Hoefel, Ana Lúcia; Kucharski, Luiz Carlos

2018-06-01

The relationship between metabolic disturbances and clinical events related to diabetes is well known. Yerba mate has presented a potential use as preventive and therapeutic agent on diabetes. The aim of this study was to evaluate the effect of yerba mate on different tissues of diabetic rats, focusing on energetic metabolism. Diabetes was induced by streptozotocin, followed by daily yerba mate treatment. After 30 days, the animals were euthanized to evaluate metabolic parameters on liver, adipose tissue, muscle and serum. The results showed mate treatment promoted a decrease in retroperitoneal adipose tissue in healthy animals. Muscle weight returned to control levels in diabetic rats treated with mate. There was improvement on serum glucose, creatinine, urea and total protein levels associated with mate treatment. Muscle parameters, such as glucose uptake and carbon dioxide production, were improved by mate treatment to control levels. The results evidenced the beneficial actions mate can have on metabolic disturbances of diabetes. Copyright © 2018. Published by Elsevier Masson SAS.

Biased learning affects mate choice in a butterfly.

PubMed

Westerman, Erica L; Hodgins-Davis, Andrea; Dinwiddie, April; Monteiro, Antónia

2012-07-03

Early acquisition of mate preferences or mate-preference learning is associated with signal diversity and speciation in a wide variety of animal species. However, the diversity of mechanisms of mate-preference learning across taxa remains poorly understood. Using the butterfly Bicyclus anynana we uncover a mechanism that can lead to directional sexual selection via mate-preference learning: a bias in learning enhanced ornamentation, which is independent of preexisting mating biases. Naïve females mated preferentially with wild-type males over males with enhanced wing ornamentation, but females briefly exposed to enhanced males mated significantly more often with enhanced males. In contrast, females exposed to males with reduced wing ornamentation did not learn to prefer drab males. Thus, we observe both a learned change of a preexisting mating bias, and a bias in ability to learn enhanced male ornaments over reduced ornaments. Our findings demonstrate that females are able to change their preferences in response to a single social event, and suggest a role for biased learning in the evolution of visual sexual ornamentation.

The PEDro scale had acceptably high convergent validity, construct validity, and interrater reliability in evaluating methodological quality of pharmaceutical trials.

PubMed

Yamato, Tie Parma; Maher, Chris; Koes, Bart; Moseley, Anne

2017-06-01

The Physiotherapy Evidence Database (PEDro) scale has been widely used to investigate methodological quality in physiotherapy randomized controlled trials; however, its validity has not been tested for pharmaceutical trials. The aim of this study was to investigate the validity and interrater reliability of the PEDro scale for pharmaceutical trials. The reliability was also examined for the Cochrane Back and Neck (CBN) Group risk of bias tool. This is a secondary analysis of data from a previous study. We considered randomized placebo controlled trials evaluating any pain medication for chronic spinal pain or osteoarthritis. Convergent validity was evaluated by correlating the PEDro score with the summary score of the CBN risk of bias tool. The construct validity was tested using a linear regression analysis to determine the degree to which the total PEDro score is associated with treatment effect sizes, journal impact factor, and the summary score for the CBN risk of bias tool. The interrater reliability was estimated using the Prevalence and Bias Adjusted Kappa coefficient and 95% confidence interval (CI) for the PEDro scale and CBN risk of bias tool. Fifty-three trials were included, with 91 treatment effect sizes included in the analyses. The correlation between PEDro scale and CBN risk of bias tool was 0.83 (95% CI 0.76-0.88) after adjusting for reliability, indicating strong convergence. The PEDro score was inversely associated with effect sizes, significantly associated with the summary score for the CBN risk of bias tool, and not associated with the journal impact factor. The interrater reliability for each item of the PEDro scale and CBN risk of bias tool was at least substantial for most items (>0.60). The intraclass correlation coefficient for the PEDro score was 0.80 (95% CI 0.68-0.88), and for the CBN, risk of bias tool was 0.81 (95% CI 0.69-0.88). There was evidence for the convergent and construct validity for the PEDro scale when used to evaluate methodological quality of pharmacological trials. Both risk of bias tools have acceptably high interrater reliability. Copyright © 2017 Elsevier Inc. All rights reserved.

Validation of Immunohistochemical Assays for Integral Biomarkers in the NCI-MATCH EAY131 Clinical Trial.

PubMed

Khoury, Joseph D; Wang, Wei-Lien; Prieto, Victor G; Medeiros, L Jeffrey; Kalhor, Neda; Hameed, Meera; Broaddus, Russell; Hamilton, Stanley R

2018-02-01

Biomarkers that guide therapy selection are gaining unprecedented importance as targeted therapy options increase in scope and complexity. In conjunction with high-throughput molecular techniques, therapy-guiding biomarker assays based upon immunohistochemistry (IHC) have a critical role in cancer care in that they inform about the expression status of a protein target. Here, we describe the validation procedures for four clinical IHC biomarker assays-PTEN, RB, MLH1, and MSH2-for use as integral biomarkers in the nationwide NCI-Molecular Analysis for Therapy Choice (NCI-MATCH) EAY131 clinical trial. Validation procedures were developed through an iterative process based on collective experience and adaptation of broad guidelines from the FDA. The steps included primary antibody selection; assay optimization; development of assay interpretation criteria incorporating biological considerations; and expected staining patterns, including indeterminate results, orthogonal validation, and tissue validation. Following assay lockdown, patient samples and cell lines were used for analytic and clinical validation. The assays were then approved as laboratory-developed tests and used for clinical trial decisions for treatment selection. Calculations of sensitivity and specificity were undertaken using various definitions of gold-standard references, and external validation was required for the PTEN IHC assay. In conclusion, validation of IHC biomarker assays critical for guiding therapy in clinical trials is feasible using comprehensive preanalytic, analytic, and postanalytic steps. Implementation of standardized guidelines provides a useful framework for validating IHC biomarker assays that allow for reproducibility across institutions for routine clinical use. Clin Cancer Res; 24(3); 521-31. ©2017 AACR . ©2017 American Association for Cancer Research.

Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors.

PubMed

Marcela, P; Hassan, A Abu; Hamdan, A; Dieng, H; Kumara, T K

2015-12-01

Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs.

One-shot genitalia are not an evolutionary dead end - Regained male polygamy in a sperm limited spider species

PubMed Central

2011-01-01

Background Monogynous mating systems with extremely low male mating rates have several independent evolutionary origins and are associated with drastic adaptations involving self-sacrifice, one-shot genitalia, genital damage, and termination of spermatogenesis immediately after maturation. The combination of such extreme traits likely restricts evolutionary potential perhaps up to the point of making low male mating rates irreversible and hence may constitute an evolutionary dead end. Here, we explore the case of a reversion to multiple mating from monogynous ancestry in golden orb-web spiders, Nephila senegalensis. Results Male multiple mating is regained by the loss of genital damage and sexual cannibalism but spermatogenesis is terminated with maturation, restricting males to a single loading of their secondary mating organs and a fixed supply of sperm. However, males re-use their mating organs and by experimentally mating males to many females, we show that the sperm supply is divided between copulations without reloading the pedipalps. Conclusion By portioning their precious sperm supply, males achieve an average mating rate of four females which effectively doubles the maximal mating rate of their ancestors. A heritage of one-shot genitalia does not completely restrict the potential to increase mating rates in Nephila although an upper limit is defined by the available sperm load. Future studies should now investigate how males use this potential in the field and identify selection pressures responsible for a reversal from monogynous to polygynous mating strategies. PMID:21740561

Evolution of mating systems in coral reef gobies and constraints on mating system plasticity

NASA Astrophysics Data System (ADS)

Hernaman, V.; Munday, P. L.

2007-09-01

Social and mating systems can be influenced by the distribution, abundance, and economic defendability of breeding partners and essential resources. Polygyny is predicted where males can economically defend multiple females or essential resources used by females. In contrast, monogamy is predicted where neither sex can monopolise multiple partners, either directly or through resource control, but where one mate is economically defendable. The mating system and reproductive behaviour of five species of coral reef goby were investigated and contrasted with population density and individual mobility. The two most abundant species ( Asterropteryx semipunctatus and Istigobius goldmanni) were polygynous. In contrast, the less populous and more widely dispersed epibenthic species ( Amblygobius bynoensis, Amblygobius phalaena and Valenciennea muralis) were pair forming and monogamous. All five species had low mobility, mostly remaining within metres (3 epibenthic species) or centimetres (2 cryptobenthic species) of a permanent shelter site. Interspecific differences in the mating system may have been shaped by differences in population density and the ability of reproductive individuals to economically defend breeding partners/sites. However, in a test of mating system plasticity, males of the three monogamous species did not mate polygynously when given the opportunity to do so in experimental manipulations of density and sex ratio. Mate guarding and complex spawning characteristics, which have likely co-evolved with the monogamous mating system, could contribute to mating system inflexibility by making polygynous mating unprofitable for individuals of the pair forming species, even when presented with current-day ecological conditions that usually favour polygyny.

Why Do Female Callosobruchus maculatus Kick Their Mates?

PubMed Central

van Lieshout, Emile; McNamara, Kathryn B.; Simmons, Leigh W.

2014-01-01

Sexual conflict is now recognised as an important driver of sexual trait evolution. However, due to their variable outcomes and effects on other fitness components, the detection of sexual conflicts on individual traits can be complicated. This difficulty is exemplified in the beetle Callosobruchus maculatus, where longer matings increase the size of nutritious ejaculates but simultaneously reduce female future receptivity. While previous studies show that females gain direct benefits from extended mating duration, females show conspicuous copulatory kicking behaviour, apparently to dislodge mating males prematurely. We explore the potential for sexual conflict by comparing several fitness components and remating propensity in pairs of full sibling females where each female mated with a male from an unrelated pair of full sibling males. For one female, matings were terminated at the onset of kicking, whereas the other’s matings remained uninterrupted. While fecundity (number of eggs) was similar between treatments, uninterrupted matings enhanced adult offspring numbers and fractionally also longevity. However, females whose matings were interrupted at the onset of kicking exhibited an increased propensity to remate. Since polyandry can benefit female fitness in this species, we argue that kicking, rather than being maladaptive, may indicate that females prefer remating over increased ejaculate size. It may thus be difficult to assess the presence of sexual conflict over contested traits such as mating duration when females face a trade off between direct benefits gained from one mating and indirect benefits from additional matings. PMID:24752530

Male resource defense mating system in primates? An experimental test in wild capuchin monkeys.

PubMed

Tiddi, Barbara; Heistermann, Michael; Fahy, Martin K; Wheeler, Brandon C

2018-01-01

Ecological models of mating systems provide a theoretical framework to predict the effect of the defendability of both breeding resources and mating partners on mating patterns. In resource-based mating systems, male control over breeding resources is tightly linked to female mating preference. To date, few field studies have experimentally investigated the relationship between male resource control and female mating preference in mammals due to difficulties in manipulating ecological factors (e.g., food contestability). We tested the within-group male resource defense hypothesis experimentally in a wild population of black capuchin monkeys (Sapajus nigritus) in Iguazú National Park, Argentina. Sapajus spp. represent an ideal study model as, in contrast to most primates, they have been previously argued to be characterized by female mate choice and a resource-based mating system in which within-group resource monopolization by high-ranking males drives female mating preference for those males. Here, we examined whether females (N = 12) showed a weaker preference for alpha males during mating seasons in which food distribution was experimentally manipulated to be less defendable relative to those in which it was highly defendable. Results did not support the within-group male resource defense hypothesis, as female sexual preferences for alpha males did not vary based on food defendability. We discuss possible reasons for our results, including the possibility of other direct and indirect benefits females receive in exercising mate choice, the potential lack of tolerance over food directed towards females by alpha males, and phylogenetic constraints.

One-shot genitalia are not an evolutionary dead end - regained male polygamy in a sperm limited spider species.

PubMed

Schneider, Jutta M; Michalik, Peter

2011-07-08

Monogynous mating systems with extremely low male mating rates have several independent evolutionary origins and are associated with drastic adaptations involving self-sacrifice, one-shot genitalia, genital damage, and termination of spermatogenesis immediately after maturation. The combination of such extreme traits likely restricts evolutionary potential perhaps up to the point of making low male mating rates irreversible and hence may constitute an evolutionary dead end. Here, we explore the case of a reversion to multiple mating from monogynous ancestry in golden orb-web spiders, Nephila senegalensis. Male multiple mating is regained by the loss of genital damage and sexual cannibalism but spermatogenesis is terminated with maturation, restricting males to a single loading of their secondary mating organs and a fixed supply of sperm. However, males re-use their mating organs and by experimentally mating males to many females, we show that the sperm supply is divided between copulations without reloading the pedipalps. By portioning their precious sperm supply, males achieve an average mating rate of four females which effectively doubles the maximal mating rate of their ancestors. A heritage of one-shot genitalia does not completely restrict the potential to increase mating rates in Nephila although an upper limit is defined by the available sperm load. Future studies should now investigate how males use this potential in the field and identify selection pressures responsible for a reversal from monogynous to polygynous mating strategies.

CT114 Lap Belt Arming Key Mod - User Trial

DTIC Science & Technology

2010-05-01

31 (97%) 30 (94%) 1. Ease of use to perform visual 30 (94%) 2. Ease of use to perform free play (push past) check 31 (97%) ’Note I - If a...positive lock of the lap belt. 10. Perform Free Play (Push Past) Check - Press mating ends of lap belt fittings together to demo ability to push beyond...the following items. I 2 3 4 5 6 7 37. Ease-of·use in performing visual check? 0 0 0 0 0 0 0 38. Ease-of·use in performing free play (push past

Cryptic breakpoint identified by whole-genome mate-pair sequencing in a rare paternally inherited complex chromosomal rearrangement.

PubMed

Aristidou, Constantia; Theodosiou, Athina; Ketoni, Andria; Bak, Mads; Mehrjouy, Mana M; Tommerup, Niels; Sismani, Carolina

2018-01-01

Precise characterization of apparently balanced complex chromosomal rearrangements in non-affected individuals is crucial as they may result in reproductive failure, recurrent miscarriages or affected offspring. We present a family, where the non-affected father and daughter were found, using FISH and karyotyping, to be carriers of a three-way complex chromosomal rearrangement [t(6;7;10)(q16.2;q34;q26.1), de novo in the father]. The family suffered from two stillbirths, one miscarriage, and has a son with severe intellectual disability. In the present study, the family was revisited using whole-genome mate-pair sequencing. Interestingly, whole-genome mate-pair sequencing revealed a cryptic breakpoint on derivative (der) chromosome 6 rendering the rearrangement even more complex. FISH using a chromosome (chr) 6 custom-designed probe and a chr10 control probe confirmed that the interstitial chr6 segment, created by the two chr6 breakpoints, was translocated onto der(10). Breakpoints were successfully validated with Sanger sequencing, and small imbalances as well as microhomology were identified. Finally, the complex chromosomal rearrangement breakpoints disrupted the SIM1 , GRIK2 , CNTNAP2 , and PTPRE genes without causing any phenotype development. In contrast to the majority of maternally transmitted complex chromosomal rearrangement cases, our study investigated a rare case where a complex chromosomal rearrangement, which most probably resulted from a Type IV hexavalent during the pachytene stage of meiosis I, was stably transmitted from a fertile father to his non-affected daughter. Whole-genome mate-pair sequencing proved highly successful in identifying cryptic complexity, which consequently provided further insight into the meiotic segregation of chromosomes and the increased reproductive risk in individuals carrying the specific complex chromosomal rearrangement. We propose that such complex rearrangements should be characterized in detail using a combination of conventional cytogenetic and NGS-based approaches to aid in better prenatal preimplantation genetic diagnosis and counseling in couples with reproductive problems.

Life history changes in Trogoderma variabile and T. inclusum due to mating delay with implications for mating disruption as a management tactic

USDA-ARS?s Scientific Manuscript database

Controlling postharvest pest species is a costly process with insecticide resistance and species specific control requiring multiple tactics. Mating disruption can be used to both decrease a female’s access to males and delay timing of mating and decreases overall mating success in a population and ...

Sexual conflict over mating in Gnatocerus cornutus? Females prefer lovers not fighters.

PubMed

Okada, Kensuke; Katsuki, Masako; Sharma, Manmohan D; House, Clarissa M; Hosken, David J

2014-06-22

Female mate choice and male-male competition are the typical mechanisms of sexual selection. However, these two mechanisms do not always favour the same males. Furthermore, it has recently become clear that female choice can sometimes benefit males that reduce female fitness. So whether male-male competition and female choice favour the same or different males, and whether or not females benefit from mate choice, remain open questions. In the horned beetle, Gnatocerus cornutus, males have enlarged mandibles used to fight rivals, and larger mandibles provide a mating advantage when there is direct male-male competition for mates. However, it is not clear whether females prefer these highly competitive males. Here, we show that female choice targets male courtship rather than mandible size, and these two characters are not phenotypically or genetically correlated. Mating with attractive, highly courting males provided indirect benefits to females but only via the heritability of male attractiveness. However, mating with attractive males avoids the indirect costs to daughters that are generated by mating with competitive males. Our results suggest that male-male competition may constrain female mate choice, possibly reducing female fitness and generating sexual conflict over mating.

Sexual Experience Enhances Drosophila melanogaster Male Mating Behavior and Success

PubMed Central

Saleem, Sehresh; Ruggles, Patrick H.; Abbott, Wiley K.; Carney, Ginger E.

2014-01-01

Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments. PMID:24805129

Exploiting a moment of weakness: male spiders escape sexual cannibalism by copulating with moulting females.

PubMed

Uhl, Gabriele; Zimmer, Stefanie M; Renner, Dirk; Schneider, Jutta M

2015-11-26

Sexual cannibalism is a particularly extreme example of conflict between the sexes, depriving the male of future reproduction. Theory predicts that sexual conflict should induce counter-adaptations in the victim. Observations of male spiders mating with moulting and hence largely immobile females suggest that this behaviour functions to circumvent female control and cannibalism. However, we lack quantitative estimates of natural frequencies and fitness consequences of these unconventional matings. To understand the importance of mating while moulting in cannibalistic mating systems, we combined mating experiments and paternity assessment in the laboratory with extensive field observations using the sexually cannibalistic orb-web spider Argiope bruennichi. Copulations with moulting females resulted in 97% male survival compared with only 20% in conventional matings. Mating while moulting provided similar paternity benefits compared with conventional matings. Our findings support the hypothesis that mating with moulting females evolved under sexual conflict and safely evades sexual cannibalism. Despite male benefits, natural frequencies were estimated around 44% and directly predicted by a male guarding a subadult female. Since only adult females signal their presence, the difficulty for males to locate subadult females might limit further spreading of mating with moulting females.

Exploiting a moment of weakness: male spiders escape sexual cannibalism by copulating with moulting females

PubMed Central

Uhl, Gabriele; Zimmer, Stefanie M.; Renner, Dirk; Schneider, Jutta M.

2015-01-01

Sexual cannibalism is a particularly extreme example of conflict between the sexes, depriving the male of future reproduction. Theory predicts that sexual conflict should induce counter-adaptations in the victim. Observations of male spiders mating with moulting and hence largely immobile females suggest that this behaviour functions to circumvent female control and cannibalism. However, we lack quantitative estimates of natural frequencies and fitness consequences of these unconventional matings. To understand the importance of mating while moulting in cannibalistic mating systems, we combined mating experiments and paternity assessment in the laboratory with extensive field observations using the sexually cannibalistic orb-web spider Argiope bruennichi. Copulations with moulting females resulted in 97% male survival compared with only 20% in conventional matings. Mating while moulting provided similar paternity benefits compared with conventional matings. Our findings support the hypothesis that mating with moulting females evolved under sexual conflict and safely evades sexual cannibalism. Despite male benefits, natural frequencies were estimated around 44% and directly predicted by a male guarding a subadult female. Since only adult females signal their presence, the difficulty for males to locate subadult females might limit further spreading of mating with moulting females. PMID:26607497

Sexual conflict over mating in a spider: increased fecundity does not compensate for the costs of polyandry.

PubMed

Maklakov, Alexei A; Lubin, Yael

2004-05-01

Female multiple mating (polyandry) is a widespread but costly behavior that remains poorly understood. Polyandry may arise when whatever benefits females accrue from multiple mating outweigh the costs, or males manipulate females against the females' best interests. In a polyandrous spider Stegodyphus lineatus females may mate with up to five males, but behave aggressively toward additional males after the first mating. Female aggressiveness may act to select for better quality males. Alternatively, females may try to avoid superfluous matings. To test these alternatives, we allocated females into single-mating (SM) and double-mating treatments. Double-mated females either accepted (DM) or rejected (RE) the second male. DM females laid more eggs, but did not produce more offspring than SM and RE females. Offspring of DM females were smaller at dispersal than offspring of SM and RE females. Also, nest failure was significantly more common in DM females. Paternal variables did not influence female reproductive success, whereas maternal body condition explained much of the variation. We show that polyandry is costly for females despite the production of larger clutches and suggest that multiple mating results from male manipulation of female remating behavior.

Genetic effects on mating success and partner choice in a social mammal

PubMed Central

Tung, Jenny; Charpentier, Marie JE; Mukherjee, Sayan; Altmann, Jeanne; Alberts, Susan C

2012-01-01

Mating behavior has profound consequences for two phenomena – individual reproductive success and the maintenance of species boundaries – that contribute to evolutionary processes. Studies of mating behavior in relation to individual reproductive success are common in many species, but studies of mating behavior in relation to genetic variation and species boundaries are less commonly conducted in socially complex species. Here, we leveraged extensive observations of a wild yellow baboon (Papio cynocephalus) population that has experienced recent gene flow from a close sister taxon, the anubis baboon (Papio anubis), to examine how admixture-related genetic background affects mating behavior. We identified novel effects of genetic background on mating patterns, including an advantage accruing to anubis-like males and assortative mating among both yellow-like and anubis-like pairs. These genetic effects acted alongside social dominance rank, inbreeding avoidance, and age to produce highly nonrandom mating patterns. Our results suggest that this population may be undergoing admixture-related evolutionary change, driven in part by nonrandom mating. However, the strength of the genetic effects is mediated by behavioral plasticity and social interactions, emphasizing the strong influence of social context on mating behavior in socially complex species. PMID:22673655

Lack of behavioural evidence for kin avoidance in mate choice in a hymenopteran parasitoid (Hymenoptera: Braconidae).

PubMed

Bourdais, D; Hance, T

2009-05-01

Mechanisms for inbreeding avoidance should be prevalent in insects that reproduce by arrhenotokous haplodiploidy because of the higher potential production of unviable diploid males in inbred matings. Few studies have focused on mating strategies in insect parasitoids and even less on kinship relationships during mate choice. In this study we tested avoidance of kin as mate in the parasitic wasp Aphidius matricariae (Hymenoptera: Braconidae) using an ethological approach. Key mating parameters, such as male wing fanning, latent period before genitalia contact and duration of copulation were measured. No evidence for kin avoidance in mate choice in both A. matricariae males and females was observed in our behaviour (no choice or choice tests) tests. This lack of ethological sib mating avoidance could be due to different factors such as sex determination rule different than the single locus complementary sex determination, making lower the proportion of diploid males in case of sib matings and thus its negative consequence. The existence of other inbreeding avoidance strategies and mechanisms that reduce the probability of 2 receptive relatives meeting in nature may be common, for example, inbred mating may be rare through differential dispersal, delayed maturation, or protandry.

Weighing costs and benefits of mating in bushcrickets (Insecta: Orthoptera: Tettigoniidae), with an emphasis on nuptial gifts, protandry and mate density

PubMed Central

2012-01-01

Sexual selection is a major force driving evolution and is intertwined with ecological factors. Differential allocation of limited resources has a central role in the cost of reproduction. In this paper, I review the costs and benefits of mating in tettigoniids, focussing on nuptial gifts, their trade-off with male calling songs, protandry and how mate density influences mate choice. Tettigoniids have been widely used as model systems for studies of mating costs and benefits; they can provide useful general insights. The production and exchange of large nuptial gifts by males for mating is an important reproductive strategy in tettigoniids. As predicted by sexual selection theory spermatophylax size is condition dependent and is constrained by the need to invest in calling to attract mates also. Under some circumstances, females benefit directly from the nuptial gifts by an increase in reproductive output. However, compounds in the nuptial gift can also benefit the male by prolonging the period before the female remates. There is also a trade-off between adult male maturation and mating success. Where males mature before females (protandry) the level of protandry varies in the direction predicted by sperm competition theory; namely, early male maturation is correlated with a high level of first inseminations being reproductively successful. Lastly, mate density in bushcrickets is an important environmental factor influencing the behavioural decisions of individuals. Where mates are abundant, individuals are more choosey of mates; when they are scarce, individuals are less choosey. This review reinforces the view that tettigoniids provide excellent models to test and understand the economics of matings in both sexes. PMID:22894685

Validation of the DIFFAL, HPAC and HotSpot Dispersion Models Using the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials Witness Plate Deposition Dataset.

PubMed

Purves, Murray; Parkes, David

2016-05-01

Three atmospheric dispersion models--DIFFAL, HPAC, and HotSpot--of differing complexities have been validated against the witness plate deposition dataset taken during the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials. The small-scale nature of these trials in comparison to many other historical radiological dispersion trials provides a unique opportunity to evaluate the near-field performance of the models considered. This paper performs validation of these models using two graphical methods of comparison: deposition contour plots and hotline profile graphs. All of the models tested are assessed to perform well, especially considering that previous model developments and validations have been focused on larger-scale scenarios. Of the models, HPAC generally produced the most accurate results, especially at locations within ∼100 m of GZ. Features present within the observed data, such as hot spots, were not well modeled by any of the codes considered. Additionally, it was found that an increase in the complexity of the meteorological data input to the models did not necessarily lead to an improvement in model accuracy; this is potentially due to the small-scale nature of the trials.

Can jurors recognize missing control groups, confounds, and experimenter bias in psychological science?

PubMed

McAuliff, Bradley D; Kovera, Margaret Bull; Nunez, Gabriel

2009-06-01

This study examined the ability of jury-eligible community members (N = 248) to detect internal validity threats in psychological science presented during a trial. Participants read a case summary in which an expert testified about a study that varied in internal validity (valid, missing control group, confound, and experimenter bias) and ecological validity (high, low). Ratings of expert evidence quality and expert credibility were higher for the valid versus missing control group versions only. Internal validity did not influence verdict or ratings of plaintiff credibility and no differences emerged as a function of ecological validity. Expert evidence quality, expert credibility, and plaintiff credibility were positively correlated with verdict. Implications for the scientific reasoning literature and for trials containing psychological science are discussed.

Mechanisms of sleep plasticity due to sexual experience in Drosophila melanogaster.

PubMed

Dove, Abigail E; Cook, Brianne L; Irgebay, Zhazira; Vecsey, Christopher G

2017-10-15

Sleep can be altered by an organism's previous experience. For instance, female Drosophila melanogaster experience a post-mating reduction in daytime sleep that is purportedly mediated by sex peptide (SP), one of many seminal fluid proteins (SFPs) transferred from male to female during mating. In the present study, we first characterized this mating effect on sleep more fully, as it had previously only been tested in young flies under 12h light/12h dark conditions. We found that mating reduced sleep equivalently in 3-day-old or 14-day-old females, and could even occur in females who had been mated previously, suggesting that there is not a developmental critical period for the suppression of sleep by mating. In conditions of constant darkness, circadian rhythms were not affected by prior mating. In either constant darkness or constant light, the sleep reduction due to mating was no longer confined to the subjective day but could be observed throughout the 24-hour period. This suggests that the endogenous clock may dictate the timing of when the mating effect on sleep is expressed. We recently reported that genetic elimination of SP only partially blocked the post-mating female siesta sleep reduction, suggesting that the effect was unlikely to be governed solely by SP. We found here that the daytime sleep reduction was also reduced but not eliminated in females mated to mutant males lacking the vast majority of SFPs. This suggested that SFPs other than SP play a minimal role in the mating effect on sleep, and that additional non-SFP signals from the male might be involved. Males lacking sperm were able to induce a normal initial mating effect on female sleep, although the effect declined more rapidly in these females. This result indicated that neither the presence of sperm within the female reproductive tract nor female impregnation are required for the initial mating effect on sleep to occur, although sperm may serve to prolong the effect. Finally, we tested for contributions from other aspects of the mating experience. NorpA and eya2 mutants with disrupted vision showed normal mating effects on sleep. By separating males from females with a mesh, we found that visual and olfactory stimuli from male exposure, in the absence of physical contact, could not replicate the mating effect. Further, in ken/barbie male flies lacking external genitalia, courtship and physical contact without ejaculation were also unable to replicate the mating effect. These findings confirmed that the influence of mating on sleep does in fact require male/female contact including copulation, but may not be mediated exclusively by SP transfer. Copyright © 2017 Elsevier Inc. All rights reserved.

Reliability and Validity of Objective Measures of Physical Activity in Youth With Cerebral Palsy Who Are Ambulatory.

PubMed

O'Neil, Margaret E; Fragala-Pinkham, Maria; Lennon, Nancy; George, Ameeka; Forman, Jeffrey; Trost, Stewart G

2016-01-01

Physical therapy for youth with cerebral palsy (CP) who are ambulatory includes interventions to increase functional mobility and participation in physical activity (PA). Thus, reliable and valid measures are needed to document PA in youth with CP. The purpose of this study was to evaluate the inter-instrument reliability and concurrent validity of 3 accelerometer-based motion sensors with indirect calorimetry as the criterion for measuring PA intensity in youth with CP. Fifty-seven youth with CP (mean age=12.5 years, SD=3.3; 51% female; 49.1% with spastic hemiplegia) participated. Inclusion criteria were: aged 6 to 20 years, ambulatory, Gross Motor Function Classification System (GMFCS) levels I through III, able to follow directions, and able to complete the full PA protocol. Protocol activities included standardized activity trials with increasing PA intensity (resting, writing, household chores, active video games, and walking at 3 self-selected speeds), as measured by weight-relative oxygen uptake (in mL/kg/min). During each trial, participants wore bilateral accelerometers on the upper arms, waist/hip, and ankle and a portable indirect calorimeter. Intraclass coefficient correlations (ICCs) were calculated to evaluate inter-instrument reliability (left-to-right accelerometer placement). Spearman correlations were used to examine concurrent validity between accelerometer output (activity and step counts) and indirect calorimetry. Friedman analyses of variance with post hoc pair-wise analyses were conducted to examine the validity of accelerometers to discriminate PA intensity across activity trials. All accelerometers exhibited excellent inter-instrument reliability (ICC=.94-.99) and good concurrent validity (rho=.70-.85). All accelerometers discriminated PA intensity across most activity trials. This PA protocol consisted of controlled activity trials. Accelerometers provide valid and reliable measures of PA intensity among youth with CP. © 2016 American Physical Therapy Association.

Sperm precedence in female apple maggots alternately mated to normal and irradiated males

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, H.S.; Barry, B.D.; Burnside, J.A.

1976-01-15

A dose of irradiation (Cesium 137) of 3 krad was sufficient to sterilize both sexes of the apple maggot, Rhagoletis pomonella (Walsh). When the irradiated male (IM) mated with normal female (NF), egg production was not reduced compared with a normal mating, but the eggs were not viable. Also, two matings of 1 NF with either 2 IM or with 1 NM and 1 IM, produced fewer eggs than a single mating with 1 normal male. Sperm precedence exhibited for the 2nd of the 2 matings was not complete.

Spatial distribution and male mating success of Anopheles gambiae swarms

PubMed Central

2011-01-01

Background Anopheles gambiae mates in flight at particular mating sites over specific landmarks known as swarm markers. The swarms are composed of males; females typically approach a swarm, and leave in copula. This mating aggregation looks like a lek, but appears to lack the component of female choice. To investigate the possible mechanisms promoting the evolution of swarming in this mosquito species, we looked at the variation in mating success between swarms and discussed the factors that structure it in light of the three major lekking models, known as the female preference model, the hotspot model, and the hotshot model. Results We found substantial variation in swarm size and in mating success between swarms. A strong correlation between swarm size and mating success was observed, and consistent with the hotspot model of lek formation, the per capita mating success of individual males did not increase with swarm size. For the spatial distribution of swarms, our results revealed that some display sites were more attractive to both males and females and that females were more attracted to large swarms. While the swarm markers we recognize help us in localizing swarms, they did not account for the variation in swarm size or in the swarm mating success, suggesting that mosquitoes probably are attracted to these markers, but also perceive and respond to other aspects of the swarming site. Conclusions Characterizing the mating system of a species helps understand how this species has evolved and how selective pressures operate on male and female traits. The current study looked at male mating success of An. gambiae and discussed possible factors that account for its variation. We found that swarms of An. gambiae conform to the hotspot model of lek formation. But because swarms may lack the female choice component, we propose that the An. gambiae mating system is a lek-like system that incorporates characteristics pertaining to other mating systems such as scramble mating competition. PMID:21711542

Two MATE Transporters with Different Subcellular Localization are Involved in Al Tolerance in Buckwheat.

PubMed

Lei, Gui Jie; Yokosho, Kengo; Yamaji, Naoki; Ma, Jian Feng

2017-12-01

Buckwheat (Fagopyrum esculentum) shows high tolerance to aluminum (Al) toxicity, but the molecular mechanisms responsible for this high Al tolerance are still poorly understood. Here, we investigated the involvement of two MATE (multi-drug and toxic compound extrusion) genes in Al tolerance. Both FeMATE1 and FeMATE2 showed efflux transport activity for citrate, but not for oxalate when expressed in Xenopus oocytes. A transient assay with buckwheat leaf protoplasts using green fluorescent protein (GFP) fusion showed that FeMATE1 was mainly localized to the plasma membrane, whereas FeMATE2 was localized to the trans-Golgi and Golgi. The expression of FeMATE1 was induced by Al only in the roots, but that of FeMATE2 was up-regulated in both the roots and leaves. Furthermore, the expression of both genes only responded to Al toxicity, but not to other stresses including low pH, cadmium (Cd) and lanthanum (La). Heterologous expression of FeMATE1 or FeMATE2 in the Arabidopsis mutant atmate partially rescued its Al tolerance. Expression of FeMATE1 also partially recovered the Al-induced secretion of citrate in the transgenic lines, whereas expression of FeMATE2 did not complement the citrate secretion. Further physiological analysis showed that buckwheat roots also secreted citrate in addition to oxalate in response to Al in a dose-responsive manner. Taken together, our results indicate that FeMATE1 is involved in the Al-activated citrate secretion in the roots, while FeMATE2 is probably responsible for transporting citrate into the Golgi system for the internal detoxification of Al in the roots and leaves of buckwheat. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Inhibition of OCT2, MATE1 and MATE2-K as a possible mechanism of drug interaction between pazopanib and cisplatin.

PubMed

Sauzay, C; White-Koning, M; Hennebelle, I; Deluche, T; Delmas, C; Imbs, D C; Chatelut, E; Thomas, F

2016-08-01

We hypothesized that pazopanib is an inhibitor of cisplatin renal transporters OCT2, MATE1 and MATE2-K based on previous studies demonstrating an interaction between tyrosine kinase inhibitors and these transporters. Because several combinations of targeted therapies and cytotoxics are currently in development for cancer treatment, such an interaction is worth investigating. Experiments on HEK293 cells stably transfected to express OCT2, MATE1, MATE2-K or an empty vector (EV) were conducted. The inhibitory effect of pazopanib on these transporters was measured using the uptake of fluorescent substrate ASP+ and cisplatin in the different cell lines. The effect of pazopanib on cisplatin-induced cytotoxicity was also evaluated. A decrease of ASP+ uptake was observed in OCT2-HEK, MATE1-HEK and MATE2K-HEK cell lines after addition of pazopanib at increasing concentrations. Pazopanib inhibited cisplatin specific uptake in OCT2-HEK, MATE1-HEK and MATE2K-HEK lines. Cytotoxicity experiments showed that co-incubation of cisplatin with pazopanib multiplied up to 2.7, 2.4 and 1.6 times the EC50 values of cisplatin in OCT2-HEK, MATE1-HEK and MATE2K-HEK cell lines respectively, reaching about the same values as in EV-HEK cells. To conclude, pazopanib inhibits OCT2, MATE1 and MATE2-K, which are involved in cisplatin secretion into urine. The combination of these two drugs may lead to an interaction and increase the cisplatin-induced systemic toxicity. Given the wide variability of plasma pazopanib concentrations observed in vivo, the interaction may occur in a clinical setting, particularly in overexposed patients. The existence of a drug-drug interaction should be investigated when pazopanib is associated with a substrate of these transporters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Promiscuous mating in the harem-roosting fruit bat, Cynopterus sphinx.

PubMed

Garg, Kritika M; Chattopadhyay, Balaji; Doss D, Paramanatha Swami; A K, Vinoth Kumar; Kandula, Sripathi; Ramakrishnan, Uma

2012-08-01

Observations on mating behaviours and strategies guide our understanding of mating systems and variance in reproductive success. However, the presence of cryptic strategies often results in situations where social mating system is not reflective of genetic mating system. We present such a study of the genetic mating system of a harem-forming bat Cynopterus sphinx where harems may not be true indicators of male reproductive success. This temporal study using data from six seasons on paternity reveals that social harem assemblages do not play a role in the mating system, and variance in male reproductive success is lower than expected assuming polygynous mating. Further, simulations reveal that the genetic mating system is statistically indistinguishable from promiscuity. Our results are in contrast to an earlier study that demonstrated high variance in male reproductive success. Although an outcome of behavioural mating patterns, standardized variance in male reproductive success (I(m)) affects the opportunity for sexual selection. To gain a better understanding of the evolutionary implications of promiscuity for mammals in general, we compared our estimates of I(m) and total opportunity for sexual selection (I(m) /I(f), where I(f) is standardized variance in female reproductive success) with those of other known promiscuous species. We observed a broad range of I(m) /I(f) values across known promiscuous species, indicating our poor understanding of the evolutionary implications of promiscuous mating. © 2012 Blackwell Publishing Ltd.

Maternal effects on offspring depend on female mating pattern and offspring environment in yellow dung flies.

PubMed

Tregenza, Tom; Wedell, Nina; Hosken, David J; Ward, Paul I

2003-02-01

Direct costs and benefits to females of multiple mating have been shown to have large effects on female fecundity and longevity in several species. However, with the exception of studies examining genetic benefits of polyandry, little attention has been paid to the possible effects on offspring of multiple mating by females. We propose that nongenetic effects of maternal matings on offspring fitness are best viewed in the same context as other maternal phenotype effects on offspring that are well known even in species lacking parental care. Hence, matings can exert effects on offspring in the same way as other maternal environment variables, and are likely to interact with such effects. We have conducted a study using yellow dung flies (Scathophaga stercoraria), in which we independently manipulated female mating rate, number of mates and maternal thermal environment and measured subsequent fecundity, hatching success, and offspring life-history traits. To distinguish between direct effects of matings and potential genetic benefits of polyandry we split broods and reared offspring at three different temperature regimes. This allowed us to demonstrate that although we could not detect any simple benefits or costs to matings, there are effects of maternal environment on offspring and these effects interact with female mating regime affecting offspring fitness. Such interactions between female phenotype and the costs and benefits of matings have potentially broad implications for understanding female behavior.

Mating-type genes from the homothallic fungus Sordaria macrospora are functionally expressed in a heterothallic ascomycete.

PubMed

Pöggeler, S; Risch, S; Kück, U; Osiewacz, H D

1997-10-01

Homokaryons from the homothallic ascomycte Sordaria macrospora are able to enter the sexual pathway and to form fertile fruiting bodies. To analyze the molecular basis of homothallism and to elucidate the role of mating-products during fruiting body development, we cloned and sequenced the entire S. macrospora mating-type locus. Comparison of the Sordaria mating-type locus with mating-type idiomorphs from the heterothallic ascomycetes Neurospora crassa and Podospora anserina revealed that sequences from both idiomorphs (A/a and mat-/mat+, respectively) are contiguous in S. macrospora. DNA sequencing of the S. macrospora mating-type region allowed the identification of four open reading frames (ORFs), which were termed Smt-a1, SmtA-1, SmtA-2 and SmtA-3. While Smt-a1, SmtA-1, and SmtA-2 show strong sequence similarities with the corresponding N. crassa mating-type ORFs, SmtA-3 has a chimeric character. It comprises sequences that are similar to the A and a mating-type idiomorph from N. crassa. To determine functionality of the S. macrospora mating-type genes, we show that all ORFs are transcriptionally expressed. Furthermore, we transformed the S. macrospora mating-type genes into mat- and mat+ strains of the closely related heterothallic fungus P. anserina. The transformation experiments show that mating-type genes from S. macrospora induce fruiting body formation in P. anserina.

Context-dependent female mate choice maintains variation in male sexual activity

PubMed Central

Plath, Martin; Gismann, Jakob; Helfrich, Claudia; Bierbach, David

2017-01-01

The existence of individual variation in males' motivation to mate remains a conundrum as directional selection should favour high mating frequencies. Balancing selection resulting from (context-dependent) female mate choice could contribute to the maintenance of this behavioural polymorphism. In dichotomous choice tests, mosquitofish (Gambusia holbrooki) females preferred virtual males showing intermediate mating frequencies, reflecting females' tendencies to avoid harassment by highly sexually active males. When tested in the presence of a female shoal—which protects females from male harassment—focal females showed significantly stronger preferences for high sexual activity. A trade-off between (indirect) benefits and (direct) costs of mating with sexually active males probably explains context-dependent female mate choice, as costs depend on the social environment in which females choose their mates. No preference was observed when we tested virgin females, suggesting that the behavioural pattern described here is part of the learned behavioural repertoire of G. holbrooki females. PMID:28791157

Extrapair mating between relatives in the barn swallow: a role for kin selection?

PubMed

Kleven, Oddmund; Jacobsen, Frode; Robertson, Raleigh J; Lifjeld, Jan T

2005-12-22

Why do females of many species mate with more than one male? One of the main hypotheses suggests that female promiscuity is an insurance mechanism against the potential detrimental effects of inbreeding. Accordingly, females should preferably mate with less related males in multiple or extrapair mating. Here we analyse paternity, relatedness among mating partners, and relatedness between parents and offspring, in the socially monogamous North American barn swallow (Hirundo rustica erythrogaster). In contrast to the inbreeding avoidance hypothesis, we found that extrapair mating partners were more related than expected by random choice, and tended to be more related than social partners. Furthermore, extrapair mating resulted in genetic parents being more related to their extrapair young than to their withinpair young. We propose a new hypothesis for extrapair mating based on kin selection theory as a possible explanation to these findings.

Biomarkers and surrogate endpoints in glaucoma clinical trials.

PubMed

Medeiros, Felipe A

2015-05-01

Surrogate endpoints are often used as replacements for true clinically relevant endpoints in several areas of medicine, as they enable faster and less expensive clinical trials. However, without proper validation, the use of surrogates may lead to incorrect conclusions about the efficacy and safety of treatments. This article reviews the general requirements for validating surrogate endpoints and provides a critical assessment of the use of intraocular pressure (IOP), visual fields, and structural measurements of the optic nerve as surrogate endpoints in glaucoma clinical trials. A valid surrogate endpoint must be able to predict the clinically relevant endpoint and fully capture the effect of an intervention on that endpoint. Despite its widespread use in clinical trials, no proper validation of IOP as a surrogate endpoint has ever been conducted for any class of IOP-lowering treatments. Evidence has accumulated with regard to the role of imaging measurements of optic nerve damage as surrogate endpoints in glaucoma. These measurements are predictive of functional losses in the disease and may explain, at least in part, treatment effects on clinically relevant endpoints. The use of composite endpoints in glaucoma trials may overcome weaknesses of the use of structural or functional endpoints in isolation. Unless research is dedicated to fully develop and validate suitable endpoints that can be used in glaucoma clinical trials, we run the risk of inappropriate judgments about the value of new therapies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Mating-related behaviour of grizzly bears inhabiting marginal habitat at the periphery of their North American range.

PubMed

Edwards, Mark A; Derocher, Andrew E

2015-02-01

In comparison to core populations, peripheral populations have low density and recruitment, and are subject to different selective pressures, such as environmental conditions, food type and availability, predation, disease, etc., which may result in behavioural modifications to mating. We test the roam-to-mate hypothesis for a peripheral population of grizzly bears (Ursus arctos) at the northern extent of their North American range, in Canada's Arctic. If bears are roaming-to-mate, we predicted greater range size and daily displacement, and more linear movements for receptive animals during the mating period compared to post-mating. In contrast to our predictions, we found that in general range size and displacement increased from mating to post-mating regardless of reproductive status. When considered across both periods, females with cubs-of-the-year had smaller range use metrics than other reproductive groups, which we attribute to a counter-strategy against sexually selected infanticide and the reduced mobility of cubs. Linearity of movements remained near zero during both periods across all groups, suggesting tortuous movements more characteristic of foraging than of mate-searching. We suggest that for this population, finding quality habitat takes precedence over mate-searching in this marginal Arctic landscape. Alternatively, a more monogamous mating system and sequestering behaviour may have obscured movement differences between the two periods. The behavioural differences in mating that we observed from what is typical of core populations may reflect local adaptation to marginal conditions and could benefit the species in the face of ongoing environmental change. Copyright © 2014 Elsevier B.V. All rights reserved.

Non-random pairing in American kestrels: mate choice versus intra-sexual competition

USGS Publications Warehouse

Bortolotti, Gary R.; Iko, William M.

1992-01-01

Natural selection may influence the arrangement of individuals into mated pairs through either inter-sexual (mate choice) or intra-sexual selection (competition). A study of the American kestrel, Falco sparverius, in northern Saskatchewan distinguished between these two processes using size as a measure of the bird's competitive ability, and condition (mass scaled to body size) as an index of quality. Both sexes arrive on the study area after spring migration in equal numbers and males establish territories. Males and females that moved among territories at the time of pair formation were not different in size or condition from those that did not move, suggesting that birds were not being displaced by superior competitors, and that females moved to encounter potential mates. Within mated pairs, there was no relationship between a bird's size and the condition of its mate for either sex as would be predicted if intra-sexual competitition explained mating patterns. Instead, there was positive assortative mating by condition, suggesting that both sexes used quality as the criterion in choosing mates. There was no correlation between the sizes of males and females in mated paird. Because there were no differences in size or condition of breeding and non-breeding males, factors other than physical attributes, such as prior experience with the area, may determine a male's success in obtaining a territory. Because females that did not obtain mates were in poorer condition than those that did, males may have rejected poor quality females. The results suggest that intra-sexual competition was not important for pair formation, and that kestrels chose mates on the basis of quality.

Statistically Valid Planting Trials

Treesearch

C. B. Briscoe

1961-01-01

More than 100 million tree seedlings are planted each year in Latin America, and at least ten time'that many should be planted Rational control and development of a program of such magnitude require establishing and interpreting carefully planned trial plantings which will yield statistically valid answers to real and important questions. Unfortunately, many...

Functional pleiotropy and mating system evolution in plants: frequency-independent mating.

PubMed

Jordan, Crispin Y; Otto, Sarah P

2012-04-01

Mutations that alter the morphology of floral displays (e.g., flower size) or plant development can change multiple functions simultaneously, such as pollen export and selfing rate. Given the effect of these various traits on fitness, pleiotropy may alter the evolution of both mating systems and floral displays, two characters with high diversity among angiosperms. The influence of viability selection on mating system evolution has not been studied theoretically. We model plant mating system evolution when a single locus simultaneously affects the selfing rate, pollen export, and viability. We assume frequency-independent mating, so our model characterizes prior selfing. Pleiotropy between increased viability and selfing rate reduces opportunities for the evolution of pure outcrossing, can favor complete selfing despite high inbreeding depression, and notably, can cause the evolution of mixed mating despite very high inbreeding depression. These results highlight the importance of pleiotropy for mating system evolution and suggest that selection by nonpollinating agents may help explain mixed mating, particularly in species with very high inbreeding depression. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

An integrative mating system assessment of a nonmodel, economically important Pacific rockfish (Sebastes melanops) reveals nonterritorial polygamy and conservation implications for a large species flock.

PubMed

Karageorge, Kurt W; Wilson, Raymond R

2017-12-01

Characterizing the mating systems of long-lived, economically important Pacific rockfishes comprising the viviparous Sebastes species flock is crucial for their conservation. However, direct assignment of mating success to sires is precluded by open, offshore populations and high female fecundity. We addressed this challenge by integrating paternity-assigned mating success of females with the adult sex ratio (ASR) of the population, male evolutionary responses to receptive females, and reproductive life history traits-in the framework of sexual selection theory-to assess the mating system of Sebastes melanops . Microsatellite parentage analysis of 17 pregnant females, 1,256 of their progeny, and 106 adults from the population yielded one to four sires per brood, a mean of two sires, and a female mate frequency distribution with a truncated normal (random) pattern. The 11 multiple paternity broods all contained higher median allele richness than the six single paternity broods (Wilcoxon test: W  = 0, p  < .001), despite similar levels of average heterozygosity. By sampling sperm and alleles from different males, polyandrous females gain opportunities to enhance their sperm supply and to lower the cost of mating with genetically incompatible males through reproductive compensation. A mean of two mates per mated female with a variance of one, an ASR = 1.2 females per male, and the expected population mean of 2.4 mates for mated males (and the estimated 35 unavailable sires), fits polygamous male mate frequency distributions that distinguish polygynandry and polyandrogyny mating systems, that is, variations of polygamy, but not polyandry. Inference for polygamy is consistent with weak premating sexual selection on males, expected in mid-water, schooling S. melanops , owing to polyandrous mating, moderately aggregated receptive females, an even ASR, and no territories and nests used for reproduction. Each of these characteristics facilitates more mating males and erodes conspicuous sexual dimorphism. Evaluation of male evolutionary responses of demersal congeners that express reproductively territorial behavior revealed they have more potential mechanisms for producing premating sexual selection, greater variation in reproductive success, and a reduced breeding effective population size of adults and annual effective size of a cohort, compared to S. melanops modeled with two mates per adult. Such divergence in behavior and mating system by territorial species may differentially lower their per capita birth rates, subsequent population growth, and slow their recovery from exploitation.

Development of a genetic sexing strain in Bactrocera carambolae (Diptera: Tephritidae) by introgression of sex sorting components from B. dorsalis, Salaya1 strain.

PubMed

Isasawin, Siriwan; Aketarawong, Nidchaya; Lertsiri, Sittiwat; Thanaphum, Sujinda

2014-01-01

The carambola fruit fly, Bactrocera carambolae Drew & Hancock is a high profile key pest that is widely distributed in the southwestern ASEAN region. In addition, it has trans-continentally invaded Suriname, where it has been expanding east and southward since 1975. This fruit fly belongs to Bactrocera dorsalis species complex. The development and application of a genetic sexing strain (Salaya1) of B. dorsalis sensu stricto (s.s.) (Hendel) for the sterile insect technique (SIT) has improved the fruit fly control. However, matings between B. dorsalis s.s. and B. carambolae are incompatible, which hinder the application of the Salaya1 strain to control the carambola fruit fly. To solve this problem, we introduced genetic sexing components from the Salaya1 strain into the B. carambolae genome by interspecific hybridization. Morphological characteristics, mating competitiveness, male pheromone profiles, and genetic relationships revealed consistencies that helped to distinguish Salaya1 and B. carambolae strains. A Y-autosome translocation linking the dominant wild-type allele of white pupae gene and a free autosome carrying a recessive white pupae homologue from the Salaya1 strain were introgressed into the gene pool of B. carambolae. A panel of Y-pseudo-linked microsatellite loci of the Salaya1 strain served as markers for the introgression experiments. This resulted in a newly derived genetic sexing strain called Salaya5, with morphological characteristics corresponding to B. carambolae. The rectal gland pheromone profile of Salaya5 males also contained a distinctive component of B. carambolae. Microsatellite DNA analyses confirmed the close genetic relationships between the Salaya5 strain and wild B. carambolae populations. Further experiments showed that the sterile males of Salaya5 can compete with wild males for mating with wild females in field cage conditions. Introgression of sex sorting components from the Salaya1 strain to a closely related B. carambolae strain generated a new genetic sexing strain, Salaya5. Morphology-based taxonomic characteristics, distinctive pheromone components, microsatellite DNA markers, genetic relationships, and mating competitiveness provided parental baseline data and validation tools for the new strain. The Salaya5 strain shows a close similarity with those features in the wild B. carambolae strain. In addition, mating competitiveness tests suggested that Salaya5 has a potential to be used in B. carambolae SIT programs based on male-only releases.

Beliefs about surgery: Development and validation of an instrument to assess cognitive representations about surgery, in the context of a chronic illness.

PubMed

Francis, Jillian J; Wileman, Samantha M; Bekker, Hilary; Barton, Garry R; Ramsay, Craig R

2009-12-01

Within a trial of medical and surgical treatments for gastro-esophageal reflux disease (GORD), involving randomised arms and preference arms, we tested the applicability of the Beliefs about Medicines Questionnaire (BMQ) and developed and tested the validity of a new Beliefs about Surgery Questionnaire (BSQ). Patients with GORD (N = 43) were interviewed to elicit their beliefs about medical and surgical treatments. These contributed to the development of BSQ items. The BMQ and BSQ were completed by trial participants at baseline (randomised trial: N = 325; preference trial: N = 414). Factor analysis and discriminant function analysis were used to assess validity. Principal components analysis (PCA) largely replicated the four-factor BMQ structure. PCA of the combined BMQ/BSQ yielded six factors explaining 54.5% variance. BSQ items loaded onto distinct factors, demonstrating divergence from BMQ. As predicted, BMQ/BSQ scores enabled correct classification of 78.5% of participants to medication and surgery groups in the preference trial (chi(2)(6) = 205.9, p < 0.001) but only 54.5% (no better than chance) in the randomised trial (chi(2)(6) = 9.4, p = 0.154). The BSQ is a valid measure of perceptions about surgical treatments for GORD. With the BMQ, it provides information that may guide patients' choices about treatment. This measure may be applicable to other conditions.

Individual differences in valuing mates' physical attractiveness.

PubMed

Mathes, Eugene W; Bielser, Abby; Cassell, Ticcarra; Summers, Sarah; Witowski, Aggie

2006-10-01

To investigate correlates of valuing physical attractiveness in a mate, it was hypothesized that valuing physical attractiveness in a mate would correlate with sex and valuing promiscuous sex, status, personal physical attractiveness, beauty, and order. Men and women college students completed measures of the extent to which they valued physical attractiveness in a mate and other variables. Valuing physical attractiveness in a mate was correlated with sex (men valued physical attractiveness in a mate more than did women) and valuing promiscuous sex and status, and, for women, valuing personal physical attractiveness. The results were explained in terms of evolutionary theory.

The Evolution of Mutual Mate Choice under Direct Benefits.

PubMed

Courtiol, Alexandre; Etienne, Loïc; Feron, Romain; Godelle, Bernard; Rousset, François

2016-11-01

In nature, the intensity of mate choice (i.e., choosiness) is highly variable within and between sexes. Despite growing empirical evidence of male and/or mutual mate choice, theoretical investigations of the joint evolution of female and male choosiness are few. In addition, previous approaches have often assumed an absence of trade-off between the direct benefits per mating and the lower mating rate that results from being choosy. Here we model the joint evolution of female and male choosiness when it is solely ruled by this fundamental trade-off. We show that this trade-off can generate a diversity of stable combinations of choosiness. Mutual mate choice can evolve only if both females and males exhibit long latency after mating. Furthermore, we show that an increase in choosiness in one sex does not necessarily prevent the evolution of mutual mate choice; the outcome depends on details shaping the trade-off: the life history, the decision rule for mate choice, and how the fecundity of a pair is shaped by the quality of both individuals. Last, we discuss the power of the sensitivity of the relative searching time (i.e., of the proportion of a lifetime spent searching for mates) as a predictor of the joint evolution of choosiness.

Phenotypic plasticity in female mate choice behavior is mediated by an interaction of direct and indirect genetic effects in Drosophila melanogaster.

PubMed

Filice, David C S; Long, Tristan A F

2017-05-01

Female mate choice is a complex decision-making process that involves many context-dependent factors. In Drosophila melanogaster , a model species for the study of sexual selection, indirect genetic effects (IGEs) of general social interactions can influence female mate choice behaviors, but the potential impacts of IGEs associated with mating experiences are poorly understood. Here, we examined whether the IGEs associated with a previous mating experience had an effect on subsequent female mate choice behaviors and quantified the degree of additive genetic variation associated with this effect. Females from 21 different genetic backgrounds were housed with males from one of two distinct genetic backgrounds for either a short (3 hr) or long (48 hr) exposure period and their subsequent mate choice behaviors were scored. We found that the genetic identity of a previous mate significantly influenced a female's subsequent interest in males and preference of males. Additionally, a hemiclonal analysis revealed significant additive genetic variation associated with experience-dependent mate choice behaviors, indicating a genotype-by-environment interaction for both of these parameters. We discuss the significance of these results with regard to the evolution of plasticity in female mate choice behaviors and the maintenance of variation in harmful male traits.

No evidence for inbreeding avoidance in a natural population of song sparrows (Melospiza melodia).

PubMed

Keller, L F; Arcese, P

1998-09-01

We studied mate choice and inbreeding avoidance a natural population of song sparrows (Melospiza melodia) on Mandarte Island, Canada. Inbreeding occurred regularly: 59% all matings were between known relatives. We tested for inbreeding avoidance by comparing the observed levels of inbreeding to those expected if mate choice had been random with respect to relatedness. Independent of our assumptions about the availability of mates in the random mating model, we found that the expected and observed distributions of inbreeding coefficients were similar, as was the expected and observed frequency of close (f >/= 0.125) inbreeding. Furthermore, there was no difference in relatedness observed pairs and those that would have resulted had birds mated instead with their nearest neighbors. The only evidence to suggest any inbreeding avoidance was a reduced rate of parent-offspring matings as compared to one random mating model but not the other. Hence, despite substantial inbreeding depression in this population, we found little evidence for inbreeding avoidance through mate choice. We present a simple model to suggest that variation in inbreeding avoidance behaviors in birds may arise from differences in survival rates: in species with low survival rates, the costs of forfeiting matings to avoid inbreeding may exceed the costs of inbreeding.

Sequence-based evidence for major histocompatibility complex-disassortative mating in a colonial seabird.

PubMed

Juola, Frans A; Dearborn, Donald C

2012-01-07

The major histocompatibility complex (MHC) is a polymorphic gene family associated with immune defence, and it can play a role in mate choice. Under the genetic compatibility hypothesis, females choose mates that differ genetically from their own MHC genotypes, avoiding inbreeding and/or enhancing the immunocompetence of their offspring. We tested this hypothesis of disassortative mating based on MHC genotypes in a population of great frigatebirds (Fregata minor) by sequencing the second exon of MHC class II B. Extensive haploid cloning yielded two to four alleles per individual, suggesting the amplification of two genes. MHC similarity between mates was not significantly different between pairs that did (n = 4) or did not (n = 42) exhibit extra-pair paternity. Comparing all 46 mated pairs to a distribution based on randomized re-pairings, we observed the following (i): no evidence for mate choice based on maximal or intermediate levels of MHC allele sharing (ii), significantly disassortative mating based on similarity of MHC amino acid sequences, and (iii) no evidence for mate choice based on microsatellite alleles, as measured by either allele sharing or similarity in allele size. This suggests that females choose mates that differ genetically from themselves at MHC loci, but not as an inbreeding-avoidance mechanism.

How universal are human mate choices? Size does not matter when Hadza foragers are choosing a mate

PubMed Central

Sear, Rebecca; Marlowe, Frank W.

2009-01-01

It has been argued that size matters on the human mate market: both stated preferences and mate choices have been found to be non-random with respect to height and weight. But how universal are these patterns? Most of the literature on human mating patterns is based on post-industrial societies. Much less is known about mating behaviour in more traditional societies. Here we investigate mate choice by analysing whether there is any evidence for non-random mating with respect to size and strength in a forager community, the Hadza of Tanzania. We test whether couples assort for height, weight, body mass index (BMI), per cent fat and grip strength. We test whether there is a male-taller norm. Finally, we test for an association between anthropometric variables and number of marriages. Our results show no evidence for assortative mating for height, weight, BMI or per cent fat; no evidence for a male-taller norm and no evidence that number of marriages is associated with our size variables. Hadza couples may assort positively for grip strength, but grip strength does not affect the number of marriages. Overall we conclude that, in contrast to post-industrial societies, mating appears to be random with respect to size in the Hadza. PMID:19570778

[Defining an ethics for preventive trials].

PubMed

Chippaux, J-P

2008-04-01

Preventive trials (to prevent from infection) or prophylaxis trials (to avoid consequences of the disease) differ from other clinical trials as they apply to healthy subjects or subjects considering themselves as such: the latter do not ask for intervention even less for trial. Moreover, it is generally an experiment which aims at validating a public health intervention, the individual character of which could appear as secondary regarding the collective interest. It concerns many tools or methods: preventive or prophylactic vaccines and drugs, condoms, impregnated bed nets, etc. The field of implementation of preventive trials is large and covers routine immunization (EPI), large-scale control or eradication of endemic diseases or epidemics, for which the concept of individual risk is generally better understood. Preventive trials imply ethical obligations (high individual or collective benefits and absence of risks as there is no immediate therapeutic compensation), methodological adaptations (because the number of subjects is considerably larger than for therapeutic trials) and a sensitive valorization towards a large population who is not asking for the recommended intervention. As regard the benefits, it is also necessary to consider the costs in comparison with the expected efficacy The methodological constraints are important because the demonstration of both safety and efficacy requires a very large number of subjects to validate the product. It is often necessary to use indirect or substitutive markers and indicators (title of protective antibodies rather than definite clinical protection) which need a preliminary validation. Before carrying out a preventive or prophylactic trial, it is advisable to specify the objectives in order to assess the real profits and absence of risks during the trial and after the implementation of the tested product. Preventive trials require a phase of technological transfer to guarantee the application of the validated tools for the benefit of the population at stake. In this respect, if trials for prevention are now well codified both on ethical and methodological aspects, trials for prophylaxis (filariasis with ivermectin, schistosomiasis with praziquantel, malaria with intermittent "preventive" treatment or HIV with antiretroviral treatment, for example) still remain a difficult issue at both ethical and methodological levels.

KSC-06pd0555

NASA Image and Video Library

2006-03-10

VANDENBERG AIR FORCE BASE, CALIF. - On the ramp adjacent to the runway at Vandenberg Air Force Base in California, the Space Technology 5's Pegasus rocket is placed in position to be mated to the underside of an Orbital Sciences L-1011 carrier aircraft. The ST5, which contains three microsatellites with miniaturized redundant components and technologies, is mated to its launch vehicle, Orbital Sciences' Pegasus XL. Each of the ST5 microsatellites will validate New Millennium Program selected technologies, such as the Cold Gas Micro-Thruster and X-Band Transponder Communication System. After deployment from the Pegasus, the micro-satellites will be positioned in a “string of pearls” constellation that demonstrates the ability to position them to perform simultaneous multi-point measurements of the magnetic field using highly sensitive magnetometers. The data will help scientists understand and map the intensity and direction of the Earth’s magnetic field, its relation to space weather events, and affects on our planet. Launch of ST5 and the Pegasus XL will be from underneath the belly of an L-1011 carrier aircraft from Vandenberg Air Force Base.

Men and women are from Earth: examining the latent structure of gender.

PubMed

Carothers, Bobbi J; Reis, Harry T

2013-02-01

Taxometric methods enable determination of whether the latent structure of a construct is dimensional or taxonic (nonarbitrary categories). Although sex as a biological category is taxonic, psychological gender differences have not been examined in this way. The taxometric methods of mean above minus below a cut, maximum eigenvalue, and latent mode were used to investigate whether gender is taxonic or dimensional. Behavioral measures of stereotyped hobbies and physiological characteristics (physical strength, anthropometric measurements) were examined for validation purposes, and were taxonic by sex. Psychological indicators included sexuality and mating (sexual attitudes and behaviors, mate selectivity, sociosexual orientation), interpersonal orientation (empathy, relational-interdependent self-construal), gender-related dispositions (masculinity, femininity, care orientation, unmitigated communion, fear of success, science inclination, Big Five personality), and intimacy (intimacy prototypes and stages, social provisions, intimacy with best friend). Constructs were with few exceptions dimensional, speaking to Spence's (1993) gender identity theory. Average differences between men and women are not under dispute, but the dimensionality of gender indicates that these differences are inappropriate for diagnosing gender-typical psychological variables on the basis of sex. (c) 2013 APA, all rights reserved.

Single-gene deletions that restore mating competence to diploid yeast.

PubMed

Schmidlin, Tom; Kaeberlein, Matt; Kudlow, Brian A; MacKay, Vivian; Lockshon, Daniel; Kennedy, Brian K

2008-03-01

Using the Saccharomyces cerevisiae MATa/MATalpha ORF deletion collection, homozygous deletion strains were identified that undergo mating with MATa or MATalpha haploids. Seven homozygous deletions were identified that confer enhanced mating. Three of these, lacking CTF8, CTF18, and DCC1, mate at a low frequency with either MATa or MATalpha haploids. The products of these genes form a complex involved in sister chromatid cohesion. Each of these strains also exhibits increased chromosome loss rates, and mating likely occurs due to loss of one copy of chromosome III, which bears the MAT locus. Three other homozygous diploid deletion strains, ylr193cDelta/ylr193cDelta, yor305wDelta/yor305wDelta, and ypr170cDelta/ypr170cDelta, mate at very low frequencies with haploids of either or both mating types. However, an ist3Delta/ist3Delta strain mates only with MATa haploids. It is shown that IST3, previously linked to splicing, is required for efficient processing of the MATa1 message, particularly the first intron. As a result, the ist3Delta/ist3Delta strain expresses unbalanced ratios of Matalpha to Mata proteins and therefore mates with MATa haploids. Accordingly, mating in this diploid can be repressed by introduction of a MATa1 cDNA. In summary, this study underscores and elaborates upon predicted pathways by which mutations restore mating function to yeast diploids and identifies new mutants warranting further study.

Why do males choose heterospecific females in the red spider mite?

PubMed

Sato, Yukie; Staudacher, Heike; Sabelis, Maurice W

2016-01-01

In some species, males readily show courtship behaviour towards heterospecific females and even prefer them to females of their own species. This behaviour is generally explained by indiscriminate mating to acquire more mates, but may partly be explained by male mate preference mechanisms that have developed to choose among conspecific females, as male preference for larger females causes mating with larger heterospecific females. Recently, we found that males of the red spider mite, Tetranychus evansi collected from Spain (invasive population), prefer to mate with females of the two-spotted spider mite, T. urticae rather than with conspecific females. In spider mites, mate preference for non-kin individuals has been observed. Here, we investigated if T. evansi males collected from the area of its origin (Brazil) also show preference for heterospecific females. Secondly, we investigated if mate preference of T. evansi males for heterospecific females is affected by their relatedness to conspecific females which are offered together with heterospecific females. We found that mate preference for heterospecific females exists in Brazilian T. evansi, suggesting that the preference for heterospecific females is not a lack of evolved premating isolation with an allopatric species. We found that T. evansi males showed lower propensity to mate with heterospecific females when alternative females were non-kin in the two iso-female lines collected from Brazil. However, the effect of relatedness on male mate preference was not significant. We discuss alternative hypotheses explaining why T. evansi males prefer to mate with T. urticae females.

SEXUAL SELECTION THROUGH FEMALE CHOICE IN LAWES' PAROTIA, A LEK-MATING BIRD OF PARADISE.

PubMed

Pruett-Jones, S G; Pruett-Jones, M A

1990-05-01

We studied sexual selection in Lawes' Parotia, a lek-mating bird of paradise, during 1981-1983 in Papua New Guinea. There was a high variance in mating success among males, with fewer than half of the individuals mating in any one year. This variance was independent of male-male interactions and disruptions. A role of female choice in sexual selection was suggested by the patterns of female visitation to courts and statistical correlations across males between phenotypic traits and mating success. Females repeatedly visited most males in their home ranges and began visiting males up to six weeks before mating. In one or more years, six aspects of male behavior and one morphological variable were positively correlated with mating success, but the probability values were not significant using a simultaneous inference test. Calculation of combined probability values across all three years revealed that one aspect of male display behavior, the probability of display, positively and significantly influenced mating status. The probability of display was also significantly correlated with relative mating success among males. Females showed strong fidelity to mates, both within and between seasons. Display sites of male Lawes' Parotia are variably dispersed, but mating success did not differ for grouped and solitary males. These data confirm an important role of female choice in sexual selection in birds of paradise but also suggest that female choice may be unrelated to the process of lek-initiation in this species. © 1990 The Society for the Study of Evolution.

Behavioral and physiological polymorphism in males of the austral lizard Liolaemus sarmientoi.

PubMed

Fernández, Jimena B; Bastiaans, Elizabeth; Medina, Marlin; Méndez De la Cruz, Fausto R; Sinervo, Barry R; Ibargüengoytía, Nora R

2018-02-01

Integrative behavioral studies show that the interplay between individual physiology and social behavior influences the ecology of the species, ultimately affecting individual fitness. Particularly in lizards, color polymorphism is associated with differential behaviors and reproductive strategies, which are evident in mature males during the mating season. Dominant males generally have greater endurance, higher body temperature, and larger bodies than submissive males, so they can acquire and defend larger territories and have greater access to females for mating. We studied whether the color morphs observed in males of one of the world's southernmost reptiles, Liolaemus sarmientoi, are related to behavioral variation during agonistic interactions, thermal physiology, morphology, and/or locomotor stamina. Liolaemus sarmientoi males exhibit three color morphs: red (RR), red-yellow (RY), and yellow (YY). These lizards exhibit subtle behavioral displays and we did not observe stamina differences among morphs. However, we found that RR males are more aggressive than YY males during agonistic encounters. In addition, greater body temperature change during trials, higher field body temperatures, and greater head sizes of RR males compared to RY or YY indicate that RR is a dominant morph, which may influence their ability to acquire and defend territory and tactics for achieving reproductive success.

Adaptive genetic complementarity in mate choice coexists with selection for elaborate sexual traits

PubMed Central

Oh, Kevin P; Badyaev, Alexander V

2006-01-01

Choice of genetically unrelated mates is widely documented, yet it is not known how self-referential mate choice can co-occur with commonly observed directional selection on sexual displays. Across 10 breeding seasons in a wild bird population, we found strong fitness benefits of matings between genetically unrelated partners and show that self-referential choice of genetically unrelated mates alternates with sexual selection on elaborate plumage. Seasonal cycles of diminishing variation in ornamentation, caused by early pairing of the most elaborated males, and influx of increasingly genetically unrelated available mates caused by female-biased dispersal, lead to temporal fluctuations in the target of mate choice and enabled coexistence of directional selection for ornament elaboration with adaptive pairing of genetically unrelated partners. PMID:16822752

An Evolutionary Perspective on Mate Rejection.

PubMed

Kelly, Ashleigh J; Dubbs, Shelli L; Barlow, Fiona Kate

2016-01-01

We argue that mate rejection and ex-partner relationships are important, multifaceted topics that have been underresearched in social and evolutionary psychology. Mate rejection and relationship dissolution are ubiquitous and form integral parts of the human experience. Both also carry with them potential risks and benefits to our fitness and survival. Hence, we expect that mate rejection would have given rise to evolved behavioral and psychological adaptations. Herein, we outline some of the many unanswered questions in evolutionary psychology on these topics, at each step presenting novel hypotheses about how men and women should behave when rejecting a mate or potential mate or in response to rejection. We intend these hypotheses and suggestions for future research to be used as a basis for enriching our understanding of human mating from an evolutionary perspective.

The impact of Wolbachia, male age and mating history on cytoplasmic incompatibility and sperm transfer in Drosophila simulans.

PubMed

Awrahman, Z A; Champion de Crespigny, F; Wedell, N

2014-01-01

Most insects harbour a variety of maternally inherited endosymbionts, the most widespread being Wolbachia pipientis that commonly induce cytoplasmic incompatibility (CI) and reduced hatching success in crosses between infected males and uninfected females. High temperature and increasing male age are known to reduce the level of CI in a variety of insects. In Drosophila simulans, infected males have been shown to mate at a higher rate than uninfected males. By examining the impact of mating rate independent of age, this study investigates whether a high mating rate confers an advantage to infected males through restoring their compatibility with uninfected females over and above the effect of age. The impact of Wolbachia infection, male mating rate and age on the number of sperm transferred to females during copulation and how it relates to CI expression was also assessed. As predicted, we found that reproductive compatibility was restored faster in males that mate at higher rate than that of low mating and virgin males, and that the effect of mating history was over and above the effect of male age. Nonvirgin infected males transferred fewer sperm than uninfected males during copulation, and mating at a high rate resulted in the transfer of fewer sperm per mating irrespective of infection status. These results indicate that the advantage to infected males of mating at a high rate is through restoration of reproductive compatibility with uninfected females, whereas uninfected males appear to trade off the number of sperm transferred per mating with female encounter rate and success in sperm competition. This study highlights the importance Wolbachia may play in sexual selection by affecting male reproductive strategies. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Molecular cloning and functional characterization of DkMATE1 involved in proanthocyanidin precursor transport in persimmon (Diospyros kaki Thunb.) fruit.

PubMed

Yang, Sichao; Jiang, Yun; Xu, Liqing; Shiratake, Katsuhiro; Luo, Zhengrong; Zhang, Qinglin

2016-11-01

Persimmon fruits accumulate a large amount of proanthocyanidins (PAs) in "tannin cells" during development that cause the sensation of astringency due to coagulation of oral proteins. Pollination-constant non-astringent (PCNA) is a spontaneous mutant persimmon phenotype that loses its astringency naturally on the tree at maturity; while the more common non-PCNA fruits remain rich in PAs until they are fully ripened. Here, we isolated a DkMATE1 gene encoding a Multidrug And Toxic Compound Extrusion (MATE) family protein from the Chinese PCNA (C-PCNA) 'Eshi 1'. Expression patterns of DkMATE1 were positively correlated with the accumulation of PAs in different types of persimmons fruits during fruit development. An analysis of the inferred amino acid sequences and phylogenetic relationships indicated that DkMATE1 is a putative PA precursor transporter, and subcellular localization assays revealed that DkMATE1 is localized in the vacuolar membrane. Ectopic expression of the DkMATE1 in Arabidopsis tt12 mutant supported that DkMATE1 could complement its biological function in transporting epicatechin 3'-O-glucoside as a PAs precursor from the cytoplasm to vacuole. Furthermore, the transient over-expression and silencing of DkMATE1 in 'Mopanshi' persimmon leaves resulted in a significant increase and a decrease in PA content, respectively. The analysis of cis-elements in DkMATE1 promoter regions indicated that DkMATE1 might be regulated by DkMYB4, another well-known structural gene in persimmon. Overall, our results show that DkMATE1 may be an essential PA precursor membrane transporter that plays an important role in PA biosynthesis in persimmon. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Azadirachtin impact on mate choice, female sexual receptivity and male activity in Drosophila melanogaster (Diptera: Drosophilidae).

PubMed

Aribi, N; Oulhaci, M C; Kilani-Morakchi, S; Sandoz, J C; Kaiser, L; Denis, B; Joly, D

2017-11-01

Azadirachtin, a neem compound (Azadirachta indica) with medical and anti-insect properties, is one the most successful botanical pesticides in agricultural use. However, its controversial impact on non-targeted species and its mechanism of action need to be clarified. In addition, Azadirachtin impact on pre- and post-mating traits remains largely undocumented. The current study examined the effects of Azadirachtin on Drosophila melanogaster as a non-target and model species. Azadirachtin was applied topically at its LD 50 (0.63μg) on the day of adult emergence and its effect was evaluated on several traits of reproductive behavior: mate choice, male activity, female sexual receptivity, sperm storage and female sterility. In choice and no choice conditions, only male treatment reduced mating probability. Female treatment impaired mating probability only when males had the choice. Males' mating ability may have been impaired by an effect of the treatment on their mobility. Such an effect was observed in the actimeter, which revealed that treated males were less active than untreated ones, and this effect persisted over 8days. Azadirachtin treatment had, however, no effect on the nycthemeral rhythm of those males. Even when mating occurred, Azadirachtin treatment impaired post-mating responses especially when females or both sexes were treated: remating probability increases and female fertility (presence of larvae) decreases. No impairment was observed on the efficiency of mating, evaluated by the presence of sperm in the spermatheca or the ventral receptacle. Male treatment only had no significant effect on these post-mating responses. These findings provide clear evidence that Azadirachtin alters the reproductive behavior of both sexes in D. melanogaster via mating and post-mating processes. Copyright © 2017 Elsevier Inc. All rights reserved.

Mate choice for major histocompatibility complex complementarity in a strictly monogamous bird, the grey partridge (Perdix perdix).

PubMed

Rymešová, Dana; Králová, Tereza; Promerová, Marta; Bryja, Josef; Tomášek, Oldřich; Svobodová, Jana; Šmilauer, Petr; Šálek, Miroslav; Albrecht, Tomáš

2017-01-01

Sexual selection has been hypothesised as favouring mate choice resulting in production of viable offspring with genotypes providing high pathogen resistance. Specific pathogen recognition is mediated by genes of the major histocompatibility complex (MHC) encoding proteins fundamental for adaptive immune response in jawed vertebrates. MHC genes may also play a role in odour-based individual recognition and mate choice, aimed at avoiding inbreeding. MHC genes are known to be involved in mate choice in a number of species, with 'good genes' (absolute criteria) and 'complementary genes' (self-referential criteria) being used to explain MHC-based mating. Here, we focus on the effect of morphological traits and variation and genetic similarity between individuals in MHC class IIB (MHCIIB) exon 2 on mating in a free-living population of a monogamous bird, the grey partridge. We found no evidence for absolute mate choice criteria as regards grey partridge MHCIIB genotypes, i.e., number and occurrence of amino acid variants, though red chroma of the spot behind eyes was positively associated with male pairing success. On the other hand, mate choice at MHCIIB was based on relative criteria as females preferentially paired with more dissimilar males having a lower number of shared amino acid variants. This observation supports the 'inbreeding avoidance' and 'complementary genes' hypotheses. Our study provides one of the first pieces of evidence for MHC-based mate choice for genetic complementarity in a strictly monogamous bird. The statistical approach employed can be recommended for testing mating preferences in cases where availability of potential mates (recorded with an appropriate method such as radio-tracking) shows considerable temporal variation. Additional genetic analyses using neutral markers may detect whether MHC-based mate choice for complementarity emerges as a by-product of general inbreeding avoidance in grey partridges.

Inbreeding Avoidance Drives Consistent Variation of Fine-Scale Genetic Structure Caused by Dispersal in the Seasonal Mating System of Brandt’s Voles

PubMed Central

Liu, Xiao Hui; Yue, Ling Fen; Wang, Da Wei; Li, Ning; Cong, Lin

2013-01-01

Inbreeding depression is a major evolutionary and ecological force influencing population dynamics and the evolution of inbreeding-avoidance traits such as mating systems and dispersal. Mating systems and dispersal are fundamental determinants of population genetic structure. Resolving the relationships among genetic structure, seasonal breeding-related mating systems and dispersal will facilitate our understanding of the evolution of inbreeding avoidance. The goals of this study were as follows: (i) to determine whether females actively avoided mating with relatives in a group-living rodent species, Brandt’s voles (Lasiopodomys brandtii), by combined analysis of their mating system, dispersal and genetic structure; and (ii) to analyze the relationships among the variation in fine-genetic structure, inbreeding avoidance, season-dependent mating strategies and individual dispersal. Using both individual- and population-level analyses, we found that the majority of Brandt’s vole groups consisted of close relatives. However, both group-specific FISs, an inbreeding coefficient that expresses the expected percentage rate of homozygosity arising from a given breeding system, and relatedness of mates showed no sign of inbreeding. Using group pedigrees and paternity analysis, we show that the mating system of Brandt’s voles consists of a type of polygyny for males and extra-group polyandry for females, which may decrease inbreeding by increasing the frequency of mating among distantly-related individuals. The consistent variation in within-group relatedness, among-group relatedness and fine-scale genetic structures was mostly due to dispersal, which primarily occurred during the breeding season. Biologically relevant variation in the fine-scale genetic structure suggests that dispersal during the mating season may be a strategy to avoid inbreeding and drive the polygynous and extra-group polyandrous mating system of this species. PMID:23516435

Model Validation Against The Modelers’ Data Archive

DTIC Science & Technology

2014-08-01

completion of the planned Jack Rabbit 2 field trials. The relevant task for the effort addressed here is Task 4 of the current Interagency Agreement, as...readily simulates the Prairie Grass sulfur dioxide plumes. Also, Jack Rabbit II field trials are set to be completed during FY16. Once these data are...available, they will also be used to validate the combined models. This validation may prove to be more useful, as the Jack Rabbit II will release

Mating behaviour of Pseudodiaptomus annandalei (Copepoda Calanoida) with emphasis on rejection rate

NASA Astrophysics Data System (ADS)

Dur, G.; Souissi, S.; Schmitt, F. G.; Hwang, J. S.; Cheng, S. H.

2009-04-01

Mating behaviour has important consequences at both individual and population levels. Reproductive fitness is of paramount importance to sustain the success of planktonic copepod populations in aquatic environments. The calanoid copepod Pseudodiaptomus annandalei has one of the largest geographical ranges for Indo-Pacific Pseudodiaptomidae. It is also of great importance in fish culture pounds south of Taiwan. However, the mating behavior of this species has never been studied. Mating and predatory behaviour are conceptually the same. In both cases, the encounter and the interactions occur between two individuals with opposite characteristics: predator-prey for predation; male-female for mating. The mating behaviour may be defined as a sequence of encounter, pursuit, capture and copulation. Several observed behaviour suggest that both sexes asses and choose among available mates before the copulation. Pre-copulatory mate choice in copepods may manifest as mate guarding where males attached to CV females until their final moult, complicated pre-copulatory dance and escaping. During our preliminary observations, we notice that P. annandalei females escape by shaking, often violently, the males that have caught them. Consequently for such a species the act of mating may be visualized as a chain of six events (i.e. search, encounter, pursuit, capture, selective dance, copulation).Within this chain, encounter, capture and copulation are conditional events depending on the successful conclusion of their preceding events in the chain. In this study, we examined the different step in the mating behaviour of the scarcely studied sub-tropical copepod, Pseudodiaptomus annandalei, collected from the Danshuei estuary (North Taiwan). The individuals were observed using a 3D optical system to obtain simultaneous front and side views. Males, when placed in the water where females had previously swum in, showed significant increase of their swimming velocities. Additionally, their swimming trajectories are more convoluted, indicating that males explore larger volume of fluid to increase the probability to encounter a female. The mate finding behaviour appears to depend not only on chemical signal but also on hydromechanical signals. Some males exhibited shifts of direction when females were passing by. When male intercepted a chemical trail left by a female, they initiate tracking behaviour racing up the trail with increasing speed. Males pursued pheromone trails up to 24 sec old and 10 mm long. Most studies of mating behaviour have focused on detection and sometimes pursuit, but few have addressed the other components of successful mating, namely, capture and copulation. Moreover, mate choice issue has largely been ignored in regards to pelagic copepods. Consequently very few are known about the plasticity of rejection rates as a function of mate encounter rates. The second aim of this experiment is to describe the process used by female to select their mate and to fill the gap in the quantification of mating success. Once caught by a male, P. annandalei's females entered in intensive dance which sometimes lead to shake off the males suggesting a female mate choice. The three-dimensional trajectories described by the couple during this event were characterized by fast loops and intense jumps. Individual's access to mates may be affected by operational sex ratios, causing strong variation in mating success. We finally manipulated adult sex ratios of the brackish copepod P. annandalei, to examine the influence of population sex ratio on mating success of P. annandalei in a final set of experiment concluding the investigation. It should be notice that, to our knowledge, it the first quantification ever done before. The plasticity of rejection rate was therefore investigated as a function of sex-ratio and mate encounter rate. The encounter rate reached maximum value for balanced proportion of male and female and decreased as the sex ratio unbalanced. Higher value of success was nevertheless observed for a pro-male sex-ratio.

The effects of anxiety upon attention allocation to affective stimuli.

PubMed

Waters, Allison M; Nitz, Ashley B; Craske, Michelle G; Johnson, Chris

2007-04-01

Pictures of emotionally aversive, neutral, and pleasant scenes were presented for 500 ms, followed by a probe presented in the same location (valid trials) or an alternate location (invalid trials) as the picture. Response-times to the probes were recorded in low (N=20) and high (N=27) trait anxious participants. Results revealed an overall negative cue validity effect of shorter reaction times (RTs) on invalid than valid trials, suggestive of an inhibition of return effect. Moreover, high trait anxious females showed a reduced negative cue validity effect for aversive pictures in comparison with neutral and pleasant pictures, suggestive of selective interference by the unpleasant material. By contrast, low trait anxious females showed an enhanced negative cue validity effect for aversive pictures relative to neutral and pleasant pictures, suggestive of attentional avoidance of the aversive content. The emotional content of picture cues did not significantly affect RTs in males, regardless of anxiety status. The results suggest that biased attention processes for aversive stimuli may contribute to the greater female propensity for anxiety disorders.

Ecological correlates of mate fidelity in two Arctic-breeding sandpipers

USGS Publications Warehouse

Sandercock, Brett K.; Lank, David B.; Lanctot, Richard B.; Kempenaers, Bart; Cooke, Fred

2000-01-01

Monogamous birds exhibit considerable interspecific variation in rates of mate fidelity between years, but the reasons for this variation are still poorly understood. In a 4-year study carried out in western Alaska, mate-fidelity rates in Semipalmated Sandpipers (Calidris pusilla; mate fidelity was 47% among pairs where at least one mate returned and 94% among pairs where both mates returned) were substantially higher than in Western Sandpipers (Calidris mauri; 25 and 67%, respectively), despite the similar breeding biology of these sibling species. Divorce was not a response to nesting failure in Western Sandpipers, and mate change had no effect on the reproductive performance of either species. Nor were mate-fidelity rates related to differential rates of breeding dispersal, because the species did not differ in site fidelity. Reunited pairs and males that changed mates showed strong site tenacity, while females that changed mates moved farther. Differences in local survival rates or habitat are also unlikely to explain mate fidelity, since the two species did not differ in local survival rates, ϕ (Western Sandpipers: ϕ –hat = 0.57 ± 0.05 (mean ± SE), Semipalmated Sandpipers: ϕ –hat = 0.66 ± 0.06), and they bred in the same area, sometimes using the same nest cups. Although we were able to reject the above explanations, it was not possible to determine whether mate retention was lower in Western Sandpipers than in Semipalmated Sandpipers because of interspecific differences in mating tactics, time constraints imposed by migration distance, or a combination of these factors. Western Sandpipers exhibited greater sexual size dimorphism, but also migrated for shorter distances and tended to nest earlier and more asynchronously than Semipalmated Sandpipers. Finally, we show that conventional methods underestimate divorce rates, and interspecific comparisons may be biased if breeding-dispersal and recapture rates are not considered.

Characterization of CcSTOP1; a C2H2-type transcription factor regulates Al tolerance gene in pigeonpea.

PubMed

Daspute, Abhijit Arun; Kobayashi, Yuriko; Panda, Sanjib Kumar; Fakrudin, Bashasab; Kobayashi, Yasufumi; Tokizawa, Mutsutomo; Iuchi, Satoshi; Choudhary, Arbind Kumar; Yamamoto, Yoshiharu Y; Koyama, Hiroyuki

2018-01-01

Al-responsive citrate-transporting CcMATE1 function and its regulation by CcSTOP1 were analyzed using NtSTOP1 -KD tobacco- and pigeonpea hairy roots, respectively, CcSTOP1 binding sequence of CcMATE1 showed similarity with AtALMT1 promoter. The molecular mechanisms of Aluminum (Al) tolerance in pigeonpea (Cajanus cajan) were characterized to provide information for molecular breeding. Al-inducible citrate excretion was associated with the expression of MULTIDRUGS AND TOXIC COMPOUNDS EXCLUSION (CcMATE1), which encodes a citrate transporter. Ectopic expression of CcMATE1-conferred Al tolerance to hairy roots of transgenic tobacco with the STOP1 regulation system knocked down. This gain-of-function approach clearly showed CcMATE1 was involved in Al detoxification. The expression of CcMATE1 and another Al-tolerance gene, ALUMINUM SENSITIVE 3 (CcALS3), was regulated by SENSITIVE TO PROTON RHIZOTOXICITY1 (CcSTOP1) according to loss-of-function analysis of pigeonpea hairy roots in which CcSTOP1 was suppressed. An in vitro binding assay showed that the Al-responsive CcMATE1 promoter contained the GGNVS consensus bound by CcSTOP1. Mutation of GGNVS inactivated the Al-inducible expression of CcMATE1 in pigeonpea hairy roots. This indicated that CcSTOP1 binding to the promoter is critical for CcMATE1 expression. The STOP1 binding sites of both the CcMATE1 and AtALMT1 promoters contained GGNVS and a flanking 3' sequence. The GGNVS region was identical in both CcMATE1 and AtALMT1. By contrast, the 3' flanking sequence with binding affinity to STOP1 did not show similarity. Putative STOP1 binding sites with similar structures were also found in Al-inducible MATE and ALMT1 promoters in other plant species. The characterized Al-responsive CcSTOP1 and CcMATE1 genes will help in pigeonpea breeding in acid soil tolerance.

49 CFR 179.14 - Coupler vertical restraint system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... mating coupler (or simulated coupler) having only frictional vertical force resistance at the mating interface; or a mating coupler (or simulated coupler) having the capabilities described in paragraph (a) of this section; (2) The testing apparatus shall simulate the vertical coupler performance at the mating...

Mating success of males with and without wing patch in Drosophila biarmipes.

PubMed

Hegde, S N; Chethan, B K; Krishna, M S

2005-10-01

Some males of D. biarmipes--synonym of D. rajasekari and D. raychaudhuri have a black patch on the wing. The patch extends from the apical margin of wing to the third longitudinal vein. Field and laboratory studies have been carried out in D. biarmipes to study role of male's wing patch in mating success. The field study shows that nature favors D. biarmipes males with patch. Although males without patch mated, males with patch have higher mating success suggesting the role of wing patch during courtship. Further, among mating males, males with patch had longer wings than males without patch. During courtship, males with patch oriented and mated faster; performed courtship acts such as tapping, scissoring, vibration, licking and twist dance more times than males without patch in both competitive and non-competitive situations. The results indicate that there is a casual relationship between the presence of wing patch, mating speed and success. Also there is a correlation between presence of wing patch, size of the flies and mating success.

Water turbidity by algal blooms causes mating system breakdown in a shallow-water fish, the sand goby Pomatoschistus minutus.

PubMed

Järvenpää, Marja; Lindström, Kai

2004-11-22

Eutrophication as a result of human activity has resulted in increased algal blooms and turbidity in aquatic environments. We investigated experimentally the effect of algal turbidity on the mating system and sexual selection in the sand goby, Pomatoschistus minutus (Pallas), a marine fish with a resource-defence mating system and paternal care. Owing to male-male competition and female choice, large males can monopolize multiple mates, while some males do not achieve mating at all. We show that the number of eggs laid was the same in both turbid and clear tanks but that mating success was more evenly distributed among males in turbid than in clear water. The opportunity for sexual selection was lower in turbid conditions. In turbid conditions mating success was less skewed towards large males. Our results suggest that increased turbidity can change mating systems and decrease the opportunity for sexual selection as well as selection intensity.

Trial-by-Trial Changes in a Priori Informational Value of External Cues and Subjective Expectancies in Human Auditory Attention

PubMed Central

Arjona, Antonio; Gómez, Carlos M.

2011-01-01

Background Preparatory activity based on a priori probabilities generated in previous trials and subjective expectancies would produce an attentional bias. However, preparation can be correct (valid) or incorrect (invalid) depending on the actual target stimulus. The alternation effect refers to the subjective expectancy that a target will not be repeated in the same position, causing RTs to increase if the target location is repeated. The present experiment, using the Posner's central cue paradigm, tries to demonstrate that not only the credibility of the cue, but also the expectancy about the next position of the target are changedin a trial by trial basis. Sequences of trials were analyzed. Results The results indicated an increase in RT benefits when sequences of two and three valid trials occurred. The analysis of errors indicated an increase in anticipatory behavior which grows as the number of valid trials is increased. On the other hand, there was also an RT benefit when a trial was preceded by trials in which the position of the target changed with respect to the current trial (alternation effect). Sequences of two alternations or two repetitions were faster than sequences of trials in which a pattern of repetition or alternation is broken. Conclusions Taken together, these results suggest that in Posner's central cue paradigm, and with regard to the anticipatory activity, the credibility of the external cue and of the endogenously anticipated patterns of target location are constantly updated. The results suggest that Bayesian rules are operating in the generation of anticipatory activity as a function of the previous trial's outcome, but also on biases or prior beliefs like the “gambler fallacy”. PMID:21698164

Size, sounds and sex: interactions between body size and harmonic convergence signals determine mating success in Aedes aegypti.

PubMed

Cator, Lauren J; Zanti, Zacharo

2016-12-01

Several new mosquito control strategies will involve the release of laboratory reared males which will be required to compete with wild males for mates. Currently, the determinants of male mating success remain unclear. The presence of convergence between male and female harmonic flight tone frequencies during a mating attempt have been found to increase male mating success in the yellow fever mosquito, Aedes aegypti. Size has also been implicated as a factor in male mating success. Here, we investigated the relationships among body size, harmonic convergence signalling, and mating success. We predicted that harmonic convergence would be an important determinant of mating success and that large individuals would be more likely to converge. We used diet to manipulate male and female body size and then measured acoustic interactions during mating attempts between pairs of different body sizes. Additionally, we used playback experiments to measure the direct effect of size on signalling performance. In live pair interactions, harmonic convergence was found to be a significant predictor of copula formation. However, we also found interactions between harmonic convergence behaviour and body size. The probability that a given male successfully formed a copula was a consequence of his size, the size of the female encountered, and whether or not they converged. While convergence appears to be predictive of mating success regardless of size, the positive effect of convergence was modulated by size combinations. In playbacks, adult body size did not affect the probability of harmonic convergence responses. Both body size and harmonic convergence signalling were found to be determinants of male mating success. Our results suggest that in addition to measuring convergence ability of mass release lines that the size distribution of released males may need to be adjusted to complement the size distribution of females. We also found that diet amount alone cannot be used to increase male mating success or convergence probability. A clearer understanding of convergence behaviours, their relationship to mating success, and factors influencing convergence ability would provide the groundwork for improving the mating performance of laboratory reared lines.

The mating behavior of Iguana iguana

USGS Publications Warehouse

Rodda, G.H.

1992-01-01

Over a 19 month period I observed the social behaviors of individually recognized green iguanas, Iguana iguana, at three sites in the llanos of Venezuela. The behavior of iguanas outside the mating season differed from that seen during the mating season in three major ways: (1) during normal waking hours outside the breeding season, adult iguanas spent the majority of time immobile, apparently resting; (2) their interactions involved fewer high intensity displays; and (3) their day to day movements were often nomadic. During the mating season, one site was watched continuously during daylight hours (iguanas sleep throughout the night), allowing a complete count of all copulation attempts (N = 250) and territorial interactions. At all sites, dominant males controlled access to small mating territories. Within the territories there did not appear to be any resources needed by females or their offspring. Thus, females could choose mates directly on the basis of male phenotype. Females aggregated in the mating territories of the largest males and mated preferentially with them. Territorial males copulated only once per day, although on several occasions more than one resident female was receptive on the same day. A few small nonterritorial males exhibited pseudofemale behavior (i.e., they abstained from sexual competition), but most nonterritorial males stayed on the periphery of mating territories and attempted to force copulations on unguarded females (peripheral male behavior). Uncooperative females were mounted by as many as three males simultaneously. Females resisted 95% of the 200 observed mating attempts by peripheral males, but only 56% of the attempts by territorial males (N = 43). The selectivity of the females probably increased the genetic representation of the territorial males in the next generation. During the mating season females maintained a dominance hierarchy among themselves. Low ranked females tended to be excluded from preferred mating territories. In this system, both sexes may be subjected to sexual selection. I hypothesize that the ecological factors responsible for the unusual mating system are related to the lack of defendable resources, the iguana's folivory, and the high density of iguanas present in preferred mating areas.

Mixing Methods in Randomized Controlled Trials (RCTs): Validation, Contextualization, Triangulation, and Control

ERIC Educational Resources Information Center

Spillane, James P.; Pareja, Amber Stitziel; Dorner, Lisa; Barnes, Carol; May, Henry; Huff, Jason; Camburn, Eric

2010-01-01

In this paper we described how we mixed research approaches in a Randomized Control Trial (RCT) of a school principal professional development program. Using examples from our study we illustrate how combining qualitative and quantitative data can address some key challenges from validating instruments and measures of mediator variables to…

Are You "Tilting at Windmills" or Undertaking a Valid Clinical Trial?

PubMed Central

Zariffa, Jose; Kramer, John L.K.

2011-01-01

In this review, several aspects surrounding the choice of a therapeutic intervention and the conduct of clinical trials are discussed. Some of the background for why human studies have evolved to their current state is also included. Specifically, the following questions have been addressed: 1) What criteria should be used to determine whether a scientific discovery or invention is worthy of translation to human application? 2) What recent scientific advance warrants a deeper understanding of clinical trials by everyone? 3) What are the different types and phases of a clinical trial? 4) What characteristics of a human disorder should be noted, tracked, or stratified for a clinical trial and what inclusion /exclusion criteria are important to enrolling appropriate trial subjects? 5) What are the different study designs that can be used in a clinical trial program? 6) What confounding factors can alter the accurate interpretation of clinical trial outcomes? 7) What are the success rates of clinical trials and what can we learn from previous clinical trials? 8) What are the essential principles for the conduct of valid clinical trials? PMID:21786433

Sperm economy between female mating frequency and male ejaculate allocation.

PubMed

Abe, Jun; Kamimura, Yoshitaka

2015-03-01

Why females of many species mate multiply is a major question in evolutionary biology. Furthermore, if females accept matings more than once, ejaculates from different males compete for fertilization (sperm competition), which confronts males with the decision of how to allocate their reproductive resources to each mating event. Although most existing models have examined either female mating frequency or male ejaculate allocation while assuming fixed levels of the opposite sex's strategies, these strategies are likely to coevolve. To investigate how the interaction of the two sexes' strategies is influenced by the level of sperm limitation in the population, we developed models in which females adjust their number of allowable matings and males allocate their ejaculate in each mating. Our model predicts that females mate only once or less than once at an even sex ratio or in an extremely female-biased condition, because of female resistance and sperm limitation in the population, respectively. However, in a moderately female-biased condition, males favor partitioning their reproductive budgets across many females, whereas females favor multiple matings to obtain sufficient sperm, which contradicts the predictions of most existing models. We discuss our model's predictions and relationships with the existing models and demonstrate applications for empirical findings.

Male traits, mating tactics and reproductive success in the buff-breasted sandpiper, Tryngites subruficollis

USGS Publications Warehouse

Lanctot, Richard B.; Weatherhead, Patrick J.; Kempenaers, Bart; Scribner, Kim T.

1998-01-01

Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest that male desertion of leks was not dependent on a male's characteristics nor on the size of the lek he was presently attending. Males did join leks with larger males than their previous lek, perhaps to mate with females attracted to these larger 'hotshot' males. Males at both leks and solitary sites successfully mated. Lek tenure did not affect mating success, although lekking males appeared to mate more frequently than solitary males. Courtship disruption and to a lesser extent, female mimicry, were effective at preventing females from mating at leks, and may offer a partial explanation for female mating off leks. Our analysis that combined all males together within a year (regardless of mating tactic) indicated that males that attended leks for longer periods of time and that had fewer wing spots were significantly more likely to mate. Given some evidence that wing spotting declines with age, and that females inspect male underwings during courtship, the latter result suggests that female choice may play some role in determining male success. We suggest that male buff-breasted sandpipers may use alternative mating tactics more readily than males in other 'classic' lek-breeding species because: (1) unpredictable breeding conditions in this species' high arctic breeding range leads to low lek stability, which in turn hinders mate selection mechanisms mediated by male dominance and female choice; and (2) males are not constrained by morphological markings that indicate status or sex. Both characteristics may reduce the reproductive benefits associated with males adopting one mating tactic and result in a sort of scramble competition in which males switch between tactics as local conditions change.

A Monte Carlo analysis of breast screening randomized trials.

PubMed

Zamora, Luis I; Forastero, Cristina; Guirado, Damián; Lallena, Antonio M

2016-12-01

To analyze breast screening randomized trials with a Monte Carlo simulation tool. A simulation tool previously developed to simulate breast screening programmes was adapted for that purpose. The history of women participating in the trials was simulated, including a model for survival after local treatment of invasive cancers. Distributions of time gained due to screening detection against symptomatic detection and the overall screening sensitivity were used as inputs. Several randomized controlled trials were simulated. Except for the age range of women involved, all simulations used the same population characteristics and this permitted to analyze their external validity. The relative risks obtained were compared to those quoted for the trials, whose internal validity was addressed by further investigating the reasons of the disagreements observed. The Monte Carlo simulations produce results that are in good agreement with most of the randomized trials analyzed, thus indicating their methodological quality and external validity. A reduction of the breast cancer mortality around 20% appears to be a reasonable value according to the results of the trials that are methodologically correct. Discrepancies observed with Canada I and II trials may be attributed to a low mammography quality and some methodological problems. Kopparberg trial appears to show a low methodological quality. Monte Carlo simulations are a powerful tool to investigate breast screening controlled randomized trials, helping to establish those whose results are reliable enough to be extrapolated to other populations and to design the trial strategies and, eventually, adapting them during their development. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Evidence for impairments in using static line drawings of eye gaze cues to orient visual-spatial attention in children with high functioning autism.

PubMed

Goldberg, Melissa C; Mostow, Allison J; Vecera, Shaun P; Larson, Jennifer C Gidley; Mostofsky, Stewart H; Mahone, E Mark; Denckla, Martha B

2008-09-01

We examined the ability to use static line drawings of eye gaze cues to orient visual-spatial attention in children with high functioning autism (HFA) compared to typically developing children (TD). The task was organized such that on valid trials, gaze cues were directed toward the same spatial location as the appearance of an upcoming target, while on invalid trials gaze cues were directed to an opposite location. Unlike TD children, children with HFA showed no advantage in reaction time (RT) on valid trials compared to invalid trials (i.e., no significant validity effect). The two stimulus onset asynchronies (200 ms, 700 ms) did not differentially affect these findings. The results suggest that children with HFA show impairments in utilizing static line drawings of gaze cues to orient visual-spatial attention.

Risk assessment and comparative effectiveness of left ventricular assist device and medical management in ambulatory heart failure patients: design and rationale of the ROADMAP clinical trial.

PubMed

Rogers, Joseph G; Boyle, Andrew J; O'Connell, John B; Horstmanshof, Douglas A; Haas, Donald C; Slaughter, Mark S; Park, Soon J; Farrar, David J; Starling, Randall C

2015-02-01

Mechanical circulatory support is now a proven therapy for the treatment of patients with advanced heart failure and cardiogenic shock. The role for this therapy in patients with less severe heart failure is unknown. The objective of this study is to examine the impact of mechanically assisted circulation using the HeartMate II left ventricular assist device in patients who meet current US Food and Drug Administration-defined criteria for treatment but are not yet receiving intravenous inotropic therapy. This is a prospective, nonrandomized clinical trial of 200 patients treated with either optimal medical management or a mechanical circulatory support device. This trial will be the first prospective clinical evaluation comparing outcomes of patients with advanced ambulatory heart failure treated with either ongoing medical therapy or a left ventricular assist device. It is anticipated to provide novel insights regarding relative outcomes with each treatment and an understanding of patient and provider acceptance of the ventricular assist device therapy. This trial will also provide information regarding the risk of events in "stable" patients with advanced heart failure and guidance for the optimal timing of left ventricular assist device therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

The dance of male Anopheles gambiae in mating swarms

USDA-ARS?s Scientific Manuscript database

The mating behavior of the malaria vector Anopheles gambiae is of great interest from a fundamental and applied perspective. One of the most important elements of mating in this species is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and inseminat...

Dual fitness benefits of post-mating sugar meals for female hawkmoths (Hyles lineata).

PubMed

von Arx, Martin; Sullivan, Kayleigh A; Raguso, Robert A

2013-04-01

The white-lined sphinx moth (Hyles lineata: Sphingidae) is the most widespread and abundant hawkmoth pollinator in North America and plays a major role in the reproductive biology of many plant species. H. lineata visits a wide range of plants, which differ in the quality and quantity (e.g. caloric content, volume) of the nectar reward that they offer in exchange for pollination services. Some of these plants represent a suitable oviposition substrate as well as a profitable nectar source, allowing mated H. lineata females to mix foraging and oviposition bouts. We investigated the effects of post-mating nectar intake on the reproductive success of female H. lineata. While all experimental females had access to a 20% sucrose solution during the pre-mating phase (avg. 2.7 days) we manipulated the post-mating diet, assigning mated females to three experimental groups (sucrose fed, water fed, or unfed). Mated females with access to sucrose lived twice as long and produced more fertile eggs at double the rate of control moths that were starved or water-fed after mating. Thus, the sugar component of floral nectar positively affects the physiology of mated H. lineata at multiple levels, which translates into strong selection for mated females to continue nectar foraging during or between oviposition bouts. Copyright © 2013 Elsevier Ltd. All rights reserved.

Male mate choice influences female promiscuity in Soay sheep

PubMed Central

Preston, B.T.; Stevenson, I.R.; Pemberton, J.M.; Coltman, D.W.; Wilson, K.

2005-01-01

In most animal species, males are predicted to compete for reproductive opportunities, while females are expected to choose between potential mates. However, when males’ rate of reproduction is constrained, or females vary widely in ‘quality’, male mate choice is also predicted to occur. Such conditions exist in the promiscuous mating system of feral Soay sheep on St Kilda, Scotland, where a highly synchronized mating season, intense sperm competition and limitations on sperm production constrain males’ potential reproductive rate, and females vary substantially in their ability to produce successful offspring. We show that, consistent with predictions, competitive rams focus their mating activity and siring success towards heavier females with higher inclusive fitness. To our knowledge, this is the first time that male mate choice has been identified and shown to lead to assortative patterns of parentage in a natural mammalian system, and occurs despite fierce male–male competition for mates. An additional consequence of assortative mating in this population is that lighter females experience a series of unstable consorts with less adept rams, and hence are mated by a greater number of males during their oestrus. We have thus also identified a novel male-driven mechanism that generates variation in female promiscuity, which suggests that the high levels of female promiscuity in this system are not part of an adaptive female tactic to intensify post-copulatory competition between males. PMID:15734690

Male mate choice influences female promiscuity in Soay sheep.

PubMed

Preston, B T; Stevenson, I R; Pemberton, J M; Coltman, D W; Wilson, K

2005-02-22

In most animal species, males are predicted to compete for reproductive opportunities, while females are expected to choose between potential mates. However, when males' rate of reproduction is constrained, or females vary widely in 'quality', male mate choice is also predicted to occur. Such conditions exist in the promiscuous mating system of feral Soay sheep on St Kilda, Scotland, where a highly synchronized mating season, intense sperm competition and limitations on sperm production constrain males' potential reproductive rate, and females vary substantially in their ability to produce successful offspring. We show that, consistent with predictions, competitive rams focus their mating activity and siring success towards heavier females with higher inclusive fitness. To our knowledge, this is the first time that male mate choice has been identified and shown to lead to assortative patterns of parentage in a natural mammalian system, and occurs despite fierce male-male competition for mates. An additional consequence of assortative mating in this population is that lighter females experience a series of unstable consorts with less adept rams, and hence are mated by a greater number of males during their oestrus. We have thus also identified a novel male-driven mechanism that generates variation in female promiscuity, which suggests that the high levels of female promiscuity in this system are not part of an adaptive female tactic to intensify post-copulatory competition between males.

Choosy Wolves? Heterozygote Advantage But No Evidence of MHC-Based Disassortative Mating.

PubMed

Galaverni, Marco; Caniglia, Romolo; Milanesi, Pietro; Lapalombella, Silvana; Fabbri, Elena; Randi, Ettore

2016-03-01

A variety of nonrandom mate choice strategies, including disassortative mating, are used by vertebrate species to avoid inbreeding, maintain heterozygosity and increase fitness. Disassortative mating may be mediated by the major histocompatibility complex (MHC), an important gene cluster controlling immune responses to pathogens. We investigated the patterns of mate choice in 26 wild-living breeding pairs of gray wolf (Canis lupus) that were identified through noninvasive genetic methods and genotyped at 3 MHC class II and 12 autosomal microsatellite (STR) loci. We tested for deviations from random mating and evaluated the covariance of genetic variables at functional and STR markers with fitness proxies deduced from pedigree reconstructions. Results did not show evidences of MHC-based disassortative mating. Rather we found a higher peptide similarity between mates at MHC loci as compared with random expectations. Fitness values were positively correlated with heterozygosity of the breeders at both MHC and STR loci, whereas they decreased with relatedness at STRs. These findings may indicate fitness advantages for breeders that, while avoiding highly related mates, are more similar at the MHC and have high levels of heterozygosity overall. Such a pattern of MHC-assortative mating may reflect local coadaptation of the breeders, while a reduction in genetic diversity may be balanced by heterozygote advantages. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Variation in mating systems of salamanders: mate guarding or territoriality?

PubMed

Deitloff, Jennifer; Alcorn, Michael A; Graham, Sean P

2014-07-01

Two of the most common mating tactics in vertebrates are mate guarding and territoriality, yet much of the research on these strategies has focused on mating systems in birds, despite novel insights gained from studying less traditional systems. North American stream salamanders that comprise the Eurycea bislineata complex represent an excellent nontraditional system for comparing mating strategies because these species exhibit a continuum of male morphologies, diverse habitat associations, and various potential mating strategies. We studied two species within this complex that exhibit the extremes of this continuum, Eurycea aquatica (robust morph) and Eurycea cirrigera (slender morph). The larger head in males of E. aquatica is due to larger musculature around the jaw and may be associated with aggressive behavior. Therefore, we hypothesized that the robust morphology exhibited by males of E. aquatica provides benefits during either territorial defense or mate defense and that males of E. cirrigera would not exhibit aggression in either scenario. We found that neither species exhibited aggressive behavior to defend a territory. However, in the presence of a female, males of E. aquatica were significantly more aggressive toward intruding males than were males of E. cirrigera. Therefore, mate-guarding behavior occurs in E. aquatica, and the enlarged head of males likely aids in deterring rivals. This is the first demonstration of mate-guarding behavior in a plethodontid, the most speciose family of salamanders. Copyright © 2014 Elsevier B.V. All rights reserved.

Oxytocin receptor density is associated with male mating tactics and social monogamy

PubMed Central

Ophir, Alexander G.; Gessel, Ana; Zheng, Da-Jiang; Phelps, Steven M.

2012-01-01

Despite its well-described role in female affiliation, the influence of oxytocin on male pairbonding is largely unknown. However, recent human studies indicate that this nonapeptide has a potent influence on male behaviors commonly associated with monogamy. Here we investigated the distribution of oxytocin receptors (OTR) throughout the forebrain of the socially monogamous male prairie vole (Microtus ochrogaster). Because males vary in both sexual and spatial fidelity, we explored the extent to which OTR predicted monogamous or non-monogamous patterns of space use, mating success and sexual fidelity in free-living males. We found that monogamous males expressed higher OTR density in the nucleus accumbens than non-monogamous males, a result that mirrors species differences in voles with different mating systems. OTR density in the posterior portion of the insula predicted mating success. Finally, OTR in the hippocampus and septohippocampal nucleus, which are nuclei associated with spatial memory, predicted patterns of space use and reproductive success within mating tactics. Our data highlight the importance of oxytocin receptor in neural structures associated with pairbonding and socio-spatial memory in male mating tactics. The role of memory in mating systems is often neglected, despite the fact that mating tactics impose an inherently spatial challenge for animals. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating pairbonding and mating tactics is crucial to fully appreciate the suite of factors driving mating systems. PMID:22285648

Impact of geographical origin on mating behaviour in two species of Biomphalaria (Planorbidae: Gastropoda).

PubMed

Rupp, J C; Woolhouse, M E

1999-12-01

Studies of inbreeding and outcrossing have traditionally concentrated on matings within populations. The influence of geographical origin on mate choice in animals from different populations has received less attention. We investigated whether planorbid snails mated preferentially within their own population or with snails from other populations. Snails from three Biomphalaria pfeifferi strains and three B. glabrata strains were allowed to mate with conspecifics in the laboratory. We recorded their matings at night using time-lapse video. When they could choose between sympatric and allopatric snails, Biomphalaria snails significantly preferred the former: snails of each population mated more often with sympatric than with allopatric snails. This tendency to avoid outcrossing may indicate that, in some species, local adaptations can be more valuable than genetic novelties. Copyright 1999 The Association for the Study of Animal Behaviour.

Multiple mating and its relationship to brood size in pregnant fishes versus pregnant mammals and other viviparous vertebrates

PubMed Central

Avise, John C.; Liu, Jin-Xian

2011-01-01

We summarize the literature on rates of multiple paternity and sire numbers per clutch in viviparous fishes vs. mammals, two vertebrate groups in which pregnancy is common but entails very different numbers of embryos (for species surveyed, piscine broods averaged >10-fold larger than mammalian litters). As deduced from genetic parentage analyses, multiple mating by the pregnant sex proved to be common in assayed species but averaged significantly higher in fish than mammals. However, within either of these groups we found no significant correlations between brood size and genetically deduced incidence of multiple mating by females. Overall, these findings offer little support for the hypothesis that clutch size in pregnant species predicts the outcome of selection for multiple mating by brooders. Instead, whatever factors promote multiple mating by members of the gestating sex seem to do so in surprisingly similar ways in live-bearing vertebrates otherwise as different as fish and mammals. Similar conclusions emerged when we extended the survey to viviparous amphibians and reptiles. One notion consistent with these empirical observations is that although several fitness benefits probably accrue from multiple mating, logistical constraints on mate-encounter rates routinely truncate multiple mating far below levels that otherwise could be accommodated, especially in species with larger broods. We develop this concept into a “logistical constraint hypothesis” that may help to explain these mating outcomes in viviparous vertebrates. Under the logistical constraint hypothesis, propensities for multiple mating in each species register a balance between near-universal fitness benefits from multiple mating and species-idiosyncratic logistical limits on polygamy. PMID:21482777

MHC class II-assortative mate choice in European badgers (Meles meles).

PubMed

Sin, Yung Wa; Annavi, Geetha; Newman, Chris; Buesching, Christina; Burke, Terry; Macdonald, David W; Dugdale, Hannah L

2015-06-01

The major histocompatibility complex (MHC) plays a crucial role in the immune system, and in some species, it is a target by which individuals choose mates to optimize the fitness of their offspring, potentially mediated by olfactory cues. Under the genetic compatibility hypothesis, individuals are predicted to choose mates with compatible MHC alleles, to increase the fitness of their offspring. Studies of MHC-based mate choice in wild mammals are under-represented currently, and few investigate more than one class of MHC genes. We investigated mate choice based on the compatibility of MHC class I and II genes in a wild population of European badgers (Meles meles). We also investigated mate choice based on microsatellite-derived pairwise relatedness, to attempt to distinguish MHC-specific effects from genomewide effects. We found MHC-assortative mating, based on MHC class II, but not class I genes. Parent pairs had smaller MHC class II DRB amino acid distances and smaller functional distances than expected from random pairings. When we separated the analyses into within-group and neighbouring-group parent pairs, only neighbouring-group pairs showed MHC-assortative mating, due to similarity at MHC class II loci. Our randomizations showed no evidence of genomewide-based inbreeding, based on 35 microsatellite loci; MHC class II similarity was therefore the apparent target of mate choice. We propose that MHC-assortative mate choice may be a local adaptation to endemic pathogens, and this assortative mate choice may have contributed to the low MHC genetic diversity in this population. © 2015 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.

Comparative analysis of the mating-type loci from Neurospora crassa and Sordaria macrospora: identification of novel transcribed ORFs.

PubMed

Pöggeler, S; Kück, U

2000-03-01

The mating-type locus controls mating and sexual development in filamentous ascomycetes. In the heterothallic ascomycete Neurospora crassa, the genes that confer mating behavior comprise dissimilar DNA sequences (idiomorphs) in the mat a and mat A mating partners. In the homothallic fungus Sordaria macrospora, sequences corresponding to both idiomorphs are located contiguously in the mating-type locus, which contains one chimeric gene, Smt A-3, that includes sequences which are similar to sequences found at the mat A and mat a mating-type idiomorphs in N. crassa. In this study, we describe the comparative transcriptional analysis of the chimeric mating-type region of S. macrospora and the corresponding region of the N. crassa mat a idiomorph. By means of RT-PCR experiments, we identified novel intervening sequences in the mating-type loci of both ascomycetes and, hence, concluded that an additional ORF, encoding a putative polypeptide of 79 amino acids, is present in the N. crassa mat a idiomorph. Furthermore, our analysis revealed co-transcription of the novel gene with the mat a-1 gene in N. crassa. The same mode of transcription was found in the corresponding mating-type region of S. macrospora, where the chimeric Smt A-3 gene is co-transcribed with the mat a-specific Smt a-1 gene. Analysis of a Smt A-3 cDNA revealed optional splicing of two introns. We believe that this is the first report of co-transcription of protein-encoding nuclear genes in filamentous fungi. Possible functions of the novel ORFs in regulating mating-type gene expression are discussed.

Mate Choice in Mus musculus Is Relative and Dependent on the Estrous State

PubMed Central

Zinck, Léa; Lima, Susana Q.

2013-01-01

Mate choice is a critical behavioral decision process with profound impact on evolution. However, the mechanistic basis of mate choice is poorly understood. In this study we focused on assortative mate choice, which is known to contribute to the reproductive isolation of the two European subspecies of house mouse, Mus musculus musculus and Mus musculus domesticus. To understand the decision process, we developed both full mating and limited-contact paradigms and tested musculus females' preference for musculus versus domesticus males, mimicking the natural musculus/domesticus contact zone. As hypothesized, when allowed to mate we found that sexually receptive musculus females exhibited a robust preference to mate with musculus males. In contrast, when non-receptive, females did not exhibit a preference and rather alternated between males in response to male mount attempts. Moreover in a no-choice condition, females mated readily with males from both subspecies. Finally, when no physical contact was allowed, and therefore male's behavior could not influence female's behavior, female's preference for its own subspecies was maintained independently of the estrous state. Together, our results suggest that the assortative preference is relative and based on a comparison of the options available rather than on an absolute preference. The results of the limited-contact experiments highlight the interplay between female's internal state and the nature of the interaction with prospective mates in the full mating conditions. With these experiments we believe we established an assortative mate preference assay that is appropriate for the investigation of its underlying substrates. PMID:23762466

MHC-disassortative mate choice and inbreeding avoidance in a solitary primate.

PubMed

Huchard, Elise; Baniel, Alice; Schliehe-Diecks, Susanne; Kappeler, Peter M

2013-08-01

Sexual selection theory suggests that choice for partners carrying dissimilar genes at the major histocompatibility complex (MHC) may play a role in maintaining genetic variation in animal populations by limiting inbreeding or improving the immunity of future offspring. However, it is often difficult to establish whether the observed MHC dissimilarity among mates drives mate choice or represents a by-product of inbreeding avoidance based on MHC-independent cues. Here, we used 454-sequencing and a 10-year study of wild grey mouse lemurs (Microcebus murinus), small, solitary primates from western Madagascar, to compare the relative importance on the mate choice of two MHC class II genes, DRB and DQB, that are equally variable but display contrasting patterns of selection at the molecular level, with DRB under stronger diversifying selection. We further assessed the effect of the genetic relatedness and of the spatial distance among candidate mates on the detection of MHC-dependent mate choice. Our results reveal inbreeding avoidance, along with disassortative mate choice at DRB, but not at DQB. DRB-disassortative mate choice remains detectable after excluding all related dyads (characterized by a relatedness coefficient r > 0), but varies slightly with the spatial distance among candidate mates. These findings suggest that the observed deviations from random mate choice at MHC are driven by functionally important MHC genes (like DRB) rather than passively resulting from inbreeding avoidance and further emphasize the need for taking into account the spatial and genetic structure of the population in correlative tests of MHC-dependent mate choice. © 2013 John Wiley & Sons Ltd.

Site fidelity, mate fidelity, and breeding dispersal in American kestrels

USGS Publications Warehouse

Steenhof, K.; Peterson, B.E.

2009-01-01

We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

Balancing in- and out-breeding by the predatory mite Phytoseiulus persimilis.

PubMed

Atalay, Demet; Schausberger, Peter

2018-02-01

In- and out-breeding depressions are commonly observed phenomena in sexually reproducing organisms with a patchy distribution pattern, and spatial segmentation and/or isolation of groups. At the genetic level, inbreeding depression is due to increased homozygosity, whereas outbreeding depression is due to inferior genetic compatibility of mates. Optimal outbreeding theory suggests that intermediate levels of mate relatedness should provide for the highest fitness gains. Here, we assessed the fitness consequences of genetic relatedness between mates in plant-inhabiting predatory mites Phytoseiulus persimilis, which are obligatory sexually reproducing but haplo-diploid. Both females and males arise from fertilized eggs but males lose the paternal chromosome set during embryogenesis, dubbed pseudo-arrhenotoky. Phytoseiulus persimilis are highly efficacious in reducing crop-damaging spider mite populations and widely used in biological control. Using iso-female lines of two populations, from Sicily and Greece, we assessed the fecundity of females, and sex ratio of their offspring, that mated with either a sibling, a male from the same population or a male from the other population. Additionally, we recorded mating latency and duration. Females mating with a male from the same population produced more eggs, with a lower female bias, over a longer time than females mating with a sibling or with a male from the other population. Mating latency was unaffected by mate relatedness; mating duration was disproportionally long in sibling couples, likely indicating female reluctance to mate and sub-optimal spermatophore transfer. Our study provides a rare example of in- and out-breeding depression in a haplo-diploid arthropod, supporting the optimal outbreeding theory.

Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha)

PubMed Central

Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

2017-01-01

Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm–egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm–egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm–egg interactions. PMID:28051059

Cost-effectiveness of nivolumab for recurrent or metastatic head and neck cancer☆.

PubMed

Ward, Matthew C; Shah, Chirag; Adelstein, David J; Geiger, Jessica L; Miller, Jacob A; Koyfman, Shlomo A; Singer, Mendel E

2017-11-01

Nivolumab is the first drug to demonstrate a survival benefit for platinum-refractory recurrent or metastatic head and neck cancer. We performed a cost-utility analysis to assess the economic value of nivolumab as compared to alternative standard agents in this context. Using data from the CheckMate 141 trial, we constructed a Markov simulation model from the US payer's perspective to evaluate the cost-effectiveness of nivolumab compared to physician choice of either cetuximab, methotrexate or docetaxel. Alternative strategies considered included: single-agent cetuximab, methotrexate or docetaxel, or first testing for PD-L1 to select for nivolumab. Costs were extracted from Medicare and utilities from the literature and CheckMate. Probabilistic sensitivity analysis (PSA) was used to evaluate parameter uncertainty. $100,000/QALY was the primary threshold for cost-effectiveness. When comparing nivolumab to the standard arm of CheckMate, nivolumab demonstrated an incremental cost-effectiveness ratio (ICER) of $140,672/QALY. When comparing standard therapies, methotrexate was the most cost-effective with similar results for docetaxel. Nivolumab was cost-effective compared to single-agent cetuximab (ICER $89,786/QALY). Treatment selection by PD-L1 immunohistochemistry did not markedly improve the cost-effectiveness of nivolumab. Factors likely to positively impact the cost-effectiveness of nivolumab include better baseline quality-of-life, poor tolerability of standard treatments and/or a lower cost of nivolumab. Nivolumab is preferred to single-agent cetuximab but requires a willingness-to-pay of at least $150,000/QALY to be considered cost-effective when compared to docetaxel or methotrexate. Selection by PD-L1 does not markedly improve the cost-effectiveness of nivolumab. This informs patient selection and clinical care-path development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Postmating-prezygotic isolation is not an important source of selection for reinforcement within and between species in Drosophila pseudoobscura and D. persimilis.

PubMed

Lorch, Patrick D; Servedio, Maria R

2005-05-01

Most work on adaptive speciation to date has focused on the role of low hybrid fitness as the force driving reinforcement (the evolution of premating isolation after secondary contact that reduces the likelihood of matings between populations). However, recent theoretical work has shown that postmating, prezygotic incompatibilities may also be important in driving premating isolation. We quantified premating, postmating-prezygotic, and early postzygotic fitness effects in crosses among three populations: Drosophila persimilis, D. pseudoobscura USA (sympatric to D. persimilis), and D. pseudoobscura Bogotá (allopatric to D. persimilis). Interspecific matings were more likely to fail when they involved the sympatric populations than when they involved the allopatric populations, consistent with reinforcement. We also found that failure rate in sympatric mating trials depended on whether D. persimilis females were paired with D. pseudoobscura males or the reverse. This asymmetry most likely indicates differences in discrimination against heterospecific males by females. By measuring egg laying rate, fertilization success and hatching success, we also compared components of postmating-prezygotic and early postzygotic isolation. Postmating-prezygotic fitness costs were small and not distinguishable between hetero- and conspecific crosses. Early postzygotic fitness effects due to hatching success differences were also small in between-population crosses. There was, however, a postzygotic fitness effect that may have resulted from an X-linked allele found in one of the two strains of D. pseudoobscura USA. We conclude that the postmating-prezygotic fitness costs we measured probably did not drive premating isolation in these species. Premating isolation is most likely driven in sympatric populations by previously known hybrid male sterility.

Effects of maternal lines and mating systems on lamb carcass merit

USDA-ARS?s Scientific Manuscript database

Objectives: The objective of this study was to analyze the carcass composition of lambs produced from different mating systems. Materials and Methods: Lambs (n = 1,237) were produced by a multi- sire mating of three maternal lines (Katahdin (KN), Polypay (PP), and Easycare (EZ)) in two mating system...

Evidence for mate guarding behavior in the Taylor's checkerspot butterfly

Treesearch

Victoria J. Bennett; Winston P. Smith; Matthew G. Betts

2011-01-01

Discerning the intricacies of mating systems in butterflies can be difficult, particularly when multiple mating strategies are employed and are cryptic and not exclusive. We observed the behavior and habitat use of 113 male Taylor's checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct mating strategies were...

Development and Psychometric Evaluation of the HPV Clinical Trial Survey for Parents (CTSP-HPV) Using Traditional Survey Development Methods and Community Engagement Principles.

PubMed

Cunningham, Jennifer; Wallston, Kenneth A; Wilkins, Consuelo H; Hull, Pamela C; Miller, Stephania T

2015-12-01

This study describes the development and psychometric evaluation of HPV Clinical Trial Survey for Parents with Children Aged 9 to 15 (CTSP-HPV) using traditional instrument development methods and community engagement principles. An expert panel and parental input informed survey content and parents recommended study design changes (e.g., flyer wording). A convenience sample of 256 parents completed the final survey measuring parental willingness to consent to HPV clinical trial (CT) participation and other factors hypothesized to influence willingness (e.g., HPV vaccine benefits). Cronbach's a, Spearman correlations, and multiple linear regression were used to estimate internal consistency, convergent and discriminant validity, and predictively validity, respectively. Internal reliability was confirmed for all scales (a ≥ 0.70.). Parental willingness was positively associated (p < 0.05) with trust in medical researchers, adolescent CT knowledge, HPV vaccine benefits, advantages of adolescent CTs (r range 0.33-0.42), supporting convergent validity. Moderate discriminant construct validity was also demonstrated. Regression results indicate reasonable predictive validity with the six scales accounting for 31% of the variance in parents' willingness. This instrument can inform interventions based on factors that influence parental willingness, which may lead to the eventual increase in trial participation. Further psychometric testing is warranted. © 2015 Wiley Periodicals, Inc.

Big Data in Designing Clinical Trials: Opportunities and Challenges

PubMed Central

Mayo, Charles S.; Matuszak, Martha M.; Schipper, Matthew J.; Jolly, Shruti; Hayman, James A.; Ten Haken, Randall K.

2017-01-01

Emergence of big data analytics resource systems (BDARSs) as a part of routine practice in Radiation Oncology is on the horizon. Gradually, individual researchers, vendors, and professional societies are leading initiatives to create and demonstrate use of automated systems. What are the implications for design of clinical trials, as these systems emerge? Gold standard, randomized controlled trials (RCTs) have high internal validity for the patients and settings fitting constraints of the trial, but also have limitations including: reproducibility, generalizability to routine practice, infrequent external validation, selection bias, characterization of confounding factors, ethics, and use for rare events. BDARS present opportunities to augment and extend RCTs. Preliminary modeling using single- and muti-institutional BDARS may lead to better design and less cost. Standardizations in data elements, clinical processes, and nomenclatures used to decrease variability and increase veracity needed for automation and multi-institutional data pooling in BDARS also support ability to add clinical validation phases to clinical trial design and increase participation. However, volume and variety in BDARS present other technical, policy, and conceptual challenges including applicable statistical concepts, cloud-based technologies. In this summary, we will examine both the opportunities and the challenges for use of big data in design of clinical trials. PMID:28913177

Big Data in Designing Clinical Trials: Opportunities and Challenges.

PubMed

Mayo, Charles S; Matuszak, Martha M; Schipper, Matthew J; Jolly, Shruti; Hayman, James A; Ten Haken, Randall K

2017-01-01

Emergence of big data analytics resource systems (BDARSs) as a part of routine practice in Radiation Oncology is on the horizon. Gradually, individual researchers, vendors, and professional societies are leading initiatives to create and demonstrate use of automated systems. What are the implications for design of clinical trials, as these systems emerge? Gold standard, randomized controlled trials (RCTs) have high internal validity for the patients and settings fitting constraints of the trial, but also have limitations including: reproducibility, generalizability to routine practice, infrequent external validation, selection bias, characterization of confounding factors, ethics, and use for rare events. BDARS present opportunities to augment and extend RCTs. Preliminary modeling using single- and muti-institutional BDARS may lead to better design and less cost. Standardizations in data elements, clinical processes, and nomenclatures used to decrease variability and increase veracity needed for automation and multi-institutional data pooling in BDARS also support ability to add clinical validation phases to clinical trial design and increase participation. However, volume and variety in BDARS present other technical, policy, and conceptual challenges including applicable statistical concepts, cloud-based technologies. In this summary, we will examine both the opportunities and the challenges for use of big data in design of clinical trials.

Predicting Performance in Higher Education Using Proximal Predictors.

PubMed

Niessen, A Susan M; Meijer, Rob R; Tendeiro, Jorge N

2016-01-01

We studied the validity of two methods for predicting academic performance and student-program fit that were proximal to important study criteria. Applicants to an undergraduate psychology program participated in a selection procedure containing a trial-studying test based on a work sample approach, and specific skills tests in English and math. Test scores were used to predict academic achievement and progress after the first year, achievement in specific course types, enrollment, and dropout after the first year. All tests showed positive significant correlations with the criteria. The trial-studying test was consistently the best predictor in the admission procedure. We found no significant differences between the predictive validity of the trial-studying test and prior educational performance, and substantial shared explained variance between the two predictors. Only applicants with lower trial-studying scores were significantly less likely to enroll in the program. In conclusion, the trial-studying test yielded predictive validities similar to that of prior educational performance and possibly enabled self-selection. In admissions aimed at student-program fit, or in admissions in which past educational performance is difficult to use, a trial-studying test is a good instrument to predict academic performance.

Practical Aspects of Designing and Conducting Validation Studies Involving Multi-study Trials.

PubMed

Coecke, Sandra; Bernasconi, Camilla; Bowe, Gerard; Bostroem, Ann-Charlotte; Burton, Julien; Cole, Thomas; Fortaner, Salvador; Gouliarmou, Varvara; Gray, Andrew; Griesinger, Claudius; Louhimies, Susanna; Gyves, Emilio Mendoza-de; Joossens, Elisabeth; Prinz, Maurits-Jan; Milcamps, Anne; Parissis, Nicholaos; Wilk-Zasadna, Iwona; Barroso, João; Desprez, Bertrand; Langezaal, Ingrid; Liska, Roman; Morath, Siegfried; Reina, Vittorio; Zorzoli, Chiara; Zuang, Valérie

This chapter focuses on practical aspects of conducting prospective in vitro validation studies, and in particular, by laboratories that are members of the European Union Network of Laboratories for the Validation of Alternative Methods (EU-NETVAL) that is coordinated by the EU Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM). Prospective validation studies involving EU-NETVAL, comprising a multi-study trial involving several laboratories or "test facilities", typically consist of two main steps: (1) the design of the validation study by EURL ECVAM and (2) the execution of the multi-study trial by a number of qualified laboratories within EU-NETVAL, coordinated and supported by EURL ECVAM. The approach adopted in the conduct of these validation studies adheres to the principles described in the OECD Guidance Document on the Validation and International Acceptance of new or updated test methods for Hazard Assessment No. 34 (OECD 2005). The context and scope of conducting prospective in vitro validation studies is dealt with in Chap. 4 . Here we focus mainly on the processes followed to carry out a prospective validation of in vitro methods involving different laboratories with the ultimate aim of generating a dataset that can support a decision in relation to the possible development of an international test guideline (e.g. by the OECD) or the establishment of performance standards.

A Genome-wide Combinatorial Strategy Dissects Complex Genetic Architecture of Seed Coat Color in Chickpea

PubMed Central

Bajaj, Deepak; Das, Shouvik; Upadhyaya, Hari D.; Ranjan, Rajeev; Badoni, Saurabh; Kumar, Vinod; Tripathi, Shailesh; Gowda, C. L. Laxmipathi; Sharma, Shivali; Singh, Sube; Tyagi, Akhilesh K.; Parida, Swarup K.

2015-01-01

The study identified 9045 high-quality SNPs employing both genome-wide GBS- and candidate gene-based SNP genotyping assays in 172, including 93 cultivated (desi and kabuli) and 79 wild chickpea accessions. The GWAS in a structured population of 93 sequenced accessions detected 15 major genomic loci exhibiting significant association with seed coat color. Five seed color-associated major genomic loci underlying robust QTLs mapped on a high-density intra-specific genetic linkage map were validated by QTL mapping. The integration of association and QTL mapping with gene haplotype-specific LD mapping and transcript profiling identified novel allelic variants (non-synonymous SNPs) and haplotypes in a MATE secondary transporter gene regulating light/yellow brown and beige seed coat color differentiation in chickpea. The down-regulation and decreased transcript expression of beige seed coat color-associated MATE gene haplotype was correlated with reduced proanthocyanidins accumulation in the mature seed coats of beige than light/yellow brown seed colored desi and kabuli accessions for their coloration/pigmentation. This seed color-regulating MATE gene revealed strong purifying selection pressure primarily in LB/YB seed colored desi and wild Cicer reticulatum accessions compared with the BE seed colored kabuli accessions. The functionally relevant molecular tags identified have potential to decipher the complex transcriptional regulatory gene function of seed coat coloration and for understanding the selective sweep-based seed color trait evolutionary pattern in cultivated and wild accessions during chickpea domestication. The genome-wide integrated approach employed will expedite marker-assisted genetic enhancement for developing cultivars with desirable seed coat color types in chickpea. PMID:26635822

Loaded transducer for downhole drilling components

DOEpatents

Hall, David R [Provo, UT; Fox, Joe [Spanish Fork, UT; Daly, Jeffery E [Cypress, TX

2009-05-05

A system for transmitting information between downhole components has a first downhole component with a first mating surface and a second downhole component having a second mating surface configured to substantially mate with the first mating surface. The system also has a first transmission element with a first communicating surface and is mounted within a recess in the first mating surface. The first transmission element also has an angled surface. The recess has a side with multiple slopes for interacting with the angled surface, each slope exerting a different spring force on the first transmission element. A second transmission element has a second communicating surface mounted proximate the second mating surface and adapted to communicate with the first communicating surface.

No discrimination against previous mates in a sexually cannibalistic spider

NASA Astrophysics Data System (ADS)

Fromhage, Lutz; Schneider, Jutta M.

2005-09-01

In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

Multiple convergent supergene evolution events in mating-type chromosomes.

PubMed

Branco, Sara; Carpentier, Fantin; Rodríguez de la Vega, Ricardo C; Badouin, Hélène; Snirc, Alodie; Le Prieur, Stéphanie; Coelho, Marco A; de Vienne, Damien M; Hartmann, Fanny E; Begerow, Dominik; Hood, Michael E; Giraud, Tatiana

2018-05-21

Convergent adaptation provides unique insights into the predictability of evolution and ultimately into processes of biological diversification. Supergenes (beneficial gene linkage) are striking examples of adaptation, but little is known about their prevalence or evolution. A recent study on anther-smut fungi documented supergene formation by rearrangements linking two key mating-type loci, controlling pre- and post-mating compatibility. Here further high-quality genome assemblies reveal four additional independent cases of chromosomal rearrangements leading to regions of suppressed recombination linking these mating-type loci in closely related species. Such convergent transitions in genomic architecture of mating-type determination indicate strong selection favoring linkage of mating-type loci into cosegregating supergenes. We find independent evolutionary strata (stepwise recombination suppression) in several species, with extensive rearrangements, gene losses, and transposable element accumulation. We thus show remarkable convergence in mating-type chromosome evolution, recurrent supergene formation, and repeated evolution of similar phenotypes through different genomic changes.

Mate choice in fruit flies is rational and adaptive.

PubMed

Arbuthnott, Devin; Fedina, Tatyana Y; Pletcher, Scott D; Promislow, Daniel E L

2017-01-17

According to rational choice theory, beneficial preferences should lead individuals to sort available options into linear, transitive hierarchies, although the extent to which non-human animals behave rationally is unclear. Here we demonstrate that mate choice in the fruit fly Drosophila melanogaster results in the linear sorting of a set of diverse isogenic female lines, unambiguously demonstrating the hallmark of rational behaviour, transitivity. These rational choices are associated with direct benefits, enabling males to maximize offspring production. Furthermore, we demonstrate that female behaviours and cues act redundantly in mate detection and assessment, as rational mate choice largely persists when visual or chemical sensory modalities are impaired, but not when both are impaired. Transitivity in mate choice demonstrates that the quality of potential mates varies significantly among genotypes, and that males and females behave in such a way as to facilitate adaptive mate choice.

Consideration of Cosmetic Surgery As Part of Women's Benefit-Provisioning Mate Retention Strategy.

PubMed

Atari, Mohammad; Barbaro, Nicole; Sela, Yael; Shackelford, Todd K; Chegeni, Razieh

2017-01-01

Individuals perform mate retention behaviors to minimize the risk of partner infidelity and relationship dissolution. The current study investigates whether consideration of cosmetic surgery can be conceptualized as part of a broader strategy of mate retention for women, but not men. We hypothesized that women's consideration of cosmetic surgery would be positively associated with performance frequencies of Benefit-Provisioning and Cost-Inflicting mate retention behaviors. We recruited 203 individuals (54% women) in committed heterosexual relationships from Tehran, Iran. Results indicate a positive association between consideration of cosmetic surgery and Benefit-Provisioning mate retention behaviors for women, but not men. There was no association between consideration of cosmetic surgery and Cost-Inflicting mate retention behaviors. Women therefore may consider cosmetic surgery to improve their physical attractiveness as part of a Benefit-Provisioning strategy to retain a long-term mate. We discuss limitations of the study and highlight future directions for research from an evolutionary perspective.

ASSORTATIVE MATING CAN IMPEDE OR FACILITATE FIXATION OF UNDERDOMINANT ALLELES

PubMed Central

NEWBERRY, MITCHELL G; MCCANDLISH, DAVID M; PLOTKIN, JOSHUA B

2017-01-01

Underdominant mutations have fixed between divergent species, yet classical models suggest that rare underdominant alleles are purged quickly except in small or subdivided populations. We predict that underdominant alleles that also influence mate choice, such as those affecting coloration patterns visible to mates and predators alike, can fix more readily. We analyze a mechanistic model of positive assortative mating in which individuals have n chances to sample compatible mates. This one-parameter model naturally spans random mating (n =1) and complete assortment (n → ∞), yet it produces sexual selection whose strength depends non-monotonically on n. This sexual selection interacts with viability selection to either inhibit or facilitate fixation. As mating opportunities increase, underdominant alleles fix as frequently as neutral mutations, even though sexual selection and underdominance independently each suppress rare alleles. This mechanism allows underdominant alleles to fix in large populations and illustrates how life history can affect evolutionary change. PMID:27497738

Through evolution's eyes: extracting mate preferences by linking visual attention to adaptive design.

PubMed

Krupp, Daniel Brian

2008-02-01

Information is crucial to decision-making, including mate choice decisions. Perceptual systems, such as attention, evolved in part to forage for reproductive information; consequently, these systems can be used to reveal mate preferences. Here, I consider the place of visual information in human mate choice and provide a rationale for pressing into service methods drawn from the attention literature for the study of mate choice decisions. Because visual attention is allocated automatically and selectively, it may be used to complement common methods of mate preference assessment, such as self-report questionnaires and measures of genital arousal, while avoiding some of the pitfalls of these methods. Beyond the utility of increasing confidence in extant research findings by employing relatively unobtrusive methods, visual attention paradigms can also allow researchers to explore a variety of questions that are rarely asked, such as those concerned with signal efficiency and tradeoffs in the assessment of mate value.

Explanatory Versus Pragmatic Trials: An Essential Concept in Study Design and Interpretation.

PubMed

Merali, Zamir; Wilson, Jefferson R

2017-11-01

Randomized clinical trials often represent the highest level of clinical evidence available to evaluate the efficacy of an intervention in clinical medicine. Although the process of randomization serves to maximize internal validity, the external validity, or generalizability, of such studies depends on several factors determined at the design phase of the trial including eligibility criteria, study setting, and outcomes of interest. In general, explanatory trials are optimized to demonstrate the efficacy of an intervention in a highly selected patient group; however, findings from these studies may not be generalizable to the larger clinical problem. In contrast, pragmatic trials attempt to understand the real-world benefit of an intervention by incorporating design elements that allow for greater generalizability and clinical applicability of study results. In this article we describe the explanatory-pragmatic continuum for clinical trials in greater detail. Further, a well-accepted tool for grading trials on this continuum is described, and applied, to 2 recently published trials pertaining to the surgical management of lumbar degenerative spondylolisthesis.

46 CFR 11.463 - General requirements for national endorsements as master, mate (pilot), and apprentice mate...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false General requirements for national endorsements as master... national endorsements as master, mate (pilot), and apprentice mate (steersman) of towing vessels. (a) The Coast Guard issues the following endorsements for towing vessels: (1) Master of towing vessels. (2...

Registration of RMBUP-C4, a random mated population with Gossypium hirsutum L. alleles, introgresssed into Upland cotton germplasm

USDA-ARS?s Scientific Manuscript database

RMBUP-C4 (Random Mated Barbadense Upland Population Cycle 4) (Reg. No. GP_____: PI______) is a unique random mated germplasm population of Upland cotton (Gossypium hirsutum L.) which has introgression of G. barbadense L. alleles. This population involved five cycles of random mating beginning ...

Investigating a novel pathway by which pheromone-based mating disruption may protect crops

USDA-ARS?s Scientific Manuscript database

Pheromone-based mating disruption has been a successful, relatively new technology that growers use to reduce key insect populations. Mating disruption systems function by sending out false plumes of the insect sex pheromones – this interferes with the insect’s ability to find a mate, preempting egg...

When the difference is in the details: a critique of Zentner and Mitura (2012) "Stepping out of the caveman's shadow: Nations' gender gap predicts degree of sex differentiation in mate preferences".

PubMed

Schmitt, David P

2012-10-29

In a recent 10-nation study, Zentner and Mitura (2012) reported observing smaller sex differences in mate preferences within nations that have higher gender parity. As noted in previous research, and in a re-analysis of Zentner and Mitura's own data, sex differences in some mate preferences (e.g., long-term mate preferences for physical attractiveness) are either unrelated to or actually get larger with higher national gender parity. It is critically important to distinguish among mate preference domains when looking for patterns of sexual differentiation across nations. Indeed, for many psychological domains (e.g., attachment styles, Big Five traits, Dark Triad traits, self-esteem, personal values, depression, emotional expression, crying behavior, intimate partner violence, tested mental abilities, health indicators; see Schmitt, 2012), sex differences are demonstrably larger in nations with higher sociopolitical gender parity. By not distinguishing among mate preferences, Zentner and Mitura committed a form of the ecological fallacy-making false conclusions about individual mate preferences when looking only at associations among groups of mate preferences.

No evidence for the effect of MHC on male mating success in the brown bear.

PubMed

Kuduk, Katarzyna; Babik, Wieslaw; Bellemain, Eva; Valentini, Alice; Zedrosser, Andreas; Taberlet, Pierre; Kindberg, Jonas; Swenson, Jon E; Radwan, Jacek

2014-01-01

Mate choice is thought to contribute to the maintenance of the spectacularly high polymorphism of the Major Histocompatibility Complex (MHC) genes, along with balancing selection from parasites, but the relative contribution of the former mechanism is debated. Here, we investigated the association between male MHC genotype and mating success in the brown bear. We analysed fragments of sequences coding for the peptide-binding region of the highly polymorphic MHC class I and class II DRB genes, while controlling for genome-wide effects using a panel of 18 microsatellite markers. Male mating success did not depend on the number of alleles shared with the female or amino-acid distance between potential mates at either locus. Furthermore, we found no indication of female mating preferences for MHC similarity being contingent on the number of alleles the females carried. Finally, we found no significant association between the number of MHC alleles a male carried and his mating success. Thus, our results provided no support for the role of mate choice in shaping MHC polymorphism in the brown bear.

No evidence of inbreeding avoidance in a polygynous ungulate: the reindeer (Rangifer tarandus).

PubMed

Holand, Oystein; Askim, Kjartan R; Røed, Knut H; Weladji, Robert B; Gjøstein, Hallvard; Nieminen, Mauri

2007-02-22

In polygynous species, mate choice is an integrated part of sexual selection. However, whether mate choice occurs independently of the genetic relatedness among mating pairs has received little attention, although inbreeding may have fitness consequences. We studied whether genetic relatedness influenced females' choice of partner in a highly polygynous ungulate--the reindeer (Rangifer tarandus)--in an experimental herd during two consecutive rutting seasons; the herd consisting of 75 females in 1999 and 74 females in 2000 was exposed to three 4.5-year-old adults and three 1.5-year-old young males, respectively. The females' distribution during peak rut was not influenced by their genetic relatedness with the dominant males of the mating groups. Further, genetic relatedness did not influence the actual choice of mating partner. We conclude that inbreeding avoidance through mating group choice as well as choice of mating partner, two interconnected processes of female mate choice operating at two different scales in space and time, in such a highly female-biased reindeer populations with low level of inbreeding may not occur.

Mate choice promotes inbreeding avoidance in the two-spotted spider mite.

PubMed

Tien, N S H; Massourakis, G; Sabelis, M W; Egas, M

2011-06-01

Since inbreeding in Tetranychus urticae can reduce offspring fitness, sexual selection may favour disassortative mate choice with respect to relatedness of the mating partners. We tested whether T. urticae shows this preference for mating with unrelated partners. We chose an experimental set-up with high potential for female choosiness, since females only mate once and are therefore expected to be the choosier gender. An adult virgin female was placed together with two adult males from the same population. One male was unrelated and the other male was related-a brother with whom she had grown up. Significantly more copulations (64%) took place with the unrelated male. Time to mating did not depend on the female-to-male relatedness. The remaining (non-copulating) male tried to interfere with the ongoing mating in the majority of cases, but this interference did not depend on the female-to-male relatedness. These results imply that T. urticae (a) can recognize kin (via genetic and/or environmental similarity) and (b) has the potential to avoid inbreeding through mate choice.

Protective effect of medroxyprogesterone acetate plus testosterone against radiation-induced damage to the reproductive function of male rats and their offspring.

PubMed

Jégou, B; Velez de la Calle, J F; Bauché, F

1991-10-01

This study attempted to protect spermatogenesis and the reproductive performance of rats against the effects of acute scrotal exposure to x-rays. Daily subcutaneous injections of medroxyprogesterone acetate (8 mg/kg) plus testosterone (1 mg/kg) (MT group) were administered for 55 days (experiment A) or 15 days (experiment B). The rats were irradiated (3 grays) on the last day of MT pretreatment (MTX group). In both experiments, on days 1 and 130 posttreatment, rats from each of the four groups (control, x-irradiated, MT, and MTX groups) were killed to measure the weight of the reproductive organs and the number of epididymal spermatozoa. Breeding was started 3 days posttreatment by housing all males from the four groups each with two virgin females for six successive periods of 19 days, separated by a period of 2 days. The percentage of fertile males, the litter size, postimplantation losses, and dominant lethal mutations were calculated. In experiment A, in the last fertility trial, animals of both sexes were selected at random from the progeny of each group (F1). When they were adults, their fertility was tested in a mating trial. A fertility trial was also performed with the F2 males. Our data essentially reveal that (i) in addition to their adverse quantitative effects on spermatogenesis, x-rays also produce a significant increase in dominant lethal mutations in all germ cell classes, including stem spermatogonia; (ii) the F1 and F2 male descendants of irradiated male rats provoked abnormal rates of postimplantation losses in their female mates; (iii) the short as well as the long MT pretreatment protects testicular function of irradiated rats; and (iv) in experiment A, MT pretreatment totally prevented qualitative damage to spermatozoa and protected the descendants of the irradiated animals against altered spermatogenesis as well as against genetic damage in germ cells. In conclusion, pretreatment with MT, even for a short period of time, offers a method for potentially reducing the toxic and genotoxic effects of irradiation on the male reproductive system.

Protective effect of medroxyprogesterone acetate plus testosterone against radiation-induced damage to the reproductive function of male rats and their offspring.

PubMed Central

Jégou, B; Velez de la Calle, J F; Bauché, F

1991-01-01

This study attempted to protect spermatogenesis and the reproductive performance of rats against the effects of acute scrotal exposure to x-rays. Daily subcutaneous injections of medroxyprogesterone acetate (8 mg/kg) plus testosterone (1 mg/kg) (MT group) were administered for 55 days (experiment A) or 15 days (experiment B). The rats were irradiated (3 grays) on the last day of MT pretreatment (MTX group). In both experiments, on days 1 and 130 posttreatment, rats from each of the four groups (control, x-irradiated, MT, and MTX groups) were killed to measure the weight of the reproductive organs and the number of epididymal spermatozoa. Breeding was started 3 days posttreatment by housing all males from the four groups each with two virgin females for six successive periods of 19 days, separated by a period of 2 days. The percentage of fertile males, the litter size, postimplantation losses, and dominant lethal mutations were calculated. In experiment A, in the last fertility trial, animals of both sexes were selected at random from the progeny of each group (F1). When they were adults, their fertility was tested in a mating trial. A fertility trial was also performed with the F2 males. Our data essentially reveal that (i) in addition to their adverse quantitative effects on spermatogenesis, x-rays also produce a significant increase in dominant lethal mutations in all germ cell classes, including stem spermatogonia; (ii) the F1 and F2 male descendants of irradiated male rats provoked abnormal rates of postimplantation losses in their female mates; (iii) the short as well as the long MT pretreatment protects testicular function of irradiated rats; and (iv) in experiment A, MT pretreatment totally prevented qualitative damage to spermatozoa and protected the descendants of the irradiated animals against altered spermatogenesis as well as against genetic damage in germ cells. In conclusion, pretreatment with MT, even for a short period of time, offers a method for potentially reducing the toxic and genotoxic effects of irradiation on the male reproductive system. PMID:1833765

Reducing distress and improving social functioning in daily life in people with auditory verbal hallucinations: study protocol for the ‘Temstem’ randomised controlled trial

PubMed Central

Scheffers, Dorien; Tromp, Nynke; Nuij, Chani; Delespaul, Philippe; Riper, Heleen; van der Gaag, Mark; van den Berg, David

2018-01-01

Introduction Auditory verbal hallucinations (AVH) are prevalent experiences that can induce distress and impede social functioning. While most voice hearers benefit from antipsychotic medication or cognitive–behavioural therapy, additional effective interventions are needed to reduce the burden of experiencing AVH. ‘Temstem’ is an easily accessible and useable smartphone application that was developed by designers in close cooperation with voice hearers and experts. By using language games, Temstem aims to reduce distress and improve social functioning. Methods This is a single-blind multicentre randomised controlled trial with two arms: ‘Temstem+AVH monitoring’ versus ‘AVH monitoring’ (total n=100). Participants are adult patients who suffer daily from AVH and will be recruited in outpatient units. Primary assessment in daily life is made by the Experience Sampling Method (ESM) and daily monitoring with the PsyMate app. During an ESM period of 6 days, participants assess their mental state (including AVH and context) several times a day by filling in short questionnaires. There are three 6-day ESM periods: at baseline (week 0–1), post-treatment (weeks 5–6) and follow-up (weeks 9–10). In addition, during the entire 10-week study period, all participants monitor their AVH two times a day with a short assessment via the PsyMate app. Participants in the Temstem+AVH monitoring condition are provided with the Temstem app from week 1 to 6. Other assessments made at baseline, post-treatment and follow-up are based on questionnaires and a clinical interview. Ethics and dissemination The results from this study will provide an evaluation of the effectiveness of Temstem, a non-invasive and easily accessible app for voice hearers, and insight into the determinants of optimal use. Results will be disseminated unreservedly, irrespective of the magnitude or direction of the effects. This study protocol was approved by the Medical Ethics Committee of the VU University Medical Centre (METC number: 2015.435/NL53684.029.15). Trial registration number ISRCTN75717636; Pre-results. PMID:29511020

Egg production and oviposition in the tobacco budworm: effect of age at mating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Proshold, F.I.; Karpenko, C.P.; Graham, C.K.

1982-01-01

Female tobacco budworms, Heliothis virescens (F.) (Lepidoptera: Noctuidae), that emerged in the laboratory contained no mature eggs, although ooecyte development had proceeded as far as yolk deposition in the ultimate egg of each ovariole. After 18 h, ca. one mature egg per ovariole was present. If the females subsequently remained unmated, maturation of additional eggs was curvilinear with age and leveled off at ca. 500 eggs per female at 120 h. If the females mated, there was an inverse relationship between egg production and age mated; maximal production occurred when females mated the first night postemergence (ca. 30 h), andmore » production then diminished until females mating at 5 days or more laid only slightly more eggs than virgin females. However, there was also a direct relationship between length of life and age of mating. Females that mated at 1 or 2 days showed a signficant correlation between numbers of eggs produced and longevity and between numbers of eggs and pupal weight. Virgin females and females that mated at 3 days showed a significant correlation between eggs and longevity but not between eggs and pupal weight. There was no significant correlation between eggs and pupal weight or longevity for females that mated at 5 days or later.« less

Genetic versus census estimators of the opportunity for sexual selection in the wild.

PubMed

Dunn, Stacey J; Waits, Lisette P; Byers, John A

2012-04-01

Abstract The existence of a direct link between intensity of sexual selection and mating-system type is widely accepted. However, the quantification of sexual selection has proven problematic. Several measures of sexual selection have been proposed, including the operational sex ratio (OSR), the breeding sex ratio (BSR), and the opportunity for sexual selection (I(mates)). For a wild population of pronghorn (Antilocapra americana), we calculated OSR and BSR. We estimated I(mates) from census data on the spatial and temporal distribution of receptive females in rut and from a multigenerational genetic pedigree. OSR and BSR indicated weak sexual selection on males, but census and pedigree I(mates) suggested stronger sexual selection on males than on females. OSR and BSR correlated with census but not pedigree estimates of I(mates), and census I(mates) did not correlate with pedigree estimates. This suggests that the behavioral mating system, as deduced from the spatial and temporal distribution of females, does not predict the genetic mating system of pronghorn. The differences we observed between estimators were primarily due to female mate sampling and choice and to the sex ratio. For most species, behavioral data are not perfectly accurate and therefore will be an insufficient alternative to using multigenerational pedigrees to quantify sexual selection.

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster.

PubMed

Gorter, Jenke A; Billeter, Jean-Christophe

2017-07-17

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors remains poorly understood. In Drosophila melanogaster, environmental cues, such as food availability, affect mating activity offering a tractable system to investigate the mechanisms modulating sexual behavior. In D. melanogaster, environmental cues are often sensed via the chemosensory gustatory and olfactory systems. Here, we present a method to test the effect of environmental chemical cues on mating behavior. The assay consists of a small mating arena containing food medium and a mating couple. The mating frequency for each couple is continuously monitored for 24 h. Here we present the applicability of this assay to test environmental compounds from an external source through a pressurized air system as well as manipulation of the environmental components directly in the mating arena. The use of a pressurized air system is especially useful to test the effect of very volatile compounds, while manipulating components directly in the mating arena can be of value to ascertain a compound's presence. This assay can be adapted to answer questions about the influence of genetic and environmental cues on mating behavior and fecundity as well as other male and female reproductive behaviors.

Worthless donations: male deception and female counter play in a nuptial gift-giving spider

PubMed Central

2011-01-01

Background In nuptial gift-giving species, benefits of acquiring a mate may select for male deception by donation of worthless gifts. We investigated the effect of worthless gifts on mating success in the spider Pisaura mirabilis. Males usually offer an insect prey wrapped in silk; however, worthless gifts containing inedible items are reported. We tested male mating success in the following experimental groups: protein enriched fly gift (PG), regular fly gift (FG), worthless gift (WG), or no gift (NG). Results Males that offered worthless gifts acquired similar mating success as males offering nutritional gifts, while males with no gift experienced reduced mating success. The results suggest that strong selection on the nuptial gift-giving trait facilitates male deception by donation of worthless gifts. Females terminated matings faster when males offered worthless donations; this demonstrate a cost of deception for the males as shorter matings lead to reduced sperm transfer and thus give the deceiving males a disadvantage in sperm competition. Conclusion We propose that the gift wrapping trait allows males to exploit female foraging preference by disguising the gift content thus deceiving females into mating without acquiring direct benefits. Female preference for a genuine prey gift combined with control over mating duration, however, counteracts the male deception. PMID:22082300

Worthless donations: male deception and female counter play in a nuptial gift-giving spider.

PubMed

Albo, Maria J; Winther, Gudrun; Tuni, Cristina; Toft, Søren; Bilde, Trine

2011-11-14

In nuptial gift-giving species, benefits of acquiring a mate may select for male deception by donation of worthless gifts. We investigated the effect of worthless gifts on mating success in the spider Pisaura mirabilis. Males usually offer an insect prey wrapped in silk; however, worthless gifts containing inedible items are reported. We tested male mating success in the following experimental groups: protein enriched fly gift (PG), regular fly gift (FG), worthless gift (WG), or no gift (NG). Males that offered worthless gifts acquired similar mating success as males offering nutritional gifts, while males with no gift experienced reduced mating success. The results suggest that strong selection on the nuptial gift-giving trait facilitates male deception by donation of worthless gifts. Females terminated matings faster when males offered worthless donations; this demonstrate a cost of deception for the males as shorter matings lead to reduced sperm transfer and thus give the deceiving males a disadvantage in sperm competition. We propose that the gift wrapping trait allows males to exploit female foraging preference by disguising the gift content thus deceiving females into mating without acquiring direct benefits. Female preference for a genuine prey gift combined with control over mating duration, however, counteracts the male deception.

Evolution of the hemiascomycete yeasts: on life styles and the importance of inbreeding.

PubMed

Knop, Michael

2006-07-01

The term 'breeding system' is used to describe the morphological and behavioural aspects of the sexual life cycle of a species. The yeast breeding system provides three alternatives that enable hapoids to return to the diploid state that is necessary for meiosis: mating of unrelated haploids (amphimixis), mating between spores from the same tetrad (intratetrad mating, automixis) and mother daughter mating upon mating type switching (haplo-selfing). The frequency of specific mating events affects the level of heterozygosity present in individuals and the genetic diversity of populations. This review discusses the reproductive strategies of yeasts, in particular S. cerevisiae (Bakers' or budding yeast). Emphasis is put on intratetrad mating, its implication for diversity, and how the particular genome structure could have evolved to ensure the preservation of a high degree of heterozygosity in conjunction with frequent intratetrad matings. I also discuss how the ability of yeast to control the number of spores that are formed accounts for high intratetrad mating rates and for enhanced transmission of genomic variation. I extend the discussion to natural genetic variation and propose that a high level of plasticity is inherent in the yeast breeding system, which may allow variation of the breeding behaviour in accordance with the needs imposed by the environment. (c) 2006 Wiley Periodicals, Inc.

Intra-population variation in behavior modification by the acanthocephalan Acanthocephalus dirus: are differences mediated by host condition?

PubMed

Caddigan, Sara C; Barkauskas, Rima T; Sparkes, Timothy C

2014-11-01

The acanthocephalan parasite Acanthocephalus dirus infects the freshwater isopod Caecidotea intermedius as an intermediate host before completing its life cycle in a fish. Male C. intermedius infected by A. dirus parasites are less likely to engage in mating behavior than uninfected males but there is a significant intra-population variation in the occurrence of this behavioral change. Previous studies on uninfected isopods have shown that glycogen content is a predictor of male mating behavior and we examined whether the intra-population variation in the mating behavior of infected male C. intermedius could be explained by this relationship. A field-based behavioral experiment was used to quantify intra-population variation in male mating behavior, which showed that 50% of infected males were responsive to females and 50% were not responsive. Biochemical analysis of responsive and non-responsive males revealed that glycogen content was a predictor of the mating behavior for uninfected males but was not a predictor of mating behavior for infected males. For infected males, parasite intensity was a predictor of mating behavior. Males that contained more A. dirus parasites were less likely to undergo modification of mating behavior. We propose that the intra-population variation in the mating behavior of infected C. intermedius identified in nature was not mediated by host condition.

A sex-specific trade-off between mating preferences for genetic compatibility and body size in a cichlid fish with mutual mate choice.

PubMed

Thünken, Timo; Meuthen, Denis; Bakker, Theo C M; Baldauf, Sebastian A

2012-08-07

Mating preferences for genetic compatibility strictly depend on the interplay of the genotypes of potential partners and are therein fundamentally different from directional preferences for ornamental secondary sexual traits. Thus, the most compatible partner is on average not the one with most pronounced ornaments and vice versa. Hence, mating preferences may often conflict. Here, we present a solution to this problem while investigating the interplay of mating preferences for relatedness (a compatibility criterion) and large body size (an ornamental or quality trait). In previous experiments, both sexes of Pelvicachromis taeniatus, a cichlid fish with mutual mate choice, showed preferences for kin and large partners when these criteria were tested separately. In the present study, test fish were given a conflicting choice between two potential mating partners differing in relatedness as well as in body size in such a way that preferences for both criteria could not simultaneously be satisfied. We show that a sex-specific trade-off occurs between mating preferences for body size and relatedness. For females, relatedness gained greater importance than body size, whereas the opposite was true for males. We discuss the potential role of the interplay between mating preferences for relatedness and body size for the evolution of inbreeding preference.

Mating Goals Moderate Power's Effect on Conspicuous Consumption Among Women.

PubMed

Zhao, Taiyang; Jin, Xiaotong; Xu, Wei; Zuo, Xiaomeng; Cui, Hongjing

2017-01-01

This study aimed to use evolutionary psychology to explain conspicuous consumption's relationship with mating goals among women. We used experiments to show that power moderates conspicuous consumption's relationship with mating goals among women through an underlying relationship with women's social comparison tendencies. In Study 1, the participants read a passage describing a young woman wearing a coat made by a conspicuous brand (vs. an ordinary brand) who aimed to attract a desired man (vs. aiming to guard against potential competitors' attempts to disrupt her established intimate relationship). Participants in the conspicuous-brand condition were more confident that the young woman would succeed in mate attraction and guarding than participants in the ordinary-brand condition, suggesting the participants believed the conspicuous brands facilitated mate attraction and mate guarding more than ordinary brands. Study 2 manipulated the participants' power states and mating goals and measured participants' social comparison tendencies and conspicuous consumption index values. In the mate-guarding condition, high-power participants showed more inclination toward conspicuous consumption than low-power participants. In the mate-attraction condition, low-power participants showed a greater inclination toward conspicuous consumption than did high-power participants. Comparison orientation also mediated power's effect on conspicuous consumption inclination. The evolutionary psychological basis for the above findings is discussed, and suggestions are offered regarding product marketing.

A sex-specific trade-off between mating preferences for genetic compatibility and body size in a cichlid fish with mutual mate choice

PubMed Central

Thünken, Timo; Meuthen, Denis; Bakker, Theo C. M.; Baldauf, Sebastian A.

2012-01-01

Mating preferences for genetic compatibility strictly depend on the interplay of the genotypes of potential partners and are therein fundamentally different from directional preferences for ornamental secondary sexual traits. Thus, the most compatible partner is on average not the one with most pronounced ornaments and vice versa. Hence, mating preferences may often conflict. Here, we present a solution to this problem while investigating the interplay of mating preferences for relatedness (a compatibility criterion) and large body size (an ornamental or quality trait). In previous experiments, both sexes of Pelvicachromis taeniatus, a cichlid fish with mutual mate choice, showed preferences for kin and large partners when these criteria were tested separately. In the present study, test fish were given a conflicting choice between two potential mating partners differing in relatedness as well as in body size in such a way that preferences for both criteria could not simultaneously be satisfied. We show that a sex-specific trade-off occurs between mating preferences for body size and relatedness. For females, relatedness gained greater importance than body size, whereas the opposite was true for males. We discuss the potential role of the interplay between mating preferences for relatedness and body size for the evolution of inbreeding preference. PMID:22513859

Person mobility in the design and analysis of cluster-randomized cohort prevention trials.

PubMed

Vuchinich, Sam; Flay, Brian R; Aber, Lawrence; Bickman, Leonard

2012-06-01

Person mobility is an inescapable fact of life for most cluster-randomized (e.g., schools, hospitals, clinic, cities, state) cohort prevention trials. Mobility rates are an important substantive consideration in estimating the effects of an intervention. In cluster-randomized trials, mobility rates are often correlated with ethnicity, poverty and other variables associated with disparity. This raises the possibility that estimated intervention effects may generalize to only the least mobile segments of a population and, thus, create a threat to external validity. Such mobility can also create threats to the internal validity of conclusions from randomized trials. Researchers must decide how to deal with persons who leave study clusters during a trial (dropouts), persons and clusters that do not comply with an assigned intervention, and persons who enter clusters during a trial (late entrants), in addition to the persons who remain for the duration of a trial (stayers). Statistical techniques alone cannot solve the key issues of internal and external validity raised by the phenomenon of person mobility. This commentary presents a systematic, Campbellian-type analysis of person mobility in cluster-randomized cohort prevention trials. It describes four approaches for dealing with dropouts, late entrants and stayers with respect to data collection, analysis and generalizability. The questions at issue are: 1) From whom should data be collected at each wave of data collection? 2) Which cases should be included in the analyses of an intervention effect? and 3) To what populations can trial results be generalized? The conclusions lead to recommendations for the design and analysis of future cluster-randomized cohort prevention trials.

Personality differentially affects individual mate choice decisions in female and male Western mosquitofish (Gambusia affinis).

PubMed

Chen, Bo-Jian; Liu, Kai; Zhou, Lin-Jun; Gomes-Silva, Guilherme; Sommer-Trembo, Carolin; Plath, Martin

2018-01-01

Consistent individual differences in behavioral tendencies (animal personality) can affect individual mate choice decisions. We asked whether personality traits affect male and female mate choice decisions similarly and whether potential personality effects are consistent across different mate choice situations. Using western mosquitofish (Gambusia affinis) as our study organism, we characterized focal individuals (males and females) twice for boldness, activity, and sociability/shoaling and found high and significant behavioral repeatability. Additionally, each focal individual was tested in two different dichotomous mate choice tests in which it could choose between computer-animated stimulus fish of the opposite sex that differed in body size and activity levels, respectively. Personality had different effects on female and male mate choice: females that were larger than average showed stronger preferences for large-bodied males with increasing levels of boldness/activity (i.e., towards more proactive personality types). Males that were larger than average and had higher shoaling tendencies showed stronger preferences for actively swimming females. Size-dependent effects of personality on the strength of preferences for distinct phenotypes of potential mating partners may reflect effects of age/experience (especially in females) and social dominance (especially in males). Previous studies found evidence for assortative mate choice based on personality types or hypothesized the existence of behavioral syndromes of individuals' choosiness across mate choice criteria, possibly including other personality traits. Our present study exemplifies that far more complex patterns of personality-dependent mate choice can emerge in natural systems.

Temporal variation in size-assortative mating and male mate choice in a spider with amphisexual care

NASA Astrophysics Data System (ADS)

Moura, Rafael R.; Gonzaga, Marcelo O.

2017-04-01

Males should be more selective when they have a high investment in reproduction, especially in species with biparental or paternal care. In this context, male mate choice can promote size-assortative mating (SAM) when (1) large males win intrasexual disputes, (2) large females are more fecund, and (3) males prefer larger females to smaller ones. In the spider Manogea porracea, males exhibit high reproductive investment by building their webs above those of females and exhibiting extended care of offspring in the absence of females. Under these circumstances, we expect the occurrence of SAM and male preference for large females. Herein, we performed observations and experiments in the field to evaluate the hypotheses that (1) M. porracea mates assortatively by size and (2) SAM is influenced by male mate choice. Furthermore, we measured variables that could affect mating patterns, the sex ratios, and densities of both sexes. Pairing in M. porracea was positively size-assortative in 2012, but not in 2013. Large males won most disputes for mates and preferred larger females, which produced more eggs. The inconsistency in detection of SAM was due to population dynamics, namely variations in sex ratio and population density across the breeding season. Furthermore, we found that the significance of male mate choice on sexual selection of body size in M. porracea strongly depends on the competition intensity for mating opportunities. The traditional sexual selection hypothesis of SAM needs to be reviewed and must include measures of competition intensity.

Mate choice for neutral and MHC genetic characteristics in Alpine marmots: different targets in different contexts?

PubMed

Ferrandiz-Rovira, Mariona; Allainé, Dominique; Callait-Cardinal, Marie-Pierre; Cohas, Aurélie

2016-07-01

Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra-pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal.

Re-mating across years and intralineage polygyny are associated with greater than expected levels of inbreeding in wild red deer

PubMed Central

Stopher, K V; Nussey, D H; Clutton-Brock, T H; Guinness, F; Morris, A; Pemberton, J M

2012-01-01

The interaction between philopatry and nonrandom mating has important consequences for the genetic structure of populations, influencing co-ancestry within social groups but also inbreeding. Here, using genetic paternity data, we describe mating patterns in a wild population of red deer (Cervus elaphus) which are associated with marked consequences for co-ancestry and inbreeding in the population. Around a fifth of females mate with a male with whom they have mated previously, and further, females frequently mate with a male with whom a female relative has also mated (intralineage polygyny). Both of these phenomena occur more than expected under random mating. Using simulations, we demonstrate that temporal and spatial factors, as well as skew in male breeding success, are important in promoting both re-mating behaviours and intralineage polygyny. However, the information modelled was not sufficient to explain the extent to which these behaviours occurred. We show that re-mating and intralineage polygyny are associated with increased pairwise relatedness in the population and a rise in average inbreeding coefficients. In particular, the latter resulted from a correlation between male relatedness and rutting location, with related males being more likely to rut in proximity to one another. These patterns, alongside their consequences for the genetic structure of the population, have rarely been documented in wild polygynous mammals, yet they have important implications for our understanding of genetic structure, inbreeding avoidance and dispersal in such systems. PMID:23039875

Are Human Mating Preferences with Respect to Height Reflected in Actual Pairings?

PubMed Central

Stulp, Gert; Buunk, Abraham P.; Pollet, Thomas V.; Nettle, Daniel; Verhulst, Simon

2013-01-01

Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the actual partner. People value height in their partner and we investigated to what extent preferences for height are realised in actual couples. We used data from the Millennium Cohort Study (UK) and compared the distribution of height difference in actual couples to simulations of random mating to test how established mate preferences map on to actual mating patterns. In line with mate preferences, we found evidence for: (i) assortative mating (r = .18), (ii) the male-taller norm, and, for the first time, (iii) for the male-not-too-tall norm. Couples where the male partner was shorter, or over 25 cm taller than the female partner, occurred at lower frequency in actual couples than expected by chance, but the magnitude of these effects was modest. We also investigated another preference rule, namely that short women (and tall men) prefer large height differences with their partner, whereas tall women (and short men) prefer small height differences. These patterns were also observed in our population, although the strengths of these associations were weaker than previously reported strength of preferences. We conclude that while preferences for partner height generally translate into actual pairing, they do so only modestly. PMID:23342102

Are human mating preferences with respect to height reflected in actual pairings?

PubMed

Stulp, Gert; Buunk, Abraham P; Pollet, Thomas V; Nettle, Daniel; Verhulst, Simon

2013-01-01

Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the actual partner. People value height in their partner and we investigated to what extent preferences for height are realised in actual couples. We used data from the Millennium Cohort Study (UK) and compared the distribution of height difference in actual couples to simulations of random mating to test how established mate preferences map on to actual mating patterns. In line with mate preferences, we found evidence for: (i) assortative mating (r = .18), (ii) the male-taller norm, and, for the first time, (iii) for the male-not-too-tall norm. Couples where the male partner was shorter, or over 25 cm taller than the female partner, occurred at lower frequency in actual couples than expected by chance, but the magnitude of these effects was modest. We also investigated another preference rule, namely that short women (and tall men) prefer large height differences with their partner, whereas tall women (and short men) prefer small height differences. These patterns were also observed in our population, although the strengths of these associations were weaker than previously reported strength of preferences. We conclude that while preferences for partner height generally translate into actual pairing, they do so only modestly.

Why (and When) Straight Women Trust Gay Men: Ulterior Mating Motives and Female Competition.

PubMed

Russell, Eric M; Ta, Vivian P; Lewis, David M G; Babcock, Meghan J; Ickes, William

2017-04-01

Previous findings indicate that heterosexual women experience a greater sense of comfort and trust in their friendships with gay men than in their friendships with heterosexual individuals. In the present studies, we tested a hypothesis that not only explains why women exhibit increased trust in gay men but also yields novel predictions about when (i.e., in what contexts) this phenomenon is likely to occur. Specifically, we propose that gay men's lack of motives to mate with women or to compete with them for mates enhances women's trust in gay men and openness to befriend them. Study 1 demonstrated that women placed greater trust in a gay man's mating-but not non-mating (e.g., career) advice-than in the same advice given by heterosexual individuals. Study 2 showed that women perceived a gay man to be more sincere in scenarios relevant to sexual and competitive mating deception. In Study 3, exposing women to a visualization of increased mating competition enhanced their trust in gay men; when mating competition was salient, women's trust in mating information from a gay man was amplified. Study 4 showed that women who perceived higher levels of mating competition were more open to befriending gay men. Together, these converging findings support our central hypothesis, which not only provides a distal explanation for the trust that straight women place in gay men, but also provides novel insights into previously unidentified contexts that facilitate the formation and strengthening of this unique bond.

Evolution of male strategies with sex-ratio-dependent pay-offs: connecting pair bonds with grandmothering.

PubMed

Loo, Sara L; Hawkes, Kristen; Kim, Peter S

2017-09-19

Men's provisioning of mates and offspring has been central to ideas about human evolution because paternal provisioning is absent in our closest evolutionary cousins, the great apes, and is widely assumed to result in pair bonding, which distinguishes us from them. Yet mathematical modelling has shown that paternal care does not readily spread in populations where competition for multiple mates is the common male strategy. Here we add to models that point to the mating sex ratio as an explanation for pairing as pay-offs to mate guarding rise with a male-biased sex ratio. This is of interest for human evolution because our grandmothering life history shifts the mating sex ratio from female- to male-biased. Using a difference equation model, we explore the relative pay-offs for three competing male strategies (dependant care, multiple mating, mate guarding) in response to changing adult sex ratios. When fertile females are abundant, multiple mating prevails. As they become scarce, mate guarding triumphs. The threshold for this shift depends on guarding efficiency. Combined with mating sex ratios of hunter-gatherer and chimpanzee populations, these results strengthen the hypothesis that the evolution of our grandmothering life history propelled the shift to pair bonding in the human lineage.This article is part of the themed issue 'Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies'. © 2017 The Author(s).

Oxytocin receptor density is associated with male mating tactics and social monogamy.

PubMed

Ophir, Alexander G; Gessel, Ana; Zheng, Da-Jiang; Phelps, Steven M

2012-03-01

Despite its well-described role in female affiliation, the influence of oxytocin on male pairbonding is largely unknown. However, recent human studies indicate that this nonapeptide has a potent influence on male behaviors commonly associated with monogamy. Here we investigated the distribution of oxytocin receptors (OTR) throughout the forebrain of the socially monogamous male prairie vole (Microtus ochrogaster). Because males vary in both sexual and spatial fidelity, we explored the extent to which OTR predicted monogamous or non-monogamous patterns of space use, mating success and sexual fidelity in free-living males. We found that monogamous males expressed higher OTR density in the nucleus accumbens than non-monogamous males, a result that mirrors species differences in voles with different mating systems. OTR density in the posterior portion of the insula predicted mating success. Finally, OTR in the hippocampus and septohippocampal nucleus, which are nuclei associated with spatial memory, predicted patterns of space use and reproductive success within mating tactics. Our data highlight the importance of oxytocin receptor in neural structures associated with pairbonding and socio-spatial memory in male mating tactics. The role of memory in mating systems is often neglected, despite the fact that mating tactics impose an inherently spatial challenge for animals. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating pairbonding and mating tactics is crucial to fully appreciate the suite of factors driving mating systems. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior. Published by Elsevier Inc.

Developmental Environment Effects on Sexual Selection in Male and Female Drosophila melanogaster

PubMed Central

Morimoto, Juliano; Pizzari, Tommaso; Wigby, Stuart

2016-01-01

The developmental environment can potentially alter the adult social environment and influence traits targeted by sexual selection such as body size. In this study, we manipulated larval density in male and female Drosophila melanogaster, which results in distinct adult size phenotypes–high (low) densities for small (large) adults–and measured sexual selection in experimental groups consisting of adult males and females from high, low, or a mixture of low and high larval densities. Overall, large adult females (those reared at low larval density) had more matings, more mates and produced more offspring than small females (those reared at high larval density). The number of offspring produced by females was positively associated with their number of mates (i.e. there was a positive female Bateman gradient) in social groups where female size was experimentally varied, likely due to the covariance between female productivity and mating rate. For males, we found evidence that the larval environment affected the relative importance of sexual selection via mate number (Bateman gradients), mate productivity, paternity share, and their covariances. Mate number and mate productivity were significantly reduced for small males in social environments where males were of mixed sizes, versus social environments where all males were small, suggesting that social heterogeneity altered selection on this subset of males. Males are commonly assumed to benefit from mating with large females, but in contrast to expectations we found that in groups where both the male and female size varied, males did not gain more offspring per mating with large females. Collectively, our results indicate sex-specific effects of the developmental environment on the operation of sexual selection, via both the phenotype of individuals, and the phenotype of their competitors and mates. PMID:27167120

Sexual selection in Drosophila silvestris of Hawaii.

PubMed

Spiess, E B; Carson, H L

1981-05-01

Previous discovery that Drosophila melanogaster females tend to discriminate in mating against phenotypes of earliest courting males prompted a study of the Hawaiian species D. silvestris. Tibial bristle variation in males from opposite coasts of the island of Hawaii functions in courtship, and the possibility that females can distinguish males differing in the tibial trait is explored. Mating tests, designed to give each female and male an alternative choice between two individuals of opposite sex every 30 min, consisted of intrapopulation tests with a strain derived from an eastern (Kilauea) population and interpopulation tests between that strain and one derived from a western (Kahuku) population. Males were given initial combat tests, with "winners" then used in mating (except one test with "loser" males). Matings (52-55%) were classified into categories according to the readiness of the female to mate and sequence of courtship. Low-threshold females (accepting the first male after less than four courtship bouts) occurred at 30-35%. Among intrapopulational tests, females (with higher threshold) accepted first- and second-courting males about equally (25:36, respectively), but for male success in mating, the winning of initial intermale combats and the uniformity of courtship effort tended to be important criteria. Among interpopulation tests, homogamic matings were nearly equal (25% each), but heterogamic matings contrasted in that Kilauea females were reluctant to mate with Kahuku males (14%), while reciprocal matings occurred most frequently (34%). Females favored males second to court, particularly when a Kilauea male (with extra tibial bristles) was the second male. Thus a morphological feature likely to be influential in mating is demonstrated to be so; and sexual selection is operating via male-male combat plus discrimination in favor of particular opposite-sex individuals in this species.

Female Choice or Male Sex Drive? The Advantages of Male Body Size during Mating in Drosophila Melanogaster.

PubMed

Jagadeeshan, Santosh; Shah, Ushma; Chakrabarti, Debarti; Singh, Rama S

2015-01-01

The mating success of larger male Drosophila melanogaster in the laboratory and the wild has been traditionally been explained by female choice, even though the reasons are generally hard to reconcile. Female choice can explain this success by virtue of females taking less time to mate with preferred males, but so can the more aggressive or persistent courtships efforts of large males. Since mating is a negotiation between the two sexes, the behaviors of both are likely to interact and influence mating outcomes. Using a series of assays, we explored these negotiations by testing for the relative influence of male behaviors and its effect on influencing female courtship arousal threshold, which is the time taken for females to accept copulation. Our results show that large males indeed have higher copulation success compared to smaller males. Competition between two males or an increasing number of males had no influence on female sexual arousal threshold;-females therefore may have a relatively fixed 'arousal threshold' that must be reached before they are ready to mate, and larger males appear to be able to manipulate this threshold sooner. On the other hand, the females' physiological and behavioral state drastically influences mating; once females have crossed the courtship arousal threshold they take less time to mate and mate indiscriminately with large and small males. Mating quicker with larger males may be misconstrued to be due to female choice; our results suggest that the mating advantage of larger males may be more a result of heightened male activity and relatively less of female choice. Body size per se may not be a trait under selection by female choice, but size likely amplifies male activity and signal outputs in courtship, allowing them to influence female arousal threshold faster.

Sex ratio and gamete size across eastern North America in Dictyostelium discoideum, a social amoeba with three sexes.

PubMed

Douglas, T E; Strassmann, J E; Queller, D C

2016-07-01

Theory indicates that numbers of mating types should tend towards infinity or remain at two. The social amoeba, Dictyostelium discoideum, however, has three mating types. It is therefore a mystery how this species has broken the threshold of two mating types, but has not increased towards a much higher number. Frequency-dependent selection on rare types in combination with isogamy, a form of reproduction involving gametes similar in size, could explain the evolution of multiple mating types in this system. Other factors, such as drift, may be preventing the evolution of more than three. We first looked for evidence of isogamy by measuring gamete size associated with each type. We found no evidence of size dissimilarities between gametes. We then looked for evidence of balancing selection, by examining mating type distributions in natural populations and comparing genetic differentiation at the mating type locus to that at more neutral loci. We found that mating type frequency varied among the three populations we examined, with only one of the three showing an even sex ratio, which does not support balancing selection. However, we found more population structure at neutral loci than the mating type locus, suggesting that the three mating types are indeed maintained at intermediate frequencies by balancing selection. Overall, the data are consistent with balancing selection acting on D. discoideum mating types, but with a sufficiently weak rare sex advantage to allow for drift, a potential explanation for why these amoebae have only three mating types. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Genetic and environmental factors associated with laboratory rearing affect survival and assortative mating but not overall mating success in Anopheles gambiae sensu stricto.

PubMed

Paton, Doug; Touré, Mahamoudou; Sacko, Adama; Coulibaly, Mamadou B; Traoré, Sékou F; Tripet, Frédéric

2013-01-01

Anopheles gambiae sensu stricto, the main vector of malaria in Africa, is characterized by its vast geographical range and complex population structure. Assortative mating amongst the reproductively isolated cryptic forms that co-occur in many areas poses unique challenges for programs aiming to decrease malaria incidence via the release of sterile or genetically-modified mosquitoes. Importantly, whether laboratory-rearing affects the ability of An. gambiae individuals of a given cryptic taxa to successfully mate with individuals of their own form in field conditions is still unknown and yet crucial for mosquito-releases. Here, the independent effects of genetic and environmental factors associated with laboratory rearing on male and female survival, mating success and assortative mating were evaluated in the Mopti form of An. gambiae over 2010 and 2011. In semi-field enclosures experiments and despite strong variation between years, the overall survival and mating success of male and female progeny from a laboratory strain was not found to be significantly lower than those of the progeny of field females from the same population. Adult progeny from field-caught females reared at the larval stage in the laboratory and from laboratory females reared outdoors exhibited a significant decrease in survival but not in mating success. Importantly, laboratory individuals reared as larvae indoors were unable to mate assortatively as adults, whilst field progeny reared either outdoors or in the laboratory, as well as laboratory progeny reared outdoors all mated significantly assortatively. These results highlight the importance of genetic and environment interactions for the development of An. gambiae's full mating behavioral repertoire and the challenges this creates for mosquito rearing and release-based control strategies.

Synergistic selection between ecological niche and mate preference primes diversification.

PubMed

Boughman, Janette W; Svanbäck, Richard

2017-01-01

The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Patterns of MHC-dependent mate selection in humans and nonhuman primates: a meta-analysis.

PubMed

Winternitz, J; Abbate, J L; Huchard, E; Havlíček, J; Garamszegi, L Z

2017-01-01

Genes of the major histocompatibility complex (MHC) in vertebrates are integral for effective adaptive immune response and are associated with sexual selection. Evidence from a range of vertebrates supports MHC-based preference for diverse and dissimilar mating partners, but evidence from human mate choice studies has been disparate and controversial. Methodologies and sampling peculiarities specific to human studies make it difficult to know whether wide discrepancies in results among human populations are real or artefact. To better understand what processes may affect MHC-mediated mate choice across humans and nonhuman primates, we performed phylogenetically controlled meta-analyses using 58 effect sizes from 30 studies across seven primate species. Primates showed a general trend favouring more MHC-diverse mates, which was statistically significant for humans. In contrast, there was no tendency for MHC-dissimilar mate choice, and for humans, we observed effect sizes indicating selection of both MHC-dissimilar and MHC-similar mates. Focusing on MHC-similar effect sizes only, we found evidence that preference for MHC similarity was an artefact of population ethnic heterogeneity in observational studies but not among experimental studies with more control over sociocultural biases. This suggests that human assortative mating biases may be responsible for some patterns of MHC-based mate choice. Additionally, the overall effect sizes of primate MHC-based mating preferences are relatively weak (Fisher's Z correlation coefficient for dissimilarity Zr = 0.044, diversity Zr = 0.153), calling for careful sampling design in future studies. Overall, our results indicate that preference for more MHC-diverse mates is significant for humans and likely conserved across primates. © 2016 John Wiley & Sons Ltd.

Reproductive investment when mate quality varies: differential allocation versus reproductive compensation.

PubMed

Harris, W Edwin; Uller, Tobias

2009-04-27

Reproductive investment decisions form an integral part of life-history biology. Selection frequently favours plasticity in investment that can generate maternal effects on offspring development. For example, if females differentially allocate resources based on mate attractiveness or quality, this can create a non-genetic link between mate attractiveness and offspring fitness with potential consequences for ecological and evolutionary dynamics. It is therefore important to understand under what conditions differential investment into offspring in relation to male quality is expected to occur and the direction of the effect. Two opposite predictions, increased investment into offspring produced with high-quality mates (differential allocation (DA)) and increased investment with low-quality males (reproductive compensation (RC)) have been suggested but no formal theoretical treatment justifying the assumptions underlying these two hypotheses has been conducted to date. Here, we used a state-based approach to investigate the circumstances under which the variation in mate quality results in differential female investment into offspring and how this interacts with female energetic resource levels. We found that a pattern of increased investment when mating with high-quality mates (i.e. DA) was the most common optimal investment strategy for females in our model. By contrast, increased investment when mating with low-quality mates (i.e. RC) was predicted only when the relative impact of parental investment on offspring quality was low. Finally, we found that the specific pattern of investment in relation to male quality depends on female energetic state, the likelihood for future mating opportunities and the expected future distribution of mate quality. Thus, the female's age and body condition should be important factors mediating DA and RC, which may help to explain the equivocal results of empirical studies.

Mating behavior of adolescent male chimpanzees (Pan troglodytes) at Ngogo, Kibale National Park, Uganda.

PubMed

Watts, David P

2015-04-01

Male mating tactics vary extensively in many primates. Some variation occurs because adolescent males often are sexually active but cannot invest heavily in mating effort because of their limited ability to compete directly with adults and because they are still investing in growth; consequently, most of their mating attempts may be surreptitious and/or with females whose fecundity is low. Chimpanzees (Pan troglodytes) have a complex mating system: most copulations occur between estrous females with full sexual swelling and multiple males in group settings where the potential for sperm competition is high, but males sometimes mate-guard females, and sometimes male-female pairs mate exclusively with each other while avoiding other males during "consortships." Among other factors, dominance ranks, coalition formation, and variation in male-female association influence male mating and reproductive success. Mating effort increases from adolescence into prime adulthood. At Gombe and Mahale, adolescent males copulated more with nulliparous than with parous females, and mostly when females were unlikely to be ovulating, partly because of low adult male interest in nulliparous females and partly because of aggression from or avoidance of adult males. Adolescents thus had low probabilities of siring infants. However, adolescents are known to have gained some paternity at Gombe and in other populations, and their mating behavior deserves more study. I present data on mating by adolescent males in an unusually large chimpanzee community at Ngogo, Kibale National Park, Uganda. Adolescents at Ngogo also copulated more with nulliparous than parous females and mostly copulated outside of periovulatory periods. Also, they directed less aggression at estrous females than did adult males. However, they gained lower shares of copulations than reported for Gombe and Mahale, regardless of female parity, and received more aggression from adult males. These differences might partly reflect the influence of variation in the number of males per community on male mating tactics.

Methamphetamine enhances sexual behavior in female rats.

PubMed

Winland, Carissa; Haycox, Charles; Bolton, Jessica L; Jampana, Sumith; Oakley, Benjamin J; Ford, Brittany; Ornelas, Laura; Burbey, Alexandra; Marquette, Amber; Frohardt, Russell J; Guarraci, Fay A

2011-06-01

The present study evaluated the effects of methamphetamine (MA) on sexual behavior in female rats. In Experiment 1, ovariectomized, hormone-primed rats were injected with MA (1.0mg/kg, i.p.) or saline prior to a test for mate choice wherein females could mate with two males simultaneously. Female rats treated with saline returned to their preferred mate faster after receiving intromissions and visited their preferred mate at a higher rate than their non-preferred mate. In contrast, MA-treated female rats spent a similar amount of time with their preferred and non-preferred mate and failed to return to their preferred mate faster than to their non-preferred mate following intromissions. Two weeks later, the females received the same drug treatment but were tested for partner preference wherein females could spend time near a male or female stimulus rat. All subjects spent more time near the male stimulus than the female stimulus. However, the MA-treated rats visited the male stimulus more frequently and spent less time near the female stimulus than the saline-treated rats. Similar to Experiment 1, female rats in Experiment 2 were tested for mate choice and then two weeks later tested for partner preference; however, females received three daily injections of MA (1.0mg/kg, i.p.) or saline. Females treated chronically with MA returned to both males faster following intromissions than females treated with saline, independent of preference (i.e., preferred mate and non-preferred mate). Furthermore, MA-treated rats were more likely to leave either male (i.e., preferred or non-preferred mate) than saline-treated rats after receiving sexual stimulation. Although MA-treated subjects spent more time near the male stimulus than the female stimulus, they spent less time near either when compared to saline-treated subjects. The present results demonstrate that MA affects sexual behavior in female rats partly by increasing locomotion and partly by directly affecting sexual behavior. Copyright © 2011 Elsevier Inc. All rights reserved.

Pampas deer (Ozotoceros bezoarticus) courtship and mating behavior

PubMed Central

2012-01-01

Background Pampas deer, Ozotoceros bezoarticus (Linnaeus 1758), is a South American grazing deer categorized as "near threatened". However, knowledge about pampas deer behavior including courtship and mating is scarce and incomplete. The aim of this study was to characterize the courtship and mating behavior of the pampas deer (Ozotoceros bezoarticus), an endangered species from South America. Methods We performed focal observations of 5 males allocated at the Estación de Cría de Fauna Autóctona Cerro Pan de Azúcar, Uruguay, 4 times a day from 5 to 20 minutes each time on a daily basis from February to May. During that period we recorded all courtship and mating behaviors, as well as quantified the frequency of the specific behaviors shown. As mating were rarely observed, we recorded that behavior when it was observed in the context of other studies performed in the same population during the following 2 years. Results During the observation period we recorded 928 courtships and 5 mating periods. In addition, we recorded 10 more matings performed during other studies, totaling 15. The duration of each mating calculated from the 15 recordings was 3.9 ± 0.4 s, and the total period of female receptivity (from first to last mating acceptance) was 8.2 ± 1.1 min. Main observed courtship behaviors in males were “chase” and “ostentation”, while the most observed close to mating were “chinning”, “raised head” and “anogenital sniffing”. The most observed behaviors in females during the mating period were “vulva exhibition” and “move away”. Conclusion This is the first detailed report in pampas deer mating behavior. Estrus lasted only 8 min accepting only 3 short copulations per estrus. However, female behavior during courtship can be characterized as highly proceptive. PMID:23062236

Ultimate Drivers and Proximate Correlates of Polyandry in Predatory Mites

PubMed Central

Schausberger, Peter; Patiño-Ruiz, J. David; Osakabe, Masahiro; Murata, Yasumasa; Sugimoto, Naoya; Uesugi, Ryuji; Walzer, Andreas

2016-01-01

Polyandry is more widespread than anticipated from Bateman’s principle but its ultimate (evolutionary) causes and proximate (mechanistic) correlates are more difficult to pinpoint than those of polygyny. Here, we combined mating experiments, quantification of reproductive traits and microsatellite genotyping to determine the fitness implications of polyandry in two predatory mite species, where males are highly polygynous (up to 45 fertilized females during life), whereas females range from monandry to various polyandry levels. The medium-level polyandrous (up to eight male mates possible) Neoseiulus californicus received clear direct and indirect benefits: multiply mated females produced more offspring with higher survival chances over longer times than singly mated females. In contrast, singly and multiply mated females of the low-level polyandrous (commonly two male mates at maximum) Phytoseiulus persimilis produced similar numbers of offspring having similar survival chances. In both species, multiple mating resulted in mixed offspring paternities, opening the chance for indirect fitness benefits such as enhanced genetic compatibility, complementarity and/or variability. However, the female re-mating likelihood and the paternity chance of non-first male mates were lower in P. persimilis than in N. californicus. Regarding proximate factors, in both species first mating duration and female re-mating likelihood were negatively correlated. Based on occasional fertilization failure of first male mates in P. persimilis, and mixed offspring paternities in both species, we argue that fertilization assurance and the chance to gain indirect fitness benefits are the ultimate drivers of polyandry in P. persimilis, whereas those of N. californicus are higher offspring numbers coupled with enhanced offspring viability and possibly other indirect fitness benefits. Overall, the adaptive significance and proximate events well reflected the polyandry levels. Our study provides a key example for linking behavioral experiments, quantification of reproductive traits and paternity analysis via offspring genotyping to explain the evolution of differing levels of polyandry. PMID:27100395

Ultimate Drivers and Proximate Correlates of Polyandry in Predatory Mites.

PubMed

Schausberger, Peter; Patiño-Ruiz, J David; Osakabe, Masahiro; Murata, Yasumasa; Sugimoto, Naoya; Uesugi, Ryuji; Walzer, Andreas

2016-01-01

Polyandry is more widespread than anticipated from Bateman's principle but its ultimate (evolutionary) causes and proximate (mechanistic) correlates are more difficult to pinpoint than those of polygyny. Here, we combined mating experiments, quantification of reproductive traits and microsatellite genotyping to determine the fitness implications of polyandry in two predatory mite species, where males are highly polygynous (up to 45 fertilized females during life), whereas females range from monandry to various polyandry levels. The medium-level polyandrous (up to eight male mates possible) Neoseiulus californicus received clear direct and indirect benefits: multiply mated females produced more offspring with higher survival chances over longer times than singly mated females. In contrast, singly and multiply mated females of the low-level polyandrous (commonly two male mates at maximum) Phytoseiulus persimilis produced similar numbers of offspring having similar survival chances. In both species, multiple mating resulted in mixed offspring paternities, opening the chance for indirect fitness benefits such as enhanced genetic compatibility, complementarity and/or variability. However, the female re-mating likelihood and the paternity chance of non-first male mates were lower in P. persimilis than in N. californicus. Regarding proximate factors, in both species first mating duration and female re-mating likelihood were negatively correlated. Based on occasional fertilization failure of first male mates in P. persimilis, and mixed offspring paternities in both species, we argue that fertilization assurance and the chance to gain indirect fitness benefits are the ultimate drivers of polyandry in P. persimilis, whereas those of N. californicus are higher offspring numbers coupled with enhanced offspring viability and possibly other indirect fitness benefits. Overall, the adaptive significance and proximate events well reflected the polyandry levels. Our study provides a key example for linking behavioral experiments, quantification of reproductive traits and paternity analysis via offspring genotyping to explain the evolution of differing levels of polyandry.

Impact of Experimental Conditions on the Evaluation of Interactions between Multidrug and Toxin Extrusion Proteins and Candidate Drugs.

PubMed

Lechner, Christian; Ishiguro, Naoki; Fukuhara, Ayano; Shimizu, Hidetada; Ohtsu, Naoko; Takatani, Masahito; Nishiyama, Kotaro; Washio, Ikumi; Yamamura, Norio; Kusuhara, Hiroyuki

2016-08-01

Multidrug and toxin extrusion transporters (MATEs) have a determining influence on the pharmacokinetic profiles of many drugs and are involved in several clinical drug-drug interactions (DDIs). Cellular uptake assays with recombinant cells expressing human MATE1 or MATE2-K are widely used to investigate MATE-mediated transport for DDI assessment; however, the experimental conditions and used test substrates vary among laboratories. We therefore initially examined the impact of three assay conditions that have been applied for MATE substrate and inhibitor profiling in the literature. One of the tested conditions resulted in significantly higher uptake rates of the three test substrates, [(14)C]metformin, [(3)H]thiamine, and [(3)H]1-methyl-4-phenylpyridinium (MPP(+)), but IC50 values of four tested MATE inhibitors varied only slightly among the three conditions (<2.5-fold difference). Subsequently, we investigated the uptake characteristics of the five MATE substrates: [(14)C]metformin, [(3)H]thiamine, [(3)H]MPP(+), [(3)H]estrone-3-sulfate (E3S), and rhodamine 123, as well as the impact of the used test substrate on the inhibition profiles of 10 MATE inhibitors at one selected assay condition. [(3)H]E3S showed atypical uptake characteristics compared with those observed with the other four substrates. IC50 values of the tested inhibitors were in a similar range (<4-fold difference) when [(14)C]metformin, [(3)H]thiamine, [(3)H]MPP(+), or [(3)H]E3S were used as substrates but were considerably higher with rhodamine 123 (9.8-fold and 4.1-fold differences compared with [(14)C]metformin with MATE1 and MATE2-K, respectively). This study demonstrated for the first time that the impact of assay conditions on IC50 determination is negligible, that kinetic characteristics differ among used test substrates, and that substrate-dependent inhibition exists for MATE1 and MATE2-K, giving valuable insight into the assessment of clinically relevant MATE-mediated DDIs in vitro. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Including nonadditive genetic effects in mating programs to maximize dairy farm profitability.

PubMed

Aliloo, H; Pryce, J E; González-Recio, O; Cocks, B G; Goddard, M E; Hayes, B J

2017-02-01

We compared the outcome of mating programs based on different evaluation models that included nonadditive genetic effects (dominance and heterozygosity) in addition to additive effects. The additive and dominance marker effects and the values of regression on average heterozygosity were estimated using 632,003 single nucleotide polymorphisms from 7,902 and 7,510 Holstein cows with calving interval and production (milk, fat, and protein yields) records, respectively. Expected progeny values were computed based on the estimated genetic effects and genotype probabilities of hypothetical progeny from matings between the available genotyped cows and the top 50 young genomic bulls. An index combining the traits based on their economic values was developed and used to evaluate the performance of different mating scenarios in terms of dollar profit. We observed that mating programs with nonadditive genetic effects performed better than a model with only additive effects. Mating programs with dominance and heterozygosity effects increased milk, fat, and protein yields by up to 38, 1.57, and 1.21 kg, respectively. The inclusion of dominance and heterozygosity effects decreased calving interval by up to 0.70 d compared with random mating. The average reduction in progeny inbreeding by the inclusion of nonadditive genetic effects in matings compared with random mating was between 0.25 to 1.57 and 0.64 to 1.57 percentage points for calving interval and production traits, respectively. The reduction in inbreeding was accompanied by an average of A$8.42 (Australian dollars) more profit per mating for a model with additive, dominance, and heterozygosity effects compared with random mating. Mate allocations that benefit from nonadditive genetic effects can improve progeny performance only in the generation where it is being implemented, and the gain from specific combining abilities cannot be accumulated over generations. Continuous updating of genomic predictions and mate allocation programs are required to benefit from nonadditive genetic effects in the long term. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Chronic unpredictable mild stress-induced depressive-like behavior and dysregulation of brain levels of biogenic amines in Drosophila melanogaster.

PubMed

Araujo, Stífani Machado; Poetini, Marcia Rósula; Bortolotto, Vandreza Cardoso; de Freitas Couto, Shanda; Pinheiro, Franciane Cabral; Meichtry, Luana Barreto; de Almeida, Francielli Polet; Santos Musachio, Elize Aparecida; de Paula, Mariane Trindade; Prigol, Marina

2018-05-24

The etiopathogenesis of depression may involve repeated exposure to several unpredictable stressors. This study was conducted to investigate changes induced by chronic unpredictable mild stress (CUMS) and to assess behavioral and neurochemical changes that predict depressive-like behavior in Drosophila melanogaster. Male Drosophila melanogaster flies were exposed to CUMS with several stressors (cold, heat, starvation, and sleep deprivation) in an unpredictable and chronic manner for ten days. At the end of treatment, in vivo behavioral tests (open field, aggression, forced swimming, mating, light/dark box, male fertility evaluation, sucrose preference, weight evaluation) and ex vivo analyses (dopamine and serotonin levels) were performed. Using this CUMS model, we obtained results that contribute to the construction of a depressive model in Drosophila, where we reproduce some behavioral phenotypes corresponding to depressive symptoms, such as immobility in the forced swimming test, less exploration in the light/dark test, changes in mating behavior, changes in the aggressiveness test, reduced sucrose preference, and weight-loss, in addition to a significant reduction in the levels of serotonin and dopamine when compared to the control group. Fluoxetine was used in our study as a positive control to demonstrate that CUMS-induced depressive-like behaviors in flies can be reversed by antidepressants. In conclusion, male Drosophila melanogaster exposed to CUMS display a depressive-like phenotype, and, while this poses some limitations as an animal model for depression, it meets some of the criteria required to be a valid model, such as good face and construct validity. Copyright © 2018. Published by Elsevier B.V.

An integrative view of sexual selection in Tribolium flour beetles.

PubMed

Fedina, Tatyana Y; Lewis, Sara M

2008-05-01

Sexual selection is a major force driving the evolution of diverse reproductive traits. This evolutionary process is based on individual reproductive advantages that arise either through intrasexual competition or through intersexual choice and conflict. While classical studies of sexual selection focused mainly on differences in male mating success, more recent work has focused on the differences in paternity share that may arise through sperm competition or cryptic female choice whenever females mate with multiple males. Thus, an integrative view of sexual selection needs to encompass processes that occur not only before copulation (pre-mating), but also during copulation (peri-mating), as well as after copulation (post-mating), all of which can generate differences in reproductive success. By encompassing mechanisms of sexual selection across all of these sequential reproductive stages this review takes an integrative approach to sexual selection in Tribolium flour beetles (Coleoptera: Tenebrionidae), a particularly well-studied and economically important model organism. Tribolium flour beetles colonize patchily distributed grain stores, and juvenile and adult stages share the same food resources. Adults are highly promiscuous and female reproduction is distributed across an adult lifespan lasting approximately 1 year. While Tribolium males produce an aggregation pheromone that attracts both sexes, there appears to be little pre-mating discrimination among potential mates by either sex. However, recent work has revealed several peri-mating and post-mating mechanisms that determine how offspring paternity is apportioned among a female's mates. During mating, Tribolium females reject spermatophore transfer and limit sperm numbers transferred by males with low phenotypic quality. Although there is some conflicting evidence, male copulatory leg-rubbing appears to be associated with overcoming female resistance to insemination and does not influence a male's subsequent paternity share. Evidence suggests that Tribolium beetles have several possible post-mating mechanisms that they may use to bias paternity. Male sperm precedence has been extensively studied in Tribolium spp. and the related Tenebrio molitor, and several factors influencing male paternity share among a female's progeny have been identified. These include oviposition time, inter-mating interval, male strain/genotype, the mating regimen of a male's mother, male starvation, and tapeworm infection. Females exert muscular control over sperm storage, although there is no evidence to date that females use this to differentiate among mates. Females could also influence offspring paternity by re-mating with additional males, and T. castaneum females more readily accept spermatophores when they are re-mating with more attractive males. Additional work is needed to examine the possible roles played by both male and female accessory gland products in determining male paternity share. Sexual selection during pre-mating episodes may be reinforced or counteracted by peri- and post-copulatory selection, and antagonistic coevolution between the sexes may be played out across reproductive stages. In Tribolium, males' olfactory attractiveness is positively correlated with both insemination success and paternity share, suggesting consistent selection across different reproductive stages. Similar studies across sequential reproductive stages are needed in other taxa to provide a more integrative view of sexual selection.

Results from a blind and a non-blind randomised trial run in parallel: experience from the Estonian Postmenopausal Hormone Therapy (EPHT) Trial.

PubMed

Veerus, Piret; Fischer, Krista; Hakama, Matti; Hemminki, Elina

2012-04-04

The Estonian Postmenopausal Hormone Therapy (EPHT) Trial assigned 4170 potential participants prior to recruitment to blind or non-blind hormone therapy (HT), with placebo or non-treatment the respective alternatives. Before having to decide on participation, women were told whether they had been randomised to the blind or non-blind trial. Eligible women who were still willing to join the trial were recruited. After recruitment participants in the non-blind trial (N = 1001) received open-label HT or no treatment, participants in the blind trial (N = 777) remained blinded until the end of the trial. The aim of this paper is to analyse the effect of blinding on internal and external validity of trial outcomes. Effect of blinding was calculated as the hazard ratio of selected chronic diseases, total mortality and all outcomes. For analysing the effect of blinding on external validity, the hazard ratios from women recruited to the placebo arm and to the non-treatment arm were compared with those not recruited; for analysing the effect of blinding on internal validity, the hazard ratios from the blind trial were compared with those from the non-blind trial. The women recruited to the placebo arm had less cerebrovascular disease events (HR 0.43; 95% CI: 0.26-0.71) and all outcomes combined (HR 0.76; 95% CI: 0.63-0.91) than those who were not recruited. Among women recruited or not recruited to the non-treatment arm, no differences were observed for any of the outcomes studied.Among women recruited to the trial, the risk for coronary heart disease events (HR 0.77; 95% CI: 0.64-0.93), cerebrovascular disease events (HR 0.66; 95%CI: 0.47-0.92), and all outcomes combined (HR 0.82; 95% CI: 0.72-0.94) was smaller among participants in the blind trial than in the non-blind trial. There was no difference between the blind and the non-blind trial for total cancer (HR 0.95; 95% CI: 0.64-1.42), bone fractures (0.93; 95% CI: 0.74-1.16), and total mortality (HR 1.03; 95% CI: 0.53-1.98). The results from blind and non-blind trials may differ, even if the target population is the same. Blinding may influence both internal and external validity. The effect of blinding may vary for different outcome events. [ISRCTN35338757].

Multi-year evaluation of mating disruption treatments against gypsy moth

Treesearch

Patrick C. Tobin; Kevin W. Thorpe; Laura M. Blackburn

2007-01-01

Mating disruption is the use of synthetic pheromone flakes that are aerially applied to foliage with the goal of interfering with male gypsy moths? ability to locate females and mate. Mating disruption is the primary tactic against gypsy moth used in the Gypsy Moth Slow-the-Spread Project (STS) [Tobin et al. 2004. Amer. Entomol. 50:200].

Under soggy skies on a Sunday morning, the Space Shuttle Endeavour is encased in the Mate-DeMate gantry during turnaround processing at NASA DFRC

NASA Image and Video Library

2008-12-07

Under soggy skies on a Sunday morning, the Space Shuttle Endeavour is encased in the Mate-DeMate gantry during turnaround processing at NASA's Dryden Flight Research Center following its STS-126 landing at Edwards Air Force Base a week earlier.

The relationship between health and mating success in humans

PubMed Central

Rhodes, Gillian 

2017-01-01

Health has been claimed to play an important role in human sexual selection, especially in terms of mate choice. Our preferences for attractive individuals are said to represent evolved adaptations for finding high-quality, healthy mates. If this is true, then we expect health to predict mating success in humans. We tested this hypothesis using several important physiological indicators of health, including immune function, oxidative stress and semen quality, and self-reported measures of sexual behaviour that contribute to mating success. In contrast to our hypothesis, we did not find a relationship between the physiological measures of health and sexual behaviour. Our results provide little support for claims that health, at least the health measures we used, increases mating success in relatively healthy humans. PMID:28280558

Is a controlled randomised trial the non-plus-ultra design? A contribution to discussion on comparative, controlled, non-randomised trials.

PubMed

Gaus, Wilhelm; Muche, Rainer

2013-05-01

Clinical studies provide formalised experience for evidence-based medicine (EBM). Many people consider a controlled randomised trial (CRT, identical to a randomised controlled trial RCT) to be the non-plus-ultra design. However, CRTs also have limitations. The problem is not randomisation itself but informed consent for randomisation and masking of therapies according to today's legal and ethical standards. We do not want to de-rate CRTs, but we would like to contribute to the discussion on clinical research methodology. Informed consent to a CRT and masking of therapies plainly select patients. The excellent internal validity of CRTs can be counterbalanced by poor external validity, because internal and external validity act as antagonists. In a CRT, patients may feel like guinea pigs, this can decrease compliance, cause protocol violations, reduce self-healing properties, suppress unspecific therapeutic effects and possibly even modify specific efficacy. A control group (comparative study) is most important for the degree of evidence achieved by a trial. Study control by detailed protocol and good clinical practice (controlled study) is second in importance and randomisation and masking is third (thus the sequence CRT instead of RCT). Controlled non-randomised trials are just as ambitious and detailed as CRTs. We recommend clinicians and biometricians to take high quality controlled non-randomised trials into consideration more often. They combine good internal and external validity, better suit daily medical practice, show better patient compliance and fewer protocol violations, deliver estimators unbiased by alienated patients, and perhaps provide a clearer explanation of the achieved success. Copyright © 2013 Elsevier Inc. All rights reserved.

Validation of clinic weights from electronic health records against standardized weight measurements in weight loss trials.

PubMed

Xiao, Lan; Lv, Nan; Rosas, Lisa G; Au, David; Ma, Jun

2017-02-01

To validate clinic weights in electronic health records against researcher-measured weights for outcome assessment in weight loss trials. Clinic and researcher-measured weights from a published trial (BE WELL) were compared using Lin's concordance correlation coefficient, Bland and Altman's limits of agreement, and polynomial regression model. Changes in clinic and researcher-measured weights in BE WELL and another trial, E-LITE, were analyzed using growth curve modeling. Among BE WELL (n = 330) and E-LITE (n = 241) participants, 96% and 90% had clinic weights (mean [SD] of 5.8 [6.1] and 3.7 [3.9] records) over 12 and 15 months of follow-up, respectively. The concordance correlation coefficient was 0.99, and limits of agreement plots showed no pattern between or within treatment groups, suggesting overall good agreement between researcher-measured and nearest-in-time clinic weights up to 3 months. The 95% confidence intervals for predicted percent differences fell within ±3% for clinic weights within 3 months of the researcher-measured weights. Furthermore, the growth curve slopes for clinic and researcher-measured weights by treatment group did not differ significantly, suggesting similar inferences about treatment effects over time, in both trials. Compared with researcher-measured weights, close-in-time clinic weights showed high agreement and inference validity. Clinic weights could be a valid pragmatic outcome measure in weight loss studies. © 2017 The Obesity Society.

Mate choice could be random in female rats (Rattus norvegicus).

PubMed

Le Moëne, Olivia; Snoeren, Eelke M

2018-02-01

Female mate choice is often investigated in terms of reproductive success in order to understand how male characteristics contribute to sexual attractiveness. Previous studies have found that females rats prefer mating with their first encounter rather than males visited subsequently, suggesting that the rewarding value of this first encounter is enough to reinforce mating with the first partner. Using a multiple chambers paradigm, we allowed female rats to copulate freely with three males placed each in a different chamber. Then, we switched the males' position, and let the female interact with them freely again within the same session. We tested whether female mate choice was relying rather on a preferred male rat or on a preferred mating location. The results showed that females spent most time with the male in the chamber of 1st entry in the beginning, but as soon as male rats switched chambers, the female rat continued to copulate with the new male in the same chamber of 1st entry, instead of mating with her previously preferred male rat. This suggests that the male preference is an artefact of location preference. Therefore, female mate choice seems to be rather random than the consequence of an individual choice based on male characteristics. This finding, although contradictory with the intuitive feeling that mate choice is a crucial feature in sexual and reproductive behavior, is supported by several recent observations. In the coming years, behavioral neuroscience should bring light to the brain processes at work in random mate choice. Copyright © 2017 Elsevier Inc. All rights reserved.

Banded mongooses avoid inbreeding when mating with members of the same natal group.

PubMed

Sanderson, Jennifer L; Wang, Jinliang; Vitikainen, Emma I K; Cant, Michael A; Nichols, Hazel J

2015-07-01

Inbreeding and inbreeding avoidance are key factors in the evolution of animal societies, influencing dispersal and reproductive strategies which can affect relatedness structure and helping behaviours. In cooperative breeding systems, individuals typically avoid inbreeding through reproductive restraint and/or dispersing to breed outside their natal group. However, where groups contain multiple potential mates of varying relatedness, strategies of kin recognition and mate choice may be favoured. Here, we investigate male mate choice and female control of paternity in the banded mongoose (Mungos mungo), a cooperatively breeding mammal where both sexes are often philopatric and mating between relatives is known to occur. We find evidence suggestive of inbreeding depression in banded mongooses, indicating a benefit to avoiding breeding with relatives. Successfully breeding pairs were less related than expected under random mating, which appeared to be driven by both male choice and female control of paternity. Male banded mongooses actively guard females to gain access to mating opportunities, and this guarding behaviour is preferentially directed towards less closely related females. Guard-female relatedness did not affect the guard's probability of gaining reproductive success. However, where mate-guards are unsuccessful, they lose paternity to males that are less related to the females than themselves. Together, our results suggest that both sexes of banded mongoose use kin discrimination to avoid inbreeding. Although this strategy appears to be rare among cooperative breeders, it may be more prominent in species where relatedness to potential mates is variable, and/or where opportunities for dispersal and mating outside of the group are limited. © 2015 John Wiley & Sons Ltd.

Mate choice trade-offs and women's preference for physically attractive men.

PubMed

Waynforth, D

2001-09-01

Researchers studying human sexuality have repeatedly concluded that men place more emphasis on the physical attractiveness of potential mates than women do, particularly in long-term sexual relationships. Evolutionary theorists have suggested that this is the case because male mate value (the total value of the characteristics that an individual possesses in terms of the potential contribution to his or her mate's reproductive success) is better predicted by social status and economic resources, whereas women's mate value hinges on signals conveyed by their physical appearance. This pattern may imply that women trade off attractiveness for resources in mate choice. Here I test whether a trade-off between resources and attractiveness seems to be occurring in the mate choice decisions of women in the United States. In addition, the possibility that the risk of mate desertion drives women to choose less attractive men as long-term mates is tested. The results were that women rated physically attractive men as more likely to cheat or desert a long-term relationship, whereas men did not consider attractive women to be more likely to cheat. However, women showed no aversion to the idea of forming long-term relationships with attractive men. Evidence for a trade-off between resources and attractiveness was found for women, who traded off attractiveness, but not other traits, for resources. The potential meaning of these findings, as well as how they relate to broader issues in the study of sex differences in the evolution of human mate choice for physical traits, is discussed.

Yerba mate enhances probiotic bacteria growth in vitro but as a feed additive does not reduce Salmonella Enteritidis colonization in vivo.

PubMed

Gonzalez-Gil, Francisco; Diaz-Sanchez, Sandra; Pendleton, Sean; Andino, Ana; Zhang, Nan; Yard, Carrie; Crilly, Nate; Harte, Federico; Hanning, Irene

2014-02-01

Yerba mate (Ilex paraguariensis) is a tea known to have beneficial effects on human health and antimicrobial activity against some foodborne pathogens. Thus, the application of yerba mate as a feed additive for broiler chickens to reduce Salmonella colonization was evaluated. The first in vitro evaluation was conducted by suspending Salmonella Enteritidis and lactic acid bacteria (LAB) in yerba mate extract. The in vivo evaluations were conducted using preventative and horizontal transmission experiments. In all experiments, day-of-hatch chicks were treated with one of the following 1) no treatment (control); 2) ground yerba mate in feed; 3) probiotic treatment (Lactobacillus acidophilus and Pediococcus; 9:1 administered once on day of hatch by gavage); or 4) both yerba mate and probiotic treatments. At d 3, all chicks were challenged with Salmonella Enteritidis (preventative experiment) or 5 of 20 chicks (horizontal transmission experiment). At d 10, all birds were euthanized, weighed, and cecal contents enumerated for Salmonella. For the in vitro evaluation, antimicrobial activity was observed against Salmonella and the same treatment enhanced growth of LAB. For in vivo evaluations, none of the yerba mate treatments significantly reduced Salmonella Enteritidis colonization, whereas the probiotic treatment significantly reduced Salmonella colonization in the horizontal transmission experiment. Yerba mate decreased chicken BW and decreased the performance of the probiotic treatment when used in combination. In conclusion, yerba mate had antimicrobial activity against foodborne pathogens and enhanced the growth of LAB in vitro, but in vivo yerba mate did not decrease Salmonella Enteritidis colonization.

[Correlation between genetic differences of mates and pathogenicity of Schistosoma japonicum in definitive host].

PubMed

Wen-Qiao, Huang; Yuan-Jian, Zhu; Da-Bing, Lv; Xia, Zhou; Ying-Nan, Yang; Hong-Xiang, Zhu-Ge

2016-05-24

To explore the correlation between the genetic dissimilarity and heterozygosity of mates and the pathogenicity of Schistosoma japonicum in the definitive host. By using seven microsatellite loci markers, S. japonicum genotyping of sixteen pairs randomly mated was performed, the genetic dissimilarity and heterozygosity were calculated between the mates, and the correlation between the genetic dissimilarity and heterozygosity of the mates and the pathogenicity of S. japonicum in the definitive host was evaluated. There was a significant correlation between the genetic similarity of S. japonicum mates and the mean number of eggs per worm pair in the liver and intestinal tissue ( r = 0.501 6, P < 0.05; r = 0.796 5, P < 0.01, respectively) and the hatching rate of deposited eggs in the liver ( r = 0.508 3, P < 0.05), respectively. There was no correlation between the genetic similarity of the mates and hepatosplenomegaly per worm pair ( r = 0.109 5, P > 0.05; r = 0.265 3, P > 0.05, respectively) and the average diameter of granuloma in the liver ( r = -0.272 7, P > 0.05), respectively. There was no correlation between the heterozygosity of the mates and all the pathological parameters of S. japonicum in the definitive host ( P > 0.05). There is the correlation between the genetic dissimilarity of the mates and the pathogenicity of S. japonicum in the definitive host, and the genetic dissimilarity is greater, pathogenicity is weaker. There is no correlation between heterozygosity of the mates and the pathogenicity of S. japonicum in the definitive host.

Assortative mating for human height: A meta‐analysis

PubMed Central

Simons, Mirre J.P.; Grasman, Sara; Pollet, Thomas V.

2016-01-01

Abstract Objectives The study of assortative mating for height has a rich history in human biology. Although the positive correlation between the stature of spouses has often been noted in western populations, recent papers suggest that mating patterns for stature are not universal. The objective of this paper was to review the published evidence to examine the strength of and universality in assortative mating for height. Methods We conducted an extensive literature review and meta‐analysis. We started with published reviews but also searched through secondary databases. Our search led to 154 correlations of height between partners. We classified the populations as western and non‐western based on geography. These correlations were then analyzed via meta‐analytic techniques. Results 148 of the correlations for partner heights were positive and the overall analysis indicates moderate positive assortative mating (r = .23). Although assortative mating was slightly stronger in countries that can be described as western compared to non‐western, this difference was not statistically significant. We found no evidence for a change in assortative mating for height over time. There was substantial residual heterogeneity in effect sizes and this heterogeneity was most pronounced in western countries. Conclusions Positive assortative mating for height exists in human populations, but is modest in magnitude suggesting that height is not a major factor in mate choice. Future research is necessary to understand the underlying causes of the large amount of heterogeneity observed in the degree of assortative mating across human populations, which may stem from a combination of methodological and ecological differences. PMID:27637175

Mating flights select for symmetry in honeybee drones ( Apis mellifera)

NASA Astrophysics Data System (ADS)

Jaffé, Rodolfo; Moritz, Robin F. A.

2010-03-01

Males of the honeybee ( Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

Mating flights select for symmetry in honeybee drones (Apis mellifera).

PubMed

Jaffé, Rodolfo; Moritz, Robin F A

2010-03-01

Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen's visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

Sex begets violence: mating motives, social dominance, and physical aggression in men.

PubMed

Ainsworth, Sarah E; Maner, Jon K

2012-11-01

There are sizable gender differences in aggressive behavior, with men displaying a much higher propensity for violence than women. Evolutionary theories suggest that men's more violent nature derives in part from their historically greater need to compete over access to potential mates. The current research investigates this link between mating and male violence and provides rigorous experimental evidence that mating motives cause men to behave violently toward other men. In these studies, men and women were primed with a mating motive and then performed a noise-blast aggression task. Being primed with mating led men, but not women, to deliver more painful blasts of white noise to a same-sex partner (but not an opposite-sex partner). This effect was particularly pronounced among men with an unrestricted sociosexual orientation, for whom competition over access to new mates is an especially relevant concern. Findings also suggest that mating-induced male violence is motivated by a desire to assert one's dominance over other men: when men were given feedback that they had won a competition with their partner (and thus had achieved dominance through nonaggressive means), the effect of the mating prime on aggression was eliminated. These findings provide insight into the motivational roots of male aggression and illustrate the value of testing theories from evolutionary biology with rigorous experimental methods. (c) 2012 APA, all rights reserved.

Functional characterization of MAT1-1-specific mating-type genes in the homothallic ascomycete Sordaria macrospora provides new insights into essential and nonessential sexual regulators.

PubMed

Klix, V; Nowrousian, M; Ringelberg, C; Loros, J J; Dunlap, J C; Pöggeler, S

2010-06-01

Mating-type genes in fungi encode regulators of mating and sexual development. Heterothallic ascomycete species require different sets of mating-type genes to control nonself-recognition and mating of compatible partners of different mating types. Homothallic (self-fertile) species also carry mating-type genes in their genome that are essential for sexual development. To analyze the molecular basis of homothallism and the role of mating-type genes during fruiting-body development, we deleted each of the three genes, SmtA-1 (MAT1-1-1), SmtA-2 (MAT1-1-2), and SmtA-3 (MAT1-1-3), contained in the MAT1-1 part of the mating-type locus of the homothallic ascomycete species Sordaria macrospora. Phenotypic analysis of deletion mutants revealed that the PPF domain protein-encoding gene SmtA-2 is essential for sexual reproduction, whereas the alpha domain protein-encoding genes SmtA-1 and SmtA-3 play no role in fruiting-body development. By means of cross-species microarray analysis using Neurospora crassa oligonucleotide microarrays hybridized with S. macrospora targets and quantitative real-time PCR, we identified genes expressed under the control of SmtA-1 and SmtA-2. Both genes are involved in the regulation of gene expression, including that of pheromone genes.

Functional Characterization of MAT1-1-Specific Mating-Type Genes in the Homothallic Ascomycete Sordaria macrospora Provides New Insights into Essential and Nonessential Sexual Regulators▿†

PubMed Central

Klix, V.; Nowrousian, M.; Ringelberg, C.; Loros, J. J.; Dunlap, J. C.; Pöggeler, S.

2010-01-01

Mating-type genes in fungi encode regulators of mating and sexual development. Heterothallic ascomycete species require different sets of mating-type genes to control nonself-recognition and mating of compatible partners of different mating types. Homothallic (self-fertile) species also carry mating-type genes in their genome that are essential for sexual development. To analyze the molecular basis of homothallism and the role of mating-type genes during fruiting-body development, we deleted each of the three genes, SmtA-1 (MAT1-1-1), SmtA-2 (MAT1-1-2), and SmtA-3 (MAT1-1-3), contained in the MAT1-1 part of the mating-type locus of the homothallic ascomycete species Sordaria macrospora. Phenotypic analysis of deletion mutants revealed that the PPF domain protein-encoding gene SmtA-2 is essential for sexual reproduction, whereas the α domain protein-encoding genes SmtA-1 and SmtA-3 play no role in fruiting-body development. By means of cross-species microarray analysis using Neurospora crassa oligonucleotide microarrays hybridized with S. macrospora targets and quantitative real-time PCR, we identified genes expressed under the control of SmtA-1 and SmtA-2. Both genes are involved in the regulation of gene expression, including that of pheromone genes. PMID:20435701

Fitness Benefits of Mate Choice for Compatibility in a Socially Monogamous Species

PubMed Central

Ihle, Malika; Kempenaers, Bart; Forstmeier, Wolfgang

2015-01-01

Research on mate choice has primarily focused on preferences for quality indicators, assuming that all individuals show consensus about who is the most attractive. However, in some species, mating preferences seem largely individual-specific, suggesting that they might target genetic or behavioral compatibility. Few studies have quantified the fitness consequences of allowing versus preventing such idiosyncratic mate choice. Here, we report on an experiment that controls for variation in overall partner quality and show that zebra finch (Taeniopygia guttata) pairs that resulted from free mate choice achieved a 37% higher reproductive success than pairs that were forced to mate. Cross-fostering of freshly laid eggs showed that embryo mortality (before hatching) primarily depended on the identity of the genetic parents, whereas offspring mortality during the rearing period depended on foster-parent identity. Therefore, preventing mate choice should lead to an increase in embryo mortality if mate choice targets genetic compatibility (for embryo viability), and to an increase in offspring mortality if mate choice targets behavioral compatibility (for better rearing). We found that pairs from both treatments showed equal rates of embryo mortality, but chosen pairs were better at raising offspring. These results thus support the behavioral, but not the genetic, compatibility hypothesis. Further exploratory analyses reveal several differences in behavior and fitness components between “free-choice” and “forced” pairs. PMID:26366558

Influence of mating disruption on the reproductive biology of the vine mealybug, Planococcus ficus (Hemiptera: Pseudococcidae), under field conditions.

PubMed

Cocco, Arturo; Muscas, Enrico; Mura, Alessandra; Iodice, Andrea; Savino, Francesco; Lentini, Andrea

2018-05-08

Although mating disruption is increasingly being used to control the worldwide grapevine pest vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), its mode of action remains unclear. A three-year field experiment was carried out to investigate the effects of mating disruption on the development and reproduction of the vine mealybug. The influence of mating disruption applied over consecutive years on the pest population density was also evaluated. The percentage of ovipositing females was significantly reduced in disrupted plots by 18.8-66.2%, depending on the year. The absence of ovipositing females in disrupted plots in the autumn of the second and third year indicates the effectiveness of mating disruption throughout the whole growing season. Mating disruption consistently prolonged the pre-oviposition period in all years by up to 12.5 days. Our findings provide new insights into the mechanisms underlying the pheromone-based control of the vine mealybug and indicate that the reduction of the pest population density is due to both a decrease and delay in female mating. In addition, the population density of vine mealybugs under mating disruption decreased over years, indicating that consecutive applications of this control strategy would significantly increase the effectiveness of controlling the vine mealybug by mating disruption. This article is protected by copyright. All rights reserved.

46 CFR 11.425 - Requirements for mate of ocean self-propelled vessels of less than 200 GRT.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for mate of ocean self-propelled vessels of... Deck Officer Endorsements § 11.425 Requirements for mate of ocean self-propelled vessels of less than 200 GRT. (a) The minimum service required to qualify for the endorsement as mate of ocean self...

The Mating Game: A Classroom Activity for Undergraduates that Explores the Evolutionary Basis of Sex Roles

ERIC Educational Resources Information Center

Moore, Dani; Holbrook, C. Tate; Meadows, Melissa G.; Taylor, Lisa A.

2012-01-01

In species that reproduce sexually, an individual's fitness depends on its ability to secure a mate (or mates). Although both males and females are selected to maximize their reproductive output, the mating strategies of the two sexes can differ dramatically. We present a classroom simulation that allows undergraduates to actively experience how…

Firefly Mating Algorithm for Continuous Optimization Problems

PubMed Central

Ritthipakdee, Amarita; Premasathian, Nol; Jitkongchuen, Duangjai

2017-01-01

This paper proposes a swarm intelligence algorithm, called firefly mating algorithm (FMA), for solving continuous optimization problems. FMA uses genetic algorithm as the core of the algorithm. The main feature of the algorithm is a novel mating pair selection method which is inspired by the following 2 mating behaviors of fireflies in nature: (i) the mutual attraction between males and females causes them to mate and (ii) fireflies of both sexes are of the multiple-mating type, mating with multiple opposite sex partners. A female continues mating until her spermatheca becomes full, and, in the same vein, a male can provide sperms for several females until his sperm reservoir is depleted. This new feature enhances the global convergence capability of the algorithm. The performance of FMA was tested with 20 benchmark functions (sixteen 30-dimensional functions and four 2-dimensional ones) against FA, ALC-PSO, COA, MCPSO, LWGSODE, MPSODDS, DFOA, SHPSOS, LSA, MPDPGA, DE, and GABC algorithms. The experimental results showed that the success rates of our proposed algorithm with these functions were higher than those of other algorithms and the proposed algorithm also required fewer numbers of iterations to reach the global optima. PMID:28808442

Gasket Assembly for Sealing Mating Surfaces

NASA Technical Reports Server (NTRS)

Bryant, Melvin A., III (Inventor)

2003-01-01

A pair of substantially opposed mating surfaces are joined to each other and sealed in place by means of an electrically-conductive member which is placed in proximity to the mating surfaces. The electrically-conductive member has at least one element secured thereto which is positioned to contact the mating surfaces, and which softens when the electrically-conductive member is heated by passing an electric current therethrough. The softened element conforms to the mating surfaces, and upon cooling of the softened element the mating surfaces are joined together in an effective seal. Of particular significance is an embodiment of the electrically-conductive member which is a gasket having an electrically-conductive gasket base and a pair of the elements secured to opposite sides of the gasket base. This embodiment is positioned between the opposed mating surfaces to be joined to each other. Also significant is an embodiment of the electrically-conductive member which is an electrically-conductive sleeve having an element secured to its inner surface. This embodiment surrounds cylindrical members the bases of which are the substantially opposed mating surfaces to be joined, and the element on the inner surface of the sleeve contacts the outer surfaces of the cylindrical members.

Origin and occurrence of sexual and mating systems in Crustacea: a progression towards communal living and eusociality.

PubMed

Subramoniam, T

2013-12-01

Crustaceans are known for their unrivalled diversity of sexual systems, as well as peculiar mating associations to achieve maximum mating success and fertilization accomplishment. Although sexes are separate in most species, various types of hermaphroditism characterize these predominantly aquatic arthropods. A low operational sex ratio between female and male, together with temporally limited receptivity of females towards males, imposes restrictions on the structuring of mating systems in crustaceans. The basic mating systems consist of monogamy, polygamy, mate guarding and pure searching. Understandably, ecological influences may also play a determinative role in the evolution of such sexual and mating systems in crustaceans. An important outcome of the crustacean sexual biology is the development of complex social structures in many aquatic species, in much the same way insects have established them in terrestrial conditions. In addition, groups like isopods and certain families of brachyuran crabs have shown terrestrial adaptation, exhibiting peculiar reproductive modes, sometimes reminiscent of their terrestrial counterparts, insects. Many caridean shrimps, living in symbiotic relationship with other marine invertebrates in the coral reef habitats, have reached pinnacle of complexity in sexuality and peculiar mating behaviours, resulting in communal living and establishing advanced social systems, such as eusociality.

Firefly Mating Algorithm for Continuous Optimization Problems.

PubMed

Ritthipakdee, Amarita; Thammano, Arit; Premasathian, Nol; Jitkongchuen, Duangjai

2017-01-01

This paper proposes a swarm intelligence algorithm, called firefly mating algorithm (FMA), for solving continuous optimization problems. FMA uses genetic algorithm as the core of the algorithm. The main feature of the algorithm is a novel mating pair selection method which is inspired by the following 2 mating behaviors of fireflies in nature: (i) the mutual attraction between males and females causes them to mate and (ii) fireflies of both sexes are of the multiple-mating type, mating with multiple opposite sex partners. A female continues mating until her spermatheca becomes full, and, in the same vein, a male can provide sperms for several females until his sperm reservoir is depleted. This new feature enhances the global convergence capability of the algorithm. The performance of FMA was tested with 20 benchmark functions (sixteen 30-dimensional functions and four 2-dimensional ones) against FA, ALC-PSO, COA, MCPSO, LWGSODE, MPSODDS, DFOA, SHPSOS, LSA, MPDPGA, DE, and GABC algorithms. The experimental results showed that the success rates of our proposed algorithm with these functions were higher than those of other algorithms and the proposed algorithm also required fewer numbers of iterations to reach the global optima.

A sociobiological origin of pregnancy failure in domestic dogs

PubMed Central

Bartoš, Luděk; Bartošová, Jitka; Chaloupková, Helena; Dušek, Adam; Hradecká, Lenka; Svobodová, Ivona

2016-01-01

Among domestic dog breeders it is common practice to transfer a domestic dog bitch out of her home environment for mating, bringing her back after the mating. If the home environment contains a male, who is not the father of the foetuses, there is a potential risk of future infanticide. We collected 621 records on mating of 249 healthy bitches of 11 breed-types. The highest proportion of successful pregnancies following mating occurred in bitches mated within their home pack and remaining there. Bitches mated elsewhere and then returned to a home containing at least one male had substantially lower incidence of maintained pregnancy in comparison with bitches mated by a home male. After returning home, housing affected strongly the frequency of pregnancy success. Bitches mated elsewhere but released into a home pack containing a home male were four times more likely to maintain pregnancy than bitches which were housed individually after returning home. Suppression of pregnancy in situations where a bitch is unable to confuse a home male about parentage may be seen as an adaptation to avoid any seemingly unavoidable future loss of her progeny to infanticide after birth and thus to save energy. PMID:26917034

EVOLUTION OF DIVERGENT FEMALE MATING PREFERENCE IN RESPONSE TO EXPERIMENTAL SEXUAL SELECTION

PubMed Central

Debelle, Allan; Ritchie, Michael G; Snook, Rhonda R

2014-01-01

Sexual selection is predicted to drive the coevolution of mating signals and preferences (mating traits) within populations, and could play a role in speciation if sexual isolation arises due to mating trait divergence between populations. However, few studies have demonstrated that differences in mating traits between populations result from sexual selection alone. Experimental evolution is a promising approach to directly examine the action of sexual selection on mating trait divergence among populations. We manipulated the opportunity for sexual selection (low vs. high) in populations of Drosophila pseudoobscura. Previous studies on these experimental populations have shown that sexual selection manipulation resulted in the divergence between sexual selection treatments of several courtship song parameters, including interpulse interval (IPI) which markedly influences male mating success. Here, we measure female preference for IPI using a playback design to test for preference divergence between the sexual selection treatments after 130 generations of experimental sexual selection. The results suggest that female preference has coevolved with male signal, in opposite directions between the sexual selection treatments, providing direct evidence of the ability of sexual selection to drive the divergent coevolution of mating traits between populations. We discuss the implications in the context sexual selection and speciation. PMID:24931497

Online Mate-Retention Tactics on Facebook Are Associated With Relationship Aggression.

PubMed

Brem, Meagan J; Spiller, Laura C; Vandehey, Michael A

2015-10-01

A measure of Facebook-related mate-retention tactics was developed to investigate the relationship between online behaviors and intimate partner aggression. One hundred and seventy-seven young adults (65 men, 112 women) completed questionnaires that included measures of online and offline mate-retention tactics, Facebook jealousy, Facebook surveillance, and intimate partner violence. A factor analysis yielded four subscales for the Facebook Mate-Retention Tactic Inventory (FMRTI): Care and Affection, Jealousy and Surveillance, Possession Signals, and Punishment of Infidelity Threat. The FMRTI total scores were positively correlated with Facebook jealousy, Facebook surveillance, and use of offline mate-retention tactics. The Jealousy and Surveillance subscale uniquely predicted intimate partner psychological and physical aggression over and above existing measures. Facebook mate-retention tactics fully mediated the relation between Facebook jealousy and both intimate partner psychological and physical aggression. The current study provides preliminary evidence for conceptualizing Facebook as an environment for the use of mate-retention tactics that have real-life implications for intimate partner violence. © The Author(s) 2014.

A computational approach to animal breeding.

PubMed

Berger-Wolf, Tanya Y; Moore, Cristopher; Saia, Jared

2007-02-07

We propose a computational model of mating strategies for controlled animal breeding programs. A mating strategy in a controlled breeding program is a heuristic with some optimization criteria as a goal. Thus, it is appropriate to use the computational tools available for analysis of optimization heuristics. In this paper, we propose the first discrete model of the controlled animal breeding problem and analyse heuristics for two possible objectives: (1) breeding for maximum diversity and (2) breeding a target individual. These two goals are representative of conservation biology and agricultural livestock management, respectively. We evaluate several mating strategies and provide upper and lower bounds for the expected number of matings. While the population parameters may vary and can change the actual number of matings for a particular strategy, the order of magnitude of the number of expected matings and the relative competitiveness of the mating heuristics remains the same. Thus, our simple discrete model of the animal breeding problem provides a novel viable and robust approach to designing and comparing breeding strategies in captive populations.

Phenolic acids and methylxanthines composition and antioxidant properties of mate (Ilex paraguariensis) residue.

PubMed

Vieira, Manoela A; Maraschin, Marcelo; Pagliosa, Cristiane M; Podestá, Rossana; de Simas, Karina N; Rockenbach, Ismael Ivan; Amboni, Renata D de M C; Amante, Edna R

2010-04-01

Ilex paraguariensis is known to contain compounds with antioxidant properties, such as phenolic acids, and its stimulant properties are attributed to methylxanthines, such as caffeine. The aims of this study were to evaluate the phenolic, methylxanthinic, and tannin composition of a mate residue (mate powder), to compare the quali-quantitative phenolic composition and the antioxidant potential of extracts obtained from distinct solvent systems. Among the extracts prepared with different solvents, the 80% methanol extract showed the highest total polyphenol content (11.51 g/100 g) and antioxidant activity. HPLC analysis showed that 4,5 dicaffeoylquinic acid is the major component of the phenolic fraction of mate powder. The caffeine, theobromine, and tannin contents in mate powder were 1.01, 0.10, and 0.29 g/100 g, respectively. Consumption of mate powder would significantly contribute to antioxidant and stimulant intake, providing high amounts of phenolic acids, tannins, and methylxanthines with biological effects potentially beneficial for human health. This article contributes to the minimization of residues in yerba-mate processing.