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Males

Distribution by Scientific Domains
Medical Sciences44%
Life Sciences40%
Psychology4%
Earth and Environmental Science4%
Humanities and Social Sciences3%
6 Other Domains5%
Distribution within Medical Sciences
Neurology6%
Cardiovascular Disease4%
99 Other Subdomains86%

Kinds of Males

  • active male
  • adolescent male
  • adult male
  • affected male
  • ageing male
  • alpha male
  • american male
  • another male
  • asian male
  • attractive male
  • black male
  • breeding male
  • castrated male
  • caucasian male
  • chinese male
  • conspecific male
  • control male
  • different male
  • diploid male
  • dominant male
  • elderly male
  • experience male
    		•
  • f1 male
  • fertile male
  • fewer male
  • first male
  • gay male
  • group male
  • haploid male
  • healthy male
  • heterospecific male
  • high-quality male
  • hispanic male
  • homosexual male
  • human male
  • hybrid male
  • immature male
  • immigrant male
  • individual male
  • infertile male
  • intact male
  • japanese male
  • juvenile male
  • large male
    		•
  • larger male
  • macropterou male
  • mated male
  • mature male
  • multiple male
  • normal male
  • old male
  • older male
  • one adult male
  • one male
  • only male
  • other male
  • paired male
  • parental male
  • polygynous male
  • prefer male
  • quality male
  • resident male
  • rival male
  • satellite male
  • second male
  • single male
    		•
  • small male
  • smaller male
  • sub-adult male
  • subadult male
  • subordinate male
  • territorial male
  • treated male
  • unfamiliar male
  • unmated male
  • unrelated male
  • untreated male
  • virgin male
  • white male
  • wild-type male
  • year old male
  • yellow male
  • young adult male
  • young male
  • yr-old male

    • Terms modified by Males

  • male Lewi rat
  • male Long-Evan rat
  • male accessory gland
  • male accessory gland infection
  • male adolescent
  • male adult
  • male adult rat
  • male age
  • male ageing study
  • male aggression
  • male albino rat
  • male animals
  • male athlete
  • male attitude
  • male attractiveness
  • male baby
  • male beagle dog
  • male behaviour
  • male bias
  • male bird
  • male birth
  • male body size
  • male brain
  • male breast
  • male breast cancer
  • male breast carcinoma
  • male c mouse
  • male c57bl/6 mouse
  • male c57bl/6j mouse
  • male cadaver
  • male calf
  • male call
  • male cancer patient
  • male care
  • male carrier
  • male case
  • male cat
  • male child
  • male choice
  • male circumcision
  • male college student
  • male competition
  • male condition
  • male contest competition
  • male control
  • male counterpart
  • male courtship
  • male courtship behavior
  • male cricket
  • male development
  • male dispersal
    		•
  • male display
  • male dog
  • male dominance
  • male donor
  • male egg
  • male embryo
  • male employee
  • male erectile dysfunction
  • male excess
  • male f344 rat
  • male factor
  • male factor infertility
  • male female
  • male fertility
  • male fetus
  • male fetuse
  • male fischer
  • male fish
  • male fitness
  • male flower
  • male fly
  • male friendship
  • male function
  • male gamete
  • male gender
  • male gene flow
  • male genital organ
  • male genital tract
  • male genitalia
  • male genotype
  • male germ cell
  • male gonad
  • male group
  • male groups
  • male guppy
  • male hamster
  • male harassment
  • male helper
  • male hypogonadism
  • male individual
  • male infant
  • male infertility
  • male inpatient
  • male interaction
  • male interest
  • male investment
  • male karyotype
  • male lamb
  • male littermate
  • male lizard
  • male longevity
    		•
  • male mass
  • male mate choice
  • male mating rate
  • male mating success
  • male mating tactic
  • male member
  • male mortality
  • male moth
  • male mouse
  • male neonate
  • male nestling
  • male new zealand white rabbits
  • male newborn
  • male nude mouse
  • male odor
  • male offender
  • male offspring
  • male only
  • male ornament
  • male ornamentation
  • male parent
  • male parental care
  • male participant
  • male partner
  • male patient
  • male performance
  • male perpetrator
  • male phase
  • male phenotype
  • male pig
  • male plant
  • male population
  • male predominance
  • male preference
  • male preponderance
  • male prisoner
  • male production
  • male progeny
  • male pup
  • male quality
  • male rabbits
  • male rainbow trout
  • male rape
  • male rat
  • male rate
  • male ratio
  • male recipient
  • male relative
  • male reproduction
  • male reproductive function
  • male reproductive health
    		•
  • male reproductive organ
  • male reproductive success
  • male reproductive system
  • male reproductive tactic
  • male reproductive tract
  • male resident
  • male respondent
  • male rhesus monkey
  • male sample
  • male sd rat
  • male sex
  • male sex pheromone
  • male sexual behavior
  • male sexual dysfunction
  • male sexual function
  • male sheep
  • male sibling
  • male signal
  • male singing
  • male size
  • male sling
  • male smoker
  • male song
  • male specimen
  • male spider
  • male spouse
  • male sprague
  • male sprague dawley rat
  • male sprague-dawley rat
  • male stage
  • male sterile
  • male sterility
  • male student
  • male subject
  • male survivor
  • male tilapia
  • male trait
  • male twin
  • male used
  • male veteran
  • male violence
  • male volunteer
  • male wage
  • male wistar albino rat
  • male wistar rat
  • male worker
  • male youth

    • Selected Abstracts

    HAVE MALE AND FEMALE GENITALIA COEVOLVED?

    EVOLUTION, Issue 9 2005
    A PHYLOGENETIC ANALYSIS OF GENITALIC MORPHOLOGY AND SEXUAL SIZE DIMORPHISM IN WEB-BUILDING SPIDERS (ARANEAE: ARANEOIDEA)
    Abstract Sexual size dimorphism (SSD) can strongly influence the evolution of reproductive strategies and life history. If SSD is extreme, and other characters (e.g., genitalic size) also increase with size, then functional conflicts may arise between the sexes. Spiders offer an excellent opportunity to investigate this issue because of their wide range of SSD. By using modern phylogenetic methods with 16 species of orb-weaving spiders, we provide strong evidence for the "positive genitalic divergence" model, implying that sexual genitalic dimorphism (SGD) increases as SSD increases. This pattern is supported by an evolutionary mismatch between the absolute sizes of male and female genitalia across species. Indeed, our findings reveal a dramatic reversal from male genitalia that are up to 87X larger than female genitalia in size-monomorphic species to female genitalia that are up to 2.8X larger in extremely size-dimorphic species. We infer that divergence in SGD could limit SSD both in spiders, and potentially in other taxa as well. Further, male and female body size, as well as male and female genitalia size, are decoupled evolutionarily. Finally, we show a negative scaling (hypoallometry) of male and female genitalic morphology within sexes. Evolutionary forces specific to each sex, such as larger female size (increased fecundity) or smaller male size (enhanced mate-searching ability), may be balanced by stabilizing selection on relative genitalic size. [source]

    MULTIVARIATE QUANTITATIVE GENETICS AND THE LEK PARADOX: GENETIC VARIANCE IN MALE SEXUALLY SELECTED TRAITS OF DROSOPHILA SERRATA UNDER FIELD CONDITIONS

    EVOLUTION, Issue 12 2004
    Emma Hine
    Abstract Single male sexually selected traits have been found to exhibit substantial genetic variance, even though natural and sexual selection are predicted to deplete genetic variance in these traits. We tested whether genetic variance in multiple male display traits of Drosophila serrata was maintained under field conditions. A breeding design involving 300 field-reared males and their laboratory-reared offspring allowed the estimation of the genetic variance-covariance matrix for six male cuticular hydrocarbons (CHCs) under field conditions. Despite individual CHCs displaying substantial genetic variance under field conditions, the vast majority of genetic variance in CHCs was not closely associated with the direction of sexual selection measured on field phenotypes. Relative concentrations of three CHCs correlated positively with body size in the field, but not under laboratory conditions, suggesting condition-dependent expression of CHCs under field conditions. Therefore condition dependence may not maintain genetic variance in preferred combinations of male CHCs under field conditions, suggesting that the large mutational target supplied by the evolution of condition dependence may not provide a solution to the lek paradox in this species. Sustained sexual selection may be adequate to deplete genetic variance in the direction of selection, perhaps as a consequence of the low rate of favorable mutations expected in multiple trait systems. [source]

    PARTNER AGGRESSION SEVERITY AS A RISK MARKER FOR MALE AND FEMALE VIOLENCE RECIDIVISM

    JOURNAL OF MARITAL AND FAMILY THERAPY, Issue 3 2006
    Erica M. Woodin
    Pretreatment aggression severity was examined as a risk marker for recidivism in the treatment of partner aggression. Intact married couples experiencing husband-to-wife partner aggression were recruited from the community and participated in either conjoint group treatment or gender-specific group treatment. Elevated levels of husband and wife physical aggression and wife psychological aggression before treatment predicted the continuation and severity of physical aggression by both spouses during treatment and in the following year, with no significant differences across treatment formats. These results indicate that high levels of psychological and physical aggression signify a poor prognosis for both conjoint and gender-specific group treatment programs, suggesting the need for interventions of greater intensity, duration, and/or focus for individuals highest in psychological and physical aggression. [source]

    A 24-YEAR-OLD MALE WITH HEADACHES

    BRAIN PATHOLOGY, Issue 4 2010
    Zhongchuan Will Chen MDCM
    First page of article [source]

    A 16-YEAR-OLD MALE WITH A CEREBELLAR MASS

    BRAIN PATHOLOGY, Issue 1 2009
    Gabrielle A. Yeaney MD
    First page of article [source]

    48 YEAR OLD MALE WITH SUDDEN ONSET OF RIGHT SIDED WEAKNESS

    BRAIN PATHOLOGY, Issue 2 2006
    Alexander Easton MBBS PhD
    No abstract is available for this article. [source]

    A 71-YEAR-OLD MALE WITH 4 DECADES OF SYMPTOMS REFERABLE TO BOTH CENTRAL AND PERIPHERAL NERVOUS SYSTEM

    BRAIN PATHOLOGY, Issue 4 2005
    Dianna Quan MD
    First page of article [source]

    THE WEBSITE,GIRL': CONTEMPORARY THEORIES ABOUT MALE,FEMININITY'

    BRITISH JOURNAL OF PSYCHOTHERAPY, Issue 1 2005
    Marie Maguire
    ABSTRACT I explore a bisexual male patient's need to differentiate highly problematic,feminine'identifications - originating in childhood sexual abuse and impingement by men as well as women - from identifications with more admired aspects of his mother. My main focus is on the patient's sexual identity - the personal meaning he gave to being male - rather than on his bisexuality - his desire for both sexes. In psychoanalytic literature powerful opposite-sex identifications are usually associated either with psychotic confusion or celebrated as a source of psychic strength. The co-existence of problematic and highly valued cross-sex identifications is rarely discussed. I also look at how this patient re-negotiated his identity through the transference relationship with a female psychotherapist, given that his,masculinity'derived mainly from childhood experiences of 'stealing'his mother's phallic power. Through a wideranging theoretical review I conclude that we need to draw together opposing psychoanalytic perspectives about maternal and paternal power, opening up new ways of thinking about triangular relationships in the transference. [source]

    PURGING THE GENOME WITH SEXUAL SELECTION: REDUCING MUTATION LOAD THROUGH SELECTION ON MALES

    EVOLUTION, Issue 3 2009
    Michael C. Whitlock
    Healthy males are likely to have higher mating success than unhealthy males because of differential expression of condition-dependent traits such as mate searching intensity, fighting ability, display vigor, and some types of exaggerated morphological characters. We therefore expect that most new mutations that are deleterious for overall fitness may also be deleterious for male mating success. From this perspective, sexual selection is not limited to influencing those genes directly involved in exaggerated morphological traits but rather affects most, if not all, genes in the genome. If true, sexual selection can be an important force acting to reduce the frequency of deleterious mutations and, as a result, mutation load. We review the literature and find various forms of indirect evidence that sexual selection helps to eliminate deleterious mutations. However, direct evidence is scant, and there are almost no data available to address a key issue: is selection in males stronger than selection in females? In addition, the total effect of sexual selection on mutation load is complicated by possible increases in mutation rate that may be attributable to sexual selection. Finally, sexual selection affects population fitness not only through mutation load but also through sexual conflict, making it difficult to empirically measure how sexual selection affects load. Several lines of enquiry are suggested to better fill large gaps in our understanding of sexual selection and its effect on genetic load. [source]

    THE EVOLUTION OF FEMALE MATING PREFERENCES: DIFFERENTIATION FROM SPECIES WITH PROMISCUOUS MALES CAN PROMOTE SPECIATION

    EVOLUTION, Issue 10 2006
    Mark A. McPeek
    Abstract Females of many species are frequently courted by promiscuous males of their own and other closely related species. Such mating interactions may impose strong selection on female mating preferences to favor trait values in conspecific males that allow females to discriminate them from their heterospecific rivals. We explore the consequences of such selection in models of the evolution of female mating preferences when females must interact with heterospecific males from which they are completely postreproductively isolated. Specifically, we allow the values of both the most preferred male trait and the tolerance of females for males that deviate from this most preferred trait to evolve. Also, we consider situations in which females base their mating decisions on multiple male traits and must interact with males of multiple species. Females will rapidly differentiate in preference when they sometimes mistake heterospecific males for suitable mates, and the differentiation of female preference will select for conspecific male traits to differentiate as well. In most circumstances, this differentiation continues indefinitely, but slows substantially once females are differentiated enough to make mistakes rare. Populations of females with broader preference functions (i.e., broader tolerance for males with trait values that deviate from females most preferred values) will evolve further to differentiate if the shape of the function cannot evolve. Also, the magnitude of separation that evolves is larger and achieved faster when conspecific males have lower relative abundance. The direction of differentiation is also very sensitive to initial conditions if females base their mate choices on multiple male traits. We discuss how these selection pressures on female mate choice may lead to speciation by generating differentiation among populations of a progenitor species that experiences different assemblages of heterospecifics. Opportunities for differentiation increase as the number of traits involved in mate choice increase and as the number of species involved increases. We suggest that this mode of speciation may have been particularly prevalent in response to the cycles of climatic change throughout the Quaternary that forced the assembly and disassembly of entire communities on a continentwide basis. [source]

    DOES LARGE BODY SIZE IN MALES EVOLVE TO FACILITATE FORCIBLE INSEMINATION?

    EVOLUTION, Issue 11 2005
    A STUDY ON GARTER SNAKES
    Abstract 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 malemale 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. [source]

    DO FEMALE SPIDERS SELECT HEAVIER MALES FOR THE GENES FOR BEHAVIORAL AGGRESSIVENESS THEY OFFER THEIR OFFSPRING?

    EVOLUTION, Issue 6 2003
    S. E. RIECHERT
    Abstract., We explore the hypothesis that females choose to mate with heavier males for the genes for behavioral aggressiveness they offer their offspring in the desert spider, Agelenopsis aperta. Behavioral aggressiveness is important to competition for limited resources in the field and is thus correlated with the mass spiders achieve. We established four crosses based on the body mass relationships of parents subjected to selection in their natural environment (female mass/male mass: HI/HI, HI/LO, LO/HI, and LO/LO) and reared the F1 offspring in a noncompetitive laboratory environment. Offspring size and mass at maturity were measured, life history parameters recorded, and behavioral aggressiveness scored in a series of tests. Significant familial effects were detected in all of these measures, but pertinent cross effects were observed only in the assays measuring behavioral aggressiveness. The results were summarized in terms of the fitness costs to HI females of mating with LO males (fewer female offspring of the more aggressive phenotypes) and the benefits to LO females of mating with HI males (fewer fearful offspring of both sexes). [source]

    ORIGINAL RESEARCH,COUPLES' SEXUAL DYSFUNCTIONS: Erectile Dysfunction (ED) is a Shared Sexual Concern of Couples I: Couple Conceptions of ED

    THE JOURNAL OF SEXUAL MEDICINE, Issue 10 2009
    William A. Fisher PhD
    ABSTRACT Introduction., Erectile dysfunction (ED) may be regarded as a shared sexual concern with a significant negative impact on both patients and their partners. Aim., The current research sought to explore the degree of concordance or divergence of couple members' perceptions of the specific functional impairments characterizing the man's ED, and the concordance or discordance of their attitudes, beliefs and experiences about the male partner's erectile difficulty. Methods., Questionnaires were sent to partners of men who participated in the Men's Attitudes to Life Events and Sexuality (MALES) 2004 study, who consented to their partner's involvement. A modified version of the questionnaire used in the MALES study was employed, adapted to reflect the female partner's perspective. Questionnaire responses were analyzed in relation to responses provided by male study participants. Main Outcome Measure., A 65-item questionnaire assessing women's perceptions, beliefs, and attitudes regarding aspects of ED. Results., High levels of concordance between couple members were observed across almost all items. Women's perceptions of both the specific functional impairments characterizing their partner's ED and the frequency of the partner's erection difficulty were strongly associated with assessments the men themselves had made. Significant associations were also observed between couple members' responses relating to their beliefs about the causes of ED, effects of ED on the relationship, communication about ED, finding a solution to ED, and attitudes toward medication. A number of specific male,female discordant perceptions and attitudes were also identified. Conclusions., Findings of this study demonstrate a high degree of concordance in couple members' perceptions of the male partner's ED, and in their attitudes and beliefs about ED. Specific instances of discordance between couple members may contribute to treatment avoidance or couple conflict. Fisher WA, Eardley I, McCabe M, and Sand M. Erectile Dysfunction (ED) is a shared sexual concern of couples I: Couple conceptions of ED. J Sex Med 2009;6:2746,2760. [source]

    Identification of potential substrate proteins for the periplasmic Escherichia coli chaperone Skp

    PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 23-24 2008
    Svenja Jarchow
    Abstract The "seventeen kilodalton protein" (Skp) is a predominant periplasmic chaperone of Escherichia coli, which is involved in the biogenesis of abundant outer membrane proteins (OMPs) such as OmpA, PhoE, and LamB. In this study the substrate profile of Skp was investigated in a proteomics approach. Skp was overexpressed in a deficient E. coli strain as a fusion protein with the Strep,tag and captured, together with any host proteins associated with it, from the periplasmic cell extract under mild conditions via one-step Strep,Tactin affinity chromatography. Copurified substrate proteins were then identified by high resolution 2-DE with immobilized pH-gradients, followed by MALDI-TOF MS. Apart from the known Skp substrates, including OmpA and LamB, more than 30 other interacting proteins were detected, especially from the outer membrane, among these FadL and BtuB, and from the periplasm such as MalE and OppA. Thus, Skp does not only serve as a specialized chaperone for a small set of OMPs, but it seems to exhibit a broader substrate spectrum, including soluble periplasmic proteins. These findings should prompt further investigation into the physiological role of Skp and may promote its use for the bacterial production of biochemically active heterologous proteins whose folding requires secretion into the oxidizing milieu of the periplasm. [source]

    Crystallization, data collection and data processing of maltose-binding protein (MalE) from the phytopathogen Xanthomonas axonopodis pv. citri

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2009
    C. S. Souza
    Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293,K using the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6122, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20,Å, and contained two molecules in the asymetric unit. It diffracted to 2.24,Å resolution. [source]

    Do parasitoids diversify in response to host-plant shifts by herbivorous insects?

    ECOLOGICAL ENTOMOLOGY, Issue 4 2001
    James T. Cronin
    Summary 1. For herbivorous insects, the incorporation of a novel host into the diet, and subsequent formation of distinct host associations (races), is thought to be a significant early step in the speciation process. While many studies have addressed this issue, virtually nothing is known about the evolutionary response of natural enemies to herbivore host-race formation. 2. The hypothesis that the parasitoid wasp Eurytoma gigantea (Hymenoptera: Eurytomidae) has formed host races in direct response to the host shift and subsequent host-race formation by its host, the gallmaker Eurosta solidaginis (Diptera: Tephritidae) was tested. Emergence time, mating preference, and female oviposition preference were determined for parasitoids derived from galls of each Eurosta host race. 3. Male and female E. gigantea overlap broadly in their emergence times from each Eurosta host race, suggesting that there is no phenological barrier to gene flow. 4. In choice experiments, female parasitoids did not mate assortatively: females that emerged from one Eurosta host race were equally likely to mate with males from either Eurosta host race. 5. Oviposition behaviour experiments revealed that female parasitoids do not prefer to oviposit on their host race of origin and that there is no overall preference for one host race, even though fitness is higher when parasitoids are reared from Eurosta galls of the Solidago gigantea host race than when reared from Eurosta galls of the Solidago altissima host race. 6. These results suggest that E. gigantea has not diverged in parallel with its host in response to the herbivore host-plant shift. Further studies are needed before the ubiquity of this diversification mechanism can be evaluated fully. [source]

    Changes in the Distribution of Male and Female Wages Accounting for Employment Composition Using Bounds

    ECONOMETRICA, Issue 2 2007
    Richard Blundell
    This paper examines changes in the distribution of wages using bounds to allow for the impact of nonrandom selection into work. We show that worst case bounds can be informative. However, because employment rates in the United Kingdom are often low, they are not informative about changes in educational or gender wage differentials. Thus we explore ways to tighten these bounds using restrictions motivated from economic theory. With these assumptions, we find convincing evidence of an increase in inequality within education groups, changes in educational differentials, and increases in the relative wages of women. [source]

    A double-blind, randomized, parallel group study to compare the efficacy, safety and tolerability of slow-release oral morphine versus methadone in opioid-dependent in-patients willing to undergo detoxification

    ADDICTION, Issue 9 2009
    Ekkehard Madlung-Kratzer
    ABSTRACT Aims Evaluation of the efficacy and safety of slow-release oral morphine (SROM) compared with methadone for detoxification from methadone and SROM maintenance treatment. Design Randomized, double-blind, double-dummy, comparative multi-centre study with parallel groups. Setting Three psychiatric hospitals in Austria specializing in in-patient detoxification. Participants Male and female opioid dependents (age > 18 years) willing to undergo detoxification from maintenance therapy in order to reach abstinence. Interventions Abstinence was reached from maintenance treatment by tapered dose reduction of either SROM or methadone over a period of 16 days. Measurements Efficacy analyses were based on the number of patients per treatment group completing the study, as well as on the control of signs and symptoms of withdrawal [measured using Short Opioid Withdrawal Scale (SOWS)] and suppression of opiate craving. In addition, self-reported somatic and psychic symptoms (measured using Symptom Checklist SCL-90-R) were monitored. Findings Of the 208 patients enrolled into the study, 202 were eligible for analysis (SROM: n = 102, methadone: n = 100). Completion rates were 51% in the SROM group and 49% in the methadone group [difference between groups: 2%; 95% confidence interval (CI): ,12% to 16%]. The rate of discontinuation in the study was high mainly because of patients voluntarily withdrawing from treatment. No statistically significant differences between treatment groups were found in terms of signs and symptoms of opiate withdrawal, craving for opiates or self-reported symptoms. SROM and methadone were both well tolerated. Conclusions Detoxification from maintenance treatment with tapered dose reduction of SROM is non-inferior to methadone. [source]

    Trapping noctuid moths with synthetic floral volatile lures

    ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2002
    Robert L. Meagher Jr.
    Abstract Male and female noctuid moths were collected from plastic bucket traps that were baited with different synthetic floral chemicals and placed in peanut fields. Traps baited with phenylacetaldehyde, benzyl acetate, and a blend of phenylacetaldehyde, benzyl acetate, and benzaldehyde collected more soybean looper moths, Pseudoplusia includens (Walker), than benzaldehyde-baited or unbaited traps. Females comprised over 67% of the moths captured and most were mated. At peak capture, over 90 male and female moths per night were collected. In another experiment, phenylacetaldehyde delivered in plastic stoppers attracted more P. includens moths than traps baited using other substrates, but this chemical delivered in wax attracted more velvetbean caterpillar moths (Anticarsia gemmatalis Hübner). Other noctuid male and female moths collected included Agrotis subterranea (F.), Argyrogramma verruca (F.), Helicoverpa zea (Boddie), and several Spodoptera species. Aculeate Hymenoptera were collected in large numbers, especially in traps baited with phenylacetaldehyde delivered from stoppers. [source]

    DNA damage in mice treated with sulfur dioxide by inhalation

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3 2005
    Ziqiang Meng
    Abstract Sulfur dioxide (SO2) is a ubiquitous air pollutant produced by the burning of fossil fuels. In this study, single-cell gel electrophoresis (the Comet assay) was used to evaluate the DNA damage produced by inhalation exposure of mice to SO2. Male and female mice were housed in exposure chambers and treated with 14.00 ± 1.25, 28.00 ± 1.98, 56.00 ± 3.11, and 112.00 ± 3.69 mg/m3 SO2 for 6 hr/day for 7 days, while control groups were exposed to filtered air. Comet assays were performed on blood lymphocytes and cells from the brain, lung, liver, spleen, kidney, intestine, and testicles of the animals. SO2 caused significant, dose-dependent increases in DNA damage, as measured by Olive tail moment, in all the cell types analyzed from both sexes of mice. The results indicate that inhalation exposure to SO2 damages the DNA of multiple organs in addition to the lung, and suggests that this damage could result in mutation, cancer, and other diseases related to DNA damage. Further work will be required to understand the ultimate toxicological significance of this damage. These data also suggest that detecting DNA damage in blood lymphocytes, using the Comet assay, may serve as a useful tool for evaluating the impact of pulmonary SO2 exposure in human biomonitoring studies. Environ. Mol. Mutagen., 2005. © 2005 Wiley-Liss, Inc. [source]

    Chronic copper toxicity in the estuarine copepod Acartia tonsa at different salinities

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010
    Mariana M. Lauer
    Abstract Chronic Cu toxicity was evaluated in the euryhaline copepod Acartia tonsa. Male and female copepods were exposed (6 d) separately to different combinations of Cu concentration and water salinity (5, 15, and 30 ppt) using different routes of exposure (waterborne, waterborne plus dietborne, and dietborne). After exposure, groups of one male and three female copepods were allowed to reproduce for 24,h. In control copepods, egg production augmented with increasing water salinity. However, egg hatching rate did not change. Copper exposure reduced egg production and hatching rate in all water salinities tested, but the reproductive response was dependent on the route of Cu exposure. Median effective concentration (EC50) values for egg production after waterborne exposure were 9.9, 36.8, and 48.8,µg/L dissolved Cu at water salinities of 5, 15, and 30 ppt, respectively. For waterborne plus dietborne exposure, they were significantly higher (40.1, 63.7, and 109.9,µg /L, respectively). After dietborne exposure, approximately 40% decrease in egg production was observed, independently of Cu concentration and water salinity tested. At water salinities of 5 and 30 ppt, egg hatching rate reduced after waterborne exposure, together or not with the dietborne exposure. At water salinity of 15 ppt, Cu toxicity was only observed after dietborne exposure. Data indicate that egg production is a more reliable reproductive endpoint to measure chronic Cu toxicity in copepods than egg hatching rate in a wide range of water salinities. They also suggest that both water salinity and route of Cu exposure should be taken into account in the development of a chronic biotic ligand model version for estuarine and marine environments. Environ. Toxicol. Chem. 2010;29:2297,2303. © 2010 SETAC [source]

    Biochemical and histopathological effects in pearl dace (Margariscus margarita) chronically exposed to a synthetic estrogen in a whole lake experiment

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2006
    Vince P. Palace
    Abstract Potential effects of exposure to the synthetic estrogen 17,-ethynylestradiol (EE2) were examined in several species of fish from a lake experimentally treated with environmentally relevant concentrations of the contaminant. Ethynylestradiol was added to Lake 260, a small Precambrian shield lake at the Experimental Lakes Area in northwestern Ontario, Canada, from May to October of 2001, 2002, and 2003. Mean concentrations of EE2 in epilimnetic waters ranged between 4.5 and 8.1 ng/L during the three years, with overall means of 6.1 (±2.8), 5.0 (±1.8), and 4.8 (±1.0) ng/L for the three years, respectively. Male and female pearl dace (Margariscus margarita) captured after EE2 additions began contained up to 4,000-fold higher concentrations of the egg yolk precursor vitellogenin than fish captured from the same lake before the EE2 additions or when compared to fish from reference lakes. Edema in the ovaries, inhibited development of testicular tissue, intersex, and histopathological kidney lesions were all evident in fish exposed to EE2. Some indications that EE2 exposure affected in vitro steroidogenic capacity of the ovaries and the testes existed, although results were not always consistent between years. Pearl dace abundance was similar in the lake treated with EE2 and the reference lake. A trend exists toward a reduced overall population of pearl dace from the treated and reference lakes, as do indications that young-of-the-year size classes are less abundant in the EE2-treated lake. Biochemical and histopathological impacts observed in fish exposed to EE2 in this study have not yet been linked to clear population level impacts in pearl dace. Monitoring of these populations is ongoing. [source]

    Effects of the androgenic growth promoter 17-,-trenbolone on fecundity and reproductive endocrinology of the fathead minnow,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2003
    Gerald T. Ankley
    Abstract Trenbolone acetate is a synthetic steroid that is extensively used in the United States as a growth promoter in beef cattle. The acetate is administered to livestock via slow-release implants; some is converted by the animal to 17-,-trenbolone, a relatively potent androgen receptor agonist in mammalian systems. Recent studies indicate that excreted 17-,-trenbolone is comparatively stable in animal waste, suggesting the potential for exposure to aquatic animals via direct discharge, runoff, or both. However, little is known concerning the toxicity of trenbolone to fish. Our goal was to assess the effects of 17-,-trenbolone on reproductive endocrinology of the fathead minnow (Pimephales promelas). An in vitro competitive binding study with the fathead minnow androgen receptor demonstrated that 17-,-trenbolone had a higher affinity for the receptor than that of the endogenous ligand, testosterone. Male and female fish were exposed for 21 d to nominal (target) concentrations of 17-,-trenbolone ranging from 0.005 to 50 ,g/L. Fecundity of the fish was significantly reduced by exposure to measured test concentrations , 0.027 ,g/ L. The 17-,-trenbolone was clearly androgenic in vivo at these concentrations, as evidenced by the de novo production in females of dorsal (nuptial) tubercles, structures normally present only on the heads of mature males. Plasma steroid (testosterone and ,-estradiol) and vitellogenin concentrations in the females all were significantly reduced by exposure to 17-,-trenbolone. The 17-,-trenbolone also altered reproductive physiology of male fathead minnows, albeit at concentrations much higher than those producing effects in females. Males exposed to 17-,-trenbolone at 41 ,g/L (measured) exhibited decreased plasma concentrations of 11-ketotestosterone and increased concentrations of ,-estradiol and vitellogenin. Overall, our studies indicate that 17-,-trenbolone is a potent androgen and reproductive toxicant in fish. Given the widespread use of trenbolone acetate as a growth promoter, and relative stability of its metabolites in animal wastes, further studies are warranted to assess potential ecological risk. [source]

    Male and Female Meadow Voles, Microtus pennsylvanicus, Differ in Their Responses to Heterospecific/Conspecific Over-Marks

    ETHOLOGY, Issue 9 2010
    Christian T. Vlautin
    Voles use runways, paths, and trails that may also be used by rabbits and mink. These shared areas could contain the scent marks of conspecifics and heterospecifics. Thus, it is likely that the scent marks of heterospecifics may overlap or be overlapped by those of voles, forming over-marks. Much is known about how voles respond to over-marks of two different conspecifics. However, we do not know how they would respond to an opposite-sex conspecific whose scent marks are in an over-mark with the scent marks of predator or the scent marks of a non-predator heterospecifics. We tested the hypothesis that meadow voles, Microtus pennsylvanicus, differ in their response to the scent mark of the opposite-sex conspecific if the scent mark was overlapped by that of a mink, a vole predator, or rabbit, a vole non-predator. We found that female but not male voles showed a preference for the scent marks of the opposite-sex conspecifics that were part of the mink-vole over-mark when compared to those of opposite-sex conspecifics that were not part of the over-mark. This preference by female voles was independent of whether the male vole was the top-scent donor or bottom-scent donor of the over-mark. Male and female voles showed no preference between the scent marks of the opposite-sex conspecifics whose marks were part of or not part of the rabbit-vole over-mark. Sex differences in the manner that meadow voles respond to rabbit-vole and mink-vole over-marks are discussed. [source]

    Diversity of the Vocal Signals of Concave-Eared Torrent Frogs (Odorrana tormota): Evidence for Individual Signatures

    ETHOLOGY, Issue 11 2009
    Albert S. Feng
    Male concave-eared torrent frogs (Odorrana tormota) have an unusually large call repertoire and have been shown to communicate ultrasonically. We investigated the individual specificity of male advertisement calls in order to explore the acoustic bases of individual recognition, which was demonstrated in an accompanying study. Vocalizations of 15 marked males were recorded in the field. A quantitative analysis of the signals revealed eight basic call-types. Two of them (the single- and multi-note long-calls) were investigated in more detail. Long-calls were characterized by pronounced and varying frequency modulation patterns, and abundant occurrence of nonlinear phenomena (NLP), i.e., frequency jumps, subharmonics, biphonations and deterministic chaos. The occurrence of NLP was predictable from the contour of the fundamental frequency in the harmonic segment preceding the onset of the NLP, and this prediction showed individual-specific patterns. Fifteen acoustic variables of the long calls were measured, all of which were significantly different among individuals, except biphonic segment duration. Discriminant function analysis (DFA) showed that 54.6% of the calls could be correctly assigned to individual frogs. The correct classification was above chance level, suggesting that individual specificity of calls underlie the ability of males to behaviorally discriminate the vocal signals of their neighbors from those of strangers, a remarkable feat for a frog species with a diverse vocal repertoire. The DFA classification results were lower than those for other anurans, however. We hypothesize that there is a tradeoff between an increase in the fundamental frequency of vocalizations to avoid masking by low-frequency ambient background noise, and a decrease in individual-specific vocal tract information extractable from the signal. [source]

    Individual Odour Similarity and Discrimination in the Coruro (Spalacopus cyanus, Octodontidae)

    ETHOLOGY, Issue 6 2006
    Petra Hagemeyer
    Previous studies of subterranean, fossorial and above-ground rodents have demonstrated that similarities in individual odours covary with genetic similarities thus supporting the theory of odour-genes covariance (i.e. the closer the individuals are genetically, the greater the similarities between their odours). We used the habituation-generalization paradigm, where the subject is exposed to the same odour stimulus in three consecutive habituation trials followed by two test trials in which the odour from two other individuals are presented successively. Using this test design, we showed that the socially living coruros (Spalacopus cyanus) discriminate individuals on the basis of their ano-genital odours and also respond to odour similarities between individuals. Male and female subjects treated ano-genital odours of two same-sex family members and also the odours of two sibling strangers as different to each other. At the same time, they treated the odours of siblings as similar compared with the odour of an unrelated individual. No gender differences were detected. Our results contrast with those from other rodent species that did not spontaneously discriminate between individual odours of siblings from a different family than their own. The polygyneous lifestyle may provide the selective background for that difference. Additional research will be necessary to explore this hypothesis and to rule out differences due to dietary preferences and due to the type of paradigm chosen for the tests. [source]

    Effect of a Dummy Audience on Male,Male Interactions in Siamese Fighting Fish, Betta splendens

    ETHOLOGY, Issue 2 2006
    Teresa L. Dzieweczynski
    Recent research on Siamese fighting fish, Betta splendens, and other taxa has demonstrated that an audience can cause males to alter their behavior in aggressive interactions. One factor not taken into account in these studies is how exactly the audience influences these interactions. It is possible that a live audience may interact with the subjects, creating an active communication network rather than a signaler,receiver dyad with a passive audience. Here, we used a dummy audience to control for information exchange between the audience and the interactants that might cause them to modify their behavior. Audience treatments included dummies of male and female B. splendens, a dummy cichlid, and a control condition with no audience present. The presence of a dummy audience did not influence male,male interactions. However, males spent the most time near the audience tank when the audience was a dummy of a B. splendens. This suggests that some factor other than the physical presence of the audience is responsible for the modification of behavior found in previous audience effect studies in Siamese fighting fish. However, we cannot rule out definitively that our dummy audience is viewed as unimportant by the opponents and, thus, ignored. Further research is necessary to determine which component of the audience is important for producing audience effects. [source]

    Do Male Veiled Chameleons, Chamaeleo calyptratus, Adjust their Courtship Displays in Response to Female Reproductive Status?

    ETHOLOGY, Issue 6 2002
    Erin C. Kelso
    Variation in male courtship behavior may be due to inherent differences among males or may arise from males adjusting their courtship displays according to female responsiveness. Female veiled chameleons, Chamaeleo calyptratus, exhibit two distinctive suites of body coloration and behavior patterns that vary according to receptive and non-receptive stages of their reproductive cycle. We presented male chameleons with both receptive and non-receptive females, and recorded differences in their mating frequency, courtship intensity and courtship behavior patterns. As expected, males were more likely to court and attempt mating with receptive females. Although fewer males courted non-receptive females, their courtship displays were significantly longer than those directed towards receptive females. Males also adjusted the contents of their displays according to female reproductive condition. Certain behavior patterns were unique to courtship displays directed towards each class of females. Males exhibited the behavior pattern `head roll' only when paired with receptive females, and `chin rub' was displayed only during courtship of non-receptive females. We hypothesize that these differences in male courtship frequency, intensity and content reflect differences in female reproductive value. Although males may benefit from mating with both receptive and non-receptive females, the costs associated with courtship may depend on female responsiveness. Thus, males adjust their courtship tactics accordingly. [source]

    Multiple Paternity and Similar Variance in Reproductive Success of Male and Female Wood Mice (Apodemus sylvaticus) Housed in an Enclosure

    ETHOLOGY, Issue 10 2001
    Susan Bartmann
    The mating system and variance in individual reproductive success in wood mice (Apodemus sylvaticus) were analysed genetically and using observational studies within a large cage system in an outdoor enclosure. Four experimental groups contained four males and four females, each individually marked with a transponder (small computer chips injected under the skin) allowing individual detection of animals underground or within nest boxes without disturbance. The probability of paternity was analysed by comparing frequencies of cohabitation of males and females. In addition, DNA microsatellite analysis revealed reproductive success of each individual. Multiple paternity was found in 85% of all litters, which were sired by up to all four males. Males with a greater body mass, possibly indicative of a higher rank, sired more offspring than those with lower body mass. Interestingly, variance in the reproductive success of males and females did not differ. There was no indication that paternity could be assessed by the time males resided with a female shortly before she became pregnant. Our results indicate wood mice probably have a promiscuous mating system. [source]

    Intra- and Inter-seasonal Variation in the Socio-Spatial Behavior of Adult Male Collared Lizards, Crotaphytus collaris (Reptilia, Crotaphytidae)

    ETHOLOGY, Issue 1 2001
    Troy A. Baird
    When individuals maintain strong inter-seasonal philopatry to the same territories, males may be able to re-establish territory occupancy without intense intra-sexual aggression, and instead spend more time courting females early in the reproductive season. Furthermore, when some males have prior experience defending the same territories, it may be necessary for young males to exhibit higher levels of aggression because they are establishing a territory for the first time. We tested these hypotheses by examining within-season (1992 and 1997) temporal variation in the social behavior of adult male collared lizards of known age and prior territorial experience in a population where inter-season philopatry to territories is high. Contrary to expectations, the frequency of aggression exhibited by males with and without prior territorial experience did not differ. The frequency of intra-sexual aggression was higher in 1992 than in 1997, perhaps because male competitors were more abundant in 1992. Although there was an interactive effect of year, male display and patrol were low at the beginning of the reproductive season in Apr. and May, reached peaks during midseason in June, and then decreased as reproduction ended in July. The size of territories showed a similar pattern, with males defending larger areas in June. Our data support the philopatry hypothesis in that the establishment of territories occurred without high levels of aggression early in the season, perhaps because territory boundaries have been well defined by high rates of patrol and advertisement during the middle of the previous season. Inter-sexual interactions were most frequent in June rather than at the beginning of the reproductive season. Adult females are producing their second clutches and yearling females are producing their first clutches in June. The high rate of inter-sexual encounters in June supports the hypothesis that males allocate more time to courtship when females are receptive because there are more reproductively active females at this time. The temporal pattern of activities in adult Crotaphytus collaris appears to function as a compromise between competing intra- and inter-sexual social demands on males, allowing males to maximize mating opportunities as well as maintain future access to productive territories. [source]