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Sample records for problematic ant taxon

  1. Rediscovery and reclassification of the dipteran taxon Nothomicrodon Wheeler, an exclusive endoparasitoid of gyne ant larvae

    PubMed Central

    Pérez-Lachaud, Gabriela; Jahyny, Benoit J. B.; Ståhls, Gunilla; Rotheray, Graham; Delabie, Jacques H. C.; Lachaud, Jean-Paul

    2017-01-01

    The myrmecophile larva of the dipteran taxon Nothomicrodon Wheeler is rediscovered, almost a century after its original description and unique report. The systematic position of this dipteran has remained enigmatic due to the absence of reared imagos to confirm indentity. We also failed to rear imagos, but we scrutinized entire nests of the Brazilian arboreal dolichoderine ant Azteca chartifex which, combined with morphological and molecular studies, enabled us to establish beyond doubt that Nothomicrodon belongs to the Phoridae (Insecta: Diptera), not the Syrphidae where it was first placed, and that the species we studied is an endoparasitoid of the larvae of A. chartifex, exclusively attacking sexual female (gyne) larvae. Northomicrodon parasitism can exert high fitness costs to a host colony. Our discovery adds one more case to the growing number of phorid taxa known to parasitize ant larvae and suggests that many others remain to be discovered. Our findings and literature review confirm that the Phoridae is the only taxon known that parasitizes both adults and the immature stages of different castes of ants, thus threatening ants on all fronts. PMID:28361946

  2. The taxon concept: is it taxonic?

    PubMed

    Grove, William M

    2008-06-01

    The question of whether the concept of a "taxon" (a nonarbitrary latent category) is itself categorical, or is a matter of degree, has lain dormant within taxometrics. I analyze the problem conceptually. Part of the meaning of "taxon," I hold, goes beyond the manifest statistical properties of admixed probability distributions; any of certain forms of causal nexus leading to admixed distributions are involved as well. I defend the thesis that the threshold question, "Is there a taxon?" has a yes-or-no answer, establishing that "taxonicity" is categorical (taxonic), but also that as some taxa are much more readily distinguished from their complement classes than are others, the taxon question is also quantitative. It is on this basis that Meehl and others held the view that taxonicity is a matter of degree; however, they were wrong to hold that it is only a matter of degree.

  3. Policy Problematization

    ERIC Educational Resources Information Center

    Webb, P. Taylor

    2014-01-01

    This article places Michel Foucault's concept of "problematization" in relation to educational policy research. My goal is to examine a key assumption of policy related to "solving problems" through such technologies. I discuss the potential problematization has to alter conceptions of policy research; and, through this…

  4. A Problematic Heading.

    ERIC Educational Resources Information Center

    Stake, Robert E.

    2001-01-01

    Discusses the problematic future of program evaluation, especially in the field of education, in the context of testing and politics and with regard to epistemology. Evaluators must learn to focus on the complex knowledge of program coping and merit, rather than merely tracking simplistic indicator variables. (SLD)

  5. Honey Ants.

    ERIC Educational Resources Information Center

    Conway, John R.

    1984-01-01

    Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

  6. Increased taxon sampling greatly reduces phylogenetic error.

    PubMed

    Zwickl, Derrick J; Hillis, David M

    2002-08-01

    Several authors have argued recently that extensive taxon sampling has a positive and important effect on the accuracy of phylogenetic estimates. However, other authors have argued that there is little benefit of extensive taxon sampling, and so phylogenetic problems can or should be reduced to a few exemplar taxa as a means of reducing the computational complexity of the phylogenetic analysis. In this paper we examined five aspects of study design that may have led to these different perspectives. First, we considered the measurement of phylogenetic error across a wide range of taxon sample sizes, and conclude that the expected error based on randomly selecting trees (which varies by taxon sample size) must be considered in evaluating error in studies of the effects of taxon sampling. Second, we addressed the scope of the phylogenetic problems defined by different samples of taxa, and argue that phylogenetic scope needs to be considered in evaluating the importance of taxon-sampling strategies. Third, we examined the claim that fast and simple tree searches are as effective as more thorough searches at finding near-optimal trees that minimize error. We show that a more complete search of tree space reduces phylogenetic error, especially as the taxon sample size increases. Fourth, we examined the effects of simple versus complex simulation models on taxonomic sampling studies. Although benefits of taxon sampling are apparent for all models, data generated under more complex models of evolution produce higher overall levels of error and show greater positive effects of increased taxon sampling. Fifth, we asked if different phylogenetic optimality criteria show different effects of taxon sampling. Although we found strong differences in effectiveness of different optimality criteria as a function of taxon sample size, increased taxon sampling improved the results from all the common optimality criteria. Nonetheless, the method that showed the lowest overall

  7. Fire ants

    MedlinePlus

    ... please enable JavaScript. Fire ants are red-colored insects. A sting from a fire ant delivers a ... poison control. Those who have an allergy to insect bites or stings should carry a bee sting ...

  8. Ant Tower

    NASA Astrophysics Data System (ADS)

    Mlot, Nathan; Shinotsuka, Sho; Hu, David

    2010-11-01

    Ants walk via adhesive drops of fluid extruded by their feet. They also use these drops as mortar to build structures such as rafts, bridges and towers, each composed of thousands of ants linked together. We investigate experimentally the construction of triangular ant towers braced by hydrophobic walls. Particular attention is paid to the relationship between tower height and contact angle hysteresis of the wall. We rationalize tower height according to ant adhesion, and tower shape according to the constraints on a column of constant strength.

  9. Problematic Internet use: an overview.

    PubMed

    Aboujaoude, Elias

    2010-06-01

    There is wide agreement that the Internet can serve as a tool that enhances well-being. It is more difficult, however, to find consensus around the issue of problematic Internet use. That may be in part because scientific investigation has lagged far behind technological advances and media attention. The diagnostic schemas that have been proposed since 1996, and the screening tools that have been developed, stress similarities with substance use, impulse control disorders, and obsessive-compulsive disorder. Prevalence figures vary as a function of the diagnostic definition used, the age group studied, and whether the surveys were conducted online. Studies suggest high comorbidity rates with mood disorders and, among younger individuals, attention-deficit/hyperactivity disorder. Treatment should address any comorbid conditions present, as those may be causing, or exacerbating, problematic Internet use. Interventions that may specifically target problematic Internet use include cognitive behavioral therapy and selective serotonin reuptake inhibitors, but detailed guidelines must await further studies. For a medium that has so radically changed how we conduct our lives, the Internet's effects on our psychology remain understudied. More research is needed into the pathophysiology, epidemiology, natural course, and treatment of problematic Internet use. In addition, the more subtle psychological changes, such as disinhibition, that seem to characterize people's online behavior also deserve attention, even if they cannot be seen as necessarily pathological.

  10. Foundational issues concerning taxa and taxon names.

    PubMed

    Ereshefsky, Marc

    2007-04-01

    In a series of articles, Rieppel (2005, Biol. Philos. 20:465-487; 2006a, Cladistics 22:186-197; 2006b, Systematist 26:5-9), Keller et al. (2003, Bot. Rev. 69:93-110), and Nixon and Carpenter (2000, Cladistics 16:298-318) criticize the philosophical foundations of the PhyloCode. They argue that species and higher taxa are not individuals, and they reject the view that taxon names are rigid designators. Furthermore, they charge supporters of the individuality thesis and rigid designator theory with assuming essentialism, committing logical inconsistencies, and offering proposals that render taxonomy untestable. These charges are unsound. Such charges turn on confusions over rigid designator theory and the distinction between kinds and individuals. In addition, Rieppel's, Keller et al.'s, and Nixon and Carpenter's proposed alternatives are no better and have their own problems. The individuality thesis and rigid designator theory should not be quickly abandoned.

  11. Likelihood inference of non-constant diversification rates with incomplete taxon sampling.

    PubMed

    Höhna, Sebastian

    2014-01-01

    Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species) and taxon sampling is not uniform. Instead, taxa are frequently sampled to obtain at least one representative per subgroup (e.g. family) and thus to maximize diversity (diversified sampling). So far, such complications have been ignored, potentially biasing the conclusions that have been reached. In this study I derive the likelihood of a birth-death process with non-constant (time-dependent) diversification rates and diversified taxon sampling. Using simulations I test if the true parameters and the sampling method can be recovered when the trees are small or medium sized (fewer than 200 taxa). The results show that the diversification rates can be inferred and the estimates are unbiased for large trees but are biased for small trees (fewer than 50 taxa). Furthermore, model selection by means of Akaike's Information Criterion favors the true model if the true rates differ sufficiently from alternative models (e.g. the birth-death model is recovered if the extinction rate is large and compared to a pure-birth model). Finally, I applied six different diversification rate models--ranging from a constant-rate pure birth process to a decreasing speciation rate birth-death process but excluding any rate shift models--on three large-scale empirical phylogenies (ants, mammals and snakes with respectively 149, 164 and 41 sampled species). All three phylogenies were constructed by diversified taxon sampling, as stated by the authors. However only the snake phylogeny supported diversified taxon sampling. Moreover, a parametric bootstrap test revealed that none of the tested models provided a good fit to the observed data. The model assumptions, such as homogeneous rates across species or no rate shifts, appear to be

  12. Interaction between Locale and Taxon Strategies in Human Spatial Learning

    ERIC Educational Resources Information Center

    Redhead, Edward S.; Hamilton, Derek A.

    2007-01-01

    Three computer-based experiments which tested human participants in a non-immersive virtual watermaze task sought to determine factors which dictate whether the presence of a visual platform disrupts locale learning and taxon learning. In Experiment 1, the visible platform disrupted locale but not taxon learning based on viewpoint-independent and…

  13. [Assessment of problematic alcohol use].

    PubMed

    Rumpf, H-J; Bischof, G; Freyer-Adam, J; Coder, B

    2009-11-01

    An overview with respect to the identification of patients with risky drinking, alcohol abuse or alcohol dependence is given. As a first step, a simple screening questionnaire should be used. Self-statements in standardized questionnaires are more valid than standard laboratory markers. A useful instrument is for example BASIC. In screening positive patients, an in-depth diagnosis is necessary and helps to distinguish between different forms of problematic alcohol use. Depending on the severity of the alcohol problem, brochures, internet-programs, counselling or referral to treatment services is helpful.

  14. Ant nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The image is available at http://www.jpl.nasa.gov/pictures/wfpc .

    The nebula, imaged on July 20, 1997, and June 30, 1998, by Hubble's Wide Field and Planetary Camera 2, was observed by Drs. Raghvendra Sahai and John Trauger of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Bruce Balick of the University of Washington in Seattle; and Vincent Icke of Leiden University in the Netherlands. JPL designed and built the camera.

    The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the 'ant's' body as a pair of fiery lobes protruding from a dying, Sun- like star. The Ant Nebula is located between 3,000 and 6,000 light years from Earth in the southern constellation Norma.

    The image challenges old ideas about what happens to dying stars. This observation, along with other pictures of various remnants of dying stars called planetary nebulae, shows that our Sun's fate will probably be much more interesting, complex and dramatic than astronomers previously believed.

    Although the ejection of gas from the dying star in the Ant Nebula is violent, it does not show the chaos one might expect from an ordinary explosion, but instead shows symmetrical patterns. One possibility is that the central star has a closely orbiting companion whose gravitational tidal forces shape the outflowing gas. A second possibility is that as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Electrically charged winds, much like those in our Sun's solar wind but millions of times denser and moving at speeds up to 1,000 kilometers per second (more than 600 miles per second) from the star, follow the twisted field lines on their way

  15. The Ants Have It!

    ERIC Educational Resources Information Center

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  16. Addictive personality and problematic mobile phone use.

    PubMed

    Takao, Motoharu; Takahashi, Susumu; Kitamura, Masayoshi

    2009-10-01

    Mobile phone use is banned or regulated in some circumstances. Despite recognized safety concerns and legal regulations, some people do not refrain from using mobile phones. Such problematic mobile phone use can be considered to be an addiction-like behavior. To find the potential predictors, we examined the correlation between problematic mobile phone use and personality traits reported in addiction literature, which indicated that problematic mobile phone use was a function of gender, self-monitoring, and approval motivation but not of loneliness. These findings suggest that the measurements of these addictive personality traits would be helpful in the screening and intervention of potential problematic users of mobile phones.

  17. Conversion disorder: a problematic diagnosis.

    PubMed

    Nicholson, Timothy R J; Stone, Jon; Kanaan, Richard A A

    2011-11-01

    The diagnosis of conversion disorder is problematic. Since doctors have conceptually and practically differentiated the symptoms from neurological ('organic') disease it has been presumed to be a psychological disorder, but the psychological mechanism, and how this differs from feigning (conscious simulation), has remained elusive. Although misdiagnosis of neurological disease as conversion disorder is uncommon, it remains a concern for clinicians, particularly for psychiatrists who may be unaware of the positive ways in which neurologists can exclude organic disease. The diagnosis is anomalous in psychiatry in that current diagnostic systems require that feigning is excluded and that the symptoms can be explained psychologically. In practice, feigning is very difficult to either disprove or prove, and a psychological explanation cannot always be found. Studies of childhood and adult psychological precipitants have tended to support the relevance of stressful life events prior to symptom onset at the group level but they are not found in a substantial proportion of cases. These problems highlight serious theoretical and practical issues not just for the current diagnostic systems but for the concept of the disorder itself. Psychology, physiology and functional imaging techniques have been used in attempts to elucidate the neurobiology of conversion disorder and to differentiate it from feigning, but while intriguing results are emerging they can only be considered preliminary. Such work looks to a future that could refine our understanding of the disorder. However, until that time, the formal diagnostic requirement for associated psychological stressors and the exclusion of feigning are of limited clinical value. Simplified criteria are suggested which will also encourage cooperation between neurology and psychiatry in the management of these patients.

  18. Prevalence of problematic internet use in Slovenia

    PubMed Central

    Király, Orsolya; Maraz, Aniko; Nagygyörgy, Katalin; Demetrovics, Zsolt

    2016-01-01

    Abstract Background Internet use is an integral part of our everyday activities; however, Internet use may become problematic and harmful in a minority of cases. The majority of reported prevalence rates of problematic Internet use refer to adolescent samples, whereas epidemiological studies on representative adult populations are lacking. This study aimed to reveal the prevalence and characteristics of problematic Internet use in Slovenia. Methods Problematic Internet Use Questionnaire (PIUQ) was included in European Health Interview Study (EHIS) on representative Slovenian sample. The frequency of Internet use and problematic Internet use were both assessed. Results 59.9% of Slovenian adult population uses the Internet daily, and 3.1% are at risk of becoming problematic Internet users, 11% in the age group from 20 to 24 years. Those being at risk for becoming problematic Internet users are younger (mean age 31.3 vs. 48.3 for non-problematic users), more likely to be males (3.6% of males, whereas 2.6% of females are affected), students (12.0%), unemployed (6.3%) or unable to work (8.7%), single (6.5%), with high education (4.5%). Regression analysis revealed that the strongest predictor of being at risk for problematic Internet use is age (ß=-0.338, p<0.001); followed by high educational level (ß=0.145; p<0.001) and student status (ß=0.136; p<0.001). Conclusion 3.1% of Slovenian adult population are at risk of becoming problematic Internet users, whereas 3 out of 20 Slovenian adolescents aged from 18 to 19 years are at risk (14.6%). Prevention programs and treatment for those affected are paramount, especially for the young generation. PMID:27703540

  19. 7 CFR 360.500 - Petitions to add a taxon to the noxious weed list.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Petitions to add a taxon to the noxious weed list. 360... to add a taxon to the noxious weed list. A person may petition the Administrator to have a taxon added to the noxious weeds lists in § 360.200. Details of the petitioning process for adding a taxon...

  20. Repeated evolution of fungal cultivar specificity in independently evolved ant-plant-fungus symbioses.

    PubMed

    Blatrix, Rumsaïs; Debaud, Sarah; Salas-Lopez, Alex; Born, Céline; Benoit, Laure; McKey, Doyle B; Attéké, Christiane; Djiéto-Lordon, Champlain

    2013-01-01

    Some tropical plant species possess hollow structures (domatia) occupied by ants that protect the plant and in some cases also provide it with nutrients. Most plant-ants tend patches of chaetothyrialean fungi within domatia. In a few systems it has been shown that the ants manure the fungal patches and use them as a food source, indicating agricultural practices. However, the identity of these fungi has been investigated only in a few samples. To examine the specificity and constancy of ant-plant-fungus interactions we characterised the content of fungal patches in an extensive sampling of three ant-plant symbioses (Petalomyrmex phylax/Leonardoxa africana subsp. africana, Aphomomyrmex afer/Leonardoxa africana subsp. letouzeyi and Tetraponera aethiops/Barteria fistulosa) by sequencing the Internal Transcribed Spacers of ribosomal DNA. For each system the content of fungal patches was constant over individuals and populations. Each symbiosis was associated with a specific, dominant, primary fungal taxon, and to a lesser extent, with one or two specific secondary taxa, all of the order Chaetothyriales. A single fungal patch sometimes contained both a primary and a secondary taxon. In one system, two founding queens were found with the primary fungal taxon only, one that was shown in a previous study to be consumed preferentially. Because the different ant-plant symbioses studied have evolved independently, the high specificity and constancy we observed in the composition of the fungal patches have evolved repeatedly. Specificity and constancy also characterize other cases of agriculture by insects.

  1. Improved phylogenomic taxon sampling noticeably affects nonbilaterian relationships.

    PubMed

    Pick, K S; Philippe, H; Schreiber, F; Erpenbeck, D; Jackson, D J; Wrede, P; Wiens, M; Alié, A; Morgenstern, B; Manuel, M; Wörheide, G

    2010-09-01

    Despite expanding data sets and advances in phylogenomic methods, deep-level metazoan relationships remain highly controversial. Recent phylogenomic analyses depart from classical concepts in recovering ctenophores as the earliest branching metazoan taxon and propose a sister-group relationship between sponges and cnidarians (e.g., Dunn CW, Hejnol A, Matus DQ, et al. (18 co-authors). 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature 452:745-749). Here, we argue that these results are artifacts stemming from insufficient taxon sampling and long-branch attraction (LBA). By increasing taxon sampling from previously unsampled nonbilaterians and using an identical gene set to that reported by Dunn et al., we recover monophyletic Porifera as the sister group to all other Metazoa. This suggests that the basal position of the fast-evolving Ctenophora proposed by Dunn et al. was due to LBA and that broad taxon sampling is of fundamental importance to metazoan phylogenomic analyses. Additionally, saturation in the Dunn et al. character set is comparatively high, possibly contributing to the poor support for some nonbilaterian nodes.

  2. Improved Phylogenomic Taxon Sampling Noticeably Affects Nonbilaterian Relationships

    PubMed Central

    Pick, K.S.; Philippe, H.; Schreiber, F.; Erpenbeck, D.; Jackson, D.J.; Wrede, P.; Wiens, M.; Alié, A.; Morgenstern, B.; Manuel, M.; Wörheide, G.

    2010-01-01

    Despite expanding data sets and advances in phylogenomic methods, deep-level metazoan relationships remain highly controversial. Recent phylogenomic analyses depart from classical concepts in recovering ctenophores as the earliest branching metazoan taxon and propose a sister-group relationship between sponges and cnidarians (e.g., Dunn CW, Hejnol A, Matus DQ, et al. (18 co-authors). 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature 452:745–749). Here, we argue that these results are artifacts stemming from insufficient taxon sampling and long-branch attraction (LBA). By increasing taxon sampling from previously unsampled nonbilaterians and using an identical gene set to that reported by Dunn et al., we recover monophyletic Porifera as the sister group to all other Metazoa. This suggests that the basal position of the fast-evolving Ctenophora proposed by Dunn et al. was due to LBA and that broad taxon sampling is of fundamental importance to metazoan phylogenomic analyses. Additionally, saturation in the Dunn et al. character set is comparatively high, possibly contributing to the poor support for some nonbilaterian nodes. PMID:20378579

  3. Psychopathological factors associated with problematic alcohol and problematic Internet use in a sample of adolescents in Germany.

    PubMed

    Wartberg, Lutz; Brunner, Romuald; Kriston, Levente; Durkee, Tony; Parzer, Peter; Fischer-Waldschmidt, Gloria; Resch, Franz; Sarchiapone, Marco; Wasserman, Camilla; Hoven, Christina W; Carli, Vladimir; Wasserman, Danuta; Thomasius, Rainer; Kaess, Michael

    2016-06-30

    In Germany, high prevalence rates for problematic alcohol use and problematic Internet use in adolescents were reported. The objective of the present study was to identify psychopathological factors associated with these two behavior patterns. To our knowledge, this is the first investigation assessing psychopathological factors for both problematic alcohol and problematic Internet use in the same sample of adolescents. We surveyed a sample of 1444 adolescents in Germany regarding problematic alcohol use, problematic Internet use, psychopathology and psychological well-being. We conducted binary logistic regression analyses. 5.6% of the sample showed problematic alcohol use, 4.8% problematic Internet use, and 0.8% both problematic alcohol and problematic Internet use. Problematic alcohol use was higher in adolescents with problematic Internet use compared to those without problematic Internet use. Conduct problems and depressive symptoms were statistically significant associated with both problematic alcohol and problematic Internet use. Prosocial behavior was related to problematic Internet use. Male gender and less peer problems were associated with problematic alcohol use. For the first time associations between adolescent problematic alcohol and problematic Internet use due to common psychopathological factors were identified. However, in addition to shared factors, we found also specific psychopathological correlates associated with these two behavior patterns.

  4. Forensic evaluation of problematic Internet use.

    PubMed

    Recupero, Patricia R

    2008-01-01

    Problematic Internet use appears to be a growing concern in many criminal and civil legal proceedings. Problems range from inappropriate personal use of the Internet in the workplace and excessive use of online games, pornography, and gambling, to cyberbullying among children and adolescents and numerous forms of criminal activity. Forensic psychiatric evaluations may help courts or other agencies to understand individual cases and to discern whether a psychiatric disability may be involved. Furthermore, the forensic psychiatrist may be asked to formulate a prognosis or to suggest which treatments may be helpful. Among the multiple underlying pathophysiologic mechanisms that explain problematic Internet use are: addiction, compulsion, impulse-control problems, and mood disorders. There is no definitive or standard treatment protocol for evaluation or treatment of problematic Internet use per se. A comprehensive evaluation should address the underlying psychopathology or personal problems that prompt or contribute to the problematic Internet use. This article suggests approaches that may help forensic psychiatrists to conduct a thorough evaluation with reasonable treatment recommendations. Different formulations of the problem and a discussion of DSM-IV factors are offered to provide starting points for the evaluation and to help psychiatrists to understand how problematic Internet use may relate to Axis I disorders or other factors.

  5. Problematic Internet Usage and Immune Function

    PubMed Central

    Reed, Phil; Vile, Rebecca; Osborne, Lisa A.; Romano, Michela; Truzoli, Roberto

    2015-01-01

    Problematic internet use has been associated with a variety of psychological comorbidities, but it relationship with physical illness has not received the same degree of investigation. The current study surveyed 505 participants online, and asked about their levels of problematic internet usage (Internet Addiction Test), depression and anxiety (Hospital Anxiety and Depression Scales), social isolation (UCLA Loneliness Questionnaire), sleep problems (Pittsburgh Sleep Quality Index), and their current health – General Health Questionnaire (GHQ-28), and the Immune Function Questionnaire. The results demonstrated that around 30% of the sample displayed mild or worse levels of internet addiction, as measured by the IAT. Although there were differences in the purposes for which males and females used the internet, there were no differences in terms of levels of problematic usage between genders. The internet problems were strongly related to all of the other psychological variables such as depression, anxiety, social-isolation, and sleep problems. Internet addiction was also associated with reduced self-reported immune function, but not with the measure of general health (GHQ-28). This relationship between problematic internet use and reduced immune function was found to be independent of the impact of the co-morbidities. It is suggested that the negative relationship between level of problematic internet use and immune function may be mediated by levels of stress produced by such internet use, and subsequent sympathetic nervous activity, which related to immune-supressants, such as cortisol. PMID:26244339

  6. The dissociative experiences taxon is related to fantasy proneness.

    PubMed

    Giesbrecht, Timo; Merckelbach, Harald; Geraerts, Elke

    2007-09-01

    Some authors have argued that nonpathological dissociation should be distinguished from a taxon form of pathological dissociation, which is indexed by the Dissociative Experiences Scale Taxon (DES-T). We tested to what extent DES-T scores are independent from fantasy immersion and whether DES-T scores are uniquely related to trauma self-reports. To this end, subsamples of undergraduate students (n = 930), healthy adults (n = 20), schizophrenic patients (n = 22), borderline personality disordered patients (n = 20), patients with mood disorder without psychosis (n = 19), and women with a history of childhood sexual abuse (n = 55) completed the Dissociative Experiences Scale and a measure of fantasy immersion. DES-T scores were related to absorption and fantasy immersion to a lesser extent than the original DES. However, the fact that nontrivial percentages within all groups, except for the healthy adults, were classified as taxon members casts doubts on the assumption that DES-T is a reliable index of pathological dissociation. Also, we found that the DES-T was not exclusively related to reports of childhood sexual abuse.

  7. The functional analysis of problematic verbal behavior

    PubMed Central

    Ewing, Christopher B.; Magee, Sandy K.; Ellis, Janet

    2002-01-01

    This study describes procedures and outcomes in a functional analysis of problem behavior of 2 public school students. For a 13-year-old honors student, bizarre tacts (labeled as psychotic speech by school staff) were maintained by attention. For a 15-year-old with autism, the functional analysis revealed that perseverative mands for toileting were controlled by attention; mands for edible items were controlled by access to any food item; and mands for nonedible items were maintained by access to the specific item manded. The “problematic” aspects of the verbal behavior differed—the bizarre speech was problematic based on its content, but the perseverative verbalizations resulted in high response cost for classroom staff. Research in the area of problematic verbal behavior is sparse and warrants further attention from behavior analysts who work in public school settings. This research demonstrates the applicability and relevance of functionally analyzing problematic verbal behavior in public school settings. PMID:22477228

  8. The allometry of brain miniaturization in ants.

    PubMed

    Seid, Marc A; Castillo, Armando; Wcislo, William T

    2011-01-01

    Extensive studies of vertebrates have shown that brain size scales to body size following power law functions. Most animals are substantially smaller than vertebrates, and extremely small animals face significant challenges relating to nervous system design and function, yet little is known about their brain allometry. Within a well-defined monophyletic taxon, Formicidae (ants), we analyzed how brain size scales to body size. An analysis of brain allometry for individuals of a highly polymorphic leaf-cutter ant, Atta colombica, shows that allometric coefficients differ significantly for small (<1.4 mg body mass) versus large individuals (b = 0.6003 and 0.2919, respectively). Interspecifically, allometric patterns differ for small (<0.9 mg body mass) versus large species (n = 70 species). Using mean values for species, the allometric coefficient for smaller species (b = 0.7961) is significantly greater than that for larger ones (b = 0.669). The smallest ants had brains that constitute ∼15% of their body mass, yet their brains were relatively smaller than predicted by an overall allometric coefficient of brain to body size. Our comparative and intraspecific studies show the extent to which nervous systems can be miniaturized in taxa exhibiting behavior that is apparently comparable to that of larger species or individuals.

  9. Relaxation/Covert Rehearsal for Problematic Children.

    ERIC Educational Resources Information Center

    Fling, Sheila; McKenzie, Patricia

    A study was conducted to determine whether group relaxation training combined with guided fantasy as a method of covert cognitive rehearsal would be more effective than story-listening or no special treatment in enabling "problematic" children to decrease muscle tension, activity level, and behavior problems and to increase academic performance…

  10. Problematic Internet Use: Perceptions of Addiction Counsellors

    ERIC Educational Resources Information Center

    Acier, Didier; Kern, Laurence

    2011-01-01

    Despite a growing number of publications on problematic Internet use (PIU), there is no consensus on the nature of the phenomenon, its constituent criteria, and its clinical threshold. This qualitative study examines the perceptions of addiction counsellors who have managed individuals with PIU in Quebec (Canada). Four focus groups were conducted…

  11. Developing terrestrial, multi-taxon indices of biological integrity: An example from coastal sage scrub

    USGS Publications Warehouse

    Diffendorfer, J.E.; Fleming, G.M.; Duggan, J.M.; Chapman, R.E.; Rahn, M.E.; Mitrovich, M.J.; Fisher, R.N.

    2007-01-01

    We screened 351 species or genera for their response to disturbance in coastal sage scrub (CSS) to develop a 15-metric, 5-taxon Index of Biological Integrity (IBI). We collected data on ants, birds, herpetofauna, small mammals, and plants for two years on 46 sites established across a gradient of disturbance in three reserves. The gradient spanned relatively intact CSS with thick stands of shrubs, to former CSS stands type-converted to exotic grasses. ANOVAs and clustering analyses indicated the IBI could distinguish four levels of disturbance in CSS. General measures of community structure, such as richness, did not show changes across the gradient for most taxa, and responses of taxa across the gradient were varied and rarely correlated. However, turnover in species or genera across the gradient was common across all taxa as shrub-obligate life forms were replaced by those favoring grassy or disturbed habitats. Our data indicate index-based approaches based on data collected across disturbance gradients may outperform more traditional community level metrics when responses to anthropogenic influences are complex and vary across species. ?? 2007 Elsevier Ltd. All rights reserved.

  12. Fire Ant Bites

    MedlinePlus

    ... be wary of these systemic reactions. They are: serum sickness, seizures, mononeuritis, nephrotic syndrome, and worsening of preexisting cardiopulmonary disease. When you first identify the fire ant you ...

  13. A Standardized Reference Data Set for Vertebrate Taxon Name Resolution.

    PubMed

    Zermoglio, Paula F; Guralnick, Robert P; Wieczorek, John R

    2016-01-01

    Taxonomic names associated with digitized biocollections labels have flooded into repositories such as GBIF, iDigBio and VertNet. The names on these labels are often misspelled, out of date, or present other problems, as they were often captured only once during accessioning of specimens, or have a history of label changes without clear provenance. Before records are reliably usable in research, it is critical that these issues be addressed. However, still missing is an assessment of the scope of the problem, the effort needed to solve it, and a way to improve effectiveness of tools developed to aid the process. We present a carefully human-vetted analysis of 1000 verbatim scientific names taken at random from those published via the data aggregator VertNet, providing the first rigorously reviewed, reference validation data set. In addition to characterizing formatting problems, human vetting focused on detecting misspelling, synonymy, and the incorrect use of Darwin Core. Our results reveal a sobering view of the challenge ahead, as less than 47% of name strings were found to be currently valid. More optimistically, nearly 97% of name combinations could be resolved to a currently valid name, suggesting that computer-aided approaches may provide feasible means to improve digitized content. Finally, we associated names back to biocollections records and fit logistic models to test potential drivers of issues. A set of candidate variables (geographic region, year collected, higher-level clade, and the institutional digitally accessible data volume) and their 2-way interactions all predict the probability of records having taxon name issues, based on model selection approaches. We strongly encourage further experiments to use this reference data set as a means to compare automated or computer-aided taxon name tools for their ability to resolve and improve the existing wealth of legacy data.

  14. Phylogenomic Insights into the Evolution of Stinging Wasps and the Origins of Ants and Bees.

    PubMed

    Branstetter, Michael G; Danforth, Bryan N; Pitts, James P; Faircloth, Brant C; Ward, Philip S; Buffington, Matthew L; Gates, Michael W; Kula, Robert R; Brady, Seán G

    2017-04-03

    The stinging wasps (Hymenoptera: Aculeata) are an extremely diverse lineage of hymenopteran insects, encompassing over 70,000 described species and a diversity of life history traits, including ectoparasitism, cleptoparasitism, predation, pollen feeding (bees [Anthophila] and Masarinae), and eusociality (social vespid wasps, ants, and some bees) [1]. The most well-studied lineages of Aculeata are the ants, which are ecologically dominant in most terrestrial ecosystems [2], and the bees, the most important lineage of angiosperm-pollinating insects [3]. Establishing the phylogenetic affinities of ants and bees helps us understand and reconstruct patterns of social evolution as well as fully appreciate the biological implications of the switch from carnivory to pollen feeding (pollenivory). Despite recent advancements in aculeate phylogeny [4-11], considerable uncertainty remains regarding higher-level relationships within Aculeata, including the phylogenetic affinities of ants and bees [5-7]. We used ultraconserved element (UCE) phylogenomics [7, 12] to resolve relationships among stinging-wasp families, gathering sequence data from >800 UCE loci and 187 samples, including 30 out of 31 aculeate families. We analyzed the 187-taxon dataset using multiple analytical approaches, and we evaluated several alternative taxon sets. We also tested alternative hypotheses for the phylogenetic positions of ants and bees. Our results present a highly supported phylogeny of the stinging wasps. Most importantly, we find unequivocal evidence that ants are the sister group to bees+apoid wasps (Apoidea) and that bees are nested within a paraphyletic Crabronidae. We also demonstrate that taxon choice can fundamentally impact tree topology and clade support in phylogenomic inference.

  15. Three energy variables predict ant abundance at a geographical scale.

    PubMed Central

    Kaspari, M; Alonso, L; O'Donnell, S

    2000-01-01

    Energy theory posits three processes that link local abundance of ectotherms to geographical gradients in temperature. A survey of 49 New World habitats found a two order of magnitude span in the abundance (nests m(-2)) of ground nesting ants (Formicidae). Abundance increased with net primary productivity (r2=0.55), a measure of the baseline supply of harvestable energy. Abundance further increased with mean temperature (r2=0.056), a constraint on foraging activity for this thermophilic taxon. Finally for a given mean temperature, ants were more abundant in seasonal sites with longer, colder winters (r2 = 0.082) that help ectotherm taxa sequester harvested energy in non-productive months. All three variables are currently changing on a global scale. All should be useful in predicting biotic responses to climate change. PMID:10737406

  16. Myrmecomorba nylanderiae gen. et sp. nov., a microsporidian parasite of the tawny crazy ant Nylanderia fulva.

    PubMed

    Plowes, Robert M; Becnel, James J; LeBrun, Edward G; Oi, David H; Valles, Steven M; Jones, Nathan T; Gilbert, Lawrence E

    2015-07-01

    A new microsporidian genus and species, Myrmecomorba nylanderiae, is described from North American populations of the tawny crazy ant, Nylanderia fulva. This new species was found to be heterosporous producing several types of binucleate spores in both larval and adult stages and an abortive octosporoblastic sporogony in adult ants. While microsporidia are widespread arthropod parasites, this description represents only the fifth species described from an ant host. Molecular analysis indicated that this new taxon is phylogenetically closely allied to the microsporidian family Caudosporidae, a group known to parasitize aquatic black fly larvae. We report the presence of 3 spore types (Type 1 DK, Type 2 DK, and octospores) with infections found in all stages of host development and reproductive castes. This report documents the first pathogen infecting N. fulva, an invasive ant of considerable economic and ecological consequence.

  17. Fire Ant Allergy

    MedlinePlus

    ... Pongdee, MD, FAAAAI Fire ants are a stinging insect typically found in the South/Southeast areas of ... specialized training and skills to test for stinging insect allergy and develop a plan to manage allergies. ...

  18. Convergent coevolution in the domestication of coral mushrooms by fungus-growing ants.

    PubMed Central

    Munkacsi, A. B.; Pan, J. J.; Villesen, P.; Mueller, U. G.; Blackwell, M.; McLaughlin, D. J.

    2004-01-01

    Comparisons of phylogenetic patterns between coevolving symbionts can reveal rich details about the evolutionary history of symbioses. The ancient symbiosis between fungus-growing ants, their fungal cultivars, antibiotic-producing bacteria and cultivar-infecting parasites is dominated by a pattern of parallel coevolution, where the symbionts of each functional group are members of monophyletic groups. However, there is one outstanding exception in the fungus-growing ant system, the unidentified cultivar grown only by ants in the Apterostigma pilosum group. We classify this cultivar in the coral-mushroom family Pterulaceae using phylogenetic reconstructions based on broad taxon sampling, including the first mushroom collected from the garden of an ant species in the A. pilosum group. The domestication of the pterulaceous cultivar is independent from the domestication of the gilled mushrooms cultivated by all other fungus-growing ants. Yet it has the same overall assemblage of coevolved ant-cultivar-parasite-bacterium interactions as the other ant-grown fungal cultivars. This indicates a pattern of convergent coevolution in the fungus-growing ant system, where symbionts with both similar and very different evolutionary histories converge to functionally identical interactions. PMID:15315892

  19. Ants and ant scent reduce bumblebee pollination of artificial flowers.

    PubMed

    Cembrowski, Adam R; Tan, Marcus G; Thomson, James D; Frederickson, Megan E

    2014-01-01

    Ants on flowers can disrupt pollination by consuming rewards or harassing pollinators, but it is difficult to disentangle the effects of these exploitative and interference forms of competition on pollinator behavior. Using highly rewarding and quickly replenishing artificial flowers that simulate male or female function, we allowed bumblebees (Bombus impatiens) to forage (1) on flowers with or without ants (Myrmica rubra) and (2) on flowers with or without ant scent cues. Bumblebees transferred significantly more pollen analogue both to and from ant-free flowers, demonstrating that interference competition with ants is sufficient to modify pollinator foraging behavior. Bees also removed significantly less pollen analogue from ant-scented flowers than from controls, making this the first study to show that bees can use ant scent to avoid harassment at flowers. Ant effects on pollinator behavior, possibly in addition to their effects on pollen viability, may contribute to the evolution of floral traits minimizing ant visitation.

  20. Two issues in archaeological phylogenetics: taxon construction and outgroup selection.

    PubMed

    O'Brien, Michael J; Lyman, R Lee; Saab, Youssef; Saab, Elias; Darwent, John; Glover, Daniel S

    2002-03-21

    Cladistics is widely used in biology and paleobiology to construct phylogenetic hypotheses, but rarely has it been applied outside those disciplines. There is, however, no reason to suppose that cladistics is not applicable to anything that evolves by cladogenesis and produces a nested hierarchy of taxa. This includes cultural phenomena such as languages and tools recovered from archaeological contexts. Two methodological issues assume primacy in attempts to extend cladistics to archaeological materials: the construction of analytical taxa and the selection of appropriate outgroups. In biology the species is the primary taxonomic unit used, irrespective of the debates that have arisen in phylogenetic theory over the nature of species. Also in biology the phylogenetic history of a group of taxa usually is well enough known that an appropriate taxon can be selected as an outgroup. No analytical unit parallel to the species exists in archaeology, and thus taxa have to be constructed specifically for phylogenetic analysis. One method of constructing taxa is paradigmatic classification, which defines classes (taxa) on the basis of co-occurring, unweighted character states. Once classes have been created, a form of occurrence seriation-an archaeological method based on the theory of cultural transmission and heritability-offers an objective basis for selecting an outgroup.

  1. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Petitions to remove a taxon from the noxious weed...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501 Petitions to remove a taxon from the noxious weed lists. A person may petition the Administrator to remove...

  2. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Petitions to remove a taxon from the noxious weed...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501 Petitions to remove a taxon from the noxious weed lists. A person may petition the Administrator to remove...

  3. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Petitions to remove a taxon from the noxious weed...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501 Petitions to remove a taxon from the noxious weed lists. A person may petition the Administrator to remove...

  4. Confocal microscopy refines generic concept of a problematic taxon: rediagnosis of the genus Neoprothrix and remarks on female anatomy of eriophyoids (Acari: Eriophyoidea).

    PubMed

    Chetverikov, Philipp E; Desnitskiy, Alexey G; Navia, Denise

    2015-02-16

    Due to the higher resolution, confocal microscopy (CLSM) can be applied to refine the origin of tiny structures of the autofluorescent exoskeletons of microarthropods (mites in particular) which are hard to visualize using traditional differential interference contract light microscopy (DIC LM) and phase contrast light microscopy (PC LM). Three-dimensional (3D) reconstructions of the prodorsal shield topography of eriophyoid mites using Neoprothrix hibiscus Reis and Navia as a model, suggest that the structures originally treated as paired setae vi are two internal rod-like apodemes. Based on this, the genus Neoprothrix is excluded from the subfamily Prothricinae Amrine and transferred to the subfamily Sierraphytoptinae Keifer. Observations on partially cleared specimens of N. hibiscus showed that remnants of the central nervous system, paired glands and developing oocytes can be visualized using DIC LM and CLSM methods. New high quality microscope images are provided of recently described "flower-shaped" structures and two main components of yolk inclusions of the mature eggs inside the oviduct.

  5. Alate susceptibility in ants

    PubMed Central

    Ho, Eddie K H; Frederickson, Megan E

    2014-01-01

    Pathogens are predicted to pose a particular threat to eusocial insects because infections can spread rapidly in colonies with high densities of closely related individuals. In ants, there are two major castes: workers and reproductives. Sterile workers receive no direct benefit from investing in immunity, but can gain indirect fitness benefits if their immunity aids the survival of their fertile siblings. Virgin reproductives (alates), on the other hand, may be able to increase their investment in reproduction, rather than in immunity, because of the protection they receive from workers. Thus, we expect colonies to have highly immune workers, but relatively more susceptible alates. We examined the survival of workers, gynes, and males of nine ant species collected in Peru and Canada when exposed to the entomopathogenic fungus Beauveria bassiana. For the seven species in which treatment with B. bassiana increased ant mortality relative to controls, we found workers were significantly less susceptible compared with both alate sexes. Female and male alates did not differ significantly in their immunocompetence. Our results suggest that, as with other nonreproductive tasks in ant colonies like foraging and nest maintenance, workers have primary responsibility for colony immunity, allowing alates to specialize on reproduction. We highlight the importance of colony-level selection on individual immunity in ants and other eusocial organisms. PMID:25540683

  6. Psychometric development of the Problematic Pornography Use Scale.

    PubMed

    Kor, Ariel; Zilcha-Mano, Sigal; Fogel, Yehuda A; Mikulincer, Mario; Reid, Rory C; Potenza, Marc N

    2014-05-01

    Despite the increased social acceptance and widespread use of pornography over the past few decades, reliable and valid instruments assessing problematic use of pornography are lacking. This paper reports the findings of three studies aimed at developing and validating a new scale measuring problematic pornography use. The Problematic Pornography Use Scale (PPUS) items showed high internal consistency, convergent validity, and construct validity. Exploratory and confirmatory factor analyses revealed four core factors relating to proposed domains of problematic pornography use. High PPUS scores were positively correlated with measures of psychopathology, low self-esteem and poor attachment. Although PPUS scores were related to other behavioral addictions, problematic pornography use as operationalized in the current paper appears to be uniquely distinguished from features of behavioral addictions relating to gambling and Internet use. Findings highlight the potential use of the PPUS for future research and possible clinical applications by defining problematic pornography use as a behavioral addiction.

  7. Utilization of Anting-Anting (Acalypha indica) Leaves as Antibacterial

    NASA Astrophysics Data System (ADS)

    Batubara, Irmanida; Wahyuni, Wulan Tri; Firdaus, Imam

    2016-01-01

    Anting-anting (Acalypha indica) plants is a species of plant having catkin type of inflorescence. This research aims to utilize anting-anting as antibacterial toward Streptococcus mutans and degradation of biofilm on teeth. Anting-anting leaves were extracted by maceration technique using methanol, chloroform, and n-hexane. Antibacterial and biofilm degradation assays were performed using microdilution technique with 96 well. n-Hexane extracts of anting-anting leaves gave the best antibacterial potency with minimum inhibitory concentration and minimum bactericidal concentration value of 500 μg/mL and exhibited good biofilm degradation activity. Fraction of F3 obtained from fractionation of n-hexane's extract with column chromatography was a potential for degradation of biofilm with IC50 value of 56.82 μg/mL. Alkaloid was suggested as antibacterial and degradation of biofilm in the active fraction.

  8. Routing Vehicles with Ants

    NASA Astrophysics Data System (ADS)

    Tan, Wen Fang; Lee, Lai Soon; Majid, Zanariah Abdul; Seow, Hsin Vonn

    Routing vehicles involve the design of an optimal set of routes for a fleet of vehicles to serve a number of customers with known demands. This research develops an Ant Colony Optimization for the vehicle routing with one central depot and identical vehicles. The procedure simulates the behavior of real ants that always find the shortest path between their nest and a food source through a form of communication, pheromone trail. Finally, preliminary results on the learning of the algorithm testing on benchmark data set will be presented in this paper.

  9. An overview of problematic internet use.

    PubMed

    Spada, Marcantonio M

    2014-01-01

    Problematic Internet use (PIU), which has become a global social issue, can be broadly conceptualized as an inability to control one's use of the Internet which leads to negative consequences in daily life. The aim of this paper is to give a brief overview of the gradually evolving body of literature on PIU. This shows that the definitions and diagnostic criteria that have been proposed, and the assessment tools that have been developed, stress similarities between PIU, addictive behaviours and impulse-control disorders. Disagreements regarding diagnostic criteria and the lack of large epidemiological studies have resulted in difficulties in establishing the prevalence of PIU in the general population. Studies suggest high comorbidity rates between PIU and numerous psychiatric disorders highlighting the importance of focusing on comorbidity in treatment. There is growing evidence that genetic, personality and individual differences in automatic and controlled aspects of self-regulation may promote the development of PIU. Pharmacological and psychotherapeutic treatments specific to PIU have received limited testing in large, rigorous studies however preliminary evidence suggests that both psychotropic medications (Escitalopram, Naltrexone and Methylphenidate) and cognitive behaviour therapy may have some utility in the treatment of PIU. More research is needed on areas which remain unclear and contribute to the prognosis of PIU, in particular the temporal relationships between psychiatric disorder and PIU, mechanisms of comorbidity and the more subtle psychological changes that occur through Internet use.

  10. The ants go marching millions by millions: invasive ant research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...

  11. The Ants Go Marching Millions by Millions: Invasive Ant Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...

  12. Army ants: an evolutionary bestseller?

    PubMed

    Berghoff, Stefanie M

    2003-09-02

    Army ants are characterized by a complex combination of behavioral and morphological traits. Molecular data now indicate that army ant behavior has a unique evolutionary origin and has been conserved for over more than 100 million years.

  13. Tiny, Powerful, Awesome Ants!

    ERIC Educational Resources Information Center

    Tate, Kathleen

    2007-01-01

    Peering through a thematic science lens--elementary students embarked on a one-week study of ants during a month-long summer school program. This integrated unit addressed reading and writing skills while developing the science-process skills of observation, inferring, and communicating in a motivating and authentic way. Pre- and post-assessments…

  14. Ants: the supreme soil manipulators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review focuses on the semiochemical interactions between ants and their soil environment. Ants occupy virtually every ecological niche and have evolved mechanisms to not just cope with, but also manipulate soil organisms. The metapleural gland, specific to ants was thought to be the major sourc...

  15. Ant allergens and hypersensitivity reactions in response to ant stings.

    PubMed

    Potiwat, Rutcharin; Sitcharungsi, Raweerat

    2015-12-01

    Hypersensitivity reactions caused by ant stings are increasingly recognized as an important cause of death by anaphylaxis. Only some species of ants ( e.g. Solenopsis spp., Myrmecia spp., and Pachycondyla spp.) cause allergic reactions. Ant species are identified by evaluating the morphologic structures of worker ants or by molecular techniques. Ant venom contains substances, including acids and alkaloids, that cause toxic reactions, and those from Solenopsis invicta or the imported fire ant have been widely studied. Piperidine alkaloids and low protein contents can cause local reactions (sterile pustules) and systemic reactions (anaphylaxis). Imported fire ant venoms are cross-reactive; for example, the Sol i 1 allergen from S. invicta has cross-reactivity with yellow jacket phospholipase. The Sol i 3 allergen is a member of the antigen 5 family that has amino acid sequence identity with vespid antigen 5. The clinical presentations of ant hypersensitivity are categorized into immediate and delayed reactions: immediate reactions, such as small local reactions, large local reactions, and systemic reactions, occur within 1-4 hours after the ant stings, whereas delayed reactions, such as serum sickness and vasculitis, usually occur more than 4 hours after the stings. Tools for the diagnosis of ant hypersensitivity are skin testing, serum specific IgE, and sting challenge tests. Management of ant hypersensitivity can be divided into immediate (epinephrine, corticosteroids), symptomatic (antihistamines, bronchodilators), supportive (fluid resuscitation, oxygen therapy), and preventive (re-sting avoidance and immunotherapy) treatments.

  16. An Examination of Predictor Variables for Problematic Internet Use

    ERIC Educational Resources Information Center

    Bulut Serin, Nerguz

    2011-01-01

    This study examines problematic Internet use among university students in terms of gender, while also gauging the impact of personality traits, life satisfaction and loneliness variables on problematic Internet use. A total of 411 university students studying Education in North Cyprus participated in the study. The participants were selected using…

  17. Ants and the fossil record.

    PubMed

    LaPolla, John S; Dlussky, Gennady M; Perrichot, Vincent

    2013-01-01

    The dominance of ants in the terrestrial biosphere has few equals among animals today, but this was not always the case. The oldest ants appear in the fossil record 100 million years ago, but given the scarcity of their fossils, it is presumed they were relatively minor components of Mesozoic insect life. The ant fossil record consists of two primary types of fossils, each with inherent biases: as imprints in rock and as inclusions in fossilized resins (amber). New imaging technology allows ancient ant fossils to be examined in ways never before possible. This is particularly helpful because it can be difficult to distinguish true ants from non-ants in Mesozoic fossils. Fossil discoveries continue to inform our understanding of ancient ant morphological diversity, as well as provide insights into their paleobiology.

  18. The Frugal Cosmic Ant

    NASA Astrophysics Data System (ADS)

    2007-09-01

    Using ESO's Very Large Telescope Interferometer and its unique ability to see small details, astronomers have uncovered a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape. ESO PR Photo 42/07 ESO PR Photo 42/07 A Disc in the Ant Nebula The Ant Nebula is one of the most striking planetary nebulae known. Planetary nebulae - whose name arises because most are spherical and looked like planets when they were first discovered through older, less powerful telescopes - are glowing structures of gas cast off by solar-like stars at the ends of their lives. The morphology of the Ant Nebula - a bright core, three nested pairs of bipolar lobes and a ring-like outflow - is so unique that it was nicknamed the 'Chamber of Horrors' of planetary nebulae in the late 1950s. But how can a spherical star produce such complex structures? The answer, many astronomers think, requires understanding of the discs surrounding the central star. By their nature, these discs bear witness to the phenomena that lead to the asymmetrical structures of planetary nebulae. "The challenge is to actually detect these discs," explains team leader Olivier Chesneau, from the Observatoire de la Côte d'Azur, France. "Most astronomical instruments do not have a sharp enough view to find, let alone study them. The Very Large Telescope Interferometer however, with its exceptionally high spatial resolution, is a powerful disc-hunter." The disc of the Ant Nebula, which cannot be detected with a single 8.2-m VLT Unit Telescope, was uncovered in the interferometric mode where two 8.2-m Unit Telescopes were used to combine light, through the MID-infrared Interferometric instrument (MIDI). The observations reveal a flat, nearly edge-on disc whose major axis is perpendicular to the axis of the bipolar lobes. The disc extends from about 9 times the mean distance between the Earth and the

  19. Unraveling Trichoderma species in the attine ant environment: description of three new taxa.

    PubMed

    Montoya, Quimi Vidaurre; Meirelles, Lucas Andrade; Chaverri, Priscila; Rodrigues, Andre

    2016-05-01

    Fungus-growing "attine" ants forage diverse substrates to grow fungi for food. In addition to the mutualistic fungal partner, the colonies of these insects harbor a rich microbiome composed of bacteria, filamentous fungi and yeasts. Previous work reported some Trichoderma species in the fungus gardens of leafcutter ants. However, no studies systematically addressed the putative association of Trichoderma with attine ants, especially in non-leafcutter ants. Here, a total of 62 strains of Trichoderma were analyzed using three molecular markers (ITS, tef1 and rpb2). In addition, 30 out of 62 strains were also morphologically examined. The strains studied correspond to the largest sampling carried out so far for Trichoderma in the attine ant environment. Our results revealed the richness of Trichoderma in this environment, since we found 20 Trichoderma species, including three new taxa described in the present work (Trichoderma attinorum, Trichoderma texanum and Trichoderma longifialidicum spp. nov.) as well as a new phylogenetic taxon (LESF 545). Moreover, we show that all 62 strains grouped within different clades across the Trichoderma phylogeny, which are identical or closely related to strains derived from several other environments. This evidence supports the transient nature of the genus Trichoderma in the attine ant colonies. The discovery of three new species suggests that the dynamic foraging behavior of these insects might be responsible for accumulation of transient fungi into their colonies, which might hold additional fungal taxa still unknown to science.

  20. Distributed nestmate recognition in ants

    PubMed Central

    Esponda, Fernando; Gordon, Deborah M.

    2015-01-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  1. Distributed nestmate recognition in ants.

    PubMed

    Esponda, Fernando; Gordon, Deborah M

    2015-05-07

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response.

  2. Is problematic mobile phone use explained by chronotype and personality?

    PubMed

    Demirhan, Eda; Randler, Christoph; Horzum, Mehmet Barış

    2016-01-01

    In this study, the relationships among problematic mobile phone use, age, gender, personality and chronotype of Turkish university students were examined. The study included 902 university students (73% female, 27% male) and their participation in the study was anonymous and voluntary. Data were collected from each participant by assessing a demographic questionnaire, Composite Scale of Morningness (CSM) as a measure of chronotype, the Big Five Inventory (BIG-5) for personality assessment and Mobile Phone Problem Usage Scale (MPPUS). The most important result was that CSM scores were the best predictor for problematic mobile phone usage, and as a consequence, evening-oriented university students scored higher on the MPPUS. This result remained, even when compared with the most influential personality predictor, conscientiousness. In addition, while extraversion positively predicted, emotional stable and chronotype negatively predicted problematic mobile phone use. Lastly, age and gender were not predictors of problematic mobile phone use.

  3. "Social Anxiety Disorder Carved at its Joints": evidence for the taxonicity of social anxiety disorder.

    PubMed

    Weeks, Justin W; Carleton, R Nicholas; Asmundson, Gordon J G; McCabe, Randi E; Antony, Martin M

    2010-10-01

    Previous findings suggest that social anxiety disorder may be best characterized as having a dimensional latent structure (Kollman et al., 2006; Weeks et al., 2009). We attempted to extend previous taxometric investigations of social anxiety by examining the latent structure of social anxiety disorder symptoms in a large sample comprised of social anxiety disorder patients (i.e., putative taxon members) and community residents/undergraduate respondents (i.e., putative complement class members). MAXEIG and MAMBAC were performed with indicator sets drawn from a self-report measure of social anxiety symptoms, the Social Interaction Phobia Scale (Carleton et al., 2009). MAXEIG and MAMBAC analyses, as well as comparison analyses utilizing simulated taxonic and dimensional datasets, yielded converging evidence that social anxiety disorder has a taxonic latent structure. Moreover, 100% of the confirmed social anxiety disorder patients in our overall sample were correctly assigned to the identified taxon class, providing strong support for the external validity of the identified taxon; and k-means cluster analysis results corroborated our taxometric base-rate estimates. Implications regarding the conceptualization, diagnosis, and assessment of social anxiety disorder are discussed.

  4. Fire ant microsporidia acquired by parasitoid flies of fire ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microsporidium Kneallhazia (formerly Thelohania) solenopsae and parasitoid flies in the genus Pseudacteon are natural enemies of the invasive fire ant, Solenopsis invicta. Pseudacteon flies oviposit into adult fire ants, where maggots that eclose from eggs migrate to the ants’ head, pupate, and...

  5. Knowledge Management in Taxonomy and Biostratigraphy using TaxonConcept Software

    NASA Astrophysics Data System (ADS)

    Klump, J.; Huber, R.; Goetz, S.

    2005-12-01

    The use of fossils to constrain age models for geological samples is not as straightforward as it might seem. Even though index fossils have been defined as biostratigraphic time markers ambiguity arises from the synonymous use of taxonomic names. Progress in our understanding of the origin of certain species have sometimes lead to substantial changes in the taxonomic classification of these organisms. TaxonConcept was created as part of the Stratigraphy.net initiative as a tool to manage taxonomic information and complex knowledge networks to help resolve taxonomic ambiguities in biostratigraphy. Its workflow is based on the principles of open nomenclature. Open nomenclature allows researchers to comment on the identification of a specimen which cannot exactly be determined and is frequently used in synonymy lists. The use of such synonymy lists in TaxonConcept allows to work with taxonomic classifications that are uncertain, or where several versions exist. Every single taxonomic entity in TaxonConcept is recorded with its relevant citations in the literature. This allows to manage information on taxonomy. The members of working groups using TaxonConcept can record their opinion on the taxonomic classification of each taxon in the framework of open nomenclature and annotate it in free text. This managed and structured collection of taxonomic opinions is an example of knowledge management. Taxonomic opinions are otherwise dispersed throughout the literature, if recorded at all, and are only available to the specialist. Assembled as a collection, they represent our knowledge on the taxonomy of a certain group of organisms. In the terminology of computer science, the semantic relationships between taxonomic terms are an ontology. Open nomenclature offers a formal framework that lends itself very well to describe the nature of the relations between taxonomic terms. The use of such synonymy lists in a taxonomic information system allows interesting search options

  6. Temperature: Human Regulating, Ants Conforming

    ERIC Educational Resources Information Center

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  7. Phylogeny of the Genus Nocardia Based on Reassessed 16S rRNA Gene Sequences Reveals Underspeciation and Division of Strains Classified as Nocardia asteroides into Three Established Species and Two Unnamed Taxons

    PubMed Central

    Roth, Andreas; Andrees, Sebastian; Kroppenstedt, Reiner M.; Harmsen, Dag; Mauch, Harald

    2003-01-01

    Conventional identification of Nocardia in the routine laboratory remains problematic due to a paucity of reliable phenotypic tests and due to the yet-unresolved taxonomy of strains classified as belonging to the species Nocardia asteroides, which comprises the type strain and isolates with drug pattern types II and VI. The 16S rRNA gene of 74 representative strains of the genus Nocardia, encompassing 25 established species, was sequenced in order to provide a molecular basis for accurate species identification and with the aim of reassessing the phylogeny of taxons assigned to the species N. asteroides. The result of this phylogenetic analysis confirms that the interspecies heterogeneity of closely related nocardial species can be considerably low (a sequence divergence of only 0.5% was found between N. paucivorans and N. brevicatena). We observed a sequence microheterogeneity (sequence divergence of fewer than five bases) in 8 of 11 species of which more than one strain in the species was studied. At least 10 taxons were found that merit description as new species. Strains previously classified as N. asteroides fell into five distinct phylogenetic groups: the type strain cluster (N. asteroides sensu strictu), N. abscessus, N. cyriacigeorgica, and two clusters closely related to N. carnea or N. flavorosea. The strains within the latter two groups probably represent new species, pending further genetic and phenotypic evaluation. Restricted phenotypic data revealed that N. abscessus, N. cyriacigeorgica, and the two Nocardia species taxons are equivalent to drug patterns I, VI, and II, respectively. In the future, these data will help in finding species-specific markers after adoption of a more precise nomenclature for isolates closely related to N. asteroides and unravel confusing phenotypic data obtained in the past for unresolved groups of strains that definitely belong to separate taxons from a phylogenetic point of view. PMID:12574299

  8. Prevalence of problematic mobile phone use in British adolescents.

    PubMed

    Lopez-Fernandez, Olatz; Honrubia-Serrano, Luisa; Freixa-Blanxart, Montserrat; Gibson, Will

    2014-02-01

    The problematic use of mobile phones among adolescents has not been widely studied. There are very few instruments for assessing potential technological addiction to mobile phones, or for categorizing different types of users or uses. The most widely used scale is the Mobile Phone Problem Use Scale (MPPUS), which is used to study adult populations, and has been applied in various forms in international contexts. The aims of this study were to adapt the Spanish version of this scale (MPPUSA) to British adolescents, and then to estimate the prevalence of possible problematic users. A questionnaire was administered to a sample of 1,529 secondary school pupils aged between 11 and 18 years, with 1,026 completed questionnaires being collected. The analysis showed that the factor and construct validity and reliability were comparable to those obtained in previous studies. The prevalence of problematic users among the students was 10%, and the typical problematic user tended to be an adolescent between 11 and 14 years old, studying in a public school, who considered themselves to be an expert user of this technology, who made extensive use of his/her mobile phone, and who attributed the same problem of use among their peers. These users presented notable scores in all the symptoms covered by the scale used to assess problematic use. In conclusion, the adaptation of the MPPUSA as a screening scale for British adolescents presents good sensitivity and specificity for detecting the main addictive symptoms proposed in this validated version.

  9. The development of the Problematic Series WatchingScale (PSWS)

    PubMed Central

    Orosz, Gábor; Bőthe, Beáta; Tóth-Király, István

    2016-01-01

    Background and aims The goal of the present study was to create a short ProblematicSeries Watching Scale (PSWS). Methods On the basis of the six components model of Griffiths (2005), six items were identifiedcovering all components of problematic series watching. Confirmatoryfactor analyses were carried out on two independent samples (N1 = 366, N2 = 752). Results The PSWS has appropriate factor structure and reliability. Theamount of free time was not, but the series watching time was associatedwith PSWS scores. Women had higher scores than men. Discussion Before PSWS, no prior scale has been created to measure problematicseries watching. Further research is needed to properly assess itsvalidity and reliability; and for examining whether extensive serieswatching can lead to health-related and psychosocial problems. Conclusions In the increasingly digitalized world there are many motivationalforces which encourage people watching online series. In the lightof these changes, research on problematic series watching will beprogressively relevant. PMID:28092185

  10. The development of the Problematic Series WatchingScale (PSWS).

    PubMed

    Orosz, Gábor; Bőthe, Beáta; Tóth-Király, István

    2016-03-01

    Background and aims The goal of the present study was to create a short ProblematicSeries Watching Scale (PSWS). Methods On the basis of the six components model of Griffiths ( 2005 ), six items were identifiedcovering all components of problematic series watching. Confirmatoryfactor analyses were carried out on two independent samples (N1  = 366, N2  = 752). Results The PSWS has appropriate factor structure and reliability. Theamount of free time was not, but the series watching time was associatedwith PSWS scores. Women had higher scores than men. Discussion Before PSWS, no prior scale has been created to measure problematicseries watching. Further research is needed to properly assess itsvalidity and reliability; and for examining whether extensive serieswatching can lead to health-related and psychosocial problems. Conclusions In the increasingly digitalized world there are many motivationalforces which encourage people watching online series. In the lightof these changes, research on problematic series watching will beprogressively relevant.

  11. Psychopathy as a Taxon: Evidence That Psychopaths Are a Discrete Class.

    ERIC Educational Resources Information Center

    Harris, Grant T.; And Others

    1994-01-01

    Applied taxometric analyses to construct of psychopathy (as measured by Psychopathy Checklist) and to several variables reflecting antisocial childhood, adult criminality, and criminal recidivism. Findings from 653 serious offenders assessed or treated in maximum-security institution supported existence of taxon underlying psychopathy. Childhood…

  12. Dimensionality vs Taxonicity of Schizotypy: Some New Data and Challenges Ahead

    PubMed Central

    Everett, Kirsty V.; Linscott, Richard J.

    2015-01-01

    Heterogeneity in the expression of schizotypy may arise from underlying dimensional processes or a taxonic population structure. In a 2-phase study, we tested the taxonicity of self-reported schizotypy within a general psychiatric sample (n = 109) and examined taxon validity by testing its association with clinical schizotaxia in follow-up subsamples. Taxometric analyses indicated a taxonic structure (schizotypy prevalence = 38.8%) provided the best description of the underlying population distribution. After a year, schizotypal (n = 14) and nonschizotypal (n = 14) subsamples returned for diagnosis of clinical schizotaxia by assessment of executive functioning, attention, memory, and negative symptoms. Seven patients met diagnostic criteria, all members of the schizotypy class. Schizotypy was associated with impaired attention and memory, more negative symptoms, poorer global functioning, and more extensive psychiatric histories. We reconcile inconsistencies in the literature by discussing threats to the validity of this and similar research on Meehl’s taxonomic model of schizotypy, including conceptual limitations of the lexical hypothesis and conventions of factor analysis. Scrutiny of Meehl’s model should involve disambiguation and better measurement of the schizotaxia-schizotypy phenotype. PMID:25810059

  13. Relations among loneliness, social anxiety, and problematic Internet use.

    PubMed

    Caplan, Scott E

    2007-04-01

    The model of problematic Internet use advanced and tested in the current study proposes that individuals' psychosocial well-being, along with their beliefs about interpersonal communication (both face-to-face and online) are important cognitive predictors of negative outcomes arising from Internet use. The study examined the extent to which social anxiety explains results previously attributed to loneliness as a predictor of preference for online social interaction and problematic Internet use. The results support the hypothesis that the relationship between loneliness and preference for online social interaction is spurious, and that social anxiety is the confounding variable.

  14. FORMIDABEL: The Belgian Ants Database

    PubMed Central

    Brosens, Dimitri; Vankerkhoven, François; Ignace, David; Wegnez, Philippe; Noé, Nicolas; Heughebaert, André; Bortels, Jeannine; Dekoninck, Wouter

    2013-01-01

    Abstract FORMIDABEL is a database of Belgian Ants containing more than 27.000 occurrence records. These records originate from collections, field sampling and literature. The database gives information on 76 native and 9 introduced ant species found in Belgium. The collection records originated mainly from the ants collection in Royal Belgian Institute of Natural Sciences (RBINS), the ‘Gaspar’ Ants collection in Gembloux and the zoological collection of the University of Liège (ULG). The oldest occurrences date back from May 1866, the most recent refer to August 2012. FORMIDABEL is a work in progress and the database is updated twice a year. The latest version of the dataset is publicly and freely accessible through this url: http://ipt.biodiversity.be/resource.do?r=formidabel. The dataset is also retrievable via the GBIF data portal through this link: http://data.gbif.org/datasets/resource/14697 A dedicated geo-portal, developed by the Belgian Biodiversity Platform is accessible at: http://www.formicidae-atlas.be Purpose: FORMIDABEL is a joint cooperation of the Flemish ants working group “Polyergus” (http://formicidae.be) and the Wallonian ants working group “FourmisWalBru” (http://fourmiswalbru.be). The original database was created in 2002 in the context of the preliminary red data book of Flemish Ants (Dekoninck et al. 2003). Later, in 2005, data from the Southern part of Belgium; Wallonia and Brussels were added. In 2012 this dataset was again updated for the creation of the first Belgian Ants Atlas (Figure 1) (Dekoninck et al. 2012). The main purpose of this atlas was to generate maps for all outdoor-living ant species in Belgium using an overlay of the standard Belgian ecoregions. By using this overlay for most species, we can discern a clear and often restricted distribution pattern in Belgium, mainly based on vegetation and soil types. PMID:23794918

  15. Discovery–dominance trade-off among widespread invasive ant species

    PubMed Central

    Bertelsmeier, Cleo; Avril, Amaury; Blight, Olivier; Jourdan, Hervé; Courchamp, Franck

    2015-01-01

    Ants are among the most problematic invasive species. They displace numerous native species, alter ecosystem processes, and can have negative impacts on agriculture and human health. In part, their success might stem from a departure from the discovery–dominance trade-off that can promote co-existence in native ant communities, that is, invasive ants are thought to be at the same time behaviorally dominant and faster discoverers of resources, compared to native species. However, it has not yet been tested whether similar asymmetries in behavioral dominance, exploration, and recruitment abilities also exist among invasive species. Here, we establish a dominance hierarchy among four of the most problematic invasive ants (Linepithema humile, Lasius neglectus, Wasmannia auropunctata, Pheidole megacephala) that may be able to arrive and establish in the same areas in the future. To assess behavioral dominance, we used confrontation experiments, testing the aggressiveness in individual and group interactions between all species pairs. In addition, to compare discovery efficiency, we tested the species’ capacity to locate a food resource in a maze, and the capacity to recruit nestmates to exploit a food resource. The four species differed greatly in their capacity to discover resources and to recruit nestmates and to dominate the other species. Our results are consistent with a discovery–dominance trade-off. The species that showed the highest level of interspecific aggressiveness and dominance during dyadic interactions. PMID:26257879

  16. Discovery-dominance trade-off among widespread invasive ant species.

    PubMed

    Bertelsmeier, Cleo; Avril, Amaury; Blight, Olivier; Jourdan, Hervé; Courchamp, Franck

    2015-07-01

    Ants are among the most problematic invasive species. They displace numerous native species, alter ecosystem processes, and can have negative impacts on agriculture and human health. In part, their success might stem from a departure from the discovery-dominance trade-off that can promote co-existence in native ant communities, that is, invasive ants are thought to be at the same time behaviorally dominant and faster discoverers of resources, compared to native species. However, it has not yet been tested whether similar asymmetries in behavioral dominance, exploration, and recruitment abilities also exist among invasive species. Here, we establish a dominance hierarchy among four of the most problematic invasive ants (Linepithema humile, Lasius neglectus, Wasmannia auropunctata, Pheidole megacephala) that may be able to arrive and establish in the same areas in the future. To assess behavioral dominance, we used confrontation experiments, testing the aggressiveness in individual and group interactions between all species pairs. In addition, to compare discovery efficiency, we tested the species' capacity to locate a food resource in a maze, and the capacity to recruit nestmates to exploit a food resource. The four species differed greatly in their capacity to discover resources and to recruit nestmates and to dominate the other species. Our results are consistent with a discovery-dominance trade-off. The species that showed the highest level of interspecific aggressiveness and dominance during dyadic interactions.

  17. Problematic Internet use and problematic alcohol use from the cognitive-behavioral model: a longitudinal study among adolescents.

    PubMed

    Gámez-Guadix, Manuel; Calvete, Esther; Orue, Izaskun; Las Hayas, Carlota

    2015-01-01

    Problematic Internet use (PIU) and problematic alcohol use are two pervasive problems during adolescence that share similar characteristics and predictors. The first objective of this study was to analyze the temporal and reciprocal relationships among the main components of PIU from the cognitive-behavioral model (preference for online social interaction, mood regulation through the Internet, deficient self-regulation, and negative consequences). The second objective was to examine the temporal and reciprocal relationships between PIU components and problematic alcohol use. We also examined whether these relationships differ between males and females. The sample comprised 801 Spanish adolescents (mean age=14.92, SD=1.01) who completed the measures both at Time 1 (T1) and Time 2 (T2) six months apart. We used structural equation modeling to analyze the relationship among the variables. Results showed that deficient self-regulation at T1 predicted an increase in preference for online interactions, mood regulation, and negative consequences of the Internet at T2. In turn, the emergence of negative consequences of PIU at T1 predicted a rise in problematic alcohol use at T2. Longitudinal relationships between different components of PIU and between the components of PIU and problematic alcohol use were invariant across genders. Deficient self-regulation, consisting of diminished self-control over cognition and behaviors related to the Internet, plays a central role in the maintenance of PIU, increasing the preference for online interactions, mood regulation, and negative consequences from Internet use over time. In turn, adolescents who present negative consequences of PIU are vulnerable targets for problematic alcohol use.

  18. A Grounded Theory of Counseling Students Who Report Problematic Peers

    ERIC Educational Resources Information Center

    Parker, Lindy K.; Chang, Catherine Y.; Corthell, Kimere K.; Walsh, Maggie E.; Brack, Greg; Grubbs, Natalie K.

    2014-01-01

    All counselors, including students, are responsible for intervening when a colleague shows signs of impairment. This grounded theory study investigated experiences of 12 counseling students who reported problematic peers. An emergent theory of the peer reporting process is presented, along with implications for counselor educators and suggestions…

  19. Problematizing the Race Consciousness of Women of Color.

    ERIC Educational Resources Information Center

    Brush, Paula Stewart

    2001-01-01

    Suggests that feminist studies of the intersection of race and gender have failed to problematize the race consciousness of women of color. Situates debates about the situation historically, focusing on the situation of black women. Argues that feminist studies assume race consciousness among all women of color, revealing race consciousness as an…

  20. Prediction of Problematic Internet Use by Attachment in University Students

    ERIC Educational Resources Information Center

    Kozan, Hatice Irem Ozteke; Kesici, Sahin; Buyukbayraktar, Cagla Girgin; Yalcin, S. Barbaros

    2017-01-01

    Aim of this research is to examine the predictive power of attachment style on problematic internet use among university students. Participants of study consist of 481 university students (230 girls). Results indicate that there is a negative correlation between secure attachment style and social benefit/social comfort and there is a positive…

  1. The Effects of Meal Schedule and Quantity on Problematic Behavior.

    ERIC Educational Resources Information Center

    Wacker, David P.; And Others

    1996-01-01

    Two case examples (a toddler with severe developmental delays and a 7-year old with severe mental retardation) illustrating effects of meal schedule and food quantity on displays of problematic behavior are offered. Brief functional analyses of aberrant behavior provided useful information for interpreting distinct patterns of behavior. (DB)

  2. Scaffolding Dynamics and the Emergence of Problematic Learning Trajectories

    ERIC Educational Resources Information Center

    Steenbeek, Henderien; Jansen, Louise; van Geert, Paul

    2012-01-01

    This study aims at examining problematic learning trajectories of students with emotional behavioral disorders (EBD) by means of a longitudinal and time serial (micro genetic) study of individual instruction sessions during arithmetic lessons. Micro genetic analysis techniques were applied on the variable "responsiveness" in the scaffolding…

  3. Loyalty: Why Is It so Problematic in Athletics?

    ERIC Educational Resources Information Center

    Stoll, Sharon Kay

    2012-01-01

    What is loyalty and why is it problematic in athletics? The author discusses the ethical lapses that can occur when a powerful social value, "loyalty," trumps individuals' ability to make moral decisions. She argues that education about morality should be a necessary part of sport education and explains how moral education programs can make a…

  4. The Validity and Reliability of the Problematic Internet Usage Scale

    ERIC Educational Resources Information Center

    Ceyhan, Esra; Ceyhan, Aydogan Aykut; Gurcan, Aysen

    2007-01-01

    In this research, it was aimed to develop an instrument for determining problematic internet usage of university students. Factorial structure of the data collected from 1658 university students revealed three factors. Of these, the first factor is called negative consequences of the internet and accounted for 25.36% of the variance, the second…

  5. Prevalence of Problematic Video Gaming among Ontario Adolescents

    ERIC Educational Resources Information Center

    Turner, Nigel E.; Paglia-Boak, Angela; Ballon, Bruce; Cheung, Joyce T. W.; Adlaf, Edward M.; Henderson, Joanna; Chan, Vincy; Rehm, Jurgen; Hamilton, Hayley; Mann, Robert E.

    2012-01-01

    Video game playing has become a very popular activity among adolescents. Its impact on the mental health and well-being of players is just beginning to be explored. This paper reports on the prevalence of problematic gaming in a representative sample of 2,832 Ontario students in grades 7 to 12. The survey included questions about the school grade,…

  6. A Content Analysis of Problematic Behavior in Counselor Education Programs

    ERIC Educational Resources Information Center

    Brown, Maranda

    2013-01-01

    Counselor education programs are obligated by accreditation standards and professional codes of ethics to identify counselors-in-training whose academic, clinical, and personal performance indicate problematic behavior that would potentially prevent them from entering the profession (McAdams, Foster, & Ward, 2007; Rust, Raskin, & Hill,…

  7. De-Problematizing 'GMOs': Suggestions for Communicating about Genetic Engineering.

    PubMed

    Blancke, Stefaan; Grunewald, Wim; De Jaeger, Geert

    2017-03-01

    The public debates concerning genetic engineering (GE) involve many non-scientific issues. The ensuing complexity is one reason why biotechnologists are reluctant to become involved. By sharing our personal experiences in science communication and suggesting ways to de-problematize GE, we aim to inspire our colleagues to engage with the public.

  8. Trap-mulching Argentine ants.

    PubMed

    Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

    2006-10-01

    Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies.

  9. Genetic evidence for intra- and interspecific slavery in honey ants (genus Myrmecocystus).

    PubMed

    Kronauer, D J C; Gadau, J; Hölldobler, B

    2003-04-22

    The New World honey ant species Myrmecocystus mimicus is well known for its highly stereotyped territorial tournaments, and for the raids on conspecific nests that can lead to intraspecific slavery. Our results from mitochondrial and nuclear markers show that the raided brood emerges in the raiding colony and is subsequently incorporated into the colony's worker force. We also found enslaved conspecifics in a second honey ant species, M. depilis, the sister taxon of M. mimicus, which occurs in sympatry with M. mimicus at the study site. Colonies of this species furthermore contained raided M. mimicus workers. Both species have an effective mating frequency that is not significantly different from 1. This study provides genetic evidence for facultative intra- and interspecific slavery in the genus Myrmecocystus. Slavery in ants has evolved repeatedly and supposedly by different means. We propose that, in honey ants, secondary contact between two closely related species that both exhibit intraspecific slavery gave rise to an early form of facultative interspecific slavery.

  10. A cryptic taxon of Galápagos tortoise in conservation peril.

    PubMed

    Russello, Michael A; Glaberman, Scott; Gibbs, James P; Marquez, Cruz; Powell, Jeffrey R; Caccone, Adalgisa

    2005-09-22

    As once boldly stated, 'bad taxonomy can kill', highlighting the critical importance of accurate taxonomy for the conservation of endangered taxa. The concept continues to evolve almost 15 years later largely because most legal protections aimed at preserving biological diversity are based on formal taxonomic designations. In this paper we report unrecognized genetic divisions within the giant tortoises of the Galápagos. We found three distinct lineages among populations formerly considered a single taxon on the most populous and accessible island of Santa Cruz; their diagnosability, degree of genetic divergence and phylogenetic placement merit the recognition of at least one new taxon. These results demonstrate the fundamental importance of continuing taxonomic investigations to recognize biological diversity and designate units of conservation, even within long-studied organisms such as Galápagos tortoises, whose evolutionary heritage and contribution to human intellectual history warrant them special attention.

  11. Comparative Genomics of Bifidobacterium animalis subsp. lactis Reveals a Strict Monophyletic Bifidobacterial Taxon

    PubMed Central

    Milani, Christian; Duranti, Sabrina; Lugli, Gabriele Andrea; Bottacini, Francesca; Strati, Francesco; Arioli, Stefania; Foroni, Elena; Turroni, Francesca; van Sinderen, Douwe

    2013-01-01

    Strains of Bifidobacterium animalis subsp. lactis are extensively exploited by the food industry as health-promoting bacteria, although the genetic variability of members belonging to this taxon has so far not received much scientific attention. In this article, we describe the complete genetic makeup of the B. animalis subsp. lactis Bl12 genome and discuss the genetic relatedness of this strain with other sequenced strains belonging to this taxon. Moreover, a detailed comparative genomic analysis of B. animalis subsp. lactis genomes was performed, which revealed a closely related and isogenic nature of all currently available B. animalis subsp. lactis strains, thus strongly suggesting a closed pan-genome structure of this bacterial group. PMID:23645200

  12. A cryptic taxon of Galápagos tortoise in conservation peril

    PubMed Central

    Russello, Michael A; Glaberman, Scott; Gibbs, James P; Marquez, Cruz; Powell, Jeffrey R; Caccone, Adalgisa

    2005-01-01

    As once boldly stated, ‘bad taxonomy can kill’, highlighting the critical importance of accurate taxonomy for the conservation of endangered taxa. The concept continues to evolve almost 15 years later largely because most legal protections aimed at preserving biological diversity are based on formal taxonomic designations. In this paper we report unrecognized genetic divisions within the giant tortoises of the Galápagos. We found three distinct lineages among populations formerly considered a single taxon on the most populous and accessible island of Santa Cruz; their diagnosability, degree of genetic divergence and phylogenetic placement merit the recognition of at least one new taxon. These results demonstrate the fundamental importance of continuing taxonomic investigations to recognize biological diversity and designate units of conservation, even within long-studied organisms such as Galápagos tortoises, whose evolutionary heritage and contribution to human intellectual history warrant them special attention. PMID:17148189

  13. Monoculture of Leafcutter Ant Gardens

    PubMed Central

    Mueller, Ulrich G.; Scott, Jarrod J.; Ishak, Heather D.; Cooper, Michael; Rodrigues, Andre

    2010-01-01

    Background Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. Methodology/Principal Findings Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens) and extended lifespans (10–20 years). In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells), and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. Conclusions/Significance Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants), an analog of artificial selection. PMID:20844760

  14. Merging ancient and modern DNA: extinct seabird taxon rediscovered in the North Tasman Sea.

    PubMed

    Steeves, Tammy E; Holdaway, Richard N; Hale, Marie L; McLay, Emma; McAllan, Ian A W; Christian, Margaret; Hauber, Mark E; Bunce, Michael

    2010-02-23

    Ancient DNA has revolutionized the way in which evolutionary biologists research both extinct and extant taxa, from the inference of evolutionary history to the resolution of taxonomy. Here, we present, to our knowledge, the first study to report the rediscovery of an 'extinct' avian taxon, the Tasman booby (Sula tasmani), using classical palaeontological data combined with ancient and modern DNA data. Contrary to earlier work, we show an overlap in size between fossil and modern birds in the North Tasman Sea (classified currently as S. tasmani and Sula dactylatra fullagari, respectively). In addition, we show that Holocene fossil birds have mitochondrial control region sequences that are identical to those found in modern birds. These results indicate that the Tasman booby is not an extinct taxon: S. dactylatra fullagari O'Brien & Davies, 1990 is therefore a junior synonym of Sula tasmani van Tets, Meredith, Fullagar & Davidson, 1988 and all North Tasman Sea boobies should be known as S. d. tasmani. In addition to reporting the rediscovery of an extinct avian taxon, our study highlights the need for researchers to be cognizant of multidisciplinary approaches to understanding taxonomy and past biodiversity.

  15. Evidence of taxon cycles in an Indo-Pacific passerine bird radiation (Aves: Pachycephala)

    PubMed Central

    Jønsson, Knud Andreas; Irestedt, Martin; Christidis, Les; Clegg, Sonya M.; Holt, Ben G.; Fjeldså, Jon

    2014-01-01

    Many insular taxa possess extraordinary abilities to disperse but may differ in their abilities to diversify and compete. While some taxa are widespread across archipelagos, others have disjunct (relictual) populations. These types of taxa, exemplified in the literature by selections of unrelated taxa, have been interpreted as representing a continuum of expansions and contractions (i.e. taxon cycles). Here, we use molecular data of 35 out of 40 species of the avian genus Pachycephala (including 54 out of 66 taxa in Pachycephala pectoralis (sensu lato), to assess the spatio-temporal evolution of the group. We also include data on species distributions, morphology, habitat and elevational ranges to test a number of predictions associated with the taxon-cycle hypothesis. We demonstrate that relictual species persist on the largest and highest islands across the Indo-Pacific, whereas recent archipelago expansions resulted in colonization of all islands in a region. For co-occurring island taxa, the earliest colonists generally inhabit the interior and highest parts of an island, with little spatial overlap with later colonists. Collectively, our data support the idea that taxa continuously pass through phases of expansions and contractions (i.e. taxon cycles). PMID:24403319

  16. Paroxetine Treatment of Problematic Pornography Use: A Case Series

    PubMed Central

    Gola, Mateusz; Potenza, Marc N.

    2016-01-01

    Background How best to conceptualize problematic pornography use (PPU) and intervene most effectively remain debated, with obsessive–compulsive disorder (OCD) and addiction frameworks. We investigated the efficacy of the serotonin-reuptake inhibitor paroxetine in combination with cognitive-behavioral therapy in the treatment of problematic pornography use (PPU). Case presentation Three heterosexual males with PPU were treated with cognitive-behavioral therapy and paroxetine. Frequency of pornography use, other sexual behaviors, and anxiety were assessed during treatment. Discussion Paroxetine treatment, although seemingly initially effective in reducing pornography use and anxiety, appeared related to new compulsive sexual behaviors after 3 months. Conclusions Paroxetine may hold promise for short-term reduction of PPU and related anxiety, but new potentially distressing sexual behaviors may emerge. The cases suggest that PPU may arise from multiple domains. We propose an explanation of the effects based on recent neuroscientific research on sexual behaviors and alcohol use. PMID:27440474

  17. Paroxetine Treatment of Problematic Pornography Use: A Case Series.

    PubMed

    Gola, Mateusz; Potenza, Marc N

    2016-09-01

    Background How best to conceptualize problematic pornography use (PPU) and intervene most effectively remain debated, with obsessive-compulsive disorder (OCD) and addiction frameworks. We investigated the efficacy of the serotonin-reuptake inhibitor paroxetine in combination with cognitive-behavioral therapy in the treatment of problematic pornography use (PPU). Case presentation Three heterosexual males with PPU were treated with cognitive-behavioral therapy and paroxetine. Frequency of pornography use, other sexual behaviors, and anxiety were assessed during treatment. Discussion Paroxetine treatment, although seemingly initially effective in reducing pornography use and anxiety, appeared related to new compulsive sexual behaviors after 3 months. Conclusions Paroxetine may hold promise for short-term reduction of PPU and related anxiety, but new potentially distressing sexual behaviors may emerge. The cases suggest that PPU may arise from multiple domains. We propose an explanation of the effects based on recent neuroscientific research on sexual behaviors and alcohol use.

  18. Cyberbullying, problematic internet use, and psychopathologic symptoms among Korean youth.

    PubMed

    Jung, Young-Eun; Leventhal, Bennett; Kim, Young Shin; Park, Tae Won; Lee, Sheen-Hoo; Lee, Myeongmi; Park, Seon Hee; Yang, Jong-Chul; Chung, Young-Chul; Chung, Sang-Keun; Park, Jong-Il

    2014-05-01

    To evaluate the associations between cyberbullying behaviors and problematic internet use, and to compare psychopathologic symptoms in victims, perpetrators, and victims-perpetrators of cyberbullying to those in youths who were not involved in cyberbullying. A total of 4531 youths (11-14 years of age) were recruited from elementary and middle schools. Among 4531 youths, 9.7% were involved in cyberbullying; 3.3% were only victims; 3.4% were only perpetrators; and 3.0% were victims-perpetrators. Cyberbullying behaviors were associated with problematic internet use as well as various psychopathologic symptoms. Depressive symptoms were associated with cyberbullying victimization, and rule-breaking behaviors and aggressive behaviors have relevance to cyberbullying perpetration. Greater attention needs to be paid to identify youths earlier who are involved in cyberbullying and prevent serious adverse consequences in them.

  19. Does Adolescent Weight Status Predict Problematic Substance Use Patterns?

    PubMed Central

    Lanza, H. Isabella; Grella, Christine E.; Chung, Paul J.

    2014-01-01

    Objectives To identify underlying patterns of cigarette smoking, alcohol use, and marijuana use in young adulthood, and ascertain whether adolescent over-weight or obesity status predicts problematic substance use patterns. Methods The study included 15,119 participants from the National Longitudinal Study of Adolescent Health (Add Health) at Wave 1 (11-19 years) and Wave 3 (18-26 years). Latent class analysis was conducted. Results Participants were classified into a Low Substance Use (35%), Regular Smokers (12%), High-risk Alcohol use (33%), or High Substance Use (20%) class. Over-weight/obese adolescents had a greater likelihood of belonging to the Regular Smokers class. Conclusions Overweight/obese adolescents are at higher risk of engaging in regular cigarette smoking without problematic alcohol or marijuana use. PMID:24933140

  20. Cyberbullying, Problematic Internet Use, and Psychopathologic Symptoms among Korean Youth

    PubMed Central

    Jung, Young-Eun; Leventhal, Bennett; Kim, Young Shin; Lee, Sheen-Hoo; Lee, Myeongmi; Park, Seon Hee; Yang, Jong-Chul; Chung, Young-Chul; Chung, Sang-Keun; Park, Jong-Il

    2014-01-01

    To evaluate the associations between cyberbullying behaviors and problematic internet use, and to compare psychopathologic symptoms in victims, perpetrators, and victims-perpetrators of cyberbullying to those in youths who were not involved in cyberbullying. A total of 4531 youths (11-14 years of age) were recruited from elementary and middle schools. Among 4531 youths, 9.7% were involved in cyberbullying; 3.3% were only victims; 3.4% were only perpetrators; and 3.0% were victims-perpetrators. Cyberbullying behaviors were associated with problematic internet use as well as various psychopathologic symptoms. Depressive symptoms were associated with cyberbullying victimization, and rule-breaking behaviors and aggressive behaviors have relevance to cyberbullying perpetration. Greater attention needs to be paid to identify youths earlier who are involved in cyberbullying and prevent serious adverse consequences in them. PMID:24719154

  1. Surgical Options in the Problematic Arteriovenous Haemodialysis Access.

    PubMed

    Forsythe, Rachael O; Chemla, Eric S

    2015-12-01

    The aim of the paper is to review surgical options in problematic arteriovenous haemodialysis access--in particular, to explore and discuss some surgical alternatives to interventional radiology in the case of failing, failed or complicated arteriovenous access. There is copious evidence to support endovascular techniques to treat non-maturation, stenosis, thrombosis and other complications of arteriovenous access. However, there may be times when the surgery-first approach might be a useful adjunct, alternative or even preferable, including the creation or revision of an anastomosis in the forearm, which may yield better patency rates than endovascular intervention. The creation and maintenance of haemodialysis access can be a complex process and the surgeon and the interventional radiologist should work closely together. The distinct roles of the surgeon and the interventional radiologist in the treatment of a problematic arteriovenous access remain debatable and the authors suggest a multidisciplinary team approach when planning treatment of access complications, which may require repeated interventions.

  2. Emotional Openness, problematic eating behaviours, and overweight in adolescents.

    PubMed

    Walther, Mireille; Hilbert, Anja

    2015-04-01

    Overweight, a common health condition in adolescence, has been linked with difficulties in emotional processing. This study investigates associations between emotional processing, conceptualised through the model of Emotional Openness (EO), problematic eating behaviours, including Eating in the Absence of Hunger and disinhibited eating, and overweight in adolescents. Several self-report instruments were completed by 160 youngsters (mean age: 14.36±0.61years) from the community, including 39 overweight and obese adolescents (24.5%). In girls, bootstrap analyses supported a mediating effect of restrained eating on the relation between three EO dimensions and body mass index percentile, in particular the communication of emotions, the cognitive-conceptual representation of emotions, and the perception of bodily indicator of emotions. No mediating effect was found in boys. These results have important implications for psychological weight management interventions, as they underline the relevance of work on emotional processing in order to reduce problematic eating behaviours.

  3. How Ants Drop Out: Ant Abundance on Tropical Mountains

    PubMed Central

    Longino, John T.; Branstetter, Michael G.; Colwell, Robert K.

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops. PMID:25098722

  4. Factors associated with problematic drug use among psychiatric outpatients 1

    PubMed Central

    Corradi-Webster, Clarissa Mendonça; Gherardi-Donato, Edilaine Cristina da Silva

    2016-01-01

    ABSTRACT Objective: to examine the factors associated with problematic drug use among psychiatric outpatients. Method: a cross-sectional study was carried out in two mental health services. Eligible individuals were patients of these mental health services, who used them within the data collection period. Instruments: standardized questionnaire with sociodemographic, social network, social harm, and clinical information; Alcohol, Smoking and Substance Involvement Screening Test; Barratt Impulsiveness Scale; Holmes and Rahe Stress Scale. Statistical analysis was performed using parametric statistics considering a significance level of p ≤ 0.05. Study participants were 243 patients, with 53.9% of these presenting problematic drug use. Results: the most important independent predictors of problematic drug use were marital status (OR = 0.491), religious practice (OR = 0.449), satisfaction with financial situation (OR = 0.469), having suffered discrimination (OR = 3.821) and practicing sports activities in previous 12 months (OR = 2.25). Conclusion: the variables found to be predictors were those related to the social context of the patient, there, it is recommended that mental health services valorize psychosocial actions, seeking to know the social support network of patients, their modes of socialization, their financial needs, and their experiences of life and suffering. PMID:27901217

  5. Macroevolutionary assembly of ant/plant symbioses: Pseudomyrmex ants and their ant-housing plants in the Neotropics

    PubMed Central

    Chomicki, Guillaume; Ward, Philip S.; Renner, Susanne S.

    2015-01-01

    Symbioses include some of the clearest cases of coevolution, but their origin, loss or reassembly with different partners can rarely be inferred. Here we use ant/plant symbioses involving three plant clades to investigate the evolution of symbioses. We generated phylogenies for the big-eyed arboreal ants (Pseudomyrmecinae), including 72% of their 286 species, as well as for five of their plant host groups, in each case sampling more than 61% of the species. We show that the ant-housing Vachellia (Mimosoideae) clade and its ants co-diversified for the past 5 Ma, with some species additionally colonized by younger plant-nesting ant species, some parasitic. An apparent co-radiation of ants and Tachigali (Caesalpinioideae) was followed by waves of colonization by the same ant clade, and subsequent occupation by a younger ant group. Wide crown and stem age differences between the ant-housing genus Triplaris (Polygonaceae) and its obligate ant inhabitants, and stochastic trait mapping, indicate that its domatium evolved earlier than the ants now occupying it, suggesting previous symbioses that dissolved. Parasitic ant species evolved from generalists, not from mutualists, and are younger than the mutualistic systems they parasitize. Our study illuminates the macroevolutionary assembly of ant/plant symbioses, which has been highly dynamic, even in very specialized systems. PMID:26582029

  6. Macroevolutionary assembly of ant/plant symbioses: Pseudomyrmex ants and their ant-housing plants in the Neotropics.

    PubMed

    Chomicki, Guillaume; Ward, Philip S; Renner, Susanne S

    2015-11-22

    Symbioses include some of the clearest cases of coevolution, but their origin, loss or reassembly with different partners can rarely be inferred. Here we use ant/plant symbioses involving three plant clades to investigate the evolution of symbioses. We generated phylogenies for the big-eyed arboreal ants (Pseudomyrmecinae), including 72% of their 286 species, as well as for five of their plant host groups, in each case sampling more than 61% of the species. We show that the ant-housing Vachellia (Mimosoideae) clade and its ants co-diversified for the past 5 Ma, with some species additionally colonized by younger plant-nesting ant species, some parasitic. An apparent co-radiation of ants and Tachigali (Caesalpinioideae) was followed by waves of colonization by the same ant clade, and subsequent occupation by a younger ant group. Wide crown and stem age differences between the ant-housing genus Triplaris (Polygonaceae) and its obligate ant inhabitants, and stochastic trait mapping, indicate that its domatium evolved earlier than the ants now occupying it, suggesting previous symbioses that dissolved. Parasitic ant species evolved from generalists, not from mutualists, and are younger than the mutualistic systems they parasitize. Our study illuminates the macroevolutionary assembly of ant/plant symbioses, which has been highly dynamic, even in very specialized systems.

  7. Ants medicate to fight disease.

    PubMed

    Bos, Nick; Sundström, Liselotte; Fuchs, Siiri; Freitak, Dalial

    2015-11-01

    Parasites are ubiquitous, and the ability to defend against these is of paramount importance. One way to fight diseases is self-medication, which occurs when an organism consumes biologically active compounds to clear, inhibit, or alleviate disease symptoms. Here, we show for the first time that ants selectively consume harmful substances (reactive oxygen species, ROS) upon exposure to a fungal pathogen, yet avoid these in the absence of infection. This increased intake of ROS, while harmful to healthy ants, leads to higher survival of exposed ants. The fact that ingestion of this substance carries a fitness cost in the absence of pathogens rules out compensatory diet choice as the mechanism, and provides evidence that social insects medicate themselves against fungal infection, using a substance that carries a fitness cost to uninfected individuals.

  8. Do aphids actively search for ant partners?

    PubMed

    Fischer, Christophe Y; Vanderplanck, Maryse; Lognay, Georges C; Detrain, Claire; Verheggen, François J

    2015-04-01

    The aphid-ant mutualistic relationships are not necessarily obligate for neither partners but evidence is that such interactions provide them strong advantages in terms of global fitness. While it is largely assumed that ants actively search for their mutualistic partners namely using volatile cues; whether winged aphids (i.e., aphids' most mobile form) are able to select ant-frequented areas had not been investigated so far. Ant-frequented sites would indeed offer several advantages for these aphids including a lower predation pressure through ant presence and enhanced chances of establishing mutuaslistic interactions with neighbor ant colonies. In the field, aphid colonies are often observed in higher densities around ant nests, which is probably linked to a better survival ensured by ants' services. Nevertheless, this could also result from a preferential establishment of winged aphids in ant-frequented areas. We tested this last hypothesis through different ethological assays and show that the facultative myrmecophilous black bean aphid, Aphis fabae L., does not orientate its search for a host plant preferentially toward ant-frequented plants. However, our results suggest that ants reduce the number of winged aphids leaving the newly colonized plant. Thus, ants involved in facultative myrmecophilous interactions with aphids appear to contribute to structure aphid populations in the field by ensuring a better establishment and survival of newly established colonies rather than by inducing a deliberate plant selection by aphid partners based on the proximity of ant colonies.

  9. A problematic early tetrapod from the Mississippian of Nevada

    USGS Publications Warehouse

    Thomson, K.S.; Shubin, N.S.; Poole, F.G.

    1998-01-01

    We report here the discovery of a new taxon of Paleozoic tetrapod from the Late Mississippian of Nevada (330-340 Ma). It has a unique vertebral column with principal centra having vertical anterior and posterior faces, ventrally incomplete accessory centra located antero-dorsally in each centrum, and enlarged presacral/sacral vertebrae. The head and pectoral girdle were not preserved but the large femur, robust pelvic girdle and enlarged sacral vertebrae possibly indicate a terrestrial mode of life. This new form significantly extends the western geographic range of known Mississippian tetrapods. It presents a mosaic of primitive and derived features, indicating that continued revision of traditional accounts of vertebral homology and the early diversifications of Paleozoic tetrapods will be necessary.

  10. Ant opsins: sequences from the Saharan silver ant and the carpenter ant.

    PubMed

    Popp, M P; Grisshammer, R; Hargrave, P A; Smith, W C

    1996-03-01

    cDNA clones encoding opsins from compound eyes of carpenter ant, Camponotus abdominalis, and Saharan silver ant, Cataglyphis bombycina, were isolated from cDNA libraries. The opsin cDNAs from each species code for deduced proteins with 378 amino acids which are 92% identical. Of the 30 amino acid differences between the two proteins, 13 are non-conservative. Eight of these non-conservative substitutions are within the membrane spanning domain. The presence of a potential Schiff-base counterion in helix III in both species suggests that these opsins are the protein moiety of the visible range pigments. When compared to all known opsins, these opsins are most similar to the opsin from preying mantis (76% identity at the amino acid level). Phyletic comparisons group the two ant opsins with the other arthropod long wavelength opsins.

  11. Cyatta abscondita: Taxonomy, Evolution, and Natural History of a New Fungus-Farming Ant Genus from Brazil

    PubMed Central

    Sosa-Calvo, Jeffrey; Schultz, Ted R.; Brandão, Carlos R. F.; Klingenberg, Christiana; Feitosa, Rodrigo M.; Rabeling, Christian; Bacci, Maurício; Lopes, Cauê T.; Vasconcelos, Heraldo L.

    2013-01-01

    Cyatta abscondita, a new genus and species of fungus-farming ant from Brazil, is described based on morphological study of more than 20 workers, two dealate gynes, one male, and two larvae. Ecological field data are summarized, including natural history, nest architecture, and foraging behavior. Phylogenetic analyses of DNA sequence data from four nuclear genes indicate that Cyatta abscondita is the distant sister taxon of the genus Kalathomyrmex, and that together they comprise the sister group of the remaining neoattine ants, an informal clade that includes the conspicuous and well-known leaf-cutter ants. Morphologically, Cyatta abscondita shares very few obvious character states with Kalathomyrmex. It does, however, possess a number of striking morphological features unique within the fungus-farming tribe Attini. It also shares morphological character states with taxa that span the ancestral node of the Attini. The morphology, behavior, and other biological characters of Cyatta abscondita are potentially informative about plesiomorphic character states within the fungus-farming ants and about the early evolution of ant agriculture. PMID:24260403

  12. Cyatta abscondita: taxonomy, evolution, and natural history of a new fungus-farming ant genus from Brazil.

    PubMed

    Sosa-Calvo, Jeffrey; Schultz, Ted R; Brandão, Carlos R F; Klingenberg, Christiana; Feitosa, Rodrigo M; Rabeling, Christian; Bacci, Maurício; Lopes, Cauê T; Vasconcelos, Heraldo L

    2013-01-01

    Cyatta abscondita, a new genus and species of fungus-farming ant from Brazil, is described based on morphological study of more than 20 workers, two dealate gynes, one male, and two larvae. Ecological field data are summarized, including natural history, nest architecture, and foraging behavior. Phylogenetic analyses of DNA sequence data from four nuclear genes indicate that Cyatta abscondita is the distant sister taxon of the genus Kalathomyrmex, and that together they comprise the sister group of the remaining neoattine ants, an informal clade that includes the conspicuous and well-known leaf-cutter ants. Morphologically, Cyatta abscondita shares very few obvious character states with Kalathomyrmex. It does, however, possess a number of striking morphological features unique within the fungus-farming tribe Attini. It also shares morphological character states with taxa that span the ancestral node of the Attini. The morphology, behavior, and other biological characters of Cyatta abscondita are potentially informative about plesiomorphic character states within the fungus-farming ants and about the early evolution of ant agriculture.

  13. Comparison of problematic internet and alcohol use and attachment styles among industrial workers in Korea.

    PubMed

    Shin, Sang-Eun; Kim, Nam-Seok; Jang, Eun-Young

    2011-11-01

    The objective of this article is to fully understand Internet addiction, we aimed to compare the attachment styles and psychopathologies associated with problematic Internet use with those related to alcohol use. Through the participation of 141 male participants, the present study assessed problematic Internet and alcohol use, attachment, psychopathology, and demographic data via the use of self-rating questionnaires. We explored the significant predictors among avoidant and anxious attachments, depression, anxiety, and phobia to explain problematic Internet and alcohol use. The results showed that anxious attachment, depression, and anxiety could explain problematic alcohol use. In contrast, both anxious and avoidant attachment as well as depression and phobia explained problematic Internet use. Additionally, depression moderated the effects of avoidant attachment on problematic Internet use. We demonstrated that the interaction of attachment and psychopathology predicts problematic Internet use originating from an earlier stage of life than that associated with problematic alcohol use.

  14. Ant Ecdysteroid Extraction and Radioimmunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecdysteroids are a group of steroid compounds present in many plant and invertebrate species. In arthropods, they function primarily as hormones involved in the regulation of molting. This protocol describes how to extract ecdysteroid hormones from ant specimens and subsequently quantify circulating...

  15. Ants, Wasps, and Bees (Hymenoptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stinging wasps, bees, and ants are a problem for farm workers, particularly at harvest when these insects are attracted to ripe fruits. Researchers at the USDA-ARS Yakima Agricultural Research Laboratory, Wapato, WA, together with personnel at Oral Roberts University compiled available information o...

  16. Optimal cue integration in ants

    PubMed Central

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-01-01

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy. PMID:26400741

  17. Optimal cue integration in ants.

    PubMed

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-10-07

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy.

  18. Using Ants To Investigate the Environment.

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2003-01-01

    Describes three inquiry-based activities designed for students to begin to understand complex environmental relationships in their own backyard. Includes investigations of ants, which allow students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenances, and increase student…

  19. Raves & rants about invasive crazy ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crazy ants” is a name that refers to various species of ants that are characterized by erratic, scurrying, or running, behavior when disturbed. Two of these species, the yellow crazy ant and the Caribbean or Rasberry [sic] crazy ant, are invasive with extremely large populations that inundate lands...

  20. Using Ants to Investigate the Environment

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2005-01-01

    The best place for students to begin to understand complex environmental relationships is in their own back yards. Doing investigations of ants allows students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenance, and increase their understanding of the environment and their…

  1. Evaluating and interpreting cross-taxon congruence: Potential pitfalls and solutions

    NASA Astrophysics Data System (ADS)

    Gioria, Margherita; Bacaro, Giovanni; Feehan, John

    2011-05-01

    Characterizing the relationship between different taxonomic groups is critical to identify potential surrogates for biodiversity. Previous studies have shown that cross-taxa relationships are generally weak and/or inconsistent. The difficulties in finding predictive patterns have often been attributed to the spatial and temporal scales of these studies and on the differences in the measure used to evaluate such relationships (species richness versus composition). However, the choice of the analytical approach used to evaluate cross-taxon congruence inevitably represents a major source of variation. Here, we described the use of a range of methods that can be used to comprehensively assess cross-taxa relationships. To do so, we used data for two taxonomic groups, wetland plants and water beetles, collected from 54 farmland ponds in Ireland. Specifically, we used the Pearson correlation and rarefaction curves to analyse patterns in species richness, while Mantel tests, Procrustes analysis, and co-correspondence analysis were used to evaluate congruence in species composition. We compared the results of these analyses and we described some of the potential pitfalls associated with the use of each of these statistical approaches. Cross-taxon congruence was moderate to strong, depending on the choice of the analytical approach, on the nature of the response variable, and on local and environmental conditions. Our findings indicate that multiple approaches and measures of community structure are required for a comprehensive assessment of cross-taxa relationships. In particular, we showed that selection of surrogate taxa in conservation planning should not be based on a single statistic expressing the degree of correlation in species richness or composition. Potential solutions to the analytical issues associated with the assessment of cross-taxon congruence are provided and the implications of our findings in the selection of surrogates for biodiversity are discussed.

  2. Possible problematic situations for the Europa cryorobotic mission

    NASA Astrophysics Data System (ADS)

    Kereszturi, A.

    We analyzed some possible dangerous and problematic situations which can take place during the descend of the Europa exlporer cryorobot inside the ice crust. Our work summarizing the followings: 1. consequences of the differences in the ice thickness and time of descend based on our and other workers' ice thickness estimations, 2. consequences of the tectonic movements in the crust during the descend of the cryorobot, 3. consequences of salt rich diapiric/cryomagmatic intrusions on the descend of the probe, 4. consequences of liquid water bodies inside the ice crust during the descend, 5. usage of the whole cryorobot below the ice crust as a robotic submarine.

  3. Political power beyond the State: problematics of government. 1992.

    PubMed

    Rose, Nikolas; Miller, Peter

    2010-01-01

    This paper sets out an approach to the analysis of political power in terms of problematics of government. It argues against an overvaluation of the 'problem of the State' in political debate and social theory. A number of conceptual tools are suggested for the analysis of the many and varied alliances between political and other authorities that seek to govern economic activity, social life and individual conduct. Modern political rationalities and governmental technologies are shown to be intrinsically linked to developments in knowledge and to the powers of expertise. The characteristics of liberal problematics of government are investigated, and it is argued that they are dependent upon technologies for 'governing at a distance', seeking to create locales, entities and persons able to operate a regulated autonomy. The analysis is exemplified through an investigation of welfarism as a mode of 'social' government. The paper concludes with a brief consideration of neo-liberalism which demonstrates that the analytical language structured by the philosophical opposition of state and civil society is unable to comprehend contemporary transformations in modes of exercise of political power.(1).

  4. The problematization of medical tourism: a critique of neoliberalism.

    PubMed

    Smith, Kristen

    2012-04-01

    The past two decades have seen the extensive privatisation and marketisation of health care in an ever reaching number of developing countries. Within this milieu, medical tourism is being promoted as a rational economic development strategy for some developing nations, and a makeshift solution to the escalating waiting lists and exorbitant costs of health care in developed nations. This paper explores the need to problematize medical tourism in order to move beyond one dimensional neoliberal discourses that have, to date, dominated the arena. In this problematization, the paper discusses a range of understandings and uses of the term 'medical tourism' and situates it within the context of the neoliberal economic development of health care internationally. Drawing on theory from critical medical anthropology and health and human rights perspectives, the paper critically analyzes the assumed independence between the medical tourism industry and local populations facing critical health issues, where social, cultural and economic inequities are widening in terms of access, cost and quality of health care. Finally, medical tourism is examined in the local context of India, critiquing the increasingly indistinct roles played by government and private sectors, whilst linking these shifts to global market forces.

  5. Monitoring the Impact of Solution Concepts within a Given Problematic

    NASA Astrophysics Data System (ADS)

    Cavallucci, Denis; Rousselot, François; Zanni, Cecilia

    It is acknowledged that one of the most critical issues facing today’s organizations concerns the substantial leaps required to methodologically structure innovation. Among other published work, some suggest that a complete rethinking of current practices is required. In this article, we propose a methodology aiming at providing controlled R&D choices based on a monitoring of the impact Solution Concepts provoke on a problematic situation. Initially this problematic situation is modeled in a graph form, namely a Problem Graph. It has the objective to assists R&D managers when choosing which activities to support and bring them concrete arguments to defend their choices. We postulate that by improving the robustness of such approaches we help deciders to switch from intuitive decisions (mostly built upon their past experiences, fear regarding risks, and awareness of the company’s level of acceptance of novelties) to thoroughly constructed inventive problem solving strategies. Our approach will be discussed using a computer application that illustrates our hypothesis after being tested in several industrial applications.

  6. Problematic Online Pornography Use: A Media Attendance Perspective.

    PubMed

    Sirianni, Joseph M; Vishwanath, Arun

    2016-01-01

    Since the rise of the popularity of the Internet, the accessibility of pornography has been a growing concern. One particular concern is the potential risk for addictive behaviors to occur as a result of the ease of viewing online pornographic material. The research presented herein explored online pornography addiction using a media attendance perspective, which allows media critics to examine the needs that people seek to fulfill from engaging with various media. Past studies that have used a media attendance perspective to explore media addiction, rephrased here as problematic media use, have done so using social cognitive theory and the concept of deficient self-regulation. Deficient self-regulation may be experienced by all media consumers and can range from normally impulsive media choices to pathological media choices which may result in detrimental life consequences. Borrowing from this, the current study reevaluated online pornography addiction using deficient self-regulation within a sociocognitive framework of media attendance. Results of our model show deficient self-regulation influences habitual online pornography consumption. Moreover, online pornography use motivated by social needs is perpetuated by deficient self-regulation and may lead to negative life consequences in some individuals. These findings contribute a new perspective and framework for understanding problematic online pornography use.

  7. Problematizing health coaching for chronic illness self-management.

    PubMed

    Howard, Lisa M; Ceci, Christine

    2013-09-01

    To address the growing costs associated with chronic illness care, many countries, both developed and developing, identify increased patient self-management or self-care as a focus of healthcare reform. Health coaching, an implementation strategy to support the shift to self-management, encourages patients to make lifestyle changes to improve the management of chronic illness. This practice differs from traditional models of health education because of the interactional dynamics between nurse and patient, and an orientation to care that ostensibly centres and empowers patients. The theoretical underpinnings of coaching reflect these differences, however in its application, the practices arranged around health coaching for chronic illness self-management reveal the social regulation and professional management of everyday life. This becomes especially problematic in contexts defined by economic constraint and government withdrawal from activities related to the 'care' of citizens. In this paper, we trace the development of health coaching as part of nursing practice and consider the implications of this practice as an emerging element of chronic illness self-management. Our purpose is to highlight health coaching as an approach intended to support patients with chronic illness and at the same time, problematize the tensions contained in (and by) this practice.

  8. [Biological basis of problematic internet use (PIN) and therapeutic implications].

    PubMed

    Bauernhofer, Kathrin; Papousek, Ilona; Fink, Andreas; Unterrainer, Human Friedrich; Weiss, Elisabeth M

    2015-01-01

    The repetitive excessive use of internet has led to an increasing number of reports about the negative consequences of overuse and is now viewed as an important public health issue, although the diagnosis of internet addiction remains problematic. Increasing knowledge about the neurobiological mechanism of behavioral addictions will promote future research and is essential for the development of specific and effective treatment. Growing evidence suggests that the neurobiological substrates and pathways of internet addiction resemble those of substance dependency and other forms of behavioral addictions. This paper reviews the current neuroimaging findings and genetic influencing factors for problematic internet use (PIN)/internet addiction. Recent evidence from neuro-scientific studies has pointed out that certain dysfunctions in the prefrontal cortex possibly driven by impaired dopamine neurotransmission are related to symptoms of internet addiction. Finally the literature on psychological and pharmacological interventions for internet addiction will be discussed. However, due to a lack of methodological sound treatment studies in this field it is currently impossible to recommend any evidence-based treatment of internet addiction.

  9. Wanting and liking: Separable components in problematic eating behavior?

    PubMed

    Polk, Sarah E; Schulte, Erica M; Furman, Celina R; Gearhardt, Ashley N

    2016-11-11

    Some individuals may have an addictive-like response to certain foods, possibly contributing to problematic eating. Highly processed foods, with added fats and/or refined carbohydrates, are suggested to be most associated with addictive-like eating. The incentive sensitization theory suggests that wanting (e.g. craving) may drive compulsive drug use rather than liking (e.g. enjoyment), but it is unknown whether highly processed foods elicit similar wanting and liking patterns as drugs of abuse, or whether individual differences exist. The current study examines the association of highly processed foods with craving and liking, and whether these relationships differ by food addiction symptomology, cognitive restraint, or body mass index (BMI). Participants (n = 216) reported craving and liking for 35 foods and completed the Yale Food Addiction Scale (YFAS) and Three Factor Eating Questionnaire (TFEQ). Highly processed foods were craved more overall. Craving of highly processed foods was predicted negatively by restraint and positively by YFAS score. Liking of highly processed foods was predicted negatively by restraint and positively by BMI. In conclusion, craving and liking appear distinct with respect to highly processed foods, and may be influenced by addictive-like eating, cognitive restraint, and BMI. This suggests that the incentive sensitization framework may also be relevant for problematic food consumption, especially for individuals reporting food addiction symptoms.

  10. Methods for Casting Subterranean Ant Nests

    PubMed Central

    Tschinkel, Walter R.

    2010-01-01

    The study of subterranean ant nests has been impeded by the difficulty of rendering their structures in visible form. Here, several different casting materials are shown to make perfect casts of the underground nests of ants. Each material (dental plaster, paraffin wax, aluminum, zinc) has advantages and limitations, which are discussed. Some of the materials allow the recovery of the ants entombed in the casts, allowing a census of the ants to be connected with features of their nest architecture. The necessary equipment and procedures are described in the hope that more researchers will study this very important aspect of ant natural history. PMID:20673073

  11. Delineating Species with DNA Barcodes: A Case of Taxon Dependent Method Performance in Moths

    PubMed Central

    Kekkonen, Mari; Mutanen, Marko; Kaila, Lauri; Nieminen, Marko; Hebert, Paul D. N.

    2015-01-01

    The accelerating loss of biodiversity has created a need for more effective ways to discover species. Novel algorithmic approaches for analyzing sequence data combined with rapidly expanding DNA barcode libraries provide a potential solution. While several analytical methods are available for the delineation of operational taxonomic units (OTUs), few studies have compared their performance. This study compares the performance of one morphology-based and four DNA-based (BIN, parsimony networks, ABGD, GMYC) methods on two groups of gelechioid moths. It examines 92 species of Finnish Gelechiinae and 103 species of Australian Elachistinae which were delineated by traditional taxonomy. The results reveal a striking difference in performance between the two taxa with all four DNA-based methods. OTU counts in the Elachistinae showed a wider range and a relatively low (ca. 65%) OTU match with reference species while OTU counts were more congruent and performance was higher (ca. 90%) in the Gelechiinae. Performance rose when only monophyletic species were compared, but the taxon-dependence remained. None of the DNA-based methods produced a correct match with non-monophyletic species, but singletons were handled well. A simulated test of morphospecies-grouping performed very poorly in revealing taxon diversity in these small, dull-colored moths. Despite the strong performance of analyses based on DNA barcodes, species delineated using single-locus mtDNA data are best viewed as OTUs that require validation by subsequent integrative taxonomic work. PMID:25849083

  12. Automatic Classification of a Taxon-Rich Community Recorded in the Wild

    PubMed Central

    Potamitis, Ilyas

    2014-01-01

    There is a rich literature on automatic species identification of a specific target taxon as regards various vocalizing animals. Research usually is restricted to specific species – in most cases a single one. It is only very recently that the number of monitored species has started to increase for certain habitats involving birds. Automatic acoustic monitoring has not yet been proven to be generic enough to scale to other taxa and habitats than the ones described in the original research. Although attracting much attention, the acoustic monitoring procedure is neither well established yet nor universally adopted as a biodiversity monitoring tool. Recently, the multi-instance multi-label framework on bird vocalizations has been introduced to face the obstacle of simultaneously vocalizing birds of different species. We build on this framework to integrate novel, image-based heterogeneous features designed to capture different aspects of the spectrum. We applied our approach to a taxon-rich habitat that included 78 birds, 8 insect species and 1 amphibian. This dataset constituted the Multi-label Bird Species Classification Challenge-NIPS 2013 where the proposed approach achieved an average accuracy of 91.25% on unseen data. PMID:24826989

  13. Quantifying Ant Activity Using Vibration Measurements

    PubMed Central

    Oberst, Sebastian; Baro, Enrique Nava; Lai, Joseph C. S.; Evans, Theodore A.

    2014-01-01

    Ant behaviour is of great interest due to their sociality. Ant behaviour is typically observed visually, however there are many circumstances where visual observation is not possible. It may be possible to assess ant behaviour using vibration signals produced by their physical movement. We demonstrate through a series of bioassays with different stimuli that the level of activity of meat ants (Iridomyrmex purpureus) can be quantified using vibrations, corresponding to observations with video. We found that ants exposed to physical shaking produced the highest average vibration amplitudes followed by ants with stones to drag, then ants with neighbours, illuminated ants and ants in darkness. In addition, we devised a novel method based on wavelet decomposition to separate the vibration signal owing to the initial ant behaviour from the substrate response, which will allow signals recorded from different substrates to be compared directly. Our results indicate the potential to use vibration signals to classify some ant behaviours in situations where visual observation could be difficult. PMID:24658467

  14. Quantifying ant activity using vibration measurements.

    PubMed

    Oberst, Sebastian; Baro, Enrique Nava; Lai, Joseph C S; Evans, Theodore A

    2014-01-01

    Ant behaviour is of great interest due to their sociality. Ant behaviour is typically observed visually, however there are many circumstances where visual observation is not possible. It may be possible to assess ant behaviour using vibration signals produced by their physical movement. We demonstrate through a series of bioassays with different stimuli that the level of activity of meat ants (Iridomyrmex purpureus) can be quantified using vibrations, corresponding to observations with video. We found that ants exposed to physical shaking produced the highest average vibration amplitudes followed by ants with stones to drag, then ants with neighbours, illuminated ants and ants in darkness. In addition, we devised a novel method based on wavelet decomposition to separate the vibration signal owing to the initial ant behaviour from the substrate response, which will allow signals recorded from different substrates to be compared directly. Our results indicate the potential to use vibration signals to classify some ant behaviours in situations where visual observation could be difficult.

  15. Taxon-specific responses of Southern Ocean diatoms to Fe enrichment revealed by synchrotron radiation FTIR microspectroscopy

    NASA Astrophysics Data System (ADS)

    Sackett, O.; Armand, L.; Beardall, J.; Hill, R.; Doblin, M.; Connelly, C.; Howes, J.; Stuart, B.; Ralph, P.; Heraud, P.

    2014-10-01

    Photosynthesis by marine diatoms contributes substantially to global biogeochemical cycling and ecosystem productivity. It is widely accepted that diatoms are extremely sensitive to changes in Fe availability, with numerous in situ experiments demonstrating rapid growth and increased export of elements (e.g. C, Si and Fe) from surface waters as a result of Fe addition. Less is known about the effects of Fe enrichment on the phenotypes of diatoms, such as associated changes in nutritional value - furthermore, data on taxon-specific responses are almost non-existent. Enhanced supply of nutrient-rich waters along the coast of the subantarctic Kerguelen Island provide a valuable opportunity to examine the responses of phytoplankton to natural Fe enrichment. Here we demonstrate the use of synchrotron radiation Fourier Transform Infrared (SR-FTIR) microspectroscopy to analyse changes in the macromolecular composition of diatoms collected along the coast and plateau of Kerguelen Island, Southern Ocean. SR-FTIR microspectroscopy enabled the analysis of individual diatom cells from mixed communities of field-collected samples, thereby providing insight into in situ taxon-specific responses in relation to changes in Fe availability. Phenotypic responses were taxon-specific in terms of intraspecific variability and changes in proteins, amino acids, phosphorylated molecules, silicate/silicic acid and carbohydrates. In contrast to some previous studies, silicate/silicic acid levels increased under Fe enrichment, in conjunction with increases in carbohydrate stores. The highly abundant taxon Fragilariopsis kerguelensis displayed a higher level of phenotypic plasticity than Pseudo-nitzschia spp., while analysis of the data pooled across all measured taxa showed different patterns in macromolecular composition compared to those for individual taxon. This study demonstrates that taxon-specific responses to Fe enrichment may not always be accurately reflected by bulk community

  16. Taxon-specific responses of Southern Ocean diatoms to Fe enrichment revealed by synchrotron radiation FTIR microspectroscopy

    NASA Astrophysics Data System (ADS)

    Sackett, O.; Armand, L.; Beardall, J.; Hill, R.; Doblin, M.; Connelly, C.; Howes, J.; Stuart, B.; Ralph, P.; Heraud, P.

    2014-05-01

    Photosynthesis by marine diatoms contributes substantially to global biogeochemical cycling and ecosystem productivity. It is widely accepted that diatoms are extremely sensitive to changes in Fe availability, with numerous in situ experiments demonstrating rapid growth and increased export of elements (e.g. C, Si and Fe) from surface waters as a result of Fe addition. Less is known about the effects of Fe enrichment on the phenotypes of diatoms, such as associated changes in nutritional value, furthermore data on taxon-specific responses is almost non-existent. Enhanced supply of nutrient-rich waters along the coast of the subantarctic Kerguelen Island provide a valuable opportunity to examine the responses of phytoplankton to natural Fe enrichment. Here we demonstrate the use of synchrotron radiation Fourier Transform Infrared (SR-FTIR) microspectroscopy to analyse changes in the macromolecular composition of diatoms collected along the coast and plateau of Kerguelen Island, Southern Ocean. SR-FTIR microspectroscopy enabled the analysis of individual diatom cells from mixed communities of field-collected samples, thereby providing insight into in situ taxon-specific responses in relation to changes in Fe availability. Phenotypic responses were taxon-specific in terms of intraspecific variability and changes in proteins, amino acids, phosphorylated molecules, silicate and carbohydrates. In contrast to some previous studies, silicate levels increased under Fe enrichment, in conjunction with increases in carbohydrate stores. The highly abundant taxon Fragilariopsis kerguelensis displayed a higher level of phenotypic plasticity than Pseudo-nitzschia spp., while analysis of the data pooled across all measured taxa showed different patterns in macromolecular composition compared to those for individual taxon. This study demonstrates that taxon-specific responses to Fe enrichment may not always be accurately reflected by bulk community measurements, highlighting the

  17. Problematic internet use and problematic online gaming are not the same: findings from a large nationally representative adolescent sample.

    PubMed

    Király, Orsolya; Griffiths, Mark D; Urbán, Róbert; Farkas, Judit; Kökönyei, Gyöngyi; Elekes, Zsuzsanna; Tamás, Domokos; Demetrovics, Zsolt

    2014-12-01

    There is an ongoing debate in the literature whether problematic Internet use (PIU) and problematic online gaming (POG) are two distinct conceptual and nosological entities or whether they are the same. The present study contributes to this question by examining the interrelationship and the overlap between PIU and POG in terms of sex, school achievement, time spent using the Internet and/or online gaming, psychological well-being, and preferred online activities. Questionnaires assessing these variables were administered to a nationally representative sample of adolescent gamers (N=2,073; Mage=16.4 years, SD=0.87; 68.4% male). Data showed that Internet use was a common activity among adolescents, while online gaming was engaged in by a considerably smaller group. Similarly, more adolescents met the criteria for PIU than for POG, and a small group of adolescents showed symptoms of both problem behaviors. The most notable difference between the two problem behaviors was in terms of sex. POG was much more strongly associated with being male. Self-esteem had low effect sizes on both behaviors, while depressive symptoms were associated with both PIU and POG, affecting PIU slightly more. In terms of preferred online activities, PIU was positively associated with online gaming, online chatting, and social networking, while POG was only associated with online gaming. Based on our findings, POG appears to be a conceptually different behavior from PIU, and therefore the data support the notion that Internet Addiction Disorder and Internet Gaming Disorder are separate nosological entities.

  18. Problematizing Disciplinarity, Transdisciplinary Problematics.

    PubMed

    Osborne, Peter

    2015-09-01

    This article situates current debates about transdisciplinarity within the deeper history of academic disciplinarity, in its difference from the notions of inter- and multi-disciplinarity. It offers a brief typology and history of established conceptions of transdisciplinarity within science and technology studies. It then goes on to raise the question of the conceptual structure of transdisciplinary generality in the humanities, with respect to the incorporation of the 19th- and 20th-century German and French philosophical traditions into the anglophone humanities, under the name of 'theory'. It identifies two distinct - dialectical and anti-dialectical, or dialectical and transversal - transdisciplinary trajectories. It locates the various contributions to the special issue of which it is the introduction within this conceptual field, drawing attention to the distinct contribution of the French debates about structuralism and its aftermath - those by Serres, Foucault, Derrida, Guattari and Latour, in particular. It concludes with an appendix on Foucault's place within current debates about disciplinarity and academic disciplines.

  19. Problematizing Disciplinarity, Transdisciplinary Problematics

    PubMed Central

    2015-01-01

    This article situates current debates about transdisciplinarity within the deeper history of academic disciplinarity, in its difference from the notions of inter- and multi-disciplinarity. It offers a brief typology and history of established conceptions of transdisciplinarity within science and technology studies. It then goes on to raise the question of the conceptual structure of transdisciplinary generality in the humanities, with respect to the incorporation of the 19th- and 20th-century German and French philosophical traditions into the anglophone humanities, under the name of ‘theory’. It identifies two distinct – dialectical and anti-dialectical, or dialectical and transversal – transdisciplinary trajectories. It locates the various contributions to the special issue of which it is the introduction within this conceptual field, drawing attention to the distinct contribution of the French debates about structuralism and its aftermath – those by Serres, Foucault, Derrida, Guattari and Latour, in particular. It concludes with an appendix on Foucault’s place within current debates about disciplinarity and academic disciplines. PMID:26456992

  20. Introduced fire ants can exclude native ants from critical mutualist-provided resources.

    PubMed

    Wilder, Shawn M; Barnum, Thomas R; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

    2013-05-01

    Animals frequently experience resource imbalances in nature. For ants, one resource that may be particularly valuable for both introduced and native species is high-carbohydrate honeydew from hemipteran mutualists. We conducted field and laboratory experiments: (1) to test if red imported fire ants (Solenopsis invicta) competed with native ants for access to mutualisms with aphids, and (2) to quantify the effects of aphid honeydew presence or absence on colony growth of native ants. We focused on native dolichoderine ants (Formicidae, Dolichoderinae) because they are abundant ants that have omnivorous diets that frequently include mutualist-provided carbohydrates. At two sites in the southeastern US, native dolichoderine ants were far less frequent, and fire ants more frequent, at carbohydrate baits than would be expected based on their frequency in pitfall traps. A field experiment confirmed that a native ant species, Dorymyrmex bureni, was only found tending aphids when populations of S. invicta were suppressed. In the laboratory, colonies of native dolichoderine ants with access to both honeydew and insect prey had twice as many workers and over twice as much brood compared to colonies fed only ad libitum insect prey. Our results provide the first experimental evidence that introduced ants compete for access to mutualist-provided carbohydrates with native ants and that these carbohydrates represent critical resources for both introduced and native ants. These results challenge traditional paradigms of arthropod and ant nutrition and contribute to growing evidence of the importance of nutrition in mediating ecological interactions.

  1. Temperament Dispositions, Problematic Eating Behaviours and Overweight in Adolescents.

    PubMed

    Walther, Mireille; Hilbert, Anja

    2016-01-01

    Obesity, a common health condition in adolescence leading to severe medical complications, is assumed to be influenced by temperament factors. This paper investigates associations between reactive and regulative temperament, problematic eating behaviours and excess weight. Several self-report instruments were completed by 130 adolescents (mean age 14.13 ± 0.61 years), including 27 overweight and obese individuals (20.8%). Bootstrap analysis revealed a mediating effect of restrained eating on the relation between reactive temperament and body mass index percentile, which differed according to gender: Restrained eating, which predicted weight gain, was more present in girls having a higher sensitivity to reward and in boys showing a higher sensitivity to punishment. No effect of regulative temperament was found. These results have important implications for weight management programmes, as they suggest that reducing restrained eating by working on temperament may help to control weight.

  2. Quality of interpersonal relationships and problematic Internet use in adolescence.

    PubMed

    Milani, Luca; Osualdella, Dania; Di Blasio, Paola

    2009-12-01

    International literature has identified a stable correlation between problems in the sphere of adolescents' personal relationships and potential Internet dependence. The objective of this research is to verify in an Italian context the relationship among problematic Internet use (PIU), the quality of interpersonal relationships, and the cognitive strategies habitually used by adolescents to face daily problems. The participants in the research were 98 adolescents ages 14 to 19 (M = 16.28 years). The following instruments were administered to the participants: the Internet Addiction Test (IAT), the Test of Interpersonal Relationships (TRI); and the Children's Coping Strategies Checklist (CCSC). Parents of the participants were administered the Child Behavior Checklist (CBCL). Of the participants, 36.7% showed signs of PIU. These adolescents use the Internet for many hours per week; most utilize dysfunctional coping strategies and show worse interpersonal relations than peers who do not show signs of PIU.

  3. The current dialogue between phenomenology and psychiatry: a problematic misunderstanding.

    PubMed

    Abettan, Camille

    2015-11-01

    A revival of the dialogue between phenomenology and psychiatry currently takes place in the best international journals of psychiatry. In this article, we analyse this revival and the role given to phenomenology in this context. Although this dialogue seems at first sight interesting, we show that it is problematic. It leads indeed to use phenomenology in a special way, transforming it into a discipline dealing with empirical facts, so that what is called "phenomenology" has finally nothing to do with phenomenology. This so-called phenomenology tallies however with what we have always called semiology. We try to explain the reasons why phenomenology is misused in that way. In our view, this transformation of phenomenology into an empirical and objectifying discipline is explained by the role attributed to phenomenology by contemporary authors, which is to solve the problems raised by the Diagnostic and Statistical Manual of Mental Disorders.

  4. Measuring and analyzing the causes of problematic Internet use.

    PubMed

    Chiang, I-Ping; Su, Yung-Hsiang

    2012-11-01

    Since Internet surfing became a daily activity, people have changed their behavior. This research analyzes the causes of problematic Internet use through an online survey, where 1,094 samples were collected. Based on the results of structural equation modeling analysis, the following conclusions are reached: First, novelty, security, and efficiency increase users' online trust. Second, information and efficiency enhance users' sharing and anonymity online. Third, greater trust in Internet environments leads to an increase in a user's cognitive bias toward online behavioral responsibility and Internet addiction. Fourth, a user's attitude toward online sharing further increases the cognitive bias toward online copyright. Fifth, a user's attitude toward anonymity increases cognitive bias toward online copyright, online behavioral responsibility, and deepens Internet addiction.

  5. At-Risk/Problematic Shopping and Gambling in Adolescence.

    PubMed

    Yip, Sarah W; Mei, Songli; Pilver, Corey E; Steinberg, Marvin A; Rugle, Loreen J; Krishnan-Sarin, Suchitra; Hoff, Rani A; Potenza, Marc N

    2015-12-01

    Elevated levels of both pathological gambling (PG) and problem shopping (PS) have been reported among adolescents, and each is associated with a range of other negative health/functioning measures. However, relationships between PS and PG, particularly during adolescence, are not well understood. In this study, we explored the relationship between different levels of problem-gambling severity and health/functioning characteristics, gambling-related social experiences, gambling behaviors and motivations among adolescents with and without at-risk/problematic shopping (ARPS). Survey data from Connecticut high school students (n = 2,100) were analyzed using bivariate analyses and logistic regression modeling. Although at-risk/problematic gambling (ARPG) was not increased among adolescents with ARPS, adolescents with ARPG (vs non-gamblers) were more likely to report having experienced a growing tension or anxiety that could only be relieved by shopping and missing other obligations due to shopping. In comparison to the non-ARPS group, a smaller proportion of respondents in the ARPS group reported paid part-time employment, whereas a greater proportion of respondents reported excessive gambling by peers and feeling concerned over the gambling of a close family member. In general, similar associations between problem-gambling severity and measures of health/functioning and gambling-related behaviors and motivations were observed across ARPS and non-ARPS adolescents. However, associations were weaker among ARPS adolescents for several variables: engagement in extracurricular activities, alcohol and caffeine use and gambling for financial reasons. These findings suggest a complex relationship between problem-gambling severity and ARPS. They highlight the importance of considering co-occurring risk behaviors such as ARPS when treating adolescents with at-risk/problem gambling.

  6. At-risk/problematic shopping and gambling in adolescence

    PubMed Central

    Pilver, Corey E.; Steinberg, Marvin A.; Rugle, Loreen J.; Krishnan-Sarin, Suchitra; Hoff, Rani A.; Potenza, Marc N.

    2016-01-01

    Elevated levels of both pathological gambling (PG) and problem shopping (PS) have been reported among adolescents, and each is associated with a range of other negative health/functioning measures. However, relationships between PS and PG, particularly during adolescence, are not well understood. In this study, we explored the relationship between different levels of problem-gambling severity and health/functioning characteristics, gambling-related social experiences, gambling behaviors and motivations among adolescents with and without at-risk/problematic shopping (ARPS). Survey data from Connecticut high school students (n=2,100) were analyzed using bivariate analyses and logistic regression modeling. Although at-risk/problematic gambling (ARPG) was not increased among adolescents with ARPS, adolescents with ARPG (versus non-gamblers) were more likely to report having experienced a growing tension or anxiety that could only be relieved by shopping and missing other obligations due to shopping. In comparison to the non-ARPS group, a smaller proportion of respondents in the ARPS group reported paid part-time employment, whereas a greater proportion of respondents reported excessive gambling by peers and feeling concerned over the gambling of a close family member. In general, similar associations between problem-gambling severity and measures of health/functioning and gambling-related behaviors and motivations were observed across ARPS and non-ARPS adolescents. However, associations were weaker among ARPS adolescents for several variables: engagement in extracurricular activities, alcohol and caffeine use and gambling for financial reasons. These findings suggest a complex relationship between problem-gambling severity and ARPS. They highlight the importance of considering co-occurring risk behaviors such as ARPS when treating adolescents with at-risk/problem gambling. PMID:25117852

  7. Fire ant-detecting canines: a complementary method in detecting red imported fire ants.

    PubMed

    Lin, Hui-Min; Chi, Wei-Lien; Lin, Chung-Chi; Tseng, Yu-Ching; Chen, Wang-Ting; Kung, Yu-Ling; Lien, Yi-Yang; Chen, Yang-Yuan

    2011-02-01

    In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment.

  8. Ants on plants: a meta-analysis of the role of ants as plant biotic defenses.

    PubMed

    Rosumek, Felix B; Silveira, Fernando A O; de S Neves, Frederico; de U Barbosa, Newton P; Diniz, Livia; Oki, Yumi; Pezzini, Flavia; Fernandes, G Wilson; Cornelissen, Tatiana

    2009-06-01

    We reviewed the evidence on the role of ants as plant biotic defenses, by conducting meta-analyses for the effects of experimental removal of ants on plant herbivory and fitness with data pooled from 81 studies. Effects reviewed were plant herbivory, herbivore abundance, hemipteran abundance, predator abundance, plant biomass and reproduction in studies where ants were experimentally removed (n = 273 independent comparisons). Ant removal exhibited strong effects on herbivory rates, as plants without ants suffered almost twice as much damage and exhibited 50% more herbivores than plants with ants. Ants also influenced several parameters of plant fitness, as plants without ants suffered a reduction in biomass (-23.7%), leaf production (-51.8%), and reproduction (-24.3%). Effects were much stronger in tropical regions compared to temperate ones. Tropical plants suffered almost threefold higher herbivore damage than plants from temperate regions and exhibited three times more herbivores. Ant removal in tropical plants resulted in a decrease in plant fitness of about 59%, whereas in temperate plants this reduction was not statistically significant. Ant removal effects were also more important in obligate ant-plants (=myrmecophytes) compared to plants exhibiting facultative relationships with hemiptera or those plants with extrafloral nectaries and food bodies. When only tropical plants were considered and the strength of the association between ants and plants taken into account, plants with obligate association with ants exhibited almost four times higher herbivory compared to plants with facultative associations with ants, but similar reductions in plant reproduction. The removal of a single ant species increased plant herbivory by almost three times compared to the removal of several ant species. Altogether, these results suggest that ants do act as plant biotic defenses, but the effects of their presence are more pronounced in tropical systems, especially in

  9. Statoviruses, A novel taxon of RNA viruses present in the gastrointestinal tracts of diverse mammals.

    PubMed

    Janowski, Andrew B; Krishnamurthy, Siddharth R; Lim, Efrem S; Zhao, Guoyan; Brenchley, Jason M; Barouch, Dan H; Thakwalakwa, Chrissie; Manary, Mark J; Holtz, Lori R; Wang, David

    2017-04-01

    Next-generation sequencing has expanded our understanding of the viral populations that constitute the mammalian virome. We describe a novel taxon of viruses named Statoviruses, for Stool associated Tombus-like viruses, present in multiple metagenomic datasets. These viruses define a novel clade that is phylogenetically related to the RNA virus families Tombusviridae and Flaviviridae. Five distinct statovirus types were identified in human, macaque, mouse, and cow gastrointestinal tract samples. The prototype genome, statovirus A, was frequently identified in macaque stool samples from multiple geographically distinct cohorts. Another genome, statovirus C1, was discovered in a stool sample from a human child with fever, cough, and rash. Further experimental data will clarify whether these viruses are infectious to mammals or if they originate from another source present in the mammalian gastrointestinal tract.

  10. An environmental bacterial taxon with a large and distinct metabolic repertoire.

    PubMed

    Wilson, Micheal C; Mori, Tetsushi; Rückert, Christian; Uria, Agustinus R; Helf, Maximilian J; Takada, Kentaro; Gernert, Christine; Steffens, Ursula A E; Heycke, Nina; Schmitt, Susanne; Rinke, Christian; Helfrich, Eric J N; Brachmann, Alexander O; Gurgui, Cristian; Wakimoto, Toshiyuki; Kracht, Matthias; Crüsemann, Max; Hentschel, Ute; Abe, Ikuro; Matsunaga, Shigeki; Kalinowski, Jörn; Takeyama, Haruko; Piel, Jörn

    2014-02-06

    Cultivated bacteria such as actinomycetes are a highly useful source of biomedically important natural products. However, such 'talented' producers represent only a minute fraction of the entire, mostly uncultivated, prokaryotic diversity. The uncultured majority is generally perceived as a large, untapped resource of new drug candidates, but so far it is unknown whether taxa containing talented bacteria indeed exist. Here we report the single-cell- and metagenomics-based discovery of such producers. Two phylotypes of the candidate genus 'Entotheonella' with genomes of greater than 9 megabases and multiple, distinct biosynthetic gene clusters co-inhabit the chemically and microbially rich marine sponge Theonella swinhoei. Almost all bioactive polyketides and peptides known from this animal were attributed to a single phylotype. 'Entotheonella' spp. are widely distributed in sponges and belong to an environmental taxon proposed here as candidate phylum 'Tectomicrobia'. The pronounced bioactivities and chemical uniqueness of 'Entotheonella' compounds provide significant opportunities for ecological studies and drug discovery.

  11. 'Candidatus Phytoplasma hispanicum', a novel taxon associated with Mexican periwinkle virescence disease of Catharanthus roseus.

    PubMed

    Davis, Robert E; Harrison, Nigel A; Zhao, Yan; Wei, Wei; Dally, Ellen L

    2016-09-01

    Mexican periwinkle virescence (MPV) phytoplasma was originally discovered in diseased plants of Madagascar periwinkle (Catharanthus roseus) in Yucatán, Mexico. On the basis of results from RFLP analysis of PCR-amplified 16S rRNA gene sequences, strain MPV was previously classified as the first known member of phytoplasma group 16SrXIII, and a new subgroup (16SrXIII-A) was established to accommodate MPV phytoplasma. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain MPV represents a lineage distinct from previously described 'CandidatusPhytoplasma' species. Nucleotide sequence alignments revealed that strain MPV shared less than 97.5 % 16S rRNA gene sequence similarity with all previously described 'Ca.Phytoplasma' species. Based on unique properties of the DNA, we propose recognition of Mexican periwinkle virescence phytoplasma strain MPV as representative of a novel taxon, 'CandidatusPhytoplasma hispanicum'.

  12. Macrochaete gen. nov. (Nostocales, Cyanobacteria), a taxon morphologically and molecularly distinct from Calothrix.

    PubMed

    Berrendero Gómez, Esther; Johansen, Jeffrey R; Kaštovský, Jan; Bohunická, Markéta; Čapková, Kateřina

    2016-08-01

    Historically, the genus Calothrix included all noncolonial, tapered, heterocytous filaments within the cyanobacteria. However, recent molecular phylogenies show that "Calothrix" defined in this sense represents five distinct clades. The type species of Calothrix is marine, with solitary basal heterocytes, no akinetes, and distal ends tapering abruptly into short hairs. We examined the morphology and phylogeny of 45 tapering cyanobacteria in the Rivulariaceae, including freshwater and marine representatives of both Calothrix (35 strains) and its sister taxon Rivularia (10 strains). The marine Calothrix fall into two lineages, but we lack the generitype and so cannot identify the clade corresponding to the type species. The freshwater and soil Calothrix fall into the C. parietina clade and are characterized by having a basal heterocyte, no akinetes, and gradual tapering-but not into a long hyaline hair. Macrochaete gen. nov. is a freshwater taxon sister to the Calothrix lineages but clearly separated from Rivularia. The species in this genus differ morphologically from Calothrix by their ability to produce two heteromorphic basal heterocytes and specific secondary structures of the 16S-23S ITS. An additional feature present in most species is the presence of a distal, long hyaline hair, but this character has incomplete penetrance due to its expression only under specific environmental conditions (low phosphate), and in one species appears to be lost. We recognize three species: M. psychrophila (type species) from cold environments (high mountains, Antarctica), M. santannae from wet walls of subtropical South America, and M. lichenoides, a phycobiont of lichens from Europe.

  13. Development of taxon-specific sequences of common wheat for the detection of genetically modified wheat.

    PubMed

    Iida, Mayu; Yamashiro, Satomi; Yamakawa, Hirohito; Hayakawa, Katsuyuki; Kuribara, Hideo; Kodama, Takashi; Furui, Satoshi; Akiyama, Hiroshi; Maitani, Tamio; Hino, Akihiro

    2005-08-10

    Qualitative and quantitative Polymerase Chain Reaction (PCR) systems aimed at the specific detection and quantification of common wheat DNA are described. Many countries have issued regulations to label foods that include genetically modified organisms (GMOs). PCR technology is widely recognized as a reliable and useful technique for the qualitative and quantitative detection of GMOs. Detection methods are needed to amplify a target GM gene, and the amplified results should be compared with those of the corresponding taxon-specific reference gene to obtain reliable results. This paper describes the development of a specific DNA sequence in the waxy-D1 gene for common wheat (Triticum aestivum L.) and the design of a specific primer pair and TaqMan probe on the waxy-D1 gene for PCR analysis. The primers amplified a product (Wx012) of 102 bp. It is indicated that the Wx012 DNA sequence is specific to common wheat, showing homogeneity in qualitative PCR results and very similar quantification accuracy along 19 distantly related common wheat varieties. In Southern blot and real-time PCR analyses, this sequence showed either a single or a low number of copy genes. In addition, by qualitative and quantitative PCR using wx012 primers and a wx012-T probe, the limits of detection of the common wheat genome were found to be about 15 copies, and the reproducibility was reliable. In consequence, the PCR system using wx012 primers and wx012-T probe is considered to be suitable for use as a common wheat-specific taxon-specific reference gene in DNA analyses, including GMO tests.

  14. On the Complexity of the Saccharomyces bayanus Taxon: Hybridization and Potential Hybrid Speciation

    PubMed Central

    Pérez-Través, Laura; Lopes, Christian A.; Querol, Amparo; Barrio, Eladio

    2014-01-01

    Although the genus Saccharomyces has been thoroughly studied, some species in the genus has not yet been accurately resolved; an example is S. bayanus, a taxon that includes genetically diverse lineages of pure and hybrid strains. This diversity makes the assignation and classification of strains belonging to this species unclear and controversial. They have been subdivided by some authors into two varieties (bayanus and uvarum), which have been raised to the species level by others. In this work, we evaluate the complexity of 46 different strains included in the S. bayanus taxon by means of PCR-RFLP analysis and by sequencing of 34 gene regions and one mitochondrial gene. Using the sequence data, and based on the S. bayanus var. bayanus reference strain NBRC 1948, a hypothetical pure S. bayanus was reconstructed for these genes that showed alleles with similarity values lower than 97% with the S. bayanus var. uvarum strain CBS 7001, and of 99–100% with the non S. cerevisiae portion in S. pastorianus Weihenstephan 34/70 and with the new species S. eubayanus. Among the S. bayanus strains under study, different levels of homozygosity, hybridization and introgression were found; however, no pure S. bayanus var. bayanus strain was identified. These S. bayanus hybrids can be classified into two types: homozygous (type I) and heterozygous hybrids (type II), indicating that they have been originated by different hybridization processes. Therefore, a putative evolutionary scenario involving two different hybridization events between a S. bayanus var. uvarum and unknown European S. eubayanus-like strains can be postulated to explain the genomic diversity observed in our S. bayanus var. bayanus strains. PMID:24705561

  15. On the complexity of the Saccharomyces bayanus taxon: hybridization and potential hybrid speciation.

    PubMed

    Pérez-Través, Laura; Lopes, Christian A; Querol, Amparo; Barrio, Eladio

    2014-01-01

    Although the genus Saccharomyces has been thoroughly studied, some species in the genus has not yet been accurately resolved; an example is S. bayanus, a taxon that includes genetically diverse lineages of pure and hybrid strains. This diversity makes the assignation and classification of strains belonging to this species unclear and controversial. They have been subdivided by some authors into two varieties (bayanus and uvarum), which have been raised to the species level by others. In this work, we evaluate the complexity of 46 different strains included in the S. bayanus taxon by means of PCR-RFLP analysis and by sequencing of 34 gene regions and one mitochondrial gene. Using the sequence data, and based on the S. bayanus var. bayanus reference strain NBRC 1948, a hypothetical pure S. bayanus was reconstructed for these genes that showed alleles with similarity values lower than 97% with the S. bayanus var. uvarum strain CBS 7001, and of 99-100% with the non S. cerevisiae portion in S. pastorianus Weihenstephan 34/70 and with the new species S. eubayanus. Among the S. bayanus strains under study, different levels of homozygosity, hybridization and introgression were found; however, no pure S. bayanus var. bayanus strain was identified. These S. bayanus hybrids can be classified into two types: homozygous (type I) and heterozygous hybrids (type II), indicating that they have been originated by different hybridization processes. Therefore, a putative evolutionary scenario involving two different hybridization events between a S. bayanus var. uvarum and unknown European S. eubayanus-like strains can be postulated to explain the genomic diversity observed in our S. bayanus var. bayanus strains.

  16. Taxon interactions control the distributions of cryoconite bacteria colonizing a High Arctic ice cap.

    PubMed

    Gokul, Jarishma K; Hodson, Andrew J; Saetnan, Eli R; Irvine-Fynn, Tristram D L; Westall, Philippa J; Detheridge, Andrew P; Takeuchi, Nozomu; Bussell, Jennifer; Mur, Luis A J; Edwards, Arwyn

    2016-08-01

    Microbial colonization of glacial ice surfaces incurs feedbacks which affect the melting rate of the ice surface. Ecosystems formed as microbe-mineral aggregates termed cryoconite locally reduce ice surface albedo and represent foci of biodiversity and biogeochemical cycling. Consequently, greater understanding the ecological processes in the formation of functional cryoconite ecosystems upon glacier surfaces is sought. Here, we present the first bacterial biogeography of an ice cap, evaluating the respective roles of dispersal, environmental and biotic filtration occurring at local scales in the assembly of cryoconite microbiota. 16S rRNA gene amplicon semiconductor sequencing of cryoconite colonizing a Svalbard ice cap coupled with digital elevation modelling of physical parameters reveals the bacterial community is dominated by a ubiquitous core of generalist taxa, with evidence for a moderate pairwise distance-decay relationship. While geographic position and melt season duration are prominent among environmental predictors of community structure, the core population of taxa appears highly influential in structuring the bacterial community. Taxon co-occurrence network analysis reveals a highly modular community structured by positive interactions with bottleneck taxa, predominantly Actinobacteria affiliated to isolates from soil humus. In contrast, the filamentous cyanobacterial taxon (assigned to Leptolyngbya/Phormidesmis pristleyi) which dominates the community and binds together granular cryoconite are poorly connected to other taxa. While our study targeted one ice cap, the prominent role of generalist core taxa with close environmental relatives across the global cryosphere indicate discrete roles for cosmopolitan Actinobacteria and Cyanobacteria as respective keystone taxa and ecosystem engineers of cryoconite ecosystems colonizing ice caps.

  17. Problematic Internet Use and Problematic Online Gaming Are Not the Same: Findings from a Large Nationally Representative Adolescent Sample

    PubMed Central

    Griffiths, Mark D.; Urbán, Róbert; Farkas, Judit; Kökönyei, Gyöngyi; Elekes, Zsuzsanna; Tamás, Domokos; Demetrovics, Zsolt

    2014-01-01

    Abstract There is an ongoing debate in the literature whether problematic Internet use (PIU) and problematic online gaming (POG) are two distinct conceptual and nosological entities or whether they are the same. The present study contributes to this question by examining the interrelationship and the overlap between PIU and POG in terms of sex, school achievement, time spent using the Internet and/or online gaming, psychological well-being, and preferred online activities. Questionnaires assessing these variables were administered to a nationally representative sample of adolescent gamers (N=2,073; Mage=16.4 years, SD=0.87; 68.4% male). Data showed that Internet use was a common activity among adolescents, while online gaming was engaged in by a considerably smaller group. Similarly, more adolescents met the criteria for PIU than for POG, and a small group of adolescents showed symptoms of both problem behaviors. The most notable difference between the two problem behaviors was in terms of sex. POG was much more strongly associated with being male. Self-esteem had low effect sizes on both behaviors, while depressive symptoms were associated with both PIU and POG, affecting PIU slightly more. In terms of preferred online activities, PIU was positively associated with online gaming, online chatting, and social networking, while POG was only associated with online gaming. Based on our findings, POG appears to be a conceptually different behavior from PIU, and therefore the data support the notion that Internet Addiction Disorder and Internet Gaming Disorder are separate nosological entities. PMID:25415659

  18. Problems with the claim of ecotype and taxon status of the wolf in the Great Lakes region

    USGS Publications Warehouse

    Cronin, Matthew A.; Mech, L. David

    2009-01-01

    Koblmuller et al. (2009) analysed molecular genetic data of the wolf in the Great Lakes (GL) region of the USA and concluded that the animal was a unique ecotype of grey wolf and that genetic data supported the population as a discrete wolf taxon. However, some of the literature that the researchers used to support their position actually did not, and additional confusion arises from indefinite use of terminology. Herein, we discuss the problems with designation of a wolf population as a taxon or ecotype without proper definition and assessment of criteria.

  19. Path integration in desert ants, Cataglyphis fortis

    PubMed Central

    Müller, Martin; Wehner, Rüdiger

    1988-01-01

    Foraging desert ants, Cataglyphis fortis, continually keep track of their own posotions relative to home— i.e., integrate their tortuous outbound routes and return home along straight (inbound) routes. By experimentally manipulating the ants' outbound trajectories we show that the ants solve this path integration problem not by performing a true vector summation (as a human navigator does) but by employing a computationally simple approximation. This approximation is characterized by small, but systematic, navigational errors that helped us elucidate the ant's way of computing its mean home vector. PMID:16593958

  20. Major evolutionary transitions in ant agriculture.

    PubMed

    Schultz, Ted R; Brady, Seán G

    2008-04-08

    Agriculture is a specialized form of symbiosis that is known to have evolved in only four animal groups: humans, bark beetles, termites, and ants. Here, we reconstruct the major evolutionary transitions that produced the five distinct agricultural systems of the fungus-growing ants, the most well studied of the nonhuman agriculturalists. We do so with reference to the first fossil-calibrated, multiple-gene, molecular phylogeny that incorporates the full range of taxonomic diversity within the fungus-growing ant tribe Attini. Our analyses indicate that the original form of ant agriculture, the cultivation of a diverse subset of fungal species in the tribe Leucocoprineae, evolved approximately 50 million years ago in the Neotropics, coincident with the early Eocene climatic optimum. During the past 30 million years, three known ant agricultural systems, each involving a phylogenetically distinct set of derived fungal cultivars, have separately arisen from the original agricultural system. One of these derived systems subsequently gave rise to the fifth known system of agriculture, in which a single fungal species is cultivated by leaf-cutter ants. Leaf-cutter ants evolved remarkably recently ( approximately 8-12 million years ago) to become the dominant herbivores of the New World tropics. Our analyses identify relict, extant attine ant species that occupy phylogenetic positions that are transitional between the agricultural systems. Intensive study of those species holds particular promise for clarifying the sequential accretion of ecological and behavioral characters that produced each of the major ant agricultural systems.

  1. Interpersonal relationships, coping strategies and problematic internet use in adolescence: an italian study.

    PubMed

    Milani, Luca; Osualdella, Dania; Di Blasio, Paola

    2009-01-01

    In a few years the Internet has become one of the most relevant means of socialization and entertainment for Italian adolescents. Studies have established a correlation between poor interpersonal relationship, poor cognitive coping strategies and Problematic Internet Use. The aim of the research was to study the characteristics and correlates of Problematic Internet Use in an Italian sample of adolescents. 98 Italian adolescents aged 14-19 were administered checklists assessing Problematic Internet Use, quality of interpersonal relationships, and cognitive-driven coping strategies. Of the participants, 36.7% are characterized by Problematic Internet Use. This subsample showed poorer interpersonal relationships and cognitive coping strategies compared to the non-problematic subsample. Overall quality of interpersonal relationships and cognitive coping strategies were found to be predictors of the level of Internet Problematic Use.

  2. Usefulness of fire ant genetics in insecticide efficacy trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mature fire ant colonies contain an average of 80,000 worker ants. For this study, eight fire ant workers were randomly sampled from each colony. DNA fingerprints for each individual ant were generated using 21 simple sequence repeats (SSR) markers that were developed from fire ant DNA by other lab...

  3. Is New Zealand vegetation really 'problematic'? Dansereau's puzzles revisited.

    PubMed

    Wilson, J Bastow; Lee, William G

    2012-05-01

    Over four decades ago, Pierre Dansereau, the noted North American ecologist, proposed six features of New Zealand vegetation as being problematic or unusual in a global context. We examine his propositions in the light of current ecological knowledge to determine whether or not these can still be considered unusual characteristics of New Zealand vegetation. (1) 'Climatic change is still progressing' resulting in disequilibrium between species' distributions and the present climate. New data and methods of analysis now available have removed the impression that Dansereau gained of imprecise zonation, unclear vegetation/climate relations and missing vegetation types. Communities cited as having regeneration failure can now be seen as even-aged stands that developed after major disturbance, although there are other, also non-climatic, explanations. However, the cause of the Westland 'Nothofagus gap' has become more, rather than less, controversial. (2) 'Continuity of community composition defies classification' and 'Very few New Zealand associations have faithful species' are correct observations, but perhaps equally true of vegetation elsewhere. Dansereau's assertion of low species richness in New Zealand is not supported by the comparative data available. (3) 'Lack of intolerant [i.e. mid-seral] trees …' is not evident with newer information. The order of species in succession, seen as unclear by Dansereau, has been determined by a range of approaches, largely confirming each other. (4) 'Discrepancies of form and function …' in divaricate shrubs and widespread heteroblasty are still controversial, with many more explanations. Several abiotic explanations have failed to stand up to investigation. Explanations in terms of herbivory have been well supported, although the extinction of the large avian herbivores makes certainty impossible. (5) 'Incidence of hybridization …' remains problematic. We do not know whether the incidence is unusually high, as Dansereau

  4. Effectiveness of vegetation-based biodiversity offset metrics as surrogates for ants.

    PubMed

    Hanford, Jayne K; Crowther, Mathew S; Hochuli, Dieter F

    2017-02-01

    Biodiversity offset schemes are globally popular policy tools for balancing the competing demands of conservation and development. Trading currencies for losses and gains in biodiversity value at development and credit sites are usually based on several vegetation attributes combined to yield a simple score (multimetric), but the score is rarely validated prior to implementation. Inaccurate biodiversity trading currencies are likely to accelerate global biodiversity loss through unrepresentative trades of losses and gains. We tested a model vegetation multimetric (i.e., vegetation structural and compositional attributes) typical of offset trading currencies to determine whether it represented measurable components of compositional and functional biodiversity. Study sites were located in remnant patches of a critically endangered ecological community in western Sydney, Australia, an area representative of global conflicts between conservation and expanding urban development. We sampled ant fauna composition with pitfall traps and enumerated removal by ants of native plant seeds from artificial seed containers (seed depots). Ants are an excellent model taxon because they are strongly associated with habitat complexity, respond rapidly to environmental change, and are functionally important at many trophic levels. The vegetation multimetric did not predict differences in ant community composition or seed removal, despite underlying assumptions that biodiversity trading currencies used in offset schemes represent all components of a site's biodiversity value. This suggests that vegetation multimetrics are inadequate surrogates for total biodiversity value. These findings highlight the urgent need to refine existing offsetting multimetrics to ensure they meet underlying assumptions of surrogacy. Despite the best intentions, offset schemes will never achieve their goal of no net loss of biodiversity values if trades are based on metrics unrepresentative of total

  5. Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles

    ERIC Educational Resources Information Center

    Zettler, Jennifer A.; Collier, Alexander; Leidersdorf, Bil; Sanou, Missa Patrick

    2010-01-01

    Urban students often have limited access to field sites for ecological studies. Ubiquitous ants and their mounds can be used to study and test ecology-based questions. We describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

  6. A twin study of problematic internet use: its heritability and genetic association with effortful control.

    PubMed

    Li, Mengjiao; Chen, Jie; Li, Naishi; Li, Xinying

    2014-08-01

    Our goal was to estimate genetic and environmental sources of influence on adolescent problematic internet use, and whether these individual differences can be explained by effortful control, an important aspect of self-regulation. A sample of 825 pairs of Chinese adolescent twins and their parents provided reports of problematic internet use and effortful control. Univariate analysis revealed that genetic factors explained 58-66% of variance in problematic internet use, with the rest explained by non-shared environmental factors. Sex difference was found, suggesting boys' problematic internet use was more influenced by genetic influences than girls' problematic internet use. Bivariate analysis indicated that effortful control accounted for a modest portion of the genetic and non-shared environmental variance in problematic internet use among girls. In contrast, among boys, effortful control explained between 6% (parent report) and 20% (self-report) of variance in problematic internet use through overlapping genetic pathways. Adolescent problematic internet use is heritable, and poor effortful control can partly explain adolescent problematic internet use, with effects stronger for boys. Implications for future research are discussed.

  7. Longitudinal associations between depression and problematic substance use in the Youth Partners in Care study.

    PubMed

    McKowen, James W; Tompson, Martha C; Brown, Timothy A; Asarnow, Joan R

    2013-01-01

    Large-scale treatment studies suggest that effective depression treatment and reduced depression are associated with improved substance use outcomes. Yet information is limited regarding the longitudinal association between depressive symptoms and problematic substance use and its predictors, particularly in real-world practice settings. Using latent growth modeling, we examined the (a) longitudinal association between depressive symptoms and problematic substance use, (b) impact of depressive symptoms on problematic substance use, (c) impact of problematic substance use on depressive symptoms, and (d) role of co-occurring symptoms on depression and problematic substance use. Participants were part of the Youth Partners in Care study, an effectiveness trial evaluating a quality improvement intervention for youth depression through primary care. This ethnically diverse sample included youths aged 13 to 21 years screening positive for depression from 5 health care organizations. Participants were followed 4 times over an 18-month period and assessed for both depressive symptoms and problematic substance use. Both depressive symptoms and problematic substance use declined over time. Higher baseline depressive symptoms predicted a slower decline in problematic substance use, but baseline problematic substance use did not predict changes in depressive symptoms. These prospective associations remained robust controlling for co-occurring symptoms. Results support prior large-scale depression studies indicating depression burden negatively impacts substance use outcome and extends these findings to real-world practice settings. Findings underscore the importance of addressing depression severity in youth with concurrent substance use problems, even in the context of comorbid symptoms of anxiety, delinquency, and aggression.

  8. eHealth Intervention for Problematic Internet Use (PIU).

    PubMed

    Lam, Lawrence T; Lam, Mary K

    2016-12-01

    Excessive use of the Internet is considered a problematic behaviour by clinicians and researchers. Cognitive behaviour therapy (CBT) has been advocated for a long time as a treatment approach and has been extended to include family therapy in the recent years. As eTherapy (eHealth) has become an important component in the treatment of many mental health problems, it is prudent to explore the current status of the eHealth approach as an intervention option for this problem. This systematic review aims to examine the current development of online intervention programmes for this particular condition. The PRISMA guidelines for systematic reviews and meta-analysis were employed to conduct the search for literature following a systematic and structured approach. Of the 182 articles screened, three satisfied the selection criteria. Information was extracted and analysed systematically for each study and tabulated. All these studies were pilot studies with small sample sizes. Two of these articles aimed to explore the therapeutic efficacy of newly developed online intervention programmes for Internet addiction (IA) and online gaming addiction. The third article described the design and development of an App for smartphone addiction. The results obtained from this review have provided insight into the on-going development of eHealth interventions as well as the health informatics approaches in offering a possible and practical solution to tackle this growing problem.

  9. Prediction of problematic wine fermentations using artificial neural networks.

    PubMed

    Román, R César; Hernández, O Gonzalo; Urtubia, U Alejandra

    2011-11-01

    Artificial neural networks (ANNs) have been used for the recognition of non-linear patterns, a characteristic of bioprocesses like wine production. In this work, ANNs were tested to predict problems of wine fermentation. A database of about 20,000 data from industrial fermentations of Cabernet Sauvignon and 33 variables was used. Two different ways of inputting data into the model were studied, by points and by fermentation. Additionally, different sub-cases were studied by varying the predictor variables (total sugar, alcohol, glycerol, density, organic acids and nitrogen compounds) and the time of fermentation (72, 96 and 256 h). The input of data by fermentations gave better results than the input of data by points. In fact, it was possible to predict 100% of normal and problematic fermentations using three predictor variables: sugars, density and alcohol at 72 h (3 days). Overall, ANNs were capable of obtaining 80% of prediction using only one predictor variable at 72 h; however, it is recommended to add more fermentations to confirm this promising result.

  10. Examining Correlates of Problematic Internet Pornography Use Among University Students

    PubMed Central

    Harper, Cody; Hodgins, David C.

    2016-01-01

    Background and aims The phenomenon of Internet pornography (IP) addiction is gainingincreasing attention in the popular media and psychological research. What has not been tested empirically is how frequency and amount ofIP use, along with other individual characteristics, are related tosymptoms of IP addiction. Methods 105 female and 86 male university students (mean age 21) from Calgary,Canada, were administered measures of IP use, psychosocial functioning (anxiety and depression, life and relationship satisfaction), addictivepropensities, and addictive IP use. Results Men reported earlier age of exposure and more frequent current IP use than women. Individuals not in relationships reported more frequent use than those in relationships. Frequency of IP use wasnot generally correlated with psychosocial functioning but was significantly positively correlated with level of IP addiction. Higher level of IP addiction was associated with poorer psychosocial functioning and problematic alcohol, cannabis, gambling and, in particular, video game use. A curvilinear association was found between frequency of IP use and level of addiction such that daily or greater IP use was associated with a sharp rise in addictive IP scores. Discussion The failure to find a strong significant relationship between IP use and general psychosocial functioning suggests that the overall effect of IP use is not necessarily harmful in and of itself. Addictiveuse of IP, which is associated with poorer psychosocial functioning, emerges when people begin to use IP daily. PMID:27156383

  11. The evolution of genome size in ants

    PubMed Central

    2008-01-01

    Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae) remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta), and the two published estimates for this species differ by 146.7 Mb (0.15 pg). Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile), Neotropical army ants (genera Eciton and Labidus), trapjaw ants (Odontomachus), fungus-growing ants (Apterostigma, Atta and Sericomyrmex), harvester ants (Messor, Pheidole and Pogonomyrmex), carpenter ants (Camponotus), a fire ant (Solenopsis), and a bulldog ant (Myrmecia). Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae) and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may include occasional

  12. Spectacular Batesian mimicry in ants.

    PubMed

    Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

    2004-10-01

    The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

  13. Spectacular Batesian mimicry in ants

    NASA Astrophysics Data System (ADS)

    Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

    2004-10-01

    The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

  14. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species

    PubMed Central

    Moorhouse, Tom P; Poole, Alison E; Evans, Laura C; Bradley, David C; Macdonald, David W

    2014-01-01

    Invasive species are a major cause of species extinction in freshwater ecosystems, and crayfish species are particularly pervasive. The invasive American signal crayfish Pacifastacus leniusculus has impacts over a range of trophic levels, but particularly on benthic aquatic macroinvertebrates. Our study examined the effect on the macroinvertebrate community of removal trapping of signal crayfish from UK rivers. Crayfish were intensively trapped and removed from two tributaries of the River Thames to test the hypothesis that lowering signal crayfish densities would result in increases in macroinvertebrate numbers and taxon richness. We removed 6181 crayfish over four sessions, resulting in crayfish densities that decreased toward the center of the removal sections. Conversely in control sections (where crayfish were trapped and returned), crayfish density increased toward the center of the section. Macroinvertebrate numbers and taxon richness were inversely correlated with crayfish densities. Multivariate analysis of the abundance of each taxon yielded similar results and indicated that crayfish removals had positive impacts on macroinvertebrate numbers and taxon richness but did not alter the composition of the wider macroinvertebrate community. Synthesis and applications: Our results demonstrate that non-eradication-oriented crayfish removal programmes may lead to increases in the total number of macroinvertebrates living in the benthos. This represents the first evidence that removing signal crayfish from riparian systems, at intensities feasible during control attempts or commercial crayfishing, may be beneficial for a range of sympatric aquatic macroinvertebrates. PMID:24634733

  15. Why do phylogenomic data sets yield conflicting trees? Data type influences the avian tree of life more than taxon sampling.

    PubMed

    Reddy, Sushma; Kimball, Rebecca T; Pandey, Akanksha; Hosner, Peter A; Braun, Michael J; Hackett, Shannon J; Han, Kin-Lan; Harshman, John; Huddleston, Christopher J; Kingston, Sarah; Marks, Ben D; Miglia, Kathleen J; Moore, William S; Sheldon, Frederick H; Witt, Christopher C; Yuri, Tamaki; Braun, Edward L

    2017-03-27

    Phylogenomics, the use of large-scale data matrices in phylogenetic analyses, has been viewed as the ultimate solution to the problem of resolving difficult nodes in the tree of life. However, it has become clear that analyses of these large genomic datasets can also result in conflicting estimates of phylogeny. Here we use the early divergences in Neoaves, the largest clade of extant birds, as a 'model system' to understand the basis for incongruence among phylogenomic trees. We were motivated by the observation that trees from two recent avian phylogenomic studies exhibit conflicts. Those studies used different strategies: 1) collecting many characters [∼42 mega base pairs (Mbp) of sequence data] from 48 birds, sometimes including only one taxon for each major clade; and 2) collecting fewer characters (∼0.4 Mbp) from 198 birds, selected to subdivide long branches. However, the studies also used different data types: the taxon-poor data matrix comprised 68% non-coding sequences whereas coding exons dominated the taxon-rich data matrix. This difference raises the question of whether the primary reason for incongruence is the number of sites, the number of taxa, or the data type. To test among these alternative hypotheses we assembled a novel, large-scale data matrix comprising 90% non-coding sequences from 235 bird species. Although increased taxon sampling appeared to have a positive impact on phylogenetic analyses the most important variable was data type. Indeed, by analyzing different subsets of the taxa in our data matrix we found that increased taxon sampling actually resulted in increased congruence with the tree from the previous taxon-poor study (which had a majority of non-coding data) instead of the taxon-rich study (which largely used coding data). We suggest that the observed differences in the estimates of topology for these studies reflect data-type effects due to violations of the models used in phylogenetic analyses, some of which may be

  16. Hey! A Fire Ant Stung Me!

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? Hey! A Fire Ant Stung Me! KidsHealth > For Kids > Hey! A Fire Ant Stung Me! Print A A ... For Kids For Parents MORE ON THIS TOPIC Hey! A Bee Stung Me! Hey! A Scorpion Stung ...

  17. The Use of Ants in Field Work.

    ERIC Educational Resources Information Center

    Skinner, Gary J.

    1988-01-01

    Provided is a brief description of the biology and taxonomy of British ants. Suggested are a range of exercises which could be used for class or project work in secondary biology classes. Illustrates many ecological, behavioral and physiological points regarding the species of ants found in Great Britain. (Author/CW)

  18. The Biochemical Toxin Arsenal from Ant Venoms

    PubMed Central

    Touchard, Axel; Aili, Samira R.; Fox, Eduardo Gonçalves Paterson; Escoubas, Pierre; Orivel, Jérôme; Nicholson, Graham M.; Dejean, Alain

    2016-01-01

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents. PMID:26805882

  19. Improving Emergency Management by Modeling Ant Colonies

    DTIC Science & Technology

    2015-03-01

    Charles D. Michener and Mary H. Michener, “American Social Insects: A Book About Bees, Ants, Wasps, and Termites ” (New York: D Van Nostrand, 1951...no. 2 (1978): 183–216. Michener, Charles D. and Mary H. Michener. American Social Insects: A Book About Bees, Ants, Wasps, and Termites . New York

  20. Neuropeptidomics of the carpenter ant Camponotus floridanus.

    PubMed

    Schmitt, Franziska; Vanselow, Jens T; Schlosser, Andreas; Kahnt, Jörg; Rössler, Wolfgang; Wegener, Christian

    2015-03-06

    Ants show a rich behavioral repertoire and a highly complex organization, which have been attracting behavioral and sociobiological researchers for a long time. The neuronal underpinnings of ant behavior and social organization are, however, much less understood. Neuropeptides are key signals that orchestrate animal behavior and physiology, and it is thus feasible to assume that they play an important role also for the social constitution of ants. Despite the availability of different ant genomes and in silico prediction of ant neuropeptides, a comprehensive biochemical survey of the neuropeptidergic communication possibilities of ants is missing. We therefore combined different mass spectrometric methods to characterize the neuropeptidome of the adult carpenter ant Camponotus floridanus. We also characterized the local neuropeptide complement in different parts of the nervous and neuroendocrine system, including the antennal and optic lobes. Our analysis identifies 39 neuropeptides encoded by different prepropeptide genes, and in silico predicts new prepropeptide genes encoding CAPA peptides, CNMamide as well as homologues of the honey bee IDLSRFYGHFNT- and ITGQGNRIF-containing peptides. Our data provides basic information about the identity and localization of neuropeptides that is required to anatomically and functionally address the role and significance of neuropeptides in ant behavior and physiology.

  1. The Biochemical Toxin Arsenal from Ant Venoms.

    PubMed

    Touchard, Axel; Aili, Samira R; Fox, Eduardo Gonçalves Paterson; Escoubas, Pierre; Orivel, Jérôme; Nicholson, Graham M; Dejean, Alain

    2016-01-20

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents.

  2. Urban Pest Management of Ants in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keeping pace with the dynamic and evolving landscape of invasive ants in California presents a formidable challenge to the pest management industry. Pest management professionals (PMPs) are on the frontlines when it comes to battling these exotic ant pests, and are often the first ones to intercept ...

  3. Problematic Exercise in Anorexia Nervosa: Testing Potential Risk Factors against Different Definitions.

    PubMed

    Rizk, Melissa; Lalanne, Christophe; Berthoz, Sylvie; Kern, Laurence; Godart, Nathalie

    2015-01-01

    "Hyperactivity" has a wide prevalence range of 31% to 80% in the anorexia nervosa literature that could be partly due to the plethora of definitions provided by researchers in this field. The purpose of this study was two-fold: 1) To assess the variance across prevalence rates of problematic exercise encountered in patients with anorexia nervosa, in relation to seven different definitions found in the literature. 2) To examine how core eating disorder symptoms and the dimensions of emotional profile are associated with these different definitions and the impact of these definitions on the assessment of patients' quality of life. Exercise was evaluated in terms of duration, intensity, type and compulsion using a semi-structured questionnaire administered to 180 women suffering from severe anorexia nervosa. Seven different definitions of problematic exercise were identified in the literature: three entailing a single dimension of problematic exercise (duration, compulsion or intensity) and four combining these different dimensions. Emotional profile scores, obsessive-compulsive symptoms, eating disorder symptomatology, worries and concerns about body shape, self-esteem and quality of life were assessed using several established questionnaires. The prevalence of problematic exercise varied considerably from, 5% to 54%, depending on the number of criteria used for its definition. The type and level of eating disorder symptomatology was found to be associated with several definitions of problematic exercise. Surprisingly, a better self-reported quality of life was found among problematic exercisers compared to non-problematic exercisers in three of the definitions. The different definitions of problematic exercise explain the broad prevalence ranges and the conflicting associations generally reported in the literature between problematic exercise and eating disorder-related psychological parameters. There is an urgent need for a valid consensus on the definition of

  4. Problematic Exercise in Anorexia Nervosa: Testing Potential Risk Factors against Different Definitions

    PubMed Central

    Rizk, Melissa; Lalanne, Christophe; Berthoz, Sylvie; Kern, Laurence; Godart, Nathalie

    2015-01-01

    “Hyperactivity” has a wide prevalence range of 31% to 80% in the anorexia nervosa literature that could be partly due to the plethora of definitions provided by researchers in this field. The purpose of this study was two-fold: 1) To assess the variance across prevalence rates of problematic exercise encountered in patients with anorexia nervosa, in relation to seven different definitions found in the literature. 2) To examine how core eating disorder symptoms and the dimensions of emotional profile are associated with these different definitions and the impact of these definitions on the assessment of patients’ quality of life. Exercise was evaluated in terms of duration, intensity, type and compulsion using a semi-structured questionnaire administered to 180 women suffering from severe anorexia nervosa. Seven different definitions of problematic exercise were identified in the literature: three entailing a single dimension of problematic exercise (duration, compulsion or intensity) and four combining these different dimensions. Emotional profile scores, obsessive-compulsive symptoms, eating disorder symptomatology, worries and concerns about body shape, self-esteem and quality of life were assessed using several established questionnaires. The prevalence of problematic exercise varied considerably from, 5% to 54%, depending on the number of criteria used for its definition. The type and level of eating disorder symptomatology was found to be associated with several definitions of problematic exercise. Surprisingly, a better self-reported quality of life was found among problematic exercisers compared to non-problematic exercisers in three of the definitions. The different definitions of problematic exercise explain the broad prevalence ranges and the conflicting associations generally reported in the literature between problematic exercise and eating disorder-related psychological parameters. There is an urgent need for a valid consensus on the definition

  5. Ant-seed mutualisms: Can red imported fire ants sour the relationship?

    USGS Publications Warehouse

    Zettler, J.A.; Spira, T.P.; Allen, C.R.

    2001-01-01

    Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. In recovered seeds fed to ant colonies, fire ants scarified 80% of S. canadensis seeds and destroyed 86% of V. rotundifolia seeds. Our study is the first to document that red imported fire ants are attracted to and remove seeds of species adapted for ant dispersal. Moreover, fire ants might damage these seeds and discard them in sites unfavorable for germination and seedling establishment. ?? 2001 Elsevier Science Ltd. All rights reserved.

  6. ANT2-defective fibroblasts exhibit normal mitochondrial bioenergetics

    PubMed Central

    Prabhu, Dolly; Goldstein, Amy C.; El-Khoury, Riyad; Rak, Malgorzata; Edmunds, Lia; Rustin, Pierre; Vockley, Jerry; Schiff, Manuel

    2015-01-01

    Adenine nucleotide translocase 2 (ANT2) transports glycolytic ATP across the inner mitochondrial membrane. Patients with ANT2 deletion were recently reported. We aimed at characterizing mitochondrial functions in ANT2-defective fibroblasts. In spite of ANT2 expression in fibroblasts, we observed no difference between ANT2-defective and control fibroblasts for mitochondrial respiration, respiratory chain activities, mitochondrial membrane potential and intracellular ATP levels. This indicates that ANT2 insufficiency does not alter fibroblast basal mitochondrial bioenergetics. PMID:26000237

  7. Effects of aromatic cedar mulch on the Argentine ant and the odorous house ant (Hymenoptera: Formicidae).

    PubMed

    Meissner, H E; Silverman, J

    2001-12-01

    In laboratory studies, the Argentine ant, Linepithema humile (Mayr), and the odorous house ant, Tapinoma sessile (Say), avoided aromatic cedar mulch as a nesting substrate. Both ant species were killed when confined with fresh aromatic cedar mulch in sealed containers. However, when confined with cedar mulch that had been aged outdoors for up to 140 d, mortality of L. humile was complete regardless of mulch age, whereas T. sessile mortality declined significantly over the mulch-aging period. Argentine ant susceptibility to aromatic cedar mulch was also greater than that of the odorous house ant when colonies were restricted to mulch in open trays. In addition, commercial aromatic cedar oil was lethal to both ant species. Our results suggest that aromatic cedar mulch may serve as an effective component of a comprehensive urban ant management program.

  8. Microclimatic conditions of Lasius flavus ant mounds

    NASA Astrophysics Data System (ADS)

    Véle, Adam; Holuša, Jaroslav

    2016-11-01

    Like other organisms, ants require suitable microclimatic conditions for their development. Thus, ant species inhabiting colder climates build nest mounds that rise above the soil surface, presumably to obtain heating from solar radiation. Although some ant species construct mounds of organic materials, which generate substantial heat due to microbial metabolism, Lasius flavus mounds consists mostly of soil, not organic material. The use of artificial shading in the current study demonstrated that L. flavus depends on direct solar radiation to regulate the temperature in its mound-like nests. Temperatures were much lower in shaded mounds than in unshaded mounds and were likely low enough in shaded mounds to reduce ant development and reproduction. In areas where L. flavus and similar ants are undesirable, they might be managed by shading.

  9. Microclimatic conditions of Lasius flavus ant mounds.

    PubMed

    Véle, Adam; Holuša, Jaroslav

    2016-11-23

    Like other organisms, ants require suitable microclimatic conditions for their development. Thus, ant species inhabiting colder climates build nest mounds that rise above the soil surface, presumably to obtain heating from solar radiation. Although some ant species construct mounds of organic materials, which generate substantial heat due to microbial metabolism, Lasius flavus mounds consists mostly of soil, not organic material. The use of artificial shading in the current study demonstrated that L. flavus depends on direct solar radiation to regulate the temperature in its mound-like nests. Temperatures were much lower in shaded mounds than in unshaded mounds and were likely low enough in shaded mounds to reduce ant development and reproduction. In areas where L. flavus and similar ants are undesirable, they might be managed by shading.

  10. Ants defend aphids against lethal disease.

    PubMed

    Nielsen, Charlotte; Agrawal, Anurag A; Hajek, Ann E

    2010-04-23

    Social insects defend their own colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. Here we report that Formica podzolica ants tending milkweed aphids, Aphis asclepiadis, protect aphid colonies from lethal fungal infections caused by an obligate aphid pathogen, Pandora neoaphidis. In field experiments, bodies of fungal-killed aphids were quickly removed from ant-tended aphid colonies. Ant workers were also able to detect infective conidia on the cuticle of living aphids and responded by either removing or grooming these aphids. Our results extend the long-standing view of ants as mutualists and protectors of aphids by demonstrating focused sanitizing and quarantining behaviour that may lead to reduced disease transmission in aphid colonies.

  11. Child maltreatment, alexithymia, and problematic internet use in young adulthood.

    PubMed

    Yates, Tuppett M; Gregor, Margo A; Haviland, Mark G

    2012-04-01

    The goals of this study were to (a) examine the phenomenology and developmental correlates of problematic Internet use (PIU) in a large and diverse college student sample; (b) evaluate a developmental process model of PIU in which the expected association between child maltreatment and PIU would be explained by alexithymia; and (c) explore these relations as a function of gender and race. PIU was assessed in a sample of 1,470 college students (62.9 percent female, 37.1 percent male; M(age)=19.13 years [SD=1.49]; 46.1 percent Asian, 28.2 percent Hispanic, 16.3 percent White, 5.9 percent Black, and 3.5 percent Multiracial/Other) who participated in a larger study of young adult adaptation, which included measures of child maltreatment, alexithymia, self-concept, social support, and psychopathology. Males and Asian students endorsed higher levels of PIU than females and other ethnoracial groups, respectively. PIU was related to contemporaneous maladaptation in the form of decreased self-concept, lower social support, and increased psychopathology across groups. Experiences of child maltreatment were related to increased PIU, and mediation analyses showed that this relation was partially explained by alexithymia. These relations were comparable across males and females and between Asian and non-Asian respondents. The analyses provide evidence for the significant role of child maltreatment and the cognitive-affective deficits it precipitates in understanding pathways toward PIU in young adulthood. Our findings suggest that maltreated youth are at disproportionate risk for PIU, and their capacities to regulate and process emotion are important targets for prevention and therapeutic intervention.

  12. Persistence of pollination mutualisms in the presence of ants.

    PubMed

    Wang, Yuanshi; Wang, Shikun

    2015-01-01

    This paper considers plant-pollinator-ant systems in which the plant-pollinator interaction is mutualistic but ants have both positive and negative effects on plants. The ants also interfere with pollinators by preventing them from accessing plants. While a Beddington-DeAngelis (BD) formula can describe the plant-pollinator interaction, the formula is extended in this paper to characterize the pollination mutualism under the ant interference. Then, a plant-pollinator-ant system with the extended BD functional response is discussed, and global dynamics of the model demonstrate the mechanisms by which pollination mutualism can persist in the presence of ants. When the ant interference is strong, it can result in extinction of pollinators. Moreover, if the ants depend on pollination mutualism for survival, the strong interference could drive pollinators into extinction, which consequently lead to extinction of the ants themselves. When the ant interference is weak, a cooperation between plant-ant and plant-pollinator mutualisms could occur, which promotes survival of both ants and pollinators, especially in the case that ants (respectively, pollinators) cannot survive in the absence of pollinators (respectively, ants). Even when the level of ant interference remains invariant, varying ants' negative effect on plants can result in survival/extinction of both ants and pollinators. Therefore, our results provide an explanation for the persistence of pollination mutualism when there exist ants.

  13. The genus Nonomuraea: A review of a rare actinomycete taxon for novel metabolites.

    PubMed

    Sungthong, Rungroch; Nakaew, Nareeluk

    2015-05-01

    The genus Nonomuraea is a rare actinomycete taxon with a long taxonomic history, while its generic description was recently emended. The genus is less known among the rare actinomycete genera as its taxonomic position was revised several times. It can be found in diverse ecological niches, while most of its member species were isolated from soil samples. However, new trends to discover the genus in other habitats are increasing. Generic abundance of the genus was found to be dependent on geographical changes. Novel sources together with selective and invented isolation techniques might increase a chance to explore the genus and its novel candidates. Interestingly, some of its members have been revealed as a valuable source of novel metabolites for medical and industrial purposes. Broad-range of potent bioactive compounds including antimicrobial, anticancer, and antipsychotic substances, broad-spectrum antibiotics and biocatalysts can be synthesized by the genus. In order to investigate biosynthetic pathways of the bioactive compounds and self-resistant mechanisms to these compounds, the links from genes to metabolites have yet been needed for further discovery and biotechnological development of the genus Nonomuraea.

  14. Assessing an unknown evolutionary process: effect of increasing site-specific knowledge through taxon addition.

    PubMed

    Pollock, D D; Bruno, W J

    2000-12-01

    Assessment of the evolutionary process is crucial for understanding the effect of protein structure and function on sequence evolution and for many other analyses in molecular evolution. Here, we used simulations to study how taxon sampling affects accuracy of parameter estimation and topological inference in the absence of branch length asymmetry. With maximum-likelihood analysis, we find that adding taxa dramatically improves both support for the evolutionary model and accurate assessment of its parameters when compared with increasing the sequence length. Using a method we call "doppelgänger trees," we distinguish the contributions of two sources of improved topological inference: greater knowledge about internal nodes and greater knowledge of site-specific rate parameters. Surprisingly, highly significant support for the correct general model does not lead directly to improved topological inference. Instead, substantial improvement occurs only with accurate assessment of the evolutionary process at individual sites. Although these results are based on a simplified model of the evolutionary process, they indicate that in general, assuming processes are not independent and identically distributed among sites, more extensive sampling of taxonomic biodiversity will greatly improve analytical results in many current sequence data sets with moderate sequence lengths.

  15. Trade-off between taxon diversity and functional diversity in European lake ecosystems.

    PubMed

    Grossmann, Lars; Beisser, Daniela; Bock, Christina; Chatzinotas, Antonis; Jensen, Manfred; Preisfeld, Angelika; Psenner, Roland; Rahmann, Sven; Wodniok, Sabina; Boenigk, Jens

    2016-12-01

    Inferring ecosystem functioning and ecosystem services through inspections of the species inventory is a major aspect of ecological field studies. Ecosystem functions are often stable despite considerable species turnover. Using metatranscriptome analyses, we analyse a thus-far unparalleled freshwater data set which comprises 21 mainland European freshwater lakes from the Sierra Nevada (Spain) to the Carpathian Mountains (Romania) and from northern Germany to the Apennines (Italy) and covers an altitudinal range from 38 m above sea level (a.s.l) to 3110 m a.s.l. The dominant taxa were Chlorophyta and streptophytic algae, Ciliophora, Bacillariophyta and Chrysophyta. Metatranscriptomics provided insights into differences in community composition and into functional diversity via the relative share of taxa to the overall read abundance of distinct functional genes on the ecosystem level. The dominant metabolic pathways in terms of the fraction of expressed sequences in the cDNA libraries were affiliated with primary metabolism, specifically oxidative phosphorylation, photosynthesis and the TCA cycle. Our analyses indicate that community composition is a good first proxy for the analysis of ecosystem functions. However, differential gene regulation modifies the relative importance of taxa in distinct pathways. Whereas taxon composition varies considerably between lakes, the relative importance of distinct metabolic pathways is much more stable, indicating that ecosystem functioning is buffered against shifts in community composition through a functional redundancy of taxa.

  16. Single-taxon field measurements of bacterial gene regulation controlling DMSP fate.

    PubMed

    Varaljay, Vanessa A; Robidart, Julie; Preston, Christina M; Gifford, Scott M; Durham, Bryndan P; Burns, Andrew S; Ryan, John P; Marin, Roman; Kiene, Ronald P; Zehr, Jonathan P; Scholin, Christopher A; Moran, Mary Ann

    2015-07-01

    The 'bacterial switch' is a proposed regulatory point in the global sulfur cycle that routes dimethylsulfoniopropionate (DMSP) to two fundamentally different fates in seawater through genes encoding either the cleavage or demethylation pathway, and affects the flux of volatile sulfur from ocean surface waters to the atmosphere. Yet which ecological or physiological factors might control the bacterial switch remains a topic of considerable debate. Here we report the first field observations of dynamic changes in expression of DMSP pathway genes by a single marine bacterial species in its natural environment. Detection of taxon-specific gene expression in Roseobacter species HTCC2255 during a month-long deployment of an autonomous ocean sensor in Monterey Bay, CA captured in situ regulation of the first gene in each DMSP pathway (dddP and dmdA) that corresponded with shifts in the taxonomy of the phytoplankton community. Expression of the demethylation pathway was relatively greater during a high-DMSP-producing dinoflagellate bloom, and expression of the cleavage pathway was greater in the presence of a mixed diatom and dinoflagellate community [corrected].These field data fit the prevailing hypothesis for bacterial DMSP gene regulation based on bacterial sulfur demand, but also suggest a modification involving oxidative stress response, evidenced as upregulation of catalase via katG, when DMSP is demethylated.

  17. A New Taxon of Basal Ceratopsian from China and the Early Evolution of Ceratopsia

    PubMed Central

    Han, Fenglu; Forster, Catherine A.; Clark, James M.; Xu, Xing

    2015-01-01

    Ceratopsia is one of the best studied herbivorous ornithischian clades, but the early evolution of Ceratopsia, including the placement of Psittacosaurus, is still controversial and unclear. Here, we report a second basal ceratopsian, Hualianceratops wucaiwanensis gen. et sp. nov., from the Upper Jurassic (Oxfordian) Shishugou Formation of the Junggar Basin, northwestern China. This new taxon is characterized by a prominent caudodorsal process on the subtemporal ramus of the jugal, a robust quadrate with an expansive quadratojugal facet, a prominent notch near the ventral region of the quadrate, a deep and short dentary, and strongly rugose texturing on the lateral surface of the dentary. Hualianceratops shares several derived characters with both Psittacosaurus and the basal ceratopsians Yinlong, Chaoyangsaurus, and Xuanhuaceratops. A new comprehensive phylogeny of ceratopsians weakly supports both Yinlong and Hualianceratops as chaoyangsaurids (along with Chaoyangsaurus and Xuanhuaceratops), as well as the monophyly of Chaoyangosauridae + Psittacosaurus. This analysis also weakly supports the novel hypothesis that Chaoyangsauridae + Psittacosaurus is the sister group to the rest of Neoceratopsia, suggesting a basal split between these clades before the Late Jurassic. This phylogeny and the earliest Late Jurassic age of Yinlong and Hualianceratops imply that at least five ceratopsian lineages (Yinlong, Hualianceratops, Chaoyangsaurus + Xuanhuaceratops, Psittacosaurus, Neoceratopsia) were present at the beginning of the Late Jurassic. PMID:26649770

  18. Single-taxon field measurements of bacterial gene regulation controlling DMSP fate

    PubMed Central

    Varaljay, Vanessa A; Robidart, Julie; Preston, Christina M; Gifford, Scott M; Durham, Bryndan P; Burns, Andrew S; Ryan, John P; Marin III, Roman; Kiene, Ronald P; Zehr, Jonathan P; Scholin, Christopher A; Ann Moran, Mary

    2015-01-01

    The ‘bacterial switch' is a proposed regulatory point in the global sulfur cycle that routes dimethylsulfoniopropionate (DMSP) to two fundamentally different fates in seawater through genes encoding either the cleavage or demethylation pathway, and affects the flux of volatile sulfur from ocean surface waters to the atmosphere. Yet which ecological or physiological factors might control the bacterial switch remains a topic of considerable debate. Here we report the first field observations of dynamic changes in expression of DMSP pathway genes by a single marine bacterial species in its natural environment. Detection of taxon-specific gene expression in Roseobacter species HTCC2255 during a month-long deployment of an autonomous ocean sensor in Monterey Bay, CA captured in situ regulation of the first gene in each DMSP pathway (dddP and dmdA) that corresponded with shifts in the taxonomy of the phytoplankton community. Expression of the cleavage pathway was relatively greater during a high-DMSP-producing dinoflagellate bloom, and expression of the demethylation pathway was greater in the presence of a mixed diatom and dinoflagellate community. These field data fit the prevailing hypothesis for bacterial DMSP gene regulation based on bacterial sulfur demand, but also suggest a modification involving oxidative stress response, evidenced as upregulation of catalase via katG, when DMSP is demethylated. PMID:25700338

  19. Negevirus: a Proposed New Taxon of Insect-Specific Viruses with Wide Geographic Distribution

    PubMed Central

    Vasilakis, Nikos; Forrester, Naomi L.; Palacios, Gustavo; Nasar, Farooq; Savji, Nazir; Rossi, Shannan L.; Guzman, Hilda; Wood, Thomas G.; Popov, Vsevolod; Gorchakov, Rodion; González, Ana Vázquez; Haddow, Andrew D.; Watts, Douglas M.; da Rosa, Amelia P. A. Travassos; Weaver, Scott C.; Lipkin, W. Ian

    2013-01-01

    Six novel insect-specific viruses, isolated from mosquitoes and phlebotomine sand flies collected in Brazil, Peru, the United States, Ivory Coast, Israel, and Indonesia, are described. Their genomes consist of single-stranded, positive-sense RNAs with poly(A) tails. By electron microscopy, the virions appear as spherical particles with diameters of ∼45 to 55 nm. Based on their genome organization and phylogenetic relationship, the six viruses, designated Negev, Ngewotan, Piura, Loreto, Dezidougou, and Santana, appear to form a new taxon, tentatively designated Negevirus. Their closest but still distant relatives are citrus leposis virus C (CiLV-C) and viruses in the genus Cilevirus, which are mite-transmitted plant viruses. The negeviruses replicate rapidly and to high titer (up to 1010 PFU/ml) in mosquito cells, producing extensive cytopathic effect and plaques, but they do not appear to replicate in mammalian cells or mice. A discussion follows on their possible biological significance and effect on mosquito vector competence for arboviruses. PMID:23255793

  20. 'Candidatus phytoplasma ziziphi', a novel phytoplasma taxon associated with jujube witches'-broom disease.

    PubMed

    Jung, Hee-Young; Sawayanagi, Toshimi; Kakizawa, Shigeyuki; Nishigawa, Hisashi; Wei, Wei; Oshima, Kenro; Miyata, Shin-ichi; Ugaki, Masashi; Hibi, Tadaaki; Namba, Shigetou

    2003-07-01

    Phylogenetic relationships of five jujube witches'-broom (JWB) phytoplasma isolates from four different districts, and other phytoplasmas, were investigated by 16S rDNA PCR amplification and sequence analysis. The 16S rDNA sequences of any pair of the five isolates of JWB phytoplasmas were > 99.5% similar. The JWB phytoplasma 16S rDNA sequences were most closely related to that of the elm yellows (EY) phytoplasma in 16S-group VIII. Phylogenetic analysis of the 16S rDNA sequences from the JWB phytoplasma isolates, together with sequences from most of the phytoplasmas archived in GenBank, produced a tree in which the JWB isolates clustered as a discrete subgroup. The uniqueness of the JWB phytoplasma appears to be correlated with a specific insect vector (Hishimonus sellatus) and the host plant (Zizyphus jujuba), or with a specific geographical distribution. The unique properties of the JWB phytoplasma sequences clearly indicate that it represents a novel taxon, 'Candidatus Phytoplasma ziziphi'.

  1. 'Candidatus Phytoplasma castaneae', a novel phytoplasma taxon associated with chestnut witches' broom disease.

    PubMed

    Jung, Hee-Young; Sawayanagi, Toshimi; Kakizawa, Shigeyuki; Nishigawa, Hisashi; Miyata, Shin-ichi; Oshima, Kenro; Ugaki, Masashi; Lee, Joon-Tak; Hibi, Tadaaki; Namba, Shigetou

    2002-09-01

    In Korea, Japanese chestnut trees (Castanea crenata Sieb. and Zucc.) showing symptoms indicative of witches' broom disease, including abnormally small leaves and yellowing of young leaves, were examined. Since the symptoms were suggestive of a phytoplasma infection, tissues were assayed for phytoplasmas by PCR analysis using a pair of universal primers that amplify a 1.4-kbp phytoplasma 16S rDNA fragment. The phytoplasma-specific fragment was amplified from diseased plants, but not from healthy plants, indicating that a phytoplasma was the causal agent of the chestnut witches' broom (CnWB) disease. The phylogenetic relationship of the CnWB phytoplasma to other phytoplasmas was examined by sequence analysis of the 16S rDNA. A phylogenetic analysis of 16S rDNA sequences of the phytoplasmas placed the CnWB phytoplasma within a distinct subgroup in the phytoplasma clade of the class Mollicutes. The phylogenetic tree indicated that the CnWB phytoplasma is related most closely to coconut phytoplasmas and suggested that they share a common ancestor. The unique properties of the CnWB phytoplasma sequences clearly establish that it represents a novel taxon, 'Candidatus Phytoplasma castaneae'.

  2. 'Candidatus Phytoplasma brasiliense', a new phytoplasma taxon associated with hibiscus witches' broom disease.

    PubMed

    Montano, H G; Davis, R E; Dally, E L; Hogenhout, S; Pimentel, J P; Brioso, P S

    2001-05-01

    Hibiscus rosa-sinensis is a valuable ornamental species widely planted in Brazil. Many plants are affected by witches' broom disease, which is characterized by excessive axillary branching, abnormally small leaves, and deformed flowers, symptoms that are characteristic of diseases attributed to phytoplasmas. A phytoplasma was detected in diseased Hibiscus by amplification of rRNA operon sequences by PCRs, and was characterized by RFLP and nucleotide sequence analyses of 16S rDNA. The collective RFLP patterns of amplified 16S rDNA differed from the patterns described previously for other phytoplasmas. On the basis of the RFLP patterns, the hibiscus witches' broom phytoplasma was classified in a new 16S rRNA RFLP group, designated group 16SrXV. A phylogenetic analysis of 16S rDNA sequences from this and other phytoplasmas identified the hibiscus witches' broom phytoplasma as a member of a distinct subclade (designated subclade xiv) of the class Mollicutes. A phylogenetic tree constructed on the basis of 16S rRNA gene sequences was consistent with the hypothesis that there was divergent evolution of hibiscus witches' broom phytoplasma and its closest relatives (members of 16S rRNA RFLP group 16SrII) from a common ancestor. On the basis of unique properties of the DNA from hibiscus witches' broom phytoplasma, it is proposed that it represents a new taxon, namely 'Candidatus Phytoplasma brasiliense'.

  3. Integration of approaches in David Wake's model-taxon research platform for evolutionary morphology.

    PubMed

    Griesemer, James

    2013-12-01

    What gets integrated in integrative scientific practices has been a topic of much discussion. Traditional views focus on theories and explanations, with ideas of reduction and unification dominating the conversation. More recent ideas focus on disciplines, fields, or specialties; models, mechanisms, or methods; phenomena, problems. How integration works looks different on each of these views since the objects of integration are ontologically and epistemically various: statements, boundary conditions, practices, protocols, methods, variables, parameters, domains, laboratories, and questions all have their own structures, functions and logics. I focus on one particular kind of scientific practice, integration of "approaches" in the context of a research system operating on a special kind of "platform." Rather than trace a network of interactions among people, practices, and theoretical entities to be integrated, in this essay I focus on the work of a single investigator, David Wake. I describe Wake's practice of integrative evolutionary biology and how his integration of approaches among biological specialties worked in tandem with his development of the salamanders as a model taxon, which he used as a platform to solve, re-work and update problems that would not have been solved so well by non-integrative approaches. The larger goal of the project to which this paper contributes is a counter-narrative to the story of 20th century life sciences as the rise and march of the model organisms and decline of natural history.

  4. Comprehensive gene and taxon coverage elucidates radiation patterns in moths and butterflies.

    PubMed

    Mutanen, Marko; Wahlberg, Niklas; Kaila, Lauri

    2010-09-22

    Lepidoptera (butterflies and moths) represent one of the most diverse animals groups. Yet, the phylogeny of advanced ditrysian Lepidoptera, accounting for about 99 per cent of lepidopteran species, has remained largely unresolved. We report a rigorous and comprehensive analysis of lepidopteran affinities. We performed phylogenetic analyses of 350 taxa representing nearly 90 per cent of lepidopteran families. We found Ditrysia to be a monophyletic taxon with the clade Tischerioidea + Palaephatoidea being the sister group of it. No support for the monophyly of the proposed major internested ditrysian clades, Apoditrysia, Obtectomera and Macrolepidoptera, was found as currently defined, but each of these is supported with some modification. The monophyly or near-monophyly of most previously identified lepidopteran superfamilies is reinforced, but several species-rich superfamilies were found to be para- or polyphyletic. Butterflies were found to be more closely related to 'microlepidopteran' groups of moths rather than the clade Macrolepidoptera, where they have traditionally been placed. There is support for the monophyly of Macrolepidoptera when butterflies and Calliduloidea are excluded. The data suggest that the generally short diverging nodes between major groupings in basal non-tineoid Ditrysia are owing to their rapid radiation, presumably in correlation with the radiation of flowering plants.

  5. Mycobacterial contamination of metalworking fluids: involvement of a possible new taxon of rapidly growing mycobacteria.

    PubMed

    Moore, J S; Christensen, M; Wilson, R W; Wallace, R J; Zhang, Y; Nash, D R; Shelton, B

    2000-01-01

    Contamination of air and metalworking fluid (MWF) systems with a rapidly growing mycobacterium (RGM) was detected in 1995 in a single manufacturing plant with recent cases of hypersensitivity pneumonitis (HP). Extensive environmental sampling was performed to determine the extent of the contamination and its variability over time. RGM were present in multiple indoor air samples, 100% of the central MWF storage tanks, and 75% of the freestanding cutting, drilling, and grinding machines. With one exception, contamination was limited to a recently introduced formulation (brand) of semisynthetic MWF used in 95% of the facility's machining operations. In general, the mycobacterial counts were stable over time, with the degree of contamination ranging from 10(2)-10(7) colony forming units (CFU)/mL. A few systems were culture positive for the mycobacterium (> 10(1) CFU/mL), changed to culture negative (< 10(1) CFU/mL), then changed back to culture positive without explanation. Samples obtained from diluted (5%) but unused MWF, a replenishment line with 2% unused MWF, an MWF pasteurizer, city water, and deionized water were culture negative for this species of mycobacterium. Inoculation and growth studies demonstrated that this mycobacterium does not grow in liquid samples of 5% unused MWF. By molecular techniques, the mycobacterial isolates consisted of a single strain and represented a previously undescribed taxon closely related to Mycobacterium chelonae/abscessus. The relationship of this mycobacterium to the cases of HP is unknown.

  6. Biological richness of a large urban cemetery in Berlin. Results of a multi-taxon approach

    PubMed Central

    Blick, Theo; Hannig, Karsten; Kowarik, Ingo; Lemke, Andreas; Otte, Volker; Scharon, Jens; Schönhofer, Axel; Teige, Tobias; von der Lippe, Moritz; Seitz, Birgit

    2016-01-01

    Abstract Background Urban green spaces can harbor a considerable species richness of plants and animals. A few studies on single species groups indicate important habitat functions of cemeteries, but this land use type is clearly understudied compared to parks. Such data are important as they (i) illustrate habitat functions of a specific, but ubiquitous urban land-use type and (ii) may serve as a basis for management approaches. New information We sampled different groups of plants and animals in the Weißensee Jewish Cemetery in Berlin (WJC) which is one of the largest Jewish cemeteries in Europe. With a total of 608 species of plants and animals, this first multi-taxon survey revealed a considerable biological richness in the WJC. In all, 363 wild-growing vascular plant, 72 lichen and 26 bryophyte taxa were recorded. The sampling also yielded 34 bird and 5 bat species as well as 39 ground beetle, 5 harvestman and 64 spider species. Some species are new records for Berlin. PMID:27099549

  7. Genetic characterization, molecular epidemiology, and phylogenetic relationships of insect-specific viruses in the taxon Negevirus.

    PubMed

    Nunes, Marcio R T; Contreras-Gutierrez, María Angélica; Guzman, Hilda; Martins, Livia C; Barbirato, Mayla Feitoza; Savit, Chelsea; Balta, Victoria; Uribe, Sandra; Vivero, Rafael; Suaza, Juan David; Oliveira, Hamilton; Nunes Neto, Joaquin P; Carvalho, Valeria L; da Silva, Sandro Patroca; Cardoso, Jedson F; de Oliveira, Rodrigo Santo; da Silva Lemos, Poliana; Wood, Thomas G; Widen, Steven G; Vasconcelos, Pedro F C; Fish, Durland; Vasilakis, Nikos; Tesh, Robert B

    2017-04-01

    The recently described taxon Negevirus is comprised of a diverse group of insect-specific viruses isolated from mosquitoes and phlebotomine sandflies. In this study, a comprehensive genetic characterization, molecular, epidemiological and evolutionary analyses were conducted on nearly full-length sequences of 91 new negevirus isolates obtained in Brazil, Colombia, Peru, Panama, USA and Nepal. We demonstrated that these arthropod restricted viruses are clustered in two major phylogenetic groups with origins related to three plant virus genera (Cilevirus, Higrevirus and Blunevirus). Molecular analyses demonstrated that specific host correlations are not present with most negeviruses; instead, high genetic variability, wide host-range, and cross-species transmission were noted. The data presented here also revealed the existence of five novel insect-specific viruses falling into two arthropod-restrictive virus taxa, previously proposed as distinct genera, designated Nelorpivirus and Sandewavirus. Our results provide a better understanding of the molecular epidemiology, evolution, taxonomy and stability of this group of insect-restricted viruses.

  8. An Investigation of Problematic Internet Usage Behaviors on Turkish University Students

    ERIC Educational Resources Information Center

    Ceyhan, Esra; Ceyhan, A. Aykut

    2007-01-01

    This research aims at examining the relationships between problematic internet usage (PIU) behavior and some demographic information and qualifications related to internet use of Turkish university students. The research was conducted with 2084 university students. Data was collected by means of Problematic Internet Usage Scale (Ceyhan, Ceyhan…

  9. Exploration of Problematic Internet Use and Social Interaction Anxiety among Turkish Pre-Service Teachers

    ERIC Educational Resources Information Center

    Cuhadar, Cem

    2012-01-01

    The current study investigated the relationship between problematic Internet use and social interaction anxiety among pre-service teachers. Participants were 1235 students attending teacher training programs at a Turkish state university. The "Problematic Internet Use Scale" and "Social Interaction Anxiety Scale" were used to…

  10. Teachers' Views on Risk Factors for Problematic School Absenteeism in Swedish Primary School Students

    ERIC Educational Resources Information Center

    Gren-Landell, Malin; Ekerfelt Allvin, Cornelia; Bradley, Maria; Andersson, Maria; Andersson, Gerhard

    2015-01-01

    In the present online survey, 158 teachers in regular and special education teaching in grades six to nine were asked to rate the importance of probable reasons for problematic school absenteeism. On average, the teachers estimated that among their students, 19 students had presented with problematic school absenteeism over the last five years.…

  11. Problematic Student in the Experiential Group: Professional and Ethical Challenges for Counselor Educators

    ERIC Educational Resources Information Center

    Goodrich, Kristopher M.; Luke, Melissa

    2012-01-01

    This article updates and adds to the literature about problematic counselors-in-training, specifically centered on the requisite experiential group component in the Association for Specialists in Group Work Professional Training Standards (2000) and CACREP (2009) curriculum. The authors review the literature regarding problematic behavior, present…

  12. A preliminary investigation into the prevalence and prediction of problematic cell phone use

    PubMed Central

    Smetaniuk, Peter

    2014-01-01

    Background and aims: Likening mobile phone use dependency to the classification of excessive behaviors may be necessarily equivalent in seriousness to previously established addictions such as problematic computing or excessive gambling. The aim of the study explores into the behavior of excessive use of mobile phones as a pathological behavior. Methods: Two studies investigated criteria for problematic mobile phone usage by examining student (Study 1, N = 301) and nonstudent (Study 2, N = 362) responses to a set of adapted mobile phone addiction inventories. Study 1 investigated cell phone addiction inventories as constructs designed to measure problematic cell phone use. Additionally, Study 2 sought to predict age, depression, extraversion, emotional stability, impulse control, and self-esteem as independent variables that augment respondents’ perceptions of problematic use. Results: The results from Study 1 and Study 2 indicate that 10 to 25% of the participants tested exhibited problematic cell phone usage. Additionally, age, depression, extraversion, and low impulse control are the most suitable predictors for problematic use. Conclusions: The results of the two studies indicate that problematic mobile phone use does occur and ought to be taken seriously by the psychological community. Presently, there is limited data providing conclusive evidence for a comprehensible categorization of cell phone addiction, as well as a unified explanatory model specific to problematic mobile phone use. Studies such as this one may contribute substantial findings, adding scientific significance, and offering a valuable submission for the ongoing progress of creating intervention frameworks relative to “virtual addictions”. PMID:25215213

  13. Problematic use of social network sites: the interactive relationship between gratifications sought and privacy concerns.

    PubMed

    Chen, Hsuan-Ting; Kim, Yonghwan

    2013-11-01

    Problematic Internet use has long been a matter of concern; however, few studies extend this line of research from general Internet use to the use of social network sites (SNSs), or explicate the problematic use of SNSs by understanding what factors may enhance or reduce users' compulsive behaviors and excessive form of use on SNSs. Building on literature that found a positive relationship between gratifications sought from the Internet and problematic Internet use, this study first explores the types of gratifications sought from SNSs and examines their relationship with problematic SNS use. It found that three types of gratifications-diversion, self-presentation, and relationship building-were positively related to problematic SNS use. In addition, with a growing body of research on SNS privacy, a moderating role of privacy concerns on SNSs has been proposed to understand how it can influence the relationship between gratifications sought from SNSs and problematic SNS use. The findings suggest that different subdimensions of privacy concerns interact with gratifications sought in different manners. In other words, privacy concerns, including unauthorized secondary use and improper access, play a more influential role in constraining the positive relationship between gratifications sought and problematic SNS use when individuals seek to build relationships on SNSs. However, if individuals seek to have diversion on SNSs, their privacy concerns will be overridden by their gratifications sought, which in turn leads to problematic SNS use. Implications of these findings for future research are discussed.

  14. Exploration of Problematic Internet Use and Loneliness among Distance Education Students

    ERIC Educational Resources Information Center

    Ozgur, Hasan; Demiralay, Tülay; Demiralay, Ilkay

    2014-01-01

    The current study investigated the relationship between problematic Internet use and levels of loneliness among 311 distance education students. "The Problematic Internet Use Scale" and "UCLA-Loneliness Scale III" were used to collect the data. Independentsamples t-test and one-way ANOVA were conducted to examine the…

  15. A Comparative Study of Problematic Internet Use and Loneliness among Turkish and Korean Prospective Teachers

    ERIC Educational Resources Information Center

    Tutgun, Aylin; Deniz, Levent; Moon, Man-Ki

    2011-01-01

    The main aim of this study is to compare the problematic internet use and its relation to loneliness among two nations' prospective teachers, Turkey and South Korea. Five hundred and ninety five prospective teachers from three universities, two from Turkey and one from South Korea participated in the study. Generalized Problematic Internet Use…

  16. Problematic game play: the diagnostic value of playing motives, passion, and playing time in men.

    PubMed

    Kneer, Julia; Rieger, Diana

    2015-04-30

    Internet gaming disorder is currently listed in the DSM-not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing.

  17. Problematic Game Play: The Diagnostic Value of Playing Motives, Passion, and Playing Time in Men

    PubMed Central

    Kneer, Julia; Rieger, Diana

    2015-01-01

    Internet gaming disorder is currently listed in the DSM—not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing. PMID:25942516

  18. FDTD-ANT User Manual

    NASA Technical Reports Server (NTRS)

    Zimmerman, Martin L.

    1995-01-01

    This manual explains the theory and operation of the finite-difference time domain code FDTD-ANT developed by Analex Corporation at the NASA Lewis Research Center in Cleveland, Ohio. This code can be used for solving electromagnetic problems that are electrically small or medium (on the order of 1 to 50 cubic wavelengths). Calculated parameters include transmission line impedance, relative effective permittivity, antenna input impedance, and far-field patterns in both the time and frequency domains. The maximum problem size may be adjusted according to the computer used. This code has been run on the DEC VAX and 486 PC's and on workstations such as the Sun Sparc and the IBM RS/6000.

  19. Ant-Based Cyber Security

    SciTech Connect

    Haack, Jereme N.; Fink, Glenn A.; Maiden, Wendy M.; McKinnon, Archibald D.; Templeton, Steven J.; Fulp, Errin W.

    2011-07-12

    We describe a swarming-agent-based, mixed-initiative approach to infrastructure defense where teams of humans and software agents defend cooperating organizations in tandem by sharing insights and solutions without violating proprietary boundaries. The system places human administrators at the appropriate level where they provide system guidance while lower-level agents carry out tasks humans are unable to perform quickly enough to mitigate today’s security threats. Cooperative Infrastructure Defense (CID) uses our ant-based approach to enable dialogue between humans and agents to foster a collaborative problem-solving environment, increase human situational awareness and influence using visualization and shared control. We discuss theoretical implementation characteristics along with results from recent proof-of-concept implementations.

  20. Differentiating children with and without a history of repeated problematic sexual behavior.

    PubMed

    Curwen, Tracey; Jenkins, Jennifer M; Worling, James R

    2014-01-01

    Many adolescents who sexually offend commenced problematic sexual behaviors as children. There is little evidence to indicate which children may be at risk to continue problematic sexual behaviors and which children will desist once identified. The goal of this study was to determine variables that differentiate children who repeated problematic sexual behaviors following adult reprimand from those who did not. Predictive accuracy of 33 risk variables was investigated using 62 children assessed for problematic sexual behaviors. Eight individual variables were related to group membership, and a total score based on the combination of these variables was predictive of group membership. The results indicate variables that may assist in identifying children requiring intervention versus those likely to discontinue problematic sexual behaviors once they are identified and reprimanded.

  1. Blunted ventral striatal responses to anticipated rewards foreshadow problematic drug use in novelty-seeking adolescents.

    PubMed

    Büchel, Christian; Peters, Jan; Banaschewski, Tobias; Bokde, Arun L W; Bromberg, Uli; Conrod, Patricia J; Flor, Herta; Papadopoulos, Dimitri; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Walter, Henrik; Ittermann, Bernd; Mann, Karl; Martinot, Jean-Luc; Paillère-Martinot, Marie-Laure; Nees, Frauke; Paus, Tomas; Pausova, Zdenka; Poustka, Luise; Rietschel, Marcella; Robbins, Trevor W; Smolka, Michael N; Gallinat, Juergen; Schumann, Gunter; Knutson, Brian

    2017-02-21

    Novelty-seeking tendencies in adolescents may promote innovation as well as problematic impulsive behaviour, including drug abuse. Previous research has not clarified whether neural hyper- or hypo-responsiveness to anticipated rewards promotes vulnerability in these individuals. Here we use a longitudinal design to track 144 novelty-seeking adolescents at age 14 and 16 to determine whether neural activity in response to anticipated rewards predicts problematic drug use. We find that diminished BOLD activity in mesolimbic (ventral striatal and midbrain) and prefrontal cortical (dorsolateral prefrontal cortex) regions during reward anticipation at age 14 predicts problematic drug use at age 16. Lower psychometric conscientiousness and steeper discounting of future rewards at age 14 also predicts problematic drug use at age 16, but the neural responses independently predict more variance than psychometric measures. Together, these findings suggest that diminished neural responses to anticipated rewards in novelty-seeking adolescents may increase vulnerability to future problematic drug use.

  2. The Interactive Effects of Affect Lability, Negative Urgency, and Sensation Seeking on Young Adult Problematic Drinking

    PubMed Central

    Karyadi, Kenny; Coskunpinar, Ayca; Dir, Allyson L.; Cyders, Melissa A.

    2013-01-01

    Prior studies have suggested that affect lability might reduce the risk for problematic drinking among sensation seekers by compensating for their deficiencies in emotional reactivity and among individuals high on negative urgency by disrupting stable negative emotions. Due to the high prevalence of college drinking, this study examined whether affect lability interacted with sensation seeking and negative urgency to influence college student problematic drinking. 414 college drinkers (mean age: 20, 77% female, and 74% Caucasian) from a US Midwestern University completed self-administered questionnaires online. Consistent with our hypotheses, our results indicated that the effects of sensation seeking and negative urgency on problematic drinking weakened at higher levels of affect lability. These findings emphasize the importance of considering specific emotional contexts in understanding how negative urgency and sensation seeking create risk for problematic drinking among college students. These findings might also help us better understand how to reduce problematic drinking among sensation seekers and individuals high on negative urgency. PMID:24826366

  3. Blunted ventral striatal responses to anticipated rewards foreshadow problematic drug use in novelty-seeking adolescents

    PubMed Central

    Büchel, Christian; Peters, Jan; Banaschewski, Tobias; Bokde, Arun L. W.; Bromberg, Uli; Conrod, Patricia J.; Flor, Herta; Papadopoulos, Dimitri; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Walter, Henrik; Ittermann, Bernd; Mann, Karl; Martinot, Jean-Luc; Paillère-Martinot, Marie-Laure; Nees, Frauke; Paus, Tomas; Pausova, Zdenka; Poustka, Luise; Rietschel, Marcella; Robbins, Trevor W.; Smolka, Michael N.; Gallinat, Juergen; Schumann, Gunter; Knutson, Brian; Arroyo, Mercedes; Artiges, Eric; Aydin, Semiha; Bach, Christine; Barbot, Alexis; Barker, Gareth; Bruehl, Ruediger; Cattrell, Anna; Constant, Patrick; Crombag, Hans; Czech, Katharina; Dalley, Jeffrey; Decideur, Benjamin; Desrivieres, Sylvane; Fadai, Tahmine; Fauth-Buhler, Mira; Feng, Jianfeng; Filippi, Irinia; Frouin, Vincent; Fuchs, Birgit; Gemmeke, Isabel; Genauck, Alexander; Hanratty, Eanna; Heinrichs, Bert; Heym, Nadja; Hubner, Thomas; Ihlenfeld, Albrecht; Ing, Alex; Ireland, James; Jia, Tianye; Jones, Jennifer; Jurk, Sarah; Kaviani, Mehri; Klaassen, Arno; Kruschwitz, Johann; Lalanne, Christophe; Lanzerath, Dirk; Lathrop, Mark; Lawrence, Claire; Lemaitre, Hervé; Macare, Christine; Mallik, Catherine; Mar, Adam; Martinez-Medina, Lourdes; Mennigen, Eva; de Carvahlo, Fabiana Mesquita; Mignon, Xavier; Millenet, Sabina; Miranda, Ruben; Müller, Kathrin; Nymberg, Charlotte; Parchetka, Caroline; Pena-Oliver, Yolanda; Pentilla, Jani; Poline, Jean-Baptiste; Quinlan, Erin Burke; Rapp, Michael; Ripke, Stephan; Ripley, Tamzin; Robert, Gabriel; Rogers, John; Romanowski, Alexander; Ruggeri, Barbara; Schmäl, Christine; Schmidt, Dirk; Schneider, Sophia; Schubert, Florian; Schwartz, Yannick; Sommer, Wolfgang; Spanagel, Rainer; Speiser, Claudia; Spranger, Tade; Stedman, Alicia; Stephens, Dai; Strache, Nicole; Ströhle, Andreas; Struve, Maren; Subramaniam, Naresh; Theobald, David; Vetter, Nora; Vulser, Helene; Weiss, Katharina; Whelan, Robert; Williams, Steve; Xu, Bing; Yacubian, Juliana; Yu, Tao; Ziesch, Veronika

    2017-01-01

    Novelty-seeking tendencies in adolescents may promote innovation as well as problematic impulsive behaviour, including drug abuse. Previous research has not clarified whether neural hyper- or hypo-responsiveness to anticipated rewards promotes vulnerability in these individuals. Here we use a longitudinal design to track 144 novelty-seeking adolescents at age 14 and 16 to determine whether neural activity in response to anticipated rewards predicts problematic drug use. We find that diminished BOLD activity in mesolimbic (ventral striatal and midbrain) and prefrontal cortical (dorsolateral prefrontal cortex) regions during reward anticipation at age 14 predicts problematic drug use at age 16. Lower psychometric conscientiousness and steeper discounting of future rewards at age 14 also predicts problematic drug use at age 16, but the neural responses independently predict more variance than psychometric measures. Together, these findings suggest that diminished neural responses to anticipated rewards in novelty-seeking adolescents may increase vulnerability to future problematic drug use. PMID:28221370

  4. The impact of shyness on problematic internet use: the role of loneliness.

    PubMed

    Huan, Vivien S; Ang, Rebecca P; Chong, Wan Har; Chye, Stefanie

    2014-01-01

    In recent years, research indicated that the problematic effects of Internet use must be examined together with individual differences present in its users with which such effects are contingent. This study examined loneliness in adolescents as a mediator of the relationship between shyness and their generalized problematic Internet use (PIU). A total of 1469 adolescents (48.5% male, 51.5% female) from Grade 8 and Grade 9 classes participated in this study. Using the Social Reticence Scale (SRS), the revised UCLA Loneliness scale and the Generalized Problematic Internet Use scale, initial findings indicated significant correlations among the three variables. Results from the study further revealed that loneliness completely mediated the relationship between shyness and generalized problematic Internet use. Implications for intervention work addressing both loneliness and shyness issues facing adolescents who are problematic users of the Internet were discussed.

  5. Cognitive deficits in problematic drinkers with and without mild to borderline intellectual disability.

    PubMed

    van Duijvenbode, Neomi; Didden, Robert; VanDerNagel, Joanne El; Korzilius, Hubert Plm; Engels, Rutger Cme

    2016-01-01

    We examined cognitive deficits in problematic drinkers with and without mild to borderline intellectual disability (MBID). Problematic drinkers were expected to show a significantly lower estimated performance IQ (PIQ), but not a lower estimated verbal IQ (VIQ), compared to light drinkers. Participants ( N = 474) were divided into four groups based on IQ and severity of alcohol use-related problems. IQ was estimated using (a short form of) the Wechsler Adult Intelligence Scale third edition. Severity of alcohol use-related problems was assessed using the Alcohol Use Disorder Identification Test. Overall, there were no significant differences between light and problematic drinkers on estimated VIQ. Within the group without MBID, estimated PIQ was significantly lower. Estimated PIQ was not lower in problematic drinkers with MBID compared to light drinkers with MBID. The results are indicative of cognitive deficits in problematic drinkers without MBID. Screening for cognitive deficits with additional instruments is advised.

  6. Self-Esteem and Problematic Drinking in China: A Mediated Model

    PubMed Central

    Zhai, Hui; Yang, Yanjie; Sui, Hong; Wang, Wenbo; Chen, Lu; Qiu, Xiaohui; Yang, Xiuxian; Qiao, Zhengxue; Wang, Lin; Zhu, Xiongzhao; Yang, Jiarun

    2015-01-01

    Background Although self-esteem is related to problematic drinking, the mechanisms by which it affects drinking remain unclear. The purpose of this study was to determine whether coping mechanisms mediate the relationship between self-esteem and problematic drinking among Chinese men and women with alcohol use disorders and to recommend appropriate interventions for drinking problems. Methods A cross-sectional survey was conducted in Harbin, Heilongjiang Province, China. A sample of 5,689 community residents was screened, and 517 male and 172 female problematic drinkers were chosen to participate in this study. A self-esteem scale, a coping questionnaire and an alcohol use disorder identification test were completed in order to assess participants’ self-esteem, coping mechanisms and alcohol use disorders, respectively. Participants’ socio-demographic data were also gathered at this stage. The resulting data were examined via descriptive statistics, correlations and bootstrap analyses. Results Lower self-esteem levels were related to problematic drinking, and there were no gender differences in the relationship between self-esteem and problematic drinking. A relationship between low self-esteem and negative coping was observed only in men. Negative coping thus mediated the relationship between self-esteem and problematic drinking among men, but this was not the case for women. Positive coping did not mediate the relationship between self-esteem and problematic drinking among the participants, regardless of gender. Conclusions Self-esteem and coping strategies are correlated among problematic drinkers. In addition, there are gender differences in the manners in which negative coping mediates the relationship between self-esteem and problematic drinking. Problematic drinking interventions directed at males should simultaneously address low self-esteem and negative coping. PMID:26451595

  7. Exploring Associations between Problematic Internet Use, Depressive Symptoms and Sleep Disturbance among Southern Chinese Adolescents.

    PubMed

    Tan, Yafei; Chen, Ying; Lu, Yaogui; Li, Liping

    2016-03-14

    The primary aim of this study was to examine associations between problematic Internet use, depression and sleep disturbance, and explore whether there were differential effects of problematic Internet use and depression on sleep disturbance. A total of 1772 adolescents who participated in the Shantou Adolescent Mental Health Survey were recruited in 2012 in Shantou, China. The Chinese version of the Internet Addiction Test (IAT) was used to evaluate the prevalence and severity of Internet addiction. The Chinese version of the Pittsburgh Sleep Quality Index (PSQI), a 10-item version of the Center for Epidemiologic Studies Depression Scale (CESD-10), and other socio-demographic measures were also completed. Multiple regression analysis was used to test the mediating effect of problematic Internet use and depression on sleep disturbance. Among the participants, 17.2% of adolescents met the criteria for problematic Internet use, 40.0% were also classified as suffering from sleep disturbance, and 54.4% of students had depressive symptoms. Problematic Internet use was significantly associated with depressive symptoms and sleep disturbance. The correlation between depressive symptoms and sleep disturbance was highly significant. Both problematic Internet use (β = 0.014; Sobel test Z = 12.7, p < 0.001) and depression (β = 0.232; Sobel test Z = 3.39, p < 0.001) had partially mediating effects on sleep disturbance and depression was of greater importance for sleep disturbance than problematic Internet use. There is a high prevalence of problematic Internet use, depression and sleep disturbance among high school students in southern China, and problematic Internet use and depressive symptoms are strongly associated with sleep disturbance. This study provides evidence that problematic Internet use and depression have partially mediating effects on sleep disturbance. These results are important for clinicians and policy makers with useful information for prevention and

  8. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    PubMed

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  9. How to be an ant on figs

    NASA Astrophysics Data System (ADS)

    Bain, Anthony; Harrison, Rhett D.; Schatz, Bertrand

    2014-05-01

    Mutualistic interactions are open to exploitation by one or other of the partners and a diversity of other organisms, and hence are best understood as being embedded in a complex network of biotic interactions. Figs participate in an obligate mutualism in that figs are dependent on agaonid fig wasps for pollination and the wasps are dependent on fig ovules for brood sites. Ants are common insect predators and abundant in tropical forests. Ants have been recorded on approximately 11% of fig species, including all six subgenera, and often affect the fig-fig pollinator interaction through their predation of either pollinating and parasitic wasps. On monoecious figs, ants are often associated with hemipterans, whereas in dioecious figs ants predominantly prey on fig wasps. A few fig species are true myrmecophytes, with domatia or food rewards for ants, and in at least one species this is linked to predation of parasitic fig wasps. Ants also play a role in dispersal of fig seeds and may be particularly important for hemi-epiphytic species, which require high quality establishment microsites in the canopy. The intersection between the fig-fig pollinator and ant-plant systems promises to provide fertile ground for understanding mutualistic interactions within the context of complex interaction networks.

  10. Analysis of acoustic communication by ants.

    PubMed

    Hickling, R; Brown, R L

    2000-10-01

    An analysis is presented of acoustic communication by ants, based on near-field theory and on data obtained from the black imported fire ant Solenopsis richteri and other sources. Generally ant stridulatory sounds are barely audible, but they occur continuously in ant colonies. Because ants appear unresponsive to airborne sound, myrmecologists have concluded that stridulatory signals are transmitted through the substrate. However, transmission through the substrate is unlikely, for reasons given in the paper. Apparently ants communicate mainly through the air, and the acoustic receptors are hairlike sensilla on the antennae that respond to particle sound velocity. This may seem inconsistent with the fact that ants are unresponsive to airborne sound (on a scale of meters), but the inconsistency can be resolved if acoustic communication occurs within the near field, on a scale of about 100 mm. In the near field, the particle sound velocity is significantly enhanced and has a steep gradient. These features can be used to exclude extraneous sound, and to determine the direction and distance of a near-field source. Additionally, we observed that the tracheal air sacs of S. richteri can expand within the gaster, possibly amplifying the radiation of stridulatory sound.

  11. The agricultural pathology of ant fungus gardens

    PubMed Central

    Currie, Cameron R.; Mueller, Ulrich G.; Malloch, David

    1999-01-01

    Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests. These specialized garden parasites, belonging to the microfungus genus Escovopsis (Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies. Consistent with theory of virulence evolution under this mode of pathogen transmission, Escovopsis is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality. The specialized parasite Escovopsis is more prevalent in gardens of the more derived ant lineages than in gardens of the more “primitive” (basal) ant lineages. Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens. PMID:10393936

  12. Extrafloral nectar fuels ant life in deserts

    PubMed Central

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-01-01

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant–plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities. PMID:25381258

  13. Differential Recruitment of Camponotus femoratus (Fabricius) Ants in Response to Ant Garden Herbivory.

    PubMed

    Vicente, R E; Dáttilo, W; Izzo, T J

    2014-12-01

    Although several studies have shown that ants can recognize chemical cues from their host plants in ant-plant systems, it is poorly demonstrated in ant gardens (AGs). In this interaction, ant species constantly interact with various epiphyte species. Therefore, it is possible to expect a convergence of chemical signals released by plants that could be acting to ensure that ants are able to recognize and defend epiphyte species frequently associated with AGs. In this study, it was hypothesized that ants recognize and differentiate among chemical stimuli released by AG epiphytes and non-AG epiphytes. We experimentally simulated leaf herbivore damage on three epiphyte species restricted to AGs and a locally abundant understory herb, Piper hispidum, in order to quantify the number of recruited Camponotus femoratus (Fabricius) defenders. When exposed to the AG epiphytes Peperomia macrostachya and Codonanthe uleana leaves, it was observed that the recruitment of C. femoratus workers was, on average, respectively 556% and 246% higher than control. However, the number of ants recruited by the AG epiphyte Markea longiflora or by the non-AG plant did not differ from paper pieces. This indicated that ants could discern between chemicals released by different plants, suggesting that ants can select better plants. These results can be explained by evolutionary process acting on both ants' capability in discerning plants' chemical compounds (innate attraction) or by ants' learning based on the epiphyte frequency in AGs (individual experience). To disentangle an innate behavior, a product of classical coevolutionary process, from an ant's learned behavior, is a complicated but important subject to understand in the evolution of ant-plant mutualisms.

  14. Problematizing a general physics class: Understanding student engagement

    NASA Astrophysics Data System (ADS)

    Spaid, Mark Randall

    teacher interventions during inquiry lessons which promote scientific inquiry are sometimes successful in moving students from a conforming learning approach to performing, those students usually regress to a previous orientation due to affective and conative factors, especially if they believe the instructional discourse is inadequate. When working in cooperative groups, the disparate epistemologies of students from each learning orientation category becomes problematic.

  15. Ant-lepidopteran associations along African forest edges.

    PubMed

    Dejean, Alain; Azémar, Frédéric; Libert, Michel; Compin, Arthur; Hérault, Bruno; Orivel, Jérôme; Bouyer, Thierry; Corbara, Bruno

    2017-02-01

    Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

  16. Ant-lepidopteran associations along African forest edges

    NASA Astrophysics Data System (ADS)

    Dejean, Alain; Azémar, Frédéric; Libert, Michel; Compin, Arthur; Hérault, Bruno; Orivel, Jérôme; Bouyer, Thierry; Corbara, Bruno

    2017-02-01

    Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

  17. Pheromone disruption of Argentine ant trail integrity

    USGS Publications Warehouse

    Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

    2008-01-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

  18. A cross-taxon analysis of insect-associated bacterial diversity.

    PubMed

    Jones, Ryan Thomas; Sanchez, Leticia Gonzales; Fierer, Noah

    2013-01-01

    Although it is well known that plants and animals harbor microbial symbionts that can influence host traits, the factors regulating the structure of these microbial communities often remain largely undetermined. This is particularly true for insect-associated microbial communities, as few cross-taxon comparisons have been conducted to date. To address this knowledge gap and determine how host phylogeny and ecology affect insect-associated microbial communities, we collected 137 insect specimens representing 39 species, 28 families, and 8 orders, and characterized the bacterial communities associated with each specimen via 16S rRNA gene sequencing. Bacterial taxa within the phylum Proteobacteria were dominant in nearly all insects sampled. On average, the insect-associated bacterial communities were not very diverse, with individuals typically harboring fewer than 8 bacterial phylotypes. Bacterial communities also tended to be dominated by a single phylotype; on average, the most abundant phylotype represented 54.7% of community membership. Bacterial communities were significantly more similar among closely related insects than among less-related insects, a pattern driven by within-species community similarity but detected at every level of insect taxonomy tested. Diet was a poor predictor of bacterial community composition. Individual insect species harbored remarkably unique communities: the distribution of 69.0% of bacterial phylotypes was limited to unique insect species, whereas only 5.7% of phylotypes were detected in more than five insect species. Together these results suggest that host characteristics strongly regulate the colonization and assembly of bacterial communities across insect lineages, patterns that are driven either by co-evolution between insects and their symbionts or by closely related insects sharing conserved traits that directly select for similar bacterial communities.

  19. Taxon-specific growth and selective microzooplankton grazing of phytoplankton in the Northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Gaul, Wilhelm; Antia, Avan N.

    2001-10-01

    Taxon-specific microzooplankton dynamics were studied along a transect through the North Atlantic Drift from 70°N 04°E to 40°N 20°W during July 1997 using serial dilution and nutrient-enrichment experiments. Nutrient concentrations and microzooplankton composition indicated postbloom conditions at 40°N, 47°N, and 50°N, a transitional system at 54°N, and bloom conditions at 62°N and 70°N. The ratio of microzooplankton to phytoplankton biomass was inversely related to nitrate and phosphate concentrations. Potential grazing thresholds were observed in four of nine experiments at 40-66% of the initial phytoplankton concentration. Grazing losses were determined for six pigment-specific classes of phytoplankton. Selective grazing losses of phytoplankton taxa ranged from 73% to 248% of the nonselective grazing losses predicted according to their biomass contributions. The grazing selectivity varied considerably between communities, with the microherbivores showing positive selection for cyanobacteria and dinoflagellates and predominantly avoidance of chlorophyta and bacillariophyceae. Microzooplankton did not show a preference for the dominant phytoplankton taxa, but grazed preferentially on fast-growing phytoplankton with minor contributions (<15%) to the phytoplankton biomass. However, bacillariophyceae were the major contributors to phytoplankton biomass and accounted for major fractions of the total losses through microzooplankton grazing. Microzooplankton consumed the equivalent of 0.12-5.5 times their own biomass daily on a carbon basis, amounting to 65-197% of gross phytoplankton production. With the conservative assumption that 20% of the consumed phytoplankton was converted to microzooplankton biomass, the latter was estimated to contribute 27-381% to the net production of the entire microzooplankton community. We therefore conclude that the taxonomic structure and the net production of the microzooplankton communities were significantly affected by the

  20. Framing the Salmonidae Family Phylogenetic Portrait: A More Complete Picture from Increased Taxon Sampling

    PubMed Central

    Crête-Lafrenière, Alexis; Weir, Laura K.; Bernatchez, Louis

    2012-01-01

    Considerable research efforts have focused on elucidating the systematic relationships among salmonid fishes; an understanding of these patterns of relatedness will inform conservation- and fisheries-related issues, as well as provide a framework for investigating evolutionary mechanisms in the group. However, uncertainties persist in current Salmonidae phylogenies due to biological and methodological factors, and a comprehensive phylogeny including most representatives of the family could provide insight into the causes of these difficulties. Here we increase taxon sampling by including nearly all described salmonid species (n = 63) to present a time-calibrated and more complete portrait of Salmonidae using a combination of molecular markers and analytical techniques. This strategy improved resolution by increasing the signal-to-noise ratio and helped discriminate methodological and systematic errors from sources of difficulty associated with biological processes. Our results highlight novel aspects of salmonid evolution. First, we call into question the widely-accepted evolutionary relationships among sub-families and suggest that Thymallinae, rather than Coregoninae, is the sister group to the remainder of Salmonidae. Second, we find that some groups in Salmonidae are older than previously thought and that the mitochondrial rate of molecular divergence varies markedly among genes and clades. We estimate the age of the family to be 59.1 MY (CI: 63.2-58.1 MY) old, which likely corresponds to the timing of whole genome duplication in salmonids. The average, albeit highly variable, mitochondrial rate of molecular divergence was estimated as ∼0.31%/MY (CI: 0.27–0.36%/MY). Finally, we suggest that some species require taxonomic revision, including two monotypic genera, Stenodus and Salvethymus. In addition, we resolve some relationships that have been notoriously difficult to discern and present a clearer picture of the evolution of the group. Our findings

  1. Two new cytotypes reinforce that Micronycteris hirsuta Peters, 1869 does not represent a monotypic taxon

    PubMed Central

    2013-01-01

    Background The genus Micronycteris is a diverse group of phyllostomid bats currently comprising 11 species, with diploid number (2n) ranging from 26 to 40 chromosomes. The karyotypic relationships within Micronycteris and between Micronycteris and other phyllostomids remain poorly understood. The karyotype of Micronycteris hirsuta is of particular interest: three different diploid numbers were reported for this species in South and Central Americas with 2n = 26, 28 and 30 chromosomes. Although current evidence suggests some geographic differentiation among populations of M. hirsuta based on chromosomal, morphological, and nuclear and mitochondrial DNA markers, the recognition of new species or subspecies has been avoided due to the need for additional data, mainly chromosomal data. Results We describe two new cytotypes for Micronycteris hirsuta (MHI) (2n = 26 and 25, NF = 32), whose differences in diploid number are interpreted as the products of Robertsonian rearrangements. C-banding revealed a small amount of constitutive heterochromatin at the centromere and the NOR was located in the interstitial portion of the short arm of a second pair, confirmed by FISH. Telomeric probes hybridized to the centromeric regions and weakly to telomeric regions of most chromosomes. The G-banding analysis and chromosome painting with whole chromosome probes from Carollia brevicauda (CBR) and Phyllostomus hastatus (PHA) enabled the establishment of genome-wide homologies between MHI, CBR and PHA. Conclusions The karyotypes of Brazilian specimens of Micronycteris hirsuta described here are new to Micronycteris and reinforce that M. hirsuta does not represent a monotypic taxon. Our results corroborate the hypothesis of karyotypic megaevolution within Micronycteris, and strong evidence for this is that the entire chromosome complement of M. hirsuta was shown to be derivative with respect to species compared in this study. PMID:24359225

  2. Using Ant Communities For Rapid Assessment Of Terrestrial Ecosystem Health

    SciTech Connect

    Wike, L

    2005-06-01

    health of the ecosystem. The IBI, though originally for Midwestern streams, has been successfully adapted to other ecoregions and taxa (macroinvertebrates, Lombard and Goldstein, 2004) and has become an important tool for scientists and regulatory agencies alike in determining health of stream ecosystems. The IBI is a specific type of a larger group of methods and procedures referred to as Rapid Bioassessment (RBA). These protocols have the advantage of directly measuring the organisms affected by system perturbations, thus providing an integrated evaluation of system health because the organisms themselves integrate all aspects of their environment and its condition. In addition to the IBI, the RBA concept has also been applied to seep wetlands (Paller et al. 2005) and terrestrial systems (O'Connell et al. 1998, Kremen et al. 1993, Rodriguez et al. 1998, Rosenberg et al. 1986). Terrestrial RBA methods have lagged somewhat behind those for aquatic systems because terrestrial systems are less distinctly defined and seem to have a less universal distribution of an all-inclusive taxon, such as fish in the IBI, upon which to base an RBA. In the last decade, primarily in Australia, extensive development of an RBA using ant communities has shown great promise. Ants have the same advantage for terrestrial RBAs that fish do for aquatic systems in that they are an essential and ubiquitous component of virtually all terrestrial ecosystems. They occupy a broad range of niches, functional groups, and trophic levels and they possess one very important characteristic that makes them ideal for RBA because, similar to the fishes, there is a wide range of tolerance to conditions within the larger taxa. Within ant communities there are certain groups, genera, or species that may be very robust and abundant under even the harshest impacts. There are also taxa that are very sensitive to disturbance and change and their presence or absence is also indicative of the local conditions. Also, as

  3. Reactions by army ant workers to nestmates having had contact with sympatric ant species.

    PubMed

    Dejean, Alain; Corbara, Bruno

    2014-11-01

    It was recently shown that Pheidole megacephala colonies (an invasive species originating from Africa) counterattack when raided by the army ant, Eciton burchellii. The subsequent contact permits Pheidole cuticular compounds (that constitute the "colony odour") to be transferred onto the raiding Eciton, which are then not recognised by their colony-mates and killed. Using a simple method for transferring cuticular compounds, we tested if this phenomenon occurs for Neotropical ants. Eciton workers rubbed with ants from four sympatric species were released among their colony-mates. Individuals rubbed with Solenopsis saevissima or Camponotus blandus workers were attacked, but not those rubbed with Atta sexdens, Pheidole fallax or with colony-mates (control lot). So, the chemicals of certain sympatric ant species, but not others, trigger intra-colonial aggressiveness in Eciton. We conclude that prey-ant chemicals might have played a role in the evolution of army ant predatory behaviour, likely influencing prey specialization in certain cases.

  4. A basic need theory approach to problematic Internet use and the mediating effect of psychological distress.

    PubMed

    Wong, Ting Yat; Yuen, Kenneth S L; Li, Wang On

    2014-01-01

    The Internet provides an easily accessible way to meet certain needs. Over-reliance on it leads to problematic use, which studies show can be predicted by psychological distress. Self-determination theory proposes that we all have the basic need for autonomy, competency, and relatedness. This has been shown to explain the motivations behind problematic Internet use. This study hypothesizes that individuals who are psychologically disturbed because their basic needs are not being met are more vulnerable to becoming reliant on the Internet when they seek such needs satisfaction from online activities, and tests a model in which basic needs predict problematic Internet use, fully mediated by psychological distress. Problematic Internet use, psychological distress, and basic needs satisfaction were psychometrically measured in a sample of 229 Hong Kong University students and structural equation modeling was used to test the hypothesized model. All indices showed the model has a good fit. Further, statistical testing supported a mediation effect for psychological distress between needs satisfaction and problematic Internet use. The results extend our understanding of the development and prevention of problematic Internet use based on the framework of self-determination theory. Psychological distress could be used as an early predictor, while preventing and treating problematic Internet use should emphasize the fulfillment of unmet needs.

  5. A basic need theory approach to problematic Internet use and the mediating effect of psychological distress

    PubMed Central

    Wong, Ting Yat; Yuen, Kenneth S. L.; Li, Wang On

    2015-01-01

    The Internet provides an easily accessible way to meet certain needs. Over-reliance on it leads to problematic use, which studies show can be predicted by psychological distress. Self-determination theory proposes that we all have the basic need for autonomy, competency, and relatedness. This has been shown to explain the motivations behind problematic Internet use. This study hypothesizes that individuals who are psychologically disturbed because their basic needs are not being met are more vulnerable to becoming reliant on the Internet when they seek such needs satisfaction from online activities, and tests a model in which basic needs predict problematic Internet use, fully mediated by psychological distress. Problematic Internet use, psychological distress, and basic needs satisfaction were psychometrically measured in a sample of 229 Hong Kong University students and structural equation modeling was used to test the hypothesized model. All indices showed the model has a good fit. Further, statistical testing supported a mediation effect for psychological distress between needs satisfaction and problematic Internet use. The results extend our understanding of the development and prevention of problematic Internet use based on the framework of self-determination theory. Psychological distress could be used as an early predictor, while preventing and treating problematic Internet use should emphasize the fulfillment of unmet needs. PMID:25642201

  6. Psychometric properties of the problematic online gaming questionnaire short-form and prevalence of problematic online gaming in a national sample of adolescents.

    PubMed

    Pápay, Orsolya; Urbán, Róbert; Griffiths, Mark D; Nagygyörgy, Katalin; Farkas, Judit; Kökönyei, Gyöngyi; Felvinczi, Katalin; Oláh, Attila; Elekes, Zsuzsanna; Demetrovics, Zsolt

    2013-05-01

    The rise and growing popularity of online games has led to the appearance of excessive gaming that in some cases can lead to physical and psychological problems. Several measures have been developed to explore the nature and the scale of the phenomenon. However, few measures have been validated psychometrically. The aim of the present study was to test the psychometric properties of the 12-item Problematic Online Gaming Questionnaire Short-Form (POGQ-SF) and to assess the prevalence of problematic online gaming. Data collection was carried out to assess the prevalence of problematic online gaming in a national representative adolescent sample by using an offline (pen and pencil) method. A total of 5,045 secondary school students were assessed (51% male, mean age 16.4 years, SD=0.9 years) of which 2,804 were gamers (65.4% male, mean age 16.4 years, SD=0.9 years). Confirmatory factor analysis was applied to test the measurement model of problematic online gaming, and latent profile analysis was used to identify the proportion of gamers whose online game use can be considered problematic. Results showed that the original six-factor model yielded appropriate fit to the data, and thus the POGQ-SF has appropriate psychometric properties. Latent profile analysis revealed that 4.6% of the adolescents belong to a high risk group and an additional 13.3% to a low risk group. Due to its satisfactory psychometric characteristics, the 12-item POGQ-SF appears to be an adequate tool for the assessment of problematic online gaming.

  7. Multitasking in a plant-ant interaction: how does Acacia myrtifolia manage both ants and pollinators?

    PubMed

    Martínez-Bauer, Angélica E; Martínez, Gerardo Cerón; Murphy, Daniel J; Burd, Martin

    2015-06-01

    Plant associations with protective ants are widespread among angiosperms, but carry the risk that ants will deter pollinators as well as herbivores. Such conflict, and adaptations to ameliorate or prevent the conflict, have been documented in African and neotropical acacias. Ant-acacia associations occur in Australia, but little is known of their ecology. Moreover, recent phylogenetic evidence indicates that Australian acacias are only distantly related to African and American acacias, providing an intercontinental natural experiment in the management of ant-pollinator conflict. We examined four populations of Acacia myrtifolia over a 400-km environmental gradient in southeastern Australia using ant and pollinator exclusion as well as direct observation of ants and pollinators to assess the potential for ant-pollinator conflict to affect seed set. Native bees were the only group of floral visitors whose visitation rates were a significant predictor of fruiting success, although beetles and wasps may play an important role as "insurance" pollinators. We found no increase in pollinator visitation or fruiting success following ant exclusion, even with large sample sizes and effective exclusion. Because ants are facultative visitors to A. myrtifolia plants, their presence may be insufficient to interfere greatly with floral visitors. It is also likely that the morphological location of extrafloral nectaries tends to draw ants away from reproductive parts, although we commonly observed ants on inflorescences, so the spatial separation is not strict. A. myrtifolia appears to maintain a generalized mutualism over a wide geographic range without the need for elaborate adaptations to resolve ant-pollinator conflict.

  8. Positive effects of shade and shelter construction by ants on leafhopper-ant mutualism.

    PubMed

    Moya-Raygoza, Gustavo; Larsen, Kirk J

    2008-12-01

    The myrmecophilous five-spotted gamagrass leafhopper, Dalbulus quinquenotatus DeLong and Nault, and its tending ants on gamagrass Tripsacum dactyloides L. were examined to determine the influence of shade and ant-constructed shelters on the population sizes of D. quinquenotatus and ants. Gamagrass plants hosting ants and leafhoppers were exposed to 50, 30, or 0% artificially constructed shade. The greatest numbers of leafhoppers and ants were found on plants that received 50% shade. Shelters made by the ant Solenopsis geminata (F.) contained large numbers of leafhoppers and ants but were found only on T. dactyloides exposed to 50% shade in artificially constructed habitats. Additional sampling was conducted on wild gamagrass plants in the field to explore the presence of ants tending leafhoppers in shelters and to evaluate whether ant-constructed shelters protect leafhopper nymphs from parasitoid wasps. Large aggregations of S. geminata in shelters were also found in natural gamagrass habitats. Leafhopper nymphs living in shelters made by S. geminata may be protected against the dryinid wasp parasitoid Anteon ciudadi Olmi. No sheltered nymphs were parasitized by dryinids, whereas 24% of unsheltered nymphs had dryinid parasitism.

  9. Fire disturbance disrupts an acacia ant-plant mutualism in favor of a subordinate ant species.

    PubMed

    Sensenig, Ryan L; Kimuyu, Duncan K; Ruiz Guajardo, Juan Carlos; Veblen, Kari E; Riginos, Corinna; Young, Truman P

    2017-03-08

    Although disturbance theory has been recognized as a useful framework in examining the stability of ant-plant mutualisms, very few studies have examined the effects of fire disturbance on these mutualisms. In myrmecophyte-dominated savannas, fire and herbivory are key drivers that could influence ant-plant mutualisms by causing complete colony mortality and/or decreasing colony size, which potentially could alter dominance hierarchies if subordinate species are more fire resilient. We used a large-scale, replicated fire experiment to examine long-term effects of fire on acacia-ant community composition. To determine if fire shifted ant occupancy from a competitive dominant to a subordinate ant species we surveyed the acacia-ant community in 6-7-year-old burn sites and examined how the spatial scale of these burns influenced ant community responses. We then used two short-term fire experiments to explore possible mechanisms for the shifts in community patterns observed. Because survival of ant colonies is largely dependent on their ability to detect and escape an approaching fire, we first tested the evacuation response of all four ant species when exposed to smoke (fire signal). Then to better understand how fire and its interaction with large mammal herbivory affect the density of ants per tree, we quantified ant worker density in small prescribed burns within herbivore exclusion plots. We found clear evidence suggesting that fire disturbance favored the subordinate ant Crematogaster nigriceps more than the dominant and strong mutualist ant C. mimosae, whereby C. nigriceps: 1) was the only species to occupy a greater proportion of trees in 6-7 year old burn sites compared to unburned sites, 2) had higher burn/unburn tree ratios with increasing burn size; and 3) evacuated significantly faster than C. mimosae in the presence of smoke. Fire and herbivory had opposite effects on ant density per meter of branch for both C. nigriceps and C. mimosae, with fire decreasing

  10. Exploration adjustment by ant colonies

    PubMed Central

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  11. Seeking verisimilitude in a class: a systematic review of evidence that the criterial clinical symptoms of schizophrenia are taxonic.

    PubMed

    Linscott, Richard J; Allardyce, Judith; van Os, Jim

    2010-07-01

    This review examines whether there is evidence that the criterion symptoms of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) schizophrenia are taxonic--that schizophrenia is not part of a single distribution of normality. Two taxometric methods, coherent cut kinetics (CCK) and latent variable modeling (LVM), are demonstrated to be sensitive to latent classes and, therefore, were regarded as providing relevant statistical evidence. A systematic literature search identified 24 articles describing analyses of 28 participant cohorts in which CCK or LVM methods were used with one or more criterion symptoms of schizophrenia. Virtually all analyses yielded results that, on first impression, favored taxonic over dimensional interpretations of the latent structure of schizophrenia. However, threats to the internal and external validity of these studies--including biased or inadequate analyses, violation of statistical assumptions, inadequate indicator screening, and the introduction of systematic error through recruitment and sampling--critically undermine this body of work. Uncertainties about the potential effects of perceptual biases, unimodal assessment, and item parceling are also identified, as are limitations in seeking to validate classes with single or double dissociations of outcomes. We conclude that there is no reason to seriously doubt a single-distribution model of schizophrenia because there is no evidence that provides a serious test of this null hypothesis. A second fundamental question remains outstanding: is schizophrenia truly a group of schizophrenias, with taxonic divisions separating its types? We make design and analysis suggestions for future research addressing these questions.

  12. Evidence that insect herbivores are deterred by ant pheromones.

    PubMed Central

    Offenberg, Joachim; Nielsen, Mogens Gissel; MacIntosh, Donald J; Havanon, Sopon; Aksornkoae, Sanit

    2004-01-01

    It is well documented that ants can protect plants against insect herbivores, but the underlying mechanisms remain almost undocumented. We propose and test the pheromone avoidance hypothesis--an indirect mechanism where insect herbivores are repelled not only by ants but also by ant pheromones. Herbivores subjected to ant predation will experience a selective advantage if they evolve mechanisms enabling them to avoid feeding within ant territories. Such a mechanism could be based on the ability to detect and evade ant pheromones. Field observations and data from the literature showed that the ant Oecophylla smaragdina distributes persistent pheromones throughout its territory. In addition, a laboratory test showed that the beetle Rhyparida wallacei, which this ant preys on, was reluctant to feed on leaves sampled within ant territories compared with leaves sampled outside territories. Thus, this study provides an example of an ant-herbivore system conforming to the pheromone avoidance hypothesis. PMID:15801596

  13. Toxic industrial deposit remediation by ant activity

    NASA Astrophysics Data System (ADS)

    Jilkova, Veronika; Frouz, Jan

    2016-04-01

    Toxic industrial deposits are often contaminated by heavy metals and the substrates have low pH values. In such systems, soil development is thus slowed down by high toxicity and acidic conditions which are unfavourable to soil fauna. Ants (Hymenoptera, Formicidae) are considered tolerant to heavy metal pollution and are known to increase organic matter content and microbial activity in their nests. Here, we focused on soil remediation caused by three ant species (Formica sanguinea, Lasius niger, and Tetramorium sp.) in an ore-washery sedimentation basin near Chvaletice (Czech Republic). Soil samples were taken from the centre of ant nests and from the nest surroundings (>3 m from nests). Samples were then analyzed for microbial activity and biomass and contents of organic matter and nutrients. As a result, ant species that most influenced soil properties was F. sanguinea as there were higher microbial activity and total nitrogen and ammonia contents in ant nests than in the surrounding soil. We expected such a result because F. sanguinea builds conspicuous large nests and is a carnivorous species that brings substantial amounts of nitrogen in insect prey to their nests. Effects of the other two ant species might be lower because of smaller nests and different feeding habits as they rely mainly on honeydew from aphids or on plant seeds that do not contain much nutrients.

  14. Entangled active matter: From cells to ants

    NASA Astrophysics Data System (ADS)

    Hu, D. L.; Phonekeo, S.; Altshuler, E.; Brochard-Wyart, F.

    2016-07-01

    Both cells and ants belong to the broad field of active matter, a novel class of non-equilibrium materials composed of many interacting units that individually consume energy and collectively generate motion or mechanical stresses. However cells and ants differ from fish and birds in that they can support static loads. This is because cells and ants can be entangled, so that individual units are bound by transient links. Entanglement gives cells and ants a set of remarkable properties usually not found together, such as the ability to flow like a fluid, spring back like an elastic solid, and self-heal. In this review, we present the biology, mechanics and dynamics of both entangled cells and ants. We apply concepts from soft matter physics and wetting to characterize these systems as well as to point out their differences, which arise from their differences in size. We hope that our viewpoints will spur further investigations into cells and ants as active materials, and inspire the fabrication of synthetic active matter.

  15. Antarctic Tephra Database (AntT)

    NASA Astrophysics Data System (ADS)

    Kurbatov, A.; Dunbar, N. W.; Iverson, N. A.; Gerbi, C. C.; Yates, M. G.; Kalteyer, D.; McIntosh, W. C.

    2014-12-01

    Modern paleoclimate research is heavily dependent on establishing accurate timing related to rapid shifts in Earth's climate system. The ability to correlate these events at local, and ideally at the intercontinental scales, allows assessment, for example, of phasing or changes in atmospheric circulation. Tephra-producing volcanic eruptions are geologically instantaneous events that are largely independent of climate. We have developed a tephrochronological framework for paleoclimate research in Antarctic in a user friendly, freely accessible online Antarctic tephra (AntT) database (http://cci.um.maine.edu/AntT/). Information about volcanic events, including physical and geochemical characteristics of volcanic products collected from multiple data sources, are integrated into the AntT database.The AntT project establishes a new centralized data repository for Antarctic tephrochronology, which is needed for precise correlation of records between Antarctic ice cores (e.g. WAIS Divide, RICE, Talos Dome, ITASE) and global paleoclimate archives. The AntT will help climatologists, paleoclimatologists, atmospheric chemists, geochemists, climate modelers synchronize paleoclimate archives using volcanic products that establishing timing of climate events in different geographic areas, climate-forcing mechanisms, natural threshold levels in the climate system. All these disciplines will benefit from accurate reconstructions of the temporal and spatial distribution of past rapid climate change events in continental, atmospheric, marine and polar realms. Research is funded by NSF grants: ANT-1142007 and 1142069.

  16. Congestion and communication in confined ant traffic

    NASA Astrophysics Data System (ADS)

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

    2014-03-01

    Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

  17. The macroevolutionary dynamics of ant diversification.

    PubMed

    Pie, Marcio R; Tschá, Marcel K

    2009-11-01

    The availability of increasingly comprehensive phylogenies has provided unprecedented opportunities to assess macroevolutionary patterns, yet studies on invertebrate diversification are few. In particular, despite the ecological and evolutionary importance of ants, little is known about their tempo and mode of diversification. Recent advances in ant phylogenetics can now provide a basis for rigorous analyses of the diversification of ant lineages. The goals of the present study are threefold. First, we demonstrate that a hypothesized disproportionate increase in ant diversification during the angiosperm radiation is largely artifactual. Rather, current evidence points to a fairly constant rate of lineage growth during its history. Moreover, an analysis of diversification patterns across the ant phylogeny indicates considerable rate heterogeneity among lineages. Indeed, and contrary to the expectation if lineages had experienced a single rate of lineage increase, we found no correspondence between genus age and diversity. Finally, we demonstrate a statistically significant phylogenetic signal in ant diversification: closely related genera have diversities that are more similar to one another than one would expect by chance. This suggests that the capacity for diversification may be itself a biological trait that evolved during the radiation of the family Formicidae.

  18. Microfungal "weeds" in the leafcutter ant symbiosis.

    PubMed

    Rodrigues, A; Bacci, M; Mueller, U G; Ortiz, A; Pagnocca, F C

    2008-11-01

    Leafcutter ants (Formicidae: tribe Attini) are well-known insects that cultivate basidiomycete fungi (Agaricales: Lepiotaceae) as their principal food. Fungus gardens are monocultures of a single cultivar strain, but they also harbor a diverse assemblage of additional microbes with largely unknown roles in the symbiosis. Cultivar-attacking microfungi in the genus Escovopsis are specialized parasites found only in association with attine gardens. Evolutionary theory predicts that the low genetic diversity in monocultures should render ant gardens susceptible to a wide range of diseases, and additional parasites with roles similar to that of Escovopsis are expected to exist. We profiled the diversity of cultivable microfungi found in 37 nests from ten Acromyrmex species from Southern Brazil and compared this diversity to published surveys. Our study revealed a total of 85 microfungal strains. Fusarium oxysporum and Escovopsis were the predominant species in the surveyed gardens, infecting 40.5% and 27% of the nests, respectively. No specific relationship existed regarding microfungal species and ant-host species, ant substrate preference (dicot versus grass) or nesting habit. Molecular data indicated high genetic diversity among Escovopsis isolates. In contrast to the garden parasite, F. oxysporum strains are not specific parasites of the cultivated fungus because strains isolated from attine gardens have similar counterparts found in the environment. Overall, the survey indicates that saprophytic microfungi are prevalent in South American leafcutter ants. We discuss the antagonistic potential of these microorganisms as "weeds" in the ant-fungus symbiosis.

  19. Asymmetric hybridization in Rhododendron agastum: a hybrid taxon comprising mainly F1s in Yunnan, China

    PubMed Central

    Zha, Hong-Guang; Milne, Richard I.; Sun, Hang

    2010-01-01

    Background and Aims Rhododendron (Ericaceae) is a large woody genus in which hybridization is thought to play an important role in evolution and speciation, particularly in the Sino-Himalaya region where many interfertile species often occur sympatrically. Rhododendron agastum, a putative hybrid species, occurs in China, western Yunnan Province, in mixed populations with R. irroratum and R. delavayi. Methods Material of these taxa from two sites 400 km apart (ZhuJianYuan, ZJY and HuaDianBa, HDB) was examined using cpDNA and internal transcribed spacer (ITS) sequences, and amplified fragment length polymorphism (AFLP) loci, to test the possibility that R. agastum was in fact a hybrid between two of the other species. Chloroplast trnL-F and trnS-trnG sequences together distinguished R. irroratum, R. delavayi and some material of R. decorum, which is also considered a putative parent of R. agastum. Key Results All 14 R. agastum plants from the HDB site had the delavayi cpDNA haplotype, whereas at the ZJY site 17 R. agastum plants had this haplotype and four had the R. irroratum haplotype. R. irroratum and R. delavayi are distinguished by five unequivocal point mutations in their ITS sequences; every R. agastum accession had an additive pattern (double peaks) at each of these sites. Data from AFLP loci were acquired for between ten and 21 plants of each taxon from each site, and were analysed using a Bayesian approach implemented by the program NewHybrids. The program confirmed the identity of all accessions of R. delavayi, and all R. irroratum except one, which was probably a backcross. All R. agastum from HDB and 19 of 21 from ZJY were classified as F1 hybrids; the other two could not be assigned a class. Conclusions Rhododendron agastum represents populations of hybrids between R. irroratum and R. delavayi, which comprise mostly or only F1s, at the two sites examined. The sites differ in that at HDB there was no detected variation in cpDNA type or hybrid class

  20. Clonal diversity of the taxon Porphyromonas gingivalis assessed by random amplified polymorphic DNA fingerprinting.

    PubMed Central

    Ménard, C; Mouton, C

    1995-01-01

    A total of 97 strains of the periopathogen Porphyromonas gingivalis were collected. This collection included laboratory strains and clinical isolates of human origin with diverse clinical and geographical origins. Biological diversity was further increased by including 32 strains isolated from the oral cavities of nine different animal species. Genomic fingerprints of the 129 strains were generated as random amplified polymorphic DNAs (RAPDs) by the technique of PCR amplification with a single primer of arbitrary sequence. Four nonameric oligonucleotides were used as single primers, and the banding patterns of the DNA products separated on agarose gels were compared after ethidium ethidium bromide staining. Distance coeffients based on the positions of the major DNA fragments were calculated, and dendrograms were generated. We identified 102 clonal types (CTs) that could be assembled into three main groups by cluster analysis by the unweighted pair group method with mathematic averages. Group I (n = 79 CTs) included all 97 human strains and 6 monkey isolates. The strains in group II (n = 22 CTs) and III (n = 1 CT) were strongly differentiated from those in group I and included only strains of animal origin; they likely represent two cryptic species within the present P. gingivalis taxon. We observed that strains from Old World monkeys clustered together with the human genotype, whereas strains from New World monkeys clustered with the animal genotype. Our results with human strains also indicated that (i) the population structure is basically clonal, (ii) no dominant or widespread CT could be observed, and (iii) no relationship could be established between specific clusters of CTs and the periodontal status of the host. Our results corroborate previous findings by B. G. Loos, D. W. Dyer, T. S. Whittam, and R. K. Selander (Infect. Immun. 61:204-212, 1993) and suggest that P. gingivalis should be considered a commensal of the oral cavity acting as an opportunistic

  1. Long branch attraction, taxon sampling, and the earliest angiosperms: Amborella or monocots?

    PubMed Central

    Stefanović, Saša; Rice, Danny W; Palmer, Jeffrey D

    2004-01-01

    Background Numerous studies, using in aggregate some 28 genes, have achieved a consensus in recognizing three groups of plants, including Amborella, as comprising the basal-most grade of all other angiosperms. A major exception is the recent study by Goremykin et al. (2003; Mol. Biol. Evol. 20:1499–1505), whose analyses of 61 genes from 13 sequenced chloroplast genomes of land plants nearly always found 100% support for monocots as the deepest angiosperms relative to Amborella, Calycanthus, and eudicots. We hypothesized that this conflict reflects a misrooting of angiosperms resulting from inadequate taxon sampling, inappropriate phylogenetic methodology, and rapid evolution in the grass lineage used to represent monocots. Results We used two main approaches to test this hypothesis. First, we sequenced a large number of chloroplast genes from the monocot Acorus and added these plus previously sequenced Acorus genes to the Goremykin et al. (2003) dataset in order to explore the effects of altered monocot sampling under the same analytical conditions used in their study. With Acorus alone representing monocots, strongly supported Amborella-sister trees were obtained in all maximum likelihood and parsimony analyses, and in some distance-based analyses. Trees with both Acorus and grasses gave either a well-supported Amborella-sister topology or else a highly unlikely topology with 100% support for grasses-sister and paraphyly of monocots (i.e., Acorus sister to "dicots" rather than to grasses). Second, we reanalyzed the Goremykin et al. (2003) dataset focusing on methods designed to account for rate heterogeneity. These analyses supported an Amborella-sister hypothesis, with bootstrap support values often conflicting strongly with cognate analyses performed without allowing for rate heterogeneity. In addition, we carried out a limited set of analyses that included the chloroplast genome of Nymphaea, whose position as a basal angiosperm was also, and very recently

  2. Snake mitochondrial genomes: phylogenetic relationships and implications of extended taxon sampling for interpretations of mitogenomic evolution

    PubMed Central

    2010-01-01

    alethinophidians. Conclusions Mitochondrial gene sequence data alone may not be able to robustly resolve basal divergences among alethinophidian snakes. Taxon sampling plays an important role in identifying mitogenomic evolutionary events within snakes, and in testing hypotheses explaining their origin. Dramatic rate shifts in mitogenomic evolution occur within Scolecophidia as well as Alethinophidia, thus falsifying the hypothesis that these shifts in snakes are associated exclusively with evolution of a non-burrowing lifestyle, macrostomatan feeding ecology and/or duplication of the control region, both restricted to alethinophidians among living snakes. PMID:20055998

  3. Psychological Factors and Alcohol Use in Problematic Mobile Phone Use in the Spanish Population

    PubMed Central

    De-Sola, José; Talledo, Hernán; Rubio, Gabriel; de Fonseca, Fernando Rodríguez

    2017-01-01

    This research aims to study the existing relationships among the factors of state anxiety, depression, impulsivity, and alcohol consumption regarding problematic mobile phone use, as assessed by the Mobile Phone Problem Use Scale. The study was conducted among 1,126 participants recruited among the general Spanish population, aged 16–65 years, by assessing the predictive value of these variables regarding this problematic use. Initially tobacco use was also considered being subsequently refused because of the low internal consistency of the scale used. In general terms, the results show that this problematic use is mainly related to state anxiety and impulsivity, through the dimensions of Positive and Negative Urgency. Considering its predictive value, multiple regression analysis reveals that state anxiety, positive and negative urgency, and alcohol consumption may predict problematic mobile phone use, ruling out the influence of depression. PMID:28217101

  4. Psychological Factors and Alcohol Use in Problematic Mobile Phone Use in the Spanish Population.

    PubMed

    De-Sola, José; Talledo, Hernán; Rubio, Gabriel; de Fonseca, Fernando Rodríguez

    2017-01-01

    This research aims to study the existing relationships among the factors of state anxiety, depression, impulsivity, and alcohol consumption regarding problematic mobile phone use, as assessed by the Mobile Phone Problem Use Scale. The study was conducted among 1,126 participants recruited among the general Spanish population, aged 16-65 years, by assessing the predictive value of these variables regarding this problematic use. Initially tobacco use was also considered being subsequently refused because of the low internal consistency of the scale used. In general terms, the results show that this problematic use is mainly related to state anxiety and impulsivity, through the dimensions of Positive and Negative Urgency. Considering its predictive value, multiple regression analysis reveals that state anxiety, positive and negative urgency, and alcohol consumption may predict problematic mobile phone use, ruling out the influence of depression.

  5. Refining Measures for Assessing Problematic/Addictive Digital Gaming Use in Clinical and Research Settings.

    PubMed

    Faust, Kyle; Faust, David

    2015-08-12

    Problematic or addictive digital gaming (including all types of electronic devices) can and has had extremely adverse impacts on the lives of many individuals across the world. The understanding of this phenomenon, and the effectiveness of treatment design and monitoring, can be improved considerably by continuing refinement of assessment tools. The present article briefly overviews tools designed to measure problematic or addictive use of digital gaming, the vast majority of which are founded on the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria for other addictive disorders, such as pathological gambling. Although adapting DSM content and strategies for measuring problematic digital gaming has proven valuable, there are some potential issues with this approach. We discuss the strengths and limitations of current methods for measuring problematic or addictive gaming and provide various recommendations that might help in enhancing or supplementing existing tools, or in developing new and even more effective tools.

  6. Factorial validity of the Problematic Facebook Use Scale for adolescents and young adults.

    PubMed

    Marino, Claudia; Vieno, Alessio; Altoè, Gianmarco; Spada, Marcantonio M

    2017-02-15

    Background and aims Recent research on problematic Facebook use has highlighted the need to develop a specific theory-driven measure to assess this potential behavioral addiction. The aim of the present study was to examine the factorial validity of the Problematic Facebook Use Scale (PFUS) adapted from Caplan's Generalized Problematic Internet Scale model. Methods A total of 1,460 Italian adolescents and young adults (aged 14-29 years) participated in the study. Confirmatory factor analyses were performed in order to assess the factorial validity of the scale. Results Results revealed that the factor structure of the PFUS provided a good fit to the data. Furthermore, results of the multiple group analyses supported the invariance of the model across age and gender groups. Discussion and conclusions This study provides evidence supporting the factorial validity of the PFUS. This new scale provides a theory-driven tool to assess problematic use of Facebook among male and female adolescents and young adults.

  7. Too many swipes for today: The development of the Problematic Tinder Use Scale (PTUS).

    PubMed

    Orosz, Gábor; Tóth-Király, István; Bőthe, Beáta; Melher, Dóra

    2016-09-01

    Background and aims Tinder is a very popular smartphone-based geolocated dating application. The goal of the present study was creating a short Problematic Tinder Use Scale (PTUS). Methods Griffiths' ( 2005 ) six-component model was implemented for covering all components of problematic Tinder use. Confirmatory factor analyses were carried out on a Tinder user sample (N = 430). Results Both the 12- and the 6-item versions were tested. The 6-item unidimensional structure has appropriate reliability and factor structure. No salient demography-related differences were found. Users irrespectively to their relationship status have similar scores on PTUS. Discussion Tinder users deserve the attention of scientific examination considering their large proportion among smartphone users. It is especially true considering the emerging trend of geolocated online dating applications. Conclusions Before PTUS, no prior scale has been created to measure problematic Tinder use. The PTUS is a suitable and reliable measure to assess problematic Tinder use.

  8. Too many swipes for today: The development of the Problematic Tinder Use Scale (PTUS)

    PubMed Central

    Orosz, Gábor; Tóth-Király, István; Bőthe, Beáta; Melher, Dóra

    2016-01-01

    Background and aims Tinder is a very popular smartphone-based geolocated dating application. The goal of the present study was creating a short Problematic Tinder Use Scale (PTUS). Methods Griffiths’ (2005) six-component model was implemented for covering all components of problematic Tinder use. Confirmatory factor analyses were carried out on a Tinder user sample (N = 430). Results Both the 12- and the 6-item versions were tested. The 6-item unidimensional structure has appropriate reliability and factor structure. No salient demography-related differences were found. Users irrespectively to their relationship status have similar scores on PTUS. Discussion Tinder users deserve the attention of scientific examination considering their large proportion among smartphone users. It is especially true considering the emerging trend of geolocated online dating applications. Conclusions Before PTUS, no prior scale has been created to measure problematic Tinder use. The PTUS is a suitable and reliable measure to assess problematic Tinder use. PMID:27415602

  9. Refining Measures for Assessing Problematic/Addictive Digital Gaming Use in Clinical and Research Settings

    PubMed Central

    Faust, Kyle; Faust, David

    2015-01-01

    Problematic or addictive digital gaming (including all types of electronic devices) can and has had extremely adverse impacts on the lives of many individuals across the world. The understanding of this phenomenon, and the effectiveness of treatment design and monitoring, can be improved considerably by continuing refinement of assessment tools. The present article briefly overviews tools designed to measure problematic or addictive use of digital gaming, the vast majority of which are founded on the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria for other addictive disorders, such as pathological gambling. Although adapting DSM content and strategies for measuring problematic digital gaming has proven valuable, there are some potential issues with this approach. We discuss the strengths and limitations of current methods for measuring problematic or addictive gaming and provide various recommendations that might help in enhancing or supplementing existing tools, or in developing new and even more effective tools. PMID:26274977

  10. Assessment of problematic internet use by the Compulsive Internet Use Scale and the Internet Addiction Test: a sample of problematic and pathological gamblers.

    PubMed

    Guertler, Diana; Rumpf, Hans-Juergen; Bischof, Anja; Kastirke, Nadin; Petersen, Kay Uwe; John, Ulrich; Meyer, Christian

    2014-01-01

    This study aims to analyze psychometric properties and validity of the Compulsive Internet Use Scale (CIUS) and the Internet Addiction Test (IAT) and, second, to determine a threshold for the CIUS which matches the IAT cut-off for detecting problematic Internet use. A total of 292 subjects with problematic or pathological gambling (237 men, 55 women) aged 14-63 years and with private Internet use for at least 1 h per working or weekend day were recruited via different recruitment channels. Results include that both scales were internally consistent (Cronbach's α=0.9) and had satisfactory convergent validity (r=0.75; 95% CI 0.70-0.80). The correlation with duration of private Internet use per week was significantly higher for the CIUS (r=0.54) compared to the IAT (r=0.40). Among all participants, 25.3% were classified as problematic Internet users based on the IAT with a cut-off≥40. The highest proportion of congruent classified cases results from a CIUS cut-off ≥18 (sensitivity 79.7%, specificity 79.4%). However, a higher cut-off (≥21) seems to be more appropriate for prevalence estimation of problematic Internet use.

  11. Everybody Is…Drinking! Interpretation Bias in Problematic Drinkers with and without Mild to Borderline Intellectual Disability

    ERIC Educational Resources Information Center

    van Duijvenbode, Neomi; Didden, Robert; Korzilius, Hubert P. L. M.; Engels, Rutger C. M. E.

    2016-01-01

    Background: Problematic alcohol use is characterized by disrupted associative processing of environmental clues, where problematic drinkers interpret ambiguous, alcohol-relevant clues in an alcohol-related way. The present study examined the strength of this interpretation bias in a large sample (N = 230) of light and problematic drinkers with and…

  12. Problematic internet use is associated with structural alterations in the brain reward system in females.

    PubMed

    Altbäcker, Anna; Plózer, Enikő; Darnai, Gergely; Perlaki, Gábor; Horváth, Réka; Orsi, Gergely; Nagy, Szilvia Anett; Bogner, Péter; Schwarcz, Attila; Kovács, Norbert; Komoly, Sámuel; Clemens, Zsófia; Janszky, József

    2016-12-01

    Neuroimaging findings suggest that excessive Internet use shows functional and structural brain changes similar to substance addiction. Even though it is still under debate whether there are gender differences in case of problematic use, previous studies by-passed this question by focusing on males only or by using gender matched approach without controlling for potential gender effects. We designed our study to find out whether there are structural correlates in the brain reward system of problematic Internet use in habitual Internet user females. T1-weighted Magnetic Resonance (MR) images were collected in 82 healthy habitual Internet user females. Structural brain measures were investigated using both automated MR volumetry and voxel based morphometry (VBM). Self-reported measures of problematic Internet use and hours spent online were also assessed. According to MR volumetry, problematic Internet use was associated with increased grey matter volume of bilateral putamen and right nucleus accumbens while decreased grey matter volume of orbitofrontal cortex (OFC). Similarly, VBM analysis revealed a significant negative association between the absolute amount of grey matter OFC and problematic Internet use. Our findings suggest structural brain alterations in the reward system usually related to addictions are present in problematic Internet use.

  13. Associations between problematic gaming and psychiatric symptoms among adolescents in two samples.

    PubMed

    Vadlin, Sofia; Åslund, Cecilia; Hellström, Charlotta; Nilsson, Kent W

    2016-10-01

    The aim of the present study was to investigate associations between problematic gaming and psychiatric symptoms among adolescents. Data from adolescents in the SALVe cohort, including adolescents in Västmanland who were born in 1997 and 1999 (N=1868; 1034 girls), and data from consecutive adolescent psychiatric outpatients in Västmanland (N=242; 169 girls) were analyzed. Adolescents self-rated on the Gaming Addiction Identification Test (GAIT), Adult ADHD Self-Report Scale Adolescent version (ASRS-A), Depression Self-Rating Scale Adolescent version (DSRS-A), Spence Children's Anxiety Scale (SCAS), and psychotic-like experiences (PLEs). Multivariable logistic regression analyses were performed, and adjusted for sex, age, study population, school bullying, family maltreatment, and interactions by sex, with two-way interactions between psychiatric measurements. Boys had higher self-rated problematic gaming in both samples, whereas girls self-rated higher in all psychiatric domains. Boys had more than eight times the probability, odds ratio (OR), of having problematic gaming. Symptoms of ADHD, depression and anxiety were associated with ORs of 2.43 (95% CI 1.44-4.11), 2.47 (95% CI 1.44-4.25), and 2.06 (95% CI 1.27-3.33), respectively, in relation to coexisting problematic gaming. Problematic gaming was associated with psychiatric symptoms in adolescents; when problematic gaming is considered, the probability of coexisting psychiatric symptoms should also be considered, and vice versa.

  14. Drinking Motives Mediate the Relationship between Facets of Mindfulness and Problematic Alcohol Use.

    PubMed

    Vinci, Christine; Spears, Claire A; Peltier, MacKenzie R; Copeland, Amy L

    2016-06-01

    Mindfulness is a multi-faceted construct, and research suggests that certain components (e.g., Acting with Awareness, Nonjudging) are associated with less problematic alcohol use. Recent research has examined whether specific drinking motives mediate the relationship between facets of mindfulness and alcohol use. The current study sought to extend this research by examining whether certain drinking motives would mediate the relationship between facets of mindfulness and problematic alcohol use in a sample of 207 college students classified as engaging in problematic drinking. Participants completed the Five Facet Mindfulness Questionnaire (FFMQ), Drinking Motives Questionnaire-Revised (DMQ-R), and Alcohol Use Disorders Identification Test (AUDIT). Results indicated that lower levels of Coping motives significantly mediated the relationship between greater Acting with Awareness and lower AUDIT score and between greater Nonjudging and lower AUDIT score. Lower levels of Conformity motives significantly mediated the relationship between greater Acting with Awareness and lower AUDIT score. These findings offer insight into specific mechanisms through which mindfulness is linked to less problematic drinking, and also highlight associations among mindfulness, drinking motives, and alcohol use among a sample of problematic college student drinkers. Future research should determine whether interventions that emphasize Acting with Awareness and Nonjudging facets of mindfulness and/or target coping and conformity motives could be effective for reducing problematic drinking in college students.

  15. [The model of the big five personality factors and problematic Internet use in Colombian youth].

    PubMed

    Puerta-Cortés, Diana Ximena; Carbonell, Xavier

    2014-01-01

    The aim of the study was to relate the basic dimensions of personality formulated by the model of the big five factors with problematic Internet use in a sample of 411 Colombian youngsters, 18-28 years of age, attending three private universities. Online survey questionnaires were administered for: socio-demographics and Internet usage habits, the Big Five Inventory (John, Donahue and Kentle, 1991), to assess personality, and the Internet Addiction Test (Young, 1998), to determine the degree of use of the Internet (controlled, problematic or addictive). The results revealed that 9.7% of the sample has a problematic Internet use. Among them, the majority were male (x2= 12.93, p= 0.01) and performing communication and leisure activities. The problematic use correlates positively with neuroticism and negatively with friendliness and responsibility. On the other hand, is not related to extraversion and openness to experience. Being female and the responsibility dimension are protective factors from problematic use, while neuroticism predicts it. In conclusion, the study data provides empirical evidence of the relationship between personality and problematic Internet use.

  16. Problematic alcohol use among individuals with HIV: relations with everyday memory functioning and HIV symptom severity.

    PubMed

    Heinz, Adrienne J; Fogler, Kethera A; Newcomb, Michael E; Trafton, Jodie A; Bonn-Miller, Marcel O

    2014-07-01

    Problematic alcohol use has been shown to negatively impact cognitive functions germane to achieving optimal HIV health outcomes. The present study, a secondary data analysis, examined the impact of problematic alcohol use on aspects of everyday memory functioning in a sample of 172 HIV-infected individuals (22 % female; Mage = 48.37 years, SD = 8.64; 39 % Black/non-Hispanic). Additionally, we tested whether self-reported memory functioning explained the relation between problematic alcohol use and HIV symptom severity. Results indicated that problematic patterns of alcohol use were associated with lower total memory functioning, retrieval (e.g., recall-difficulty) and memory for activity (e.g., what you did yesterday) and greater HIV symptom severity. Memory functioning mediated the relation between problematic alcohol use and HIV symptom severity. However, the direction of this relation was unclear as HIV symptom severity also mediated the relation between problematic alcohol use and memory functioning. Findings highlight the importance of integrated care for HIV and alcohol use disorders and suggest that routine alcohol and cognitive screenings may bolster health outcomes among this vulnerable population.

  17. The ant's estimation of distance travelled: experiments with desert ants, Cataglyphis fortis.

    PubMed

    Sommer, S; Wehner, R

    2004-01-01

    Foraging desert ants, Cataglyphis fortis, monitor their position relative to the nest by path integration. They continually update the direction and distance to the nest by employing a celestial compass and an odometer. In the present account we addressed the question of how the precision of the ant's estimate of its homing distance depends on the distance travelled. We trained ants to forage at different distances in linear channels comprising a nest entrance and a feeder. For testing we caught ants at the feeder and released them in a parallel channel. The results show that ants tend to underestimate their distances travelled. This underestimation is the more pronounced, the larger the foraging distance gets. The quantitative relationship between training distance and the ant's estimate of this distance can be described by a logarithmic and an exponential model. The ant's odometric undershooting could be adaptive during natural foraging trips insofar as it leads the homing ant to concentrate the major part of its nest-search behaviour on the base of its individual foraging sector, i.e. on its familiar landmark corridor.

  18. Are ant-aphid associations a tritrophic interaction? Oleander aphids and Argentine ants.

    PubMed

    Bristow, C M

    1991-09-01

    Oleander aphids, (Aphis nerii), which are sporadically tended by ants, were used as a moded system to examine whether host plant factors associated with feeding site influenced the formation of ant-aphid associations. Seasonal patterns of host plant utilization and association with attendant ants were examined through bi-weekly censuses of the aphid population feeding on thirty ornamental oleander plands (Nerium oleander) in northern California in 1985 and 1986. Colonies occurred on both developing and senescing plant terminals, including leaf tips, floral structures, and pods. Aphids preferentially colonized leaf terminals early in the season, but showed no preference for feeding site during later periods. Argentine ants (Iridomyrmex humilis) occasionally tended aphid colonies. Colonies on floral tips were three to four times more likely to attract ants than colonies on leaf tips, even though the latter frequently contained more aphids. Ants showed a positive recruitment response to colonies on floral tips, with a significant correlation between colony size and number of ants. There was no recruitment response to colonies on leaf tips. These patterns were reproducible over two years despite large fluctuations in both aphid population density and ant activity. In a laboratory bioassay of aphid palatability, the generalist predator,Hippodamia convergens, took significantly more aphids reared on floral tips compared to those reared on leaf tips. The patterns reported here support the hypothesis that tritrophic factors may be important in modifying higher level arthropod mutualisms.

  19. Ecology of a fig ant-plant

    NASA Astrophysics Data System (ADS)

    Harrison, Rhett D.

    2014-05-01

    Mutualistic interactions are embedded in networks of interactions that affect the benefits accruing to the mutualistic partners. Figs and their pollinating wasps are engaged in an obligate mutualism in which the fig is dependent on the fig pollinator for pollination services and the pollinator is dependent on fig ovules for brood sites. This mutualism is exploited by non-pollinating fig wasps that utilise the same ovules, but do not provide a pollination service. Most non-pollinating wasps oviposit from outside the inflorescence (syconium), where they are vulnerable to ant predation. Ficus schwarzii is exposed to high densities of non-pollinating wasps, but Philidris sp. ants patrolling the syconia prevent them from ovipositing. Philidris rarely catch wasps, but the fig encourages the patrolling by providing a reward through extra-floral nectaries on the surface of syconia. Moreover, the reward is apparently only produced during the phase when parasitoids are ovipositing. An ant-exclusion experiment demonstrated that, in the absence of ants, syconia were heavily attacked and many aborted as a consequence. Philidris was normally rare on the figs during the receptive phase or at the time of day when wasp offspring are emerging, so predation on pollinators was limited. However, Myrmicaria sp. ants, which only occurred on three trees, preyed substantially on pollinating as well as non-pollinating wasps. F. schwarzii occurs in small clusters of trees and has an exceptionally rapid crop turnover. These factors appear to promote high densities of non-pollinating wasps and, as a consequence, may have led to both a high incidence of ants on trees and increased selective pressure on fig traits that increase the payoffs of the fig-ant interaction for the fig. The fig receives no direct benefit from the reward it provides, but protects pollinating wasps that will disperse its pollen.

  20. The descent of ant: field-measured performance of gliding ants.

    PubMed

    Munk, Yonatan; Yanoviak, Stephen P; Koehl, M A R; Dudley, Robert

    2015-05-01

    Gliding ants avoid predatory attacks and potentially mortal consequences of dislodgement from rainforest canopy substrates by directing their aerial descent towards nearby tree trunks. The ecologically relevant measure of performance for gliding ants is the ratio of net horizontal to vertical distance traveled over the course of a gliding trajectory, or glide index. To study variation in glide index, we measured three-dimensional trajectories of Cephalotes atratus ants gliding in natural rainforest habitats. We determined that righting phase duration, glide angle, and path directness all significantly influence variation in glide index. Unsuccessful landing attempts result in the ant bouncing off its target and being forced to make a second landing attempt. Our results indicate that ants are not passive gliders and that they exert active control over the aerodynamic forces they experience during their descent, despite their apparent lack of specialized control surfaces.

  1. Ant colony optimization algorithm for continuous domains based on position distribution model of ant colony foraging.

    PubMed

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm.

  2. Impacts of residual insecticide barriers on perimeter-invading ants, with particular reference to the odorous house ant, Tapinoma sessile.

    PubMed

    Scharf, Michael E; Ratliff, Catina R; Bennett, Gary W

    2004-04-01

    Three liquid insecticide formulations were evaluated as barrier treatments against perimeter-invading ants at a multifamily housing complex in West Lafayette, IN. Several ant species were present at the study site, including (in order of abundance) pavement ant, Tetramorium caespitum (L.); honey ant, Prenolepis imparis (Say); odorous house ant, Tapinoma sessile (Say); thief ant, Solenopsis molesta (Say); acrobat ant, Crematogaster ashmeadi (Mayr); crazy ant, Paratrechina longicornis (Latrielle), field ants, Formica spp.; and carpenter ant Camponotus pennsylvanicus (DeGeer). Studies began in May 2001 and concluded 8 wk later in July. Individual replicate treatments were placed 0.61 in (2 feet) up and 0.92 m (3 feet) out from the ends of 46.1 by 10.1-m (151 by 33-foot) apartment buildings. Ant sampling was performed with 10 placements of moist cat food for 1 h within treatment zones, followed by capture and removal of recruited ants for later counting. All treatments led to substantial reductions in ant numbers relative to untreated controls. The most effective treatment was fipronil, where 2% of before-treatment ant numbers were present at 8 wk after treatment. Both imidacloprid and cyfluthrin barrier treatments had efficacy comparative with fipronil, but to 4 and 2 wk, respectively. Odorous house ants were not sampled before treatment. Comparisons of ant species composition between treatments and controls revealed an increase in odorous house ant frequencies at 1-8 wk after treatment in treated locations only. These results demonstrate efficacy for both nonrepellent and repellent liquid insecticides as perimeter treatments for pest ants. In addition, our findings with odorous house ant highlight an apparent invasive-like characteristic of this species that may contribute to its dramatic increase in structural infestation rates in many areas of the United States.

  3. Statistical Mechanics of Collective Transport by Ants

    NASA Astrophysics Data System (ADS)

    Pinkoviezky, Itai; Gelblum, Aviram; Fonio, Ehud; Ghosh, Abhijit; Gov, Nir; Feinerman, Ofer

    Collective decisions and cooperation within groups are essential for the survival of many species. Conflicts within the group must be suppressed but conformism may render the system unresponsive to new information. Collective transport by ants is therefore an ideal model system to study how animal groups optimize these opposing requirements. We combine experiments and theory to characterize the collective transport. The ants are modeled as binary Ising spins, representing the two roles ants can perform during transport. It turns out that the ants poise themselves collectively near a critical point where the response to a newly attached ant is maximized. We identify the size as being proportional to an inverse effective temperature and thus the system can exhibit a mesoscopic transition between order and disorder by manipulating the size. Constraining the cargo with a string makes the system behave as a strongly non-linear pendulum. Theoretically we predict that a Hopf bifurcation occurs at a critical size followed by a global bifurcation where full swings emerge. Remarkably, these theoretical predictions were verified experimentally.

  4. Fossil evidence for the early ant evolution

    NASA Astrophysics Data System (ADS)

    Perrichot, Vincent; Lacau, Sébastien; Néraudeau, Didier; Nel, André

    2008-02-01

    Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.

  5. Early ant trajectories: spatial behaviour before behaviourism.

    PubMed

    Wehner, Rüdiger

    2016-04-01

    In the beginning of the twentieth century, when Jacques Loeb's and John Watson's mechanistic view of life started to dominate animal physiology and behavioural biology, several scientists with different academic backgrounds got engaged in studying the wayfinding behaviour of ants. Largely unaffected by the scientific spirit of the time, they worked independently of each other in different countries: in Algeria, Tunisia, Spain, Switzerland and the United States of America. In the current literature on spatial cognition these early ant researchers--Victor Cornetz, Felix Santschi, Charles Turner and Rudolf Brun--are barely mentioned. Moreover, it is virtually unknown that the great neuroanatomist Santiago Ramón y Cajal had also worked on spatial orientation in ants. This general neglect is certainly due to the fact that nearly all these ant researchers were scientific loners, who did their idiosyncratic investigations outside the realm of comparative physiology, neurobiology and the behavioural sciences of the time, and published their results in French, German, and Spanish at rather inaccessible places. Even though one might argue that much of their work resulted in mainly anecdotal evidence, the conceptual approaches of these early ant researchers preempt much of the present-day discussions on spatial representation in animals.

  6. Disentangling effects of abiotic factors and biotic interactions on cross-taxon congruence in species turnover patterns of plants, moths and beetles

    NASA Astrophysics Data System (ADS)

    Duan, Meichun; Liu, Yunhui; Yu, Zhenrong; Baudry, Jacques; Li, Liangtao; Wang, Changliu; Axmacher, Jan C.

    2016-04-01

    High cross-taxon congruence in species diversity patterns is essential for the use of surrogate taxa in biodiversity conservation, but presence and strength of congruence in species turnover patterns, and the relative contributions of abiotic environmental factors and biotic interaction towards this congruence, remain poorly understood. In our study, we used variation partitioning in multiple regressions to quantify cross-taxon congruence in community dissimilarities of vascular plants, geometrid and arciinid moths and carabid beetles, subsequently investigating their respective underpinning by abiotic factors and biotic interactions. Significant cross-taxon congruence observed across all taxon pairs was linked to their similar responses towards elevation change. Changes in the vegetation composition were closely linked to carabid turnover, with vegetation structure and associated microclimatic conditions proposed causes of this link. In contrast, moth assemblages appeared to be dominated by generalist species whose turnover was weakly associated with vegetation changes. Overall, abiotic factors exerted a stronger influence on cross-taxon congruence across our study sites than biotic interactions. The weak congruence in turnover observed particularly between plants and moths highlights the importance of multi-taxon approaches based on groupings of taxa with similar turnovers, rather than the use of single surrogate taxa or environmental proxies, in biodiversity assessments.

  7. Disentangling effects of abiotic factors and biotic interactions on cross-taxon congruence in species turnover patterns of plants, moths and beetles

    PubMed Central

    Duan, Meichun; Liu, Yunhui; Yu, Zhenrong; Baudry, Jacques; Li, Liangtao; Wang, Changliu; Axmacher, Jan C.

    2016-01-01

    High cross-taxon congruence in species diversity patterns is essential for the use of surrogate taxa in biodiversity conservation, but presence and strength of congruence in species turnover patterns, and the relative contributions of abiotic environmental factors and biotic interaction towards this congruence, remain poorly understood. In our study, we used variation partitioning in multiple regressions to quantify cross-taxon congruence in community dissimilarities of vascular plants, geometrid and arciinid moths and carabid beetles, subsequently investigating their respective underpinning by abiotic factors and biotic interactions. Significant cross-taxon congruence observed across all taxon pairs was linked to their similar responses towards elevation change. Changes in the vegetation composition were closely linked to carabid turnover, with vegetation structure and associated microclimatic conditions proposed causes of this link. In contrast, moth assemblages appeared to be dominated by generalist species whose turnover was weakly associated with vegetation changes. Overall, abiotic factors exerted a stronger influence on cross-taxon congruence across our study sites than biotic interactions. The weak congruence in turnover observed particularly between plants and moths highlights the importance of multi-taxon approaches based on groupings of taxa with similar turnovers, rather than the use of single surrogate taxa or environmental proxies, in biodiversity assessments. PMID:27032533

  8. Disentangling effects of abiotic factors and biotic interactions on cross-taxon congruence in species turnover patterns of plants, moths and beetles.

    PubMed

    Duan, Meichun; Liu, Yunhui; Yu, Zhenrong; Baudry, Jacques; Li, Liangtao; Wang, Changliu; Axmacher, Jan C

    2016-04-01

    High cross-taxon congruence in species diversity patterns is essential for the use of surrogate taxa in biodiversity conservation, but presence and strength of congruence in species turnover patterns, and the relative contributions of abiotic environmental factors and biotic interaction towards this congruence, remain poorly understood. In our study, we used variation partitioning in multiple regressions to quantify cross-taxon congruence in community dissimilarities of vascular plants, geometrid and arciinid moths and carabid beetles, subsequently investigating their respective underpinning by abiotic factors and biotic interactions. Significant cross-taxon congruence observed across all taxon pairs was linked to their similar responses towards elevation change. Changes in the vegetation composition were closely linked to carabid turnover, with vegetation structure and associated microclimatic conditions proposed causes of this link. In contrast, moth assemblages appeared to be dominated by generalist species whose turnover was weakly associated with vegetation changes. Overall, abiotic factors exerted a stronger influence on cross-taxon congruence across our study sites than biotic interactions. The weak congruence in turnover observed particularly between plants and moths highlights the importance of multi-taxon approaches based on groupings of taxa with similar turnovers, rather than the use of single surrogate taxa or environmental proxies, in biodiversity assessments.

  9. Evidence-Informed Clinical Practice Recommendations for Treatment of Type 1 Diabetes Complicated by Problematic Hypoglycemia

    PubMed Central

    Choudhary, Pratik; Rickels, Michael R.; Senior, Peter A.; Vantyghem, Marie-Christine; Maffi, Paola; Kay, Thomas W.; Keymeulen, Bart; Inagaki, Nobuya; Saudek, Frantisek; Lehmann, Roger

    2015-01-01

    Problematic hypoglycemia, defined as two or more episodes per year of severe hypoglycemia or as one episode associated with impaired awareness of hypoglycemia, extreme glycemic lability, or major fear and maladaptive behavior, is a challenge, especially for patients with long-standing type 1 diabetes. Individualized therapy for such patients should include a composite target: optimal glucose control without problematic hypoglycemia. Therefore, we propose a tiered, four-stage algorithm based on evidence of efficacy given the limitations of educational, technological, and transplant interventions. All patients with problematic hypoglycemia should undergo structured or hypoglycemia-specific education programs (stage 1). Glycemic and hypoglycemia treatment targets should be individualized and reassessed every 3–6 months. If targets are not met, one diabetes technology—continuous subcutaneous insulin infusion or continuous glucose monitoring—should be added (stage 2). For patients with continued problematic hypoglycemia despite education (stage 1) and one diabetes technology (stage 2), sensor-augmented insulin pumps preferably with an automated low-glucose suspend feature and/or very frequent contact with a specialized hypoglycemia service can reduce hypoglycemia (stage 3). For patients whose problematic hypoglycemia persists, islet or pancreas transplant should be considered (stage 4). This algorithm provides an evidence-informed approach to resolving problematic hypoglycemia; it should be used as a guide, with individual patient circumstances directing suitability and acceptability to ensure the prudent use of technology and scarce transplant resources. Standardized reporting of hypoglycemia outcomes and inclusion of patients with problematic hypoglycemia in studies of new interventions may help to guide future therapeutic strategies. PMID:25998294

  10. Establishing food site vectors in desert ants.

    PubMed

    Bolek, Siegfried; Wittlinger, Matthias; Wolf, Harald

    2012-02-15

    When returning to the site of a successful previous forage, where does one search for the goodies? Should one rely on experience from the previous homebound journey, or should one consider the outbound journey as well, or even exclusively? Desert ants are particularly well suited for pursuing this question because of their primary reliance on path integration in open and featureless desert habitats. Path integration has been studied particularly with regard to homing after lengthy foraging trips. The ants also use path integration to return to plentiful feeding sites, but what is memorised for revisiting the feeder remains controversial. Here, we demonstrate that desert ants consider, and indeed linearly average, both outbound and inbound travel for their return to a familiar feeder. This may be interpreted as a strategy to reduce navigation errors.

  11. Desert ants learn vibration and magnetic landmarks.

    PubMed

    Buehlmann, Cornelia; Hansson, Bill S; Knaden, Markus

    2012-01-01

    The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

  12. Moribund Ants Do Not Call for Help

    PubMed Central

    Miler, Krzysztof

    2016-01-01

    When an antlion captures a foraging ant, the victim’s nestmates may display rescue behaviour. This study tested the hypothesis that the expression of rescue behaviour depends on the life expectancy of the captured ant. This hypothesis predicts that the expression of rescue behaviour will be less frequent when the captured ant has a lower life expectancy than when it has a higher life expectancy because such a response would be adaptive at the colony level. Indeed, significant differences were found in the frequency of rescue behaviours in response to antlion victims with differing life expectancies. In agreement with prediction, victims with lower life expectancies were rescued less frequently, and those rescues had a longer latency and shorter duration. There was also a qualitative difference in the behaviour of rescuers to victims from the low and high life expectancy groups. Several explanations for these findings are proposed. PMID:26986741

  13. Molecular phylogeny and divergence times of Malagasy tenrecs: Influence of data partitioning and taxon sampling on dating analyses

    PubMed Central

    2008-01-01

    Background Malagasy tenrecs belong to the Afrotherian clade of placental mammals and comprise three subfamilies divided in eight genera (Tenrecinae: Tenrec, Echinops, Setifer and Hemicentetes; Oryzorictinae: Oryzorictes, Limnogale and Microgale; Geogalinae:Geogale). The diversity of their morphology and incomplete taxon sampling made it difficult until now to resolve phylogenies based on either morphology or molecular data for this group. Therefore, in order to delineate the evolutionary history of this family, phylogenetic and dating analyses were performed on a four nuclear genes dataset (ADRA2B, AR, GHR and vWF) including all Malagasy tenrec genera. Moreover, the influence of both taxon sampling and data partitioning on the accuracy of the estimated ages were assessed. Results Within Afrotheria the vast majority of the nodes received a high support, including the grouping of hyrax with sea cow and the monophyly of both Afroinsectivora (Macroscelidea + Afrosoricida) and Afroinsectiphillia (Tubulidentata + Afroinsectivora). Strongly supported relationships were also recovered among all tenrec genera, allowing us to firmly establish the grouping of Geogale with Oryzorictinae, and to confirm the previously hypothesized nesting of Limnogale within the genus Microgale. The timeline of Malagasy tenrec diversification does not reflect a fast adaptive radiation after the arrival on Madagascar, indicating that morphological specializations have appeared over the whole evolutionary history of the family, and not just in a short period after colonization. In our analysis, age estimates at the root of a clade became older with increased taxon sampling of that clade. Moreover an augmentation of data partitions resulted in older age estimates as well, whereas standard deviations increased when more extreme partition schemes were used. Conclusion Our results provide as yet the best resolved gene tree comprising all Malagasy tenrec genera, and may lead to a revision of tenrec

  14. Detection of Mitochondrial COII DNA Sequences in Ant Guts as a Method for Assessing Termite Predation by Ants

    PubMed Central

    Fayle, Tom M.; Scholtz, Olivia; Dumbrell, Alex J.; Russell, Stephen; Segar, Simon T.; Eggleton, Paul

    2015-01-01

    Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs. PMID:25853549

  15. Detection of mitochondrial COII DNA sequences in ant guts as a method for assessing termite predation by ants.

    PubMed

    Fayle, Tom M; Scholtz, Olivia; Dumbrell, Alex J; Russell, Stephen; Segar, Simon T; Eggleton, Paul

    2015-01-01

    Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs.

  16. Ant-gardens of tropical Asian rainforests.

    PubMed

    Kaufmann, Eva; Maschwitz, Ulrich

    2006-05-01

    Ant-garden (AG) associations are systems of epiphytic plants and arboricolous (i.e., tree-living) ants, in which the ants build fragile carton nests containing organic material. They collect and incorporate seeds or fruits of epiphytes that then germinate and grow on the nest [sensu Corbara et al. (1999) 38:73-89]. The plant roots stabilize the nest carton. AGs have been well-known in the neotropics for more than 100 years. In contrast, reports on similar associations in the paleotropics are scarce so far. After discovering a first common AG system on giant bamboo [Kaufmann et al. (2001) 48:125-133], we started a large-scale survey for AGs in Peninsular Malaysia, Borneo, Java, and southern Thailand. A great variety of AG systems (altogether including 18 ant species and 51 plant species) was discovered and is described in the present paper. The high number of species participating in AG associations was reflected by a great variability in the specific appearances of the nest gardens. Frequently, further groups of organisms (e.g., hemipteran trophobionts, fungi) were also involved. Preference patterns of particular ant and epiphyte species for each other and for particular phorophytes (carrier trees) were detected. We integrate domatia-producing, so-called ant-house epiphytes in our study and compare their phases of establishment, as well as other characteristics, to "classical" AGs, coming to the conclusion that they should be regarded only as a special type of AG epiphyte and not as a separate ecological category.

  17. Ant-gardens of tropical Asian rainforests

    NASA Astrophysics Data System (ADS)

    Kaufmann, Eva; Maschwitz, Ulrich

    2006-05-01

    Ant-garden (AG) associations are systems of epiphytic plants and arboricolous (i.e., tree-living) ants, in which the ants build fragile carton nests containing organic material. They collect and incorporate seeds or fruits of epiphytes that then germinate and grow on the nest [sensu Corbara et al. (1999) 38:73-89]. The plant roots stabilize the nest carton. AGs have been well-known in the neotropics for more than 100 years. In contrast, reports on similar associations in the paleotropics are scarce so far. After discovering a first common AG system on giant bamboo [Kaufmann et al. (2001) 48:125-133], we started a large-scale survey for AGs in Peninsular Malaysia, Borneo, Java, and southern Thailand. A great variety of AG systems (altogether including 18 ant species and 51 plant species) was discovered and is described in the present paper. The high number of species participating in AG associations was reflected by a great variability in the specific appearances of the nest gardens. Frequently, further groups of organisms (e.g., hemipteran trophobionts, fungi) were also involved. Preference patterns of particular ant and epiphyte species for each other and for particular phorophytes (carrier trees) were detected. We integrate domatia-producing, so-called ant-house epiphytes in our study and compare their phases of establishment, as well as other characteristics, to “classical” AGs, coming to the conclusion that they should be regarded only as a special type of AG epiphyte and not as a separate ecological category.

  18. An ant's-eye view of an ant-plant protection mutualism.

    PubMed

    Lanan, M C; Bronstein, J L

    2013-07-01

    Ant protection of extrafloral nectar (EFN)-secreting plants is a common form of mutualism found in most habitats around the world. However, very few studies have considered these mutualisms from the ant, rather than the plant, perspective. In particular, a whole-colony perspective that takes into account the spatial structure and nest arrangement of the ant colonies that visit these plants has been lacking, obscuring when and how colony-level foraging decisions might affect tending rates on individual plants. Here, we experimentally demonstrate that recruitment of Crematogaster opuntiae (Buren) ant workers to the EFN-secreting cactus Ferocactus wislizeni (Englem) is not independent between plants up to 5 m apart. Colony territories of C. opuntiae are large, covering areas of up to 5,000 m(2), and workers visit between five and 34 EFN-secreting barrel cacti within the territories. These ants are highly polydomous, with up to 20 nest entrances dispersed throughout the territory and interconnected by trail networks. Our study demonstrates that worker recruitment is not independent within large polydomous ant colonies, highlighting the importance of considering colonies rather than individual workers as the relevant study unit within ant/plant protection mutualisms.

  19. An ants-eye view of an ant-plant protection mutualism

    PubMed Central

    Lanan, M. C.; Bronstein, J. L.

    2013-01-01

    Ant protection of extrafloral nectar-secreting plants (EFN plants) is a common form of mutualism found in most habitats around the world. However, very few studies have considered these mutualisms from the ant, rather than the plant, perspective. In particular, a whole-colony perspective that takes into account the spatial structure and nest arrangement of the ant colonies that visit these plants has been lacking, obscuring when and how colony-level foraging decisions might affect tending rates on individual plants. Here, we experimentally demonstrate that recruitment of Crematogaster opuntiae (Buren) ant workers to the extrafloral nectar-secreting cactus Ferocactus wislizeni (Englem) is not independent between plants up to 5m apart. Colony territories of C. opuntiae are large, covering areas of up to 5000m2, and workers visit between five and thirty-four extrafloral nectar-secreting barrel cacti within the territories. These ants are highly polydomous, with up to twenty nest entrances dispersed throughout the territory and interconnected by trail networks. Our study demonstrates that worker recruitment is not independent within large polydomous ant colonies, highlighting the importance of considering colonies rather than individual workers as the relevant study unit within ant/plant protection mutualisms PMID:23515612

  20. Wolbachia transmission dynamics in Formica wood ants

    PubMed Central

    2008-01-01

    Background The role of Wolbachia endosymbionts in shaping the mitochondrial diversity of their arthropod host depends on the effects they have on host reproduction and on the mode of transmission of the bacteria. We have compared the sequence diversity of wsp (Wolbachia surface protein gene) and the host mtDNA in a group of Formica ant species that have diverged approximately 0.5 million years ago (MYA). The aim was to study the relationship of Wolbachia and its ant hosts in terms of vertical and horizontal transmission of the bacteria. Results All studied ant species were doubly infected with two Wolbachia strains (wFex1 and wFex4) all over their geographical distribution area in Eurasia. The most common haplotypes of these strains were identical with strains previously described from a more distantly related Formica ant, with an estimated divergence time of 3.5 – 4 MYA. Some strain haplotypes were associated to the same or closely related mtDNA haplotypes as expected under vertical transmission. However, in several cases the wsp haplotypes coexisted with distant mtDNA haplotypes, a pattern which is more compatible with horizontal transmission of the bacteria. Conclusion Two lines of evidence suggest that the sharing of Wolbachia strains by all F. rufa species is rather due to horizontal than vertical transmission. First, the fact that endosymbiont strains identical to those of F. rufa ants have been found in another species that diverged 3.5–4 MYA strongly suggests that horizontal transfer can and does occur between Formica ants. Second, the frequent sharing of identical Wolbachia strains by distant mitochondrial lineages within the F. rufa group further shows that horizontal transmission has occurred repeatedly. Nevertheless, our dataset also provides some evidence for longer-term persistence of infection, indicating that Wolbachia infection within this host clade has been shaped by both horizontal and vertical transmission of symbionts. The fact that all

  1. Ant-plants and fungi: a new threeway symbiosis.

    PubMed

    Defossez, Emmanuel; Selosse, Marc-André; Dubois, Marie-Pierre; Mondolot, Laurence; Faccio, Antonella; Djieto-Lordon, Champlain; McKey, Doyle; Blatrix, Rumsaïs

    2009-06-01

    Symbioses between plants and fungi, fungi and ants, and ants and plants all play important roles in ecosystems. Symbioses involving all three partners appear to be rare. Here, we describe a novel tripartite symbiosis in which ants and a fungus inhabit domatia of an ant-plant, and present evidence that such interactions are widespread. We investigated 139 individuals of the African ant-plant Leonardoxa africana for occurrence of fungus. Behaviour of mutualist ants toward the fungus within domatia was observed using a video camera fitted with an endoscope. Fungi were identified by sequencing a fragment of their ribosomal DNA. Fungi were always present in domatia occupied by mutualist ants but never in domatia occupied by opportunistic or parasitic ants. Ants appear to favour the propagation, removal and maintenance of the fungus. Similar fungi were associated with other ant-plants in Cameroon. All belong to the ascomycete order Chaetothyriales; those from L. africana formed a monophyletic clade. These new plant-ant-fungus associations seem to be specific, as demonstrated within Leonardoxa and as suggested by fungal phyletic identities. Such tripartite associations are widespread in African ant-plants but have long been overlooked. Taking fungal partners into account will greatly enhance our understanding of symbiotic ant-plant mutualisms.

  2. Ambivalent versus Problematic Social Ties: Implications for Psychological Health, Functional Health, and Interpersonal Coping

    PubMed Central

    Rook, Karen S.; Luong, Gloria; Sorkin, Dara H.; Newsom, Jason T.; Krause, Neal

    2013-01-01

    Older adults often seek to manage their social networks to foster positive interactions, but they nonetheless sometimes experience negative interactions that detract from their health and well-being. Negative interactions may occur with ambivalent social partners (i.e., partners involved in both positive and negative exchanges) or exclusively problematic social partners (i.e., partners involved negative exchanges only), but conflicting views exist in the literature regarding which type of social partner is likely to be more detrimental to older adults’ physical and emotional health. This study examined the implications of the two kinds of network members for physical and psychological health and interpersonal coping responses in a representative sample of 916 older adults. Within this elderly sample, older age was associated with fewer ambivalent kin ties and fewer exclusively problematic kin ties. Analyses revealed that ambivalent social ties were more strongly related to functional health limitations than were exclusively problematic social ties, whereas problematic ties were more consistently related to psychological health than were ambivalent ties. Furthermore, negative exchanges that occurred with exclusively problematic social ties, as compared to those that occurred with ambivalent social ties, were associated with more avoidant and fewer conciliatory coping responses, stronger and longer-lasting negative emotions, and lower perceived coping effectiveness. A comprehensive understanding of the significance of social network ties in older adults’ lives may benefit not only from attention to sources of social support but also from efforts to distinguish between different sources of conflict and disappointment. PMID:22775360

  3. Problematic internet pornography use: The role of craving, desire thinking, and metacognition.

    PubMed

    Allen, Andrew; Kannis-Dymand, Lee; Katsikitis, Mary

    2017-07-01

    Defined as sexually explicit material that elicits erotic thoughts, feelings, and behaviours, internet pornography is a prevalent form of media that may facilitate problematic use and craving for engagement. Research suggests that superordinate cognitions and information processing, such as desire thinking and metacognition, are central to the activation and escalation of craving in addictive behaviours. The current study aimed to contribute to the literature by testing the proposed metacognitive model of desire thinking and craving in a sample of problematic pornography users, while revising the model by incorporating negative affect. From a theoretical perspective, environmental cues trigger positive metacognitions about desire thinking that directly influence desire thinking, resulting in the escalation of craving, negative metacognitions, and negative affect. Participants were recruited via an online survey and screened for problematic internet pornography use. Path analyses were used to investigate relationships among the aforementioned constructs in a final sample of 191 participants. Consistent with previous research, results of this study validated the existence of metacognitive processes in the activation of desire thinking and escalation of craving, while indicating that desire thinking has the potential to influence negative affect. Additionally, results supported the role of significant indirect relationships between constructs within the revised model of metacognition, desire thinking, and psychopathology. Collectively, the findings demonstrate the clinical value of a metacognitive conceptualisation of problematic pornography use. Exploring the metacognitive mechanisms that underpin problematic internet pornography use may give rise to the development of new treatment and relapse prevention strategies.

  4. Associations of body weight perception and weight control behaviors with problematic internet use among Korean adolescents.

    PubMed

    Park, Subin; Lee, Yeeun

    2017-05-01

    We examined the association of body mass index (BMI), body weight perception, and weight control behaviors with problematic Internet use in a nationwide sample of Korean adolescents. Cross-sectional data from the 2010 Korean Youth Risk Behavior Web-based Survey collected from 37,041 boys and 33,655 girls in middle- and high- schools (grades 7-12) were analyzed. Participants were classified into groups based on BMI (underweight, normal weight, overweight, and obese), body weight perception (underweight, normal weight, and overweight), and weight control behavior (no weight control behavior, appropriate weight control behavior, inappropriate weight control behavior). The risk of problematic Internet use was assessed with the Korean Internet Addiction Proneness Scale for Youth-Short Form. Both boys and girls with inappropriate weight control behavior were more likely to have problematic Internet use. Underweight, overweight, and obese boys and girls were more likely to have problematic Internet use. For both boys and girls, subjective perception of underweight and overweight were positively associated with problematic Internet use. Given the negative effect of inappropriate weight control behavior, special attention needs to be given to adolescents' inappropriate weight control behavior, and an educational intervention for adolescents to control their weight in healthy ways is needed.

  5. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging.

    PubMed

    Lange, Denise; Calixto, Eduardo Soares; Del-Claro, Kleber

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system.

  6. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging

    PubMed Central

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system. PMID:28046069

  7. Self-organized criticality in ant brood tending.

    PubMed

    O'Toole, D V; Robinson, P A; Myerscough, M R

    2003-03-07

    A new stochastic lattice gas model of ant brood tending is formulated to examine the role played by repulsive ant-ant interactions in the even distribution of care among brood members. The deterministic limit of the model is known to be self-organized critical. Numerical simulations of the model show that the ant-ant repulsion facilitates an even distribution of brood care in the middle of the brood. This provides a possible explanation for the fact that ants sort their brood so that the youngest brood (which are most in need of care) are placed in the middle. Simulations show that the uniformity of brood care distribution is optimal when ants operate in a regime intermediate between completely random and completely deterministic. A certain degree of randomness helps ants to avoid becoming trapped in suboptimal configurations but does not destroy the long-range correlations that are inherent to self-organized critical systems.

  8. Seeking Verisimilitude in a Class: A Systematic Review of Evidence That the Criterial Clinical Symptoms of Schizophrenia Are Taxonic

    PubMed Central

    Linscott, Richard J.; Allardyce, Judith; van Os, Jim

    2010-01-01

    This review examines whether there is evidence that the criterion symptoms of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) schizophrenia are taxonic—that schizophrenia is not part of a single distribution of normality. Two taxometric methods, coherent cut kinetics (CCK) and latent variable modeling (LVM), are demonstrated to be sensitive to latent classes and, therefore, were regarded as providing relevant statistical evidence. A systematic literature search identified 24 articles describing analyses of 28 participant cohorts in which CCK or LVM methods were used with one or more criterion symptoms of schizophrenia. Virtually all analyses yielded results that, on first impression, favored taxonic over dimensional interpretations of the latent structure of schizophrenia. However, threats to the internal and external validity of these studies—including biased or inadequate analyses, violation of statistical assumptions, inadequate indicator screening, and the introduction of systematic error through recruitment and sampling—critically undermine this body of work. Uncertainties about the potential effects of perceptual biases, unimodal assessment, and item parceling are also identified, as are limitations in seeking to validate classes with single or double dissociations of outcomes. We conclude that there is no reason to seriously doubt a single-distribution model of schizophrenia because there is no evidence that provides a serious test of this null hypothesis. A second fundamental question remains outstanding: is schizophrenia truly a group of schizophrenias, with taxonic divisions separating its types? We make design and analysis suggestions for future research addressing these questions. PMID:19176472

  9. 'Candidatus Phytoplasma tamaricis', a novel taxon discovered in witches'-broom-diseased salt cedar (Tamarix chinensis Lour.).

    PubMed

    Zhao, Yan; Sun, Qingrong; Wei, Wei; Davis, Robert E; Wu, Wei; Liu, Qingzhong

    2009-10-01

    Salt cedar trees with pronounced witches'-broom symptoms were observed in their natural habitat in China. 16S rRNA gene sequences unique to phytoplasmas were detected in every DNA sample extracted from stem and leaf tissues of the symptomatic trees, revealing a direct association between phytoplasma infection and the salt cedar witches'-broom (SCWB) disease. Phylogenetic analysis of the SCWB phytoplasma 16S rRNA gene sequence indicated that the SCWB phytoplasma belonged to a subclade consisting of several mutually distinct 'Candidatus Phytoplasma' taxa including 'Ca. Phytoplasma prunorum', 'Ca. Phytoplasma mali', 'Ca. Phytoplasma pyri' and 'Ca. Phytoplasma spartii'. Pairwise sequence similarity scores calculated from an alignment of near full-length 16S rRNA genes revealed that SCWB phytoplasma shared 96.6 % or less sequence similarity with each previously described or proposed 'Ca. Phytoplasma' taxon, justifying the recognition of SCWB phytoplasma as a novel taxon, 'Candidatus Phytoplasma tamaricis'. The distinct virtual RFLP pattern derived from the SCWB phytoplasma 16S rRNA gene sequence, together with its lower-than-threshold similarity coefficient values with RFLP patterns of any of the 29 previously established groups, supported the recognition of a new 16Sr group, designated 16SrXXX, salt cedar witches'-broom phytoplasma group.

  10. Unraveling the sequence information in COI barcode to achieve higher taxon assignment based on Indian freshwater fishes.

    PubMed

    Chakraborty, Mohua; Ghosh, Sankar Kumar

    2015-04-01

    Efficacy of cytochrome c oxidase subunit I (COI) DNA barcode in higher taxon assignment is still under debate in spite of several attempts, using the conventional DNA barcoding methods, to assign higher taxa. Here we try to understand whether nucleotide and amino acid sequence in COI gene carry sufficient information to assign species to their higher taxonomic rank, using 160 species of Indian freshwater fishes. Our results reveal that with increase in the taxonomic rank, sequence conservation decreases for both nucleotides and amino acids. Order level exhibits lowest conservation with 50% of the nucleotides and amino acids being conserved. Among the variable sites, 30-50% were found to carry high information content within an order, while it was 70-80% within a family and 80-99% within a genus. High information content shows sites with almost conserved sequence but varying at one or two locations, which can be due to variations at species or population level. Thus, the potential of COI gene in higher taxon assignment is revealed with validation of ample inherent signals latent in the gene.

  11. Maladaptive cognitions predict changes in problematic gaming in highly-engaged adults: A 12-month longitudinal study.

    PubMed

    Forrest, Cameron J; King, Daniel L; Delfabbro, Paul H

    2017-02-01

    Understanding the role of maladaptive gaming-related cognitions may assist in screening and interventions for problematic gaming, including Internet gaming disorder (IGD). Cognitive-behavioural interventions that target specific cognitions related to gaming may be more effective than more general approaches that focus only on preoccupation with games. Although past research has identified cross-sectional associations between maladaptive cognitions and problematic gaming, it is less clear whether these cognitions can predict future changes in problematic gaming behaviour. The present study employed an 18-item measure of gaming cognition, assessing perfectionism, cognitive salience, regret, and behavioural salience, to investigate potential changes in problematic gaming over a 12-month period. The sample included 465 Australian adults (84% male, Mage=26.2years). It was found that individuals who became problematic gamers over 12months had higher baseline scores on perfectionism (d=1.20), cognitive salience (d=0.74) and regret (d=0.69) than those who remained non-problematic gamers. Problematic gamers who became non-problematic gamers had lower baseline perfectionism scores (d=0.62) than those who remained problematic gamers. Cognitive change accounted for an additional 28% of variance in problematic gaming scores beyond gender, age, and frequency of gaming. These findings suggest that maladaptive gaming-related cognitions could be screened in clinical trials to aid in case formulation and inform decisions on needed interventions to deliver optimal client outcomes.

  12. Measuring Problematic Mobile Phone Use: Development and Preliminary Psychometric Properties of the PUMP Scale

    PubMed Central

    Merlo, Lisa J.; Stone, Amanda M.; Bibbey, Alex

    2013-01-01

    This study aimed to develop and assess the psychometric properties of an English language measure of problematic mobile phone use. Participants were recruited from a university campus, health science center, and other public locations. The sample included 244 individuals (68.4% female) aged 18–75. Results supported a unidimensional factor structure for the 20-item self-report Problematic Use of Mobile Phones (PUMP) Scale. Internal consistency was excellent (α = 0.94). Strong correlations (r = .76, P < .001) were found between the PUMP Scale and an existing scale of cellular phone dependency that was validated in Asia, as well as items assessing frequency and intensity of mobile phone use. Results provide preliminary support for the use of the PUMP Scale to measure problematic use of mobile phones. PMID:24826371

  13. Narrative evolution and assimilation of problematic experiences in a case of pharmacotherapy for schizophrenia.

    PubMed

    Osatuke, Katerine; Reid, Mary; Stiles, William B; Kasckow, John W; Zisook, Sidney; Mohamed, Somaia

    2011-01-01

    This case study applied the assimilation model to examine the changing narrative of an outpatient with schizophrenia and symptoms of depression across a successful pharmacotherapy. The assimilation model describes how clients assimilate painful, problematic experiences. Therapeutic progress is understood to reflect increasing assimilation, measured by the Assimilation of Problematic Experiences Scale (APES). The authors used a 15-min semistructured interview (Problematic Experiences Questionnaire) to elicit narrative descriptions of the patient's problems and coping across five interviews throughout his 12-week treatment. They describe how the patient's narrative and APES ratings of his main problems by two clinicians changed in concert through treatment, explain these developments using assimilation concepts, and interpret the results in relation to assimilation and insight in schizophrenia.

  14. Which facets of mindfulness are related to problematic eating among patients seeking bariatric surgery?

    PubMed

    Levin, Michael E; Dalrymple, Kristy; Himes, Susan; Zimmerman, Mark

    2014-04-01

    There has been growing research indicating the potential positive benefits of mindfulness-based interventions for obesity, but few studies have examined the relationship of mindfulness processes to obesity-related behaviors, particularly among clinical populations such as bariatric surgery candidates. The current study examined the relationship of specific mindfulness facets to a variety of problematic eating behaviors assessed through diagnostic interviews in a clinical sample of 820 patients seeking bariatric surgery. Results indicated that greater mindfulness on specific facets, particularly acting with awareness, was related to less binge and emotional eating. Greater mindfulness was also related, though less consistently, to less habitual overeating and grazing. The observing facet was generally unrelated to problematic eating, but in a few cases being more observant related to having greater eating problems. The results of the study and future directions are discussed in relation to research on problematic eating in obesity and mindfulness-based interventions.

  15. Water surface locomotion in tropical canopy ants.

    PubMed

    Yanoviak, S P; Frederick, D N

    2014-06-15

    Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s(-1), with some swimming at absolute speeds >10 cm s(-1). Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants.

  16. The Kanizsa triangle illusion in foraging ants.

    PubMed

    Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2016-01-01

    The Kanizsa triangle, wherein three Pac-Man configurations symmetrically face inwards, is a well-known illusion. By exposing foraging ants (Lasius niger) to Kanizsa-shaped honeydew solutions, we studied the origin of this illusion. More specifically, we examined whether foraging ants showed different movement reactions to local honeydew patterns formed by nestmates. This novel phenomenon could serve as an abstract model of the Kanizsa triangle illusion under the assumption that such an illusion could arise through the sum of each agent's limited global cognitions, because each agent could not perceive the entire subjective contours. Even a subjective consciousness consists of some parts which have no identical perception and could be an illusion. We succeeded in inducing foragers to move along the sides of a Kanizsa triangle when Pac-Man-shaped inducers were introduced. Furthermore, foragers appeared to form Y-shaped trajectories when dot-shaped or inverse Kanizsa inducers were used. Based on our findings, we propose an agent-based ant model that compares modelled behaviour with experimental phenomena. Our abstract model could be used to explain such cognitive phenomena for bottom-up processes, because ants cannot perceive the given subjective contours, instead simply move along the edges.

  17. Hey! A Fire Ant Stung Me!

    MedlinePlus

    ... nest in the ground, and then create a mound of dirt over the nest. These mounds can grow up to 18 inches high and ... burning. Someone who steps on a fire ant mound will get a lot of stings at once ...

  18. A global database of ant species abundances

    USGS Publications Warehouse

    Gibb, Heloise; Dunn, Rob R.; Sanders, Nathan J.; Grossman, Blair F.; Photakis, Manoli; Abril, Silvia; Agosti, Donat; Andersen, Alan N.; Angulo, Elena; Armbrecht, Ingre; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Bruhl, Carsten; Castracani, Cristina; Cerda, Xim; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Ellison, Aaron M.; Enriquez, Martha L.; Fayle, Tom M.; Feener Jr., Donald H.; Fisher, Brian L.; Fisher, Robert N.; Fitpatrick, Matthew C.; Gomez, Cristanto; Gotelli, Nicholas J.; Gove, Aaron; Grasso, Donato A.; Groc, Sarah; Guenard, Benoit; Gunawardene, Nihara; Heterick, Brian; Hoffmann, Benjamin; Janda, Milan; Jenkins, Clinton; Kaspari, Michael; Klimes, Petr; Lach, Lori; Laeger, Thomas; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Luke, Sarah H.; Majer, Jonathan; McGlynn, Terrence P.; Menke, Sean; Mezger, Dirk; Mori, Alessandra; Moses, Jimmy; Munyai, Thinandavha Caswell; Pacheco, Renata; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; Resasco, Julian; Retana, Javier; Silva, Rogerio R.; Sorger, Magdalena D.; Souza, Jorge; Suarez, Andrew V.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Weiser, Michael D.; Yates, Michelle; Parr, Catherine L.

    2017-01-01

    What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of more than 2693 species and 7953 morphospecies from local assemblages collected at 4212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type and degree of disturbance. The aim of compiling this dataset was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardised methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing dataset.

  19. A global database of ant species abundances.

    PubMed

    Gibb, Heloise; Dunn, Rob R; Sanders, Nathan J; Grossman, Blair F; Photakis, Manoli; Abril, Silvia; Agosti, Donat; Andersen, Alan N; Angulo, Elena; Armbrecht, Inge; Arnan, Xavier; Baccaro, Fabricio B; Bishop, Tom R; Boulay, Raphaël; Brühl, Carsten; Castracani, Cristina; Cerda, Xim; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A; Ellison, Aaron M; Enriquez, Martha L; Fayle, Tom M; Feener, Donald H; Fisher, Brian L; Fisher, Robert N; Fitzpatrick, Matthew C; Gómez, Crisanto; Gotelli, Nicholas J; Gove, Aaron; Grasso, Donato A; Groc, Sarah; Guenard, Benoit; Gunawardene, Nihara; Heterick, Brian; Hoffmann, Benjamin; Janda, Milan; Jenkins, Clinton; Kaspari, Michael; Klimes, Petr; Lach, Lori; Laeger, Thomas; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Luke, Sarah H; Majer, Jonathan; McGlynn, Terrence P; Menke, Sean; Mezger, Dirk; Mori, Alessandra; Moses, Jimmy; Munyai, Thinandavha Caswell; Pacheco, Renata; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M; Resasco, Julian; Retana, Javier; Silva, Rogerio R; Sorger, Magdalena D; Souza, Jorge; Suarez, Andrew; Tista, Melanie; Vasconcelos, Heraldo L; Vonshak, Merav; Weiser, Michael D; Yates, Michelle; Parr, Catherine L

    2017-03-01

    What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51 ,388 ant abundance and occurrence records of more than 2,693 species and 7,953 morphospecies from local assemblages collected at 4,212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type, and degree of disturbance. The aim of compiling this data set was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardized methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing data set.

  20. Enhanced Pest Ant Control with Hydrophobic Bait

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ants occupy every ecological niche in the world where they contribute to the ecosystem, e.g., as scavengers and aerators of the soil. However, when they are transported, usually through human activities, to new locations they have powerful negative impacts on their adopted homeland. Five of the 17 l...

  1. Serotonin depresses feeding behaviour in ants.

    PubMed

    Falibene, Agustina; Rössler, Wolfgang; Josens, Roxana

    2012-01-01

    Feeding behaviour is a complex functional system that relies on external signals and the physiological state of the animal. This is also the case in ants as they vary their feeding behaviour according to food characteristics, environmental conditions and - as they are social insects - to the colony's requirements. The biogenic amine serotonin (5-HT) was shown to be involved in the control and modulation of many actions and processes related to feeding in both vertebrates and invertebrates. In this study, we investigated whether 5-HT affects nectar feeding in ants by analysing its effect on the sucking-pump activity. Furthermore, we studied 5-HT association with tissues and neuronal ganglia involved in feeding regulation. Our results show that 5-HT promotes a dose-dependent depression of sucrose feeding in Camponotus mus ants. Orally administered 5-HT diminished the intake rate by mainly decreasing the volume of solution taken per pump contraction, without modifying the sucrose acceptance threshold. Immunohistochemical studies all along the alimentary canal revealed 5-HT-like immunoreactive processes on the foregut (oesophagus, crop and proventriculus), while the midgut and hindgut lacked 5-HT innervation. Although the frontal and suboesophageal ganglia contained 5-HT immunoreactive cell bodies, serotonergic innervation in the sucking-pump muscles was absent. The results are discussed in the frame of a role of 5-HT in feeding control in ants.

  2. Video game playing in high school students: health correlates, gender differences and problematic gaming

    PubMed Central

    Desai, Rani A.; Krishnan-Sarin, Suchitra; Cavallo, Dana; Potenza, Marc N.

    2013-01-01

    There is concern about the potential for negative impact of video games on youth. However the existing literature on gaming is inconsistent and has often focused on aggression. Health correlates of gaming and the prevalence and correlates of problematic gaming have not been systematically studied. We anonymously surveyed 4,028 adolescents about gaming, reported problems with gaming, and other health behaviors. 51.2% of the sample reported gaming (76.3% of boys and 29.2% of girls). There were no negative health correlates of gaming in boys, and lower odds of smoking regularly; however, girls who reported gaming were less likely to report depression, and more likely to report getting into serious fights and carrying a weapon to school. Among gamers, 4.9% reported problematic gaming, defined as reporting trying to cut back, experiencing an irresistible urge to play, and experiencing a growing tension that could only be relieved by playing. Boys were more likely to report these problems (5.8%) than girls (3.0%). Correlates of problematic gaming included regular cigarette smoking, drug use, depression, and serious fights. Results suggest that gaming is largely normative in boys and not associated with many health factors. In girls, however, gaming appears associated with more externalizing behaviors and fewer internalizing symptoms. The prevalence of problematic gaming is low but not insignificant, and problematic gaming may be contained within a larger spectrum of externalizing behaviors. More research is needed to define safe levels of gaming, refine the definition of problematic gaming, and evaluate effective prevention and intervention strategies. PMID:21078729

  3. Dynamics of an ant-plant-pollinator model

    NASA Astrophysics Data System (ADS)

    Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

    2015-03-01

    In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

  4. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... at an official exotic animal establishment. (1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection. (2) The ante-mortem inspector shall remain...

  5. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... at an official exotic animal establishment. (1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection. (2) The ante-mortem inspector shall remain...

  6. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... at an official exotic animal establishment. (1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection. (2) The ante-mortem inspector shall remain...

  7. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... at an official exotic animal establishment. (1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection. (2) The ante-mortem inspector shall remain...

  8. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... at an official exotic animal establishment. (1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection. (2) The ante-mortem inspector shall remain...

  9. Fire ant control with Entomopathogens in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fire ants, Solenopsis richteri and Solenopsis invicta, are stinging invasive ants from South America that infest over 129.5 million hectares in the southern United States. In the southern U.S., eradication is no longer considered possible and toxicant-based fire ant baiting is currently the primary...

  10. Mutualistic ants as an indirect defence against leaf pathogens.

    PubMed

    González-Teuber, Marcia; Kaltenpoth, Martin; Boland, Wilhelm

    2014-04-01

    Mutualistic ants are commonly considered as an efficient indirect defence against herbivores. Nevertheless, their indirect protective role against plant pathogens has been scarcely investigated. We compared the protective role against pathogens of two different ant partners, a mutualistic and a parasitic ant, on the host plant Acacia hindsii (Fabaceae). The epiphytic bacterial community on leaves was evaluated in the presence and absence of both ant partners by cultivation and by 454 pyrosequencing of the 16S rRNA gene. Pathogen-inflicted leaf damage, epiphytic bacterial abundance (colony-forming units) and number of operational taxonomic units (OTUs) were significantly higher in plants inhabited by parasitic ants than in plants inhabited by mutualistic ants. Unifrac unweighted and weighted principal component analyses showed that the bacterial community composition on leaves changed significantly when mutualistic ants were removed from plants or when plants were inhabited by parasitic ants. Direct mechanisms provided by ant-associated bacteria would contribute to the protective role against pathogens. The results suggest that the indirect defence of mutualistic ants also covers the protection from bacterial plant pathogens. Our findings highlight the importance of considering bacterial partners in ant-plant defensive mutualisms, which can contribute significantly to ant-mediated protection from plant pathogens.

  11. Model Specification Searches Using Ant Colony Optimization Algorithms

    ERIC Educational Resources Information Center

    Marcoulides, George A.; Drezner, Zvi

    2003-01-01

    Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.

  12. 9 CFR 354.121 - Ante-mortem inspection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Inspection Procedures; Ante-Mortem Inspections § 354.121 Ante-mortem inspection. An ante-mortem inspection of...

  13. Non-substance-addictive behaviors in youth: pathological gambling and problematic Internet use.

    PubMed

    Brezing, Christina; Derevensky, Jeffrey L; Potenza, Marc N

    2010-07-01

    Adolescence is characterized by participation in multiple novel and potentially risky behaviors. Amongst these behaviors are gambling and use of the Internet, and excessive engagement in these activities (as seen in pathological gambling and problematic Internet use) may be accompanied by serious impairments in school, mental health, and social functioning. This article reviews the potential impact of pathological gambling and problematic Internet use in youth, the relevance of subsyndromal levels of participation, and how prevention and treatment strategies may be considered and tested within a developmental framework.

  14. Low empathy is associated with problematic use of the Internet: Empirical evidence from China and Germany.

    PubMed

    Melchers, Martin; Li, Mei; Chen, Yafei; Zhang, Wanqi; Montag, Christian

    2015-10-01

    As empathy has not been investigated in the context of problematic use of the Internet, we conducted a study to test for a potential link. In samples from China (N=438) and Germany (N=202), two self-report measures for empathic behavior and one self-report measure for problematic Internet use (PIU) were administered in adolescents/students. Across both cultures lower empathy was associated with more PIU. The present study underlines the importance to take into account empathy related questionnaires for a better understanding of Internet overuse in the future.

  15. Plant lock and ant key: pairwise coevolution of an exclusion filter in an ant-plant mutualism.

    PubMed Central

    Brouat, C.; Garcia, N.; Andary, C.; McKey, D.

    2001-01-01

    Although observations suggest pairwise coevolution in specific ant-plant symbioses, coevolutionary processes have rarely been demonstrated. We report on, what is to the authors' knowledge, the strongest evidence yet for reciprocal adaptation of morphological characters in a species-specific ant-plant mutualism. The plant character is the prostoma, which is a small unlignified organ at the apex of the domatia in which symbiotic ants excavate an entrance hole. Each myrmecophyte in the genus Leonardoxa has evolved a prostoma with a different shape. By performing precise measurements on the prostomata of three related myrmecophytes, on their specific associated ants and on the entrance holes excavated by symbiotic ants at the prostomata, we showed that correspondence of the plant and ant traits forms a morphological and behavioural filter. We have strong evidence for coevolution between the dimensions and shape of the symbiotic ants and the prostoma in one of the three ant-Leonardoxa associations. PMID:11600077

  16. Ant species identity mediates reproductive traits and allocation in an ant-garden bromeliad

    PubMed Central

    Leroy, Céline; Corbara, Bruno; Pélozuelo, Laurent; Carrias, Jean-François; Dejean, Alain; Céréghino, Régis

    2012-01-01

    Background and Aims Determining the sources of variation in floral morphology is crucial to understanding the mechanisms underlying Angiosperm evolution. The selection of floral and reproductive traits is influenced by the plant's abiotic environment, florivores and pollinators. However, evidence that variations in floral traits result from mutualistic interactions with insects other than pollinators is lacking in the published literature and has rarely been investigated. We aimed to determine whether the association with either Camponotus femoratus or Pachycondyla goeldii (both involved in seed dispersal and plant protection) mediates the reproductive traits and allocation of Aechmea mertensii, an obligatory ant-garden tank-bromeliad, differently. Methods Floral and reproductive traits were compared between the two A. mertensii ant-gardens. The nitrogen flux from the ants to the bromeliads was investigated through experimental enrichments with stable isotopes (15N). Key Results Camponotus femoratus-associated bromeliads produced inflorescences up to four times longer than did P. goeldii-associated bromeliads. Also, the numbers of flowers and fruits were close to four times higher, and the number of seeds and their mass per fruit were close to 1·5 times higher in C. femoratus than in P. goeldii-associated bromeliads. Furthermore, the 15N-enrichment experiment showed that C. femoratus-associated bromeliads received more nitrogen from ants than did P. goeldii-associated bromeliads, with subsequent positive repercussions on floral development. Greater benefits were conferred to A. mertensii by the association with C. femoratus compared with P. goeldii ants. Conclusions We show for the first time that mutualistic associations with ants can result in an enhanced reproductive allocation for the bromeliad A. mertensii. Nevertheless, the strength and direction of the selection of floral and fruit traits change based on the ant species and were not related to light

  17. Can the Argentine ant ( Linepithema humile Mayr) replace native ants in myrmecochory?

    NASA Astrophysics Data System (ADS)

    Gómez, Crisanto; Oliveras, Jordi

    2003-04-01

    We analyse the influence of the Argentine ant ( Linepithema humile Mayr) on the seed dispersal process of the myrmecochorous plants Euphorbia characias, E. biumbellata, Genista linifolia, G. triflora, G. monspessulana and Sarothamnus arboreus. The observations were made in two study plots of Mediterranean cork-oak secondary forest (invaded and non-invaded by L. humile). The presence of L. humile implies the displacement of all native ant species that disperse seeds. Seed transports in the non-invaded zone were carried out by eight ant species. In the invaded zone, L. humile workers removed and transported seeds to the nest. In vertebrate exclusion trials, we observed the same level of seed removal in the invaded and non-invaded zones. Two findings could explain this result. Although mean time to seed localization was higher for native ants (431.7 s) than that for L. humile (150.5 s), the mean proportion of seeds transported after being detected was higher (50.1%) in non-invaded than in invaded (16.8%) zones. The proportion of seeds removed and transported into an ant nest after an ant-seed interaction had dramatically reduced from non-invaded (41.9%) to invaded (7.4%) zones. The levels of seed dispersal by ants found prior to invasion are unlikely to be maintained in invaded zones. However, total replacement of seed dispersal function is possible if contact iteration finally offers similar levels or quantities of seeds reaching the nests. The results obtained confirm that the Argentine ant invasion may affect myrmecochory dramatically in the Mediterranean biome.

  18. The association between problematic cellular phone use and risky behaviors and low self-esteem among Taiwanese adolescents

    PubMed Central

    2010-01-01

    Background Cellular phone use (CPU) is an important part of life for many adolescents. However, problematic CPU may complicate physiological and psychological problems. The aim of our study was to examine the associations between problematic CPU and a series of risky behaviors and low self-esteem in Taiwanese adolescents. Methods A total of 11,111 adolescent students in Southern Taiwan were randomly selected into this study. We used the Problematic Cellular Phone Use Questionnaire to identify the adolescents with problematic CPU. Meanwhile, a series of risky behaviors and self-esteem were evaluated. Multilevel logistic regression analyses were employed to examine the associations between problematic CPU and risky behaviors and low self-esteem regarding gender and age. Results The results indicated that positive associations were found between problematic CPU and aggression, insomnia, smoking cigarettes, suicidal tendencies, and low self-esteem in all groups with different sexes and ages. However, gender and age differences existed in the associations between problematic CPU and suspension from school, criminal records, tattooing, short nocturnal sleep duration, unprotected sex, illicit drugs use, drinking alcohol and chewing betel nuts. Conclusions There were positive associations between problematic CPU and a series of risky behaviors and low self-esteem in Taiwanese adolescents. It is worthy for parents and mental health professionals to pay attention to adolescents' problematic CPU. PMID:20426807

  19. Childhood and Adolescent Sexuality, Islam, and Problematics of Sex Education: A Call for Re-Examination

    ERIC Educational Resources Information Center

    Tabatabaie, Alireza

    2015-01-01

    This paper offers a critical examination of the problematics of childhood and adolescent sexuality and sex education in an Islamic context. By exploring conceptions of (pre-marital) sexuality, childhood, and maturity/adulthood, it is suggested that: (i) "childhood" and "sexuality" do not coexist harmoniously in Islamic…

  20. Physiological markers of biased decision-making in problematic Internet users

    PubMed Central

    Nikolaidou, Maria; Fraser, Danaë Stanton

    2016-01-01

    Background and aims Addiction has been reliably associated with biased emotional reactions to risky choices. Problematic Internet use (PIU) is a relatively new concept and its classification as an addiction is debated. Implicit emotional responses were measured in individuals expressing nonproblematic and problematic Internet behaviors while they made risky/ambiguous decisions to explore whether they showed similar responses to those found in agreed-upon addictions. Methods The design of the study was cross sectional. Participants were adult Internet users (N = 72). All testing took place in the Psychophysics Laboratory at the University of Bath, UK. Participants were given the Iowa Gambling Task (IGT) which provides an index of an individual’s ability to process and learn probabilities of reward and loss. Integration of emotions into current decision-making frameworks is vital for optimal performance on the IGT and thus, skin conductance responses (SCRs) to reward, punishment, and in anticipation of both were measured to assess emotional function. Results Performance on the IGT did not differ between the groups of Internet users. However, problematic Internet users expressed increased sensitivity to punishment as revealed by stronger SCRs to trials with higher punishment magnitude. Discussion and conclusions PIU seems to differ on behavioral and physiological levels with other addictions. However, our data imply that problematic Internet users were more risk-sensitive, which is a suggestion that needs to be incorporated into in any measure and, potentially, any intervention for PIU. PMID:27554505

  1. Problematic Internet Use among Turkish University Students: A Multidimensional Investigation Based on Demographics and Internet Activities

    ERIC Educational Resources Information Center

    Tekinarslan, Erkan; Gurer, Melih Derya

    2011-01-01

    This study investigated the Turkish undergraduate university students' problematic Internet use (PIU) levels on different dimensions based on demographics (e.g., gender, Internet use by time of day), and Internet activities (e.g., chat, entertainment, social networking, information searching, etc.). Moreover, the study explored some predictors of…

  2. Features and Predictors of Problematic Internet Use in Chinese College Students

    ERIC Educational Resources Information Center

    Huang, R. L.; Lu, Z.; Liu, J. J.; You, Y. M.; Pan, Z. Q.; Wei, Z.; He, Q.; Wang, Z. Z.

    2009-01-01

    This study was set to investigate the prevalence of problematic internet use (PIU) among college students and the possible factors related to this disorder. About 4400 college students, ranging from freshmen to juniors, from eight different universities in Wuhan, China were surveyed. Young's Diagnostic Questionnaire for Internet Addiction (YDQ)…

  3. Relationships between problematic behaviors and motor abilities of children with cerebral palsy

    PubMed Central

    Uesugi, Masayuki; Miyamoto, Akira; Nanba, Yosifumi; Otani, Yoshitaka; Takemasa, Seiichi; Hujii, Shun

    2015-01-01

    [Purpose] This study aimed to examine whether motor abilities of children with cerebral palsy are related to their problematic behaviors. [Subjects] The subjects were children with mental retardation who were undergoing physical therapy. [Methods] Twenty-one examiners, 13 physical therapists, and 8 occupational therapists treated and examined the subjects by using the Japanese version of the Aberrant Behavior Checklist. The Japanese version of the Aberrant Behavior Checklist scores were compared between the Gross Motor Function Classification System I to III (12 subjects) and Gross Motor Function Classification System IV and V groups (17 subjects). [Results] Lethargy and stereotypy scores significantly differed between the groups, proving that patients with Gross Motor Function Classification System levels IV and V have more severe problematic behaviors. [Conclusion] In this study, only five types of problematic behaviors, namely irritability, lethargy, stereotypy, hyperactivity, and inappropriate speech, were examined. Despite this limitation, the study clarifies that problematic behaviors of children with cerebral palsy, except lethargy and stereotypy, have little relationship with their motor abilities. PMID:26504335

  4. Longitudinal Examination of PTSD Symptoms and Problematic Alcohol Use as Risk Factors for Adolescent Victimization

    ERIC Educational Resources Information Center

    McCart, Michael R.; Zajac, Kristyn; Kofler, Michael J.; Smith, Daniel W.; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2012-01-01

    The current study examined associations between posttraumatic stress disorder (PTSD) symptoms and future interpersonal victimization among adolescents, after accounting for the impact of early victimization exposure, gender, ethnicity, and household income. In addition, problematic alcohol use was tested as a mediator of the relation between PTSD…

  5. Modeling the contribution of personality, social identity and social norms to problematic Facebook use in adolescents.

    PubMed

    Marino, Claudia; Vieno, Alessio; Pastore, Massimiliano; Albery, Ian P; Frings, Daniel; Spada, Marcantonio M

    2016-12-01

    Facebook is the most popular social networking site in the world providing the opportunity to maintain and/or establish relationships, to share media contents and experiences with friends, and to easily communicate with them. Despite the resources and the innovative social features offered by Facebook research has emerged indicating that its use may become problematic, with negative consequences on personal psycho-social well-being, especially among adolescents and young adults. The main aim of this study was to examine the unique contribution of personality traits and social influence processes (i.e. subjective norms, group norms, and social identity) to perceived frequency of Facebook Use and Problematic Facebook Use in a sample of adolescents. A total of 968 Italian adolescents participated in the study. Structural equation modeling showed that emotional stability, extraversion, conscientiousness and norms directly predicted Problematic Facebook Use, whereas gender, group norms and social identity predicted perceived frequency of Facebook use. In conclusion, both personal and social variables appear to explain perceived frequency of Facebook use and Problematic Facebook Use among adolescents, and should be taken into account by researchers and educational practitioners.

  6. Interpreting problematic behavior: systematic compensatory adaptations as emergent phenomena in autism.

    PubMed

    Damico, Jack S; Nelson, Ryan L

    2005-01-01

    Based upon an emergent account of pragmatic ability and disability, this article provides theoretical and empirical support for a conceptually deeper understanding of some systematic behaviors that have served as diagnostic indices in communicatively impaired populations. Specifically, by employing conversation analysis, several examples of problematic behaviors in autism are analysed as a specific type of compensatory adaptation. Theoretical and clinical implications are discussed.

  7. Electrophysiological correlates of problematic Internet use: Critical review and perspectives for future research.

    PubMed

    D'Hondt, Fabien; Billieux, Joël; Maurage, Pierre

    2015-12-01

    Problematic behaviors have emerged with the exponential development of the Internet access, with some individuals failing to constrain their Internet use despite its negative impact on their daily lives. Recent neuropsychological and neuroscience studies have suggested that problematic Internet use is notably associated with increased cue-reactivity and reduced inhibitory control. This review of the electroencephalography (EEG) literature shows that most studies have found that impaired self-control abilities (i.e., inhibition and error monitoring) are associated with underactivated frontal regions in problematic Internet users (PIUs). However, some EEG studies in the domain have also demonstrated alterations in the processing of Internet-related cues and emotional stimuli. As a whole, these data therefore suggest that both reflective (top-down) and automatic/affective (bottom-up) systems, postulated by dual-process models as being determinants in decision making, are impaired among PIUs. On this basis, new research avenues are proposed to better understand the development and maintenance of problematic Internet use, according to six main directions respectively related to (1) the identification of vulnerability biomarkers, (2) the investigation of possible lower level cognitive impairments, (3) the exploration of core reflective and automatic/affective symptoms, (4) the evaluation of Internet use heterogeneity and comorbidities, (5) the development of new neuroscience strategies and (6) the elaboration of behavioral and cognitive interventions.

  8. Factors Associated with Problematic Vocalizations in Nursing Home Residents with Dementia

    ERIC Educational Resources Information Center

    Beck, Cornelia; Richards, Kathy; Lambert, Corinne; Doan, Rebecca; Landes, Reid D.; Whall, Ann; Algase, Donna; Kolanowski, Ann; Feldman, Zachary

    2011-01-01

    Purpose of the Study: Problematic vocalizations (PVs) are the most frequent and persistent disruptive behaviors exhibited by nursing home residents with dementia. Understanding factors associated with these behaviors are important to prevent or reduce them. We used the Need-Driven Dementia-Compromised Behavior model to identify the characteristics…

  9. A Placebo Double-Blind Pilot Study of Dextromethorphan for Problematic Behaviors in Children with Autism

    ERIC Educational Resources Information Center

    Woodard, Cooper; Groden, June; Goodwin, Matthew; Bodfish, James

    2007-01-01

    We used a mixed group/single-case, double-blind, placebo-controlled, ABAB design to examine the safety and efficacy of the glutamate antagonist dextromethorphan for the treatment of problematic behaviors and core symptoms in eight children diagnosed with autism. All participants had increased levels of irritability at baseline as measured by the…

  10. Problematic video game use: estimated prevalence and associations with mental and physical health.

    PubMed

    Mentzoni, Rune Aune; Brunborg, Geir Scott; Molde, Helge; Myrseth, Helga; Skouverøe, Knut Joachim Mår; Hetland, Jørn; Pallesen, Ståle

    2011-10-01

    A nationwide survey was conducted to investigate the prevalence of video game addiction and problematic video game use and their association with physical and mental health. An initial sample comprising 2,500 individuals was randomly selected from the Norwegian National Registry. A total of 816 (34.0 percent) individuals completed and returned the questionnaire. The majority (56.3 percent) of respondents used video games on a regular basis. The prevalence of video game addiction was estimated to be 0.6 percent, with problematic use of video games reported by 4.1 percent of the sample. Gender (male) and age group (young) were strong predictors for problematic use of video games. A higher proportion of high frequency compared with low frequency players preferred massively multiplayer online role-playing games, although the majority of high frequency players preferred other game types. Problematic use of video games was associated with lower scores on life satisfaction and with elevated levels of anxiety and depression. Video game use was not associated with reported amount of physical exercise.

  11. "Wasting Talent"? Gender and the Problematics of Academic Disenchantment and Disengagement with Leadership

    ERIC Educational Resources Information Center

    Blackmore, Jill

    2014-01-01

    Confronted with the processes of massification, commercialisation, internationalisation and reduced funding, universities also face an ageing academic workforce, with implications of a shrinking pool from which to recruit managerial and research leaders. A feminist analysis suggests that the policy problematic has been wrongly conceptualised as…

  12. Acceptance and commitment therapy as a treatment for problematic internet pornography viewing.

    PubMed

    Twohig, Michael P; Crosby, Jesse M

    2010-09-01

    Despite the prevalence of problematic Internet pornography viewing and the breadth of intervention approaches to potentially address it, no studies to address this problem have been reported to date. An emerging treatment approach, Acceptance and Commitment Therapy (ACT), holds promise as a treatment for Internet pornography viewing because of its focus on processes hypothesized to underlie this maladaptive behavior. In the first experiment on the treatment of problematic Internet pornography viewing, 6 adult males who reported that their Internet pornography viewing was affecting their quality of life were treated in eight 1.5-hour sessions of ACT for problematic pornography viewing. The effects of the intervention were assessed in a multiple-baseline-across-participants design with time viewing pornography as the dependent variable. Treatment resulted in an 85% reduction in viewing at posttreatment with results being maintained at 3-month follow-up (83% reduction). Increases were seen on measures of quality of life, and reductions were seen on measures of OCD and scrupulosity. Weekly measures of ACT-consistent processes showed reductions that corresponded with reductions in viewing. Large reductions were seen on a measure of psychological flexibility, and minor reductions were seen on measures of thought-action fusion and thought control. Overall, results suggest the promise of ACT as a treatment for problematic Internet pornography viewing and the value of future randomized trials of this approach.

  13. Growing up Perfect: Perfectionism, Problematic Internet Use, and Career Indecision in Emerging Adults

    ERIC Educational Resources Information Center

    Lehmann, Ilana S.; Konstam, Varda

    2011-01-01

    Among emerging adults who are career indecisive, perfectionism and problematic Internet use (PIU) are underdeveloped areas of inquiry. The authors examined the relationship between perfectionism and PIU to measure their contributions to career indecision. The full model was significant, yielding an R[superscript 2] of 0.46 (p less than 0.0001).…

  14. Internet gaming addiction, problematic use of the internet, and sleep problems: a systematic review.

    PubMed

    Lam, Lawrence T

    2014-04-01

    The effect of problematic use of the Internet on mental health, particularly depression among young people, has been established but without a probable model for the underlying mechanism. In this study, a model is presented to describe possible pathways for the linkage between Internet gaming addiction and depression possibly mediated by sleep problems. A systematic review was conducted to gather epidemiological evidence to support or refute the link between addictive Internet gaming, problematic Internet use, and sleep problems including insomnia and poor sleep quality. Seven studies were identified through a systematic literature search, of these three related to addictive Internet gaming and four on problematic Internet uses and sleep problems. Information was extracted and analysed systematically from each of the studies and tabulated as a summary. Results of the review suggest that additive gaming, particularly massively multiplayer online role-playing games MMORPG, might be associated with poorer quality of sleep. Results further indicated that problematic Internet use was associated with sleep problems including subjective insomnia and poor sleep quality.

  15. Adolescent Problematic Social Networking and School Experiences: The Mediating Effects of Sleep Disruptions and Sleep Quality.

    PubMed

    Vernon, Lynette; Barber, Bonnie L; Modecki, Kathryn L

    2015-07-01

    An important developmental task for adolescents is to become increasingly responsible for their own health behaviors. Establishing healthy sleep routines and controlling media use before bedtime are important for adequate, quality sleep so adolescents are alert during the day and perform well at school. Despite the prevalence of adolescent social media use and the large percentage of computers and cell phones in adolescents' bedrooms, no studies to date have investigated the link between problematic adolescent investment in social networking, their sleep practices, and associated experiences at school. A sample of 1,886 students in Australia aged between 12 and 18 years of age completed self-report data on problematic social networking use, sleep disturbances, sleep quality, and school satisfaction. Structural equation modeling (SEM) substantiated the serial mediation hypothesis: for adolescents, problematic social networking use significantly increased sleep disturbances, which adversely affected perceptions of sleep quality that, in turn, lowered adolescents' appraisals of their school satisfaction. This significant pattern was largely driven by the indirect effect of sleep disturbances. These findings suggest that adolescents are vulnerable to negative consequences from social networking use. Specifically, problematic social networking is associated with poor school experiences, which result from poor sleep habits. Promoting better sleep routines by minimizing sleep disturbances from social media use could improve school experiences for adolescents with enhanced emotional engagement and improved subjective well-being.

  16. University Students' Problematic Internet Use and Communication Skills According to the Internet Use Purposes

    ERIC Educational Resources Information Center

    Ceyhan, Aydogan Aykut

    2011-01-01

    This study was carried out to investigate whether the levels of university students' problematic internet use and of perceived communication skills differ with respect to their basic internet use purposes. The participants were 411 university students [215 of whom were females (52.30%) and 196 of whom were males (47.70%)]. In the study, the…

  17. Predictors and patterns of problematic Internet game use using a decision tree model.

    PubMed

    Rho, Mi Jung; Jeong, Jo-Eun; Chun, Ji-Won; Cho, Hyun; Jung, Dong Jin; Choi, In Young; Kim, Dai-Jin

    2016-09-01

    Background and aims Problematic Internet game use is an important social issue that increases social expenditures for both individuals and nations. This study identified predictors and patterns of problematic Internet game use. Methods Data were collected from online surveys between November 26 and December 26, 2014. We identified 3,881 Internet game users from a total of 5,003 respondents. A total of 511 participants were assigned to the problematic Internet game user group according to the Diagnostic and Statistical Manual of Mental Disorders Internet gaming disorder criteria. From the remaining 3,370 participants, we used propensity score matching to develop a normal comparison group of 511 participants. In all, 1,022 participants were analyzed using the chi-square automatic interaction detector (CHAID) algorithm. Results According to the CHAID algorithm, six important predictors were found: gaming costs (50%), average weekday gaming time (23%), offline Internet gaming community meeting attendance (13%), average weekend and holiday gaming time (7%), marital status (4%), and self-perceptions of addiction to Internet game use (3%). In addition, three patterns out of six classification rules were explored: cost-consuming, socializing, and solitary gamers. Conclusion This study provides direction for future work on the screening of problematic Internet game use in adults.

  18. Physiological markers of biased decision-making in problematic Internet users.

    PubMed

    Nikolaidou, Maria; Fraser, Danaë Stanton; Hinvest, Neal

    2016-09-01

    Background and aims Addiction has been reliably associated with biased emotional reactions to risky choices. Problematic Internet use (PIU) is a relatively new concept and its classification as an addiction is debated. Implicit emotional responses were measured in individuals expressing nonproblematic and problematic Internet behaviors while they made risky/ambiguous decisions to explore whether they showed similar responses to those found in agreed-upon addictions. Methods The design of the study was cross sectional. Participants were adult Internet users (N = 72). All testing took place in the Psychophysics Laboratory at the University of Bath, UK. Participants were given the Iowa Gambling Task (IGT) which provides an index of an individual's ability to process and learn probabilities of reward and loss. Integration of emotions into current decision-making frameworks is vital for optimal performance on the IGT and thus, skin conductance responses (SCRs) to reward, punishment, and in anticipation of both were measured to assess emotional function. Results Performance on the IGT did not differ between the groups of Internet users. However, problematic Internet users expressed increased sensitivity to punishment as revealed by stronger SCRs to trials with higher punishment magnitude. Discussion and conclusions PIU seems to differ on behavioral and physiological levels with other addictions. However, our data imply that problematic Internet users were more risk-sensitive, which is a suggestion that needs to be incorporated into in any measure and, potentially, any intervention for PIU.

  19. Parenting Style as a Mediator between Children's Negative Emotionality and Problematic Behavior in Early Childhood

    ERIC Educational Resources Information Center

    Paulussen-Hoogeboom, Marja C.; Stams, Geert Jan J. M.; Hermanns, Jo M. A.; Peetsma, Thea T. D.; van den Wittenboer, Godfried L. H.

    2008-01-01

    Negative emotionality is considered to be the core of the "difficult temperament" concept (J. E. Bates, 1989; R. L. Shiner, 1998). In this correlational study, the authors examined whether the relations between children's negative emotionality and problematic behavior (internalizing and externalizing) were partially mediated by parenting…

  20. Academic Self-Efficacy and Academic Procrastination as Predictors of Problematic Internet Use in University Students

    ERIC Educational Resources Information Center

    Odaci, Hatice

    2011-01-01

    Although computers and the internet, indispensable tools in people's lives today, facilitate life on the one hand, they have brought new risks with them on the other. Internet dependency, or problematic internet use, has emerged as a new concept of addiction. Parallel to this increasing in society in general, it is also on the rise among…

  1. Exploring the association of ego defense mechanisms with problematic internet use in a Pakistani medical school.

    PubMed

    Waqas, Ahmed; Rehman, Abdul; Malik, Aamenah; Aftab, Ramsha; Allah Yar, Aroosa; Allah Yar, Arooj; Rai, Aitzaz Bin Sultan

    2016-09-30

    The present study was designed to analyze association between problematic internet use and use of ego defense mechanisms in medical students. This cross-sectional study was undertaken at CMH Lahore Medical College (CMH LMC) in Lahore, Pakistan from 1st March, 2015 to 30th May, 2015. 522 medical and dental students were included in the study. The questionnaire consisted of three sections: a) demographic characteristics of respondent b) the Defense Style Questionnaire-40 (DSQ-40) and c) the Internet Addiction Test (IAT). All data were analyzed in SPSS v20. Chi square, Independent sample t test and One Way ANOVA were run to analyze association of different variables with scores on IAT. Multiple regression analysis was used to delineate ego defenses as predictors of problematic internet use. A total of 32 (6.1%) students reported severe problems with internet usage. Males had higher scores on IAT i.e had more problematic use of internet. Scores on internet addiction test (IAT) were negatively associated with sublimation and positively associated with projection, denial, autistic fantasy, passive aggression and displacement. There was a high prevalence of problematic use of internet among medical and dental students. It had significant associations with several defense mechanisms.

  2. Relationship between Levels of Problematic Internet Usage and Motivation to Study in University Students

    ERIC Educational Resources Information Center

    Reed, Phil; Reay, Emma

    2015-01-01

    This study explored the relationship between problematic levels of Internet use and motivation to study in a university sample. One hundred and sixty-two participants were recruited online and completed four questionnaires: Internet Addiction Test, Hospital Anxiety and Depression Scale, Emotional-Social Loneliness Scale, and the Motivated…

  3. Loneliness and Shyness in Adolescent Problematic Internet Users: The Role of Social Anxiety

    ERIC Educational Resources Information Center

    Huan, Vivien S.; Ang, Rebecca P.; Chye, Stefanie

    2014-01-01

    Background: Davis' ("Comput Hum Behav" 17:187-195, 2001) cognitive-behavioral model of problematic Internet use (PIU) proposed and theorized that certain psychopathological characteristics present within an individual, predispose him to PIU. Objective: This study extended Davis' model in hypothesizing that social anxiety mediates in a…

  4. Problematic Internet Use, Loneliness and Dating Anxiety among Young Adult University Students

    ERIC Educational Resources Information Center

    Odaci, Hatice; Kalkan, Melek

    2010-01-01

    The Internet, an important modern means of obtaining information and establishing communication with others, has become an increasingly essential element of human life. Although Internet use makes life easier, it can become problematic in the event of non-functional use. Debate and research into whether Internet addiction is a cause or an effect…

  5. Surveying Teens in School to Assess the Prevalence of Problematic Drug Use

    ERIC Educational Resources Information Center

    Falck, Russel S.; Nahhas, Ramzi W.; Li, Linna; Carlson, Robert G.

    2012-01-01

    Background: Illicit drug use by school-aged teens can adversely affect their health and academic achievement. This study used a survey administered in schools to assess the prevalence of problematic drug use among teenagers in a Midwestern community. Methods: Self-report data were collected from 11th- and 12th-grade students (N = 3974) in 16…

  6. Toward a "Modest Pedagogy": Reflections on the Problematics of Critical Pedagogy.

    ERIC Educational Resources Information Center

    Tinning, Richard

    2002-01-01

    Discusses difficulties in "doing" critical pedagogy with postmodern students, considering the advantages of working toward a "modest pedagogy" (modeled after Law's modest sociology), which takes seriously the problematic issue of knowledge and schooling, yet avoids some of the pitfalls of Enlightenment thinking and the neglect…

  7. The Impact of Gestalt Group Psychotherapy on Parents' Perceptions of Children Identified as Problematic.

    ERIC Educational Resources Information Center

    Little, Linda F.

    Gestalt therapy respects parents' perceptions of their children and does not attempt to train parents to become therapists for their children. To examine the impact of Gestalt group psychotherapy on parents' perceptions of children identified as problematic, an experimental group of 10 parents participated in 10 2-hour Gestalt sessions. A group of…

  8. "Tower, Am I Cleared to Land?": Problematic Communication in Aviation Discourse

    ERIC Educational Resources Information Center

    Howard, John W., III

    2008-01-01

    This study examined problematic communication in pilot-air traffic controller (ATC) interaction. More than 15 hours of pilot-ATC dialogue were collected by monitoring control tower frequencies at 15 U.S. airports. The transcribed data yielded a total of 34 ATCs, 270 pilots, and 1,799 turns of talk. Analyses revealed that (a) communication…

  9. Healthcare Information Technology Backsourcing, Problematic Outsourcing Manipulations, and Multisupplier Backsourcing Methodologies

    ERIC Educational Resources Information Center

    Garske, Steven Ray

    2010-01-01

    Backsourcing is the act of an organization changing an outsourcing relationship through insourcing, vendor change, or elimination of the outsourced service. This study discovered numerous problematic outsourcing manipulations conducted by suppliers, and identified backsourcing methodologies to correct these manipulations across multiple supplier…

  10. Problematic Transitions from School to Employment: Freeters and NEETs in Japan and Germany

    ERIC Educational Resources Information Center

    Pilz, Matthias; Schmidt-Altmann, Kirsten; Eswein, Mikiko

    2015-01-01

    In the international debate surrounding transitions from school to employment, Japan and Germany are regularly cited as examples of success. This article draws on the Japanese concepts represented by two problematic groups--freeters and NEETs--to demonstrate that over recent years, young people in both countries have also been facing serious…

  11. Getting to the Source: An Instrument for Examining the Dynamics of Problematic Interactions

    ERIC Educational Resources Information Center

    Cui, Xia

    2014-01-01

    A major challenge faced in research seeking to investigate the underlying dynamics of problematic interactions is that, when asked about the rationale underpinning what they said and did--their "theory of action in-use" (Argyris and Schön, 1974, 1978, 1996)--participants are often unaware of what prompts their behaviour--or decide to…

  12. The Role of Structural Characteristics in Problematic Video Game Play: An Empirical Study

    ERIC Educational Resources Information Center

    King, Daniel L.; Delfabbro, Paul H.; Griffiths, Mark D.

    2011-01-01

    The research literature suggests that the structural characteristics of video games may play a considerable role in the initiation, development and maintenance of problematic video game playing. The present study investigated the role of structural characteristics in video game playing behaviour within a sample of 421 video game players aged…

  13. Predictors and patterns of problematic Internet game use using a decision tree model

    PubMed Central

    Rho, Mi Jung; Jeong, Jo-Eun; Chun, Ji-Won; Cho, Hyun; Jung, Dong Jin; Choi, In Young; Kim, Dai-Jin

    2016-01-01

    Background and aims Problematic Internet game use is an important social issue that increases social expenditures for both individuals and nations. This study identified predictors and patterns of problematic Internet game use. Methods Data were collected from online surveys between November 26 and December 26, 2014. We identified 3,881 Internet game users from a total of 5,003 respondents. A total of 511 participants were assigned to the problematic Internet game user group according to the Diagnostic and Statistical Manual of Mental Disorders Internet gaming disorder criteria. From the remaining 3,370 participants, we used propensity score matching to develop a normal comparison group of 511 participants. In all, 1,022 participants were analyzed using the chi-square automatic interaction detector (CHAID) algorithm. Results According to the CHAID algorithm, six important predictors were found: gaming costs (50%), average weekday gaming time (23%), offline Internet gaming community meeting attendance (13%), average weekend and holiday gaming time (7%), marital status (4%), and self-perceptions of addiction to Internet game use (3%). In addition, three patterns out of six classification rules were explored: cost-consuming, socializing, and solitary gamers. Conclusion This study provides direction for future work on the screening of problematic Internet game use in adults. PMID:27499227

  14. Predicting Problematic Alcohol Use with the DSM-5 Alternative Model of Personality Pathology

    PubMed Central

    Creswell, Kasey G.; Bachrach, Rachel L.; Wright, Aidan G.C.; Pinto, Anthony; Ansell, Emily

    2015-01-01

    There is high comorbidity between personality disorders and alcohol use disorders, which appears related to individual differences in underlying personality dimensions of behavioral undercontrol and affective dysregulation. Very little is known about how the DSM-5 Section III trait model of personality pathology relates to alcohol problems, however, or how the strength of the relationship between personality pathology and alcohol problems changes with age and across gender. The current study examined these questions in a sample of 877 participants using the General Assessment of Personality Disorder to assess general personality dysfunction, the Personality Inventory for DSM-5 to measure specific traits, and the Alcohol Use Disorder Identification Test to assess problematic alcohol use. Results demonstrated that general personality pathology (Criterion A) was significantly related to problematic alcohol use after controlling for age and gender effects. Further, two of the five higher-order personality trait domains (Criterion B), Antagonism and Disinhibition, remained significant predictors of problematic alcohol use after accounting for the influence of general personality pathology; however, general personality pathology no longer predicted hazardous alcohol use once Antagonism and Disinhibition were added into the model. Finally, these two specific traits interacted with age, such that Antagonism was a stronger predictor of AUDIT scores among older individuals and Disinhibition was a stronger predictor of alcohol problems among younger individuals. Findings support the general validity of this new personality disorder diagnostic system and suggest important age effects in the relationship between traits and problematic alcohol use. PMID:26389625

  15. Problematizing the Processes of Participation in Networks: Working through the Rhetoric

    ERIC Educational Resources Information Center

    Ferreira, Jo-Anne; Davis, Julie

    2012-01-01

    Participation in networks, both as a concept and process, is widely supported in environmental education as a democratic and equitable pathway to individual and social change for sustainability. However, the processes of participation in networks are rarely problematized. Rather, it is assumed that we inherently know how to participate in…

  16. Problematic Approach to English Learning and Teaching: A Case in Indonesia

    ERIC Educational Resources Information Center

    Panggabean, Himpun

    2015-01-01

    This article deals with problematic approach to English learning and teaching due to misleading conception on the nature of English and on the process of acquiring it as well as the clues to the issues. The clues are: Firstly, English is not more difficult than any other languages, including Indonesian language, "Bahasa Indonesia".…

  17. Early Childhood Service Delivery for Families Living with Childhood Disability: Disabling Families through Problematic Implicit Ideology

    ERIC Educational Resources Information Center

    Breen, Lauren J.

    2009-01-01

    The aim of this paper is to unpack the implicit ideology underpinning early childhood service delivery for families living with childhood disability. The family as the unit of care is central to the philosophy and practice of early childhood services. However, the practice of family-centred care can be problematic; it is based upon neo-liberal…

  18. [Ants: species-area relationship in tropical dry forest fragments].

    PubMed

    Lozano-Zambrano, Fabio H; Ulloa-Chacón, Patricia; Armbrecht, Inge

    2009-01-01

    We analyzed the effect of fragmentation on ant species-area and specimen frequency-area relationships in nine patches of tropical dry forest in the middle Cauca river basin in Colombia. Species richness and specimen relative frequency of ants were positively correlated with area, whereas no significant correlation was found between species richness and the degree of isolation calculated for the forest patches. As the fragmentation affects different functional groups in different ways, we analyzed the species-area relationship for separate functional groups of ants. According to the habitat requirements we found that the species richness increased faster as area increased for ants inhabiting decomposing wood, followed by ants associated with trees, while species richness of ants living under dead leaves did not correlate with area. According to the food preference, species richness was positively correlated with area for the army ant group, while no significant correlation was found for solitary hunters or for leaf-cutting ants. Ant species richness and specimen density were calculated from equal size samples and examined in relation to the habitat area. An inverse correlation was found only for specimen density, the opposite of what was expected. To our knowledge this is one of the first studies showing differential responses of functional groups of ants to habitat loss. Moreover, it emphasizes the conservation value of small forest fragments for ants in a tropical dry forest.

  19. The interactions of ants with their biotic environment

    PubMed Central

    Renner, Susanne S.

    2017-01-01

    This special feature results from the symposium ‘Ants 2016: ant interactions with their biotic environments’ held in Munich in May 2016 and deals with the interactions between ants and other insects, plants, microbes and fungi, studied at micro- and macroevolutionary levels with a wide range of approaches, from field ecology to next-generation sequencing, chemical ecology and molecular genetics. In this paper, we review key aspects of these biotic interactions to provide background information for the papers of this special feature. After listing the major types of biotic interactions that ants engage in, we present a brief overview of ant/ant communication, ant/plant interactions, ant/fungus symbioses, and recent insights about ants and their endosymbionts. Using a large molecular clock-dated Formicidae phylogeny, we map the evolutionary origins of different ant clades' interactions with plants, fungi and hemiptera. Ants' biotic interactions provide ideal systems to address fundamental ecological and evolutionary questions about mutualism, coevolution, adaptation and animal communication. PMID:28298352

  20. The evolution of multiple mating in army ants.

    PubMed

    Kronauer, Daniel J C; Johnson, Robert A; Boomsma, Jacobus J

    2007-02-01

    The evolution of mating systems in eusocial Hymenoptera is constrained because females mate only during a brief period early in life, whereas inseminated queens and their stored sperm may live for decades. Considerable research effort during recent years has firmly established that obligate multiple mating has evolved only a few times: in Apis honeybees, Vespula wasps, Pogonomyrmex harvester ants, Atta and Acromyrmex leaf-cutting ants, the ant Cataglyphis cursor, and in at least some army ants. Here we provide estimates of queen-mating frequency for New World Neivamyrmex and Old World Aenictus species, which, compared to other army ants, have relatively small colonies and little size polymorphism among workers. To provide the first overall comparative analysis of the evolution of army ant mating systems, we combine these new results with previous estimates for African Dorylus and New World Eciton army ants, which have very large colonies and considerable worker polymorphism. We show that queens of Neivamyrmex and Aenictus mate with the same high numbers of males (usually ca. 10-20) as do queens of army ant species with very large colony sizes. We infer that multiple queen mating is ancestral in army ants and has evolved over 100 million years ago as part of the army ant adaptive syndrome. A comparison of army ants and honeybees suggests that mating systems in these two distantly related groups may have been convergently shaped by strikingly similar selective pressures.

  1. Host ant independent oviposition in the parasitic butterfly Maculinea alcon

    PubMed Central

    Fürst, Matthias A.; Nash, David R.

    2010-01-01

    Parasitic Maculinea alcon butterflies can only develop in nests of a subset of available Myrmica ant species, so female butterflies have been hypothesized to preferentially lay eggs on plants close to colonies of the correct host ants. Previous correlational investigations of host-ant-dependent oviposition in this and other Maculinea species have, however, shown equivocal results, leading to a long-term controversy over support for this hypothesis. We therefore conducted a controlled field experiment to study the egg-laying behaviour of M. alcon. Matched potted Gentiana plants were set out close to host-ant nests and non-host-ant nests, and the number and position of eggs attached were assessed. Our results show no evidence for host-ant-based oviposition in M. alcon, but support an oviposition strategy based on plant characteristics. This suggests that careful management of host-ant distribution is necessary for conservation of this endangered butterfly. PMID:19864269

  2. Red legs and golden gasters: Batesian mimicry in Australian ants.

    PubMed

    Merrill, D N; Elgar, M A

    2000-05-01

    There are numerous reports of invertebrates that are visual mimics of ants, but no formal reports of mimicry of an ant, by an ant. Two endemic Australian ants, Myrmecia fulvipes and Camponotus bendigensis are remarkably similar in colour and size; both are generally black but have red legs and golden gasters. The density and hue of the pubescence of each ant's gaster are relatively uncommon in ants, but are very rare when combined with the black forebody and red legs. The ants are similarly sized but are smaller than other species closely related to M. fulvipes. The range of C. bendigensis lies entirely within that of M. fulvipes, and both species excavate ground nests in open woodland. Finally, workers of both species are crepuscular and forage solitarily. These data suggest that the relatively benign formicine C. bendigensis is a Batesian mimic of the formidable myrmeciine M. fulvipes.

  3. Red legs and golden gasters: Batesian mimicry in australian ants

    NASA Astrophysics Data System (ADS)

    Merrill, D. N.; Elgar, Mark A.

    There are numerous reports of invertebrates that are visual mimics of ants, but no formal reports of mimicry of an ant, by an ant. Two endemic Australian ants, Myrmecia fulvipes and Camponotus bendigensis are remarkably similar in colour and size; both are generally black but have red legs and golden gasters. The density and hue of the pubescence of each ant's gaster are relatively uncommon in ants, but are very rare when combined with the black forebody and red legs. The ants are similarly sized but are smaller than other species closely related to M. fulvipes. The range of C. bendigensis lies entirely within that of M. fulvipes, and both species excavate ground nests in open woodland. Finally, workers of both species are crepuscular and forage solitarily. These data suggest that the relatively benign formicine C. bendigensis is a Batesian mimic of the formidable myrmeciine M. fulvipes.

  4. Harvester ant bioassay for assessing hazardous chemical waste sites

    SciTech Connect

    Gano, K.A.; Carlile, D.W.; Rogers, L.E.

    1984-12-01

    A technique was developed for using harvester ants, Pogonomyrmex owhyeei, in terrestrial bioassays. Procedures were developed for maintaining stock populations, handling ants, and exposing ants to toxic materials. Relative toxicities were determined by exposing ants to 10 different materials. These materials included three insecticides, Endrin, Aldrin, and Dieldrin; one herbicide, 2,4-D; three oil-like compounds, wood preservative, drilling fluid, and slop oil; and three heavy metals, copper, zinc, and cadmium. Ants were exposed in petri dishes containing soil amended with a particular toxicant. Under these test conditions, ants showed no sensitivity to the metals or 2,4-D. Ants were sensitive to the insecticides and oils in repeated tests, and relative toxicity remained consistent throughout. Aldrin was the most toxic material, followed by Dieldrin, Endrin, wood preservative, drilling fluid, and slop oil. 10 refs., 2 figs., 2 tabs.

  5. Fast and Flexible: Argentine Ants Recruit from Nearby Trails

    PubMed Central

    Flanagan, Tatiana P.; Pinter-Wollman, Noa M.; Moses, Melanie E.; Gordon, Deborah M.

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources. PMID:23967129

  6. Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys

    NASA Technical Reports Server (NTRS)

    Clark, P. E.; Rilee, M. L.; Curtis, S. A.

    2003-01-01

    ANTS (Autonomous Nano-Technology Swarm), a large (1000 member) swarm of nano to picoclass (10 to 1 kg) totally autonomous spacecraft, are being developed as a NASA advanced mission concept. ANTS, based on a hierarchical insect social order, use an evolvable, self-similar, hierarchical neural system in which individual spacecraft represent the highest level nodes. ANTS uses swarm intelligence attained through collective, cooperative interactions of the nodes at all levels of the system. At the highest levels this can take the form of cooperative, collective behavior among the individual spacecraft in a very large constellation. The ANTS neural architecture is designed for totally autonomous operation of complex systems including spacecraft constellations. The ANTS (Autonomous Nano Technology Swarm) concept has a number of possible applications. A version of ANTS designed for surveying and determining the resource potential of the asteroid belt, called PAM (Prospecting ANTS Mission), is examined here.

  7. Insect navigation: do ants live in the now?

    PubMed

    Graham, Paul; Mangan, Michael

    2015-03-01

    Visual navigation is a critical behaviour for many animals, and it has been particularly well studied in ants. Decades of ant navigation research have uncovered many ways in which efficient navigation can be implemented in small brains. For example, ants show us how visual information can drive navigation via procedural rather than map-like instructions. Two recent behavioural observations highlight interesting adaptive ways in which ants implement visual guidance. Firstly, it has been shown that the systematic nest searches of ants can be biased by recent experience of familiar scenes. Secondly, ants have been observed to show temporary periods of confusion when asked to repeat a route segment, even if that route segment is very familiar. Taken together, these results indicate that the navigational decisions of ants take into account their recent experiences as well as the currently perceived environment.

  8. Fast and flexible: argentine ants recruit from nearby trails.

    PubMed

    Flanagan, Tatiana P; Pinter-Wollman, Noa M; Moses, Melanie E; Gordon, Deborah M

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  9. Lerneca inalata beripocone subsp. nov. (Orthoptera: Phalangopsidae; Luzarinae): a new taxon for the northern Pantanal of Brazil.

    PubMed

    Lima, Raysa Martins; Martins, Luciano De Pinho; Pereira, Marcelo Ribeiro; Ganchev, Todor D; Jahn, Olaf; Lhano, Marcos Gonçalves; Marques, Marinêz Isaac; Schuchmann, Karl-L

    2016-10-17

    The first record of the Orthoptera species Lerneca inalata for Brazil is presented here. The taxon is represented by a new subspecies Lerneca inalata beripocone subsp. nov. (Phalangopsidae, Luzarinae), collected in the Pantanal of Poconé, Mato Grosso, Brazil. This work includes morphological and morphometric data as well as descriptions of female genitalia and calling song. The new subspecies has as diagnostic features the male genitalia with six ventral spines on the B sclerite, the first spine having a subtle bifurcation; the mid-region of the strongly sclerotized pseudepiphallus; inclination of C sclerite with slightly concave curvature; tegmina-length ratio and the speculum (syn. mirror) width approximately three times the length of the apical area. The description of the female genitalia and the calling song is presented for the first time for the species Lerneca inalata. A distribution map covers the local occurrence of its subspecies.

  10. Molecular evidence for a single taxon, Anopheles nuneztovari s. l., from two endemic malaria regions in Colombia

    PubMed Central

    Jaramillo, Luz Marina; Gutiérrez, Lina A; Luckhart, Shirley; Conn, Jan E; Correa, Margarita M

    2012-01-01

    To elucidate the Anopheles nuneztovari s.l. taxonomic status at a microgeographic level in four malaria endemic localities from Antioquia and Córdoba, Colombia, fragments of the Cytochrome oxidase subunit I (COI) and the white gene were used. The COI analysis showed low genetic differentiation with FST levels between −0.02 and 0.137 and Nm values between 3 and infinity, indicating the presence of high gene flow among An. nuneztovari s.l. populations from the four localities. The COI network showed a single most common haplotype, 1 (n=55), present in all localities, as the likely ancestral haplotype. Analysis of the white gene showed that An. nuneztovari s.l. populations from both departments grouped with haplotypes 19 and 20, which are part of lineage 3 previously reported. The results of the present study suggest that An. nuneztovari s.l. is a single taxon in the area of the present study. PMID:22241127

  11. Tracking Effects of Problematic Social Networking on Adolescent Psychopathology: The Mediating Role of Sleep Disruptions.

    PubMed

    Vernon, Lynette; Modecki, Kathryn L; Barber, Bonnie L

    2017-01-01

    Concerns are growing about adolescents' problematic social networking and possible links to depressed mood and externalizing behavior. Yet there remains little understanding of underlying processes that may account for these associations, including the mediating role of sleep disruption. This study tests this putative mediating process and examines change in problematic social networking investment and disrupted sleep, in relation to change in depressed mood and externalizing behavior. A sample of 874 students (41% male; 57.2% Caucasian; baseline M age = 14.4 years) from 27 high schools were surveyed. Participants' problematic social networking, sleep disruption, and psychopathology (depressed mood, externalizing behaviors) were measured annually over 3 years. Longitudinal mediation was tested using latent trajectories of problematic social networking use, sleep disruption, and psychopathology. Both problematic social networking and sleep disruption underwent positive linear growth over time. Adolescents who increasingly invested in social networking reported increased depressed mood, with around 53% of this association explained by the indirect effect of increased sleep disruptions. Further, adolescents who increasingly invested in social networking also reported increased externalizing behavior; some of this relation was explained (13%) via increased sleep disruptions. However an alternative model in which increased externalizing was associated with increased social networking, mediated by sleep disruptions, indicated a reciprocal relation of similar magnitude. It is important for parents, teachers, and psychologists to minimize the negative effects of social networking on adolescents' psychopathology. Interventions should potentially target promoting healthy sleep habits through reductions in social networking investment and rescheduling usage away from bedtime.

  12. The effect of parental involvement on problematic social behaviors among school-age children in Kentucky.

    PubMed

    Robl, Joyce M; Jewell, Tracey D; Kanotra, Sarojini

    2012-12-01

    This study examines the associations among parental active involvement and healthy role modeling behavior with social behavior among children in Kentucky and the nation. Data from the 2007 National Survey of Children's Health was used, limited to children 6-17 years old. The dependent variable was a composite measure of problematic social behavior. Independent variables included parental involvement, parental healthy role modeling, and demographic variables. Chi square tests of independence were completed for bivariate analyses and multivariable logistic regression models were developed for Kentucky and the nation. The prevalence of problematic social behaviors in children was 10.4 % in Kentucky and 8.8 % in the nation. The parents of children in Kentucky who often exhibited problematic social behavior reported poor parent-child communication (50.4 %), not coping well with parenthood (56.5 %), parental aggravation (48.3 %), and less emotional help with parenting (9.1 %). The factor with the largest magnitude of association in Kentucky (adjusted odds ratio [AOR] = 6.2; 95 % confidence interval [CI]: 1.6, 24.5) and the nation (AOR = 4.8; 95 % CI: 3.3, 7.0) was observed for whether or not the parent communicated well with the child. Additional factors associated with problematic social behavior among children in Kentucky were living in a single parent, mother-led household, and having a parent with fair or poor mental health. Public health programs that target factors addressing the parent-child dyad, parent-child communication, and model healthy relationships may reduce the occurrence of problematic social behavior in 6-17-year-old children in Kentucky.

  13. How to Handle Speciose Clades? Mass Taxon-Sampling as a Strategy towards Illuminating the Natural History of Campanula (Campanuloideae)

    PubMed Central

    Mansion, Guilhem; Parolly, Gerald; Crowl, Andrew A.; Mavrodiev, Evgeny; Cellinese, Nico; Oganesian, Marine; Fraunhofer, Katharina; Kamari, Georgia; Phitos, Dimitrios; Haberle, Rosemarie; Akaydin, Galip; Ikinci, Nursel; Raus, Thomas; Borsch, Thomas

    2012-01-01

    Background Speciose clades usually harbor species with a broad spectrum of adaptive strategies and complex distribution patterns, and thus constitute ideal systems to disentangle biotic and abiotic causes underlying species diversification. The delimitation of such study systems to test evolutionary hypotheses is difficult because they often rely on artificial genus concepts as starting points. One of the most prominent examples is the bellflower genus Campanula with some 420 species, but up to 600 species when including all lineages to which Campanula is paraphyletic. We generated a large alignment of petD group II intron sequences to include more than 70% of described species as a reference. By comparison with partial data sets we could then assess the impact of selective taxon sampling strategies on phylogenetic reconstruction and subsequent evolutionary conclusions. Methodology/Principal Findings Phylogenetic analyses based on maximum parsimony (PAUP, PRAP), Bayesian inference (MrBayes), and maximum likelihood (RAxML) were first carried out on the large reference data set (D680). Parameters including tree topology, branch support, and age estimates, were then compared to those obtained from smaller data sets resulting from “classification-guided” (D088) and “phylogeny-guided sampling” (D101). Analyses of D088 failed to fully recover the phylogenetic diversity in Campanula, whereas D101 inferred significantly different branch support and age estimates. Conclusions/Significance A short genomic region with high phylogenetic utility allowed us to easily generate a comprehensive phylogenetic framework for the speciose Campanula clade. Our approach recovered 17 well-supported and circumscribed sub-lineages. Knowing these will be instrumental for developing more specific evolutionary hypotheses and guide future research, we highlight the predictive value of a mass taxon-sampling strategy as a first essential step towards illuminating the detailed evolutionary

  14. Evolutionary history of "early-diverging" eukaryotes: the excavate taxon Carpediemonas is a close relative of Giardia.

    PubMed

    Simpson, Alastair G B; Roger, Andrew J; Silberman, Jeffrey D; Leipe, Detlef D; Edgcomb, Virginia P; Jermiin, Lars S; Patterson, David J; Sogin, Mitchell L

    2002-10-01

    Diplomonads, such as Giardia, and their close relatives retortamonads have been proposed as early-branching eukaryotes that diverged before the acquisition-retention of mitochondria, and they have become key organisms in attempts to understand the evolution of eukaryotic cells. In this phylogenetic study we focus on a series of eukaryotes suggested to be relatives of diplomonads on morphological grounds, the "excavate taxa". Phylogenies of small subunit ribosomal RNA (SSU rRNA) genes, alpha-tubulin, beta-tubulin, and combined alpha- + beta-tubulin all scatter the various excavate taxa across the diversity of eukaryotes. But all phylogenies place the excavate taxon Carpediemonas as the closest relative of diplomonads (and, where data are available, retortamonads). This novel relationship is recovered across phylogenetic methods and across various taxon-deletion experiments. Statistical support is strongest under maximum-likelihood (ML) (when among-site rate variation is modeled) and when the most divergent diplomonad sequences are excluded, suggesting a true relationship rather than an artifact of long-branch attraction. When all diplomonads are excluded, our ML SSU rRNA tree actually places retortamonads and Carpediemonas away from the base of the eukaryotes. The branches separating excavate taxa are mostly not well supported (especially in analyses of SSU rRNA data). Statistical tests of the SSU rRNA data, including an "expected likelihood weights" approach, do not reject trees where excavate taxa are constrained to be a clade (with or without parabasalids and Euglenozoa). Although diplomonads and retortamonads lack any mitochondria-like organelle, Carpediemonas contains double membrane-bounded structures physically resembling hydrogenosomes. The phylogenetic position of Carpediemonas suggests that it will be valuable in interpreting the evolutionary significance of many molecular and cellular peculiarities of diplomonads.

  15. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach

    PubMed Central

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  16. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach.

    PubMed

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  17. Size matters: nest colonization patterns for twig-nesting ants

    PubMed Central

    Jiménez-Soto, Estelí; Philpott, Stacy M

    2015-01-01

    Understanding the drivers of ant diversity and co-occurrence in agroecosystems is fundamental because ants participate in interactions that influence agroecosystem processes. Multiple local and regional factors influence ant community assembly. We examined local factors that influence the structure of a twig-nesting ant community in a coffee system in Mexico using an experimental approach. We investigated whether twig characteristics (nest entrance size and diversity of nest entrance sizes) and nest strata (canopy shade tree or coffee shrub) affected occupation, species richness, and community composition of twig-nesting ants and whether frequency of occupation of ant species varied with particular nest entrance sizes or strata. We conducted our study in a shaded coffee farm in Chiapas, Mexico, between March and June 2012. We studied ant nest colonization by placing artificial nests (bamboo twigs) on coffee shrubs and shade trees either in diverse or uniform treatments. We also examined whether differences in vegetation (no. of trees, canopy cover and coffee density) influenced nest colonization. We found 33 ant species occupying 73% of nests placed. Nest colonization did not differ with nest strata or size. Mean species richness of colonizing ants was significantly higher in the diverse nest size entrance treatment, but did not differ with nest strata. Community composition differed between strata and also between the diverse and uniform size treatments on coffee shrubs, but not on shade trees. Some individual ant species were more frequently found in certain nest strata and in nests with certain entrance sizes. Our results indicate that twig-nesting ants are nest-site limited, quickly occupy artificial nests of many sizes, and that trees or shrubs with twigs of a diversity of entrance sizes likely support higher ant species richness. Further, individual ant species more frequently occupy nests with different sized entrances promoting ant richness on individual

  18. Bioturbation by Fire Ants in the Coastal Prairie of Texas

    NASA Astrophysics Data System (ADS)

    Cameron, G.; Williams, L.

    2001-12-01

    Fire ants (Solenopsis invicta) were introduced to the US in the early part of the last century. They have spread throughout the southeastern US in the absence of native competitors and predators with a range limited by abiotic factors. Each fire ant mound contains thousands of individuals, can be large, and can be numerous enough to comprise a dominant feature of the landscape. Studies of this species have focused upon its spread, formation of single- and multiple-queen colonies, genetic structure, and impact on native fauna and human health. Some studies have analyzed native fire ant-soil interactions, but few studies have examined the process of bioturbation by introduced fire ants in native ecosystems. Fire ants on the coastal prairie of Texas primarily are of the multiple-queen type that exhibit a much higher density of mounds than the single-queen type. Consequently, mound-building activities by fire ants can have a marked effect upon soil structure and nutrient content and may affect soil organisms and plants. Fire ant activity, mound density, mound dispersion, soil texture, soil permeability, soil moisture content, and soil nutrients were measured. Fire ants mounds are visible aboveground from April-November. Density of mounds was 117-738/ha, and average mound lifespan was 3.6 months with only 9% of the mounds remaining active throughout the entire season. Mounds were dispersed randomly. Foraging activity by fire ants was from June through October with a peak in July. Annual soil turnover was estimated by collecting and weighing mounds. There was no effect of ant mounds on soil texture, but water infiltration was higher in areas with ant mounds. Early-season samples showed no nutrient differences, but late-season samples showed that ant mounds contained higher amounts of micronutrients than random samples of soil. These data are compared to similar data on effects of mounds from native ants and from native and introduced ants in different habitats.

  19. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem.

    PubMed

    Stuble, Katharine L; Kirkman, L Katherine; Carroll, C Ronald; Sanders, Nathan J

    2011-06-01

    The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable.

  20. Interaction between Mutualisms: Ant-tended butterflies exploit enemy-free space provided by ant-treehopper associations.

    PubMed

    Kaminski, Lucas A; Freitas, André V L; Oliveira, Paulo S

    2010-09-01

    Although mutualisms have been intensively investigated, demonstration of indirect effects between co-occurring mutualistic systems is rare. For instance, the ecological consequences of co-occurrence of ant-tended insects on a plant have never been examined for survival effects on either trophobiont species. Here, we assess the selective pressures mediating co-occurrence of a facultative ant-tended butterfly (Parrhasius polibetes) with ant-tended treehoppers (Guayaquila xiphias) on Schefflera vinosa shrubs. We evaluated host plant selection and caterpillar survival in P. polibetes in the presence and absence of ant-treehopper associations. Paired trials revealed that butterflies preferably oviposit on branches hosting ant-tended treehoppers when they had a choice between those and branches without this interaction. Presence of ant-tended treehoppers on a branch reduced the abundance of P. polibetes' natural enemies and improved caterpillar survival in both premyrmecophylic and ant-tended phases. Thus ant-tended treehoppers create an enemy-free space on foliage that butterflies exploit to protect larval offspring. These findings connect two widely documented ant-trophobiont mutualisms and highlight the importance of considering multiple interactions for a proper understanding of ant-plant-herbivore systems. Detection of other ant-based mutualisms on oviposition to improve offspring survival may have represented an important evolutionary step in the process of host plant selection in facultative myrmecophilous butterflies.

  1. Ant nest corrosion -- Exploring the labyrinth

    SciTech Connect

    Elliott, P.; Corbett, R.A.

    1999-07-01

    The phenomenon of ant nest (formicary) corrosion is reviewed. Current theories indicate that attack requires the simultaneous presence of moisture, oxygen and a corrodent, usually an organic acid, such as formic acid. Morphological features are presented using several recent case studies as examples. This paper seeks to create more answers to this less appreciated phenomenon that causes premature corrosion failure in copper tubes used typically for refrigeration or air conditioning applications.

  2. Ant fat extraction with a Soxhlet extractor.

    PubMed

    Smith, Chris R; Tschinkel, Walter R

    2009-07-01

    Stored fat can be informative about the relative age of an ant, its nutritional status, and the nutritional status of the colony. Several methods are available for the quantification of stored fat. Before starting a project involving fat extraction, investigators should weigh the advantages and disadvantages of different methods in order to choose the one that is best suited to the question being addressed. This protocol, although not as accurate as some alternatives, facilitates the rapid quantification of many individuals.

  3. Ant-Man and the quantum realm

    NASA Astrophysics Data System (ADS)

    Michalakis, Spiros

    2015-11-01

    I was in Los Angeles airport, stuffing French fries into my mouth and waiting for a flight to Charlotte, North Carolina, when my phone buzzed. The e-mail was from the Science and Entertainment Exchange, a non-profit organization working to elevate the level of science in the movies, and it told me to report to Atlanta to consult on a new superhero movie: Ant-Man.

  4. Ant foraging on extrafloral nectaries of Qualea grandiflora (Vochysiaceae) in cerrado vegetation: ants as potential antiherbivore agents.

    PubMed

    Oliveira, P S; da Silva, A F; Martins, A B

    1987-12-01

    Qualea grandiflora is a typical tree of Brazilian cerrados (savanna-like vegetation) that bears paired extrafloral nectaries (EFNs) along its stems. Results show that possession of EFNs increases ant density on Q. grandiflora shrubs over that of neighbouring non-nectariferous plants. Frequency of ant occupancy and mean number of ants per plant were much higher on Qualea than on plants lacking EFNs. These differences resulted in many more live termitebaits being attacked by foraging ants on Qualea than on neighbours without EFNs. Termites were attacked in equal numbers and with equal speeds on different-aged leaves of Qualea. The greatest potential for herbivore deterrence was presented by Camponotus ants (C. crassus, C. rufipes and C. aff. blandus), which together attacked significantly more termites than nine other ant species grouped. EFNs are regarded as important promoters of ant activity on cerado plants.

  5. Polydomy in the ant Ectatomma opaciventre

    PubMed Central

    Tofolo, Viviane C.; Giannotti, Edilberto; Neves, Erika F.; Andrade, Luis H. C.; Lima, Sandro M.; Súarez, Yzel R.; Antonialli-Junior, William F.

    2014-01-01

    Tropical ants commonly exhibit a hyper-dispersed pattern of spatial distribution of nests. In polydomous species, nests may be satellites, that is, secondary structures of the main nest, where the queen is found. In order to evaluate whether the ant Ectatomma opaciventre Roger (Formicidae: Ectatomminae) uses the strategy of building polydomous nests, the spatial distribution pattern of 33 nests in a 1,800 m2 degraded area located in Rio Claro, SP, Brazil, were investigated using the nearest neighbor method. To complement the results of this investigation, the cuticular chemical profile of eight colonies was analyzed using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The nests of E. opaciventre presented a hyper-dispersed or regular distribution, which is the most common in ants. The analysis of the cuticular hydrocarbons apparently confirmed the hypothesis that this species is polydomous, since the chemical profiles of all studied colonies with nests at different sites were very similar to the chemical signature of the single found queen and were also different from those of colonies used as control. PMID:25373168

  6. Dispersal Polymorphisms in Invasive Fire Ants

    PubMed Central

    Helms, Jackson A.; Godfrey, Aaron

    2016-01-01

    In the Found or Fly (FoF) hypothesis ant queens experience reproduction-dispersal tradeoffs such that queens with heavier abdomens are better at founding colonies but are worse flyers. We tested predictions of FoF in two globally invasive fire ants, Solenopsis geminata (Fabricius, 1804) and S. invicta (Buren, 1972). Colonies of these species may produce two different monogyne queen types—claustral queens with heavy abdomens that found colonies independently, and parasitic queens with small abdomens that enter conspecific nests. Claustral and parasitic queens were similarly sized, but the abdomens of claustral queens weighed twice as much as those of their parasitic counterparts. Their heavier abdomens adversely impacted morphological predictors of flight ability, resulting in 32–38% lower flight muscle ratios, 55–63% higher wing loading, and 32–33% higher abdomen drag. In lab experiments maximum flight durations in claustral S. invicta queens decreased by about 18 minutes for every milligram of abdomen mass. Combining our results into a simple fitness tradeoff model, we calculated that an average parasitic S. invicta queen could produce only 1/3 as many worker offspring as a claustral queen, but could fly 4 times as long and have a 17- to 36-fold larger potential colonization area. Investigations of dispersal polymorphisms and their associated tradeoffs promises to shed light on range expansions in invasive species, the evolution of alternative reproductive strategies, and the selective forces driving the recurrent evolution of parasitism in ants. PMID:27082115

  7. Using VisANT to Analyze Networks

    PubMed Central

    Hu, Zhenjun

    2014-01-01

    VisANT is a Web-based workbench for the integrative analysis of biological networks with unique features such as exploratory navigation of interaction network and multi-scale visualization and inference with integrated hierarchical knowledge. It provides functionalities for convenient construction, visualization, and analysis of molecular and higher order networks based on functional (e.g., expression profiles, phylogenetic profiles) and physical (e.g., yeast two-hybrid, chromatin-immunoprecipitation and drug target) relations from either the Predictome database or user-defined data sets. Analysis capabilities include network structure analysis, overrepresentation analysis, expression enrichment analysis etc. Additionally, network can be saved, accessed, and shared online. VisANT is able to develop and display meta-networks for meta-nodes that are structural complexes or pathways or any kind of subnetworks. Further, VisANT supports a growing number of standard exchange formats and database referencing standards, e.g., PSI-MI, KGML, BioPAX, SBML(in progress) Multiple species are supported to the extent that interactions or associations are available (i.e., public datasets or Predictome database). PMID:25422679

  8. ANT tuner retrofit for LEB cavity

    SciTech Connect

    Walling, L.; Goren, Y.; Kwiatkowski, S.

    1994-03-01

    This report describes a ferrite tuner design for the LEB cavity that utilizes techniques for bonding ferrite to metallic cooling plates that is utilized in the high-power rf and microwave industry. A test tuner was designed to fit into the existing LEB-built magnet and onto the Grimm LEB Cavity. It will require a new vacuum window in order to attain maximal tuning range and high voltage capability and a new center conductor of longer length and a different vacuum window connection than the Grimm center conductor. However, the new center conductor will be essentially identical to the Grimm center conductor in its basic construction and in the way it connects to the stand for support. The tuner is mechanically very similar to high-power stacked circulators built by ANT of Germany and was designed according to ANT`s established engineering and design criteria and SSC LEB tuning and power requirements. The tuner design incorporates thin tiles of ferrite glued using a high-radiation-resistance epoxy to copper-plated stainless steel cooling plates of thickness 6.5 mm with water cooling channels inside the plates. The cooling plates constitute 16 pie-shaped segments arranged in a disk. They are electrically isolated from each other to suppress eddy currents. Five of these disks are arranged in parallel with high-pressure rf contacts between the plates at the outer radius. The end walls are slotted copper-plated stainless steel of thickness 3 mm.

  9. Recognition of Social Identity in Ants

    PubMed Central

    Bos, Nick; d’Ettorre, Patrizia

    2012-01-01

    Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend of hydrocarbons present on the cuticle of every individual (the “label”). Recognition occurs when an ant encounters another individual, and compares the label it perceives to an internal representation of its own colony odor (the “template”). A mismatch between label and template leads to rejection of the encountered individual. Although advances have been made in our understanding of how the label is produced and acquired, contradictory evidence exists about information processing of recognition cues. Here, we review the literature on template acquisition in ants and address how and when the template is formed, where in the nervous system it is localized, and the possible role of learning. We combine seemingly contradictory evidence in to a novel, parsimonious theory for the information processing of nestmate recognition cues. PMID:22461777

  10. Dispersal Polymorphisms in Invasive Fire Ants.

    PubMed

    Helms, Jackson A; Godfrey, Aaron

    2016-01-01

    In the Found or Fly (FoF) hypothesis ant queens experience reproduction-dispersal tradeoffs such that queens with heavier abdomens are better at founding colonies but are worse flyers. We tested predictions of FoF in two globally invasive fire ants, Solenopsis geminata (Fabricius, 1804) and S. invicta (Buren, 1972). Colonies of these species may produce two different monogyne queen types-claustral queens with heavy abdomens that found colonies independently, and parasitic queens with small abdomens that enter conspecific nests. Claustral and parasitic queens were similarly sized, but the abdomens of claustral queens weighed twice as much as those of their parasitic counterparts. Their heavier abdomens adversely impacted morphological predictors of flight ability, resulting in 32-38% lower flight muscle ratios, 55-63% higher wing loading, and 32-33% higher abdomen drag. In lab experiments maximum flight durations in claustral S. invicta queens decreased by about 18 minutes for every milligram of abdomen mass. Combining our results into a simple fitness tradeoff model, we calculated that an average parasitic S. invicta queen could produce only 1/3 as many worker offspring as a claustral queen, but could fly 4 times as long and have a 17- to 36-fold larger potential colonization area. Investigations of dispersal polymorphisms and their associated tradeoffs promises to shed light on range expansions in invasive species, the evolution of alternative reproductive strategies, and the selective forces driving the recurrent evolution of parasitism in ants.

  11. Biodiversity below ground: probing the subterranean ant fauna of Amazonia.

    PubMed

    Ryder Wilkie, Kari T; Mertl, Amy L; Traniello, James F A

    2007-09-01

    Ants are abundant, diverse, and ecologically dominant in tropical forests. Subterranean ants in particular are thought to have a significant environmental impact, although difficulties associated with collecting ants underground and examining their ecology and behavior have limited research. In this paper, we present the results of a study of subterranean ant diversity in Amazonian Ecuador that employs a novel probe to facilitate the discovery of species inhabiting the soil horizon. Forty-seven species of ants in 19 genera, including new and apparently rare species, were collected in probes. Approximately 19% of the species collected at different depths in the soil were unique to probe samples. Analysis of similarity (ANOSIM) results showed that the species composition of ants collected with the probe was significantly different from samples collected using other techniques. Additionally, ANOSIM computations indicated the species assemblage of ants collected 12.5 cm below the surface was significantly different from those found at 25, 37.5, and 50 cm. Ant diversity and species accumulation rates decreased with increasing depth. There were no species unique to the lowest depths, suggesting that subterranean ants may not be distributed deep in the soil in Amazonia due to the high water table. The technique we describe could be used to gain new insights into the distribution and biology of subterranean ant species and other members of the species-rich soil invertebrate macrofauna.

  12. Behavioral mechanisms underlie an ant-plant mutualism.

    PubMed

    Rudgers, Jennifer A; Hodgen, Jillian G; White, J Wilson

    2003-03-01

    Predators can reduce herbivory by consuming herbivores (a consumptive effect) and by altering herbivore behavior, life history, physiology or distribution (non-consumptive effects). The non-consumptive, or trait-mediated, effects of predators on prey may have important functions in the dynamics of communities. In a facultative ant-plant mutualism, we investigated whether these non-consumptive effects influenced the host plants of prey. Here, predaceous ants (Forelius pruinosus) consume and disturb a dominant lepidopteran folivore (Bucculatrix thurberiella) of wild cotton plants (Gossypium thurberi). Season-long ant exclusion experiments revealed that ants had a larger proportional effect on damage by B. thurberiella than on caterpillar abundance, a result that suggests ants have a strong non-consumptive effect. Behavioral experiments conducted in two populations over 2 years demonstrated that B. thurberiella caterpillars were substantially less likely to damage wild cotton leaves in the presence of ants due to ant-induced changes in caterpillar behavior. In the absence of ants caterpillars spent more time stationary (potential feeding time) and less time dropping from leaves by a thread of silk than when ants were present. Furthermore, ants altered the spatial distribution of both caterpillars and damage; caterpillars spent relatively more time on the upper surfaces of leaves and caused damage further from the leaf margin in ant exclusion treatments. Both direct encounters with ants and information conveyed when ants walked onto leaves were key events leading to the anti-predator behaviors of caterpillars. This study contributes to a small body of evidence from terrestrial systems demonstrating that the trait-mediated effects of predators can cascade to the host plants of prey.

  13. Chemically armed mercenary ants protect fungus-farming societies

    PubMed Central

    Adams, Rachelle M. M.; Liberti, Joanito; Illum, Anders A.; Jones, Tappey H.; Nash, David R.; Boomsma, Jacobus J.

    2013-01-01

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies. PMID:24019482

  14. Chemically armed mercenary ants protect fungus-farming societies.

    PubMed

    Adams, Rachelle M M; Liberti, Joanito; Illum, Anders A; Jones, Tappey H; Nash, David R; Boomsma, Jacobus J

    2013-09-24

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies.

  15. An Investigation of the Problematic Internet Use of Teacher Candidates Based on Personality Types, Shyness and Demographic Factors

    ERIC Educational Resources Information Center

    Ozturk, Ebru; Kaymak Ozmen, Suna

    2011-01-01

    Researches proved that a new psychological disorder of problematic Internet use was associated with individual characteristics as loneliness, shyness, anxiety, depression, personality type, and self-cognition. But there appears to be little consensus about Problematic Internet Use disorder. Consequently the aim of study was to investigate…

  16. Measurement and Analysis of the Cognitive-Behavioral Model of Generalized Problematic Internet Use among Mexican Adolescents

    ERIC Educational Resources Information Center

    Gamez-Guadix, Manuel; Villa-George, Fabiola I.; Calvete, Esther

    2012-01-01

    The objectives of this study were to analyze the psychometric properties of the Generalized Problematic Internet Use Scale 2 (GPIUS2) and to examine the cognitive-behavioral theoretical model of problematic Internet use in a sample of 1491 Mexican adolescents (47.6% female, mean age = 14.51). Results showed that the GPIUS2 has adequate construct…

  17. Predictiveness of Identity Status, Main Internet Use Purposes and Gender on University Students' the Problematic Internet Use

    ERIC Educational Resources Information Center

    Ceyhan, Esra

    2010-01-01

    This study aims at revealing the relationships between the problematic Internet use of university students and their identity status, main Internet use purposes, and gender. A total of 464 university students participated in the study, and the research data were collected through the Problematic Internet Use Scale, the Extended Objective Measure…

  18. Problematic Social Media Use: Results from a Large-Scale Nationally Representative Adolescent Sample

    PubMed Central

    Bányai, Fanni; Zsila, Ágnes; Király, Orsolya; Maraz, Aniko; Elekes, Zsuzsanna; Griffiths, Mark D.; Andreassen, Cecilie Schou

    2017-01-01

    Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs. PMID:28068404

  19. Problematic substance use in Hispanic adolescents and young adults: Implications for prevention efforts

    PubMed Central

    Grigsby, Timothy J.; Forster, Myriam; Soto, Daniel W.; Baezconde-Garbanati, Lourdes; Unger, Jennifer B.

    2014-01-01

    Using data collected between 2005–2012 from a longitudinal study of acculturation patterns and substance use among Hispanic youth in Southern California (N = 2,722), we fit multivariate logistic regression models to estimate the association of type and frequency of drug use, friend and parent drug use, cultural orientation (measured by the ARSMA-II), and psychological distress (CES-D score) in 10th grade with problematic substance use (measured with the RAPI) in (i) 11th grade and (ii) young adulthood. We conclude that future intervention efforts with Hispanic adolescents and young adults should target polysubstance and problem users and emphasize inter-individual, structural and cultural processes as they relate to problematic substance use. PMID:24779502

  20. The case of Lisa and the assimilation model: the interrelatedness of problematic voices.

    PubMed

    Brinegar, Meredith Glick; Salvi, Lisa M; Stiles, William B

    2008-11-01

    This study examines Lisa, a successful case of emotion-focused therapy, using the assimilation model as a lens to view and understand her changes. The assimilation model construes problems as voices, or parts of the self, that are unwanted and kept separate from other voices in the community that constitute the self. Progress in therapy, then, is construed as increasing the assimilation or integration of problematic voices into the community. Lisa made significant progress assimilating two distinct but related voices, described as movement through the Assimilation of Problematic Experiences Sequence. In the course of the analysis, the case of Lisa also informed the assimilation model by raising issues concerning the interrelatedness of problems and the dynamic nature of assimilation in the context of a multivoiced self.

  1. Problematic Social Media Use: Results from a Large-Scale Nationally Representative Adolescent Sample.

    PubMed

    Bányai, Fanni; Zsila, Ágnes; Király, Orsolya; Maraz, Aniko; Elekes, Zsuzsanna; Griffiths, Mark D; Andreassen, Cecilie Schou; Demetrovics, Zsolt

    2017-01-01

    Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs.

  2. Reduced Chitinase Activities in Ant Plants of the Genus Macaranga

    NASA Astrophysics Data System (ADS)

    Heil, Martin; Fiala, Brigitte; Linsenmair, K. Eduard; Boller, Thomas

    Many plant species have evolved mutualistic associations with ants, protecting their host against detrimental influences such as herbivorous insects. Letourneau (1998) reported in the case of Piper that ants defend their plants principally against stem-boring insects and also reduce fungal infections on inflorescences. Macaranga plants that were experimentally deprived of their symbiotic Crematogaster ants suffered heavily from shoot borers and pathogenic fungi (Heil 1998). Here we report that ants seem to reduce fungal infections actively in the obligate myrmecophyte Macarangatriloba (Euphorbiaceae), while ant-free plants can be easily infected. We also found extremely low chitinase activity in Macaranga plants. The plants' own biochemical defense seems to be reduced, and low chitinase activity perhaps may represent a predisposition for the evolution of myrmecophytism. These plants are therefore highly dependent on their ants, which obviously function not only as an antiherbivore defense but also as an effective agent against fungal pathogens.

  3. Cascading trait-mediated interactions induced by ant pheromones

    PubMed Central

    Hsieh, Hsun-Yi; Liere, Heidi; Soto, Estelí J; Perfecto, Ivette

    2012-01-01

    Trait-mediated indirect interactions (TMII) can be as important as density-mediated indirect interactions. Here, we provide evidence for a novel trait-mediated cascade (where one TMII affects another TMII) and demonstrate that the mechanism consists of a predator eavesdropping on chemical signaling. Ants protect scale insects from predation by adult coccinellid beetles – the first TMII. However, parasitic phorid flies reduce ant foraging activity by 50% – the second TMII, providing a window of opportunity for female beetles to oviposit in high-quality microsites. Beetle larvae are protected from ant predation and benefit from living in patches with high scale densities. We demonstrate that female beetles can detect pheromones released by the ant when attacked by phorids, and that only females, and especially gravid females, are attracted to the ant pheromone. As ants reduce their movement when under attack by phorids, we conclude that phorids facilitate beetle oviposition, thus producing the TMII cascade. PMID:23139877

  4. Cascading trait-mediated interactions induced by ant pheromones.

    PubMed

    Hsieh, Hsun-Yi; Liere, Heidi; Soto, Estelí J; Perfecto, Ivette

    2012-09-01

    Trait-mediated indirect interactions (TMII) can be as important as density-mediated indirect interactions. Here, we provide evidence for a novel trait-mediated cascade (where one TMII affects another TMII) and demonstrate that the mechanism consists of a predator eavesdropping on chemical signaling. Ants protect scale insects from predation by adult coccinellid beetles - the first TMII. However, parasitic phorid flies reduce ant foraging activity by 50% - the second TMII, providing a window of opportunity for female beetles to oviposit in high-quality microsites. Beetle larvae are protected from ant predation and benefit from living in patches with high scale densities. We demonstrate that female beetles can detect pheromones released by the ant when attacked by phorids, and that only females, and especially gravid females, are attracted to the ant pheromone. As ants reduce their movement when under attack by phorids, we conclude that phorids facilitate beetle oviposition, thus producing the TMII cascade.

  5. Image feature extraction based multiple ant colonies cooperation

    NASA Astrophysics Data System (ADS)

    Zhang, Zhilong; Yang, Weiping; Li, Jicheng

    2015-05-01

    This paper presents a novel image feature extraction algorithm based on multiple ant colonies cooperation. Firstly, a low resolution version of the input image is created using Gaussian pyramid algorithm, and two ant colonies are spread on the source image and low resolution image respectively. The ant colony on the low resolution image uses phase congruency as its inspiration information, while the ant colony on the source image uses gradient magnitude as its inspiration information. These two ant colonies cooperate to extract salient image features through sharing a same pheromone matrix. After the optimization process, image features are detected based on thresholding the pheromone matrix. Since gradient magnitude and phase congruency of the input image are used as inspiration information of the ant colonies, our algorithm shows higher intelligence and is capable of acquiring more complete and meaningful image features than other simpler edge detectors.

  6. Problematic usage among highly-engaged players of massively multiplayer online role playing games.

    PubMed

    Peters, Christopher S; Malesky, L Alvin

    2008-08-01

    One popular facet of Internet gaming is the massively multiplayer online role playing game (MMORPG). Some individuals spend so much time playing these games that it creates problems in their lives. This study focused on players of World of Warcraft. Factor analysis revealed one factor related to problematic usage, which was correlated with amount of time played, and personality characteristics of agreeableness, conscientiousness, neuroticism, and extraversion.

  7. Predicting problematic alcohol use with the DSM-5 alternative model of personality pathology.

    PubMed

    Creswell, Kasey G; Bachrach, Rachel L; Wright, Aidan G C; Pinto, Anthony; Ansell, Emily

    2016-01-01

    High comorbidity between personality disorders and alcohol use disorders appears related to individual differences in underlying personality dimensions of behavioral undercontrol and affective dysregulation. However, very little is known about how the Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5) Section III trait model of personality pathology relates to alcohol problems or how the strength of the relationship between personality pathology and alcohol problems changes with age and across gender. The current study examined these questions in a sample of 877 participants using the General Assessment of Personality Disorder to assess general personality dysfunction, the Personality Inventory for DSM-5 to measure specific traits, and the Alcohol Use Disorder Identification Test (AUDIT) to assess problematic alcohol use. Results demonstrated that general personality pathology (Criterion A) was significantly related to problematic alcohol use after controlling for age and gender effects. Furthermore, 2 of the 5 higher-order personality trait domains (Criterion B), Antagonism and Disinhibition, remained significant predictors of problematic alcohol use after accounting for the influence of general personality pathology; however, general personality pathology no longer predicted hazardous alcohol use once Antagonism and Disinhibition were added into the model. Finally, these 2 specific traits interacted with age, such that Antagonism was a stronger predictor of AUDIT scores among older individuals and Disinhibition was a stronger predictor of alcohol problems among younger individuals. Findings support the general validity of this new personality disorder diagnostic system and suggest important age effects in the relationship between traits and problematic alcohol use. (PsycINFO Database Record

  8. The interdependence of family functioning and problematic internet use in a representative quota sample of adolescents.

    PubMed

    Wartberg, Lutz; Kammerl, Rudolf; Rosenkranz, Moritz; Hirschhäuser, Lena; Hein, Sandra; Schwinge, Christiane; Petersen, Kay-Uwe; Rainer, Thomasius

    2014-01-01

    Few studies have been carried out investigating the interdependence of family structures or interactions and excessive adolescent Internet use. In this study, we surveyed a representative German quota sample of 1,744 adolescents aged between 14 and 17 years with standardized questionnaires. Adolescents assessed their perceived own functioning in the family with the Self-Rating Scale (FB-S) of the German version of the Family Assessment Measure III, and reported on problematic Internet use with the Compulsive Internet Use Scale (CIUS). To predict problematic Internet use (CIUS summary score), we conducted a multiple stepwise linear regression analysis with the seven FB-S scales, the FB-S overall index, and gender and age as explanatory variables. For the full sample, a model with only one predictor (FB-S overall index) that summarizes the quality of family functioning produced a corrected coefficient of determination of 0.239 and explained variance of nearly 24%. t Test results for unpaired samples showed significant differences in the mean values of the FB-S scales and the FB-S overall index for comparisons of both sexes, as well as of a lower age group and higher age group. The prediction of problematic Internet use between both sexes and both age groups showed comparable findings (males: corrected coefficient of determination=0.288; females: corrected coefficient of determination=0.183; lower age group: corrected coefficient of determination=0.231; higher age group: corrected coefficient of determination=0.251), each with a single predictor (FB-S overall index). The results emphasize the importance of family functioning for the occurrence of problematic Internet use in adolescents.

  9. Measuring the Prevalence of Problematic Respondent Behaviors among MTurk, Campus, and Community Participants

    PubMed Central

    Cacioppo, Stephanie; Norman, Greg J.; Cacioppo, John T.

    2016-01-01

    The reliance on small samples and underpowered studies may undermine the replicability of scientific findings. Large sample sizes may be necessary to achieve adequate statistical power. Crowdsourcing sites such as Amazon’s Mechanical Turk (MTurk) have been regarded as an economical means for achieving larger samples. Because MTurk participants may engage in behaviors which adversely affect data quality, much recent research has focused on assessing the quality of data obtained from MTurk samples. However, participants from traditional campus- and community-based samples may also engage in behaviors which adversely affect the quality of the data that they provide. We compare an MTurk, campus, and community sample to measure how frequently participants report engaging in problematic respondent behaviors. We report evidence that suggests that participants from all samples engage in problematic respondent behaviors with comparable rates. Because statistical power is influenced by factors beyond sample size, including data integrity, methodological controls must be refined to better identify and diminish the frequency of participant engagement in problematic respondent behaviors. PMID:27351378

  10. An ongoing study of group treatment for men involved in problematic Internet-enabled sexual behavior.

    PubMed

    Orzack, Maressa Hecht; Voluse, Andrew C; Wolf, David; Hennen, John

    2006-06-01

    Exponential advances have been made regarding computer/Internet technology in the past decade. This growth, in large part, can be attributed to greater access to, affordability of, and anonymity while on the computer. However, this progress has also produced negative psychological issues. Problematic Internet-enabled sexual behavior (IESB) has increasingly affected individuals' family relationships, work productivity, and academic success. This article is the first-known, empirically based outcome study regarding the effectiveness of group therapy treatment for men with problematic IESB. These closed-groups, which ran for 16 weeks, used a combination of Readiness to Change (RtC), Cognitive Behavioral Therapy (CBT), and Motivational Interviewing (MI) interventions. Five groups were analyzed for this paper (yielding a total N of 35), with the average member's age being 44.5 years old. Three different scales (the Orzack Time Intensity Survey, the BASIS-32, and the BDI) were used to track participants' progress across time. The results demonstrated that this group treatment intervention significantly increased members' quality of life and decreased the severity of their depressive symptoms. However, the protocol failed to reduce participants' inappropriate computer use. Regarding comorbidity, the results showed the following: members in the "anxiety" category responded best to the current treatment, those in the "mood" cluster responded relatively positively, and those in the "A-D/HD" category failed to respond significantly. It is clear from this report that more attention must be focused on the treatment of problematic IESB, as opposed to exploratory studies.

  11. No site unseen: predicting the failure to control problematic Internet use among young adults.

    PubMed

    Yamada, Tetsuhiro; Moshier, Samantha J; Otto, Michael W

    2016-11-01

    Problematic Internet use has been associated with the neglect of valued activities such as work, exercise, social activities, and relationships. In the present study, we expanded the understanding of problematic Internet use by identifying an important predictor of the inability to curb Internet use despite the desire to do so. Specifically, in a college student sample reporting a mean of 27.8 h of recreational Internet use in the past week, we investigated the role of distress intolerance (DI)-an individual difference variable that refers to the inability of an individual to tolerate emotional discomfort and to engage in goal-directed behavior when distressed-to predict the failure to meet personal restrictions on Internet use. Consistent with hypotheses, DI emerged as a significant predictor of the failure to meet self-control goals in both bivariate and multivariate models, indicating that DI offers unique prediction of self-control failure with problematic Internet use. Given that DI is a modifiable trait, these results encourage consideration of DI-focused early intervention strategies.

  12. Is “Maturing out” of Problematic Alcohol Involvement Related to Personality Change?

    PubMed Central

    Littlefield, Andrew K.; Sher, Kenneth J.; Wood, Phillip K.

    2009-01-01

    Problematic alcohol involvement typically peaks in the early 20s and declines with age. This maturing out of alcohol involvement is usually attributed to individuals attaining adult statuses incompatible with heavy drinking. Nevertheless, little is known about how changes in problematic alcohol use during emerging/early adulthood relate to changes in etiologically relevant personality traits that also change during this period. This study examined the relation between changes in problematic alcohol involvement and personality (measures of impulsivity, neuroticism, and extraversion) from ages 18 to 35 in a cohort of college students (N = 489) at varying risk for alcohol use disorders. Latent growth models indicated that both normative and individual changes in alcohol involvement occur between ages 18 and 35 and that these changes are associated with changes in neuroticism and impulsivity. Moreover, marital and parental role statuses did not appear to be third-variable explanations of the associated changes in alcohol involvement and personality. Findings suggest that personality change may be an important mechanism in the maturing-out effect. PMID:19413410

  13. Parenting style as a mediator between children's negative emotionality and problematic behavior in early childhood.

    PubMed

    Paulussen-Hoogeboom, Marja C; Stams, Geert Jan J M; Hermanns, Jo M A; Peetsma, Thea T D; van den Wittenboer, Godfried L H

    2008-09-01

    Negative emotionality is considered to be the core of the difficult temperament concept (J. E. Bates, 1989; R. L. Shiner, 1998). In this correlational study, the authors examined whether the relations between children's negative emotionality and problematic behavior (internalizing and externalizing) were partially mediated by parenting style (authoritative and authoritarian) in a community sample of 196 3-year-old children and their mothers. The authors assessed maternal perception of child negative emotionality using the Children's Behavior Questionnaire (M. K. Rothbart, S. A. Ahadi, K. L. Hershey, & P. Fisher, 2001) and assessed problematic child behavior by means of maternal report using the Child Behavior Checklist (T. M. Achenbach, 1992). The results showed that the relations between child negative emotionality and internalizing and externalizing behaviors were partially mediated by mothers' authoritative parenting style. Moreover, when the authors used confirmatory factor analysis to decontaminate possible overlap in item content between measures assessing temperament and problematic behavior, the association between negative emotionality and internalizing behavior was fully mediated by authoritative parenting.

  14. Patient engagement and problematic behaviours in nurse-staffed residential rehabilitation units

    PubMed Central

    Meaden, Alan; Commander, Martin; Cowan, Colin; Edwards, Tom

    2014-01-01

    Aims and method To build on previous research findings by examining engagement and problematic behaviours of patients in 10 residential rehabilitation units. Two measures were completed on patients in community rehabilitation, longer-term complex care and high-dependency units (109 patients in total). Data were analysed and categorised into higher-engagement ratings across the domains of engagement and behaviour over the past 6 months and lifetime in terms of presence of the behaviour and likelihood of resulting harm. Results Data were available for 73% of patients. All aspects of engagement were consistently low for all units, with highest levels in community rehabilitation units. Levels of problematic behaviours were similar across all units. Socially inappropriate behaviours and failure to complete everyday activities were evident for over half of all patients and higher for lifetime prevalence. Verbal aggression was at significantly lower levels in community units. Lifetime behaviours likely to lead to harm were much more evident in high-dependency units. Clinical implications Despite some benefits of this type of care, patients continue to present challenges in engagement and problematic behaviours that require new approaches and a change in focus. PMID:25505624

  15. Problematic Internet Use, Mental Health and Impulse Control in an Online Survey of Adults

    PubMed Central

    Yau, Yvonne H. C.; Potenza, Marc N.; White, Marney A.

    2013-01-01

    Background and Aims Internet use has become a popular entertainment source and has become highly integrated into daily life. However, some people display problematic or addictive usage of the Internet. The present study attempts to fill current knowledge gaps regarding at-risk/problematic Internet use (ARPIU) and its relation to various health and functioning measures. Methods Online survey data from 755 adults in the United States were analyzed using chi-square and ANOVAs. Results The ARPIU group did not differ from the non-ARPIU group with respect to substance use. Individuals with ARPIU were, however, more likely to report at-risk/problematic engagement in video-game playing and gambling. Compared to the non-ARPIU group, the ARPIU group reported poorer self-control and higher levels of impulsivity and depression. Conclusions ARPIU appears associated with other risk behaviors, particularly those that might be performed on the Internet. Future studies should examine the extent to which the Internet may promote engagement in these risk behaviors and the extent to which preventative interventions targeting better self-control or negative mood states might help a range of non-substance-related addictive behaviors. PMID:24294501

  16. Problematic Internet Use in University Students: associated factors and differences of gender.

    PubMed

    Fernández-Villa, Tania; Alguacil Ojeda, Juan; Almaraz Gómez, Ana; Cancela Carral, José María; Delgado-Rodríguez, Miguel; García-Martín, Miguel; Jiménez-Mejías, Eladio; Llorca, Javier; Molina, Antonio José; Ortíz Moncada, Rocío; Valero-Juan, Luiz Félix; Martín, Vicente

    2015-12-15

    The aim of this paper is to make a descriptive analysis of Problematic Internet Use in college students, evaluating the possible association with health problems and addictive behaviors, as well as gender differences in user types. A total of 2,780 students participated in the study between 2011 and 2014, 29% of them being males (age 20.8 ± 5.1 years) and 71% females (age 20.3 ± 4.4 years). The prevalence of Problematic Internet Use (PIU) assessed by the Internet Addiction Test was 6.08%. Being under 21 years of age and studying for degrees in subjects other than the health sciences were associated factors with a higher frequency of this problem, no differences by gender or type of address were found. The results show a significant association with some health problems (migraines, back pain, excess weight or obesity, insufficient rest), psychological aspects (risk of eating disorders, risk of mental disorder, depression), family problems and discrimination; with no associations with substance use (alcohol, cannabis or tobacco) being found. Concerning the time of Internet use, weekly hours were significantly higher in women than in men, both the total time as for leisure. The analysis of the profile use in problematic users revealed that males are related to aspects of entertainment such as games or shopping online and females are related to aspects of socialization, such as chats and social networks.

  17. From betrayal to the bottle: investigating possible pathways from trauma to problematic substance use.

    PubMed

    Delker, Brianna C; Freyd, Jennifer J

    2014-10-01

    Research in both community and clinical settings has found that exposure to cumulative interpersonal trauma predicts substance use problems. Less is known about betrayal as a dimension of trauma exposure that predicts substance use, and about the behavioral and psychological pathways that explain the relation between trauma and substance use. In a sample of 362 young adults, this study evaluated three intervening pathways between betrayal trauma exposure prior to age 18 years and problematic substance use: (a) substance use to cope with negative affect, (b) difficulty discerning and/or heeding risk, and (c) self-destructiveness. In addition, exposure to trauma low in betrayal (e.g., earthquake) was included in the model. Bootstrap tests of indirect effects revealed that betrayal trauma prior to age 18 years was associated with problematic substance use via posttraumatic stress and two intervening pathways: difficulty discerning/heeding risk (β = .07, p < .001), and self-destructiveness (β = .12, p < .001). Exposure to lower betrayal trauma was not associated with posttraumatic stress or problematic substance use. Results contribute to a trauma-informed understanding of substance use that persists despite potentially harmful consequences.

  18. Consuming fire ants reduces northern bobwhite survival and weight gain

    USGS Publications Warehouse

    Myers, P.E.; Allen, Craig R.; Birge, Hannah E.

    2014-01-01

    Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein source, making it difficult to disentangle their net effect on bobwhite chicks. To help investigate these effects, we conducted a laboratory experiment to understand (1) whether or not bobwhites consume fire ants, and (2) how the benefits of this consumption compare to the deleterious impacts of bobwhite chick exposure to fire ants. Sixty bobwhite chicks were separated into two groups of 30; one group was provided with starter feed only and the second group was provided with feed and fire ants. Bobwhite chicks were observed feeding on fire ants. Chicks that fed on fire ants had reduced survival and weight gain. Our results show that, while fire ants increase potential food sources for northern bobwhite, their net effect on bobwhite chicks is deleterious. This information will help inform land managers and commercial bobwhite rearing operations.

  19. Do Herbivores Eavesdrop on Ant Chemical Communication to Avoid Predation?

    PubMed Central

    Gonthier, David J.

    2012-01-01

    Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis), I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis), exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor) and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment) relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min.) revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus), ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants. PMID:22235248

  20. Protein structure optimization with a "Lamarckian" ant colony algorithm.

    PubMed

    Oakley, Mark T; Richardson, E Grace; Carr, Harriet; Johnston, Roy L

    2013-01-01

    We describe the LamarckiAnt algorithm: a search algorithm that combines the features of a "Lamarckian" genetic algorithm and ant colony optimization. We have implemented this algorithm for the optimization of BLN model proteins, which have frustrated energy landscapes and represent a challenge for global optimization algorithms. We demonstrate that LamarckiAnt performs competitively with other state-of-the-art optimization algorithms.

  1. Do herbivores eavesdrop on ant chemical communication to avoid predation?

    PubMed

    Gonthier, David J

    2012-01-01

    Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis), I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis), exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor) and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment) relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min.) revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus), ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants.

  2. Spatial scale and cross-taxon congruence of terrestrial vertebrate and vascular plant species richness in China.

    PubMed

    Qian, Hong; Kissling, W Daniel

    2010-04-01

    In ecology and biogeography it is often recognized that the species richness of different groups of organisms is spatially congruent (and thus positively correlated). However, ecological phenomena are often scale dependent and can change with spatial scale (i.e., grain size and extent). Because species richness gradients are also correlated with environmental gradients and plant species richness is thought to influence animal species richness, the relative roles of environment and plant richness in influencing cross-taxon congruence of animal richness at different spatial scales remain poorly explored. In this study, we examine the spatial concordance in species richness among terrestrial vertebrates and vascular plants at two spatial grain sizes (local and regional) across China. We hypothesize that (H1) cross-taxon richness relationships are weaker at the local scale; (H2) climatic predictors of species richness are stronger at the regional scale; (H3) effects of habitat heterogeneity on species richness are stronger at the local scale; (H4) plant richness positively affects vertebrate richness after accounting for environmental effects; and (H5) the plant-vertebrate richness relationship is weaker at the regional scale. We found significant and positive correlations between species richness of the groups, with correlations being stronger at the regional scale than at the local scale (supporting H1). Climate has weaker effects on species richness at the regional scale than at the local scale (rejecting H2), and for vertebrates (but not for plants) effects of habitat heterogeneity are stronger at the local scale (supporting hypothesis H3). Plant richness positively affects vertebrate richness after accounting for environmental effects (supporting H4), but the effect is stronger for the two endothermic groups (mammals and birds) than for the two ectothermic groups (reptiles and amphibians). In contrast to hypothesis H5, the effect of plant richness on species

  3. ['Nothing' or 'just a bit'? 'Much' or 'too much'? Impulsivity traits as markers of severity transitions within non-problematic and problematic ranges of alcohol and Internet use].

    PubMed

    J F, Navas; A, Torres; A, Cándido; J C, Perales

    2014-01-01

    This study aims to explore the relationship between impulsivity traits and perceived negative consequences of alcohol consumption and Internet use. More specifically, impulsivity traits - positive and negative urgency, sensation seeking, lack of premeditation, and lack of perseverance - in (1) the occurrence of initial negative consequences linked to use, and (2) the transition from consequences possibly indicating a problematic behavior to consequences very likely indicating a clinical problem. For this, 709 first-year college students were assessed using the UPPS-P impulsive behavior scale, and the Multicage CAD-4 scale for addictive behaviors. Logistic regressions were used to discriminate (a) between individuals with a 0-score and individuals with a 1-score in the Multicage scales (low severity range), and (b) between individuals with a 2-score and individuals with 3/4-score (high severity range), separately for alcohol and Internet use. For alcohol use, positive urgency and lack of premeditation marked the transition from 0 to 1 scores, whereas negative urgency marked the transition from 2 to 3/4 scores. For Internet use, however, none of the UPPS-P dimensions significantly marked the transition from 0 to 1 (occurrence of initial negative consequences), and positive urgency marked the transition from 2 to 3/4 (from possible to very likely problematic behavior). Negative urgency arises as a pathologization marker for alcohol abuse, whereas changes in non-clinical levels are linked to impulsivity elicited by appetitive emotions. Impulsivity does not seem to play any role in low severity levels of Internet use, and positive urgency marks the transition between high severity scores. These differential patterns are indicative of different etiological paths for excessive Internet use and substance abuse.

  4. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    PubMed Central

    Hooper-Bui, L.M.; Kwok, E.S.C.; Buchholz, B.A.; Rust, M.K.; Eastmond, D.A.; Vogel, J.S.

    2015-01-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony. PMID:26504258

  5. Ant patchiness: a spatially quantitative test in coffee agroecosystems

    NASA Astrophysics Data System (ADS)

    Philpott, Stacy M.

    2006-08-01

    Arboreal ants form patchy spatial patterns in tropical agroforest canopies. Such patchy distributions more likely occur in disturbed habitats associated with lower ant diversity and resource availability than in forests. Yet, few studies have quantitatively examined these patchy patterns to statistically test if ants are non-randomly distributed or at what scale. Coffee agroecosystems form a gradient of management intensification along which vegetative complexity and ant diversity decline. Using field studies and a spatially explicit randomization model, I investigated ant patchiness in coffee agroecosystems in Chiapas, Mexico varying in management intensity to examine if: (1) coffee intensification affects occurrence of numerically dominant ants, (2) numerical dominants form statistically distinguishable single-species patches in coffee plants, (3) shade trees play a role in patch location, and (4) patch formation or size varies with management intensity. Coffee intensification correlated with lower occurrence frequency of numerically dominant species generally and of one of four taxa examined. All dominant ant species formed patches but only Azteca instabilis was patchy around shade trees. Ant patchiness did vary somewhat with spatial scale and with strata (within the coffee layer vs around shade trees). Patchiness, however, did not vary with management intensity. These results provide quantitative evidence that numerically dominant ants are patchy within the coffee layer at different scales and that shade tree location, but not coffee management intensity, may play a role in the formation of patchy distributions.

  6. Improved Ant Colony Clustering Algorithm and Its Performance Study

    PubMed Central

    Gao, Wei

    2016-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational efficiency and accuracy of the ant colony clustering algorithm. The abstraction ant colony clustering algorithm is used to cluster benchmark problems, and its performance is compared with the ant colony clustering algorithm and other methods used in existing literature. Based on similar computational difficulties and complexities, the results show that the abstraction ant colony clustering algorithm produces results that are not only more accurate but also more efficiently determined than the ant colony clustering algorithm and the other methods. Thus, the abstraction ant colony clustering algorithm can be used for efficient multivariate data clustering. PMID:26839533

  7. Five new records of ants (Hymenoptera: Formicidae) for Nebraska

    USGS Publications Warehouse

    Nemec, Kristine T.; Trager, James C.; Manley, Elizabeth; Allen, Craig R.

    2012-01-01

    Ants are ubiquitous and influential organisms in terrestrial ecosystems. About 1,000 ant species occur in North America, where they are found in nearly every habitat (Fisher and Cover 2007). Ants are critical to ecological processes and structure. Ants affect soils via tunneling activity (Baxter and Hole 1967), disperse plant seeds (Lengyel et al. 2009), prey upon a variety of insects and other invertebrates (Way and Khoo 1992, Folgarait 1998), are often effective primary consumers through their prodigious consumption of floral and especially extrafloral nectar, and honeydew (Tobin 1994), and serve as prey for invertebrates (Gotelli 1996, Gastreich 1999) and vertebrates (Reiss 2001).

  8. Insecticide transfer efficiency and lethal load in Argentine ants

    NASA Astrophysics Data System (ADS)

    Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-10-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  9. Ant Homing Ability Is Not Diminished When Traveling Backwards

    PubMed Central

    Ardin, Paul B.; Mangan, Michael; Webb, Barbara

    2016-01-01

    Ants are known to be capable of homing to their nest after displacement to a novel location. This is widely assumed to involve some form of retinotopic matching between their current view and previously experienced views. One simple algorithm proposed to explain this behavior is continuous retinotopic alignment, in which the ant constantly adjusts its heading by rotating to minimize the pixel-wise difference of its current view from all views stored while facing the nest. However, ants with large prey items will often drag them home while facing backwards. We tested whether displaced ants (Myrmecia croslandi) dragging prey could still home despite experiencing an inverted view of their surroundings under these conditions. Ants moving backwards with food took similarly direct paths to the nest as ants moving forward without food, demonstrating that continuous retinotopic alignment is not a critical component of homing. It is possible that ants use initial or intermittent retinotopic alignment, coupled with some other direction stabilizing cue that they can utilize when moving backward. However, though most ants dragging prey would occasionally look toward the nest, we observed that their heading direction was not noticeably improved afterwards. We assume ants must use comparison of current and stored images for corrections of their path, but suggest they are either able to chose the appropriate visual memory for comparison using an additional mechanism; or can make such comparisons without retinotopic alignment. PMID:27147991

  10. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    SciTech Connect

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  11. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    DOE PAGES

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; ...

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), butmore » dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.« less

  12. Ant plant herbivore interactions in the neotropical cerrado savanna

    NASA Astrophysics Data System (ADS)

    Oliveira, Paulo S.; Freitas, André V. L.

    2004-12-01

    The Brazilian cerrado savanna covers nearly 2 million km2 and has a high incidence on foliage of various liquid food sources such as extrafloral nectar and insect exudates. These liquid rewards generate intense ant activity on cerrado foliage, making ant plant herbivore interactions especially prevalent in this biome. We present data on the distribution and abundance of extrafloral nectaries in the woody flora of cerrado communities and in the flora of other habitats worldwide, and stress the relevance of liquid food sources (including hemipteran honeydew) for the ant fauna. Consumption by ants of plant and insect exudates significantly affects the activity of the associated herbivores of cerrado plant species, with varying impacts on the reproductive output of the plants. Experiments with an ant plant butterfly system unequivocally demonstrate that the behavior of both immature and adult lepidopterans is closely related to the use of a risky host plant, where intensive visitation by ants can have a severe impact on caterpillar survival. We discuss recent evidence suggesting that the occurrence of liquid rewards on leaves plays a key role in mediating the foraging ecology of foliage-dwelling ants, and that facultative ant plant mutualisms are important in structuring the community of canopy arthropods. Ant-mediated effects on cerrado herbivore communities can be revealed by experiments performed on wide spatial scales, including many environmental factors such as soil fertility and vegetation structure. We also present some research questions that could be rewarding to investigate in this major neotropical savanna.

  13. Improved Ant Colony Clustering Algorithm and Its Performance Study.

    PubMed

    Gao, Wei

    2016-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational efficiency and accuracy of the ant colony clustering algorithm. The abstraction ant colony clustering algorithm is used to cluster benchmark problems, and its performance is compared with the ant colony clustering algorithm and other methods used in existing literature. Based on similar computational difficulties and complexities, the results show that the abstraction ant colony clustering algorithm produces results that are not only more accurate but also more efficiently determined than the ant colony clustering algorithm and the other methods. Thus, the abstraction ant colony clustering algorithm can be used for efficient multivariate data clustering.

  14. Signals can trump rewards in attracting seed-dispersing ants.

    PubMed

    Turner, Kyle M; Frederickson, Megan E

    2013-01-01

    Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes) of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds.

  15. Looking and homing: how displaced ants decide where to go.

    PubMed

    Zeil, Jochen; Narendra, Ajay; Stürzl, Wolfgang

    2014-01-01

    We caught solitary foragers of the Australian Jack Jumper ant, Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked their subsequent paths with a differential GPS. We find that upon surfacing from their transport vials onto a release platform, most ants move into the home direction after looking around briefly. The ants use a systematic scanning procedure, consisting of saccadic head and body rotations that sweep gaze across the scene with an average angular velocity of 90° s(-1) and intermittent changes in turning direction. By mapping the ants' gaze directions onto the local panorama, we find that neither the ants' gaze nor their decisions to change turning direction are clearly associated with salient or significant features in the scene. Instead, the ants look most frequently in the home direction and start walking fast when doing so. Displaced ants can thus identify home direction with little translation, but exclusively through rotational scanning. We discuss the navigational information content of the ants' habitat and how the insects' behaviour informs us about how they may acquire and retrieve that information.

  16. Enhanced ant colony optimization for multiscale problems

    NASA Astrophysics Data System (ADS)

    Hu, Nan; Fish, Jacob

    2016-03-01

    The present manuscript addresses the issue of computational complexity of optimizing nonlinear composite materials and structures at multiple scales. Several solutions are detailed to meet the enormous computational challenge of optimizing nonlinear structures at multiple scales including: (i) enhanced sampling procedure that provides superior performance of the well-known ant colony optimization algorithm, (ii) a mapping-based meshing of a representative volume element that unlike unstructured meshing permits sensitivity analysis on coarse meshes, and (iii) a multilevel optimization procedure that takes advantage of possible weak coupling of certain scales. We demonstrate the proposed optimization procedure on elastic and inelastic laminated plates involving three scales.

  17. Toxicity of formic acid against red imported fire ants, Solenopsis invicta Buren

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Formic acid is a common defensive chemical of formicine ants. Ants often compete with other ants for resources. However, the toxicity of formic acid to any ant species has not been well understood. This study examined the toxicity of formic acid against the red imported fire ants, Sole...

  18. [Syagrus romanzoffiana (Arecaceae) seed utilization by ants in a secondary forest in South Brazil].

    PubMed

    Silva, Fernanda R; Begnini, Romualdo M; Klier, Vinícius A; Scherer, Karla Z; Lopes, Benedito C; Castellani, Tânia T

    2009-01-01

    Ants can nest in a wide variety of substracts. This paper shows Syagrus romanzoffiana seed utilization by ants in an Atlantic secondary forest. We report 29 seeds occupied by small-bodied ants, with 27 of them showing at least two ant development stages. Although a large number of seeds were sampled, a low level of ant occupation was observed.

  19. Hooked on Facebook: The Role of Social Anxiety and Need for Social Assurance in Problematic Use of Facebook.

    PubMed

    Lee-Won, Roselyn J; Herzog, Leo; Park, Sung Gwan

    2015-10-01

    There is a growing concern that excessive and uncontrolled use of Facebook not only interferes with performance at school or work but also poses threats to physical and psychological well-being. The present research investigated how two individual difference variables--social anxiety and need for social assurance--affect problematic use of Facebook. Drawing on the basic premises of the social skill model of problematic Internet use, we hypothesized that social anxiety and need for social assurance would be positively correlated with problematic use of Facebook. Furthermore, it was predicted that need for social assurance would moderate the relationship between social anxiety and problematic use. A cross-sectional online survey was conducted with a college student sample in the United States (N=243) to test the proposed hypotheses. Results showed that both social anxiety and need for social assurance had a significant positive association with problematic use of Facebook. More importantly, the data demonstrated that need for social assurance served as a significant moderator of the relationship between social anxiety and problematic Facebook use. The positive association between social anxiety and problematic Facebook use was significant only for Facebook users with medium to high levels of need for social assurance but not for those with a low level of need for social assurance. Theoretical and practical implications of these findings were discussed.

  20. Dispersal and diversity in the earliest North American sauropodomorph dinosaurs, with a description of a new taxon.

    PubMed

    Rowe, Timothy B; Sues, Hans-Dieter; Reisz, Robert R

    2011-04-07

    Sauropodomorph dinosaurs originated in the Southern Hemisphere in the Middle or Late Triassic and are commonly portrayed as spreading rapidly to all corners of Pangaea as part of a uniform Late Triassic to Early Jurassic cosmopolitan dinosaur fauna. Under this model, dispersal allegedly inhibited dinosaurian diversification, while vicariance and local extinction enhanced it. However, apomorphy-based analyses of the known fossil record indicate that sauropodomorphs were absent in North America until the Early Jurassic, reframing the temporal context of their arrival. We describe a new taxon from the Kayenta Formation of Arizona that comprises the third diagnosable sauropodomorph from the Early Jurassic of North America. We analysed its relationships to test whether sauropodomorphs reached North America in a single sweepstakes event or in separate dispersals. Our finding of separate arrivals by all three taxa suggests dispersal as a chief factor in dinosaurian diversification during at least the early Mesozoic. It questions whether a 'cosmopolitan' dinosaur fauna ever existed, and corroborates that vicariance, extinction and dispersal did not operate uniformly in time or under uniform conditions during the Mesozoic. Their relative importance is best measured in narrow time slices and circumscribed geographical regions.

  1. Taxon-specific metagenomics of Trichoderma reveals a narrow community of opportunistic species that regulate each other’s development

    PubMed Central

    Friedl, Martina A.

    2012-01-01

    In this paper, we report on the in situ diversity of the mycotrophic fungus Trichoderma (teleomorph Hypocrea, Ascomycota, Dikarya) revealed by a taxon-specific metagenomic approach. We designed a set of genus-specific internal transcribed spacer (ITS)1 and ITS2 rRNA primers and constructed a clone library containing 411 molecular operational taxonomic units (MOTUs). The overall species composition in the soil of the two distinct ecosystems in the Danube floodplain consisted of 15 known species and two potentially novel taxa. The latter taxa accounted for only 1.5 % of all MOTUs, suggesting that almost no hidden or uncultivable Hypocrea/Trichoderma species are present at least in these temperate forest soils. The species were unevenly distributed in vertical soil profiles although no universal factors controlling the distribution of all of them (chemical soil properties, vegetation type and affinity to rhizosphere) were revealed. In vitro experiments simulating infrageneric interactions between the pairs of species that were detected in the same soil horizon showed a broad spectrum of reactions from very strong competition over neutral coexistence to the pronounced synergism. Our data suggest that only a relatively small portion of Hypocrea/Trichoderma species is adapted to soil as a habitat and that the interaction between these species should be considered in a screening for Hypocrea/Trichoderma as an agent(s) of biological control of pests. PMID:22075025

  2. A multi-taxon approach reveals the effect of management intensity on biodiversity in Alpine larch grasslands.

    PubMed

    Nascimbene, Juri; Fontana, Veronika; Spitale, Daniel

    2014-07-15

    In the Alps, larch grasslands form one of the most pleasing aspects of the landscape. However, their effectiveness in contributing to biodiversity conservation may depend on the intensity of their management. We used a multi-taxon approach to evaluate the effects of the intensification of management practices and those of abandonment on the biodiversity of the main autotrophic organisms hosted in this habitat, including vascular plants, bryophytes, and lichens. The study was carried out in the eastern part of South Tyrol, in the Italian Alps, where the diversity patterns of these three organismal groups were compared among intensively managed, extensively managed, and abandoned stands. The management intensity was found to strongly influence the biodiversity of the organisms, with a general pattern indicating the best conditions in extensively managed stands. Both abandonment and management intensification were detrimental to biodiversity through different mechanisms that led to species loss or to major shifts in species composition. However, the most negative effects were related to management intensification, mainly due to the high nitrogen supply, providing evidence for the increasing impact of eutrophication on Alpine environments.

  3. Development, polymorphism, and cross-taxon utility of EST-SSR markers from safflower (Carthamus tinctorius L.).

    PubMed

    Chapman, Mark A; Hvala, John; Strever, Jason; Matvienko, Marta; Kozik, Alexander; Michelmore, Richard W; Tang, Shunxue; Knapp, Steven J; Burke, John M

    2009-12-01

    Due to their highly polymorphic and codominant nature, simple-sequence repeat (SSR) markers are a common choice for assaying genetic diversity and genetic mapping. In this paper, we describe the generation of an expressed-sequence tag (EST) collection for the oilseed crop safflower and the subsequent development of EST-SSR markers for the genetic analysis of safflower and related species. We assembled 40,874 reads into 19,395 unigenes, of which 4,416 (22.8%) contained at least one SSR. Primer pairs were developed and tested for 384 of these loci, resulting in a collection of 104 polymorphic markers that amplify reliably across 27 accessions (3 species) of the genus Carthamus. These markers exhibited a high level of polymorphism, with an average of 6.0 +/- 0.4 alleles per locus and an average gene diversity of 0.54 +/- 0.03 across Carthamus species. In terms of cross-taxon transferability, 50% of these primer pairs produced an amplicon in at least one other species in the Asteraceae, and 28% produced an amplicon in at least one species outside the safflower subfamily (i.e., lettuce, sunflower, and/or Gerbera). These markers represent a valuable resource for the genetic analysis of safflower and related species, and also have the potential to facilitate comparative map-based analyses across a broader array of taxa within the Asteraceae.

  4. Sequence of the canine herpesvirus thymidine kinase gene: taxon-preferred amino acid residues in the alphaherpesviral thymidine kinases.

    PubMed

    Rémond, M; Sheldrick, P; Lebreton, F; Foulon, T

    1995-12-01

    Multiple sequence alignments of evolutionarily related proteins are finding increasing use as indicators of critical amino acid residues necessary for structural stability or involved in functional domains responsible for catalytic activities. In the past, a number of alignments have provided such information for the herpesviral thymidine kinases, for which three-dimensional structures are not yet available. We have sequenced the thymidine kinase gene of a canine herpesvirus, and with a multiple alignment have identified amino acids preferentially conserved in either of two taxons, the genera Varicellovirus and Simplexvirus, of the subfamily Alphaherpesvirinae. Since some regions of the thymidine kinases show otherwise elevated levels of substitutional tolerance, these conserved amino acids are candidates for critical residues which have become fixed through selection during the evolutionary divergence of these enzymes. Several pairs with distinctive patterns of distribution among the various viruses occur in or near highly conserved sequence motifs previously proposed to form the catalytic site, and we speculate that they may represent interacting, co-ordinately variable residues.

  5. Phosphorus Availability, Phytoplankton Community Dynamics, and Taxon-Specific Phosphorus Status in the Gulf of Aqaba, Red Sea

    NASA Astrophysics Data System (ADS)

    Mackey, K. R.; Labiosa, R. G.; Calhoun, M.; Street, J. H.; Post, A. F.; Paytan, A.

    2006-12-01

    The relationships among phytoplankton taxon-specific phosphorus-status, phytoplankton community composition, and nutrient levels were assessed over three seasons in the Gulf of Aqaba, Red Sea. During summer and fall, stratified surface waters were depleted of nutrients and picophytoplankton populations comprised the majority of cells (80% and 88% respectively). In winter, surface nutrient concentrations were higher and larger phytoplankton were more abundant (63%). Cell specific alkaline phosphatase activity (APA) derived from enzyme labeled fluorescence was consistently low (less than 5%) in the picophytoplankton throughout the year, whereas larger cells expressed elevated APA during the summer and fall but less in the winter. A nutrient addition bioassay during the fall showed that, relative to control, APA was reduced by half in larger cells following addition of orthophosphate, whereas the APA of picophytoplankton remained low (less than 1%) across all treatments and the control. These results indicate that the most abundant phytoplankton are not limited by orthophosphate and only some subpopulations (particularly of larger cells) exhibit orthophosphate-limitation throughout the year. Our results indicate that orthophosphate availability influences phytoplankton ecology, correlating with shifts in phytoplankton community structure and the nutrient status of individual cells. The role of dissolved organic phosphorus as an important phosphorus source for marine phytoplankton in oligotrophic settings and the need for evaluating nutrient limitation at the taxa and/or single cell level (rather than inferring it from nutrient concentrations and ratios or bulk enzyme activity measurements) are highlighted.

  6. Dispersal and diversity in the earliest North American sauropodomorph dinosaurs, with a description of a new taxon

    PubMed Central

    Rowe, Timothy B.; Sues, Hans-Dieter; Reisz, Robert R.

    2011-01-01

    Sauropodomorph dinosaurs originated in the Southern Hemisphere in the Middle or Late Triassic and are commonly portrayed as spreading rapidly to all corners of Pangaea as part of a uniform Late Triassic to Early Jurassic cosmopolitan dinosaur fauna. Under this model, dispersal allegedly inhibited dinosaurian diversification, while vicariance and local extinction enhanced it. However, apomorphy-based analyses of the known fossil record indicate that sauropodomorphs were absent in North America until the Early Jurassic, reframing the temporal context of their arrival. We describe a new taxon from the Kayenta Formation of Arizona that comprises the third diagnosable sauropodomorph from the Early Jurassic of North America. We analysed its relationships to test whether sauropodomorphs reached North America in a single sweepstakes event or in separate dispersals. Our finding of separate arrivals by all three taxa suggests dispersal as a chief factor in dinosaurian diversification during at least the early Mesozoic. It questions whether a ‘cosmopolitan’ dinosaur fauna ever existed, and corroborates that vicariance, extinction and dispersal did not operate uniformly in time or under uniform conditions during the Mesozoic. Their relative importance is best measured in narrow time slices and circumscribed geographical regions. PMID:20926438

  7. Nectar Theft and Floral Ant-Repellence: A Link between Nectar Volume and Ant-Repellent Traits?

    PubMed Central

    Ballantyne, Gavin; Willmer, Pat

    2012-01-01

    As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions. PMID:22952793

  8. Shape transition during nest digging in ants

    PubMed Central

    Toffin, Etienne; Di Paolo, David; Campo, Alexandre; Detrain, Claire; Deneubourg, Jean-Louis

    2009-01-01

    Nest building in social insects is among the collective processes that show highly conservative features such as basic modules (chambers and galleries) or homeostatic properties. Although ant nests share common characteristics, they exhibit a high structural variability, of which morphogenesis and underlying mechanisms remain largely unknown. We conducted two-dimensional nest-digging experiments under homogeneous laboratory conditions to investigate the shape diversity that emerges only from digging dynamics and without the influence of any environmental heterogeneity. These experiments revealed that, during the excavation, a morphological transition occurs because the primary circular cavity evolves into a ramified structure through a branching process. Such a transition is observed, whatever the number of ants involved, but occurs more frequently for a larger number of workers. A stochastic model highlights the central role of density effects in shape transition. These results indicate that nest digging shares similar properties with various physical, chemical, and biological systems. Moreover, our model of morphogenesis provides an explanatory framework for shape transitions in decentralized growing structures in group-living animals. PMID:19846774

  9. Coevolution between attine ants and actinomycete bacteria: a reevaluation.

    PubMed

    Mueller, Ulrich G; Dash, Debadutta; Rabeling, Christian; Rodrigues, Andre

    2008-11-01

    We reassess the coevolution between actinomycete bacteria and fungus-gardening (attine) ants. Actinomycete bacteria are of special interest because they are metabolic mutualists of diverse organisms (e.g., in nitrogen-fixation or antibiotic production) and because Pseudonocardia actinomycetes are thought to serve disease-suppressing functions in attine gardens. Phylogenetic information from culture-dependent and culture-independent microbial surveys reveals (1) close affinities between free-living and ant-associated Pseudonocardia, and (2) essentially no topological correspondence between ant and Pseudonocardia phylogenies, indicating frequent bacterial acquisition from environmental sources. Identity of ant-associated Pseudonocardia and isolates from soil and plants implicates these environments as sources from which attine ants acquire Pseudonocardia. Close relatives of Atta leafcutter ants have abundant Pseudonocardia, but Pseudonocardia in Atta is rare and appears at the level of environmental contamination. In contrast, actinomycete bacteria in the genera Mycobacterium and Microbacterium can be readily isolated from gardens and starter-cultures of Atta. The accumulated phylogenetic evidence is inconsistent with prevailing views of specific coevolution between Pseudonocardia, attine ants, and garden diseases. Because of frequent acquisition, current models of Pseudonocardia-disease coevolution now need to be revised. The effectiveness of Pseudonocardia antibiotics may not derive from advantages in the coevolutionary arms race with specialized garden diseases, as currently believed, but from frequent recruitment of effective microbes from environmental sources. Indeed, the exposed integumental structures that support actinomycete growth on attine ants argue for a morphological design facilitating bacterial recruitment. We review the accumulated evidence that attine ants have undergone modifications in association with actinomycete bacteria, but we find

  10. The effect of diet and opponent size on aggressive interactions involving caribbean crazy ants (Nylanderia fulva).

    PubMed

    Horn, Katherine C; Eubanks, Micky D; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants.

  11. The Effect of Diet and Opponent Size on Aggressive Interactions Involving Caribbean Crazy Ants (Nylanderia fulva)

    PubMed Central

    Horn, Katherine C.; Eubanks, Micky D.; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants. PMID:23776702

  12. Aphid egg protection by ants: a novel aspect of the mutualism between the tree-feeding aphid Stomaphis hirukawai and its attendant ant Lasius productus

    NASA Astrophysics Data System (ADS)

    Matsuura, Kenji; Yashiro, Toshihisa

    2006-10-01

    Aphids often form mutualistic associations with ants, in which the aphids provide the ants with honeydew and the ants defend the aphids from predators. In this paper, we report aphid egg protection by ants as a novel aspect of the deeply interdependent relationship between a tree-feeding aphid and its attendant ant. The ant Lasius productus harbours oviparous females, males, and eggs of the hinoki cypress-feeding aphid Stomaphis hirukawai in its nests in winter. We investigated the behaviour of ants kept with aphid eggs in petri dishes to examine whether the ants recognise the aphid eggs and tend them or only provide a refuge for the aphids. Workers carried almost all of the aphid eggs into the nest within 24 h. The ants indiscriminately tended aphid eggs collected from their own colonies and those from other ant colonies. The ants cleaned the eggs and piled them up in the nest, and egg tending by ants dramatically increased aphid egg survival rates. Starving the ants showed no significant effect on aphid egg survivorship. Without ants, aphid eggs were rapidly killed by fungi. These results suggested that grooming by the ants protected the aphid eggs, at least, against pathogenic fungi. This hygienic service afforded by the ants seems indispensable for egg survival of these aphids in an environment rich in potentially pathogenic microorganisms.

  13. Eggs of Mallada desjardinsi (Neuroptera: Chrysopidae) are protected by ants: the role of egg stalks in ant-tended aphid colonies.

    PubMed

    Hayashi, Masayuki; Nomura, Masashi

    2014-08-01

    In ant-aphid mutualisms, ants usually attack and exclude enemies of aphids. However, larvae of the green lacewing Mallada desjardinsi (Navas) prey on ant-tended aphids without being excluded by ants; these larvae protect themselves from ants by carrying aphid carcasses on their backs. Eggs of M. desjardinsi laid at the tips of stalks have also been observed in ant-tended aphid colonies in the field. Here, we examined whether the egg stalks of M. desjardinsi protect the eggs from ants and predators. When exposed to ants, almost all eggs with intact stalks were untouched, whereas 50-80% of eggs in which stalks had been severed at their bases were destroyed by ants. In contrast, most eggs were preyed upon by larvae of the lacewing Chrysoperla nipponensis (Okamoto), an intraguild predator of M. desjardinsi, regardless of whether their stalks had been severed. These findings suggest that egg stalks provide protection from ants but not from C. nipponensis larvae. To test whether M. desjardinsi eggs are protected from predators by aphid-tending ants, we introduced C. nipponensis larvae onto plants colonized by ant-tended aphids. A significantly greater number of eggs survived in the presence of ants because aphid-tending ants excluded larvae of C. nipponensis. This finding indicates that M. desjardinsi eggs are indirectly protected from predators by ants in ant-tended aphid colonies.

  14. Current and potential ant impacts in the Pacific region

    USGS Publications Warehouse

    Loope, Lloyd L.; Krushelnycky, Paul D.

    2007-01-01

    Worldwide, ants are a powerful ecological force, and they appear to be dominant components of animal communities of many tropical and temperate ecosystems in terms of biomass and numbers of individuals (Bluthgen et al. 2000). For example, ants comprise up to 94% of arthropod individuals in fogging samples taken from diverse lowland tropical rainforest canopies, and 86% of the biomass (Davidson et al. 2003). The majority of these ant species and individuals obtain carbohydrates either from extrafloral nectaries or from sap-feeding Hemiptera that pass carbohydrate-rich “honeydew” to attending ants while concentrating nitrogen (N) from N-poor plant sap (Davidson et al. 2003). Honeydew and nectar represent key resources for arboreal ant species, although most ant species are at least partly carnivorous or scavengers (Bluthgen et al. 2004). In contrast to most of the terrestrial world, the biotas of many Pacific islands evolved without ants. Whereas endemic ant species are found in New Zealand (ca. 10 spp.), Tonga (ca. 10 spp.), and Samoa (ca. 12 spp.), other islands of Polynesia and parts of Micronesia likely lack native ants (Wilson and Taylor 1967, Wetterer 2002, Wetterer and Vargo 2003). About 20 Indo-Australian and western Pacific ant species range to the east and north of Samoa, but it is unclear how many of these were transported there by humans at some time (Wilson and Taylor 1967). Most of the remainder of the ant species currently found on Pacific islands are widespread species that fall in the category of “tramp species,” dispersed by recent human commerce and generally closely tied to human activity and urban areas (Wilson and Taylor 1967, McGlynn 1999). In Pacific island situations, some of these tramp ant species are able to thrive beyond areas of human activity. Relatively few ant species have been successful invaders of native communities on continents, and these include most of the species that pose the greatest problems for Pacific islands

  15. Fecundity and longevity of Argentine ant (Hymenoptera: Formicidae) queens in response to irradiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. As little is known about irradiation effects on ants, radiotolerance of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae...

  16. Dynamics and shape of large fire ant rafts

    PubMed Central

    Mlot, Nathan J.; Tovey, Craig; Hu, David L.

    2012-01-01

    To survive floods, fire ants link their bodies together to build waterproof rafts. Such rafts can be quite large, exceeding 100,000 individuals in size. In this study, we make two improvements on a previously reported model on the construction rate of rafts numbering between 3,000 and 10,000 individuals. That model was based upon experimental observations of randomly-directed linear ant trajectories atop the raft. Here, we report anomalous behavior of ants atop larger rafts of up to 23,000 ants. As rafts increase in size, the behavior of ants approaches diffusion, which is in closer alignment with other studies on the foraging and scouting patterns of ants. We incorporate this ant behavior into the model. Our modified model predicts more accurately the growth of large rafts. Our previous model also relied on an assumption of raft circularity. We show that this assumption is not necessary for large rafts, because it follows from the random directionality of the ant trajectories. Our predicted relationship between raft size and circularity closely fits experimental data. PMID:23336030

  17. Do long-lived ants affect soil microbial communities?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to test the hypothesis that desert ant species that build nests that remain viable at a particular point in space for more than a decade produce soil conditions that enhance microbial biomass and functional diversity. We studied the effects of a seed-harvester ant, Pogonomyrm...

  18. Colony-level impacts of parasitoid flies on fire ants.

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

    The red imported fire ant is becoming a global ecological problem, having invaded the United States, Puerto Rico, New Zealand and, most recently, Australia. In its established areas, this pest is devastating natural biodiversity. Early attempts to halt fire ant expansion with pesticides actually enhanced its spread. Phorid fly parasitoids from South America have now been introduced into the United States as potential biological control agents of the red imported fire ant, but the impact of these flies on fire ant populations is currently unknown. In the laboratory, we show that an average phorid density of as little as one attacking fly per 200 foraging ants decreased colony protein consumption nearly twofold and significantly reduced numbers of large-sized workers 50 days later. The high impact of a single phorid occurred mainly because ants decreased foraging rates in the presence of the flies. Our experiments, the first (to our knowledge) to link indirect and direct effects of phorids on fire ants, demonstrate that colonies can be stressed with surprisingly low parasitoid densities. We interpret our findings with regard to the more complex fire ant-phorid interactions in the field. PMID:12204130

  19. Tracing the Rise of Ants - Out of the Ground

    PubMed Central

    Lucky, Andrea; Trautwein, Michelle D.; Guénard, Benoit S.; Weiser, Michael D.; Dunn, Robert R.

    2013-01-01

    The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil). Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today. PMID:24386323

  20. ANT COMMUNITIES AND LIVESTOCK GRAZING IN THE GREAT BASIN, USA

    EPA Science Inventory

    The objectives of this study were to determine if metrics for ant species assemblages can be used as indicators of rangeland condition, and to determine the influence of vegetation and ground cover variables, factors often influenced by livestock grazing, on ant communities. The ...

  1. Transgenerational effects and the cost of ant tending in aphids.

    PubMed

    Tegelaar, Karolina; Glinwood, Robert; Pettersson, Jan; Leimar, Olof

    2013-11-01

    In mutualistic interactions, partners obtain a net benefit, but there may also be costs associated with the provision of benefits for a partner. The question of whether aphids suffer such costs when attended by ants has been raised in previous work. Transgenerational effects, where offspring phenotypes are adjusted based on maternal influences, could be important in the mutualistic interaction between aphids and ants, in particular because aphids have telescoping generations where two offspring generations can be present in a mature aphid. We investigated the immediate and transgenerational influence of ant tending on aphid life history and reproduction by observing the interaction between the facultative myrmecophile Aphis fabae and the ant Lasius niger over 13 aphid generations in the laboratory. We found that the effect of ant tending changes dynamically over successive aphid generations after the start of tending. Initially, total aphid colony weight, aphid adult weight and aphid embryo size decreased compared with untended aphids, consistent with a cost of ant association, but these differences disappeared within four generations of interaction. We conclude that transgenerational effects are important in the aphid-ant interactions and that the costs for aphids of being tended by ants can vary over generations.

  2. Thelohania solenopsae as a factor of fire ant populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inadvertent introduction of fire ants into the United States over 70 years ago initially resulted in large-scale efforts to eradicate the invasive pest. Large populations, mobility, and ability to occupy diverse habitats make fire ants a dominant arthropod in infested regions and very difficult...

  3. Sucking pump activity in feeding behaviour regulation in carpenter ants.

    PubMed

    Falibene, Agustina; Gontijo, Alberto de Figueiredo; Josens, Roxana

    2009-06-01

    Modulation of liquid feeding-rate would allow insects to ingest more food in the same time when this was required. Ants can vary nectar intake rate by increasing sucking pump frequency according to colony requirements. We analysed electrical signals generated by sucking pump activity of ants during drinking solutions of different sucrose concentrations and under different carbohydrate-deprivation levels. Our aim was to define parameters that characterize the recordings and analyse their relationship with feeding behaviour. Signals showed that the initial and final frequencies of sucking pump activity, as well as the difference between them were higher in sugar-deprived ants. However, these parameters were not influenced by sucrose solution concentration, which affected the number of pump contractions and the volume per contraction. Unexpectedly, we found two different responses in feeding behaviour of starved and non-starved ants depending on concentration. Starved ants drank dilute solutions for the same length of time as non-starved ants but ingested higher volumes. While drinking the concentrated solutions, starved ants drank the same volume, but did so in a shorter time than the non-starved ones. Despite these differences, for each analysed concentration the total number of pump contractions remained constant independently of sugar-deprivation level. These results are discussed in the frame of feeding regulation and decision making in ant foraging behaviour.

  4. Tracing the rise of ants - out of the ground.

    PubMed

    Lucky, Andrea; Trautwein, Michelle D; Guénard, Benoit S; Weiser, Michael D; Dunn, Robert R

    2013-01-01

    The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil). Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today.

  5. Chaos-order transition in foraging behavior of ants.

    PubMed

    Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

    2014-06-10

    The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants' physical abilities, and ants' knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal.

  6. Thermal constraints on foraging of tropical canopy ants.

    PubMed

    Spicer, Michelle Elise; Stark, Alyssa Y; Adams, Benjamin J; Kneale, Riley; Kaspari, Michael; Yanoviak, Stephen P

    2017-04-01

    Small cursorial ectotherms risk overheating when foraging in the tropical forest canopy, where the surfaces of unshaded tree branches commonly exceed 50 °C. We quantified the heating and subsequent cooling rates of 11 common canopy ant species from Panama and tested the hypothesis that ant workers stop foraging at temperatures consistent with the prevention of overheating. We created hot experimental "sunflecks" on existing foraging trails of four ant species from different clades and spanning a broad range of body size, heating rate, and critical thermal maxima (CTmax). Different ant species exhibited very different heating rates in the lab, and these differences did not follow trends predicted by body size alone. Experiments with ant models showed that heating rates are strongly affected by color in addition to body size. Foraging workers of all species showed strong responses to heating and consistently abandoned focal sites between 36 and 44 °C. Atta colombica and Azteca trigona workers resumed foraging shortly after heat was removed, but Cephalotes atratus and Dolichoderus bispinosus workers continued to avoid the heated patch even after >5 min of cooling. Large foraging ants (C. atratus) responded slowly to developing thermal extremes, whereas small ants (A. trigona) evacuated sunflecks relatively quickly, and at lower estimated body temperatures than when revisiting previously heated patches. The results of this study provide the first field-based insight into how foraging ants respond behaviorally to the heterogeneous thermal landscape of the tropical forest canopy.

  7. Odorous House Ants (Tapinoma sessile) as Back-Seat Drivers of Localized Ant Decline in Urban Habitats

    PubMed Central

    Salyer, Adam; Bennett, Gary W.; Buczkowski, Grzegorz A.

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban ‘invasion’. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a

  8. Odorous house ants (Tapinoma sessile) as back-seat drivers of localized ant decline in urban habitats.

    PubMed

    Salyer, Adam; Bennett, Gary W; Buczkowski, Grzegorz A

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban 'invasion'. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a "back

  9. A Brief Manualized Treatment for Problematic Caffeine Use: A Randomized Control Trial

    PubMed Central

    Evatt, Daniel P.; Juliano, Laura M.; Griffiths, Roland R.

    2015-01-01

    Objective The goal of the present investigation was to develop and test a brief therapist-guided manualized treatment for problematic caffeine use including cognitive-behavioral strategies and 5-weeks of progressively decreased consumption. Methods Individuals seeking treatment for problematic caffeine use (mean daily caffeine consumption of 666.0 mg at baseline) were randomized using a waitlist-control design to receive immediate (N = 33) treatment or delayed (N = 34) treatment (∼6 weeks later). A one-hour long treatment session designed to help individuals quit or reduce caffeine consumption was provided by a trained counselor along with a take-home booklet. After the treatment session, participants completed daily diaries of caffeine consumption for 5 weeks. They returned for follow-up assessments at 6, 12, and 26 weeks and had a telephone interview at 52-weeks post-treatment. Results Treatment resulted in a significant reduction in self reported caffeine use and salivary caffeine levels. No significant post-treatment increases in caffeine use were observed for up to one year follow-up. Comparisons to the waitlist control condition revealed that reductions in caffeine consumption were due to treatment and not the passing of time, with a treatment effect size of R2 = .35 for the model. Conclusions A brief one-session manualized intervention with follow-up was efficacious at reducing caffeine consumption. Future research should replicate and extend these findings, as well as consider factors affecting dissemination of treatment for problematic caffeine use to those in need. PMID:26501499

  10. Eavesdropping on cooperative communication within an ant-butterfly mutualism

    NASA Astrophysics Data System (ADS)

    Elgar, Mark A.; Nash, David R.; Pierce, Naomi E.

    2016-10-01

    Signalling is necessary for the maintenance of interspecific mutualisms but is vulnerable to exploitation by eavesdropping. While eavesdropping of intraspecific signals has been studied extensively, such exploitation of interspecific signals has not been widely documented. The juvenile stages of the Australian lycaenid butterfly, Jalmenus evagoras, form an obligate association with several species of attendant ants, including Iridomyrmex mayri. Ants protect the caterpillars and pupae, and in return are rewarded with nutritious secretions. Female and male adult butterflies use ants as signals for oviposition and mate searching, respectively. Our experiments reveal that two natural enemies of J. evagoras, araneid spiders and braconid parasitoid wasps, exploit ant signals as cues for increasing their foraging and oviposition success, respectively. Intriguingly, selection through eavesdropping is unlikely to modify the ant signal.

  11. Improved Ant Algorithms for Software Testing Cases Generation

    PubMed Central

    Yang, Shunkun; Xu, Jiaqi

    2014-01-01

    Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to porduce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations. PMID:24883391

  12. An ant colony algorithm on continuous searching space

    NASA Astrophysics Data System (ADS)

    Xie, Jing; Cai, Chao

    2015-12-01

    Ant colony algorithm is heuristic, bionic and parallel. Because of it is property of positive feedback, parallelism and simplicity to cooperate with other method, it is widely adopted in planning on discrete space. But it is still not good at planning on continuous space. After a basic introduction to the basic ant colony algorithm, we will propose an ant colony algorithm on continuous space. Our method makes use of the following three tricks. We search for the next nodes of the route according to fixed-step to guarantee the continuity of solution. When storing pheromone, it discretizes field of pheromone, clusters states and sums up the values of pheromone of these states. When updating pheromone, it makes good resolutions measured in relative score functions leave more pheromone, so that ant colony algorithm can find a sub-optimal solution in shorter time. The simulated experiment shows that our ant colony algorithm can find sub-optimal solution in relatively shorter time.

  13. Shaken, not stirred: a serendipitous study of ants and earthquakes.

    PubMed

    Lighton, John R B; Duncan, Frances D

    2005-08-01

    There is anecdotal evidence for profound behavioral changes prior to and during earthquakes in many organisms, including arthropods such as ants. Behavioral or physiological analysis has often, in light of these reports, been proposed as a means of earthquake prediction. We report here a serendipitous study of the effect of the powerful Landers earthquake in the Mojave Desert, USA (Richter magnitude 7.4) on ant trail dynamics and aerobic catabolism in the desert harvester ant Messor pergandei. We monitored trail traffic rates to and from the colony, trail speed, worker mass distributions, rates of aerobic catabolism and temperature at ant height before and during the earthquake, and for 3 days after the earthquake. Contrary to anecdotal reports of earthquake effects on ant behavior, the Landers earthquake had no effect on any measured aspect of the physiology or behavior of M. pergandei. We conclude that anecdotal accounts of the effects of earthquakes or their precursors on insect behavior should be interpreted with caution.

  14. Eavesdropping on cooperative communication within an ant-butterfly mutualism.

    PubMed

    Elgar, Mark A; Nash, David R; Pierce, Naomi E

    2016-10-01

    Signalling is necessary for the maintenance of interspecific mutualisms but is vulnerable to exploitation by eavesdropping. While eavesdropping of intraspecific signals has been studied extensively, such exploitation of interspecific signals has not been widely documented. The juvenile stages of the Australian lycaenid butterfly, Jalmenus evagoras, form an obligate association with several species of attendant ants, including Iridomyrmex mayri. Ants protect the caterpillars and pupae, and in return are rewarded with nutritious secretions. Female and male adult butterflies use ants as signals for oviposition and mate searching, respectively. Our experiments reveal that two natural enemies of J. evagoras, araneid spiders and braconid parasitoid wasps, exploit ant signals as cues for increasing their foraging and oviposition success, respectively. Intriguingly, selection through eavesdropping is unlikely to modify the ant signal.

  15. A theoretical model for uni-directional ant trails

    NASA Astrophysics Data System (ADS)

    Kayacan, Ozhan

    2011-03-01

    A theoretical model of uni-directional ant traffic, motivated by the motion of ants in trail is proposed. Two different type of ants, one of which smells very well and the other does not, are considered. The flux of ants in this model is investigated as functions of the probability of evaporation rate of pheromone. The obtained results indicate that the mean velocity of the ants varies non-monotonically with their density. In addition, it is observed that phase transition in the flux and the mean velocity vs. density occurs at certain density for a fixed evaporation rate. The effective hopping probability is investigated as well depending on the evaporation rate of pheromone. It is worth to note that the proposed model can be generalized for vehicular traffic on freeways.

  16. Improved ant algorithms for software testing cases generation.

    PubMed

    Yang, Shunkun; Man, Tianlong; Xu, Jiaqi

    2014-01-01

    Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to produce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations.

  17. Egg-laying butterflies distinguish predaceous ants by sight.

    PubMed

    Sendoya, Sebastián F; Freitas, André V L; Oliveira, Paulo S

    2009-07-01

    Information about predation risks is critical for herbivorous insects, and natural selection favors their ability to detect predators before oviposition and to select enemy-free foliage when offspring mortality risk is high. Food plants are selected by ovipositing butterflies, and offspring survival frequently varies among plants because of variation in the presence of predators. Eunica bechina butterflies oviposit on Caryocar brasiliense, an ant-defended plant. Experiments with dried Camponotus and Cephalotes ants pinned to leaves revealed that butterflies use ant size and form as visual cues to avoid ovipositing on plant parts occupied by ants more likely to kill larval offspring. Presence of sap-sucking bugs did not affect butterfly oviposition. This is the first demonstration that visual recognition of predators can mediate egg-laying decisions by an insect herbivore and that an insect will discriminate among different species of potential predators. This unusual behavioral capability permits specialization on a risky, ant-defended food plant.

  18. [Problematic medical and psychological issues concerning rehabilitation of crews during the after-sea-dutymen period].

    PubMed

    Liseenko, A N; Artemenko, E S; Demeev, Ya A; Shchur, M S

    2015-09-01

    The analysis of the causes of lack of effective functioning of the medical and psychological rehabilitation of crew of the Navy in the Pacific Fleet is performed. Possible ways of solving existing problematic issues are suggested. For determination of fatigue and overwork it was suggested to undertake mandatory initial medical and psychological screening examination of crews immediately before the return to the naval base, using a simple and affordable methods of testing. Medical and psychological rehabilitation of soldiers after the long sea voyages proposed to take immediate military sanatorium of the Ministry of Defense of the Russian Federation (on the territorial principle).

  19. Problematic projection to the in-sample subspace for a kernelized anomaly detector

    SciTech Connect

    Theiler, James; Grosklos, Guen

    2016-03-07

    We examine the properties and performance of kernelized anomaly detectors, with an emphasis on the Mahalanobis-distance-based kernel RX (KRX) algorithm. Although the detector generally performs well for high-bandwidth Gaussian kernels, it exhibits problematic (in some cases, catastrophic) performance for distances that are large compared to the bandwidth. By comparing KRX to two other anomaly detectors, we can trace the problem to a projection in feature space, which arises when a pseudoinverse is used on the covariance matrix in that feature space. Here, we show that a regularized variant of KRX overcomes this difficulty and achieves superior performance over a wide range of bandwidths.

  20. Naming and Claiming Cancer among African American Women: An Application of Problematic Integration Theory

    PubMed Central

    Cohen, Elisia L.

    2009-01-01

    This study examines how a sample of African American women understands the uncertainties fundamental to cancer risk communication. Utilizing data from four focus groups, Problematic Integration (PI) theory is applied as an interpretive lens for illustrating their felt difficulties of talking openly about cancer and breast cancer in everyday life. The women describe worry about cancer and its prevalence among African American women; ambivalence and uncertainty; belief that what is not uncertain is certain and awful; fear and avoidance; contradictions in “claiming” and “rebuking” cancer; and hopefulness. PMID:20160969