Aggressive Calls Research Articles

The potential role of reproductive interference in the decline of native green treefrogs following Cuban treefrog invasions

Reproductive interference is increasingly implicated in the decline of native taxa following alien species invasions. We examined reproductive interference in the context of acoustic modulation of hormone levels and declines in native green treefrogs (Hyla cinerea) following invasions of Cuban treefrogs (Osteopilus septentrionalis) in the southeastern United States. The motivation for our study stemmed from similarities in spectro-temporal properties of Cuban treefrog courtship calls and green treefrog aggressive calls. The aggressive calls of green treefrogs stimulate glucocorticoid production in rival conspecific males, which suppresses androgen production and reproductive behavior. We thus hypothesized that native male green treefrogs exposed to advertisement calls of this invasive species exhibit increased levels of circulating glucocorticoids. We found that broadcast aggressive calls of green treefrogs stimulated glucocorticoid production in conspecific males but that Cuban treefrog vocalizations did not increase glucocorticoid levels in green treefrogs. In natural choruses, the density of calling male green treefrogs and the proportion of non-calling males were positively correlated with glucocorticoid levels and negatively correlated with androgens, whereas body size was positively correlated with androgens. After controlling for these variables, there was no evidence that hormone levels or behavior differed in choruses of green treefrogs in the presence and absence of Cuban treefrogs. Together, our results suggest that interactions among male green treefrogs modulate hormone levels but that the presence of Cuban treefrogs, calling or not, is not altering levels of glucocorticoids or androgens in breeding male green treefrogs.

Acoustic Repertoire and Calling Behavior of the Gliding Treefrog, Agalychnis spurrelli (Anura: Hylidae)

Acoustic communication is essential for reproductive success in frogs. Males produce different types of calls to attract females, advertise territoriality or location in a chorus, or communicate with heterospecifics. Quantitative descriptions of amphibian calls provide basic information for taxonomic, ecological, evolutionary, and conservation studies. Here, we describe the acoustic repertoire of Agalychnis spurrelli and discuss this species' reproductive behavior on the basis of observations made over the course of a breeding season in May–December 2007. Males produced one type of advertisement call and two types of aggressive calls (calls A and B) that differed in temporal and spectral frequency. The advertisement call was a single note. Aggressive call A was a long-pulsed single note, and call B was composed of more than two notes per call. Calling behavior was influenced by chorus size and male-to-male proximity, with males altering their advertisement calls with the increase of chorus size and eventually producing aggressive calls. These results suggest that A. spurrelli might exhibit graded aggressive signaling, helping males to delimit their calling site and reducing the number of agonistic encounters.

Acoustic variability among male gladiator frogs, Boana goiana (Lutz, 1968) (Anura: Hylidae): an 18-year analysis across several reproductive seasons

Abstract Male anurans emit different call types in specific social contexts. Such calls represent a communication pathway for species recognition, mate choice, and male-male competition mediation. The acoustic parameters of these calls can be under directional and/or stabilizing selection due to female choice, which influences intra- and inter-individual call variation. Herein, we investigated the inter-year variation of the advertisement and aggressive calls of the gladiator frog Boana goiana, analysing a temporal series encompassing 18 years of sampling (1996-2014). We measured and analysed the following acoustic parameters: call duration, call repetition rate, number of pulses, pulse duration, pulse repetition rate, and dominant frequency. For both call types, the dominant frequency was classified as a static parameter (CVintra < 5%), while call duration was a dynamic parameter (CVintra > 12%). The advertisement call of B. goiana presents the attributes that could allow individual recognition in the chorus, and we suggest that the aggressive calls might also be important for the individual recognition process. Pulse duration of the advertisement and aggressive calls decreased over the years, as well as the repetition rate of the aggressive calls, which could be related to male body size decrease over the years probably related to habitat alteration. This study provides data on the variation of anuran acoustic features over the longest time span ever analysed. Such studies are less invasive and useful for conservation purposes, since they can detect changes in the reproductive behaviour of populations that might be under environmental modification pressure.

Taxis bold as love: the influence of aggressive calls on acoustic attraction of female gray treefrogs, Hyla versicolor

We studied female phonotaxis in gray treefrogs to learn how male aggressive calling influences female choice of a mate from the perspective of the aggressive signaler and his male target. Although aggressive calls on their own attracted some females, when allowed to choose, all females preferred advertisement calls to aggressive calls. We wanted to ascertain also whether such calls could reduce the attractiveness of a nearby advertising male relative to an advertising male that was not close to a male giving aggressive calls. If so, it would be a good reason for a male to move away from a male giving aggressive calls. We found that females were indifferent to aggressive calls which were broadcast following and adjacent to a source of advertisement calls when the choice alternative was a more distant source of advertisement calls. However, this was not always the case when aggressive calls and advertisement calls overlapped. Angular separation from a source of overlapping aggressive calls did not improve the attractiveness of advertisement calls relative to advertisement calls adjacent to a source of such aggressive calls. In a final test, we simulated an aggressive exchange with a winner and a retreating loser. Females allowed to eavesdrop failed to discriminate. Thus, there may be no cost to moving away and a potential gain in terms of reduced acoustic interference. Loud calls or physical intrusions by conspecific males may cause male frogs to give aggressive calls. Although acoustic features of aggressive vocalizations may be well-described, we are largely ignorant of their utility and potential costs to producing and nearby males. We investigated whether the production of aggressive calls would compromise the attractiveness of male gray treefrogs to potential mates. Choruses of frogs may be especially suitable venues for eavesdropping, a phenomenon also ripe for investigation. Accordingly, we tested whether females exposed to simulated aggressive vocal exchanges would discriminate in favor of putative winners. We found that aggressive calling can reduce the signaler’s attractiveness but, lacking acoustic interference, not that of a neighbor. Females failed to discriminate between a simulated retreating loser and winner suggesting that such outcomes are irrelevant to females or that their ability to eavesdrop is limited.

On the courtship, breeding behaviour and vocalisation of Rhinella ornata (Spix, 1824) (Anura, Bufonidae): a well-marked escalated behaviour in a lek-like system

Courtship and breeding behaviour of anurans is species-specific and defined by vocalisation, although breeding activities are still understudied for many species. Here, we describe the courtship behaviour and unpublished associated vocalisation (release and aggressive calls) of Rhinella ornata at a degraded area of the Brazilian Atlantic Rainforest within Xixova-Japui State Park (PEXJ). Fifteen subjects distributed in five subgroups in the same lek-like systems were observed during two consecutive nights in September 2015, totalling eight fieldwork hours. A total of 79 vocalisations were analysed, and the behavioural sequence of activities carried out by the subjects was described. Results show a pattern regarding the behavioural sequence exhibited by males, starting with the arrival of the resident male at the calling site and its vocalisation to an intruder male. Although this sequence did not vary between the five observed groups, a slight difference in the time they started was reported, but with a narrow range. We also provided the first description of the release call for this species. The overall behavioural tactics of R. ornata to approach females seem uncommon among bufonids. Although further investigation is required to better understand additional aspects of the courtship and breeding behaviour of R. ornata, our findings improve the overall understanding of this species’ biology.

Male serrate-legged treefrogs adjust competition strategies according to visual or chemical cues from females.

There is increasing evidence that many anurans use multimodal cues to detect, discriminate and/or locate conspecifics and thus modify their behaviors. To date, however, most studies have focused on the roles of multimodal cues in female choice or male-male interactions. In the present study, we conducted an experiment to investigate whether male serrate-legged small treefrogs (Kurixalus odontotarsus) used visual or chemical cues to detect females and thus altered their competition strategies in different calling contexts. Three acoustic stimuli (advertisement calls, aggressive calls and compound calls) were broadcast in a randomized order after a spontaneous period to focal males in one of four treatment groups: combined visual and chemical cues of a female, only chemical cues, only visual cues and a control (with no females). We recorded the vocal responses of the focal males during each 3 min period. Our results demonstrate that males reduce the total number of calls in response to the presence of females, regardless of how they perceived the females. In response to advertisement calls and compound calls, males that perceived females through chemical cues produced relatively fewer advertisement calls but more aggressive calls. In addition, they produced relatively more aggressive calls during the playback of aggressive calls. Taken together, our study suggests that male Kodontotarsus adjust their competition strategies according to the visual or chemical cues of potential mates and highlights the important role of multisensory cues in male frogs' perception of females.

Mechanisms of Convergent Egg Provisioning in Poison Frogs.

Parental provisioning of offspring with physiological products (nursing) occurs in many animals, yet little is known about the neuroendocrine basis of nursing in non-mammalian species. Within amphibians, maternal provisioning has evolved multiple times, with mothers of some species feeding unfertilized eggs to their developing offspring until tadpoles complete metamorphosis [1-3]. We conducted field studies in Ecuador and Madagascar to ask whether convergence at the behavioral level provides similar benefits to offspring and relies on shared neural mechanisms in dendrobatid and mantellid poison frogs. At an ecological level, we found that nursing allows poison frogs to provide chemical defenses to their tadpoles in both species. At the neural level, nursing was associated with increased activity in the lateral septum and preoptic area, demonstrating recruitment of shared brain regions in the convergent evolution of nursing within frogs and across vertebrates [4]. In contrast, only mantellids showed increased oxytocin neuron activity akin to that in nursing mammals [5], suggesting evolutionary versatility in molecular mechanisms. Our findings demonstrate that maternal provisioning provides similar potential benefits to offspring and relies on similar brain regions in poison frog species with convergently evolved toxicity and maternal care. VIDEO ABSTRACT.

Effect of Call Types on White-Breasted Waterhen (Amaurornis phoenicurus) Response to Playbacks on Pratas Island, Taiwan

The White-breasted Waterhen (Amaurornis phoenicurus) is the only bird species known to breed on Pratas Island, Taiwan, for the past few decades. Since they are secretive and very difficult to observe, responses to different call playbacks were tested experimentally in the field to determine if call type affects response of birds to improve future surveys. Playbacks of two different call types (advertising call and aggressive call) were carried out at 26 stations in the east region of the island in April, June, July, and August 2016. The frequency of response and behavioral reaction of waterhens to playbacks were recorded within a 6-min test period at each station. Playbacks of the advertising call elicited more responses at stations than did aggressive calls. Two-way Repeated Measures ANOVA revealed a significant difference in response frequencies for the main effect of call type, but no difference was found for monthly effect and an interaction term for call type and month. This study provides evidence that playback experiments of the advertising call during the courtship period can be an effective way to monitor the population size of a secretive species such as the White-breasted Waterhen.

Great Himalayan leaf-nosed bats modify vocalizations to communicate threat escalation during agonistic interactions

Bats vocalize extensively within various social contexts. Nevertheless, studies of agonistic interactions, associating vocalizations signalling the emotional state of a caller with individual signatures during aggressive vocalizations remain scarce. Here, we examined whether male Great Himalayan leaf-nosed bats (Hipposideros armiger) modify their aggressive vocalizations during agonistic interactions depending on the level of aggression, and whether these vocalizations encode individual signatures. We applied a cost-benefit analysis to audio-video recordings of 50 dyadic agonistic interactions to categorize displays into two levels of aggression intensity (low aggression: bared teeth, slightly pulled up body and/or wings; high aggression: rapidly flapping wings, punching, biting). Male H. armiger used graded visual agonistic displays accompanied by bent upward frequency modulation (bUFM) vocalizations to defend their roosting territories. At high aggression intensities, males decreased the minimum frequency of aggressive calls and increased the frequency bandwidth. Males also transferred energy from the second harmonic to the first harmonic as the threat escalated. These systematic modifications of acoustic parameters as aggressive intensity fluctuated corresponded to prosodic modifications in human speech, indicating that emotion-related acoustic cues are a common feature of acoustic communication in mammals. In addition, we found that the aggressive calls of eight adult males encoded discriminable signatures, and that males could discriminate among individuals based on these aggressive calls. Such discrimination is probably useful for individual identification among rival neighbours.

Quiet violence: Savannah Sparrows respond to playback‐simulated rivals using low‐amplitude songs as aggressive signals

AbstractWhen animals compete over resources such as breeding territories, they often use signals to communicate their aggressive intentions. By studying which signals are associated with aggressive interactions, we gain a deeper appreciation of animal behaviour. We studied aggressive signalling in male Savannah Sparrows, Passerculus sandwichensis, focusing on signals that precede physical attack against territorial intruders. We simulated intruders using song playback and taxidermic models, and we determined which behaviours were associated with physical attack. Previous studies that have used this approach suggest that many species produce songs of dramatically lower amplitude, or “soft songs,” as signals of aggressive intention. Savannah Sparrows, however, are not known to produce soft songs, and therefore, they provided an interesting system for testing signals that predict attack. Of 93 playback subjects, 23 males attacked the simulated intruder and 70 did not. To our surprise, Savannah Sparrows produced soft songs, and the number of soft songs was a significant predictor of attack on the simulated intruder. Birds also showed a nonsignificant tendency to produce more “chip” calls prior to attack on the simulated intruder, whereas three other measured behaviours (aggressive calls, wing waving and passes over the model) did not predict attack. Our study contributes to the growing body of research on aggressive territorial signals and reveals that soft song is an even more widespread signal of aggression in songbirds than previously recognized.

Are aggressive vocalizations the honest signals of body size and quality in female Asian particoloured bats?

Animals make calls to give conspecifics information about themselves. Based on these calls, the receiver makes decisions that affect survival and reproduction. However, not all of the signals are reliable. Honest signals are either costly to produce or are constrained by physical or physiological factors that cannot be faked. Aggressive calls during antagonistic interactions are both costly and constrained by physiology. The female Asian particoloured bat (Vespertilio sinensis) produces aggressive displays and vocalizations when confronted by an intruder conspecific competing for roost position. We tested whether the aggressive calls of female Asian particoloured bats encode reliable information about the body size and the quality of the caller, and, subsequently, whether aggressive calls predicted a winning percentage that was calculated as the number of winning interactions divided by the total number of agonistic interactions. At the syllable level, there were significant positive relationships between the duration of various syllables and forearm length, bite force and winning percentage. In addition, frequency-related syllable parameters, such as peak frequency, minimum frequency, maximum frequency and bandwidth, were negatively correlated with immune response and winning percentage. At the call level, heavier bats that produced calls with shorter mean inter-syllable silences had higher winning percentage and healthier bats produced calls with lower maximum frequency. There was a significant positive relationship between immune response and vocal complexity, but no significant relationship was found between winning percentage and vocal complexity. These results suggested that aggressive calls in female Asian particoloured bats may be honest signals of body size and quality during the antagonistic interactions. Indeed, the reliability of acoustic communication in bats may be key to an in-depth understanding of the function and evolution of social calls in bats. Although aggressive encounters for finite resources occur frequently in many species of animals, fights to the death are quite rare in nature. Before any physical encounter, most animals exchange signals indicating fighting ability to help both contestants decide whether to retreat or to engage further in the conflict. Our results suggested that the acoustic parameters controlled by the body size and/or quality indices of Vespertilio sinensis females were significantly correlated with winning percentage. Thus female Asian particoloured bats may use aggressive vocalizations to transmit information about their body size and/or body quality (commonly used as a proxy for fighting ability) to their rivals. The rivals would be able to predict the outcome of an escalated conflict based on this information in order to decide whether to escalate or de-escalate the aggressive encounter, thereby reducing unnecessary costs.

Phenotypic integration and the evolution of signal repertoires: A case study of treefrog acoustic communication.

Animal signals are inherently complex phenotypes with many interacting parts combining to elicit responses from receivers. The pattern of interrelationships between signal components reflects the extent to which each component is expressed, and responds to selection, either in concert with or independently of others. Furthermore, many species have complex repertoires consisting of multiple signal types used in different contexts, and common morphological and physiological constraints may result in interrelationships extending across the multiple signals in species’ repertoires. The evolutionary significance of interrelationships between signal traits can be explored within the framework of phenotypic integration, which offers a suite of quantitative techniques to characterize complex phenotypes. In particular, these techniques allow for the assessment of modularity and integration, which describe, respectively, the extent to which sets of traits covary either independently or jointly. Although signal and repertoire complexity are thought to be major drivers of diversification and social evolution, few studies have explicitly measured the phenotypic integration of signals to investigate the evolution of diverse communication systems. We applied methods from phenotypic integration studies to quantify integration in the two primary vocalization types (advertisement and aggressive calls) in the treefrogs Hyla versicolor, Hyla cinerea, and Dendropsophus ebraccatus. We recorded male calls and calculated standardized phenotypic variance–covariance (P) matrices for characteristics within and across call types. We found significant integration across call types, but the strength of integration varied by species and corresponded with the acoustic similarity of the call types within each species. H. versicolor had the most modular advertisement and aggressive calls and the least acoustically similar call types. Additionally, P was robust to changing social competition levels in H. versicolor. Our findings suggest new directions in animal communication research in which the complex relationships among the traits of multiple signals are a key consideration for understanding signal evolution.

Rapid effects of elevated stress hormones on male courtship signals suggest a major role for the acute stress response in intra‐ and intersexual selection

AbstractShort‐term elevations in circulating stress hormones (glucocorticoids) often mediate reduced investment in reproductive behaviour in favour of self‐maintenance and survival, but the significance of these effects in sexual selection and communication remain largely unexplored.Here we examine the acute stress response in the context of intra‐ and intersexual selection in the green treefrogHyla cinerea. Males of this species produce agonistic acoustic signals that stimulate elevations in the stress hormone corticosterone (CORT) in rival males, suggesting a central role forCORTin male–male competition. We hypothesized that elevatedCORTlevels in losers of vocal contests mediate an increase in the energy allocated towards self‐maintenance and survival that compromises investment in courtship signalling, resulting in reduced attractiveness to females.Consistent with this hypothesis, we show thatCORTadministration to calling males, simulatingCORTproduction in vocal contest losers, caused a rapid reduction in the duration of advertisement calls and vocal effort. ElevatedCORTalso increased the propensity to produce aggressive calls during simulated territorial intrusions that was followed by an increased probability of non‐calling “satellite” mating behaviour. This suite ofCORTeffects on vocal behaviour are known to decrease attractiveness to females and were not related to a decrease in androgen level or differences in body condition inCORT‐ vs. saline‐injected males.Our results suggest thatCORTproduction during intraspecific vocal contests compromises male attractiveness. Male vocalizations may therefore reliably indicate recent contest outcomes and/or the stress status of males, implicatingCORTas a mediator of honest signalling. We propose that the effects of agonistic acoustic signals onCORTproduction in this species are maintained byCORT‐mediated life‐history trade‐offs; decreased conspicuous signalling in high stress‐responsive males potentially increases survival by reducing the likelihood of escalated contests with dominant males and detection by predators. Adoption of alternative non‐calling satellite mating tactics may contribute to maintaining individual variation in stress responsiveness by increasing the chances that competitively inferior males acquire mates.Aplain language summaryis available for this article.

Nighttime behavioral study of flying foxes on the southern coast of West Java, Indonesia.

Flying foxes are important in the maintenance of forests and diversity. However, knowledge of their behavioral ecology, especially of movement and foraging patterns, which are essential for conservation and management of their populations, are not well known. Therefore, movement behavior of two individuals of Pteropus vampyrus were examined using an Argos telemetry system, and foraging pattern of Pteropus spp. was directly observed, at West Java province, Indonesia in October 2017. The maximum distance between the location at which bats were released and their furthest roost, recorded via satellite telemetry, was approximately 100 km. This reflects the long-distance flight ability of P. vampyrus. Daytime roosting sites and nighttime foraging places consisted of several types of habitats, such as intact forests, agricultural lands, and residential areas. This evidence indicated that there was habitat overlap between humans and bats in West Java province. According to direct observation of the behaviors of flying foxes at two locations within residential areas, various activities such as wing spreading, excretion, fighting, aggressive calls, movement, hanging relax, and hanging alert were found. The number of bat-visits to the trees varied among night hours, and had a positive correlation with the number of fruit dropping. The data obtained in this study have improved our understanding of nighttime behavior and habitat utilization of P. vampyrus, that can be used to support landscape management, species conservation, and disease prevention in regions of Southeast Asia.

The acoustic repertoire of the Atlantic Forest Rocket Frog and its consequences for taxonomy and conservation (Allobates, Aromobatidae).

The use of acoustic signals is a common characteristic of most anuran species to mediate intraspecific communication. Besides many social purposes, one of the main functions of these signals is species recognition. For this reason, this phenotypic trait is normally applied to taxonomy or to construct evolutionary relationship hypotheses. Here the acoustic repertoire of five populations of the genus Allobates from the Brazilian Atlantic Forest are presented for the first time, on a vulnerable to extinction Neotropical taxon. The description of males’ advertisement and aggressive calls and a female call emitted in a courtship context are presented. In addition, the advertisement calls of individuals from distinct geographical regions were compared. Differences in frequency range and note duration may imply in taxonomic rearrangements of these populations, once considered distinct species, and more recently, proposed as a single species, Allobates olfersioides. Calls of the male from the state of Rio de Janeiro do not overlap spectrally with calls of males from northern populations, while the shorter notes emitted by males from Alagoas also distinguishes this population from the remaining southern populations. Therefore, it is likely that at least two of the junior synonyms should be revalidated. Similarities among male advertisement and female calls are generally reported in other anuran species; these calls may have evolved from a preexisting vocalization common to both sexes. Male aggressive calls were different from both the male advertisement and female calls, since it was composed by a longer and multi-pulsed note. Aggressive and advertisement calls generally have similar dominant frequencies, but they have temporal distinctions. Such patterns were corroborated with the Atlantic Forest Rocket Frogs. These findings may support future research addressing the taxonomy of the group, behavioral evolution, and amphibian conservation.

Advertisement and aggressive calls of Pithecopus azureus (Anura: Phyllomedusidae) from the border of Brazil and Paraguay

The categories of calls previously described for the closely related species Pithecopus azureus and P. hypochondrialis are reassessed. In addition, the advertisement and aggressive calls of P. azureus from Brazil-Paraguay border in southwestern state of Mato Grosso do Sul in western Brazil are redescribed. Intraspecific comparisons of call traits are made for populations of P. azureus from Argentina and Bolivia, and the vocalization of P. azureus is also compared with that of the closely related species of the P. hypochondrialis Group (subclade of lowland species). Given the similarities among the advertisement calls of P. azureus, P. hypochondrialis, and P. nordestinus, it seems that acoustic traits, at least solely, should not be employed as reliable diagnostic characters among these species

Nightly calling patterns in a Neotropical gladiator frog

In anurans, vocalization is the primary communication form and acoustic parameters are influenced by climatic conditions, but also by social contexts. We investigated calling site use and within-individual variation of acoustic parameters throughout the night in the gladiator-frog Hypsiboas goianus. We expected that large males would call closer to the water and at higher perches to avoid dehydration and maximize sound propagation. Furthermore, we tested the prediction that males would emit more aggressive calls early in the night and more advertisement calls late at night. Male size was not correlated with either distance from the water or perch height. However, as expected, males of H. goianus adopted a calling strategy that consisted of emitting more aggressive calls early in the night and more advertisement calls later in the night. Furthermore, repetition rate and interval between notes of the aggressive calls and repetition rate of the advertisement calls showed within-individual variation throughout the night that agreed with our expectations. The calling strategy of H. goianus is probably related to the establishment of calling sites early in the night and an investment in female attraction in the middle of the night when males’ aggressive interactions have faded away, or due to habituation increasing the males’ aggressive thresholds. This is the first study investigating within-individual patterns of acoustic parameters of calls throughout the night for anurans.

Territorial olive frogs display lower aggression towards neighbours than strangers based on individual vocal signatures

Some territorial animals display a form of social recognition in which they direct low levels of aggression towards established neighbours, but maintain greater readiness to respond aggressively towards unfamiliar individuals. In many taxa, such as songbirds, this so-called ‘dear enemy’ effect involves discrimination between neighbours and strangers based on individually distinctive vocal signatures. Although most anuran amphibians (frogs and toads) are highly vocal, and many are also territorial, we know very little about neighbour–stranger discrimination in this group. In the present study of the olive frog, Babina adenopleura (Ranidae), we show that the vocal signals of males are individually distinct, and that territory holders use this information to direct lower levels of aggression towards their nearby neighbours. Analyses of individual variation in advertisement calls revealed many individually distinctive spectral and temporal acoustic properties, with spectral properties contributing most towards statistical discrimination among individuals. In a field playback experiment that simulated territorial intrusions, territorial males had higher thresholds for producing aggressive calls in response to the advertisement calls of their nearby neighbours compared with those of strangers. A simple model based on sound attenuation due to spherical spreading estimated that males responded aggressively to strangers at distances that were approximately twice as far away as for neighbours and that were similar to intermale distances recorded in the field. Together, results from this study indicate that territorial male olive frogs develop vocally mediated dear enemy relationships with their nearby neighbours. These results highlight the potential for convergence in social recognition systems across diverse taxa.

Verification of Mediated Effect of Athletic Ability Beliefs in the Relations between Learning Environments Perceived in the Physical Education (PE) Class and Task Persistence

Objectives: The purpose of this study was to inquire into the mediated effect of athletic ability beliefs in the relations between the PE learning environments perceived in the PE class and task persistence. Methods/Statistical Analysis: To achieve such a research purpose, this study selected a total of 418 copies as final valid sample using convenience sampling of junior high school students at the five schools located in a metropolitan area. As for data processing, this study implemented hypothesis testing after confirming the goodness of fit test of the whole model using SPSS 18.0 and AMOS 18.0. Findings: First, effort and challenge perception in PE learning environment was confirmed to have a positive influence on increased beliefs while competence perception was found to have a negative influence on fixed beliefs and threat perception was found to have a positive influence on entity belief. Second, it was found that increased beliefs in athletic ability beliefs had a significant influence on task persistence positively while entity belief didn’t have a significant influence on task persistence. Third, it was found that effort, challenge perception, and competence perception of learning environment had a positive influence on task persistence. Lastly, it was confirmed that increased beliefs in the relations between effort, challenge perception and task persistence of learning environment play a mediating role. Improvements/Applications: This study confirmed that students’ aggressive class participation behavior calls for the learning environment, which is challenging, and makes it possible for students to put in a great deal of effort for their learning process, and a positive belief and volition that students themselves can do it in the results of this research.

Risk stratification in prostate cancer treated with radiation therapy: a window of opportunity for new clinical trials

Prostate cancer (PCa) is the most incident male cancer in USA and in Europe (1,2). Among malignant solid tumors that constantly require careful and specialized management planning, PCa is a multifaceted disease for which the decision making process has to precisely evaluate several variables concerning the tumor and its host. PCa may present a wide spectrum of clinical situations that require different interventional options. Due to the prostate specific antigen (PSA) “revolution”, in the past years, the health operators’ community has mainly focused on the identification of the indolent disease in order to avoid overtreatment; and active surveillance has been considered as a reasonable and primary choice for a substantial portion of patients. On the other hand, more recently, the definition of PCa subtypes with a clinical behavior more comparable to other aggressive solid tumors calls for different considerations about this kind of disease, especially in light of the new therapeutic agents’ availability. In particular, clinical studies aimed at defining the comparative validity of the current treatment approaches in high-risk localized disease and possibly exploring alternative therapeutic strategies, are urgently needed.