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The knowledge about natural history of a species is fundamental for the proposition of theories in population, community, and behavioral ecology. Dermatonotus muelleri (Boettger, 1885) is one of the several Neotropical anuran species that still lacks basic information. These frogs are widely distributed in South America and present many peculiar morphological features, such as a reduced head size and a tongue morphology that suggests a specialized diet in ants and termites. In this study, we describe the reproductive ecology of D. muelleri, with special attention to the mechanisms that regulates (i) the reproductive synchrony between males and females, (ii) the operational sex ratio (OSR), and (iii) if size is a good predictor of pairs formation (assortative mating). We found that D. muelleri aggregates in short periods of reproductive activity (one to five consecutive nights) to reproduce. During the reproductive events, males and females arrive at the breeding sites in synchrony, using environmental (temperature and pluviosity) and biotic (termite reproductive swarms and male calling) cues. Also, there is a high population density (1,079 ± 816 individuals, n = 11 reproductive events), with a biased OSR toward the number of males. The intense malemale competition prevents any female choice, and the call function is related more to reduction of predation costs to females. We did not find size assortative mating in D. muelleri. The lack of size assortative mating may be a consequence of different pressure selection of males and females. While females where selected to have larger body size and offspring production, at the cost of reproductive lifespan, males are subject to an intense malemale competition which prevents the expression of female preferences. [ABSTRACT FROM AUTHOR]

Operational sex ratio (OSR) is predicted to influence the direction and intensity of sexual selection. Thus, as the relative numbers of reproductively active males vs females change, the behavioural competition among males and their differences in reproductive success are also predicted to change. While these outcomes seem intuitively obvious, there have been few experimental tests that examine these predictions. Here, we experimentally tested the relationship between OSR and reproductive behaviour in sheepshead minnows (Cyprinodon variegatus) competing in laboratory-based pools. Males and females were assigned to one of three OSRs (female-biased, equal, or male-biased). We monitored aggression, territory size, and number of eggs acquired by the most aggressive male, termed the "focal male," in the pool. We used microsatellite analyses to determine the parentage of the eggs within the focal males' territories. Focal males, by definition, were the most aggressive individual in their pools, but the degree of their aggressiveness and number of spawning sites they controlled were not influenced by OSR. Compared to focal males in the equal and male-biased OSRs, focal males in the female-biased OSR did receive more eggs but the OSR did not appear to influence the percentage of eggs they fathered on their own spawning sites. We speculate that a focal male's competitive ability is more important to reproductive success than the number of other males and females present. [ABSTRACT FROM AUTHOR]

Despite ongoing advances in sexual selection theory, the evolution of mating decisions remains enigmatic. Cognitive processes often require simultaneous processing of multiple sources of information from environmental and social cues. However, little experimental data exist on how cognitive ability affects such fitness‐associated aspects of behaviour. Using advanced tracking techniques, we studied mating behaviours of guppies artificially selected for divergence in relative brain size, with known differences in cognitive ability, when predation threat and sex ratio was varied. In females, we found a general increase in copulation behaviour in when the sex ratio was female biased, but only large‐brained females responded with greater willingness to copulate under a low predation threat. In males, we found that small‐brained individuals courted more intensively and displayed more aggressive behaviours than large‐brained individuals. However, there were no differences in female response to males with different brain size. These results provide further evidence of a role for female brain size in optimal decision‐making in a mating context. In addition, our results indicate that brain size may affect mating display skill in male guppies. We suggest that it is important to consider the association between brain size, cognitive ability and sexual behaviour when studying how morphological and behavioural traits evolve in wild populations. [ABSTRACT FROM AUTHOR]

Global Navigation Satellite Systems (GNSS) were not initially designed to be used for precise scientific applications. However, a smart signal processing can provide a satellite–receiver range measurement with millimeter accuracy. If the differential technique has become an essential method, the PPP mode is today an increasingly popular alternative. But, whatever the approach, GNSS have revolutionized the realization of space and time frames and the many applications requiring post-processed or real-time precise positioning. [ABSTRACT FROM AUTHOR]

This research shows some ways, as Organizational Social Responsibility actions, used by some organizations of the cultural industry at the city of Santiago de Cali. Within a case study methodology, this paper is aimed to provide some management and education parameters to enable those organizations's sustainability and social welfare actions. Qualitative methodology is used on city's six cultural organizations. First, a bibliographic specialized documents review enabled semistructured interviews. Second, interviews were carried out within two groups: a) members of the city's county cultural industry; b) People who belongs to the six cultural organizations. Results show that there are some absences to compliance guidelines in the city's cultural sector. Consequently, it is difficult both the creation of public policies and training spaces about Organizational Social Responsibility of the studied organizations. [ABSTRACT FROM AUTHOR]

Coercive copulation is frequent in promiscuous mating systems, generating both benefits (e.g. higher copulation rate) and costs (e.g. injuries and fewer foraging opportunities). The negative consequences of sexual harassment are expected to increase with increasing population density with male-biased operational sex ratio (OSR). This study offers an example in which the frequency and severity of the injuries inflicted on female tortoises during forced copulations increased with population density and biased OSR. Male Hermann's tortoises (Testudo hermanni) harass females during courtship, ramming and biting them until they eventually force mating. They also use their horny and mobile tail to stimulate females, sometimes damaging their cloaca. We compared the frequency and severity of cloacal injuries between two populations in the Republic of Macedonia. Under high density and balanced OSR at one site (Konjsko), 25% of females exhibited cloacal injuries. Under very high density and extremely biased OSR at another site (Golem Grad Island), 75% of females were wounded, often severely. Furthermore, exclusively on Golem Grad, many small and immature females were courted and wounded. This behavioural shift toward juveniles generated costs without benefits. Perhaps brutal reproductive behaviours in male Hermann's tortoises evolved under low or moderate population densities? Under very high densities, coercive mating seems maladaptive, negatively affecting females and possibly further skewing OSR. [ABSTRACT FROM AUTHOR]

Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexually selected traits in females. At the same time, the focus has shifted from documenting sexual selection to exploring variation and spatiotemporal dynamics of sexual selection, and their evolutionary consequences. Here, I review insights from a model system with exceptionally dynamic sexual selection, the two-spotted goby fish Gobiusculus flavescens. The species displays a complete reversal of sex roles over a 3-month breeding season. The reversal is driven by a dramatic change in the operational sex ratio, which is heavily male-biased at the start of the season and heavily female-biased late in the season. Early in the season, breeding-ready males outnumber mature females, causing males to be highly competitive, and leading to sexual selection on males. Late in the season, mating-ready females are in excess, engage more in courtship and aggression than males, and rarely reject mating opportunities. With typically many females simultaneously courting available males late in the season, males become selective and prefer more colorful females. This variable sexual selection regime likely explains why both male and female G. flavescens have ornamental colors. The G. flavescens model system reveals that sexual behavior and sexual selection can be astonishingly dynamic in response to short-term fluctuations in mating competition. Future work should explore whether sexual selection is equally dynamic on a spatial scale, and related spatiotemporal dynamics. [ABSTRACT FROM AUTHOR]

In polygynous species, sexual selection is mostly driven by male ability to monopolize access to females in oestrous. In ungulates, the operational sex ratio (OSR), i.e. the proportion of males to individuals ready to mate, varies throughout the peak rut, resulting from the temporal variation in the number of females in oestrous. But the way males adjust their mating tactics to maximise their access to females in oestrous (i.e. as OSR varies) is yet to be investigated. Using 15 years of behavioural observations in reindeer ( Rangifer tarandus ), we compared the relative importance of time within the rutting season (days to the peak-rut) and the OSR to explain the variation in the propensity (i.e. the frequency after controlling for the potential number of encounters) of young and adult dominant males to engage in four mating tactics: herding females, chasing other males, investigating female reproductive status, and courting females. Male-male agonistic behaviour was the most frequent mating behaviour, followed by herding. As predicted, dominant male mating tactics changed over the rutting season: first herding, then chasing other males, and finally investigating and courting females. In contrast to our prediction, we did not find support for the OSR theory. We noted some discrepancies in how young and adult dominant males adjusted their tactics during the mating season, adults being more efficient in timing and in performing their behaviour to maximise access to females in oestrous. The reported sequence of mating tactics may be more efficient than a static mating tactic to monopolize females in oestrous, regardless of the population composition. [ABSTRACT FROM AUTHOR]

Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that 'choosiness' of potential mates is environmentally and socially labile, that is, induced - not fixed - in 'the choosy sex' with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within-individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points. [ABSTRACT FROM AUTHOR]

Size-assortative mating (SAM) is a widespread phenomenon related to individual fitness. In our study, we examined: (i) the appearance of SAM, and (ii) the effect of sex ratio on intensity of SAM in wild populations of two explosively breeding anurans, common frogs, Rana temporaria, and common toads, Bufo bufo. Despite a higher male-biased operational sex ratio (OSR) in toads, the body lengths of the paired males and females were significantly correlated only in frogs. Increasing male-male competition, assessed via the OSR, resulted in a stronger correlation also in frogs only. Thus, great variability in the presence and intensity of SAM has been observed within both studied species. [ABSTRACT FROM AUTHOR]

Background In plants, the growth of an aerial organ to its characteristic size relies on the coordination of cell proliferation and expansion. These two different processes occur successively during organ development, with a period of overlap. However, the mechanism underlying the cooperative and coordinative regulation of cell proliferation and expansion during organ growth remains poorly understood. Results This study characterized a new Arabidopsis ORGAN SIZE RELATED (OSR) gene, OSR2, which participates in the regulation of cell expansion process during organ growth. OSR2 was expressed primarily in tissues or organs undergoing growth by cell expansion, and the ectopic expression of OSR2 resulted in enlarged organs, primarily through enhancement of cell expansion. We further show that OSR2 functions redundantly with ARGOS-LIKE (ARL), another OSR gene that regulates cell expansion in organ growth. Moreover, morphological and cytological analysis of triple and quadruple osr mutants verified that the four OSR members differentially but cooperatively participate in the regulation of cell proliferation and cell expansion and thus the final organ size. Conclusions Our results reveal that OSR2 is functional in the regulation of cell expansion during organ growth, which further implicates the involvement of OSR members in the regulation of both cell proliferation and expansion and thus the final organ size. These findings, together with our previous studies, strongly suggest that OSR-mediated organ growth may represent an evolutionary mechanism for the cooperative regulation of cell proliferation and expansion during plant organogenesis. [ABSTRACT FROM AUTHOR]

The proportion of sexually receptive males in relation to females (operational sex ratio, OSR) is often invoked as an important determinant of the potential for sexual selection. Although the opportunity for sexual selection metric (I s) is frequently used to estimate such potential, recent doubts have been cast about its capacity to disentangle the relative effect of sexual competition from that of random matings with increasing bias in OSR. To address this, we performed a meta-analysis to evaluate whether the potential for sexual selection in males increases as OSR becomes more male biased and to estimate the relative effects of random matings and sexual competition on this relationship. We performed the analyses using two data sets (one with I s values and one with I dif values, which estimate how far mate monopolization deviates from the minimum possible for each population). We found that the relationship between OSR and I s varied from positive to neutral, while I dif was unrelated to OSR variation. This indicates that variation in reproductive success among individuals due to random matings or sexual competition is not influenced by OSR. However, when the correlation between OSR and I s was positive, random matings appeared to be important in I s estimations. Perhaps the responses of males and females differ from species to species as OSR becomes more male biased, disrupting the relationship between OSR and I s when species are pooled. [ABSTRACT FROM AUTHOR]

Embryonic development of the respiratory system is regulated by a series of mesenchymal-epithelial interactions that are only partially understood. Mesenchymal FGF and Wnt2/Wnt2b signaling are implicated in specification of mammalian pulmonary progenitors from the ventral foregut endoderm, but their epistatic relationship and downstream targets are largely unknown. In addition, how wnt2 and wnt2b are regulated in the developing foregut mesenchyme is unknown. We show that the Odd-skippedrelated (Osr) zinc-finger transcriptional repressors Osr1 and Osr2 are redundantly required for Xenopus lung specification in a molecular pathway linking foregut pattering by FGFs to Wnt-mediated lung specification and RA-regulated lung bud growth. FGF and RA signals are required for robust osr1 and osr2 expression in the foregut endoderm and surrounding lateral plate mesoderm (lpm) prior to respiratory specification. Depletion of both Osr1 and Osr2 (Osr1/Osr2) results in agenesis of the lungs, trachea and esophagus. The foregut lpm of Osr1/Osr2-depleted embryos fails to express wnt2, wnt2b and raldh2, and consequently Nkx2.1+ progenitors are not specified. Our data suggest that Osr1/Osr2 normally repress bmp4 expression in the lpm, and that BMP signaling negatively regulates the wnt2b domain. These results significantly advance our understanding of early lung development and may impact strategies to differentiate respiratory tissue from stem cells. [ABSTRACT FROM AUTHOR]

A biased operational sex ratio (OSR) can have multiple, confounding effects on reproductive fitness. A biased OSR can increase harassment and mating activity directed towards potential mates but may also increase the ability of potential mates to choose a good partner if lower quality mates are screened out through competitive interactions. Additionally, a biased OSR may affect reproductive fitness through changes in male ejaculate content or in female reproductive response. We quantified how a male-biased OSR (1:1, 2:1, or 5:1 male to female) affected the size of a female's first egg clutch and her offspring's survivorship in the housefly, Musca domestica. A male-biased OSR increased female fitness: females laid more eggs in their first clutch, had increased offspring survivorship at a 2:1 versus 1:1 OSR, and had equivalent fitness with a 5:1 male to female OSR. Courtship activity increased when the OSR was male-biased but was not a significant predictor of female fitness. Trials where females chose their mates versus trials where a random male was chosen for them had equivalent first clutch sizes and offspring survivorship. These results suggest that there are cryptic effects from a male-biased OSR on female fitness that are most likely driven by pre-copulatory social environment. [ABSTRACT FROM AUTHOR]

Abstract: Fluctuating selection has often been proposed as an explanation for the maintenance of genetic variation in personality. Here I argue that the temporal dynamics of the sex ratio can be a powerful source of fluctuating selection on personality traits, and develop this hypothesis with respect to humans. First, I review evidence that sex ratios modulate a wide range of social processes related to mating and parenting. Since most personality traits affect mating and parenting behavior, changes in the sex ratio can be expected to result in variable selection on personality. I then show that the temporal dynamics of the sex ratio are intrinsically characterized by fluctuations at various timescales. Finally, I address a number of evolutionary genetic challenges to the hypothesis. I conclude that the sex ratio hypothesis is a plausible explanation of genetic variation in human personality, and may be fruitfully applied to other species as well. [Copyright &y& Elsevier]

Most studies of intrasexual mating competition have focused only on males, and have typically shown an increase in aggression and a decrease in courtship rate with increasing operational sex ratio (OSR), the ratio of ready-to-mate males to females. We manipulated the number of males (1, 2 or 4) and females (2, 4, 8 or 16) in a factorial design to investigate mating competition and courtship rate in Japanese medaka, a species with conventional sex roles, over a broad range of OSRs (0.0625 to 2), and in relation to the density of both sexes. As predicted, the rates of intrasexual interactions by both males and females increased with the number of competitors and decreased with the number of potential mates, whereas the rates of courtship decreased with the number of competitors and increased with the number of mates. At OSRs between 0.35 and 2, males engaged in more intrasexual interactions and courtship behaviour than females. However, females became the more competitive sex at OSRs less than 0.35, and engaged in more courtship than males at OSRs greater than 2, rather than at an OSR of 1, as predicted by conventional mating system theory. Our results indicate that OSR can predict the considerable within-sex variability in reproductive behaviour of both males and females, regardless of which sex is more competitive. [Copyright &y& Elsevier]

Females that invest adaptively in their offspring are predicted to channel more resources to the sex that will be at an advantage in the prevailing environmental conditions. Here, we report, for the first time, that female Trinidadian guppy, Poecilia reticulata, respond in reproductively distinct ways when faced with differences in operational sex ratio. We show that females assigned to a female-biased sex ratio produce larger male offspring than females in an environment in which males predominate. Given the link between size at birth and fitness, and the marked reproductive skew in this species, larger male offspring are expected to have reproductive advantages in guppy populations with an excess of females. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 414–419. [ABSTRACT FROM AUTHOR]

Calcium was added to CeZrO4 mixed oxide by wet impregnation with a Ca nitrate solution to achieve solids with nominal Ca/(Ce+Zr) atomic ratios of 0.01, 0.02, 0.05, 0.1, 0.2, and 0.5. The solids were calcined at 873 K to decompose the Ca nitrate to CaO. The determination of oxygen storage capacity complete (OSCC) and FTIR studies of the formation of surface superoxide radicals (O− 2) were conducted to study the oxygen storage and release (OSR) properties of the solids. Both measurements indicate that the OSR properties clearly deteriorated for samples with nominal Ca/(Ce+Zr) at. ratios >0.01 (0.9 atoms of Ca nm−2). The degree of deactivation increased with increasing Ca loading; for the sample with the largest Ca loading, the OSCC was ca. 3-fold lower than that of bare CeZrO4. The solids also were characterized by TGA, chemical analysis by TXRF, XRD, N2 isotherms, and XPS. The results indicate that the Ca remained on the surface of the CeZrO4 as supported CaO; the formation of large bulky crystals of CeZrCa mixed oxides by solid-state reaction between the Ca phase and the CeZrO4 did not occur. For Ca loading below the amount required to completely cover the surface (which, experimentally, is ca. 18 atoms of Ca per nm2 of surface), CaO existed as very well-dispersed CaO domains few atoms thick. Above this value, the surface was completely covered by CaO, and three-dimensional crystals of CaO were formed. Given these results, we propose that the main mechanism for the deterioration of OSR properties of CeZrO4 by incorporation of CaO on the surface by impregnation is fouling: CaO physically prevents contact between the O2 gas and the surface sites of the CeZrO4. It also is likely that a very limited solid-state reaction occurs between the latter two phases, with a CaZrO3-like amorphous oxide formed at the grain boundaries. The formation of this amorphous oxide also can chemically contribute to the deactivation. The relevance of these results in the understanding of the deactivation of TWC by Ca is discussed. [Copyright &y& Elsevier]

A significant decline was found in the quantity of eggs that polygynous male beaugregory damselfish Stegastes leucosticus received after reducing the number of available females, which indicated that a significant number of females was removed from the experimental community. The operational sex ratio (OSR) hypothesis, which presumes that a sex becomes increasingly more selective as the number of alternative mates increases, was not supported as the variance in male mating success was unchanged after the females were removed. The relative mating success among males was also unchanged. That is, male ranks remained relatively the same (pre-test and post-test) after the removal of females. The large variance in male mating success within this species may be a function of polymorphic mate preferences exhibited by females that may be based on male location. [Copyright &y& Elsevier]

ΣΔ ADCs show promising perspectives in the field of compressive sensing (CS). A major limitation related to the first‐order ΣΔ is its high oversampling ratio (OSR) that is required for a specific bit resolution. An extension to the high‐order incremental ΣΔ for the implementation of a dedicated image sensor is presented. By extending the concept of the ΣΔ CS ADC, optimal working points can be reached between the OSR and the compression ratio. Simulations of a particular fourth‐order ADC combined with the authors column‐based Bernoulli CS scheme show a severe relaxation on the ADC master clock. [ABSTRACT FROM AUTHOR]