15 research outputs found
Modern interpretation of risk factors in breast cancer of women
Breast cancer is a major public health problem, being the most common cancer diagnosed in women and accounting for more than 1 in 10 new diagnoses of cancer each year. It is the most common neoplasm of women under the age of 40 and the second leading cause of cancer death in this age group, with more frequent detection of pathogenic mutations in breast cancer susceptibility genes. Women with BRCA1 and BRCA2 mutations are about 70% more likely to develop breast cancer. The incidence is rising in most countries and it is expected to have a growing trend in the next 20 years, despite the current efforts to prevent the disease. In order to improve the survival rate, it is necessary to make a diagnosis as early as possible and to initiate the appropriate therapeutic management as soon as possible. Therefore, in order to detect breast formations, mammography screening is very important, breast density being an important factor in predicting the risk of breast cancer. Thus, the presence of high breast density represents a 4-6 times higher risk of developing breast cancer compared to women with low breast density. Aging and menopause are also risk factors for breast cancer. Hormone replacement therapy for postmenopausal women has the benefit of relieving symptoms such as hot flashes, depression or sleep disturbances, but it increases the risk of developing breast cancer
Older males whistle better: Age and body size are encoded in the mating calls of a nest-building amphibian (Anura: Leptodactylidae)
Courtship acoustic displays in anuran amphibians are energetically costly and risky, but have a major role in mating success since they encode relevant information regarding the caller’s identity and status. Age and size are essential traits shaping fitness, reproductive success and life-history strategies, and thus are expected to also have a role in courtship displays. We tested this assumption in a species of nest-building frogs, Leptodactylus bufonius, in northern Argentina.We conducted the first detailed quantitative description of
the males’ mating calls and assessed the effects of biological traits (i.e., body size parameters and individual age) and local climate (i.e., air temperature and humidity) on the main acoustic features of these calls (i.e., call duration, intercall duration, dominant frequency, and dominant frequency modulation). The calls were short (mean SE, 0.163 0.004 s), whistle-like, single notes with harmonic structure. The dominant frequency (1381.7 16.2 Hz) decreased with arm length (2 = 4.7012, df = 1, p = 0.030). Call duration and dominant frequency were the most static parameters at intraindividual level, indicating their role in individual recognition. Temperature and humidity shaped the temporal acoustic parameters, and the dominant frequency. Our findings suggest that the acoustic features of the mating calls in amphibians could promote female mate choice in relation to both size and age and open up new questions for future research: are females more attracted to older males, and what are the specific costs and benefits? We suggest that mating calls may direct female preferences toward males of certain size and age classes, ultimately shaping the life-history strategies in a given population. Finally, we found discrepancies in the mating calls of L. bufonius recorded from Corrientes and those previously described from other populations, which suggests that multiple species may have been
recorded under the same name.This work was supported by Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina, through Postdoctoral fellowships to FM, by the Romanian Ministry of Research, Innovation and Digitization, CNCS –UEFISCDI, through project number: PN-III-P1-1.1-PD-2021-0260, within PNCDI III (FS), and by the SYNTHESYS Project ES-TAF6704, http://www.synthesys.info/, which was financed by European Community Research Infrastructure Action under the FP7 “Capacities” Program at the Museo Museo Nacional de Ciencias Naturales (CSIC) (FS and RM).Peer reviewe
A case of color aberration in a fire salamander (Salamandra salamandra) larva
Color aberrations in salamanders are caused by defective chromatophores or by disrupted synthesis of the pigments, and have been previously reported in Europe. In this paper we report the first case of leucism in a fire salamander larva from a cave-dwelling population in Romania. The leucistic larva was larger and heavier compared to the other larvae from the same breeding habitat
Breed fast, die young - Demography of a Neotropical fossorial frog
Information regarding age- and size-related parameters is of paramount importance both to understanding the life-history of populations, and for designing effective conservation strategies; however, such base-line data lacks for many species, especially for those inhabiting tropical habitats. Using skeletochronology, we provide the first detailed information regarding the demography of the Pacific horned frog, Ceratophrys stolzmanni, a vulnerable, fossorial amphibian, that lives in the Tumbesian dry-forests of Ecuador. The species shows an intense growth rate during the first activity season, both before and after metamorphosis. Sexual maturity is achieved by both sexes before the first year of life, after which growth rates abruptly decrease. Females are on average larger, but not older, than males, mean age being two years in both sexes. The rapid sexual maturation is associated with a short life-span, the observed maximum longevity being three years in males and four years in females. The short reproductive life-span, which offers few mating opportunities, might have important implications for the conservation of this species, that can be especially at risk in the case of prolonged droughts expected to affect its habitat
Data_Sheet_1_Older males whistle better: Age and body size are encoded in the mating calls of a nest-building amphibian (Anura: Leptodactylidae).XLSX
Courtship acoustic displays in anuran amphibians are energetically costly and risky, but have a major role in mating success since they encode relevant information regarding the caller’s identity and status. Age and size are essential traits shaping fitness, reproductive success and life-history strategies, and thus are expected to also have a role in courtship displays. We tested this assumption in a species of nest-building frogs, Leptodactylus bufonius, in northern Argentina. We conducted the first detailed quantitative description of the males’ mating calls and assessed the effects of biological traits (i.e., body size parameters and individual age) and local climate (i.e., air temperature and humidity) on the main acoustic features of these calls (i.e., call duration, inter-call duration, dominant frequency, and dominant frequency modulation). The calls were short (mean ± SE, 0.163 ± 0.004 s), whistle-like, single notes with harmonic structure. The dominant frequency (1381.7 ± 16.2 Hz) decreased with arm length (χ2 = 5.244, df = 1, p = 0.022) and had an upward modulation (456.4 ± 11.0 Hz) which increased with age (χ2 = 4.7012, df = 1, p = 0.030). Call duration and dominant frequency were the most static parameters at intra-individual level, indicating their role in individual recognition. Temperature and humidity shaped the temporal acoustic parameters, and the dominant frequency. Our findings suggest that the acoustic features of the mating calls in amphibians could promote female mate choice in relation to both size and age and open up new questions for future research: are females more attracted to older males, and what are the specific costs and benefits? We suggest that mating calls may direct female preferences toward males of certain size and age classes, ultimately shaping the life-history strategies in a given population. Finally, we found discrepancies in the mating calls of L. bufonius recorded from Corrientes and those previously described from other populations, which suggests that multiple species may have been recorded under the same name.</p
Presentation_1_Older males whistle better: Age and body size are encoded in the mating calls of a nest-building amphibian (Anura: Leptodactylidae).PDF
Courtship acoustic displays in anuran amphibians are energetically costly and risky, but have a major role in mating success since they encode relevant information regarding the caller’s identity and status. Age and size are essential traits shaping fitness, reproductive success and life-history strategies, and thus are expected to also have a role in courtship displays. We tested this assumption in a species of nest-building frogs, Leptodactylus bufonius, in northern Argentina. We conducted the first detailed quantitative description of the males’ mating calls and assessed the effects of biological traits (i.e., body size parameters and individual age) and local climate (i.e., air temperature and humidity) on the main acoustic features of these calls (i.e., call duration, inter-call duration, dominant frequency, and dominant frequency modulation). The calls were short (mean ± SE, 0.163 ± 0.004 s), whistle-like, single notes with harmonic structure. The dominant frequency (1381.7 ± 16.2 Hz) decreased with arm length (χ2 = 5.244, df = 1, p = 0.022) and had an upward modulation (456.4 ± 11.0 Hz) which increased with age (χ2 = 4.7012, df = 1, p = 0.030). Call duration and dominant frequency were the most static parameters at intra-individual level, indicating their role in individual recognition. Temperature and humidity shaped the temporal acoustic parameters, and the dominant frequency. Our findings suggest that the acoustic features of the mating calls in amphibians could promote female mate choice in relation to both size and age and open up new questions for future research: are females more attracted to older males, and what are the specific costs and benefits? We suggest that mating calls may direct female preferences toward males of certain size and age classes, ultimately shaping the life-history strategies in a given population. Finally, we found discrepancies in the mating calls of L. bufonius recorded from Corrientes and those previously described from other populations, which suggests that multiple species may have been recorded under the same name.</p
Food level and light conditions affect the antipredator behavior in larvae of a stream-breeding amphibian
Understanding how long-term changes in environmental conditions influence the way that individuals cope with threats is essential in the context of behavioral adaptation to a rapidly changing world. However, little is known about the behavioral responses to predation risk for individuals that experienced different environmental conditions for extended periods of time, such as food levels and light conditions. In this experimental study, we tested whether previous long-term exposure to different food levels (low versus high) and light conditions (0-hour light versus 8-hour light) play a significant role in shaping the antipredator response (i.e., the probability of emerging from the refuge and the distance moved) to stimuli from caged larval dragonflies, in larvae of the fire salamander (Salamandra salamandra). Specifically, we quantified behavioral differences in the response to predation risk in larval salamanders that were reared in the laboratory for two months under controlled food and light conditions. The results of this study showed that the interaction between food level and light conditions affected the antipredator behavior of the larvae. Fire salamander larvae maintained at low food levels and in 8-hour light conditions emerged from the refuge with a higher probability (i.e., took more risk) than larvae maintained at high food levels and all other combinations of light conditions. Thus, our results highlight the complexity of antipredator responses, pointing attention to the fact that interactions among environmental factors are likely to determine the magnitude of antipredator response
Food level and light conditions affect the antipredator behavior in larvae of a stream-breeding amphibian
Understanding how long-term changes in environmental conditions influence the way that individuals cope with threats is essential in the context of behavioral adaptation to a rapidly changing world. However, little is known about the behavioral responses to predation risk for individuals that experienced different environmental conditions for extended periods of time, such as food levels and light conditions. In this experimental study, we tested whether previous long-term exposure to different food levels (low versus high) and light conditions (0-h light versus 8-h light) plays a significant role in shaping the antipredator response (i.e., the probability of emerging from the refuge and the distance moved) to stimuli from caged larval dragonflies, in larvae of the fire salamander (Salamandra salamandra). Specifically, we quantified behavioral differences in the response to predation risk in larval salamanders that were reared in the laboratory for 2 months under controlled food and light conditions. The results of this study showed that the interaction between food level and light conditions affected the antipredator behavior of the larvae. Fire salamander larvae maintained at low food levels and in 8-h light conditions emerged from the refuge with a higher probability (i.e., took more risk) than larvae maintained at high food levels and all other combinations of light conditions. Thus, our results highlight the complexity of antipredator responses, pointing attention to the fact that interactions among environmental factors are likely to determine the magnitude of antipredator response
Diversity and distribution of amphibians in Romania
Nineteen species of amphibians inhabit Romania, 9 of which reach their range limit on this territory. Based on published occurrence reports, museum collections and our own data we compiled a national database of amphibian occurrences. We georeferenced 26779 amphibian species occurrences, and performed an analysis of their spatial patterns, checking for hotspots and patterns of species richness. The results of spatial statistic analyses supported the idea of a biased sampling for Romania, with clear hotspots of increased sampling efforts. The sampling effort is biased towards species with high detectability, protected areas, and large cities. Future sampling efforts should be focused mostly on species with a high rarity score in order to accurately map their range. Our results are an important step in achieving the long-term goals of increasing the efficiency of conservation efforts and evaluating the species range shifts under climate change scenarios