36 research outputs found
Reproductive output, foraging destinations, and isotopic niche of olive ridley and loggerhead sea turtles, and their hybrids, in Brazil
Hybridization is a fundamental evolutionary and ecological process with significant conservation ramifications. Sea turtle hybridization occurs at unusually high frequencies along the northeastern coast of Brazil. To better understand the process, we studied the reproductive output, migration patterns (through satellite telemetry), and isotopic niches of loggerhead turtles Caretta caretta and olive ridley turtles Lepidochelys olivacea and their hybrids. We classified 154 nesting females as loggerhead (n = 91), olive ridley (n = 38), or hybrid (n = 25) based on mitochondrial and nuclear DNA. Further, we compared nesting female morphological data and reproductive parameters (clutch size, emergence success, hatchling production, incubation period) of 405 nests among hybrids and parental species. We found no significant differences among the 3 groups when hatchling production was corrected for female body size, indicating that hybrids and parental species produce similar numbers of hatchlings per clutch. Satellite tracking of 8 post-nesting hybrid females revealed shared foraging grounds with both parental species, as well as neritic migrations between foraging and nesting areas similar to those previously reported for loggerheads and olive ridleys. Analyses of 13C and 15N isotope values (n = 69) further confirmed this pattern, as hybrid isotopic niches overlapped extensively with both parental species. Thus, given the similarities presented between hybrids and their parental species in reproductive, ecological, and behavioral characteristics, we conclude that these hybrids may persist along with other sea turtle nesting populations in the area, with research and conservation implications. © The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited
The neural correlates of dreaming.
Consciousness never fades during waking. However, when awakened from sleep, we sometimes recall dreams and sometimes recall no experiences. Traditionally, dreaming has been identified with rapid eye-movement (REM) sleep, characterized by wake-like, globally 'activated', high-frequency electroencephalographic activity. However, dreaming also occurs in non-REM (NREM) sleep, characterized by prominent low-frequency activity. This challenges our understanding of the neural correlates of conscious experiences in sleep. Using high-density electroencephalography, we contrasted the presence and absence of dreaming in NREM and REM sleep. In both NREM and REM sleep, reports of dream experience were associated with local decreases in low-frequency activity in posterior cortical regions. High-frequency activity in these regions correlated with specific dream contents. Monitoring this posterior 'hot zone' in real time predicted whether an individual reported dreaming or the absence of dream experiences during NREM sleep, suggesting that it may constitute a core correlate of conscious experiences in sleep
Consensus Paper: Cerebellum and Social Cognition.
The traditional view on the cerebellum is that it controls motor behavior. Although recent work has revealed that the cerebellum supports also nonmotor functions such as cognition and affect, only during the last 5 years it has become evident that the cerebellum also plays an important social role. This role is evident in social cognition based on interpreting goal-directed actions through the movements of individuals (social "mirroring") which is very close to its original role in motor learning, as well as in social understanding of other individuals' mental state, such as their intentions, beliefs, past behaviors, future aspirations, and personality traits (social "mentalizing"). Most of this mentalizing role is supported by the posterior cerebellum (e.g., Crus I and II). The most dominant hypothesis is that the cerebellum assists in learning and understanding social action sequences, and so facilitates social cognition by supporting optimal predictions about imminent or future social interaction and cooperation. This consensus paper brings together experts from different fields to discuss recent efforts in understanding the role of the cerebellum in social cognition, and the understanding of social behaviors and mental states by others, its effect on clinical impairments such as cerebellar ataxia and autism spectrum disorder, and how the cerebellum can become a potential target for noninvasive brain stimulation as a therapeutic intervention. We report on the most recent empirical findings and techniques for understanding and manipulating cerebellar circuits in humans. Cerebellar circuitry appears now as a key structure to elucidate social interactions
EMT and stemness: flexible processes tuned by alternative splicing in development and cancer progression
Solitary extramedullary plasmacytoma of the thyroid gland associated with multinodular goiter: case report and review of the literature
Solitary extramedullary plasmacytoma (SEP) is a rare malignant neoplasm arising from plasma cells most commonly occurring in the nasal cavity, nasopharynx and larynx. Thyroid involvement is rare and less than 75 cases of SEP of the thyroid gland have been reported to date. A 74-year-old woman with an history of multinodular goiter presented with dysphonia and painful neck swelling, related to a rapidly growing nodule in the right thyroidlobe. Thyroid function tests showed subclinical hypothyroidism;no evidence of Hashimoto's disease was found. Ultrasound confirmed the presence of an isoechoic nodule, 35 mm in diameter, with a CDIII vascular pattern. FNAC showed a monotonous population of atypical cells, interpreted as suspicious for malignant neoplasia (Thyr. 4). The patient underwent total thyroidectomy. Histopathological examination showed a unencapsulatedneoplasm composed of atypical tumour cells characterized by abundant cytoplasm and eccentric nuclei. At immunohistochemistry, tumour cells revealed diffuse reactivity for CD138 and CD45RB and predominant staining for kappa chains. Pan-cytokeratins, TTF1, thyreoglobulin, calcitonin, CD20 and CD79a were negative. Clinically, a complete multiple myeloma workup was negative. On this basis, a definitive diagnosis of SEP was made. At 16 months follow-up, the patient showed good clinical conditions without evidence of multiple myeloma. In conclusion,SEP should be considered in the differential diagnosis of a rapidly enlarging thyroid nodule. Clinical correlation and immunocytochemistry are crucial in avoiding pitfalls. Surgery remains the best modality of treatment whenever the lesion is localized and easily removable
Reproductive output, foraging destinations, and isotopic niche of olive ridley and loggerhead sea turtles, and their hybrids, in Brazil
Hybridization is a fundamental evolutionary and ecological process with significant conservation ramifications. Sea turtle hybridization occurs at unusually high frequencies along the northeastern coast of Brazil. To better understand the process, we studied the reproductive output, migration patterns (through satellite telemetry), and isotopic niches of loggerhead turtles Caretta caretta and olive ridley turtles Lepidochelys olivacea and their hybrids. We classified 154 nesting females as loggerhead (n = 91), olive ridley (n = 38), or hybrid (n = 25) based on mitochondrial and nuclear DNA. Further, we compared nesting female morphological data and reproductive parameters (clutch size, emergence success, hatchling production, incubation period) of 405 nests among hybrids and parental species. We found no significant differences among the 3 groups when hatchling production was corrected for female body size, indicating that hybrids and parental species produce similar numbers of hatchlings per clutch. Satellite tracking of 8 post-nesting hybrid females revealed shared foraging grounds with both parental species, as well as neritic migrations between foraging and nesting areas similar to those previously reported for loggerheads and olive ridleys. Analyses of 13C and 15N isotope values (n = 69) further confirmed this pattern, as hybrid isotopic niches overlapped extensively with both parental species. Thus, given the similarities presented between hybrids and their parental species in reproductive, ecological, and behavioral characteristics, we conclude that these hybrids may persist along with other sea turtle nesting populations in the area, with research and conservation implications.</jats:p
The effects of inclusion levels of urea-treated potato pulp silage in concentrate and roughage sources on finishing performance and carcass quality in cull beef cows
Appropriate morphometrics for the first assessment of juvenile green turtle (Chelonia mydas) age and growth in the south-western Atlantic
Nesting ecology of Podocnemis expansa (Schweigger, 1812) and Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae) in the Javaés River, Brazil
Nest site has influence on incubation duration and hatching success of two Neotropical turtles, the Giant Amazon River Turtle (Podocnemis expansa) and Yellow-Spotted Side-Neck Turtle (Podocnemis unifilis - "Tracajá"). The 2000 and 2001 nesting seasons have been monitored at the Javaés River in Bananal Island, Brazil. Although they nest on the same beaches, there is a separation of the nesting areas of P unifilis and P. expansa nests on the upper parts of the beach. The incubation duration for P. expansa is influenced by the nesting period, the height of the nest from the river, the clutch size, and the grain size in the site of the nest. Nests of Podocnemis expansa placed in coarse sediments have shorter incubation duration than those placed in finer sediments. The hatching success in P. expansa is influenced by grain size, incubation duration, and nesting period. The grain size is negatively correlated with hatching success, indicating that the nests situated in finer-grained sand have better chances of successful egg hatching than those in coarser-grained sand. Nests of the end of the reproductive season have lower hatching success and incubation duration than those at the start of the season. For P. unifilis, the nesting period and nest depth influence the incubation duration; moreover, the river dynamics significantly affect the hatching success. The oscillation of the river level and the moment of initial increase, the height of the nest from the river level, and the nesting period are all decisive components for hatching success. The results of this research show the importance of protecting areas with great geological diversity, wherein the features of the environment can affect the microenvironment of nests, with consequences on incubation duration and hatching success
