Diving behaviour of the critically endangered tope shark Galeorhinus galeus in the Natural Reserve of Bahia San Blas, northern Patagonia

Background:Tope sharks (Galeorhinus galeus) aggregate in large numbers during spring and summer in closedgulfs and bays in northern Patagonia; these locations are considered the main nursery areas for the species.However, little is known about the spatial ecology or diel behaviour of this critically endangered species. The aimwas to evaluate the short-term diving behaviour and habitat preferences of tope sharks using electronic tagging.Findings:Five female tope sharks, four adult and one sub-adult, were tagged with pop-up satellite archival tags inthe Natural Reserve of Bahía San Blas, northern Patagonia, during spring 2011 and 2012. High-resolution archiveddata were collected for 40 days, including 29 days for two recovered tags. Sharks travelled up to 51.2 km after release.Archived data indicated that female tope sharks preferred to remain within 24.5 m of the surface and that there wereno diel changes in preference. Individuals spent most of the time within 10 m of the surface during the day (80%) andat night (83%), and were primarily in water between 17°C and 19°C (day, 75%; night, 70%). Moreover, tope sharksexhibited vertical oscillatory movement (‘yo-yo diving’). Maximum vertical speeds and dive depths were recordedat night. Ascents from depth had a greater speed than descents, overall.Conclusions:Female tope sharks were found in shallow coastal areas during November at Bahía San Blas, near thesurface at relatively restricted depths and temperatures. Longer tracking periods will be important for describingthe species’migratory movements across the south-west Atlantic.Fil: Cuevas, Juan Martín. Universidad Nacional de la Matanza. Instituto de Medio Ambiente; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; ArgentinaFil: Garcia, Mirta Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Di Giacomo, Edgardo Ernesto. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentin

The Risks We Dread: A Social Circle Account

What makes some risks dreadful? We propose that people are particularly sensitive to threats that could kill the number of people that is similar to the size of a typical human social circle. Although there is some variability in reported sizes of social circles, active contact rarely seems to be maintained with more than about 100 people. The loss of this immediate social group may have had survival consequences in the past and still causes great distress to people today. Therefore we hypothesize that risks that threaten a much larger number of people (e.g., 1000) will not be dreaded more than those that threaten to kill “only” the number of people typical for social circles. We found support for this hypothesis in 9 experiments using different risk scenarios, measurements of fear, and samples from different countries. Fear of risks killing 100 people was higher than fear of risks killing 10 people, but there was no difference in fear of risks killing 100 or 1000 people (Experiments 1–4, 7–9). Also in support of the hypothesis, the median number of deaths that would cause maximum level of fear was 100 (Experiments 5 and 6). These results are not a consequence of lack of differentiation between the numbers 100 and 1000 (Experiments 7 and 8), and are different from the phenomenon of “psychophysical numbing” that occurs in the context of altruistic behavior towards members of other communities rather than in the context of threat to one's own community (Experiment 9). We discuss several possible explanations of these findings. Our results stress the importance of considering social environments when studying people's understanding of and reactions to risks

New record of the critically endangered striped smooth-hound, mustelus fasciatus (Garman, 1913) (chondrichthyes, triakidae), in the southwest Atlantic

We report the southernmost known occurrence in the Atlantic Ocean of the striped smooth-hound, Mustelus fasciatus (Garman, 1913). The shark, a female measuring 106 cm TL, was fished in warm coastal waters, with a salinity of 33,189 PSU, of central Argentina (40°52ʹ13ʺ S, 062°18ʹ42ʺ W). This report increases by 205 km southward the known range of this endemic and Critically Endangered species.Fil: Cuevas, Juan Martín. Wildlife Conservation Society; Estados Unidos. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Gómez, Sebastián Eduardo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Garcia, Mirta Lidia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Deletions in the N-terminal segment of the plasma membrane Ca2+ pump impair the expression of a correctly folded functional enzyme

Mutant cDNAs encoding h4 plasma membrane Ca2+ pumps with deletions in the N-terminal segment have been constructed and expressed in COS cells. As judged by immunoblotting, each construct was expressed at a high level similar to that of the wild-type enzyme. The removal of the first six amino acids had no effect on the Ca2+ transport activity, but deletions in the segment 15-75 reduced the activity to undetectable levels. The d(43-56)h4 mutant, lacking amino acids 43-56, was also efficiently expressed in stable form in CHO cells. The Ca2+ transport activity of d(43-56)h4 in this system was about 40% of that of the wild type. The d(43-56)h4 enzyme exhibited a similar affinity for Ca2+, a slightly increased apparent affinity for ATP, and a slightly lower sensitivity to inhibition by vanadate than the wild-type enzyme. Analysis of the phosphoenzyme intermediate formed in the presence of lanthanum showed that the phosphorylation reaction was not affected, but the maximum amount of phosphoenzyme was reduced to the same extent as the Ca2+ transport activity. These results suggest that the expressed d(43-56)h4 was a mixture of fully active and inactive enzyme. The d(43-56)h4 enzyme was more easily degraded by proteases and had a higher sensitivity to heat inactivation than the wild type suggesting that the loss of function was due to the improper folding and instability, of the mutant protein. On the basis of these findings, it appears that the N-terminal segment of the plasma membrane Ca2+ pump is neither essential for synthesis nor for catalytic activity but is critical for the expression of a correctly folded functional enzyme.Fil: Adamo, Hugo Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Grimaldi, Mirta E.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Garcia Arguinzonis, Maisa I.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Student Perception of the Integrated PBL MBCHB-III Program Curriculum in a Medical University

Introduction: Integrated PBL is now an accepted method of teaching the medical curriculum. The objective of this study was to determine MBChB-III students’ perceptions about some key aspects related to our integrated PBL curriculum.Methods: This was an anonymous, questionnaire based, descriptive study, involving the Walter Sisulu University MBChB year 3 students as participants. The short questionnaire focused on key student perception areas related to integrated PBL curriculumResults: More than half of the students felt that the curriculum enhanced analytical skills, and was reasoning and learning centered. 29.5% of the students felt that the desired goals and objectives were not clear enough. About 90% felt that they felt they could recognize discipline interrelations. While 61.7% of students felt that the curriculum facilitated active learning opportunities, more than 70% felt that it increased the workload and stress levels. About half of the students expressed overall satisfaction with the level of content integration.Conclusion: Students generally presented favorable perceptions of the integrated MBChB-III PBL curriculum.  There were concerns about the associated heavy workload and stress. Student counseling with respect to time and stress management coupled with improvements in curriculum design would be helpful in addressing the issue

Reproductive biology of the spotback skate Atlantoraja castelnaui in the south-west Atlantic Ocean

This study provides information on the reproduction of spotback skate Atlantoraja castelnaui. A total of 232 individuals (119 females and 113 males) were obtained from surveys carried out between 2003 and 2006, from the south-west Atlantic Ocean, between 34 and 42° S and <50 m deep; another 514 specimens (241 females and 273 males) were obtained between 2005 and 2007 from commercial fishery operations carried out in the same area and landings in the port of Mar del Plata, Argentina. Males ranged from 185 to 1250 mm total length (L T) and females from 243 to 1368 mm L T. Length at maturity was estimated to be 980 mm for males and 1089 mm L T for females. Lack of variation of testis mass together with the continuous production of mature spermatocyst and spermatozoa in deferent ducts suggested that males can reproduce throughout the year. Females reproduced year-round with peaks of reproductive activity an integral part of a continuous cycle. This conclusion is corroborated by the seasonal variation of ovaries, oviducal gland and the occurrence of females with eggs in the uterus throughout the year. Results from this study indicate that A. castelnaui is very susceptible to fishery pressure.Fil: Colonello, J. C.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Garcia, Mirta Lidia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Lasta, C.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Menni, Roberto Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Palynostratigraphy of the Tithonian-Hauterivian interval, West-Central Neuquén Basin, Argentina

Se presenta una palinozonación preliminar para el intervalo Tithoniano-Hauteriviano en el cen- tro-oeste de la Cuenca Neuquina. Teniendo en cuenta las apariciones masivas de taxones continenta- les y marinos y la presencia de palinomorfos con valor cronológico se reconocieron para el Tithoniano tardío-?Berriasiano temprano las zonas de Dichadogonyaulax culmula y Aptea notialis y la Zona de Microcachryidites antarcticus. La Zona 1 (Berriasiano tardío-?Valanginiano temprano), correlacionable con la Zona de Callialasporites-Contignisporites-Staplinisporites de Patagonia Austral, está caracterizada por la abundancia de Callialasporites y ausencia de Cyclusphaera. Se reconoció la Zona de Cyclusphaera psilata-Classopollis asociada a especies de microplancton, como C elyphus rallus , Leiosphaeridia y Leiofusa , para el Valanginiano tardío (Zona 2). Se da una evalua- ción paleoambiental para el intervalo estratigráfico en estudio, considerando la relación de palino- morfos continentales versus marinos.A preliminary approach to a zonal definition for the Tithonian-Hauterivian interval of the West-Central Neuquén Basin is presented. The limits of the zone as well as the first and last appearance data of index species are located. There were recognized the Dichadogonyaulax culmula, Aptea notialis and Microcachryidites antarcticus zones for the Late Tithonian-?Early Berriasian. Due to the great abundance of Callialasporites and the absence of Cyclusphaera, Zone 1 (Late Berriasian-?Early Valanginian) is correlated with the Callialasporites-Contignisporites- Staplinisporites Zone of Patagonia Austral. It was recognized the Cyclusphaera psilata-Classopollis Zone associated with Celyphus rallus, Leiosphaeridia and Leiofusa among others for the Late Valanginian (Zone 2). Taking into account the terrestrial-marine relationships, paleoenvironmental conditions for the studied interval are discussed.Fil: Quattrocchio, Mirta Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur; ArgentinaFil: Martínez, Manuel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur; ArgentinaFil: Garcia, Victor Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur; ArgentinaFil: Zavala, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur; Argentin

Behavioral and morphological contrasts on the reproduction of two prolonged breeders of the genus Physalaemus (Anura: Leptodactylidae)

The reproduction is one of the main events in the life of an organism, and anurans stand out among vertebrates because of the diversity of their reproductive strategies. We studied the reproduction of two syntopic species, Physalaemus aff. albonotatus and P. santafecinus, and comparatively described their reproductive activity pattern, advertisement calls, calling sites, daily calling activity, amplexus behavior, foam nests, and microhabitats in foam nests. In regards to the reproductive activity pattern, both species were defined as prolonged breeders. However, P. santafecinus exhibited a behavior like explosive breeders: it had a faster reproductive response against rains than P. aff. albonotatus. The calling activity was restricted exclusively to night hours in P. santafecinus, whereas P. aff. albonotatus called during both night and day. The advertisement calls of both species showed a rich harmonic structure, and were characterized by a bimodal harmonic dominance. The species differed significantly in microhabitat calling sites, foam nests, and microhabitats in foam nests. Namely, P. santafecinus frequently called and constructed its nests in sites more exposed than those of P. aff. albonotatus. The general differences in reproductive behaviors observed between the species principally agree with their different reproductive activity patterns.Fil: Cajade, Rodrigo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Garcia, Mirta Lidia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ictiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Di Pietro, Diego Omar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Basso, Nestor Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentin

Cartografiar el conocimiento en la Universidad hoy. Una investigación de caso en la perspectiva compleja

te artículo asume procesos y resultados de una investigación sobre el conocimiento en la universidad desde la perspectiva compleja. Presenta el “caso” de una carrera universitaria. Se trabaja la trama teoría-práctica, a la luz de las evidencias provenientes de las fuentes de diferentes actores, tomando, a la universidad como institución auto-eco-organizativa en un transcurrir recursivo, dialógico, complementario y hologramático. El conocimiento que en ella se construye y valida es explicado/comprendido en procesos integradores en la disputa disciplina- multidisciplina- interdisciplina- transdisciplina. Desde lo teórico, se focaliza en perspectivas epistemológicas y educacionales complejas que aportan principios organizadores del pensar superadores de estilos anquilosados, disjuntos y simplificadores. Desde lo empírico, revela lo que piensan y accionan los actores de la comunidad educativa. Se da cuenta de  resultados entretejidos obtenidos a través de métodos, técnicas e instrumentos que responden a una investigación cualitativa -cuantitativa atravesados por la triangulació

Collective moderation of hate, toxicity, and extremity in online discussions

How can citizens moderate hate, toxicity, and extremism in online discourse? We analyze a large corpus of more than 130,000 discussions on German Twitter over the turbulent four years marked by the migrant crisis and political upheavals. With a help of human annotators, language models, machine learning classifiers, and longitudinal statistical analyses, we discern the dynamics of different dimensions of discourse. We find that expressing simple opinions, not necessarily supported by facts but also without insults, relates to the least hate, toxicity, and extremity of speech and speakers in subsequent discussions. Sarcasm also helps in achieving those outcomes, in particular in the presence of organized extreme groups. More constructive comments such as providing facts or exposing contradictions can backfire and attract more extremity. Mentioning either outgroups or ingroups is typically related to a deterioration of discourse in the long run. A pronounced emotional tone, either negative such as anger or fear, or positive such as enthusiasm and pride, also leads to worse outcomes. Going beyond one-shot analyses on smaller samples of discourse, our findings have implications for the successful management of online commons through collective civic moderation