The cane or marine toad, Rhinella marina (Anura, Bufonidae): two genetically and morphologically distinct species.

Rhinella marina is a Neotropical toad that has been introduced widely worldwide. Its toxic effects to frog-eating predators threaten the native and domestic fauna of some regions where it has been introduced. Despite previous studies suggesting two genetically distinct cryptic species within R. marina, one east and one west of the Andes, its taxonomic status remained unresolved due to the absence of morphological complementary evidence. For the first time, data from two mitochondrial genes (ND3 and CR) and 23 morphometric landmarks are combined to evaluate the taxonomic status of this species. Our results support the hypothesis of two separate evolutionary lineages within R. marina and demonstrate that these lineages have significantly diverged in skull shape. We identified two distinct morphotypes, one eastern and one Andean western, with no overlapping morphospaces. The geographic pattern of genetic variation was consistent with a stable structured population with no evidence of recent demographic or geographic expansions. The concordance between the observed geographic patterns in morphometric and genic traits calls for the recognition of two species under R. marina name.

Fishery of the Green Jack Caranx caballus (Osteichytes: Carangidae) in Las Perlas Archipelago, Pacific Panama.

Green Jacks, Caranx caballus, are distributed along the Eastern Pacific coast. In Panama, C. caballus was heavily fished around Las Perlas Archipelago to sustain local markets until 2007, when the archipelago was declared a marine protected area. This first study in Panama, analyzed a sample of 4 990 individuals from Las Perlas, obtained monthly from June 2005 to June 2006, from landings at the central fish market. Average total length was 36.1 +/- 6.4cm and optimum length 38.9cm. Approximately 68% of fish lengths were within +/-10% of the optimal length but only six (15%) were considered mega-spawners. The von Bertalanffy parameters describe a long-lived and fast growing species, while mortality rates revealed that C. caballus is under high fishing pressure. Standard length at which half of the population is mature was 38.8cm, and the size at which individuals matured massively, 33cm. Only 10-13% of the fish were immature. C. caballus reproduces two to three times per year, with peaks in December, April, and probably September, and recruits to the population at least twice per year. Catch per unit effort (CPUE) was best predicted by minimum annual values of the Multivariate ENSO/LNSO Index (MEI) (R2=0.54). Results show that C. caballus in Pacific Panama is overfished. We recommend the raising of the minimum capture/landing size of this species in order to increase the proportion of mega-spawners in the population and guarantee the sustainability of this resource.

Fishery of the Green Jack Caranx caballus (Osteichytes: Carangidae) in Las Perlas Archipelago, Pacific Panama

Green Jacks, Caranx caballus, are distributed along the Eastern Pacific coast. In Panama, C. caballus was heavily fished around Las Perlas Archipelago to sustain local markets until 2007, when the archipelago was declared a marine protected area. This first study in Panama, analyzed a sample of 4 990 individuals from Las Perlas, obtained monthly from June 2005 to June 2006, from landings at the central fish market. Average total length was 36.1±6.4cm and optimum length 38.9cm. Approximately 68% of fish lengths were within ±10% of the optimal length but only six (15%) were considered mega-spawners. The von Bertalanffy parameters describe a long-lived and fast growing species, while mortality rates revealed that C. caballus is under high fishing pressure. Standard length at which half of the population is mature was 38.8cm, and the size at which individuals matured massively, 33cm. Only 10-13% of the fish were immature. C. caballus reproduces two to three times per year, with peaks in December, April, and probably September, and recruits to the population at least twice per year. Catch per unit effort (CPUE) was best predicted by minimum annual values of the Multivariate ENSO/ LNSO Index (MEI) (R²=0.54). Results show that C. caballus in Pacific Panama is overfished. We recommend the raising of the minimum capture/landing size of this species in order to increase the proportion of megaspawners in the population and guarantee the sustainability of this resource.

El jurel verde o “cojinúa”, Caranx caballus, se distribuye a lo largo de la costa del Pacífico Oriental. En el Archipiélago de Las Perlas, Panamá, la cojinúa fue pescada sin control para sostener mercados locales hasta el 2007, fecha en la que esta región fue declarada área marina protegida. En este primer estudio para Panamá, se analizaron desde junio de 2005 a junio de 2006, 4 990 individuos en las descargas del Mercado Central de Mariscos provenientes de Las Perlas. La longitud media total de esta especie fue de 36.1±6.4cm y la longitud óptima, 38.9cm. Aproximadamente, 68% de los individuos muestreados poseen longitudes dentro de ±10% de la longitud óptima, pero sólo seis (15%) eran mega-reproductores. Los parámetros de la ecuación de von Bertalanffy describen la especie como de larga vida y de rápido crecimiento, mientras que las tasas de mortalidad indican que la cojinúa está bajo una alta presión de pesca. La longitud estándar a la que la mitad de la población es sexualmente madura es 38.8cm y el tamaño de maduración masiva, 33cm. Sólo entre el 10-13% de los individuos muestreados son inmaduros. La cojinúa se reproduce 2-3 veces al año, con picos en diciembre, abril y probablemente septiembre, y recluta a la población por lo menos dos veces al año. Los valores mínimos anuales del Índice ENSO/LNSO multivariado (MEI) son los mejores predictores de la CPUE de esta especie (R²=0.54). Nuestros resultados demuestran que la cojinúa en el Pacífico Panameño está sobreexplotada por lo que recomendamos elevar la talla mínima de captura para permitir que aumente la proporción de mega-reproductores en la población con el fin de garantizar la sostenibilidad del recurso.

Imagination and society: the role of visual sociology.

The paper presents the field of Visual Sociology as an approach that makes use of photographs, films, documentaries, videos, to capture and assess aspects of social life and social signals. It overviews some relevant works in the field, it deals with methodological and epistemological issues, by raising the question of the relation between the observer and the observed, and makes reference to some methods of analysis, such as those proposed by the Grounded Theory, and to some connected tools for automatic qualitative analysis, like NVivo. The relevance of visual sociology to the study of social signals lies in the fact that it can validly integrate the information, introducing a multi-modal approach in the analysis of social signals.

Attentional modulation of neuromagnetic evoked responses in early human visual cortex and parietal lobe following a rank-order rule.

Top-down voluntary attention modulates the amplitude of magnetic evoked fields in the human visual cortex. Whether such modulation is flexible enough to adapt to the demands of complex tasks in which abstract rules must be applied to select a target in the presence of distracters remains unclear. We recorded brain neuromagnetic activity using whole-head magnetoencephalography in 14 human subjects during a rule-guided target selection task, and applied event-related Synthetic Aperture Magnetometry to image instantaneous changes in neuromagnetic source activity throughout the brain. During the task subjects selected one of two stimuli (the target) and ignored the other (the distracter) based on a color-rank rule (color 1 > color 2 > color 3). Our results revealed that in early visual color-sensitive areas and the parietal cortex visual stimuli evoke activity that scaled following the rank-order rule. This effect was stronger and occurred later in the parietal lobe (~200 ms after target/distracter onset) relative to early visual areas (~180 ms). Moreover, we found that transient changes in the target's motion direction evoked stronger responses relative to similar changes in the distracter at ~180 ms from change onset in contralateral areas hMT+/V5. These results suggest that during target selection and allocation of attention to a stimulus, top-down signals adjust their intensity following complex selection rules according to the organism's priorities, thereby differentially modulating neuromagnetic activity across visual cortical areas.

Conflicting representations of pain: a qualitative analysis of health care professionals' discourse.

INTRODUCTION: Studies regarding health care professionals' representations of pain indicate that doctors and nurses tend to concentrate on the organic origin of pain, and to view pain as subordinate to diagnosis and treatment of the disease; they also tend to underestimate the psychological and psychosocial components of pain, which means that they generally view the patient's subjective experience as secondary. This leads to an underestimation of pain. OBJECTIVE: The objective of this study was to analyze the representations of pain held by doctors, head nurses, and nurses in two Italian hospitals, focusing on how these representations are shaped according to the local culture in which they are constructed and negotiated. METHODS: Our study is based on a socio-constructionist approach, drawing on semi-structured, in-depth interviews with 26 health care professionals. RESULTS: The results show similarities and differences in how health care professionals construct their representations of pain. Three main issues emerged. First, the contents of these representations are strictly related to participants' job position and professional training; second, the representation of pain is significantly influenced by the values and meanings associated with the different professions; and third, there are two conflicting representations of pain, focusing on the objectivity vs the subjectivity of pain, respectively. CONCLUSIONS: To promote significant change regarding pain management within hospital organizations, it is essential to construct shared representations of the problem and its implications, particularly as regards relations with the patient. This change should take place at the educational as well as the socio-organizational level, and it should take into account ideas and proposals from the subjects involved.

Chronology of mercury enrichment factors in reef corals from western Venezuela.

Mining and deforestation in the early 20th century, the development of petrochemical industries during the 1950s, and the constant weathering of natural deposits of cinabrium (HgS) have made Golfo Triste, Venezuela, a region impacted by mercury (Hg). We studied the chronology of Hg in coral skeletons of Siderastrea siderea (1 colony, 1900-1996) and Montastraea faveolata (2 colonies, 1930-1999) from Parque Nacional San Esteban. Maximum values of Hg/Ca ratios and standard deviations of Hg enrichment factors occurred in the 1940s, 1960s, and 1980s, and matched maxima of decadal rainfall. Values from the 1950s and 1970s matched periods of abundant but constantly decreasing rainfall and hence were best explained by the combination of runoff and the sudden bioavailability of Hg in the region. This sudden availability likely was associated with activities of the chlorine-caustic soda and fertilizer plants of Morón petrochemical complex, industries that started producing large amounts of Hg in 1958.

Historical decline in coral reef growth after the Panama Canal.

The Panama Canal is near its vessel size and tonnage handling capacity, and Panamanians have decided to expand it. The expansion of the Canal may consider the historical long-lasting impacts on marine coastal habitats particularly on sensitive coral reefs. These potential impacts were discussed during the national referendum as were other equally important issues, such as its effects on forests, watersheds, and water supply. Coral growth rates provide a direct measure of coral fitness and past environmental conditions comparable to analyses of tree rings. We examined stable isotopes, metal geochemical tracers, and growth rates on a century-long (1880-1989) chronology based on 77 cores of the dominant reef-building coral Siderastrea siderea collected near the Caribbean entrance to the canal. Our results showed a gradual decline in coral growth unrelated to changes in sea surface temperature but linked to runoff and sedimentation to coastal areas resulting from the construction and operation of the Panama Canal.

Can the RNA of the cowpea chlorotic mottle virus be released through a channel by means of free diffusion? A test in silico.

Cowpea chlorotic mottle virus (CCMV), a plant virus which is member of the Bromoviridae family, is used as a model for the diffusion of a random, short, single stranded RNA, [5'-R(PGpGpApCpUpUpCpGpGpUpCpC)-3')], through a channel on the pseudo-three-fold axis using molecular dynamic simulations. This proposition is based the fact that CCMV undergoes a dynamic structural transition as a response to changes of pH, temperature and ionic strength. Results indicate that the RNA looses its secondary structure and moves into the capside channel by free diffusion. These results are congruent with the hypothesis suggesting that the CCMV capside does not have to dissolve in order to release the RNA into the host.

Dollo's law and the re-evolution of shell coiling.

Gastropods have lost the quintessential snail feature, the coiled shell, numerous times in evolution. In many cases these animals have developed a limpet morphology with a cap-shaped shell and a large foot. Limpets thrive in marginal habitats such as hydrothermal vents, the high-energy rocky intertidal areas and fresh water, but they are considered to be evolutionary dead-ends, unable to re-evolve a coiled shell and therefore unable to give rise to the diversity seen among coiled snails. The re-evolution of a coiled shell, or any complex character, is considered unlikely or impossible (Dollo's law) because the loss of the character is followed by the loss of the genetic architecture and developmental mechanisms that underlie that character. Here, we quantify the level of coiling in calyptraeids, a family of mostly uncoiled limpets, and show that coiled shells have re-evolved at least once within this family. These results are the first demonstration, to our knowledge, of the re-evolution of coiling in a gastropod, and show that the developmental features underlying coiling have not been lost during 20-100 Myr of uncoiled evolutionary history. This is the first example of the re-evolution of a complex character via a change in developmental timing (heterochrony) rather than a change in location of gene expression (heterotopy).