34 research outputs found
Movement Patterns for a Critically Endangered Species, the Leatherback Turtle (Dermochelys coriacea), Linked to Foraging Success and Population Status
Foraging success for pelagic vertebrates may be revealed by horizontal and vertical movement patterns. We show markedly different patterns for leatherback turtles in the North Atlantic versus Eastern Pacific, which feed on gelatinous zooplankton that are only occasionally found in high densities. In the Atlantic, travel speed was characterized by two modes, indicative of high foraging success at low speeds (<15 km dâ1) and transit at high speeds (20â45 km dâ1). Only a single mode was evident in the Pacific, which occurred at speeds of 21 km dâ1 indicative of transit. The mean dive depth was more variable in relation to latitude but closer to the mean annual depth of the thermocline and nutricline for North Atlantic than Eastern Pacific turtles. The most parsimonious explanation for these findings is that Eastern Pacific turtles rarely achieve high foraging success. This is the first support for foraging behaviour differences between populations of this critically endangered species and suggests that longer periods searching for prey may be hindering population recovery in the Pacific while aiding population maintenance in the Atlantic
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Global profiling of alternative RNA splicing events provides insights into molecular differences between various types of hepatocellular carcinoma
Location Prediction Based on Transition Probability Matrices Constructing from Sequential Rules for Spatial-Temporal K-Anonymity Dataset
The CshA DEAD-box RNA helicase is important for quorum sensing control in Staphylococcus aureus
Performing MR-guided biopsies in clinical routine: factors that influence accuracy and procedure time
OBJECTIVE: To assess the accuracy, the duration and factors that influence the duration of MRI-guided liver or soft-tissue biopsies.
METHODS: Nineteen liver biopsies and 19 soft-tissue biopsies performed using 1.5T-MRI guidance were retrospectively analysed. Diagnostic performance and complications were assessed. Intervention time was subdivided into preparation period, puncture period and control period. Correlation between procedure time and target size, skin-to-target-distance, used sequences and interventionalists' experience were analysed.
RESULTS: Overall sensitivity, specificity and accuracy were 0.86, 1.0 and 0.92, respectively. Two minor complications occurred. Overall median procedure time was 103.5Â min. Liver biopsies lasted longer than soft-tissue biopsies (mean([soft-tissue]): 73.0Â min, mean([liver]): 134.1Â min, Pâ<â0.001). The most time consuming part was the preparation period in both, soft-tissue and liver biopsies corresponding to 59.6% and 47.4% of the total intervention time, respectively. Total procedure time in liver biopsies (Pâ=â0.027) and puncture period in liver and soft-tissue biopsies (P [liver])â=â0.048, P ([soft-tissue])â=â0.005) was significantly prolonged for longer skin-to-target-distances. Lower numbers of image acquisitions P ([liver])â=â0.0007, P ([soft-tissue])â=â0.0012) and interventionalists' experience reduces the procedure duration significantly (Pâ<â0.05), besides all false-negative results appeared during the first five biopsies of each individual radiologist. CONCLUSION: The interventionalists' experience, skin-to-target-distances and number of image acquisition influence the procedure time significantly.
KEY POINTS: âąAppropriate training and supervision is essential for inexperienced interventionalists. âąTwo perpendicular image orientations should confirm the correct biopsy needle position. âąCommunication between interventionalist and technician is essential for a fluent biopsy procedure. âąTo shorten intervention time appropriate previous imaging is essential
Tratamento da congestão pélvica associada a varizes dos membros inferiores: relato de uma pequena série de casos Treatment of pelvic congestion associated with varicose veins of the lower limbs: report of a small number of cases
A sĂndrome de congestĂŁo pĂ©lvica Ă© definida por critĂ©rios anatĂŽmicos, hemodinĂąmicos e clĂnicos, decorrentes da hipertensĂŁo e estase venocapilar no territĂłrio pĂ©lvico, podendo ser estendido aos membros inferiores. A presença de varizes dos membros inferiores pode estar ou nĂŁo relacionada ao refluxo do sistema safeno e, nos casos de ausĂȘncia do refluxo safeno, o refluxo pĂ©lvico apresenta-se como importante fator etiolĂłgico responsĂĄvel pelo aparecimento e recidiva da doença venosa nos membros inferiores. Os autores relatam uma pequena sĂ©rie de trĂȘs casos de pacientes jovens portadoras de sĂndrome de congestĂŁo pĂ©lvica associada Ă varizes dos membros inferiores tratadas por embolização pĂ©lvica e tratamento cirĂșrgico das varizes de membros inferiores, no mesmo tempo cirĂșrgico, com bons resultados iniciais e ausĂȘncia de complicaçÔes embĂłlicas.<br>The pelvic congestion syndrome is defined by anatomical criteria, hemodynamic and clinical result of hypertension and venocapillary stasis in the pelvic area and can be extended to the lower limbs. The presence of varicose veins of the lower limbs may or may not correlate reflux of the saphenous system and, in cases of absence of saphenous reflux, the reflux pelvic presents itself as an important etiological factor responsible for recurrence of venous disease in lower limbs. The authors report a small series of three cases of young patients suffering from pelvic congestion syndrome associated with varicose veins of the lower limbs treated by pelvic embolization and surgical treatment of varicose veins of the lower limbs during the surgical procedure with good initial results and no embolic complications