55 research outputs found
Plane-Wave Diffraction from Resistive-Filled Circular Hole in Infinite Resistive Plane: An Analytically Regularizing Approach
Moving Toward a Strategy for Addressing Climate Displacement of Marine Resources: A Proof-of-Concept
Realistic predictions of climate change effects on natural resources are central to adaptation policies that try to reduce these impacts. However, most current forecasting approaches do not incorporate species-specific, process-based biological information, which limits their ability to inform actionable strategies. Mechanistic approaches, incorporating quantitative information on functional traits, can potentially predict species- and population-specific responses that result from the cumulative impacts of small-scale processes acting at the organismal level, and can be used to infer population-level dynamics and inform natural resources management. Here we present a proof-of-concept study using the European anchovy as a model species that shows how a trait-based, mechanistic species distribution model can be used to explore the vulnerability of marine species to environmental changes, producing quantitative outputs useful for informing fisheries management. We crossed scenarios of temperature and food to generate quantitative maps of selected mechanistic model outcomes (e.g., Maximum Length and Total Reproductive Output). These results highlight changing patterns of source and sink spawning areas as well as the incidence of reproductive failure. This study demonstrates that model predictions based on functional traits can reduce the degree of uncertainty when forecasting future trends of fish stocks. However, to be effective they must be based on high spatial- and temporal resolution environmental data. Such a sensitive and spatially explicit predictive approach may be used to inform more effective adaptive management strategies of resources in novel climatic conditions
Substrate Micropatterning as a New in Vitro Cell Culture System to Study Myelination
Artículo de publicación ISIMyelination is a highly regulated developmental
process whereby oligodendrocytes in the central nervous system
and Schwann cells in the peripheral nervous system ensheathe axons
with a multilayered concentric membrane. Axonal myelination
increases the velocity of nerve impulse propagation. In this work,
we present a novel in vitro system for coculturing primary dorsal root
ganglia neurons along with myelinating cells on a highly restrictive
and micropatterned substrate. In this new coculture system, neurons
survive for several weeks, extending long axons on defined Matrigel
tracks. On these axons, myelinating cells can achieve robust myelination, as demonstrated by the distribution of compact myelin
and nodal markers. Under these conditions, neurites and associated myelinating cells are easily accessible for studies on the
mechanisms of myelin formation and on the effects of axonal damage on the myelin sheath.Regenerative Medicine and Nanomedicine Initiative of the Canadian Institutes of Health Research (CIHR)
RMF-7028
FONDECYT
1080252
CIHR
Ministry of Industry of Canada
Rio Tinto Alcan
Molson Foundatio
Rapid and Long-Lasting Increase in Sites for Synapse Assembly during Late-Phase Potentiation in Rat Hippocampal Neurons
Long-term potentiation in hippocampal neurons has stages that correspond to the stages of learning and memory. Early-phase (10–30 min) potentiation is accompanied by rapid increases in clusters or puncta of presynaptic and postsynaptic proteins, which depend on actin polymerization but not on protein synthesis. We have now examined changes in pre- and postsynaptic puncta and structures during glutamate-induced late-phase (3 hr) potentiation in cultured hippocampal neurons. We find that (1) the potentiation is accompanied by long-lasting maintenance of the increases in puncta, which depends on protein synthesis, (2) most of the puncta and synaptic structures are very dynamic, continually assembling and disassembling at sites that are more stable than the puncta or structures themselves, (3) the increase in presynaptic puncta appears to be due to both rapid and more gradual increases in the number of sites where the puncta may form, and also to the stabilization of existing puncta, (4) under control conditions, puncta of postsynaptic proteins behave similarly to puncta of presynaptic proteins and share sites with them, and (5) the increase in presynaptic puncta is accompanied by a similar increase in presumably presynaptic structures, which may form at distinct as well as shared sites. The new sites could contribute to the transition between the early and late phase mechanisms of plasticity by serving as seeds for the formation and maintenance of new synapses, thus acting as local “tags” for protein synthesis-dependent synaptic growth during late-phase plasticity
L’isterectomia peripartum: la nostra esperienza
Obiettivo: determinare l'incidenza, l'indicazione e l'associazione con il parto cesareo dell'isterectomia peripartum (I.P.), la morbilità e la mortalità materna e neonatale. Materiale e metodo: sono stati esaminati tutti i casi di isterectomia peripartum osservati presso l’U.O. di Ostetricia e Ginecologia dell'A.O.S. S. Antonio Abate di Trapani dall’1/01/2001 al 31/05/2006. Risultati: sono stati eseguiti 13 interventi di I.P. pari al 2,26‰ parti di cui 46,1% come isterectomia totale, e 53,9% come isterectomia
subtotale. Il 69,2% degli interventi praticati è stato eseguito in condizioni d'emergenza mentre il 30,8% è stato programmato. Le indicazioni sono state: placenta previa accreta (38,4%), placenta accreta n.i. (7,6%), metrorragia da distacco intempestivo di placenta, Hellp sindrome e CID (38,3%), atonia uterina resistente a terapia medica
(15,5%) e rottura d'utero (7,6%). Otto pazienti (61,6%) erano precesarizzate. In 12 pazienti (92,4%) l'intervento è stato eseguito durante o subito dopo parto cesareo. È stata osservata una morte materna per embolia polmonare mentre, per quanto riguarda la morbilità, il 38,4 % delle pazienti è stato trasferito in terapia intensiva, una paziente è stata sottoposta a 4 laparotomie successive. Non si è avuto
alcun caso di mortalità neonatale. Conclusioni: la placenta previa accreta è la più comune indicazione all'intervento di isterectomia peripartum; essa è proporzionalmente
associata con il numero di pregressi parti cesarei che predispongono la cavità uterina ad inserzioni più basse e profonde
La pre-induzione del travaglio di parto nella gravidanza > 41ª settimana. Impiego di una preparazione di dinoprostone a lento rilascio
Obiettivo:gli Autori hanno valutato la sicurezza e l’efficacia del dinoprostone a rilascio continuo e costante, 10 mg in 12 ore, nell’indurre il ripening cervix e/o l’inizio del travaglio. Materiali e metodi: lo studio è stato condotto su un gruppo di 78 gravide con epoca gestazionale > 41 settimane con o senza oligoidramnios suddivise in 2 gruppi in base all’indice di Bishop. Il I gruppo (indice di Bishop � 4) è costituito da 51 casi, pari al 65,3%, di cui 38 sono primigravide e 13 sono pluripare. Il II gruppo (indice di Bishop � 5 e �7) è costituito da 27 casi pari al 34,7%, di cui 20 sono primigravide e 7 sono pluripare. Il dispositivo contenente il dinoprostone
è stato inserito nel fornice vaginale posteriore. È stato eseguito il monitoraggio continuo della F.C.F e della contrattilità uterina nelle prime 2 ore e poi ad intervalli frequenti e regolari. Il dispositivo è stato rimosso prima delle 12 ore nelle seguenti condizioni: maturazione
completa della cervice uterina, inizio del travaglio, rottura delle membrane, distress fetale, contrazioni uterine ipertoniche, effetti secondari sistemici della PGE2. È stato rimosso dopo 12 ore in caso di indice di Bishop invariato, ed è stato applicato un nuovo dispositivo dopo 12 ore. L’efficacia del farmaco è stata valutata dal numero delle pazienti in cui si è determinata la maturazione cervicale e/o l’inizio del travaglio entro 48 ore dall’applicazione del dispositivo e la sua sicurezza in base all’incidenza di effetti collaterali sulla madre e sul feto. Risultati: il ripening cervix e/o l’inizio del travaglio è stato indotto
in 51 casi (65,3%): 26 pazienti sono del I gruppo (pari al 50,7%) e 25 sono del II gruppo (pari al 92,7%). In 37 casi (47,5%) il parto è stato espletato mediante taglio cesareo. In nessuna paziente è stato necessario rimuovere il dispositivo vaginale per complicazioni materne o fetali.
Conclusioni: i nostri dati hanno evidenziato che il tasso di successo è influenzato in parte dalle condizioni del collo ed in minor misura dalla parità. L’ incidenza del parto operativo (47,5%) e dei fallimenti (34,7%) concorda con quella riferita dalla letteratura nei gruppi di donne selezionate in base all’indice di Bishop ed alla parit
Functional trait-based layers - an aquaculture siting tool for the Mediterranean Sea
Aquaculture, the current fastest-growing food sector, is one of the major opportunities that could be reaped to cope with the increased demand for proteins from the sea and simultaneously generate economic growth while ensuring sustainable use of natural resources. The number of tools and approaches suggested to promote the selection of suitable areas - focusing mostly on the management of potential conflicting uses at sea - is rapidly increasing. However, to date, there is a lack of information regarding spatial planning according to a trait-based approach encompassing the functional and biological data of farmed species; a gap that may lead to selecting unsuitable areas for farming. To fill this gap, our study builds on a functional trait-based mechanistic approach based on the Dynamic Energy Budget (DEB) theory allowing to generated species and site-specific predictions of aquaculture performances and the related environmental impact. We applied this approach to a commercial species farmed in the Mediterranean Sea, namely, the European seabass (Dicentrarchus labrax). We used three seeding sizes (1.5, 2, 2.5 g) to run model simulations and answer a crucial question for farm management, i.e. the selection of the best seeding size. A sensitivity analysis coupled with our simulations allowed to spatially represent the performance growth and environmental impact per seeding size across Mediterranean countries. The accuracy of the model's outcome was strengthened by using high-resolution satellite data over a wide area of investigation (c.a. 302,000 km2). The novel informative obtained layers combine both the modelling of aquaculture performance and related environmental impact to fill a lacking perspective within both AZAs (Allocated Zones for Aquaculture) and AZEs (Allowable Zones of Effect) concepts. Our approach allowed discriminating the best zones for European sea bass aquaculture at country level for each of the tested seeding sizes. High-resolution predictions of aquaculture performances and impact were provided for each of the nineteen Mediterranean coastal countries, zooming at Exclusive Economic Zone scale (EEZ). We highlighted pole-ward negative patterns with the best values in the Southern basin; Libya, Tunisia and Egypt in particular. Our spatial contextualization - through high resolution mapped outcomes - represents an effective and salient tool for stakeholders and policy makers, based on the translation of complex computational modelling results into easy-to-read maps. The highlighted patterns may provide scientific evidence for proactive capacity-building programmes at country level in the future
Hemorheological pattern in different groups of athletes submitted to cardio-pulmonary exercise test
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