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1.
Nat Commun ; 12(1): 5677, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34584083

RESUMO

Tsunami warning centres face the challenging task of rapidly forecasting tsunami threat immediately after an earthquake, when there is high uncertainty due to data deficiency. Here we introduce Probabilistic Tsunami Forecasting (PTF) for tsunami early warning. PTF explicitly treats data- and forecast-uncertainties, enabling alert level definitions according to any predefined level of conservatism, which is connected to the average balance of missed-vs-false-alarms. Impact forecasts and resulting recommendations become progressively less uncertain as new data become available. Here we report an implementation for near-source early warning and test it systematically by hindcasting the great 2010 M8.8 Maule (Chile) and the well-studied 2003 M6.8 Zemmouri-Boumerdes (Algeria) tsunamis, as well as all the Mediterranean earthquakes that triggered alert messages at the Italian Tsunami Warning Centre since its inception in 2015, demonstrating forecasting accuracy over a wide range of magnitudes and earthquake types.

2.
Neurobiol Stress ; 13: 100280, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33457471

RESUMO

Along with neuronal mechanisms devoted to memory consolidation -including long term potentiation of synaptic strength as prominent electrophysiological correlate, and inherent dendritic spines stabilization as structural counterpart- negative control of memory formation and synaptic plasticity has been described at the molecular and behavioral level. Within this work, we report a role for the epigenetic corepressor Lysine Specific Demethylase 1 (LSD1) as a negative neuroplastic factor whose stress-enhanced activity may participate in coping with adverse experiences. Constitutively increasing LSD1 activity via knocking out its dominant negative splicing isoform neuroLSD1 (neuroLSD1KO mice), we observed extensive structural, functional and behavioral signs of excitatory decay, including disrupted memory consolidation. A similar LSD1 increase, obtained with acute antisense oligonucleotide-mediated neuroLSD1 splicing knock down in primary neuronal cultures, dampens spontaneous glutamatergic transmission, reducing mEPSCs. Remarkably, LSD1 physiological increase occurs in response to psychosocial stress-induced glutamatergic signaling. Since this mechanism entails neuroLSD1 splicing downregulation, we conclude that LSD1/neuroLSD1 ratio modulation in the hippocampus is instrumental to a negative homeostatic feedback, restraining glutamatergic neuroplasticity in response to glutamate. The active process of forgetting provides memories with salience. With our work, we propose that softening memory traces of adversities could further represent a stress-coping process in which LSD1/neuroLSD1 ratio modulation may help preserving healthy emotional references.

3.
Sci Rep ; 6: 35007, 2016 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-27725733

RESUMO

The 2011 Tohoku earthquake produced an unexpected large amount of shallow slip greatly contributing to the ensuing tsunami. How frequent are such events? How can they be efficiently modelled for tsunami hazard? Stochastic slip models, which can be computed rapidly, are used to explore the natural slip variability; however, they generally do not deal specifically with shallow slip features. We study the systematic depth-dependence of slip along a thrust fault with a number of 2D dynamic simulations using stochastic shear stress distributions and a geometry based on the cross section of the Tohoku fault. We obtain a probability density for the slip distribution, which varies both with depth, earthquake size and whether the rupture breaks the surface. We propose a method to modify stochastic slip distributions according to this dynamically-derived probability distribution. This method may be efficiently applied to produce large numbers of heterogeneous slip distributions for probabilistic tsunami hazard analysis. Using numerous M9 earthquake scenarios, we demonstrate that incorporating the dynamically-derived probability distribution does enhance the conditional probability of exceedance of maximum estimated tsunami wave heights along the Japanese coast. This technique for integrating dynamic features in stochastic models can be extended to any subduction zone and faulting style.

4.
J Am Acad Audiol ; 10(10): 521-8, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10613348

RESUMO

We compared auditory, cognitive, and language test results in a pair of dizygotic twins, one of whom showed symptoms of central auditory processing disorder (CAPD). Results highlight the importance of testing binaural function. In particular, electrophysiologic measures of dichotic listening effectively demonstrated the auditory-specific nature of this child's listening problems. The importance of a thorough and comprehensive evaluation of children suspected of CAPD is stressed.


Assuntos
Doenças em Gêmeos/diagnóstico , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Audiometria de Tons Puros/métodos , Criança , Cognição/fisiologia , Testes com Listas de Dissílabos , Doenças em Gêmeos/genética , Potenciais Evocados , Potenciais Evocados Auditivos do Tronco Encefálico , Humanos , Idioma , Transtornos do Desenvolvimento da Linguagem/genética , Masculino , Percepção da Fala/fisiologia , Gêmeos Dizigóticos
5.
Braz J Biol ; 72(1): 97-111, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22437390

RESUMO

Recent reports have shown an increase in potentially harmful phytoplankton in Santos bay (Southeastern Brazilian Coast), located in a highly urbanised estuarine complex. Prediction of blooms is, thus, essential but the phytoplankton community structure in very dynamic regions is difficult to determine. In the present work, we discriminate bloom forming microphytoplankton dominance and their relationship to physical and meteorological variables to look for patterns observed in different tides and seasons. Comparing 8 distinct situations, we found five scenarios of dominance that could be related to winds, tides and rainfall: i) Surfers, diatoms occurring during high surf zone energies; ii) Sinkers, represented by larger celled diatoms during spring tide, after periods of high precipitation rates; iii) Opportunistic mixers, composed of chain forming diatoms with small or elongate cells occurring during neap tides; iv) Local mixers, microplanktonic diatoms and dinoflagellates which occurred throughout the 298 sampling stations; and v) Mixotrophic dinoflagellates, after intense estuarine discharges. Results suggest alterations in the temporal patterns for some bloom-forming species, while others appeared in abundances above safe limits for public health. This approach can also illustrate possible impacts of changes in freshwater discharge in highly urbanised estuaries.


Assuntos
Fitoplâncton/classificação , Baías , Brasil , Densidade Demográfica , Dinâmica Populacional , Estações do Ano , Movimentos da Água , Vento
6.
J Phys Condens Matter ; 24(10): 104005, 2012 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-22354892

RESUMO

Internal surfaces of nanocavities are an exceptionally useful laboratory wherein one can spotlight the factors ruling the intricate interplay between morphology and chemistry at silicon surfaces. At the same time, they offer unparalleled opportunities to validate the assignment of vibrational signals of silicon-terminating species under almost ideal experimental conditions. In the case of hydrogen, evidence will be provided of the detailed evolution of H-related species at surfaces depending on their orientation. Also, preliminary results concerning nitrogen at and around nanocavity surfaces will be reported.

7.
Appl Immunohistochem Mol Morphol ; 19(4): 306-12, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21293256

RESUMO

Goal of this study was to asses the performance of Aperio computer-assisted analysis for HER2 immunohistochemical measurement in 292 equivocally (score2+) HercepTest immunoreactive breast cancer cases, evaluated by an experienced pathologist and analyzed with fluorescent in situ hybridization (FISH). The automatic Aperio categorization and the percentage of immunoreactive cells as evaluated by the computer and by the pathologist were recorded. Computer-assisted analysis classified 7 (2.4%) cases as negative (0), 136 (46.6%) as faintly positive (1+), 134 (40.5%) as moderately positive (2+), and 15 (5.1%) as strongly positive (3+). Correlative component analysis (CCA) classification is associated with Her2 amplification (P<0.0001). Compared with the human evaluation, automated CCA classification would save 157 (58%) FISH analyses, while not identifying 15 amplified cases (6% false-negative rate). The mean computer percentage value (CPV) is 18.44% standard deviation ±19.00 (range, 0.01 to 76.10). CPV and the pathologist percentage value are significantly associated and correlated (P<0.001) and have similar sensitivity and specificity in identifying Her2 FISH-amplified cases. CPV has a very low interobserver variation. The difference in CPV in amplified and nonamplified subgroups is statistically significant (P<0.001). Receiver operating characteristic analysis indicates that CPV is good at separating FISH nonamplified from amplified cases (P<0.001). The optimal cut-off value maximizing both sensitivity and specificity is 17.6% (sensitivity=73.3%, specificity=71.6%). Using a different cut-off value (2% of positive cells) we would have missed only 3 amplified cases (1% false-negative rate) while not submitting to FISH 52 cases (18% of the whole series). This false-negative rate is well below the expected false-negative rate usually observed in score 1 cases, supporting the use of CCA with a modified cut-off value in routine diagnostics for equivocally stained HER2 cases.


Assuntos
Neoplasias da Mama/diagnóstico , Carcinoma/diagnóstico , Receptor ErbB-2/metabolismo , Automação Laboratorial/instrumentação , Automação Laboratorial/métodos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma/metabolismo , Carcinoma/patologia , Aprovação de Equipamentos , Diagnóstico por Computador , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Metástase Neoplásica , Valor Preditivo dos Testes , Prognóstico , Sensibilidade e Especificidade , Estados Unidos
8.
Phys Rev B Condens Matter ; 38(18): 13282-13290, 1988 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9946307
9.
Phys Rev B Condens Matter ; 49(8): 5291-5299, 1994 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10011480
12.
Riv Patol Nerv Ment ; 100(5): 275-87, 1979.
Artigo em Italiano | MEDLINE | ID: mdl-318026

RESUMO

A 57 years-old woman developed a right hemiparesis with dysphasia four weeks after left Herpes Zoster Ophthalmicus. The CSF was normal while cerebral angiography showed segmental narrowing of the left carotid syphon and terminal branches. The patient's condition improved during the next few days with almost full recovery. Herpes Zoster Ophthalmicus followed by a controlateral hemiparesis or hemiplegia is a relatively infrequent clinical syndrome. After a review of the relevant literature and discussion of the various theories of causation, the authors suggest a chance relation between the two pathological conditions.


Assuntos
Hemiplegia/complicações , Herpes Zoster Oftálmico/complicações , Afasia/complicações , Transtornos Cerebrovasculares/complicações , Feminino , Humanos , Pessoa de Meia-Idade
13.
Artigo em Inglês | MEDLINE | ID: mdl-7244575

RESUMO

A woman of 65 years, after a period of painful paraesthesiae in the legs, developed a polyneuritic syndrome and also sphincter disturbance. At first the c.s.f. showed albuminocytological dissociation. The polyneuropathy was initially thought to be of diabetic origin, as the blood sugar was moderately raised. For nearly two years the symptoms were not very disabling, in spite of variations in severity, but then there was a sudden onset of severe paraplegia with a sensory level of D 6--7 and bilateral extensor responses. Myelography was abnormal but inconclusive. Her clinical condition gradually deteriorated and severe pressure sores developed. Death occurred five years after the appearance of the first symptoms. Post-mortem examination revealed diffuse necrosis in most of the thoracic region of the cord which showed at this level a large arterio-venous angioma on its posterior part.


Assuntos
Malformações Arteriovenosas/patologia , Medula Espinal/irrigação sanguínea , Idoso , Feminino , Humanos , Necrose , Medula Espinal/patologia , Compressão da Medula Espinal/patologia , Degeneração Walleriana
14.
Riv Patol Nerv Ment ; 103(3): 105-13, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6622937

RESUMO

A 23 years old man suffering from SSPE died 18 months after the onset of the disease. The clinical picture, EEG and immunological tests were typical for SSPE, and so was the anatomo-pathological investigation; the only difference was that the Cowdry type A inclusion bodies were absent. The peculiarity of this case consists in the fact that the disease appeared in an adult. In the literature we found very few cases of SSPE with such a late onset.


Assuntos
Encéfalo/patologia , Panencefalite Esclerosante Subaguda/patologia , Adulto , Biópsia , Córtex Cerebral/patologia , Eletroencefalografia , Humanos , Masculino , Panencefalite Esclerosante Subaguda/diagnóstico
15.
FASEB J ; 13(11): 1395-403, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10428763

RESUMO

Several types of ionic channels on the outer membrane of the nuclear envelope communicate with the nuclear cisternae. These are distinct from nucleocytoplasmic pathways, the nuclear pores that span the double membrane of the envelope and are the route for RNA and protein traffic in the nucleus. Recent data indicate that the nuclear pores may also function as ion channels. The most probable candidate for nucleocytoplasmic ion flux is a 300-400 pS pathway observed in many nuclear preparations. Morphological and functional studies of nuclear envelope suggest a tight relationship between the large conductance channel and the pore complex. However, there is no direct evidence for gating of the nuclear pore or its ability to open and close as a conventional channel. This study shows that in liver nuclei isolated from newborn mouse, there is a substantial correspondence between the number of pores and the number of channels recorded during patch-clamp. This is not the case for adult nuclei. Although pore density is comparable, some nuclear cytoskeletal components, such as actin and nonmuscle myosin, show a significant increase in the adult preparation. Previous studies demonstrate the presence of these two proteins in association with the pore complex. Here we show that by using actin filament disrupter, we were able to increase the number of active channels in adult isolated nuclei. We suggest that a functional interaction between actin filaments and the nuclear pore complex could regulate nucleocytoplasmic permeability.


Assuntos
Canais Iônicos/fisiologia , Fígado/fisiologia , Membrana Nuclear/fisiologia , Animais , Núcleo Celular/fisiologia , Ativação do Canal Iônico/fisiologia , Transporte de Íons , Fígado/ultraestrutura , Camundongos , Técnicas de Patch-Clamp
16.
Cell Biol Int ; 21(11): 747-57, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9768473

RESUMO

Nuclear patch clamp is an emerging research field that aims to disclose the electrical phenomena underlying macromolecular transport across the nuclear envelope (NE), its properties as an ion barrier and its function as an intracellular calcium store. The authors combined the patch clamp technique with atomic force microscopy (AFM) to investigate the structure-function relationship of NE. In principle, patch clamp currents, recorded from the NE can indicate the activity of the nuclear pore complexes (NPCs) and/or of ion channels in the two biomembranes that compose the NE. However, the role of the NPCs is still nuclear because the observed NE current in patch clamp experiments is lower than expected from the known density of the NPCs. Therefore, AFM was applied to link patch clamp currents to structure. The membrane patch was excised from the nuclear envelope and, after electrical evaluation, transferred from the patch pipette to a substrate. We could identify the native nuclear membrane patches with AFM at a lateral and a vertical resolution of 3 nm and 0.1 nm, respectively. It was shown that complete NE together with NPCs can be excised from the nucleus after their functional identification in patch clamp experiments. However, we also show that membranes of the endoplasmic reticulum can contaminate the tip of the patch pipette during nuclear patch clamp experiments. This possibility must be considered carefully in nuclear patch clamp experiments.


Assuntos
Núcleo Celular/fisiologia , Núcleo Celular/ultraestrutura , Microscopia de Força Atômica/métodos , Membrana Nuclear/fisiologia , Membrana Nuclear/ultraestrutura , Técnicas de Patch-Clamp , Animais , Relação Estrutura-Atividade , Xenopus laevis
17.
Biophys J ; 81(5): 2580-9, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11606272

RESUMO

Despite growing concern about electromagnetic radiation, the interaction between 50- to 60-Hz fields and biological structures remains obscure. Epidemiological studies have failed to prove a significantly correlation between exposure to radiation fields and particular pathologies. We demonstrate that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms: it antagonizes the shift in cell membrane surface charges that occur during the early phases of differentiation and it modulates hyperpolarizing K channels by increasing intracellular Ca. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. We propose that cells are normally protected against electromagnetic insult. Pathologies may arise, however, if intracellular Ca regulation or K channel activation malfunctions.


Assuntos
Bucladesina/farmacologia , Cálcio/metabolismo , Cálcio/efeitos da radiação , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Citoproteção/fisiologia , Potenciais da Membrana/efeitos da radiação , Radiação , Animais , Cálcio/farmacologia , Diferenciação Celular/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/efeitos da radiação , Membrana Celular/metabolismo , Membrana Celular/efeitos da radiação , Glioma/metabolismo , Lantânio/farmacologia , Manganês/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Neuroblastoma/metabolismo , Canais de Potássio/efeitos dos fármacos , Eletricidade Estática , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/metabolismo
18.
FASEB J ; 14(9): 1171-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10834939

RESUMO

NCC27 belongs to a family of small, highly conserved, organellar ion channel proteins. It is constitutively expressed by native CHO-K1 and dominantly localized to the nucleus and nuclear membrane. When CHO-K1 cells are transfected with NCC27-expressing constructs, synthesized proteins spill over into the cytoplasm and ion channel activity can then be detected on the plasma as well as nuclear membrane. This provided a unique opportunity to directly compare electrophysiological characteristics of the one cloned channel, both on the nuclear and cytoplasmic membranes. At the same time, as NCC27 is unusually small for an ion channel protein, we wished to directly determine whether it is a membrane-resident channel in its own right. In CHO-K1 cells transfected with epitope-tagged NCC27 constructs, we have demonstrated that the NCC27 conductance is chloride dependent and that the electrophysiological characteristics of the channels are essentially identical whether expressed on plasma or nuclear membranes. In addition, we show that a monoclonal antibody directed at an epitope tag added to NCC27 rapidly inhibits the ability of the expressed protein to conduct chloride, but only when the antibody has access to the tag epitope. By selectively tagging either the amino or carboxyl terminus of NCC27 and varying the side of the membrane from which we record channel activity, we have demonstrated conclusively that NCC27 is a transmembrane protein that directly forms part of the ion channel and, further, that the amino terminus projects outward and the carboxyl terminus inward. We conclude that despite its relatively small size, NCC27 must form an integral part of an ion channel complex.


Assuntos
Membrana Celular/metabolismo , Canais de Cloreto/metabolismo , Membrana Nuclear/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Células CHO , Membrana Celular/efeitos dos fármacos , Canais de Cloreto/química , Canais de Cloreto/genética , Canais de Cloreto/imunologia , Cloretos/metabolismo , Cloretos/farmacologia , Cricetinae , Condutividade Elétrica , Epitopos/imunologia , Potenciais da Membrana/efeitos dos fármacos , Membrana Nuclear/efeitos dos fármacos , Técnicas de Patch-Clamp , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/metabolismo , Transfecção
19.
Eur J Neurosci ; 11(3): 959-66, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10103089

RESUMO

Ras-GRF, a neuron-specific Ras exchange factor of the central nervous system, was transfected in the SK-N-BE neuroblastoma cell line and stable clones were obtained. When exposed to retinoic acid, these clones showed a remarkable enhancement of Ras-GRF expression with a concomitant high increase in the level of active (GTP-bound) Ras already after 24 h of treatment. In the presence of retinoic acid, the transfected cells stopped growing and acquired a differentiated neuronal-like phenotype more rapidly than the parental ones. Cells expressing Ras-GRF also exhibited a more hyperpolarized membrane potential. Moreover, treatment with retinoic acid led to the appearance of an inward rectifying potassium channel with electrophysiological properties similar to IRK1. This current was present in a large number of cells expressing Ras-GRF, while only a small percentage of parental cells exhibited this current. However, Northern analysis with a murine cDNA probe indicated that IRK1 mRNA was induced by retinoic acid at a similar level in both kinds of cells. Brief treatment with a specific inhibitor of the mitogen-activated protein kinase (MAPK) pathway reduced the number of transfected cells showing IRK1 activity. These findings suggest that activation of the Ras pathway accelerates neuronal differentiation of this cell line. In addition, our results suggest that Ras-GRF and/or Ras-pathway may have a modulatory effect on IRK1 channel activity.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Drosophila , Neurônios/citologia , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/genética , Proteínas/genética , Tretinoína/farmacologia , Northern Blotting , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas de Ciclo Celular/genética , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Eletrofisiologia , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina , Humanos , Ativação do Canal Iônico/fisiologia , Neuroblastoma , Neurônios/química , Neurônios/enzimologia , Fosfoproteínas Fosfatases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-ret , RNA Mensageiro/análise , Receptores Proteína Tirosina Quinases/genética , Transfecção , Células Tumorais Cultivadas , Fatores ras de Troca de Nucleotídeo Guanina , ras-GRF1
20.
J Physiol ; 529 Pt 3: 541-52, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11195932

RESUMO

NCC27 is a nuclear chloride ion channel, identified in the PMA-activated U937 human monocyte cell line. NCC27 mRNA is expressed in virtually all cells and tissues and the gene encoding NCC27 is also highly conserved. Because of these factors, we have examined the hypothesis that NCC27 is involved in cell cycle regulation. Electrophysiological studies in Chinese hamster ovary (CHO-K1) cells indicated that NCC27 chloride conductance varied according to the stage of the cell cycle, being expressed only on the plasma membrane of cells in G2/M phase. We also demonstrate that Cl- ion channel blockers known to block NCC27 led to arrest of CHO-K1 cells in the G2/M stage of the cell cycle, the same stage at which this ion channel is selectively expressed on the plasma membrane. These data strongly support the hypothesis that NCC27 is involved, in some as yet undetermined manner, in regulation of the cell cycle.


Assuntos
Ciclo Celular/fisiologia , Canais de Cloreto/fisiologia , Animais , Antracenos/farmacologia , Células CHO , Membrana Celular/metabolismo , Tamanho Celular/fisiologia , Canais de Cloreto/genética , Cloretos/fisiologia , Sequência Conservada/genética , Cricetinae , Condutividade Elétrica , Eletrofisiologia , Fase G2 , Expressão Gênica , Glicolatos/farmacologia , Membranas Intracelulares/metabolismo , Canais Iônicos/genética , Canais Iônicos/metabolismo , Mitose , Família Multigênica , Transfecção
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