61 research outputs found
Concomitant Congenital Diaphagmatic Hernia (CDH) and bilateral bacterial glomerulonephritis in a pet chinchilla (Chinchilla lanigera)
Background: The domestic chinchilla has been descended from Chinchilla lanigera (long-tailed Chinchilla) or Chinchilla chinchilla (short-tailed Chinchilla). Both species of chinchilla are currently listed as endangered by the IUCN Red List of Threatened Species. Over the past 20 years, they have spread as pets and overall knowledge about their care is improving. The present case report describes a congenital diaphragmatic hernia in a Chinchilla lanigera. Case presentation: A 1-year-old, 420 g female chinchilla (Chinchilla lanigera) was presented for clinical examination due to 2 days haematuria episodes and anorexia. A complete haematological analysis was performed, showing a moderate neutrophilia and severe renal involvement. X-rays showed severe intestinal meteorism affecting mostly the cecum, and a soft tissue density mass with translucent areas located in the caudal thorax, making it hard to distinguish the cardiac silhouette. A barium swallow (barium sulfate) was performed and after 20 min, radiograms were performed again, showing part of the stomach dislocated in thorax. Ultrasound was also carried out, confirming the partial stomach herniation into the thoracic cavity and a severe nephropathy. The patient was euthanized according to the owner’s wish and a complete necropsy was performed. The diagnosis was congenital diaphragmatic hernia concomitant to a severe bilateral bacterial glomerulonephritis. Discussion and conclusions: Diaphragmatic hernias can be either congenital or acquired. About CDHs in pet chinchillas, literature is still lacking. In this patient there was no history of previous traumas. No scar tissue or thickening involved margins of the pathological diaphragm window at the necropsy, supporting the hypothesis of a congenital defect. Glomerulonephritis most often results from immune-mediated mechanisms, generally after the deposition of soluble immune complexes within the glomeruli. This mechanism is favoured by a prolonged antigenemia that could occur during specific viral infections, chronic bacterial infections, chronic parasitism, autoimmune diseases and neoplasia. Few cases of nephritis are described in chinchillas (Chinchilla lanigera), mostly related to bacterial sepsis or less commonly involving fungi. The evidence of bacterial aggregates in kidneys at the histopathology, confirmed the infective aetiology. No relationship between the diaphragmatic hernia and glomerulonephritis was found in this report
Auditory temporal processing in healthy aging: a magnetoencephalographic study
<p>Abstract</p> <p>Background</p> <p>Impaired speech perception is one of the major sequelae of aging. In addition to peripheral hearing loss, central deficits of auditory processing are supposed to contribute to the deterioration of speech perception in older individuals. To test the hypothesis that auditory temporal processing is compromised in aging, auditory evoked magnetic fields were recorded during stimulation with sequences of 4 rapidly recurring speech sounds in 28 healthy individuals aged 20 – 78 years.</p> <p>Results</p> <p>The decrement of the N1m amplitude during rapid auditory stimulation was not significantly different between older and younger adults. The amplitudes of the middle-latency P1m wave and of the long-latency N1m, however, were significantly larger in older than in younger participants.</p> <p>Conclusion</p> <p>The results of the present study do not provide evidence for the hypothesis that auditory temporal processing, as measured by the decrement (short-term habituation) of the major auditory evoked component, the N1m wave, is impaired in aging. The differences between these magnetoencephalographic findings and previously published behavioral data might be explained by differences in the experimental setting between the present study and previous behavioral studies, in terms of speech rate, attention, and masking noise. Significantly larger amplitudes of the P1m and N1m waves suggest that the cortical processing of individual sounds differs between younger and older individuals. This result adds to the growing evidence that brain functions, such as sensory processing, motor control and cognitive processing, can change during healthy aging, presumably due to experience-dependent neuroplastic mechanisms.</p
Auditory encoding abnormalities in children with autism spectrum disorder suggest delayed development of auditory cortex
Matching the neural adaptation in the rat ventral cochlear nucleus produced by artificial (electric) and acoustic stimulation of the cochlea
To investigate neural adaptive properties, near-field evoked potentials were recorded from a chronically implanted electrode in the ventral cochlear nucleus in awake Long-Evans rats exposed to acoustic stimuli or receiving intracochlear electric stimulation. Stimuli were 250-ms trains of repetitive acoustic clicks (10, 30 and 50 dB SPL) or biphasic electric pulses (30, 50 and 70 µA) with intratrain pulse rates ranging from 100 to 1000 pulses per second (pps). The amplitude of the first negative (N1) to positive (P1) component of the average evoked potentials was measured for each consecutive individual pulse in the train. While a progressive exponential decrease in N1-P1 amplitude was observed as a function of the position of the pulse within the train for both types of stimulation, the decrement of electric responses (adaptive pattern) was substantially less prominent than that observed for acoustic stimuli. Based on this difference, the present work was extended by modifying electric stimuli in order to try to restore normal adaptation phenomena. The results suggest the feasibility of mimicking acoustic adaptation by stimulation with exponentially decreasing electric pulse trains, which may be clinically applicable in the auditory implant field
EXCHANGE AND CRYSTALLINE FIELD IN METALLIC COMPOUNDS.Coexistence of superconductivity and long range magnetic order
La découverte récente des composés supraconducteurs (RE)Mo6X8 (X = S, Se) et (RE)Rh4B4 (RE = terre rare) nous offre une possibilité unique d'étudier le problème de la coexistence de la supraconductivité et du magnétisme. Dans HoMo6S8 et ErRh4B4 on trouve que la supraconductivité est détruite dès l'apparition de l'ordre ferromagnétique. Par contre, dans plusieurs autres composés du type (RE)Mo6S8 on trouve un antiferromagnétisme qui coexiste avec l'état supraconducteur. Une analyse des champs critiques de ces composés - montre l'existence d'une augmentation anormale du pairbreaking en dessous de la transition magnétique.The recent discovery of the superconducting compounds of the type (RE)Mo6X8 (X = S, Se) and (RE)Rh4B4 (RE = rare earth) offers unique possibility to study the problem of coexistence of superconductivity and magnetism since they contain a regular lattice of RE-ions. In HoMo6S8 and ErRh4B4 superconductivity is destroyed at the onset of a long range ferromagnetic order. In several other (RE)Mo6X8 compounds one finds antiferromagnetic order and the superconducting state remains below the magnetic transition. An analysis of Hc2 data shows that in the (RE)Mo6S8 compounds an anomalous increase of the pairbreaking occurs below the magnetic transition
INTELLIGIBILITÉ DE LA PAROLE AVEC IMPLANT COCHLÉAIRE MULTICANAUX ET DISCRIMINATIONS TEMPORELLES
Afin de mieux comprendre les raisons du succés ou de l'insuccés d'un implant cochléaire pour un patient donne il est nécessaire d'analyser les performances psychophysique élémentaires en relation avec la perception de la parole. Dans cette perspective on a étudié chez cinq patients porteurs d'un implant intracochléaire multicanaux leurs capacités d'analyse temporelle et de perception consonantique. Les mesures d'analyse temporelle ont été la détection d'un silence dans un bruit ainsi que la détection d'un intervalle entre deux clics, pour la reconnaissance des consonnes on a établi une matrice de confusion sur douze consonnes, communes aux langues européennes, les consonnes étaient intervocaliques dans le contexte a (aCa). Les résultats ont indiqué une corrélation entre la résolution temporelle pour deux clics sur 1'électrode de la base de la cochlée et l'identification du lieu d'articulation des consonnes. De telles informations devraient pouvoir être prises en compte pour une adaptation individuelle de la stratégie de codage par implant cochléaire.In order to better understand the reasons for success or failure of a cochlear implant system for a given patient it appears necessary to analyse the basic psychophysical capacities in relation with specch perception. In this perspective we have studied in five patients with an intracochlear multichannel implant their capacities of temporal analysis and their perception of consonants. For temporal analysis we have measured the detection of a silent gap in noise and that of an interval between two clicks, for consonant perception we have established a confusion matrix based on twelve consonants, common to european languages, they were presented as intervocalic in an a context (aCa). The results indicated a correlation between temporal resolution for two clicks at the basal electrode in the cochlea and the perception of place of articulation of consonants. Such informations would be worth taking into account for an individual adaptation of a coding strategy with a cochlear implant
L’ATROPINA COME COADIUVANTE NELLA TERAPIA DELLE SINDROMI RESPIRATORIE RIPRODUTTIVE (SRP) DEGLI OFIDI: INDAGINE PRELIMINARE
Scopo del lavoro - Questo studio si prefigge di mettere a confronto il grado di resistenza ossea omerale tra diverse specie di rapaci per dimostrare come l’insorgenza di fratture sia maggiore in alcune specie rispetto che altre per fattori di predisposizione dovuti alle diversità anatomiche esistenti tra le diverse specie esaminate, rilevate attraverso uno studio comparativo con tomografo industriale Micro-Macrofocus per la ricostruzione 3D degli omeri e prove di resistenza con metodo Charpie. Materiali e metodi - Le specie messe a confronto in questo studio sono 4 soggetti (2 Buteo bute; 2 Falco peregrinus). Gli animali erano deceduti per varie patologie. Lo studio è stato effettuato sugli omeri destri. La prima fase di studio è stata realizzata mediante esame tomografico con un Tomografo Industriale Micro-Macrofocus. Per l’esecuzione delle tomografie sugli omeri è stato utilizzato un focal spot size di 250 μm. Durante la scansione, il macchinario ha fornito in tempo reale una ricostruzione video dell’immagine del campione sotto forma di sinogramma. Successivamente si è proceduto alla ricostruzione video delle immagini degli omeri, mettendo in successione tutte le varie scansioni ottenute in due sensi, uno prossimo-distale e uno in senso latero-laterale. Successivamente si è proceduto alle misurazioni in specifici punti anatomici: Epifisi Prossimale (a livello del forame pneumatico e della sommità della tuberosità deltoidea), Diafisi (porzione centrale del corpo della diafisi) ed Epifisi Distale (al di sopra dei condili distali), dove sono stati misurati specificatamente il diametro di sezione esterna, il diametro di sezione interna, lo spessore della corticale, le dimensione ed il numero delle trabecole ossee. Per la valutazione della densità è stato misurato (a livello della diafisi) il livello di densità apparente della corticale ossea (riportata su Scala dei grigi,) mediante coefficiente di Hunsfield (UH). La seconda fase di questo studio, ha messo a confronto mediante prove ad impatto secondo il modello Charpie, le proprietà meccaniche degli omeri delle due specie prese in esame. Sono stati valutati: l’energia assorbita dal campione e l’andamento della Forza. Tutti i singoli campioni ossei esaminati durante le tomografie sono stati misurati nei diversi punti prestabiliti, sono stati calcolati i valori medi di ogni misura per tutti i soggetti appartenenti alla stessa specie. È stato possibile mettere a confronto più semplicemente i valori medi di tutte le misure e fare così un confronto tra le due specie. Risultati - La scansione di ogni singolo campione ha avuto una durata media di circa 20 minuti. Conclusioni - L’omero di Falco Pellegrino è un osso di piccole dimensioni in lunghezza, ma certamente voluminoso; lo si può per l’appunto definire un osso molto compatto e resistente. Detta resistenza è confermata dall’elevatissimo numero rispetto le altre specie di trabecole ossee sia a livello dell’epifisi prossimale che distale, nonché da una spessa corticale sempre a livello delle dette epifisi, ma ancor più a livello diafisario. Questo quindi dovrebbe risultare più resistente rispetto le altre specie. L’omero di Poiana, se pur voluminoso, si mostra estremamente fragile. Ciò è dovuto certamente all’esiguo spessore della corticale nei vari suoi punti ed alla scarsa presenza di trabecole di sottile fattura. Anche le misurazioni con la scala dei grigi per la densità e le relative prove ad impatto confermano la debolezza della corticale. Sicuramente sono tra i soggetti più predisposti a fratture. Confrontando le prove ad impatto eseguite sui campioni ossei di Poiana e Falco Pellegrino, in base ai dati ottenuti ed alla loro interpretazione si è notato che i campioni ossei di Falco Pellegrino rispetto quello di Poiana sono molto più resistenti; ciò è stato confermato anche dai dati numerici rilevati durante le, in cui densità , numero e dimensioni delle trabecole, spessore della corticale hanno valori statisticmente maggiori nel Falco Pellegrino rispetto la poiana
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