176 research outputs found

    The association of serotype and pulsed-field gel electrophoresis genotype in isolates of Streptococcus pneumoniae isolated in Israel

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    SummaryThe relationship between Streptococcus pneumoniae isolates causing invasive infections in children admitted to a single center in central Israel was examined by pulsed-field gel electrophoresis (PFGE) and serotyping. Although there was a close correlation between serotype and PFGE clone, the genetic diversity varied by serotype, with some genotypes comprising multiple serotypes. Additionally, clones C and D were associated with higher penicillin minimum inhibitory concentrations. Serotyping alone may be insufficient for epidemiological mapping of pneumococcal isolates in the era of pneumococcal conjugate polysaccharide vaccines

    Time reversal methods in acousto-elastodynamics

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    The aim of the article is to solve an inverse problem in order to determine the presence and some properties of an elastic “inclusion” (an unknown object, characterized by elastic properties discriminant from the surrounding medium) from partial observa- tions of acoustic waves, scattered by the inclusion. The method will require developing techniques based on Time Reversal methods. A finite element method based on varia- tional acousto-elastodynamics formulation will be derived and used to solve to solve the forward, and then, the time reversed problem. A criterion, derived from the reverse time migration framework, is introduced, to help use to construct images of the inclusions to be determined. Our approach will be applied to configurations modeling breast cancer detection, using simulated ultrasound waves

    EFFECT OF MICROWAVE POWER ON QUALITY PARAMETERS OF PECTIN EXTRACTED FROM MANGO PEEL

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    The present study aims to use microwave pow-er to facilitate the extraction of pectin from dried mango peels, and also to explore the effect of power on some quality parameters of the resultant pectin. Chemical composition of dried mango peels ascertained a high percent of total pectin, being 16.01 % (on dry weight basis). With respect to microwave heating, the optimal experimented power was 600W, and 6 minutes as the best short holding time, which gave 12.80 % yield, 86.54% recovery and 77.20% anhydrogalacturonic acid (AGA) of extracted pectin. Comparing to the commercial pectin, the results of some physico–chemical characterstics of isolated pectin, revealed that the pectin isolated by microwave heating from mango peels, being to some extent analogous to the commercial pectin with respect to its qualities, such as high methoxyl pectin, high degree of estri-fication (DE), and high percent of AGA besides its high viscosity, followed by the pectin isolated using the conventional method. Statistical analysis of organoleptic data showed no significant differ-ences between strawberry jam prepared by using commercial pectin and that treated with pectin isolated by microwave heating as affecting their texture, color, taste and preference. Besides, high significant differences were detected between var-ious concentrations of added pectin, with respect to the texture alone. Generally, the utilization of pectin isolated from mango peels using microwave heating in jam processing gave high quality attrib-utes resembling that of the commercial pectin when added to strawberry jam and this would also lead to gain economical benefits

    Children with mixed developmental language disorder have more insecure patterns of attachment.

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    Developmental Language disorders (DLD) are developmental disorders that can affect both expressive and receptive language. When severe and persistent, they are often associated with psychiatric comorbidities and poor social outcome. The development of language involves early parent-infant interactions. The quality of these interactions is reflected in the quality of the child's attachment patterns. We hypothesized that children with DLD are at greater risk of insecure attachment, making them more vulnerable to psychiatric comorbidities. Therefore, we investigated the patterns of attachment of children with expressive and mixed expressive- receptive DLD. Forty-six participants, from 4 years 6 months to 7 years 5 months old, 12 with expressive Specific Language Impairment (DLD), and 35 with mixed DLD, were recruited through our learning disorder clinic, and compared to 23 normally developing children aged 3 years and a half. The quality of attachment was measured using the Attachment Stories Completion Task (ASCT) developed by Bretherton. Children with developmental mixed language disorders were significantly less secure and more disorganized than normally developing children. Investigating the quality of attachment in children with DLD in the early stages could be important to adapt therapeutic strategies and to improve their social and psychiatric outcomes later in life

    Cholinergic control of striatal GABAergic microcircuits

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    Cholinergic interneurons (CINs) are essential elements of striatal circuits and functions. Although acetylcholine signaling via muscarinic receptors (mAChRs) has been well studied, more recent data indicate that postsynaptic nicotinic receptors (nAChRs) located on striatal GABAergic interneurons (GINs) are equally critical. One example is that CIN stimulation induces large disynaptic inhibition of striatal projection neurons (SPNs) mediated by nAChR activation of GINs. Although these circuits are ideally positioned to modulate striatal output, the neurons involved are not definitively identified because of an incomplete mapping of CINs-GINs interconnections. Here, we show that CINs modulate four GINs populations via an intricate mechanism involving co-activation of presynaptic and postsynaptic mAChRs and nAChRs. Using optogenetics, we demonstrate the participation of tyrosine hydroxylase-expressing GINs in the disynaptic inhibition of SPNs via heterotypic electrical coupling with neurogliaform interneurons. Altogether, our results highlight the importance of CINs in regulating GINs microcircuits via complex synaptic/heterosynaptic mechanisms

    Differential processing of thalamic information via distinct striatal interneuron circuits

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    Recent discoveries of striatal GABAergic interneurons require a new conceptualization of the organization of intrastriatal circuitry and their cortical and thalamic inputs. We investigated thalamic inputs to the two populations of striatal neuropeptide Y (NPY) interneurons, plateau low threshold spike (PLTS) and NPY-neurogliaform (NGF) cells. Optogenetic activation of parafascicular inputs evokes suprathreshold monosynaptic glutamatergic excitation in NGF interneurons and a disynaptic, nicotinic excitation through cholinergic interneurons. In contrast, the predominant response of PLTS interneurons is a disynaptic inhibition dependent on thalamic activation of striatal tyrosine hydroxylase interneurons (THINs). In contrast, THINs do not innervate NGF or fast spiking interneurons, showing significant specificity in THINs outputs. Chemospecific ablation of THINs impairs prepulse inhibition of the acoustic startle response suggesting an important behavioural role of this disynaptic pathway. Our findings demonstrate that the impact of the parafascicular nucleus on striatal activity and some related behaviour critically depend on synaptic interactions within interneuronal circuits

    Calcaneal nonunion: three cases and a review of the literature

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    The long-term follow-up of intra-articular calcaneal fractures is often accompanied by complications. Frequently occurring are arthrosis, arthrofibrosis of the subtalar joint, and malunion. Uncommon is the calcaneal nonunion. A total of three cases is presented in this report, including a review of the literature. The occurrence of a nonunion appears to be more common after conservative treatment, but the pathophysiology remains unclear, however smoking may play a role

    Neuropilin 2/Plexin-A3 receptors regulate the functional connectivity and the excitability in the layers 4 and 5 of the cerebral cortex

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    The functions of cortical networks are progressively established during development by series of events shaping the neuronal connectivity. Synaptic elimination, which consists of removing the supernumerary connections generated during the earlier stages of cortical development, is one of the latest stages in neuronal network maturation. The semaphorin 3F coreceptors neuropilin 2 (Nrp2) and plexin-A3 (PlxnA3) may play an important role in the functional maturation of the cerebral cortex by regulating the excess dendritic spines on cortical excitatory neurons. Yet, the identity of the connections eliminated under the control of Nrp2/PlxnA3 signaling is debated, and the importance of this synaptic refinement for cortical functions remains poorly understood. Here, we show that Nrp2/PlxnA3 controls the spine densities in layer 4 (L4) and on the apical dendrite of L5 neurons of the sensory and motor cortices. Using a combination of neuroanatomical, ex vivo electrophysiology, and in vivo functional imaging techniques in Nrp2 and PlxnA3 KO mice of both sexes, we disprove the hypothesis that Nrp2/PlxnA3 signaling is required to maintain the ectopic thalamocortical connections observed during embryonic development. We also show that the absence of Nrp2/PlxnA3 signaling leads to the hyperexcitability and excessive synchronization of the neuronal activity in L5 and L4 neuronal networks, suggesting that this system could participate in the refinement of the recurrent corticocortical connectivity in those layers. Altogether, our results argue for a role of semaphorin–Nrp2/PlxnA3 signaling in the proper maturation and functional connectivity of the cerebral cortex, likely by controlling the refinement of recurrent corticocortical connections
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