Neuronal death affects selectively granule cell precursors of the cerebellum and the dopaminergic neurons of midbrain in the weaver mutant mouse. The weaver phenotype is associated with a missense ...mutation in the gene coding for the GIRK2 potassium channel, which results in chronic depolarization. Using DNA gel electrophoresis, electron microscopy (EM), the in situ end-labeling (ISEL) technique at the light and EM level, and immunohistochemistry for apoptosis-related proteins c-Jun and proliferating cell nuclear antigen (PCNA), we have investigated the mechanisms of cell death in cerebellum and substantia nigra. Between postnatal day P1 and P21, in the external germinal layer of the cerebellum, most degenerating granule cell precursors were found to aggregate to form clusters. Degenerating cells exhibited strong nuclear staining for ISEL, c-Jun, and PCNA and had a typical apoptotic morphology by EM. Increased c-Jun and ISEL staining were also occasionally seen in Purkinje cells. Between P14 and P21, when dopaminergic neurons start to degenerate, staining for ISEL, c-Jun, and PCNA in weaver substantia nigra was the same as in controls. By EM, however, we found only in weaver mice numerous dopaminergic cells that showed extensive vacuolar and autophagic changes of cytoplasm, preservation of membrane and organelle integrity, and absence of chromatin condensation or DNA fragmentation by EM-ISEL. The combination of vacuolar and autophagic changes identifies a novel type of non-necrotic, nonapoptotic cell death. After biochemical analysis of DNA, a clear-cut laddering, suggestive of oligonucleosomal fragmentation, was present in samples from weaver cerebellum. Cell death diversity appears to be influenced by specific features of target cells. These findings may be relevant for understanding the mechanisms of cell death in neurodegenerative diseases.
Laryngeal endoscopy plays a determinant role in clinical evaluation of dysphagia. The examination is performed by means of a trans-nasal approach with a flexible fiberoptic endoscope, able to ...visualize the pre- and post-deglutitory steps of the pharyngeal phase of swallowing. In patients with tracheostomy, it is possible to visualize the glottic or neoglottic function during the intra-deglutitory phase, performing the examination through a trans-tracheostomic route. The procedure and indications of this endoscopic technique are described.
The growing diffusion of distributed generation and its impact on voltage profiles increases the need for regulating voltage also in low-voltage (LV) networks, particularly at active user's premise. ...The quality of voltages should be ensured by devices that are fast-acting, economical, compact and easy to be installed, without a negative impact on the reliability of the network and its users. With this aim, a new simple, cheap and compact device for supporting voltage control at LV active users' premises has recently been proposed; it is based on a transformer that is able to change its winding configuration by static switches. In this paper, the design of the static-commutated device is described and analyzed; various laboratory tests for validating the control structure are presented. The results show the effectiveness of the control strategy to ensure an adequate voltage quality at LV active users' premises.
Two procedures are suggested to select a representative subset from a large data set. The first is based on the use of the estimate of the multivariate probability density distribution by means of ...the potential functions technique. The first object selected for the subset is that for which the probability density is larger. Then, the distribution is corrected, by subtraction of the contribution of the selected object multiplied by a selection factor. The second procedure uses genetic algorithms to individuate the subset that reproduces the variance–covariance matrix with the minimum error. Both methods meet the requirement to obtain a representative subset, but the results obtained with the method based on potential functions are generally more satisfactory in the case when the original set is not a random sample from an infinite population, but is the finite population itself. Several examples show how the extraction of a representative subset from a large data set can give some advantages in the use of representation techniques (i.e., eigenvector projection, non-linear maps, Kohonen maps) and in class modelling techniques.
The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) flew on May 13\(^{\text{th}}\) and 14\(^{\text{th}}\) of 2023. Consisting of two novel optical telescopes, the payload ...utilized next-generation instrumentation for the observations of extensive air showers from near space. One instrument, the fluorescence telescope (FT) searched for Ultra-High Energy Cosmic Rays (UHECRs) by recording the atmosphere below the balloon in the near-UV with a 1~\(\mu\)s time resolution using 108 multi-anode photomultiplier tubes with a total of 6,912 channels. Validated by pre-flight measurements during a field campaign, the energy threshold was estimated around 2~EeV with an expected event rate of approximately 1 event per 10 hours of observation. Based on the limited time afloat, the expected number of UHECR observations throughout the flight is between 0 and 2. Consistent with this expectation, no UHECR candidate events have been found. The majority of events appear to be detector artifacts that were not rejected properly due to a shortened commissioning phase. Despite the earlier-than-expected termination of the flight, data were recorded which provide insights into the detectors stability in the near-space environment as well as the diffuse ultraviolet emissivity of the atmosphere, both of which are impactful to future experiments.
We compare two different formalisms for modeling the energy deposition of macroscopically sized/massive quark nuggets (a.k.a. macros) in the Earth's atmosphere. We show that for a reference mass of 1 ...g, there is a discrepancy in the macro luminosity of about 14 orders of magnitude between the predictions of the two formalisms. Armed with our finding we estimate the sensitivity for macro detection at space-based (Mini-EUSO and POEMMA) and suborbital (EUSO-SPB2) experiments.
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