Search results for "lemma"
showing 10 items of 210 documents
Aidòs. Percorsi di etica del limite
2022
Come già Platone intuì con il mito di Protagora, la tecnica è figlia della finitezza. C’è tecnica, infatti, lì dove c’è bisogno di migliorare; ma lo stesso bisogno di migliorare è segno che non c’è ancora compimento. Nel crescente darsi da fare della tecnologia per strappare alla vita la sua imperfezione si nasconde così uno strano paradosso: lo scopo della tecnica non può che essere il proprio togliersi. Solo lì dove non ci sarà più tecnica, infatti, potrà esserci quella pienezza a cui l’uomo, tramite la tecnica, aspira. Ne consegue che il progresso qualitativo e quantitativo della tecnologia, lungi dall’avvicinarci gradualmente a un ultimo limite che sarà finalmente superato, è cifra di u…
Homozygous mutations incaveolin-3cause a severe form of rippling muscle disease
2003
Heterozygous missense mutations in the caveolin-3 gene (CAV3) cause different muscle disorders. Most patients with CAV3 alterations present with rippling muscle disease (RMD) characterized by signs of increased muscle irritability without muscle weakness. In some patients, CAV3 mutations underlie the progressive limb-girdle muscular dystrophy type 1C (LGMD1C). Here, we report two unrelated patients with novel homozygous mutations (L86P and A92T) in CAV3. Both presented with a more severe clinical phenotype than usually seen in RMD. Immunohistochemical and immunoblot analyses of muscle biopsies showed a strong reduction of caveolin-3 in both homozygous RMD patients similar to the findings in…
DNA-fragmentation and expression of apoptosis-related proteins in muscular dystrophies
1997
Although numerous sarcolemmal protein defects in muscular dystrophies have been identified, the mechanisms linking these defects and muscle fibre degeneration are not fully characterized. As there is evidence that apoptosis is part of muscle fibre loss in dystrophin-deficient mdx-mice, apoptotic muscle fibre death may also play a role in humans with muscular dystrophies. We investigated in-situ DNA-fragmentation by the TUNEL-method and expression of apoptosis-related proteins immunohistochemically in 14 children suffering from deficiencies of dystrophin, adhalin, and merosin, and found TUNEL-positive chromatin-cleavage of muscle fibre nuclei in about 10% of non-necrotic muscle fibres. DNA-f…
Data Backup Dilemma
2016
When the Great East Japan Earthquake struck in 2011, several municipalities lost their residential data including backup. Since none of them had ever considered the total loss of data, data backup policy had been paid little attention. In many cases, the backup tapes were simply stored inside the server room, just beside the server rack. Following the calamity, the Japanese national government tried to introduce a data backup system to municipalities using the cloud. The purpose was to secure the safekeeping of backup data. However, municipalities were reluctant to go along with this since overcoming the loss of network connectivity during an earthquake remained foremost in their minds. The…
On Fibrations Between Internal Groupoids and Their Normalizations
2018
We characterize fibrations and $$*$$ -fibrations in the 2-category of internal groupoids in terms of the comparison functor from certain pullbacks to the corresponding strong homotopy pullbacks. As an application, we deduce the internal version of the Brown exact sequence for $$*$$ -fibrations from the internal version of the Gabriel–Zisman exact sequence. We also analyse fibrations and $$*$$ -fibrations in the category of arrows and study when the normalization functor preserves and reflects them. This analysis allows us to give a characterization of protomodular categories using strong homotopy kernels and a generalization of the Snake Lemma.
More planet and less profit? The ethical dilemma of an oil producing nation
2019
Every oil producing nation is confronted with a complex and fundamental ethical dilemma. On the one hand, there are moral arguments for the nation to use the petroleum resource for the benefit of society and make it available for countries who do not have this natural resource endowment. On the other hand, there are moral arguments for not extracting and using fossil fuels because of CO2 emissions. In short, this creates tension between the need for government revenues to finance welfare benefits and the objective of preserving the environment. A complicating factor is that a nation's domestic oil and gas activities are in its nature global because the activities have a direct impact on the…
Malignant proliferating trichilemmal tumours: an histopathological and immunohistochemical study of three cases with DNA ploidy and morphometric eval…
1998
Aims: Malignant proliferating trichilemmal tumours (MPTT) are rare neoplasms capable of tissue invasion and metastasis, the diagnosis of which is based essentially on histological features. In difficult cases, however, evaluation of additional parameters may be needed to diagnose malignancy. Methods and results We report three cases of MPTT in which, in addition to the histological features, we have determined the DNA ploidy, nuclear area and proliferative fraction. CD34 immunoreactivity has also been tested. Two cases were aneuploid, and one diploid with increased proliferating index. PCNA immunostaining labelled 40% and 80% of tumour cells in aneuploid tumours and 30% of the diploid neopl…
Muscle degeneration in neuramindase 1 deficient mice results from infiltration of the muscle fibers by expanded connective tissue
2010
AbstractNeuraminidase 1 (NEU1) regulates the catabolism of sialoglycoconjugates in lysosomes. Congenital NEU1 deficiency in children is the basis of sialidosis, a severe neurosomatic disorder in which patients experience a broad spectrum of clinical manifestations varying in the age of onset and severity. Osteoskeletal deformities and muscle hypotonia have been described in patients with sialidosis. Here we present the first comprehensive analysis of the skeletal muscle pathology associated with loss of Neu1 function in mice. In this animal model, skeletal muscles showed an expansion of the epimysial and perimysial spaces, associated with proliferation of fibroblast-like cells and abnormal …
Desmin pathology in neuromuscular diseases
1993
Desmin is an intermediate filament protein that in striated muscle is normally located at Z-bands, beneath the sarcolemma, and prominently at neuromuscular junctions. It is abundant during myogenesis and in regenerating fibers, but decreases in amount with maturation; in regenerating and denervated muscle fibers it is co-expressed with vimentin. Aggregates of desmin occur as nonspecific cytoplasmic bodies or cytoplasmic spheroid complexes, similar to the aggregates of keratin filaments in Mallory bodies or the neurofilament aggregates in Lewy bodies. In all three instances, alpha-B crystallin may be associated with desmin. There are now increasing numbers of neuromuscular disorders in which…
Filamin C accumulation is a strong but nonspecific immunohistochemical marker of core formation in muscle.
2002
Filamin C is the muscle isoform of a group of large actin-crosslinking proteins. On the one hand, filamin C is associated with the Z-disk of the myofibrillar apparatus and binds to myotilin; on the other hand, it interacts with the sarcoglycan complex at the sarcolemma. Filamin C may be involved in reorganizing the cytoskeleton in response to signalling events and in muscle it may, in addition, fulfill structural functions at the Z-disk. An examination of biopsies from patients with multi-minicore myopathy, central core myopathy and neurogenic target fibers with core-like target formations (TF) revealed strong reactivity of all the cores and target formations with two different anti-filamin…