200 research outputs found
Probabilistic dynamic analyses of a soil-structure system subjected to a stochastic earthquake Ground-Motion
In this paper, a probabilistic dynamic analysis of a five-storey building subjected to a stochastic earthquake Ground-Motion (GM) is presented. The entire soil-structure system is considered in the analysis. The stochastic GM time-histories are based on a real recorded time history. The probabilistic dynamic analysis is performed using the classical Monte Carlo Simulation (MCS) methodology. As is well known, this method requires a great number of calls of the deterministic model. To overcome the inconvenience of the time cost, a simple deterministic model based on the "macro-element" concept is used. The main advantage of the macro-element is that the time cost for a single deterministic calculation is relatively small and thus, this model is suitable for the probabilistic dynamic analysis. The simulation of the stochastic GM time-histories is done using a fully nonstationary stochastic model in both the time and the frequency domains. This model employs filtering of a discretized white-noise process. Non-stationarity is achieved by modulating the intensity and by varying the filter properties in time. As for the probabilistic analysis, a large number of samples (say 100,000) of the stochastic GM time-histories is generated using Monte Carlo technique. For each sample, a dynamic calculation using the macro-element is performed and the following responses are retained for the probabilistic analysis: (i) the maximum horizontal displacement at the top of the building, (ii) the three maximum displacements of the footing centre, and finally (iii) the three maximum reaction forces at the contact of the soil and the footing. These results are used to compute the statistical moments of the different system responses together with the probability of exceeding of predefined thresholds for these responses
The tale on the tongue of animals in the poetry of Mohammad Osman Jalal
The book " Awakening eyes in Proverbs and Preaching" by Mohamad Osman Jalal is one of the literary works of the nineteenth century which is a linguistic content for various cultural currents and tributaries that influenced the Egyptian environment. The causes of the modern literary renaissance, from education, research, translation, journalism and others to face the remnants of the intellectual and linguistic legacy of the ages of foreign sovereignty.
It can be said that this book is one of the first translated contributions that paved the way for the creation of children's literature in the modern Arabic literature in Egypt through the arabization of some animal tales from the tales of the French poet Lafontaine.
The poet Mohammad Othman Jalal did not stop at the limits of literal translation, and did not commit to the transfer of the stories as they are in their foreign origins. He even deleted them and amended them. He also came close to the Egyptian soul. He expressed this through systems and pieces of his writings,
Autonomic neurosurgery: from microvascular decompression to image guided stimulation
The paper reviews mechanisms underlying autonomic disorders, with a focus on cardiovascular dysfunction. Neurosurgical approaches are described for medically refractory hypertension and orthostatic hypotension. After review of microvascular decompression of the rostral ventrolateral medulla, stereotactic CT and MRI guided deep brain stimulation of the periaqueductal grey matter (PAG) is evaluated. Results are presented from patient studies showing reductions in blood pressure with ventral PAG stimulation and increases in blood pressure with dorsal PAG stimulation. A rationale for the treatment of autonomic disorders by neurosurgical intervention is discussed
Binding of the five multistate species of the anthocyanin analog 7- β -D-glucopyranosyloxy-4′-hydroxyflavylium to the β -cyclodextrin derivative captisol
The host-guest chemistry of the anthocyanin analog 7-β-D-glucopyranosyloxy-4'-hydroxyflavylium (GHF) was studied in the presence of the β-cyclodextrin derivative captisol by stopped flow, UVevisible spectroscopy, flash photolysis, circular dichroism and isothermal titration calorimetry. The equilibrium and rate constants of the multistate of chemical species derived from the flavylium ion were calculated and compared with those in the absence of the host. A new procedure to obtain the host-guest association constants of the multistate (including the transient species) by superimposing the two energy level diagrams, in the presence and absence of the cyclodextrin, was developed. The results indicate that the magnitude of the association constants follows the order, trans-chalcone = cis-chalcone = hemiketal > quinoidal base > flavylium cation. The hydration equilibrium constant increases ca. 42 times in the presence of captisol as the hydration and dehydration rate constants respectively increases and decreases. The other equilibrium constants are modestly affected: the rate constants of ring closure and opening are significantly decreased in the complex and the isomerization rate constants increase in both directions. The quantum yield of the photochromic system in the presence of captisol is0.3, i.e. 3 times higher than in the absence of the host
Mycobacterium chimaera pulmonary infection complicating cystic fibrosis: a case report
<p>Abstract</p> <p>Background</p> <p><it>Mycobacterium chimaera </it>is a recently described species within the <it>Mycobacterium avium </it>complex. Its pathogenicity in respiratory tract infection remains disputed. It has never been isolated during cystic fibrosis respiratory tract infection.</p> <p>Case presentation</p> <p>An 11-year-old boy of Asian ethnicity who was born on Réunion Island presented to our hospital with cystic fibrosis after a decline in his respiratory function over the course of seven years. We found that the decline in his respiratory function was correlated with the persistent presence of a <it>Mycobacterium avium </it>complex organism further identified as <it>M. chimaera</it>.</p> <p>Conclusion</p> <p>Using sequencing-based methods of identification, we observed that <it>M. chimaera </it>organisms contributed equally to respiratory tract infections in patients with cystic fibrosis when compared with <it>M. avium </it>subsp. <it>hominissuis </it>isolates. We believe that <it>M. chimaera </it>should be regarded as an emerging opportunistic respiratory pathogen in patients with cystic fibrosis, including young children, and that its detection warrants long-lasting appropriate anti-mycobacterial treatment to eradicate it.</p
Deficiency of SARS-CoV-2 T-cell responses after vaccination in long-term allo-HSCT survivors translates into abated humoral immunity
Recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for hematological diseases are at risk of severe disease and death from COVID-19. To determine the safety and immunogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines, samples from 50 infection-naive allo-HSCT recipients (median, 92 months from transplantation, range, 7-340 months) and 39 healthy controls were analyzed for serum immunoglobulin G (IgG) against the receptor binding domain (RBD) within spike 1 (S1) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; anti–RBD-S1 IgG) and for SARS-CoV-2–specific T-cell immunity, reflected by induction of T-cell–derived interferon-g in whole blood stimulated ex vivo with 15-mer SI-spanning peptides with 11 amino acid overlap S1-spanning peptides. The rate of seroconversion was not significantly lower in allo-transplanted patients than in controls with 24% (12/50) and 6% (3/50) of patients remaining seronegative after the first and second vaccination, respectively. However, 58% of transplanted patients lacked T-cell responses against S1 peptides after 1 vaccination compared with 19% of controls (odds ratio [OR] 0.17; P 5 .009, Fisher’s exact test) with a similar trend after the second vaccination where 28% of patients were devoid of detectable specific T-cell immunity, compared with 6% of controls (OR 0.18; P 5 .02, Fisher’s exact test). Importantly, lack of T-cell reactivity to S1 peptides after vaccination heralded substandard levels (,100 BAU/mL) of anti–RBD-S1 IgG 5 to 6 months after the second vaccine dose (OR 8.2; P 5 .007, Fisher’s exact test). We conclude that although allo-HSCT recipients achieve serum anti–RBD-S1 IgG against SARS-CoV-2 after 2 vaccinations, a deficiency of SARS-CoV-2–specific T-cell immunity may subsequently translate into insufficient humoral responses
Metabolic compartmentalization in the human cortex and hippocampus: evidence for a cell- and region-specific localization of lactate dehydrogenase 5 and pyruvate dehydrogenase
BACKGROUND: For a long time now, glucose has been thought to be the main, if not the sole substrate for brain energy metabolism. Recent data nevertheless suggest that other molecules, such as monocarboxylates (lactate and pyruvate mainly) could be suitable substrates. Although monocarboxylates poorly cross the blood brain barrier (BBB), such substrates could replace glucose if produced locally.The two key enzymatiques systems required for the production of these monocarboxylates are lactate dehydrogenase (LDH; EC1.1.1.27) that catalyses the interconversion of lactate and pyruvate and the pyruvate dehydrogenase complex that irreversibly funnels pyruvate towards the mitochondrial TCA and oxydative phosphorylation. RESULTS: In this article, we show, with monoclonal antibodies applied to post-mortem human brain tissues, that the typically glycolytic isoenzyme of lactate dehydrogenase (LDH-5; also called LDHA or LDHM) is selectively present in astrocytes, and not in neurons, whereas pyruvate dehydrogenase (PDH) is mainly detected in neurons and barely in astrocytes. At the regional level, the distribution of the LDH-5 immunoreactive astrocytes is laminar and corresponds to regions of maximal 2-deoxyglucose uptake in the occipital cortex and hippocampus. In hippocampus, we observed that the distribution of the oxidative enzyme PDH was enriched in the neurons of the stratum pyramidale and stratum granulosum of CA1 through CA4, whereas the glycolytic enzyme LDH-5 was enriched in astrocytes of the stratum moleculare, the alveus and the white matter, revealing not only cellular, but also regional, selective distributions. The fact that LDH-5 immunoreactivity was high in astrocytes and occurred in regions where the highest uptake of 2-deoxyglucose was observed suggests that glucose uptake followed by lactate production may principally occur in these regions. CONCLUSION: These observations reveal a metabolic segregation, not only at the cellular but also at the regional level, that support the notion of metabolic compartmentalization between astrocytes and neurons, whereby lactate produced by astrocytes could be oxidized by neurons
Reliability of Quantitative Real-Time PCR for Bacterial Detection in Cystic Fibrosis Airway Specimens
The cystic fibrosis (CF) airway microbiome is complex; polymicrobial infections are common, and the presence of fastidious bacteria including anaerobes make culture-based diagnosis challenging. Quantitative real-time PCR (qPCR) offers a culture-independent method for bacterial quantification that may improve diagnosis of CF airway infections; however, the reliability of qPCR applied to CF airway specimens is unknown. We sought to determine the reliability of nine specific bacterial qPCR assays (total bacteria, three typical CF pathogens, and five anaerobes) applied to CF airway specimens. Airway and salivary specimens from clinically stable pediatric CF subjects were collected. Quantitative PCR assay repeatability was determined using triplicate reactions. Split-sample measurements were performed to measure variability introduced by DNA extraction. Results from qPCR were compared to standard microbial culture for Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae, common pathogens in CF. We obtained 84 sputa, 47 oropharyngeal and 27 salivary specimens from 16 pediatric subjects with CF. Quantitative PCR detected bacterial DNA in over 97% of specimens. All qPCR assays were highly reproducible at quantities ≥102 rRNA gene copies/reaction with coefficient of variation less than 20% for over 99% of samples. There was also excellent agreement between samples processed in duplicate. Anaerobic bacteria were highly prevalent and were detected in mean quantities similar to that of typical CF pathogens. Compared to a composite gold standard, qPCR and culture had variable sensitivities for detection of P. aeruginosa, S. aureus and H. influenzae from CF airway samples. By reliably quantifying fastidious airway bacteria, qPCR may improve our understanding of polymicrobial CF lung infections, progression of lung disease and ultimately improve antimicrobial treatments
Consanguinity and reproductive health among Arabs
Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity
Target Identification for Stereotactic Thalamotomy Using Diffusion Tractography
BACKGROUND: Stereotactic targets for thalamotomy are usually derived from population-based coordinates. Individual anatomy is used only to scale the coordinates based on the location of some internal guide points. While on conventional MR imaging the thalamic nuclei are indistinguishable, recently it has become possible to identify individual thalamic nuclei using different connectivity profiles, as defined by MR diffusion tractography. METHODOLOGY AND PRINCIPAL FINDINGS: Here we investigated the inter-individual variation of the location of target nuclei for thalamotomy: the putative ventralis oralis posterior (Vop) and the ventral intermedius (Vim) nucleus as defined by probabilistic tractography. We showed that the mean inter-individual distance of the peak Vop location is 7.33 mm and 7.42 mm for Vim. The mean overlap between individual Vop nuclei was 40.2% and it was 31.8% for Vim nuclei. As a proof of concept, we also present a patient who underwent Vop thalamotomy for untreatable tremor caused by traumatic brain injury and another patient who underwent Vim thalamotomy for essential tremor. The probabilistic tractography indicated that the successful tremor control was achieved with lesions in the Vop and Vim respectively. CONCLUSIONS: Our data call attention to the need for a better appreciation of the individual anatomy when planning stereotactic functional neurosurgery
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