323 research outputs found
Robust normalization and guaranteed cost control for a class of uncertain singular Markovian jump systems via hybrid impulsive control
This paper investigates the problem of robust normalization and guaranteed cost control for a class of uncertain singular Markovian jump systems. The uncertainties exhibit in both system matrices and transition rate matrix of the Markovian chain. A new impulsive and proportional-derivative control strategy is presented, where the derivative gain is to make the closed-loop system of the singular plant to be a normal one, and the impulsive control part is to make the value of the Lyapunov function does not increase at each time instant of the Markovian switching. A linearization approach via congruence transformations is proposed to solve the controller design problem. The cost function is minimized via solving an optimization problem under the designed control scheme. Finally, three examples (two numerical examples and an RC pulse divider circuit example) are provided to illustrate the effectiveness and applicability of the proposed methods
De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development
Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD
Review on catalytic cleavage of C-C inter-unit linkages in lignin model compounds: Towards lignin depolymerisation
Lignin depolymerisation has received considerable attention recently due to the pressing need to find sustainable alternatives to fossil fuel feedstock to produce chemicals and fuels. Two types of interunit linkages (C–C and C–O linkages) link several aromatic units in the structure of lignin. Between these two inter-unit linkages, the bond energies of C–C linkages are higher than that of C–O linkages, making them harder to break. However, for an efficient lignin depolymerisation, both types of inter-unit linkages have to be broken. This is more relevant because of the fact that many delignification processes tend to result in the formation of additional C–C inter-unit bonds. Here we review the strategies reported for the cleavage of C–C inter-unit linkages in lignin model compounds and lignin. Although a number of articles are available on the cleavage of C–O inter-unit linkages, reports on the selective cleavage of C–C inter-unit linkages are relatively less. Oxidative cleavage, hydrogenolysis, two-step redox-neutral process, microwave assisted cleavage, biocatalytic and photocatalytic methods have been reported for the breaking of C–C inter-unit linkages in lignin. Here we review all these methods in detail, focused only on the breaking of C–C linkages. The objective of this review is to motivate researchers to design new strategies to break this strong C–C inter-unit bonds to valorise lignins, technical lignins in particular
Muscle invasive bladder cancer in Upper Egypt: the shift in risk factors and tumor characteristics
<p>Abstract</p> <p>Background</p> <p>In Egypt, where bilharziasis is endemic, bladder cancer is the commonest cancer in males and the 2<sup>nd </sup>in females; squamous cell carcinoma (SCC) is the commonest type found, with a peculiar mode of presentation. The aim of this study is to identify and rank the risk factors of muscle invasive bladder cancer (MIBC) in Upper Egypt and describe its specific criteria of presentation and histopathology.</p> <p>Methods</p> <p>This is an analytical, hospital based, case controlled study conducted in south Egypt cancer institute through comparing MIBC cases (n = 130) with age, sex and residence matched controls (n = 260) for the presence of risk factors of MIBC. Data was collected by personal interview using a well designed questionnaire. Patients' records were reviewed for histopathology and Radiologic findings.</p> <p>Results</p> <p>The risk factors of MIBC were positive family history [Adjusted odds ratio (AOR) = 7.7], exposure to pesticides [AOR = 6.2], bladder stones [AOR = 5], consanguinity [AOR = 3.9], recurrent cystitis [AOR = 3.1], bilharziasis [odds ratio (OR) = 5.8] and smoking [OR = 5.3]. SCC represented 67.6% of cases with burning micturition being the presenting symptom in 73.8%.</p> <p>Conclusion</p> <p>MIBC in Upper Egypt is usually of the SCC type (although its percentage is decreasing), occurs at a younger age and presents with burning micturition rather than hematuria. Unlike the common belief, positive family history, parents' consanguinity, exposure to pesticides and chronic cystitis seem to play now more important roles than bilharziasis and smoking in the development of this disease in this area.</p
Stability and mobility of supported Nin (n = 1–10) clusters on ZrO2(111) and YSZ(111) surfaces: a density functional theory study
The performance of supported metal catalysts, such as nickel nanoparticles decorating yttria-stabilized zirconia (YSZ), depends on their microstructure and the metal–support interface. Here, we have used spin polarized density functional theory (DFT) to evaluate different Ni cluster geometries and determined the electronic structure of the most stable configurations. We have described the interaction of Nin (n = 1–10) clusters supported on the cubic ZrO2(111) and YSZ(111) surfaces, which show a preference for pyramidal shapes rather than flat structures wetting the surface. The interfacial interaction is characterized by charge transfer from the cluster to the surface. We also show how yttrium, present in YSZ, affects the Ni–Ni interaction. Through analysing the difference between the cohesive energy and the clustering energy, we show the preference of Ni–Ni bond formation over Ni-surface interaction; this energy difference decreases with the increase of the Nin cluster size. From the evaluation of the Ni atomic hopping rates on YSZ, we have demonstrated that under different temperature conditions, Ni atoms aggregate with other atoms and clusters, which affects the cluster size stability
Big Earth Data for Cultural Heritage in the Copernicus Era
Digital data is stepping in its golden age characterized by an increasing
growth of both classical and emerging big earth data along with trans- and multidisciplinary
methodological approaches and services addressed to the study, preservation
and sustainable exploitation of cultural heritage (CH). The availability of new
digital technologies has opened new possibilities, unthinkable only a few years ago
for cultural heritage. The currently available digital data, tools and services with
particular reference to Copernicus initiatives make possible to characterize and
understand the state of conservation of CH for preventive restoration and opened up
a frontier of possibilities for the discovery of archaeological sites from above and
also for supporting their excavation, monitoring and preservation. The different
areas of intervention require the availability and integration of rigorous information
from different sources for improving knowledge and interpretation, risk assessment
and management in order to make more successful all the actions oriented to the
preservation of cultural properties. One of the biggest challenges is to fully involve
the citizen also from an emotional point of view connecting “pixels with people”
and “bridging” remote sensing and social sensing
Novel sequence variations in LAMA2 andSGCG genes modulating cis-acting regulatory elements and RNA secondary structure
In this study, we detected new sequence variations in LAMA2 and SGCG genes in 5 ethnic populations, and analysed their effect on enhancer composition and mRNA structure. PCR amplification and DNA sequencing were performed and followed by bioinformatics analyses using ESEfinder as well as MFOLD software. We found 3 novel sequence variations in the LAMA2 (c.3174+22_23insAT and c.6085 +12delA) and SGCG (c. * 102A/C) genes. These variations were present in 210 tested healthy controls from Tunisian, Moroccan, Algerian, Lebanese and French populations suggesting that they represent novel polymorphisms within LAMA2 and SGCG genes sequences. ESEfinder showed that the c. * 102A/C substitution created a new exon splicing enhancer in the 3'UTR of SGCG genes, whereas the c.6085 +12delA deletion was situated in the base pairing region between LAMA2 mRNA and the U1snRNA spliceosomal components. The RNA structure analyses showed that both variations modulated RNA secondary structure. Our results are suggestive of correlations between mRNA folding and the recruitment of spliceosomal components mediating splicing, including SR proteins. The contribution of common sequence variations to mRNA structural and functional diversity will contribute to a better study of gene expression
Commercial refrigeration - An overview of current status
[EN] Commercial Refrigeration comprises food freezing and conservation in retail stores and supermarkets, so, it is one of the most relevant energy consumption sectors, and its relevance is increasing. This paper reviews the most recent developments in commercial refrigeration available in literature and presents a good amount of results provided these systems, covering some advantages and disadvantages in systems and working fluids. Latest researches are focused on energy savings to reduce CO2 indirect emissions due to the burning of fossil fuels. They are focused on system modifications (as dedicated subcooling or the implementation of ejectors), trigeneration technologies (electrical, heating and cooling demand) and better evaporation conditions control. Motivated by latest GWP regulations that are intended to reduce high GWP HFC emissions; R404A and R507 are going to phase out. Besides hydrocarbons and HFO, CO2 appears as one of the most promising HFC replacements because its low contribution to global warming and high efficiencies when used in transcritical and low-stage of cascade systems.The authors thankfully acknowledge "Ministerio de Educacion, Cultura y Deporte" for supporting this work through "Becas y Contratos de Formacion de Profesorado Universitario del Programa Nacional de Formacion de Recursos Humanos de Investigacion del ejercicio 2012".Mota Babiloni, A.; Navarro Esbri, J.; Barragán Cervera, Á.; Moles, F.; Peris, B.; Verdú Martín, GJ. (2015). Commercial refrigeration - An overview of current status. International Journal of Refrigeration. 57:186-196. doi:10.1016/j.ijrefrig.2015.04.013S1861965
Assessment of the Food Habits of the Moroccan Dorcas Gazelle in M’Sabih Talaa, West Central Morocco, Using the trnL Approach
Food habits of the Moroccan dorcas gazelle, Gazella dorcas massaesyla, previously investigated in the 1980s using microhistological fecal analysis, in the M’Sabih Talaa Reserve, west central Morocco, were re-evaluated over three seasons (spring, summer and autumn 2009) using the trnL approach to determine the diet composition and its seasonal variation from fecal samples. Taxonomic identification was carried out using the identification originating from the database built from EMBL and the list of plant species within the reserve. The total taxonomic richness in the reserve was 130 instead of 171 species in the 1980s. The diet composition revealed to be much more diversified (71 plant taxa belonging to 57 genus and 29 families) than it was 22 years ago (29 identified taxa). Thirty-four taxa were newly identified in the diet while 13 reported in 1986–87 were not found. Moroccan dorcas gazelle showed a high preference to Acacia gummifera, Anagallis arvensis, Glebionis coronaria, Cladanthus arabicus, Diplotaxis tenuisiliqua, Erodium salzmannii, Limonium thouini, Lotus arenarius and Zizyphus lotus. Seasonal variations occurred in both number (40–41 taxa in spring-summer and 49 taxa in autumn vs. respectively 23–22 and 26 in 1986–1987) and taxonomic type of eaten plant taxa. This dietary diversification could be attributed either to the difference in methods of analysis, trnL approach having a higher taxonomic resolution, or a potential change in nutritional quality of plants over time
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