81 research outputs found
Localization of Deformations in Finite Elastoplasticity
In this paper the guidelines for constructing a geometrical model for the localization of deformations during elastic-plastic deformations are given. A geometrical object, namely the physical metric, introduced to take into account the internal disarrangement during the plastic flow. A number of very general thermomechanical relations are obtained. Constitutive relations giving the conditions for the absence of localization phenomena are also obtained for the two different cases of decomposition of the total deformation gradient into the elastic and the plastic part (Lee, 1969; Nemat-Nasser, 1.979)
Thermodynamics of Deformable Dielectrics with a Non-Euclidean Structure as Internal Variable
In this paper we apply the geometrical theory of thermodynamics with vectorial and tensorial internal variables to a model of deformable dielectrics (which include ferro-electric crystals) due to Maugin. We explicitly consider an internal (non-Euclidean) metric as a thermodynamical non-equilibrium variable, together with polarization and temperature gradients. With the aid of Clausius-Duhem inequality we obtain the extra entropy flux and the relevant thermodynamical restrictions on entropy and free energy
Differences in tidal breathing between infants with chronic lung diseases and healthy controls
BACKGROUND: The diagnostic value of tidal breathing (TB) measurements in infants is controversially discussed. The aim of this study was to investigate to what extent the breathing pattern of sleeping infants with chronic lung diseases (CLD) differ from healthy controls with the same postconceptional age and to assess the predictive value of TB parameters. METHODS: In the age of 36–42 postconceptional weeks TB measurements were performed in 48 healthy newborns (median age and weight 7d, 3100 g) and 48 infants with CLD (80d, 2465 g)) using the deadspace-free flow-through technique. Once the infants had adapted to the mask and were sleeping quietly and breathing regularly, 20–60 breathing cycles were evaluated. Beside the shape of the tidal breathing flow-volume loop (TBFVL) 18 TB parameters were analyzed using ANOVA with Bonferroni correction. Receiver-operator characteristic (ROC) curves were calculated to investigate the discriminative ability of TB parameters. RESULTS: The incidence of concave expiratory limbs in CLD infants was 31% and significantly higher compared to controls (2%) (p < 0.001). Significant differences between CLD infants and controls were found in 11/18 TB parameters. The largest differences were seen in the mean (SD) inspiratory time 0.45(0.11)s vs. 0.65(0.14)s (p < 0.0001) and respiratory rate (RR) 55.4(14.2)/min vs. 39.2(8.6)/min (p < 0.0001) without statistically significant difference in the discriminative power between both time parameters. Most flow parameters were strongly correlated with RR so that there is no additional diagnostic value. No significant differences were found in the tidal volume and commonly used TB parameters describing the expiratory flow profile. CONCLUSION: The breathing pattern of CLD infants differs significantly from that of healthy controls. Concave TBFVL and an increased RR measured during quiet sleep and under standardized conditions may indicate diminished respiratory functions in CLD infants whereas most of the commonly used TB parameters are poorly predictive
An improved microRNA annotation of the canine genome
The domestic dog, Canis familiaris, is a valuable model for studying human diseases. The publication of the latest Canine genome build and annotation, CanFam3.1 provides an opportunity to enhance our understanding of gene regulation across tissues in the dog model system. In this study, we used the latest dog genome assembly and small RNA sequencing data from 9 different dog tissues to predict novel miRNAs in the dog genome, as well as to annotate conserved miRNAs from the miRBase database that were missing from the current dog annotation. We used both miRCat and miRDeep2 algorithms to computationally predict miRNA loci. The resulting, putative hairpin sequences were analysed in order to discard false positives, based on predicted secondary structures and patterns of small RNA read alignments. Results were further divided into high and low confidence miRNAs, using the same criteria. We generated tissue specific expression profiles for the resulting set of 811 loci: 720 conserved miRNAs, (207 of which had not been previously annotated in the dog genome) and 91 novel miRNA loci. Comparative analyses revealed 8 putative homologues of some novel miRNA in ferret, and one in microbat. All miRNAs were also classified into the genic and intergenic categories, based on the Ensembl RefSeq gene annotation for CanFam3.1. This additionally allowed us to identify four previously undescribed MiRtrons among our total set of miRNAs. We additionally annotated piRNAs, using proTRAC on the same input data. We thus identified 263 putative clusters, most of which (211 clusters) were found to be expressed in testis. Our results represent an important improvement of the dog genome annotation, paving the way to further research on the evolution of gene regulation, as well as on the contribution of post-transcriptional regulation to pathological conditions
Genome-wide microRNA screening in Nile tilapia reveals pervasive isomiRs’ transcription, sex-biased arm switching and increasing complexity of expression throughout development
MicroRNAs (miRNAs) are key regulators of gene expression in multicellular organisms. The elucidation of miRNA function and evolution depends on the identification and characterization of miRNA repertoire of strategic organisms, as the fast-evolving cichlid fishes. Using RNA-seq and comparative genomics we carried out an in-depth report of miRNAs in Nile tilapia (Oreochromis niloticus), an emergent model organism to investigate evo-devo mechanisms. Five hundred known miRNAs and almost one hundred putative novel vertebrate miRNAs have been identified, many of which seem to be teleost-specific, cichlid-specific or tilapia-specific. Abundant miRNA isoforms (isomiRs) were identified with modifications in both 5p and 3p miRNA transcripts. Changes in arm usage (arm switching) of nine miRNAs were detected in early development, adult stage and even between male and female samples. We found an increasing complexity of miRNA expression during ontogenetic development, revealing a remarkable synchronism between the rate of new miRNAs recruitment and morphological changes. Overall, our results enlarge vertebrate miRNA collection and reveal a notable differential ratio of miRNA arms and isoforms influenced by sex and developmental life stage, providing a better picture of the evolutionary and spatiotemporal dynamics of miRNAs
Association between FSHR polymorphisms and polycystic ovary syndrome among Chinese women in north China
A geometric model for the thermodynamics of simple materials
A geometric model for the thermodynamics of continuous media is
constructed, providing a clearer meaning to the commonly used
concept of `processes` and `transformations`. The aim is to
elucidate a clear ground suited to analyse thermodynamic
transformations outside equilibrium. The model is applied to the
thermodynamics of simple materials and explicit expressions for
the existence of an entropy function are obtained
Voorwoord (The broad connection)
On October the 11th 1991 the symposium The broad connection took place in the church of the Evangelic Community of Brethren at Zeist. Five speakers reflected on the connection between the minute research of the historian of ancient monuments, restoration practice and the policy for preservation. Prof. dr. ir. R. Meischke, chairman of that day, seriously wondered if this connection existed.
The symposium perfectly made clear the distance between the desired and the actual connection of the research of historic buildings and the restoration practice. Many causes can be adduced. These causes were analyzed and most of the speakers, very often historians of ancient monuments themselves, did not hesitate to dive into their own hearts. One clearly was directed to the future.
The world of the preservation of ancient monuments is in motion. Also the previously somewhat closed world of the historians of these monuments is changing. Researchers see themselves confronted with new problems of research. Conclusions from the past open perspectives and ways for the future.
History of architecture is no stranger in the columns of this Bulletin. Regularly articles are published, which are based on the thorough research of ancient monuments. The reader however can seldom look behind the scenes. Which is presented in an agreeable way often has been fought under very difficult circumstances. History of architecture thereby constantly proved its value to both restoration practice and the improvement of the knowledge of ancient monuments. Therefore the editors of this Bulletin decided to publish the contents of this lectures, which have been slightly worked up by the speakers for publication.
The lecture of Dr. L. de Vliegher, who revealed his ideas and experiences in his very own way did not lend itself for publication. Therefore this lecture has not been published. A short retrospective view on the course of the day is justified in this introduction. The occasion of this meeting was the farewell of Dr. H. Janse of the Ancient Monuments Department of the Ministry of Works because of his pensionable age. With this symposium the Ancient Monuments Department of the Ministry of Works dwelled on the research of historic buildings which has been given such an important impulse by Herman Janse and some honoured contemporaries and predecessors.
The organization has been teased somewhat by sudden diseases of speakers. Mrs. Laleman and Mr. de Vries were very well replaced by Mr. Raveschot and Mr. de Jong. The cooperation of Belgian colleagues has been consciously sought after to enlarge the connection by exchange of experiences. This day also was seized upon to present two new appearances: the book Work and mark of the stonemason, the trade of the stonemason in the Netherlands before 1800 by H. Janse and D.J. de Vries and the announcement of the establishment of the foundation History of Ancient Monuments of the Netherlands. This foundation can be an underscore of the stage of maturity this discipline has reached in the Netherlands.On October the 11th 1991 the symposium The broad connection took place in the church of the Evangelic Community of Brethren at Zeist. Five speakers reflected on the connection between the minute research of the historian of ancient monuments, restoration practice and the policy for preservation. Prof. dr. ir. R. Meischke, chairman of that day, seriously wondered if this connection existed.
The symposium perfectly made clear the distance between the desired and the actual connection of the research of historic buildings and the restoration practice. Many causes can be adduced. These causes were analyzed and most of the speakers, very often historians of ancient monuments themselves, did not hesitate to dive into their own hearts. One clearly was directed to the future.
The world of the preservation of ancient monuments is in motion. Also the previously somewhat closed world of the historians of these monuments is changing. Researchers see themselves confronted with new problems of research. Conclusions from the past open perspectives and ways for the future.
History of architecture is no stranger in the columns of this Bulletin. Regularly articles are published, which are based on the thorough research of ancient monuments. The reader however can seldom look behind the scenes. Which is presented in an agreeable way often has been fought under very difficult circumstances. History of architecture thereby constantly proved its value to both restoration practice and the improvement of the knowledge of ancient monuments. Therefore the editors of this Bulletin decided to publish the contents of this lectures, which have been slightly worked up by the speakers for publication.
The lecture of Dr. L. de Vliegher, who revealed his ideas and experiences in his very own way did not lend itself for publication. Therefore this lecture has not been published. A short retrospective view on the course of the day is justified in this introduction. The occasion of this meeting was the farewell of Dr. H. Janse of the Ancient Monuments Department of the Ministry of Works because of his pensionable age. With this symposium the Ancient Monuments Department of the Ministry of Works dwelled on the research of historic buildings which has been given such an important impulse by Herman Janse and some honoured contemporaries and predecessors.
The organization has been teased somewhat by sudden diseases of speakers. Mrs. Laleman and Mr. de Vries were very well replaced by Mr. Raveschot and Mr. de Jong. The cooperation of Belgian colleagues has been consciously sought after to enlarge the connection by exchange of experiences. This day also was seized upon to present two new appearances: the book Work and mark of the stonemason, the trade of the stonemason in the Netherlands before 1800 by H. Janse and D.J. de Vries and the announcement of the establishment of the foundation History of Ancient Monuments of the Netherlands. This foundation can be an underscore of the stage of maturity this discipline has reached in the Netherlands
- …