3,117 research outputs found
Transient resonance Raman spectroscopy and density functional theory investigation of iso-polyhalomethanes containing bromine and/or iodine atoms
Transient resonance Raman spectroscopy and density functional theory were used to investigate iso-polyhalomethanes containing bromine and/or iodine atoms. The iso-polyhalomethane species were found to have an intense electronic band in the range 350-470 nm. It was found that iso-polyhalomethane species is most likely the methylene transfer agent in the cyclopropanation reactions of olefins.published_or_final_versio
Type Iax Supernovae
Type Iax supernovae (SN Iax), also called SN 2002cx-like supernovae, are the
largest class of peculiar white dwarf (thermonuclear) supernovae, with over
fifty members known. SN Iax have lower ejecta velocity and lower luminosities,
and these parameters span a much wider range, than normal type Ia supernovae
(SN Ia). SN Iax are spectroscopically similar to some SN Ia near maximum light,
but are unique among all supernovae in their late-time spectra, which never
become fully nebular. SN Iax overwhelmingly occur in late-type host galaxies,
implying a relatively young population. The SN Iax 2012Z is the only white
dwarf supernova for which a pre-explosion progenitor system has been detected.
A variety of models have been proposed, but one leading scenario has emerged: a
type Iax supernova may be a pure-deflagration explosion of a carbon-oxygen (or
hybrid carbon-oxygen-neon) white dwarf, triggered by helium accretion to the
Chandrasekhar mass, that does not necessarily fully disrupt the star.Comment: Author version of a chapter in the 'Handbook of Supernovae', edited
by A. Alsabti and P. Murdin, Springer. 31 pages, 6 figure
Transient resonance Raman spectroscopy and density functional theory investigation of iso-CHBr 2Cl and iso-CCl 3Br photoproducts produced following ultraviolet excitation of CHBr 2Cl and CCl 3Br
Two polyhalomethanes that contain bromine and chlorine atoms (CHBr 2Cl and CCl 2Br) were studied. Transient resonance Raman spectra were obtained for the photoproducts produced after ultraviolet excitation of CHBr 2Cl and CCl 3Br in room temperature solutions and density functional theory calculations for species proposed to be products of the photodissociation reactions in the solution phase. It was found that the iso-CHBrCl-Br and iso-CHClBr-Br species are formed following ultraviolet excitation of CHBr 2Cl and the iso-CCl 2Cl-Br species formed following ultraviolet excitation of CCl 3Br in the solution phase.published_or_final_versio
An Investigation on Integrating Eastern and Western Medicine with Informatics
Today, in many western countries, acceptance of alternate forms of healthcare such as Chinese medicine (CM) is increasing. In fact, countries such as Australia, Canada, and England are going so far as to set regulations, education, and standards regarding the practice of CM in these respective countries. Further, we can see the integration between western and Chinese medicine delivery of care and treatments in many instances. Information Systems and Information Technology (IS/IT) can be a key enabler in assisting this integration. The following study examines aspects of such integrations using IS/IT and identifies that CM IS/IT is more likely to succeed when there is synthesis between key aspects of the unique environment and user requirements. This perspective is supported theoretically by adapting Churchman’s Inquiring Systems to frame CM as a combination of Hegelian and Kantian inquiring systems with the support of Singerian, Lockean, and Leibnizian inquiring systems and Knowledge Management (KM) features. Based on this, the study then proposes a new design for a patient management system in clinics and hospitals
Entropy Projection Curved Gabor with Random Forest and SVM for Face Recognition
In this work, we propose a workflow for face recognition under occlusion using the entropy projection from the curved Gabor filter, and create a representative and compact features vector that describes a face. Despite the reduced vector obtained by the entropy projection, it still presents opportunity for further dimensionality reduction. Therefore, we use a Random Forest classifier as an attribute selector, providing a 97% reduction of the original vector while keeping suitable accuracy. A set of experiments using three public image databases: AR Face, Extended Yale B with occlusion and FERET illustrates the proposed methodology, evaluated using the SVM classifier. The results obtained in the experiments show promising results when compared to the available approaches in the literature, obtaining 98.05% accuracy for the complete AR Face, 97.26% for FERET and 81.66% with Yale with 50% occlusion
P16-07. HLA-B1302 is associated with viral control in clade CRF01_AE HIV-1 infection in Thailand
A novel isolator-based system promotes viability of human embryos during laboratory processing
In vitro fertilisation (IVF) and related technologies are arguably the most challenging of all cell culture applications. The starting material is a single cell from which one aims to produce an embryo capable of establishing a pregnancy eventually leading to a live birth. Laboratory processing during IVF treatment requires open manipulations of gametes and embryos, which typically involves exposure to ambient conditions. To reduce the risk of cellular stress, we have developed a totally enclosed system of interlinked isolator-based workstations designed to maintain oocytes and embryos in a physiological environment throughout the IVF process. Comparison of clinical and laboratory data before and after the introduction of the new system revealed that significantly more embryos developed to the blastocyst stage in the enclosed isolator-based system compared with conventional open-fronted laminar flow hoods. Moreover, blastocysts produced in the isolator-based system contained significantly more cells and their development was accelerated. Consistent with this, the introduction of the enclosed system was accompanied by a significant increase in the clinical pregnancy rate and in the proportion of embryos implanting following transfer to the uterus. The data indicate that protection from ambient conditions promotes improved development of human embryos. Importantly, we found that it was entirely feasible to conduct all IVF-related procedures in the isolator-based workstations
Cytogenetic and histological studies of the brook trout, Salvelinus fontinalis (Mitchill), and the Arctic char, S-alpinus (L.) hybrids
Although brook trout and the Arctic char hybrids are able to reproduce, individuals with decreased fertility or even fish that are unable to produce any gametes have been also described. Abnormal gonadal development and disturbances in the gamete production in the char hybrid offspring may be triggered by the odd chromosome number and disturbances in their pairing during meiosis. To verify this hypothesis, cytogenetic examination and the gonadal histology analysis of the brook trout x Arctic char hybrids were carried out. Diploid chromosome number in the studied char (F-1) hybrids varied from 82 to 84 (FN = 99-102). Among 28 hybrids, 12 males, three females, nine intersex individuals and two sterile specimens were described. In the case of two individuals, gonads were not found. Diploid chromosome numbers in the males and intersex individuals varied from 82 to 84. Chromosome numbers in the females were 82 and 83 chromosomes. Two sterile fish exhibited karyotypes composed of 82 and 84 chromosomes. Predominance of the ovarian component in the intersex gonads and gonadal sex ratio distortion towards the males suggested hybrid females had problems with gonadal differentiation. However, the lack of the clear relationship between chromosome number and gonadal development in the studied hybrids did not support our hypothesis that odd chromosome number may be responsible for such reproductive disturbances in the hybrid individuals. We have presumed that sterility and intersexual development of the gonads may be caused by interactions between brook trout and Arctic char genes on the sex chromosomes and autosomes rather than unpairing of the parental chromosomes.Polish National Science Center (NCN) [N N311 525240]info:eu-repo/semantics/publishedVersio
Categorial Compositionality: A Category Theory Explanation for the Systematicity of Human Cognition
Classical and Connectionist theories of cognitive architecture seek to explain systematicity (i.e., the property of human cognition whereby cognitive capacity comes in groups of related behaviours) as a consequence of syntactically and functionally compositional representations, respectively. However, both theories depend on ad hoc assumptions to exclude specific instances of these forms of compositionality (e.g. grammars, networks) that do not account for systematicity. By analogy with the Ptolemaic (i.e. geocentric) theory of planetary motion, although either theory can be made to be consistent with the data, both nonetheless fail to fully explain it. Category theory, a branch of mathematics, provides an alternative explanation based on the formal concept of adjunction, which relates a pair of structure-preserving maps, called functors. A functor generalizes the notion of a map between representational states to include a map between state transformations (or processes). In a formal sense, systematicity is a necessary consequence of a higher-order theory of cognitive architecture, in contrast to the first-order theories derived from Classicism or Connectionism. Category theory offers a re-conceptualization for cognitive science, analogous to the one that Copernicus provided for astronomy, where representational states are no longer the center of the cognitive universe—replaced by the relationships between the maps that transform them
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