216 research outputs found

    A dentigerous cyst associated with bilaterally impacted mandibular canines in a girl: a case report

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    Introduction: A dentigerous cyst is the most common developmental odontogenic cyst and is frequently noted as an incidental finding on radiographs. The most common teeth affected are impacted mandibular third molars and permanent maxillary canines. This case involves a dentigerous cyst encompassing the right and left impacted mandibular canines and crossing the midline. This is, to the best of our knowledge, the first reported case of a dentigerous cyst encompassing non-adjacent teeth and crossing the midline. Case presentation: The patient presented to our orthodontic clinic for treatment of malocclusion. The patient was a 10-year, one-month-old Caucasian girl with a dentigerous cyst encompassing the right and left impacted mandibular canines and crossing the midline. Conclusion: This case involves an unusual clinical and radiographic presentation of a dentigerous cyst. It shows a new variant of presentation that medical professionals, specifically dentists and radiologists, should be aware of, since a dentigerous cyst crossing the midline has not been previously reported as far as we are aware. This additional knowledge is important for inclusion on differential diagnosis lists and aids in the development of a proper treatment plan

    Plane torsion waves in quadratic gravitational theories

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    The definition of the Riemann-Cartan space of the plane wave type is given. The condition under which the torsion plane waves exist is found. It is expressed in the form of the restriction imposed on the coupling constants of the 10-parametric quadratic gravitational Lagrangian. In the mathematical appendix the formula for commutator of the variation operator and Hodge operator is proved. This formula is applied for the variational procedure when the gravitational field equations are obtained in terms of the exterior differential forms.Comment: 3 May 1998. - 11

    Blue Stragglers in Galactic Open Clusters and the Integrated Spectral Energy Distributions

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    Synthetic integrated spectral properties of the old Galactic open clusters are studies in this work, where twenty-seven Galactic open clusters of ages >= 1Gyr are selected as the working sample. Based on the photometric observations of these open clusters, synthetic integrated spectrum has been made for the stellar population of each cluster. The effects of blue straggler stars (BSSs) on the conventional simple stellar population (SSP) model are analyzed on an individual cluster base. It is shown that the BSSs, whose holding positions in the color-magnitude diagrams (CMDs) cannot be predicted by the current single-star evolution theory, present significant modifications to the integrated properties of theoretical SSP model. The synthesized integrated spectral energy distributions (ISEDs) of our sample clusters are dramatically different from the SSPs based on isochrone only. The BSSs corrected ISEDs of stellar populations show systematic enhancements towards shorter wavelength in the spectra. When measured with wide-band colors in unresolvable conditions, the age of a stellar population can be seriously under-estimated by the conventional SSP model. Therefore, considering the common existence of BSS component in real stellar populations, a considerable amount of alternations on the conventional ISEDs should be expected when applying the technique of evolutionary population synthesis (EPS) to more complicated stellar systems.Comment: 45 pages, 21 figures Accepted for publication in ApJ (Feburary 1, 2005 issue

    Coherent Matter Wave Transport in Speckle Potentials

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    This article studies multiple scattering of matter waves by a disordered optical potential in two and in three dimensions. We calculate fundamental transport quantities such as the scattering mean free path s\ell_s, the Boltzmann transport mean free path \elltrb, and the Boltzmann diffusion constant DBD_B, using a diagrammatic Green functions approach. Coherent multiple scattering induces interference corrections known as weak localization which entail a reduced diffusion constant. We derive the corresponding expressions for matter wave transport in an correlated speckle potential and provide the relevant parameter values for a possible experimental study of this coherent transport regime, including the critical crossover to the regime of strong or Anderson localization.Comment: 33 pages, minor corrections, published versio

    Equation of state for Universe from similarity symmetries

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    In this paper we proposed to use the group of analysis of symmetries of the dynamical system to describe the evolution of the Universe. This methods is used in searching for the unknown equation of state. It is shown that group of symmetries enforce the form of the equation of state for noninteracting scaling multifluids. We showed that symmetries give rise the equation of state in the form p=Λ+w1ρ(a)+w2aβ+0p=-\Lambda+w_{1}\rho(a)+w_{2}a^{\beta}+0 and energy density ρ=Λ+ρ01a3(1+w)+ρ02aβ+ρ03a3\rho=\Lambda+\rho_{01}a^{-3(1+w)}+\rho_{02}a^{\beta}+\rho_{03}a^{-3}, which is commonly used in cosmology. The FRW model filled with scaling fluid (called homological) is confronted with the observations of distant type Ia supernovae. We found the class of model parameters admissible by the statistical analysis of SNIa data. We showed that the model with scaling fluid fits well to supernovae data. We found that Ωm,00.4\Omega_{\text{m},0} \simeq 0.4 and n1n \simeq -1 (β=3n\beta = -3n), which can correspond to (hyper) phantom fluid, and to a high density universe. However if we assume prior that Ωm,0=0.3\Omega_{\text{m},0}=0.3 then the favoured model is close to concordance Λ\LambdaCDM model. Our results predict that in the considered model with scaling fluids distant type Ia supernovae should be brighter than in Λ\LambdaCDM model, while intermediate distant SNIa should be fainter than in Λ\LambdaCDM model. We also investigate whether the model with scaling fluid is actually preferred by data over Λ\LambdaCDM model. As a result we find from the Akaike model selection criterion prefers the model with noninteracting scaling fluid.Comment: accepted for publication versio

    Description of the Scenario Machine

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    We present here an updated description of the "Scenario Machine" code. This tool is used to carry out a population synthesis of binary stars. Previous version of the description can be found at http://xray.sai.msu.ru/~mystery//articles/review/contents.htmlComment: 32 pages, 3 figures. Corrected typo

    Neurological manifestations of SARS-CoV-2 infection in hospitalised children and adolescents in the UK: a prospective national cohort study

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    BACKGROUND: The spectrum of neurological and psychiatric complications associated with paediatric SARS-CoV-2 infection is poorly understood. We aimed to analyse the range and prevalence of these complications in hospitalised children and adolescents. METHODS: We did a prospective national cohort study in the UK using an online network of secure rapid-response notification portals established by the CoroNerve study group. Paediatric neurologists were invited to notify any children and adolescents (age <18 years) admitted to hospital with neurological or psychiatric disorders in whom they considered SARS-CoV-2 infection to be relevant to the presentation. Patients were excluded if they did not have a neurological consultation or neurological investigations or both, or did not meet the definition for confirmed SARS-CoV-2 infection (a positive PCR of respiratory or spinal fluid samples, serology for anti-SARS-CoV-2 IgG, or both), or the Royal College of Paediatrics and Child Health criteria for paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Individuals were classified as having either a primary neurological disorder associated with COVID-19 (COVID-19 neurology group) or PIMS-TS with neurological features (PIMS-TS neurology group). The denominator of all hospitalised children and adolescents with COVID-19 was collated from National Health Service England data. FINDINGS: Between April 2, 2020, and Feb 1, 2021, 52 cases were identified; in England, there were 51 cases among 1334 children and adolescents hospitalised with COVID-19, giving an estimated prevalence of 3·8 (95% CI 2·9-5·0) cases per 100 paediatric patients. 22 (42%) patients were female and 30 (58%) were male; the median age was 9 years (range 1-17). 36 (69%) patients were Black or Asian, 16 (31%) were White. 27 (52%) of 52 patients were classified into the COVID-19 neurology group and 25 (48%) were classified into the PIMS-TS neurology group. In the COVID-19 neurology group, diagnoses included status epilepticus (n=7), encephalitis (n=5), Guillain-Barré syndrome (n=5), acute demyelinating syndrome (n=3), chorea (n=2), psychosis (n=2), isolated encephalopathy (n=2), and transient ischaemic attack (n=1). The PIMS-TS neurology group more often had multiple features, which included encephalopathy (n=22 [88%]), peripheral nervous system involvement (n=10 [40%]), behavioural change (n=9 [36%]), and hallucinations at presentation (n=6 [24%]). Recognised neuroimmune disorders were more common in the COVID-19 neurology group than in the PIMS-TS neurology group (13 [48%] of 27 patients vs 1 [<1%] of 25 patients, p=0·0003). Compared with the COVID-19 neurology group, more patients in the PIMS-TS neurology group were admitted to intensive care (20 [80%] of 25 patients vs six [22%] of 27 patients, p=0·0001) and received immunomodulatory treatment (22 [88%] patients vs 12 [44%] patients, p=0·045). 17 (33%) patients (10 [37%] in the COVID-19 neurology group and 7 [28%] in the PIMS-TS neurology group) were discharged with disability; one (2%) died (who had stroke, in the PIMS-TS neurology group). INTERPRETATION: This study identified key differences between those with a primary neurological disorder versus those with PIMS-TS. Compared with patients with a primary neurological disorder, more patients with PIMS-TS needed intensive care, but outcomes were similar overall. Further studies should investigate underlying mechanisms for neurological involvement in COVID-19 and the longer-term outcomes. FUNDING: UK Research and Innovation, Medical Research Council, Wellcome Trust, National Institute for Health Research

    Does the Burglar Also Disturb the Neighbor? Crime Spillovers on Individual Well-Being

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    Indirect psychological effects induced by crime are likely to contribute significantly to the total costs of crime beyond the financial costs of direct victimization. Using detailed crime statistics for the whole of Germany and linking them to individual-level mental health information from the German Socio-Economic Panel, we analyze whether local crime rates affect the mental health of residents. We estimate that a one standard deviation increase in local violent crime rates significantly decreases individual mental well-being among residents by, on average, one percent. Smaller effects are found for property and total crime rates. Results are insensitive to migration and not isolated to urban areas, but are rather driven by less densely populated regions. In contrast to previous literature on vulnerability to crime, we find that men, more educated and singles react more to variation in violent crime rates in their neighborhoods. One potential explanation could be that those who are more fearful of crime have developed better coping strategies and, hence, react less to changes in crime.Indirekte psychologische Effekte stellen möglicherweise einen erheblichen Teil der durch Kriminalität verursachten Gesamtkosten dar. Um zu analysieren, ob regionale Kriminalitätsraten die mentale Gesundheit beeinflussen, nutzen wir detaillierte Kriminalitätsinformationen für Deutschland und verknüpfen diese mit Informationen zu individueller mentaler Gesundheit aus dem Sozio-ökonomischen Panel. Unsere Schätzergebnisse implizieren, dass der Anstieg um eine Standardabweichung in der Gewaltverbrechensrate das mentale Wohlbefinden der lokalen Bevölkerung signifikant um durchschnittlich ein Prozent reduziert. Für Eigentumsdelikte und die Gesamtkriminalitätsrate beobachten wir geringere Effekte. Die Ergebnisse werden weder durch Wohnortwechsler beeinflusst noch sind sie auf urbane Regionen begrenzt, sondern sind vielmehr durch weniger dicht besiedelte Regionen getrieben. Im Gegensatz zur Literatur zur Angst vor Kriminalität beobachten wir, dass Männer, höher Gebildete und Alleinstehende sensibler auf Veränderungen in der regionalen Gewaltverbrechensrate reagieren. Eine Erklärung hierfür könnte sein, dass diejenigen, die mehr Angst vor Kriminalität haben, entsprechende Coping-Strategien entwickelt haben und daher auch weniger auf Veränderungen in der Kriminalitätsrate reagieren

    Sequence Diversities of Serine-Aspartate Repeat Genes among Staphylococcus aureus Isolates from Different Hosts Presumably by Horizontal Gene Transfer

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    BACKGROUND: Horizontal gene transfer (HGT) is recognized as one of the major forces for bacterial genome evolution. Many clinically important bacteria may acquire virulence factors and antibiotic resistance through HGT. The comparative genomic analysis has become an important tool for identifying HGT in emerging pathogens. In this study, the Serine-Aspartate Repeat (Sdr) family has been compared among different sources of Staphylococcus aureus (S. aureus) to discover sequence diversities within their genomes. METHODOLOGY/PRINCIPAL FINDINGS: Four sdr genes were analyzed for 21 different S. aureus strains and 218 mastitis-associated S. aureus isolates from Canada. Comparative genomic analyses revealed that S. aureus strains from bovine mastitis (RF122 and mastitis isolates in this study), ovine mastitis (ED133), pig (ST398), chicken (ED98), and human methicillin-resistant S. aureus (MRSA) (TCH130, MRSA252, Mu3, Mu50, N315, 04-02981, JH1 and JH9) were highly associated with one another, presumably due to HGT. In addition, several types of insertion and deletion were found in sdr genes of many isolates. A new insertion sequence was found in mastitis isolates, which was presumably responsible for the HGT of sdrC gene among different strains. Moreover, the sdr genes could be used to type S. aureus. Regional difference of sdr genes distribution was also indicated among the tested S. aureus isolates. Finally, certain associations were found between sdr genes and subclinical or clinical mastitis isolates. CONCLUSIONS: Certain sdr gene sequences were shared in S. aureus strains and isolates from different species presumably due to HGT. Our results also suggest that the distributional assay of virulence factors should detect the full sequences or full functional regions of these factors. The traditional assay using short conserved regions may not be accurate or credible. These findings have important implications with regard to animal husbandry practices that may inadvertently enhance the contact of human and animal bacterial pathogens

    E-Cadherin Acts as a Regulator of Transcripts Associated with a Wide Range of Cellular Processes in Mouse Embryonic Stem Cells

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    We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES) cells.In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/-) ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3.We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation
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