814 research outputs found
Viral Vector-based Improvement of Optic Nerve Regeneration: Characterization of Individual Axons\u27 Growth Patterns and Synaptogenesis in a Visual Target
Lack of axon growth ability in the central nervous system poses a major barrier to achieving functional connectivity after injury. Thus, a non-transgenic regenerative approach to reinnervating targets has important implications in clinical and research settings. Previous studies using knockout (KO) mice have demonstrated long distance axon regeneration. Using an optic nerve injury model, here we evaluate the efficacy of viral, RNAi and pharmacological approaches that target the PTEN and STAT3 pathways to improve long distance axon regeneration in wild type (WT) mice. Our data show that adeno-associated virus (AAV) expressing short hairpin RNA (shRNA) against PTEN (shPTEN) enhances retinal ganglion cell axon regeneration after crush injury. However, compared to the previous data in PTEN KO mice, AAV-shRNA results in a lesser degree of regeneration, likely due to incomplete gene silencing inherent to RNAi. In comparison, an extensive enhancement in regeneration is seen when AAV-shPTEN is coupled to AAV encoding ciliary neurotrophic factor (CNTF) and to a cyclic adenosine monophosphate (cAMP) analogue, allowing axons to travel long distances and reach their target. We apply whole tissue imaging that facilitates three-dimensional visualization of single regenerating axons and document heterogeneous terminal patterns in the targets. This shows that some axonal populations generate extensive arbors and make synapses with the target neurons. Collectively, we show a combinatorial viral RNAi and pharmacological strategy that improves long distance regeneration in WT animals and provide single fiber projection data that indicates a degree of preservation of target recognition
Mean-Field Approximation to the Master Equation for Sympathetic Cooling of Trapped Bosons
We use the mean-field approximation to simplify the master equation for
sympathetic cooling of Bosons. For the mean single-particle occupation numbers,
this approach yields the same equations as the factorization assumption
introduced in an erlier paper. The stationary or equilibrium solution of the
resulting master equation for the one-body density matrix shows that the
mean-field approximation breaks down whenever the fraction of condensate Bosons
exceeds ten percent or so of the total. Using group-theoretical methods, we
also solve the time-dependent master equation for the one-body density matrix.
Given the time dependence of the mean single-particle occupation numbers, this
solution is obtained by quadratures. It tends asymptotically towards the
equilibrium solution.Comment: submitted to PR
The manifest association structure of the single-factor model: insights from partial correlations
The association structure between manifest variables arising from the single-factor model is investigated using partial correlations. The additional insights to the practitioner provided by partial correlations for detecting a single-factor model are discussed. The parameter space for the partial correlations is presented, as are the patterns of signs in a matrix containing the partial correlations that are not compatible with a single-factor model
The contribution of Portuguese solar thermal program on the country energy efficiency
The solar radiation available all over the year is a strong reason to promote the utilization of this resource and during
the year 2009, a new program based on a 50% subside, was promoted by the Portuguese government. As expected, a
significant number of new installations were realized. In 2009 the state program provided the installation of more than
50,000 systems. The program can be considered a success on the Portuguese solar thermal collector market
Latent growth curve modeling of psychological well-being trajectories
This Paper Proposes Modeling Trajectories of Psychological Well-being Using Latent Growth Curve models (LGCMs). The psychometric scale of the General Health Questionnaire-12 (GHQ-12) is considered. Data from the British Household Panel Survey (BHPS), from years 2003 to 2006 are used. In 1991 Graetz proposed the GHQ-12 as a multidimensional scale, containing three distinct dimensions: anxiety and depression, social dysfunction and loss of confidence. Using such scale, this paper compares a second-order LGCM for the trajectories of a latent factor (measured by these three dimensions) with a LGCM for the trajectories of an overall sum score. Conditional LGCMs are then fitted; sex, age group and perceived health status are considered as the explanatory variables of the growth trajectories. Results show that the model which considers the three dimensions of subjective well-being has a larger explaining capability than the one utilizing the subjective well-being score
Remembering Parotitis in SARS-CoV-2 era
New 2019-Coronavirus (SARS-CoV-2) pandemic is presenting daily diagnostic challenges to emergency departments (ED) doctors, especially as an
increasing number of atypical clinical presentations have been reported, including acute sialadenitis (most of parotid).
We present a case of a 46-year-old obese caucasian woman, with no relevant medical history, that presented in ED with complaints suggesting parotitis,
with normal laboratory tests, at first with no virus isolation, confirmed by computed tomography. One week later, anosmia and dysgeusia were notice, and
SARS-CoV-2 was tested and confirmed.
Authors want to alert that SARS-CoV-2 should be excluded as parotitis etiology, highly important, especially in this pandemic phase, as a way of transmission controinfo:eu-repo/semantics/publishedVersio
Magnetic phase transitions in Gd64Sc36 studied using non-contact ultrasonics
The speed and attenuation of ultrasound propagation can be used to determine material properties and identify phase transitions. Standard ultrasonic contact techniques are not always convenient due to the necessity of using couplant; however, recently reliable non-contact ultrasonic techniques involving electromagnetic generation and detection of ultrasound with electromagnetic acoustic transducers (EMATs) have been developed for use on electrically conducting and/or magnetic materials. We present a detailed study of magnetic phase transitions in a single crystal sample of Gd64Sc36 magnetic alloy using contact and non-contact ultrasonic techniques for two orientations of external magnetic field. Phase diagrams are constructed based on measurements of elastic constant C33, the attenuation and the efficiency of generation when using an EMAT. The EMATs are shown to provide additional information related to the magnetic phase transitions in the studied sample, and results identify a conical helix phase in Gd64Sc36 in the magnetic field orientation
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