409 research outputs found

    Histochemistry and anatomy of phylloxera (Daktulosphaira vitifoliae) nodosities on young roots of grapevine (Vitis spp).

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    Phylloxera (Daktulosphaira vitifoliae FITCH) induce galls (nodosities) on young grapevine roots. Histological and histochemical methods were applied to study the gall's morphology and enzyme activities (peroxidases, leucine aminopeptidases and acidic phosphatases). Susceptible V. vinifera cv. Cabernet Sauvignon was compared to the resistant rootstock 5 BB (V. berlandieri x V. riparia) using aseptic dual culture conditions. The gall induction phase was analyzed before visible signs of potential resistance responses were detected. Elevated metabolic activity has been found in nodosities compared to uninfected roots. Starch granule incorporation was detected in young galls and was highest at the feeding site. As galls mature, the starch density decreased at the feeding site and increased towards the periphery of the gall. Peroxidase, acidic phosphatase and leucine aminopeptidase activities were highest at the incision. No differences in enzyme activities could be detected between the two cultivars tested.

    Experimental realization of the Yang-Baxter Equation via NMR interferometry

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    The Yang-Baxter equation is an important tool in theoretical physics, with many applications in different domains that span from condensed matter to string theory. Recently, the interest on the equation has increased due to its connection to quantum information processing. It has been shown that the Yang-Baxter equation is closely related to quantum entanglement and quantum computation. Therefore, owing to the broad relevance of this equation, besides theoretical studies, it also became significant to pursue its experimental implementation. Here, we show an experimental realization of the Yang-Baxter equation and verify its validity through a Nuclear Magnetic Resonance (NMR) interferometric setup. Our experiment was performed on a liquid state Iodotrifluoroethylene sample which contains molecules with three qubits. We use Controlled-transfer gates that allow us to build a pseudo-pure state from which we are able to apply a quantum information protocol that implements the Yang-Baxter equation.Comment: 10 pages and 6 figure

    Nonintrusive reduced order model for parametric solutions of inertia relief problems

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    The Inertia Relief (IR) technique is widely used by industry and produces equilibrated loads allowing to analyze unconstrained systems without resorting to the more expensive full dynamic analysis. The main goal of this work is to develop a computational framework for the solution of unconstrained parametric structural problems with IR and the Proper Generalized Decomposition (PGD) method. First, the IR method is formulated in a parametric setting for both material and geometric parameters. A reduced order model using the encapsulated PGD suite is then developed to solve the parametric IR problem, circumventing the so-called curse of dimensionality. With just one offline computation, the proposed PGD-IR scheme provides a computational vademecum that contains all the possible solutions for a predefined range of the parameters. The proposed approach is nonintrusive and it is therefore possible to be integrated with commercial finite element (FE) packages. The applicability and potential of the developed technique is shown using a three-dimensional test case and a more complex industrial test case. The first example is used to highlight the numerical properties of the scheme, whereas the second example demonstrates the potential in a more complex setting and it shows the possibility to integrate the proposed framework within a commercial FE package. In addition, the last example shows the possibility to use the generalized solution in a multi-objective optimization setting

    A Pilot Study of Training Peer Recovery Specialists in Behavioral Activation in the United States: Preliminary Outcomes and Predictors of Competence

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    BACKGROUND: The peer recovery specialist (PRS) workforce has rapidly expanded to increase access to substance-use disorder services for underserved communities. PRSs are not typically trained in evidence-based interventions (EBIs) outside of motivational interviewing, although evidence demonstrates the feasibility of PRS delivery of certain EBIs, such as a brief behavioral intervention, behavioral activation. However, characteristics that predict PRS competency in delivering EBIs such as behavioral activation remain unknown, and are critical for PRS selection, training, and supervision if the PRS role is expanded. This study aimed to explore the outcomes of a brief PRS training period in behavioral activation and identify predictors of competence. METHOD: Twenty PRSs in the United States completed a two-hour training on PRS-delivered behavioral activation. Participants completed baseline and post-training assessments, including roleplay and assessments of PRS characteristics, attitudes towards EBIs, and theoretically relevant personality constructs. Roleplays were coded for competence (behavioral activation specific and PRS skills more broadly, i.e., PRS competence) and changes were assessed from baseline to post-training. Linear regression models tested factors predicting post-training competence, controlling for baseline competence. RESULTS: There was a significant pre-post increase in behavioral activation competence (t = -7.02, p \u3c 0.001). Years working as a PRS significantly predicted post-training behavioral activation skills (B = 0.16, p = 0.005). No variables predicted post-training PRS competence. CONCLUSIONS: This study provides preliminary evidence that behavioral activation may be appropriate for dissemination to PRSs through brief trainings, particularly for PRSs with more work experience. However, additional research is needed to examine predictors of competence among PRSs

    Case Report: Chemotherapy Indication in a Case of Neurofibromatosis Type 1 Presenting Optic Pathway Glioma: A One-Year Clinical Case Study Using Differential Tractography Approach

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    Neurofibromatosis type 1 (NF1) is associated with peripheral and central nervous system tumors. It is noteworthy that the regions in which these tumors frequently arise are the optic pathways (OPs) and the brainstem. Thus, we decided to trace the procedure of diffusion Magnetic Resonance Imaging (dMRI) alterations along with Short-Wavelength Automated Perimetry (SWAP) examinations of the OPs after surgery and chemotherapy over 1 year, which enabled us to evaluate chemotherapy's efficacy in an NF1 patient with an OP tumor. In this study, a 25-year-old woman with NF1 and left optic radiation (OR) glioma underwent surgery to remove the glioma. Immunohistochemistry (IHC) revealed a Pilocytic Astrocytoma (PA) WHO grade I. Post-operation chemotherapy done using nine treatment cycles of administering Temozolomide (TMZ) for 5 days every 4 weeks. Applying the region of interest (ROI) differential tractography method and SWAP four times every 3 months allowed us to follow the patient's visual acuity alterations longitudinally. The differential deterministic tractography method and statistical analyses enabled us to discover the white matter (WM) tracts anisotropy alterations over time. Furthermore, statistical analyses on the SWAP results along time illustrated possible alterations in visual acuity. Then, we could compare and associate the findings with the SWAP examinations and patient symptoms longitudinally. Statistical analyses of SWAP tests revealed a significant improvement in visual fields, and longitudinal differential tractography showed myelination and dense axonal packing in the left OR after 1 year of treatment. In this study, we examined an old hypothesis suggesting that chemotherapy is more effective than radiotherapy for NF1 patients with OP gliomas (OPGs) because of the radiation side effects on the visual field, cognition, and cerebrovascular complications. Our longitudinal clinical case study involving dMRI and SWAP on a single NF1-OPG patient showed that chemotherapy did not suppress the OP myelination over time. However, it should be noted that this is a clinical case study, and, therefore, the generalization of results is limited. Future investigations might focus on genetic-based imaging, particularly in more cases. Further, meta-analyses are recommended for giving a proper Field Of View (FOV) to researchers as a subtle clue regarding precision medicine. © Copyright © 2021 Pajavand, Sharifi, Anvari, Bidari-Zerehpoosh, Shamsi, Nateghinia and Meybodi

    Sometimes you have to take the person and show them how : adapting behavioral activation for peer recovery specialist-delivery to improve methadone treatment retention

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    BACKGROUND: Despite efficacy of medication for opioid use disorder, low-income, ethno-racial minoritized populations often experience poor opioid use disorder treatment outcomes. Peer recovery specialists, individuals with lived experience of substance use and recovery, are well-positioned to engage hard-to-reach patients in treatment for opioid use disorder. Traditionally, peer recovery specialists have focused on bridging to care rather than delivering interventions. This study builds on research in other low-resource contexts that has explored peer delivery of evidence-based interventions, such as behavioral activation, to expand access to care. METHODS: We sought feedback on the feasibility and acceptability of a peer recovery specialist-delivered behavioral activation intervention supporting retention in methadone treatment by increasing positive reinforcement. We recruited patients and staff at a community-based methadone treatment center and peer recovery specialist working across Baltimore City, Maryland, USA. Semi-structured interviews and focus groups inquired about the feasibility and acceptability of behavioral activation, recommendations for adaptation, and acceptability of working with a peer alongside methadone treatment. RESULTS: Participants (N = 32) shared that peer recovery specialist-delivered behavioral activation could be feasible and acceptable with adaptations. They described common challenges associated with unstructured time, for which behavioral activation could be particularly relevant. Participants provided examples of how a peer-delivered intervention could fit well in the context of methadone treatment, emphasizing the importance of flexibility and specific peer qualities. CONCLUSIONS: Improving medication for opioid use disorder outcomes is a national priority that must be met with cost-effective, sustainable strategies to support individuals in treatment. Findings will guide adaptation of a peer recovery specialist-delivered behavioral activation intervention to improve methadone treatment retention for underserved, ethno-racial minoritized individuals living with opioid use disorder

    Non-Gaussian power grid frequency fluctuations characterized by Levy-stable laws and superstatistics

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    Multiple types of fluctuations impact the collective dynamics of power grids and thus challenge their robust operation. Fluctuations result from processes as different as dynamically changing demands, energy trading and an increasing share of renewable power feed-in. Here we analyse principles underlying the dynamics and statistics of power grid frequency fluctuations. Considering frequency time series for a range of power grids, including grids in North America, Japan and Europe, we find a strong deviation from Gaussianity best described as Lévy-stable and q-Gaussian distributions. We present a coarse framework to analytically characterize the impact of arbitrary noise distributions, as well as a superstatistical approach that systematically interprets heavy tails and skewed distributions. We identify energy trading as a substantial contribution to today’s frequency fluctuations and effective damping of the grid as a controlling factor enabling reduction of fluctuation risks, with enhanced effects for small power grids
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