488 research outputs found
Evaluation of Total Brain Acetylcholine in rats treated with inhaled Tetrahydrocannabinol. (A Bioassay Study)
A Bioassay study using rabbit ileum was used to evaluate changes in Total Brain Acetylcholine of wistar rats treated for 4, 8 and 12 weeks with inhaled tetrahydrocanabinol smoke; a widely abused substance worldwide. Puffing of cannabis smoke was performed with the use of a Hamilton syringe delivering 100-ml puffs at 20-sec intervals into the nose -only manifold for a total of 5 minutes. Smoke was first pumped into a 500ml dilution chamber with the aid of a vacuum pump. The smoke was then displaced from the dilution chamber through the nose-only manifold at 300 ml/min; that is the rats received Inhaled THC at 5ml/sec for 5 minutes. After treatment the rat Brains were accessed for Total Brain Acetylcholine (TBA) levels. To achieve this; an increasing amounts of homogenized Brain extracts from the rats in each group and Laboratory acetylcholine were used and their ability to contract the rabbit ileum when introduced into an organ bath was recorded as height of contraction which was then used to calculate actual TBA concentration. This was first done for all groups to first determine an effective dose to be used. For the actual Bioassay study the chosen effective dose of 0.5ml of Brain preparation from Control group, 4, 8, 12 weeks treated groups and standard Laboratory Acetylcholine were used to determine the concentrations of Total Brain Acetylcholine present in the Brain extracts. Atropine was also introduced to ascertain the presence of Ach in the Brain extracts. The experiments showed significant increase in TBA in the treated rats showing an accumulation of Ach in the Brain due to THC inhalation. This is part of a series of studies to establish the influence of THC on the neurotransmitter acetylcholine and cells of the Brain stem for its possible importance in neurotransmitter deficiency and related neurodegenerative diseases. Keywords: Total Brain Acetylcholine (TBA), Tetrahydrocannabinol (THC), Inhalation treatment, Bioassay,Ā Rabbit ileum,Ā Height of Contraction, Nose-Only smoke model
Coupling of a high-energy excitation to superconducting quasiparticles in a cuprate from Coherent Charge Fluctuation Spectroscopy
Dynamical information on spin degrees of freedom of proteins or solids can be
obtained by Nuclear Magnetic Resonance (NMR) and Electron Spin Resonance (ESR).
A technique with similar versatility for charge degrees of freedom and their
ultrafast correlations could move forward the understanding of systems like
unconventional superconductors. By perturbing the superconducting state in a
high-Tc cuprate using a femtosecond laser pulse, we generate coherent
oscillations of the Cooper pair condensate which can be described by an NMR/ESR
formalism. The oscillations are detected by transient broad-band reflectivity
and found to resonate at the typical scale of Mott physics (2.6 eV), suggesting
the existence of a non-retarded contribution to the pairing interaction, as in
unconventional (non Migdal-Eliashberg) theories.Comment: Accepted for publication in the Proceedings of the National Academy
of Sciences of the U.S.A. (PNAS
DETERMINANTS OF AGRICULTURAL ECONOMIC FACULTY SALARIES: A QUARTER OF A CENTURY LATER
Factors influencing the salaries of university agricultural economists were examined and compared to previous work. Results suggest the impact of publication output has remained relatively constant for the past 25 years, while other factors like grantsmanship have changed significantly. Additional analyses suggest significant impacts of appointment apportionment and Ph.D. programs.Teaching/Communication/Extension/Profession,
A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply
This paper elucidates one of the tracking schemes for a photovoltaic (PV) systems using Cuk converter operating in discontinuous inductor current mode (DICM) as an interface. A method for efficiently maximizing the output power of a solar panel supplying a load or battery bus under varying meteorological conditions is investigated and results presented therein. The incremental conductance (InCond) method of maximum power point tracking (MPPT) using the Cuks dc to dc converter operating in a discontinuous inductor current mode (DICM) was modeled and studied in relation to PV system interface. Also, laboratory setup was implemented based on the model. This was the main objective of the research. Similarly, the PV simulator was also modeled alongside with Cuk converter operating in DICM. MATLAB/SIMULINK software was used to carry out simulation test. With the incremental conductance method, the problem of sustained oscillation around the maximum power point of the solar panel which is the usual characteristic of the perturbation and observation method is essentially absent. The result disclosed that the power available for the load when MPPT was applied was 1.1 kW which gives a tolerance of 0.1% to the load it powers. But without MPPT, the available power is 0.9 kW using the same number of PV panels and batteries as back up. Hence, MPPT has 17.65% edge in power delivery over non-MPPT PV powered energy supply. An experimental prototype of a 1kW, 230V, 50Hz stand-alone solar based power supply with the incremental conductance scheme was successfully implemented using PIC 16F877 microcontroller, tested and results presented therein. The experimental results agreed with the simulated results.Keywords: Maximum Power point tracking, Cuk converter, Photovoltaic system, PIC 16F877A micro-controller, inverter, batteries
Evidence against GB virus C infection in dromedary camels
A recent publication described finding GB virus C (GBV-C) RNA in four of twenty two dromedary camel sera, and sequence analysis found that these viruses were phylogenetically clustered within human GBV-C isolates. Since all other GB viruses to date form monophyletic groups according to their host species, the close relationship between the sequences generated from camel sera and human GBV-C isolates seemed implausible, leading us to conduct an independent analysis of the sequences. Our investigation found three lines of evidence arguing against GBV-C infection in dromedary camels. First, strong evidence of artifactual sequence generation was identified for some of the sequences. Secondly, the sequence diversity within individual camel sera was ten- to one-hundred fifty two-fold greater than that described for GBV-C within a human host. Finally, GBV-C sequences generated from each camel shared near complete identity with human isolates previously described by the same laboratory. Taken together, these data strongly suggest laboratory contamination. We suggest that additional validation experiments are needed before it is possible to conclude that camels are permissive for GBV-C infection
Part of the D - dimensional Spiked harmonic oscillator spectra
The pseudoperturbative shifted - l expansion technique PSLET [5,20] is
generalized for states with arbitrary number of nodal zeros. Interdimensional
degeneracies, emerging from the isomorphism between angular momentum and
dimensionality of the central force Schrodinger equation, are used to construct
part of the D - dimensional spiked harmonic oscillator bound - states. PSLET
results are found to compare excellenly with those from direct numerical
integration and generalized variational methods [1,2].Comment: Latex file, 20 pages, to appear in J. Phys. A: Math. & Ge
Approximation of the critical buckling factor for composite panels
This article is concerned with the approximation of the critical buckling factor for thin composite plates. A new method to improve the approximation of this critical factor is applied based on its behavior with respect to lamination parameters and loading conditions. This method allows accurate approximation of the critical buckling factor for non-orthotropic laminates under complex combined loadings (including shear loading). The influence of the stacking sequence and loading conditions is extensively studied as well as properties of the critical buckling factor behavior (e.g concavity over tensor D or out-of-plane lamination parameters). Moreover, the critical buckling factor is numerically shown to be piecewise linear for orthotropic laminates under combined loading whenever shear remains low and it is also shown to be piecewise continuous in the general case. Based on the numerically observed behavior, a new scheme for the approximation is applied that separates each buckling mode and builds linear, polynomial or rational regressions for each mode. Results of this approach and applications to structural optimization are presented
Thermal and Chemical Freeze-out in Spectator Fragmentation
Isotope temperatures from double ratios of hydrogen, helium, lithium,
beryllium, and carbon isotopic yields, and excited-state temperatures from
yield ratios of particle-unstable resonances in 4He, 5Li, and 8Be, were
determined for spectator fragmentation, following collisions of 197Au with
targets ranging from C to Au at incident energies of 600 and 1000 MeV per
nucleon. A deviation of the isotopic from the excited-state temperatures is
observed which coincides with the transition from residue formation to
multi-fragment production, suggesting a chemical freeze-out prior to thermal
freeze-out in bulk disintegrations.Comment: 14 pages, 10 figures, submitted to Phys. Rev. C, small changes as
suggested by the editors and referee
Are there any gains in green-tech adoption? Unearthing the beneficial outcomes of smart-sustainable practices in Nigeria and Hong Kong built environment
Implementing Smart-sustainable practices (SSP) is crucial to achieving environmentally-friendly buildings and cities. Adequate awareness and understanding of its benefits and impacts are essential for maximizing its implementation. Hence, this study explores and establishes the key SSP benefits in the built environment of Hong Kong and Nigeria. Factors were identified through literature survey, then data was collected using questionnaires and analysed with various methods. The common key beneficial outcomes (BT) in both contexts relate to better design products with low environmental impact and enhancement of project quality and productivity. Three main clusters were established: sustainable design and resource management, innovation and business performance, and green initiatives and productivity. Based on the rank agreement analysis, there is high consensus between Hong Kong and Nigeria experts on two clustered BTs of green initiatives and sustainable products (57%) and project productivity and efficiency (100%). It is important to be cautious when applying these findings beyond the specific contexts of Nigeria and Hong Kong. The study findings have provided practical and objective means to predict and assess the probable impacts of SSP implementation while providing clients, contractors, policymakers, and practitioners with pragmatic tools and effective recommendations to promote the delivery of smart, sustainable projects worldwide
COPD care delivery pathways in five European Union countries : mapping and health care professionals' perceptions
Background: COPD is among the leading causes of chronic morbidity and mortality in the European Union with an estimated annual economic burden of ā¬25.1 billion. Various care pathways for COPD exist across Europe leading to different responses to similar problems. Determining these differences and the similarities may improve health and the functioning of health services.
Objective: The aim of this study was to compare COPD patientsā care pathway in five European Union countries including England, Ireland, the Netherlands, Greece, and Germany and to explore health care professionalsā (HCPs) perceptions about the current pathways.
Methods: HCPs were interviewed in two stages using a qualitative, semistructured email interview and a face-to-face semistructured interview.
Results: Lack of communication among different health care providers managing COPD and comorbidities was a common feature of the studied care pathways. General practitioners/family doctors are responsible for liaising between different teams/services, except in Greece where this is done through pulmonologists. Ireland and the UK are the only countries with services for patients at home to shorten unnecessary hospital stay. HCPs emphasized lack of communication, limited resources, and poor patient engagement as issues in the current pathways. Furthermore, no specified role exists for pharmacists and informal carers.
Conclusion: Service and professional integration between care settings using a unified system targeting COPD and comorbidities is a priority. Better communication between health care providers, establishing a clear role for informal carers, and enhancing patientsā engagement could optimize current care pathways resulting in a better integrated system
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