3,716 research outputs found
Guideline defined asthma management in children: how compliant are general practitioners
Asthma is a chronic debilitating illness in children. The management of this condition varies from place to place depending on the accepted guideline used in such areas. However, there is a global initiative on asthma management (GINA) that has unified all the local guidelines such that the management is almost the same worldwide. Objective: To determine the awareness of and adherence to the GINA Guideline in the management of asthma by private practitioners. Methods: Semi-structured self-administered questionnaires were given to general practitioners during one of their continuous medical education (CME) meetings on asthma facilitated by the authors of the study. The data so generated were entered in EXCEL and transferred to SPSS and analysed. Results: Out of the 50 respondents, 48 reported that they managed asthma. Six of the 50 respondents were aware of the existence and content of the GINA Guideline. However, only 2 doctors could correctly state how to treat children under-5 years according to the GINA guideline. In the case of children above-5 years, only those who could correctly treat children under-5 years also could treat children above-5 years with the GINA guidelines. No participant could correctly state the Guideline-Defined long-term management of asthma. Conclusion: Management of asthma by general practitioners does not follow the GINA Guidelines. There was also poor awareness by the doctors of the existence of the GINA guideline. There is need for frequent update programmes for general practitioners
The kinetic Alfvén-like nature of turbulent fluctuations in the Earth's magnetosheath: MMS measurement of the electron Alfvén ratio
The Magnetospheric MultiScale (MMS) mission is used to investigate turbulent fluctuations in the Earth's magnetosheath. The unique combination of multiple spacecraft and high time resolution plasma and electromagnetic field data provided by MMS makes it an ideal mission to study the nature of turbulence and energy conversion. The multiple spacecraft allow the determination of the wavevector directions and plasma frame frequencies of the fluctuations. Moreover, the particle velocities allow the determination of the ion and electron Alfvén ratios, giving an additional diagnostic to reveal the nature of the turbulent fluctuations. Finally, the currents (determined from plasma moments) and the three-dimensional electric field measurements allow the determination of a scale-dependent energy conversion rate. The results reveal that the fluctuations predominantly have kinetic Alfvén wave-like properties at wavenumbers near kpi~1 (where ρi is the ion gyroradius) and that Landau damping is an important pathway for converting energy
Possible coexistence of kinetic Alfvén and ion Bernstein modes in sub-ion scale compressive turbulence in the solar wind
We investigate compressive turbulence at sub-ion scales with measurements from the Magnetospheric
MultiScale Mission. The tetrahedral configuration and high time resolution density data obtained by calibrating
spacecraft potential allow an investigation of the turbulent density fluctuations in the solar wind and their
three-dimensional structure in the sub-ion range. The wave-vector associated with the highest energy density
at each spacecraft frequency is obtained by application of the multipoint signal resonator technique to the
four-point density data. The fluctuations show a strong wave-vector anisotropy k⊥ k� where the parallel and
perpendicular symbols are with respect to the mean magnetic-field direction. The plasma frame frequencies
show two populations, one below the proton cyclotron frequency ω<ci consistent with kinetic Alfvén wave
(KAW) turbulence. The second component has higher frequencies ω>ci consistent with ion Bernstein wave
turbulence. Alternatively, these fluctuations may constitute KAWs that have undergone multiple wave-wave
interactions, causing a broadening in the plasma frame frequencies. The scale-dependent kurtosis in this wavevector region shows a reduction in intermittency at the small scales which can also be explained by the presence
of wave activity. Our results suggest that small-scale turbulence exhibits linear-wave properties of kinetic Alfvén
and possibly ion-Bernstein (magnetosonic) waves. Based on our results, we speculate that these waves may play
a role in describing the observed reduction in intermittency at sub-ion scales
Magnetic Field Reconstruction for a Realistic Multi-Point, Multi-Scale Spacecraft Observatory
Future in situ space plasma investigations will likely involve spatially distributed observatories comprised of multiple spacecraft, beyond the four and five spacecraft configurations currently in operation. Inferring the magnetic field structure across the observatory, and not simply at the observation points, is a necessary step towards characterizing fundamental plasma processes using these unique multi-point, multi-scale data sets. We propose improvements upon the classic first-order reconstruction method, as well as a second-order method, utilizing magnetometer measurements from a realistic nine-spacecraft observatory. The improved first-order method, which averages over select ensembles of four spacecraft, reconstructs the magnetic field associated with simple current sheets and numerical simulations of turbulence accurately over larger volumes compared to second-order methods or first-order methods using a single regular tetrahedron. Using this averaging method on data sets with fewer than nine measurement points, the volume of accurate reconstruction compared to a known magnetic vector field improves approximately linearly with the number of measurement points
Using Sensors and Generators of H2O2 to Elucidate the Toxicity Mechanism of Piperlongumine and Phenethyl Isothiocyanate
Aims: Chemotherapeutics target vital functions that ensure survival of cancer cells, including their increased reliance on defense mechanisms against oxidative stress compared to normal cells. Many chemotherapeutics exploit this vulnerability to oxidative stress by elevating the levels of intracellular reactive oxygen species (ROS). A quantitative understanding of the oxidants generated and how they induce toxicity will be important for effective implementation and design of future chemotherapeutics. Molecular tools that facilitate measurement and manipulation of individual chemical species within the context of the larger intracellular redox network present a means to develop this understanding. In this work, we demonstrate the use of such tools to elucidate the roles of H[subscript 2]O[subscript 2] and glutathione (GSH) in the toxicity mechanism of two ROS-based chemotherapeutics, piperlongumine and phenethyl isothiocyanate. Results: Depletion of GSH as a result of treatment with these compounds is not an important part of the toxicity mechanisms of these drugs and does not lead to an increase in the intracellular H[subscript 2]O[subscript 2] level. Measuring peroxiredoxin-2 (Prx-2) oxidation as evidence of increased H[subscript 2]O[subscript 2], only piperlongumine treatment shows elevation and it is GSH independent. Using a combination of a sensor (HyPer) along with a generator (D-amino acid oxidase) to monitor and mimic the drug-induced H[subscript 2O[subscript 2] production, it is determined that H[subscript 2]O[subscript 2] produced during piperlongumine treatment acts synergistically with the compound to cause enhanced cysteine oxidation and subsequent toxicity. The importance of H[subscript 2]O[subscript 2] elevation in the mechanism of piperlongumine promotes a hypothesis of why certain cells, such as A549, are more resistant to the drug than others. Innovation and Conclusion: The approach described herein sheds new light on the previously proposed mechanism of these two ROS-based chemotherapeutics and advocates for the use of both sensors and generators of specific oxidants to isolate their effects. Antioxid. Redox Signal. 24, 924–938.National Science Foundation (U.S.). Graduate Research Fellowship ProgramBurroughs Wellcome Fund (Career Award at the Scientific Interface
CPT and Lorentz-invariance violation
The largest gap in our understanding of nature at the fundamental level is
perhaps a unified description of gravity and quantum theory. Although there are
currently a variety of theoretical approaches to this question, experimental
research in this field is inhibited by the expected Planck-scale suppression of
quantum-gravity effects. However, the breakdown of spacetime symmetries has
recently been identified as a promising signal in this context: a number of
models for underlying physics can accommodate minuscule Lorentz and CPT
violation, and such effects are amenable to ultrahigh-precision tests. This
presentation will give an overview of the subject. Topics such as motivations,
the SME test framework, mechanisms for relativity breakdown, and experimental
tests will be reviewed. Emphasis is given to observations involving antimatter.Comment: 6 page
Developing SME performance management practices: interventions for improving productivity
Purpose The paper is a proof of concept (PoC) intervention study aimed for developing performance management (PM) practices in manufacturing small and medium-sized enterprises (SMEs) with the longer-term aim enabling the SMEs to improve their productivity. The intervention was designed and deployed by a collaborative quartet of academics, management consultants, accountancy firm and a commercial bank manager. Design/methodology/approach The paper firstly musters a set of initialising PM practices aligned to productivity improvement. These are utilised to design a knowledge transfer intervention for deployment with a set of manufacturing SMEs incorporating some associated productivity tools. The evaluation of the intervention utilised a case study approach founded on a logic model of the intervention to assess the development of the PM practices. Findings The intervention contributed to a partial development of the mustered practices and the productivity diagnostic based on the multi-factor productivity (MFP) abstraction and a data extraction protocol had the strongest impact. The study revealed the importance of the three interlaced factors: Depth of engagement, feedback opportunities and the intervention gradient (the increase of independent action from the participating SME's and the diminishment of the external intervention effort). Research limitations/implications The case study is based on a limited number of individual SME's, and within just the manufacturing sector. Practical implications SME businesses will require a more sustained programme of interventions than this pilot to develop PM capability, and depth of engagement within the SME is critical. Professional stakeholders can be utilised in recruitment of firms for intervention programmes. Business can start developing PM capability prior to PMS implementation using the tools from this programme. Originality/value The productivity diagnostic tool, based on a synthesis of MFP and the performance pyramid, an array of potential initialising practices for PM capability and discovery of potential mechanisms for PM practice development
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