5,922 research outputs found
The Perceptions of New Middle School Teachers Regarding Teacher Job Satisfaction
Teacher attrition has been a problem for school systems for more than 30 years. Large numbers of new teachers leave the profession within their first 5 years of service, creating a significant cost associated with hiring and training of replacement teachers. Attrition is problematic for a middle school in the state of Georgia. New teachers at the school have disclosed that induction did not meet their needs. In addition, the district has experienced budget cutbacks and demographic shifts in the student population, increasing the rate new teachers have left the school. The purpose of this study was to explore and give voice to the new teachers\u27 perceptions about the profession, their preparation for classroom teaching, and their understanding of the school\u27s climate and culture. Using Herzberg\u27s theory of motivation, a qualitative case explored perceptions of 10 teachers who had fewer than 5 years teaching experience. The research questions were focused on perceived satisfaction with teaching, preparedness for classroom teaching, and satisfaction with the climate and culture of the school. The data were collected through face-to-face interviews using an interview protocol. Findings revealed that novice teachers were satisfied with the teaching profession, but satisfaction changed over time as they became more immersed in the daily routines necessary for students and classroom management. The data showed that novice teachers were dissatisfied with the climate and culture of the school. In response to the findings, a professional development support group project for novice teachers was developed. This project contributes to positive social change by providing a safe and trusted environment for new teachers to help each other manage challenges and assimilate into their new school environment
Towards zero solid waste: utilising tannery waste as a protein source for poultry feed
Zero waste is now a strongly emerging issue for sustainable industrial development where minimisation and utilisation of waste are a priority in the leather industry. In a tannery hides and skins converted in to leather through various processes. Approximately 20% (w/w) of the chrome containing tannery solid waste (TSW) is generated from one tonne of raw hides and skins. However, tannery solid waste may also be a resource if it is managed expertly as we move towards zero waste. This research illustrates the potential of tannery solid waste as a poultry feed additive. An oxidation method was used to achieve 95% of dechroming rate of chrome tanned waste followed with thermal and enzymatic treatment to produce gelatin solution and collagen concentrates. The thermal stability and fibre structure of samples were analysed by Differential Scanning Calorimeter (DSC) and Scanning Electron Microscope (SEM). Protein content and fourteen amino acid concentrations were determined using amino acid analysis. High Performance Liquid Chromatography (HPLC) was used to compare the amino acid composition with wheat and soya bean meal that is conventionally used in poultry feed. The nutrient requirements for poultry feed vary according to the purpose for which they have been developed. The high content of arginine, leucine, threonine, serine and methionine in the extract were of a sufficient level for poultry feed. Hexavalent chromium test was performed and showed that levels of the metal were low enough to be used in feed additives. In addition, the extracted product showed 75% digestibility (in vitro) and appears that treated TSW may be utilised in poultry feed, this demonstrates a clear example of waste utilisation. In Bangladesh plans are being formed to use the extract in poultry feed production
A General Theory of Non-equilibrium Dynamics of Lipid-protein Fluid Membranes
We present a general and systematic theory of non-equilibrium dynamics of
multi-component fluid membranes, in general, and membranes containing
transmembrane proteins, in particular. Developed based on a minimal number of
principles of statistical physics and designed to be a meso/macroscopic-scale
effective description, the theory is formulated in terms of a set of equations
of hydrodynamics and linear constitutive relations. As a particular emphasis of
the theory, the equations and the constitutive relations address both the
thermodynamic and the hydrodynamic consequences of the unconventional material
characteristics of lipid-protein membranes and contain proposals as well as
predictions which have not yet been made in already existed work on membrane
hydrodynamics and which may have experimental relevance. The framework
structure of the theory makes possible its applications to a range of
non-equilibrium phenomena in a range of membrane systems, as discussions in the
paper of a few limit cases demonstrate.Comment: 22 pages, 2 figures, minor changes and addition
Electroformation in a flow chamber with solution exchange as a means of preparation of flaccid giant vesicles
A recently described technique (Estes and Mayer, Biochim. Biophys. Acta 1712
(2005) 152--160) for the preparation of giant unilamellar vesicles (GUVs) in
solutions with high ionic strength is examined. By observing a series of
osmotic swellings followed by vesicle bursts upon a micropipette transfer of a
single POPC GUV from a sucrose solution into an isoosmolar glycerol solution, a
value for the permeability of POPC membrane for glycerol, P = (2.09+/-0.82) x
10^{-8} m/s, has been obtained. Based on this result, an alternative mechanism
is proposed for the observed exchange of vesicle interior. With modifications,
the method of Estes and Mayer is then applied to preparation of flaccid GUVs.Comment: 13 pages, 10 figures, accepted for publication in Colloids and
Surfaces B: Biointerface
Making sense of being at 'high risk' of coronary heart disease within primary prevention
Current NHS policy advocates screening to identify individuals at ‘high risk’ of cardiovascular
disease (CHD) in primary care. This paper utilizes the work of Radley to explore
how ‘high risk’ of CHD patients make sense of their new risk status. Results are
presented here from a nested qualitative study within a quantitative randomized trial of a
CHD risk intervention in primary care. ‘Discovery’ interviews were conducted with ‘high
risk’ participants (n=38, mean age=55) two weeks after intervention and thematically
analyzed. In response to perceived threat, many participants sought to both ‘minimize’
and ‘normalize’ their risk status. They also reported intentions to act, particularly
concerning dietary change and exercise, although less so for smoking amongst the lower
SES participants. Such perceptions and intentions were contextualized within the lifecourse
of later middle-age, so that both being at risk, and being treated for risk, were
normalized as part of growing older. Social position, such as gender and SES, was also
implicated. CHD risk interventions should be context-sensitive to the life-course and
social position of those who find themselves at ‘high risk’ of CHD in later middle-age
Simulations and experimental demonstrations of encoding for X-ray coherent scattering
Diffraction data may be measured using approaches that lead to ambiguity in the interpretation of scattering distributions. Thus, the encoding and decoding of coherent scattering distributions have been considered with a view to enabling unequivocal data interpretation. Two encoding regimes are considered, where encoding occurs between the X-ray source and sample, and where the encoder is placed between the sample and detector. In the first case, the successful recovery of diffraction data formed from the interrogation of powder samples with annular incident beams is presented using a coded aperture approach. In the second regime, encoding of Debye cones is shown to enable recovery of the sample position relative to the detector. The errors associated with both regimes are considered and the advantages of combining the two discussed
Beyond beliefs: risk assessment technologies shaping patients' experiences of heart disease prevention
Social science research on lifestyle-related diseases typically focuses on patients' understandings and beliefs and takes the clinical risk for granted. We interviewed 30 healthy UK patients at high risk of heart disease, recruited from a family history trial at 2weeks and 6months after a discussion with a clinician about their risk, lifestyle and medications. The participants took four different paths: (i) pharmaceutical (most common, risk reduction with cholesterol lowering statins), (ii) mixed (statins and behaviour change), (iii) behavioural (behaviour change, focus on wellbeing) and (iv) 'lost' (no prevention, difficult social/personal circumstances). Drawing on Berg we argue that coronary heart disease (CHD) risk assessment technologies are formal tools that generate, rather than represent, high risk in a way that patients often experience lifestyle change as futile, because it rarely reduces their cholesterol to targets defined by the tools. We suggest social scientists studying incipient or 'proto-diseases', such as CHD risk, should not only focus on understandings but also investigate the technologies (and the associated guidelines, policies, clinical practice and pharmaceutical industry operations) that generate incipient diseases and patients' experiences of them. However, technologies do not determine experience and we also discuss elements that direct patients down other than the pharmaceutical path. © 2011 The Authors. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd
Law of corresponding states for osmotic swelling of vesicles
As solute molecules permeate into a vesicle due to a concentration difference
across its membrane, the vesicle swells through osmosis. The swelling can be
divided into two stages: (a) an "ironing" stage, where the volume-to-area ratio
of the vesicle increases without a significant change in its area; (b) a
stretching stage, where the vesicle grows while remaining essentially
spherical, until it ruptures. We show that the crossover between these two
stages can be represented as a broadened continuous phase transition.
Consequently, the swelling curves for different vesicles and different
permeating solutes can be rescaled into a single, theoretically predicted,
universal curve. Such a data collapse is demonstrated for giant unilamellar
POPC vesicles, osmotically swollen due to the permeation of urea, glycerol, or
ethylene glycol. We thereby gain a sensitive measurement of the solutes'
membrane permeability coefficients, finding a concentration-independent
coefficient for urea, while those of glycerol and ethylene glycol are found to
increase with solute concentration. In addition, we use the width of the
transition, as extracted from the data collapse, to infer the number of
independent bending modes that affect the thermodynamics of the vesicle in the
transition region.Comment: 10 page
Simulations and experimental demonstrations of encoding for X-ray coherent scattering
Diffraction data may be measured using approaches that lead to ambiguity in the interpretation of scattering distributions. Thus, the encoding and decoding of coherent scatter distributions have been considered with a view to enabling unequivocal data interpretation. Two encoding regimes are considered where encoding occurs between the X-ray source and sample, and where the encoder is placed between the sample and detector. In the first case, the successful recovery of diffraction data formed from the interrogation of powder samples with annular incident beams is presented using a coded aperture approach. In a second regime, encoding of Debye cones is shown to enable recovery of sample position relative to the detector. The errors associated with both regimes are considered and the advantages of combining both discussed
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