1,453 research outputs found
The Impact of Investing in Research and Development on Performance: Evidence from Jordan
This research aimed to investigate the effect of investing in research and development on the performance of Jordanian companies. Investment in research and development was measured by the ratio of investment to sales and the number of researchers. Financial performance was measured by financial ratios. The population of the study consisted of 45 industrial companies listed on the Amman Stock Exchange. Data was obtained only from 21 companies for seven years. The results indicate that the level of investment in research and development is very low compared to international standards. The results also show no significant relationships between investment in research and development and the financial performance of the companies. The research provides some conclusions and recommendations in light of the results
PROPEL: implementation of an evidence based pelvic floor muscle training intervention for women with pelvic organ prolapse: a realist evaluation and outcomes study protocol
Abstract Background Pelvic Organ Prolapse (POP) is estimated to affect 41%–50% of women aged over 40. Findings from the multi-centre randomised controlled “Pelvic Organ Prolapse PhysiotherapY” (POPPY) trial showed that individualised pelvic floor muscle training (PFMT) was effective in reducing symptoms of prolapse, improved quality of life and showed clear potential to be cost-effective. However, provision of PFMT for prolapse continues to vary across the UK, with limited numbers of women’s health physiotherapists specialising in its delivery. Implementation of this robust evidence from the POPPY trial will require attention to different models of delivery (e.g. staff skill mix) to fit with differing care environments. Methods A Realist Evaluation (RE) of implementation and outcomes of PFMT delivery in contrasting NHS settings will be conducted using multiple case study sites. Involving substantial local stakeholder engagement will permit a detailed exploration of how local sites make decisions on how to deliver PFMT and how these lead to service change. The RE will track how implementation is working; identify what influences outcomes; and, guided by the RE-AIM framework, will collect robust outcomes data. This will require mixed methods data collection and analysis. Qualitative data will be collected at four time-points across each site to understand local contexts and decisions regarding options for intervention delivery and to monitor implementation, uptake, adherence and outcomes. Patient outcome data will be collected at baseline, six months and one year follow-up for 120 women. Primary outcome will be the Pelvic Organ Prolapse Symptom Score (POP-SS). An economic evaluation will assess the costs and benefits associated with different delivery models taking account of further health care resource use by the women. Cost data will be combined with the primary outcome in a cost effectiveness analysis, and the EQ-5D-5L data in a cost utility analysis for each of the different models of delivery. Discussion Study of the implementation of varying models of service delivery of PFMT across contrasting sites combined with outcomes data and a cost effectiveness analysis will provide insight into the implementation and value of different models of PFMT service delivery and the cost benefits to the NHS in the longer term
Combined multi-modal assessment of glaucomatous damage with electroretinography and optical coherence tomography/angiography
Purpose: To compare the diagnostic performance and to evaluate the interrelationship of electroretinographical and structural and vascular measures in glaucoma. Methods: For 14 eyes of 14 healthy controls and 15 eyes of 12 patients with glaucoma ranging from preperimetric to advanced stages optical coherence tomog-raphy (OCT), OCT-angiography (OCT-A), and electrophysiological measures (multifocal photopic negative response ratio [mfPhNR] and steady-state pattern electroretinogra-phy [ssPERG]) were applied to assess changes in retinal structure, microvasculature, and function, respectively. The diagnostic performance was assessed via area-under-curve (AUC) measures obtained from receiver operating characteristics analyses. The interre-lation of the different measures was assessed with correlation analyses. Results: The mfPhNR, ssPERG amplitude, parafoveal (pfVD) and peripapillary vessel density (pVD), macular ganglion cell inner plexiform layer thickness (mGCIPL) and peripapillary retinal nerve fiber layer thickness (pRNFL) were significantly reduced in glaucoma. The AUC for mfPhNR was highest among diagnostic modalities (AUC: 0.88, 95% confidence interval: 0.75–1.0, P < 0.001), albeit not statistically different from that for macular (mGCIPL: 0.76, 0.58–0.94, P < 0.05; pfVD: 0.81, 0.65–0.97, P < 0.01) or peripapillary imaging (pRNFL: 0.85, 0.70–1.0, P < 0.01; pVD: 0.82, 0.68–0.97, P < 0.01). Combined functional/vascular measures yielded the highest AUC (mfPhNR-pfVD: 0.94, 0.85–1.0, P < 0.001). The functional/structural measure correlation (mfPhNR-mGCIPL correlation coefficient [rs ]: 0.58, P = 0.001; mfPhNR-pRNFL rs: 0.66, P < 0.001) was stronger than the functional-vascular correlation (mfPhNR-pfVD rs: 0.29, P = 0.13; mfPhNR-pVD rs: 0.54, P = 0.003). Conclusions: The combination of ERG measures and OCT-A improved diagnostic performance and enhanced understanding of pathophysiology in glaucoma. Translational Relevance: Multimodal assessment of glaucoma damage improves diagnostics and monitoring of disease progression
Low-voltage organic thin-film transistors based on [n]phenacenes
Low-voltage p-channel organic thin-film transistors based on [n]phenacene (n = 5, 6 or 7) were fabricated on glass and on flexible poly(ethylene 2,6-naphthalate) (PEN) substrates. For the first time, these phenacenes were combined with two ultrathin gate dielectrics based on aluminium oxide and a monolayer of octadecyl-phosphonic acid in three different transistor structures. Regardless of the substrate and the transistor structure, the field-effect mobility is found to increase with increasing length of the conjugated [n]phenacene core, leading to the best performance for [7]phenacene. The largest average field-effect mobility we have obtained is 0.27 cm2/V·s for transistors on glass and 0.092 cm2/V·s for transistors on flexible PEN
Trichinella spiralis secretes abundant unencapsulated small RNAs with potential effects on host gene expression
Many organisms, including parasitic nematodes, secrete small RNAs into the extracellular environment, largely encapsulated within small vesicles. Parasite-secreted material often contains microRNAs (miRNAs), raising the possibility that they might regulate host genes in target cells. Here we characterise secreted RNAs from the parasitic nematode Trichinella spiralis at two different life stages. We show that adult T. spiralis, which inhabit intestinal mucosa, secrete miRNAs within vesicles. Unexpectedly, T. spiralis muscle stage larvae, which live intracellularly within skeletal muscle cells, secrete miRNAs that appear not to be encapsulated. Notably, secreted miRNAs include a homologue of mammalian miRNA-31, which has an important role in muscle development. Our work therefore suggests that RNAs may be secreted without encapsulation in vesicles, with implications for the biology of T. spiralis infection
On Aharonov-Casher bound states
In this work bound states for the Aharonov-Casher problem are considered.
According to Hagen's work on the exact equivalence between spin-1/2
Aharonov-Bohm and Aharonov-Casher effects, is known that the
term cannot be neglected in the
Hamiltonian if the spin of particle is considered. This term leads to the
existence of a singular potential at the origin. By modeling the problem by
boundary conditions at the origin which arises by the self-adjoint extension of
the Hamiltonian, we derive for the first time an expression for the bound state
energy of the Aharonov-Casher problem. As an application, we consider the
Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the
expression for the harmonic oscillator energies and compare it with the
expression obtained in the case without singularity. At the end, an approach
for determination of the self-adjoint extension parameter is given. In our
approach, the parameter is obtained essentially in terms of physics of the
problem.Comment: 11 pages, matches published versio
Photodesorption of water ice: a molecular dynamics study
Absorption of ultraviolet radiation by water ice coating interstellar grains
can lead to dissociation and desorption of the ice molecules. These processes
are thought to be important in the gas-grain chemistry in molecular clouds and
protoplanetary disks, but very few quantitative studies exist. We compute the
photodesorption efficiencies of amorphous water ice and elucidate the
mechanisms by which desorption occurs. Classical molecular dynamics
calculations were performed for a compact amorphous ice surface at 10 K thought
to be representative of interstellar ice. Dissociation and desorption of H2O
molecules in the top six monolayers are considered following absorption into
the first excited electronic state with photons in the 1300-1500 Angstrom
range. The trajectories of the H and OH photofragments are followed until they
escape or become trapped in the ice. The probability for H2O desorption per
absorbed UV photon is 0.5-1% in the top three monolayers, then decreases to
0.03% in the next two monolayers, and is negligible deeper into the ice. The
main H2O removal mechanism in the top two monolayers is through separate
desorption of H and OH fragments. Removal of H2O molecules from the ice, either
as H2O itself or its products, has a total probability of 2-3% per absorbed UV
photon in the top two monolayers. In the third monolayer the probability is
about 1% and deeper into the ice the probability of photodesorption falling to
insignificant numbers. The probability of any removal of H2O per incident
photon is estimated to be 3.7x10^-4, with the probability for photodesorption
of intact H2O molecules being 1.4x10^-4 per incident photon. When no desorption
occurs, the H and OH products can travel up to 70 and 60 Angstroms inside or on
top of the surface during which they can react with other species.Comment: 12 pages, 10 figures, A&A, in pres
Band profiles and band strengths in mixed H2O:CO ices
A laboratory study on the band profiles and band strengths of H2O in CO ice,
and vice versa, is presented and interpreted in terms of two models. The
results show that a mutual interaction takes place between the two species in
the solid, which alters the band positions and band strengths. It is found that
the band strengths of the H2O bulk stretch, bending and libration vibrational
bands decrease linearly by a factor of up to 2 when the CO concentration is
increased from 0 to 80%. By contrast, the band strength of the free OH stretch
increases linearly. The results are compared to a recently performed
quantitative study on H2O:CO2 ice mixtures. It is shown that for mixing ratios
of 1:0.5 H2O:X and higher, the H2O bending mode offers a good tracer to
distinguish between CO2 or CO in H2O ice. Additionally, it is found that the
band strength of the CO fundamental remains constant when the water
concentration is increased in the ice. The integrated absorbance of the 2152
cm-1 CO feature, with respect to the total integrated CO absorption feature, is
found to be a good indicator of the degree of mixing of CO in the H2O:CO
laboratory ice system. From the change in the H2O absorption band strength in
laboratory ices upon mixing we conclude that astronomical water ice column
densities on various lines of sight can be underestimated by up to 25% if
significant amounts of CO and CO2 are mixed in.Comment: 9 pages, 10 figure
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