3,066 research outputs found
A holistic approach to eye care for older people
Many eye diseases, such as cataract and age-related macular degeneration, occur more frequently as we advance in years. As a consequence, eye care workers are likely to encounter older people more frequently than any other group.The holistic approach to treating an older person involves considering the complete person, both physically and psychologically. You should consider every aspect of that person that has an impact on their health and wellbeing. This will greatly improve the outcome of the consultation and any subsequent treatment, both for the older patient and for the eye care worker.It is equally important to treat every older person who seeks care with respect, in a way that preserves his or her dignity and autonomy
Phase modulation induced by cooperative effects in electromagnetically induced transparency
We analyze the influence of dipole-dipole interactions in an
electromagnetically induced transparency setup at high density. We show both
analytically and numerically that the polarization contribution to the local
field strongly modulates the phase of a weak pulse. We give an intuitive
explanation for this local field induced phase modulation and show that it
distinctively differs from the nonlinear self-phase modulation a strong pulse
experiences in a Kerr medium
Corporate Social Responsibility and Product Differentiation
We explore how the source of motivations for Corporate Social Responsibility (CSR) affects market outcomes. The first source is consumer-led; firms practice CSR because consumers value it. If one firm practices CSR it achieves a competitive advantage. If all firms practice CSR, market shares and price remain similar but profits fall, resulting in a Prisoner’s Dilemma. The other source is firm-led CSR that also generates prices, market shares, and revenue that are the same as when neither firms nor consumers care about CSR case, but firms allocate profit to equilibrate its marginal valuation of CSR and financial reward to owners
Use of the Full Length Transcript (FLT) from Mirabilis Mosaic Caulimovirus to Express Chimeric Genes in Plants
A full-length transcript promoter from mirabilis mosaic caulimovirus (MMV) is identified and its DNA sequence given. The promoter functions as a strong and uniform promoter for chimeric genes inserted into plant cells. This strong promoter function is exhibited by histochemical assay in seeds and floral organs and by reproductive scores of transgenic plants including the promoter. The promoter preferably includes a 3′ untranslated region that may be from the MMV itself or from a heterologous source with respect to the promoter. The promoter is used in a chimeric gene and in methods for transforming plant cells to obtain transgenic plants, plant tissues, plant cells and seeds incorporating the MMV promoter. The MMV FLT promoter shows greater activity (14 to 24 fold) than the CaMV 35S promoter. A modified MMV FLt promoter with duplicated enhancer domains shows greater activity (3 fold) than with a single enhancer domain
Effect of transcription factor resource sharing on gene expression noise
Gene expression is intrinsically a stochastic (noisy) process with important implications for cellular functions. Deciphering the underlying mechanisms of gene expression noise remains one of the key challenges of regulatory biology. Theoretical models of transcription often incorporate the kinetics of how transcription factors (TFs) interact with a single promoter to impact gene expression noise. However, inside single cells multiple identical gene copies as well as additional binding sites can compete for a limiting pool of TFs. Here we develop a simple kinetic model of transcription, which explicitly incorporates this interplay between TF copy number and its binding sites. We show that TF sharing enhances noise in mRNA distribution across an isogenic population of cells. Moreover, when a single gene copy shares it\u27s TFs with multiple competitor sites, the mRNA variance as a function of the mean remains unaltered by their presence. Hence, all the data for variance as a function of mean expression collapse onto a single master curve independent of the strength and number of competitor sites. However, this result does not hold true when the competition stems from multiple copies of the same gene. Therefore, although previous studies showed that the mean expression follows a universal master curve, our findings suggest that different scenarios of competition bear distinct signatures at the level of variance. Intriguingly, the introduction of competitor sites can transform a unimodal mRNA distribution into a multimodal distribution. These results demonstrate the impact of limited availability of TF resource on the regulation of noise in gene expression
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Wireless capsule gastrointestinal endoscopy: direction of arrival estimation based localization survey
One of the significant challenges in Capsule Endoscopy (CE) is to precisely determine the pathologies location. The localization process is primarily estimated using the received signal strength from sensors in the capsule system through its movement in the gastrointestinal (GI) tract. Consequently, the wireless capsule endoscope (WCE) system requires improvement to handle the lack of the capsule instantaneous localization information and to solve the relatively low transmission data rate challenges. Furthermore, the association between the capsule’s transmitter position, capsule location, signal reduction and the capsule direction should be assessed. These measurements deliver significant information for the instantaneous capsule localization systems based on TOA (time of arrival) approach, PDOA (phase difference of arrival), RSS (received signal strength), electromagnetic, DOA (direction of arrival) and video tracking approaches are developed to locate the WCE precisely. The current article introduces the acquisition concept of the GI medical images using the endoscopy with a comprehensive description of the endoscopy system components. Capsule localization and tracking are considered to be the most important features of the WCE system, thus the current article emphasizes the most common localization systems generally, highlighting the DOA-based localization systems and discusses the required significant research challenges to be addressed
A Formal Account of the Open Provenance Model
On the Web, where resources such as documents and data are published, shared, transformed, and republished, provenance is a crucial piece of metadata that would allow users to place their trust in the resources they access. The Open Provenance Model (OPM) is a community data model for provenance that is designed to facilitate the meaningful interchange of provenance information between systems. Underpinning OPM is a notion of directed graph, where nodes represent data products and processes involved in past computations, and edges represent dependencies between them; it is complemented by graphical inference rules allowing new dependencies to be derived. Until now, however, the OPM model was a purely syntactical endeavor. The present paper extends OPM graphs with an explicit distinction between precise and imprecise edges. Then a formal semantics for the thus enriched OPM graphs is proposed, by viewing OPM graphs as temporal theories on the temporal events represented in the graph. The original OPM inference rules are scrutinized in view of the semantics and found to be sound but incomplete. An extended set of graphical rules is provided and proved to be complete for inference. The paper concludes with applications of the formal semantics to inferencing in OPM graphs, operators on OPM graphs, and a formal notion of refinement among OPM graphs
CO J=2-1 line emission in cluster galaxies at z~1: fueling star formation in dense environments
We present observations of CO J=2-1 line emission in infrared-luminous
cluster galaxies at z~1 using the IRAM Plateau de Bure Interferometer. Our two
primary targets are optically faint, dust-obscured galaxies (DOGs) found to lie
within 2 Mpc of the centers of two massive (>10^14 Msun) galaxy clusters. CO
line emission is not detected in either DOG. We calculate 3-sigma upper limits
to the CO J=2-1 line luminosities, L'_CO < 6.08x10^9 and < 6.63x10^9 K km/s
pc^2. Assuming a CO-to-H_2 conversion factor derived for ultraluminous infrared
galaxies in the local Universe, this translates to limits on the cold molecular
gas mass of M_H_2 < 4.86x10^9 Msun and M_H_2 < 5.30x10^9 Msun. Both DOGs
exhibit mid-infrared continuum emission that follows a power-law, suggesting
that an AGN contributes to the dust heating. As such, estimates of the star
formation efficiencies in these DOGs are uncertain. A third cluster member with
an infrared luminosity, L_IR < 7.4x10^11 Lsun, is serendipitously detected in
CO J=2-1 line emission in the field of one of the DOGs located roughly two
virial radii away from the cluster center. The optical spectrum of this object
suggests that it is likely an obscured AGN, and the measured CO line luminosity
is L'_CO = (1.94 +/- 0.35)x10^10 K km/s pc^2, which leads to an estimated cold
molecular gas mass M_H_2 = (1.55+/-0.28)x10^10 Msun. A significant reservoir of
molecular gas in a z~1 galaxy located away from the cluster center demonstrates
that the fuel can exist to drive an increase in star-formation and AGN activity
at the outskirts of high-redshift clusters.Comment: 22 pages, 4 figures; accepted for publication in Ap
Supply chain optimisation of pyrolysis plant deployment using goal programming
This paper presents a goal programming model to optimise the deployment of pyrolysis plants in Punjab, India. Punjab has an abundance of waste straw and pyrolysis can convert this waste into alternative bio-fuels, which will facilitate the provision of valuable energy services and reduce open field burning. A goal programming model is outlined and demonstrated in two case study applications: small scale operations in villages and large scale deployment across Punjab's districts. To design the supply chain, optimal decisions for location, size and number of plants, downstream energy applications and feedstocks processed are simultaneously made based on stakeholder requirements for capital cost, payback period and production cost of bio-oil and electricity. The model comprises quantitative data obtained from primary research and qualitative data gathered from farmers and potential investors. The Punjab district of Fatehgarh Sahib is found to be the ideal location to initially utilise pyrolysis technology. We conclude that goal programming is an improved method over more conventional methods used in the literature for project planning in the field of bio-energy. The model and findings developed from this study will be particularly valuable to investors, plant developers and municipalities interested in waste to energy in India and elsewhere
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