Aging: A Predisposition to Dry Eyes

Dry eye syndrome is a disease of the ocular surface and tear film that is prevalent in older adults. Even though the degree of visual acuity loss in dry eye patients is commonly mild-to-moderate, in the aging population, this minimal change in visual status can lead to a significant decrease in visual function and quality of life. A healthy ocular surface is maintained by appropriate tear production and tear drainage, and deficiencies in this delicate balance can lead to dryness. In the aging eye, risk factors such as polypharmacy, androgen deficiency, decreased blink rates, and oxidative stress can predispose the patient to developing dry eye that is frequently more severe, has higher economic costs, and leads to worse consequences to the well-being of the patient. Understanding why elderly patients are at higher risk for developing dry eyes can provide insights into the diagnosis and management of the growing number of older adults struggling with dry eye and minimize the burden of disease on our aging population

Electron and Phonon Confinement and New Surface Phonon Modes in CdSe-CdS Core-Shell Nanocrystals

Optical and vibrational properties of bare and CdS shelled CdSe nanocrystalline particles are investigated. To confirm the formation of such nanocrystals in our samples we estimate their average particle sizes and size distributions using TEM measurements. From the line profile analysis of the images the core-shell structure in the particles has been confirmed. The blue shift in optical absorption spectra, analyzed using theoretical estimates based on the effective bond order model, establishes the electron confinement in the nanoparticles. Unique characteristics of the nanocrystals (which are absent in the corresponding bulk material), such as confinement of optical phonons and the appearance of surface phonons, are then discussed. Making use of the dielectric response function model we are able to match the experimental and theoretical values of the frequencies of the surface phonons. We believe that our studies using optical probes provide further evidence on the existence of core-shell structures in CdSe-CdS type materials.Comment: 19 pages 8 figure

Stereo Acoustic Perception based on Real Time Video Acquisition for Navigational Assistance

A smart navigation system (an Electronic Travel Aid) based on an object detection mechanism has been designed to detect the presence of obstacles that immediately impede the path, by means of real time video processing. The algorithm can be used for any general purpose navigational aid. This paper is discussed, keeping in mind the navigation of the visually impaired, and is not limited to the same. A video camera feeds images of the surroundings to a Da- Vinci Digital Media Processor, DM642, which works on the video, frame by frame. The processor carries out image processing techniques whose result contains information about the object in terms of image pixels. The algorithm aims to select the object which, among all others, poses maximum threat to the navigation. A database containing a total of three sounds is constructed. Hence, each image translates to a beep, where every beep informs the navigator of the obstacles directly in front of him. This paper implements an algorithm that is more efficient as compared to its predecessors.Comment: 12 pages, 8 figures, 1 table, SIPM-2012, pp. 97-108, 2012; http://airccj.org/CSCP/vol2/csit2311.pd

Addressing Structural Racism in the Health Workforce

One of the greatest challenges facing the United States are health inequities among racial/ethnic and other marginalized populations. The deep-rooted structural racism embedded in our social systems, including our health care system and health workforce, is a core cause of racial health inequities. 1 Among many definitions of institutionalized or structural racism, Dr Jones 2 best defines it as: “Differential access to goods, services and opportunities of society by race ... It is structural, having been codified in our institutions of custom, practice, and law, so there need not be an identifiable perpetrator.” Dr Jones further explains that to set things right in our country, we have to address this type of racism that is embedded in all of our systems. Historical and existing structural obstacles have significantly reduced access to health professions education among marginalized populations in the United States.3,4 This has rendered an underrepresentation of Black, Latino, and Native persons in health professions schools, practice, and leadership. 5,6 This commentary presents the evidence of and potential avenues for beginning to address structural racism in the health care workforce. We discuss how historical and present-day racism impacts recruitment and retention of historically excluded groups in the health professions (eg, Black, Latino, and Native people) and the investments needed to dis- mantle the impacts of structural racism on the diversity of our health workforce

Etiologic factors related to unsatisfactory ThinPrep cervical cytology: Evaluation and potential solutions to improve

BACKGROUND: In cervical cytology, the unsatisfactory rates for ThinPrep (TP) are slightly higher compared to SurePath. We examined various causes and explored potential for resolution of this discrepancy. MATERIALS AND METHODS: Totally, 19,422 cases were reviewed and 1000 unsatisfactory specimens were selected and analyzed. 531 specimens were available for wash protocol. Out of 114 unsatisfactory specimens associated with atrophic cellular changes (ACC), 48 were resubmitted by provider and reevaluated. RESULTS: Lubricant and lubricant-like debris/contamination (LUBE) was the most common cause of unsatisfactory specimens (68%; 681/1000) followed by blood (7.5%); ACC only (without other interfering factors) (2.4%); inflammation (3.0%); and combinations thereof (1.9%). 11.5% showed scant cellularity without an identifiable cause. 3.3% were virtually acellular. Wash protocol improved cellularity in 48% (256/531) of cases. However, only 29% (73/256) of those were satisfactory (with more than 5000 cells). Quantitative reduction in LUBE after wash protocol varied with different morphological subtypes. Interpretation patterns on satisfactory specimens after wash protocol were comparable to the results on selected cohort of specimens during the same study period. Out of 114 ACC, wash protocol was performed on 68 ACC specimens leading to satisfactory TP in 24% (16/68). Totally, 48 cases reported as unsatisfactory with ACC, were resubmitted by the providers between 2 weeks and 2 years. 44 (92%) showed increased cellularity, out of which 52% (23/44) did not show ACC. CONCLUSION: LUBE was the most common cause of unsatisfactory TP in addition to interference by blood and association with atrophic changes. Knowing the morphological spectrum of LUBE would help to identify it as the cause of unsatisfactory TP. Communicating the cause of unsatisfactory TP such as LUBE, ACC, and blood would hint the provider to take appropriate precaution during submission of the repeat specimen, leading to improved patient care

Salt Tolerance Mechanisms in Perennial Fodder Grasses

Salinity stress is one of the most damaging stresses in crop plants. It reduces the productivity of the soil and makes it unsuitable for crop cultivation. Fodder crops are considered the best alternative in such uncultivable land. Using salinity-affected land for pasture development is the best alternative to utilize such lands. However, the extent of salinity tolerance varies among different grass species. In this study, Pearl millet Napier hybrids (PMN hybrid) and guinea grass varieties were studied for salinity tolerance in artificially created saline soils in the ratio of 13:7:1:2 (NaCl: Na2SO4: MgCl: CaSO4, respectively) to understand the salinity tolerance mechanisms existing in perennial fodder grasses. Morphologically, the plant height increased in saline-tolerant PMN hybrid varieties, creating more space in nonphotosynthetic tissues to store accumulated salts away from photosynthetic tissues. Whereas in guinea grass tolerant varieties, tiller number increased under salinity. The fresh weight was highest under salinity in the PMN hybrids. In contrast, dry weight was high in control (no salt) plants, implying more water accumulation in PMN hybrids under salinity to dilute the concentration of salts absorbed by the plant. In Guinea grass, varieties like DGG1 had lower leaf succulence than control and high salt excretion through leaf hairs. Tissue tolerance in PMN hybrids was less compared to guinea grass. Membrane stability was maintained in saline-tolerant varieties. The double bond index increased in tolerant PMN hybrid varieties under salinity compared to control, implying fatty acid remodelling for maintaining the stability of membranes under salinity. Fodder grasses adopt various saline tolerance mechanisms based on their growth habit and morphology

Probing liquid surface waves, liquid properties and liquid films with light diffraction

Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we revisit the classical method of probing such waves (wavelengths of the order of mm) as well as inherent properties of liquids and liquid films on liquids, using optical diffraction. A combination of simulation and experiment is proposed to trace out the surface wave profiles in various situations (\emph{eg.} for one or more vertical, slightly immersed, electrically driven exciters). Subsequently, the surface tension and the spatial damping coefficient (related to viscosity) of a variety of liquids are measured carefully in order to gauge the efficiency of measuring liquid properties using this optical probe. The final set of results deal with liquid films where dispersion relations, surface and interface modes, interfacial tension and related issues are investigated in some detail, both theoretically and experimentally. On the whole, our observations and analyses seem to support the claim that this simple, low--cost apparatus is capable of providing a wealth of information on liquids and liquid surface waves in a non--destructive way.Comment: 25 pages, 12 figures, to appear in Measurement Science and Technology (IOP

Vacuum energy of a massive scalar field in the presence of a semi-transparent cylinder

We compute the ground state energy of a massive scalar field in the background of a cylindrical shell whose potential is given by a delta function. The zero point energy is expressed in terms of the Jost function of the related scattering problem, the renormalization is performed with the help of the heat kernel expansion. The energy is found to be negative for attractive and for repulsive backgrounds as well.Comment: 17 pages, 5 figure

Improved Precision Measurement of the Casimir Force

We report an improved precision measurement of the Casimir force. The force is measured between a large Al coated sphere and flat plate using an Atomic Force Microscope. The primary experimental improvements include the use of smoother metal coatings, reduced noise, lower systematic errors and independent measurement of surface separations. Also the complete dielectric spectrum of the metal is used in the theory. The average statistical precision remains at the same 1% of the forces measured at the closest separation