Adaptive optics scanning laser ophthalmoscopy for in vivo imaging of lamina cribrosa

The lamina cribrosa has been postulated from in vitro studies as an early site of damage in glaucoma. Prior in vivo measures of laminar morphology have been confounded by ocular aberrations. In this study the lamina cribrosa was imaged after correcting for ocular aberrations using the adaptive optics scanning laser ophthalmoscope (AOSLO) in normal and glaucomatous eyes of rhesus monkeys. All measured laminar morphological parameters showed increased magnitudes in glaucomatous eyes relative to fellow control eyes, indicating altered structure. The AOSLO provides high-quality images of the lamina cribrosa and may have potential as a tool for early identification of glaucoma.     

Quantum rod bioconjugates as targeted probes for confocal and two-photon fluorescence imaging of cancer cells

Live cell imaging using CdSe/CdS/ZnS quantum rods (QRs) as targeted optical probes is reported. The QRs, synthesized in organic media using a binary surfactant mixture, were dispersed in aqueous media using mercaptoundecanoic acid (MUA) and lysine. Transferrin (Tf) was linked to the QRs to produce QR-Tf bioconjugates that were used for targeted in vitro delivery to a human cancer cell line. Confocal and two-photon imaging were used to confirm receptor-mediated uptake of QR-Tf conjugates into the HeLa cells, which overexpress the transferrin receptor (TfR). Uptake was not observed with QRs that lacked Tf functionalization or with cells that were presaturated with free Tf and then treated with Tf-functionalized QRs.     

Organically modified silica nanoparticles with covalently incorporated photosensitizer for photodynamic therapy of cancer

We report a novel nanoformulation of a photosensitizer (PS), for photodynamic therapy (PDT) of cancer, where the PS molecules are covalently incorporated into organically modified silica (ORMOSIL) nanoparticles. We found that the covalently incorporated PS molecules retained their spectroscopic and functional properties and could robustly generate cytotoxic singlet oxygen molecules upon photoirradiation. The synthesized nanoparticles are of ultralow size ( approximately 20 nm) and are highly monodispersed and stable in aqueous suspension. The advantage offered by this covalently linked nanofabrication is that the drug is not released during systemic circulation, which is often a problem with physical encapsulation. These nanoparticles are also avidly uptaken by tumor cells in vitro and demonstrate phototoxic action, thereby highlighting their potential in diagnosis and PDT of cancer.     

Role and impact of surfactants in carbon nanotube dispersions and sorting

Carbon nanotubes (CNTs) are proving to be versatile nanomaterials that exhibit superior and attractive electrical, optical, chemical, physical, and mechanical properties. Different kinds of CNTs exist, and their associated properties have been actively explored and widely exploited from fundamental studies to practical applications. Obtaining high-quality CNTs in large volumes is desirable, especially for scalable electronic, photonic, chemical, and mechanical systems. At present, abundant but random CNTs are synthesized by various growth methods including arc discharge, chemical vapor deposition, and molecular beam epitaxy. An economical way to secure pristine CNTs is to disperse the raw soot of CNTs in solutions, from which purified CNTs are collected via sorting methods. Individual CNTs are generally hydrophobic, not readily soluble, requiring an agent, known as a surfactant to facilitate effective dispersions. Furthermore, the combination of surfactants, polymers, DNA, and other additives can enhance the purity of specific types of CNTs in confidence dispersions. With highly-pure CNTs, designated functional devices are built to demonstrate improved performance. This review surveys and highlights the essential roles and significant impacts of surfactants in dispersing and sorting CNTs.     

Evictions,large owners,and serial filings: findings from Atlanta

Abstract

Evictions cause substantial harm to lower-income families and neighborhoods. We find that eviction filings include many ‘serial filings’, in which landlords file repeatedly on the same tenant. We analyze serial and nonserial filing rates at the property level, and the share of a property’s filings that are serial filings. Regressions on building, location, and neighborhood characteristics reveal factors associated with higher serial and nonserial filing rates and serial share. We find that the largest owners and larger buildings tend to have high serial shares. When looking at nonserial filings, which are more likely to result in tenant displacement, neighborhood race is a strong independent predictor; properties in Black neighborhoods have substantially higher nonserial filing rates, other things equal. Another key result is that sales in the prior three years have a significant, nontrivial positive effect on the nonserial filing rate, so that property turnover is a significant predictor of rising evictions. We discuss implications for policy and further research.     

Impairment of cellular immunity in west Greenland sledge dogs (Canis familiaris) dietary exposed to polluted minke whale (Balaenoptera acutorostrata) blubber

Minke whale (Balaenoptera acutorostrata) blubber is rich in organohalogen contaminants, mercury, and n-3 fatty acids. In the present study we show that a daily intake of 50-200 g of minke whale blubber causes an impairment of the nonspecific and specific cellular immune system in the West Greenland sledge dog (Canis familiaris). Immune reactions were measured by mitogen (PHA, Con A) and antigen (KLH) intradermal testing, and as the study used exposure levels similar to those of Inuits and polar bears (Ursus maritimus), it is reasonable to infer that Inuits and polar bears suffer from similar decreased resistance to diseases. It is speculated that food sources are depleted by thinning sea ice due to climate change and that more research should assess the forecasted rise in additive immunopathy effects in polar bears. Additionally, our study suggests that the fatty acid composition may be of importance when investigating combined immunotoxic effects of contaminated food resources in future Inuit and polar bear studies.     

Interactive stereoscopic displays

Interactive stereo displays allow for the existence of a natural interaction between the user and the stereo images depicted on the display. In the type of display discussed here, this interaction takes the form of tracking the user's head and hand/arm position. Sensing the user's head position allows for the creation of motion parallax information, an immersive depth cue that can be added to the binocular parallax already present in the display. Sensing the user's hand or arm position allows the user to manipulate the spatial attributes of virtual objects and scenes presented on the display, which can enhance spatial reasoning. Moreover, allowing the user to manipulate virtual objects may permit the creation of a sense of spatial relations among elements in the display via proprioception, which may augment the two parallax cues. The congruence among binocular parallax, motion parallax, and proprioception should increase the sense of depth in the display and increase viewing comfort, as well as enhance the ability of our intuitive reasoning system to make reasoned sense out of the perceptual information. These advantages should make interactive stereo displays, which may be classified as a form of cognitive enhancement display, the display of choice in the future.     

Nature, decay, and spiraling of the effects of fear-inducing arguments and HIV counseling and testing: A meta-analysis of the short- and long-term outcomes of HIV-prevention interventions.

[Correction Notice: An erratum for this article was reported in Vol 26(6) of Health Psychology (see record 2007-16656-022). Several corrections that were omitted are found in this erratum.] Objective: To examine the long-term efficacy of both fear-inducing arguments and HIV counseling and testing at encouraging and maintaining knowledge about HIV transmission and prevention, as well as condom use. Design: Analyses were conducted with a sample of 150 treatment groups and 34 controls and included measures of change at an immediate follow-up and a delayed follow-up. Main outcome measures: The main outcome measures were perceived risk of HIV infection, knowledge about HIV, and condom use. Results: Results indicated that receiving fear-inducing arguments increased perceptions of risk at the immediate follow-up but decreased knowledge and condom use, whereas resolving fear via HIV counseling and testing decreased perceptions of risk and increased knowledge and condom use at both the immediate and delayed follow-ups. The effects on perceived risk and knowledge decreased over time, but the effects on condom use became more pronounced. Conclusion: Inducing fear is not an effective way to promote HIV-relevant learning or condom use either immediately following the intervention or later on. However, HIV counseling and testing can provide an outlet for HIV-related anxiety and, subsequently, gains in both knowledge and behavior change immediately and longitudinally. (PsycINFO Database Record (c) 2010 APA, all rights reserved)