Exploring atmospheric optical turbulence: observations across zenith angles.

We present measurements of the atmospheric optical turbulence as a function of zenith angle using two identical instruments, Shack-Hartmann Image Motion Monitors (SHIMMs), to measure atmospheric parameters concurrently. One instrument was pointed near zenith, while the other collected data by tracking a single star until it set and thus sampling zenith angles continuously to the horizon. By comparing these measurements, we can attribute changes in the atmospheric parameters to the changing zenith angle rather than variations in local turbulence conditions. The primary purpose of this experiment is to make comparisons between the measurements of the scintillation index, σ I2, and Fried parameter, r 0, with current theories. In this demonstration, we find that there is a strong agreement between the models and the instrument up until zenith angles of 70∘, above which model and measurements begin to deviate. We discuss various ways in which limitations in models and our instrument may cause these deviations.

Lighten UP! A Community-Based Group Intervention to Promote Eudaimonic Well-Being in Older Adults: A Multi-Site Replication with 6 Month Follow-Up.

Objectives: Eudaimonic well-being (EWB), increasingly recognized as a critical component of health, typically declines in later life, and there are no existing programs to sustain or increase EWB in older adults. Lighten UP! is an 8-week program to promote EWB through facilitated group sessions in community settings and at-home practice. Building on earlier pilot research, the current study assessed the effect of the Lighten UP! Program using a longitudinal, multi-site design. Methods: Men and women (N = 169) aged 60 and over were recruited from three Wisconsin communities. EWB, life satisfaction, depression, and diverse aspects of health were assessed before and after the program and at 6-month follow up. Results: Participants reported significantly increased EWB; these changes were maintained 6 months later. The specific EWB domains of self-acceptance, positive relations, and personal growth showed the most robust gains. Participants also showed significant and sustained declines in depressive symptoms, anxiety, and hostility. Conclusions: Lighten UP! Program confirmed its positive effects for enhancing EWB in older adults living in multiple community settings. Clinical Implications: Programs that sustain or enhance EWB in older adults can be expected to yield improvements in diverse aspects of mental and physical health.

Traceable interferometry using binary reconfigurable holograms.

We describe the characterization of a ferroelectric-liquid-crystal-on-silicon (FLCOS) spatial light modulator (SLM) in the production of holograms for use in interferometric metrology. It has already been shown that such a device can be used in producing small-amplitude arbitrary reference surfaces with small but appreciable errors due to the contaminating effect of higher-order structures being propagated through the spatial filter. Here we further quantify the size of these residuals for increasingly large aberrations up to nine waves rms Zernike astigmatism, showing a Zernike-corrected rms wavefront error of roughly 0.06 waves with high vibrational stability. We also present measurements of a vacuum window element using the FLCOS device to drastically reduce interferometric fringe density, showing a residual wavefront error of 0.046 waves rms with dominant components originating from test piece structure rather than holographic errors.

Modal liquid crystal array of optical elements.

In this study, a novel liquid crystal array based on modal control principle is proposed and demonstrated. The advanced device comprises a six striped electrode structure that forms a configurable 2D matrix of optical elements. A simulation program based on the Frank-Oseen equations and modal control theory has been developed to predict the device electrooptic response, that is, voltage distribution, interference pattern and unwrapped phase. A low-power electronics circuit, that generates complex waveforms, has been built for driving the device. A combined variation of the waveform amplitude and phase has provided a high tuning versatility to the device. Thus, the simulations have demonstrated the generation of a liquid crystal prism array with tunable slope. The proposed device has also been configured as an axicon array. Test measurements have allowed us to demonstrate that electrooptic responses, simulated and empirical, are fairly in agreement.

Optical binding mechanisms: a conceptual model for Gaussian beam traps.

Optical binding interactions between laser-trapped spherical microparticles are familiar in a wide range of trapping configurations. Recently it has been demonstrated that these experiments can be accurately modeled using Mie scattering or coupled dipole models. This can help confirm the physical phenomena underlying the inter-particle interactions, but does not necessarily develop a conceptual understanding of the effects that can lead to future predictions. Here we interpret results from a Mie scattering model to obtain a physical description which predict the behavior and trends for chains of trapped particles in Gaussian beam traps. In particular, it describes the non-uniform particle spacing and how it changes with the number of particles. We go further than simply demonstrating agreement, by showing that the mechanisms "hidden" within a mathematically and computationally demanding Mie scattering description can be explained in easily-understood terms.

Adenovirus in blood clots from cases of infectious hepatitis.

Adenovirus type 5 was isolated from blood clots from 27 of 30 sporadic cases of infectious hepatitis. Only one isolation of virus, also adenovirus 5, was made from blood clots from 70 persons with no known contact with infectious hepatitis.

Emergent properties in optically bound matter.

Sub-micron particles have been observed to spontaneously form regular two-dimensional structures in counterpropagating evanescent laser fields. We show that collective properties of large numbers of optically-trapped particles can be qualitatively different to the properties of small numbers. This is demonstrated both with a computer model and with experimental results. As the number of particles in the structure is increased, optical binding forces can be sufficiently large to overcome the optical landscape imposed by the interference fringes of the laser beams and impose a different, competing structure.

Tuneable planar integrated optical systems.

Planar integrated free-space optical systems are well suited for a variety of applications, such as optical interconnects and security devices. Here, we demonstrate for the first time dynamic functionality of such microoptical systems by the integration of adaptive liquid-crystal-devices.

Eigenmodes of a hydrodynamically coupled micron-size multiple-particle ring.

We use a continuous acquisition, high-speed camera with integrated centroid tracking to simultaneously measure the positions of a ring of micron-sized particles held in holographic optical tweezers. Hydrodynamic coupling between the particles gives a set of eigenmodes, each one independently relaxing with a characteristic decay rate (eigenvalue) that can be measured using our positional data. Despite the finite particle size, we find an excellent agreement between the measured eigenvalues and those numerically predicted by Oseen theory applied to the two-dimensional (2D) ring geometry. Particle motions are also analyzed in terms of the alternative eigenmode set obtained by wrapping onto the ring the eigenmodes of a 1D periodic chain. We identify the modes for which the periodic chain is a good approximation to the ring and those for which it is not.

Paleoecology and paleoceanography of the Athel silicilyte, Ediacaran-Cambrian boundary, Sultanate of Oman.

The Athel silicilyte is an enigmatic, hundreds of meters thick, finely laminated quartz deposit, in which silica precipitated in deep water (>~100-200 m) at the Ediacaran-Cambrian boundary in the South Oman Salt Basin. In contrast, Meso-Neoproterozoic sinks for marine silica were dominantly restricted to peritidal settings. The silicilyte is known to contain sterane biomarkers for demosponges, which today are benthic, obligately aerobic organisms. However, the basin has previously been described as permanently sulfidic and time-equivalent shallow-water carbonate platform and evaporitic facies lack silica. The Athel silicilyte thus represents a unique and poorly understood depositional system with implications for late Ediacaran marine chemistry and paleoecology. To address these issues, we made petrographic observations, analyzed biomarkers in the solvent-extractable bitumen, and measured whole-rock iron speciation and oxygen and silicon isotopes. These data indicate that the silicilyte is a distinct rock type both in its sedimentology and geochemistry and in the original biology present as compared to other facies from the same time period in Oman. The depositional environment of the silicilyte, as compared to the bounding shales, appears to have been more reducing at depth in sediments and possibly bottom waters with a significantly different biological community contributing to the preserved biomarkers. We propose a conceptual model for this system in which deeper, nutrient-rich waters mixed with surface seawater via episodic mixing, which stimulated primary production. The silica nucleated on this organic matter and then sank to the seafloor, forming the silicilyte in a sediment-starved system. We propose that the silicilyte may represent a type of environment that existed elsewhere during the Neoproterozoic. These environments may have represented an important locus for silica removal from the oceans.

Intra-operative deviation in limb alignment occurring at implantation in total knee arthroplasty.

BACKGROUND: Long-term survival of knee replacement depends on accurate alignment. Despite improvements in cut accuracy mal-alignment of 3° or more is still seen. All methods share common implantation techniques. This study examines the effect of implantation on overall limb alignment relating it to cut alignment and trial alignment. METHODS: A retrospective review of navigated primary knee replacements was undertaken (n=113). Overall coronal limb alignments for the aggregated cuts, trial and final implanted components were examined. RESULTS: All 113 knees had coronal aggregated cut alignment within 2° of neutral (range: 2° varus to 2° valgus). With trial components 99 knees (88%) had an overall coronal limb alignment within 2° of neutral (range: 3° varus to 4° valgus). After final implantation 106 knees (94%) were within 2° of neutral (range: 4° varus to 4° valgus). Forty eight knees (42%) showed no alignment deviation occurring between trial and the final implanted prostheses and 16 knees (14%) shoed a deviation of 2° or more. There was a correlation of both aggregated cut (r=0.284, p=0.002) and trial (r=0.794, p<0.001) with final alignment. There was no significant difference between the final alignment and the aggregated cut alignment(mean difference=-0.15°, p=0.254) or trial alignment (mean difference -0.13°, p=0.155). CONCLUSIONS: Even when the aggregated alignment produced by the bone cuts is accurate, inaccuracy in final alignment can result from the implantation process. It may be productive for surgeons to concentrate on the implantation process to improve alignment and reduce outliers.

Methane sources in arctic thermokarst lake sediments on the North Slope of Alaska.

The permafrost on the North Slope of Alaska is densely populated by shallow lakes that result from thermokarst erosion. These lakes release methane (CH4 ) derived from a combination of ancient thermogenic pools and contemporary biogenic production. Despite the potential importance of CH4 as a greenhouse gas, the contribution of biogenic CH4 production in arctic thermokarst lakes in Alaska is not currently well understood. To further advance our knowledge of CH4 dynamics in these lakes, we focused our study on (i) the potential for microbial CH4 production in lake sediments, (ii) the role of sediment geochemistry in controlling biogenic CH4 production, and (iii) the temperature dependence of this process. Sediment cores were collected from one site in Siqlukaq Lake and two sites in Sukok Lake in late October to early November. Analyses of pore water geochemistry, sedimentary organic matter and lipid biomarkers, stable carbon isotopes, results from CH4 production experiments, and copy number of a methanogenic pathway-specific gene (mcrA) indicated the existence of different sources of CH4 in each of the lakes chosen for the study. Analysis of this integrated data set revealed that there is biological CH4 production in Siqlukaq at moderate levels, while the very low levels of CH4 detected in Sukok had a mixed origin, with little to no biological CH4 production. Furthermore, methanogenic archaea exhibited temperature-dependent use of in situ substrates for methanogenesis, and the amount of CH4 produced was directly related to the amount of labile organic matter in the sediments. This study constitutes an important first step in better understanding the actual contribution of biogenic CH4 from thermokarst lakes on the coastal plain of Alaska to the current CH4 budgets.

Dasatinib Induced Avascular Necrosis of Femoral Head in Adult Patient with Chronic Myeloid Leukemia.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of the Philadelphia (Ph) chromosome resulting from the reciprocal translocation t(9;22)(q34;q11). The molecular consequence of this translocation is the generation of the BCR-ABL fusion gene, which encodes a constitutively active protein tyrosine kinase. The oncogenic protein tyrosine kinase, which is located in the cytoplasm, is responsible for the leukemia phenotype through the constitutive activation of multiple signaling pathways involved in the cell cycle and in adhesion and apoptosis. Avascular necrosis of the femoral head (AVNFH) is not a specific disease. It occurs as a complication or secondary to various causes. These conditions probably lead to impaired blood supply to the femoral head. The diagnosis of AVNFH is based on clinical findings and is supported by specific radiological manifestations. We reported a case of a 34-year-old Sudanese female with CML who developed AVNFH after receiving dasatinib as a second-line therapy. Though the mechanism by which dasatinib can cause avascular necrosis (AVN) is not clear, it can be postulated because of microcirculatory obstruction of the femoral head. To the best of our knowledge and after extensive literature search, this is the first reported case of AVNFH induced by dasatinib in a patient with CML.

Cytomegalovirus-induced Hemorrhagic Colitis in a Patient with Chronic Myeloid Leukemia (Chronic Phase) on Dasatinib as an Upfront Therapy.

Dasatinib is a kinase inhibitor indicated for the treatment of newly diagnosed adults with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic phase and accelerated (myeloid or lymphoid blast) phase, and CML with resistance or intolerance to prior therapy including imatinib and in adults with Ph+ acute lymphoblastic leukemia1 The most common adverse reactions (≥15%) in patients with newly diagnosed chronic-phase (CP) CML include myelosuppression, fluid retention, and diarrhea, whereas in patients with resistance or intolerance to prior imatinib therapy, side effects include myelosuppression, fluid retention, diarrhea, headache, dyspnea, skin rash, fatigue, nausea, and hemorrhage. We report a 39-year-old Ethiopian female patient who received dasatinib as upfront therapy for the treatment of CP-CML who experienced chronic diarrhea for two months, which progressed to hemorrhagic colitis due to cytomegalovirus (CMV) infection of the colon. To our knowledge, this is the first case of CMV colitis in a patient receiving dasatinib as upfront therapy.

Cytotoxicity-associated effects of reactive oxygen species on endothelin-1 secretion by pulmonary endothelial cells.

In this study bovine pulmonary artery endothelial cells (BPAEC) were used as a model system to investigate the effects of the hypoxanthine-xanthine oxidase (HXXO) oxygen radical donor system on ET-1 secretion into pulmonary vasculature. Incubation of BPAEC with HXXO for 4 h caused a significant reduction in ET-1 secretion, which was significantly offset by allopurinol or catalase, but not by Cu/Zn superoxide dismutase (SOD). ET-1 secretion was also reduced by H2O2, and this effect was again significantly offset by catalase. XO alone also reduced ET-1 secretion, but to a significantly lesser degree than did HXXO, and this effect was not offset by allopurinol, catalase, or SOD. None of the oxidant treatments were associated with a loss of immunoreactive ET-1 from endothelial cell medium containing synthetic peptide. The HXXO- and H2O2-mediated reductions in ET-1 secretion were accompanied by evidence of reduced cell viability. This loss of viability was absent when cells were treated with HXXO + catalase, allopurinol, or mercaptopropionyl glycine, but not when SOD was present. We conclude that under conditions of oxidative stress, the pulmonary vascular endothelium responds by secreting less ET-1. This may be relevant to its vasodilator functions in the pulmonary vasculature, which would therefore be compromised when the endothelium is exposed to oxidant stress.

A study of acute respiratory disease in families exposed to different levels of Air pollution in the Great Salt Lake basin, Utah, 1971-1972 and 1972-1973.

The reported incidence of acute respiratory illness in families exposed to different concentrations of air pollution was studied during two consecutive school years. The purpose of the study was to determine the effect of increased exposure to sulfur dioxide and suspended particulate matter. In each of four study communities, the mothers of approximately 250 white families were contacted biweekly to obtain information regarding the occurrence of respiratory symptoms in each family member. Annual mean ambient sulfur dioxide concentrations in one community for the three years included in the study (1971-1973) were well above the current air quality standard of 80 micrograms/m3, while in the other three communities the annual sulfur dioxide concentrations were much lower (usually less than 40 micrograms/m3). Suspended particulate matter concentrations in high sulfur dioxide community were close to the limit designated by the annual standard (75 micrograms/m3) but actual exposures in the four communities probably were not excessive. Regression analyses of the data collected showed inconsistent associations between illness rates and educational attainment of the head of household, crowding in the home, bronchitis in parents or smoking of parents. However, once the effects of these factors were removed the adjusted rates showed little association with community of residence. It was concluded that the higher concentrations of sulfur dioxide in the Utah atmosphere could not be the cause of increases in acute respiratory illness in the exposed populations.

Multiconjugate adaptive optics: laboratory experience.

We present the results from a laboratory multiconjugate adaptive optics experiment. The experiment is differentiated from other published work in that it has a programmable deterministic turbulence generator and an output science camera. The turbulence was generated using a dual layer turbulence emulator, and then corrected using an AO system with 2 wavefront correctors and a Shack-Hartman wavefront sensor, which processed information from five artificial guide stars. We report our results and also describe some of the problems.

Control optimization of spherical modal liquid crystal lenses.

Liquid crystal modal lenses are switchable lenses with a continuous phase variation across the lens. A critical issue for such lenses is the minimization of phase aberrations. In this paper we present results of a simulation of control signals that have a range of harmonics. Experimental results using optimal sinusoidal and rectangular voltages are presented. A lack of uniqueness in the specification of the control voltage parameters is explained. The influence of a variable duty cycle of the control voltage on an adaptive lens is investigated. Finally we present experimental results showing a liquid crystal lens varying its focal length.

Dual-conjugate wavefront generation for adaptive optics.

We present results of the isoplanatic performance of an astronomical adaptive optics system in the laboratory, by using a dual layer turbulence simulator. We describe how the performance of adaptive correction degrades with off--axis angle. These experiments demonstrate that it is now possible to produce quantifiable multi-layer turbulence in the laboratory as a precursor to constructing multi-conjugate adaptive optics.

Bronchogenic sarcomatoid squamous cell carcinoma with osteoclast-like giant cells.

A 60-year-old man developed a widely metastatic spindle cell neoplasm with admixed osteoclast-like giant cells indistinguishable from malignant giant cell tumor of soft parts. Autopsy revealed a bronchogenic sarcomatoid squamous cell carcinoma that was the primary source of the sarcomatoid metastases. The osteoclast-like giant cells in the metastatic lesions were negative for lysozyme on immunoperoxidase staining. This finding suggested that the multinucleated giant cells were not formed as a cellular response to hemorrhage or to cellular debris induced by the tumor. Extraosseous neoplasms with osteoclast-like giant cells are rare neoplasms that may occur in a variety of organs. This case is the second reported case of a primary neoplasm in the lung that contained these osteoclast-like giant cells. These tumors may cause considerable diagnostic confusion.