Highly efficient interconnection for use with a multistage optical switching network with orthogonally polarized data and address information

A novel optical interconnection is introduced for a multistage optical switching network that uses orthogonally polarized data and address information. The network is unique in that the data information is never regenerated and remains in optical form throughout (i.e., it is never converted into electrical information). This has two main consequences: (1) the bandwidth of the data is not restricted by electrical circuit considerations, and (2) the optical interconnections from one stage of the network to the next must be highly efficient. The interconnection meets several goals: high efficiency, preservation of cross polarization of data and address, low cross talk between polarizations, good manufacturability, resistance to misalignment caused by thermal expansion, and absence of significant aberrations. In addition, sychronization of the signals is maintained, as the optical path lengths for all routes through the system are equal.     

Two-dimensional wavelet transform and application to holographic particle velocimetry

The goal of holographic particle velocimetry is to infer fluid velocity patterns from images reconstructed from doubly exposed holograms of fluid volumes seeded with small particles. The advantages offered by in-line holography in this context usually make it the method of choice, but seeding densities sufficient to achieve high spatial resolution in the sampling of the velocity fields cause serious degradation, through speckle, of the signal-to-noise ratio in the reconstructed images. The in-line method also leads to a great depth of field in paraxial viewing of reconstructed images, making it essentially impossible to estimate particle depth with useful accuracy. We present here an analysis showing that these limitations can be circumvented by variably scaled correlation, or wavelet transformation. The shift variables of the wavelet transform are provided automatically by the optical correlation methodology. The variable scaling of the wavelet transform derives, in this case, directly from the need to accommodate varying particle depths. To provide such scaling, we use a special optical system incorporating prescribed variability in spacings and focal length of lenses to scan through the range of particle depths.

Calculation shows, among other benefits, improvement by approximately two orders of magnitude in depth resolution. A much higher signal-to-noise ratio together with faster data extraction and processing should be attainable.

     

Analysis of layered scattering materials by pulsed photothermal radiometry: application to photon propagation in tissue

A model of pulsed photothermal radiometry (PPTR) based on optical diffusion theory is presented for a turbid, two-layer, semi-infinite medium containing a surface layer whose optical absorption and scattering properties differ from that of the underlying layer. Assuming one-dimensional geometry, we develop expressions for the depth-dependent fluence distributions and radiant-energy-density profiles and for the time dependence of the PPTR signal. Experimental tests of the PPTR model in a series of layered phantoms of varying optical properties are described. The results of these tests are consistent with the model predictions.     

Measuring the surface defects of a fabry-perot étalon

A simple method for mapping the surface defects of a Fabry-Perot étalon is described. Images of the fringes of equal thickness are acquired as the plate separation is altered in a stepwise manner. This information is processed to yield a map of the location of the surface defects, and can be further used to estimate the effect of varying plate reflectance on the instrument function.     

Glycosylation patterns of membrane proteins of the jellyfish Cyanea capillata

Integral and membrane-associated proteins extracted from neuron-enriched perirhopalial tissue of the jellyfish Cyanea capillata were probed with a panel of lectins that recognize sugar epitopes of varying complexity. Of the 13 lectins tested, only concanavalin A, jacalin lectin and tomato lectin stained distinct bands on Western blots, indicating the presence of repeating alpha-1,6-mannoses, terminal Gal-alpha-1,6-GalNAc and repeating beta-1,4-linked GlcNAc, respectively. In whole-mounted perirhopalial tissue, jacalin lectin stained several cell types, including neurons, muscle, cilia and mucus strands. Tomato lectin stained secretory cells intensely, and neurons in a punctate fashion. Concanavalin A stained cytoplasmic epitopes in both ecto- and endodermal cells, and ectodermal secretory cells and the mucus strands emanating from them. With the exception of tomato lectin's sugar epitope, the other sugar epitopes identified in this study are "non-complex". This study suggests that while glycosylation of integral and membrane-associated proteins occurs in Cyanea, the sugars post-translationally linked to these proteins tend to be simple.     

Effect of contrast concentration on abdominal enhancement in the rabbit: spiral computed tomography evaluation

BACKGROUND: Langerhans' cell histiocytosis (LCH) is an uncommon, poorly understood granulomatous disease, characterized by the idiopathic proliferation of Langerhan's cells or their marrow precursors. In 1985, the Philadelphia Work-shop adopted the term "Langerhans' cell histiocytosis" (LCH) to differentiate it from reactive and neoplastic causes of histiocytosis. METHODS: This study includes 73 pediatric patients diagnosed with this condition in Dublin, Ireland, and Nottingham, England, during a 34-year period (1959 to 1993). These patients are reviewed with respect to clinical presentation, difficulty with making a histological diagnosis, their management, and outcome. RESULTS: A total of 49 patients (67%) had head and neck involvement. Bony involvement was the most frequent sign, most frequently located in the skull. There were 11 deaths (15%) in this series, all associated with multisystem disease, and nine of these deaths were in children younger than 2 years of age. CONCLUSIONS: The role of otolaryngologists is important in the early and accurate evaluation, staging, and diagnosis of LCH. It may mimic more common diseases, such as otitis externa, acute mastoiditis, skin rash, gingivitis, or cervical lymphadenopathy. Patients with multisystem disease may be so ill at presentation that the head and neck lesions may be overlooked. The current management of LCH has become increasingly conservative, and in the 1990s, fewer cases are given chemotherapy or radiotherapy. The prognosis is very good for single-system disease and poor for multisystem disseminated disease with early onset.     

From research to practice: the effects of the jointly sponsored dissemination of an arthritis self-care nursing intervention

Various educational programs have been developed and found to be effective in the self-management of arthritis. This study reexamined the effectiveness of one such program, "Bone Up On Arthritis" (BUOA), when the program was delivered by a community-based service organization to a sample of persons (N = 154) who differed widely in disease type and demographic characteristics. Arthritis Foundation staff implemented BUOA at four national sites; data were collected and analyzed by University of Michigan nurse researchers. Investigators found improved scores on all outcome measures (self-care behavior, helplessness, pain, dysfunction, and depression). These findings suggest that "Bone Up" is an effective nursing intervention in multiple organizational and community environments and for diverse patient populations.     

Feedstock powder processing research needs for additive manufacturing development

Additive manufacturing (AM) promises to redesign traditional manufacturing by enabling the ultimate in agility for rapid component design changes in commercial products and for fabricating complex integrated parts. By significantly increasing quality and yield of metallic alloy powders, the pace for design, development, and deployment of the most promising AM approaches can be greatly accelerated, resulting in rapid commercialization of these advanced manufacturing methods. By successful completion of a critical suite of processing research tasks that are intended to greatly enhance gas atomized powder quality and the precision and efficiency of powder production, researchers can help promote continued rapid growth of AM. Other powder-based or spray-based advanced manufacturing methods could also benefit from these research outcomes, promoting the next wave of sustainable manufacturing technologies for conventional and advanced materials.     

Duration of treatment with progesterone and regression of persistent ovarian follicles in cattle

The objective of the present study was to determine the duration of elevated concentrations of progesterone necessary to induce atresia of persistent ovarian follicles. Heifers were administered 25 mg of PGF2alpha on d 6 and 7 (d 0 = d of synchronized estrus) and a norgestomet implant from d 6 to 14. Ovaries were monitored by ultrasonography, and blood samples were collected on d 3, 5, 7, 9, 11, and 12 and daily from d 14 until ovulation. On d 12, heifers received either two progesterone-releasing intravaginal devices (PRID) for 6 h (6-h; n = 5), two PRID for 24 h (24-h; n = 5), or no treatment (CON; n = 5). Blood samples were collected at 15-min intervals from h -6 to 30 (PRID insertion = h 0) and analyzed for concentrations of LH. Characteristics of LH secretion were determined for consecutive 6-h periods (Period 0 to 5). Hourly blood samples, collected from h 0 to 29, were analyzed for concentrations of 17beta-estradiol (estradiol) and progesterone. The dominant ovarian follicles present on d 7 increased in size to 15.4+/-.3 mm on d 12 ("persistent follicle"). Following removal of the PRID and norgestomet implants, atresia of persistent follicles and ovulation of new follicles were induced in one of five and in four of five heifers in the 6-h and 24-h treatments, respectively. Persistent follicles ovulated after withdrawal of norgestomet in all other heifers. Concentrations of progesterone were increased from h 1 to 7 in the 6-h and h 1 to 26 in the 24-h treatment. Frequency of LH pulses was reduced (P < .05) during Periods 1 to 2 in the 6-h and Periods 1 to 5 in the 24-h treatment relative to the CON treatment. By h 10, concentrations of estradiol in the 6-h and 24-h treatments were lower (P < . 05) than in the CON treatment. This suppression continued through h 29 in the 24-h treatment (P < .05), whereas concentrations in the 6-h treatment were intermediate to those of the CON and 24-h treatments after h 14. Suppression of pulsatile LH release and estradiol secretion was evident with 6 and 24 h of treatment with progesterone, but only the 24-h treatment induced atresia of persistent follicles in a majority of the heifers.