Ion beam micromachining of integrated optics components

Thin film integrated optics components such as light guides, modulators, directional couplers, and polarizers demand high quality edge smoothness and high resolution pattern formation in dimensions down to submicrometer size. Fabrication techniques combining holographic and scanning electron beam lithography with ion beam micromachining have produced planar phase gratings with intervals as small as 2800 Å, guiding channel couplers in GaAs, and also wire- grid polarizers for 10.6-µm radiation

14-3-3s Protein Expression in Canine Renal Cell Carcinomas

14-3-3σ is a protein expressed in many epithelial tissues associated with essential cell functions, including cell-cycle control, apoptosis, and cytoskeletal integrity. There is a paucity of knowledge of the tumorigenesis of canine renal cell carcinomas (RCCs), and the histological origin of this tumor has not been established. This study analyzed the expression of 14-3-3σ, Ki-67, cytokeratins, and vimentin in 40 canine RCCs. Aberrant expression of 14-3-3σ was demonstrated in 15 (38%) cases and was associated with a significantly shorter survival time (P < .002). In contrast to canine RCC, normal kidney did not express 14-3-3σ. The Ki-67 proliferation index did not show utility as a prognostic factor. The distal convoluted tubular epithelium in normal kidneys coexpressed cytokeratins and vimentin, and thus maintenance of this coexpression pattern in canine RCC suggests that most tumors arise from the distal segment of the nephron. These results suggest that 14-3-3σ is a potential negative prognostic factor and a possible therapeutic target

Malignant Cutaneous Peripheral Nerve Sheath Tumour with Rhabdomyosarcomatous Differentiation (Triton Tumour) in a Domestic Cat

Divergent differentiation is encountered frequently within human malignant peripheral nerve sheath tumours (MPNSTs). The new component is often a rhabdomyosarcoma, but in animals this specific form of divergent differentiation within MPNSTs has only been reported once (in a dog). Incisional wedge biopsy of a locally extensive, ventral abdominal wall mass, which extended from the dermis to the subcutis, from a 12-year-old female domestic shorthaired cat, was performed. The tissue was examined with routine haematoxylin and eosin staining and immunohistochemical methods. A malignant neoplasm with spindle and polygonal cell components and progression towards a rhabdomyosarcomatous phenotype was observed. Both neoplastic cell populations exhibited strong expression of vimentin and there was multifocal expression of S100 and desmin. There was strong cytoplasmic labelling for α-sarcomeric actin and muscle actin and weak labelling for myoglobin within the cells positive for desmin. There was multifocal positive nuclear labelling for myogenin. Glial fibrillary acidic protein, α-smooth muscle actin, microphthalmia-associated transcription factor and melanoma antigen recognized by T cells were not expressed. Microscopical features, aided by immunohistochemistry, identified a MPNST with progression towards a rhabdomyosarcomatous phenotype, a so-called ‘triton tumour’. A Schwann cell component could account for the divergent patterns of growth, given the plasticity of the neural crest. Nerve sheath tumours have been reported in the skin and subcutis of cats and are a differential diagnosis of feline cutaneous spindle cell neoplasms

Correlation effects in ionic crystals: I. The cohesive energy of MgO

High-level quantum-chemical calculations, using the coupled-cluster approach and extended one-particle basis sets, have been performed for (Mg2+)n (O2-)m clusters embedded in a Madelung potential. The results of these calculations are used for setting up an incremental expansion for the correlation energy of bulk MgO. This way, 96% of the experimental cohesive energy of the MgO crystal is recovered. It is shown that only 60% of the correlation contribution to the cohesive energy is of intra-ionic origin, the remaining part being caused by van der Waals-like inter-ionic excitations.Comment: LaTeX, 20 pages, no figure

Non-ancient solution of the Ricci flow

For any complete noncompact K$\ddot{a}$hler manifold with nonnegative and bounded holomorphic bisectional curvature,we provide the necessary and sufficient condition for non-ancient solution to the Ricci flow in this paper.Comment: seven pages, latex fil

Critical region of the random bond Ising model

We describe results of the cluster algorithm Special Purpose Processor simulations of the 2D Ising model with impurity bonds. Use of large lattices, with the number of spins up to $10^6$, permitted to define critical region of temperatures, where both finite size corrections and corrections to scaling are small. High accuracy data unambiguously show increase of magnetization and magnetic susceptibility effective exponents $\beta$ and $\gamma$, caused by impurities. The $M$ and $\chi$ singularities became more sharp, while the specific heat singularity is smoothed. The specific heat is found to be in a good agreement with Dotsenko-Dotsenko theoretical predictions in the whole critical range of temperatures.Comment: 11 pages, 16 figures (674 KB) by request to authors: [email protected] or [email protected], LITP-94/CP-0

The middle-out perspective:an approach to formalise 'normal practice' in public health advocacy

AIMS: The middle-out perspective (MOP) provides a lens to examine how actors positioned between government (top) and individuals (bottom) act to promote broader societal changes from the middle-out (rather than the top-down or bottom-up). The MOP has been used in recent years in the fields of energy, climate change, and development studies. We argue that public health practitioners involved with advocacy activities and creating alliances to amplify health promotion actions will be familiar with the general MOP concept if not the formal name. The article aims to demonstrate this argument. METHODS: This article introduces the MOP conceptual framework and customises it for a public health audience by positioning it among existing concepts and theories for actions within public health. Using two UK case studies (increasing signalised crossing times for pedestrians and the campaign for smoke-free legislation), we illustrate who middle actors are and what they can do to result in better public health outcomes. RESULTS: These case studies show that involving a wider range of middle actors, including those not traditionally involved in improving the public's health, can broaden the range and reach of organisations and individuals involving in advocating for public health measures. They also demonstrate that middle actors are not neutral. They can be recruited to improve public health outcomes, but they may also be exploited by commercial interests to block healthy policies or even promote a health-diminishing agenda. CONCLUSION: Using the MOP as a formal approach can help public health organisations and practitioners consider potential 'allies' from outside traditional health-related bodies or professions. Formal mapping can expand the range of who are considered potential middle actors for a particular public health issue. By applying the MOP, public health organisations and staff can enlist the additional leverage that is brought to bear by involving additional middle actors in improving the public's health

Factors which are associated with dental decay in the older individual

Objectives: To improve reliability of salivary bacterial cultures as a surrogate for plaque levels of cariogenic bacterial species by reporting the salivary CFUs of these organisms as a function of the number of teeth. Design: Cross-sectional collection of data in a convenience sample of adults over 60 years of age. Setting: Hospital Dental clinic, University bacteriology laboratory. Subjects: 523 older dentate subjects, average age 70, including 412 subjects who were in an independent living status and 111 in a dependent-living situation. Main outcome measures : Subjects were examined for decay and the presence of salivary factors including the levels of S. mutans , lactobacilli, yeast and other bacteria. The salivary levels of the bacteria were adjusted for the number of teeth in the mouth, and the resultant values were entered into multivariable logistic regression models along with clinical and other salivary parameters. Results: Mutans streptococci levels reported as CFUs/ml saliva per tooth were significantly associated with coronal surface decay, and lactobacilli, reported in a similar way, were significantly associated with root surface decay. Salivary levels of yeasts, which had previously been associated with decay in this population, were no longer significant using this construct. Conclusions : This construct of reporting salivary bacteriological data as a function of tooth number and per ml saliva could improve the reliability of bacteriological data obtained in epidemiological studies investigating the role of bacteria in dental decay in the elderly.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72626/1/j.1741-2358.1999.00037.x.pd