The effects of punctual occlusion on hydrogel contact lens comfort

Background: Many hydrogel contact lens wearers suffer from discomfort due to a variety of factors including dry eyes, old age, environmental conditions, and even contact lenses. Many patients relieve this discomfort with frequent instillation of lubrication drops, however, this can become quite inconvenient and expensive. In some cases, doctors may treat patients with punctal occlusion when there is severe discomfort that is accompanied by pathological dry eye signs. Doctors often do not offer punctal occlusion to simply improve contact lens comfort alone. It is proposed that through the placement of temporary punctal plugs, effects of punctal occlusion on the comfort of hydrogel contact lens comfort can be observed and quantified. Methods: Hydrogel contact lens wearers with healthy eyes were invited to participate in the study. Subjects completed a subjective questionnaire pertaining to the comfort of their current contact lenses. Dissolvable collagen plugs were inserted in the subject\u27s lower puncta. A second questionnaire was completed by the patient to report post-procedural contact lens comfort. The post-procedural questionnaires were completed 48 hours after plug insertion and mailed to the project location. Results: The majority of patients experienced an increase in over all contact lens comfort, as well as improvements in specific discomforts, such as light sensitivity, itching, burning, tired eyes, and ease of contact lens removal. Conclusion: This study illustrates that punctal occlusion is a treatment option for patients who desire an increase in the comfort of their hydrogel contact lenses

Robotic work cell for packing canisters

The purpose of this project is to reduce the manufacturing cost of the special order 2500cc truck canisters produced at Rochester Products\u27 Lee Road facility. This was accomplished by designing and developing a robotic work cell to pack the canisters into baskets at the injection mold machine. A literature search was conducted to gain a broader understanding of robotic applications and end-effector design. In developing this cell, the layout of the work cell components was determined, a suitable robot was selected, and an end-effector was designed, built and tested

Simulations of isoprene: Ozone reactions for a general circulation/chemical transport model

A parameterized reaction mechanism has been created to examine the interactions between isoprene and other tropospheric gas-phase chemicals. Tests of the parameterization have shown that its results match those of a more complex reaction set to a high degree of accuracy. Comparisons between test runs have shown that the presence of isoprene at the start of a six day interval can enhance later ozone concentrations by as much as twenty-nine percent. The test cases used no input fluxes beyond the initial time, implying that a single input of a biogenic hydrocarbon to an airmass can alter its ozone chemistry over a time scale on the order of a week

Young children's explorations of average through informal inferential reasoning

This study situates children's early notions of average within an inquiry classroom to investigate the rich inferential reasoning that young children drew on to make sense of the questions: Is there a typical height for a student in year 3? If so, what is it? Based on their deliberations over several lessons, students' ideas about average and typicality evolved as meaning reasonable, contrary to atypical, most common (value or interval), middle, normative, and representative of the population. The case study reported here documents a new direction for the development of children's conceptions of average in a classroom designed to elicit their informal inferential reasoning about data

Endomorphisms of quantized Weyl algebras

Belov-Kanel and Kontsevich conjectured that the group of automorphisms of the n'th Weyl algebra and the group of polynomial symplectomorphisms of C^2 are canonically isomorphic. We discuss how this conjecture can be approached by means of (second) quantized Weyl algebras at roots of unity

Holomorphic automorphisms of Danielewski surfaces II -- structure of the overshear group

We apply Nevanlinna theory for algebraic varieties to Danielewski surfaces and investigate their group of holomorphic automorphisms. Our main result states that the overshear group which is known to be dense in the identity component of the holomorphic automorphism group, is a free amalgamated product.Comment: 24 page

Affine modifications and affine hypersurfaces with a very transitive automorphism group

We study a kind of modification of an affine domain which produces another affine domain. First appeared in passing in the basic paper of O. Zariski (1942), it was further considered by E.D. Davis (1967). The first named author applied its geometric counterpart to construct contractible smooth affine varieties non-isomorphic to Euclidean spaces. Here we provide certain conditions which guarantee preservation of the topology under a modification. As an application, we show that the group of biregular automorphisms of the affine hypersurface $X \subset C^{k+2}$ given by the equation $uv=p(x_1,...,x_k)$ where $p \in C[x_1,...,x_k],$ acts $m-$transitively on the smooth part reg$X$ of $X$ for any $m \in N.$ We present examples of such hypersurfaces diffeomorphic to Euclidean spaces.Comment: 39 Pages, LaTeX; a revised version with minor changes and correction