Orthodontic Bracket Manufacturing Tolerances and Dimensional Differences between Select Self-Ligating Brackets

In all manufacturing processes there are tolerances; however, orthodontic bracket manufacturers seldom state the slot dimensional tolerances. This experiment develops a novel method of analyzing slot profile dimensions using photographs of the slot. Five points are selected along each wall, and lines are fitted to define a trapezoidal slot shape. This investigation measures slot height at the slot's top and bottom, angles between walls, slot taper, and the linearity of each wall. Slot dimensions for 30 upper right central incisor self-ligating stainless steel brackets from three manufacturers were evaluated. Speed brackets have a slot height 2% smaller than the nominal 0.559 mm size and have a slightly convergent taper. In-Ovation brackets have a divergent taper at an average angle of 1.47 degrees. In-Ovation is closest to the nominal value of slot height at the slot base and has the smallest manufacturing tolerances. Damon Q brackets are the most rectangular in shape, with nearly 90-degree corners between the slot bottom and walls. Damon slot height is on average 3% oversized

Ion-neutral sympathetic cooling in a hybrid linear rf Paul and magneto-optical trap

Long range polarization forces between ions and neutral atoms result in large elastic scattering cross sections, e.g., 10^6 a.u. for Na+ on Na or Ca+ on Na at cold and ultracold temperatures. This suggests that a hybrid ion-neutral trap should offer a general means for significant sympathetic cooling of atomic or molecular ions. We present SIMION 7.0 simulation results concerning the advantages and limitations of sympathetic cooling within a hybrid trap apparatus, consisting of a linear rf Paul trap concentric with a Na magneto-optical trap (MOT). This paper explores the impact of various heating mechanisms on the hybrid system and how parameters related to the MOT, Paul trap, number of ions, and ion species affect the efficiency of the sympathetic cooling

Back to the Future: Lorraine v. Markel American Insurance Co. and New Findings on the Admissibility of Electronically Stored Information

Imagine the following hypothetical, patterned on an actual case pending in federal court, and you can begin to appreciate why there is a growing awareness of the need to have clear analytical thinking regarding the admissibility of electronically stored information, variously referred to as “ESI,” “digital,” “electronic,” “computer generated,” or “computer stored” evidence in state and federal courts. ConsumerPro is a corporation that provides installment credit to consumers with poor or un-established credit records to enable them to purchase on credit expensive electronic and computer products like flat screen televisions, computers, and entertainment systems. Under their business plan, a purchaser agrees to buy a product in installments, such as automatic withdrawals from a bank account, and only after the purchaser has made a series of payments is the product shipped to the purchaser, who then continues to make payments until the purchase price is fully paid

Early Music Ensemble Madrigal Singers Concert Choir

Center for the Performing Arts Sunday Afternoon March 21, 2004 3:00p.m

A Pilot Online Survey Assessing Risk Factors for HIV Acquisition in the Navy and Marine Corps, 2005-2010

The Department of Defense policy Don\u27t Ask, Don\u27t Tell (DADT) ended in September, 2011. The Navy Bloodborne Infection Management Center conducted a post-DADT pilot survey of HIV seroconverters identified when the DADT policy was in effect. Sailors and Marines newly diagnosed as HIV positive from 2005 to 2010 were invited to participate in an online survey. A structured questionnaire elicited risk information about the 3-year period before HIV diagnosis. Respondents reported engaging commonly in same sex sexual activity, having concurrent partners, and poor condom use for anal sex. In this first post-DADT repeal report of self-reported behaviors, male-to-male sexual contact was a much more common mode of infection than previously reported. Several opportunities for primary prevention messaging now possible after DADT repeal are evident

The Size and Culturability of Patient-Generated SARS-CoV-2 Aerosol

BACKGROUND: Aerosol transmission of COVID-19 is the subject of ongoing policy debate. Characterizing aerosol produced by people with COVID-19 is critical to understanding the role of aerosols in transmission. OBJECTIVE: We investigated the presence of virus in size-fractioned aerosols from six COVID-19 patients admitted into mixed acuity wards in April of 2020. METHODS: Size-fractionated aerosol samples and aerosol size distributions were collected from COVID-19 positive patients. Aerosol samples were analyzed for viral RNA, positive samples were cultured in Vero E6 cells. Serial RT-PCR of cells indicated samples where viral replication was likely occurring. Viral presence was also investigated by western blot and transmission electron microscopy (TEM). RESULTS: SARS-CoV-2 RNA was detected by rRT-PCR in all samples. Three samples confidently indicated the presence of viral replication, all of which were from collected sub-micron aerosol. Western blot indicated the presence of viral proteins in all but one of these samples, and intact virions were observed by TEM in one sample. SIGNIFICANCE: Observations of viral replication in the culture of submicron aerosol samples provides additional evidence that airborne transmission of COVID-19 is possible. These results support the use of efficient respiratory protection in both healthcare and by the public to limit transmission

Computer-assisted detection of cemento-enamel junction in intraoral ultrasonographs

The cemento-enamel junction (CEJ) is an important reference point for various clinical measurements in oral health assessment. Identifying CEJ in ultrasound images is a challenging task for dentists. In this study, a computer-assisted detection method is proposed to identify the CEJ in ultrasound images, based on the curvature change of the junction outlining the upper edge of the enamel and cementum at the cementum–enamel intersection. The technique consists of image preprocessing steps for image enhancement, segmentation, and edge detection to locate the boundary of the enamel and cementum. The effects of the image preprocessing and the sizes of the bounding boxes enclosing the CEJ were studied. For validation, the algorithm was applied to 120 images acquired from human volunteers. The mean difference of the best performance between the proposed method and the two raters’ measurements was an average of 0.25 mm with reliability ≥ 0.98. The proposed method has the potential to assist dental professionals in CEJ identification on ultrasonographs to provide better patient care