University of Massachusetts Boston

About: University of Massachusetts Boston is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Health care. The organization has 6541 authors who have published 12918 publications receiving 411731 citations. The organization is also known as: UMass Boston.

Systems methods and instruments for minimally invasive surgery

Abstract: Systems, methods, and miniature instruments (e.g., 12, 30, 40, 50, and 102) are disclosed for minimally invasive surgical procedures. A miniature surgical instrument can be inserted directly into a body cavity (16) through a cannula (10, 118) in a way that a surgeon can insert his or her hand into the cavity (16) through a separate minimal incision and use the miniature instruments. A miniature surgical system can include: a cannula (10, 118) having a hollow body configured to receive a miniature surgical instrument (102) and a tether (13, 104) connected to the instrument; and a plunger (108) sized to engage a proximal end of the body and including a conduit (106) therethrough for receiving the tether. The system can also include the tether and the instrument. During use, the instruments can be quickly and safely removed from the body cavity to enable the surgeon to use his or her fingers, e.g., to manipulate tissue.

First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring

Abstract: The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data. To this end, we construct a large library of models based on general relativistic magnetohydrodynamic (GRMHD) simulations and synthetic images produced by general relativistic ray tracing. We compare the observed visibilities with this library and confirm that the asymmetric ring is consistent with earlier predictions of strong gravitational lensing of synchrotron emission from a hot plasma orbiting near the black hole event horizon. The ring radius and ring asymmetry depend on black hole mass and spin, respectively, and both are therefore expected to be stable when observed in future EHT campaigns. Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity. If the black hole spin and M87's large scale jet are aligned, then the black hole spin vector is pointed away from Earth. Models in our library of non-spinning black holes are inconsistent with the observations as they do not produce sufficiently powerful jets. At the same time, in those models that produce a sufficiently powerful jet, the latter is powered by extraction of black hole spin energy through mechanisms akin to the Blandford-Znajek process. We briefly consider alternatives to a black hole for the central compact object. Analysis of existing EHT polarization data and data taken simultaneously at other wavelengths will soon enable new tests of the GRMHD models, as will future EHT campaigns at 230 and 345 GHz.

The Composing Processes of Advanced ESL Students: Six Case Studies

Abstract: The most recent research in composition has given us important insights into the composing process. This research has revealed that composing is a non-linear, exploratory, and generative process whereby writers discover and reformulate their ideas as they attempt to approximate meaning. A study of the composing processes of advanced ESL students was undertaken to investigate the extent to which these students experience writing as a process of discovering and creating meaning and the extent to which second language factors affect this process. The findings indicate that skilled ESL writers explore and clarify ideas and attend to language-related concerns primarily after their ideas have been delineated. Since it is believed that the teaching of composition should be informed by and based upon what writing actually entails, an understanding of the composing process calls into question approaches that are prescriptive, formulaic, and overly concerned with correctness. Instead, it suggests the importance of instruction that gives students direct experiences with the composing process, that establishes a dynamic teaching/learning relationship between writers and their readers, and that enhances further linguistic development in the context of making and communicating meaning.

First M87 Event Horizon Telescope Results. II. Array and Instrumentation

Abstract: The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of ~1.3 mm, EHT angular resolution (λ/D) is ~25 μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of the EHT, detail the technology and instrumentation that enable observations, and provide measures of its performance. Meeting the EHT science objectives has required several key developments that have facilitated the robust extension of the VLBI technique to EHT observing wavelengths and the production of instrumentation that can be deployed on a heterogeneous array of existing telescopes and facilities. To meet sensitivity requirements, high-bandwidth digital systems were developed that process data at rates of 64 gigabit s^(−1), exceeding those of currently operating cm-wavelength VLBI arrays by more than an order of magnitude. Associated improvements include the development of phasing systems at array facilities, new receiver installation at several sites, and the deployment of hydrogen maser frequency standards to ensure coherent data capture across the array. These efforts led to the coordination and execution of the first Global EHT observations in 2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87.

Sequence-specific inhibition of small RNA function

Abstract: The present invention relates to the discovery of a method for inhibiting RNA silencing in a target sequence-specific manner. RNA silencing requires a set of conserved cellular factors to suppress expression of gene-encoded polypeptide. The invention provides compositions for sequence-specific inactivation of the RISC component of the RNA silencing pathway, and methods of use thereof. The RISC inactivators of the present invention enable a variety of methods for identifying and characterizing miRNAs and siRNAs, RISC-associated factors, and agents capable of modulating RNA silencing. Therapeutic methods and compositions incorporating RISC inactivators and therapeutic agents identified through use of RISC inactivators are also featured.