Current-voltage Relation For A Field Ionizing He Beam Detector

Emerging interest in utilizing the transverse coherence properties of thermal energy atomic and molecular beams motivates the development of ionization detectors with near unit detection efficiency and adequate spatial resolution to resolve interference fringes of submicron dimension. We demonstrate that a field ionization tip coupled to a charged particle detector meets these requirements. We have systematically studied the current-voltage relationship for field ionization of helium using tungsten tips in diffuse gas and in a supersonic helium beam. For all 16 tips used in this study, the dependence of ion current on voltage for tips of fixed radius was found to differ from that for tips held at constant surface electric field. A scaling analysis is presented to explain this difference. Ion current increased on average to the 2.8 power of voltage for a tip at fixed field and approximately fifth power of voltage for fixed radius for a liquid nitrogen cooled tip in room temperature helium gas. For the helium beam, ion current increased as 2.2 power of voltage with constant surface field. The capture region of the tips was found to be up to 0.1 mu m(2) for diffuse gas and 0.02 mu m(2) in the beam. Velocity dependence and orientation of tip to beam were also studied

Konbit : bridging social, cultural, and political worlds by accelerating job growth and creation for the illiterate, disconnected workers

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 75-77).Current employment technology typically relies on the concept of a CV or resume -a highly precise and constructed document. The creation of this document requires intricate knowledge of a process that is often opaque to those living in developed nations, who rely on training and experience to write compelling CV's. For those living in developing countries, this process is more difficult, and for those that have no internet access or are illiterate, creating a first-world resume is nearly impossible. That said, when firstworld organizations in developing countries bring with them their expectations of hiring which may or may not fit with the natives of that country. We propose a system, "Konbit," that creates a cultural and technological bridge between those with skills in developing countries and those with first-world expectations of potential employees. This platform allows literate or illiterate workers to describe their skills and life experiences as story-like messages in their native language, requires no technological upgrades from these workers, and transforms and offers this data as deep, humanized characterizations of potential employees. Non-profit organizations (NGOs) and government organizations (GOs) can search this data in a technologically modern format, viewing an automatically constructed resume for each caller. While other systems attempt to create miniature CV's via SMS-based messaging, these systems are not accessible by the illiterate and impose western CV-based culture onto applicants, resulting in low-fidelity representations given that SMS text messages are by nature short and inappropriate for extensive data input. Given the focus on the most is connected workers, Konbit deployed and received data from over 10,000 people in Port-au-Prince, Haiti, where the literacy rate, at the time of writing, was around 50% and the unemployment rate was more than 80%. This system was also beta-tested with 30 Haitian-Americans in Miami, Florida. The implications of the thesis will be relevant to any area - developed or developing - that is affected by illiteracy, poor training, or cultural gaps between workers and employers, and may serve as a more effective tool for employee characterization and interviewing in all job sectors.by Greg Elliott.S.M

Gears

Discussion Grou

Eliminating a Rotordynamic Instability of a 12 MW Overhung, Radial Inflow Expander

Case Stud

Monocyte distribution width enhances early sepsis detection in the emergency department beyond SIRS and qSOFA

BACKGROUND: The initial presentation of sepsis in the emergency department (ED) is difficult to distinguish from other acute illnesses based upon similar clinical presentations. A new blood parameter, a measurement of increased monocyte volume distribution width (MDW), may be used in combination with other clinical parameters to improve early sepsis detection. We sought to determine if MDW, when combined with other available clinical parameters at the time of ED presentation, improves the early detection of sepsis. METHODS: A retrospective analysis of prospectively collected clinical data available during the initial ED encounter of 2158 adult patients who were enrolled from emergency departments of three major academic centers, of which 385 fulfilled Sepsis-2 criteria, and 243 fulfilled Sepsis-3 criteria within 12 h of admission. Sepsis probabilities were determined based on MDW values, alone or in combination with components of systemic inflammatory response syndrome (SIRS) or quick sepsis-related organ failure assessment (qSOFA) score obtained during the initial patient presentation (i.e., within 2 h of ED admission). RESULTS: Abnormal MDW (\u3e 20.0) consistently increased sepsis probability, and normal MDW consistently reduced sepsis probability when used in combination with SIRS criteria (tachycardia, tachypnea, abnormal white blood count, or body temperature) or qSOFA criteria (tachypnea, altered mental status, but not hypotension). Overall, and regardless of other SIRS or qSOFA variables, MDW \u3e 20.0 (vs. MDW ≤ 20.0) at the time of the initial ED encounter was associated with an approximately 6-fold increase in the odds of Sepsis-2, and an approximately 4-fold increase in the odds of Sepsis-3. CONCLUSIONS: MDW improves the early detection of sepsis during the initial ED encounter and is complementary to SIRS and qSOFA parameters that are currently used for this purpose. This study supports the incorporation of MDW with other readily available clinical parameters during the initial ED encounter for the early detection of sepsis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03145428. First posted May 9, 2017. The first subjects were enrolled June 19, 2017, and the study completion date was January 26, 2018

Human Hendra Virus Encephalitis Associated with Equine Outbreak, Australia, 2008

Emergence of this virus is a serious medical, veterinary, and public health challenge

Earnings Management: The Effect of Ex Ante Earnings Expectations

Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Genetic risk for schizophrenia and developmental delay is associated with shape and microstructure of midline white-matter structures

Genomic copy number variants (CNVs) are amongst the most highly penetrant genetic risk factors for neuropsychiatric disorders. The scarcity of carriers of individual CNVs and their phenotypical heterogeneity limits investigations of the associated neural mechanisms and endophenotypes. We applied a novel design based on CNV penetrance for schizophrenia (Sz) and developmental delay (DD) that allows us to identify structural sequelae that are most relevant to neuropsychiatric disorders. Our focus on brain structural abnormalities was based on the hypothesis that convergent mechanisms contributing to neurodevelopmental disorders would likely manifest in the macro- and microstructure of white matter and cortical and subcortical grey matter. Twenty one adult participants carrying neuropsychiatric risk CNVs (including those located at 22q11.2, 15q11.2, 1q21.1, 16p11.2 and 17q12) and 15 age- and gender-matched controls underwent T1-weighted structural, diffusion and relaxometry MRI. The macro- and microstructural properties of the cingulum bundles were associated with penetrance for both developmental delay and schizophrenia, in particular curvature along the anterior-posterior axis (Sz: pcorr = 0.026; DD: pcorr = 0.035) and intracellular volume fraction (Sz: pcorr = 0.019; DD: pcorr = 0.064). Further principal component analysis showed alterations in the interrelationships between the volumes of several midline white-matter structures (Sz: pcorr = 0.055; DD: pcorr = 0.027). In particular, the ratio of volumes in the splenium and body of the corpus callosum was significantly associated with both penetrance scores (Sz: p = 0.037; DD; p = 0.006). Our results are consistent with the notion that a significant alteration in developmental trajectories of midline white-matter structures constitutes a common neurodevelopmental aberration contributing to risk for schizophrenia and intellectual disability