2,801 research outputs found

    Deflation and the international Great Depression: a productivity puzzle

    Get PDF
    This paper presents a dynamic, stochastic general equilibrium study of the causes of the international Great Depression. We use a fully articulated model to assess the relative contributions of deflation/monetary shocks, which are the most commonly cited shocks for the Depression, and productivity shocks. We find that productivity is the dominant shock, accounting for about 2/3 of the Depression, with the monetary shock accounting for about 1/3. The main reason deflation doesn't account for more of the Depression is because there is no systematic relationship between deflation and output during this period. Our finding that a persistent productivity shock is the key factor stands in contrast to the conventional view that a continuing sequence of unexpected deflation shocks was the major cause of the Depression. We also explore what factors might be causing the productivity shocks. We find some evidence that they are largely related to industrial activity, rather than agricultural activity, and that they are correlated with real exchange rates and non-deflationary shocks to the financial sector.Depressions ; Deflation (Finance) ; Production (Economic theory)

    Inhibition of the EGF receptor by binding of MIG6 to an activating kinase domain interface.

    Get PDF
    Members of the epidermal growth factor receptor family (EGFR/ERBB1, ERBB2/HER2, ERBB3/HER3 and ERBB4/HER4) are key targets for inhibition in cancer therapy. Critical for activation is the formation of an asymmetric dimer by the intracellular kinase domains, in which the carboxy-terminal lobe (C lobe) of one kinase domain induces an active conformation in the other. The cytoplasmic protein MIG6 (mitogen-induced gene 6; also known as ERRFI1) interacts with and inhibits the kinase domains of EGFR and ERBB2 (refs 3-5). Crystal structures of complexes between the EGFR kinase domain and a fragment of MIG6 show that a approximately 25-residue epitope (segment 1) from MIG6 binds to the distal surface of the C lobe of the kinase domain. Biochemical and cell-based analyses confirm that this interaction contributes to EGFR inhibition by blocking the formation of the activating dimer interface. A longer MIG6 peptide that is extended C terminal to segment 1 has increased potency as an inhibitor of the activated EGFR kinase domain, while retaining a critical dependence on segment 1. We show that signalling by EGFR molecules that contain constitutively active kinase domains still requires formation of the asymmetric dimer, underscoring the importance of dimer interface blockage in MIG6-mediated inhibition

    Commodification and transfiguration: Socially mediated identity in technology and theology

    Get PDF
    Social media platforms like Facebook and Twitter allow users to create an online identity with preferences, photos including ā€˜selfiesā€™ and links to other users. These platforms allow users to present and edit their identities or profiles in accordance with their subjective desires and aspirations as well as in response to feedback from others. Defining individual identity online presents new challenges for many individuals. This article explores those challenges and engages the culture and the practices of online identity formation critically. Identity formation online raises profound theological questions, which are explored in relation to Christian theology and its understanding of personhood as defined in relationship. This view originates in the earliest Christian theology as an attempt to understand the Christian God as three identities that are mutually defined by their relationship to each other. The article asks how the experience of identity formation online in social media can challenge and inform a Christian view of the human relationship with the divine

    The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric Spheroid

    Full text link
    We investigate the relationship between several previously identified Galactic halo stellar structures in the direction of Virgo using imaging and spectroscopic observations of F turnoff stars and blue horizontal branch stars from the Sloan Digital Sky Survey (SDSS) and the Sloan Extension for Galactic Understanding and Exploration (SEGUE). We show that the Sagittarius dwarf leading tidal tail does not pass through the solar neighborhood; it misses the Sun by more than 15 kpc, passing through the Galactic plane outside the Solar Circle. It also is not spatially coincident with the large stellar overdensity S297+63-20.5 in the Virgo constellation. S297+63-20.5 has a distinct turnoff color and kinematics. Faint (g ~ 20.3) turnoff stars in S297+63-20.5 have line-of-sight, Galactic standard of rest velocities V(GSR)= 130 +/- 10 km/s, opposite in sign to infalling Sgr tail stars. The path of the Sgr leading tidal tail is also inconsistent with the positions of some of the nearer stars with which it has been associated, and whose velocities have favored models with prolate Milky Way potentials. We additionally show that the number densities of brighter (g ~ 19.8) F turnoff stars are not symmetric about the Galactic center, and that this discrepancy is not primarily due to the S297+63-20.5 moving group. Either the spheroid is asymmetric about the Galactic center, or there are additional substructures that conspire to be on the same side of the Galaxy as S297+63-20.5. The S297+63-20.5 overdensity in Virgo is likely associated with two other previously identified Virgo substructures: the Virgo Stellar Stream (VSS) and the Virgo Overdensity (VOD). However, the velocity difference between the VSS and S297+63-20.5 and the difference in distance estimates between the VOD and S297+63-20.5 must be reconciled.Comment: 10 figures, ApJ in pres

    Passive Laser Power Stabilization via an Optical Spring

    Get PDF
    Metrology experiments can be limited by the noise produced by the laser involved via small fluctuations in the laser's power or frequency. Typically, active power stabilization schemes consisting of an in-loop sensor and a feedback control loop are employed. Those schemes are fundamentally limited by shot noise coupling at the in-loop sensor. In this letter we propose to use the optical spring effect to passively stabilize the classical power fluctuations of a laser beam. In a proof of principle experiment, we show that the relative power noise of the laser is stabilized from approximately 2Ɨ10āˆ’52 \times 10^{-5} Hzāˆ’1/2^{-1/2} to a minimum value of 1.6Ɨ10āˆ’71.6 \times 10^{-7} Hzāˆ’1/2^{-1/2}, corresponding to the power noise reduction by a factor of 125125. The bandwidth at which stabilization occurs ranges from 400400 Hz to 100100 kHz. The work reported in this letter further paves the way for high power laser stability techniques which could be implemented in optomechanical experiments and in gravitational wave detectors

    SPACE: Enhancing Life on Earth. Proceedings Report

    Get PDF
    The proceedings of the 12th National Space Symposium on Enhancing Life on Earth is presented. Technological areas discussed include: Space applications and cooperation; Earth sensing, communication, and navigation applications; Global security interests in space; and International space station and space launch capabilities. An appendices that include featured speakers, program participants, and abbreviation & acronyms glossary is also attached

    Mechanism of Activation and Inhibition of the HER4/ErbB4 Kinase

    Get PDF
    SummaryHER4/ErbB4 is a ubiquitously expressed member of the EGF/ErbB family of receptor tyrosine kinases that is essential for normal development of the heart, nervous system, and mammary gland. We report here crystal structures of the ErbB4 kinase domain in active and lapatinib-inhibited forms. Active ErbB4 kinase adopts an asymmetric dimer conformation essentially identical to that observed to be important for activation of the EGF receptor/ErbB1 kinase. Mutagenesis studies of intact ErbB4 in Ba/F3 cells confirm the importance of this asymmetric dimer for activation of intact ErbB4. Lapatinib binds to an inactive form of the ErbB4 kinase in a mode equivalent to its interaction with the EGF receptor. All ErbB4 residues contacted by lapatinib are conserved in the EGF receptor and HER2/ErbB2, which lapatinib also targets. These results demonstrate that key elements of kinase activation and inhibition are conserved among ErbB family members

    Magnetic Resonance Imaging Follow-up of Targeted Biopsy-negative Prostate Lesions

    Get PDF
    BACKGROUND: The optimal radiological follow-up of prostate lesions negative on magnetic resonance imaging (MRI)-targeted biopsy (MRI-TB) is yet to be optimised. OBJECTIVE: To present medium-term radiological and clinical follow-up of biopsy-negative lesions. DESIGN, SETTING, AND PARTICIPANTS: The records for men who underwent multiparametric MRI at the UCLH one-stop clinic for suspected prostate cancer between September 2017 and March 2020 were reviewed (nĀ =Ā 1199). Patients with Likert 4 or 5 lesions were considered (nĀ =Ā 495), and those with a subsequent negative MRI-TB comprised the final study population (nĀ =Ā 91). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Baseline and follow-up MRI and biopsy data (including prostate-specific antigen [PSA], prostate volume, radiological scores, and presence of any noncancerous pathology) were extracted from reports. The last follow-up date was the date of the last test or review in clinic. RESULTS AND LIMITATIONS: Median follow-up was 1.8 yr (656 d, interquartile range [IQR] 359-1008). At baseline, the median age was 65.4 yr (IQR 60.7-70.0), median PSA was 7.1 ng/ml (IQR 4.7-10.0), median prostate volume was 54 ml (IQR 39.5-75.0), and median PSA density (PSAD) was 0.13 ng/ml2 (IQR 0.09-0.18). Eighty-six men (95%) had Likert 4 lesions, while the remaining five (5%) had Likert 5 lesions. Only 21 men (23%) had a single lesion; most had at least two. Atrophy was the most prevalent pathology on MRI-TB, present in 64 men (74%), and followed by acute inflammation in 42 (46%), prostatic intraepithelial neoplasia in 33 (36%), chronic inflammation in 18 (20%), atypia in 13 (14%), and granulomatous inflammation in three (3%). Fifty-eight men had a second MRI study (median 376 d, IQR 361-412). At the second MRI, median PSAD decreased to 0.11 ng/ml2 (IQR 0.08-0.18). A Likert 4 or 5 score persisted only in five men (9%); 40 men (69%) were scored Likert 3, while the remaining 13 (22%) were scored Likert 2 (no lesion). Of 45 men with a Likert ā‰„3 score, most only had one lesion at the second MRI (28 men; 62%). Of six men with repeat MRI-TB during the study period, two were subsequently diagnosed with prostate cancer and both had persistent Likert 4 scores (at baseline and at least one follow-up MRI). CONCLUSIONS: Most biopsy-negative MRI lesions in the prostate resolve over time, but any persistent lesions should be closely monitored. PATIENT SUMMARY: Lesions in the prostate detected via magnetic resonance imaging (MRI) scans that are negative for cancer on biopsy usually resolve. Repeat MRI can indicate persistent lesions that might need a second biopsy
    • ā€¦
    corecore