86 research outputs found

    Academic Performance and Behavioral Patterns

    Get PDF
    Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students

    Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

    Get PDF
    Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

    TESS hunt for young and maturing exoplanets (THYME). VI. an 11 Myr giant planet transiting a very-low-mass star in lower centaurus crux

    Get PDF
    Mature super-Earths and sub-Neptunes are predicted to be ≃ Jovian radius when younger than 10 Myr. Thus, we expect to find 5–15 R⊕ planets around young stars even if their older counterparts harbor none. We report the discovery and validation of TOI 1227b, a 0.85 ± 0.05 RJ (9.5 R⊕) planet transiting a very-low-mass star (0.170 ± 0.015 M⊙) every 27.4 days. TOI 1227's kinematics and strong lithium absorption confirm that it is a member of a previously discovered subgroup in the Lower Centaurus Crux OB association, which we designate the Musca group. We derive an age of 11 ± 2 Myr for Musca, based on lithium, rotation, and the color–magnitude diagram of Musca members. The TESS data and ground-based follow-up show a deep (2.5%) transit. We use multiwavelength transit observations and radial velocities from the IGRINS spectrograph to validate the signal as planetary in nature, and we obtain an upper limit on the planet mass of ≃0.5 MJ. Because such large planets are exceptionally rare around mature low-mass stars, we suggest that TOI 1227b is still contracting and will eventually turn into one of the more common <5 R⊕ planets

    New structural insights into the role of TROVE2 complexes in the on-set and pathogenesis of systemic lupus eythematosus determined by a combiantion of QCM-D and DPI

    Full text link
    The final publication is available at link.springer.com.[EN] The mechanism of self-recognition of the autoantigen TROVE2, a common biomarker in autoimmune diseases, has been studied with a quartz crystal microbalance with dissipation monitoring (QCM-D) and dual polarization interferometry (DPI). The complementarity and remarkable analytical features of both techniques has allowed new insights into the onset of systemic lupus erythematosus (SLE) to be achieved at the molecular level. The in vitro study for SLE patients and healthy subjects suggests that anti-TROVE2 autoantibodies may undergo an antibody bipolar bridging. An epitope-paratope-specific binding initially occurs to activate a hidden Fc receptor in the TROVE2 tertiary structure. This bipolar mechanism may contribute to the pathogenic accumulation of anti-TROVE2 autoantibody immune complex in autoimmune disease. Furthermore, the specific calcium-dependent protein-protein bridges point out at how the TRIM21/TROVE2 association might occur, suggesting that the TROVE2 protein could stimulate the intracellular immune signaling via the TRIM21 PRY-SPRY domain. These findings may help to better understand the origins of the specificity and affinity of TROVE2 interactions, which might play a key role in the SLE pathogenesis. This manuscript gives one of the first practical applications of two novel functions (-df/dD and Delta h/molec) for the analysis of the data provided by QCM-D and DPI. In addition, it is the first time that QCM-D has been used for mapping hidden Fc receptors as well as linear epitopes in a protein tertiary structure.We would like to thank Sylvia Daunert for her invaluable help with the discussion of the paper. Furthermore, we acknowledge financial support from the Generalitat Valenciana (GVA-PROMETEOII/2014/040) as well as the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund under award numbers CTQ2013-45875-R and CTQ2013-42914-RJuste-Dolz, AM.; Do Nascimento, NM.; Monzó, IS.; Grau-García, E.; Roman-Ivorra, JA.; López-Paz, JL.; Escorihuela Fuentes, J.... (2019). New structural insights into the role of TROVE2 complexes in the on-set and pathogenesis of systemic lupus eythematosus determined by a combiantion of QCM-D and DPI. Analytical and Bioanalytical Chemistry. 411(19):4709-4720. https://doi.org/10.1007/s00216-018-1407-xS4709472041119Kakatia S, Teronpia R, Barmanb B. Frequency, pattern and determinants of flare in systemic lupus erythematosus: a study from North East India. Egypt Rheumatol. 2015;37:S55–9.Kuhn A, Wenzel J, Weyd H. Photosensitivity, apoptosis, and cytokines in the pathogenesis of lupus erythematosus: a critical review. Clinic Rev Allerg Immunol. 2014;47:148–62.American Lupus Foundation. 2016. http://www.lupus.org .World Health Organization. Environmental health criteria 236. Geneva: WHO Press; 2006.Li W, Titov AA, Morel L. An update on lupus animal models. Curr Opin Rheumatol. 2017;29:1040–8711.Routsias JG, Tzioufas AG, Moutsopoulos HM. The clinical value of intracellular autoantigens B-cell epitopes in systemic rheumatic diseases. Clin Chim Acta. 2004;340:1–25.Franceschini F, Cavazzana I. Anti-Ro/SSA and La/SSB antibodies. Autoimmunity. 2005;38:55–63.Kelekar A, Saitta MR, Keene JD. Molecular composition of Ro small ribonucleoprotein complexes in human cells. Intracellular localization of the 60- and 52-kD proteins. J Clin Ivest. 1994;93:1637–44.Slobbe RL, Pluk W, van Venrooij WJ, Prujin GJM. Ro ribonucleoprotein assembly in vitro: identification of RNA-protein and protein-protein interactions. J Mol Biol. 1992;2:361–6.Chen X, Taylor DW, Fowler CC, Galan JE, Wang HW, Wolin SL. An RNA degradation machine sculpted by Ro autoantigen and noncoding RNA. Cell. 2013;153:166–77.Stein AJ, Fuchs G, Fu C, Wolin SL, Reinisch KM. Structural insights into RNA quality control: the Ro autoantigen binds misfolded RNAs via its central cavity. Cell. 2005;121:529–39.Reed JH, Gordon TP. Autoimmunity: Ro60-associated RNA takes its toll on disease pathogenesis. Nat Rev Rheumatol. 2016;12:136–8.Sim S, Weinberg DE, Fuchs G, Choi K, Chung J, Wolin SL. The subcellular distribution of an RNA quality control protein, the Ro autoantigen, is regulated by noncoding Y RNA binding. Mol Biol Cell. 2009;20:1555–64.Reed JH, Jackson MW, Gordon TP. A B cell apotope of Ro 60 in systemic lupus erythematosus. Arthritis Rheum. 2008;58:1125–9.Wolin SL, Reinisch KM. The Ro 60 kDa autoantigen comes into focus: interpreting epitope mapping experiments on the basis of structure. Autoimmun Rev. 2006;5:367–72.Routsias JG, Tzioufas AG. B-cell epitopes of the intracellular autoantigens Ro/SSA and La/SSB: tools to study the regulation of the autoimmune response. J Autoimmun. 2010;35:256–64.Whittaker CA, Hynes RO. Distribution and evolution of von Willebrand/integrin a domains: widely dispersed domains with roles in cell adhesion and elsewere. Mol Bio Cell. 2002;13:3369–87.Lacy DB, Wigelsworth DJ, Scobie HM, Young JA, Collier RJ. Crystal structure of the von Willebrand factor a domain of human capillary morphogenesis protein 2: an anthrax toxin receptor. Proc Natl Acad Sci U S A. 2004;101:6367–72.O’Brien CA, Wolin SL. A possible role for the 60-kD Ro autoantigen in a discard pathway for defective 5S rRNA precursors. Genes Dev. 1994;8:2891–903.Chen X, Wolin SL. The Ro 60 autoantigen : insights into cellular function and role in autoimmunity. J Mol Med (Berl). 2004;82:232–9.Escorihuela J, González-Martínez MA, López-Paz JL, Puchades R, Maquieira A, Gimenez-Romero D. Dual-polarization interferometry: a novel technique to light up the nanomolecular world. Chem Rev. 2014;115:265–94.do Nascimento NM, Juste-Dolz A, Bueno PR, Monzó I, Tejero R, Lopez-Paz JL, et al. Mapping molecular binding by means of conformational dynamics measurements. RSC Adv. 2018;8:867–76.do Nascimento NM, Juste-Dolz A, Grau-García E, Román-Ivorra J, Puchades R, Maquieira A, et al. Label-free piezoelectric biosensor for prognosis and diagnosis of systemic lupus erythematosus. Biosens. Bioelectron. 2016;90:166–73.Seo MH, Park J, Kim E, Hohng S, Kim HS. Protein conformational dynamics dictate the binding affinity for a ligand. Nat Commun. 2014;5:3724.Lakshmanan RS, Efremov V, O’Donnell JS, Killard AJ. Measurement of the viscoelastic properties of blood plasma clot formation in response to tissue factor concentration-dependent activation. Anal Bioanal Chem. 2016;408:6581–8.Fakhrullin RF, Vinter VG, Zamaleeva AI, Matveeva MV, Kourbanov RA, Temesgen BK, et al. Quartz crystal microbalance immunosensor for the detection of antibodies to double-stranded DNA. Anal Bioanl Chem. 2007;388:367–75.Shen F, Rojas OJ, Genzer J, Gurgel PV, Carbonell RG. Affinity interactions of human immunoglobulin G with short peptides: role of ligand spacer on binding, kinetics, and mass transfer. Anal Bioanl Chem. 2015;408:1829–41.Fogarty AC, Laage D. Water dynamics in protein hydration shells: the molecular origins of the dynamical perturbation. J Phys Chem B. 2014;118:7715–29.Born B, Kim SJ, Ebbinghaus S, Gruebelebc M, Havenith M. The terahertz dance of water with the proteins: the effect of protein flexibility on the dynamical hydration shell of ubiquitin. Faraday Discuss. 2009;141:161–73.Yoshimi R, Ueda A, Ozato K, Ishigatsubo Y. Clinical and pathological roles of Ro/SSA autoantibody system. Clin Dev Immunol. 2012;2012:606195.Boire G, Gendron M, Monast N, Bastin B, Ménard HA. Purification of antigenically intact Ro ribonucleoproteins; biochemical and immunological evidence that the 52-kD protein is not a Ro protein. Clin Exp Immunol. 1995;100:489–98.Gazzaruso C, Montecucco CM, Geroldi D, Garzaniti A, Finardi G. Severe hypercalcemia and systemic lupus erythematosus. Joint Bone Spine. 2000;67:485–8.Hassan AB, Lundberg IE, Isenberg D, Wahren-Herlenius M. Serial analysis of Ro/SSA and La/SSB antibody levels and correlation with clinical disease activity in patients with systemic lupus erythematosus. Scand J Rheumatol. 2002;31:133–9.Huang RY, Chen G. Higher order structure characterization of protein therapeutics by hydrogen/deuterium exchange mass spectrometry. Anal Bioanal Chem. 2014;406:6541–58.Yu F, Roy S, Arevalo E, Schaeck J, Wang J, Holte K, et al. Characterization of heparin-protein interaction by saturation transfer difference (STD) NMR. Anal Bioanal Chem. 2014;406:3079–89.Rizzuto R, Pozzan T. Microdomains of intracellular Ca2+: molecular determinants and functional consequences. Physiol Rev. 2006;86:369–408.Gaipl US, Kuhn A, Sheriff A, Munoz LE, Franz S, Voll RE, et al. Clearance of apoptotic cells in human SLE. Curr Dir Autoimmun. 2006;9:173–87.Falati S, Edmead CE, Poole AW. Glycoprotein Ib-V-IX, a receptor for Von Willebrand factor, couples physically and functionally to the Fc receptor gamma-chain, Fyn, and Lyn to activate human platelets. Blood. 1999;94:1648–56.Muñoz LE, Lauber K, Schiller M, Manfredi AA, Herrmann M. The role of defective clearance of apoptotic cells in systemic autoimmunity. Nat Rev Rheumatol. 2010;6:280–9

    TESS Hunt for Young and Maturing Exoplanets (THYME). III. A Two-planet System in the 400 Myr Ursa Major Group

    Get PDF
    Exoplanets can evolve significantly between birth and maturity as their atmospheres, orbits, and structures are shaped by their environment. Young planets (<<1 Gyr) offer the opportunity to probe these sculpting processes. However, most of the known young planets orbit prohibitively faint stars. We present the discovery of two planets transiting HD 63433 (TOI 1726, TIC 130181866), a young Sun-like (M=0.99±0.03M_*=0.99\pm0.03) star. Through kinematics, lithium abundance, and rotation, we confirm that HD 63433 is a member of the Ursa Major moving group (τ=414±23\tau=414\pm23 Myr). Based on the TESS light curve and updated stellar parameters, the planet radii are 2.15±0.10R2.15\pm0.10R_\oplus and 2.67±0.12R2.67\pm0.12R_\oplus, the orbital periods are 7.11 and 20.55 days, and the orbital eccentricities are lower than abut 0.2. Using HARPS-N velocities, we measure the Rossiter-McLaughlin signal of the inner planet, demonstrating the orbit is prograde. Since the host star is bright (V=6.9), both planets are amenable to transmission spectroscopy, radial velocity measurements of their masses, and more precise determination of the stellar obliquity. This system is therefore poised to play an important role in our understanding of planetary system evolution in the first billion years after formation

    Skin Electroporation: Effects on Transgene Expression, DNA Persistence and Local Tissue Environment

    Get PDF
    BACKGROUND: Electrical pulses have been used to enhance uptake of molecules into living cells for decades. This technique, often referred to as electroporation, has become an increasingly popular method to enhance in vivo DNA delivery for both gene therapy applications as well as for delivery of vaccines against both infectious diseases and cancer. In vivo electrovaccination (gene delivery followed by electroporation) is currently being investigated in several clinical trials, including DNA delivery to healthy volunteers. However, the mode of action at molecular level is not yet fully understood. METHODOLOGY/PRINCIPAL FINDINGS: This study investigates intradermal DNA electrovaccination in detail and describes the effects on expression of the vaccine antigen, plasmid persistence and the local tissue environment. Gene profiling of the vaccination site showed that the combination of DNA and electroporation induced a significant up-regulation of pro-inflammatory genes. In vivo imaging of luciferase activity after electrovaccination demonstrated a rapid onset (minutes) and a long duration (months) of transgene expression. However, when the more immunogenic prostate specific antigen (PSA) was co-administered, PSA-specific T cells were induced and concurrently the luciferase expression became undetectable. Electroporation did not affect the long-term persistence of the PSA-expressing plasmid. CONCLUSIONS/SIGNIFICANCE: This study provides important insights to how DNA delivery by intradermal electrovaccination affects the local immunological responses of the skin, transgene expression and clearance of the plasmid. As the described vaccination approach is currently being evaluated in clinical trials, the data provided will be of high significance

    The Novel Mouse Mutation Oblivion Inactivates the PMCA2 Pump and Causes Progressive Hearing Loss

    Get PDF
    Progressive hearing loss is common in the human population, but we have few clues to the molecular basis. Mouse mutants with progressive hearing loss offer valuable insights, and ENU (N-ethyl-N-nitrosourea) mutagenesis is a useful way of generating models. We have characterised a new ENU-induced mouse mutant, Oblivion (allele symbol Obl), showing semi-dominant inheritance of hearing impairment. Obl/+ mutants showed increasing hearing impairment from post-natal day (P)20 to P90, and loss of auditory function was followed by a corresponding base to apex progression of hair cell degeneration. Obl/Obl mutants were small, showed severe vestibular dysfunction by 2 weeks of age, and were completely deaf from birth; sensory hair cells were completely degenerate in the basal turn of the cochlea, although hair cells appeared normal in the apex. We mapped the mutation to Chromosome 6. Mutation analysis of Atp2b2 showed a missense mutation (2630C→T) in exon 15, causing a serine to phenylalanine substitution (S877F) in transmembrane domain 6 of the PMCA2 pump, the resident Ca2+ pump of hair cell stereocilia. Transmembrane domain mutations in these pumps generally are believed to be incompatible with normal targeting of the protein to the plasma membrane. However, analyses of hair cells in cultured utricular maculae of Obl/Obl mice and of the mutant Obl pump in model cells showed that the protein was correctly targeted to the plasma membrane. Biochemical and biophysical characterisation showed that the pump had lost a significant portion of its non-stimulated Ca2+ exporting ability. These findings can explain the progressive loss of auditory function, and indicate the limits in our ability to predict mechanism from sequence alone

    Testing the leadership and organizational change for implementation (LOCI) intervention in substance abuse treatment: A cluster randomized trial study protocol

    Get PDF
    © 2017 The Author(s). Background: Evidence-based practice (EBP) implementation represents a strategic change in organizations that requires effective leadership and alignment of leadership and organizational support across organizational levels. As such, there is a need for combining leadership development with organizational strategies to support organizational climate conducive to EBP implementation. The leadership and organizational change for implementation (LOCI) intervention includes leadership training for workgroup leaders, ongoing implementation leadership coaching, 360° assessment, and strategic planning with top and middle management regarding how they can support workgroup leaders in developing a positive EBP implementation climate. Methods: This test of the LOCI intervention will take place in conjunction with the implementation of motivational interviewing (MI) in 60 substance use disorder treatment programs in California, USA. Participants will include agency executives, 60 program leaders, and approximately 360 treatment staff. LOCI will be tested using a multiple cohort, cluster randomized trial that randomizes workgroups (i.e., programs) within agency to either LOCI or a webinar leadership training control condition in three consecutive cohorts. The LOCI intervention is 12months, and the webinar control intervention takes place in months 1, 5, and 8, for each cohort. Web-based surveys of staff and supervisors will be used to collect data on leadership, implementation climate, provider attitudes, and citizenship. Audio recordings of counseling sessions will be coded for MI fidelity. The unit of analysis will be the workgroup, randomized by site within agency and with care taken that co-located workgroups are assigned to the same condition to avoid contamination. Hierarchical linear modeling (HLM) will be used to analyze the data to account for the nested data structure. Discussion: LOCI has been developed to be a feasible and effective approach for organizations to create a positive climate and fertile context for EBP implementation. The approach seeks to cultivate and sustain both effective general and implementation leadership as well as organizational strategies and support that will remain after the study has ended. Development of a positive implementation climate for MI should result in more positive service provider attitudes and behaviors related to the use of MI and, ultimately, higher fidelity in the use of MI. Trial registration: This study is registered with Clinicaltrials.gov ( NCT03042832 ), 2 February 2017, retrospectively registered

    The role of the mitochondria and the endoplasmic reticulum contact sites in the development of the immune responses

    Get PDF
    Abstract Mitochondria and endoplasmic reticulum (ER) contact sites (MERCs) are dynamic modules enriched in subset of lipids and specialized proteins that determine their structure and functions. The MERCs regulate lipid transfer, autophagosome formation, mitochondrial fission, Ca2+ homeostasis and apoptosis. Since these functions are essential for cell biology, it is therefore not surprising that MERCs also play a critical role in organ physiology among which the immune system stands by its critical host defense function. This defense system must discriminate and tolerate host cells and beneficial commensal microorganisms while eliminating pathogenic ones in order to preserve normal homeostasis. To meet this goal, the immune system has two lines of defense. First, the fast acting but unspecific innate immune system relies on anatomical physical barriers and subsets of hematopoietically derived cells expressing germline-encoded receptors called pattern recognition receptors (PRR) recognizing conserved motifs on the pathogens. Second, the slower but very specific adaptive immune response is added to complement innate immunity. Adaptive immunity relies on another set of specialized cells, the lymphocytes, harboring receptors requiring somatic recombination to be expressed. Both innate and adaptive immune cells must be activated to phagocytose and process pathogens, migrate, proliferate, release soluble factors and destroy infected cells. Some of these functions are strongly dependent on lipid transfer, autophagosome formation, mitochondrial fission, and Ca2+ flux; this indicates that MERCs could regulate immunity

    Study protocol for the translating research in elder care (TREC): building context – an organizational monitoring program in long-term care project (project one)

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>While there is a growing awareness of the importance of organizational context (or the work environment/setting) to successful knowledge translation, and successful knowledge translation to better patient, provider (staff), and system outcomes, little empirical evidence supports these assumptions. Further, little is known about the factors that enhance knowledge translation and better outcomes in residential long-term care facilities, where care has been shown to be suboptimal. The project described in this protocol is one of the two main projects of the larger five-year Translating Research in Elder Care (TREC) program.</p> <p>Aims</p> <p>The purpose of this project is to establish the magnitude of the effect of organizational context on knowledge translation, and subsequently on resident, staff (unregulated, regulated, and managerial) and system outcomes in long-term care facilities in the three Canadian Prairie Provinces (Alberta, Saskatchewan, Manitoba).</p> <p>Methods/Design</p> <p>This study protocol describes the details of a multi-level – including provinces, regions, facilities, units within facilities, and individuals who receive care (residents) or work (staff) in facilities – and longitudinal (five-year) research project. A stratified random sample of 36 residential long-term care facilities (30 urban and 6 rural) from the Canadian Prairie Provinces will comprise the sample. Caregivers and care managers within these facilities will be asked to complete the TREC survey – a suite of survey instruments designed to assess organizational context and related factors hypothesized to be important to successful knowledge translation and to achieving better resident, staff, and system outcomes. Facility and unit level data will be collected using standardized data collection forms, and resident outcomes using the Resident Assessment Instrument-Minimum Data Set version 2.0 instrument. A variety of analytic techniques will be employed including descriptive analyses, psychometric analyses, multi-level modeling, and mixed-method analyses.</p> <p>Discussion</p> <p>Three key challenging areas associated with conducting this project are discussed: sampling, participant recruitment, and sample retention; survey administration (with unregulated caregivers); and the provision of a stable set of study definitions to guide the project.</p
    corecore