2,457 research outputs found
Social media-predicted personality traits and values can help match people to their ideal jobs
© 2019 National Academy of Sciences. All rights reserved. Work is thought to be more enjoyable and beneficial to individuals and society when there is congruence between one's personality and one's occupation. We provide large-scale evidence that occupations have distinctive psychological profiles, which can successfully be predicted from linguistic information unobtrusively collected through social media. Based on 128,279 Twitter users representing 3,513 occupations, we automatically assess user personalities and visually map the personality profiles of different professions. Similar occupations cluster together, pointing to specific sets of jobs that one might be well suited for. Observations that contradict existing classifications may point to emerging occupations relevant to the 21st century workplace. Findings illustrate how social media can be used to match people to their ideal occupation
Dynamics of allosteric transitions in GroEL
The chaperonin GroEL-GroES, a machine which helps some proteins to fold,
cycles through a number of allosteric states, the state, with high affinity
for substrate proteins (SPs), the ATP-bound state, and the
() complex. Structures are known for each
of these states. Here, we use a self-organized polymer (SOP) model for the
GroEL allosteric states and a general structure-based technique to simulate the
dynamics of allosteric transitions in two subunits of GroEL and the heptamer.
The transition, in which the apical domains undergo counter-clockwise
motion, is mediated by a multiple salt-bridge switch mechanism, in which a
series of salt-bridges break and form. The initial event in the transition, during which GroEL rotates clockwise, involves a
spectacular outside-in movement of helices K and L that results in K80-D359
salt-bridge formation. In both the transitions there is considerable
heterogeneity in the transition pathways. The transition state ensembles (TSEs)
connecting the , , and states are broad with the the
TSE for the transition being more plastic than the TSE. The results suggest that GroEL functions as a
force-transmitting device in which forces of about (5-30) pN may act on the SP
during the reaction cycle.Comment: 32 pages, 10 figures (Longer version than the one published
Upper bounds for the secure key rate of decoy state quantum key distribution
The use of decoy states in quantum key distribution (QKD) has provided a
method for substantially increasing the secret key rate and distance that can
be covered by QKD protocols with practical signals. The security analysis of
these schemes, however, leaves open the possibility that the development of
better proof techniques, or better classical post-processing methods, might
further improve their performance in realistic scenarios. In this paper, we
derive upper bounds on the secure key rate for decoy state QKD. These bounds
are based basically only on the classical correlations established by the
legitimate users during the quantum communication phase of the protocol. The
only assumption about the possible post-processing methods is that double click
events are randomly assigned to single click events. Further we consider only
secure key rates based on the uncalibrated device scenario which assigns
imperfections such as detection inefficiency to the eavesdropper. Our analysis
relies on two preconditions for secure two-way and one-way QKD: The legitimate
users need to prove that there exists no separable state (in the case of
two-way QKD), or that there exists no quantum state having a symmetric
extension (one-way QKD), that is compatible with the available measurements
results. Both criteria have been previously applied to evaluate single-photon
implementations of QKD. Here we use them to investigate a realistic source of
weak coherent pulses. The resulting upper bounds can be formulated as a convex
optimization problem known as a semidefinite program which can be efficiently
solved. For the standard four-state QKD protocol, they are quite close to known
lower bounds, thus showing that there are clear limits to the further
improvement of classical post-processing techniques in decoy state QKD.Comment: 10 pages, 3 figure
Cognitive Performance and Cerebrospinal Fluid Markers in Preclinical Alzheimer's Disease: Results from the Gothenburg H70 Birth Cohort Studies
BACKGROUND: We have previously shown that older adults with preclinical Alzheimer's disease (AD) pathology in cerebrospinal fluid (CSF) had slightly worse performance in Mini-Mental State Examination (MMSE) than participants without preclinical AD pathology. OBJECTIVE: We therefore aimed to compare performance on neurocognitive tests in a population-based sample of 70-year-olds with and without CSF AD pathology. METHODS: The sample was derived from the population-based Gothenburg H70 Birth Cohort Studies in Sweden. Participants (n = 316, 70 years old) underwent comprehensive cognitive examinations, and CSF Aβ-42, Aβ-40, T-tau, and P-tau concentrations were measured. Participants were classified according to the ATN system, and according to their Clinical Dementia Rating (CDR) score. Cognitive performance was examined in the CSF amyloid, tau, and neurodegeneration (ATN) categories. RESULTS: Among participants with CDR 0 (n = 259), those with amyloid (A+) and/or tau pathology (T+, N+) showed similar performance on most cognitive tests compared to participants with A-T-N-. Participants with A-T-N+ performed worse in memory (Supra span (p = 0.003), object Delayed (p = 0.042) and Immediate recall (p = 0.033)). Among participants with CDR 0.5 (n = 57), those with amyloid pathology (A+) scored worse in category fluency (p = 0.003). CONCLUSION: Cognitively normal participants with amyloid and/or tau pathology performed similarly to those without any biomarker evidence of preclinical AD in most cognitive domains, with the exception of slightly poorer memory performance in A-T-N+. Our study suggests that preclinical AD biomarkers are altered before cognitive decline
Modulation of DNA topoisomerase II activity and expression in melanoma cells with acquired drug resistance
The role of DNA topoisomerases (Topo) IIα and IIβ was investigated in various drug-resistant melanoma cells. Melanoma cells resistant to etoposide, exhibited an up to tenfold reduced Topo II activity corresponding to an increasing degree of drug resistance indicating that modulation of Topo II activity contribute to the drug-resistant phenotype. The reduction of Topo II activity was reflected by decreased nuclear amounts of both Topo II isoforms. © 2000 Cancer Research Campaig
P2-138: Disruption of a conserved ion pair E884-R958 in EGFR differentially alters kinase inhibitor sensitivity and downstream signaling
Functional Dynamics of PDZ Binding Domains: A Normal Mode Analysis
PDZ (Post-synaptic density-95/discs large/zonula occludens-1) domains are
relatively small (80 to 120 residues) protein binding modules central in the
organization of receptor clusters and in the association of cellular proteins.
Their main function is to bind C-terminals of selected proteins that are
recognized through specific amino-acids in their carboxyl end. Binding is
associated with a deformation of the PDZ native structure and is responsible
for dynamical changes in regions not in direct contact with the target. We
investigate how this deformation is related to the harmonic dynamics of the PDZ
structure and show that one low-frequency collective normal mode, characterized
by the concerted movements of different secondary structures, is involved in
the binding process. Our results suggest that even minimal structural changes
are responsible of communication between distant regions of the protein, in
agreement with recent Nuclear Magnetic Resonance (NMR) experiments. Thus PDZ
domains are a very clear example of how collective normal modes are able to
characterize the relation between function and dynamics of proteins, and to
provide indications on the precursors of binding/unbonding events.Comment: 25 pages, 10 figures, submitted to Biophysical Journa
Subtle Differences in Cognition in 70-Year-Olds with Elevated Cerebrospinal Fluid Neurofilament Light and Neurogranin: A H70 Cross-Sectional Study
BACKGROUND: Most research on cerebrospinal fluid (CSF) neurofilament light protein (NfL) as a marker for neurodegeneration and neurogranin (Ng) for synaptic dysfunction has largely focused on clinical cohorts rather than population-based samples. OBJECTIVE: We hypothesized that increased CSF levels of NfL and Ng are associated with subtle cognitive deficits in cognitively unimpaired (CU) older adults. METHODS: The sample was derived from the Gothenburg H70 Birth Cohort Studies and comprised 258 CU 70-year-olds, with a Clinical Dementia Rating score of zero. All participants underwent extensive cognitive testing. CSF levels of NfL and Ng, as well as amyloid β1 - 42, total tau, and phosphorylated tau, were measured. RESULTS: Participants with high CSF NfL performed worse in one memory-based test (Immediate recall, p = 0.013) and a language test (FAS, p = 0.016). Individuals with high CSF Ng performed worse on the memory-based test Supra Span (p = 0.035). When stratified according to CSF tau and Aβ42 concentrations, participants with high NfL and increased tau performed worse on a memory test than participants normal tau concentrations (Delayed recall, p = 0.003). In participants with high NfL, those with pathologic Aβ42 concentrations performed worse on the Delayed recall memory (p = 0.044). In the high Ng group, participants with pathological Aβ42 concentrations had lower MMSE scores (p = 0.027). However, in regression analysis we found no linear correlations between CSF NfL or CSF Ng in relation to cognitive tests when controlled for important co-variates. CONCLUSION: Markers of neurodegeneration and synaptic pathology might be associated with subtle signs of cognitive decline in a population-based sample of 70-year-olds
Outcome of Contemporary Percutaneous Coronary Intervention in the Elderly and the Very Elderly: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium
Background: There is a paucity of data on the outcome of contemporary percutaneous coronary intervention (PCI) in the elderly. Accordingly, we assessed the impact of age on outcome of a large cohort of patients undergoing PCI in a regional collaborative registry. Hypothesis: Increasing age is associated with a higher incidence of procedural‐related complications. Methods: We evaluated the outcome of 152373 patients who underwent PCI from 2003 to 2008 in the 31 hospitals participating in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium. The procedural outcomes of the cohort were compared by dividing patients into <70 years of age, 70 to 79 years, 80 to 84 years, 85 to 89 years, and ≥90 years. Results: Of the cohort, 64.64% were <70 years of age, 23.83% were 70 to 79 years, 7.85% were 80 to 84 years, 3.09% were 85 to 89 years, and 0.58% were 90 years or older. Increasing age was associated with an increase in all‐cause in‐hospital mortality, contrast‐induced nephropathy, transfusion, stroke/transient ischemic attack, and vascular complications. The overall in‐hospital mortality rate was 1.09% and increased from 0.67% in those younger than 70 years up to 5.44% in those 90 years old or greater. The mortality rate in patients over 80 years approached 12% to 15% for those with ST‐segment myocardial infarction and 39% in cardiogenic shock patients. Conclusions: The proportion of elderly patients referred for PCI is increasing. Procedural complications increase with age, and patients presenting with unstable symptoms are at the highest risk. © 2011 Wiley Periodicals, Inc. This work was supported by Blue Cross Blue Shield of Michigan. The authors have no other funding, financial relationships, or conflicts of interest to disclose.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86865/1/20926_ftp.pd
Chromosome alterations in human hepatocellular carcinomas correlate with aetiology and histological grade – results of an explorative CGH meta-analysis
All available comparative genomic hybridisation (CGH) analyses (n=31, until 12/2003) of human hepatocellular carcinomas (HCCs; n=785) and premalignant dysplastic nodules (DNs; n=30) were compiled and correlated with clinical and histological parameters. The most prominent amplifications of genomic material were present in 1q (57.1%), 8q (46.6%), 6p (22.3%), and 17q (22.2%), while losses were most prevalent in 8p (38%), 16q (35.9%), 4q (34.3%), 17p (32.1%), and 13q (26.2%). Deletions of 4q, 16q, 13q, and 8p positively correlated with hepatitis B virus aetiology, while losses of 8p were more frequently found in hepatitis C virus-negative cases. In poorly differentiated HCCs, 13q and 4q were significantly under-represented. Moreover, gains of 1q were positively correlated with the occurrence of all other high-frequency alterations in HCCs. In DNs, amplifications were most frequently present in 1q and 8q, while deletions occurred in 8p, 17p, 5p, 13q, 14q, and 16q. In conclusion, aetiology and dedifferentiation correlate with specific genomic alterations in human HCCs. Gains of 1q appear to be rather early events that may predispose to further chromosomal abnormalities. Thus, explorative CGH meta-analysis generates novel and testable hypotheses regarding the cause and functional significance of genomic alterations in human HCCs
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