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Measurement errors are omnipresent in network data. Most studies observe an erroneous network instead of the desired error-free network. It is well known that such errors can have a severe impact on network metrics, especially on centrality measures: a central node in the observed network might be less central in the underlying, error-free network. The robustness is a common concept to measure these effects. Studies have shown that the robustness primarily depends on the centrality measure, the type of error (e.g., missing edges or missing nodes), and the network topology (e.g., tree-like, core-periphery). Previous findings regarding the influence of network size on the robustness are, however, inconclusive. We present empirical evidence and analytical arguments indicating that there exist arbitrary large robust and non-robust networks and that the average degree is well suited to explain the robustness. We demonstrate that networks with a higher average degree are often more robust. For the degree centrality and Erdős–Rényi (ER) graphs, we present explicit formulas for the computation of the robustness, mainly based on the joint distribution of node degrees and degree changes which allow us to analyze the robustness for ER graphs with a constant average degree or increasing average degree.
The concentration of radiocarbon (14C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their 14C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-average marine record of radiocarbon from 0–55 cal kBP and serves as a baseline for regional oceanic variation. Marine20 is intended for calibration of marine radiocarbon samples from non-polar regions; it is not suitable for calibration in polar regions where variability in sea ice extent, ocean upwelling and air-sea gas exchange may have caused larger changes to concentrations of marine radiocarbon. The Marine20 curve is based upon 500 simulations with an ocean/atmosphere/biosphere box-model of the global carbon cycle that has been forced by posterior realizations of our Northern Hemispheric atmospheric IntCal20 14C curve and reconstructed changes in CO2 obtained from ice core data. These forcings enable us to incorporate carbon cycle dynamics and temporal changes in the atmospheric 14C level. The box-model simulations of the global-average marine radiocarbon reservoir age are similar to those of a more complex three-dimensional ocean general circulation model. However, simplicity and speed of the box model allow us to use a Monte Carlo approach to rigorously propagate the uncertainty in both the historic concentration of atmospheric 14C and other key parameters of the carbon cycle through to our final Marine20 calibration curve. This robust propagation of uncertainty is fundamental to providing reliable precision for the radiocarbon age calibration of marine based samples. We make a first step towards deconvolving the contributions of different processes to the total uncertainty; discuss the main differences of Marine20 from the previous age calibration curve Marine13; and identify the limitations of our approach together with key areas for further work. The updated values for ΔR, the regional marine radiocarbon reservoir age corrections required to calibrate against Marine20, can be found at the data base http://calib.org/marine/.
Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
To investigate the association between energy drink (ED) use and sleep-related disturbances in a population-based sample of young adults from the Raine Study.
Analysis of cross-sectional data obtained from self-administered questionnaires to assess ED use and sleep disturbance (Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire (FOSQ-10) and the Pittsburgh Sleep Symptoms Questionnaire–Insomnia (PSSQ-I)). Regression modelling was used to estimate the effect of ED use on sleep disturbances. All models adjusted for various potential confounders.
Males and females, aged 22 years, from Raine Study Gen2–22 year follow-up.
Of the 1115 participants, 66 % were never/rare users (i.e. <once/month) of ED, 17·0 % were occasional users (i.e. >once/month to <once/week) and 17 % were frequent users (≥once/week). Compared with females, a greater proportion of males used ED occasionally (19 % v. 15 %) or frequently (24 % v. 11 %). Among females, frequent ED users experienced significantly higher symptoms of daytime sleepiness (FOSQ-10: β = 0·93, 95 % CI 0·32, 1·54, P = 0·003) and were five times more likely to experience insomnia (PSSQ-I: OR = 5·10, 95 % CI 1·81, 14·35, P = 0·002) compared with never/rare users. No significant associations were observed in males for any sleep outcomes.
We found a positive association between ED use and sleep disturbances in young adult females. Given the importance of sleep for overall health, and ever-increasing ED use, intervention strategies are needed to curb ED use in young adults, particularly females. Further research is needed to determine causation and elucidate reasons for gender-specific findings.
Systematic monitoring of exanthema is largely absent from public health surveillance despite emerging diseases and threats of bioterrorism. Michigan Child Care Related Infections Surveillance Program (MCRISP) is the first online program in child care centers to report pediatric exanthema.
MCRISP aggregated daily counts of children sick, absent, or reported ill by parents. We extracted all MCRISP exanthema cases from October 1, 2014 through June 30, 2019. Cases were assessed with descriptive statistics and counts were used to construct epidemic curves.
360 exanthema cases were reported from 12,233 illnesses over 4.5 seasons. Children ages 13-35 months had the highest rash occurrence (45%, n = 162), followed by 36-59 months (41.7%, n = 150), 0-12 months (12.5%, n = 45), and kindergarten (0.8%, n = 3). Centers reported rashes of hand-foot-mouth disease (50%, n = 180), nonspecific rash without fever (15.3%, n = 55), hives (8.1%, n = 29), fever with nonspecific rash (6.9%, n = 25), roseola (3.3%, n = 12), scabies (2.5%, n = 9), scarlet fever (2.5%, n = 9), impetigo (2.2%, n = 8), abscess (1.95, n = 7), viral exanthema without fever (1.7%, n = 6), varicella (1.7%, n = 6), pinworms (0.8%, n = 3), molluscum (0.6%, n = 2), cellulitis (0.6%, n = 2), ringworm (0.6%, n = 2), and shingles (0.2%, n = 1).
Child care surveillance networks have the potential to act as sentinel public health tools for surveillance of pediatric exanthema outbreaks.
This study examined psychological constructs (delay discounting, grit, future time perspective and subjective social status) in relation to food security status and body weight.
A simultaneous triangulation mixed methods design was used to collect quantitative and qualitative data. Quantitative data were collected in fifty-six adults. Independent variables included food security status (food secure or food insecure) and BMI category (normal weight or overweight/obese). Participants, matched on race (African American and White), were categorised into four food security status by BMI category groups. Psychological constructs were measured via validated questionnaires. Qualitative data were collected in a subsample of twelve participants via in-depth interviews.
This study was conducted in Baton Rouge, Louisiana.
The sample was 66 % female and 48 % African American with a mean age of 32·3 (sd 9·2) years and BMI of 28·8 (sd 7·7) kg/m2.
Quantitative results showed that food-insecure participants with overweight/obesity had greater delay discounting (–3·78 v. –6·16, P = 0·01; –3·78 v. –5·75, P = 0·02) and poorer grit (3·37 v. 3·99, P = 0·02; 3·37 v. 4·02, P = 0·02 ) than their food-secure counterparts and food-insecure participants with normal weight. Food-insecure participants with overweight/obesity also had a shorter time period for financial planning (0·72 v. 4·14, P = 0·02) than food-secure participants with normal weight. Qualitative data largely supported quantitative findings with participants discussing varied perceptions of psychological constructs.
This study found differences in delaying gratification, grit and financial planning between food security status and body weight groups.
Streaming ice accounts for a major fraction of global ice flux, yet we cannot yet fully explain the dominant controls on its kinematics. In this contribution, we use an anisotropic full-Stokes thermomechanical flow solver to characterize how mechanical anisotropy and temperature distribution affect ice flux. For the ice stream and glacier geometries we explored, we found that the ice flux increases 1–3% per °C temperature increase in the margin. Glaciers and ice streams with crystallographic fabric oriented approximately normal to the shear plane increase by comparable amounts: an otherwise isotropic ice stream containing a concentrated transverse single maximum fabric in the margin flows 15% faster than the reference case. Fabric and temperature variations independently impact ice flux, with slightly nonlinear interactions. We find that realistic variations in temperature and crystallographic fabric both affect ice flux to similar degrees, with the exact effect a function of the local fabric and temperature distributions. Given this sensitivity, direct field-based measurements and models incorporating additional factors, such as water content and temporal evolution, are essential for explaining and predicting streaming ice dynamics.
The Cognitive Abilities Screening Instrument (CASI) is a screening test of global cognitive function used in research and clinical settings. However, the CASI was developed using face validity and has not been investigated via empirical tests such as factor analyses. Thus, we aimed to develop and test a parsimonious conceptualization of the CASI rooted in cognitive aging literature reflective of crystallized and fluid abilities.
Secondary data analysis implementing confirmatory factor analyses where we tested the proposed two-factor solution, an alternate one-factor solution, and conducted a χ2 difference test to determine which model had a significantly better fit.
Data came from 3,491 men from the Kuakini Honolulu-Asia Aging Study.
The Cognitive Abilities Screening Instrument.
Findings demonstrated that both models fit the data; however, the two-factor model had a significantly better fit than the one-factor model. Criterion validity tests indicated that participant age was negatively associated with both factors and that education was positively associated with both factors. Further tests demonstrated that fluid abilities were significantly and negatively associated with a later-life dementia diagnosis.
We encourage investigators to use the two-factor model of the CASI as it could shed light on underlying cognitive processes, which may be more informative than using a global measure of cognition.
Less is known about the relationship between conduct disorder (CD), callous–unemotional (CU) traits, and positive and negative parenting in youth compared to early childhood. We combined traditional univariate analyses with a novel machine learning classifier (Angle-based Generalized Matrix Learning Vector Quantization) to classify youth (N = 756; 9–18 years) into typically developing (TD) or CD groups with or without elevated CU traits (CD/HCU, CD/LCU, respectively) using youth- and parent-reports of parenting behavior. At the group level, both CD/HCU and CD/LCU were associated with high negative and low positive parenting relative to TD. However, only positive parenting differed between the CD/HCU and CD/LCU groups. In classification analyses, performance was best when distinguishing CD/HCU from TD groups and poorest when distinguishing CD/HCU from CD/LCU groups. Positive and negative parenting were both relevant when distinguishing CD/HCU from TD, negative parenting was most relevant when distinguishing between CD/LCU and TD, and positive parenting was most relevant when distinguishing CD/HCU from CD/LCU groups. These findings suggest that while positive parenting distinguishes between CD/HCU and CD/LCU, negative parenting is associated with both CD subtypes. These results highlight the importance of considering multiple parenting behaviors in CD with varying levels of CU traits in late childhood/adolescence.
Previous studies of patients with unipolar depression have shown that early decrease of prefrontal EEG cordance in theta band can predict clinical response to various antidepressants. We have now examined whether decrease of prefrontal quantitative EEG (QEEG) cordance value after 1 week of venlafaxine treatment predicts clinical response to venlafaxine in resistant patients.
We analyzed 25 inpatients who finished 4-week venlafaxine treatment. EEG data were monitored at baseline and after 1 week of treatment. QEEG cordance was computed at three frontal electrodes in theta frequency band. Depressive symptoms and clinical status were assessed using Montgomery–Åsberg Depression Rating Scale (MADRS), Beck Depression Inventory-Short Form (BDI-S) and Clinical Global Impression (CGI).
Eleven of 12 responders (reduction of MADRS ≥50%) and only 5 of 13 non-responders had decreased prefrontal QEEG cordance value after the first week of treatment (p = 0.01). The decrease of prefrontal cordance after week 1 in responders was significant (p = 0.03) and there was no significant change in non-responders. Positive and negative predictive values of cordance reduction for response were 0.7 and 0.9, respectively.
The reduction of prefrontal theta QEEG cordance value after first week of treatment might be helpful in the prediction of response to venlafaxine.
The Antarctic Impulsive Transient Antenna (ANITA) balloon experiment was designed to detect radio signals initiated by high-energy neutrinos and cosmic ray (CR) air showers. These signals are typically discriminated by the polarization and phase inversions of the radio signal. The reflected signal from CRs suffer phase inversion compared to a direct ‘tau neutrino’ event. In this paper, we study subsurface reflection, which can occur without phase inversion, in the context of the two anomalous up-going events reported by ANITA. It is found that subsurface layers and firn density inversions may plausibly account for the events, while ice fabric layers and wind ablation crusts could also play a role. This hypothesis can be tested with radar surveying of the Antarctic region in the vicinity of the anomalous ANITA events. Future experiments should not use phase inversion as a sole criterion to discriminate between down-going and up-going events, unless the subsurface reflection properties are well understood.