Modest Bias Research Articles

Mnemonic brain state engagement is diminished in healthy aging.

Healthy older adults typically show impaired episodic memory - memory for when and where an event oc-curred - but intact semantic memory - knowledge for general information and facts. As older adults also have difficulty inhibiting the retrieval of prior knowledge from memory, their selective decline in episodic memory may be due to a tendency to over engage the retrieval state, a brain state in which attention is focused internally in an attempt to access prior knowledge. The retrieval state trades off with the encoding state, a brain state which supports the formation of new memories. Therefore, episodic memory declines in older adults may be the result of differential engagement in mnemonic brain states. Our hypothesis is that older adults are biased toward a retrieval state. We recorded scalp electroencephalography while young, middle-aged and older adults performed a memory task in which they were explicitly directed to either encode the currently presented object stimulus or retrieve a previously presented, categorically-related object stimulus. We used multivariate pattern analysis of spectral activity to decode engagement in the retrieval vs. encoding state. We find that all three age groups can follow top-down instructions to selectively engage in encoding or retrieval and that we can decode mnemonic states for all age groups. However, we find that mnemonic brain state engagement is diminished for older adults relative to middle-aged adults. Our interpretation is that a combination of executive control deficits and a modest bias to retrieve modulates older adults' mnemonic state engagement. Together, these findings suggest that dif-ferential mnemonic state engagement may underlie age-related memory changes.

Day-to-day reliability of basal heart rate and short-term and ultra short-term heart rate variability assessment by the Equivital eq02+ LifeMonitor in US Army soldiers

IntroductionThe present study determined the (1) day-to-day reliability of basal heart rate (HR) and HR variability (HRV) measured by the Equivital eq02+ LifeMonitor and (2) agreement of ultra short-term HRV...

Investigating the potential of X chromosome shredding for mouse genetic biocontrol

CRISPR-Cas9 technology has facilitated development of strategies that can potentially provide more humane and effective methods to control invasive vertebrate species, such as mice. One promising strategy is X chromosome shredding which aims to bias offspring towards males, resulting in a gradual and unsustainable decline of females. This method has been explored in insects with encouraging results. Here, we investigated this strategy in Mus musculus by targeting repeat DNA sequences on the X chromosome with the aim of inducing sufficient DNA damage to specifically eliminate X chromosome-bearing sperm during gametogenesis. We tested three different guide RNAs (gRNAs) targeting different repeats on the X chromosome, together with three male germline-specific promoters for inducing Cas9 expression at different stages of spermatogenesis. A modest bias towards mature Y-bearing sperm was detected in some transgenic males, although this did not translate into significant male-biasing of offspring. Instead, cleavage of the X chromosome during meiosis typically resulted in a spermatogenic block, manifest as small testes volume, empty tubules, low sperm concentration, and sub/infertility. Our study highlights the importance of controlling the timing of CRISPR-Cas9 activity during mammalian spermatogenesis and the sensitivity of spermatocytes to X chromosome disruption.

Predicting a Higher Heating Value for Torrefied Kesambi Leaf Biobriquettes through Ultimate Analysis

The escalating global pursuit of sustainable energy solutions has led to the emergence of biomass-derived fuels, such as biobriquettes, as feasible substitutes for traditional fossil fuels. Kesambi leaves, which are abundant in Southeast Asia and boast a high calorific value, represent a promising prospect for the production of biobriquettes. In this investigation, a conclusive analytical method is employed to construct a predictive framework for estimating the Higher Heating Value (HHV) of torrefied kesambi leaf biobriquettes. By incorporating ash content (PS), volatile matter (BR), carbon (C), hydrogen (H), and oxygen (O) percentages, alongside experimental HHV data, through multiple linear regression and elemental composition data acquired from proximal analysis, the model aims to forecast HHV. The model’s modest positive Mean Bias Error (MBE) and satisfactory Root Mean Square Error (RMSE) suggest a good fit. The substantial R-squared value indicates the model’s capability to adeptly capture HHV variability. Ultimately, this approach grounded in fundamental principles contributes significantly to the sustainable exploitation of biomass resources by providing a pragmatic and effective technique for predicting HHV for kesambi leaf biobriquettes.

Reliability of the Metabolic Response During Steady-State Exercise at FATmax in Young Men with Obesity

ABSTRACT Purpose: In this study we evaluated the reliability of blood lactate levels (BLa), energy expenditure and substrate utilization during prolonged exercise at the intensity that elicits maximal fat oxidation (FATmax). Furthermore, we investigated the accuracy of a single graded exercise test (GXT) for predicting energy metabolism at FATmax. Methods: Seventeen young men with obesity (26 ± 6 years; 36.4 ± 7.2 %body fat) performed a GXT on a treadmill in a fasted state (10–12 h) for the assessment of FATmax and cardiorespiratory fitness. Afterward, each subject performed two additional prolonged FATmax trials (102 ± 11 beats·min−1; 60-min) separated by 7 days. Indirect calorimetry was used for the assessment of energy expenditure and substrate utilization kinetics whereas capillary blood samples were taken for the measurement of BLa. Results: The BLa (limits of agreement (LoA): −1.2 to 0.8 mmol∙L−1; p = 1.0), fat utilization (LoA: −8.0 to 13.4 g∙h−1; p = 0.06), and carbohydrate utilization (LoA: −27.6 to 22.4 g∙h−1; p = 0.41) showed a good agreement whereas a modest systematic bias was found for energy expenditure (LoA: −16811 to 33355 kJ∙h−1; p < 0.05). All the aforementioned parameters showed a moderate to good reliability (Intraclass correlation coefficient: 0.67–0.92). The GXT overestimated fat (~46%) and carbohydrate (~26%) utilization as well as energy expenditure (36%) during steady-state exercise at FATmax. Conversely the GXT underestimated BLa (~28%). Conclusion: a single GXT cannot be used for an accurate prediction of energy metabolism during prolonged exercise in men with obesity. Thus, an additional steady-state FATmax trial (40–60 min) should be performed for a tailored and precise exercise prescription.

Evaluating and Enhancing Snow Compaction Process in the Noah‐MP Land Surface Model

AbstractThe accuracy of snow density in land surface model (LSM) simulations impacts the accuracy of simulated terrestrial water and energy budgets. However, there has been little research that has focused on enhancing snow compaction in operationally used LSMs. A baseline snow simulation with the widely used Noah‐MP LSM systematically overestimates snow depth by 55 mm even after removing daily snow water equivalent (SWE) biases. To reduce uncertainties associated with snow compaction, we enhance the most sensitive Noah‐MP snow compaction parameter—the empirical parameter for compaction due to overburden (Cbd)—such that Cbd is calculated as a function of surface air temperature as opposed to a fixed value in the baseline simulation. This enhancement improves accuracy in simulated snow compaction across the majority of western U.S. (WUS) SNOTEL test sites (biases reduced at 88% of test sites), with modest bias reductions in cooler accumulation periods (biases reduced at 70% of test sites) and substantial improvements during warmer ablation periods (biases reduced at 99% of test sites). Relatively larger improvements during warm conditions are attributable to the default Cbd value being reasonable for cold temperatures (≤−5°C). Improvements in simulated snow depth and density with observations outside of the training sites and optimization periods support that the snow compaction enhancement is transferable in space and time. Differences between enhanced and baseline gridded simulations across the total WUS support that the enhancement can have important impacts on snowpack evolution, snow albedo feedback, and snow hydrology.

Analysis of Codon Usage Bias of Six Genes of Replicase/Coat Protein of Tobacco Mosaic Virus

Background: Tobacco mosaic virus (TMV) stands as a highly studied virus and consequently, its features and composition are extensively understood. It has been found to induce diverse infections in numerous plant species, with tobacco leaves being notably affected, showing mottled browning. Presently, the sole available method to control its spread is by removing infected plants. Understanding codon use bias is crucial as it could play a pivotal role in molecular interventions aimed at halting the virus’s replication and multiplication, thereby helping to contain its propagation. Methods: Currently, the research focuses on assessing codon bias within six genes related to the replicase/coat protein of TMV, namely TMVgp1, TMVgp2, TMVgp3, TMVgp4, TMVgp5 and TMVgp6. To conduct this analysis, various methods such as relative dinucleotide abundance, relative synonymous codon usage (RSCU), neutrality plot and parity rule 2 (PR2) plot were employed. Result: All of the identified genes had a modest codon bias, according to the study on codon usage, as well as the function of mutation pressure in gene TMVgp3 and natural selection in genes TMVgp1, TMVgp2, TMVgp4, TMVgp5 and TMVgp6. The Research into codon use bias showed that the TMV virus’s chosen genes are subjected to naturally occurring selection as well as mutational pressure.

A Guardbanding Method for Managing False Accept Risk under Process Bias

The test uncertainty ratio (TUR) is often used to ensure false-accept risk is minimal for a given measurement. The commonly used guidance requires either a TUR greater than 4, or appropriate guardbanding, to result in a global false-accept probability of less than 2 %. However, this guidance assumes the distribution of units under test is centered between the tolerance limits and fails to achieve 2 % false accept probability when the product distribution is shifted toward one of the limits. A new guardbanding calculation is proposed that accounts for this potential bias in the product distribution. This guardband method may be applied when no assumptions should be made, and no information is available about the bias of the product distribution and works to ensure a 2 % or lower false accept probability for all TURs (including TURs greater than 4) in the presence of modest product bias.

Marijuana Use and Perceptions of Employment Suitability

Abstract: The present study extends research on marijuana social acceptance and employment suitability in the United States by examining how hiring managers view substance use-related content in social networking profiles. Specifically, this research focused on the weight hiring managers placed on social networking posts containing recreational marijuana content, medicinal marijuana content, and alcohol content when assessing potential candidates. With a sample of 405 hiring managers who evaluated experimentally manipulated social networking profiles, the results demonstrated a modest negative hiring bias against recreational marijuana content, with stronger negative effects for alcohol content. At the same time, social networking content related to medicinal marijuana content did not have a significant effect on perceptions of employment suitability. These findings highlight the nuanced nature of substance use stigma in today’s evolving society.

Tunable non-reciprocal waveguide using spoof plasmon polariton coupling to a gaseous magnetoplasmon.

We experimentally demonstrate non-reciprocal (one-way) waveguiding in a microstrip transmission line tailored to support the propagation of spoof plasmon polaritons. Time-reversal symmetry is broken by coupling the microstrip fields to a magnetized gaseous plasma discharge column thereby exciting non-reciprocal magnetoplasmons at the interface between the plasma and a surrounding quartz envelope. The magnetic bias introduces asymmetry in the dispersion of the surface plasmon polaritons at the gaseous plasma-dielectric interface, resulting in a breaking of the bidirectionality of the wave propagation in the microstrip. The isolation generated at conditions of modest magnetic bias is measured to be nearly 60 dB, and tunable by varying the plasma density through the voltage applied to the discharge. The advantage of using magnetized gaseous plasmas to produce this unidirectional waveguide structure is that it can be turned on or off at rates limited by the production and recombination of the plasma.

1296-P: Comparison of Fingerstick and Venous Plasma Glucose in the Ugandan Diabetes in Low-Resource Populations Study

As Africa is experiencing the most rapid rise in the world of type 2 diabetes (T2D), identifying feasible, accurate ways to measure glucose is imperative. While venous glucose (ven-glucose) is recommended, cost and lack of access to pre-analytical processing often rules out this option. Fingerstick measurement of capillary glucose (fs-glucose) is a potential alternative. But data on the correlation between fs-glucose and ven-glucose are scant. Hence OGTT were performed in 512 Ugandans (Male: 46% (234/512), age: 43±17y (mean±SD) enrolled in the Diabetes in Low Resource Populations Study with fs-glucose (Contour Plus Glucometer) and ven-glucose (Glucokinase Method, Roche Cobas 6000) obtained at 0h and 2h. To determine correlation, bias and levels of agreement, Pearson’s correlations and Bland Altman analyses were performed. T2D, preT2D and normal glucose tolerance occurred in 2% (9/512), 18% (92/512) and 80% (411/512), resp. At 0h, fs-glucose and ven-glucose were modestly correlated (r= 0.56) (Fig) with a modest bias for lower glucose by fs-glucose 0.28 mmol/L (95% CI: 0.23, -0.34). At 2h, glucose, fs-glucose and ven-glucose were highly correlated (r=0.92) (Fig) with modest bias for higher glucose by fs-glucose 0.60 mmol/L (95% CI: 0.53, 0.66) mmol/L. Overall, fs-glucose may be an alternative to ven-glucose in Africans where the prevalence of undetected T2D is high and resources are limited. Disclosure A.J.Niwaha: None. A.E.Sumner: None. H.Nkabura: None. R.J.Mukasa: None. N.Mubiru: None. P.A.Balungi: None. I.Sekitoleko: None. B.Mpairwe: None.

Prepregnancy obesity and risk of placental inflammation at term: a selection bias analysis

Placental histopathology is a resource for investigating obesity-associated pregnancy conditions. However, studies oversample adverse pregnancies, biasing findings. We examine the association between prepregnancy obesity (risk factor for inflammation) and histologic placental inflammation (correlated with impaired infant neurodevelopment) and how selection bias may influence the association. Singleton term deliveries between 2008 and 2012 from the Magee Obstetric Maternal and Infant database were analyzed. Prepregnancy body mass index (BMI) was categorized as underweight, lean (referent), overweight, and obese. Outcomes were diagnoses of acute (acute chorioamnionitis and fetal inflammation) and chronic placental inflammation (chronic villitis). Risk ratios for associations between BMI and placental inflammation were estimated using selection bias approaches: complete case, exclusion of pregnancy complications, multiple imputation, and inverse probability weighting. E-values approximated how susceptible estimates were to residual selection bias. Across methods, obesity was associated with an 8-15% lower risk of acute chorioamnionitis, a 7%-14% lower risk of acute fetal inflammation, and a 12%-30% higher risk of chronic villitis relative to lean women. E-values indicated modest residual selection bias could explain away associations, though few measured indications of placental evaluations met this threshold. Obesity may contribute to placental inflammation, and we highlight robust methods to analyze clinical data susceptible to selection bias.

Peak-end bias in retrospective recall of depressive symptoms on the PHQ-9.

Mental health care is built around patient recall and report of clinical symptoms. However, memories of events and experiences rely on cognitive heuristics that influence our recall. The peak-end bias, which refers to the tendency for the most intense and proximate aspects of an experience to disproportionately influence our memory, has been understudied in the context of mental health symptoms and may unduly influence self-reported symptoms, even in the context of standardized assessments. To determine whether the peak-end bias applies to the report of depressive symptoms on the standardized Patient Health Questionnaire-9 (PHQ-9) assessment, we compared two scores from daily mood assessments collected over a 2-week period from 4,322 medical interns (56% women; 60% non-Hispanic White). The peak-end-mood score, which averaged the single lowest and most recent mood scores over 2 weeks had a significantly stronger correlation with the PHQ-9 than the mean-mood score, which averaged all mood scores during the 2 weeks. Likelihood ratio tests and fit statistics provided further support that the peak-end-mood score was a significantly better predictor of depression than the mean-mood score. Results were consistent when limiting the sample to those with mild-to-severe depressive symptoms, and when only examining the two primary mood items as the dependent variable. These findings provide evidence for a modest peak-end recall bias for mood and depressive symptoms. There may be benefits to implementing intermittent assessment strategies to support clinical decision-making. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Self-consistent nanoflare heating in model active regions: MHD avalanches

ABSTRACT Straightened cylindrical models of coronal loops have been standard for decades, and shown to support nanoflare-like heating, but the influence of geometric curvature in models upon the heating produced has not been discussed in depth. Heating, its spatiotemporal distributions, and the associated mechanisms responsible are discussed, and compared with those from straightened models of a coronal loop. Previously, magnetohydrodynamic avalanches have been generalized to curved loops, and shown to be viable. From that study, the associated heating is analysed and discussed in depth. Heating is seen to arise from processes originally instigated, yet not dominated, by magnetic reconnection, producing bursty, aperiodic nanoflares, dispersed evenly throughout the corona, but with a modest bias away from footpoints. One novelty arising is the simultaneous yet independent occurrence of nanoflare-like events at disjoint sites along individual strands, anticipating some features recently seen in ‘campfires’ by Solar Orbiter. With a view to future refinements in the model and to the inclusion of additional physical effects, the implications of this analysis are discussed.

Self-consistent nanoflare heating in model active regions: MHD avalanches in curved coronal arcades

AbstractMHD avalanches involve small, narrowly localized instabilities spreading across neighbouring areas in a magnetic field. Cumulatively, many small events release vast amounts of stored energy. Straight cylindrical flux tubes are easily modelled, between two parallel planes, and can support such an avalanche: one unstable flux tube causes instability to proliferate, via magnetic reconnection, and then an ongoing chain of like events. True coronal loops, however, are visibly curved, between footpoints on the same solar surface. With 3D MHD simulations, we verify the viability of MHD avalanches in the more physically realistic, curved geometry of a coronal arcade. MHD avalanches thus amplify instability across strong solar magnetic fields and disturb wide regions of plasma. Contrasting with the behaviour of straight cylindrical models, a modified ideal MHD kink mode occurs, more readily and preferentially upwards in the new, curved geometry. Instability spreads over a region far wider than the original flux tubes and than their footpoints. Consequently, sustained heating is produced in a series of ‘nanoflares’ collectively contributing substantially to coronal heating. Overwhelmingly, viscous heating dominates, generated in shocks and jets produced by individual small events. Reconnection is not the greatest contributor to heating, but is rather the facilitator of those processes that are. Localized and impulsive, heating shows no strong spatial preference, except a modest bias away from footpoints, towards the loop’s apex. Remarkable evidence emerges of ‘campfire’ like events, with simultaneous, reconnection-induced nanoflares at separate sites along coronal strands, akin to recent results from Solar Orbiter. Effects of physically realistic plasma parameters, and the implications for thermodynamic models, with energetic transport, are discussed.

Influence of Rat Central Thalamic Neurons on Foraging Behavior in a Hazardous Environment.

Foraging entails a complex balance between approach and avoidance alongside sensorimotor and homeostatic processes under the control of multiple cortical and subcortical areas. Recently, it has become clear that several thalamic nuclei located near the midline regulate motivated behaviors. However, one midline thalamic nucleus that projects to key nodes in the foraging network, the central medial thalamic nucleus (CMT), has received little attention so far. Therefore, the present study examined CMT contributions to foraging behavior using inactivation and unit recording techniques in male rats. Inactivation of CMT or the basolateral amygdala (BLA) with muscimol abolished the normally cautious behavior of rats in the foraging task. Moreover, CMT neurons showed large but heterogeneous activity changes during the foraging task, with many neurons decreasing or increasing their discharge rates, with a modest bias for the latter. A generalized linear model revealed that the nature (inhibitory vs excitatory) and relative magnitude of the activity modulations seen in CMT neurons differed markedly from those of principal BLA cells but were very similar to those of fast-spiking BLA interneurons. Together, these findings suggest that CMT is an important regulator of foraging behavior. In the Discussion, we consider how CMT is integrated into the network of structures that regulate foraging.SIGNIFICANCE STATEMENT Foraging entails a complex balance between approach and avoidance alongside sensorimotor and homeostatic processes under the control of multiple cortical and subcortical areas. Although the central medial thalamic nucleus (CMT) is connected to many nodes in this network, its role in the regulation of foraging behavior has not been investigated so far. Here, we examined CMT contributions to foraging behavior using inactivation and unit recording techniques. We found that CMT inactivation abolishes the normally cautious foraging behavior of rats and that CMT neurons show large but heterogeneous changes in firing rates during the foraging task. Together, these results suggest that CMT is an important regulator of foraging behavior.

Diffusion-driven formation of Co[formula omitted]O[formula omitted] nanopetals layers for photoelectrochemical degradation of organophosphate pesticides

A new light is shed on the formation mechanism of Co3O4 nanopetals on Si-based photoanodes by thermal oxidation of a deposited metallic film, and on their use for the rapid chemisorption, the photoelectrochemical detection and subsequent removal of harmful fenitrothion (FNT), a commonly used organophosphate pesticide which represents a serious risk to the public health. Using Au clusters as markers for the external surface of the as-deposited film, the results of complementary experiments indicate that the Co3O4 petal formation during oxidizing annealing is related to the non-uniform Co out-diffusion and oxidation rather than to a local melting, as previously suggested. When grown on Si photoanodes under controlled conditions, Co3O4 nanopetals are stable and exhibit high photoelectrocatalytic activity due to the increased active area with respect to the corresponding thin film. These nanostructures work efficiently for FNT sensing (sensitivity of 0.1 μA/(cm2μM)) through the direct coordination of the FNT nitro-groups on the Co(II) centers, that inhibit the Co(II) oxidation. Furthermore, we demonstrate that a low amount of this nanostructured film, polarized at a modest bias (1.45 V vs RHE) and under visible light illumination (100 mW/cm2), can efficiently remove the pesticide in water with a time constant of 1 h without the need for catalyst recollection, and remains stable, thus making it suitable for environmental remediation applications.

Codon Usage Bias in Phytoplankton

Non-random usage of synonymous codons, known as “codon bias”, has been described in many organisms, from bacteria to Drosophila, but little is known about it in phytoplankton. This phenomenon is thought to be driven by selection for translational efficiency. As the efficacy of selection is proportional to the effective population size, species with large population sizes, such as phytoplankton, are expected to have strong codon bias. To test this, we measured codon bias in 215 strains from Haptophyta, Chlorophyta, Ochrophyta (except diatoms that were studied previously), Dinophyta, Cryptophyta, Ciliophora, unicellular Rhodophyta and Chlorarachniophyta. Codon bias is modest in most groups, despite the astronomically large population sizes of marine phytoplankton. The strength of the codon bias, measured with the effective number of codons, is the strongest in Haptophyta and the weakest in Chlorarachniophyta. The optimal codons are GC-ending in most cases, but several shifts to AT-ending codons were observed (mainly in Ochrophyta and Ciliophora). As it takes a long time to reach a new equilibrium after such shifts, species having AT-ending codons show a lower frequency of optimal codons compared to other species. Genetic diversity, calculated for species with more than three strains sequenced, is modest, indicating that the effective population sizes are many orders of magnitude lower than the astronomically large census population sizes, which helps to explain the modest codon bias in marine phytoplankton. This study represents the first comparative analysis of codon bias across multiple major phytoplankton groups.

Optimal Methods for Reducing Proxy-Introduced Bias on Patient-Reported Outcome Measurements for Group-Level Analyses.

Caregivers, or proxies, often complete patient-reported outcomes (PROs) on behalf of patients; yet, research has demonstrated proxies rate patient outcomes worse than patients rate their own outcomes. To improve interpretability of PROs in group-level analyses, our study aimed to identify optimal approaches for reducing proxy-introduced bias in the analysis of PROs. Data were simulated based on 200 patients with stroke and their proxies who both completed 9 PROMIS domains as part of a cross-sectional study. The sample size was varied as 50, 100, 200, and 500, and the proportion of patients with proxy-respondents was varied as 10%, 20%, and 50%. Six methods for handling proxy-completions were investigated: (1) complete case analysis; (2) proxy substitution; (3) Method 2 plus proxy adjustment; (4) Method 3 including inverse-probability of treatment weighting; (5) multiple imputation; (6) linear equating. These methods were evaluated by comparing average bias in PROMIS T-scores (estimated versus observed patient-only responses), as well as by comparing estimated regression coefficients to models using patient-only responses. Overall mean T-score differences ranged from 0 to 1.75. The range of mean differences varied by the 6 methods with methods 1 and 5 providing estimates closest to the observed mean. In regression models, all but inverse-probability of treatment weighting resulted in low bias when proxy-completions were 10% to 20%. With 50% proxy-completions, method 5 resulted in less accurate estimations while methods 1 to 3 provided less proxy-introduced bias. Bias remained low across domain and varying sample sizes but increased with larger percentages of proxy-respondents. Our study found modest proxy-introduced bias when estimating PRO scores or regression estimates across multiple domains of health. This bias remained low, even when sample size was 50 and there were large proportions of proxy-completions. While many of these methods can be chosen for including proxies in stroke PRO research with <20% proxy-respondents, proxy substitution with adjustment resulted in low bias with 50% proxy-respondents.

Cheating at Craps

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.