Comparison of Different Response Time Outlier Exclusion Methods: A Simulation Study

In response time (RT) research, RT outliers are typically excluded from statistical analysis to improve the signal-to-noise ratio. Nevertheless, there exist several methods for outlier exclusion. This poses the question, how these methods differ with respect to recovering the uncontaminated RT distribution. In the present simulation study, two RT distributions with a given population difference were simulated in each iteration. RTs were replaced by outliers following two different approaches. The first approach generated outliers at the tails of the distribution, the second one inserted outliers overlapping with the genuine RT distribution. We applied ten different outlier exclusion methods and tested, how many pairs of distributions significantly differed. Outlier exclusion methods were compared in terms of bias. Bias was defined as the deviation of the proportion of significant differences after outlier exclusion from the proportion of significant differences in the uncontaminated samples (before introducing outliers). Our results showed large differences in bias between the exclusion methods. Some methods showed a high rate of Type-I errors and should therefore clearly not be used. Overall, our results showed that applying an exclusion method based on z-scores / standard deviations introduced only small biases, while the absence of outlier exclusion showed the largest absolute bias.

Association of colon adenocarcinoma in situ in polyp with subsequent colon cancer: A population-based retrospective study.

e15605 Background: Adenocarcinoma in situ (pTis) of the colon is defined as malignant cells confined within epithelium or mucosa. Since pTis is not invasive, polypectomy alone is usually adequate, especially if resection margins are cancer-free. We performed a population-based study to investigate the association of intrapolyp pTis and subsequent colon cancer. Methods: We queried the SEER database (1975-2017) for patients with pTis in adenoma. We further filtered patients with subsequent colon cancers. Standard incidence ratios (SIRs) were used to evaluate the excess risk of developing subsequent colon cancers comparing to the general population. Difference between patients who did or did not develop colon cancer were analyzed using Chi-square test. Results: A total of 15164 patients with pTis were identified. Among them, 736 (4.85%) patients developed subsequent colon cancer. Age ≥70 years, pTis in villous adenoma, polyp in hepatic flexure, splenic flexure, transverse colon, descending colon, and diagnosis year before 2000 were associated with increased risk of developing subsequent colon malignancy (all p< 0.05). Polypectomy comparing to colectomy (total, subtotal or partial) is associated with a higher rate of developing subsequent colon cancers ( p < 0.05). In patients with intrapolyp pTis, observation/expectation (O/E) of developing colon cancers are elevated to 4.76, 1.84, 1.66, and 1.28 within one year, 1-5 year, 5-10 year, and after ten years, respectively (all p< 0.05). O/E for the male and female is 1.80 and 1.63 (both p< 0.05); for the white and black is 1.64 and 2.21(both p< 0.05). Conclusions: Subsequent colon cancers developed in 4.85% of pTis patients. Excess risk of developing subsequent colon cancers is highest in the first year, and declines with time but persists beyond ten years. Male and black have the highest excess risk. Factors like older age, villous adenoma, location from hepatic flexure to descending colon, and polypectomy are associated with developing subsequent colon cancers.

Development of sorghum mutant genotypes and analysis of their agro-morphological diversity

Sorghum is one of the most important cereal grains in Africa's Sub-Saharan region, used for human consumption and animal feed, but its production is hampered by biotic and abiotic constraints, necessitating genetic improvement of sorghum. The goal of this experiment was to use the ethyl methane sulfonate induced mutation technique to develop superior genotypes for sorghum production and quality for food and industry in order to achieve food security. The concentration of EMS was initially optimized by calculating LD50. Both Argity and Dekeba genotypes were treated with six different concentrations of EMS (0.10, 0.25, 0.30, 0.50, 0.75 and 1.00 %) and three different soaking periods (7, 8 and 9 hrs). The 0.25% EMS concentration at 8 hrs was chosen because it had a 50% seed survival rate and the highest frequency of mutations to generate M1 seeds. From M2 and M3, about 4000 and 2000 mutant populations were screened, respectively. For trait characterization, 190 mutated lines were selected from a mutant population of 2000M2. The 190 mutant populations and two parents were evaluated for genetic diversity, character association, and genetic divergence. For the observed quantitative phenotypic traits, analyses of variance showed substantial inter-population difference. When compared to their parent cultivars, the study mean of six treatment populations in each cultivar showed significantly superior quantitative phenotypic traits. Plant height, flowering date, maturity date, stem diameter, grain weight, and thousand seed weight varied with 81.48, 77, 42.03, 56.11, 11.44, and 96.68 % heritability in the mutant lines, according to agro-morphological characterization. The elite mutants were identified using principal component analysis based on their agro-morphological traits, while Pearson's correlation findings showed a positive correlation between yield component traits. Finally, our research allowed the identification of new promising mutant genotypes that could be tested in multi-local trials to assess their agronomic efficiency.

Gender and Regional Disparities in Incidence of Hepatocellular Carcinoma in Autoimmune Hepatitis: A Systematic Review and Meta-analysis

BackgroundRecent studies have identified an increased risk of hepatocellular carcinoma (HCC) in autoimmune hepatitis (AIH). Gender and regional disparities in incidence of HCC in AIH continue to be reported worldwide. Nevertheless, the magnitude of this gap remains unknown.MethodWe searched several databases including PubMed, Embase, Web of Science, Cochrane Library, Wangfang Data, CNKI and Sinomed. Incidence rates of HCC in AIH were combined and analyzed following the EBayes method. Incidence rate ratios were pooled to assess the gender differences. The impact of population difference, gender, age, cirrhotic condition was further analyzed with subgroup analysis and linear regression analysis.Result39 studies meeting our eligibility criteria were chosen for the analysis. The pooled incidence rate of HCC in AIH was 3.54 per 1,000 person-years (95%CI = 2.76–4.55). Pooled IRR for the risk of HCC in male AIH patients compared to female was 2.16 (95%CI = 1.25–3.75), with mild heterogeneity among studies. The pooled HCC incidence rate in AIH by continents was as follows: Europe 2.37 per 1,000 person-years (95%CI = 1.45–3.88), Asia 6.18 per 1,000 person-years (95%CI = 5.51–6.93), North America 2.97 per 1,000 person-years (95%CI = 2.40–3.68), Oceania 2.60 (95%CI = 0.54–7.58). The pooled HCC incidence rate in AIH related cirrhosis by continent was as follows: Europe 6.35 per 1,000 person-years (95%CI = 3.94–10.22), Asia 17.02 per 1,000 person-years (95%CI = 11.18–25.91), North America 10.89 per 1,000 person-years (95%CI = 6.69–17.74).ConclusionA higher HCC incidence in AIH was observed among male and in Asian populations. Routine HCC surveillance is cost effective for patients with AIH cirrhosis, especially for those in Asian populations.

Examination and Comparison of Theta Band Connectivity in Left- and Right-Hand Dominant Individuals throughout a Motor Skill Acquisition

The majority of the population identifies as right-hand dominant, with a minority 10.6% identifying as left-hand dominant. Social factors may partially skew the distribution, but it remains that left-hand dominant individuals make up approximately 40 million people in the United States alone and yet, remain underrepresented in the motor control literature. Recent research has revealed behavioral and neurological differences between populations, therein overturning assumptions of a simple hemispheric flip in motor-related activations. The present work showed differentially adaptable motor programs between populations and found fundamental differences in methods of skill acquisition highlighting underlying neural strategies unique to each population. Difference maps and descriptive metrics of coherent activation patterns showed differences in how theta oscillations were utilized. The right-hand group relied on occipital parietal lobe connectivity for visual information integration necessary to inform the motor task, while the left-hand group relied on a more frontal lobe localized cognitive based approach. The findings provide insight into potential alternative methods of information integration and emphasize the importance for inclusion of the left-hand dominant population in the growing conceptualization of the brain promoting the generation of a more complete, stable, and accurate understanding of our complex biology.

Quantifying genetic heterogeneity between continental populations for human height and body mass index

Genome-wide association studies (GWAS) in samples of European ancestry have identified thousands of genetic variants associated with complex traits in humans. However, it remains largely unclear whether these associations can be used in non-European populations. Here, we seek to quantify the proportion of genetic variation for a complex trait shared between continental populations. We estimated the between-population correlation of genetic effects at all SNPs ($$r_{g}$$ r g ) or genome-wide significant SNPs ($$r_{{g\left( {GWS} \right)}}$$ r g GWS ) for height and body mass index (BMI) in samples of European (EUR; $$n = 49,839$$ n = 49 , 839 ) and African (AFR; $$n = 17,426$$ n = 17 , 426 ) ancestry. The $$\hat{r}_{g}$$ r ^ g between EUR and AFR was 0.75 ($${\text{s}}.{\text{e}}. = 0.035$$ s . e . = 0.035 ) for height and 0.68 ($${\text{s}}.{\text{e}}. = 0.062$$ s . e . = 0.062 ) for BMI, and the corresponding $$\hat{r}_{{g\left( {GWS} \right)}}$$ r ^ g GWS was 0.82 ($${\text{s}}.{\text{e}}. = 0.030$$ s . e . = 0.030 ) for height and 0.87 ($${\text{s}}.{\text{e}}. = 0.064$$ s . e . = 0.064 ) for BMI, suggesting that a large proportion of GWAS findings discovered in Europeans are likely applicable to non-Europeans for height and BMI. There was no evidence that $$\hat{r}_{g}$$ r ^ g differs in SNP groups with different levels of between-population difference in allele frequency or linkage disequilibrium, which, however, can be due to the lack of power.

Study of Palatal Rugae Patterns and their Use in Sex and Ethnicity Identification in a Sample of Adult Egyptians and Malaysians

Background: Palatal rugoscopy is the use of palatal rugae for identification of unknown persons. The majority of the population in Egypt consists of Egyptian people. However, some Malaysian people live in Alexandria city of Egypt for the purpose of education. So in case of mass disaster, there is a critical need for a reliable and easy method to differentiate between Malaysians and Egyptians. Aim: Study palatal rugae patterns in two diverse populations; Egyptians and Malaysians and its relation to sex and population difference. Subjects: Eighty students of Alexandria Faculty of Dentistry; forty Egyptians (20 females and 20 males) and forty Malaysians (20 males and 20 females). The age ranged 18-30 years. Results: Significant difference was noted between Malaysian males and females according to total number of rugae on both sides. Malaysians had significantly higher total rugae number on both sides than Egyptians. Curved shape was the predominant shape in the total sample. Significant difference was detected between Egyptians and Malaysians according to the predominant palatal rugae direction on both left and right sides. Egyptian females had significantly higher percentage of absent unification than Egyptian males. Linear regression models for sex and ethnicity identification were built up.

Population difference gratings created on vibrational transitions by nonoverlapping subcycle THz pulses

We study theoretically a possibility of creation and ultrafast control (erasing, spatial frequency multiplication) of population density gratings in a multi-level resonant medium having a resonance transition frequency in the THz range. These gratings are produced by subcycle THz pulses coherently interacting with a nonlinear medium, without any need for pulses to overlap, thereby utilizing an indirect pulse interaction via an induced coherent polarization grating. High values of dipole moments of the transitions in the THz range facilitate low field strength of the needed THz excitation. Our results clearly show this possibility in multi-level resonant media. Our theoretical approach is based on an approximate analytical solution of time-dependent Schrödinger equation (TDSE) using perturbation theory. Remarkably, as we show here, quasi-unipolar subcycle pulses allow more efficient excitation of higher quantum levels, leading to gratings with a stronger modulation depth. Numerical simulations, performed for THz resonances of the $$H_20$$ H 2 0 molecule using Bloch equations for density matrix elements, are in agreement with analytical results in the perturbative regime. In the strong-field non-perturbative regime, the spatial shape of the gratings becomes non-harmonic. A possibility of THz radiation control using such gratings is discussed. The predicted phenomena open novel avenues in THz spectroscopy of molecules with unipolar and quasi-unipolar THz light bursts and allow for better control of ultra-short THz pulses.

Imaging Sequences for Hyperpolarized Solids

Hyperpolarization is one of the approaches to enhance Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) signal by increasing the population difference between the nuclear spin states. Imaging hyperpolarized solids opens up extensive possibilities, yet is challenging to perform. The highly populated state is normally not replenishable to the initial polarization level by spin-lattice relaxation, which regular MRI sequences rely on. This makes it necessary to carefully “budget” the polarization to optimize the image quality. In this paper, we present a theoretical framework to address such challenge under the assumption of either variable flip angles or a constant flip angle. In addition, we analyze the gradient arrangement to perform fast imaging to overcome intrinsic short decoherence in solids. Hyperpolarized diamonds imaging is demonstrated as a prototypical platform to test the theory.