Nonparametric Rank Test Research Articles

Hispanic Cancer Survivors Exposed to Multiple Natural Disasters: Pre-Post-Disaster Changes in Anxiety, Depression, PTSD, Perceived Stress, and Physical Symptom Burden.

Studies evaluating the effects of natural disasters on cancer outcomes are scarce, especially among USA ethnic minority groups, and none have focused on the effects of concurrent natural disasters and the COVID-19 pandemic. The goal of this secondary data analysis is to explore the impact of concurrent exposure to COVID-19 and earthquakes on psychological distress and symptom burden among Puerto Rican cancer survivors. This secondary data analysis (n = 101) was part of a longitudinal case-control cohort study (n = 402) aimed at describing unmet psychological needs among Puerto Rican cancer patients and non-cancer subjects previously exposed to Hurricane María in 2017. The research team pooled data from participants (cancer survivors and non-cancer group) from their baseline assessments and from follow-up assessments conducted during January-July 2020 (earthquake and the lockdown period). A descriptive, paired t-test, non-parametric mean rank test, and two-sided Pearson correlation analyses were performed. Psychological distress and cancer symptom burden diminished over time. Resilience was significantly correlated with all the psychological and symptom burden variables during both pre- and post-earthquake and COVID-19 assessment periods. The results support the role of resilience, social support, and post-traumatic growth as potential protective factors preventing psychological distress and diminishing cancer symptom burden among cancer survivors exposed to natural disasters and the COVID-19 pandemic.

The Psychological Impact of COVID-19: A Comparative Analysis of Pre-Lockdown and During-Lockdown Periods Among Saudi General Population.

Prior research has revealed substantial psychological impacts of COVID-19 among the general population. However, there is a noticeable gap in studies addressing the enduring anxiety levels before and during lockdown periods of the COVID-19 pandemic. The study assessed and compared the psychological impact of the COVID-19 pandemic before and during lockdown periods among the general population in Saudi Arabia. A validated and reliable General Anxiety Disorder (GAD)-7 instrument was used to quantify stress levels by measuring anxiety. Nonprobability snowball sampling was used to collect data from 516 participants residing in Saudi Arabia. The difference in scores for each of the seven related questions of GAD-7 was determined using a non-parametric Wilcoxon rank test. A mild level of anxiety was consistently observed both before and during the lockdown, as indicated by GAD-7 scores of 6.17 (SD = 5.5) before the lockdown and 6.42 (SD = 5.7) during the lockdown. There were no differences in GAD-7 scores before 6.17 (SD = 5.5) and during 6.42 (SD = 5.7) the lockdown periods. However, levels of moderate anxiety increased by 5% during the lockdown period. Anxiety levels before and during lockdown were significantly associated with gender (χ2 (3, n = 516) =11.23 p = 0.01) and employment status (χ2 (3, n = 516) = 9.41 p = 0.024). Among the GAD-7 questionnaire items, item number 1 ("Feeling nervous, anxious, or on edge") (p= 0.00) and item number 7 ("Feeling afraid as if something awful might happen") (p= 0.025) showed a significant association with anxiety levels before and during the lockdown periods. The enduring prevalence of mild anxiety, persisting both before and during the lockdown periods, underscores the profound impact of COVID-19 on the mental health of the general population in Saudi Arabia.

An extended event study methodology and its application in the HNA group's overseas market contraction

This paper introduces a novel framework for analyzing the performance of cross-border merger and acquisition (M&A) activities in international business. It investigates whether the contraction of overseas market activities can mitigate financial crises, using the case study of a Chinese multinational enterprise (MNE). Traditional event study methodology, commonly used for assessing business performance changes, relies on assumptions of normality and homoscedasticity in data. However, real financial data often exhibits high volatility and non-normal distribution, rendering traditional methods inadequate for estimation. To address this limitation, we propose an enhanced analytical framework integrating the Shapiro–Wilk test, event studies, quantile regression, and nonparametric rank tests. This approach provides more robust estimates, facilitating a more accurate and comprehensive analysis of business performance changes under specific events. Applying this methodology to assess the short-term performance of HNA Group, a cross-border airline in China, during its financial crisis, we find that while overseas market contraction events generate overall positive short-term value for enterprises, the impact varies depending on the assets sold. However, given HNA Group's substantial debt burden, the positive effect is minimal, indicating that overseas market contraction alone is insufficient as a "self-help" strategy in addressing corporate financial crises.

Multi-omics combined test performance effectiveness on opportunistic screening of high-risk liver cancer population

Objective: To validate the performance of a multi-omics combined test for early screening of high-risk liver cancer populations. Methods: 173 high-risk patients with liver cancer were prospectively screened in a real-world setting, and 164 cases were finally enrolled. B-ultrasound, alpha-fetoprotein (AFP), and HCC screens were conducted in all patients. A multi-omics early screening test was performed for liver cancer in combination with multi-gene methylation, TP53/TERT/CTNNB1 mutations, AFP, and abnormal prothrombin (PIVKA-II). Differences in rates were compared using the chi-square test, adjusted chi-square test, or Fisher's exact probability method for count data. A non-parametric rank test (Mann-Whitney) was used to compare the differences between the two groups of data. Results: The HCCscreen detection had a sensitivity of 100% for liver cancer screening, 93.8% for liver cancer and precancerous diseases, 34.1% for positive predictive value, 99.2% for negative predictive value, and 0.89 for an area under the curve (AUC). Parallel detection of AFP, AFP+B-ultrasound, and methylation+mutation had a sensitivity/specificity and AUC of 31.3%/88.5% (AUC=0.78), 56.3%/88.2% (AUC=0.86), and 81.3%/82.4 % (AUC=0.84). At the same time, the disease severity range was significantly correlated with the methylation+mutation score, HCCscreen score, or positive detection rate (PDR). There was no significant correlation between AFP serum levels and methylation+mutation or HCCscreen scores, while there was a significant linear correlation between methylation+mutation scores and HCCscreen scores (r = 0.73, P < 0.001). Conclusion: In real-world settings, HCCscreen shows high sensitivity for screening opportunistic, high-risk liver cancer populations. Furthermore, it may efficaciously detect liver cancer and precancerous diseases, with superior performance to AFP and AFP+ultrasound. Hence, HCCscreen has the potential to become an effective screening tool that is superior to existing screening methods for high-risk liver cancer populations.

Need assessment of medical school curriculum for MOOCs: perspectives of instructors and students of Shiraz University of Medical Sciences

IntroductionDesigning, developing, and implementing a course without assessing and prioritizing instructional needs may result in inefficiency due to the disregard for the actual needs of the target population. The present study aimed to determine and prioritize medical students’ instructional needs regarding Massive Open Online Courses (MOOCs) at Shiraz University of Medical Sciences.MethodsThis survey study was carried out in three stages (2020–2021) using the Delphi technique. Purposive and snowball sampling methods were used to select the instructors. The students were selected through simple random sampling. The first round of the Delphi technique involved a questionnaire consisting of one open-ended question, completed by 49 basic/clinical faculty members and 47 senior medical students. In the second round, a 5-point Likert scale-based questionnaire was used to prioritize the instructional needs. The reliability of the questionnaire was verified by Cronbach’s alpha coefficient. In the third round, a focus group was used. A total of six expert faculty members and one senior medical student were invited to the focus group session to prioritize the needs. Data were analyzed using Friedman’s non-parametric ranking test in SPSS version 26.ResultsTen instructional needs priorities were extracted, including common pharmacotherapies (antibiotics and narcotics), prescriptions, physiology, anatomy, physical examination, electrocardiography interpretation, radiography, computed tomography scans, serum electrolyte disorders, and cardiovascular and internal (endocrine and metabolic) diseases. The chi-squared calculated value (715.584) indicated a significant difference in the importance of the questionnaire’s questions (P < 0.001). These questions did not have equal value, and the importance, from the respondent’s point of view and the observed distribution of ranks, was not the output of a random factor.ConclusionsThe findings of this study can be used to design MOOCs, revise instructional programs, and adapt the curriculum to meet the needs of general practitioners, which will, in turn, help meet the medical needs of the general population.

Tests of goods market integration between China and African BRI countries

AbstractThe Chinese Government has promulgated the “Belt and Road Initiative” (BRI) to increase trade flows and integrate goods markets between China and BRI countries. The validity of purchasing power parity (PPP) implies well‐integrated goods markets, a precondition for further economic convergence, and the next stage of economic integration in factor, service, and financial markets. Our study aims to examine the validity of the PPP and the extent of goods market integration between China and selected BRI countries in Africa. Since the functional form of the cointegrating relationship may not be exact or linear, we adopt the nonparametric rank tests for analysis without prior knowledge and specification of the functional form. We also address the rank problems that occur in multivariate rank tests. Our empirical results provide strong evidence of an unrestricted PPP relationship with reasonably strong evidence of nonlinearity in the data. We also find that some African BRI countries have experienced goods market integration with China during the second‐half period only. This indicates that the introduction of the BRI in 2013 and China's active involvement in African economic development through BRI projects are leading to enhanced goods market integration between China and Africa. The results indicate favorable prospects of closer economic cooperation in the factor, service, and financial markets to build a free trade area or common markets with BRI countries in Africa.

Tests of goods market integration between China and European countries: a nonlinear nonparametric approach

ABSTRACT The validity of purchasing power parity (PPP) between two economies implies goods markets of the two are well integrated. This is a pre-condition for further economic convergence. This study examines validity of the PPP between China and European countries. Since the functional form of the cointegrating relationship may not be exact or linear, we adopt the nonparametric rank tests for analysis, without prior specification of the functional form. We also address the rank problems that occur in multivariate rank tests. The results indicate strong support for nonlinear PPP relationships between China and European countries, especially during the second subsample period. This indicates China’s rising economic power, particularly in the most recent decade. Although there have been disputes between China and Europe, these results suggest favorable prospects for closer economic cooperation between the two sides and the need for formulation of common policies to pursue an integrated market in the future.

Contrast-Enhanced Ultrasound and High Sensitive Doppler for Monitoring Outcomes of Uterine Artery Embolization

To monitor fibroid microvascularity using contrast-enhanced ultrasound (CEUS) and a new high-sensitive Doppler mode (SMI) for assessment of uterine artery embolization (UAE) outcomes. Forty women with symptomatic uterine fibroids scheduled for UAE were enrolled in this Institutional Review Board-approved study. Subjects underwent three examinations (day 0, 15, and 90 post-UAE) with Color Doppler (CDI), power Doppler (PDI), color and monochrome SMI (cSMI and mSMI), and CEUS imaging of the fibroids. Clips were assessed by two radiologists classifying fibroids based on their vascularity. Fibroid fractional vascularity (FV; % of enhanced pixels within the fibroid) and flow intensity (as mean brightness level of the enhanced pixels) were quantified. Results were analyzed using repeated measures ANOVA and nonparametric Wilcoxon sign rank tests. Inter-reader agreement was assessed with κ-values. There was overall agreement between readers for all imaging modalities and examination times (P=.25; κ=0.70). The FV analysis showed statistically significant differences between CEUS and the Doppler imaging modes (CDI, PDI, cSMI, and mSMI) for the three examination times were compared (P<.0001). The comparison using CDI, PDI, and cSMI showed no statistically significant difference (P=.53). The flow intensity analysis comparison between the Doppler imaging modes (CDI, PDI, cSMI and mSMI) and examination times showed statistically significant differences between all the Doppler imaging modalities (P=.02), except for the 90days post-UAE (P=.34). When the comparison was made for CDI, PDI, and cSMI there was no statistically significant differences (P<.47). CEUS and SMI can accurately evaluate fibroid microvascularity, and therefore, can be a noninvasive and accurate method for monitoring outcomes following UAE treatment.

Evaluation of separating media for autopolymerizing acrylic resin fabricated on 3D-printed acrylate-based resin dental casts

Statement of problemLimited data are available regarding the most suitable separating medium for fabricating dental acrylic resin prostheses or appliances on 3-dimensional (3D)-printed resin casts. PurposeThe purpose of this in vitro study was to investigate and evaluate different separating media in terms of the ease of removal and detail reproduction of an autopolymerizing acrylic resin fabricated on acrylate-based 3D-printed resin casts. Material and methodsA cube-shaped cast was designed with a built-in truncated cone-shaped hole and a V-shaped groove at the base. Seventy-five casts were 3D-printed using acrylate-based resin and assigned to 5 groups according to the applied separating media: Siliform BEA (silicone-based), IMPRIMO 3D (alginate-based), 3D Modellisolierung (wax-based), TECHNOSIL (alginate-based), and none (control). After the application of the separating media, the truncated cone-shaped holes in the specimens were filled with autopolymerizing acrylic resin. The efficacy of the separating media was evaluated according to the ease of removal on a scale of 1 to 3 and accurate detail reproduction of the V-shaped groove on a scale of 1 to 3 under ×6 magnification. The nonparametric Kruskal-Wallis rank test was used to identify significant differences among the separating media (α=.05). ResultsSignificant differences were found among the groups (P<.001). Siliform BEA and 3D Modellisolierung had the best mean rank in both the ease of removal and detail reproduction scores, which were significantly different from those of the alginate-based separating media (IMPRIMO 3D and TECHNOSIL) and the control group (P<.01). ConclusionsThe dedicated silicone- and wax-based separating media for 3D-printed casts exhibited the most favorable performance in terms of ease of removal and detail reproduction.

The Effectiveness of the E-Book “Aku Siap Pubertas (ASiaP)” in Improving the Role of Mothers and Children's Readiness for Puberty

Adolescents experience successive hormonal, physical, psychological and social changes. Adolescents detach themselves emotionally from their parents to assume social roles. As many as 47.7% of teenagers often feel anxious, and 84% feel repeated feelings of anxiety. One of the anxieties that are handled is the physical changes during puberty. The results of this research on family support are still relatively low, namely 12%. Families are overprotective, lack attention, and feel confused about adolescent emotions. Objective: To determine the effect of e-books on knowledge, attitudes, mother's role and children's readiness to face puberty. Methods: The research design is quasi-experimental. They conducted research in March-September 2022 in the Malaka Jaya sub-district, East Jakarta, with a total sample of 59 mothers and adolescents. The data results were analyzed using the non-parametric Wilcoxon Rank and linear regression tests. Results: This study shows the effect of e-books on knowledge, attitudes and the role of mothers in dealing with pubertal changes with a significance of 0.000, 0.04 and 0.000. Education affects learning with a value of 0.000 and a regression coefficient of 2.787, which means that education increases a mother's knowledge by 2.7 times. There 91.1% of children are ready to be cheerful and ready to go through puberty, with a significance of 0.002. Conclusion: Using e-books increases mothers' role in facing puberty changes, and adolescents can go through puberty well.

Unattended home sleep studies for the diagnosis of obstructive sleep apnea in a population of French children

BackgroundAmbulatory exams were preferred in children during the COVID-19 pandemic. Polysomnography (PSG), the gold standard for obstructive sleep apnea (OSA) diagnosis, requires several leads and sensors to be attached to the child's body. Children are more comfortable with respiratory polygraphic (RP) recording, which needs fewer sensors. ObjectiveTo compare respiratory parameters obtained by home RP with those obtained by home PSG with the device installed at the child's home by a trained sleep nurse from a national health care provider. MethodsData from home PSGs performed in children aged 2–19 years were retrospectively included. The obstructive apnea-hypopnea index (OAHI) was computed in PSG and then in RP after removing the sleep signals. The two indexes were compared using non-parametric paired Wilcoxon rank test, Bland-Altman analysis and sensitivity–specificity analysis. Results44 PSGs of 44 children were included with only 34 (77%) PSGs interpretable. Median (min-max) OAHI was significantly underestimated in RP than in PSG (2.2 (0–25) vs 4.0 (0.4–28), p < 0.0001), confirmed also by the Bland-Altman diagram, the magnitude of the difference being mean ± standard deviation −1.7 ± 1.7. The sensitivity and specificity of OAHI in RP to identify an OAHI ≥2/h in PSG was 0.91 for both. ConclusionUnattended ambulatory RP performed at child's house and installed under carefully controlled conditions is a useful exam for diagnosing OSA in children with or without comorbidities. However, RP must be installed in a supervised environment and interpreted with caution as it tends to underestimate OSA severity.

HUBUNGAN ANTARA KADAR KOLESTEROL TOTAL DENGAN KADAR HIGH SENSITIVITY C-REACTIVE PROTEIN (HS-CRP) PADA PENDERITA DIABETES MELLITUS TIPE 2

Type 2 Diabetes Mellitus patients can cause oxidative stress which can trigger complications, namely cardiovascular disease. Increased levels of total cholesterol can cause atherosclerosis which can cause blockage of blood vessels so that it becomes one of the causes of cardiovascular disease. Atherosclerosis can cause inflammation and tissue damage so that the result of this inflammation causes an increase in levels of High sensitivity C-Reactive Protein (Hs-CRP). High sensitivity C-Reactive Protein (Hs-CRP) can be called the most significant predictor of inflammation markers of the risk of cardiovascular events. The purpose of this study was to determine the correlation between total cholesterol levels and levels of High sensitivity C Reactive Protein (Hs-CRP) in patients with Type 2 Diabetes Mellitus. This type of research was an analytical observation using a cross sectional approach. The results of statistical analysis using a non-parametric spearman rank test from the correlation test, the significance value of 24 samples was 0.392, then p0.05 the Correlation Coefficient was -0.183, which means that there is no correlation between total cholesterol levels and Hs-CRP levels in people with diabetes mellitus type 2 which is weakly correlated.

Examining rational bubbles in global natural gas prices: Evidence from frequency domain estimates

Natural gas plays important role in the global energy sources, hence understanding its price behavior is important to various economic agents. This study examined whether rational bubbles existed in the three major natural gas markets by employing Fourier unit root tests and a nonparametric rank test for cointegration. Data comprises monthly data on the three largest natural gas indices in the world – Henry hub (USA), European and Asian (Japan) for the period from 2000M1–2021M12. The results reveal that the efficient market hypothesis holds in the market ruling out the possibility of arbitrage opportunities. The rank test estimates at 0.009677, 0.009872, and 0.009657 at 1% significant level for the pre-COVID-19 sample period, and at 0.009671, 0.09874, and 0.009661 at 1% significant level for the full sample period contradict the rational explosive bubble framework that suggests deviation of prices from the fundamentals. This suggests that natural gas prices markets are efficient at least in the weak form, the implication is that disruptions in the market will be short-lived as the market will fundamentally adjust back to equilibrium.

Probing parity violation with the four-point correlation function of BOSS galaxies

Parity-violating physics in the early Universe can leave detectable traces in late-time observables. Whilst vector- and tensor-type parity-violation can be observed in the $B$-modes of the cosmic microwave background, scalar-type signatures are visible only in the four-point correlation function (4PCF) and beyond. This work presents a blind test for parity-violation in the 4PCF of the BOSS CMASS sample, considering galaxy separations in the range $[20,160]h^{-1}\mathrm{Mpc}$. The parity-odd 4PCF contains no contributions from standard $\Lambda$CDM physics and can be efficiently measured using recently developed estimators. Data are analyzed using both a non-parametric rank test (comparing the BOSS 4PCFs to those of realistic simulations) and a compressed $\chi^2$ analysis, with the former avoiding the assumption of a Gaussian likelihood. These find similar results, with the rank test giving a detection probability of $99.6\%$ ($2.9\sigma$). This provides significant evidence for parity-violation, either from cosmological sources or systematics. We perform a number of systematic tests: although these do not reveal any observational artefacts, we cannot exclude the possibility that our detection is caused by the simulations not faithfully representing the statistical properties of the BOSS data. Our measurements can be used to constrain physical models of parity-violation. As an example, we consider a coupling between the inflaton and a $U(1)$ gauge field and place bounds on the latter's energy density, which are several orders of magnitude stronger than those previously reported. Upcoming probes such as DESI and Euclid will reveal whether our detection of parity-violation is due to new physics, and strengthen the bounds on a variety of models.

One Year On: Evaluation of the Cambridgeshire and Peterborough Staff Mental Health Service, a Bespoke Mental Health Clinic for Healthcare Workers

AimsThe Staff Mental Health Service (SMHS) at the Cambridgeshire and Peterborough NHS Foundation Trust is a multidisciplinary team providing rapid access assessments and treatments to NHS staff in all roles. The service was launched in September 2020 and obtained recurrent funding in 2021. Previously we reported initial clinical findings from the service suggesting high rates of moderate to severe depression, anxiety, and post-traumatic stress symptoms (Kaser et al. 2021). In this report, we present the clinical and demographic findings, and post-treatment outcomes from the first-year evaluation of the SMHS.MethodsDemographic and clinical data were collected as part of service evaluation at the SMHS. Depression, anxiety, and posttraumatic stress symptoms were evaluated by Patient Health Questionnaire (PHQ-9), Generalised Anxiety Disorder Assessment (GAD-7), and Posttraumatic Symptom Checklist – Civilian Version (PCL-C). Non-parametric Wilcoxon rank test was used to compare pre- and post-treatment symptom scores.ResultsThe service received 515 referrals in the first year. 39.6% of the patients were off work at the time of the referral. 81.2% patients were female and 75.3% were of white ethnicity. Median time from referral to assessment was 14 days. According to the clinical data (n = 320), 85.3% of the patients had moderate to severe depressive symptoms (mean PHQ-9: 16.25 ± 6.1), and 80.9% of the patients had moderate to severe levels of anxiety symptoms (mean GAD-7: 13.62 ± 4.7). Staff patients endorsed high levels of traumatic stress with 82.5% scoring higher than the established cut-off (PCL-C &gt; 14) (PCL-C mean score: 19.14 ± 5.7). Analyses from patients completing treatment at the service showed significant improvements in depression (Z=−3.38, p = 0.001), anxiety (Z= -4.09, p &lt; 0.001), and PTSD symptoms (Z= -4.99, p &lt; 0.001).ConclusionThe Staff Mental Health Service had a persistent noticeable demand in its first year corresponding to two percent of the total workforce of the local trusts. Healthcare workers presenting to the service had high rates of moderate to severe depression, anxiety, and PTSD symptoms. Multidisciplinary treatment at the SMHS led to significant improvements in psychiatric symptoms. A health economics analysis of the service is currently underway.

P16 Strengthening surveillance systems for antimicrobial resistance in urinary tract infections in Kenya

BackgroundUrinary tract infections (UTIs) are amongst the most common conditions leading to outpatient visits and are also one of the most common causes of inappropriate antibiotic usage. Addressing antimicrobial resistance (AMR) requires strengthening surveillance system in Kenya where UTI is a problem with health systems having limited capacity for accurate laboratory identification of UTI pathogens. Empirical treatment to manage UTIs is the most common problem due to limited microbiology capacity. These include shortages of suitable training, equipment, quality control procedures and professional expertise to make an accurate clinical interpretation of urine cultures. This leads to reporting normal flora as pathogens.ObjectivesTo deliver training on the identification and antibiotic susceptibility testing of bacterial isolates from urine infections at participating hospitals in the Kenyan AMR surveillance network and measure competency levels in staff participating in the training with the aim of strengthening the Kenyan surveillance system.MethodsA 1 day baseline visit to the five sites was made between October and November 2021 using a standardized checklist to assess laboratory capacity. This was followed by urine processing training conducted between November 2021 and January 2022 in Malindi, Jaramogi, Kitale, Nakuru and Nyeri County Hospitals. Training materials were developed with the input of Aga Khan University Hospital. A 5 day in-person training course was delivered at each of the five hospitals, which targeted an average of 2–3 laboratory staff per hospital. The competencies of the laboratory staff were assessed by written pre-assessment and post-assessment tests. A standardized practical assessment was achieved by use of five different control organisms. The scores were done by doing an average performance score at each hospital laboratory.ResultsOut of 13 trainees, 8 were male and 5 were female. The median number of years since qualification for these staff was 6 (IQR 2–9). The median number of total months of microbiology training time was 2.3 (IQR 1–7). The median pre-training and post-training scores were 46% and 90%, respectively; non-parametric Wilcoxon rank test showed statistical difference (P < 0.0001) between pre-training and post-training. All participants improved from pre-to post- training assessment from the 5 day training with marked improvement amongst from staff with lowest previous level of laboratory training.ConclusionsTraining microbiology staff in the accurate processing of urine sample will be an important activity for a Kenyan AMR surveillance system. These training materials, if delivered by an experienced trainer, can achieve a clear improvement in knowledge levels and practical competence for real-life microbiology identifications.

A WhatsApp-based introductory histopathology and cytology course for first-year pathology postgraduate students.

Background The first-year pathology postgraduates can take a long time to learn the basic skills of microscopy, which can become a barrier to learning. Methods A WhatsApp group comprising all 14 postgraduate first-year students with one senior resident and one faculty as group administrators was formed. For the study, 50 routine cases (35 histopathology cases and 15 cytopathology cases) captured by using a smartphone camera and annotated using image-editing software, along with relevant descriptions and weblinks, were sent to the WhatsApp group. A pre- and post-test comprising 15 cases each was conducted and the results were compared by non-parametric Wilcoxon rank test. A feedback form about the effectiveness of this method of learning was circulated at the end of the study. Results The results of the post-test were better than the pre-test by the non-parametric Wilcoxon rank test. Both the active participants (>10 posts) and passive participants of the study group showed statistically significant improvement in the scores and posted a similar number of intellectually thought-provoking posts. The students' responses to the questionnaire also indicated that they liked the new method of instruction. Conclusion This pilot study shows that smartphone-based learning methods can supplant the traditional methods of teaching for pathology postgraduates.

Non-Parametric Statistic for Testing Cumulative Abnormal Stock Returns

Due to the non-normality of stock returns, nonparametric rank tests are gaining accceptance relative to parametric tests in financial economics event studies. In rank tests, financial assets’ multiple day cumulative abnormal returns (CARs) are replaced by cumulated ranks. This paper proposes modifications to the existing approaches to improve robustness to cross-sectional correlation of returns arising from calendar time overlapping event windows. Simulations show that the proposed rank test is well specified in testing CARs and is robust towards both complete and partial overlapping event windows.

Correlation of visual area with tremor improvement after MRgFUS thalamotomy in Parkinson's disease.

MRI-guided focused ultrasound (MRgFUS) thalamotomy is a novel and minimally invasive alternative for medication-refractory tremor in Parkinson's disease (PD). However, the impact of MRgFUS thalamotomy on spontaneous neuronal activity in PD remains unclear. The purpose of the current study was to evaluate the effects of MRgFUS thalamotomy on local fluctuations in neuronal activity as measured by the fractional amplitude of low-frequency fluctuations (fALFF) in patients with PD. Participants with PD undergoing MRgFUS thalamotomy were recruited. Tremor scores were assessed before and 3 and 12 months after treatment using the Clinical Rating Scale for Tremor. MRI data were collected before and 1 day, 1 week, 1 month, 3 months, and 12 months after thalamotomy. The fALFF was calculated. A whole-brain voxel-wise paired t-test was used to identify significant changes in fALFF at 12 months after treatment compared to baseline. Then fALFF in the regions with significant differences were extracted from fALFF maps of patients for further one-way repeated-measures ANOVA to investigate its dynamic alterations. The association between fALFF changes induced by thalamotomy and tremor improvement were evaluated using the nonparametric Spearman rank test. Nine participants with PD (mean age ± SD 64.7 ± 6.1 years, 8 males) were evaluated. Voxel-based analysis showed that fALFF in the left occipital cortex (Brodmann area 17 [BA17]) significantly decreased at 12 months after thalamotomy compared to baseline (voxel p < 0.001, cluster p < 0.05 family-wise error [FWE] corrected). At baseline, fALFF in the left occipital BA17 in patients was elevated compared with that in 9 age- and gender-matched healthy subjects (p < 0.05). Longitudinal analysis displayed the dynamic changes of fALFF in this region (F (5,40) = 3.61, p = 0.009). There was a significant positive correlation between the falling trend in fALFF in the left occipital BA17 and hand tremor improvement after treatment over 3 time points (Spearman's rho = 0.44, p = 0.02). The present study investigated the impact of MRgFUS ventral intermediate nucleus thalamotomy on spontaneous neural activity in medication-refractory tremor-dominant PD. The visual area is, for the first time, reported as relevant to tremor improvement in PD after MRgFUS thalamotomy, suggesting a distant effect of MRgFUS thalamotomy and the involvement of specific visuomotor networks in tremor control in PD.

Validity and reliability of global ratings of satisfaction with epilepsy surgery.

We aimed to assess the reliability and validity of single-item global ratings (GR) of satisfaction with epilepsy surgery. We recruited 240 patients from four centers in Canada and Sweden who underwent epilepsy surgery ≥1year earlier. Participants completed a validated questionnaire on satisfaction with epilepsy surgery (the ESSQ-19), plus a single-item GR of satisfaction with epilepsy surgery twice, 4-6weeks apart. They also completed validated questionnaires on quality of life, depression, health state utilities, epilepsy severity and disability, medical treatment satisfaction and social desirability. Test-retest reliability of the GR was assessed with the intra-class correlation coefficient (ICC). Construct and criterion validity were examined with polyserial correlations between the GR measure of satisfaction and validated questionnaires and with the ESSQ-19summary score. Non-parametric rank tests evaluated levels of satisfaction, and ROC analysis assessed the ability of GRs to distinguish among clinically different patient groups. Median age and time since surgery were 42years (IQR 32-54) and 5years (IQR 2-8), respectively. The GR demonstrated good to excellent test-retest reliability (ICC=0.76; 95% CI 0.67-0.84) and criterion validity (0.85; 95% CI 0.81-0.89), and moderate correlations in the expected direction with instruments assessing quality of life (0.59; 95% CI 0.51-0.63), health utilities (0.55; 95% CI 0.45-0.65), disability (-0.51; 95% CI -0.41, -0.61), depression (-0.48; 95% CI -0.38, -0.58), and epilepsy severity (-0.48; 95% CI -0.38, -0.58). As expected, correlations were lower for social desirability (0.40; 95% CI 0.28-0.52) and medical treatment satisfaction (0.33; 95% CI 0.21-0.45). The GR distinguished participants who were seizure-free (AUC 0.75; 95% CI 0.67-0.82), depressed (AUC 0.75; 95% CI 0.67-0.83), and self-rated as having more severe epilepsy (AUC 0.78; 95% CI 0.71-0.85) and being more disabled (AUC 0.82; 95% CI 0.74-0.90). The GR of epilepsy surgery satisfaction showed good measurement properties, distinguished among clinically different patient groups, and appears well-suited for use in clinical practice and research.