Statistical Link Research Articles

Pilonidal Disease Management in Young Adults: A Retrospective Analysis of Practices in a single tertiary centre in Bahrain

Abstract Background Pilonidal disease is a prevalent skin condition that predominantly affects young males. This study, conducted at Salmaniya Medical Complex in Bahrain, aimed to analyze the demographics, treatment methodologies, and complications associated with pilonidal disease. Materials and Methods We analyzed the medical records of 56 patients, comparing our practices to the American Society of Colon and Rectal Surgeons (ASCRS) guidelines. Variables collected included patient demographics (age and gender), details on preoperative and postoperative antibiotics, the type of surgical intervention performed, the closure technique used, and follow-up results at 2 months post-discharge, Results Our findings confirmed the high prevalence of the disease in young males (75%), with a median age at presentation being 20.5 years. Our practices showed minimal compliance (≤69%) to key recommendations. We found no documented practices for hair removal, phenol application, fibrin glue, or minimally invasive approaches. The most common surgical approach was primary closure (60%), followed by flap reconstruction (16%) and leaving wounds open (7%). The commonest complications were wound dehiscence and surgical site infection (27% each). Post-operative complications were significant, with 67.6% in patients who received pre- operative antibiotics and 63.6% in those who received post-operative antibiotics. However, no statistical link to closure type was found, likely due to our small sample size. Conclusion We recommend reassessing our management protocols to align with ASCRS guidelines and considering non-operative treatments to reduce morbidity. This study underscores the need for guideline adherence and the potential benefits of non-operative treatments in managing pilonidal disease.

Structural corporate ownership links to corporate cash and financial earnings: New evidence from non-financial firms

Institutional and executive shares account for the majority of ownership and have a considerable impact on the firm’s future financing, investment, earnings, and other corporate decision-making activities. This study aims to investigate the statistical links of institutional ownership and executive ownership on financial earnings and the corporate cash level of non-financial firms using a balanced dataset of 200 non-financial listed firms in PSX (Pakistan Stock Exchange) during the period 2013 to 2018. Among many advanced econometric methods, fixed effect models with pooled ordinary least square (OLS) estimation were found more appropriate to our investigation. Our main findings are twofold. The outcome of our analysis indicates that institutional ownership and executive ownership are significantly related to financial earnings. Further, our results suggest that there is a significant relationship between executive ownership and corporate cash level, as well as a positive and significant relationship between institutional ownership and finance. The cash level of firms can only be identified and predicted through executive ownership in a developing economy like Pakistan. This study provides insightful information for non-financial industry shareholders and policymakers in Pakistan.

Service Delivery In Insurance Companies: Does Cultural Alignment Matter?

Background: In the last decade, Kenyan insurance companies have faced increased competition, changing consumer needs, and globalization which have potential adverse effects on service delivery. Despite the various initiatives that have been undertaken to resolve such challenges, there is evidence of delays in the processing of insurance claims, low claims settlement ratio and policy processing time. Therefore, this research focused was examining how cultural alignment impact service delivery within the Nairobi City County insurance industry in Kenya. It was anchored on, theory of dynamic capabilities, and service delivery dynamic theory. Employing a descriptive research design, the study encompassed 56 insurance companies, with a target population of 203 functional heads in finance, marketing, human resources, and customer service across these firms. Materials and Methods: Slovin's formula was employed to help determine the appropriate sample size while a combination of simple random and stratified random sampling were utilized in drawing the respondents. For gathering of data, structured questionnaire was deployed for both the piloting and actual undertaking of the research. The piloting was conducted in Britam Insurance Company with a sample size of 10%. The research instruments yielded both quantitative and qualitative data that was then analyzed appropriately for a comprehensive exploration of the possible statistical links among the variables. Descriptive results were then presented through frequency distributions, means, percentages, standard deviations and means. Deeper analyses involving inferential tests like the regressions tests were then performed to examine the presence or absence of statistical associations among the variables. Findings were summarized in bar charts, tables and pie charts. Results: The study found that cultural alignment was established to positively influence delivery of services among the insurance companies. Conclusion: The study therefore made recommendations on the need to conduct regular training sessions to ensure clarity and transparency in decision-making, fostering a collaborative culture that empowers employees at all levels. In addition, leaders should actively model desired behaviors and traits, creating a role model effect that encourages employees to embody these values

Cluster of Differentiation Markers and Human Leukocyte Antigen Expression in Chronic Lymphocytic Leukemia Patients: Correlations and Clinical Relevance.

Chronic lymphocytic leukemia (CLL) is a distinct category of lymphoproliferative disorder characterized by the clonal expansion of mature B cells, followed by their accumulation in primary and secondary lymphoid organs. Cluster of differentiation (CD) markers such as CD79b, CD45, CD23, CD22 and CD81 serve as reliable prognostic indicators in CLL as well as the human leukocyte antigen (HLA) with its well-documented associations with various cancers. This study aims to investigate, for the first time, potential connections between HLA typing and CD marker expression in CLL. Although it is one of the most prevalent neoplasms, there is a need for biomarkers that can improve survival. This study included 66 CLL patients and 100 controls, with all samples analyzed using biochemical methods, flow cytometry, and cytomorphology. Next-generation sequencing was performed for HLA typing. The results indicate that several CD markers are statistically associated with different HLA alleles, specifically CD45 with HLA-C*07:01:01; CD79b with HLA-DPA1*02:01:02; CD23 with HLA-B*39:01:01; CD22 with HLA-B*49:01:01, HLA-C*07:01:01, HLA-DPB1*02:01:02, and HLA-DRB1*07:01:01; and CD81 with HLA-DPB1*04:02:01, HLA-DQA1*01:04:01, and HLA-DQB1*05:03:01. In conclusion, this research demonstrates significant statistical links between HLA genes and immunophenotypic markers in CLL patients, shedding new light on the immunological context of CLL.

Physical and Statistical Links between Errors at the Surface, in the Boundary Layer, and in the Free Atmosphere in Medium-Range Numerical Weather Predictions

Physical and Statistical Links between Errors at the Surface, in the Boundary Layer, and in the Free Atmosphere in Medium-Range Numerical Weather Predictions

Psychological capital and well-being: An opportunity for teachers' well-being? Scoping review of the scientific literature in psychology and educational sciences

In a context marked by teachers' shortage, prioritizing teachers' well-being emerges as one of the factors that can encourage them to stay in the profession. Well-being is a multidimensional concept and difficult to define and measure. Moreover, its link with Psychological Capital (PsyCap), a concept that includes personal psychological resources (hope, self-efficacy, resilience, and optimism) (Luthans & Youssef, 2004), has received little attention in the educational sciences. The main objective of this paper is therefore to investigate the links between these two concepts from a theoretical point of view in psychology and educational sciences. For this purpose, the scoping review methodology (Tricco et al., 2018) is mobilized to identify research issues, methodological questions, and the various links between well-being and PsyCap. Based on a systematic review of 376 bibliographic references conducted in the main databases in psychology and educational sciences, 32 articles were selected analysed. The data extracted indicate that these concepts particularly affect teachers (42.11 % of subjects concerned, N = 42,750). In addition, all the sources selected report significant and positive statistical links between well-being and PsyCap. These results suggest possible avenues for research on teachers' well-being.

Reynolds number effects in shock-wave/turbulent boundary-layer interactions

We investigate Reynolds number effects in strong shock-wave/turbulent boundary-layer interactions (STBLI) by leveraging a new database of wall-resolved and long-integrated large-eddy simulations. The database encompasses STBLI with massive boundary-layer separation at Mach $2.0$ , impinging-shock angle $40^{\circ }$ and friction Reynolds numbers ${\textit {Re}}_\tau$ $355$ , $1226$ and $5118$ . Our analysis shows that the shape of the reverse-flow bubble is notably different at low and high Reynolds number, while the mean-flow separation length, separation-shock angle and incipient plateau pressure are rather insensitive to Reynolds number variations. Velocity statistics reveal a shift in the peak location of the streamwise Reynolds stress from the separation-shock foot to the core of the detached shear layer at high Reynolds number, which we attribute to increased pressure transport in the separation-shock excursion domain. Additionally, in the high Reynolds case, the separation shock originates deep within the turbulent boundary, resulting in intensified wall-pressure fluctuations and spanwise variations associated with the passage of coherent velocity structures. Temporal spectra of various signals show energetic low-frequency content in all cases, along with a distinct peak in the bubble-volume spectra at a separation-length-based Strouhal number $St_{L_{sep}}\approx 0.1$ . The separation shock is also found to lag behind bubble-volume variations, consistent with the acoustic propagation time from reattachment to separation and a downstream mechanism driving the shock motion. Finally, dynamic mode decomposition of three-dimensional fields suggests a Reynolds-independent statistical link among separation-shock excursions, velocity streaks and large-scale vortices at low frequencies.

Mutations and mortality in very young patients with breast cancer.

e13157 Background: Breast cancer diagnoses in young women have increased over the last 10 years. Despite decreasing mortality rates for breast cancer, disparities continue to exist for specific populations including Black women and premenopausal women. Recent studies observe a 41% increased death rate in Black women compared to White women, and a two-fold increased mortality in women younger than 50 years. Many biological and societal factors can affect breast cancer mortality. We sought to evaluate the relationship between germline mutations (GM), breast cancer subtype, and mortality based on race in a unique, young breast cancer patient population. Methods: We assembled a 10-year retrospective chart review (2012 to 2022) of 773 women diagnosed with breast cancer under the age of 40 in a regional health network. Data was collected from electronic medical records. Associations were assessed using the chi-square test using SAS version 9.4. Results: Out of the 773 patient information collected, 60% of patients were White, 36% Black, and 3% Other. A total of 675 patients had genetic results and 124 patients with documented GM. Of patients with GM, 48 were Black and 74 were White. 13 patients with germline mutations had documented deaths. There was no statistical link between germline mutations and mortality. Of the 13 patients, 4 (30%) were Black and 9 (70%) were White. There was no statistical difference amongst area deprivation index (ADI) quintiles for mortality in patients with GM. Of the 675 patients with genetics data, 72 patients without GM died which includes 31 Black patients, 38 White patients, 3 Other. Based on our data, there is a higher prevalence of germline mutations (60%) in White patients over Black patients and a descriptive predominance of mortality despite absence of statistical significance. More patients who resided in areas of higher ADI (2-4) with GM died than in areas of lower ADI. Conclusions: Our data demonstrates a descriptive prevalence in mortality among young White patients compared to young Black patients. Across the USA, the Black population is 13% and in Louisiana, that population is 33%. Given that our cohort population was 36% Black, it is noteworthy that we were unable to demonstrate a statistical mortality predominance among these young patients. [Table: see text]

SOCIO-PHYSIOLOGICAL FACTORS OF FORMING COMMUNICATIVE TOLERANCE AMONG UNIVERSITY LECTURERS IN THE EDUCATIONAL ENVIRONMENT

By analyzing the impact of social psychological factors, the article delves into how university lecturers cultivate communicative tolerance throughout their professional development. Purpose of the study. The study aims to identify the specific socio-psychological factors that have shaped the communicative tolerance of university lecturers. Materials and methods of research. Utilizing theoretical approaches, the research involved an in-depth analysis of fundamental concepts within psychological and philosophical frameworks. Additionally, the study employed various mathematical statistical methods, such as correlation, factor, and cluster analyses, to explore the complex interplay of factors influencing communicative tolerance. In the study, various diagnostic tools were utilized as well, i.e. the Tolerance Index express questionnaire (by G.U. Soldatova, O.A. Kravtsova, O.E. Khukhlaev, L.A. Shaigerova), the Communicative Tolerance Questionnaire (by V.V. Boyko), Methodology for the evaluation of the level of empathic abilities (by V.V. Boyko), the Sixteen Personality-factor questionnaire (16 PF) (by R. Cattell), Methodology for the Diagnosis of interpersonal relationships (DME) (by T. Leary). Research results. The findings of the research provide a theoretical analysis of communicative tolerance development, shedding light on its significance and role within the professional realm of lecturers. The insufficient development of critical thinking among university lecturers has been validated through empirical data analysis, highlighting the impact of various internal and external social psychological factors on their communicative tolerance. Factors such as empathy, emotional maturity, emotional-volitional qualities, communicative qualities, positive communicative attitude, social maturity, and professional maturity play a significant role in shaping the level of communicative tolerance exhibited by university lecturers. Additionally, a strong statistical correlation was identified in the study, emphasizing the need for further research in this area. The study found a strong statistical link (ρ<0.01) between positive communication attitude and communication tolerance, despite the absence of a statistically significant correlation between empathic abilities and communication tolerance. Research findings indicated that teachers who demonstrated moderate levels of empathy also displayed the greatest communication tolerance. Additionally, significant connections were uncovered between communication tolerance and various characteristics, such as emotional-volitional traits like “emotional stability” (ρ<0). Practical implications. The obtained results of the study could be used in additional vocational training, job placement and job training schemes in order to improve the professional competence of teaching staff.

PD-L1 expression in tumor and inflammatory cells is associated with favorable tumor features and favorable prognosis in muscle-invasive urothelial carcinoma of the bladder not treated by immune checkpoint inhibitors

BackgroundA high level of PD-L1 expression is the most relevant predictive parameter for response to immune checkpoint inhibitor (CPI) therapy in urinary bladder cancer. Existing data on the relationship between PD-L1 expression and the natural course of disease are controversial and sparse.MethodsTo expand our understanding of the relationship between PD-L1 expression and parameters of cancer aggressiveness, PD-L1 was analyzed on tissue microarrays containing 2710 urothelial bladder carcinomas including 512 patients with follow-up data who underwent radical cystectomy and follow-up therapies in the pre-immune checkpoint inhibitor therapy era.ResultsTumor cell positivity in ≥10% of cells were seen in 513 (20%) and an immune cell positivity occurred in 872 (34%) of 2566 interpretable cancers. PD-L1 positivity in tumor cells increased from pTaG2 low grade (0.9% positive) to pTaG3 high grade (4.1%; p = 0.0255) and was even higher in muscle-invasive (pT2–4) carcinomas (29.3%; p < 0.0001). However, within pT2–4 carcinomas, PD-L1 positivity was linked to low pT stage (p = 0.0028), pN0 (p < 0.0001), L0 status (p = 0.0005), and a better prognosis within 512 patients with cystectomy who never received CPIs (p = 0.0073 for tumor cells and p = 0.0086 for inflammatory cells). PD-L1 staining in inflammatory cells was significantly linked to PD-L1 staining in tumor cells (p < 0.0001) and both were linked to a positive p53 immunostaining (p < 0.0001).ConclusionIt cannot be fully excluded that the strong statistical link between PD-L1 status and favorable histological tumor features as well as better prognosis could influence the outcome of studies evaluating CPIs in muscle-invasive urothelial carcinoma.

Exploring Two Years of Stunting Trends: Insights from Tidore Kepulauan

Stunting, as a complex issue, demands a serious and comprehensive approach. Accelerating efforts to reduce stunting is imperative and requires collaboration from all stakeholders, including the Tidore government, private sector, community, and families. Furthermore, addressing this issue necessitates extensive longitudinal research to investigate its prevalence and influencing factors. To tackle this, a crucial study is essential to unveil the prevalence trends of stunting from 2022 to 2023, covering the last two years in the Tidore Kepulauan. The primary goal of this research is to provide a comprehensive overview of stunting trends in Tidore through long-term analysis, exploring prevalence fluctuations. Employing a descriptive statistical approach, this study relies on numerical data as its primary foundation, focusing on in-depth descriptive analysis of stunting prevalence trends in the Tidore Kepulauan over the last two years. Data from the Directorate General of Regional Development's website reveals significant variations among villages in 2022. Villages like Gurabati (1.2%), Toloa (2.1%), and Maregam (3.8%) exhibit low rates, whereas Topo (45.5%), Topo Tiga (23.1%), and Maitara Tengah (20.6%) have high rates. Specific efforts are needed in high-prevalence villages to improve child nutrition and overall community well-being. The 2023 prevalence data shows significant variations among villages, with some areas displaying alarmingly high rates. Descriptive statistical analysis links stunting in the Tidore Kepulauan to several key factors. Malnutrition (32.4%), inadequate nutritional intake, and prenatal malnutrition (28.2%) are major contributors. Genetic factors (16.2%), poor hygiene (4.8%), and viral/bacterial infections (4.1%) also play roles. Lower economic levels and other factors contribute in smaller proportions (2.8% and 3.0% respectively). Although 8.5% of respondents are unaware of the causes, this analysis provides a comprehensive overview of factors that need attention to combat stunting in the Tidore Kepulauan.

European summer weather linked to North Atlantic freshwater anomalies in preceding years

Abstract. Amplified Arctic ice loss in recent decades has been linked to the increased occurrence of extreme mid-latitude weather. The underlying mechanisms remain elusive, however. One potential link occurs through the ocean as the loss of sea ice and glacial ice leads to increased freshwater fluxes into the ocean. Thus, in this study, we examine the link between North Atlantic freshwater anomalies and European summer weather. Combining a comprehensive set of observational products, we show that stronger freshwater anomalies are associated with a sharper sea surface temperature front between the subpolar and the subtropical North Atlantic in winter, an increased atmospheric instability above the sea surface temperature front, and a large-scale atmospheric circulation that induces a northward shift in the North Atlantic Current, strengthening the sea surface temperature front. In the following summer, the lower-tropospheric winds are deflected northward along the enhanced sea surface temperature front and the European coastline, forming part of a large-scale atmospheric circulation anomaly that is associated with warmer and drier weather over Europe. The identified statistical links are significant on timescales from years to decades and indicate an enhanced predictability of European summer weather at least a winter in advance, with the exact regions and amplitudes of the warm and dry weather anomalies over Europe being sensitive to the location, strength, and extent of North Atlantic freshwater anomalies in the preceding winter.

Determinants of Supply Chain Performance in the Energy Sector in Kenya: A Case Study of the Kenya Power.

The current supply chain management in Kenya energy sector is deficient of an acceptable SCM performance level due to the inability to connect every willing buyer, and the cost of rural electrification by grid development due to dispersion as is expected in the service charter. The general objective of the study was to establish the determinants of supply chain performance in the energy sector in Kenya with an inclination to KPLC. The specific objectives of the study were to; determine the effect of information communication technology on supply chain performance of KPLC; examine the effect of buyer-supplier relationship on supply chain performance of KPLC; determine the effect of procurement professionalism on supply chain performance of KPLC and establish the effect of contract management on performance of KPLC. The study employed a descriptive research design. The researcher used stratified random sampling technique. The study population was 698 employees working in KPLC from which 254 respondents were selected. Questionnaires were used as the main data collection instrument and a pilot study was undertaken to pretest the questionnaires for validity and reliability. For the purpose of analyzing the data that was gathered, and the Statistical Package for Social Sciences Version 24 was utilized in analysis. In order to establish the statistical link between the independent factors and the predicted variable, the study made utilization of the regression model. Descriptive statistics were computed whereby frequencies, percentages and means were clearly shown in the form of both tables and figures. The study revealed that a unit increase in the elements of information communication technology, procurement professionalism, buyer-supplier relationship and contract management will translate to improvement of supply chain performance in KPLC. the study recommends that KPLC and other firms in the energy sector should exploit the aforementioned determinants in a hierarchical order. This would enable KPLC and other firms in the energy sector to focus on the determinants with the most positive significant effect on supply chain performance and prioritize resources allocation and deployment appropriately. The study recommends this order, buyer-supplier relationships, followed by contract management while information communication technology and procurement professionalism should be exploited concurrently.

Chronic leg ulcers in Senegal: Epidemiological and etiological study on 154 cases

Background: Our aim was to establish the epidemiological and etiological profile of chronic leg ulcers (CLUs) in Senegal. Methodology: We conducted a retrospective, descriptive, analytical study at the Dermatology Department of Aristide Le Dantec University Hospital Center (HALD) in Dakar from January 2008 to January 2018 (10 years). Data was entered in Excel and analyzed with Epi Info 7. Results: We recorded 154 cases. The sex ratio was 1.75. The main causes were vascular in 69 cases (44.8%), infectious in 29 (18.8%), and sickle cell disease in 15 (9.7%). Etiology has not been identified in 23 patients (15.1%). Vascular origin was venous in 64 cases (92% of vascular causes) without any statistical link with sex (p = 0.408), arterial in 3 (4%), and mixed in 2 (3%). Conclusion: In Senegal, LCUs are predominantly observed in young males. Causes are dominated by venous insufficiency, followed by infection. Key words: Chronic leg ulcer, Venous insufficiency, Senegal

Non-Linear Association of Serum Sex Hormone Binding Globulin Concentration with Female Infertility.

Accumulating proofs suggested that disturbance of serum sex hormone-binding globulin (SHBG) concentration can affect the reproductive system. However, the effect of serum SHBG on female infertility remains to be clarified. Data from 1,787 adults from the National Health and Nutrition Examination Survey (NHANES) was applied to examine the correlation between serum SHBG and female infertility. Multivariate logistic regression was used to evaluate the independent association between serum SHBG and female infertility. Furthermore, generalized additive model (GAM) and two-piecewise linear regression model were applied to assess the underlying non-linear association in our participants. We observed a reverse association between serum SHBG and infertility based on a fully-adjusted model (OR = 0.99, 95% CI: 0.99-1, p = 0.002), and the results were stable in several sensitive analyses. Furthermore, we detected a non-linear link by GAM and two-piecewise linear regression model. A protective association was observed at < 58.84 nmol/L serum SHGB; in contrast, no statistical link was found at > 58.84 nmol/L serum SHGB. Our results provide evidence for a non-linear association with serum SHBG and female infertility. This finding needs to be further confirmed in future large-scale prospective cohort studies.

Impact of debt structure on profitability of non-financial listed joint stock firms

The relationship between debt structure and profitability has drawn the attention by many researchers. One of the earliest papers which can be mentioned is the study by Modigliani and Miller (1958). In order to contribute to the literature and practical evidence to this topic, our paper investigates the impact of debt structure on the profitability of Vietnam non-financial listed joint stock companies (JSCs). By using the panel data of an eight year period for 976 JSCs, from 2013 to 2020, we get a sample of 7,808 observations. Return on assets (ROA) and return on equity (ROE) are dependent variables and are considered as profitability measures. Stata 16 software is used to test the link between profitability and the other six independent variables. The result shows that short-term debt (STDA) and growth opportunities (GRTH) have their positive and significant statistical impact on both ROA and ROE. Meanwhile, total debt (TDA) and long-term debt (LTDA) have their opposite influences. Firm size (SIZ) has different significant statistical effects on these dependent variables and net sales growth (SG) has an insignificant statistical link on profitability. Based on the findings, some recommendations are proposed to increase their profitability by optimizing debt structure in the listed firms in an emerging country and Vietnam as the case study.

The Relationship Between Self-Esteem and Self-Presentation Strategies and the Construction of a Network Self-Image by Users of Social Networks

The article is devoted to an empirical analysis of the relationship between self-esteem and strategies for self-presentation and the construction of a network Self-image of users of social networks. In the definition and study of self-esteem, differences were taken into account not only in the level of self-esteem as such, but also in its various types, determined by a different combination of two dimensions of self-esteem: self-disposition (self-worth) and competence. To measure self-esteem, methods were used – the Rosenberg Self-esteem Scale (RSES), the Tafarodi and Swan scale (SLCS). The Online Self Presentation Scale (POSS) developed by K. Fullwood, B.M. James and C.H. Chen-Wilson was used to identify strategies for self-presentation in social networks and to construct a network Self-image. The conducted analysis showed the absence of significant statistical links between the level of self-esteem, both global and by individual components, and indicators of the intensity of use of social networks. The results of comparing the level of self-esteem among users with a different network role, that is, a predominant level of activity in online communications, turned out to be more definite. The interrelationships between the level and type of self-esteem, on the one hand, and strategies of self-presentation and the construction of a network self-image, on the other hand, are revealed. It has been proven that users with low self-esteem significantly distort their Self-image when communicating on social networks, tend to idealize their Self-image and show a desire to adjust their image to the expectations of a specific network audience. People with high self-esteem demonstrate more conservative models of online communication, are not inclined to self-promotion and idealization of the Self-image, as well as to the divergence of Self-images in various networks and communities.

The Relationship of ABO and Rh Blood Group Types With Severe COVID-19 Disease Mortality in ICU Patients: Insights From a Single-Center Experience in Southern Saudi Arabia.

Introduction The global COVID-19 pandemic has triggered an unprecedented public health crisis, emphasizing the need to understand factors influencing disease outcomes. This study explores the role of genetic variations in blood group antigens, particularly ABO and RhD, in shaping mortality rates among critically ill COVID-19 patients in the southern region of Saudi Arabia. Methods Utilizing a retrospective, noninterventional approach, we analyzed medical records of 594 COVID-19 patients admitted to the intensive care unit (ICU) at Aseer Central Hospital from August 2020 to April 2021. The cohort, with a mean age of 60.5 years, consisted of a predominantly male population. Results The study encompassed a diverse age range of 18 to 103 years, with a mean age of 60.5 ± 17.3 years. Of the 594 patients, 398 (67%) were male, and only 5 (0.8%) had a history of smoking. Blood group distribution revealed 275 (48.4%) with O-, 189 (33.3%) with A+, and 51 (9%) with AB- types. Predominant chronic conditions included diabetes mellitus (35.5%). Tragically, 320 patients (54.6%) experienced mortality, with a 100% mortality rate for the B+ blood group and 92.9% for O- blood group. Conclusion This analysis establishes significant statistical links, underscoring the pivotal role of blood type, particularly the Rh factor, in influencing mortality risk among critically ill COVID-19 patients. These findings contribute valuable insights into risk stratification and personalized care for severe cases, emphasizing the importance of genetic considerations in understanding disease outcomes.

Contest Schemes and Dynamic Incentive Provision

Simple contest schemes, which tend to use extreme contemporaneous peer benchmarking, are generally thought to be less efficient at motivating productive and cooperative effort than explicit bonus contracts that optimally weight observed own and peer outputs. We show, however, that contest schemes can outperform explicit bonus contracts in a two-period dynamic setting if periodic output is correlated over time, and contract terms can be renegotiated. In our model, all parties update their beliefs about ex ante unknown time-invariant noise upon observing first-period outputs, and second-period wage offers are updated accordingly. This creates first-period shirking incentives for the agents. We show that relative to bonus contracts, the extreme contemporaneous peer benchmarking in contest schemes can weaken or even eliminate the adverse incentives created by prior-period benchmarking, even though the available information and the learning process are the same under both schemes. This dynamic advantage allows contest schemes to outperform repeated bonus contracts for a wide range of parameter values, despite imposing higher static efficiency losses in each period. If competing agents are assigned to sufficiently similar tasks, a contest scheme’s ability to sever the statistical link between periods can yield not only higher early productive effort compared with bonus contracts, but also less uncooperative behavior, despite putting the agents in a more contest-like situation. This paper was accepted by Brian Bushee, accounting. Supplemental Material: The online appendices are available at https://doi.org/10.1287/mnsc.2022.00035 .

Modulation of North Atlantic extratropical cyclones and extreme weather in Europe during North American cold spells

Recent research has established a statistical link between North American cold spells (CS) and concurrent wet or windy extremes in Europe. Here, we investigate whether such a link can be related to changes in the characteristics of North Atlantic extratropical cyclones (hereafter cyclones). Despite large regions of anomalous baroclinicity during periods of North American CS, the number of cyclones across the North Atlantic as a whole is not significantly above climatology. However, we observe rates of explosive cyclogenesis significantly above climatology. We further find that CS over different North American regions are associated with large-scale atmospheric configurations displaying a strenghtened jet stream in the vicinity of the CS and different upper-level wind anomalies in the East Atlantic. These, in turn, modulate the regional distributions and characteristics of cyclones in the North Atlantic and Europe. We compute a fixed-radius cyclone footprint which we use to associate extreme precipitation and wind occurrences to individual cyclones. For eastern Canada CS, the North Atlantic jet extends over Northern Europe, resulting in a heightened numbers of cyclones for the British Isles and Scandinavia, while France, the British Isles, Northern Europe and Scandinavia all experience more intense cyclones. The British Isles consistently experience wind extremes associated with cyclones during east Canada CS. For central Canada CS, the jet is displaced poleward and only partly extends over Europe, resulting in an above average cyclone density in the eastern Atlantic and a higher number of cyclones affecting Iberia only. Iberia consistently experiences precipitation extremes associated with the cyclones during central Canada CS. For eastern United States CS, the jet is displaced equatorward and extends over Southern Europe, with a significantly heightened number of cyclones affecting Iberia and France. Iberia experiences wind extremes associated with the cyclones during eastern United States CS. Our results provide a dynamical explanation for previous statistical findings on the concurrence of North American CS and wet or windy extremes over Europe.