Market access restrictions have been the focus of attention for various market players, but there are fewer studies on the competitive mechanism of market access restrictions on firms\' product sales. This paper investigates the competitive mechanism of leader-follower product sales based on market access restrictions and forward contracts. First, the mechanism of leader-follower sales decisions based on market access restrictions and forward contracts is clarified. Second, it models the forward default risk suffered by followers and the profit rate of leader-follower based on market access restrictions and forward considerations by Bayes\' posterior probability method. Moreover, it severely explores the impact mechanisms of the degree of market access restrictions on leaders and followers when followers do not adopt and adopt forwards and makes a simulation analysis. The results show that: (i) When followers do not employ forward contracts, the less restrictive degree of market access increases the supply of leaders, and leaders\' competition for product sales further leads to a decrease in the provision of followers. (ii) When followers use forwards, leaders\' and followers\' expected discounted profit rates decrease with the total supply of products in the market increases. (iii) If the degree of market access restrictions is low, the followers suffer an increased forward default risk, resulting in their rate of revenue decrease. The findings of this paper have some practical significance and policy implications for the regulator to adjust the degree of market access restriction in each restricted access area, to establish a reasonable and efficient competitive environment for product sales, as well as for firms to choose the optimal way of competing for product sales.

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BACKGROUND: The recommendations for the use of and selection of covered stent grafts in patients with aortoiliac occlusive disease are limited.
OBJECTIVE: The GORE VBX FORWARD clinical study aims to demonstrate the superiority of the GORE VIABAHN VBX Balloon Expandable Endoprosthesis (VBX device) for primary patency when compared to bare metal stenting (BMS) for the treatment of complex iliac artery occlusive disease.
METHODS: A prospective, multicenter, randomized control study in the United States, European Union, United Kingdom, Australia, and New Zealand will enroll patients with symptomatic, complex iliac artery occlusive disease. In this study, iliac artery occlusive disease is defined as a unilateral or bilateral disease with single or multiple lesions (with >50% stenosis or chronic total occlusion) each between 4 and 11 cm in length. In an attempt to more closely match real-world practices, patients with minor tissue loss (Rutherford class 5) and patients requiring hemodialysis will be included. Baseline aortoiliac angiography will be performed to assess target lesion characteristics and determine final patient eligibility. Once the patient is confirmed and guidewires are in place across the target lesions, the patient will be randomized in a 1:1 format to treatment with either the VBX device or a BMS. The BMS can be balloon- or self-expanding and must be approved for the iliac artery occlusive disease indication. Patients, the independent core laboratory reviewers, and Clinical Events Committee members will be blinded from the assigned treatment. Dual antithrombotic medical therapy is required through a minimum of 3 months post procedure. The primary end point is 12‑month primary patency and will be adjudicated by an independent imaging core laboratory and Clinical Events Committee. Key secondary end points will be tested for superiority and include technical, acute procedural, and clinical success; changes in Ankle-brachial index; patient quality of life; primary patency; freedom from restenosis; primary-assisted patency; secondary patency; freedom from target lesion revascularizations; cumulative reintervention rate; amputation-free survival; survival; and change in Rutherford category. Study follow-up will continue through 5 years.
RESULTS: Outcomes will be reported following study completion. Enrollment is anticipated to start in October 2023.
CONCLUSIONS: The results of this study will provide definitive, level 1 clinical evidence to clinicians on the optimal choice of stent device to use for the treatment of complex iliac artery occlusive disease. The FORWARD study is powered for superiority and includes only complex, unilateral, or bilateral lesions involving the common or external iliac arteries. This study is a multidisciplinary endeavor involving vascular surgery, interventional cardiology, and interventional radiology across multiple countries with a blinded core laboratory review of end points in hopes that the outcomes will be widely accepted and incorporated into practice guidelines for optimal treatment of patients with complex iliac artery occlusive disease.
BACKGROUND: ClinicalTrials.gov NCT05811364; https://clinicaltrials.gov/study/NCT05811364.
UNASSIGNED: PRR1-10.2196/51480.

Previous studies have reported that Black children with food allergy (FA) have higher risk of atopic comorbidities than White children.
Our study sought to understand if disparities in the prevalence of atopic comorbidities among children with FA are driven by individual and community-level socioeconomic status (SES).
We analyzed data from a prospective, multicenter cohort investigating the natural history of pediatric atopy: the Food Allergy Outcomes Related to White and African American Racial Differences (FORWARD) study. A validated, multicomponent area deprivation index (ADI) percentile score was tabulated by the census block group for each subject\'s home address. The association of ADI with atopic comorbidities in FA was assessed via multivariable regression analysis.
Of the 700 children in this study, the mean ADI was 37.7 (95% confidence interval: 35.6-39.7). The mean ADI was higher in children with asthma (43.3) compared with those without asthma (31.8), which remained significant after adjusting for race (P < .0001). Children with allergic rhinitis (AR) had a higher mean ADI (39.1) compared with those without (33.4) (P = .008). ADI was associated with secondhand smoking, parents\' education, and household income. Black children had a higher risk for asthma after adjusting for ADI and SES-related factors.
The independent association of ADI with asthma and AR, regardless of race, suggests a role of neighborhood-level socioeconomic deprivation in the development of these conditions among children with FA. Black children with FA remained at higher risk for asthma after adjusting for SES-related variables, which can indicate an independent risk for asthma in these children.

Rugby is a popular sport requiring high-intensity and maximal speed actions. Numerous studies have demonstrated that physical performance variables, such as strength, sprinting, and jumping, are different between the forwards and backs. However, there is little information about muscle morphological characteristics specific for each rugby playing position. This study aimed to clarify the morphological characteristics of the thigh muscles in forwards and backs. Ultrasound images were obtained from the proximal, middle, and distal regions of the thigh. Then, the anatomical cross-sectional areas of particular muscles in the hamstrings and quadriceps femoris were calculated for seven forwards, seven backs, and ten non-athletes. The anatomical cross-sectional areas were normalised by the two-third power of lean body mass, and the normalised values of the three regions were averaged as that of the individual muscle. In the hamstrings, the normalised anatomical cross-sectional areas of the biceps femoris long head were significantly greater in forwards than in non-athletes, whereas those of the semitendinosus were significantly greater in backs than in non-athletes. Furthermore, in the quadriceps femoris, the normalised anatomical cross-sectional areas of the rectus femoris and vastus intermedius were significantly greater in forwards than in backs and non-athletes. These results suggest that forwards have great muscularity of the biceps femoris long head and vastus intermedius which can generate large force, whereas backs possess great muscularity of the semitendinosus which can generate high contraction velocity. These findings allow coaches to design more effective training programs according to particular rugby playing positions.

There is a higher rate of falls in the first year after a stroke, and the ability to step in different directions is essential for avoiding a fall and navigating small spaces where falls commonly occur. The lateral transfer of weight is important for stabilizing the body before initiating a step. Hence, understanding the ability to control lateral weight transfer (WT) in different step directions might help understand falls in individuals with stroke. The present study aimed to compare the WT characteristics (onset time, duration, mediolateral center of pressure (ML COP) velocity, and ML COP displacement) and hip abduction torque preceding a lateral and forward voluntary step between individuals with stroke (paretic and non-paretic leg) and controls. Twenty individuals with stroke and ten controls performed voluntary choice reaction tests in the lateral and forward directions. Ten trials (five on each side-right and left) were performed for each step direction. The overall primary findings were that (1) the WT before a lateral step was shorter and initiated earlier, with a larger ML COP displacement and greater hip abductor torque in the stepping leg than the forward step, (2) there was greater hip abductor produced in the stance leg before a forward step than a lateral step, (3) the WT before the lateral step took longer to initiate and was slower to execute in individuals with stroke regardless of the leg (4) the WT before the forward step had more differences in the paretic than the non-paretic leg. Thus, for the first time, it was shown that the WT characteristics and hip abduction torque during the WT are different according to step direction and also appear to be impaired in individuals with stroke. These results have implications for understanding the direction that individuals with stroke are more susceptible to being unable to recover balance and are at risk of falling.

Geophysical inversion is often ill-posed because of its nonlinearity and the ordinary measured data of measured data. To deal with these problems, an artificial neural network (ANN) has been introduced with the capability of a nonlinear and complex problem for geophysical inversion. This study aims to invert 2D cross-hole electrical resistivity tomography data using a feedforward back-propagation neural network (FBNN) approach. To generate the synthetic data to train the model, eighteen forward models (100 to 600 Ω.m homogeneous medium and three different locations of 10 Ω.m of the grouted bulb) with a dipole-dipole array configuration were adopted. The effect of the hyperparameter on the performance of the proposed FBNN model was examined. Various datasets from the laboratory testing result were also tested using the suggested FBNN model and then the error between the actual and predicted area in each model was determined. The results show that our suggested FBNN model, with the trainrp training function, 4 hidden layers, 75 neurons in each hidden layer, 0.8 learning rate, 1 of momentum coefficient, and 54,000 training data points, has higher performance and better accuracy than other models. It was found that the error value of the FBNN model was about 15% to 18% lower compared to the conventional inversion model.

This study investigated the hierarchical structure of physical characteristics in elite young (i.e., U17-U19) basketball players according to playing positions. In addition, their predictive value of physical characteristics was determined for the evaluation of players\' physical preparedness. Sixty elite male basketball players performed 13 standardized specific field tests in order to assess the explosive power of lower limbs, speed, and change-of-direction speed. They were divided into three groups according to playing positions (guard [n = 28], forward [n = 22], center [n = 10]). The basic characteristics of the tested sample were: age = 17.36 ± 1.04 years, body height = 192.80 ± 4.49 cm, body mass = 79.83 ± 6.94 kg, and basketball experience = 9.38 ± 2.10 years for guards; age = 18.00 ± 1.00 years, body height = 201.48 ± 3.14 cm, body mass = 90.93 ± 9.85 kg, and basketball experience = 9.93 ± 2.28 years for forwards; and age = 17.60 ± 1.43 years; body height = 207.20 ± 3.29 cm, body mass = 104.00 ± 9.64 kg, and basketball experience = 9.20 ± 1.62 years for centers. For all playing positions factor analysis extracted three factors, which cumulatively explained 76.87, 88.12 and 87.63% of variance, respectively. The assessed performance measures were defined as significant (p < 0.001), with regression models of physical performance index (PPINDEX). PPINDEX of guards = -6.860 + (0.932 × t-test) - (1.656 × Acceleration 15 m) - (0.020 × Countermovement jump); PPINDEX of forwards = -3.436 - (0.046 × Countermovement jump with arm swing) - (1.295 × Acceleration 15 m) + (0.582 × Control of dribbling); PPINDEX of centers = -4.126 + (0.604 × Control of dribbling) - (1.315 × Acceleration 15 m) - (0.037 × Sargent jump). A model for the evaluation of physical performance of young basketball players has been defined. In addition, this model could be used as a reference model for selection procedures, as well as to monitor the efficacy of applied training programmes within the short, medium and long-term periodization.

Racial differences in access to allergen-free food have not been fully described among children with food allergy (FA).
To examine access to allergen-free foods among Black and White children with FA.
Black and White children with FA were enrolled in Food Allergy Outcomes Related to White and African American Racial Differences (FORWARD), a multisite prospective cohort study at 4 urban US centers. Caregivers completed questionnaires regarding access to allergen-free foods. Univariable statistics described demographics. Bivariable statistics evaluated crude associations with access to allergen-free foods. Multivariable logistic regression evaluated the adjusted effect of race on access to allergen-free foods. Geospatial analyses examined the distribution of race, socioeconomic status, and food desert residence.
Among participants (n = 336), White caregivers (88.1%) were more likely to report access to allergen-free foods than Black caregivers (59%) (P < .001). White caregivers were more likely to purchase allergen-free foods online (35.2%) than Black caregivers (12%) (P < .001). Although Black children were more likely to live in a food desert, access to allergen-free food was not related to food desert residence. In the unadjusted analysis, White children were 5.2 times as likely to have access than Black children (P < .001); after adjusting for demographics, this increase in access was no longer significant (P = .08). Other predictors of access to allergen-free foods included online food purchasing, annual household income, respondent education level, milk allergy, and child age >5 years.
In the FORWARD cohort, Black children have less access to allergen-free foods than White children, but much of the difference is accounted for by socioeconomic status and other participant characteristics.

Despite major differences in health profiles and rates of health care utilization between African American and White children with food allergy (FA), the detailed phenotypic variables that can potentially impact these outcomes have not been thoroughly studied.
We aimed to characterize phenotypic differences such as allergies to different foods and allergic comorbidities between African American and White children with FA enrolled in the Food Allergy Outcomes Related to White and African American Racial Differences study.
Our active, prospective, multicenter cohort study is currently enrolling African American and White children aged 0 to 12 years diagnosed with FA and followed by allergy/immunology clinics at 4 urban tertiary centers in the United States. To evaluate associations between race and phenotypic variables, we used multivariable logistic regression, adjusting for important demographic and confounding factors, as well as potential household clustering.
As of May 2020, there were 239 African Americans and 425 Whites with complete intake information enrolled in the study. In comparison with Whites, we found that African Americans had significantly higher adjusted odds of allergy to finfish (odds ratio [OR]: 2.54, P < .01) and shellfish (OR: 3.10, P < .001). African Americans also had higher adjusted odds of asthma than Whites (asthma prevalence of 60.5% in African Americans and 27.2% in Whites; OR: 2.70, P < .001). In addition, shellfish allergy was associated with asthma, after controlling for race.
Among a diverse cohort of children with physician-diagnosed FA, we observed that African American children had higher odds of allergy to shellfish and finfish, and higher rates of asthma. Interestingly, having asthma was independently associated with allergy to shellfish, after controlling for race.