43 research outputs found

    Gender and Culture in a Threshold Public Goods Game: Japan versus Canada,

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    We compare male and female behavior in Japan and Canada in the context of a threshold public goods game with both a strong free-riding equilibrium and many socially efficient threshold equilibria. Although higher rewards produce higher contributions, neither culture nor gender has any significant impact on the equilibrium selected, the amount contributed or the provision success rate. Nonetheless, culture and gender do affect behavior. Japanese females coordinate significantly less closely than Canadian females, while Japanese males coordinate significantly less closely than either Canadian males or Canadian females around an equilibrium. Coordination is related both to conforming and less variable behavior.

    Gender and Culture in a Threshold Public Goods Game : Japan versus Canada

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    Voluntary provision of threshold public goods with continuous contributions: experimental evidence.

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    Abstract This paper examines experimentally the effects of allowing individuals to contribute any desired proportion of their endowments toward a threshold public good. Permitting continuous rather than binary ''all-or-nothing'' contributions significantly increases contributions and facilitates provision. A money-back guarantee further encourages provision, especially when the threshold is high. A high threshold discourages provision in the absence, but not in the presence of a money-back guarantee. High rewards also significantly increase contributions and provision. Sufficiently high rewards elicit convergence of contributions to the threshold, rather than the deterioration towards free riding, often reported in previous studies

    Cardiac interventions in patients with achondroplasia: a systematic review.

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    Patients with achondroplasia and other causes of dwarfism suffer from increased rates of cardiovascular disease relative to the remainder of the population. Few studies have examined these patients when undergoing cardiac surgery or percutaneous intervention. This systematic review examines the literature to determine outcomes following cardiac intervention in this unique population. An electronic search was performed in the English literature to identify all reports of achondroplasia, dwarfism, and cardiac intervention. Of the 5,274 articles identified, 14 articles with 14 cases met inclusion criteria. Patient-level data was extracted and analyzed. Median patient age was 55.5 [interquartile ranges (IQR), 43.8, 59.8] years, median height 102.0 [98.8, 112.5] cm, median BMI 32.1 [27.0, 45.9], and 57.1% (8/14) were male. Of these 14 patients, nine had the following documented skeletal abnormalities: 66.7% (6/9) had scoliosis, 66.7% (6/9) had kyphosis, 11.1% (1/9) had lordosis, 11.1% (1/9) pectus carinatum and 11.1% (1/9) spinal stenosis. Coronary artery disease was present in 53.8% (7/13), and 30.8% (4/13) patients previously suffered a myocardial infarction. Of the eight patients who underwent cardiac surgery, 37.5% (3/8) underwent multivessel coronary artery bypass grafting, 37.5% (3/8) underwent aortic valve replacement, 25.0% (2/8) underwent type A aortic dissection repair, and the remaining 12.5% (1/8) underwent pulmonary thromboendarterectomy. Six patients underwent percutaneous intervention. Median cardiopulmonary bypass time was 136.5 [110.0, 178.8] minutes. Median arterial cannula size was 20.0 [20.0, 24.0] Fr. Bicaval cannulation was performed in all cases describing cannulation strategy (5/5). Median superior vena cava cannula size was 28.0 [28.0, 28.0] Fr, and inferior vena cava cannula size was 28.0 [28.0, 28.0] Fr. No mortality was reported with a median follow up time of 6.0 [6.0, 10.5] months. In conclusion, Common cardiac procedures can be performed with reasonable safety in this patient population. Operative adjustments may need to be made with respect to equipment to accommodate patient-specific needs

    Accessory Lateral Head of the Right Gastrocnemius Muscle in a 65 year-old White Male Donor

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    The three muscles that form the calf muscle or triceps surae include the soleus muscle, the gastrocnemius muscle, and the plantaris muscle. Generally, the gastrocnemius muscle consists of a larger medial head and relatively smaller lateral head. It is responsible for plantar flexion of the foot. The lateral head arises from the posterior lateral femoral condyle and the larger medial head originates from the posterior medial femoral condyle. The medial and lateral heads of the gastrocnemius muscle along with the soleus muscle combine to form the Achilles tendon, which inserts onto the posterior surface of the calcaneus. Since the gastrocnemius muscle crosses three joints including the knee and subtalar joints, it can be vulnerable to injury, especially in mature athletes who experience sudden and swift changes in direction associated with muscular overstretching. Other causes of gastrocnemius muscle injury include maximal knee extension and full ankle dorsiflexion. Since the muscle is already prone to injury, anatomical variations of the gastrocnemius muscles may be symptomatic. With muscle variations, there are potential implications and effects on the other structures within the popliteal fossa. Many different anatomical variations have been identified during routine dissections and reported in the literature. Understanding details of these variations is important for diagnostic, surgical and clinical practice and patient management. Here we report on a 65-year-old White Male cadaveric donor with an accessory lateral head of the gastrocnemius muscle found incidentally during a routine dissection

    Bifurcation of the Brachial Artery into Brachioradial and Brachioulnar Arteries in the Proximal Arm: Case Report and Clinical Significance

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    During anatomical dissection of fifty donors in the 2020 undergraduate first-year anatomy course at the Uniformed Services University of the Health Sciences, a high origin of the radial and ulnar arteries, also known as a brachioradial artery and a brachioulnar artery, was observed on the left arm of a 90 year-old White female donor. The bifurcation of the brachial artery occurred in the proximal third of the arm. Both the left brachioradial and left brachioulnar arteries ran superficial and medial to the biceps brachii muscle. The brachioulnar artery continues as the UA in the forearm, ran superficial and lateral to the flexor carpi ulnaris muscle, traversed the flexor retinaculum, and continued to form the superficial arterial palmar arch. The brachioradial artery ran deep to the pronator teres muscle and continued as the RA in the forearm. It presented with an atypical branching pattern and was tortuous until it reached the hand. On the dorsum of the hand, the radial artery runs superficial to the first dorsal interosseous muscle, parallel to the first metacarpal bone. It also reached the palmar side of the hand in an unusual manner. Medical professionals, especially radiologists, orthopedic and vascular surgeons, need to be aware of these variations to avoid iatrogenic injuries during normal procedures, such as venipuncture and intravenous injections. Knowledge of these variations is also important during invasive procedures, such as elbow reconstructive surgery, percutaneous brachial catheterization, and when creating an arteriovenous fistula using the radial artery. When such variations are suspected, Doppler and angiogram studies are necessary

    Overall Prevalence and Clinical Significance of a Retroesophageal Right Subclavian with a Non-Recurrent Right Laryngeal Nerve in an 83-year-old and a 93-year-old White Male Donor

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    Head and neck anatomic variations are common and generally go undetected, but may be clinically significant or have important surgical consequences. Knowledge of various abnormalities is important for clinical decision making and the avoidance of iatrogenic complications. Anomalies of the aortic arch and its various branches are relatively common. However, rare variations with profound clinical sequelae can occur. During recent cadaveric dissection, we identified an 83-year-old and a 93-year-old White male donor who both had a right retroesophageal subclavian artery with an associated non-recurrent right laryngeal nerve. Lack of knowledge of this anatomic variation can directly result in severe consequences for patients and lead to major morbidity. Understanding this variation and recognizing it will be important for anatomists, radiologists and surgeons

    Continuous-flow left ventricular assist device outflow graft stenting: Indications and outcomes

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    Introduction: Stenosis in the continuous-flow left ventricular assist device (CF-LVAD) outflow graft can be caused by various mechanical and anatomical factors. Increasingly, percutaneous management has been utilized to re-establish adequate CF-LVAD flow. We sought to evaluate indications for such interventions and their outcomes. Methods: An electronic search was performed to identify all studies in the English literature reporting CF-LVAD outflow graft stenting for various etiologies. Twenty-one studies consisting of 26 patients were included in the analysis. Results: Median patient age was 59 years [45.8-67.0] and 65.4% (17/26) were male. 58.3% (14/24) of patients had HeartWare HVAD, 37.5% (9/24) had HeartMate II LVAD, and 4.2% (1/24) had HeartMate III LVAS. Median time from device placement to outflow graft stenting was 24.0 months [7.8-30.4]. 76.9% of patients (20/26) presented with heart failure. 34.6% (9/26) had outflow graft thrombosis, 34.6% (9/26) stenosis, 11.5% (3/26) kinking, 11.5% (3/26) pseudoaneurysm, 3.8% (1/26) external graft compression, and 3.8% (1/26) had a bronchialarterial fistula. 88.5% (23/26) procedures led to immediate flow improvement with the remaining 11.5% (3/26) receiving additional stenting. Post-intervention flows were significantly improved (4.7 L/min [4.1-4.8] post-intervention vs 2.9 L/min [2.0-3.5] initial, p=0.01). 96.2% (25/26) patients were discharged from the hospital. The 30-day mortality was 6.7% (1/15). Overall mortality during the median follow-up of 90 days [7.0-240.0] was 9.5% (2/21). Discussion: Outflow graft stenting appears to effectively alleviate CF-LVAD outflow graft obstruction with low mortality. Longer-term follow up is necessary to determine the longevity of such an intervention but early results are promising

    Does Concomitant CABG Influence the Outcomes of Post-Myocardial Infarction Ventricular Septal Defect Repair?

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    Introduction: Ventricular septal defect (VSD) following myocardial infarction (MI) is a relatively infrequent complication with high mortality. Over time, understanding of the pathology and its management has resulted in improved outcomes; however, controversies remain. Objective: We sought to investigate the effect of concomitant coronary artery bypass graft (CABG) on outcomes following post-MI VSD repair. Methods: Electronic search was performed to identify all relevant studies published from 2000 to 2018. After assessment for inclusion and exclusion criteria, 66 studies were selected for the analysis. Data were extracted and pooled for systematic review and meta-analysis. Results: Average age was 68.7 years (95% CI 67.3-70.1) with 57% (95% CI 54-60) males. Coronary angiogram was available preoperatively in 94% (95% CI 92-96) of patients. Single-vessel disease was most common (47%, 95% CI 42-52) with left anterior descending coronary artery the most commonly involved vessel (55%, 95% CI 46-63). Concomitant CABG was performed in 52% (95% CI 46-57) of patients. Of these, infarcted territory was revascularized in 54% (95% CI 23-82). No significant survival difference was observed between those who had concomitant CABG versus those without CABG at 30 days (65%, 95% CI 58-72) vs (60%, 95% CI 47-72), 1 year (59%, 95% CI 50-68) vs (51%, 95% CI 41-61), and 5 years (46%, 95% CI 38-54) vs (39%, 95% CI 27-52) respectively. Discussion: Overall, concomitant CABG did not have a significant effect on survival following VSD repair, therefore, decision on revascularization should be weighed against the risks associated with prolonged cardiopulmonary bypass

    Surgical Pulmonary Embolectomy Outcomes for Acute Pulmonary Embolism

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    Introduction: Acute pulmonary embolism (PE) is associated with significant mortality. Surgical embolectomy is a viable treatment option; however, it remains controversial due to variable outcomes. This review investigates patient outcomes following surgical embolectomy for acute PE. Methods: Electronic search was performed to identify articles reporting surgical embolectomy for treatment of PE. 32 studies were included comprising 936 patients. Demographic, perioperative, and outcome data were extracted and pooled for systematic review. Results: Mean patient age was 56.3 [95% CI 52.5; 60.1] years and 50% [46; 55] were male. 82% had right ventricular dysfunction [62; 93], 80% [67; 89] had unstable hemodynamics, and 9% [5; 16] experienced cardiac arrest. Massive PE and submassive PE were present in 83% of patients [43; 97] and 13% [2; 56], respectively. Before embolectomy, 33% of patients [14; 60] underwent systemic thrombolysis and 14% [8; 24] catheter embolectomy. Preoperatively, 47% of patients were ventilated [26; 70] and 36% had percutaneous cardiopulmonary support [11; 71]. Mean operative time and mean cardiopulmonary bypass time were 170 [101; 239] and 56 [42; 70] minutes, respectively. Intraoperative mortality was 4% [2; 8]. Mean hospital and ICU stay were 10 [6; 14] and 2 [1; 3] days, respectively. Mean postoperative systolic pulmonary artery pressure (sPAP) was significantly decreased from preoperative (sPAP 57.8 mmHg [53; 62.7]) to postoperative period (sPAP 31.3 mmHg [24.9; 37.8]), p \u3c0.01). In-hospital mortality was 16% [12; 21]. Overall survival at five years was 73% [64; 81]. Discussion: Surgical embolectomy is an acceptable treatment option with favorable outcomes
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