194 research outputs found
Phase Transition Behavior of Cardinality and XOR Constraints
The runtime performance of modern SAT solvers is deeply connected to the
phase transition behavior of CNF formulas. While CNF solving has witnessed
significant runtime improvement over the past two decades, the same does not
hold for several other classes such as the conjunction of cardinality and XOR
constraints, denoted as CARD-XOR formulas. The problem of determining the
satisfiability of CARD-XOR formulas is a fundamental problem with a wide
variety of applications ranging from discrete integration in the field of
artificial intelligence to maximum likelihood decoding in coding theory. The
runtime behavior of random CARD-XOR formulas is unexplored in prior work. In
this paper, we present the first rigorous empirical study to characterize the
runtime behavior of 1-CARD-XOR formulas. We show empirical evidence of a
surprising phase-transition that follows a non-linear tradeoff between CARD and
XOR constraints
Physiological and Perceptual Demands During a Simulated “The Hundred” Batting Work-Bout in Female Cricketers
Purpose
No research has investigated the physiological and perceptual demands of female cricket players at any level or for any format, making this study unique. This is despite the growth in popularity and professionalism of the women’s game. Therefore, the purpose of this study was to determine the physiological (heart rate, oxygen consumption) and perceptual (ratings of perceived exertion, body discomfort) demands of female cricketers during a simulated “The Hundred” protocol.
Methods
Twenty female cricketers (age: 19 ± 4.53 years, stature: 167.90 ± 7.28 cm; mass: 67.30 ± 13.51 kg) currently playing for a first-class county cricket club were recruited. The protocol consisted of six sets and was designed to mimic the nonpowerplay phase of a women’s “Hundred” match. Throughout the protocol selected physiological and perceptual responses were recorded.
Results
Heart rate responses increased significantly (P < 0.05) from the first set (149 ± 14 beats/min) until the end of the third set (167 ± 10 beats/min). A further significant decrease (P < 0.05) was observed between set three (167 ± 10 beats/min) and set six (165 ± 12 beats/min). Oxygen uptake responses increased significantly (P < 0.05) from set one (22.06 ± 7.82 mL/kg/min) until set three (26.30 ± 7.58 mL/kg/min). A significant difference (P < 0.05) was also observed between set three and all the other sets. Central ratings of perceived exertion increased significantly (P < 0.05) throughout the protocol (9 ± 1.83–13 ± 3.17). Body discomfort, results indicated that the quadriceps and calves were the areas that felt the most discomfort during the protocol.
Conclusion
In conclusion, the design of training programs should mimic the demandsof the women?s format of the game and focus on individualised exercise preparation
Bilateral reversed palmaris longus muscle with trifid insertion, a rare variation
Normally the palmaris longus muscle originates from the medial epicondyle of the humerus from common flexor origin. In the middle of the forearm, the muscle belly forms a tendon which is inserted into the flexor retinaculum and the palmar aponeurosis. In our study after dissection of both forearms of a 45-year-old male cadaver we found a reversed palmaris longus muscle. This means that the palmaris longus muscle was tendinous in its proximal part and muscular in its distal part. The fleshy belly of muscle was passing over flexor retinaculum, was ensheathed by separate fascia. The muscle belly was spreading on both the sides of each palm for insertion which was trifid, that is centrally into palmar aponeurosis, laterally continuous with the fascia covering the thenar muscles and medially with Abductor digit minimi. It was having tendinous interconnection with the muscle mass of both the sides. Bilateral reversed palmaris longus muscle mentioned in the literature, was a surgical finding in a patient who suffered from edema and pain in the wrist. The overuse of the reversed palmaris longus muscle can lead to the muscle’s local hypertrophy. As per the literature a reversed palmaris longus muscle may cause a compartment syndrome with pain and edema in the wrist area, the carpal tunnel syndrome and Guyon’s syndrome. The variation is also useful to the hand surgeon, as the palmaris longus muscle is an anatomical landmark for operations in this area
Phase Transition Behavior of Cardinality and XOR Constraints
The runtime performance of modern SAT solvers is deeply connected to the phase transition behavior of CNF formulas. While CNF solving has witnessed significant runtime improvement over the past two decades, the same does not hold for several other classes such as the conjunction of cardinality and XOR constraints, denoted as CARD-XOR formulas. The problem of determining satisfiability of CARDXOR formulas is a fundamental problem with wide variety of applications ranging from discrete integration in the field of artificial intelligence to maximum likelihood decoding in coding theory. The runtime behavior of random CARD-XOR formulas is unexplored in prior work. In this paper, we present the first rigorous empirical study to characterize the runtime behavior of 1-CARD-XOR formulas. We show empirical evidence of a surprising phase-transition that follows a non-linear tradeoff between CARD and XOR constraints
\u3ci\u3eBolbophorus damnificus\u3c/i\u3e n. sp. (Digenea: Bolbophoridae) from the Channel Catfish \u3ci\u3eIctalurus punctatus\u3c/i\u3e and American White Pelican \u3ci\u3ePelecanus erythrorhynchos\u3c/i\u3e in the USA Based on Life-Cycle and Molecular Data
The common pathogenic prodiplostomulum metacercaria in the flesh, mostly near the skin, of pond-produced channel catfish Ictalurus punctatus has been demonstrated to be Bolbophorus damnificus Overstreet & Curran n. sp. The catfish acquires the infection from the snail Planorbella trivolvis, the only known first intermediate host, and the species is perpetuated through the American white pelican Pelecanus erythrorhynchos, as confirmed by experimental infections with nestling and dewormed adult pelican specimens in conjunction with molecular data. It differs from the cryptic species Bolbophorus sp., also found concurrently in the American white pelican, by having eggs 123–129 μm rather than 100–112 μm long and consistent low values for nucleotide percentage sequence similarity comparing COI, ITS 1/2, 18S rRNA and 28S rRNA fragments. Bolbophorus sp. is comparable but most likely distinct from B. confusus (Kraus, 1914), which occurs in Europe and has eggs 90–102 μm long. Its intermediate hosts were not demonstrated. The adults of neither of the confirmed North American species of Bolbophorus were encountered in any bird other than a pelican, although several shore birds feed on infected catfish, and B. damnificus can survive but not mature when protected in the mouse abdominal cavity. B. ictaluri (Haderlie, 1953) Overstreet & Curran n. comb., a species different from B. damnificus, is considered a species inquirenda
The impact of a fast bowling spell on physiological, perceptual and performance responses in non-elite cricketers
Background: The demands placed on fast bowlers may elicit unique responses that contribute towards increased injury risk and comprised performance capabilities. Despite this, very few investigations have attempted to quantify these demands and their impact on performance in cricketers.
Objective: This investigation attempted to quantify the effects of a fast bowling protocol on the musculoskeletal, physiological and perceptual responses of fast bowlers; as well as ball speed and accuracy.
Methods: Eight young adult bowlers (20 ± 2 years) participated in a 10-over bowling protocol that had been separated by intermittent fielding drills into three bowling spells respectively (4-, 3- and 3- overs). Selected responses were collected throughout the protocol.
Results: Functional strength was measured and showed no change. Heart rate responses increased significantly (p<0.05) at the start of the bowling protocol. Local ratings of perceived exertion increased significantly (p<0.05) as a function of exercise duration, while low to moderate intensities of perceived discomfort were noted in the anterior and posterior shoulder areas, upper portion of the lower limb musculature, as well as in the middle and lower back regions. Performance responses experienced no significant change.
Conclusion: There was no significant change in ball release speed and accuracy across the bowling protocol. Lower limb muscle power remained consistent and heart rates reached a steady state after the first over. In comparison, local ratings of perceived effort and body discomfort increased over time, which could mean that those unchanged measures do not accurately reflect fatigue or that perceptions are a more effective indicator of impending fatigue.
Keywords: accuracy, speed, heart rate, body discomfort, ratings of perceived exertion 
Do South African international cricket pace bowlers have similar bowling volume and injury risk associates compared to other elite fast bowlers?
BACKGROUND
While many cricket-playing nations have conducted research on bowling volume (BV) and injury risk, this relationship among international South African pace bowlers is yet to be investigated. Environmental, socio-economic, and training strategy differences warrant similar research in a South African context. The purpose of this preliminary study was to establish if South African pace bowlers have similar bowling volume and injury associates compared to other elite fast bowlers.
METHODS
This study was a prospective, observational, cohort study that monitored match and training BV and injuries among pace bowlers playing for the South African national team between April 2017 and April 2019. A sample of convenience that included fourteen bowlers was selected. Bowling volume was quantified as the number of deliveries bowled during training and competition. Acute-, chronic- and acute: chronic bowling volume ratios were independently modeled as association variables.
RESULTS
There were 39 injuries with the most being to the lumbar spine (25.64%). Moderate-to-low and a moderate-to-high acute: chronic bowling load ratios were associated with a lower risk of injury. Chronic bowling load was associated with injury (z = 2.82, p = 0.01). A low acute workload, low chronic workload, moderate-high chronic workload, and moderate-low acute: chronic ratio was also associated with an increased risk of injury.
CONCLUSION
These findings confirm that there appears to be a dose-response effect between training bowling volume and the likelihood of an injury occurring with a moderate-to-low and a moderate-to-high bowling volume ratio being optimal. Considering the small sample size, the findings should be interpreted with caution
Use of Artificial Intelligence as an Innovative Method for Liver Graft Macrosteatosis Assessment
The worldwide implementation of a liver graft pool using marginal livers (ie, grafts with a high risk of technical complications and impaired function or with a risk of transmitting infection or malignancy to the recipient) has led to a growing interest in developing methods for accurate evaluation of graft quality. Liver steatosis is associated with a higher risk of primary nonfunction, early graft dysfunction, and poor graft survival rate. The present study aimed to analyze the value of artificial intelligence (AI) in the assessment of liver steatosis during procurement compared with liver biopsy evaluation. A total of 117 consecutive liver grafts from brain-dead donors were included and classified into 2 cohorts: ≥30 versus <30% hepatic steatosis. AI analysis required the presence of an intraoperative smartphone liver picture as well as a graft biopsy and donor data. First, a new algorithm arising from current visual recognition methods was developed, trained, and validated to obtain automatic liver graft segmentation from smartphone images. Second, a fully automated texture analysis and classification of the liver graft was performed by machine-learning algorithms. Automatic liver graft segmentation from smartphone images achieved an accuracy (Acc) of 98%, whereas the analysis of the liver graft features (cropped picture and donor data) showed an Acc of 89% in graft classification (≥30 versus <30%). This study demonstrates that AI has the potential to assess steatosis in a handy and noninvasive way to reliably identify potential nontransplantable liver grafts and to avoid improper graft utilization
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