FACTORS THAT SUPPORT THE DEVELOPMENT OF FUR FARMS: THE CASE STUDY OF GREECE

This study aims to discuss the key factors that can contribute to the development of the fur industry in Greece. The industry consists of two sub-sectors i.e. production and processing of fur skins (raw material), and the production of fur garments. The profitability of fur-bearing farms, considered from the perspective of investment and further international fur trade, and both these were examined in this study because these two sub-sectors are closely linked. The results obtained from the analysis of the two fur production sub-sectors showed that the investment of capital in the industry can expect positive returns while at the same time creating well-paid jobs. Although not presenting a comparative advantage, but the foreign trade of fur garments produced in the region can gain competitiveness if some of the strategies used by Greek fur companies are adjusted. Results of the current study can be concluded that despite the weaknesses that emerge from the results of this study, both sub-sectors of the fur industry can make a significant contribution to the development of the local community of Western Macedonia

Comprehensive Evaluation of Hip Arthroscopy for Elite Athletes with Femoroacetabular Impingement and Associated Pathology

Femoroacetabular impingement (FAI) is a recognized source of debilitating hip pain among elite athletes. Hip arthroscopy, including labral repair, and FAI lesion correction have been gaining notoriety as methods to mitigate pain and enable athletes to return to their respective sports. PURPOSE: To provide a comprehensive understanding of the clinical presentation, surgical intervention, and outcomes of elite athletes suffering from hip pain attributed to FAI and associated pathology. METHODS: Elite athletes (n = 35; females = 12) from various sports, including basketball, soccer, martial arts, water polo, and weightlifting, participated. Following unsuccessful conservative management (e.g., analgesic medications, physical therapy), all participants consented to undergo hip arthroscopy. The surgical procedures were conducted under epidural anesthesia with patients in the supine position. We assessed the modified Harris hip score (MHHS) both preoperatively and at the 12-week postoperative mark. After surgery, athletes followed individualized physical therapy programs with physician supervision. RESULTS: The intraoperative findings revealed labral detachment in all 35 athletes, alongside various FAI lesions and cartilage defects. Surgical interventions included labral repair using bioabsorbable anchors, burring pincer and cam lesions, and inducing subchondral bone microfractures where necessary. Postoperatively, athletes exhibited statistically significant improvements, with a mean preoperative MHHS of 69 (at 1 week) rising to a mean postoperative MHHS of 92 (at 12 weeks) (t(34) = -9.62, p d = 2.29). Notably, 29 athletes (83%) reported being pain-free and returning to pre-surgical activity levels within 12 weeks. Three athletes (8.5%) endured residual pain due to iliopsoas tendinitis but resumed full activity between 15-18 weeks postoperatively. Three athletes (8.5%) developed heterotopic ossification but did not require reoperation. CONCLUSION: Hip arthroscopy involving classic labral and FAI lesion repair provides a successful approach for correcting hip pathology in elite athletes. This intervention, although continually evolving, remains a potent tool in the arsenal of sports medicine, allowing for the restoration of hip joint biomechanical function

Mathematical properties of the Stochastic Approximation and the Multi-Armed Bandit problem

Παρά το γεγονός ότι τα νευρωνικά δίκτυα χρησιμοποιούνταν επί δεκαετίες με εντυπωσιακά αποτελέσματα, η ανάπτυξη ενός θεωρητικού υπόβαθρου που θα εξηγούσε αυτήν τους την επιτυχία είναι σχετικά πρόσφατο επίτευγμα. Στο Κεφάλαιο 2, παρουσιάζουμε τα κυριότερα αποτελέσματα που έδωσαν απάντηση σε αυτά τα ερωτήματα. Αποδεικνύουμε το θεώρημα του Cybenko, σύμφωνα με το οποίο κάθε συνεχής και σιγμοειδής συνάρτηση είναι καθολικός προσεγγιστής. Παρουσιάζουμε επίσης αρκετές επεκτάσεις του θεωρήματος αυτού. Το Κεφάλαιο 3 είναι αφιερωμένο στη μελέτη αλγορίθμων στοχαστικής προσέγγισης, οι οποίοι στοχεύουν στην εύρεση του σταθερού σημείου ενόςτελεστή, όταν οι ακριβείς τιμές που παίρνει δεν είναι γνωστές σε εμάς, αλλά μας αποκαλύπτονται με την παρουσία θορύβου. Παρουσιάζουμε επίσης την απόδειξη του αλγορίθμου της Q-Μάθησης, η οποία αποτελεί γενίκευση μιας μεθόδου που χρησιμοποιείται ευρέως στον κλασσικό δυναμικό προγραμματισμό, της μεθόδου των διαδοχικών προσεγγίσεων, για προβλήματα στα οποία δεν έχουμε γνώση των διαφόρων παραμέτρων (πιθανότητες μετάβασης και δομή κόστους), αλλά αντίθετα μπορούμε μόνο να προσομοιώνουμε παρατηρήσεις από αυτές. Τέλος, στο Κεφάλαιο 4, μελετάμε το πρόβλημα των multi-armed bandit, το αντικείμενο του οποίου είναι ο προσδιορισμός της πιο κερδοφόρας δράσης από ένα δοσμένο σύνολο, μαζί με την ταυτόχρονη μεγιστοποίηση του αναμενόμενου κέρδους μας σε βάθος χρόνου. Αποδεικνύουμε το φράγμα των Lai-Robbins, σύμφωνα με το οποίο για μια συγκεκριμένη κλάση κατανομών, υπάρχουν όρια στο πόσο γρήγορα μπορούμε να πλησιάσουμε το βέλτιστο κέρδος, ενώ επίσης παρουσιάζουμε και έναν αλγόριθμο που επιτυγχάνει το φράγμα αυτό. Ο αλγόριθμος των Lai-robbins περιέχει αρκετά σκοτεινά σημεία τα οποία προσπαθεί να απλοποιήσει η μέθοδος upper confidence bounds των Auer et al., με την οποία ολοκληρώνουμε την εργασία μας.Despite the fact that neural networks had been used extensively for decades, a theoretical background that would explain their success was, until recently, elusive. In Chapter 2, we present the main results which settled this question, developed mostly in the early `90s. We prove Cybenko's theorem, which states that continuous and sigmoidal functions are always universal approximators, and we also study some extensions of this result. Chapter 3 is devoted to the study of stochastic approximation algorithms. The goal of these algorithms is to determine the fixed point of an operator when its values are not known to us, but they are revealed perturbed by some noise. We also present the proof of the convergence of the Q-Learning algorithm which is based on this theory. The Q-Learning algorithm is a generalization of the successive approximation method, a method used extensively in classical dynamic programming, when we have no prior information on the underlying process (transition probabilities and cost functions), but we can only draw and observe values from it. In the final chapter, we study the multi-armed bandit problem, a subfield of reinforcement learning, where the goal is to determine the most profitable action among a given set, while simultaneously, maximizing one's profit. We prove the Lai-Robbins lower bound, which shows that for a certain class of reward distributions there are limits to how fast one can reach a maximum profit, and we also present an algorithm that attains it. We conclude the chapter by studying the upper confidence bound algorithm, introduced by Auer et al., which resolves several issues of the Lai-Robbins approach

Femur Stress Fracture - Marathon

HISTORY: During a race, a 35-year-old marathon runner complained of experiencing dull, achy pain in the right groin. After the race, he occasionally experienced radiating pain in the right thigh. The athlete was examined by a general practitioner (GP). During the clinical evaluation, the athlete had no signs of tenderness or swelling. The GP suggested rest and prescribed anti-inflammatory medication. PHYSICAL EXAMINATION: Ten days later, during training, the athlete felt the same discomfort after a challenging training session. He, then, decided to see an orthopedic physician. At the clinical examination, there was no localized pain. Focal pain was present during weight bearing activities only. Initial x-rays showed no significant abnormality or fracture. However, due to the complaints of the athlete, the doctor suggested additional x-rays and an MRI. DIFFERENTIAL DIAGNOSIS: Lumbar radiculopathy Rectus femoris strain Abductor strain Trochanteric bursitis TEST AND RESULTS: - X-ray showed a fracture of the middle shaft of the femur - MRI showed a medial periosteal reaction in the femoral shaft (high fluid signal) - Pain, especially during internal rotation - Pain on the affected side with a single-leg stance - Pain during activity, reproducible on passive range of motion FINAL / WORKING DIAGNOSIS: Stress fracture of the middle shaft of the right femur TREATMENT AND OUTCOMES: Tolerate weight bearing if no displacement occurs (four months max.) Treatment by a metabolic physician (Vitamin D deficiency or other) Continuing follow-up with repeated imaging: Verify resolution and minimize the progression to displacement Surgery if conservative management fails (see #1-3) Intramedullary rodding (surgical procedure

Sacral Stress Fracture — Wrestling

CASE HISTORY: During preseason, a 35-year-old wrestler complained of pain in his lower back concurrently with a tingling sensation in the left thigh and buttocks. PHYSICAL EXAM: The wrestler was examined by a physical therapist (PT) and, while discussing prior medical history, the athlete mentioned a previous diagnosis of a mild herniated disk (Grade 1). Upon clinical examination, the athlete demonstrated a full range of motion with some discomfort in passive hip extension. The PT suggested rest and rehabilitation through electrical stimulation, alongside the strengthening of the lumbar spine and hip abductor muscles. Ten days later, the athlete presented to an orthopedic surgeon (Ortho) complaining of the same discomfort. During the examination, the Ortho noticed the same localized tenderness over the left sacroiliac joint. Results for both the Lasegue and FABER tests were negative. Although there was no significant sign of fracture or edema, the Ortho suggested obtaining lumbar and pelvis X-Rays. He prescribed anti-inflammatory medication and performed a corticosteroid injection in the left sacroiliac joint. After treatment, the athlete had immediate relief and was able to compete the following day in his competitive event. One week later, the athlete returned to the outpatient clinic complaining that the pain was still localized in the left sacroiliac joint. The Ortho performed the hop test, which was positive. The athlete was then referred for an MRI of the spine and pelvis followed by a CT scan. DIFFERENTIAL DIAGNOSIS: 1. Spinal Disc Herniation Aggravation; 2. Sacroiliac Joint Misalignment; 3. Sciatic Neuritis; 4. Musculotendinous Strain; and 5. Sarcoma. TESTS & RESULTS: X-Ray: Clear; Hop test: Positive; MRI: a) Lumbar region: Mild L5-S1 herniation (Grade 1) with the lumbar spine curvature found to be within normal limits and b) Pelvis: Edema with associated marrow changes due to a non-displaced sacral stress fracture; CT Scan: Fracture line along with sclerosis parallel to the sacroiliac joint. FINAL DIAGNOSIS: Stress fracture on the left, anterior column of the sacrum. DISCUSSION: Clear X-Rays are associated with 20%-38% of misdiagnoses of sacral fractures. When a stress fracture is suspected, MRI should be the indicated exam, followed by a CT scan. Our clinical case gives an indication of the decision-making process so that other physicians can apply lateral thinking to their own cases. OUTCOME OF THE CASE: 1. Rehabilitation: Rest and light weight-bearing exercises (4 months) and 2. Anti-osteoporotic treatment: Calcium and Vitamin D. RETURN TO ACTIVITY AND FURTHER FOLLOW-UP: Return to participation: 5-12 months

Shoulder Arthroscopy After a Proximal Humeral Fracture Malunion: Athlete Care and Clinical Medicine in Middle-Aged Athletes

Malunion of the proximal humerus is operationally defined as healing of the fractured bone in a non-anatomical position, resulting in a painful and disabling deformity (e.g., a bone being shorter than normal, twisted or rotated in a bad position, or bent), which affects the range of motion (ROM) and functional movement. A correction and functional restoration are often needed in athletes, since their profession requires superior physical functioning. Shoulder arthroscopy has evolved dramatically over the past 15 years and has been used in cases of malunion of the humerus in athletes. However, there is a scarcity of evidence concerning middle-aged athletes. PURPOSE: To examine the benefits of shoulder arthroscopy after a proximal humeral fracture unified in malposition in middle-aged athletes. METHODS: Physical examination and imaging evaluation using 3D Computed Tomography(3D-CT), Magnetic Resonance Imaging (MRI), and shoulder radiographs (anteroposterior, internal rotation, and lateral scapular view) were used to evaluate shoulder dysfunction after proximal humeral fracture in malposition. Fourteen athletes (9 males, 5 females; Mage = 43.1, SD = 3.5) were included in this research. According to Neer classification before surgery, 11 (78%) had one part displaced and the rest three (22%) had two parts displaced. Post-operative clinical results were evaluated with self-reported pain score (1-10), UCLA scores, and shoulder abduction ROM measured with a goniometer. RESULTS: There was significant difference in pain scores (Mbefore = 8, Range: 6-9; Mafter = 4, Range: 2-6; p \u3c .001), in UCLA scores (Mbefore = 12, Range: 9-16; Mafter = 28, Range: 20-31; p \u3c .01), and in shoulder abduction ROM (Mbefore = 80, Range: 70-100; Mafter = 135, Range: 120-150; p \u3c .05). CONCLUSION: Our research provides evidence for clinical translation in improving health outcomes in middle-aged athletes with a history of proximal humeral fracture union in malposition: shoulder arthroscopy can be simultaneously beneficial in terms of decreasing pain level, increasing ROM, and restoring limb function

Germanane Monolayer Films as Antibacterial Coatings

Germanane (GeH), a graphane analogue, has attracted significant interest because of its optoelectronic properties; however, the environmental and biological effects of GeH have scarcely been investigated so far. Here we report a facile approach based on the Langmuir-Schaefer deposition to produce homogeneous and dense GeH monolayer films on various substrates. In view of possible applications and to extend the use of GeH to unexplored fields, we investigated its antibacterial activity for the first time and found that this promising 2D structure exhibits remarkable antibacterial activity against both Gram-negative and Gram-positive bacterial strains

Testing and simulation of a thermoacoustic transducer prototype

ABSTRACT Thermoacoustic transduction is the transformation of thermal energy fluctuations into sound. Devices fabricated by appropriate materials utilise such a mechanism in order to achieve acoustic wave generation by direct application of an electrical audio signal and without the use of any moving components. A thermoacoustic transducer causes local vibration of air molecules resulting in a proportional pressure change. The present work studies an implementation of this alternative audio transduction technique for a prototype developed on silicon wafer. Measurements of the performance of this hybrid solid state device are presented and compared to the theoretical principles of its operation which are evaluated via simulations