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We report here on a new measurement of the parity violating (PV) asymmetry in the scattering of polarized electrons on unpolarized protons performed with the setup of the A4-collaboration at the MAMI accelerator facility in Mainz. This experiment is the first to use counting techniques in a parity violation experiment. The kinematics of the experiment is complementary to the earlier measurements of the SAMPLE collaboration at the MIT Bates accelerator and the HAPPEX collaboration at Jefferson Lab. After discussing the experimental context of the experiments, the setup at MAMI and preliminary results are presented. [ABSTRACT FROM AUTHOR]

The mathematical modeling of swirling flames is a difficult task due to the intense coupling between turbulent transport processes and chemical kinetics in particular for instationary processes like the combustion induced vortex breakdown. In this paper a mathematical model to describe the turbulencechemistry interaction is presented. The described method consists of two parts. Chemical kinetics are taken into account with reduced chemical reaction mechanisms, which have been developed using the ILDM-Method ("Intrinsic Low-Dimensional Manifold"). The turbulence-chemistry interaction is described by solving the joint probability density function (PDF) of velocity and scalars. Simulations of test cases with simple geometries verify the developed model. [ABSTRACT FROM AUTHOR]

Numerical simulations of the ignition process of methanol and nheptane droplets in a laminar convective environment are performed using detailed reaction mechanisms and detailed transport models. The ignition delay time of a single droplet is found to decrease with increasing velocity of the convective gas flow. This decrease is attributed to the steepening of the spatial gradients of the profiles of physical variables, like species mass fractions or temperature. This steepening is originated by a stronger gas flow and leads to a speed-up of the physical transport processes. A downstream movement of the local ignition point with increasing flow velocity is observed. For higher flow velocities an ignition in the wake of the droplet followed by an upstream flame propagation is found. After ignition an envelope flame is formed. The structure of this envelope flame is studied. [ABSTRACT FROM AUTHOR]

The mathematical modeling of swirling flames is a difficult task due to the intense coupling between turbulent transport processes and chemical kinetics in particular for instationary processes like the combustion induced vortex breakdown. In this paper a mathematical model to describe the turbulence-chemistry interaction is presented. The described method consists of two parts. Chemical kinetics are taken into account with reduced chemical reaction mechanisms, which have been developed using the ILDM-Method ("Intrinsic Low-Dimensional Manifold"). The turbulencechemistry interaction is described by solving the joint probability density function (PDF) of velocity and scalars. Simulations of test cases with simple geometries verify the developed model. [ABSTRACT FROM AUTHOR]

BME is a relatively recently recognized entity. MRI has proved to be the most powerful tool to assess BME, as conventional imaging techniques are insensitive for detection of trabecular injuries. The pathogenesis of BME is variable and may be due to acute or chronic trauma or even causes without any history of obvious trauma. Distinction between traumatic and non-traumatic bone marrow edema in sports injuries is primarily based on a clinical history of trauma, as imaging features are mostly indistinguishable. In traumatic cases, the pattern of bone marrow edema, however, may reveal the mechanism of underlying trauma and is often a secondary sign for detecting associated abnormalities. The clinical significance of BME is still a matter of debate, and long-term follow-up studies are required for further evaluation of this item. [ABSTRACT FROM AUTHOR]

During the Summer Olympics in 2004 the most frequent musculoskeletal injuries consisted of muscle strains, mainly of biceps femoris, gastrocnemius, adductors and rectus femoris, stress fractures (located mainly in the tibia, navicular bone and metatarsals) and knee injuries including isolated meniscal tears, ACL ruptures followed by more complex ligamentous injuries. Subtle muscle strains could be depicted by ultrasound whereas MRI was more accurate in identifying the extent of a more severe injury. The most common injuries at the ankle joint were lateral ligamentous injuries often combined with impingement, tendinosis of the Achilles tendon and plantar fasciitis, or tears, and stress fractures of the navicular bone and metatarsals. At the shoulder, rotator cuff tears and/or instability lesions were most frequent. Lower back complaints were frequent and stress injuries of the pars interarticularis were not uncommon. [ABSTRACT FROM AUTHOR]

Appearances of acute muscle, tendon and ligament injury are well documented but thus far imaging has had a limited role in assessment of such injuries during healing. In this context ultrasound and MRI have been largely used to detect complications when clinical progress is unsatisfactory. Normal healing appearances have been documented at sites such as the Achilles tendon, hamstring musculature and cruciate ligaments and in many cases abnormalities persist for some time. Given that abnormality is present for weeks following muscle injury and months following tendon and ligament injury, follow-up imaging shortly after injury may be difficult to interpret and as yet, a clear relationship between imaging findings and clinical outcome has not been shown. At present, there are few specific criteria that may be used to distinguish normal from inadequate healing but persisting separation of muscle, tendon or ligament components is a reliable indicator of inadequate healing. Absence of regression of fluid at the site of injury or an increase in the extent of abnormality at follow-up may also be used to indicate an inadequate healing response. Algorithms integrating imaging findings into clinical management are not yet available and the ultimate role of follow-up imaging will depend upon its capacity to alter management and predict adverse outcomes. [ABSTRACT FROM AUTHOR]

Evaluation of sports-related fractures and microfractures is heavily dependent on imaging. With increased participation of children and adults in organized or recreational sports activities, radiologists are frequently asked to assist in the diagnosis and management of these patients. Plain radiographs are important in depicting and monitoring osseous fractures, avulsion injuries and osteochondral lesions. MRI is extremely valuable for assessing, grading and monitoring healing of osteochondral lesions and microfractures in the context of both acute trauma and stress injury. [ABSTRACT FROM AUTHOR]

Gaining the benefits of participation in athletics while minimizing the risk of injuries requires understanding of the relationship between sports participation and injury, and the relationship between injury and joint degeneration. It is essential for radiologist to differentiate radiological age-related changes from pathological injuries. Knowledge of the spectrum of injuries in the aging athlete will allow correct diagnosis and early return to athletic activity. [ABSTRACT FROM AUTHOR]

In conclusion, the majority of sports-related craniomaxillofacial injuries are of a minor nature including soft tissue lacerations followed by dentoalveolar fractures and minor facial bone fractures. The most frequently recorded maxillofacial bone fractures involve the mandible, the zygomatic and nasal bone and occur during team sports, such as soccer and rugby, as a consequence of an impact against another player. Dentoalveolar fractures always require intraoral periapical films to obtain adequate image detail. CT is the modality of choice for the most complete evaluation of the facial skeleton and facial soft tissues. [ABSTRACT FROM AUTHOR]

Ultrasound and MRI now provide us with tools to assess and quantify the nature of tendon and ligament disease around the ankle. They are playing an increasing role in prognosis, management and treatment for those patients with ankle injuries. [ABSTRACT FROM AUTHOR]

Most cases of anterior knee pain originate from the patellar tendon, Hoffa's fat pad or the patellofemoral joint. Most cases do not require imaging. Acute traumatic pain requires plain films to exclude fracture supplemented by MRI if patella dislocation is considered a possibility. Soft tissue overuse injuries of the patellar tendon are best assessed by ultrasound. MRI is the technique of choice for assessing the patellofemoral joint and abnormalities of Hoffa's fat pad. Plain films are of limited value in the assessment of chronic anterior knee pain. [ABSTRACT FROM AUTHOR]

MRI plays a key role in the assessment of suspected ligamentous disruption of the knee. The anterior cruciate ligament is one of the most important stabilising structures of the knee, and is frequently injured in contact sports and skiing. Successful rehabilitation of the sports related anterior cruciate ligament injury is dependent on accurate diagnosis, leading to appropriate surgical stabilisation. In the presence of anterior cruciate ligament injury, assessment of associated meniscal and posterolateral corner injury are also vital. Disruptions of the posterior cruciate ligament are less common but also important for stable knee function. Most injuries to the collateral ligaments can be treated conservatively, though acute disruptions of the medial collateral ligament can lead to a fixed flexion ‘locked' knee mimicking a bucket handle tear. [ABSTRACT FROM AUTHOR]

Meniscal injuries are very common among professional and amateur athletes and are a major cause of functional impairment of the knee. For athletes, unnecessary treatment or intervention may be as damaging to a competitive future as failure to diagnose a clinically significant injury. Therefore, rapid and accurate evaluation of possible meniscal injuries is crucial in these patients. For detection of meniscal pathology, MRI is an excellent diagnostic imaging tool, with accuracy of as high as 95%, compared to arthroscopy, remaining the gold standard. Furthermore, MRI proved useful, on the basis of its high negative predictive value, to avoid unnecessary arthroscopy and hospitalization, morbidity, and waste of limited financial and manpower resources. However, radiologists must be aware of numerous pitfalls simulating a meniscal tear. Furthermore, MRI pictures contain many details with an uncertain clinical relevance, delineating the need to correlate MRI with clinical findings in order to plan treatment optimally. [ABSTRACT FROM AUTHOR]

Medical imaging has an extremely valuable role in the differentiation between the wide range of potential causes of hip and groin pain in athletes. Without such differentiation effective treatment is difficult to achieve especially where considering overuse injuries which may even be exacerbated by treatment based on diagnostic inaccuracy. Understanding the anatomy of the anterior pubic soft tissues allows correlation with MR imaging pathoanatomical appearances and therefore a better understanding of the pathomechanism of groin pain in athletes on which to base subsequent treatment. [ABSTRACT FROM AUTHOR]

Ultrasound and MRI are important tools for diagnosing sports related injuries of the ligaments and tendons of the hand. Important injuries may involve the flexor and extensor tendons, collateral ligaments, annular pulleys, volar plate, and dorsal hood. [ABSTRACT FROM AUTHOR]

Elbow injuries in athletes are relatively uncommon, especially acute injuries. Most injuries are contributed to overuse. Throwing, using the arm as a lever or as a weight bearing joint and stopping goal fired shots are the mechanisms in which injuries most often occur. Ulnar collateral ligament injuries, lateral and medial epicondylitis, medial epicondyle apophysitis, osteochondral lesions and intraarticular loose bodies are the most common encountered injuries. Standard radiography should be the initial imaging modality but in general MRI is the most useful imaging modality to use. In certain selected cases however US and CT can replace MRI or add valuable information. [ABSTRACT FROM AUTHOR]

Shoulder pain due to trauma or overuse is a common complaint in the populations of athletes in general, with a variety of causes that are frequently diffi cult to differentiate by physical examination alone. MR imaging and ultrasonography are optimal and complementary tools to discriminate different forms of impingement and to localize and classify rotator cuff injuries. A native MR imaging protocol including axial, oblique sagittal and oblique coronal sequences is in general suitable for patients presenting with symptoms of impingement, and to assess full-thickness tears. Partial thickness rotator cuff tears are most commonly encountered in (overhead throwing) athletes, particularly on the articular side, which are best appreciated using MR arthrography including abduction- exorotation views. [ABSTRACT FROM AUTHOR]

Shoulder instability is an increasing entity among throwing athletes and proper preoperative assessment is sometimes difficult to obtain based on history and physical examination alone. Shoulder MRI with or without contrast enhancement has been proven a very valuable diagnostic modality for the detection of subtle lesions involving the capsule, labrum and ligaments. Recent and changing new concepts on the etiology of some of the instability patterns, especially microinstability, in these patients makes MRI even more valuable to determine if a particular surgical approach may be successful. Further understanding of the early capsular lesions that lead eventually to severe impairment of joint function will be followed undoubtedly by the need for further refinement of the accuracy of the MRI technique and diagnostic skills of the interpreting radiologist. [ABSTRACT FROM AUTHOR]

Ligaments and tendons are complex collagenous soft tissue elements that respond to injury in a number of ways according to the age group of the patient and the mechanism of injury. They can be imaged in a number of ways but MRI and ultrasound are the most informative techniques for assessing these structures. [ABSTRACT FROM AUTHOR]

For evaluating sports related traumatic chondral and osteochondral lesions or assessing the quality of cartilage repair, MR imaging has long since become the most important diagnostic tool. In the future, this will become even more the case as experimental imaging sequences are integrated in routine clinical examinations. The only other imaging modality that can adequately depict the articular surface is CT-arthrography. This technique is, however, unable to demonstrate bone marrow edema, an imaging finding with high clinical significance. [ABSTRACT FROM AUTHOR]

The diagnosis of sports injuries can be difficult owing to the degree of overlap of symptoms between different injuries, necessitating further imaging evaluation. Different imaging techniques, with their specific advantages and limitations, can be used to diagnose and grade such injuries. The correct use of these imaging modalities will lead to an early and accurate diagnosis preventing the development of chronic pain or other complications and thus, avoiding waste of limited financial resources. The specific merit of each imaging modality in the evaluation of sports related lesions will be further high-lighted in the next chapters and summarized in schematic boxes. [ABSTRACT FROM AUTHOR]

The use of imaging techniques is an important tool for the sports physician in establishing the correct diagnosis and choosing the appropriate treatment procedures. In addition, imaging techniques can be useful for the evaluation and monitoring of the healing process and the early identification of complications. Good communication between the radiologist and the sports physician is essential. The information the sports physician provides to the radiologist regarding the history of injury, athlete's training program and physical examination will help the radiologist choose the correct imaging technique. The sports physician should also share his/her knowledge of the special demands of the sport involved and the effects that this has on the musculoskeletal system of the athlete. The radiologist should have an interest in sport and be willing to spend some extra time with the athlete for a detailed history and to communicate with the referring sports physician. The department should be flexible enough to examine athlete within 24 h to 5 days, if warranted. Detailed feedback from the radiologist to the sports physician will help the latter to make the correct interpretation of any abnormalities and direct him/her towards the appropriate form of treatment. It is only as a result of teamwork between the sports physician and the radiologist that an optimal outcome can be achieved. [ABSTRACT FROM AUTHOR]

The objective of this study was to validate a deformable image registration technique, termed Hyperelastic Warping, for left ventricular strain measurement during the systole using cine-gated nontagged MRI with strains measured from tagged MRI. Tagged and non-tagged cine images were obtained on a 1.5 T Siemens Avanto clinical scanner with a TrueFISP imaging sequence. The Hyperelastic Warping solution was evolved using a series of non-tagged images in 10 phases from end-diastole to end-systole. The solution may be considered as ten separate Warping problems with multiple Templates and Targets. At each stage, an active contraction was initially applied to the FE model, and then Warping penalty forces were utilized to generate the final registration. Warping results for circumferential strain were correlated (R2 =0.59) with results obtain from tagged MR images analyzed with a HARP algorithm. Results for fiber stretch, LV twist, and transmural strain distribution were similar to values in the literature. Hyperelastic Warping represents a novel approach for quantifying 3-D regional strains within the myocardium with a high resolution. [ABSTRACT FROM AUTHOR]

One of the popular methods (Intrinsic Low-Dimensional Manifolds — ILDM)) of decomposition of multiscale systems into fast and slow sub-systems for reduction of their complexity is considered in the present paper. The method successfully locates a position of slow manifolds of considered system and as any other numerical approach has its own disadvantages. In particular, an application of the ILDM-method produces so-called "ghost"-manifolds that do not have any connection to the true dynamics of the system. It is shown analytically that for two-dimensional singularly perturbed system (for which the fast-slow decomposition has been already done in analytical way) the "ghost"-manifolds appear. The problem of discrimination/identification of the "ghost"-manifolds is under consideration and two numerical criteria for their identification are proposed. A number of analyzed examples demonstrate efficiency of the suggested approach. [ABSTRACT FROM AUTHOR]

A measurement of the weak form factor of the proton allows a separation of the strangeness contribution to the electromagnetic form factors. The weak form factor is accessed experimentally by the measurement of a parity violating (PV) asymmetry in the scattering of polarized electrons on unpolarized protons. We performed such measurements with the setup of the A4-experiment at the MAMI accelerator facility in Mainz. The role of strangeness in low energy nonperturbative QCD is discussed. The A4-experiment is presented as well as the results on the strangeness form factors which have been measured at two Q2-values. The plans for backward angle measurements at the MAMI facility are presented. [ABSTRACT FROM AUTHOR]

Systematic uncertainties in the recent precise determination of the strangeness magnetic moment of the nucleon are identified and quantified. In summary, GMs = −0.046 ± 0.019 μN. [ABSTRACT FROM AUTHOR]

This latest in a series of workshops on parity-violating electron scattering comes at a momentous time in the history of this subject. The first experiments to determine strange form factors of the nucleon have produced intriguing final results, and several powerful new experiments are now producing data. In addition, the precision of the technique has been improving and new experiments testing the electroweak theory have reported remarkably precise data. There has also been a great deal of progress on both the theory of strange form factors and interpretation of electroweak symmetry tests. [ABSTRACT FROM AUTHOR]

I review recent progress and developments in parity-violating electron scattering as it bears on three topics: strange quarks and hadron structure, electroweak radiative corrections, and physics beyond the Standard Model. I also discuss related developments in parity-conserving scattering with transversely polarized electrons as a probe of two-photon processes. I conclude with a perspective on the future of the field. [ABSTRACT FROM AUTHOR]