Asymptotics of continuous-time discrete state space branching processes for large initial state

Scaling limits for continuous-time branching processes with discrete state space are provided as the initial state tends to infinity. Depending on the finiteness or non-finiteness of the mean and/or the variance of the offspring distribution, the limits are in general time-inhomogeneous Gaussian processes, time-inhomogeneous generalized Ornstein-Uhlenbeck type processes or continuous-state branching processes. We also provide transfer results showing how specific asymptotic relations for the probability generating function of the offspring distribution carry over to those of the one-dimensional distributions of the branching process

On Some Scaling Limits for Branching and Coalescent Processes

Two well-known processes from the field of mathematical population genetics are treated. The two processes are a class of branching processes and partition-valued, exchangeable coalescents. In both cases process-valued scaling limits are provided as the initial population size tends to infinity. For branching processes the number of individuals is examined and for coalescents the number of blocks

Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences and Countermeasures.

Circadian (∼ 24 hour) timing systems pervade all kingdoms of life, and temporally optimize behaviour and physiology in humans. Relatively recent changes to our environments, such as the introduction of artificial lighting, can disorganize the circadian system, from the level of the molecular clocks that regulate the timing of cellular activities to the level of synchronization between our daily cycles of behaviour and the solar day. Sleep/wake cycles are intertwined with the circadian system, and global trends indicate that these too are increasingly subject to disruption. A large proportion of the world's population is at increased risk of environmentally-driven circadian rhythm and sleep disruption, and a minority of individuals are also genetically predisposed to circadian misalignment and sleep disorders. The consequences of disruption to the circadian system and sleep are profound and include myriad metabolic ramifications, some of which may be compounded by adverse effects on dietary choices. If not addressed, the deleterious effects of such disruption will continue to cause widespread health problems; therefore, implementation of the numerous behavioural and pharmaceutical interventions that can help restore circadian system alignment and enhance sleep will be important

Validation of radiological reduction criteria with intraoperative cone beam CT in unstable syndesmotic injuries

Purpose!#!Acute unstable syndesmotic lesions are regularly treated with closed or open reduction and fixation with either a positioning screw or tight rope. Conventional fluoroscopy is limited to identify a malreduction of the ankle mortise. The aim of the study was to validate the reduction criteria of intraoperative cone beam CT in unstable syndesmotic injuries by analyzing the clinical outcome.!##!Methods!#!Acute unstable syndesmotic injuries were treated with a positioning screw fixation, and the reduction in the ankle mortise was evaluated with intraoperative cone beam CT. The patients were grouped postoperatively according to the radiological reduction criteria in the intraoperative 3D images. The reduction criteria were unknown to the surgeons. Malreduction was assumed if one or more reduction criteria were not fulfilled.!##!Results!#!Seventy-three of the 127 patients could be included in the study (follow-up rate 57.5%). For 41 patients (56.2%), a radiological optimal reduction was achieved (Group 1), and in 32 patients (43.8%) a radiological adverse reduction was found (Group 2). Group 1 scored significantly higher in the Olerud/Molander score (92.44 ± 10.73 vs. 65.47 ± 28.77) (p = 0.003), revealed a significantly higher range of motion (ROM) (53.44 vs. 24.17°) (p = 0.001) and a significantly reduced Kellgren/Lawrence osteoarthritis score (1.24 vs. 1.79) (p = 0.029). The linear regression analysis revealed a correlation for the two groups with the values scored in the Olerud/Molander score (p < 0.01).!##!Conclusion!#!The reduction criteria in intraoperative cone beam CT applied to unstable syndesmotic injuries could be validated. Patients with an anatomic reduced acute unstable syndesmotic injury according to the criteria have a significantly better clinical outcome

Long-term results after non-operative and operative treatment of radial neck fractures in adults

Abstract Background The aim of this study is to determine the functional long-term outcome after non-operative and operative treatment of radial neck fractures in adults. Methods Thirty-four consecutive patients with a mean age of 46.4 (18.0 to 63.0) years with a fracture of the radial neck who were treated between 2000 and 2014 were examined regarding the clinical and radiological outcome. Twenty patients were treated non-operatively, and 14 patients underwent surgery. Results After a mean follow-up of 5.7 (2.0 to 15.7) years, the clinical scores showed good results in both groups. The Disabilities of Arm, Shoulder and Hand score was 16.1 (0 to 71.6) in the non-operative group and 8.8 (0 to 50.8) in the operative group, respectively. The Mayo Elbow Performance Score was 80.0 (30 to 95) in the non-operative group and 82.5 (35 to 95) in the non-operative group, respectively. The initial angle of the radial head towards the shaft (RHSA) was significantly higher in the operative group in the anterior-posterior plane (12.8° [2 to 23] vs. 26.3° [1 to 90], p = 0.015). In the follow-up radiographs, the RHSA was significantly lower in the operative group (15.1° [3 to 30] vs. 10.9° [3 to 18], p = 0.043). Five patients developed 7 complications in the non-operative group, and 7 patients developed 12 complications in the operative group. Revision rates were higher in the operative groups as 1 patient received radial head resection in the non-operative (5%) group while 7 patients in the operative group (50%) needed revision surgery. Conclusion A good functional long-term outcome can be expected after operative and non-operative treatment of radial neck fractures in adults. If needed due to major displacement, open reduction is associated with a higher risk of complications and the need for revision surgery but can achieve similar clinical results. Trial registration DRKS DRKS00012836 (retrospectively registered

Influence of ankle joint position on angles and distances of the ankle mortise using intraoperative cone beam CT: A cadaveric study.

BackgroundThe precise anatomical reduction of the ankle mortise is crucial for the clinical outcome in unstable syndesmotic injuries. Intraoperative cone beam computed tomography (CT), in addition to two-dimensional fluoroscopy, provides detailed information about the reduction and implant placement. The aim of this study was to analyze the influence of the joint position on the fibula position in the incisural notch and to determine the inter- and intraindividual anatomical differences in the intact ankle joints.MethodsA total of 20 fresh-frozen lower legs disarticulated in the knee joint of 10 individuals were included. The measurements were performed using a cone beam CT. The distances and angles were measured in the standard imaging planes. The mean values of distances and angles were compared during the different joint positions: 10° dorsiflexion, 0° neutral position and 20° plantar flexion.ResultsThe influence of the joint position was on average as follows: The anterior tibiofibular distance was 3.68 mm in 10° dorsiflexion, 3.66 mm (0° neutral position) and 3.59 mm (20° plantar flexion). The posterior tibiofibular distance measured 7.82mm, 7.76mm and 7.82mm. The rotation of the fibula measured ten millimeters proximal the joint line was 1.2°, 1.3° and 1.05°. The fibular rotation determined 4mm was 9.3°, 9.4° and 9.4°. On average, the following intraindividual variations were observed: superior tibiotalar clear space of 0.27mm and 0.15mm medial; and anterior tibiofibular distance of 0.42mm, 0.38mm posterior and 0.24mm in the incisural notch. The proximal angle of the fibular rotation was 0.2° and distal 0.4°. The interindividual variations of the angles and distances exceeded the intraindividual values partly by 3 to 4 fold.ConclusionsWithin the scope of this study neither the tibiofibular distance, nor the tibiofibular angle changed significantly through the different joint positions. The intraindividual differences were little while the interindividual variations of the parameters were distinctive