Many economic, political and social environments can be described as contests in which agents exert costly efforts while competing over the distribution of a scarce resource. These environments have been studied using Tullock contests, all-pay auctions and rank-order tournaments. This survey provides a comprehensive review of experimental research on these three canonical contests. First, we re...

Dystrophic epidermolysis bullosa (DEB) is due to mutations in the type VII collagen (C7) gene. Potential therapies for DEB include (i) ex vivo gene therapy and (ii) intradermal injection of gene-corrected DEB fibroblasts, lentiviral vectors expressing C7 or recombinant C7 itself. With regard to molecular engineering, the dermal fibroblast has advantages over epidermal keratinocytes for deliveri...

BACKGROUND Ipsilateral C7 nerve transfer is an available procedure in C5C6 2-root avulsion injury of the brachial plexus. However, concomitant injury of a normal-looking C7 cannot be ruled out. The efficiency of a concomitant injury of C7 transfer was investigated. METHODS Forty-two Sprague-Dawley rats were randomly assigned to 5 groups. They all underwent a 2-stage procedure. In the first st...

BACKGROUND Since the 1980s, the C7 nerve root has gained clinical relevance as a donor nerve in severe brachial plexus root avulsion injuries. Despite success with the cross-chest C7 nerve transfer, inducing injury on an otherwise normal side hinders global acceptance. By sacrificing the C7 nerve root, a predictable pattern of transient sequelae is seen, including extensor weakness and index an...

The intralaminar screw construct has been recently introduced in C6-C7 fixation. The aim of the study is to compare the stability afforded by three different C7 posterior fixation techniques using a three-dimensional finite element model of a C6-C7 cervical spine motion segment. Finite element models representing three different cervical anchor types (C7 intralaminar screw, C7 lateral mass scre...

Results In males, C7 SP is longer in 72.90% and T1 is longer in 27.1% (p <0,001); in females, C7 is longer in 42.7% and T1 is longer in 57.3% (p <0,001), respectively. Therefore, there is a statistically significant difference of C7 – T1 SP morphology. In males, the average length of C7 SP was 44,11 mm (range 23,70 mm to 61,90 mm); in females, the average length of C7 SP was 37,82 mm (range 26,...

STUDY DESIGN A biomechanical study using human spine specimens. OBJECTIVE The aim of this study was to assess whether the presence of cervical sagittal imbalance is an independent risk factor for increasing the mechanical burden on discs adjacent to cervical multilevel fusions. SUMMARY OF BACKGROUND DATA The horizontal offset distance between the C2 plumbline and C7 vertebral body (C2-C7 Sa...

INTRODUCTION This study investigated the relationship between the parameters related to the natural head position and cervical segmental angles and alignment of patients with neck pain. MATERIAL AND METHODS The lateral radiographs of the cervical spine were collected from 103 patients and were used to retrospectively analyze the correlation between the natural head position, cervical local sa...

Complement C7 deficiency is an autosomal recessive disorder well known to be associated with increased susceptibility to meningococcal infection and has mostly been reported in Caucasians. In the Korean population, no case of C7 deficiency has been reported to date. Recently we experienced an 11-yr-old girl with meningococcal meningitis who was diagnosed as having C7 deficiency based upon the u...

STUDY DESIGN Retrospective study. OBJECTIVE To assess the relationship between sagittal alignment of the cervical spine and patient-reported health-related quality-of-life scores following multilevel posterior cervical fusion, and to explore whether an analogous relationship exists in the cervical spine using T1 slope minus C2-C7 lordosis (T1S-CL). SUMMARY OF BACKGROUND DATA A recent study ...