Morphology and variability of the facial nerve trunk dependent on branching pattern, gender, anthropometric type and side of the head in Moldovan population

Background: Knowledge concerning variability of the facial nerve trunk (FNT) direction after its exit through the stylomastoid foramen is of a great clinical significance for maxillofacial surgeons, otorhinolaryngologists, oncologists, specialists in plastic and aesthetic surgery. The aim of our study was to establish the variation of the FNT direction and its peculiarities dependent on branching pattern, gender, anthropometric type and side of the head. Materials and methods: The direction of the FNT and its branching pattern were studied on 75 dissected hemifaces of adult formalized cadavers (59 male/16 female), and the morphometry of the FNT length, width and bifurcation angle was carried out. Results: Seven branching patterns of the facial nerve were established: Type I – 18.7%, Type II – 14.7%, Type III – 20%, Type IV – 14.6%, Type V – 5.3%, Type VI – 18.7%, and Type-NI – 8% (bizarre types). The FNT had a descending direction in 73.3% of cases; ascending FNT – 9.3% (including 5.3% of very short diffuse branching trunks and 1.3% of arch-shaped FNT); horizontal FNT – 10.7%; number variants – 6.7%. The male/female ratio of the descending FNT was 69.5%/87.4%; ascending – 10.2%/6.3%; horizontal – 11.9%/6.3%; number variants – 8.4% (only in male). The right/left ratio of the descending FNT was 62.9%/82.5%; ascending – 11.4%/7.5%; horizontal – 11.4%/10%; number variants – 14.3% (only on the right side). The ratio of the descending FNT in mesocephalic type (MCT) / brachycephalic type (BCT) / dolichocephalic type (DCT) was respectively 70.6%/100%/66.7%; ascending – 12.1%/0%/0%; horizontal – 12.1/0%/11.1%. Numerical variants in MCT – 5.2%, in DCT – 22.2%. The mean number of FNT in MCT/BCT/DCT was respectively 1.07/1.0/1.22. Conclusions: Three main directions are characteristic for FNT: the descending, ascending and horizontal ones, which vary dependent on branching pattern, gender, shape and side of the head

Breeding progress and preparedness for mass-scale deployment of perennial lignocellulosic biomass crops switchgrass, miscanthus, willow and poplar

Genetic improvement through breeding is one of the key approaches to increasing biomass supply. This paper documents the breeding progress to date for four perennial biomass crops (PBCs) that have high output–input energy ratios: namely Panicum virgatum (switchgrass), species of the genera Miscanthus (miscanthus), Salix (willow) and Populus (poplar). For each crop, we report on the size of germplasm collections, the efforts to date to phenotype and genotype, the diversity available for breeding and on the scale of breeding work as indicated by number of attempted crosses. We also report on the development of faster and more precise breeding using molecular breeding techniques. Poplar is the model tree for genetic studies and is furthest ahead in terms of biological knowledge and genetic resources. Linkage maps, transgenesis and genome editing methods are now being used in commercially focused poplar breeding. These are in development in switchgrass, miscanthus and willow generating large genetic and phenotypic data sets requiring concomitant efforts in informatics to create summaries that can be accessed and used by practical breeders. Cultivars of switchgrass and miscanthus can be seed-based synthetic populations, semihybrids or clones. Willow and poplar cultivars are commercially deployed as clones. At local and regional level, the most advanced cultivars in each crop are at technology readiness levels which could be scaled to planting rates of thousands of hectares per year in about 5 years with existing commercial developers. Investment in further development of better cultivars is subject to current market failure and the long breeding cycles. We conclude that sustained public investment in breeding plays a key role in delivering future mass-scale deployment of PBCs