QTL dynamics for fruit firmness and softening around an ethylene-dependent polygalacturonase gene in apple (Malus×domestica Borkh.)

Apple fruit are well known for their storage life, although a wide range of flesh softening occurs among cultivars. Loss of firmness is genetically coordinated by the action of several cell wall enzymes, including polygalacturonase (PG) which depolymerizes cell wall pectin. By the analysis of ‘Fuji’ (Fj) and ‘Mondial Gala’ (MG), two apple cultivars characterized by a distinctive ripening behaviour, the involvement of Md-PG1 in the fruit softening process was confirmed to be ethylene dependent by its transcript being down-regulated by 1-methylcyclopropene treatment in MG and in the low ethylene-producing cultivar Fj. Comparing the PG sequence of MG and Fj, a single nucleotide polymorphism (SNP) was discovered. Segregation of the Md-PG1SNP marker within a full-sib population, obtained by crossing Fj and MG, positioned Md-PG1 in the linkage group 10 of MG, co-located with a quantitative trait locus (QTL) identified for fruit firmness in post-harvest ripening. Fruit firmness and softening analysed in different stages, from harvest to post-storage, determined a shift of the QTL from the top of this linkage group to the bottom, where Md-ACO1, a gene involved in ethylene biosynthesis in apple, is mapped. This PG–ethylene-related gene has beeen positioned in the apple genome on chromosome 10, which contains several QTLs controlling fruit firmness and softening, and the interplay among the allelotypes of the linked loci should be considered in the design of a marker-assisted selection breeding scheme for apple texture

Liver abscesses with pyopericardium: Laparoscopic management in a preterm neonate

We report a 28-day-old neonate presenting with signs of fever, abdominal distension, and refusal to feed. The baby was diagnosed to have multiple liver abscesses which ruptured and a tract lead to the pericardium resulting in a pyo-pericardium. Laparoscopic drainage of the abscess cavities and the pyo-pericardium was performed. An extensive search of the literature revealed that this case is the youngest one to have undergone such simultaneous laparoscopic drainage

UNMANNED SURFACE VESSEL LIFECYCLE SUSTAINMENT ENGINEERING INVESTIGATION

Unmanned systems are quickly evolving capabilities that U.S. military services are pursuing to meet military needs. The Department of the Navy requires unmanned surface vessels (USV) to be forward deployed to accommodate tactical and operational needs. These USVs will not generate cost-effective capabilities if they cannot be sustained effectively outside of continental United States (OCONUS), thus this report provides recommendations to be used in USV life cycle sustainment planning to ensure that USVs can accommodate the Fleet’s tactical and operational needs. To ensure USVs are sustainable OCONUS, requirements were categorized according to mission needs, personnel, cost mitigation, training, and programmatic sustainability. Magic System of Systems Architecture was then used to generate a back-of-the-envelope model to output materiel availability (AM) and operational availability (AO) to verify the outputs of a more detailed ExtendSim model. Simulation and analysis concluded the primary factor affecting USV availability rates is the availability of corrective maintenance. Decreasing access to corrective maintenance facilities also initiated a cascading effect, leading to backlogs throughout the USV sustainment and deployment cycle. The finding concluded that corrective maintenance of USVs throughout their sustainment and deployment cycle should be prioritized.Approved for public release. Distribution is unlimited.Civilian, Department of the NavyCivilian, Department of the NavyCivilian, Department of the NavyCivilian, Department of the NavyCivilian, Department of the Nav