Partially-Covered Fractal Induced Turbulence On Fins Thermal Dissipation

The impacts of partially-covered fractal grids induced turbulence on the forced convective heat transfer across plate-fin heat sink at Reynolds number ReDh=22.0×103 were numerically and experimentally investigated. Results showed that partially covered grids rendered a higher thermal dissipation performance, with partially covered square fractal grid (PCSFG) registering an outstanding increase of 43% in Nusselt number relative to the no grid configuration. The analyzation via an in-house developed single particle tracking velocimetry (SPTV) system displayed the findings of unique “Turbulence Annulus” formation, which provided a small degree of predictivity in the periodic annulus oscillations. Further assessments on PCSFG revealed the preferred inter-fin flow dynamics of (i) high flow velocity, (ii) strong turbulence intensity, (iii) vigorous flow fluctuations, (iv) small turbulence length scale, and (v) heightened decelerated flow events. Furthermore, power spectra density unveiled the powerful vortex shedding effect, with PCSFG achieving fluctuation frequency f=18.5Hz close to an optimal magnitude. Such intricate flow structures pave the way for superior thermal transfer capabilities, benefiting the community in developing for higher efficiency heat transfer systems.

Androglobin, a chimeric mammalian globin, is required for male fertility

Spermatogenesis is a highly specialised process, involving multiple dedicated pathways and regulatory check-points. Defects ultimately lead to male sub-fertility or sterility, and numerous aspects of mammalian sperm formation remain unknown. The predominant expression of the latest globin family member, androglobin (Adgb) in mammalian testis tissue prompted us to assess its physiological function in spermatogenesis. Adgb knockout mice display male infertility, reduced testis weight, impaired maturation of elongating spermatids, abnormal sperm shape and ultrastructural defects in microtubule and mitochondrial organisation. Epididymal sperm from Adgb knockout animals display multiple flagellar malformations including coiled, bifide or shortened flagella, and erratic acrosomal development. Following immunoprecipitation and mass spectrometry, we could identify septin 10 (Sept10) as interactor of Adgb. The Sept10-Adgb interaction was confirmed both in vivo using testis lysates, and in vitro by reciprocal co-immunoprecipitation experiments. Furthermore, absence of Adgb leads to mislocalisation of Sept10 in sperm, indicating defective manchette and sperm annulus formation. Finally, in vitro data suggest that Adgb contributes to Sept10 proteolysis in a calmodulin (CaM)-dependent manner. Collectively, our results provide evidence that Adgb is essential for murine spermatogenesis and further suggest that interdependence between Adgb and Sept10 is required for sperm head shaping via the manchette and proper flagellum formation.

Age, growth and mortality of the yellowmouth barracuda Sphyraena viridensis (Sphyraenidae) from eastern coasts of Algeria

Age and growth of the yellowmouth barracuda Sphyraena viridensis (Cuvier, 1829) was examined in 698 individuals (184 < TL (mm) < 1210; 25 < TW (g) < 7125), sampled monthly from commercial catches in eastern coasts of Algeria between January 2007 and January 2008. Marginal increment analysis of 159 sectioned sagittal otoliths combined with information derived from length–frequency distribution showed that annulus formation occurs between June and August. Maximum observed age of males and females is 14 and 13 years respectively. Back calculations of total length-at-age were used to fit the data to the Bertalanffy growth model: TL = 1113(1 – e−0.165(t+2.251)) in males and TL = 958.3 (1 – e−0.247(t+1.422)) in females. The coefficient of allometry of the length weight relationship is 3.02 and 2.99 in males and females, respectively. Growth performance index Ø = 3.33. Natural mortality (M) was estimated as 0.45 year−1, fishing mortality (F) was 0.06 year−1and the exploitation rate (E) was 0.11.

Exploiting Wired-Pipe Technology in an Adaptive Observer for Drilling Incident Detection and Estimation

Summary We deploy an adaptive observer recently developed for general hyperbolic partial differential equation (PDE) systems to detect and diagnose various drilling incidents. The well is modeled by a distributed PDE which, contrary to lumped models, preserves fundamental properties of well-flow dynamics enabling faster and more accurate incident detection and estimation. Wired drillpipe technology with pressure sensors is needed to locate and isolate incidents. Four realistic simulation case studies demonstrating various properties of the observer are presented. Drilling incidents treated in the simulation case studies include packoff in the annulus, formation in-flows, loss of circulation, and various combinations of these. Although simulation results show that the developed observers successfully estimate properties of the incidents that they are tailored for, they do not constitute an incident-detection system for drilling. However, they provide a part of the data on which an overall incident-detection system can rely.

TDP-43 and HSP70 phase separate into anisotropic, intranuclear liquid spherical annuli

The RNA binding protein TDP-43 naturally phase separates within cell nuclei and forms cytoplasmic aggregates in age-related neurodegenerative diseases. Here we show that acetylation-mediated inhibition of TDP-43 binding to RNA produces co-de-mixing of acetylated and unmodified TDP-43 into symmetrical, intranuclear spherical annuli whose shells and cores have liquid properties. Shells are anisotropic, like liquid crystals. Consistent with our modelling predictions that annulus formation is driven by components with strong self-interactions but weak interaction with TDP-43, the major components of annuli cores are identified to be HSP70 family proteins, whose chaperone activity is required to maintain liquidity of the core. Proteasome inhibition, mimicking reduction in proteasome activity during aging, induces TDP-43-containing annuli in neurons in rodents. Thus, we identify that TDP-43 phase separation is regulated by acetylation, proteolysis, and ATPase-dependent chaperone activity of HSP70.One Sentence SummaryAcetylation of TDP-43 drives its phase separation into spherical annuli that form a liquid-inside-a-liquid-inside-a-liquid.

Validation of Annulus Formation in Golden Shiner Otoliths

Golden Shiner Notemigonus crysoleucas is found in many lakes and ponds across the southeastern United States. Though it is a common species, otolith age validation methods have not been published. The objective of this study was to confirm annulus formation in lapillar otoliths of Golden Shiners collected monthly from September 2015 through August 2016 in Lake Jackson, Florida (Leon County). We collected at least 12 individuals each month of similar length (168–249 mm; presumably of the same cohort) to document annulus formation throughout the year. We sacrificed a total of 177 individuals from the 2013 year class, and we used their lapillar otoliths for marginal incremental analysis to calculate an index of completion and validate annulus formation. The monthly index of completion was highest from January through March and lowest in May and June, indicating that annuli were deposited once per year and confirming that lapillar otoliths are a valid age estimation structure for Golden Shiners.