An advanced towed CTD chain for physical-biological high resolution in situ upper ocean measurements

Submesoscale eddies, fronts, and filaments are ubiquitous in the upper ocean and play an important role in biogeochemical and mixing processes as well as in the energy budget. To capture the high spatial variability of submesoscale processes, it is desirable to simultaneously resolve the vertical and horizontal gradients of hydrographic properties on scales of 10 m to 10 km. We present a revised towed CTD chain, for rapid quasi-synoptic in situ measurements of submesoscale oceanographic features, that is lighter, more robust and scientifically more useful than previous towed CTD chains. This new instrument provides a horizontal resolution of O(1 m) and can be towed at speeds of up to 5 ms-1 for measurements of the upper 100 m of the water column while providing a reasonable vertical resolution of O(1 m – 10 m). Individual CTD probes are equipped with temperature, conductivity, pressure and either rapid response dissolved oxygen or fluorescence sensors at multiple depths, enabling both hydrographic and biogeochemical studies at high resolution. A flexible probe hardware allows either real-time data collection or internal data logging for offline post-processing. Finally, we outline the necessary post-processing steps and provide data examples. With the presented data examples we show and conclude that the advanced towed CTD chain is a flexible and lightweight take on the towed CTD chain concept. It can easily be adapted to scientific needs and provides high quality very high resolution oceanographic data

Biallelic variants in HPDL cause pure and complicated hereditary spastic paraplegia.

Human 4-hydroxyphenylpyruvate dioxygenase-like (HPDL) is a putative iron-containing non-heme oxygenase of unknown specificity and biological significance. We report 25 families containing 34 individuals with neurological disease associated with biallelic HPDL variants. Phenotypes ranged from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spasticity and global developmental delays, sometimes complicated by episodes of neurological and respiratory decompensation. Variants included bona fide pathogenic truncating changes, although most were missense substitutions. Functionality of variants could not be determined directly as the enzymatic specificity of HPDL is unknown; however, when HPDL missense substitutions were introduced into 4-hydroxyphenylpyruvate dioxygenase (HPPD, an HPDL orthologue), they impaired the ability of HPPD to convert 4-hydroxyphenylpyruvate into homogentisate. Moreover, three additional sets of experiments provided evidence for a role of HPDL in the nervous system and further supported its link to neurological disease: (i) HPDL was expressed in the nervous system and expression increased during neural differentiation; (ii) knockdown of zebrafish hpdl led to abnormal motor behaviour, replicating aspects of the human disease; and (iii) HPDL localized to mitochondria, consistent with mitochondrial disease that is often associated with neurological manifestations. Our findings suggest that biallelic HPDL variants cause a syndrome varying from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spastic tetraplegia associated with global developmental delays

Biallelic variants in HPDL cause pure and complicated hereditary spastic paraplegia

Human 4-hydroxyphenylpyruvate dioxygenase-like (HPDL) is a putative iron-containing non-heme oxygenase of unknown specificity and biological significance. We report 25 families containing 34 individuals with neurological disease associated with biallelic HPDL variants. Phenotypes ranged from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spasticity and global developmental delays, sometimes complicated by episodes of neurological and respiratory decompensation. Variants included bona fide pathogenic truncating changes, although most were missense substitutions. Functionality of variants could not be determined directly as the enzymatic specificity of HPDL is unknown; however, when HPDL missense substitutions were introduced into 4-hydroxyphenylpyruvate dioxygenase (HPPD, an HPDL orthologue), they impaired the ability of HPPD to convert 4-hydroxyphenylpyruvate into homogentisate. Moreover, three additional sets of experiments provided evidence for a role of HPDL in the nervous system and further supported its link to neurological disease: (i) HPDL was expressed in the nervous system and expression increased during neural differentiation; (ii) knockdown of zebrafish hpdl led to abnormal motor behaviour, replicating aspects of the human disease; and (iii) HPDL localized to mitochondria, consistent with mitochondrial disease that is often associated with neurological manifestations. Our findings suggest that biallelic HPDL variants cause a syndrome varying from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spastic tetraplegia associated with global developmental delays

Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

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