Baossi–Warack monogenetic volcanoes, Adamawa Plateau,Cameroon: petrography, mineralogy and geochemistry

Three monogenetic cones in the Baossi–Warack area, Ngaoundéré, Adamawa Plateau forming part of the Cameroon Volcanic Line(CVL) are documented in this study. Basaltic lavas(<1 km^3) scattered around these vents and restricted volcaniclastic deposits were emplaced by Hawaiian and mild strombolian style eruptions. The lavas are porphyritic, mainly composed of olivine(chrysolite) and clinopyroxene(diopside and augite) phenocrysts and plagioclase(andesine) microphenocrysts. Accessory minerals include titano-magnetite and titano-hematite, nepheline,apatite and amphibole xenocrysts. Sanidine occurs in some samples and sodi-potassic albite in others. Some olivines and clinopyroxenes exhibit resorbed margins and thin reaction rims while plagioclase displays oscillatory zoning, and sieved textures as a result of magma mixing. Whole-rock geochemistry data indicates that the lavas are silica-undersaturated, composed of basanites and basalts, showing little compositional variations(SiO_2: 39.20 wt.%–48.01 wt.%,MgO: 5.29 wt.%–9.70 wt.%). Trace elements patterns of these lavas suggest they are enriched in LILE including Pb,probably due to crustal contamination. REE patterns suggest cogenetic magmas below Baossi 1 and Baossi 2 volcanoes,and distinct sources below Warack volcano and nearby lavas.The lavas studied show affinity to high-μ(HIMU), enriched type Ⅰ(EM1) and Oceanic Island Basalt(OIB)-like mantle signatures and thus indicate a heterogeneous mantle source underneath the vents as noted at other monogenetic and polygenetic volcanoes along the CVL. Primary melts derived from low degrees of partial melting(0.5%–2%) and encountered low rates of fractionation, and crustal contamination coupled with magma mixing. These melts evolved independently through structural weaknesses in the basement.

Mineralogy and geochemistry of pozzolans from the Tombel Plain,Bamileke Plateau,and Noun Plain monogenetic volcanoes in the central part of the Cameroon Volcanic Line

Pozzolans from the Tombel Plain,Bamileke Plateau,and Noun Plain,3 monogenetic volcanic fields in the central part of the Cameroon Volcanic Line(the Tombel Plain,Bamileke Plateau,and Noun Plain),were explored in order to constrain their petrology and make some predictions on their pozzolanicity.The rocks in this study include alkaline and subalkaline basalts,trachybasalts,and basanites.Most of these rocks present an overall composition that overlaps with primitive mantle,suggesting rapid ascent of magmas,limited crustal contamination and crystal fractionation of olivine,clinopyroxene,and feldspar.The pozzolans present enrichment of LREE relative to HREE and high chondrite normalized ratios of La/Yb and Tb/Yb.ranging between 7 and 20 and>1.9 respectively,similar to those of Ocean Island Basalts.Like other nearby volcanoes,partial melting in a dominantly garnet-bearing mantle zone can be assumed.Quantitative mineralogy by X-ray diffraction revealed various mineral phases with dominantly plagioclase,augite,olivine,and Fe-Ti oxides.The samples contains important amorphous phase up to 23,51,and 69 wt%in the Tombel Plain,Noun Plain,and Bamileke Plateau,respectively.This elevated amount of amorphous phases together with the sum of SiO2,Al2O3 and total Fe2O3(SAI=68.50-83.50>70 wt%)according to ASTM C618 standard and the sum of CaO,FeO,and MgO(CIM=14.5-30.52 wt%and 23.58-31.08 wt%)suggest interesting pozzolanicity character for the studied pozzolans.

Leptin gene-targeted editing in ob/ob mouse adipose tissue based on the CRISPR/Cas9 system

Gene therapy has become the most effective treatment for monogenic diseases.Congenital LEPTIN deficiency is a rare autosomal recessive monogenic obesity syndrome caused by mutations in the Leptin gene.Ob/ob mouse is a monogenic obesity model,which carries a homozygous point mutation of C to T in Exon 2 of the Leptin gene.Here,we attempted to edit the mutated Leptin gene in ob/ob mice preadipocytes and inguinal adipose tissues using CRISPR/Cas9 to correct the C to T mutation and restore the production of LEPTIN protein by adipocytes.The edited preadipocytes exhibit a correction of 5.5%of Leptin alleles and produce normal LEPTIN protein when differentiated into mature adipocytes.The ob/ob mice display correction of 1.67%of Leptin alleles,which is sufficient to restore the production and physiological functions of LEPTIN protein,such as suppressing appetite and alleviating insulin resistance.Our study suggests CRISPR/Cas9-mediated in situ genome editing as a feasible therapeutic strategy for human monogenic diseases,and paves the way for further research on efficient delivery system in potential future clinical application.

Hidradenitis Suppurativa: An Exploration of Genetic Perturbations and Immune Dysregulation

Hidradenitis suppurativa(HS)is a chronic,inflammatory skin condition that poses a significant diagnostic and therapeutic challenge for clinicians,as the underlying etiology and pathogenesis remains unclear.The host of genetic mutations and immune dysfunction has been identified to be involved in the pathogenesis of HS during recent years.These genetic defects,including monogenetic mutations altering subunits ofγ-secretase,a protease that functions through Notch signaling to maintain skin appendages,promote epithelial stability,suppress/terminate innate immune responses(ie,Toll-receptors),further have the propensity to induce aberrant cytokine responses that create to a proinflammatory environment,consequently induce hyperkeratosis and promote expression of pro-inflammatory,locally destructive matrix metalloproteinases.Cytokine-driven inflammation propagates the disease state of HS and contributes to the formation of painful subcutaneous nodules,abscesses,and eventually,fistulas and draining sinus tracts.A closer look at genetic mutations linked to the disease may explain the immune perturbations seen in HS.An understanding of the immune cells and inflammatory markers expressed in affected individuals provides insight into disease pathogenesis and can help identify therapeutic targets.