Newly recognized turbidity current structure can explain prolonged flushing of submarine canyons

Seabed-hugging flows called turbidity currents are the volumetrically most important process transporting sediment across our planet and form its largest sediment accumulations. We seek to understand the internal structure and behavior of turbidity currents by reanalyzing the most detailed direct measurements yet of velocities and densities within oceanic turbidity currents, obtained from weeklong flows in the Congo Canyon. We provide a new model for turbidity current structure that can explain why these are far more prolonged than all previously monitored oceanic turbidity currents, which lasted for only hours or minutes at other locations. The observed Congo Canyon flows consist of a short-lived zone of fast and dense fluid at their front, which outruns the slower moving body of the flow. We propose that the sustained duration of these turbidity currents results from flow stretching and that this stretching is characteristic of mud-rich turbidity current systems. The lack of stretching in previously monitored flows is attributed to coarser sediment that settles out from the body more rapidly. These prolonged seafloor flows rival the discharge of the Congo River and carry ~2% of the terrestrial organic carbon buried globally in the oceans each year through a single submarine canyon. Thus, this new structure explains sustained flushing of globally important amounts of sediment, organic carbon, nutrients, and fresh water into the deep ocean

Mycoplasma pneumoniae-associated mucositis syndrome: A rare and clinically challenging disease in a Saudi child

التهاب الأغشية المخاطية الذي تسببه المفطورة الرئوية هو مظهر للعدوى بالمفطورة الرئوية خارج الرئة، الذي قد يظهر كأضرار مخاطية معزولة (مثل العين، والفم والجهاز البولي التناسلي) أو في مزيج من الأضرار المخاطية والجلدية الصغيرة. ويعتبر التهاب الأغشية المخاطية الذي تسببه المفطورة الرئوية مظهرا نادرا يشكل سلسلة لحماميات عديدة الأشكال رئيسة ومتلازمة ستيفن جونسون. نقدم حالة طفل عمره ١٢ عاما حضر بمظاهرسريرية تقليدية لالتهاب الأغشية المخاطية بالمفطورة الرئوية، وكان تفاعل البلمرة المتسلسل للمفطورة الرئوية إيجابيا بقوة. عولج المريض بالعلاجات المضادة للجراثيم وقد تم شفاؤه. يجب على الطبيب أن يكون على دراية بهذه الحالة النادرة ويعالج المرضى وفقا لذلك

Mobilization of the temporal pole as integrated step in microsurgical clipping of pure posteriorly directed posterior communicating artery aneurysm

A pure posteriorly posterior communicating artery (PCoA) aneurysm represents a surgical challenge. This is mainly when there is a need for good exposure of the aneurysmal neck, sac, PCoA, and anterior choroidal arteries. Ruptured pure posteriorly directed PCoA aneurysm imposes significantly extra challenge as the surgeon undergoes dissection through a tight brain. Even with measures commonly used to attain brain relaxation like the lumbar drain and cisternal fenestration. Here, we describe a technique for posterior temporal pole mobilization (TPM) as an integrated part of microsurgical clipping of ruptured pure posteriorly directed PCoA aneurysms. This technique is implicated in twenty-three successive cases of ruptured PCoA aneurysms in the neurosurgery teaching hospital in Baghdad, Iraq, with no reported complications

ON-1 and BA-IX Are the Dominant Sub-Genotypes of Human Orthopneumovirus A&B in Riyadh, Saudi Arabia

Human orthopneumovirus (HOPV) is the major viral pathogen responsible for lower respiratory tract infections (LRTIs) in infants and young children in Riyadh, Saudi Arabia. Yet, predominant HOPV subtypes circulating in this region and their molecular and epidemiological characteristics are not fully ascertained. A total of 300 clinical samples involving nasopharyngeal aspirates (NPAs), throat swabs, and sputum were collected during winter seasons of 2019/2020 and 2021/2022 for HOPV subtyping and genotyping. Of the 300 samples, HOPV was identified in 55 samples (18.3%) with a distinct predominance of type A viruses (81.8%) compared to type B viruses (18.2%). Importantly, the ON1 strain of HOPV-A and BA-IX strain of HOPV-B groups were found to be responsible for all the infections. Sequence analysis revealed a duplication region within 2nd HVR of G protein gene of ON1 and BA-IX strains. This nucleotide duplication exerted a profound effect on protein length and affinity towards cell receptors. Further, these modifications may aid the HOPV in immune evasion and recurrent infections. Data from this study showed that ON-1 genotype of HOPV-A and BA-IX genotype of HOPV-B were dominant in Riyadh, Saudi Arabia. Further, a duplication of sequence within 2nd HVR of G protein gene was found

From a single whole exome read to notions of clinical screening:primary ciliary dyskinesia and RSPH9 p.Lys268del in the Arabian Peninsula

Primary ciliary dyskinesia (PCD) is a genetic disorder, usually autosomal recessive, causing early respiratory disease and later subfertility. Whole exome sequencing may enable efficient analysis for locus heterogeneous disorders such as PCD. We whole exome sequenced one consanguineous Saudi Arabian with clinically diagnosed PCD and normal laterality, to attempt ab initio molecular diagnosis. We reviewed thirteen known PCD genes and potentially autozygous regions (extended homozygosity) for homozygous exon deletions, non-dbSNP codon, splice-site base variants or small indels. Homozygous non-dbSNP changes were also reviewed exome-wide. One single molecular read representing RSPH9 p.Lys268del was observed, with no wildtype reads, and a notable deficiency of mapped reads at this location. Among all observations, RSPH9 was the strongest candidate for causality. Searching unmapped reads revealed seven more mutant reads. Direct assay for p.Lys268del (MboII digest) confirmed homozygosity in the affected individual, then confirmed homozygosity in three siblings with bronchiectasis. Our finding in southwest Saudi Arabia indicates that p.Lys268del, previously observed in two Bedouin families (Israel, UAE) is geographically widespread in the Arabian Peninsula. Analogous with cystic fibrosis CFTR p.Phe508del, screening for RSPH9 p.Lys268del (which lacks sentinel dextrocardia) in those at risk would help in early diagnosis, tailored clinical management, genetic counselling and primary prevention

Reads (from PCD affected sibling) mapped to the human genome hg19 at the p.(G300D) mutation.

<p>The read depth is 46 (not all shown due to space restrictions) with twenty six of the reads having a G at the loci and twenty having an A. The image was created using IGV [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121351#pone.0121351.ref020" target="_blank">20</a>]. NB: The <i>CTSC</i> gene is oriented the reverse strand, therefore the codon change p.G300D (GGC>GAC) is exhibiting as C>T.</p

Proxy Molecular Diagnosis from Whole-Exome Sequencing Reveals Papillon-Lefevre Syndrome Caused by a Missense Mutation in <i>CTSC</i>

<div><p>Papillon-Lefevre syndrome (PLS) is an autosomal recessive disorder characterised by severe early onset periodontitis and palmoplantar hyperkeratosis. A previously reported missense mutation in the <i>CTSC</i> gene (NM_001814.4:c.899G>A:p.(G300D)) was identified in a homozygous state in two siblings diagnosed with PLS in a consanguineous family of Arabic ancestry. The variant was initially identified in a heterozygous state in a PLS unaffected sibling whose whole exome had been sequenced as part of a previous Primary ciliary dyskinesia study. Using this information, a proxy molecular diagnosis was made on the PLS affected siblings after consent was given to study this second disorder found to be segregating within the family. The prevalence of the mutation was then assayed in the local population using a representative sample of 256 unrelated individuals. The variant was absent in all subjects indicating that the variant is rare in Saudi Arabia. This family study illustrates how whole-exome sequencing can generate findings and inferences beyond its primary goal.</p></div

Validation of NM_001814.4:c.899G>A:p.(G300D) in all family members using ARMS-PCR.

<p>For primers, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121351#pone.0121351.s004" target="_blank">S2 Table</a>. L1-L6: using AS primer for wild type. L7-L12: using AS primer for mutant. L1/7: Mother. L2/8: Father. L3/9: PLS Proband. L4/10: PLS Affected brother. L5/11: Unaffected sibling—homozygous for <i>CTSC</i> wild type allele. L6/12: PCD affected sibling who is a carrier for PLS. Ladder’s three bands are 100bp (bottom), 200bp and 300bp (top).</p