RStream: Simple and Efficient Batch and Stream Processing at Scale

Distributed data processing platforms aim to provide a balance between ease of use and performance. The question is: do they succeed? Systems like Apache Spark or Apache Flink offer a high-level programming model that results in simple and concise definition of the processing tasks, abstracting away most of the concerns associated to concurrency and distribution but at the cost of a large performance gap with custom programs that use low-level primitives to control distribution and resource usage. May we fill this gap? May alternative design choices yield better performance without sacrificing simplicity?This paper answers the above questions by introducing RStream, a novel data processing platform written in Rust. RStream provides a high-level programming model similar to that of mainstream data processing systems, which supports batch and stream processing, data transformations, grouping, aggregation, iterative computations, and time-based analytics, incurring in a much lower overhead, closer to that of custom, low-level code. In numerical terms, our evaluation shows that RStream programs present nearly identical complexity as similar programs written in Flink, delivering from 2X to 20X the throughput of Flink, rivaling custom MPI implementations

DNAJC12 deficiency: Mild hyperphenylalaninemia and neurological impairment in two siblings

Background: DNAJC12 co-chaperone protein deficiency has been recently described as a stand-alone metabolic disorder explaining many cases of mild hyperphenylalaninemia (HPA) that are not caused by variants in the PAH gene, which encodes for the hepatic enzyme phenylalanine hydroxylase (PAH), or inGCH1, PTS, QDPR, PCBD1 and DHPR, involved in tetrahydrobiopterin (BH4) biosynthesis and activity. Results: We describe two sisters born to consanguineous parents. The youngest sister (Patient 1), initially asymptomatic, tested positive at NewBorn Screening (NBS) for mild HPA. After variants in the PAH and BH4 related-genes were excluded, we performed DNAJC12 genetic analysis and found a previously described homozygous deletion [NM_021800.3: c.58_59del p.(Gly20Metfs*2)]. The older sister (Patient 2), homozygous for the same variant and exhibiting mild HPA, was diagnosed subsequently and presented with ataxia and repeated falls, upper limb dyskinesia, intentional tremor, and mild intellectual disability. Patient 1 was started on treatment with low Phenylalanine (Phe) diet, BH4, l-3,4-dihydroxyphenylalanine/carbidopa (L-DOPA) and 5-OH-Tryptophan, soon after diagnosis, and despite poor adherence to the dietary regimen, only manifested language impairment at last follow-up (age 5 years and 4 months). Patient 2, who started the same treatment at school age, experienced a minimal progression of neurological symptoms, with some improvement in her motor skills. Conclusions: These two new patients with DNAJC12-associated HPA, in addition to previous reports, point to DNAJC12 deficiency as a new metabolic syndrome that must be considered in patients with unexplained HPA