Demystifying Developers' Issues in Distributed Training of Deep Learning Software

Deep learning (DL) has been pervasive in a wide spectrum of nowadays software systems and applications. The rich features of these DL based software applications (i.e., DL software) usually rely on powerful DL models. To train powerful DL models with large datasets efficiently, it has been a common practice for developers to parallelize and distribute the computation and memory over multiple devices in the training process, which is known as distributed training. However, existing efforts in the software engineering (SE) research community mainly focus on issues in the general process of training DL models. In contrast, to the best of our knowledge, issues that developers encounter in distributed training have never been well studied. Given the surging importance of distributed training in the current practice of developing DL software, this paper fills in the knowledge gap and presents the first comprehensive study on developers' issues in distributed training. To this end, we extract and analyze 1,054 real-world developers' issues in distributed training from Stack Overflow and GitHub, two commonly used data sources for studying software issues. We construct a fine-grained taxonomy consisting of 30 categories regarding the fault symptoms and summarize common fix patterns for different symptoms. Based on the results, we suggest actionable implications and research avenues that can potentially facilitate the future development of distributed training

Consolidation considering clogging

In land reclamation projects, the vacuum preloading method has been widely used to strengthen dredged fills by removing water. However, during the improvement process, clogging inevitably occurs in the drains and soils, hindering water drainage and causing inhomogeneous consolidation results. Therefore, it is essential to evaluate the effect of clogging on the consolidation behavior of dredged slurry at different radii. In this study, analytical solutions are derived under an uneven strain assumption to calculate the consolidation in the clogging zone and the normal zone, with time-dependent discharge capacity and clogging in the soil considered. Results calculated by the proposed solutions indicated that the clogging effect slows down the development of consolidation, reduces the final consolidation degree, and increases the difference between consolidations at different radii. It is found that the influence of the clogging effect's varies with the speed of the discharge capacity decay, the value of the initial discharge capacity of the drain, the permeability, and the radius of the clogging zone. Finally, a practical application of the proposed solution is discussed, and the proposed solution is suggested for the calculation of consolidation when treating high-water-content slurry

A new species of Zhangixalus (Anura, Rhacophoridae) from Yunnan, China

We described herein Zhangixalus yunnanensis sp. nov., a new treefrog species from central and western Yunnan, China, which had previously been confused with Z. nigropunctatus, based on morphological and molecular evidence. Our phylogenetic analyses revealed that the new species is sister to the clade of Z. nigropunctatus and Z. melanoleucus with strong support (100% and 73% for BI and ML, respectively). Our morphological analysis suggested that Z. yunnanensis sp. nov. is distinctly different from all known congeners by the combination of the following morphological characters: black blotches on body flank and hind-limb, medium body size (SVL31.3–36.0 mm in males and 47.6–48.6 mm in females), head wider than long, iris yellowish-brown, dorsum uniformly green, vocal sac external, throat black, webbing greyish and fingers webbed one third and toes webbed half. Additionally, we revealed that the specimens ROM 38011 (Sa Pa, Vietnam) and VNMN 4099 (Son La, Vietnam) are neither Z. dorsoviridis nor Z. nigropunctatus, but probably represent one or two cryptic species of Zhangixalus pending further morphological and molecular data. Including the new species described herein, the genus Zhangixalus currently comprises 42 species, 30 of which are distributed in China with 11 species known from Yunnan. Amongst different zoogeographic regions in Yunnan, south-eastern Yunnan has the highest diversity of Zhangixalus, followed by western Yunnan and southern Yunnan. More studies are required to clarify the species diversity of this genus based on multiple lines of evidence (e.g. morphological and molecular data)

Large-strain self-weight consolidation of dredged sludge

Prediction for self-weight consolidation of dredged sludge is important for its reuse in civil engineering applications. In this work, considering the special nonlinear relationships of e – k and e – σ′ for dredged sludge, Gibson’s large strain consolidation equation was modified to simulate the self-weight consolidation process of dredged sludge. Using the finite difference method (FDM), the influences of four main parameters, including initial height, initial void ratio, void ratio at the liquid limit, and specific gravity of soil particles, on the consolidation process of dredged slurry were analyzed. For the aforementioned four parameters, the self-weight consolidation of dredged slurry is most sensitive to the variation of void ratio at the liquid limit, whereas its response to the change of specific gravity of soil particles is relatively subtle. Consolidation behaviors under other commonly used constitutive models were also calculated for comparison. It was found that the total settlement obtained by the present relation is larger than the results obtained using typical nonlinear constitutive relations, and the speed of consolidation is higher

Polyethylene Glycol-grafted poly alpha-lipoic acid-dexamethasone nanoparticles for osteoarthritis

Osteoarthritis (OA) is a chronic inflammatory disease that causes synovial hyperplasia, cartilage destruction, and the formation of bone spurs. Macrophages play an indispensable role in the pathogenesis of OA by producing proinflammatory cytokines. To achieve the effect of arthritis, hormones can effectively inhibit the progression of inflammation by inhibiting the secretion of inflammatory cytokines by macrophages in traditional therapy. However, the drug is quickly cleared from the joint space, and the high injection site infection rate and low local drug concentration make the clinical efficacy of corticosteroids greatly reduced. We described the design and preparation of Polyethylene Glycol-grafted Poly Alpha-lipoic Acid-dexamethasone Nanoparticles (NPDXM/PPLA), elucidated the mechanism of action of NPDXM/PPLA in the treatment of OA in mice, and provided an experimental basis for investigating the treatment of OA with polymer nanoparticles loaded with dexamethasone. Flow cytometry and confocal laser scanning microscopy were used to confirm that NPDXM/PPLA was well absorbed and released by macrophages, and it was discovered that NPDXM/PPLA could efficiently reduce the proliferation of activated macrophages (RAW 264.7 cells). Enzyme-linked immunosorbent assay revealed that NPDXM/PPLA could efficiently reduce the expression of proinflammatory cytokines IL-1β, IL-6, and TNF-α. The knee bone structure of OA mice was investigated by MicroCT, and it was discovered that intraarticular injection of NPDXM/PPLA effectively alleviated the bone damage of the articular cartilage. Therefore, NPDXM/PPLA is a potential therapeutic nanomedicine for the treatment of OA

Ca1_xLixAl1_xSi1+xN3：Eu2+ solid solutions as broadband,color-tunable and thermally robust red phosphors for superior color rendition white light-emitting diodes

日前，我院解荣军教授及其合作者在半导体照明用稀土掺杂氮化物发光材料研究上取得突破性进展。稀土发光材料是半导体照明技术中最为关键的核心材料之一，决定了半导体照明器件的发光效率、显色指数、色温和可靠性等重要性能。解荣军教授及其合作者在长期研究氮化物发光材料及半导体照明器件的工作基础上，巧妙地通过发光材料的晶体结构局域调控和能带工程设计，研究和开发了具有宽谱发射、光谱可控的高可靠性氮化物固溶体红色发光材料，成功解决了半导体照明技术中的重要科学问题和关键技术难题。该论文的第一作者为中国计量大学光学与电子技术学院的王乐副教授，解荣军和王乐为共同通讯作者，厦门大学为第一通讯单位。合作单位还有日本国立材料研究所、重庆邮电大学和台湾大学。由于文章具有创新性和重要性，被选为当期封面文章。【Abstract】Color rendition, luminous efficacy and reliability are three key technical parameters for white light-emitting diodes (wLEDs) that are dominantly determined by down-conversion phosphors. However, there is usually an inevitable trade-off between color rendition and luminescence efficacy because the spectrum of red phosphor (that is, spectral broadness and position) cannot satisfy them simultaneously. In this work, we report a very promising red phosphor that can minimize the aforementioned trade-off via structure and band-gap engineering, achieved by introducing isostructural LiSi2N3 into CaAlSiN3:Eu2+. The solid solution phosphors show both substantial spectra broadening (88→117 nm) and blueshift (652→642 nm), along with a significant improvement in thermal quenching (only a 6% reduction at 150 °C), which are strongly associated with electronic and crystal structure evolutions. The broadband and robust red phosphor thus enables fabrication of super-high color rendering wLEDs (Ra=95 and R9=96) concurrently with the maintenance of a high-luminous efficacy (101 lm W−1), validating its superiority in high-performance solid state lightings over currently used red phosphors.We are grateful for the financial support from the JSPS KAKENHI (No. 23560811), the National Natural Science Foundation of China (Nos. 51272259, 61575182, 5157223 and 51561135015), the Natural Science Foundation of Zhejiang Province (No. Y16F050012) and the Taiwan Science and Technology Authority (No. ‘MOST’ 104-2113-M-002-012-MY3 and No. 104-2119-M-002-027-MY3)

Demethyleneberberine alleviated the inflammatory response by targeting MD-2 to inhibit the TLR4 signaling

IntroductionThe colitis induced by trinitrobenzenesulfonic acid (TNBS) is a chronic and systemic inflammatory disease that leads to intestinal barrier dysfunction and autoimmunedisorders. However, the existing treatments of colitis are associated with poor outcomes, and the current strategies remain deep and long-time remission and the prevention of complications. Recently, demethyleneberberine (DMB) has been reported to be a potential candidate for the treatment of inflammatory response that relied on multiple pharmacological activities, including anti-oxidation and antiinflammation. However, the target and potential mechanism of DMB in inflammatory response have not been fully elucidated.MethodsThis study employed a TNBS-induced colitis model and acute sepsis mice to screen and identify the potential targets and molecular mechanisms of DMB in vitro and in vivo. The purity and structure of DMB were quantitatively analyzed by high-performance liquid chromatography (HPLC), mass spectrometry (MS), Hydrogen nuclear magnetic resonance spectroscopy (1H-NMR), and infrared spectroscopy (IR), respectively. The rats were induced by a rubber hose inserted approximately 8 cm through their anus to be injected with TNBS. Acute sepsis was induced by injection with LPS via the tail vein for 60 h. These animals with inflammation were orally administrated with DMB, berberine (BBR), or curcumin (Curc), respectively. The eukaryotic and prokaryotic expression system of myeloid differentiation protein-2 (MD-2) and its mutants were used to evaluate the target of DMB in inflammatory response.ReslutsDMB had two free phenolic hydroxyl groups, and the purity exceeded 99% in HPLC. DMB alleviated colitis and suppressed the activation of TLR4 signaling in TNBS-induced colitis rats and LPS-induced RAW264.7 cells. DMB significantly blocked TLR4 signaling in both an MyD88-dependent and an MyD88-independent manner by embedding into the hydrophobic pocket of the MD-2 protein with non-covalent bonding to phenylalanine at position 76 in a pi–pi T-shaped interaction. DMB rescued mice from sepsis shock induced by LPS through targeting the TLR4–MD-2 complex.ConclusionTaken together, DMB is a promising inhibitor of the MD-2 protein to suppress the hyperactivated TLR4 signaling in inflammatory response