Teaching Compositionality to CNNs

Convolutional neural networks (CNNs) have shown great success in computer vision, approaching human-level performance when trained for specific tasks via application-specific loss functions. In this paper, we propose a method for augmenting and training CNNs so that their learned features are compositional. It encourages networks to form representations that disentangle objects from their surroundings and from each other, thereby promoting better generalization. Our method is agnostic to the specific details of the underlying CNN to which it is applied and can in principle be used with any CNN. As we show in our experiments, the learned representations lead to feature activations that are more localized and improve performance over non-compositional baselines in object recognition tasks.Comment: Preprint appearing in CVPR 201

On Complete Convergence for Weighted Sums of ρ

We prove the strong law of large numbers for weighted sums ∑i=1n‍aniXi, which generalizes and improves the corresponding one for independent and identically distributed random variables and φ-mixing random variables. In addition, we present some results on complete convergence for weighted sums of ρ*-mixing random variables under some suitable conditions, which generalize the corresponding ones for independent random variables

Stabilizing subnanometer Ag(0) nanoclusters by thiolate and diphosphine ligands and their crystal structures

MOST of China [2011CB932403]; NSFC [21131005, 21021061, 20925103]; Fok Ying Tung Education Foundation [121011]The combined use of thiolate and diphosphine as surface ligands helps to stabilize subnanometer Ag(0) nanoclusters, resulting in the successful crystallization of two Ag(0)-containing nanoclusters (Ag-16 and Ag-32) for X-ray single crystal analysis. Both clusters have core-shell structures with Ag-8(6+) and Ag-22(12+) as their cores, which are not simply either fragments of face-centered cubic metals or their fivefold twinned counterparts. The clusters display UV-Vis absorption spectra consisting of molecule-like optical transitions

Zidovudine and dideoxynucleosides deplete wild-type mitochondrial DNA levels and increase deleted mitochondrial DNA levels in cultured Kearns-Sayre syndrome fibroblasts

AbstractKearns-Sayre syndrome is the most commonly diagnosed mitochondrial cytopathy and produces severe neuromuscular symptoms. The most frequent cause is a mitochondrial DNA deletion that removes a 4977-base pair segment of DNA that includes several genes encoding for respiratory chain subunits. Treatment of AIDS patients with nucleoside analogs has been reported to cause mtDNA depletion and myopathies. Here, we report that azidothymidine, dideoxyguanosine, and dideoxycytidine cause a depletion of wild-type mtDNA while increasing the levels of deleted mitochondria DNA in Kearns-Sayre syndrome fibroblasts. The result of these effects is a large increase in the relative amounts of ΔmtDNA in comparison to wild type mtDNA. We found that Kearns-Sayre syndrome fibroblasts are a mixed population of cells with deleted mtDNA comprising from 0 to over 20% of the total mtDNA in individual cells. Treatment of cloned cell lines with dideoxycytidine did not result in increased levels of ΔmtDNA. The results suggest that nucleoside analogs may act to increase the average ΔmtDNA levels in a mixed population of cells by preferentially inhibiting the proliferation of cells with little or no ΔmtDNA. This raises the possibility that modulation of deleted mtDNA levels may occur by similar mechanisms in vivo, in response to the influence of exogenous agents

Dendrocerus lui (Hymenoptera, Ceraphronoidea, Megaspilidae): a new species of Dendrocerus carpenteri species-group from China

One new species of the genus Dendrocerus Ratzeburg, 1852, D. lui Li and Wang sp. nov. is described. A key to Chinese species of males is provided. The 28S sequence was generated to supplement the association of both sexes of the new species.One new species of the genus Dendrocerus Ratzeburg, 1852, D. lui Li and Wang sp. nov. is described

Lysocardiolipin acyltransferase 1 (ALCAT1) controls mitochondrial DNA fidelity and biogenesis through modulation of MFN2 expression

Oxidative stress causes mitochondrial fragmentation and dysfunction in age-related diseases through unknown mechanisms. Cardiolipin (CL) is a phospholipid required for mitochondrial oxidative phosphorylation. The function of CL is determined by its acyl composition, which is significantly altered by the onset of age-related diseases. Here, we examine a role of acyl-CoA:lysocardiolipin acyltransferase lysocardiolipin acyltransferase 1 (ALCAT1), a lysocardiolipin acyltransferase that catalyzes pathological CL remodeling, in mitochondrial biogenesis. We show that overexpression of ALCAT1 causes mitochondrial fragmentation through oxidative stress and depletion of mitofusin mitofusin 2 (MFN2) expression. Strikingly, ALCAT1 overexpression also leads to mtDNA instability and depletion that are reminiscent of MFN2 deficiency. Accordingly, expression of MFN2 completely rescues mitochondrial fusion defect and respiratory dysfunction. Furthermore, ablation of ALCAT1 prevents mitochondrial fragmentation from oxidative stress by up-regulating MFN2 expression, mtDNA copy number, and mtDNA fidelity. Together, these findings reveal an unexpected role of CL remodeling in mitochondrial biogenesis, linking oxidative stress by ALCAT1 to mitochondrial fusion defect

Colonoscopic titanium clipping to address appendiceal stump leakage: a case report

The incidence of appendiceal stump leakage (ASL) is extremely low and heterogeneous, which has been reported to be approximately 0.5%–1.0%. It is a catastrophic complication with high mortality rate despite its low morbidity. Once it occurs, it will put the doctor in a passive position because dealing with the leakage is much more cumbersome than appendectomy. We extensively reviewed the literature on ASL, focusing on the management and prognosis. Unsurprisingly, all of the physicians advocated extended resection, which apparently gave them sufficient confidence. However, partial cecum resection, cecostomy, or terminal ileectomy is extremely invasive and destructive. So, the patients had to experience great mental and physical trauma, longer hospital stays, higher rates of wound infection, more costs, and even a third surgery. Therefore, are there any better approaches for ASL? In this article, we report a case of ASL who successfully underwent endoscopic treatment. A 70-year-old male was admitted with gangrenous perforated appendicitis with a large iliopsoas abscess. Appendectomy, iliopsoas abscess debridement and sufficient drainage, appendicular stump repair and closure, and terminal ileostomy were performed. Three months later, the patient was readmitted and the stoma reversal was performed as scheduled. Seven days later, ASL was found when a liquid diet was applied routinely due to right lower quadrant pain and low fever. Finally, with the periappendiceal abscess completely drained, we clamped the appendiceal orifice with five titanium clips under an electronic colonoscope, which eventually sealed the leakage and avoided extended resection