User Privacy Leakage in Location-based Mobile Ad Services

The online advertising ecosystem leverages its massive data collection capability to learn the properties of users for targeted ad deliveries. Many Android app developers include ad libraries in their apps as a way of monetization. These ad libraries contain advertisements from the sell-side platforms, which collect an extensive set of sensitive information to provide more relevant advertisements for their customers. Existing efforts have investigated the increasingly pervasive private data collection of mobile ad networks over time. However, there lacks a measurement study to evaluate the scale of privacy leakage of ad networks across different geographical areas. In this work, we present a measurement study of the potential privacy leakage in mobile advertising services conducted across different locations. We develop an automated measurement system to intercept mobile traffic at different locations and perform data analysis to pinpoint data collection behaviors of ad networks at both the app-level and organization-level. With 1,100 popular apps running across 10 different locations, we perform extensive threat assessments for different ad networks. Meanwhile, we explore the ad-blockers’ behavior in the ecosystem of ad networks, and whether those ad-blockers are actually capturing the users’ private data in the meantime of blocking the ads. We find that: the number of location-based ads tends to be positively related to the population density of locations, ad networks collect different types of data across different locations, and ad-blockers can block the private data leakage

Characterizing Location-based Mobile Tracking in Mobile Ad Networks

Mobile apps nowadays are often packaged with third-party ad libraries to monetize user data

Activation of aldehyde dehydrogenase-2 improves ischemic random skin flap survival in rats

ObjectiveRandom skin flaps have many applications in plastic and reconstructive surgeries. However, distal flap necrosis restricts wider clinical utility. Mitophagy, a vital form of autophagy for damaged mitochondria, is excessively activated in flap ischemia/reperfusion (I/R) injury, thus inducing cell death. Aldehyde dehydrogenase-2 (ALDH2), an allosteric tetrameric enzyme, plays an important role in regulating mitophagy. We explored whether ALDH2 activated by N-(1,3-benzodioxol-5-ylmethyl)-2,6-dichlorobenzamide (Alda-1) could reduce the risk of ischemic random skin flap necrosis, and the possible mechanism of action.MethodsModified McFarlane flap models were established in 36 male Sprague-Dawley rats assigned randomly to three groups: a low-dose Alda-1 group (10 mg/kg/day), a high-dose Alda-1 group (20 mg/kg/day) and a control group. The percentage surviving skin flap area, neutrophil density and microvessel density (MVD) were evaluated on day 7. Oxidative stress was quantitated by measuring the superoxide dismutase (SOD) and malondialdehyde (MDA) levels. Blood perfusion and skin flap angiogenesis were assessed via laser Doppler flow imaging and lead oxide-gelatin angiography, respectively. The expression levels of inflammatory cytokines (IL-1β, IL-6, and TNF-α), vascular endothelial growth factor (VEGF), ALDH2, PTEN-induced kinase 1 (PINK1), and E3 ubiquitin ligase (Parkin) were immunohistochemically detected. Indicators of mitophagy such as Beclin-1, p62, and microtubule-associated protein light chain 3 (LC3) were evaluated by immunofluorescence.ResultsAlda-1 significantly enhanced the survival area of random skin flaps. The SOD activity increased and the MDA level decreased, suggesting that Alda-1 reduced oxidative stress. ALDH2 was upregulated, and mitophagy-related proteins (PINK1, Parkin, Beclin-1, p62, and LC3) were downregulated, indicating that ALDH2 inhibited mitophagy through the PINK1/Parkin signaling pathway. Treatment with Alda-1 reduced neutrophil infiltration and expressions of inflammatory cytokines. Alda-1 significantly upregulated VEGF expression, increased the MVD, promoted angiogenesis, and enhanced blood perfusion.ConclusionALDH2 activation can effectively enhance random skin flap viability via inhibiting PINK1/Parkin-dependent mitophagy. Moreover, enhancement of ALDH2 activity also exerts anti-inflammatory and angiogenic properties

User Privacy Leakage in Location-based Mobile Ad Services

The online advertising ecosystem leverages its massive data collection capability to learn the properties of users for targeted ad deliveries. Many Android app developers include ad libraries in their apps as a way of monetization. These ad libraries contain advertisements from the sell-side platforms, which collect an extensive set of sensitive information to provide more relevant advertisements for their customers. Existing efforts have investigated the increasingly pervasive private data collection of mobile ad networks over time. However, there lacks a measurement study to evaluate the scale of privacy leakage of ad networks across different geographical areas. In this work, we present a measurement study of the potential privacy leakage in mobile advertising services conducted across different locations. We develop an automated measurement system to intercept mobile traffic at different locations and perform data analysis to pinpoint data collection behaviors of ad networks at both the app-level and organization-level. With 1,100 popular apps running across 10 different locations, we perform extensive threat assessments for different ad networks. Meanwhile, we explore the ad-blockers’ behavior in the ecosystem of ad networks, and whether those ad-blockers are actually capturing the users’ private data in the meantime of blocking the ads. We find that: the number of location-based ads tends to be positively related to the population density of locations, ad networks collect different types of data across different locations, and ad-blockers can block the private data leakage

Graphene Amplification by Continued Growth on Seed Edges

Large-area single-layer graphenes with high crystallinity are desired for electronic applications. Here we demonstrate a continued growth method to amplify an existing graphene seed, originally grown by chemical vapor deposition, by preferentially inducing nucleation at seed edges. More specifically, this approach involves a surface oxidation step after the first growth, which leads to the observed formation of oxides at the vicinity of graphene edges, along with the inevitable formation of cracks due to oxidation, and thus limit growth predominantly at those edges, as a consequence of the reduced energy barrier of methane decomposition by oxygen moieties. Consequently, we successfully grow millimeter-size secondary single-crystal graphene structures with the same lattice structure and orientation as the original seeds. Selected area electron diffraction (SAED), Raman spectroscopy characterization, along with electronic transport measurement confirmed the structure coherence after the regrowth, even in the seed/regrown grains boundary region. This clone-like method provides a venue for production of graphene electronics with reproducible properties

Xiangbin prescription for the recovery of gastrointestinal function after abdominal surgery (the XBPRS trial): study protocol for a randomized controlled trial

Abstract Background Most patients who undergo abdominal surgery recover bowel movements within a week; however, some suffer prolonged intestinal paralysis or postoperative ileus (POI) leading to complications, such as infection and intestinal adhesions, which can extend hospitalization and increase readmission rates, and consequently increasing healthcare costs. Chinese medicine is effective for accelerating the recovery of gastrointestinal function after abdominal surgery. Xiangbin prescription (XBP) is the standard prescription for this purpose in our hospital; however, randomized controlled trials of it have not yet been conducted. Methods/design This double-blind, randomized controlled clinical trial aims to recruit patients who have undergone abdominal surgery and experienced postoperative dysmotility to evaluate the efficacy and safety of XBP for preventing POI and accelerating recovery. The research will tackle the common problem of slow recovery of gastrointestinal function after surgery. The participants will be patients who undergo laparoscopic radical resection of rectal carcinoma or laparoscopic panhysterectomy of a benign lesion. Primary outcome measures will be time to first flatus, defecation, normal bowel sounds, and liquid/semi-liquid/general diet. Good Clinical Practice (GCP) standards of efficacy and safety will also be evaluated, along with objective investigation of the mechanism of action of ghrelin. Discussion This pivotal trial will be a standardized, scientific, clinical trial designed to evaluate the use of XBP for the recovery of gastrointestinal function after surgery, and it will conform to international standards for clinical trials for the recognition of traditional Chinese medicine. Trial registration Chinese Clinical Trial Registry, ID: ChiCTR-TRC-14004156. Registered on 3 January 2014

Graphene Amplification by Continued Growth on Seed Edges

Large-area single-layer graphenes with high crystallinity are desired for electronic applications. Here we demonstrate a continued growth method to amplify an existing graphene seed, originally grown by chemical vapor deposition, by preferentially inducing nucleation at seed edges. More specifically, this approach involves a surface oxidation step after the first growth, which leads to the observed formation of oxides at the vicinity of graphene edges, along with the inevitable formation of cracks due to oxidation, and thus limit growth predominantly at those edges, as a consequence of the reduced energy barrier of methane decomposition by oxygen moieties. Consequently, we successfully grow millimeter-size secondary single-crystal graphene structures with the same lattice structure and orientation as the original seeds. Selected area electron diffraction (SAED), Raman spectroscopy characterization, along with electronic transport measurement confirmed the structure coherence after the regrowth, even in the seed/regrown grains boundary region. This clone-like method provides a venue for production of graphene electronics with reproducible properties

How do different nitrogen application levels and irrigation practices impact biological nitrogen fixation and its distribution in paddy system?

publishedVersio

Modulation Effect of Mesoscale Eddies on Sequential Typhoon-Induced Oceanic Responses in the South China Sea

The impacts of mesoscale eddies on the modulation of typhoon-induced oceanic responses are important for understanding ocean dynamics. Satellite observations identified prominent ocean surface temperature and chlorophyll changes over the regions with mesoscale eddies after two sequential typhoons, e.g., Linfa and Nangka, in the South China Sea. The impacts of typhoons on the ocean surface were more prominent within cyclonic eddies than within anticyclonic eddies. The wind speed (translation speed) of Linfa was much larger (slower) than that of Nangka; thus, the changes induced by Linfa were stronger. However, the second typhoon easily generated mixing through the weak stratification induced by the first typhoon and impacted the upper ocean. The strong chlorophyll enhancement induced by Nangka was identified at a cyclonic eddy. Using a combination of reanalysis data, the depth of water origin (DWO) was applied to quantify the depth to which a typhoon’s impact could be exerted. Prominent changes were identified when the DWO reached the depth at which the temperature and nutrients differed from those within the mixed layer. This method can overcome the impacts of cloud coverage when examining a typhoon’s influence with remotely sensed data and offers a quantitative approach to determine the mechanisms responsible for typhoon-induced ocean surface changes