RESUMEN

The burgeoning field of fog computing introduces a transformative computing paradigm with extensive applications across diverse sectors. At the heart of this paradigm lies the pivotal role of edge servers, which are entrusted with critical computing and storage functions. The optimization of these servers' storage capacities emerges as a crucial factor in augmenting the efficacy of fog computing infrastructures. This paper presents a novel storage optimization algorithm, dubbed LIRU (Low Interference Recently Used), which synthesizes the strengths of the LIRS (Low Interference Recency Set) and LRU (Least Recently Used) replacement algorithms. Set against the backdrop of constrained storage resources, this research endeavours to formulate an algorithm that optimizes storage space utilization, elevates data access efficiency, and diminishes access latencies. The investigation initiates a comprehensive analysis of the storage resources available on edge servers, pinpointing the essential considerations for optimization algorithms: storage resource utilization and data access frequency. The study then constructs an optimization model that harmonizes data frequency with cache capacity, employing optimization theory to discern the optimal solution for storage maximization. Subsequent experimental validations of the LIRU algorithm underscore its superiority over conventional replacement algorithms, showcasing significant improvements in storage utilization, data access efficiency, and reduced access delays. Notably, the LIRU algorithm registers a 5% increment in one-hop hit ratio relative to the LFU algorithm, a 66% enhancement over the LRU algorithm, and a 14% elevation in system hit ratio against the LRU algorithm. Moreover, it curtails the average system response time by 2.4% and 16.5% compared to the LRU and LFU algorithms, respectively, particularly in scenarios involving large cache sizes. This research not only sheds light on the intricacies of edge server storage optimization but also significantly propels the performance and efficiency of the broader fog computing ecosystem. Through these insights, the study contributes a valuable framework for enhancing data management strategies within fog computing architectures, marking a noteworthy advancement in the field.

Asunto(s)

RESUMEN

Fuzzing has become an important method for finding vulnerabilities in software. For fuzzing programs expecting structural inputs, syntactic- and semantic-aware fuzzing approaches have been particularly proposed. However, they still cannot fuzz in-memory data stores sufficiently, since some code paths are only executed when the required data are available. In this article, we propose a data-aware fuzzing method, DAFuzz, which is designed by considering the data used during fuzzing. Specifically, to ensure different data-sensitive code paths are exercised, DAFuzz first loads different kinds of data into the stores before feeding fuzzing inputs. Then, when generating inputs, DAFuzz ensures the generated inputs are not only syntactically and semantically valid but also use the data correctly. We implement a prototype of DAFuzz based on Superion and use it to fuzz Redis and Memcached. Experiments show that DAFuzz covers 13~95% more edges than AFL, Superion, AFL++, and AFLNet, and discovers vulnerabilities over 2.7× faster. In total, we discovered four new vulnerabilities in Redis and Memcached. All the vulnerabilities were reported to developers and have been acknowledged and fixed.

RESUMEN

There is insufficient research on how to reduce the destructive effects of command-based environmental regulation through institutional design. The implementation of the National Key Monitoring Enterprises provides new evidence to assess the effects of vertical monitoring. This study integrates and matches three types of micro databases in China: industrial, pollution, and patent, and constructs firm-level panel data from 2004 to 2010. The empirical evidence shows that the policy reduces the energy use intensity of monitored enterprises by about 10.4% and sulfur dioxide emission intensity by about 23.9%. The mechanism test shows that this effect is achieved by means of energy structure optimization, process innovation, and end-of-pipe treatment, but the effect on total factor productivity is not significant. Among them, the positive impact is stronger for high-profit and emerging firms. Further, we quantify the policy-induced capacity transfer and technology spillovers from monitored enterprises to non-monitored enterprises. In terms of scale, the policy leads to a simultaneous increase in output and pollution emissions of unmonitored firms in the same industry. However, in terms of efficiency, the policy reduces the energy use intensity and pollution emission intensity of enterprises in the same industry.

Asunto(s)

RESUMEN

New ventures have stronger learning motivation but higher failure rates. In the era of the digital economy, it is necessary to clarify whether and how learning orientation gives scientific guidance for new ventures. We developed a chain multiple intermediary model following the paradigm of "orientation → capability → performance," which was empirically analyzed using data from 214 Chinese new ventures. The results show that learning orientation not only has a direct positive impact on new venture performance (NVP) but also has an indirect positive effect through the chain-mediating effect of absorptive capacity and innovation capacity. The study advances theoretical understanding of the effect and path of learning orientation on NVP, fosters in-depth research on organizational learning and dynamic capability, and provides targeted organizational learning solutions for new ventures in emerging economies.

RESUMEN

The emergence of e-commerce and express delivery services has significantly transformed business operations and consumer shopping experience. However, the resulting problem of packaging waste, particularly from overpackaging, poses serious challenges to environmental sustainability and human health. Existing research has proposed many solutions from various perspectives, but very few have considered the acceptability and consumer preference for these proposals. Using the value co-creation (VCC) theory, we established a research model to explore consumer preferences for e-commerce overpackaging solutions. A survey of 632 online consumers in Guangzhou and Shenzhen was conducted, and data were analyzed using the SmartPLS software. The results show that establishing a recycling system, government policy, and consumers' environmental awareness have a significant positive impact on consumer preference, while combined packaging has a significant negative impact. We also found that government policy plays an intermediary role in establishing a recycling system and consumer preference. Based on these findings, we recommend that enterprises establish and improve their packaging recycling systems and that e-commerce platforms provide alternative options to combined packaging. Also, the government should play a guiding and coordinating role for enterprises and consumers, and environmental awareness among consumers should actively be promoted.

Asunto(s)

RESUMEN

Perfluorooctane sulfonate (PFOS), a hepatotoxic pollutant, is detected in the human cord blood, and it may induce health risk to an embryo. In this study, we established intrauterine exposure to PFOS in mice to evaluate potential impacts of PFOS on postnatal day 1 (PND1) offspring through conducting biochemical tests, quantitative PCR, and immunostaining. As results, PFOS-exposed maternal mice showed marked hepatomegaly and induced liver steatosis in a high dose of 5 mg PFOS/kg. In PND1 mice, intrahepatic contents of triglyceride, total cholesterol, and LDL were elevated by high-dose PFOS exposure, while intracellular HDL content was decreased. As shown in quantitative PCR, functional messenger RNAs of cytochrome P4A14 (CYP4A14) for fatty acid oxidation, CD36 for hepatic fatty acid uptake, and apolipoprotein B100 (APOB) and fibroblast growth factor 21 (FGF21) for hepatic export of lipids in PND1 livers were changed when compared to those in PFOS-free controls. In further validations, immunofluorescence stains showed that hepatic CYP4A14 and CD36 immunoreactive cells were increased in PFOS-exposed PND1 mice. In addition, reduced immunofluorescence-positive cells of APOB and FGF21 were observed in PND1 livers. Collectively, these preliminary findings demonstrate that prenatal exposure to PFOS may affect lipid metabolism in liver cells of PND1 mice.

Asunto(s)

RESUMEN

BACKGROUND: Interleukin 10 (IL10) refers to a pleiotropic cytokine exerted immunoregulation. Aflatoxin B1 (AFB1) is a strong carcinogen, marked by causing immunosuppression. We determined the possible association between cord blood IL10 and AFB1-exposed patients with gestational diabetes (GD). METHODS: Cord blood samples from non-GD adults (n = 3) and GD patients (n = 3) were harvested for determining representative serological parameters by use of biochemical assays and enzyme linked immunosorbent assay (ELISA) tests. RESULTS: As results, GD patients showed no statistical comparable clinical data (hepatic function, lipids metabolism, immune cell count) to those in controls or references. Interestingly, cord blood contents of AFB1 in GD patients were significantly increased when compared to those in non-GD controls, characterized with visibly increased cord blood IL10. CONCLUSIONS: Preliminary clinical data reveal that IL10 may function as a biomarker for immunoregulation in AFB1-exposed GD patients.

Asunto(s)

RESUMEN

Previous studies have showed perfluorooctanoic acid (PFOA) inducing cytotoxicity in an organ. In addition, epidemiological data show that high level of PFOA in cord blood of a pregnant woman is detected. Therefore, we extrapolate that circulating PFOA may affect organogenesis in offspring, such as the brain. In this study, intrauterine exposure to PFOA in mice was used to characterize the potential impacts of prenatal PFOA exposure on cerebral cortex cells of postnatal 21 (PND21) offspring. In an ex vivo cell model, PND21-based cortex cells were exposed to PFOA or/and nerve growth factor (NGF)-specific inhibitor before further biochemical assays. As results, biochemical data showed increased trends of liver metabolic enzymes in sera of PFOA-treated PND21 mice. Interestingly, PFOA-treated PND21 mice resulted in increased levels of NGF in sera and cortex cells. In addition, PFOA-exposed cerebral cortex cells induced NGF and proliferating cell nuclear antigen (PCNA) expressions, while exposure to PFOA/NGF-specific inhibitor downregulated expressions of NGF and PCNA. In addition, Nissl-labeled, NGF-positive cells, and NGF protein expression in cortex cells of PFOA-treated PND21 mice were upregulated, respectively. Further, immunoblotting assays showed that intracephalic poly (ADP-ribose) polymerase (PARP) and p42/44 mitogen-activated protein kinase (MAPK) proliferation-regulated protein levels were elevated in PFOA-treated cortex cells. Taken together, our current findings indicate that the prenatal PFOA exposure may induce proliferation of cerebral cortex cells in PND21 mice through promoting intracephalic NGF expression in the cortex.

Asunto(s)

RESUMEN

Perfluorooctanoic acid (PFOA), a kind of manufactured material, is widely accumulated around environmental system and into wildlife, including human beings. Toxicologically, PFOA induces hepatomegaly (liver enlargement) in the dose- and time-dependent manners. However, biological mechanism of hepatotoxicity warrants to be further investigated. In the present study, mature male mice were exposed to dosed PFOA for 21 days before conducting biochemical tests and immunoassays. As results, decreased fast blood glucose and elevated insulin contents were observed in PFOA-dosed mice. In addition, PFOA-dosed mice resulted in increased liver functional enzymes (GPT, GOT) in serum. And lipid contents (TG, lipoproteins) in serum and liver were changed abnormally. As shown in immunohistochemistry, increased insulin- and poly (ADP-ribose) polymerase (PARP)-positive cells were showed in PFOA-exposed pancreatic tissues. Moreover, CD36-positive cells were increased in PFOA-exposed livers, while ApoB-labeled cells were reduced. Further, immunoblot data showed that hepatocellular fibroblast growth factor 21 (FGF21) in PFOA-exposed liver was down-regulated dose-dependently. Taken together, our preliminary findings demonstrated that PFOA-induced hepatocellular lipotoxicity may be linked to impairing lipid-regulated proteins, as well as inducing insulin expression from pancreatic tissue.

Asunto(s)

RESUMEN

Acetaminophen (APAP), commonly used in clinical prescription, has time- and dose-dependent side effects. Thus, further animal study warrants to be investigated to assess possible adverse effect of APAP application. Here, we conducted pre-clinical research to elucidate the molecular mechanism regarding APAP-mediated toxicological action. Our data showed that serous/urinary and hepatic/renal APAP concentrations were significantly increased when compared with normal control, which the liver tissue showed the highest level. As an acute liver damage model induced by APAP, absolute liver weight, serum enzyme (ALT), urine protein content were notably elevated. Representatively, APAP-damaged liver resulted in increased pro-apoptotic Bax and compensatory Ki-67 positive cells, while the number of anti-apoptotic Bcl2 positive cells was reduced. In addition, the immunoactivity markers for NF-κB, TRL4, TNF-α in the kidney were increased, respectively. Furthermore, intracellular TRL4 and TNF-α mRNAs in the liver and kidney showed significant up-regulation. In summary, our current findings demonstrate that APAP-mediated the specific cytotoxicity is linked to the molecular mechanisms of facilitating apoptosis and inflammatory stress in the liver and kidney.