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Generative AI in Data Center Networking: Fundamentals, Perspectives, and Case Study
No full textGenerative AI (GenAI), exemplified by Large Language Models (LLMs), such as OpenAI’s ChatGPT, is revolutionizing various fields. Central to this transformation is Data Center Networking (DCN), which not only provides the infrastructure support for GenAI operation, but also provisions GenAI services to users. Hence, this article explores the interplay between GenAI and DCNs, analyzing their symbiotic relationship and mutual advances. We begin by reviewing the current challenges of DCNs and GenAI-based solutions, such as data augmentation, process automation, and domain transfer. We then discuss the distinctive characteristics of GenAI workloads on DCNs, gaining insights that catalyze the evolution of DCNs to more effectively support GenAI. Moreover, to illustrate the seamless integration of GenAI with DCNs, we present a case study on GenAI-empowered DCN digital twins. Specifically, we employ an LLM equipped with retrieval augmented generation to formulate optimization problems for DCNs (e.g., resource allocation and routing) and adopt diffusion-deep reinforcement learning to solve optimization. The experimental results on a representative DCN optimization problem, i.e., knowledge placement, demonstrate the validity and efficiency of our proposals. We anticipate that this article can promote further research to enhance the virtuous interaction between GenAI and DCNs
Hospital-based specialist palliative care involvement before and during the COVID-19 pandemic: Secondary analysis of a regional retrospective decedent cohort study in Ottawa, Canada
No full textObjectives To determine the occurrence and clinicodemographic associations of hospital-based specialist palliative care (SPC) referral before and during the COVID-19 pandemic, timing of completed SPC consultation and comparative prevalence of € no cardiopulmonary resuscitation (CPR)' orders, and end-of-life medication use, according to SPC involvement. Design Cross-sectional secondary analysis of a retrospective cohort study with a pre-pandemic (November 2019 to February 2020) group (Pre-COVID, n=170) and two intra-pandemic (March to August 2020) groups, one without (COVID-ve, n=170) and one with COVID-19 infection (COVID+ve, n=85). In the cohort study, Pre-COVID and COVID-ve group decedents were matched 2:1 on age, sex and care service (internal medicine/intensive care unit (ICU)) at death with COVID+ve decedents. In our current secondary analysis, clinicodemographic variables associated with SPC referral were examined in multivariable logistic regression, reporting adjusted ORs (aORs) and 95% CIs. Setting One quaternary and two tertiary acute care hospitals. Participants Decedent cohort with a terminal hospital admission (N=425). Main outcome measures SPC referral (yes/no) and timing of completed SPC consultation before death. Additional outcomes included € no CPR' status and end-of-life medication prescription and dosing. Results SPC referral occurred in 70 (41.2%), 71 (41.8%) and 26 (30.6%) of the Pre-COVID, COVID-ve and COVID+ve groups, respectively (p=0.18). The aORs for SPC referral were lower for deaths in ICU (0.07; 95% CI 0.03 to 0.16) and admissions from nursing homes/long-term care (0.45; 95% CI 0.23 to 0.9), and higher for active cancer (2.5; 95% CI 1.39 to 4.39). Recipients of SPC consultation, compared with non-recipients, more frequently had a € no CPR' order, had it placed earlier and were more frequently prescribed palliative end-of-life medications. Conclusions Hospital SPC consultation rates early in the COVID-19 pandemic were largely maintained at pre-pandemic levels. Having active cancer was positively associated with SPC referral, whereas both ICU death and having a nursing home/long-term care pre-admission source were negatively associated with referral
Robust Avalanche (1.5 kV, 2 kA/cm2) in Vertical GaN Diodes on Patterned Sapphire Substrate
No full textThe lack of avalanche capability is a keylimitation of current lateral GaN devices. Despite the reportof avalanche in vertical GaN-on-GaN devices, the high wafercost hinders device commercialization. Here we demon-strate a circuit-level avalanche in vertical GaN diodeson low-cost patterned sapphire substrate (PSS), with theavalanche voltage (1.57 kV) and avalanche current den-sity (>2 kA/cm2) both being the highest reported in GaNdevices on foreign substrates. The PSS enables a lowerdislocation density than conventional sapphire substrateand is employed in high-voltage GaN devices for the firsttime. The avalanche voltage in the circuit test reaches 98%of the parallel-plane limit, further affirming that near-idealavalanche breakdown can be realized on GaN devices onforeign substrates. These results show the promise of theGaN-on-PSS platform for low-cost, robust power devices.</p
Online Collaborative Resource Allocation and Task Offloading for Multi-access Edge Computing
No full textMulti-access edge computing (MEC) is emerging as a promising paradigm to provide flexible computing services close to user devices (UDs). However, meeting the computation-hungry and delay-sensitive demands of UDs faces several challenges, including the resource constraints of MEC servers, inherent dynamic and complex features in the MEC system, and difficulty in dealing with the time-coupled and decision-coupled optimization. In this work, we first present an edge-cloud collaborative MEC architecture, where the MEC servers and cloud collaboratively provide offloading services for UDs. Moreover, we formulate an energy-efficient and delay-aware optimization problem (EEDAOP) to minimize the energy consumption of UDs under the constraints of task deadlines and long-term queuing delays. Since the problem is proved to be non-convex mixed integer nonlinear programming (MINLP), we propose an online joint communication resource allocation and task offloading approach (OJCTA). Specifically, we transform EEDAOP into a real-time optimization problem by employing the Lyapunov optimization framework. Then, to solve the real-time optimization problem, we propose a communication resource allocation and task offloading optimization method by employing the Tammer decomposition mechanism, convex optimization method, bilateral matching mechanism, and dependent rounding method. Simulation results demonstrate that the proposed OJCTA can achieve superior system performance compared to the benchmark approaches
Comparisons of Preferences Toward EQ-5D-Y-3L Health States Between Adult Own and Child Perspectives
No full textObjectives: The international valuation protocol for EQ-5D-Y-3L recommends elicitation of utilities using adults’ preference for a hypothetical 10-year-old child. Published studies have reported preference difference in adults when valuing for a child and valuing for themselves. This study aimed to obtain EQ-5D-Y-3L preferences in Hong Kong and understand the preference difference between the adult own perspective and the child perspective. Methods: We recruited 1000 and 200 adults in Hong Kong to value EQ-5D-Y-3L health states using discrete choice experiment and composite time trade-off (cTTO), respectively. Discrete choice experiment respondents were randomized to complete tasks from either adult own perspective or child perspective. cTTO respondents completed valuation from the child perspective. Relative attribute importance scores were compared between perspectives. Utility values were obtained by anchoring on the worst health state for both perspectives. Results: Both perspectives had similar relative attribute importance scores, rankings of dimensions, rescaled coefficients, and elicited values. Rank order of 5 dimensions, from highest to lowest importance, was “having pain or discomfort,” “doing usual activities,” “feeling worried, sad, or unhappy,” “mobility,” and “looking after myself” for both perspectives. The most important and least important dimensions were consistent with published EQ-5D-Y-3L value sets. Conclusions: This study revealed no remarkable difference in the relative preference for EQ-5D-Y-3L health states between the adult own and child perspectives in Hong Kong, offering insights to the development of the EQ-5D-Y-5L valuation protocol. Future research may explore the effect of perspectives on preferences elicited by cTTO in Asia.</p
Ivabradine induces RAD51 degradation, potentiating PARP inhibitor efficacy in non-germline BRCA pathogenic variant triple-negative breast cancer
No full textBackground: Triple-negative breast cancer (TNBC) is an aggressive subtype lacking targetable proteins for treatment. PARP inhibitors (PARPi) are effective in BRCA-mutated cancers but have limited utility in non-germline BRCA-mutated (non-gBRCAm) TNBC. We hypothesized that inducing BRCAness by targeting RAD51, a key homologous recombination protein, could sensitize non-gBRCAm TNBC to PARPi. Methods: EGFP-tagged RAD51 was generated and EGFP signal was monitored for identifying agents that affected RAD51 protein expression and stability. Cell viability was assayed using cell counting kit-8. Synergism of ivabradine and olaparib was determined using SynergyFinder 3.0. DR-GFP, EJ5-GFP and comet assays were employed to evaluate the degree of DNA repair and damage, respectively. Protein and mRNA levels were determined by western blot and qPCR, respectively. ChIP was used to determine the binding to ATF6 to the promoter of FBXO24. CoIP was employed to determine the interaction between RAD51 and FBXO24. Xenografts on nude mice and PDTX were in vivo models for validating the combined effect of ivabradine and olaparib. Results: Using an EGFP-RAD51 reporter, we identified ivabradine as a RAD51-reducing agent. In vitro studies with TNBC cell lines demonstrated that ivabradine synergized with PARPi to reduce cell viability (ZIP score > 10), induce apoptosis, and impair HR-mediated DNA repair. This synergy was confirmed in vivo using xenografts and patient-derived tumor xenografts, where co-treatment with clinical grade ivabradine (Coralan) and PARPi olaparib (Lynparza) led to substantial tumor growth inhibition without notable toxicity. Mechanistically, ivabradine triggered ER stress, activating ATF6 to upregulate FBXO24-dependent ubiquitination, leading to RAD51 degradation, resulting in the condition of BRCAness. Chromatin immunoprecipitation and co-immunoprecipitation confirmed the ATF6-FBXO24-RAD51 cascade. These findings reveal a novel mechanism by which ivabradine, an FDA-approved cardiac drug, induces BRCAness, by degrading RAD51 via the ATF6-FBXO24 axis, thus, by mimicking HR deficiency hypersensitizes BRCA-proficient TNBC to olaparib. Conclusion: This study highlights the translational potential of repurposing ivabradine as a therapeutic strategy for non-gBRCAm TNBC. By addressing a critical unmet need of this aggressive breast cancer subtype, it can potentially expand the utility of PARPi.</p
X-Ray Polarization in SN 1006 Southwest Shows Spatial Variations and Differences in the Radio Band
Get PDFWe report the detection of a spatial variation of X-ray polarization in the southwestern (SW) shell of supernova remnant SN 1006 (SN 1006 SW) using the Imaging X-ray Polarimetry Explorer (IXPE). The shell has an average X-ray polarization degree (PD) of 21.6% ± 4.5% and polarization angle of −48∘ ± 5∘ in the 2–4 keV energy band, similar to those in the northeastern shell. The PD varies along SN 1006 SW, with a peak PD = 40% ± 8% in the south and a significantly lower PD ≲ 27% (99% upper limit) in the west, where the shell has been proposed to be interacting with an interstellar cloud. The correlation between the PD, which reflects the magnetic orderliness, and the preshock density provides observational evidence that magnetic turbulence and amplification are environment-dependent. The high PD detected in the southern region of the shell constrains the magnetic turbulence scale to ≲0.1 pc. Moreover, by comparing the IXPE X-ray and MeerKAT radio polarization measurements for SN 1006 SW, we found that magnetic fields traced by X-ray polarization are nearly radially distributed, whereas those traced by radio polarization tend to follow a direction parallel to the Galactic plane. This suggests that the X-ray polarization probes freshly amplified magnetic fields from small-scale structures in the immediate postshock region, while the radio traces more extended regions influenced by the preexisting ambient magnetic fields.published_or_final_versio
Evaluation of dengue fever vulnerability in south and southeast asian countries: A multidimensional approach
No full textBackground: Climate change is raising the risk of dengue fever outbreaks in South and Southeast Asia, where public health challenges persist. Warmer temperatures promote year-round mosquito breeding and pathogen transmission, particularly in crowded urban areas. This underscores the urgent need for a comprehensive assessment to develop effective prevention strategies and improve health outcomes. This study evaluated the relationship between dengue fever vulnerability and disease incidence in three countries in the region. Methods: Monthly dengue surveillance data from 2012 to 2018 were collected in Sri Lanka, Malaysia, and Thailand, alongside environmental and socioeconomic data. Principal component analysis and binomial regression model were used to calculate the vulnerability index and evaluate the relationship between dengue infection, vulnerability, and its seasonality. Results: The results indicated significant spatial variations in vulnerability across the three countries. High-vulnerability regions included western coastal Sri Lanka, western and southern Thailand, and eastern Malaysia, with notable seasonal fluctuations in high-risk areas. Areas with higher vulnerability levels were associated with increased dengue fever incidence rate ratios (IRRs), particularly in Sri Lanka (IRR= 1.97, 95 % confidence interval [CI]: 1.08–3.65) and Thailand (IRR= 14.56, 95 % CI: 5.55–39.90). Notably, the IRR increased significantly during the warm seasons, particularly in August in Sri Lanka (high vs. low, IRR= 6.11, 95 % CI: 2.83–13.47) and in June in Thailand (middle-high vs. low, IRR= 23.61, 95 % CI: 9.39–61.67). Conclusions: The spatial heterogeneity of dengue vulnerability suggests that targeted public health interventions are essential for mitigating dengue fever risks, particularly in regions vulnerable to climate change