336 research outputs found
Not only Online Review but also its Helpfulness is Manipulated: Evidence from Peer to Peer Lending Forum
Online reviews have become proposed as useful information for consumers to make decision. Meanwhile, review manipulation will weaken the credibility of online reviews. Except manipulating the review text and rating, we propose that review helpfulness, an important signal for consumer to filter the reviews, could also be manipulated. This study thus explores the existence of review helpfulness manipulation and the relationship between firm quality and review manipulation. Based on a dataset from a review forum in www.wdzj.com which is the leading and largest portal of peer to peer lending industry in China, we get the following interesting results. First, due to the manipulation of review helpfulness, a manipulated positive review is more likely to receive higher helpfulness, while a manipulated negative is more likely to get lower helpfulness. Second, a manipulated review tends to be lower quality in terms of readability and word count, which are found as positive predictors for review helpfulness. Third, high quality firms tend to manipulate more positive reviews, and at the same time high quality firms will receive more negative manipulated reviews. This study extends current understanding about online review manipulation, thereby providing theoretical and practice implications
Conservative State Value Estimation for Offline Reinforcement Learning
Offline reinforcement learning faces a significant challenge of value
over-estimation due to the distributional drift between the dataset and the
current learned policy, leading to learning failure in practice. The common
approach is to incorporate a penalty term to reward or value estimation in the
Bellman iterations. Meanwhile, to avoid extrapolation on out-of-distribution
(OOD) states and actions, existing methods focus on conservative Q-function
estimation. In this paper, we propose Conservative State Value Estimation
(CSVE), a new approach that learns conservative V-function via directly
imposing penalty on OOD states. Compared to prior work, CSVE allows more
effective in-data policy optimization with conservative value guarantees.
Further, we apply CSVE and develop a practical actor-critic algorithm in which
the critic does the conservative value estimation by additionally sampling and
penalizing the states \emph{around} the dataset, and the actor applies
advantage weighted updates extended with state exploration to improve the
policy. We evaluate in classic continual control tasks of D4RL, showing that
our method performs better than the conservative Q-function learning methods
and is strongly competitive among recent SOTA methods
Outracing Human Racers with Model-based Planning and Control for Time-trial Racing
Autonomous racing has become a popular sub-topic of autonomous driving in
recent years. The goal of autonomous racing research is to develop software to
control the vehicle at its limit of handling and achieve human-level racing
performance. In this work, we investigate how to approach human expert-level
racing performance with model-based planning and control methods using the
high-fidelity racing simulator Gran Turismo Sport (GTS). GTS enables a unique
opportunity for autonomous racing research, as many recordings of racing from
highly skilled human players can served as expert emonstrations. By comparing
the performance of the autonomous racing software with human experts, we better
understand the performance gap of existing software and explore new
methodologies in a principled manner. In particular, we focus on the commonly
adopted model-based racing framework, consisting of an offline trajectory
planner and an online Model Predictive Control-based (MPC) tracking controller.
We thoroughly investigate the design challenges from three perspective, namely
vehicle model, planning algorithm, and controller design, and propose novel
solutions to improve the baseline approach toward human expert-level
performance. We showed that the proposed control framework can achieve top
0.95% lap time among human-expert players in GTS. Furthermore, we conducted
comprehensive ablation studies to validate the necessity of proposed modules,
and pointed out potential future directions to reach human-best performance.Comment: 16 pages, 13 figures, 3 table
Association between angiotensin-converting enzyme inhibitor-induced cough and the risk of lung cancer: a Mendelian randomization study
Background: Observational studies and meta-analyses have demonstrated a positive correlation between the use of angiotensin-converting enzyme inhibitors (ACEIs) and lung cancer. However, the findings remain controversial; furthermore, the relationship between ACEI-induced cough and lung cancer development remains unknown. We used Mendelian randomization (MR) to verify the association between ACEI use, ACEI-induced cough, and the risk of lung cancer.Methods: We performed a two-sample MR analysis to determine the unconfounded relationships between ACE inhibition, which mimics the effects of ACEIs, and genetic proxies for ACEI-induced cough and lung cancer. Single nucleotide polymorphisms that imitate ACE receptors and ACEI-induced cough were collected and integrated into a meta-analysis of existing genome-wide association studies for various lung cancers. The relationship was quantified using inverse variance weighting, weighted median, and MR-Egger methods.Results: A statistically significant association was observed between ACE inhibition and the risk of small cell lung cancer for Europeans (excluding rs118121655/rs80311894). Associations were identified between ACEI-induced cough and the risk of lung cancer for Europeans, although not for Asians, and between ACEI-induced cough and lung adenocarcinoma (excluding rs360206).Conclusion: Our findings reveal a relationship between ACE inhibition and lung cancer development, as well as a significant association between ACEI-induced cough and a higher risk of lung cancer for Europeans. Patients with hypertension who experience dry cough as a side effect of ACEI use should consider switching to an alternative antihypertensive treatment
Efficacy, safety, and survival of neoadjuvant immunochemotherapy in operable non-small cell lung cancer: a systematic review and meta-analysis
BackgroundNeoadjuvant immunochemotherapy may benefit patients with non-small cell lung cancer (NSCLC), but its impact requires further investigation.MethodsA meta-analysis was conducted. PubMed, Embase, Web of Science, and the Cochrane Library were searched. The study was registered in PROSPERO (registration no. CRD42022360893).Results60 studies of 3,632 patients were included. Comparing with neoadjuvant chemotherapy, neoadjuvant immunochemotherapy showed higher pCR (RR: 4.71, 95% CI: 3.69, 6.02), MPR (RR, 3.20, 95% CI: 2.75, 3.74), and ORR (RR, 1.46, 95% CI: 1.21, 1.77), fewer surgical complications (RR: 0.67, 95%CI: 0.48, 0.94), higher R0 resection rate (RR: 1.06, 95%CI: 1.03, 1.10, I2Â =Â 52%), and longer 1-year and 2-year OS, without affecting TRAEs. For neoadjuvant immunochemotherapy in NSCLC, the pooled pCR rate was 0.35 (95% CI: 0.31, 0.39), MPR was 0.59 (95% CI: 0.54, 0.63), and ORR was 0.71 (95% CI: 0.66, 0.76). The pooled incidence of all grade TRAEs was 0.70 (95% CI: 0.60, 0.81), and that of >= grade 3 TRAEs was 0.24 (95% CI: 0.16, 0.32). The surgical complications rate was 0.13 (95% CI: 0.07, 0.18) and R0 resection rate was 0.98 (95% CI: 0.96, 0.99). The pooled 1-year OS was 0.97 (95%CI: 0.96, 0.99), and 2-year OS was 0.89 (95%CI: 0.83, 0.94). Patients with squamous cell carcinoma, stage III or higher PD-L1 performed better. Notably, no significant differences were observed in pCR, MPR, and ORR between 2 or more treatment cycles. Pembrolizumab-, or toripalimab-based neoadjuvant immunochemotherapy demonstrated superior efficacy and tolerable toxicity.ConclusionAccording to our analysis, reliable efficacy, safety, and survival of neoadjuvant immunochemotherapy for operable NSCLC were demonstrated.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022360893, identifier CRD42022360893
A STUDY ON THE ANTIOXIDANT EFFECT OF CORIOLUS VERSICOLOR POLYSACCHARIDE IN RAT BRAIN TISSUES
The objective of the study was to investigate the antioxidant effect of Chinese medicine Coriolus versicolor polysaccharide on brain tissue and its mechanism in rats. SOD, MDA and GSH-Px levels in rat brain tissues were determined with SD rats as the animal model. The results showed that Coriolus versicolor polysaccharide can reduce the lipid peroxidation level in brain tissues during exhaustive exercise in rats, and can accelerate the removal of free radicals. The study concluded that its antioxidant effect is relatively apparent
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