A Simple yet Effective Framework for Active Learning to Rank

While China has become the biggest online market in the world with around 1 billion internet users, Baidu runs the world largest Chinese search engine serving more than hundreds of millions of daily active users and responding billions queries per day. To handle the diverse query requests from users at web-scale, Baidu has done tremendous efforts in understanding users' queries, retrieve relevant contents from a pool of trillions of webpages, and rank the most relevant webpages on the top of results. Among these components used in Baidu search, learning to rank (LTR) plays a critical role and we need to timely label an extremely large number of queries together with relevant webpages to train and update the online LTR models. To reduce the costs and time consumption of queries/webpages labeling, we study the problem of Activ Learning to Rank (active LTR) that selects unlabeled queries for annotation and training in this work. Specifically, we first investigate the criterion -- Ranking Entropy (RE) characterizing the entropy of relevant webpages under a query produced by a sequence of online LTR models updated by different checkpoints, using a Query-By-Committee (QBC) method. Then, we explore a new criterion namely Prediction Variances (PV) that measures the variance of prediction results for all relevant webpages under a query. Our empirical studies find that RE may favor low-frequency queries from the pool for labeling while PV prioritizing high-frequency queries more. Finally, we combine these two complementary criteria as the sample selection strategies for active learning. Extensive experiments with comparisons to baseline algorithms show that the proposed approach could train LTR models achieving higher Discounted Cumulative Gain (i.e., the relative improvement {\Delta}DCG4=1.38%) with the same budgeted labeling efforts.Comment: This paper is accepted to Machine Intelligence Research and a short version is presented in NeurIPS 2022 Workshop on Human in the Loop Learnin

Identification and characterization of class 1 integrons among Pseudomonas aeruginosa isolates from patients in Zhenjiang, China

SummaryObjectivesThe role of integrons in the spread of antibiotic resistance has been well established. The aim of this study was to investigate the resistance profiles of Pseudomonas aeruginosa isolated from patients in Zhenjiang to 13 antibiotics, and to identify the structure and dissemination of class 1 integrons.MethodsThe Kirby–Bauer disk diffusion assay was used to determine the rate of P. aeruginosa resistance. Class 1 integrons from multidrug-resistant isolates were amplified by PCR, and their PCR products were sequenced. We also analyzed the integron structures containing the same gene cassettes by restriction fragment length polymorphism (RFLP). Isolates were genotyped by pulsed-field gel electrophoresis (PFGE).ResultsThe resistance rates were between 29.6% and 90.1%. The prevalence of class 1 integrons was 38.0%. These integrons included five gene cassettes (aadB, aac6-II, blaPSE-1, dfrA17, and aadA5). The dfrA17 and aadA5 gene cassettes were found most often.ConclusionsClass 1 integrons were found to be widespread in P. aeruginosa isolated from clinical samples in the Zhenjiang area of China. The antibiotic resistance rates in class 1 integron-positive strains of P. aeruginosa were noticeably higher than those in class 1 integron-negative strains. PFGE showed that particular clones were circulating among patients

Short-interval second ejaculation improves sperm quality, blastocyst formation in oligoasthenozoospermic males in ICSI cycles: a time-lapse sibling oocytes study

BackgroundDoes short-interval second ejaculation improve sperm quality, embryo development and clinical outcomes for oligoasthenozoospermia males received intracytoplasmic sperm injection (ICSI) treatment?MethodsAll enrolled male patients underwent short-interval secondary ejaculation on the day of oocyte retrieval, and 786 sibling MII oocytes from 67 cycles were equally divided into two groups based on whether the injected spermatozoons originated from the first or second ejaculation. Semen parameters, embryo development efficiency, morphokinetic parameters and clinical outcomes were compared between the two groups to assess the efficiency and clinical value of short-interval second ejaculation in ICSI cycles.ResultsShort-interval second ejaculation significantly improved sperm motility, normal morphological rate, and sperm DNA integrity both before and after sperm swim-up. The high-quality blastocyst rate (24.79% versus 14.67%), available blastocyst rate (57.56% versus 48.44%), and oocyte utilization rate (52.93% versus 45.29%) were significantly higher in the second ejaculation group (P<0.05). The clinical pregnancy rate (59.09% versus 47.37%), implantation rate (42.11% versus 32.35%) and live birth rate (40.91% versus 31.58%) were higher in the second ejaculation group, but the differences were not significant (P>0.05). Time-lapse analysis showed that morphokinetic time points after the 7-cell stage were earlier in the second ejaculation group but without a significant difference (P>0.05), and abnormal embryo cleavage patterns between the two groups were not significantly different (P>0.05).ConclusionsShort-interval second ejaculation significantly improves sperm quality in oligoasthenozoospermic males, and is beneficial for blastocyst formation efficiency in ICSI cycles. This study suggested a non-invasive and simple but effective strategy for improving ICSI treatment outcomes

Genetic Diversity of Carbapenem-Resistant Enterobacteriaceae (CRE) Clinical Isolates From a Tertiary Hospital in Eastern China

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is increasing globally, with different molecular mechanisms described. Here we studied the molecular mechanisms of carbapenem resistance, including clonal and plasmid dissemination, of 67 CRE isolates collected between 2012 and 2016 from a tertiary hospital in Eastern China, an CRE endemic region. Species identification and susceptibility testing were performed using the BD Phoenix Automated Microbiology System. Isolates were characterized by PCR (for carbapenemases, ESBLs, AmpC and porin genes), multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and conjugation transfer experiments. Selected blaKPC-2 -harboring plasmids were subjected to next-generation sequencing using the Illumina Miseq platform. Among the 67 CRE isolates, 42 Klebsiella pneumoniae, 10 Serratia marcescens, 6 Enterobacter cloacae, 2 Raoultella ornithinolytica, 2 K. oxytoca, 1 K. aerogenes, and 4 Escherichia coli isolates were identified. Six different carbapenemases were detected, including blaKPC-2 (n = 45), blaKPC-3 (n = 1), blaNDM-1 (n = 6), blaNDM-5 (n = 1), blaIMP-4 (n = 2), and blaVIM-1 (n = 2); blaOXA-48-like genes were not detected. One E. cloacae strain possessed both blaNDM-1 and blaKPC-3, while two E. cloacae isolates harbored blaNDM-1 and blaVIM-1. ESBLs (CTX-M, SHV, and TEM) and/or AmpC (CMY, DHA, and ACT/MIR) genes were also identified in 59 isolates, including 13 strains that lacked carbapenemases. Several insertions or stop codon mutations were found within porin genes of K. pneumoniae, E. coli and S. marcescens isolates, both with and without carbapenemases. The 42 K. pneumoniae isolates belonged to 12 different sequence types (ST), with ST11 being the most common, while the 6 E. cloacae isolates comprised 4 different STs. The 10 S. marcescens all shared the same PFGE pulsotype, suggestive of clonal spread. Complete plasmid sequencing and PCR screening revealed both intra-strain and inter-species spread of a common blaKPC-2-harboring plasmid in our hospital. Taken together, our study revealed extensive genetic diversity among CRE isolates form a single Chinese hospital. CRE isolates circulating in the hospital differ significantly in their species, STs, porin genes, carbapenemase genes, and their plasmid content, highlighting the complex dissemination of CRE in this endemic region

Test Methods and Bond Performance Characterization of Shotcrete-Concrete Interface

ORSO 135461Shotcrete is becoming popular for vertical and overhead applications where conventional formwork and repairs are difficult and costly. However, the substrate and the shotcrete overlay interface can be vulnerable, and the bond properties in this region are not well understood. Furthermore, the interface bond could be adversely affected by long-term freeze-thaw weathering in northern states leading to debonding from the existing substrate and corrosion of rebars. Hence, characterization of the shotcrete-substrate interface bonds is critical for the performance evaluation of shotcrete construction. To this goal, this study evaluated the shotcrete-concrete interface bond using four representative substrate surface preparation methods: chipped, pressure-washed, sandblasted, and as-cast, under three different loading conditions: tensile, shear, and Mode-II fracture. The study also investigated the long-term freeze-thaw durability of these bonds and introduced a probabilistic damage model to predict their service lives

Guidelines for the surface preparation/rehabilitation of existing concrete and asphaltic pavements prior to an asphaltic concrete overlay

110 p.A large percentage of the asphaltic paving projects performed in Wisconsin are asphaltic overlays of existing concrete or asphaltic pavements. Due to varying performance of overlay, a standard set of guidelines is needed to determine the amount of surface preparation which provides a consistency along with more accurate and stable project budgets for this type of work. Literature review of Wisconsin Department of Transportation (WisDOT) and national practices of pre-overlay repair of existing concrete and asphaltic pavements was conducted. Previous asphalt overlay projects were reviewed and overlay performance was analyzed. In addition, three overlay projects during 2004 construction season were studied in the field. For asphalt overlay of existing concrete pavements, it was found that overlays with doweled concrete base patching performed best, followed by non-doweled concrete base patching and then asphaltic base patching. Partial depth repair is needed to fix the medium severity transverse cracks and longitudinal/transverse distressed joints in existing concrete pavement. A minimum of 3 in., practically 3 1/2 in., overlay thickness was found to be able to mitigate reflective cracking in overlay. All high-severity joints/cracks/patches should be repaired. The current International Roughness Index (IRI) in overlay was highly correlated with initial IRI of overlay, indicating the importance of profile index. The roughness prediction model used in the NCHRP 1-37A 2002 design guide was calibrated with locally available data. For asphalt overlay of existing asphalt pavements, block cracking in existing asphalt pavement does not adversely affect the overlay when milling is used. Existing asphalt pavement with extensive alligator cracking should be pulverized to prevent the reflection of underlying alligator cracking. Milling the existing asphalt pavement can not eliminate the reflection of transverse cracking in existing asphalt pavement. The ratio of overlay thickness to milling depth should be kept a minimum of 3 to prevent longitudinal cracking from re-occurring in overlay. A set of guidelines was developed to be included in the Facility Development Manual and Construction and Material Manual

Systematic Evaluation of the Field Constructability and Performance of Asphalt Mixtures Containing High Percentages of Recycled Asphalt

This study evaluates the use of high amounts of recycled asphalt pavement (RAP) and recycled asphalt shingle (RAS) in asphalt mixes for sustainable construction. While past research has focused on asphalt binders and laboratory performance testing, this study assesses the effect of high recycle content on constructability and long-term field performance. A total of 72 mix designs placed from 2016 to 2020 were evaluated for compaction characteristics, while the rutting, cracking, and roughness of 16 projects placed from 2011 to 2015 were assessed based on recycled asphalt levels and mix components. Results showed that high recycled mix projects had equivalent compaction characteristics to low RAP mix projects, except that high RAP mixes had lower variability. High RAP/RAS mixes with rejuvenators had a higher density than those without, and high recycled mix projects had comparable field performance to that of low RAP mix projects, except for lower longitudinal cracking in high RAP projects

Optimizing Asphalt Pavement Performance for Climate Zones Within Washington State

Asphalt pavement performance in Washington State varies greatly across the different climatic zones found within the state. The average surface life of pavements west of the Cascades is 16.7 years, compared to 10.9 years for pavements east of the Cascades and as low as 5 years in mountain pass areas. Currently, Washington State Department of Transportation (WSDOT) standards specify only two standard PG binders with the standard one or two grade bump to account for the climate conditions. This study evaluates potential material and construction practices to improve the longevity of pavements in the harsh climates of Eastern Washington and mountain pass areas. Promising strategies for improving pavement performance are determined from a literature review, survey of state agencies, and interviews of industry professionals. Performance history within the Washington State Pavement Management System (WSPMS) is analyzed to determine the causes of pavement failure within these climatic zones and verify the promising methods/technologies from the literature review, survey of state agencies, and interviews of industry professionals to determine if these methods/technologies have been tried in the state. Performance tests are conducted on field cores and extracted binders from some in-service pavements in Washington to quantify the effects of some of the methods/technologies. Recommendations for strategies to improve pavement performance are made for project-specific factors of traffic volume and historical failure modes.Pacific Northwest Transportation Consortiu

Study of Long-Term Field Performance of Chip Seal in Washington State

Chip seal is a pavement preservation treatment that is usually used on lower-volume routes by States and local agencies. Chip seal provides a low-cost surface treatment, improves skid resistance, and reduces the deterioration of the existing underlying pavement. Chip seals consist of a layer of aggregate (chip) spread evenly on top of an emulsion that is sprayed onto the deteriorated surface. The performance of chip seals is significantly affected by the existing conditions and pretreatment carried out before the chip seal is applied. A study was conducted by retrieving long-term performance of chip seals from the Washington pavement management system (WSPMS). In collaboration with Washington State Department of Transportation (WSDOT), twelve (12) road sections previously paved with hot mix asphalt (HMA) or chip seal and later maintained with chip seal were selected, and their performance was analyzed in terms of cracking, rutting, and roughness index (IRI). It was found that chip seal greatly reduced the cracking and slowed down the crack growth when compared to HMA overlay. However, no improvement in rutting or international roughness index (IRI) caused by the chip seal was found

Performance assessment of Wisconsin's whitetopping and ultra-thin whitetopping projects

133 p.Whitetopping (WT) overlay is a concrete overlay on the prepared existing hot mix asphalt (HMA) pavement to improve both the structural and functional capability. It?s a relatively new rehabilitation technology for deteriorated HMA. If the slab thickness is less or equal to 4 in., it is referred to as ultra-thin whitetopping (UTW). The primary objectives of this study are to catalog the WT and UTW projects in Wisconsin, document pertinent design and construction elements, assess performance and estimate a service life of these projects. A comprehensive literature review was performed. A database of the WT and UTW projects was established covering 18 projects built from 1995 to 2007 in Wisconsin. The performance of these WT and UTW projects was assessed, by means of shear strength tests on field cores, falling weight deflectometer (FWD) tests on selected projects, and field distress survey on in-service projects. FWD backcalculation methods for WT and UTW pavements were studied and a Critical Distance Method was proposed and utilized for UTW pavement. Fatigue life was analyzed using 18kip, 22kip and 26kip single axle load level. Performance assessment was conducted using both Pavement Condition Index (PCI) and Pavement Distress Index (PDI). The performance of WT projects in Wisconsin was found comparable to that in other states. WT overlay thickness, joint spacing and pavement age were found to have significant effects on pavement performance