Simpler Analyses of Union-Find

We analyze union-find using potential functions motivated by continuous algorithms, and give alternate proofs of the $O(\log\log{n})$, $O(\log^{*}n)$, $O(\log^{**}n)$, and $O(\alpha(n))$ amortized cost upper bounds. The proof of the $O(\log\log{n})$ amortized bound goes as follows. Let each node's potential be the square root of its size, i.e., the size of the subtree rooted from it. The overall potential increase is $O(n)$ because the node sizes increase geometrically along any tree path. When compressing a path, each node on the path satisfies that either its potential decreases by $\Omega(1)$, or its child's size along the path is less than the square root of its size: this can happen at most $O(\log\log{n})$ times along any tree path.Comment: 13 pages, 1 figur

Dynabench: Rethinking Benchmarking in NLP

We introduce Dynabench, an open-source platform for dynamic dataset creation and model benchmarking. Dynabench runs in a web browser and supports human-and-model-in-the-loop dataset creation: annotators seek to create examples that a target model will misclassify, but that another person will not. In this paper, we argue that Dynabench addresses a critical need in our community: contemporary models quickly achieve outstanding performance on benchmark tasks but nonetheless fail on simple challenge examples and falter in real-world scenarios. With Dynabench, dataset creation, model development, and model assessment can directly inform each other, leading to more robust and informative benchmarks. We report on four initial NLP tasks, illustrating these concepts and highlighting the promise of the platform, and address potential objections to dynamic benchmarking as a new standard for the field

The health effects of Low-carbon Province Pilot Policy in China: an empirical evidence based on China Family Panel Studies (CFPS) from 2010 to 2016

AbstractSince 2010, the Chinese government has developed several batches of low-carbon pilot provinces and cities continuously. And in the backdrop of carbon peak and carbon neutralisation recently, the carbon emission reduction policies and achievements of China have attracted more and more worldwide attention. In the field of human health, this paper investigates whether the Low-carbon Province Pilot Policy of China has positive effects on residents’ health based on the micro data of China Family Panel Studies (CFPS) from 2010 to 2016. Using the time-varying difference-in-difference model to solve the endogeneity problem commonly faced in the literature, we find that Low-carbon Province Pilot Policy has a positive impact on public health through air quality improvement and the unemployment level alleviation mainly. And in urban areas, the policy effect is more obvious than that in rural regions. This paper expands the content of national low-carbon governance effects to residents’ health further and contribute to China’s low-carbon development. Specifically, it reminds us to focus on the dynamic adjustment and effective continuation of the policy, and also the all-round support for ‘the disadvantaged’ in environmental governance process

Whole-transcriptome survey of the putative ATP-binding cassette (ABC) transporter family genes in the latex-producing laticifers of Hevea brasiliensis.

The ATP-binding cassette (ABC) proteins or transporters constitute a large protein family in plants and are involved in many different cellular functions and processes, including solute transportation, channel regulation and molecular switches, etc. Through transcriptome sequencing, a transcriptome-wide survey and expression analysis of the ABC protein genes were carried out using the laticiferous latex from Hevea brasiliensis (rubber tree). A total of 46 putative ABC family proteins were identified in the H. brasiliensis latex. These consisted of 12 'full-size', 21 'half-size' and 13 other putative ABC proteins, and all of them showed strong conservation with their Arabidopsis thaliana counterparts. This study indicated that all eight plant ABC protein paralog subfamilies were identified in the H. brasiliensis latex, of which ABCB, ABCG and ABCI were the most abundant. Real-time quantitative reverse transcription-polymerase chain reaction assays demonstrated that gene expression of several latex ABC proteins was regulated by ethylene, jasmonic acid or bark tapping (a wound stress) stimulation, and that HbABCB15, HbABCB19, HbABCD1 and HbABCG21 responded most significantly of all to the abiotic stresses. The identification and expression analysis of the latex ABC family proteins could facilitate further investigation into their physiological involvement in latex metabolism and rubber biosynthesis by H. brasiliensis

Profiling Ethylene-Responsive Genes Expressed in the Latex of the Mature Virgin Rubber Trees Using cDNA Microarray.

Ethylene is commonly used as a latex stimulant of Hevea brasiliensis by application of ethephon (chloro-2-ethylphosphonic acid); however, the molecular mechanism by which ethylene increases latex production is not clear. To better understand the effects of ethylene stimulation on the laticiferous cells of rubber trees, a latex expressed sequence tag (EST)-based complementary DNA microarray containing 2,973 unique genes (probes) was first developed and used to analyze the gene expression changes in the latex of the mature virgin rubber trees after ethephon treatment at three different time-points: 8, 24 and 48 h. Transcript levels of 163 genes were significantly altered with fold-change values ≥ 2 or ≤ -2 (q-value < 0.05) in ethephon-treated rubber trees compared with control trees. Of the 163 genes, 92 were up-regulated and 71 down-regulated. The microarray results were further confirmed using real-time quantitative reverse transcript-PCR for 20 selected genes. The 163 ethylene-responsive genes were involved in several biological processes including organic substance metabolism, cellular metabolism, primary metabolism, biosynthetic process, cellular response to stimulus and stress. The presented data suggest that the laticifer water circulation, production and scavenging of reactive oxygen species, sugar metabolism, and assembly and depolymerization of the latex actin cytoskeleton might play important roles in ethylene-induced increase of latex production. The results may provide useful insights into understanding the molecular mechanism underlying the effect of ethylene on latex metabolism of H. brasiliensis

Phylogenetic tree for <i>H. brasiliensis</i> latex ABC proteins.

<p>The amino acid sequences of the 46 latex ABC proteins were aligned using the MUSCLE program and subjected to phylogenetic analysis by the distance with neighbor-joining method using the MEGA5.05 software. The numbers on the nodes indicate the bootstrap values after 1000 replicates. The scale bar indicates the estimated number of amino acid substitutions per site. The HUGO nomenclature was followed and the ABC protein abbreviations are as follows: AOH: ABC1 homolog; ATH: ABC-two homolog; MDR: multi-drug resistance; ATM: ABC transporter of mitochondria; TAP: transporter associated with antigen processing; LLP: Lipid A-like exporter; MRP: multi-drug resistance-associated protein; PMP: peroxisomal membrane protein; RLI: RNase L inhibitor; GCN: general control non-repressible; WBC: white-brown complex; PDR: pleiotropic drug resistance; NAP: non-intrinsic ABC protein. AOH and ATH, which belong to the ABCA subfamily; MDR, TAP, ATM and LLP, which belong to the ABCB subfamily; MRP, which belongs to the ABCC subfamily; PMP, which belongs to the ABCD subfamily; RLI, which belongs to the ABCE subfamily; GCN, which belongs to the ABCF subfamily; WBC, which belongs to the ABCG subfamily and NAP, which belongs to the ABCI subfamily.</p

Regulatory effects of ethylene and JA on the gene expressions of the four HbABC transporters in the <i>H. brasiliensis</i> latex.

<p>Mature, virgin (untapped) rubber trees were treated with Ethrel (ET) or methyl-jasmonate (Me-JA) for 0.5, 1.5, 4.0, 8.0 or 24.0 h. The controls were rubber trees that had not been treated with stimulants. Three independent biological replicates were included in each sample. Fresh latex from each sample was collected and used to isolate the total RNA. The transcript abundance of each gene was detected by RT-qPCR and the values are shown as the mean ± S.D. Statistical significance was determined using Students <i>t</i>-test using SPSS 19.0 software (Chicago, U.S.A.). When compared with the control, one asterisk shows a significant difference with a <i>P</i>-value < 0.05 and two asterisks show a very significant difference with a <i>P</i>-value < 0.01.</p