1,153 research outputs found
An Empirical Study on the Evolution of Employment Structure of Transport, Storage and Post Industry of Beijing During Economic Transition in China
Employment structure of transport, storage and post industry is in continuous evolution along with the economic transition, and this paper makes an empirical study on it. This paper analyzes the change in employed laborers, employment structure and industry structure in transport, storage and post industry in Beijing, and makes a comparison with the employment proportion in third industry. Based on the above analysis, this paper gives some policy suggestions to both promote the healthy development of transport, storage and post industry in Beijing and further enhance the industry to absorb laborers
The Cellular Robustness by Genetic Redundancy in Budding Yeast
The frequent dispensability of duplicated genes in budding yeast is heralded as a hallmark of genetic robustness contributed by genetic redundancy. However, theoretical predictions suggest such backup by redundancy is evolutionarily unstable, and the extent of genetic robustness contributed from redundancy remains controversial. It is anticipated that, to achieve mutual buffering, the duplicated paralogs must at least share some functional overlap. However, counter-intuitively, several recent studies reported little functional redundancy between these buffering duplicates. The large yeast genetic interactions released recently allowed us to address these issues on a genome-wide scale. We herein characterized the synthetic genetic interactions for âŒ500 pairs of yeast duplicated genes originated from either whole-genome duplication (WGD) or small-scale duplication (SSD) events. We established that functional redundancy between duplicates is a pre-requisite and thus is highly predictive of their backup capacity. This observation was particularly pronounced with the use of a newly introduced metric in scoring functional overlap between paralogs on the basis of gene ontology annotations. Even though mutual buffering was observed to be prevalent among duplicated genes, we showed that the observed backup capacity is largely an evolutionarily transient state. The loss of backup capacity generally follows a neutral mode, with the buffering strength decreasing in proportion to divergence time, and the vast majority of the paralogs have already lost their backup capacity. These observations validated previous theoretic predictions about instability of genetic redundancy. However, departing from the general neutral mode, intriguingly, our analysis revealed the presence of natural selection in stabilizing functional overlap between SSD pairs. These selected pairs, both WGD and SSD, tend to have decelerated functional evolution, have higher propensities of co-clustering into the same protein complexes, and share common interacting partners. Our study revealed the general principles for the long-term retention of genetic redundancy
Estimating Effects of Long-Term Treatments
Estimating the effects of long-term treatments in A/B testing presents a
significant challenge. Such treatments -- including updates to product
functions, user interface designs, and recommendation algorithms -- are
intended to remain in the system for a long period after their launches. On the
other hand, given the constraints of conducting long-term experiments,
practitioners often rely on short-term experimental results to make product
launch decisions. It remains an open question how to accurately estimate the
effects of long-term treatments using short-term experimental data. To address
this question, we introduce a longitudinal surrogate framework. We show that,
under standard assumptions, the effects of long-term treatments can be
decomposed into a series of functions, which depend on the user attributes, the
short-term intermediate metrics, and the treatment assignments. We describe the
identification assumptions, the estimation strategies, and the inference
technique under this framework. Empirically, we show that our approach
outperforms existing solutions by leveraging two real-world experiments, each
involving millions of users on WeChat, one of the world's largest social
networking platforms
Examining Usersâ Knowledge Change in the Task Completion Process
This paper examines the changes of information searchersâ topic knowledge levels in the process of completing information tasks. Multi-session tasks were used in the study, which enables the convenience of eliciting usersâ topic knowledge during their process of completing the whole tasks. The study was a 3-session laboratory experiment with 24 participants, each time working on one subtask in an assigned 3-session general task. The general task was either parallel or dependently structured. Questionnaires were administered before and after each session to elicit usersâ perceptions of their knowledge levels, task attributes, and other task features, for both the overall task and the sub-tasks. Our results support the assumption that usersâ knowledge generally increases after each search session, but there were exceptions in which a âceilingâ effect was shown. We also found that knowledge was correlated with usersâ perceptions of task attributes and accomplishment. In addition, task type was found to affect several aspects of knowledge levels and knowledge change. These findings further our understanding of usersâ knowledge in information tasks and are thus helpful for information retrieval research and system design
The Impact of Non-standard Employment on Women's Employment and Countermeasures
Non-standard employment has been increasing globally over the past several decades. Women have a tendency to choose non-standard employment. This paper studies the development of non-standard employment and points out that non-standard employment has both positive and negative effect on womenâs employment .Based on which, this paper gives some policy advices, such as developing non-standard jobs to provide more employment opportunities for women, eliminating of gender discrimination in employment to achieve fair competition in the labor market, and raising the level of women human capital investment to improve their own quality
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