In web search, recency ranking refers to ranking documents by relevance which takes freshness into account. In this paper, we propose a retrieval system which automatically detects and responds to recency sensitive queries. The system detects recency sensitive queries using a high precision classifier. The system responds to recency sensitive queries by using a machine learned ranking model trained for such queries. We use multiple recency features to provide temporal evidence which effectively represents document recency. Furthermore, we propose several training methodologies important for training recency sensitive rankers. Finally, we develop new evaluation metrics for recency sensitive queries. Our experiments demonstrate the efficacy of the proposed approaches.

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This study investigated the effects of dietary supplementation with Bacillus subtilis ( B. subtilis ) or Bacillus licheniformis ( B. licheniformis ) on growth performance, immunity, antioxidant capacity, short chain fatty acid ( SCFA ) production, and the cecal microflora in broiler chickens. In total, 360 male, 1-day-old Cobb 500 birds were randomly divided into 3 groups: the control group was fed a basal diet; the B. subtilis group was fed a basal diet supplemented with 1.5 × 10 9 CFU/kg B. subtilis ; the B. licheniformis group was fed a basal diet supplemented with 1.5 × 10 9 CFU/kg B. licheniformis . Results showed that chickens supplemented with either B. subtilis or B. licheniformis had comparatively higher ( P < 0.05) body weight and average daily gain, whereas no difference ( P > 0.05) was observed in feed efficiency. Concentrations of serum IgA, IgY, and IgM, as well as anti-inflammatory IL-10 were significantly increased ( P < 0.05), and proinflammatory IL-1β and IL-6 were significantly decreased ( P < 0.05) by B. subtilis or B. licheniformis supplementation. Moreover, chickens fed with diets supplemented by either B. subtilis or B. licheniformis had greater antioxidant capacity, indicated by the notable increases ( P < 0.05) in glutathione peroxidase, superoxide dismutase, and catalase, along with decrease ( P < 0.05) in malondialdehyde. Compared to the control group, levels of SCFA, excluding acetic and propionic acid, in cecal content had improved ( P < 0.05) by adding B. licheniformis, and significant increase ( P < 0.05) in acetic and butyric acid was observed with B. subtilis supplementation. Microbial analysis showed that both B. subtilis or B. licheniformis supplementation could increase butyrate-producing bacteria such as Alistipes and Butyricicoccus , and decrease pathogenic bacteria such as the Synergistetes and Gammaproteobacteria . In summary, dietary supplemented with B. subtilis or B. licheniformis improved growth performance, immune status, and antioxidant capacity, increased SCFA production, and modulated cecal microbiota in chickens. Moreover, B. licheniformis was more effective than B. subtilis ...

The transport properties of CrI₃/h-BN/n·CrI₃ (n = 1, 2, 3, 4) MTJs under positive bias voltages exhibit an interesting odd-even effect. Significant tunneling magnetoresistance, a perfect spin filtering effect and remarkable negative differential resistance were obtained.

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The search for more types of band inversion-induced topological states is of great scientific and experimental interest. Here, we proposed that the band inversion between px,y and pz orbitals can produce a topological phase transition in honeycomb lattices.

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