Financial performance of diverse levels of early competition suppression and pre-commercial thinning on loblolly pine stand development     

Tanger  S. M.  Blazier  M. A.  Holley  A. G.  McConnell  T. E.  Vanderschaaf  C.  Clason  T. R.  KC  Dipesh 《New Forests》2021,52(2):217-235

New Forests - Competition suppression within loblolly pine plantations (Pinus taeda L.) is typically carried out within the first 2 years of a plantation, but competition control for longer...  相似文献   

Time after seawater transfer influences immune cell abundance and responses to SAV3 infection in Atlantic salmon          下载免费PDF全文

J Jarungsriapisit  L J Moore  I U Fiksdal  H Bjørgen  A Tangerås  B Köllner  E O Koppang  S Patel 《Journal of fish diseases》2018,41(8):1269-1282

Pancreas disease (PD) caused by salmonid alphavirus (SAV) severely affects salmonid aquaculture during the seawater phase. To characterize immune cells in target tissues for SAV infection, heart, pancreas and pyloric caeca were analysed from two groups of fish adapted to seawater for 2 and 9 weeks. The sections were scored for the relative abundance of cells expressing MHC class II, IgM, CD3, CD8 or neutrophil/granulocyte markers using immuno‐histochemical techniques. In general, necrosis of tissue was more severe in fish infected at 2 weeks post‐seawater transfer (wpt) compared with those infected at 9 wpt. At 9 wpt, there were higher numbers of MHC II⁺ cells in heart, pancreas and pyloric caeca, IgM⁺ cells in heart and pancreas, and CD3⁺ cells in pancreas compared to those infected at 2 wpt. The majority of the immune cells infiltrating PD‐affected tissues were MHC II⁺ and CD3⁺ cells suggesting that antigen‐presenting cells and T lymphocytes are the main types of immune cells responding to SAV infection. All the investigated cell types were also observed in pyloric caeca of infected fish, suggesting that this tissue may play a role in the immune response to SAV.  相似文献   

An empirical analysis of bill co-sponsorship in the U.S. Senate: The Tree Act of 2007     

Shaun M. Tanger  David N. Laband   《Forest Policy and Economics》2009,11(4):260-265

Public choice economists view the legislative process as a political market, in which interest groups attempt to influence the production of legislation that has pecuniary and non-pecuniary consequences for them; politicians provide these groups with relevant legislation. In this context, bill co-sponsorship acts as a signal to interest groups that a legislator is working to promote their interests and thereby maximize the payoffs received from such groups. In this paper we seek to identify factors associated with bill co-sponsorship, to determine whether interest group politics significantly explain bill co-sponsorship behavior in the U.S. Senate. Specifically, we examine Senate Bill 402, a bill seeking to amend the Internal Revenue Code of 1986 to allow a deduction for qualified timber gains. Senate co-sponsorship decisions concerning S.B. 402 are assessed using a model that identifies various political and industry (forestry) interests/characteristics. We demonstrate that a Senator's co-sponsorship of this bill is correlated with his/her seniority, tax-cutting ideology, strength of electoral victory in his/her most recent election, campaign contributions received from forestry interests, the relative contribution of forestry to Gross State Product, and the percent of total land in his/her state that is privately owned.  相似文献