Antiquity ◽  
1994 ◽  
Vol 68 (260) ◽  
pp. 604-610 ◽  
Author(s):  
Christina Pavlides ◽  
Chris Gosden

The growing story of early settlement in the northwest Pacific islands is moving from coastal sites into the rainforest. Evidence of Pleistocene cultural layers have been discovered in open-site excavations at Yombon, an area containing shifting hamlets, in West New Britain's interior tropical rainforest. These sites, the oldest in New Britain, may presently stand as the oldest open sites discovered in rainforest anywhere in the world.


2017 ◽  
pp. 67
Author(s):  
Dulce María Figueroa-Castro ◽  
Zenón Cano-Santana ◽  
Edgar Camacho-Castillo

We studied the production of reproductive structures and the reproductive phenology of five Compositae species in a xeric community in Central Mexico: Eupatorium petiolare, Tagetes lunulata, Senecio praecox, Dahlia coccinea and Verbesina virgata. The last three species were studied in two sites with contrasting light conditions. The number of reproductive structures produced by D. coccinea was higher in the open site than in the shaded one. In contrast, S.praecox had a higher production in the shaded site, but V. virgata showed no differences. The reproductive phenology of V. virgata and D. coccinea was different between sites, but it was not happen in S. praecox. The species that flowered during the dry season had a shorter reproductive period (E. petiolare: 2.8 mo; S. praecox: 2.0 mo) than those that flowered during the rainy season or during the late rainy season (D. coccinea: 11.0 mo; T. lunulala: 8.5 mo; V. virgata: 8.5 mo) , which was caused by the high duration of the mature fruit stage in these species.


Author(s):  
Lin Chen ◽  
Gan Ren ◽  
Yakun Guo ◽  
Ge Sang

The mononuclear nickel title complex (acetonitrile-κN){N-benzyl-N,N′,N′-tris[(6-methylpyridin-2-yl)methyl]ethane-1,2-diamine}nickel(II) bis(tetrafluoridoborate), [Ni(C30H35N5)(CH3CN)](BF4)2, was prepared from the reaction of Ni(BF4)2·6H2O withN-benzyl-N,N′,N′-tris[(6-methylpyridin-2-yl)methyl]ethane-1,2-diamine (bztmpen) in acetonitrile at room temperature. With an open site occupied by the acetonitrile molecule, the nickel(II) atom is chelated by five N-atom sites from the ligand and one N atom from the ligand, showing an overall octahedral coordination environment. Compared with analogues where the 6–methyl substituent is absent, the bond length around the Ni2+cation are evidently longer. Upon reductive dissociation of the acetronitrile molecule, the title complex has an open site for a catalytic reaction. The title complex has two redox couples at −1.50 and −1.80 V (versus Fc+/0) based on nickel. The F atoms of the two BF4−counter-anions are split into two groups and the occupancy ratios refined to 0.611 (18):0.389 (18) and 0.71 (2):0.29 (2).


1959 ◽  
Vol 25 ◽  
pp. 233-259 ◽  
Author(s):  
Angela Mace

Traces of Upper Palaeolithic settlement in Britain have up to the present been confined very largely to the limestone caves of the highland zone. Recent work in Holland, north Germany and Denmark during the last twenty or thirty years by Rust, Mathiassen, Schwabedissen, Bohmers and others suggests that indications of open settlement ought to occur in lowland England. Until the present investigations these were confined to surface industries from East Anglia and north Kent and to the recovery in association with remains of three horses of a small shouldered backed blade and of another without retouch from a deposit of Allerød age at Flixton (site 2) in East Yorkshire.


1999 ◽  
Vol 77 (1) ◽  
pp. 37-56 ◽  
Author(s):  
H Golchoubian ◽  
W L Waltz ◽  
J W Quail

A series of macrocyclic heterobimetallic complexes of type [Mc(tntnam)Mo](PF6)n and [Mc'(tntnim)Ni](PF6)n where Mc = Co(III) and Zn(II), Mc' = Co(II), Co(III), and Zn(II), and Mo = Ni(II), Cu(II), and Zn(II) have been synthesized and characterized. The macrocyclic ligands tntnim 2 and tntnam 3 contain two geometrically distinct compartments, 6-coordinate (closed site) and 4-coordinate (open site), which are bridged by phenolic oxygens. The heterobimetallic complexes with Zn(II) or Ni(II) in the open site are primarily formed as 5-coordinate with a chloride ion as a fifth ligand; the latter can be removed by Ag+ ion. The crystal structures of [Zn(tntnim)NiCl]PF6·C2H5OH, 5, [Zn(tntnam)Ni](PF6)2, 11, [Zn(tntnam)Cu](PF6)2, 12, and [Co(tntnam)Ni(H2O)](PF6)3·4H2O, 14 were determined. Crystal data for 5: monoclinic, T = 123 K, a = 15.822(2), b = 15.6230(10), c = 16.432(2) Å, β = 104.570(10)°, Z = 4, space group Pc, R = 0.0371 (wR2 = 0.0843) for 5826 reflections with I [Formula: see text] 2σ(I). Crystal data for 11: tetragonal, T = 123 K, a = b = 24.122(2), c = 14.397(7) Å, Z = 8, space group P41212, R = 0.0625 (wR2 = 0.1549) for 3250 reflections with I [Formula: see text] 2σ(I). Crystal data for 12: tetragonal, T = 123 K, a = b = 24.180(2), c = 14.281(4) Å, Z = 8, space group P41212, R = 0.0588 (wR2 = 0.1219) for 3452 reflections with I [Formula: see text] 2σ(I). Crystal data for 14: triclinic, T = 287 K, a = 12.664(2), b = 12.983(2), c = 16.216(3) Å, α = 80.317(14)°, β = 69.585(12)°, γ = 74.791(12)°, Z = 2, space group P[Formula: see text], R = 0.0573 (wR2 = 0.1332) for 3443 reflections with I [Formula: see text] 2σ(I). The structures were solved by direct methods and refined by full-matrix least-squares procedures. The crystal structures demonstrate that the expected trans pyridine structures are formed. The magnetic moments, electrospray mass spectra, electronic absorption and emission spectra, and redox couples are reported. Key words: cobalt, copper, nickel, zinc, heterobimetallic, macrocycle.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Toshiaki Owari ◽  
Shinichi Tatsumi ◽  
Liangzhi Ning ◽  
Mingfang Yin

To develop two-storied forest management of larch plantations in Northeast China, this study examined the height growth of Korean pine (Pinus koraiensisSieb. et Zucc.) seedlings planted under strip-cut larch canopies. We measured the height growth of the underplanted seedlings 4 years after planting. The larch canopies were of varying stand age (12, 17, and 37 years) and strip-cut width (4.5, 6.0, and 7.5 m). We measured the seedling height growth in an open site (i.e., a site with no canopy). Underplanted seedlings had a smaller height growth (12.1–20.1 cm year−1) than the seedlings planted in the open site (23.7 cm year−1). The seedlings underplanted in the wider strip-cuts tended to have greater height growth than the seedlings underplanted in the narrowest strip-cuts. A generalized linear mixed model analysis predicted the greatest seedling height growth in the open site. A 36–47% reduction in annual height growth was predicted for the narrowest strip-cuts (4.5 m) versus the open site, while a 13–36% reduction in annual height growth was predicted for the wider strip-cuts (6.0–7.5 m) versus the open site. To maintain adequate height growth, forest managers are recommended to create wider strip-cuts (i.e., ≥6.0 m) for the purpose of underplanting Korean pine seedlings in larch plantations.


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