International greenways: a Red River Valley case study

Building and preserving a network of greenways can be an intricate activity requiring interdisciplinary collaboration. Greenway segments often require local input and participation. In addition, greenways are not necessarily generic open spaces, but can be managed structurally to fulfill specific spatial and temporal requirements. This paper describes local activities in the Fargo (North Dakota)-Moorhead (Minnesota) metropolitan area related to preserving and embellishing the greenway focused around the Red River Valley of the North. This greenway is part of a larger Western Hemisphere greenway, composed of riparian corridors operating as wildlife habitat migration flyways and as resident wildlife habitat. Local activities include demonstration gardens, comprehensive corridor planning, habitat analysis, and revegetation studies. From 1985 to 1990, four spatial treatment investigations were completed, one spatial planning study was prepared, and five demonstration gardens were built. The spatial treatment investigations revealed that the wildlife occupying the greenway could be divided into four habitat-use dimensions, suggesting four important habitat associations for the greenway. The study also revealed three distinct vegetation zones for re-establishing herbaceous vegetation in non-wooded planting conditions. In addition, one experiment indicated that replanting the disturbed woodland corridor was not influenced by seedling size and that Fraxinus pennsylvanica seedlings were highly successful at surviving in a gap opening within the forest corridor. In the last experiment, a seeding application rate study indicated that seeding rates three times higher than recommended rates resulted in improved vegetation cover of non-wooded herbaceous vegetation planting sites. The spatial planning study illustrated landscape patterns for the greenway composed of a continuous tree canopy corridor, augmented by herbaceous vegetation patches, food plots, and snags. To build and manage the greenway, this investigation reaffirms the importance of multi-disciplinary collaboration, local participation, and the potential individualistic structure of a greenway. The study suggests that both broad landscape planning visions and detailed site endeavors are necessary to understand and manage the greenway successfully.     

Direct,Late-Stage Mono-N-arylation of Pentamidine: Method Development,Mechanistic Insight,and Expedient Access to Novel Antiparastitics against Diamidine-Resistant Parasites

A selective mono-N-arylation strategy of amidines under Chan-Lam conditions is described. During the reaction optimization phase, the isolation of a mononuclear Cu(II) complex provided unique mechanistic insight into the operation of Chan-Lam mono-N-arylation. The scope of the process is demonstrated, and then applied to access the first mono-N-arylated analogues of pentamidine. Sub-micromolar activity against kinetoplastid parasites was observed for several analogues with no cross-resistance in pentamidine and diminazene-resistant trypanosome strains and against Leishmania mexicana. A fluorescent mono-N-arylated pentamidine analogue revealed rapid cellular uptake, accumulating in parasite nuclei and the kinetoplasts. The DNA binding capability of the mono-N-arylated pentamidine series was confirmed by UV-melt measurements using AT-rich DNA. This work highlights the potential to use Chan-Lam mono-N-arylation to develop therapeutic leads against diamidine-resistant trypanosomiasis and leishmaniasis.     

Sugar consumption and human cancer in sites other than the digestive tract

In order to assess the relationship between dietary intake of sugar and cancer a comprehensive search of the scientific literature was undertaken. An earlier publication details an analysis of studies relating to cancers of the digestive tract (Burley, 1997). Here, a total of 69 publications were reviewed which reported the results of ecological, case-control or cohort studies which had assessed the relationship between dietary sugar intake or sucrose-containing foods and risk of cancer at other sites. Cancer sites reviewed included the breast, pancreas, prostate, testis, female reproductive system, lung and upper aerodigestive tract and bladder. For most of these cancer sites the number of studies was insufficient to reach a conclusion. For breast cancer, the data on international per capita sugar intakes suggest a consistent positive correlation with breast cancer mortality rates. However, this relationship is not consistent in within-country ecological studies or in case-control studies, in which sugar intakes have been assessed as mono- and disaccharides or as sucrose. There is some suggestion of a weak increase in risk of breast cancer with high consumption of sucrose-containing foods, such as cakes and biscuits. However, these foods provide a range of other nutrients, particularly fat, which may also be implicated in the development of breast cancer, and further studies specifically designed to address this area are required. It is apparent that there is insufficient evidence to conclude whether sugar has a role in cancer at any site.     

白肋烟品种性状与烟碱积累的关系研究

研究结果表明,白肋烟上部叶烟碱含量与株高、茎围、节距、叶数呈现极显著负相关;与移栽-现蕾时间呈现极显著负相关;与烟叶产量呈现极显著负相关。烟碱积累与烟株打顶后时间关系可用二次方程拟合且相关极显著。烟碱积累速率同品种的成熟性密切相关,晚熟品种较早、中熟品种烟碱积累速率低且随时间变化显著降低;生产上宜选用综合性状较好的品种NC3、KY8959。      

Variable effects on egg yolks and yolk lipoprotein fractions of feeding methyl sterculate to hens: Periodic changes in lipid composition and gelation temperature

As part of a study of the reasons for the large effects of a small dietary supplement of methyl sterculate on the physical properties and lipid composition of hen's egg yolk, individual yolks from sterculate-fed hens have been examined. These yolks set to a firm gel on cooling in the range 20-0 °C, but there were large variations in eggs from different hens that were accompanied by variations in the proportion of saturated fatty acid residues in the yolk lipids. Gel formation was reversible on immediate rewarming but prolonged storage at low temperature caused irreversible alterations. Diluted yolk showed analogous changes in viscosity on cooling and provided a convenient model system for examining the effect of pH, ionic strength, and the action of trypsin. From these results it is concluded that the protein of the high-lipid low-density lipoprotein of yolk is directly involved in the gelation of the yolk. A series of eggs laid by one sterculatefed hen over 30 days showed large and possibly periodic variations in the lipid composition and gelation temperature of the yolks. These results and some data from other hens suggested that large variations in yolk properties accompany a high response to sterculate feeding.     

An experimental study of air entrainment at a solid/liquid/gas interface

Some data from an experimental study of air entrainment into a fluid bath by a continuous moving plane tape is presented. The separate effects of surface tension and viscosity are described and the various modes of air entrainment are given in the context of fluid properties. The velocity of air entrainment is found to be a function of surface tension and viscosity for viscosities less than 4.65 poise. For viscosities greater than this value, the air entrainment velocity tended to a constant value of 9.5 cm sec^?1 independent of surface tension. Relationships of the form: We = k Re^a and We = c (Bo + 1)Re^d, are suggested by analogy to describe air entrainment data without and with buoyancy effects. Data from studies on four tapes and nine fluids gave a very high correlation when plotted in the above form. The data is in substantial agreement with that from similar studies, and shows that the condition Ca = We/Re = constant is not a global criteria for air entrainment by a plunging surface. The experimental data shows that air entrainment velocity may be estimated from the relationship V_AF = 67.679 (μ√(g/ρσ))^?0.672 for the normally plunging plane tapes studied.     

Structural similarity between TAFs and the heterotetrameric core of the histone octamer

A complex of two TFIID TATA box-binding protein-associated factors (TA FIIs) is described at 2.0A resolution. The amino-terminal portions of dTAFII42 and dTAFII62 from Drosophila adopt the canonical histone fold, consisting of two short alpha-helices flanking a long central alpha-helix. Like histones H3 and H4, dTAFII42 and dTAFII62 form an intimate heterodimer by extensive hydrophobic contacts between the paired molecules. In solution and in the crystalline state, the dTAFII42/dTAFII62 complex exists as a heterotetramer, resembling the (H3/H4)2 heterotetrameric core of the histone octamer, suggesting that TFIID contains a histone octamer-like substructure.     

[60]Fullerene Amino Acids and Related Derivatives

Abstract

This paper is a review of the literature concerning the preparation of [60]fullerene amino acid and peptide derivatives. The structure and applications of these derivatives to the biological and Material sciences is also presented.