Geographical ‘handicaps’ and small states: Some implications for the Pacific from a global perspective     

Harvey Armstrong  Robert Read 《Asia Pacific viewpoint》2006,47(1):79-92

Abstract: Research on the economic performance of small states has concentrated on the implications of small size and thin local markets. An interesting feature of many of the world's smallest states, of which the Pacific region has many, is that they face additional challenges than just small size. Many are remote from global markets for their products. In addition, a large number are also islands, many of which are also mountainous. Many of the smaller states are not just islands, but are also archipelagos. Hence in addition to small size, many of the world's small states also exhibit four other characteristics that may affect their economic performance: insularity, remoteness, being archipelagos and being highly mountainous entities. This paper examines the nature of the challenges posed by these four characteristics and seeks to produce empirical evidence of how difficult it has been to overcome these challenges. The paper draws on empirical evidence for 126 very small global states, dependent territories and highly autonomous regions. The paper then turns to the position of the Pacific small states and dependent territories.  相似文献   

The nature and inheritance of sweetness and acidity in the cultivated apple   总被引：2，自引：0，他引：2  

A. G. Brown  D. M. Harvey 《Euphytica》1971,20(1):68-80

Summary A survey was made of the sweetness and sourness of the fruits of apple cultivars. Measurements of the concentration of sugars and malic acid in ripe fruits were made and the variation between samples of a cultivar, between cultivars, between years and between cultivars and their tetraploid and colour sports was studied and showed a wide range of variation between cultivars but fairly constant values within cultivars.The study of a number of progenies shows that sweetness and sourness are inherited independently. Sweetness shows a quantitative pattern of inheritance and the progeny mean approximates the mid-parent value. Sourness is controlled by a single gene, with medium and high acidity being dominant to very low, superimposed on a quantitative pattern.The mean sugar and acid concentrations of a progeny and the approximate range of variation can be predicted from the sugar and acid concentrations found in the parents.  相似文献   

Conservation value of dispersed tree cover threatened by pasture management   总被引：1，自引：0，他引：1  

Celia A. Harvey  Cristobal Villanueva  Rene Gómez  Jorge Martinez 《Forest Ecology and Management》2011,261(10):1664-1674

Trees dispersed in pastures are a prominent feature of many Central American landscapes, particularly in cattle producing regions where farmers retain trees to serve as shade, fodder, timber and firewood. The presence of dispersed trees in pastures is often considered as important for the conservation of biodiversity by providing habitat and enhancing landscape connectivity. However, despite their critical productive and environmental roles, little is known about tree distribution within pastures or how farmers’ management decisions influence the trees themselves and their impact on farm productivity and biodiversity conservation. Here, we present a synthesis of (a) the abundance, composition, and size of dispersed trees in four important cattle producing regions of Costa Rica (Caňas and Río Frío) and Nicaragua (Rivas and Matiguás), based on inventory of 18,669 trees on 1492 ha of pasture, (b) the local knowledge, management and use of trees by cattle farmers, and (c) opportunities for ensuring sustainable management of dispersed trees in pasture-dominated landscapes. Dispersed trees were common in all four landscapes, with mean frequency ranging from 8.0 trees ha⁻¹ in Caňas to 33.4 trees ha⁻¹ in Matiguás. A total of 255 tree species were found in pastures across the four landscapes. The total number of tree species per landscape varied from 72 in Rivas to 101 in Caňas and Rio Frio, with mean species richness per farm ranging from 22.9 in Rio Frio to 45.9 in Matiguás. In all four landscapes, a handful of tree species dominated the pastures, with the ten most abundant species in each landscape accounting for >70% of all trees recorded. Most of these common tree species provide fruits or foliage eaten by cattle, or are important timber or firewood species, and are deliberately retained by farmers for these uses. In all four landscapes, farmers had a detailed knowledge of tree attributes affecting pasture and animal productivity, and influenced tree cover through pasture management activities and occasional tree cutting. Current farm management practices are gradually decreasing the diversity of trees in pastures, and in some cases also tree density, reducing their contribution to farm productivity and biodiversity conservation. To reverse this trend, incentives are required to encourage cattle farmers to retain and enhance tree cover in pastures, through the adoption of pasture management practices that favor the regeneration and persistence of a diverse range of tree species.  相似文献   

Metabolism of methomyl in tobacco, corn, and cabbage     

J Harvey  R W Reiser 《Journal of agricultural and food chemistry》1973,21(5):775-783

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Polychlorobiphenyls in North Atlantic ocean water   总被引：2，自引：0，他引：2  

G R Harvey  W G Steinhauer  J M Teal 《Science (New York, N.Y.)》1973,180(86):643-644

Concentrations of polychlorobiphenyls (PCB's) have been measured at the surface and at various depths in the water of the North Atlantic Ocean between 26 degrees N and 63 degrees N. The concentrations average about 20 parts per trillion and amount to an estimated 2 x 10(4) metric tons of PCB's in the upper 200 meters of water. The average concentrations of PCB's in the surface water of the Sargasso Sea are lower than those in the northern North Atlantic.  相似文献   

Primate adaptations: five new world primates     

Harvey P 《Science (New York, N.Y.)》1984,224(4650):735-736

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Methane in lake kivu: new data bearing on its origin     

Deuser WG  Degens ET  Harvey GR  Rubin M 《Science (New York, N.Y.)》1973,181(4094):51-54

Lake Kivu, an African rift lake, contains about 50 cubic kilometers of methane (at standard temperature and pressure) in its deep water. Data resulting from two recent expeditions to the lake and a reevaluation of earlier data suggest that most of the methane was formed by bacteria from abiogenetic carbon dioxide and hydrogen, rather than being of volcanic origin or having formed from decomposing organic matter.  相似文献   

ETHYLENE IS A RIPENER OF FRUITS AND VEGETABLES     

Harvey RB 《Science (New York, N.Y.)》1928,67(1738):421-422

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The spread of Ras activity triggered by activation of a single dendritic spine     

Harvey CD  Yasuda R  Zhong H  Svoboda K 《Science (New York, N.Y.)》2008,321(5885):136-140

In neurons, individual dendritic spines isolate N-methyl-d-aspartate (NMDA) receptor-mediated calcium ion (Ca2+) accumulations from the dendrite and other spines. However, the extent to which spines compartmentalize signaling events downstream of Ca2+ influx is not known. We combined two-photon fluorescence lifetime imaging with two-photon glutamate uncaging to image the activity of the small guanosine triphosphatase Ras after NMDA receptor activation at individual spines. Induction of long-term potentiation (LTP) triggered robust Ca2+-dependent Ras activation in single spines that decayed in approximately 5 minutes. Ras activity spread over approximately 10 micrometers of dendrite and invaded neighboring spines by diffusion. The spread of Ras-dependent signaling was necessary for the local regulation of the threshold for LTP induction. Thus, Ca2+-dependent synaptic signals can spread to couple multiple synapses on short stretches of dendrite.  相似文献   

A common mechanism of chromosomal translocation in T- and B-cell neoplasia   总被引：29，自引：0，他引：29  

L R Finger  R C Harvey  R C Moore  L C Showe  C M Croce 《Science (New York, N.Y.)》1986,234(4779):982-985

The chromosomal breakpoint involved in the t(8;14)(q24;q11) chromosome translocation in the SKW-3 cell line, which directly involves the 3' flanking region of the c-myc gene, was cloned and sequenced. The breakpoint on chromosome 8 mapped to a position 3 kb 3' of c-myc while the chromosome 14 breakpoint occurred 36 kb 5' of the gene for the constant region of the alpha chain of the T-cell receptor (TCR). The translocation resulted in a precise rearrangement of sequences on chromosome 8 and what appears to be a functional J alpha segment on chromosome 14. Signal sequences for V-J joining occurred at the breakpoint positions on both chromosomes 14 and 8, suggesting that the translocation occurs during TCR gene rearrangement and that it is catalyzed by the enzymatic systems involved in V-J joining reactions. The involvement of c-myc in the translocation and the association of joining signals at the breakpoints provides a parallel to the situation observed in the translocations involving c-myc and the immunoglobulin loci in B-cell neoplasms and suggests that common mechanisms of translocation and oncogene deregulation are involved in B- and T-cell malignancies.  相似文献