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1.
Journal of Crop Science and Biotechnology - The cultivation of sweet corn is expanding in Brazil, but there are serious constraints about the availability of commercial cultivars. The selection of...  相似文献   
2.
The recent change in the regional development strategy of the European Union (EU) results in an important need to study the terms of change and their respective implications. This study seeks, through a bibliometric analysis, to ascertain the developments taking place in studies on research and innovation strategies for smart specialisation (RIS3) to identify shortcomings and opportunities for future research. This bibliometric review drew upon the Scopus database with the sample selected containing all the articles containing the keywords “Research and Innovation Strategies for Smart Specialisation” or “RIS3.” This correspondingly reports how some authors maintain that the path the EU should take involves imitative innovation. Meanwhile, others propose that each region should specialise in those industries that are already established there and thus avoid targeting any areas they do not already know/specialise in. Our findings detail six clusters in RIS3 research, which help in contextualising the literature review: (a) business discovery; (b) smart specialisation; (c) innovation; (d) specialisation; (e) regional policies; and (f) regional development. This study furthermore sets out perspectives for future lines of research and correspondingly seeks to convey a vast theoretical basis that may serve as the point of departure for future studies.  相似文献   
3.
Not all economically disadvantaged—“less developed” or “lagging”—regions are the same. They are, however, often bundled together for the purposes of innovation policy design and implementation. This paper attempts to determine whether such bundling is warranted by conducting a regional level investigation for Canada, the United States, on the one hand, and Europe, on the other, to (a) identify the structural and socioeconomic factors that drive patenting in the less developed regions of North America and Europe, respectively; and (b) explore how these factors differ between the two contexts. The empirical analysis, estimated using a mixed‐model approach, reveals that, while there are similarities between the drivers of innovation in North America's and Europe's lagging regions, a number of important differences between the two continents prevail. The analysis also indicates that the territorial processes of innovation in North America's and Europe's less developed regions are more similar to those of their more developed counterparts than to one another.  相似文献   
4.

Background

Root-knot nematodes (RKN) are major pest of olive tree (Olea europaea ssp. europaea), especially in nurseries and high-density orchards. Soil samples were collected from main olive growing areas of Morocco, to characterize Meloidogyne species and to discuss the contribution of biotic and abiotic factors in their spatial distribution.

Results

RKN were found in 159 soil samples out of 305 from nurseries (52.1% occurrence) and in 11 out of 49 soil samples from orchards (23.2% occurrence). Biochemical and molecular characterisation (PAGE esterase and SCAR) revealed the dominance of M. javanica both in nurseries and orchards with minor presence of M. incognita only in nurseries, and M. arenaria in only one nursery. RKN were distributed on aggregated basis. Frequent presence of M. javanica in orchards might have come from nurseries. In contrast, the detection of M. incognita in nurseries alone suggests that this species could not reproduce in orchards because of either the competition with other plant-parasitic nematodes or unfit local habitats. The impact of environmental variables (climate, habitat origin and physicochemical characteristics of the substrates) on the distribution of Meloidogyne species is also discussed.

Conclusion

Olive nurseries in Morocco are not able to guarantee the safety of rooted plants. As a result, olive production systems are exposed to strong RKN invasion risks. Consequently, the use of healthy substrates in nurseries may prevent plant-parasitic nematode induction in orchards.
  相似文献   
5.
Landscape Ecology - Several case studies investigated the role of ecosystem services in participatory planning processes. However, no systematic study exists that cuts across a large number of...  相似文献   
6.
The Chilean Intermediate Depression to the north of Santiago has experienced a physiognomical transformation from a Prosopis chilensis woodland to an Acacia caven savanna. Today P. chilensis trees are scarce and belong mostly to the larger size classes. By contrast A. caven seems to reproduce frequently and its populations consist of individuals of all size classes. In this paper we document these changes and report the results of tests aimed at determining the causes of these physiognomical changes. We found that livestock, leporids, introduced Mediterranean forbs and agriculture account for differences in seed dispersal and survival of A. caven and P. chilensis, which can explain the documented changes in the Chilean landscape.  相似文献   
7.
A porcine in vitro fertilization (IVF) system and seminal quality parameters of frozen–thawed boar semen were used to assess the effectiveness of two different thawing rates of frozen boar semen, and to address the question of whether differences between fertility of ejaculates could be predicted in a limited field trial. In the first experiment, two thawing procedures were analysed (37°C, 30 s; 50°C, 12 s) and no differences in sperm quality were found. However, when the procedure was 50°C, 12 s the IVF results showed a higher number of sperm per penetrated oocyte and a near 10 points higher rate of pronuclear formation. In the second experiment, the fertility results obtained in the limited field trial show to be efficient enough for application in a commercial use, especially for three of the employed boars (fertility ≥80%). In this limited study, the conventional seminal parameters are not accurate enough to discriminate good and bad boars in relation to fertility. On the contrary, parameters of in vitro penetrability are more precise to predict subsequent fertilities. As conclusion, the IVF fertilization system seems to be a good tool to evaluate the quality of frozen–thawed boar semen previous to its commercial way, to verify the bank semen storage quality and a good way to assay new sperm freezing procedures, as it is the more precise evaluating method in estimating the potential fertilizing ability.  相似文献   
8.
9.
The results of 5732 records of kids born between 1985 and 1996 at Gardel Agricultural Experiment Station (INRA) in Guadeloupe, were used in order to estimate the effect of kidding day (KD) on individual preweaning growth performances, total productivity of Creole goats and litter size. The flock was subjected to a restricted mating season for a long time, by using male effect. The results of the fixed linear model showed a highly significant (P<0.001) effect of KD on growth rate and total productivity of does. Live weights of kids born around the 21st day of the kidding period (KP) was 4% to 7% higher than those of kids born the first day of the KP. For total productivity of does, this ratio did not reached more than 4%. The optimum at 70 days of age occurred around 14th day of the KD with 3% of improvement of total productivity. No effect was observed upon litter size. The genetic (co)variance components were estimated by six different Individual Animal Models. The heritability (h2) estimated from the best model, was hD2=0.25±0.05 for genetic direct effect; hM2=0.09±0.04 for genetic maternal effect and the genetic correlation between direct and maternal effects was −0.86±0.12. The use of KD could be highly recommended in a breeding program in this population of Creole meat goats, since it is quite easy to record under commercial conditions as a character related to reproductive performance.  相似文献   
10.
After the eradication of the Tse-Tse fly in the Mid-Zambezi valley, human settlements and fields extended mainly along the main rivers. In order to investigate the consequences of this human development on wildlife diversity we monitored three rivers of the Mid-Zambezi valley in Zimbabwe: Angwa, Manyame and Kadzi. The rivers were divided in segments of 200 m which were checked for spoors in order to assess the number of species and the number of individuals that used the segments. Human settlements were also recorded. We used a GIS to define the spatial characteristics of the fields present along the rivers, and related them to the distribution and abundance of wild species spoors in the river beds and banks. Our results show that the number of species in one segment of the river decreased with the increasing size of the field area bordering the segment. For all the major ungulate species, the numbers of individuals recorded per segment decreased with increasing field area. A similar trend was observed for small and medium-sized carnivores, though they were in lower numbers when present. Our analyses thus confirm that the extension of human agriculture in wildlife areas has an impact on most wild species, but we also define some threshold value of field size above which there seem to be an acceleration of the decrease in wildlife density and diversity: 3.2 ha for medium and small herbivores and carnivores; only the elephant seem to tolerate larger field area with a threshold value of 32 ha.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   
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