bluuebunny/crossref_metadata_2025_split huggingface dataset:
Horticulture exports, agro‐industrialization, and farm–nonfarm linkages with the smallholder farm sector: evidence from Senegal
Authors: Maertens Miet 
Published: February 2009

AbstractIn this article we address the question of farm–nonfarm linkages at the household level in Senegal. We examine whether increasing off‐farm employment opportunities for rural households—resulting from increased horticulture exports and associated agro‐industrialization—has benefitted the smallholder farm sector through investment linkages. We use data from a household survey in the main horticulture export region in Senegal. We find that access to unskilled employment in the export agro‐industry has contributed to the alleviation of farmers' liquidity constraints, resulting in increased smallholder agricultural production.
The increasing importance of nonfarm income and the changing use of labor and capital in rice farming: the case of Central Luzon, 1979–2003
Authors: Takahashi Kazushi , Otsuka Keijiro 
Published: February 2009

AbstractThere have been sharp increases in nonfarm income among farm households in Central Luzon for the last few decades. This study attempts to identify the effects of the increasing nonfarm income on the use of tractors and threshers and on the employment of hired labor as a substitute for family labor. We found that while the increased nonfarm income positively affects the ownership of tractors, it has no significant impact on the use of agricultural machines due presumably to the development of efficient machine rental markets. We also found that the increased nonfarm income leads to the increased use of hired labor, thereby releasing family labor to nonfarm jobs.
Molecular drug targets in myeloproliferative neoplasms: mutant ABL1, JAK2, MPL, KIT, PDGFRA, PDGFRB and FGFR1
Authors: Tefferi Ayalew 
Published: February 2009

Introduction
JAK2 and MPL mutations
KIT mutations
PDGFR mutations
FGFR1 mutations

AbstractTherapeutically validated oncoproteins in myeloproliferative neoplasms (MPN) include BCR‐ABL1 and rearranged PDGFR proteins. The latter are products of intra‐ (e.g. FIP1L1‐PDGFRA) or inter‐chromosomal (e.g.ETV6‐PDGFRB) gene fusions. BCR‐ABL1 is associated with chronic myelogenous leukaemia (CML) and mutant PDGFR with an MPN phenotype characterized by eosinophilia and in addition, in case of FIP1L1‐PDGFRA, bone marrow mastocytosis. These genotype‐phenotype associations have been effectively exploited in the development of highly accurate diagnostic assays and molecular targeted therapy. It is hoped that the same will happen in other MPN with specific genetic alterations: polycythemia vera (JAK2V617F and other JAK2 mutations), essential thrombocythemia (JAK2V617F and MPL515 mutations), primary myelofibrosis (JAK2V617F and MPL515 mutations), systemic mastocytosis (KITD816V and other KIT mutations) and stem cell leukaemia/lymphoma (ZNF198‐FGFR1 and other FGFR1 fusion genes). The current review discusses the above‐listed mutant molecules in the context of their value as drug targets.
A common hereditary single‐nucleotide polymorphism in the gene of FAS and colorectal cancer survival
Authors: Hofmann Guenter , Langsenlehner Uwe , Langsenlehner Tanja , Yazdani‐Biuki Babak , Clar Heimo , Gerger Armin , Fuerst Florentine , Samonigg Hellmut , Krippl Peter , Renner Wilfried 
Published: February 2009

AbstractApoptosis plays an important role in embryogenesis, autoimmunity and tumourigenesis. Cell surface death receptors such as TNFRSF6 (FAS) confer a major apoptotic effect. A single‐nucleotide polymorphism in the FAS promoter gene, −670A/G, modulates apoptotic signalling and has been related to susceptibility and progression of a variety of cancers. The present study aimed to evaluate the role of this polymorphism for survival of patients with colorectal cancer. We performed a retrospective analysis including 433 patients with histologically confirmed colorectal cancer. A Cox regression model including FAS ‐670 genotypes, age at diagnosis, tumour grading, primary tumour size, number of lymph nodes examined, number of metastatic lymph nodes, tumour stage and application of fluorouracil‐based adjuvant chemotherapy was used to estimate the effect of the FAS genotype on survival. FAS −670A/G genotype frequencies were 24.2% (AA), 46.3% (AG) and 29.5% (GG). Forty‐nine patients were excluded from the Cox regression analysis because of missing values. Out of the remaining 384 patients, 69 (18%) died during a follow‐up of maximum 10 years. Mean follow‐up time was 58 ± 34 months (median 55 months). Carriers of the homozygous FAS ‐670GG genotype had a significantly lower survival rate compared with AA/AG genotype carriers (relative risk 1.76, 95% confidence interval 1.08–2.87; P= 0.023). The FAS −670A/G polymorphism may be associated with overall survival time of patients with colorectal cancer.
Survivin is an essential mediator of arthritis interacting with urokinase signalling
Authors: Baran Marcin , Möllers Linda Nilsson , Andersson Sofia , Jonsson Ing‐Marie , Ekwall Anna‐Karin Hultgård , Bjersing Jan , Tarkowski Andrej , Bokarewa Maria 
Published: February 2009

AbstractProto‐oncogene survivin has recently been identified as a prognostic marker distinguishing patients with destructive rheumatoid arthritis (RA). In the present material of 132 RA patients and 82 controls, the levels of survivin correlated to urokinase (uPA) (r= 0.46), a plasminogen activator over‐expressed in inflamed joints and known to exhibit potent arthritogenic properties. Here we evaluate the functional relationship between these proteins using primary synovial fibroblasts and leucocytes of RA patients, human monocytic (THP‐1) and fibroblast (MRC‐5) cell lines. Using inhibitors of intracellular signalling, we show that uPA and survivin share common transduction pathways in synovial fibroblasts being dependent on the activity of tyrosine kinases, phosphatidylinositide 3 kinase and mitogen effector kinase. Moreover, uPA production is significantly reduced in fibroblasts if survivin synthesis has been silenced by siRNA. Importantly, silencing of survivin in fibroblasts prevented their invasive growth in knee joints of severe combined immune deficient mice. Interaction of uPA with receptor up‐regulates survivin expression in leucocytes. In turn, survivin is required for the up‐regulation of uPA receptor on the cell surface. These findings indicate that survivin is an essential mediator of arthritogenic properties of uPA regulating its synthesis in synovial fibroblasts and uPAR expression in leucocytes. Close correlation between survivin and uPA levels in patients with RA supports the importance of this connection for the pathogenesis of arthritis.
Intracrine androgenic apparatus in human bone marrow stromal cells
Authors: Sillat Tarvo , Pöllänen Raimo , Lopes Joana R.C. , Porola Pauliina , Ma Guofeng , Korhonen Matti , Konttinen Yrjö T. 
Published: February 2009

AbstractIt was suggested that human mesenchymal stromal cells might contain an intracrine enzyme machinery potentially able to synthesize the cell’s own supply of dihydrotestosterone (DHT) from dehydroepiandrosterone (DHEA) pro‐hormone produced in the adrenal cortex in the reticular zone, which is unique to primates. Indeed, 3β‐hydroxysteroid dehydrogenase (3β‐HSD) and 5α‐reductase enzyme proteins were expressed in resting mesenchymal stromal cells (MSCs) in vitro. However, the ‘bridging’ enzymes 17β‐HSDs, catalysing interconversion between 17β‐ketosteroids and 17β‐hydroxysteroids, were not found in resting MSCs, but 17β‐HSD enzyme protein was induced in a dose‐dependent manner by DHEA. Quantitative real‐time polymerase chain reactions disclosed that this was mainly due to induction of the isoform 5 catalysing this reaction in ‘forward’, androgen‐bound direction (P < 0.01). This work demonstrates that the MSCs have an intracrine machinery to convert DHEA to DHT if and when challenged by DHEA. DHEA as substrate exerts a positive, feed‐forward up‐regulation on the 17β‐hydroxy steroid dehydrogenase‐5, which may imply that DHEA‐DHT tailor‐making in MSCs is subjected to chronobiological regulation.
Children's physical activity and psychological health: the relevance of intensity
Authors: Parfitt Gaynor , Pavey Toby , Rowlands Ann V 
Published: February 2009

AbstractAim: To examine the relevance of physical activity intensity when assessing the relationship between activity and psychological health in 9–10‐year‐old children.Methods: Activity was assessed by accelerometry in 57 boys (n = 23) and girls (n = 34). Total activity and time spent in very light (≤1.9 METs) through to vigorous activity (≥6 METs) were recorded. Psychological health inventories to assess anxiety, depression and aspects of self‐worth were completed.Results: Time accumulated in very light activity had positive correlations with anxiety and depression (r > 0.30, p < 0.05) and negative correlations with aspects of physical self‐worth (r > −0.29, p < 0.05). Time accumulated in vigorous activity had negative correlations with anxiety and behavioural conduct (r > −0.30, p < 0.05) and positive correlation with aspects of physical self‐worth (r > 0.28, p < 0.05). Children spending over 4 h in very light intensity activity had more negative psychological profiles than children spending under 4 h at this intensity.Conclusion: Aspects of psychological health were negatively correlated with very light intensity activity and positively correlated with vigorous intensity activity. Further research should investigate whether reducing time spent in very light intensity activity and increasing time spent in vigorous intensity activity improves psychological health in children.
Herb layer changes (1954‐2000) related to the conversion of coppice‐with‐standards forest and soil acidification
Authors: Baeten Lander , Bauwens Bram , De Schrijver An , De Keersmaeker Luc , Van Calster Hans , Vandekerkhove Kris , Roelandt Bart , Beeckman Hans , Verheyen Kris 
Published: February 2009

AbstractQuestion: Did the composition of the herb layer of a deciduous forest on loamy soils sensitive to soil acidification change between 1954 and 2000? How are these change related to the abandonment of traditional coppice‐with‐standards forest management and increased soil acidification?Location: Central Belgium (Europe).Methods: Twenty semi‐permanent phytosociological quadrats from an ancient deciduous forest (Meerdaal forest) were carefully selected out of a total of 70 plots dating from 1954 and were revisited in 2000. Species composition and soil pH H2O were recorded using an analogous methodology. The studied period coincides with a period of forest conversion from coppice‐with‐standards towards a high forest structure and with an increase in acidifying and eutrophying deposition.Results: Between 1954 and 2000, species composition of the herb layer changed significantly. Redundancy analysis pointed to increased shade resulting from shifts in cover and species composition of the shrub and tree layer as the main driving force. Soil acidity increased and the majority of plots entered the aluminium buffer range, which potentially affected herb layer composition. Observations at the species level, especially a strong decrease in cover of the vernal species Anemone nemorosa supported this hypothesis.Conclusions: Our results show significant shifts in the forest herb layer in less than five decades. These shifts were related to an alteration in the traditional forest management regime and increased soil acidity. Whereas the effect of a changed management regime can be mitigated, soil acidification is less reversible. Testing the generality of these patterns on more extensive data sets is certainly needed.
Topographic and soil surface effects on gypsophile plant community patterns in central Mexico
Authors: Meyer Susan E. , García‐Moya Edmundo , Lagunes‐Espinoza Luz del Carmen 
Published: February 2009

Abstract. Semiarid gypsum karstlands in north central Mexico are characterized by a mosaic of shrubland and endemic gypsophile grassland community types. Proximal physical factors affecting community patterns on a local scale were investigated at an undisturbed site south of Matehuala, San Luis Potosi. Soil surface characteristics associated with depth of calcareous alluvium overlying gypsum base material were strongly correlated with distribution of desert shrub and endemic grass species. Muhlenbergia purpusii was dominant on bare gypsum soils with indurated crusts, while Bouteloua chasei was dominant where a thin veneer of alluvium permitted development of a cryptogamic crust. A high‐diversity mixed shrub‐succulent community occupied gypsum overlain by 5 ‐ 20 cm of alluvium, whereas Larrea tridentata was the principal species on gypsum overlain by > 20 cm of alluvium. Open sink walls were occupied mostly by species of the Muhlenbergia grassland, while closed sinks supported more mesophytic mixed shrubland vegetation.Physical factors operating mostly at the establishment stage are probably more important in mediating local species patterns on gypsum than factors associated with mineral nutrition. Gypsum material was much less fertile than alluvial material but did not exclude widely distributed species unless exposed at the surface.
Determination of diagnostic species with statistical fidelity measures
Authors: Chytrý Milan , Tichý Lubomír , Holt Jason , Botta‐Dukát Zoltán 
Published: February 2009

Abstract. Statistical measures of fidelity, i.e. the concentration of species occurrences in vegetation units, are reviewed and compared. The focus is on measures suitable for categorical data which are based on observed species frequencies within a vegetation unit compared with the frequencies expected under random distribution. Particular attention is paid to Bruelheide's u value. It is shown that its original form, based on binomial distribution, is an asymmetric measure of fidelity of a species to a vegetation unit which tends to assign comparatively high fidelity values to rare species. Here, a hypergeometric form of u is introduced which is a symmetric measure of the joint fidelity of species to a vegetation unit and vice versa. It is also shown that another form of the binomial u value may be defined which measures the asymmetric fidelity of a vegetation unit to a species. These u values are compared with phi coefficient, chi‐square, G statistic and Fisher's exact test. Contrary to the other measures, phi coefficient is independent of the number of relevés in the data set, and like the hypergeometric form of u and the chi‐square it is little affected by the relative size of the vegetation unit. It is therefore particularly useful when comparing species fidelity values among differently sized data sets and vegetation units. However, unlike the other measures it does not measure any statistical significance and may produce unreliable results for small vegetation units and small data sets. The above measures, all based on the comparison of observed/expected frequencies, are compared with the categorical form of the Dufrêne‐Legendre Indicator Value Index, an index strongly underweighting the fidelity of rare species.These fidelity measures are applied to a data set of 15 989 relevés of Czech herbaceous vegetation. In a small subset of this data set which simulates a phytosociological table, we demonstrate that traditional table analysis fails to determine diagnostic species of general validity in different habitats and large areas. On the other hand, we show that fidelity calculations used in conjunction with large data sets can replace expert knowledge in the determination of generally valid diagnostic species. Averaging positive fidelity values for all species within a vegetation unit is a useful approach to measure quality of delimination of the vegetation unit. We propose a new way of ordering species in synoptic species‐by‐relevé tables, using fidelity calculations.
Plant diversity, biogeography and environment in Iberia: Patterns and possible causal factors
Authors: Benayas Rey , José M. , Scheiner Samuel M. 
Published: February 2009

Abstract. We associated patterns of plant diversity with possible causal factors by considering 93 local regions in the Iberian Peninsula and Balearic Islands with respect to biogeography, environmental favourability, and environmental heterogeneity, and their relationship with measured species diversity at four different scales: mean local species richness standardized at a grain of 100 m2, total species richness in a community type within a region (regional community richness), mean compositional similarity, and mosaic diversity.Local regions in biogeographic transition zones to the North African and Atlantic floras had higher regional community richness and greater mosaic diversity than did non‐transitional regions, whereas no differences existed in mean local species richness or mean compositional similarity. Mean local species richness was positively related to environmental favourability as measured by actual evapotranspiration, but negatively related to total precipitation and temporal heterogeneity in precipitation. Mean local species richness was greatest in annual grassland and dwarf shrubland communities, and on calcareous bedrock types. Regional community richness was similarly related to actual evapotranspiration and total precipitation, but in addition was positively related to spatial heterogeneity in topography and soil water holding capacity. Mean compositional similarity decreased with increasing spatial heterogeneity and temperature seasonality. Mosaic diversity, a measure of complexity, increased with increasing local and regional richness.We hypothesize that these relationships can be explained by four ecological and evolutionary classes of causal factors: numbers of individuals, intermediate environments, limits to adaptation, and niche variation. These factors operate at various scales and manifest themselves in various ways. For example, at the site level, apparently processes that increase the number of individuals increase mean local species richness, but at the level of the entire region no such effects were found.
Species richness in deciduous forests: Effects of species pools and environmental variables
Authors: Dupré Cecilia , Wessberg Camilla , Diekmann Martin 
Published: February 2009

Abstract. The study was conducted in deciduous forests of two Swedish regions, Öland and Uppland. It had two objectives: to (1) test the species pool hypothesis by examining if differences in small‐scale species richness are related to differences in large‐scale species richness and the size of the regional species pool, and (2) to examine the relationship between species richness and productivity and its scale‐dependence.The first data set comprised 36 sites of moderate to high productivity. In each site, we recorded the presence of vascular plant species in nested plots ranging from 0.001 to 1000 m2 and measured several environmental variables. Soil pH and Ellenberg site indicator scores for nitrogen were used as estimators of productivity. The second data set included 24 transects (each with 20 1‐m2 plots) on Öland in sites with low to high productivity. Species number, soil pH and relative light intensity were determined in each plot. The forest sites on Öland were more species‐rich than the Uppland sites on all spatial scales, although environmental conditions were similar. Small‐scale and large‐scale species richness were positively correlated. The results present evidence in favour of the species pool hypothesis. In the nested‐plots data set, species number was negatively correlated with pH and nitrogen indicator scores, whereas a unimodal relationship between species number and pH was found for the transect data set. These results, as well as previously published data, support the hump‐shaped relationship between species richness and productivity in Swedish deciduous forests. Two explanations for the higher species richness of the sites with moderate productivity are given: first, these sites have a higher environmental heterogeneity and second, they have a larger ‘habitat‐specific’ species pool.
Recent fire regime characteristics and potential natural vegetation relationships in Spain
Authors: Vázquez Antonio , Pérez Beatriz , Fernández‐González Federico , Moreno José M. 
Published: February 2009

Abstract. In heavily altered landscapes, where vegetation is not natural and where people are the main source of ignitions, relationships between fire occurrence and climate conditions may be unclear. The objective of this study was to evaluate to what extent territories with similar Potential Natural Vegetation (PNV) in peninsular Spain differ in their forest fire characteristics. From 1974 to 1994, more than 174 000 fires occurred. We used (1) the Spanish data base of forest fires, (2) a PNV map and (3) a land use map. Separate fire characteristics, based either on the number of fires occurred or the area burned, were obtained for each of the ca. 5000 grid‐cells (10 km × 10 km) into which peninsular Spain is divided in the UTM projection. Also, meteorological conditions at the time of fire ignition, cause of ignition and present forest cover were referred to the same grid‐cells as external factors potentially determinant of fire occurrence. The relationships between fire regime characteristics and PNV units were explored with Principal Components Analysis (PCA). The role of the three sets of external factors in the fire characteristics was evaluated with Redundancy Analysis (RDA). Groups of similar PNV types were clearly segregated, suggesting a gradient of fire characteristics. Higher fire incidence (higher frequencies and spatial incidence of fires, but lower proportions of grid‐cells affected by large fires) was associated with Atlantic, warm territories with deciduous forests as PNV. Intermediate fire frequency and rotation period, but with a higher relative incidence of medium and large fires occurred in Mediterranean PNV units, dominated by sclerophyllous oak forests. Low fire frequency and long rotation periods, with strong seasonal and yearly variability occurred for PNV units in the cold uplands (Fagus, Pinus, Abies, Juniperus) or in the semi‐arid, shrubby PNV units. The cause of ignition best explained the patterns of forest fire characteristics, followed by weather conditions.Our results indicate that, even in human influenced regions, climate and soil conditions exert control on the resulting forest fire characteristics, as indicated by the high segregation of the PNV types. However, the role of man was crucial in shifting the patterns of fire incidence. This was so that highest fire incidence occurred in regions that, otherwise, would be expected to have a much lower one, thus posing a serious threat for such areas. PNV maps, by providing a phytogeographical framework for characterizing forest fires, could be valuable tools for applying research results to forest fire management policies, taking properly into account the underlying determinant factors.