The role of human capital in the Iberian countries' growth and convergence

This thesis examines the role of human capital in the growth and convergence of the Iberian countries. Using a newly computed series for human capital at the NUTS III level for the Portuguese regions, the comparison between Portugal and Spain suggests a positive role for human capital proxied by the average years of schooling in both Iberian countries regional growth, which supports the hypothesis that higher levels of education improved the regions‟ ability to adopt new technology; although the levels of education indicate that secondary schooling is important for technology adoption in Portugal, but not in Spain, and its effect is higher than that of tertiary education. Using Exploratory Spatial Data Analysis (ESDA), two convergence clubs are identified within the Iberia Peninsula (Core and Periphery), but convergence occurs mainly in the Periphery group and education plays a positive and significant role only in the Core club

SL analysis of rice root exudates.

<p>Root exudates from rice plants grown under phosphate starvation were analyzed with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) using multiple reaction monitoring (MRM). Chromatograms of (<b>A</b>) transitions 347.2 > 233 and (<b>B</b>) 347.2>96.8 for orobanchol; (<b>C</b>) transitions 331.2> 234 and (<b>D</b>) 331.2>96.8 for 2'<i>-epi-</i>5-deoxystrigol; (<b>E</b>) transitions 361.2>247 and (<b>F</b>) 361.2>96.8 for three putative methoxy-5-deoxystrigol isomers; (<b>G</b>) the total ion count (TIC) showing of all measured transitions and where orobanchol (8.05 min), <i>ent</i>-2'-<i>epi</i>-5-deoxystrigol (12.51 min) and the three putative methoxy-5-deoxystrigol isomers (9.87; 10.33; 10.86 min) are visible.</p

<i>Striga hermonthica</i> germination and <i>Gigaspora margarita</i> hyphal branching in the presence of SL standards.

1<p>Results extracted from Akiyama et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0104201#pone.0104201-Akiyama2" target="_blank">[26]</a>; ² MEC  =  minimum effective concentration; ³ in Akiyama et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0104201#pone.0104201-Akiyama2" target="_blank">[26]</a> these compounds are named (+)−orobanchol and (+)-2'-<i>epi</i>-orobanchol respectively, before revision of stereochemical structure whereas the present table indicates the revised stereochemistry <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0104201#pone.0104201-Xie1" target="_blank">[23]</a>.</p

MS/MS spectra of putative SL-like compounds.

<p>The spectra were measured at the retention time of each isomer: 9.87 min (<b>A</b>), 10.35 min (<b>B</b>) and 10.95 min (<b>C</b>).</p

Activity profiles of rice root exudates.

<p>Germination of <i>S. hermonthica</i> (one biological replicate; the other two are shown in ) obtained with crude exudates and exudate fractions from rice plants (<b>A</b>) treated with full nutrition (black bars); phosphate starvation (grey bars) and phosphate starvation plus 0.01 µM fluridone (white bars). Water and SL analogue GR24 (0.005, 0.05 and 0.5 µM) were used as controls. The error bars represent the standard error of 3 technical replicates. Significance levels between treatments as determined using a <i>X</i>² test are indicated: */+  =  <i>P</i><0.05; **/++  =  <i>P</i><0.01; ***/+++  =  <i>P</i><0.001; n.s.  =  <i>P</i>>0.05; *  =  control vs. phosphate starvation treatment; +  =  phosphate starvation vs. phosphate starvation plus fluridone treatment. When germination values are close to zero the statistical test cannot be performed, which is indicated with “−”. AM fungal hyphal branching induced by crude exudates (<b>B</b>) and exudate fractions (<b>C</b>) of rice treated with full nutrition (black bars) and phosphate starvation (white bars) in germinating <i>Gi. rosea</i> spores. The assay was performed with pooled samples of three biological replicates. GR24 (0.005, 0.05 and 0.5 µM) and 10% acetonitrile in water were used as controls. The bars represent the mean of the total number of new branches, the error bar the standard error of the mean (n = 20). Significance values comparing means between control treatments and phosphate starvation treatment are indicated above the bars. (*  =  <i>P<</i>0.05, **  =  <i>P<</i>0.01, ***  =  <i>P<</i>0.001).</p

Abundance of (−)−orobanchol, <i>ent</i>-2'-<i>epi</i>-5-deoxystrigol and putative SL-like compounds in phosphate starvation and fluridone treatments.

<p>Peak areas obtained with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis using multiple reaction monitoring (MRM) of root exudates of rice. (<b>A</b>) (−)−orobanchol (MRM transition 347.2 >96.8; black bars) and <i>ent</i>-2'-<i>epi</i>-5-deoxystrigol (MRM transition 331.2>234; hatched bars); (<b>B</b>–<b>D</b>) three putative SL-like compounds measured in crude exudates with the retention times: rt =  9.87 (<b>B</b>); rt = 10.3 and (<b>C</b>) rt = 10.9 (<b>D</b>) and the MRM transitions 361>96.8 (black bars) and 361>247 (white bars). All measurements taken from crude exudates of plants grown in different treatments: phosphate starvation (−P); phosphate starvation combined with fluridone (−P+F) and control treatment with full nutrient supply (C). The error bars represent the standard error of 3 biological replicates. Significance values are indicated with * (for <i>ent</i>-2'<i>-epi-</i>orobanchol and for 361>96.8 transition) and + (for 2'<i>-epi-</i>5-deoxystrigol and for 331.2>234 transition) and compare phosphate starvation (-P) treatment vs. phosphate starvation with fluridone (-P+F) and -P vs. full nutrition (C) (*/+  =  <i>P<</i>0.05, **/++  =  <i>P<</i>0.01, ***/+++  =  <i>P<</i>0.001).</p

SL structures present in rice root exudates or tested in a seed germination or hyphal branching bioassay.

<p>(<b>1</b>) (−)−orobanchol; (<b>2</b>) <i>ent</i>-2'<i>-epi-</i>5-deoxystrigol; (<b>3</b>) orobanchyl acetate and (<b>4</b>) proposed structure of 7-oxoorobanchyl acetate <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0104201#pone.0104201-Xie1" target="_blank">[23]</a>; (<b>5</b>) proposed structure of methoxy-5-deoxystrigol isomers (R¹ = OMe; R² = H) or the methyl ether of orobanchol (R¹ = H; R² = OMe); (<b>6</b>) (+)-<i>ent</i>-2'-<i>epi</i>-orobanchol; (<b>7</b>) sorgomol; (<b>8a</b>–<b>d</b>) stereoisomers of strigol (R¹ = CH₃; R² = OH); 5-deoxystrigol (R¹ = CH₃; R² = H), stereochemical configurations <b>8a</b> and <b>8c</b> are natural (strigol-type and orobanchol-type, respectively) while configurations <b>8b</b> and <b>8d</b> are not naturally occurring; (<b>9a</b>–<b>d</b>) stereoisomers of SL analogue GR24.</p