AROUSAL, FATIGUE AND MENTAL PERFORMANCE: THE EFFECTS OF FASTING ON COGNITION

This study examined the effects of skipping breakfast on selected aspects of children's cognition, specifically their memory (both immediate and one week following presentation of stimuli), mental tempo, and problem solving accuracy. Test instruments used included the Hagen Central/Incidental Recall Test, Matching Familiar Figures Test, McCarthy Digit Span and Tapping Tests. The study population consisted of 39 nine-to eleven year old healthy children who were admitted for overnight stays at a clinical research setting for two nights approximately one week apart. The study was designed to be able to adequately monitor and control subjects' food consumption. The design chosen was the cross-over design where randomly on either the first or second visit, the child skipped breakfast. In this way, subjects acted as their own controls. Subjects were tested at noon of both visits, this representing an 18-hour fast.^ Analysis focused on whether or not fasting for this period of time affected an individual's performance. Results indicated that for most of the tests, subjects were not significantly affected by skipping breakfast for one morning. However, on tests of short-term central and incidental recall, subjects who had skipped breakfast recalled significantly more of the incidental cues although they did so at no apparent expense to their storing of central information. In the area of problem-solving accuracy, subjects skipping breakfast at time two made significantly more errors on hard sections of the MFF Test. It should be noted that although a large number of tests were conducted, these two tests showed the only significant differences.^ These significant results in the areas of short-term incidental memory and in problem solving accuracy were interpreted as being an effect of subject fatigue. That is, when subjects missed breakfast, they were more likely to become fatigued and in the novel environment presented in the study setting, it is probable that these subjects responded by entering Class II fatigue which is characterized by behavioral excitability, diffused attention and altered performance patterns. ^

Targeted Deletion Of Functionally Validated Enhancers Defines Their Role in Mouse Limb Development

Transcriptional enhancers are genomic DNA sequences that contain clustered transcription factor (TF) binding sites. When combinations of TFs bind to enhancer sequences they act together with basal transcriptional machinery to regulate the timing, location and quantity of gene transcription. Elucidating the genetic mechanisms responsible for differential gene expression, including the role of enhancers, during embryological and postnatal development is essential to an understanding of evolutionary processes and disease etiology. Numerous methods are in use to identify and characterize enhancers. Several high-throughput methods generate large datasets of enhancer sequences with putative roles in embryonic development. However, few enhancers have been deleted from the genome to determine their roles in the development of specific structures, such as the limb. Manipulation of enhancers at their endogenous loci, such as the deletion of such elements, leads to a better understanding of the regulatory interactions, rules and complexities that contribute to faithful and variant gene transcription – the molecular genetic substrate of evolution and disease. To understand the endogenous roles of two distinct enhancers known to be active in the mouse embryo limb bud we deleted them from the mouse genome. I hypothesized that deletion of these enhancers would lead to aberrant limb development. The enhancers were selected because of their association with p300, a protein associated with active transcription, and because the human enhancer sequences drive distinct lacZ expression patterns in limb buds of embryonic day (E) 11.5 transgenic mice. To confirm that the orthologous mouse enhancers, mouse 280 and 1442 (M280 and M1442, respectively), regulate expression in the developing limb we generated stable transgenic lines, and examined lacZ expression. In M280-lacZ mice, expression was detected in E11.5 fore- and hindlimbs in a region that corresponds to digits II-IV. M1442-lacZ mice exhibited lacZ expression in posterior and anterior margins of the fore- and hindlimbs that overlapped with digits I and V and several wrist bones. We generated mice lacking the M280 and M1442 enhancers by gene targeting. Intercrosses between M280 -/+ and M1442 -/+, respectively, generated M280 and M1442 null mice, which are born at expected Mendelian ratios and manifest no gross limb malformations. Quantitative real-time PCR of mutant E11.5 limb buds indicated that significant changes in transcriptional output of enhancer-proximal genes accompanied the deletion of both M280 and M1442. In neonatal null mice we observed that all limb bones are present in their expected positions, an observation also confirmed by histology of E18.5 distal limbs. Fine-scale measurement of E18.5 digit bone lengths found no differences between mutant and control embryos. Furthermore, when the developmental progression of cartilaginous elements was analyzed in M280 and M1442 embryos from E13.5-E15.5, transient development defects were not detected. These results demonstrate that M280 and M1442 are not required for mouse limb development. Though M280 is not required for embryonic limb development it is required for the development and/or maintenance of body size – adult M280 mice are significantly smaller than control littermates. These studies highlight the importance of experiments that manipulate enhancers in situ to understand their contribution to development.

Zircons, isotope ratios and element analyses from tonalite and oxide gabbro of the mid-ocean ridge from ODP Hole 176-735B

A limiting factor in the accuracy and precision of U/Pb zircon dates is accurate correction for initial disequilibrium in the 238U and 235U decay chains. The longest-lived-and therefore most abundant-intermediate daughter product in the 235U isotopic decay chain is 231Pa (T1/2 = 32.71 ka), and the partitioning behavior of Pa in zircon is not well constrained. Here we report high-precision thermal ionization mass spectrometry (TIMS) U-Pb zircon data from two samples from Ocean Drilling Program (ODP) Hole 735B, which show evidence for incorporation of excess 231Pa during zircon crystallization. The most precise analyses from the two samples have consistent Th-corrected 206Pb/238U dates with weighted means of 11.9325 ± 0.0039 Ma (n = 9) and 11.920 ± 0.011 Ma (n = 4), but distinctly older 207Pb/235U dates that vary from 12.330 ± 0.048 Ma to 12.140 ± 0.044 Ma and 12.03 ± 0.24 to 12.40 ± 0.27 Ma, respectively. If the excess 207Pb is due to variable initial excess 231Pa, calculated initial (231Pa)/(235U) activity ratios for the two samples range from 5.6 ± 1.0 to 9.6 ± 1.1 and 3.5 ± 5.2 to 11.4 ± 5.8. The data from the more precisely dated sample yields estimated DPazircon/DUzircon from 2.2-3.8 and 5.6-9.6, assuming (231Pa)/(235U) of the melt equal to the global average of recently erupted mid-ocean ridge basaltic glasses or secular equilibrium, respectively. High precision ID-TIMS analyses from nine additional samples from Hole 735B and nearby Hole 1105A suggest similar partitioning. The lower range of DPazircon/DUzircon is consistent with ion microprobe measurements of 231Pa in zircons from Holocene and Pleistocene rhyolitic eruptions (Schmitt (2007; doi:10.2138/am.2007.2449) and Schmitt (2011; doi:10.1146/annurev-earth-040610-133330)). The data suggest that 231Pa is preferentially incorporated during zircon crystallization over a range of magmatic compositions, and excess initial 231Pa may be more common in zircons than acknowledged. The degree of initial disequilibrium in the 235U decay chain suggested by the data from this study, and other recent high precision datasets, leads to resolvable discordance in high precision dates of Cenozoic to Mesozoic zircons. Minor discordance in zircons of this age may therefore reflect initial excess 231Pa and does not require either inheritance or Pb loss.

El estado como eje articulador de las relaciones sociales

El presente trabajo intenta realizar una síntesis de cómo se fue articulando la sociedad a partir del modelo capitalista de producción en el período histórico que transcurre desde el impulso desarrollado en la Segunda Revolución Industrial, a finales del siglo XIX , hasta la primera década del siglo XXI. Este período determinará una forma de integración social que va estar vinculada al trabajo asalariado y ligada a un Estado más presente, articulador y distribuidor de la riqueza social. Algunos de los elementos constitutivos que sostuvieron este modelo fueron el New Deal y la política económica keynesiana, que van a perdurar hasta bien entrada la década de 1970. En esta etapa, la relación capital-trabajo va a entrar en crisis; el modelo keynesiano de pleno empleo no le es útil al capitalismo; y, por lo tanto, el Estado va a permitir la incorporación de un nuevo discurso, enarbolado por los denominados economistas liberales ortodoxos y, ya en la última década del siglo XX , por el economista norteamericano John Williamson, relacionado con un movimiento intelectual denominado "Consenso de Washington"; esto dando lugar una nueva forma de estructuración social en la que van a coexistir ganadores y perdedores del sistema. Se intenta explicar, además, el impacto que provocó en la Argentina adherir al modelo neoliberal a través de una economía abierta (1989-2002). Por último, describimos la situación de la Provincia de San Luis; los dispositivos y mecanismos que utilizó para contrarrestar los dos dígitos de desocupación producidos después del año 2002; para ello, nos referimos al Plan de Inclusión Social, expuesto a través de datos estadísticos tomados del INDEC y de la Dirección Provincial de Estadísticas y Censos de la Provincia de San Luis

El estado como eje articulador de las relaciones sociales

El presente trabajo intenta realizar una síntesis de cómo se fue articulando la sociedad a partir del modelo capitalista de producción en el período histórico que transcurre desde el impulso desarrollado en la Segunda Revolución Industrial, a finales del siglo XIX , hasta la primera década del siglo XXI. Este período determinará una forma de integración social que va estar vinculada al trabajo asalariado y ligada a un Estado más presente, articulador y distribuidor de la riqueza social. Algunos de los elementos constitutivos que sostuvieron este modelo fueron el New Deal y la política económica keynesiana, que van a perdurar hasta bien entrada la década de 1970. En esta etapa, la relación capital-trabajo va a entrar en crisis; el modelo keynesiano de pleno empleo no le es útil al capitalismo; y, por lo tanto, el Estado va a permitir la incorporación de un nuevo discurso, enarbolado por los denominados economistas liberales ortodoxos y, ya en la última década del siglo XX , por el economista norteamericano John Williamson, relacionado con un movimiento intelectual denominado "Consenso de Washington"; esto dando lugar una nueva forma de estructuración social en la que van a coexistir ganadores y perdedores del sistema. Se intenta explicar, además, el impacto que provocó en la Argentina adherir al modelo neoliberal a través de una economía abierta (1989-2002). Por último, describimos la situación de la Provincia de San Luis; los dispositivos y mecanismos que utilizó para contrarrestar los dos dígitos de desocupación producidos después del año 2002; para ello, nos referimos al Plan de Inclusión Social, expuesto a través de datos estadísticos tomados del INDEC y de la Dirección Provincial de Estadísticas y Censos de la Provincia de San Luis

El estado como eje articulador de las relaciones sociales

El presente trabajo intenta realizar una síntesis de cómo se fue articulando la sociedad a partir del modelo capitalista de producción en el período histórico que transcurre desde el impulso desarrollado en la Segunda Revolución Industrial, a finales del siglo XIX , hasta la primera década del siglo XXI. Este período determinará una forma de integración social que va estar vinculada al trabajo asalariado y ligada a un Estado más presente, articulador y distribuidor de la riqueza social. Algunos de los elementos constitutivos que sostuvieron este modelo fueron el New Deal y la política económica keynesiana, que van a perdurar hasta bien entrada la década de 1970. En esta etapa, la relación capital-trabajo va a entrar en crisis; el modelo keynesiano de pleno empleo no le es útil al capitalismo; y, por lo tanto, el Estado va a permitir la incorporación de un nuevo discurso, enarbolado por los denominados economistas liberales ortodoxos y, ya en la última década del siglo XX , por el economista norteamericano John Williamson, relacionado con un movimiento intelectual denominado "Consenso de Washington"; esto dando lugar una nueva forma de estructuración social en la que van a coexistir ganadores y perdedores del sistema. Se intenta explicar, además, el impacto que provocó en la Argentina adherir al modelo neoliberal a través de una economía abierta (1989-2002). Por último, describimos la situación de la Provincia de San Luis; los dispositivos y mecanismos que utilizó para contrarrestar los dos dígitos de desocupación producidos después del año 2002; para ello, nos referimos al Plan de Inclusión Social, expuesto a través de datos estadísticos tomados del INDEC y de la Dirección Provincial de Estadísticas y Censos de la Provincia de San Luis

Ice-algal chlorophyll a and physical properties of multi-year and first-year sea ice in the Lincoln Sea during spring

With near-complete replacement of Arctic multi-year ice (MYI) by first-year ice (FYI) predicted to occur within this century, it remains uncertain how the loss of MYI will impact the abundance and distribution of sea ice associated algae. In this study we compare the chlorophyll a (chl a) concentrations and physical properties of MYI and FYI from the Lincoln Sea during 3 spring seasons (2010-2012). Cores were analysed for texture, salinity, and chl a. We identified annual growth layers for 7 of 11 MYI cores and found no significant differences in chl a concentration between the bottom first-year-ice portions of MYI, upper old-ice portions of MYI, and FYI cores. Overall, the maximum chl a concentrations were observed at the bottom of young FYI. However, there were no significant differences in chl a concentrations between MYI and FYI. This suggests little or no change in algal biomass with a shift from MYI to FYI and that the spatial extent and regional variability of refrozen leads and younger FYI will likely be key factors governing future changes in Arctic sea ice algal biomass. Bottom-integrated chl a concentrations showed negative logistic relationships with snow depth and bulk (snow plus ice) integrated extinction coefficients; indicating a strong influence of snow cover in controlling bottom ice algal biomass. The maximum bottom MYI chl a concentration was observed in a hummock, representing the thickest ice with lowest snow depth of this study. Hence, in this and other studies MYI chl a biomass may be under-estimated due to an under-representation of thick MYI (e.g., hummocks), which typically have a relatively thin snowpack allowing for increased light transmission. Therefore, we suggest the on-going loss of MYI in the Arctic Ocean may have a larger impact on ice-associated production than generally assumed.

Agglomeration Economies in Japan: Technical Efficiency, Growth and Unemployment

This paper examines if the effects of agglomeration economies get manifested in technical efficiency and generate faster economic growth and higher (lower) levels of employment (unemployment). Using the prefecture level data for each of the two-digit groups of industries in Japan, the paper estimates region-specific technical efficiency index based on the stochastic frontier production function framework. The results of the factor analysis show that in most of the industry-groups (with a few exceptions) efficiency has a positive association with external scale variable(s). Though the relationship is not seen to be very strong, it would be equally erroneous to ignore the effect of agglomeration economies on efficiency. In the case of some of the light goods industries the agglomeration effect is relatively stronger. Further, economic growth varies positively with external scale variable(s) and unemployment rate tends to fall with respect to growth and concentration. All this tends to suggest that measures against industrial concentration may be counter-productive, particularly in the context of globalisation when countries are in dire need of raising productivity.

Procyclical Productivity and Returns-to-Scale in Philippine Manufacturing

The Philippines is regarded as a highly oligopolistic economy, and it is argued that this is a cause of the relative stagnation of the economy to neighbouring East Asian economies. This presumption might be associated with increasing returns to scale and market power, which are consistent with the procyclical total factor productivity that is observed in the Philippines and the United States. However, this study found no strong evidence supporting increasing returns for aggregate manufacturing and three-digit manufacturing industries during 1956-1980 in the Philippines, based on data constructed by Hooley (1985). Further, this study does not support external effect discussed in Caballero and Lyons (1992).

New aspects of intra-industry trade in EU countries

Using the HS eight-digit product level trade data of EU countries for the period 1988 – 2010, we analyse Intra-industry trade within EU countries as well as with Eastern European countries and with China. We find the Eastern European countries’ rise up the quality ladder, and by contrast the substantially lower prices of China’s exports to EU countries vis-à-vis China’s imports from them. The contrast between EU trade with the Eastern European countries and with China is present even in very recent years.

FTA utilization : certificate of origin data versus customs data

This paper empirically examines what kinds of elements affect the gap in free trade agreement (FTA) utilization with regard to customs data and certificates of origin (CoOs) data. We focus on Thai exports to Korea under the ASEAN-Korea FTA in 2011. As a result, we found that the products with the higher demand volatility or those with a larger number of tariff-line products within the same harmonized system (HS) six-digit code have the larger gap. Another important finding is that the difference between the HS version at the time of the FTA negotiation and the current HS version does not have significant association with the gap. These findings have important implications.

Did the least developed countries benefit from duty-free quota-free access to the Japanese market?

Countries classified as least developed countries (LDCs) were granted duty-free quota-free (DFQF) access to the Japanese market. This study examines the impact of that access and finds that, in general, it did not benefit the LDCs. The construction of concordance tables for Japan's 9 digit tariff line codes enables analysis at the tariff line level, which overcomes a possible aggregation bias. The exogenous nature of DFQF access mitigates the endogeneity problem. Various estimation models, including the triple difference estimator, show that in general the LDCs did not benefit from DFQF access to the Japanese market. The total value of imports from LDCs has been increasing, but the imports granted both zero tariffs and substantial preference margins over non-LDC countries were not successful. These findings suggest that for LDCs the tariff barrier is a relatively small obstacle: Trade is affected more strongly by other factors, such as infrastructure, nontariff barriers, geographic distance, and cultural differences.

Product quality and intra-industry trade

In this study, we argue that the conventional intra-industry trade (IIT) index does not address the quality issue directly and propose a methodology to make full use of unit-price gap information to deduce quality differences between simultaneously exported and imported products. By applying this measure to German trade data at the eight-digit level, we study the quality improvement of Chinese export goods in its IIT with Germany. We compare the case of China with those of Eastern European countries, which are also major trading partners of Germany. Our results show that the unit-value difference in IIT between Germany and Eastern European countries is clearly narrowing. However, China's export prices to Germany are much lower than Germany's export prices to China, and this gap has not narrowed over the last 23 years. This is at odds with the common perception that China's product quality has improved, as documented by Rodrik (2006) and Schott (2008). Our results support Xu (2010), which argued that incorporating the quality aspect of the exported goods weakens or even eliminates the evidence of the sophistication of Chinese export goods in Rodrik (2006).

Lift devices in the flight of Archaeopteryx

Archaeopteryx has played a central role in the debates on the origins of avian (and dinosaurian) flight, even though as a flier it probably represents a relatively late stage in the beginnings of fl ight. We report on aerodynamic tests using a life-sized model of Archaeopteryx performing in a low turbulence wind tunnel. Our results indicate that tail deflection significantly decreased take-off velocity and power consumption, and that the first manual digit could have functioned as the structural precursor of the alula. Such results demonstrate that Archaeopteryx had already evolved high-lift devices, which are functional analogues of those present in today's birds.

Synpolydactyly phenotypes correlate with size of expansions in HOXD13 polyalanine tract

Synpolydactyly (SPD) is a dominantly inherited congenital limb malformation. Typical cases have 3/4 finger and 4/5 toe syndactyly, with a duplicated digit in the syndactylous web, but incomplete penetrance and variable expressivity are common. The condition has recently been shown to be caused by expansions of an imperfect trinucleotide repeat sequence encoding a 15-residue polyalanine tract in HOXD13. We have studied 16 new and 4 previously published SPD families, with between 7 and 14 extra residues in the tract, to analyze the molecular basis for the observed variation in phenotype. Although there is no evidence of change in expansion size within families, even over six generations, there is a highly significant increase in the penetrance and severity of phenotype with increasing expansion size, affecting both hands (P = 0.012) and feet (P < 0.00005). Affected individuals from a family with a 14-alanine expansion, the largest so far reported, all have a strikingly similar and unusually severe limb phenotype, involving the first digits and distal carpals. Affected males from this family also have hypospadias, not previously described in SPD, but consistent with HOXD13 expression in the developing genital tubercle. The remarkable correlation between phenotype and expansion size suggests that expansion of the tract leads to a specific gain of function in the mutant HOXD13 protein, and has interesting implications for the role of polyalanine tracts in the control of transcription.