A Study of the Heteropoly Tungstates of Some Trivalent Metals

Abstract Not Provided

Monocular microsaccades are visual-task related

During visual fixation, we constantly move our eyes. These microscopic eye movements are composed of tremor, drift, and microsaccades. Early studies concluded that microsaccades, like larger saccades, are binocular and conjugate, as expected from Hering's law of equal innervation. Here, we document the existence of monocular microsaccades during both fixation and a discrimination task, reporting the location of the gap in a foveal, low-contrast letter C. Monocular microsaccades differ in frequency, amplitude, and peak velocity from binocular microsaccades. Our analyses show that these differences are robust to different velocity and duration criteria that have been used previously to identify microsaccades. Also, the frequency of monocular microsaccades differs systematically according to the task: monocular microsaccades occur more frequently during fixation than discrimination, the opposite of their binocular equivalents. However, during discrimination, monocular microsaccades occur more often around the discrimination threshold, particularly for each subject's dominant eye and in case of successful discrimination. We suggest that monocular microsaccades play a functional role in the production of fine corrections of eye position and vergence during demanding visual tasks

Estimating changes in ocean ventilation from early 1990s CFC-12 and late 2000s SF6 measurements

Transient tracer measurements can constrain the rates and pathways of ocean ventilation and act as proxies for biogeochemically relevant gases such as CO2 and oxygen. Various techniques have deduced changes in ocean ventilation over decadal timescales using transient tracer measurements made on repeat sections, but these require a priori assumptions about mixing in the ocean interior. Here, we introduce a simple, direct observational method that takes advantage of the similar atmospheric increase rates of chlorofluorocarbon-12 and sulfur hexafluoride, but with a time lag (offset) of 1415 years. Such repeat measurements can be directly compared without prior assumptions about mixing. A difference larger than similar to 2 years between modern sulfur hexafluoride and historical chlorofluorocarbon-12 tracer ages implies a change in ventilation, although lack of difference does not necessarily imply no change. Several tracer data sets are presented, which suggest changes in ventilation in the South Pacific and North Atlantic Oceans

Acessibilidade e utilização dos espaços verdes urbanos nas cidades de Coimbra (Portugal) e Salamanca (Espanha)

ACCESSIBILITY AND USE OF URBAN GREEN SPACES IN THE CITIES OF COIMBRA (PORTUGAL) AND SALAMANCA (SPAIN). In a society that values more and more wellbeing, health and free time, the introduction of urban green spaces (UGS) next to residential areas has become a citizen’s right and requirement. This paper analyses the distribution and accessibility of UGS in the cities of Coimbra and Salamanca and evaluates their influence on the needs of the resident populations, in terms of users’ age, frequency of usage, as well as of motivation and ways to enjoy the facilities. In Coimbra there is a concentration of UGS, whereas in Salamanca there is a dispersion of such spaces, which has resulted in the different usage that people make of them. In fact, although Coimbra offers more urban green space (per inhabitant), their usage is reduced as people go there mainly by car, contrary to what happens in Salamanca. Consequently, Coimbra’s inhabitants choose these green spaces because of the activities they can be used for, whereas Salamanca’s inhabitants choose them for their proximity

Grain dispersal mechanism in cereals arose from a genome duplication followed by changes in spatial expression of genes involved in pollen development

KEY MESSAGE: Grain disarticulation in wild progenitor of wheat and barley evolved through a local duplication event followed by neo-functionalization resulting from changes in location of gene expression. ABSTRACT: One of the most critical events in the process of cereal domestication was the loss of the natural mode of grain dispersal. Grain dispersal in barley is controlled by two major genes, Btr1 and Btr2, which affect the thickness of cell walls around the disarticulation zone. The barley genome also encodes Btr1-like and Btr2-like genes, which have been shown to be the ancestral copies. While Btr and Btr-like genes are non-redundant, the biological function of Btr-like genes is unknown. We explored the potential biological role of the Btr-like genes by surveying their expression profile across 212 publicly available transcriptome datasets representing diverse organs, developmental stages and stress conditions. We found that Btr1-like and Btr2-like are expressed exclusively in immature anther samples throughout Prophase I of meiosis within the meiocyte. The similar and restricted expression profile of these two genes suggests they are involved in a common biological function. Further analysis revealed 141 genes co-expressed with Btr1-like and 122 genes co-expressed with Btr2-like, with 105 genes in common, supporting Btr-like genes involvement in a shared molecular pathway. We hypothesize that the Btr-like genes play a crucial role in pollen development by facilitating the formation of the callose wall around the meiocyte or in the secretion of callase by the tapetum. Our data suggest that Btr genes retained an ancestral function in cell wall modification and gained a new role in grain dispersal due to changes in their spatial expression becoming spike specific after gene duplication. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00122-022-04029-8

Synergy between Pollution and Carbon Emissions Control: Comparing China and the U.S.

We estimate the potential synergy between pollution and climate control in the U.S. and China, summarizing the results as emissions cross-elasticities of control. We set a range of NOx and SO2 targets, and record the ancillary reduction in CO2 to calculate the percentage change in CO2 divided by the percentage change in NOx (SO2) denoted as ECO2,NOx (ECO2,SO2). Then we conduct the opposite experiment, setting targets for CO2 and recording the ancillary reduction in NOx and SO2 to compute ENOx,CO2 and ESO2,CO2. For ECO2,NOx and ECO2,SO2 we find low values (0.06‒0.23) in both countries with small (10%) reduction targets that rise to 0.40‒0.67 in the U.S. and 0.83‒1.03 in China when targets are more stringent (75% reduction). This pattern reflects the availability of pollution control to target individual pollutants for smaller reductions but the need for wholesale change toward non-fossil technologies when large reductions are required. We trace the especially high cross elasticities in China to its higher dependence on coal. These results are promising in that China may have more incentive to greatly reduce SO2 and NOx with readily apparent pollution benefits in China, that at the same time would significantly reduce CO2 emissions. The majority of existing studies have focused on the effect of CO2 abatement on other pollutants, typically finding strong cross effects. We find similar strong effects but with less dependence on the stringency of control, and stronger effects in the U.S. than in China.The authors are grateful to Howard Herzog and Henry Chen for their valuable inputs for this study. We acknowledge the support of the French Development Agency (AFD), ENI, ICF International, and Shell, founding sponsors of the China Climate and Energy Project, for this application of the EPPA model, and BP’s support of Waugh's thesis, which provided the foundation work for representing air pollution control in the EPPA model. We also acknowledge general industrial and government sponsors of the Joint Program on the Science and Policy of Global Change (http://globalchange.mit.edu/sponsors/all), including the DOE Integrated Assessment Grant (DE-FG02-94ER61937), through which we have developed and maintain the EPPA modeling framework

Nicotine Increases Osteoblast Activity of Induced Bone Marrow Stromal Cells in a Dose-Dependent Manner: An in Vitro Cell Structure Experiment

Previous studies by our group showed that nicotine delivered via a transdermal nicotine patch significantly enhanced posterior spinal fusion rates in rabbits. Nicotine transdermal patches provide a steady serum level; there may be a dose-dependent effect of nicotine on posterior spinal fusion. In an in vitro cell culture model of rabbit bone marrow–derived osteoblast-like cells, cells were exposed to different concentrations of nicotine (0, 20, 40, 80 ng/mL and 10, 100, 250 μg/mL). Wells were stained with an alkaline phosphatase (ALP) staining kit to determine ALP enzyme activity. Cells were stained with Von Kossa for mineralization. A two-way analysis of variance (ANOVA) using dose and time as variables showed significant differences among groups; post hoc analysis showed that the 100-μg/mL dose of nicotine significantly enhanced ALP activity over controls. A one-way ANOVA using dose as the variable showed that the 100- and 250-μg/mL doses had significantly greater mineralization than controls. Dose-response analysis revealed a statistically significant effect of nicotine dose on ALP activity and Von Kossa activity. The effects of nicotine on spinal fusion may be dose-dependent and due to stimulation of osteoblastic activity. Nicotine may not be responsible for the inhibited bone healing observed in smokers

Climate Co-benefits of Tighter SO2 and NOx Regulations in China

Air pollution has been recognized as a significant problem in China. In its Twelfth Five Year Plan (FYP), China proposes to reduce SO2 and NOx emissions significantly, and here we investigate the cost of achieving those reductions and the implications of doing so for CO2 emissions. We extend the analysis through 2050, and either hold emissions policy targets at the level specified in the Twelfth FYP, or continue to reduce them gradually. We apply a computable general equilibrium model of the Chinese economy that includes a representation of pollution abatement derived from detailed assessment of abatement technology and costs. We find that China’s SO2 and NOx emissions control targets would have substantial effects on CO2 emissions leading to emissions savings far beyond those we estimate would be needed to meet its CO2 intensity targets. However, the cost of achieving and maintaining the pollution targets can be quite high given the growing economy. In fact, we find that the Twelfth FYP pollution targets can be met while still expanding the use of coal, but if they are, then there is a lock-in effect that makes it more costly to maintain or further reduce emissions. That is, if firms were to look ahead to tighter targets, they would make different technology choices in the near term, largely turning away from increased use of coal immediately.We acknowledge the support of ENI, ICF, and Shell, initial Founding sponsors of the China Climate and Energy Project, for this application of the EPPA model. We also acknowledge BP's support of Waugh's thesis, which provided the foundation work for representing air pollution control in the EPPA model. We also acknowledge general industrial and government sponsors of the Joint Program on the Science and Policy of Global Change (http://globalchange.mit.edu/sponsors/all) through which we have developed and maintain the EPPA modeling framework