1,549 research outputs found
Dielectric molding apparatus Patent
Dielectric apparatus for heating, fusing, and hardening of organic matrix to form plastic material into shaped produc
Precipitation detector Patent
Precipitation detector and mechanism for stopping and restarting machinery at initiation and cessation of rai
Optical parameters of leaves of seven weed species
The absorption coefficient (k), infinite reflectance (R), and scattering coefficient (s) were tabulated for five wavelengths and analyzed for statistical differences for seven weed species. The wavelengths were: 0.55-micrometer, 0.65-micrometers, 0.85-micrometer, 1.65-micrometers, and 2.20-micrometer. The R of common lambsquarters (Chenopodium album L.), Johnsongrass (Sorghum halepense (L.) Pers.), and annual sowthistle (Sonchus oleraceus L.) leaves at the 0.85-micrometer wavelength were significantly (p=0.05) higher than for sunflower (Heliantus annus L.), ragweed parthenium (Parthenium hysterophorus L.), or London rocket (Sisymbrium irio L.). Annual sowthistle had the largest k value, and Plamer amaranth (Amaranthus palmer S. Wats.) had the smallest k value at the 0.65 approximately chlorophyll absorption wavelength. In general, john-songress, ragweed parthenium, or London rocket had the largest s values among the five wavelengths, wereas annual sowthistle and plamar amaranth were usually lowest
Influence of water availability in the distributions of branched glycerol dialkyl glycerol tetraether in soils of the Iberian Peninsula
The combined application of the MBT (degree of methylation) and CBT (degree
of cyclization) indices, based on the distribution of branched glycerol
dialkyl glycerol tetraethers (brGDGTs) in soils, has been proposed as a
paleoproxy to estimate mean annual temperature (MAT). CBT quantifies the
degree of cyclization of brGDGTs and relates to soil pH. MBT and the
simplified version MBT' quantify the degree of methylation of brGDGTs and
relate to MAT and soil pH. However, other factors such as soil water
availability have also been suggested to influence MBT' and possibly restrict
the combined application of the MBT' and CBT indices as a paleotemperature
proxy. To assess the effect of hydrological conditions on MBT' and CBT, a set
of 23 Iberian Peninsula soil samples, covering a MAT range from
10 to 18 °C and a mean annual precipitation (MAP) range of 405 mm to
1455 mm, was analyzed. We found that the CBT was indeed significantly
correlated with soil pH in our sample set. In contrast, MBT' was not correlated
with MAT but had a significant correlation with the aridity index (AI), a
parameter related to water availability in soils. The AI can explain 50%
of the variation of the MBT', and 70% of the residuals of MAT estimated
with the MBT/CBT proxy as compared to instrumentally measured MAT. We propose
that, in arid settings, where water may be an ecologically limiting factor,
MBT' is influenced by hydrological conditions rather than temperature. Thus,
our results suggest that the combination of MBT' and CBT indices should be
applied with caution in paleotemperature reconstructions in soils from dry
subhumid to hyperarid environments
Packings of 3D stars: stability and structure
© 2016, Springer-Verlag Berlin Heidelberg.We describe a series of experiments involving the creation of cylindrical packings of star-shaped particles, and an exploration of the stability of these packings. The stars cover a broad range of arm sizes and frictional properties. We carried out three different kinds of experiments, all of which involve columns that are prepared by raining star particles one-by-one into hollow cylinders. As an additional part of the protocol, we sometimes vibrated the column before removing the confining cylinder. We rate stability in terms of r, the ratio of the mass of particles that fall off a pile when it collapsed, to the total particle mass. The first experiment involved the intrinsic stability of the column when the confining cylinder was removed. The second kind of experiment involved adding a uniform load to the top of the column, and then determining the collapse properties. A third experiment involved testing stability to tipping of the piles. We find a stability diagram relating the pile height, h, versus pile diameter, (Formula presented.) , where the stable and unstable regimes are separated by a boundary that is roughly a power-law in h versus (Formula presented.) with an exponent that is less than unity. Increasing vibration and friction, particularly the latter, both tend to stabilize piles, while increasing particle size can destabilize the system under certain conditions
Genomic organization and evolutionary conservation of plant D-type cyclins
Plants contain more genes encoding core cell cycle regulators than other organisms but it is unclear whether these represent distinct functions. D-type cyclins (CYCD) play key roles in the G1-to-S-phase transition, and Arabidopsis (Arabidopsis thaliana) contains 10 CYCD genes in seven defined subgroups, six of which are conserved in rice (Oryza sativa). Here, we identify 22 CYCD genes in the poplar (Populus trichocarpa) genome and confirm that these six CYCD subgroups are conserved across higher plants, suggesting subgroup-specific functions. Different subgroups show gene number increases, with CYCD3 having three members in Arabidopsis, six in poplar, and a single representative in rice. All three species contain a single CYCD7 gene. Despite low overall sequence homology, we find remarkable conservation of intron/exon boundaries, because in most CYCD genes of plants and mammals, the first exon ends in the conserved cyclin signature. Only CYCD3 genes contain the complete cyclin box in a single exon, and this structure is conserved across angiosperms, again suggesting an early origin for the subgroup. The single CYCD gene of moss has a gene structure closely related to those of higher plants, sharing an identical exon/intron structure with several higher plant subgroups. However, green algae have CYCD genes structurally unrelated to higher plants. Conservation is also observed in the location of potential cyclin-dependent kinase phosphorylation sites within CYCD proteins. Subgroup structure is supported by conserved regulatory elements, particularly in the eudicot species, including conserved E2F regulatory sites within CYCD3 promoters. Global expression correlation analysis further supports distinct expression patterns for CYCD subgroups
Why growth equals power - and why it shouldn't : constructing visions of China
When discussing the success of China's transition from socialism, there is a tendency to focus on growth figures as an indication of performance. Whilst these figures are
indeed impressive, we should not confuse growth with development and assume that the former necessarily automatically generates the latter. Much has been done to
reduce poverty in China, but the task is not as complete as some observers would suggest; particularly in terms of access to health, education and welfare, and also in
dealing with relative (rather than absolute) depravation and poverty. Visions of China have been constructed that exaggerate Chinese development and power in the global
system partly to serve political interests, but partly due to the failure to consider the relationship between growth and development, partly due to the failure to disaggregate
who gets what in China, and partly due to the persistence of inter-national conceptions of globalised production, trade, and financial flows
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Commuting with a Plan: How Goal-Directed Prospection Can Offset the Strain of Commuting
To get to work, employees need to commute. Across the globe, the average commute is 38 minutes each way per day. It is well known that longer commutes have negative effects on employees’ well-being and job-related outcomes. Yet, commuting may not similarly affect all employees, since some of them may naturally engage in behaviors to offset the negative effects of longer commutes. Drawing on psychological research on self-control, we theorize how engaging in future-oriented thinking about the tasks to complete during the workday (i.e., goal-directed prospection) while commuting to work influences work outcomes. Across two field studies and one field experiment, we find that individuals higher in trait self-control are less likely to report negative effects of longer commutes. While commuting, individuals with higher trait self-control engage in goal-directed prospection, partially offsetting the strain of commuting. In a field experiment, individuals asked to engage in goal-directed prospecting during commuting reported higher levels of job satisfaction and lower levels of emotional exhaustion. Although commuting is typically seen as the least desirable part of an employee’s day, our theory and results point to the benefits of viewing it as a useful time period to engage in goal-directed prospection
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