Assay system for mesocotyl elongation and hydrotropism of maize primary root in response to low moisture gradient

We designed and validated a test system that simulates a growth environment for Zea mays L. maize seedlings under conditions of low moisture gradient in darkness. This system allowed us to simultaneously measure mesocotyl elongation and the primary root hydrotropic response in seedlings before the emergence phase in a collection of maize hybrids. We found great variation in these two traits with statistically significant reduction of their elongations under the low moisture gradient condition that indicate the richness of maize genetic diversity. Hence, the objective of designing a new test system that evaluates the association between these underground traits with the potential use to measure other traits in maize seedlings related to early vigor was achieved.

Revisiting Failure of Brittle Materials

Failures of isotropic brittle materials were revisited to find out whether there are unified failure criteria which can be applied to a load-carrying structural component made of a brittle material regardless of whether the component has a crack, a circular notch, or neither of these. To this end, a set of failure criteria were considered to determine failure of a local point which may be located at the crack tip, a notch tip, or any other location. The proposed criteria consist of two conditions, of which both must be satisfied for failure to occur. The first condition is that the local stress must not be lower than the failure strength of the material. The second condition is the stress-gradient condition. Even if the stress at a local point far exceeds the failure strength of the material, failure will not initiate until the stress gradient condition is satisfied. Four different examples cases were presented to explain the proposed failure concept.

Kinetics of protein aggregation at a temperature gradient condition

Our model system is a small step towards studying protein aggregation kinetics while mimicking in vivo temperature gradient condition and it demonstrates the unconventional multi-sigmoidal kinetic behavior.

Applying floodplain geomorphology to flood management (The Lower Vistula River upstream from Plock, Poland)

Using remote sensing extended on geological and topographical maps and verified by the field work, we present the flood management and study the geomorphic features of the floodplain of a large, sand bed, untrained but embanked river in order to determine the flood hazard and to predict future flood scenarios. In geomorphological mapping, we focus on the landforms: crevasse channels and splays, flood basin, chute channels, side arms, floodplain channels, dunes and fields of aeolian sand. We base the flood risk assessment on consultations with environmental engineers who design new technical structures that control inundation (cut-off walls and lattice levees). We describe a levee breach as a result of piping (inner erosion) in a high hydraulic gradient condition and its effect (scour hole) as an erosional landform consistent with the repetitive pattern of erosion and deposition formed by an overbank flow on a floodplain. We reveal an existence of homogenous morphodynamic reaches in the river valley.

Simultaneous Quantitation of Isoprenoid Pyrophosphates in Plasma and Cancer Cells Using LC-MS/MS

Isoprenoids (IsoP) are an important class of molecules involved in many different cellular processes including cholesterol synthesis. We have developed a sensitive and specific LC-MS/MS method for the quantitation of three key IsoPs in bio-matrices, geranyl pyrophosphate (GPP), farnesyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP). LC-MS/MS analysis was performed using a Nexera UPLC System connected to a LCMS-8060 (Shimadzu Scientific Instruments, Columbia, MD) with a dual ion source. The electrospray ionization source was operated in the negative MRM mode. The chromatographic separation and detection of analytes was achieved on a reversed phase ACCQ-TAG Ultra C18 (1.7 µm, 100 mm × 2.1 mm I.D.) column. The mobile phase consisted of (1) a 10 mM ammonium carbonate with 0.1% ammonium hydroxide in water, and (2) a 0.1% ammonium hydroxide in acetonitrile/methanol (75/25). The flow rate was set to 0.25 mL/min in a gradient condition. The limit of quantification was 0.04 ng/mL for all analytes with a correlation coefficient (r2) of 0.998 or better and a total run time of 12 min. The inter- and intra-day accuracy (85–115%) precision (<15%), and recovery (40–90%) values met the acceptance criteria. The validated method was successfully applied to quantitate basal concentrations of GPP, FPP and GGPP in human plasma and in cultured cancer cell lines. Our LC-MS/MS method may be used for IsoP quantification in different bio-fluids and to further investigate the role of these compounds in various physiological processes.

Sobolev spaces and hyperbolic fillings

LetZbe an AhlforsQ-regular compact metric measure space, where{Q>0}. For{p>1}we introduce a new (fractional) Sobolev space{A^{p}(Z)}consisting of functions whose extensions to the hyperbolic filling ofZsatisfy a weak-type gradient condition. IfZsupports aQ-Poincaré inequality with{Q>1}, then{A^{Q}(Z)}coincides with the familiar (homogeneous) Hajłasz–Sobolev space.