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Observations of the cross-shore variations of pressure gradients measured on a fixed barred beach in a large-scale laboratory wave flume are presented in this paper. The wave-induced components (0.1-1.0 Hz) of the free surface elevation, near- bottom vertical and cross-shore velocities, and pressure gradient are used in the analysis. The cross-shore variation of the pressure gradient showed the maximum value in the area of wave breaking over the bar, and the pressure gradients were considered to be influenced by the fluctuation of the water surface elevation, which are shown to be a rough proxy for the water surface slope. The cross correlation related to the vertical velocity showed no correlation in the wave breaking area. Surprisingly, although several measuring points were located in the wave breaking area or in the inner surf zone, the spatial variation of the pressure gradient and water surface elevation had a correlation coefficient greater than 0.8 with time lags approximately 0.1 of the wave period from offshore to onshore in both regular and irregular wave cases. This indicates that the near-bottom pressure gradient can be estimated using the water surface elevation over a complex barred bathymetry and through the inner surf zone. DOI: 10.1061/(ASCE)WW.1943-5460.0000055 CE Database subject headings: Pressure; Breaking waves; Laboratory tests; Barrier beaches; Surf zone. Author keywords: Pressure; Breaking waves; Laboratory tests; Barrier beaches.

Background: The phalanges are the final skeletal elements to form in the vertebrate limb and their identity is regulated by signaling at the phalanx forming region (PFR) located at the tip of the developing digit ray. Here, we seek to explore the relationship between PFR activity and phalanx morphogenesis, which define the most distal limb skeletal elements, and signals associated with termination of limb outgrowth. Results: As Grem1 is extinguished in the distal chick limb mesoderm, the chondrogenesis marker Aggrecan is up‐regulated in the metatarsals and phalanges. Fate mapping confirms that subridge mesoderm cells contribute to the metatarsal and phalanges when subridge Grem1 is down‐regulated. Grem1 overexpression specifically blocks chick phalanx development by inhibiting PFR activity. PFR activity and digit development are also disrupted following overexpression of a Gli3 repressor, which results in Grem1 expression in the distal limb and downregulation of Bmpr1b. Conclusions: Based on expression and fate mapping studies, we propose that downregulation of Grem1 in the distal limb marks the transition from metatarsal to phalanx development. This suggests that downregulation of Grem1 in the distal limb mesoderm is necessary for phalanx development. Grem1 downregulation allows for full PFR activity and phalanx progenitor cell commitment to digit fate. Key Findings: When Grem1 expression is down‐regulated in the distal limb mesoderm, cells fated to become metatarsal and phalanx are present in the subridge mesoderm.Overexpression of Grem1 in the chick leg with a replication defective retrovirus specifically inhibits phalanx development by inhibiting PFR activity.Gli3 modulates phalanx development by regulating PFR formation and activity in part through Bmpr1b and Grem1 expression, respectively.Down‐regulation of Grem1 in the distal limb marks the transition from metatarsal to phalanx development.Grem1 down‐regulation in the distal limb allows for PFR activity which is necessary for phalanx progenitor cell commitment to digit fate. [ABSTRACT FROM AUTHOR]

In centrifugal pumps for artificial hearts, a magnetic drive with lightly loaded journal bearing system is often used. In such a system, the rigidity of the bearing is small and the impeller usually rotates over the critical speed. In such cases, the rotordynamic fluid forces play an important role for shaft vibration. In the present study, the characteristics of the rotordynamic fluid forces on the impeller were examined. The rotordynamic fluid forces were measured in the cases with/without the whirling motion. It was found that the rotordynamic forces become destabilizing in a wide range of positive whirl. The effect of leakage flow was also examined. [DOI: 10.1115/1.2786477]

Global transcriptional responses to dehydration and rehydration were determined in Anabaena sp. PCC 7120. Nearly 300 genes were up- or downregulated during both dehydration and rehydration. While as many as 133 genes showed dehydration-specific downregulation, only 29 genes showed dehydration-specific upregulation. In contrast, while only 13 genes showed rehydration-specific downregulation, as many as 259 genes showed rehydration-specific upregulation. The genes upregulated during rehydration responded rapidly and transiently, whereas those upregulated during dehydration did so gradually and persistently. The expression of various genes involved in DNA repair, protein folding and NAD synthesis, as well as genes responding to nitrogen depletion and C[O.sub.2] limitation, was upregulated during rehydration. Although no genes for transcriptional regulators showed dehydration-specific upregulation, eight showed rehydration-specific upregulation. Among them, two genes, ancrpB and air0618, encode putative transcriptional activators of the cAMP receptor protein (CRP) family. DNA microarray analysis using gene disruptants revealed that AnCrpB and Air0618 regulate the genes induced by nitrogen depletion and by C[O.sub.2] limitation, respectively. We conclude that rehydration is a complex process in which the expression of certain genes, particularly those for metabolism, is dramatically induced.

Expression of L-type pyruvate kinase (L-PK) is upregulated in the liver by dietary carbohydrate. Previously, 3 carbohydrate/insulin response elements were identified in the 5'-flanking region of the L-PK gene up to bp--170. Studies of the 5'-flanking region beyond bp--183 in transgenic mice suggested that other regulatory elements may be present upstream of bp--183, but the positions of these elements were uncertain. In the present study, the existence of regulatory regions of the L-PK gene responding to stimulation by feeding was examined using in vivo hydrodynamics-based gene transfection (HT) in mouse liver. The firefly-luciferase (FL) gene, fused with various lengths of the 5'-flanking region of the L-PK gene, was introduced into mouse liver by HT. The mice had free access to a high-carbohydrate diet. In liver homogenate, luciferase activity of pL-PK(-1467)-FL (which included the 5'-flanking region from bp -1467 to +17), was markedly stimulated by feeding. 5'-Deletion up to bp -1065 caused only minor changes in luciferase activity, but further deletion up to bp -690 and bp -203 caused significant, gradual decreases in activity. Further analyses utilizing 5'-deletion mutants indicated the existence of positive regulatory regions that respond to stimulation by feeding between bp -1065 and -945, and between -300 and -203 on the L-PK gene. These results suggest that unidentified cis-acting DNA elements exist in the upstream region of the L-PK gene, and that HT is a useful approach for detecting regulatory regions of genes expressed in the liver. KEY WORDS: * L-type pyruvate kinase * mouse * hydrodynamics-based gene transfection * luciferase