Ral is a small Ras-like GTPase that regulates membrane trafficking and signaling. Here, we show that in response to planar cell polarity (PCP) signals, Ral modulates asymmetric Notch signaling in the Drosophila eye. Specification of the initially equivalent R3/R4 photoreceptor precursor cells in each developing ommatidium occurs in response to a gradient of Frizzled (Fz) signaling. The cell wit...

The Drosophila eye is composed of several hundred ommatidia that can exist in either of two chiral forms, depending on position: ommatidia in the dorsal half of the eye adopt one chiral form, whereas ommatidia in the ventral half adopt the other. Chirality appears to be specified by a polarizing signal with a high activity at the interface between the two halves (the 'equator'), which declines ...

The present study investigated the simultaneous occurrence of emergent stimulus-response relations (functional equivalence) and stimulus-stimulus relations (stimulus equivalence). After being pretrained and tested on two symbolic match-to-sample tasks (X1-Y1, X2-Y2), 20 4- and 5-year-old children were trained to emit specified responses to pairs of stimuli (A1-R1, B1-R1, A2-R2, B2-R2) in one se...

We use normal sections to relate the curvature locus of regular (resp. singular corank 1) 3-manifolds in R6 R5) with surfaces R5 R4 ). For example, we show how generate a Roman surface by family ellipses different Steiner’s way. also study relations between and cases through projections. that there is commutative diagram projections which relates loci types manifolds, therefore, second order ge...

A stem-tip necrosis disease was observed in the soybean [Glycine max (L.) Merr.] cultivar Columbia and its derivative OX686 when infected with a necrosis-causing strain of Soybean mosaic virus (SMV) in Canada. A dominant gene named Rsv3 was found in OX686 for the necrotic reaction. In the present research we have found that Columbia is resistant to all known SMV strains G1-G7, except G4. Geneti...

Dual-energy X-ray computed tomography (DECT) is a powerful tool for non-destructive evaluation for security. In security applications where DECT is used for scanning checked luggage, many different materials may be scanned in various degrees of clutter and metal objects are common. Conventionally, fi ltered back-projection (FBP) is used for image formation and there is no unifi ed treatment of ...

In CT-based security screening, a challenging problem is to correctly identify and label objects in a scene from X-ray projection data. The presence of artifacts in the reconstructed image confounds traditional segmentation and labeling methods. In this work, we focus on integrating machine learning, physical modeling and Bayesian inference in a framework for direct material identifi cation and...

We review recent developments in noncommutative deformations of instantons in R4. In the operator formalism, we study how to make noncommutative instantons by using the ADHM method, and we review the relation between topological charges and noncommutativity. In the ADHM methods, there exist instantons whose commutative limits are singular. We review smooth noncommutative deformations of instant...

The Ramsey number rk(s, n) is the minimum N such that for every red-blue coloring of the k-tuples of {1, . . . , N}, there are s integers such that every k-tuple among them is red, or n integers such that every k-tuple among them is blue. We prove the following new lower bounds for 4-uniform hypergraph Ramsey numbers: r4(5, n) > 2 n log n and r4(6, n) > 2 2 1/5 , where c is an absolute positive...

Within the developing vertebrate head, neural crest cells (NCCs) migrate from the dorsal surface of the hindbrain into the mesenchyme adjacent to rhombomeres (r)1 plus r2, r4 and r6 in three segregated streams. NCCs do not enter the intervening mesenchyme adjacent to r3 or r5, suggesting that these regions contain a NCC-repulsive activity. We have used surgical manipulations in the chick to dem...