1. When is it true? (5 points for each correct answer, -3 point for each wrong answer, 0 point for each blank) Fill in each blank with “always,” “sometimes,” or “never.” For example, • A nonsingular matrix is always invertible. • A square matrix is sometimes full-rank. • A strictly tall matrix is never onto. Here the matrix dimensions are such that each expression makes sense, but they are othe...

The idea behind boosting is to construct an accurate hypothesis from a set of hypotheses that are each guaranteed to perform slightly better than random guessing on particular distributions of data. This idea originally arose from attempts to prove the robustness of the PAC model. By robustness, we mean the notion that slight alterations to the model definitions should not result in dramaticall...

(a) Since A is full-rank and fat, Ax = b has at least one solution. From Problem 4 in HW#4, we know that since C is full-rank and tall, 〈x, y〉C := (Cx) TCy defines a valid inner product. So the problem reduces to one of finding the least-norm solution to Ax = b w.r.t. this inner product. Clearly, the required solution will be found by projecting the zero vector on the affine subspace defined by...

We have studied the inactivation of high-voltage-activated (HVA), omega-conotoxin-sensitive, N-type Ca2+ current in embryonic chick dorsal root ganglion (DRG) neurons. Voltage steps from -80 to 0 mV produced inward Ca2+ currents that inactivated in a biphasic manner and were fit well with the sum of two exponentials (with time constants of approximately 100 ms and > 1 s). As reported previously...

We have developed a simple fluorescent assay for detection of phospholipase A2 (PLA2) activity in zebrafish embryos that utilizes a fluorescent phosphatidylcholine substrate. By using this assay in conjunction with selective PLA2 inhibitors and Western blot analysis, we identified the principal activity in zebrafish embryogenesis as characteristic of the Ca2+-dependent cytosolic PLA2 (cPLA2) su...

In this paper we will study the dynamics of a non-BPS Dp-brane in the background of N BPS Dk-branes.

rho-kinase is an effector molecule of rhoa, a monomeric gtp-binding protein, and causes ca2+ sensitization through inactivation of myosin phosphatase. the major physiological functions of rho/rho-kinase cascade include contraction, proliferation and migration in cells.there are some excellent reviews about rho/rho-kinase signal pathway, most of which focus on the specific proteins of the pathwa...

The function of three of tropomyosin's sequential quasiequivalent regions was studied by deletion from skeletal muscle alpha-tropomyosin of internal residues 49-167. This deletion mutant tropomyosin spans four instead of the normal seven actins, and most of the tropomyosin region believed to interact with troponin is retained and uninterrupted in the mutant. The mutant tropomyosin was compared ...