China's Exports and Employment

Dooley et al (2003, 2004a,b,c) argue that China seeks to raise urban employment by 10-12 million persons per year, with about 30% of that coming from export growth. In fact, total employment increased by 7.5-8 million per year over 1997-2005. We estimate that export growth over 1997-2002 contributed at most 2.5 million jobs per year, with most of the employment gains coming from non-traded goods like construction. Exports grew much faster over the 2000-2005 period, which could in principal explain the entire increase in employment. However, the growth in domestic demand led to three-times more employment gains than did exports over 2000-2005, while productivity growth subtracted the same amount again from employment. We conclude that exports have become increasingly important in stimulating employment in China, but that the same gains could be obtained from growth in domestic demand, especially for tradable goods, which has been stagnant until at least 2002.

Contractual Versus Non-Contractual Trade: The Role of Institutions in China

Recent research has demonstrated the importance of institutional quality at the country level for both the volume of trade and the ability to trade in differentiated goods that rely on contract enforcement. This paper takes advantage of cross-provincial variation in institutional quality in China, and export data that distinguishes between foreign and domestic exporters and processing versus ordinary trade, to show that institutional quality is a significant factor in determining Chinese provincial export patterns. Institutions matter more for processing trade, and more for foreign firms, just as we would expect from a greater reliance on contracts in these cases.

Gait Verification using Knee Acceleration Signals

A novel gait recognition method for biometric applications is proposed. The approach has the following distinct features. First, gait patterns are determined via knee acceleration signals, circumventing difficulties associated with conventional vision-based gait recognition methods. Second, an automatic procedure to extract gait features from acceleration signals is developed that employs a multiple-template classification method. Consequently, the proposed approach can adjust the sensitivity and specificity of the gait recognition system with great flexibility. Experimental results from 35 subjects demonstrate the potential of the approach for successful recognition. By setting sensitivity to be 0.95 and 0.90, the resulting specificity ranges from 1 to 0.783 and 1.00 to 0.945, respectively

Flavour symmetry breaking in the kaon parton distribution amplitude

We compute the kaon's valence-quark (twist-two parton) distribution amplitude (PDA) by projecting its Poincare'-covariant Bethe-Salpeter wave-function onto the light-front. At a scale \zeta=2GeV, the PDA is a broad, concave and asymmetric function, whose peak is shifted 12-16% away from its position in QCD's conformal limit. These features are a clear expression of SU(3)-flavour-symmetry breaking. They show that the heavier quark in the kaon carries more of the bound-state's momentum than the lighter quark and also that emergent phenomena in QCD modulate the magnitude of flavour-symmetry breaking: it is markedly smaller than one might expect based on the difference between light-quark current masses. Our results add to a body of evidence which indicates that at any energy scale accessible with existing or foreseeable facilities, a reliable guide to the interpretation of experiment requires the use of such nonperturbatively broadened PDAs in leading-order, leading-twist formulae for hard exclusive processes instead of the asymptotic PDA associated with QCD's conformal limit. We illustrate this via the ratio of kaon and pion electromagnetic form factors: using our nonperturbative PDAs in the appropriate formulae, $F_K/F_\pi=1.23$ at spacelike-$Q^2=17\,{\rm GeV}^2$, which compares satisfactorily with the value of $0.92(5)$ inferred in $e^+ e^-$ annihilation at $s=17\,{\rm GeV}^2$.Comment: 7 pages, 2 figures, 3 table

Phases of the infinite U Hubbard model

We apply the density matrix renormalization group (DMRG) to study the phase diagram of the infinite U Hubbard model on 2-, 4-, and 6-leg ladders. Where the results are largely insensitive to the ladder width, we consider the results representative of the 2D square lattice model. We find a fully polarized ferromagnetic Fermi liquid phase when n, the density of electrons per site, is in the range 1>n>n_F ~ 4/5. For n=3/4 we find an unexpected commensurate insulating "checkerboard" phase with coexisting bond density order with 4 sites per unit cell and block spin antiferromagnetic order with 8 sites per unit cell. For 3/4 > n, the wider ladders have unpolarized groundstates, which is suggestive that the same is true in 2D

Divergence and Shannon information in genomes

Shannon information (SI) and its special case, divergence, are defined for a DNA sequence in terms of probabilities of chemical words in the sequence and are computed for a set of complete genomes highly diverse in length and composition. We find the following: SI (but not divergence) is inversely proportional to sequence length for a random sequence but is length-independent for genomes; the genomic SI is always greater and, for shorter words and longer sequences, hundreds to thousands times greater than the SI in a random sequence whose length and composition match those of the genome; genomic SIs appear to have word-length dependent universal values. The universality is inferred to be an evolution footprint of a universal mode for genome growth.Comment: 4 pages, 3 tables, 2 figure

Direction finding during mouse renal development

The adult kidney consists of hundreds of thousands of fine epithelial tubules as functional units called nephrons. Nephrons have U-shaped tubules: loops of Henle that descend from the cortex to the medulla. This radial arrangement is critical to maintain water homeostasis in the kidney. Although Henle’s loops are crucial to renal physiology, the cue(s) they uses to navigate to the medulla are not understood. In this thesis, I investigate how the loop of Henle elongates during mouse renal development and show that it is probably guided to the medulla by diffusible, heparin-binding molecules. I used immumohistochemistry (IHC) on cryosections of embryonic kidneys to study the natural anatomy of the Henle’s loop. I used a low-volume culture system to allow embryonic kidneys (both natural and tissue-engineered) to form loops of Henle ex vivo and manipulated their direction of growth. Time-lapse imaging of Lgr-5 EGFP embryonic kidneys demonstrated the movement of the apex of the loop which suggested the idea of guidance cue(s) acting on the loop of Henle. Cut-and-paste experiments showed that loops appeared to be attracted to maturing collecting duct. Co-culture with an exogenous tubule inducer suggested the embryonic spinal cord as another source to attract the loops. Using raTAL (rat thick ascending loop of Henle) and 6TA2 (embryonic collecting duct cells) cell lines, I designed and performed a cell migration assay to test whether raTAL was attracted to 6TA2 cells. raTAL cells were notably attracted to 6TA2 cells compared to other cell lines. raTAL cells were also attracted to 6TA2-conditioned medium, which indicated that raTAL cells were attracted by secreted molecule(s). To begin to characterise those secreted molecule(s), heparin-binding protein-coated beads were used in the cell migration system and showed that at least one critical guidance factor is heparin-binding. From this study, I found that the apex of the Henle’s loop does move and loops are attracted by secreted molecule(s) possibly from the collecting duct. Although target molecule(s) were unidentified, this study provides the first mechanistic information about the guidance of the loop of Henle. Moreover, this was the first study of guidance of epithelial tubule shafts (rather than tips) adding to our understanding of general tubule morphogenesis