Measuring geometric frustration in twisted inextensible filament bundles

We investigate with experiments and novel mapping the structure of a hexagonally ordered filament bundle that is held near its ends and progressively twisted around its central axis. The filaments are free to slide relative to each other and are further held under tension-free boundary conditions. Measuring the bundle packing with micro x-ray imaging, we find that the filaments develop the helical rotation $\Omega$ imposed at the boundaries. We then show that the observed structure is consistent with a mapping of the filament positions to disks packed on a dual non-Euclidean surface with a Gaussian curvature which increases with twist. We further demonstrate that the mean inter-filament distance is minimal on the surface which can be approximated by a hemisphere with an effective curvature $K_{eff} = 3\Omega^2$. Examining the packing on the dual surface, we analyze the geometric frustration of packing in twisted bundles and find the core to remain relatively hexagonally ordered with inter-filament strains growing from the bundle center, driving the formation of defects at the exterior of highly twisted bundles.Comment: 5 figure

Determinants of Neonatal and Post-neonatal Mortality in Pakistan

Ensuring the survival and well being of children is a concern of families, communities and nations throughout the world. Since the turn of the 20th century infant and child mortality in more developed countries has steadily declined and, currently, has been reduced to almost minimal levels. In contrast, although infant and child mortality has declined in the past three decades in most less developed countries, the pace of change and the magnitude of improvement vary considerably from one country to another. The inverse relationship between socio-economic variables of the parents and infant and child mortality is well established by several studies [Muhuri (1995); Forste (1994); Hobcraft, et al. (1984); Caldwell (1979); Sathar (1985, 1987)] and it holds true irrespective of the overall level of mortality in the national populations [Ruzicka (1989)]. The influence of parental education on infant and child health and mortality has proved to be universally significant [Bicego and Boerma (1993); Caldwell, et al. (1990)]. The father’s education, mother’s education and their work status each have independent effects upon child survival in developing countries [Sandiford, et al. (1995); Forste (1994); Caldwell, et al. (1983)]. Economic conditions of the household also help in explaining the variation in infant and child mortality. The nature of housing, diet, access to and availability of water and sanitary conditions as well as medical attention all depend on the economic conditions of the household. For example, poor families may reside in crowded, unhygienic housing and, thus, suffer from infectious disease associated with inadequate and contaminated water supplies and with poor sanitation [Esrey and Habicht (1986)]. Maternal factors, which are biological attributes of birth, such as the age of mother at the time of childbirth, birth order and birth interval [Forste (1994); Rutstein (1984)], have significant effects on child survival.

Novel Edge States in Self-Dual Gravity

In contrast to the Einstein-Hilbert action, the action for self-dual gravity contains vierbeins. They are eleminated at the level of observables by an $SL(2,\mathbb{C})$ gauge condition implied by the action. We argue that despite this condition, new "edge" or superselected state vectors corresponding to maps of the spheres $S^2_{\infty}$ at infinity to $SL(2, \mathbb{C})$ arise. They are characterised by new quantum numbers and they lead to mixed states. For black holes, they arise both at the horizon and the spatial infinity and may be relevant for the black hole information paradox. Similar comments can be made about the Einstein-Palatini action which uses vierbeins.Comment: 15 pages, reference added, some minor notational changes - no changes in conclusio

Database independent Migration of Objects into an Object-Relational Database

This paper reports on the CERN-based WISDOM project which is studying the serialisation and deserialisation of data to/from an object database (objectivity) and ORACLE 9i.Comment: 26 pages, 18 figures; CMS CERN Conference Report cr02_01

Anomalous Defects and Their Quantized Transverse Conductivities

Using a description of defects in solids in terms of three-dimensional gravity, we study the propagation of electrons in the background of disclinations and screw dislocations. We study the situations where there are bound states that are effectively localized on the defect and hence can be described in terms of an effective 1+1 dimensional field theory for the low energy excitations. In the case of screw dislocations, we find that these excitations are chiral and can be described by an effective field theory of chiral fermions. Fermions of both chirality occur even for a given direction of the magnetic field. The ``net'' chirality of the system however is not always the same for a given direction of the magnetic field, but changes from one sign of the chirality through zero to the other sign as the Fermi momentum or the magnitude of the magnetic flux is varied. On coupling to an external electromagnetic field, the latter becomes anomalous, and predicts novel conduction properties for these materials.Comment: New material added. ReVTeX , 31 pgs., 4 figs.(uses epsf

Charged Scalar Pair Production in Strong-Field Photon-Photon Interaction

Following the pioneering work of H. Reiss [1], we provide a covariant calculation of the charged scalar particle pair production. The calculation is facilitated by the use of two-dimensional Bessel functions and light-font coordinates.Comment: 8 page

Trade Liberalization, Financial Sector Reforms and Growth

This paper empirically investigates the impact of trade and financial liberalization on economic growth in Pakistan using annual observations over the period 1961-2005. The analysis is based on the bound testing approach of cointegration advanced by Pesaran et al (2001). The empirical findings suggest that both trade and financial policies play an important role in enhancing growth in Pakistan in the long-run. However, the short-run response of real deposit rate and trade policy variable is very low, suggesting further acceleration of reform process. The feedback coefficient suggests a very slow rate of adjustment towards long-run equilibrium. The estimated short-run dynamics are stable as indicated by CUSUMQ test.Financial Sector Reforms; Trade Liberalization; Growth; Pakistan

Modeling Probability of Path Loss for DSDV, OLSR and DYMO above 802.11 and 802.11p

This paper presents path loss model along with framework for probability distribution function for VANETs. Furthermore, we simulate three routing protocols Destination Sequenced Distance Vector (DSDV), Optimized Link State Routing (OLSR) and Dynamic MANET On-demand (DYMO) in NS-2 to evaluate and compare their performance using two Mac-layer Protocols 802.11 and 802.11p. A novel approach of this work is modifications in existing parameters to achieve high efficiency. After extensive simulations, we observe that DSDV out performs with 802.11p while DYMO gives best performance with 802.11.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc