Domain Wall Spacetimes: Instability of Cosmological Event and Cauchy Horizons

The stability of cosmological event and Cauchy horizons of spacetimes associated with plane symmetric domain walls are studied. It is found that both horizons are not stable against perturbations of null fluids and massless scalar fields; they are turned into curvature singularities. These singularities are light-like and strong in the sense that both the tidal forces and distortions acting on test particles become unbounded when theses singularities are approached.Comment: Latex, 3 figures not included in the text but available upon reques

Effects of Weaning Age and Winter Development Environment on Heifer Grazing Distribution

The objective of this experiment was to determine if early weaning (approximately 125 d) vs. normal weaning (approximately 250 d) and wintering replacement heifers in drylot versus rangeland affected heifer grazing distribution during the subsequent summer. Heifer calves from the 2009 and 2010 calf crop (n = 104 and 73, respectively) were allocated to the 2 weaning treatments and then stratified by age into the 2 winter development treatments. During the summer of yr 1 heifers were allocated to 2 pastures by winter treatment, and in yr 2, all 4 treatment combinations were allocated to separate pastures. A subset of heifers from each group was selected to wear global positioning system (GPS) collars (n=2 and 5 in yr 1 and 2, respectively). Readings were taken from the GPS every 15 min in yr 1 and every 65 s in yr 2. The GPS coordinates were then analyzed relative to ecological sites, water locations, fence locations, and temperature using Arc GIS (ESRI, Redlands, CA). Winter treatment affected (P\u3c0.05) preference index (PI) for claypan and loamy sites in 2010, and distance from water in 2011. Day of sampling affected (P\u3c0.05) claypan and loamy site PI in 2010 and thin claypan site PI in 2011. Day of sampling interacted with winter treatment (P\u3c0.05) for distance from water in 2010, sand and thin claypan site PI in 2010 and thin claypan site PI in 2011, while day of sampling interacted with weaning treatment for distance from water in 2011. A winter by weaning treatment interaction affected (P\u3c0.05) thin claypan site PI in 2011. Temperature had an effect on distance to fencelines in 2010 (P\u3c0.001). There was a temperature interaction with wintered treatment effect on distance to water in 2011 (P\u3c0.001). There was a three-way interaction (P\u3c0.05) between weaning treatment, winter treatment and ambient temperate on the distance from water and between weaning treatment, winter treatment and day of sampling on claypan and sand site PI in 2011. In conclusion, winter development influenced patterns of range utilization. Day-of-sampling interactions indicated that range heifers did not adjust preferences and thus were already adapted to the range environment, whereas drylot heifers adjusted preferences over time suggesting they re-learned how to utilize the range environment

Effects of Weaning Age and Winter Development Environment on Heifer Performance

Our objective was to determine if early weaning (about 125 d) vs. normal weaning (about 250 d) and wintering replacement heifers in drylot vs. rangeland affected heifer growth and reproductive performance. Heifer calves from the 2009 and 2010 calf crops (n = 104 and 73, respectively) were allocated to the 2 weaning treatments and then stratified by age into the 2 winter development treatments forming a 2 by 2 factorial arrangement of treatments. Heifers wintered in drylot received mixed grass and alfalfa hay (yr 1: 11.6% CP, 52.5% TDN; yr2: 12.3% CP, 53.4% TDN) plus 1.8 kg of a dried distiller’s grain (DDGS)-based supplement/hd/d (yr1: 22.7% CP, 75.8% TDN; yr 2: 25.4% CP, 76.7% TDN). Heifers wintered on rangeland also received 1.8 kg/hd/d of the same supplement. Over the winter, each treatment was allocated to a separate pen or pasture. After estrus synchronization and timed AI, all heifers were placed on rangeland to graze through the summer. During the summer of yr 1, heifers were allocated by winter treatment to 2 pastures, and in yr 2 all 4 treatment combinations were allocated to separate pastures. Responses measured were BW, ADG, pubertal status at initiation of estrus synchronization, and pregnancy status after breeding. Pubertal status was indicated by serum progesterone \u3e 1 ng/ml. A winter by weaning treatment interaction affected (P\u3c0.001) BW and ADG both years. During the winter months, range heifers were lighter and grew slower than drylot heifers, but BW did not differ due to winter treatments at the end of the summer. However, early-weaned heifers remained lighter than normal weaned heifers at the end of the summer. Weaning treatment affected (P=0.03) fall pregnancy rate (93.2%±4.0 and 74.7%±7.98 for early- and normal-weaning, respectively) in yr 2. In yr 1, there was a difference (P=0.006) between drylot and range heifers (92.7%±3.52 and 72.8%±6.47, respectively) in the proportion that obtained puberty before estrus synchronization. In conclusion, producers should consider important interactions between weaning and winter management practices when establishing a replacement heifer development program that best fits the goals of their operation

Assessing the potential impacts of a revised set of on-farm nutrient and sediment ‘basic’ control measures for reducing agricultural diffuse pollution across England

The need for improved abatement of agricultural diffuse water pollution represents cause for concern throughout the world. A critical aspect in the design of on-farm intervention programmes concerns the potential technical cost-effectiveness of packages of control measures. The European Union (EU) Water Framework Directive (WFD) calls for Programmes of Measures (PoMs) to protect freshwater environments and these comprise ‘basic’ (mandatory) and ‘supplementary’ (incentivised) options. Recent work has used measure review, elicitation of stakeholder attitudes and a process-based modelling framework to identify a new alternative set of ‘basic’ agricultural sector control measures for nutrient and sediment abatement across England. Following an initial scientific review of 708 measures, 90 were identified for further consideration at an industry workshop and 63 had industry support. Optimisation modelling was undertaken to identify a shortlist of measures using the Demonstration Test Catchments as sentinel agricultural landscapes. Optimisation selected 12 measures relevant to livestock or arable systems. Model simulations of 95% implementation of these 12 candidate ‘basic’ measures, in addition to business-as-usual, suggested reductions in the national agricultural nitrate load of 2.5%, whilst corresponding reductions in phosphorus and sediment were 11.9% and 5.6%, respectively. The total cost of applying the candidate ‘basic’ measures across the whole of England was estimated to be £450 million per annum, which is equivalent to £52 per hectare of agricultural land. This work contributed to a public consultation in 2016

Ballistic electron transport in stubbed quantum waveguides: experiment and theory

We present results of experimental and theoretical investigations of electron transport through stub-shaped waveguides or electron stub tuners (ESTs) in the ballistic regime. Measurements of the conductance G as a function of voltages, applied to different gates V_i (i=bottom, top, and side) of the device, show oscillations in the region of the first quantized plateau which we attribute to reflection resonances. The oscillations are rather regular and almost periodic when the height h of the EST cavity is small compared to its width. When h is increased, the oscillations become less regular and broad depressions in G appear. A theoretical analysis, which accounts for the electrostatic potential formed by the gates in the cavity region, and a numerical computation of the transmission probabilities successfully explains the experimental observations. An important finding for real devices, defined by surface Schottky gates, is that the resonance nima result from size quantization along the transport direction of the EST.Comment: Text 20 pages in Latex/Revtex format, 11 Postscript figures. Phys. Rev. B,in pres

Detailed electronic structure studies on superconducting MgB2_2 and related compounds

In order to understand the unexpected superconducting behavior of MgB$_2$ compound we have made electronic structure calculations for MgB$_2$ and closely related systems. Our calculated Debye temperature from the elastic properties indicate that the average phonon frequency is very large in MgB$_2$ compared with other superconducting intermetallics and the exceptionally high $T_c$ in this material can be explained through BCS mechanism only if phonon softening occurs or the phonon modes are highly anisotropic. We identified a doubly-degenerate quasi-two dimensional key-energy band in the vicinity of $E_{F}$ along $\Gamma$-A direction of BZ which play an important role in deciding the superconducting behavior of this material. Based on this result, we have searched for similar kinds of electronic feature in a series of isoelectronic compounds such as BeB$_2$, CaB$_2$, SrB$_2$, LiBC and MgB$_2$C$_2$ and found that MgB$_2$C$_2$ is one potential material from the superconductivity point of view. There are contradictory experimental results regarding the anisotropy in the elastic properties of MgB$_2$ ranging from isotropic, moderately anisotropic to highly anisotropic. In order to settle this issue we have calculated the single crystal elastic constants for MgB$_2$ by the accurate full-potential method and derived the directional dependent linear compressibility, Young's modulus, shear modulus and relevant elastic properties. We have observed large anisotropy in the elastic properties. Our calculated polarized optical dielectric tensor shows highly anisotropic behavior even though it possesses isotropic transport property. MgB$_2$ possesses a mixed bonding character and this has been verified from density of states, charge density and crystal orbital Hamiltonian population analyses

Brand origin identification by consumers: A classification perspective

The authors apply a classification perspective to (1) examine the extent to which consumers can identify the correct country of origin (COO) of different brands of consumer durables, (2) investigate the factors facilitating/hindering correct COO identification, and (3) trace the implications of correct/incorrect COO identification on brand evaluation. The results from a U.K. sample indicate that consumers' ability to classify brands correctly according to their origin is limited and also reveal substantial differences in the classification of different brands to their COO. Moreover, the key antecedent of correct COO identification is consumer ethnocentrism, with sociodemographics (e.g., age, gender) also playing a role. Finally, the authors find that though there are differences in brand evaluations depending on whether the correct COO was identified, such differences are not observed for all brands investigated

Targeted delivery of antisense oligonucleotides by molecular conjugates

Antisense oligonucleotides efficiently inhibit gene expression in vitro; however, the successful therapeutic application of this technology in vivo will require the development of improved delivery systems. In this report we describe a technique that efficiently delivers antisense oligonucleotides into cells using molecular conjugates. This technique, which was initially developed for the delivery of eukaryotic genes, is based on the construction of DNA-protein complexes that are recognized by the liver-specific asialoglycoprotein receptor. Binding of poly( l -lysine)-asialoorosomucoid (AsOR) protein conjugates with phosphorothioate antisense oligonucleotides to chloramphenicol acetyltransferase (CAT) led to the formation of 50- to 150-nm toroids. Exposure of the antisense molecular complexes (3 µM oligonucleotide) to NIH 3T3 cells genetically modified to express both the AsOR receptor and CAT, inhibited CAT expression by 54%, which was completely blocked by excess AsOR. Equivalent inhibition of CAT activity with purified oligonucleotide alone was observed at a 30 µM concentration. Furthermore, examination of the cells using indirect immunofluorescence for the presence of CAT protein showed 28% of cells exposed to the molecular conjugates lacked any detectable CAT enzyme. Cells exposed to oligonucleotide alone showed a highly variable staining pattern, and only a few of the cells were completely void of CAT protein. Together these data demonstrate that molecular conjugates provide a highly specific and efficient system for the delivery of antisense oligonucleotides.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45543/1/11188_2005_Article_BF01232652.pd

Spinor condensates and light scattering from Bose-Einstein condensates

These notes discuss two aspects of the physics of atomic Bose-Einstein condensates: optical properties and spinor condensates. The first topic includes light scattering experiments which probe the excitations of a condensate in both the free-particle and phonon regime. At higher light intensity, a new form of superradiance and phase-coherent matter wave amplification were observed. We also discuss properties of spinor condensates and describe studies of ground--state spin domain structures and dynamical studies which revealed metastable excited states and quantum tunneling.Comment: 58 pages, 33 figures, to appear in Proceedings of Les Houches 1999 Summer School, Session LXXI

Using Enterprise Education to Prepare Healthcare Professional Graduates for the Real-world

Objectives: Every year, HEIs around the world provide an increasing number of graduates with professional degrees in various areas of healthcare including for example medicine, pharmacy, dentistry and podiatry. In most cases, these graduates will get the opportunity to develop a range of generic transferable skills during their HE. Yet, many of these become self-employed or responsible for managing a business, but are not always exposed to curricula that develop their awareness of the concepts of enterprise and entrepreneurship and their role in developing economies and societies, and, thus, do not have the necessary range of enterprise skills that they will need in the real-world, whether employed or self-employed. This paper investigates the extent to which Enterprise Education (EE) is applied at professional health schools at HEIs to develop graduates’ ‘soft’ and ‘functional’ enterprise skills, and how effective the process of delivering this education is. Prior work: Previous literature mainly deals with the application of EE through business and management schools, rather than professional ones. Yet, there is a call for researching EE and skills with more focus on exploring the methods and objectives of specific disciplines. At the same time, research investigating learning in professional degrees focuses almost entirely on the development of technical skills related to the discipline, without a general perspective on developing a wider range of enterprise skills. Approach: The study draws on a qualitative research study in the pharmacy education context. Personal interviews with pharmacy employers and academics were carried out, and thematic analysis was applied to identify themes and codes. Results: Despite that experiential and interactive learning approaches, which can support the development of graduates’ enterprise skills, are applied quite often at pharmacy schools, the application of these approaches is focused on discipline-related material and, therefore, can only support the development of graduates’ ‘soft’ enterprise skills. However, there appears to be resistance against developing graduates’ ‘functional’ enterprise skills in pharmacy disciplines, especially in light of the lack of awareness of the concept of EE among academics. The study offers some possible opportunities/propositions that could facilitate the development of more enterprising healthcare graduates, while highlighting the importance of raising the awareness of academics in this regard and embedding EE as part of schools’ philosophies. Implication: This study should help professional health schools at HEIs decide more accurately on how to develop their graduates’ ‘soft’ and ‘functional’ enterprise skills, and address the needs of the real-world. Value: This study directs the attention of HEIs to support developing professional graduates who are ready for the real-world, and who can support the growth and success of any organisation whether employed or self-employed