3,061 research outputs found

    Bubble Raft Model for a Paraboloidal Crystal

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    We investigate crystalline order on a two-dimensional paraboloid of revolution by assembling a single layer of millimeter-sized soap bubbles on the surface of a rotating liquid, thus extending the classic work of Bragg and Nye on planar soap bubble rafts. Topological constraints require crystalline configurations to contain a certain minimum number of topological defects such as disclinations or grain boundary scars whose structure is analyzed as a function of the aspect ratio of the paraboloid. We find the defect structure to agree with theoretical predictions and propose a mechanism for scar nucleation in the presence of large Gaussian curvature.Comment: 4 pages, 4 figure

    Undegradable Intake Protein Supplementation of Compensating Spring-Born Steers and Summer-Born Steers During Summer Grazing

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    Three trials were conducted to determine the effects of previous winter gain (Trials 1 and 3) and age of calf (Trials 1 and 2) on response to undegradable intake protein (UIP) supplementation during summer grazing. In Trial 1, 48 spring-born steers (243 kg) were used in a 4 &#;&#;2 factorial arrangement. Steers were wintered at four rates of gain: 0.65 (FAST), 0.24 (SLOW), 0.38 (S/F), and 0.38 (F/S) kg/d. The intermediate rates of gain (S/F and F/S) were created by switching steers from slow to fast or fast to slow midway through the wintering period. Following winter treatments, steers were assigned to one of two summer treatments: supplemented (S) or nonsupplemented (NS). In Trial 2, 32 summer-born steers were wintered at an ADG of 0.25 kg/d and allotted to the same summer treatments as Trial 1. The supplement was formulated to supply 200 g/d of UIP. Steers from both trials grazed upland Sandhills range from May to September 1998. In Trial 3, 49 spring-born steers (228 kg) were used in a 2 &#;&#;7 factorial arrangement of treatments. Steers were wintered at two rates of gain, 0.71 (FAST) and 0.24 kg/d (SLOW) and then assigned randomly to one of six levels of UIP supplementation or an energy control. Protein supplements were formulated to deliver 75, 112.5, 150, 187.5 225, or 262.5 g/d of UIP. Sources of UIP for all trials were treated soybean meal and feather meal. In Trial 1, there were no (P \u3e 0.05) winter by summer treatment interactions, and UIP supplementation increased (P = 0.0001) pasture gains over NS steers. In Trial 2, supplementation increased (P = 0.001) pasture ADG of summer-born steers by 0.15 kg/d compared with NS steers. In Trial 3, a winter gain by UIP supplementation interaction was observed (P = 0.09). Gain of FAST steers responded quadratically (P = 0.09) across UIP levels, with the maximum gain occurring at the 150 g/ d UIP level. The SLOW steers responded linearly (P = 0.02) to increasing UIP levels; however, the response was negative. Levels of UIP above 150 g/d reduced steers gains; therefore, the data were reanalyzed excluding these levels. These new analyses showed that FAST steers responded linearly (P = 0.08; 0.2 kg/d) to increasing UIP, whereas the SLOW steers had no response to UIP. In Trials 1 and 3, SLOW steers experienced compensatory gain and had higher gains overall. We concluded that previous winter gain affected the response to UIP supplementation with the FAST winter gain group having a greater response

    Multidisciplinary approach to the management of children with female genital mutilation (FGM) or suspected FGM: service description and case series

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    OBJECTIVE: To describe the first dedicated clinic in the UK for children with suspected or confirmed female genital mutilation (FGM) including referral patterns, clinical findings and subsequent management. DESIGN AND SETTING: A prospective study of all children seen in a dedicated multidisciplinary FGM clinic for children over a 1-year period. POPULATION: Patients aged under 18 years referred for clinical assessment or for a second opinion on Digital Versatile Disc (DVD) images. METHODS AND MAIN OUTCOME MEASURES: Data were collected on reasons for referral, demography, genital examination findings including FGM type, and clinical recommendations. RESULTS: 38 children were referred of whom 18 (47%) had confirmed FGM; most frequently type 4 (61%). Social care and police referred 78% of cases. According to UK law FGM had been performed illegally in three cases. Anonymous information given to the police led to the referral of six children, none of whom had had FGM. CONCLUSIONS: Mandatory reporting and increased media attention may increase the numbers of referrals of children with suspected FGM. This patient group have complex needs and management in a dedicated multidisciplinary service is essential. Paediatricians and gynaecologists should have the skills to carry out the consultation and detect all types of FGM including type 4 which was the most common type seen in this series. This is the first dedicated FGM service for children in the UK and similar clinics in high-prevalence areas should be established

    Response of the Brazilian gravitational wave detector to signals from a black hole ringdown

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    It is assumed that a black hole can be disturbed in such a way that a ringdown gravitational wave would be generated. This ringdown waveform is well understood and is modelled as an exponentially damped sinusoid. In this work we use this kind of waveform to study the performance of the SCHENBERG gravitational wave detector. This first realistic simulation will help us to develop strategies for the signal analysis of this Brazilian detector. We calculated the signal-to-noise ratio as a function of frequency for the simulated signals and obtained results that show that SCHENBERG is expected to be sensitive enough to detect this kind of signal up to a distance of ∼20kpc\sim 20\mathrm{kpc}.Comment: 5 pages, 4 figures, Amaldi 5 Conference Proceedings contribution. Submitted to Class. Quantum Gra

    Sequence Dependence of Self-Interacting Random Chains

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    We study the thermodynamic behavior of the random chain model proposed by Iori, Marinari and Parisi, and how this depends on the actual sequence of interactions along the chain. The properties of randomly chosen sequences are compared to those of designed ones, obtained through a simulated annealing procedure in sequence space. We show that the transition to the folded phase takes place at a smaller strength of the quenched disorder for designed sequences. As a result, folding can be relatively fast for these sequences.Comment: 14 pages, uuencoded compressed postscript fil

    Effects of Supplementing Lactating, June-calving Cows on Second-calf Pregnancy Rates

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    A two year experiment evaluated the influence of supplementation pre-breeding on second-calf pregnancy rates in June-calving heifers. For 60 days before start of the breeding season, heifers were assigned to one of two treatments: supplementation of dried distillers grains (1.5 lb/day) to meet energy and metabolizable protein requirements or unsupplemented control. Supplementation improved body condition score during the supplementation period and resulted in increased body condition score at weaning. In year 1, feeding supplement to the dam did not change calf weight gain but feeding supplement increased calf weight in year 2. Pregnancy rates were 90% and not changed by supplementation

    Entropic Barriers, Frustration and Order: Basic Ingredients in Protein Folding

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    We solve a model that takes into account entropic barriers, frustration, and the organization of a protein-like molecule. For a chain of size MM, there is an effective folding transition to an ordered structure. Without frustration, this state is reached in a time that scales as MλM^{\lambda}, with λ≃3\lambda\simeq 3. This scaling is limited by the amount of frustration which leads to the dynamical selectivity of proteins: foldable proteins are limited to ∼300\sim 300 monomers; and they are stable in {\it one} range of temperatures, independent of size and structure. These predictions explain generic properties of {\it in vivo} proteins.Comment: 4 pages, 4 Figures appended as postscript fil
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