Closing the Loop: Creating Deliverables That Add Value

As special collections librarians and liaison librarians work together to create in­novative experiences working with primary source material, it is important to remember students have much to offer in the collaborative design process. In this case study, Prudence Doherty, a special collections librarian, and Daniel DeSanto, an instruction librarian, describe a project they initiated and implemented with upper-level education majors at the University of Vermont (UVM). The students were pre-service teachers (student teachers working toward degree and licensure) enrolled in Social Education and Social Studies, a course that focuses on teaching methods, assessment alternatives, and resources used in the elementary (K–4) classroom. The project gave the pre-service teachers an opportunity to work with three digital collections in order to design lesson plans for elementary-aged stu­dents. The project closed the loop of learn, create, and teach by requiring students to learn evaluative approaches to working with historical material and then create lesson plans based on those approaches. By creating professional resources for other teachers, the students added value to the digital collections

Ultraviolet dayglow and stellar brightness measurement from the X-15 aircraft

Airborne stellar photometry and spectrometric determination of day sky brightnes

Low Gain Avalanche Detectors (LGAD) for particle physics and synchrotron applications

A new avalanche silicon detector concept is introduced with a low gain in the region of ten, known as a Low Gain Avalanche Detector, LGAD. The detector's characteristics are simulated via a full process simulation to obtain the required doping profiles which demonstrate the desired operational characteristics of high breakdown voltage (500 V) and a gain of 10 at 200 V reverse bias for X-ray detection. The first low gain avalanche detectors fabricated by Micron Semiconductor Ltd are presented. The doping profiles of the multiplication junctions were measured with SIMS and reproduced by simulating the full fabrication process which enabled further development of the manufacturing process. The detectors are 300 μm thick p-type silicon with a resistivity of 8.5 kΩcm, which fully depletes at 116 V. The current characteristics are presented and demonstrate breakdown voltages in excess of 500 V and a current density of 40 to 100 nAcm−2 before breakdown measured at 20oC. The gain of the LGAD has been measured with a red laser (660 nm) and shown to be between 9 and 12 for an external bias voltage range from 150 V to 300 V

Minimum requirements for feedback enhanced force sensing

The problem of estimating an unknown force driving a linear oscillator is revisited. When using linear measurement, feedback is often cited as a mechanism to enhance bandwidth or sensitivity. We show that as long as the oscillator dynamics are known, there exists a real-time estimation strategy that reproduces the same measurement record as any arbitrary feedback protocol. Consequently some form of nonlinearity is required to gain any advantage beyond estimation alone. This result holds true in both quantum and classical systems, with non-stationary forces and feedback, and in the general case of non-Gaussian and correlated noise. Recently, feedback enhanced incoherent force sensing has been demonstrated [Nat. Nano. \textbf{7}, 509 (2012)], with the enhancement attributed to a feedback induced modification of the mechanical susceptibility. As a proof-of-principle we experimentally reproduce this result through straightforward filtering.Comment: 5 pages + 2 pages of Supplementary Informatio

Explosion of white dwarfs harboring hybrid CONe cores

Recently, it has been found that off-centre carbon burning in a subset of intermediate-mass stars does not propagate all the way to the center, resulting in a class of hybrid CONe cores. Here, we consider the possibility that stars hosting these hybrid CONe cores might belong to a close binary system and, eventually, become white dwarfs accreting from a non-degenerate companion at rates leading to a supernova explosion. We have computed the hydrodynamical phase of the explosion of Chandrasekhar-mass white dwarfs harboring hybrid cores, assuming that the explosion starts at the center, either as a detonation (as may be expected in some degenerate merging scenarios) or as a deflagration (that afterwards transitions into a delayed detonation). We assume these hybrid cores are made of a central CO volume, of mass M(CO), surrounded by an ONe shell. We show that, in case of a pure detonation, a medium-sized CO-rich region, M(CO)<0.4 Msun, results in the ejection of a small fraction of the mantle while leaving a massive bound remnant. Part of this remnant is made of the products of the detonation, Fe-group nuclei, but they are buried in its inner regions, unless convection is activated during the ensuing cooling and shrinking phase of the remnant. In contrast, and somehow paradoxically, delayed detonations do not leave remnants but for the minimum M(CO) we have explored, M(CO)=0.2 Msun, and even in this case the remnant is as small as 0.13 Msun. The ejecta produced by these delayed detonations are characterized by slightly smaller masses of 56Ni and substantially smaller kinetic energies than obtained for a delayed detonation of a 'normal' CO white dwarf. The optical emission expected from these explosions would hardly match the observational properties of typical Type Ia supernovae, although they make interesting candidates for the subluminous class of SN2002cx-like or SNIax.Comment: Accepted for Astronomy and Astrophysics, 11 pages, 4 figure

Nematode control in suckler beef cattle over their first two grazing seasons using a targeted selective treatment approach

peer-reviewedBackground With concerns over the development of anthelmintic resistance in cattle nematode populations, we must re-examine our approach to nematode control in cattle. Targeted selective treatments (TST), whereby individual animals are treated instead of entire groups, are being investigated as an alternative. The study objective was to determine if anthelmintic usage could be reduced using a TST-based approach to nematode control in spring-born suckler beef cattle over their first and second grazing seasons (SGS) without affecting performance. In the first grazing season (FGS), 99 calves with an initial mean (s.d.) calf age and live weight on day 0 (June 28th 2012) of 107 (23.1) days and 160 (32.5) kg, respectively, were used. The study commenced on day 0 when calves were randomised and allocated to one of two treatments; 1), standard treatment (control) and 2), TST. Control calves were treated subcutaneously with ivermectin on days 0, 41 and 82 in the FGS. All calves were treated with ivermectin on day 124 and housed on day 133. In the SGS, only heifer calves from the FGS were used and control heifers were treated with ivermectin on day 393. Animals were weighed, blood and faecal sampled every three weeks. The TST animals were treated with ivermectin if thresholds based on a combination of plasma pepsinogen concentrations, faecal egg count and/or the presence of Dictyocaulus viviparus larvae in faeces (FGS only) were reached. Results No TST calves reached the treatment threshold criteria in the FGS. The FGS average daily live weight gain (ADG ± s.e.m.) for control and TST group calves was 0.89 ± 0.02 kg and 0.94 ± 0.02 kg day−1, respectively (P = 0.17). In the SGS, all heifers were treated with ivermectin on day 431 due to clinical signs of respiratory disease. The ADG for control and TST heifers from turnout on day 321 to day 431 was 0.90 ± 0.04 and 0.80 ± 0.04 kg day−1, respectively (P = 0.03). Conclusions Spring-born FGS suckler beef calves require minimal anthelmintic treatment to maintain performance. In contrast, clinical parasitic disease may develop in the SGS unless appropriate anthelmintic treatment is provided

Evolution and nucleosynthesis of helium-rich asymptotic giant branch models

There is now strong evidence that some stars have been born with He mass fractions as high as $Y \approx 0.40$ (e.g., in $\omega$ Centauri). However, the advanced evolution, chemical yields, and final fates of He-rich stars are largely unexplored. We investigate the consequences of He-enhancement on the evolution and nucleosynthesis of intermediate-mass asymptotic giant branch (AGB) models of 3, 4, 5, and 6 M$_\odot$ with a metallicity of $Z = 0.0006$ ([Fe/H] $\approx -1.4$). We compare models with He-enhanced compositions ($Y=0.30, 0.35, 0.40$) to those with primordial He ($Y=0.24$). We find that the minimum initial mass for C burning and super-AGB stars with CO(Ne) or ONe cores decreases from above our highest mass of 6 M$_\odot$ to $\sim$ 4-5 M$_\odot$ with $Y=0.40$. We also model the production of trans-Fe elements via the slow neutron-capture process (s-process). He-enhancement substantially reduces the third dredge-up efficiency and the stellar yields of s-process elements (e.g., 90% less Ba for 6 M$_\odot$, $Y=0.40$). An exception occurs for 3 M$_\odot$, where the near-doubling in the number of thermal pulses with $Y=0.40$ leads to $\sim$ 50% higher yields of Ba-peak elements and Pb if the $^{13}$C neutron source is included. However, the thinner intershell and increased temperatures at the base of the convective envelope with $Y=0.40$ probably inhibit the $^{13}$C neutron source at this mass. Future chemical evolution models with our yields might explain the evolution of s-process elements among He-rich stars in $\omega$ Centauri.Comment: 21 pages, 16 figures, accepted for publication by MNRAS. Stellar yields included as online data table

Genetic parameters for animal mortality in pasture-based, seasonal-calving dairy and beef herds

peer-reviewedIn the absence of informative health and welfare phenotypes, breeding for reduced animal mortality could improve overall health and welfare, provided genetic variability in animal mortality exists. The objective of the present study was to estimate genetic (and other) variance components for animal mortality in pasture-based, seasonal-calving dairy and beef herds across multiple life stages as well as to quantify the genetic relationship in mortality among life stages. National mortality records were available for all cattle born in the Republic of Ireland. Cattle were grouped into three life stages based on age (0 to 30 days, 31 to 365 days, 366 to 1095 days) whereas females with ≥1 calving event were also grouped into five life stages, based on parity number (1, 2, 3, 4, and 5), considering both the initial 60 days of lactation and a cow's entire lactation period, separately. The mean mortality prevalence ranged from 0.70 to 5.79% in young animals and from 0.53 to 3.86% in cows. Variance components and genetic correlations were estimated using linear mixed models using 21,637 to 100,993 records. Where heritability estimates were different from zero, direct heritability estimates for mortality in young animals (≤1095 days) ranged from 0.006 to 0.040, whereas the genetic standard deviation ranged from 0.015 to 0.034. The contribution of a maternal genetic effect to mortality in young animals was evident up to 30 days of age in dairy herds, but this was only the case in preliminary analysis of stillbirths in beef herds. Based on the estimated genetic standard deviation in the present study, the incidence of mortality in young animals could be reduced through breeding by up to 3.4 percentage units per generation. For cows, direct heritability estimates for mortality, where different from zero, ranged from 0.003 to 0.049. The genetic standard deviation for mortality in cows ranged from 0.005 to 0.016 during the initial 60 days of lactation and ranged from 0.011 to 0.032 during the cow's entire lactation. Genetic correlations among the age groups as well as between the age groups and cow parities had high standard errors. Genetic correlations among the cow parities were moderate to strongly positive (ranging from 0.66 to 0.99) and mostly different from zero. Results from the present study can be used to inform genetic evaluations for mortality in young animals and in cows as well as the potential genetic gain achievable