Quantum Degenerate Mixture of Ytterbium and Lithium Atoms

We have produced a quantum degenerate mixture of fermionic alkali 6Li and bosonic spin-singlet 174Yb gases. This was achieved using sympathetic cooling of lithium atoms by evaporatively cooled ytterbium atoms in a far-off-resonant optical dipole trap. We observe co-existence of Bose condensed (T/T_c~0.8) 174Yb with 2.3*10^4 atoms and Fermi degenerate (T/T_F~0.3) 6Li with 1.2*10^4 atoms. Quasipure Bose-Einstein condensates of up to 3*10^4 174Yb atoms can be produced in single-species experiments. Our results mark a significant step toward studies of few and many-body physics with mixtures of alkali and alkaline-earth-like atoms, and for the production of paramagnetic polar molecules in the quantum regime. Our methods also establish a convenient scheme for producing quantum degenerate ytterbium atoms in a 1064nm optical dipole trap.Comment: 4 pages, 3 figure

Sympathetic cooling in an optically trapped mixture of alkali and spin-singlet atoms

We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of 6Li by 174Yb and extract the s-wave scattering length magnitude |a6Li-174Yb| = (13 \pm 3)a0 from the rate of inter-species thermalization. Using forced evaporative cooling of 174Yb, we achieve reduction of the 6Li temperature to below the Fermi temperature, purely through inter-species sympathetic cooling.Comment: 4 pages, 3 figure

Ovine pedomics : the first study of the ovine foot 16S rRNA-based microbiome

We report the first study of the bacterial microbiome of ovine interdigital skin based on 16S rRNA by pyrosequencing and conventional cloning with Sanger-sequencing. Three flocks were selected, one a flock with no signs of footrot or interdigital dermatitis, a second flock with interdigital dermatitis alone and a third flock with both interdigital dermatitis and footrot. The sheep were classified as having either healthy interdigital skin (H), interdigital dermatitis (ID) or virulent footrot (VFR). The ovine interdigital skin bacterial community varied significantly by flock and clinical condition. The diversity and richness of operational taxonomic units was greater in tissue from sheep with ID than H or VFR affected sheep. Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria were the most abundant phyla comprising 25 genera. Peptostreptococcus, Corynebacterium and Staphylococcus were associated with H, ID and VFR respectively. Sequences of Dichelobacter nodosus, the causal agent of ovine footrot, were not amplified due to mismatches in the 16S rRNA universal forward primer (27F). A specific real time PCR assay was used to demonstrate the presence of D. nodosus which was detected in all samples including the flock with no signs of ID or VFR. Sheep with ID had significantly higher numbers of D. nodosus (104-109 cells/g tissue) than those with H or VFR feet

Comparison of Digital Filter Hydrograph Separation with Geochemical Separation

Proceedings of the 2013 Georgia Water Resources Conference, April 10-11, 2013, Athens, Georgia.Aquatic Stormflow is defined as flow resulting directly from a storm event, while baseflow is thought to be groundwater flow that continuously occurs, most predominantly during non-storm periods. While conceptually these concepts are convenient, it is difficult to ascertain the actual flow paths of each component. In this paper we will compare common digital filters used to estimate baseflow with a geochemically derived baseflow separation. A Dynamic End Member Mixing Analysis (DEMMA) on Panola Mountain, Georgia was used by Cary (2011) to separate four stream flow components using naturally occurring chemical tracers for 22 storm events. DEMMA relies on intensive runoff and chemical sampling, and uses the flow and chemistry hysteresis to separate the hydrograph. Several digital filters were compared to the DEMMA hydrographs. While parameterized differently, each was a recursive procedure that acts as a low pass filter. In general the digital filters over estimate true baseflow for Panola (that is, true groundwater flow), and more closely resemble contributions from subsurface flow (that is soil) pathways. The one parameter filters are insensitive to calibration, although simple to use because the parameter is usually not modified. The two parameter filter (Eckhardt, 2005) was more robust in its range, but sensitive to calibration. This research provides some insight into the flow paths the digital filters may be approximating.Sponsored by: Georgia Environmental Protection Division; U.S. Department of Agriculture, Natural Resources Conservation Service; Georgia Institute of Technology, Georgia Water Resources Institute; The University of Georgia, Water Resources Faculty.This book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

United States Bureau of Mines Bulletin 5259

Report issued by the Bureau of Mines over investigations of coking-coal reserves of Logan County, West Virginia. Methods used, and measurements of coal reserves are listed. This report includes tables, and maps

The effects of diffuseness and deep perforating artery supply on outcomes after microsurgical resection of brain arteriovenous malformations

OBJECTIVE: Diffuse arteriovenous malformations (AVM) have non-compact niduses, irregular margins, and intervening brain parenchyma. Deep perforating arteries often contribute to the ragged border of these diffuse AVMs. We hypothesized that diffuseness and deep perforator supply increase the difficulties and risks associated with microsurgical AVM resection. METHODS: Diffuseness was quantified using computer-generated outlines of AVMs on angiograms, contour plots with varying image intensities, and calculations of nidus area-intensity profiles. Diffuse AVMs had nonlinear area-intensity profiles with high transition intensities ([I*] greater than 0.5). A consecutive series of 304 patients who were treated with microsurgical AVM resection over a period of 7.8 years was analyzed, along with quantification of diffuseness in a subset of 103 consecutive patients. Neurological outcomes were assessed by using the Modified Rankin Scale, and logistic regression analysis was used to identify predictors of deterioration and poor outcome at late follow-up evaluation. RESULTS: Diffuse niduses were observed in 25% of patients, and 18% of patients had deep perforating artery supply. Patients with compact AVMs were more likely to have good outcomes or overall improvement (88 and 87%, respectively) than patients with diffuse AVMs (65 and 54%, respectively) (P = 0.008 and P \u3c 0.001, respectively). Similarly, absence of deep perforator supply was associated with good outcomes or improvement in 85 and 78% of patients, respectively, compared with 63 and 64% of patients, respectively, in patients with deep perforator supply (P \u3c 0.001 and P = 0.028, respectively). By logistic regression analysis, diffuseness and deep perforator supply were both associated with significant increases in surgical risk. CONCLUSION: Diffuseness and deep perforating artery supply are subtle features of an AVM that predict worse outcomes after microsurgical resection. Diffuseness makes surgical planes more difficult to determine and follow, whereas deep perforators are friable, poorly visualized, and located in eloquent white matter tracts. The Spetzler-Martin grading scale does not directly account for these two features; however, they should be considered carefully when making treatment recommendations to patients with AVMs. Copyright © by the Congress of Neurological Surgeons

United States Bureau of Mines Bulletin 5068

Report issued by the Bureau of Mines over investigations of coking-coal reserves of Mingo County, West Virginia. Methods used, and measurements of coal reserves are listed. This report includes tables, and maps

Reliable growth estimation from mark–recapture tagging data in elasmobranchs

The somatic growth of individuals governs many aspects of a species’ life history and is an important parameter in the assessment of populations. Population growth parameters are typically derived by relating the length of individuals to their age, with ages commonly estimated from growth bands formed in calcified structures such as the vertebrae or dorsal fin spines. However, routinely utilized vertebrae aging methods may not be reliable for many elasmobranchs (sharks, rays and skates), motivating alternative approaches. This study evaluates the performance of seven techniques that estimate von Bertalanffy growth parameters from mark-recapture tagging data. Evaluation of the performance was done by applying each estimation technique to: 1) simulated error-free mark-recapture tagging data and comparing the estimated versus known simulated growth parameters; 2) simulated mark-recapture data considering individual growth variability, measurement error, different length-at-capture distributions, as well as different sample sizes and comparing the estimated versus known simulated growth parameters; and 3) mark-recapture data of 14 North Atlantic elasmobranch stocks and discussing the estimated growth parameters with respect to biological plausibility and conventional length-at-age data. All investigated estimation techniques returned the known simulated growth parameters when the data is without error. When errors are introduced in the simulation, Bayesian implementations of Fabens' (BFa) and Francis’ (BFr) methods were found to be most reliable. For the observed mark-recapture data only BFa gave biologically plausible results for all 14 elasmobranch stocks. Overall, the results suggest that BFa is a reliable alternative to conventional length-at-age methods for estimating growth parameters, especially in data-limited situations which commonly occur with elasmobranchs. The only prior information needed is limited expert knowledge on maximum length in the population or stock in question. A user guide is provided to facilitate application of the method.ISSN:0165-783