831 research outputs found

    Plurigaussian Simulation of rocktypes using data from a gold mine in Western Australia

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    Stochastic simulation of rocktypes, or the geometry of the geology, is a major area of continuing research as earth scientists seek a better understanding of an orebody as a precursor to the assignment of continuous rock properties, allowing more economically appropriate decisions regarding mine planning. This thesis analyses the suitability of particular geostatistical rock type modelling algorithms when applied to the five rocktypes evident in drill hole data from the Big Bell gold mine near Cue, Western Australia. The background of the geostatistical theory is considered, in particular the concept of the random function model and the link between the categorical statistics determined from the drill hole data and the three models used for estimation and simulation. The commonly applied indicator kriging (IK) and sequential indicator simulation (SIS) algorithms are compared in a non-sedimentary gold deposit environment to the more computationally demanding and more complex plurigaussian simulation (PGS). Comparisons between the three models are made by examining global and regional rocktype (lithotype) proportions of the outputs of the models, both visually and empirically. The models are validated by considering the contacts which occur in reality between different lithotypes and the proportion of contacts which do not conform to this reality in each of the models. This „inadmissible contact‟ ratio measures the short range validity of the estimation and simulation techniques. Finally, cores taken from the output of the models are compared to the drill hole data in terms of transition proportions between the twenty five possible transitions for the five lithotypes. Inadmissible contacts were at a minimum with PGS, and the visual and empirical natures of the PGS output were closely linked to the reality of the drill hole data. Whilst each model produced similar 3D images, PGS was a realistic balance between the clustering effect produced by IK and the fine mosaic effect from SIS. The PGS output numerically outperformed the other two models in terms of admissible contacts and connectivity, most closely matching the drill hole data. All results indicate that, whilst demanding to implement, PGS produces the most adequate model of the study region

    Teaching Law Students Through Individual Learning Styles

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    (Excerpt) Teaching can be rewarding, but it can also be frustrating when some students fail to grasp the material. Professor Robin A. Boyle of St. John’s University School of Law has been teaching Legal Research and Writing in small sections of approximately twenty to thirty students for four years. She, like many of her similarly exasperated colleagues, has repeated the same course content by using either lecture or collaborative learning, and has observed some students doing well, whereas others continued to perform poorly. Then, Dr. Rita Dunn was introduced to the law school faculty and suggested that law professors incorporate learning-styles theory into their lesson plans to accommodate students with diverse learning styles. Suddenly, there was light in the tunnel

    A Public Health Approach to Uncovering the Health-Related Needs of Teen Library Patrons

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    Widespread problems with health literacy significantly limit effective dissemination and understanding of health information, particularly among vulnerable populations. As libraries are re-envisioned as community centers and resource providers, librarians are well positioned to help patrons overcome health literacy challenges by helping them to search for and use health information. Librarians often have not had health reference training, and some are unsure of the appropriateness of their role in patrons’ health. This study presents the results of a health needs assessment done in collaboration between the Teen Services Department of a major urban library and faculty from a state university. Using survey and focus group data, the research team sought to uncover the most common health-related needs among community teens as perceived by teen services librarians and staff, preparedness to respond to these needs, and interventions in addressing these needs. Findings confirm that some teens do turn to branch libraries for health information. Additional results revealed which types of health-related questions participants felt most equipped to answer (social health) and least equipped (substance abuse) and indicate staff have had altogether little formal training to address patrons’ health questions. This needs assessment presents replicable tools and questions for libraries aiming to improve health literacy in their local communities

    Analysis of the paleomagnetism and rock magnetism of the Surco Intrusion, Peru: an attempt to obtain a Southern Hemisphere reversal record

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    Investigation of the Surco pluton, a granodioritic body approximately 12 km in diameter and age 20 Ma, located near Lima, Peru, was initiated in order to obtain a geomagnetic reversal record. More than 300 samples provide a complete section through the intrusion. Preliminary results obtained using conventional paleomagnetic techniques indicate that the western part of the pluton records the ambient field behavior well; a consistent reversed direction is followed by a partial reversed to normal transition as one progresses into the core of the intrusion. Plots of NRM vs. IRM(S) demagnetization indicate a steady decrease in the geomagnetic field intensity prior to the reversal. The intrusion does not appear to have recorded the recovery of the normal intensity after the reversal. The existence of a complete section through the intrusion permitted, in principle, the observation of a symmetrical record of the reversal from each side of the pluton. However, the results from the eastern Surco section present a confusing picture and reveal significant variations in rock magnetic and remanence properties along section. Magnetic properties of mineral separates were studied in an attempt to understand variability in the rock as a paleomagnetic recorder. In general, the feldspars contain an unstable magnetization, while the mafic minerals hold a more stable magentization. In the eastern Surco, there are considerable variations in their magnetic properties

    The chicken type III GnRH receptor homologue is predominantly expressed in the pituitary, and exhibits similar ligand selectivity to the type I receptor

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    Two GnRH isoforms (cGnRH-I and GnRH-II) and two GnRH receptor subtypes (cGnRH-R-I and cGnRH-R-III) occur in chickens. Differential roles for these molecules in regulating gonadotrophin secretion or other functions are unclear. To investigate this we cloned cGnRH-R-III from a broiler chicken and compared its structure, expression and pharmacological properties with cGnRH-R-I. The broiler cGnRH-R-III cDNA was 100% identical to the sequence reported in the red jungle fowl and white leghorn breed. Pituitary cGnRH-R-III mRNA was ∌1400-fold more abundant than cGnRH-R-I mRNA. Northern analysis indicated a single cGnRH-R-III transcript. A pronounced sex and age difference existed, with higher pituitary transcript levels in sexually mature females versus juvenile females. In contrast, higher expression levels occurred in juvenile males versus sexually mature males. Functional studies in COS-7 cells indicated that cGnRH-R-III has a higher binding affinity for GnRH-II than cGnRH-I (Kd: 0·57 vs 19·8 nM) with more potent stimulation of inositol phosphate production (ED50: 0·8 vs 4·38 nM). Similar results were found for cGnRH-R-I, (Kd: 0·51 vs 10·8 nM) and (ED50: 0·7 vs 2·8 nM). The initial rate of internalisation was faster for cGnRH-R-III than cGnRH-R-I (26 vs 15·8%/min). Effects of GnRH antagonists were compared at the two receptors. Antagonist #27 distinguished between cGnRH-R-I and cGnRH-R-III (IC50: 2·3 vs 351 nM). These results suggest that cGnRH-R-III is probably the major mediator of pituitary gonadotroph function, that antagonist #27 may allow delineation of receptor subtype function in vitro and in vivo and that tissue-specific recruitment of cGnRH-R isoforms has occurred during evolution

    Criminal Law and Procedure

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    This Article surveys recent developments in criminal procedure and law in Virginia. Because of space limitations, the authors have limited their discussion to the most significant published appellate decisions and legislation

    Patterns of depredation in the Hawai‘i deep-set longline fishery informed by fishery and false killer whale behavior

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    False killer whales (Pseudorca crassidens) depredate bait and catch in the Hawai‘i-based deep-set longline fishery, and as a result, this species is hooked or entangled more than any other cetacean in this fishery. We analyzed data collected by fisheries observers and from satellite-linked transmitters deployed on false killer whales to identify patterns of odontocete depredation that could help fishermen avoid overlap with whales. Odontocete depredation was observed on ˜6% of deep-set hauls across the fleet from 2004 to 2018. Model outcomes from binomial GAMMs suggested coarse patterns, for example, higher rates of depredation in winter, at lower latitudes, and with higher fishing effort. However, explanatory power was low, and no covariates were identified that could be used in a predictive context. The best indicator of depredation was the occurrence of depredation on a previous set of the same vessel. We identified spatiotemporal scales of this repeat depredation to provide guidance to fishermen on how far to move or how long to wait to reduce the probability of repeated interactions. The risk of depredation decreased with both space and time from a previous occurrence, with the greatest benefits achieved by moving ˜400 km or waiting ˜9 d, which reduced the occurrence of depredation from 18% to 9% (a 50% reduction). Fishermen moved a median 46 km and waited 4.7 h following an observed depredation interaction, which our analysis suggests is unlikely to lead to large reductions in risk. Satellite-tagged pelagic false killer whales moved up to 75 km in 4 h and 335 km in 24 h, suggesting that they can likely keep pace with longline vessels for at least four hours and likely longer. We recommend fishermen avoid areas of known depredation or bycatch by moving as far and as quickly as practical, especially within a day or two of the depredation or bycatch event. We also encourage captains to communicate depredation and bycatch occurrence to enable other vessels to similarly avoid high-risk areas
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