80 research outputs found
Designing Engagement for Academic Libraries
This article discusses ways to engage library users and non-users, from small tweaks to large-scale efforts. The librarian authors share their successes and lessons learned. Topics covered include library events, workshops, and passive programming. The benefits of making changes include fostering relationships and encouraging participation among library visitors to educate, entertain, and include
Investigations of soil extractable aluminium and toxicity in New Zealand soils : A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Lincoln University
Soil acidity and associated soil aluminium (Al) toxicity severely restrict the establishment, yield and persistence of legumes in New Zealand high and hill country pastures. There is an urgent need to identify soils which are most susceptible to Al toxicity and to determine what factors are involved in regulating soil extractable Al concentrations. This study investigated the relationship between soil chemical, physical and environmental variables and soil extractable Al for New Zealand soils in national, catchment and rhizosphere contexts.
The relationship between soil chemical, physical and environment variables and soil extractable AlKCl were investigated using the National Soils Database (NSD). Base saturation (BS), soil pHH2O, cation exchange capacity (CEC), total nitrogen, total carbon and soil order were strongly associated with AlKCl concentrations and relationships differed among the depth zones (0-20 cm, 20-50 cm and 50-120 cm). Soil acidity and high CEC contributed to high AlKCl concentrations, whereas a high BS and total C had a negative effect. Total N decreased with increasing AlKCl in the top 20 cm, likely as a response to Al toxicity induced limitations on biological N fixation by pasture legumes. An AlKCl concentration > 1.0 cmolc/kg, which can be toxic to sensitive plants, occurred across a pHH2O range of 3.8-6.4. Brown Soils and Podzols had the highest mean AlKCl concentrations across all depths and are likely to be more susceptible to Al toxicity.
A soil survey in the Ashburton Lakes catchment was conducted to determine which soils are most susceptible to Al toxicity and to identify which factors drive soil pHH2O and extractable AlCaCl2 at a
landscape scale. Depth in the soil profile was the strongest explanatory variable for pHH2O and AlCaCl2. Soil pHH2O increased with depth and AlCaCl2 declined. Rainfall and age were significant factors for AlCaCl2, however, there were no systematic patterns of an increase in AlCaCl2 with increasing rainfall and soil age. Differences in pHH2O among landform types were found, in contrast to no difference in AlCaCl2 concentrations. The soil pHH2O ranged from 4.7-6.0 and AlCaCl2 concentrations from 1.2 mg kg-1 to 39.1 mg kg-1, with a mean of 7.8 mg kg-1. Maps of soil pHH2O and AlCaCl2 in the 20 cm depth zone were constructed using the rules established by decision trees. Distinct areas in the landscape were identified which had higher concentrations of AlCaCl2. Higher AlCaCl2 concentrations were found at the wettest sites in the catchment (≥1266 mm), areas that seem to mirror those that were identified as most acidic in the soil pHH2O map.
The growth response and nutrient uptake of legumes (Medicago sativa L. and Trifolium ambiguum L.) as bioindicators of Al toxicity were assessed in a range of acidic soils in a glasshouse experiment. Soil extractable AlCaCl2 concentration was strongly associated with lucerne shoot yields. Lucerne shoot yield increased one to six fold with lime application, particularly between the L0P0 and 2 t lime ha-1 treatments. Yield increases were strongly associated with declines in the soil extractable AlCaCl2 concentration to below toxic levels (≤2.5 mg kg-1) and clearly demonstrated the severe plant growth restriction of Al toxicity in these high country soils. On most soils lucerne shoot yields responded more to lime than P applied. In contrast, Caucasian clover (CC) shoot yields were not affected by soil extractable Al concentration, with more consistent yields across the range of pHH2O (5.0-7.5) and the P rates applied than lucerne. This study clearly highlights the potential importance of CC use in the high country, where the growth of more sensitive species such as lucerne is restricted by Al toxicity.
The plant effect on Al mobilisation and immobilisation at the root-soil interface and the effects of pHH2O were investigated in a rhizobox experiment with legumes (Lupinus polyphyllus L. and Medicago sativa L.) in an acidic high country soil. The pHH2O was more acidic (0.1- 0.3 pH units lower) and AlCacl2 concentrations were higher (0.5 mg kg-1 and 5.4 mg kg-1) in the rhizosphere of lupin plants compared to the bulk soil. Lucerne plants had a similar soil pHH2O between the bulk and rhizosphere. Hot water extractable organic carbon levels appeared to be consistently higher in the rhizosphere and seemed to increase at the highest lime application. DGT data showed increased mobilisation of Al at the root tip of lupin and depletion along the root axis, indicative of previous removal of Al by the plant from the soil. This is the first study that has shown, in high resolution using DGT and LA-ICP-MS analysis, distinct patterns of soil Al mobilisation induced by the roots of important pasture species.
A laboratory investigation was conducted to determine if changing the molarity and extraction time of the standard CaCl2 and KCl soil Al tests altered the Al concentrations extracted. Overall, the Al concentration extracted by the KCl standard test was 16 times higher than the CaCl2 across all soils. The effect of molarity and extraction time on the Al concentrations extracted differed among the five soils tested for the two extraction methods. For the CaCl2 test, the extractable Al concentration increased (P0.05) with a further increase in molarity. For two of the soils, the Al extracted was significantly affected by the extraction time, however, the results were contrasting. On most soils the interaction of molarity and extraction time extracted significantly different concentrations of AlKCl. These findings suggest that the Al concentrations measured by the two extraction methods are affected by specific soil properties in the topsoil related to soil order.
This research has identified key variables driving soil extractable Al concentrations in a suite of New Zealand soils, and at different scales. Legume species responded differently to soil extractable AlCaCl2 and influenced pH and the amount of soil Al in the rhizosphere. Soil properties of different soil orders were also found to affect the amount of Al extracted from the soil by the two CaCl2 and KCl extraction methods. The knowledge generated from this thesis has identified specific sets of conditions (environmental, soil chemical and soil order) that have higher concentrations of extractable Al and therefore areas most likely to be susceptible to Al toxicity in New Zealand
Implementation of a Differentiated Instruction Initiative: Perspectives of Leaders
Differentiated Instruction (DI) is a framework that supports planning for diversity within K-12 classrooms. Research has grown steadily over the past 15 years that explores DI implementation, as well as beliefs and practices. Literature to date has focused heavily on the experiences of educators, with limited attention given to the role of leadership in implementing DI in schools. The current study explores the perspectives of 19 school and board-level administrators regarding the ways in which a differentiated instruction framework was implemented within their school board as well as facilitators and barriers to the implementation and uptake of the framework. Interviews revealed five themes: a) DI continuum, b) differentiated professional learning supports, c) making space for shared professional learning, d) align/integrate/embed, and e) multi-level leadership. Our findings reflect a strong belief system of most of the participants with respect to the foundations of DI as well as an understanding of effective approaches to professional learning and school change. 
Relocation of the Salvador Camarena Burial: Historical and Bioarcheological Investigations of a Mexican Migrant Worker Grave (41MV372) in Maverick County, Texas
F rom 2011 through 2014, the Texas Department of Transportation collaborated with Prewitt and Associates, Inc., to investigate an isolated grave in a remote area alongside FM 481 in Maverick County, Texas. An initial archeological investigation confirmed that the location was a historic grave, and archival records revealed that it contained the remains of Salvador Camarena, a Mexican citizen who died in Texas in January 1950. Additional research identified Camarena’s son and other family members living in Mexico, California, and Texas. With the family’s permission, the burial remains were exhumed, examined, and reinterred at La Marque Cemetery in Galveston County, Texas, where Camarena’s mother and two sisters are buried.
The bioarcheological analysis of the skeletal remains corroborates the historical information. Together, the bioarcheological and historical data provide a rare glimpse into the life and death of a migrant laborer. The burial of one immigrant worker may seem insignificant. However, the Camarena case represents a sad but common theme in the history of migrant labor. Like many before him and even more since, Camarena probably died in a foreign country seeking a means to support his family when traveling to seasonal agricultural work
Extractable aluminium in New Zealand Andisols and Inceptisols
It is critical to have a soil test that allows for the measurement of potential toxicity. A laboratory experiment was undertaken to investigate the effects of changing the concentration of salt in the extract and extraction time of the standard CaCl₂ and KCl soil Al tests on the Al concentrations extracted from 13 soils from four New Zealand soil orders. Al extracted by KCl (AlKCl) was 13 times higher than extracted by CaCl₂ (AlCaCl2) across all soils. The effect of changing extract salt concentration and extraction time on Al extracted differed among the four soil orders tested for the two extraction methods. Increasing the concentration of CaCl₂ in the extract increased (P .05) the AlCaCl2 extracted from all soils. An increase in the concentration of KCl in the extract up to 1 M increased AlKCl (P .05) with a further increase in concentration. Extraction time affected AlKCl (P < .001) for Pallic soils, while the interaction of concentration of KCl in the extract and extraction time resulted in differences (P < .001) only for the Pallic soils. These findings suggest that the Al concentrations measured by the two extraction methods are affected by specific soil properties in the topsoil related to soil order. This means that when measuring the Al bioavailability in soils, extreme care must be taken when interpreting soil Al test results
Theoretical and experimental investigation of the equation of state of boron plasmas
We report a theoretical equation of state (EOS) table for boron across a wide
range of temperatures (5.110-5.210 K) and densities
(0.25-49 g/cm), and experimental shock Hugoniot data at unprecedented high
pressures (5608118 GPa). The calculations are performed with full,
first-principles methods combining path integral Monte Carlo (PIMC) at high
temperatures and density functional theory molecular dynamics (DFT-MD) methods
at lower temperatures. PIMC and DFT-MD cross-validate each other by providing
coherent EOS (difference 1.5 Hartree/boron in energy and 5% in pressure)
at 5.110 K. The Hugoniot measurement is conducted at the National
Ignition Facility using a planar shock platform. The pressure-density relation
found in our shock experiment is on top of the shock Hugoniot profile predicted
with our first-principles EOS and a semi-empirical EOS table (LEOS 50). We
investigate the self diffusivity and the effect of thermal and pressure-driven
ionization on the EOS and shock compression behavior in high pressure and
temperature conditions We study the performance sensitivity of a polar
direct-drive exploding pusher platform to pressure variations based on
comparison of the first-principles calculations with LEOS 50 via 1D
hydrodynamic simulations. The results are valuable for future theoretical and
experimental studies and engineering design in high energy density research.
(LLNL-JRNL-748227)Comment: 12 pages, 9 figures, 2 table
Feasibility of Frequent Patient-Reported Outcome Surveillance in Patients Undergoing Hematopoietic Cell Transplantation
Patient-reported outcomes (PROs), including symptoms and health-related quality of life (HRQOL), provide a patient-centered description of hematopoietic cell transplantation (HCT)-related toxicity. These data characterize the patient experience after HCT and may have prognostic usefulness for long-term outcomes after HCT. We conducted a study of 32 patients after HCT (10 autologous HCT recipients, 11 full-intensity conditioning allogeneic HCT recipients, and 11 reduced-intensity conditioning allogeneic HCT recipients) to determine the feasibility of weekly electronic PRO collection from HCT until day (D) + 100. We used questions from the PRO version of the Common Terminology Criteria for Adverse Events to capture symptoms, and the Patient-Reported Outcomes Measurement Information System Global Health scale to measure physical and mental HRQOL. The vast majority (94%) of patients used the electronic PRO system, with only 6% opting for paper-and-pencil only. The median weekly percentage of participants who completed the surveys was 100% in all cohorts through hospital discharge, and remained 100% for the autologous HCT and reduced-intensity allogeneic HCT cohorts through D+100. Patients were satisfied with the electronic system, giving high marks for readability, comfort, and questionnaire length. Symptom severity varied by absolute level and type of symptom across the 3 cohorts, with the full-intensity allogeneic HCT cohort exhibiting the greatest median overall symptom severity, peaking at D+7. Median physical health HRQOL scores decreased with time in the 3 cohorts, and HRQOL was generally correlated with overall symptom severity. Our results demonstrate the feasibility of frequent electronic PROs in the early post-HCT period. Future studies in larger populations to explore predictive models using frequent PRO data for outcomes, including long-term HRQOL and survival, are warranted
Equation of state of warm-dense boron nitride combining computation, modeling, and experiment
The equation of state (EOS) of materials at warm dense conditions poses
significant challenges to both theory and experiment. We report a combined
computational, modeling, and experimental investigation leveraging new
theoretical and experimental capabilities to investigate warm-dense boron
nitride (BN). The simulation methodologies include path integral Monte Carlo
(PIMC), several density functional theory (DFT) molecular dynamics methods
[plane-wave pseudopotential, Fermi operator expansion (FOE), and spectral
quadrature (SQ)], activity expansion (ACTEX), and all-electron Green's function
Korringa-Kohn-Rostoker (MECCA), and compute the pressure and internal energy of
BN over a broad range of densities () and temperatures (). Our
experiments were conducted at the Omega laser facility and measured the
Hugoniot of BN to unprecedented pressures (12--30 Mbar). The EOSs computed
using different methods cross validate one another, and the experimental
Hugoniot are in good agreement with our theoretical predictions. We assess that
the largest discrepancies between theoretical predictions are 4% in pressure
and 3% in energy and occur at K. We find remarkable consistency
between the EOS from DFT calculations performed on different platforms and
using different exchange-correlation functionals and those from PIMC using
free-particle nodes. This provides strong evidence for the accuracy of both
PIMC and DFT in the warm-dense regime. Moreover, SQ and FOE data have
significantly smaller error bars than PIMC, and so represent significant
advances for efficient computation at high . We also construct tabular EOS
models and clarify the ionic and electronic structure of BN over a broad
range and quantify their roles in the EOS. The tabular models may be
utilized for future simulations of laser-driven experiments that include BN as
a candidate ablator material.Comment: 19 pages, 14 figures, 4 table
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