Preliminary estimates of mass-loss rates, changes in stable isotope composition, and invertebrate colonisation of evergreen and deciduous leaves in a Waikato, New Zealand, stream.

Rates of mass loss are important in the choice of tree species used in riparian rehabilitation because leaves that break down fast should contribute to stream food-webs more rapidly than leaves that break down more slowly. To examine comparative mass-loss rates of some native evergreen and introduced deciduous trees in a New Zealand stream, fallen leaves were incubated in bags with 2 x 3 mm mesh openings. The native trees were mahoe (Melicytus ramiflorus), kahikatea (Dacrycarpus dacrydioides), silver beech (Nothofagus menziesii), rewarewa (Knightia excelsa), tawa (Beilschmiedia tawa), and the introduced trees were silver birch (Betula pendula) and alder (Alnus glutinosa). The leaf bags were left in the Mangaotama Stream for 28 days from mid April to mid May 1995 when mean water temperature was 14.5deg.C, giving a total of 406 degree days. Rates of mass loss followed the sequence: mahoe > silver birch > alder > kahikatea > silver beech > rewarewa > tawa. Mean mass-loss rate for mahoe, assuming a negative exponential model, was 0.0507 k day-1 (0.00350 k (degree day)-1), and for tawa was 0.0036 k day-1 (0.00025 k (degree day)-1). C:N ratio decreased on average from 45:1 to 35:1, and d15N increased between 0.7 and 3.0[[perthousand]] (1.8 +/- 0.41[[perthousand]], mean +/-1 standard error), excluding kahikatea. Changes in d13C were smaller and not consistent in direction. Biomass of invertebrates was greatest in bags that had lost 25-45% of their initial leaf biomass

Gracefully Unexpected, Deeply Present and Positively Disruptive: Love and Queerness in Classroom Community.

During the winter of 2011, I was moving through some of the more overtly physical phases of gender transition. At the time, I was also a grade 6 teacher in a public elementary school. My presence as a visibly transitioning person in that environment was never intended to be a coming out; it was a choosing in… and there is a difference. I was “out” because I was visibly different, and I was visible because that difference was not expected. I - as a teacher of young children who identifies as a non-binary person, as genderqueer, as trans, and even as someone who is not willing to be ashamed of all that – was not expected. Well-intended and well-documented antidiscrimination policies defended my right to be an educator in theory, but there remained a distinct lack of people and/or practices in place that could help me to feel more welcomed in that role – or even less alone. I think that the less visible aspects of how we identify ourselves as humans are often labeled “secrets” when they are not expected, and considering that the keeping of secrets is often conflated with a rationale that encourages people to feel shame, social institutions have become very efficient at silencing unexpected differences as a matter of course

A Tribute to Arthur Krause: Delivered at Kent State, May 4, 1989

An essay in honor of Arthur Krause, father of Kent State shooting victim Allison Krause

Ecological and physical characteristics of the Te Awa O Katapaki Stream, Flagstaff, Waikato

1. The fish, macroinvertebrates, aquatic vegetation, and water quality indicate that the Te Awa O Katapaki Stream is an unpolluted, pastureland stream that is typical of the Waikato region. 2. The stream has very high nutrient concentrations that probably result from the dairy farming upstream. 3. The fish fauna is dominated by the native shortfinned eels. The presence of the migratory common smelt indicates that swimming fish species also have free access to the stream from the Waikato River. 4. Fish of high conservation value, such as giant or banded kokopu (Galaxias argenteus or G. fasciatus) were absent, which is predictable given the warm, unshaded nature of the stream. 5. Fish and invertebrates would soon recolonise the restored stream following any work in the streambed

On polarization of vector light beams: origin of Berry phase

When generalized from plane waves to general vector beams, the notion of polarization described by the Stokes parameters turns out to be defined in a momentum-associated system that is fixed by the so-called Stratton vector. As the true intrinsic degree of freedom in the language of quantum mechanics, the polarization of light beams in any fixed momentum-associated system is able to characterize their vectorial feature in the laboratory reference system. The Stratton vector is therefore the degree of freedom to distinguish the vectorial feature of light beams that have the same "polarization". Such an observable effect of the Stratton vector helps to understand why plane waves of the same helicity and the same momentum can be different by a Berry phase. This might be the first time to reveal the physical origin of the Berry phase.Comment: 13 pages and 1 figure. A discussion about the relation between the Poincar\'e vectors in different MAS's is adde

Schumpeterian Churn Dynamics And Re-gional Productivity Performance

This study tests empirically the Schumpeterian premise that the incessantturbulence of an economy in motion, apart from a production function comprised of static inputs, is capable of explaining patterns of economic growth and change. Localized employment churn"registered as job creation/destruction dynamics isused to account forvariations in U.S. metro-regional economic productivity performancesduring the 1986-99 period. The empirical results suggest that employment turnover and replacementdynamics have large and significant positive effects on localized productivity growth independent of a variety of industrial restructuring processes occurring simultaneously. While employment churn effectsare robust across U.S. Census regions, they do not exert a uniform influence on metro-regional productivity performances across time. Until 1996, job creation and destruction dynamics often canceled each other out as metro-regions underwent continued industrial restructuring. Since 1996, however, the positive effects on metro-region productivity growth have been consistently strong. In addition toa strong positiveeffect on productivity of the emergence of a localized IT sector, both an expanding service sector share of regional employment and a rising public spending share of regional outputexert powerful downward pressure on productivity growth rates

Amyloid Beta peptide's effects on NMDA receptors in PC-12 cells

Abstract only availableAmyloid-Beta peptide (Aß), a causative agent in Alzheimer's disease (AD), is known to deposit on cell membranes, disrupt cell functions, and induce cytotoxic effects including over-production of reactive oxygen species (ROS) and disruption of calcium homeostasis. In this project we develop an immortalized neuronal-like cell line (PC-12 cells) for studies of the complex interaction of Aß with neuronal cell membranes, proteins, and signaling pathways relevant to AD. When stimulated with Nerve Growth Factor, PC12 rat pheochromocytoma cells acquire a neuronal phenotype, and unlike primary cells may be passed indefinitely, allowing investigators convenient continuous study of neuronal pathways relevant to AD. In addition to development of PC12 cells for study of AD related pathways, we investigate how local membrane physical property changes induced by oligomeric Amyloid-Beta 1-42(Aß42) impact on primary functions of membrane proteins, including the N-methyl D-aspartate receptor (NMDA-R) and NADPH oxidase. A better understanding of this complex pathway may provide insight into the development of new therapies for the treatment of AD.College of Engineering Undergraduate Research Optio

Amyloid-beta peptide induces time dependent biphasic change of membrane phase properties in DITNC cells [abstract]

Abstract only availableAmyloid-beta peptide (Aβ) has been widely implicated in the pathogenesis of Alzheimer's disease (AD). In AD patients amyloid plaques accumulate extensively in the brain, a pathological archetype of the disease. To elucidate one pathway that contributes to AD dysfunction, we demonstrate that oligomeric Aβ1-42 alters the membrane phase properties of DITNC cells time-dependently, with the phase change made quantifiable through fluorescence microscopy and GP analysis. Initially, after oligomeric Aβ1-42 treatment the phase properties became more liquid-crystalline, and subsequently, after 2-3 hours the phase became more gel-like. However, in lipid vesicles the change in membrane phase properties wasn't biphasic; the phase became only more liquid-crystalline, indicating the role of cell signaling in the phenomenon. Western blot analysis demonstrated the ability of oligomeric Aβ1-42 to increase levels of phosphorylated cPLA2 on a time scale corresponding to the observed change in membrane phase, implicating cPLA2 as a likely contributor to the liquid-crystalline to gel transition, with its activation and translocation to the membrane likely the cause of the specific time frame associated with the liquid-crystalline to gel transition. Co-treatment of oligomeric Aβ1-42 with MAFP, an inhibitor of iPLA2 and cPLA2 caused the membrane to become only more liquid crystalline, while oligomeric Aβ1-42 + BEL, a specific inhibitor of iPLA2, resulted in the previously observed biphasic transition, eliminating iPLA2 as a contributor to the phenomenon. Additionally, Aβ1-42 + Apocynine, an antioxidant, caused the membrane to become only more liquid crystalline, which more specifically revealed oligomeric Aβ1-42 triggers the activation of cPLA2 through ROS generation, likely through NADPH oxidase, activating the MAPK cascade. Evaluating the effect of oligomeric Aβ1-42 on membrane phase properties provides a different view of a widely implicated pathogen in AD, revealing that it acts both to immediately cause the membrane to become more liquid-crystalline, while triggering cPLA2 to change the membrane phase to gel-like over time.College of Engineering Undergraduate Research Optio

Visualization of flows in a motored rotary combustion engine using holographic interferometry

The use of holographic interferometry to view the small- and large-scale flow field structures in the combustion chamber of a motored Wankel engine assembly is described. In order that the flow patterns of interest could be observed, small quantities of helium were injected with the intake air. Variation of the air flow patterns with engine speed, helium flow rate, and rotor position are described. The air flow at two locations within the combustion chamber was examined using this technique

Institution specific risk factors for 30 day readmission at a community hospital: a retrospective observational study

Background: As of October 1, 2012, hospitals in the United States with excess readmissions based on the Centers for Medicare and Medicaid Services (CMS) risk-adjusted ratio began being penalized. Given the impact of high readmission rates to hospitals nationally, it is important for individual hospitals to identify which patients may be at highest risk of readmission. The objective of this study was to assess the association of institution specific factors with 30-day readmission. Methods: The study is a retrospective observational study using administrative data from January 1, 2009 through December 31, 2010 conducted at a 257 bed community hospital in Massachusetts. The patients included inpatient medical discharges from the hospitalist service with the primary diagnoses of congestive heart failure, pneumonia or chronic obstructive pulmonary disease. The outcome was 30-day readmission rates. After adjusting for known factors that impact readmission, provider associated factors (i.e. hours worked and census on the day of discharge) and hospital associated factors (i.e. floor of discharge, season) were compared. Results: Over the study time period, there were 3774 discharges by hospitalists, with 637 30-day readmissions (17% readmission rate). By condition, readmission rates were 19.6% (448/2284) for congestive heart failure, 13.0% (141/1083) for pneumonia, and 14.7% (200/1358) for chronic obstructive lung disease. After adjusting for known risk factors (gender, age, length of stay, Elixhauser sum score, admission in the previous year, insurance, disposition, primary diagnosis), we found that patients discharged in the winter remained significantly more likely to be readmitted compared to the summer (OR 1.54, p = 0.0008). Patients discharged from the cardiac floor had a trend toward decreased readmission compared a medical/oncology floor (OR 0.85, p = 0.08). Hospitalist work flow factors (census and hours on the day of discharge) were not associated with readmission. Conclusions: We found that 30 day hospital readmissions may be associated with institution specific risk factors, even after adjustment for patient factors. These institution specific risk factors may be targets for interventions to prevent readmissions