Extreme Event Reconstructions for the Upper Fraser River Basin, British Columbia, Canada

Spring freshets and summer droughts have recently worsened in the Fraser River Basin, British Columbia, Canada, with significant impacts to the keystone Pacific salmon populations, the food and economic sovereignty of over eighty First Nations, and the western Canadian economy. These extreme events present a potential risk since, unlike many large and less hydroclimatically-complex and/or empounded watersheds, the Fraser River Basin is susceptible to a combination of unregulated spring freshet and summer drought events even within the same year. A major limitation for understanding past and future extreme event risk in the Fraser River Basin is that observational streamflow datasets are both short in duration and potentially forced by anthropogenic warming. They therefore provide a potentially incomplete record of natural hydrological variability and inaccurate benchmarks of long-term natural runoff extremes. While longer-term, highly-resolved (annual), tree ring (TR) based paleohydrological reconstructions are increasingly being used worldwide by water managers and stakeholders to extend short observational streamflow records, this approach is difficult in complex temperate watersheds like the Fraser. For this study I developed the first multi-century, sub-annual resolution (seasonal), paired freshet and drought reconstructions within a single watershed. I targeted the Upper Fraser Basin since it represents the headwaters and primary runoff source of the greater Fraser Basin. By focusing on sub-annual streamflow seasons, I was able to both independently reconstruct seasonal extreme flow events, and also overcome methodological limitations that precluded prior attempts to reconstruct total water-year runoff in this watershed. Newly developed and existing TR chronologies from multiple species were used as proxies for seasonal temperature and cool-season precipitation which are, in turn, drivers of streamflow in each reconstruction season. I analyzed the magnitudes, durations, and statistical probabilities of high freshets and droughts over the past 140 years. My results suggest that the instrumental records do not accurately reflect the full variability of high freshet events or drought events as both duration and magnitudes of past events are higher than any during the observed time period. There is also a change in the frequency of high freshet events towards more frequent occurrences since 1950 AD. The new extreme event reconstructions presented here provide paleoenvironmental benchmarks that can be used by water managers and stakeholders to significantly change and improve water management-relevant statistical analyses such as frequency analysis and return periods calculation, and adapt to future freshets and droughts on the Fraser River under climate change

Teachers’ and students’ perceptions of students’ ability and importance value in math and reading: a latent difference score analysis of intra-individual cross-domain differences

Informed by Eccles and colleagues’ expectancy-value theory and Möller and Marsh’s dimensional comparison theory, we examined cross-domain intra-individual differences in elementary teachers’ (N = 57) and their students’ (N = 469) ratings of students’ ability and subjective importance of math and reading. Latent difference score analyses revealed that students perceived greater intra-individual differences in their own math versus reading ability than did their teachers. Analogous results emerged for students’ and teachers’ ratings of students’ valuing (i.e., perceived importance) of math versus reading, suggesting differing dimensional comparison processes for students’ self-judgments vs. their teachers’ judgments. Cross-domain differences in teachers’ and students’ perceptions were positively associated for ratings of students’ ability but not for ratings of students’ perceived importance. Moreover, intra-individual differences varied substantially across students, in both students’ and teachers’ ratings. Students’ gender and prior achievement in math and reading contributed to this variation.Auf Basis der Erwartungs-Wert-Theorie von Eccles et al. und der Theorie dimensionaler Vergleiche von Möller und Marsh untersucht dieser Beitrag intra-individuelle Differenzen der Lernenden zwischen Mathe und Lesen bezüglich ihrer fachspezifischen Fähigkeiten und subjektiven Wichtigkeit der Fächer, beurteilt von den Lernenden (N = 469) und ihren Grundschullehrkräften (N = 57). Latente Differenzmodelle ergaben, dass die Lernenden größere intra-individuelle Unterschiede zwischen Mathe und Lesen sowohl in ihrer Fähigkeit als auch der Wichtigkeit des Fachs wahrnahmen als ihre Lehrkräfte, was auf unterschiedliche dimensionale Vergleichsprozesse bei Selbst- und Lehrkrafturteilen hindeutet. Lernenden- und Lehrkraftbeurteilung der Differenzen zwischen Mathe und Lesen waren positiv assoziiert für die Beurteilung der Fähigkeiten, aber nicht für die Beurteilung der wahrgenommenen Wichtigkeit des Fachs. Darüber hinaus variierten die intra-individuellen Unterschiede zwischen den Lernenden, sowohl in den Beurteilungen der Lernenden als auch der Lehrkräfte. Das Geschlecht der Lernenden und ihre Vorleistungen in beiden Fächern erwiesen sich als Prädiktoren dieser inter-individuellen Unterschiede

Radial Surface Density Profiles of Gas and Dust in the Debris Disk around 49 Ceti

We present ~0.4 resolution images of CO(3-2) and associated continuum emission from the gas-bearing debris disk around the nearby A star 49 Ceti, observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). We analyze the ALMA visibilities in tandem with the broad-band spectral energy distribution to measure the radial surface density profiles of dust and gas emission from the system. The dust surface density decreases with radius between ~100 and 310 au, with a marginally significant enhancement of surface density at a radius of ~110 au. The SED requires an inner disk of small grains in addition to the outer disk of larger grains resolved by ALMA. The gas disk exhibits a surface density profile that increases with radius, contrary to most previous spatially resolved observations of circumstellar gas disks. While ~80% of the CO flux is well described by an axisymmetric power-law disk in Keplerian rotation about the central star, residuals at ~20% of the peak flux exhibit a departure from axisymmetry suggestive of spiral arms or a warp in the gas disk. The radial extent of the gas disk (~220 au) is smaller than that of the dust disk (~300 au), consistent with recent observations of other gas-bearing debris disks. While there are so far only three broad debris disks with well characterized radial dust profiles at millimeter wavelengths, 49 Ceti's disk shows a markedly different structure from two radially resolved gas-poor debris disks, implying that the physical processes generating and sculpting the gas and dust are fundamentally different.Comment: 20 pages, 8 figures, accepted for publication in ApJ March 31, 2017 (submitted Nov 2016

Anxiety and Depression Are Related to Higher Activity of Sphingolipid Metabolizing Enzymes in the Rat Brain

Changes in sphingolipid metabolism have been suggested to contribute to the pathophysiology of major depression. In this study, we investigated the activity of acid and neutral sphingomyelinases (ASM, NSM) and ceramidases (AC, NC), respectively, in twelve brain regions of female rats selectively bred for high (HAB) versus low (LAB) anxiety-like behavior. Concomitant with their highly anxious and depressive-like phenotype, HAB rats showed increased activity of ASM and NSM as well as of AC and NC in multiple brain regions associated with anxiety- and depressive-like behavior, including the lateral septum, hypothalamus, ventral hippocampus, ventral and dorsal mesencephalon. Strong correlations between anxiety-like behavior and ASM activity were found in female HAB rats in the amygdala, ventral hippocampus and dorsal mesencephalon, whereas NSM activity correlated with anxiety levels in the dorsal mesencephalon. These results provide novel information about the sphingolipid metabolism, especially about the sphingomyelinases and ceramidases, in major depression and comorbid anxiety

Methyl 4,5-diacet­oxy-1-oxo-2-phenyl­perhydro-4,6-epoxy­cyclo­penta­[c]pyridine-7-carboxyl­ate ethanol solvate

The title compound, the product of an acid-catalysed Wagner–Meerwein skeletal rearrangement, crystallizes as an ethanol monosolvate, C20H21NO8·C2H6O. The title mol­ecule comprises a fused tricyclic system containing two five-membered rings (cyclo­pentane and tetra­hydro­furan) in the usual envelope conformations and one six-membered ring (piperidinone) adopting a flattened twist–boat conformation

Web-at-Risk: A Distributed Approach to Preserving our Nation's Political Cultural Heritage

This report discusses a focus group that was part of the Web-at-Risk project. The report includes the following three sections: (a) the methodology used to conduct the focus groups and analyze the data, (b) the detailed results of the analysis organized into phases of the collection development process, and (c) a discussion of the key findings

Archiving Web-Published Materials: A Needs Assessment of Librarians, Researchers, and Content Providers

Article discussing archiving web-published materials and a needs assessment of librarians, researchers, and content providers

Paleohydrological Context for Recent Floods and Droughts in the Fraser River Basin, British Columbia, Canada

The recent intensification of floods and droughts in the Fraser River Basin (FRB) of British Columbia has had profound cultural, ecological, and economic impacts that are expected to be exacerbated further by anthropogenic climate change. In part due to short instrumental runoff records, the long-Term stationarity of hydroclimatic extremes in this major North American watershed remains poorly understood, highlighting the need to use high-resolution paleoenvironmental proxies to inform on past streamflow. Here we use a network of tree-ring proxy records to develop 11 subbasin-scale, complementary flood-and drought-season reconstructions, the first of their kind. The reconstructions explicitly target management-relevant flood and drought seasons within each basin, and are examined in tandem to provide an expanded assessment of extreme events across the FRB with immediate implications for water management. We find that past high flood-season flows have been of greater magnitude and occurred in more consecutive years than during the observational record alone. Early 20th century low flows in the drought season were especially severe in both duration and magnitude in some subbasins relative to recent dry periods. Our Fraser subbasin-scale reconstructions provide long-Term benchmarks for the natural flood and drought variability prior to anthropogenic forcing. These reconstructions demonstrate that the instrumental streamflow records upon which current management is based likely underestimate the full natural magnitude, duration, and frequency of extreme seasonal flows in the FRB, as well as the potential severity of future anthropogenically forced events

Web-at-Risk: A Distributed Approach to Preserving our Nation's Political Cultural Heritage

This report is part of the Web-at-Risk project. This report includes the following three sections: (a) the methodology used to conduct the focus groups and analyze the data, (b) the detailed results of the analysis organized into phases of the collection development process, and (c) a discussion of the key findings