Natural hydroclimatic forcing of historical lake volume fluctuations at Devils Lake, North Dakota (USA)

Devils Lake, a terminal saline lake in eastern North Dakota, has experienced catastrophic flooding over the past two decades producing direct damages in excess of $1 billion ($USD). We use three long-term datasets to examine the temporal coherence between historical lake fluctuations and basic hydroclimatic drivers. Monthly precipitation and mean monthly air temperature data are used to characterize long-term precipitation delivery and evaporative demand. Monthly water balance data for a representative location are used to assess basin soil moisture conditions. A lake volume time series documents lake volume fluctuation in response to long-term precipitation and regional soil moisture conditions. Three variables are derived from the datasets, each characterizing a different aspect of the region’s hydroclimatology. A rescaling technique is applied to each variable to examine the temporal coherence and relative patterns of the variables and to identify distinct homogeneous hydroclimatic regimes during the historical period. The three rescaled variables show strong temporal coherence and confirm 1980 as an abrupt transition year between two distinct long-term hydroclimatic modes. Mode 1, a longer and drier phase, runs from 1907 to 1980, while mode 2, a shorter and wetter phase, extends from 1981 to the present. Multi-decadal and century-scale fluctuations between these two modes are the key drivers of long-term lake volume fluctuations, upon which interannual- and interdecadal-scale climatic variability are superimposed. The similar rates of change among the rescaled variables provides evidence in support of the conclusion that long-term natural hydroclimatological variability is the primary driver of observed lake volume changes at Devils Lake during the Twentieth Century and provides a foundation upon which to evaluate the potential contributing effects of anthropogenic climate change, and human alterations of the land use hydrology

A Southern Progressive: M. A. Cassidy and the Lexington Schools, 1886-1928

The 42-year career of M. A. Cassidy exemplifies the transition of public school leadership in Kentucky from non-educators who held religious-political ideologies to professional progressive educators who sought to make Kentucky schools more efficient through expertise and scientific management. This concept was fully adopted in Section 183 of the Kentucky Constitution (1891) which required the General Assembly to “provide for an efficient system of common schools throughout the state.” Confident that professional educators were best suited to devise solutions to social problems, and justified by the twin notions of equality of educational opportunity and meritocracy, Cassidy was part of a new breed of progressive educators who joined with the business community to declare that a modest amount of schooling would prepare all for a life of equality, not by restructuring society, but by making each individual better. Cassidy belonged to that class of Southern accommodationist progressive educators who saw themselves as the teachers and guardians of subordinate African Americans in whom they would cultivate “some measure of collaboration and consent.” Cassidy presents as a Southern-style reformer working in a border state, but one who held conservative and progressive ideals in equal measure. Like most white Southerners, Cassidy believed that blacks were inherently inferior to whites. But unlike his Southern peers--and despite being part of a community that did not embrace social mobility for blacks--Cassidy was an early adopter of educational equality that included blacks, albeit, in a separate system under Jim Crow. His attention to physical and operational improvements to black schools, including enhanced teacher training and the addition of innovative programs for students, was remarkable for its place and time. But apparent philosophical conflicts fall into place once we see Cassidy for who he was: a public official who necessarily had to work closely with his constituency to achieve his goals; a change agent who used the bully pulpit to extol the virtues of literacy and a proper education; a Christian in the Social Gospel tradition who saw a duty to the least among us; and a personable superintendent who used his sense of Southern gentility to attract more citizens to the enterprise

Characteristics of hypervelocity impact craters on LDEF experiment S1003 and implications of small particle impacts on reflective surfaces

The Ion Beam textured and coated surfaces EXperiment (IBEX), designated S1003, was flown on LDEF at a location 98 deg in a north facing direction relative to the ram direction. Thirty-six diverse materials were exposed to the micrometeoroid (and some debris) environment for 5.8 years. Optical property measurements indicated no changes for almost all of the materials except S-13G, Kapton, and Kapton-coated surfaces, and these changes can be explained by other environmental effects. From the predicted micrometeoroid flux of NASA SP-8013, no significant changes in optical properties of the surfaces due to micrometeoroids were expected. There were hypervelocity impacts on the various diverse materials flown on IBEX, and the characteristics of these craters were documented using scanning electron microscopy (SEM). The S1003 alumigold-coated aluminum cover tray was sectioned into 2 cm x 2 cm pieces for crater documentation. The flux curve generated from this crater data fits well between the 1969 micrometeoroid model and the Kessler debris model for particles less than 10(exp -9) gm which were corrected for the S1003 positions (98 deg to ram). As the particle mass increases, the S1003 impact data is greater than that predicted by even the debris model. This, however, is consistent with data taken on intercostal F07 by the Micrometeoroid/Debris Special Investigating Group (M/D SIG). The mirrored surface micrometeoroid detector flown on IBEX showed no change in solar reflectance and corroborated the S1003 flux curve, as well as results of this surface flown on SERT 2 and OSO 3 for as long as 21 years

Scale of Patchiness Affects the Relation Between Forage Quality and Patch Choice by Cattle

We predicted and tested the effects of scale of heterogeneity on movements and selectivity of a large grazer in a controlled field experiment. We created random mosaics of short/high quality and tall/low quality grass patches in equal proportion at grid sizes of 2x2 m and 5x5 m. Subsequently, we monitored the foraging behavior of four steers in 16 20x40 m plots over 30-minute periods. As predicted, the animals selected the short patches both by walking in a nonrandom manner and by concentrating their grazing time. Selectivity was more pronounced in large patches than in small ones. In contrast, the number of bites per feeding station was not affected by patch size, suggesting that selection between and within feeding stations are essentially different processes. We conclude that selectivity is facilitated by large scale heterogeneity, particularly by enhancing discrimination between feeding stations and larger selection units

First-Summer Survival of Largemouth Bass Cohorts: Is Early Spawning Really Best?

Previous work has demonstrated that survival of largemouth bass Micropterus salmoides through the first year of life can be size dependent, favoring larger individuals. Because size, diet biomass, lipid accumulation, and ultimately overwinter survival of juveniles are typically positively related to age, early spawning is clearly advantageous. However, a true understanding of which largemouth bass cohorts contribute to the new year-class remains somewhat unclear because these conclusions have largely been based upon fish collected during summer rather than fish collected during spring. Conceivably, even earlier hatched cohorts of largemouth bass could have existed in many of these studies, and these fish may simply not have survived to the summer collection period. In order to assess this possibility, we quantified first-summer survival of largemouth bass cohorts collected during 1992 and 1993 in Auburn, Alabama, ponds (which were 2–5 ha each). Our results indicate that it is early-hatched cohorts that likely contribute to the new year-class. Although we found that early-hatched cohorts were lost between May and July, these losses were not attributable to age-dependent mortality; instead, sampling biases associated with avoidance of seines by older, larger young-of-year largemouth bass appear to have driven these shifts. In addition, because we found that size-dependent cannibalism during summer acted to remove smaller, later-hatched largemouth bass, early hatching may enhance survival during larval and early juvenile stages in southern systems (and not just during the winter period). Given this information, fishery managers may potentially be able to implement harvest regulations that are designed to protect large, early-spawning adults, thereby increasing the probability of producing a strong year-class by enhancing first-summer growth and, ultimately, recruitment to adult stages.This research was supported in part by National Science Foundation grants DEB-9108986 and DEB-9410323 and Federal Aid in Sport Fish Restoration project F40-R (administered by the Alabama Game and Fish Division to D. R. DeVries)

A Persistent Quandary: The Rural School Improvement Project, 1953-1957

Berea College\u27s Rural School Improvement Project worked directly with more than 5,000 children and 63 teaching fellows in 39 different schools over 13 counties, and one independent school district, involving 10 county school supervisors. Project estimates claimed an indirect impact on approximately 45,000 children within the RSIP school districts. The RSIP represented the thinking of national leaders of rural education in the 1950s who promoted improved administration of the schools combined with an active community engagement program based on “full respect for human personality” and “shared judgments.” Following so many decades of poverty and isolation, it is no easy task to gauge the impact of a program like the Rural School Improvement Project on the children and communities of southeastern Kentucky. Like the progress-minded projects that came before it - and those that would come after - the seemingly intractable challenges attending the Appalachian region kept educational equity at bay. Indeed, it would take another thirty-two years before the landmark Kentucky Supreme Court decision in Rose v Council for Better Education would declare the state’s inequitable and inadequate school system to be unconstitutional. “Sixty-six” property poor, and mostly rural, school districts had sued the General Assembly citing the abiding fiscal inequities which had grown to as much as an 8:1 ratio when compared to one urban district. With the passage of the Kentucky Education Reform Act, in 1990, the General Assembly provided substantial funding equity to rural schools - before returning to its historical pattern of periodic attention amid chronic neglect

Patients with diabetes in the intensive care unit; not served by treatment, yet protected?

Diabetes is associated with severe complications and decreased life expectancy. However, in the previous issue of Critical Care, Vincent and colleagues report no difference in mortality between patients with insulin-treated diabetes and patients without diabetes in the intensive care unit (ICU), despite larger severity of illness in the diabetes group at admission. This study contributes to the growing evidence that diabetes in itself is not a risk factor for ICU mortality, although the mechanisms are not yet fully understood. On the other hand, patients with diabetes seem not to benefit from tight glycemic control during their ICU stay. Different treatment approaches may be needed for patients with diabetes and patients with stress hyperglycemia

Remote sensing applications to resource problems in South Dakota

The author has identified the following significant results. Change in the vegetative structure was taking place in the Black Hills. Temporal analysis of the areal extent of open meadows was accomplished using black and white and color infrared aerial photography. A reduction of nearly 1100 hectares of open meadows was determined using photointerpretation. Techniques were developed for the management of meandering lakes, including use of LANDSAT imagery for continuous monitoring, classification of hydrophytes on low altitude CIR imagery, and planning and evaluation of improvements and multiple uses on aerial photography and photo mosaics. LANDSAT data were analyzed statistically from small and entire study scene areas to determine the effect of soils stratifications of corn signatures. Band 5 early season and band 7 later season recorded the strongest evidence of the influence of soils on corn signatures. Significant strata were determined by a multiple range test

Energetic Adaptations along a Broad Latitudinal Gradient: Implications for Widely Distributed Assemblages

Most community-based models in ecology assume that all individuals within a species respond similarly to environmental conditions and thereby exert identical effects as consumers or prey. Rather, individuals differ among systems, with important implications for population demographics and community interactions. For widely distributed assemblages made up of poikilotherms with high first-year mortality, species-specific differences in growth reaction norms as affected by both temperature and genotype will influence biotic interactions. For a broadly distributed fish assemblage, first-year growth does not vary with latitude for a planktivorous prey species, but declines with increasing latitude for a terminal piscivore. Size-based competitive interactions between these species are likely to be more intense at high latitudes, as they spend an extended time sharing resources during early life. Such patterns probably are pervasive and must be considered when seeking to understand species interactions. Improving our knowledge of how temperature and local adaptations affect size-based interactions should enhance our ability to manage and conserve widespread assemblages