Showing papers by "Heidelberg University (Ohio) published in 2015"

Surface runoff and tile drainage transport of phosphorus in the midwestern United States.

Abstract: The midwestern United States offers some of the most productive agricultural soils in the world. Given the cool humid climate, much of the region would not be able to support agriculture without subsurface (tile) drainage because high water tables may damage crops and prevent machinery usage in fields at critical times. Although drainage is designed to remove excess soil water as quickly as possible, it can also rapidly transport agrochemicals, including phosphorus (P). This paper illustrates the potential importance of tile drainage for P transport throughout the midwestern United States. Surface runoff and tile drainage from fields in the St. Joseph River Watershed in northeastern Indiana have been monitored since 2008. Although the traditional concept of tile drainage has been that it slowly removes soil matrix flow, peak tile discharge occurred at the same time as peak surface runoff, which demonstrates a strong surface connection through macropore flow. On our research fields, 49% of soluble P and 48% of total P losses occurred via tile discharge. Edge-of-field soluble P and total P areal loads often exceeded watershed-scale areal loadings from the Maumee River, the primary source of nutrients to the western basin of Lake Erie, where algal blooms have been a pervasive problem for the last 10 yr. As farmers, researchers, and policymakers search for treatments to reduce P loading to surface waters, the present work demonstrates that treating only surface runoff may not be sufficient to reach the goal of 41% reduction in P loading for the Lake Erie Basin.

Long-term and seasonal trend decomposition of Maumee River nutrient inputs to western Lake Erie.

Abstract: Cyanobacterial blooms in western Lake Erie have recently garnered widespread attention. Current evidence indicates that a major source of the nutrients that fuel these blooms is the Maumee River. We applied a seasonal trend decomposition technique to examine long-term and seasonal changes in Maumee River discharge and nutrient concentrations and loads. Our results indicate similar long-term increases in both regional precipitation and Maumee River discharge (1975-2013), although changes in the seasonal cycles are less pronounced. Total and dissolved phosphorus concentrations declined from the 1970s into the 1990s; since then, total phosphorus concentrations have been relatively stable, while dissolved phosphorus concentrations have increased. However, both total and dissolved phosphorus loads have increased since the 1990s because of the Maumee River discharge increases. Total nitrogen and nitrate concentrations and loads exhibited patterns that were almost the reverse of those of phosphorus, with increases into the 1990s and decreases since then. Seasonal changes in concentrations and loads were also apparent with increases since approximately 1990 in March phosphorus concentrations and loads. These documented changes in phosphorus, nitrogen, and suspended solids likely reflect changing land-use practices. Knowledge of these patterns should facilitate efforts to better manage ongoing eutrophication problems in western Lake Erie.

Record-breaking Lake Erie hypoxia during 2012 drought.

Abstract: Hypoxia has been observed in the central basin of Lake Erie for decades. To understand the impact of various controlling factors, we analyze a record of hypoxic extents for Lake Erie for 1985–2012 and develop a parsimonious model of their interannual variability. We find that the 2012 North American drought and accompanying low tributary discharge was associated with a record-breaking hypoxic event in Lake Erie, whereas a record-setting harmful algal bloom in 2011 was likely associated with only mild hypoxia. River discharge and the timing of nutrient input therefore impact western basin bloom growth and central basin oxygen demand in distinct ways that merit further investigation. Overall, April to June tributary discharge, May to July soluble reactive phosphorus loading, July wind stress, and June northwesterly wind duration explain 82% of the interannual variability of hypoxia, and discharge alone explains 39%, indicating that meteorological factors need to be considered in the development of nutrient management strategies, especially as both extreme precipitation events and droughts become more frequent under a changing climate.

The Voices of School Counselors: Essential Characteristics of School Counselor Leaders.

Abstract: The majority of school counselor leadership studies focus on quantitative data. The current study contributes to the limited qualitative research surrounding school counselor leadership. The analysis of an open-ended statement from a national study gives voice to school counselor perceptions about leadership characteristics pertinent to the profession. Five themes emerged from the findings: leadership attributes, relationship attributes, communication and collaboration, exemplary program design, and advocacy. The themes align with characteristics previously identified in the school counseling literature.

If You Don’t Care, Then Why Should I? The Influence of Instructor Commitment on Student Satisfaction and Commitment

Abstract: Management education often takes place at institutions where research is one of the top priorities of the faculty and administration. In this context, and others, instructors may not be fully committed to their teaching. Yet student satisfaction with their professors is an important determinant of a university’s reputation. We explore how an instructor’s attitude about teaching influences student outcomes in general and student satisfaction and commitment specifically. Using a sample of 286 students and five different management instructors, our research establishes an instructor’s attitude about teaching, specifically the instructor’s self-rated commitment to the students in his or her class, as having a positive influence on student-rated satisfaction. Moreover, perceived instructor support is established as the explanatory mechanism that mediates the relationship between an instructor’s commitment to students and student satisfaction as well as the relationship between an instructor’s commitment to stu...

Chapter 17 – Dinoflagellates

Abstract: Dinoflagellates are a group of unicellular protists that can be identified using the light microscope, and are (usually) recognized by their golden-brown plastids, assimilative cell with indented waist, distinctive swimming pattern, and relatively large nucleus that contains visible chromosomes. Shared characteristics of the group include: two dissimilar flagella in motile cells; an unusual genome consisting of liquid, crystal-like chromosomes; and a haplontic life cycle that often contains a non-motile, dormant cyst stage. Freshwater dinoflagellates are diverse and may be phototrophic, predatory, or both (mixotrophic). They can be found in most aquatic habitats throughout the seasons; although flagship taxa, such as Ceratium, Peridinium, and Gymnodinium, are typically found as phytoplankton in calm, lentic waters during warmer months. This chapter updates taxonomy (extensive splitting of the genera Peridinium, Peridiniopsis, and Woloszynskia), identification of genera via microscopy, and adds molecular information on taxa and group systematics where available.

Teaching the Liberal Arts in the Middle Ages: The Cathedral School at Reims in the Late Tenth Century

Abstract: In the late tenth century, Gerbert of Aurillac served as the lead teacher at the cathedral school in Reims The curriculum he developed and implemented was based on a combination of classical literature, encyclopedias written in late antiquity, and Greco-Roman teaching tools This curriculum preserved and transmitted classical learning to the schools of the High Middle Ages and contributed to a wider educational revival in northern France and Germany