Bulletin No. 114 - The Movement of Nitric Nitrogen in Soil and its Relation to Nitrogen Fixation

In the spring of 1903, we commenced at the Utah Experiment Station a series of experiments, the purpose of which was to study the development and movement of nitrates in irrigated soil. The work was so outlined that it should give some very definite results, both as to the influence of water and the plant, upon the nitric nitrogen content of the soil

Ecological Distribution of Breeding Waterfowl Populations in North Dakota

The distribution of breeding waterfowl populations on various wetland habitat types was investigated in North Dakota during 1967-69. Data were obtained by stratified random sampling techniques. The total wetland acreage in North Dakota was estimated to be about 3.2 million acres. Natural basin wetlands comprised about 77 percent of the acreage and 91 percent of the number of wetlands in the state and were utilized by about 76 percent of the state\u27s breeding duck population. Among the four biotic regions of the state, numerical and areal composition of wetlands varied considerably. Natural basin wetlands varied from a low of about 4 percent of total wetland acreage in the Southwestern Slope Region to a high of 93 percent in the Prairie Pothole Region. About 84 percent of the statewide duck population occurred in the Prairie Pothole Region. Within the Prairie Pothole Region, seasonal (Class III) ponds comprised 36 and 23 percent, respectively, of the total acreage and number of wetlands, and semipermanent (Class IV) ponds and lakes comprised 18 and 3 percent, respectively, of these totals. Agriculture has had drastic effects on the wetlands in this region as evidenced by the fact that natural basin wetlands with tilled bottom soils (chiefly Class II and Class III wetlands) comprised about 29 percent of area but 52 percent of numbers of all wet- lands. In the Prairie Pothole Region, seasonal ponds and semipermanent ponds and lakes were utilized by about 48 and 27 percent, respectively, of the total breeding ducks. Optimum environmental conditions for breeding dabbling ducks were present during years when large numbers and acreages of seasonal (Class III) pond basins contained surface water. Semipermanent (Class IV) ponds and lakes were the principal habitats for breeding diving ducks, and were also important to dabbling ducks, particularly during dry years

E-Book Reading Practices in Different Subject Areas: An Exploratory Log Analysis

Print books pose inherent difficulties for researchers who want to observe users’ natural in-book reading patterns. With e-books and logs of their use it is now possible to track several aspects of users’ interactions inside e-books, including the number and duration of their sessions with an e-book and the order in which pages are viewed. This chapter reports on a study of one-year of EBL user log data from Purdue University to identify different reading patterns or ways in which users navigate within different types of e-books—authored monographs vs. edited collections--and in e-books in different subject areas. The analysis of reading logs for e-books is still very much a new venture. From this perspective the results of this chapter are exploratory and descriptive, rather than conclusive, and as much about the evolution of workable methodologies as they are about the results of the analysis. Log analysis reveals nothing about users’ circumstances or intentions; however, in tandem with usability studies, and studies based on surveys, diaries, and interviews, it can contribute to a more objective understanding of users’ interactions with e-books

An Assessment of Panel vs. Individual Instructor Ratings of Student Speeches

This study addressed the possibility of utilizing a panel of instructors to evaluate student speeches. Forty-six public speaking students were videotaped during an informative speech assignment. Instructor panels evaluated each speech using the same criteria as the real instructor. This study found that trait error exists in panel grading as it does in individual instructor evaluation. Panel and individual instructor ratings were generally similar but inferior speeches were graded lower by the panel than the real instructor. This suggests that panels may be less likely to experience leniency error and may give more accurate evaluations of weaker speeches. Considerations are offered for the possible use of panel evaluations

A field study of practice in loose housing of dairy cattle in Missouri

This bulletin is an abstract from a thesis by the author submitted to the graduate faculty of the University of Missouri in partial fulfillment of the requirements for the degree of Master of Science in Agricultural Engineering--P. [3].Digitized 2007 AES.Includes bibliographical references (pages 35-36)

SNTF immunostaining reveals previously undetected axonal pathology in traumatic brain injury

Diffuse axonal injury (DAI) is a common feature of severe traumatic brain injury (TBI) and may also be a predominant pathology in mild TBI or “concussion”. The rapid deformation of white matter at the instant of trauma can lead to mechanical failure and calcium-dependent proteolysis of the axonal cytoskeleton in association with axonal transport interruption. Recently, a proteolytic fragment of alpha-II spectrin, “SNTF”, was detected in serum acutely following mild TBI in patients and was prognostic for poor clinical outcome. However, direct evidence that this fragment is a marker of DAI has yet to be demonstrated in either humans following TBI or in models of mild TBI. Here, we used immunohistochemistry (IHC) to examine for SNTF in brain tissue following both severe and mild TBI. Human severe TBI cases (survival <7d; n = 18) were compared to age-matched controls (n = 16) from the Glasgow TBI archive. We also examined brains from an established model of mild TBI at 6, 48 and 72 h post-injury versus shams. IHC specific for SNTF was compared to that of amyloid precursor protein (APP), the current standard for DAI diagnosis, and other known markers of axonal pathology including non-phosphorylated neurofilament-H (SMI-32), neurofilament-68 (NF-68) and compacted neurofilament-medium (RMO-14) using double and triple immunofluorescent labeling. Supporting its use as a biomarker of DAI, SNTF immunoreactive axons were observed at all time points following both human severe TBI and in the model of mild TBI. Interestingly, SNTF revealed a subpopulation of degenerating axons, undetected by the gold-standard marker of transport interruption, APP. While there was greater axonal co-localization between SNTF and APP after severe TBI in humans, a subset of SNTF positive axons displayed no APP accumulation. Notably, some co-localization was observed between SNTF and the less abundant neurofilament subtype markers. Other SNTF positive axons, however, did not co-localize with any other markers. Similarly, RMO-14 and NF-68 positive axonal pathology existed independent of SNTF and APP. These data demonstrate that multiple pathological axonal phenotypes exist post-TBI and provide insight into a more comprehensive approach to the neuropathological assessment of DAI

Stable heat and moisture dissipation with dairy calves at temperatures of 50 degrees and 80 degrees F.

Missouri Agricultural Experiment Station and the United States Department of Agriculture cooperating.Includes bibliographical references (page 24)

Removal of terrestrial DOC in aquatic ecosystems of a temperate river network

Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones

Immunohistochemical Distribution of PlexinA4 in the Adult Rat Central Nervous System

PlexinA4 is the latest member to be identified of the PlexinA subfamily, critical transducers of class 3 semaphorin signaling as co-receptors to neuropilins 1 and 2. Despite functional information regarding the role of PlexinA4 in development and guidance of specific neuronal pathways, little is known about its distribution in the adult central nervous system (CNS). Here we report an in depth immunohistochemical analysis of PlexinA4 expression in the adult rat CNS. PlexinA4 staining was present in neurons and fibers throughout the brain and spinal cord, including neocortex, hippocampus, lateral hypothalamus, red nucleus, facial nucleus, and the mesencephalic trigeminal nucleus. PlexinA4 antibodies labeled fibers in the lateral septum, nucleus accumbens, several thalamic nuclei, substantia nigra pars reticulata, zona incerta, pontine reticular region, as well as in several cranial nerve nuclei. This constitutes the first detailed description of the topographic distribution of PlexinA4 in the adult CNS and will set the basis for future studies on the functional implications of PlexinA4 in adult brain physiology