Effects of Leafy Spurge (Euphorbia esula) Infestation on Breeding Birds of the Sheyenne National Grassland, ND

Leafy spurge (Euphorbia esula) is an exotic invasive weed in the northern Great Plains. We examined the effects of leafy spurge infestation on densities and nest success of breeding birds in grasslands on the Sheyenne National Grassland (SNG), ND. We categorized spurge-infested grasslands into three levels of infestation, based on the area covered by spurge patches: (a) low (0-20%), (b) medium (20-60%) and, (c) high (\u3e 60%). We surveyed 60 100-m radius circular plots (20 in each category), and searched for nests in three 16-ha plots (one in each category). There were no statistically significant differences in mean species richness or mean species diversity among the three types of survey points. Of the eight most abundant grassland birds, only Upland Sandpiper (Bartramia longicauda) densities were significantly different among spurge categories, with highest mean density (13.5 ± 4.1 birds/100 ha) occurring on medium-spurge points. However, none of these species occurred in highest densities on high-spurge points. Le Conte\u27s Sparrows (Ammodramus leconteii) and Savannah Sparrows (Passerculus sandwichensis) were significantly negatively correlated with spurge infestation (-0.23 and -0.24, respectively). Spurge infestation was not correlated with grazing intensity (number of stems/m2: rs = -0.01; % cover: rs= -0.03). Le Conte\u27s Sparrows were negatively correlated (-0.34) with grazing intensity; whereas Savannah Sparrows were positively correlated with this factor (0.28). The low-spurge plot contained the most nests (n = 24), but nests on the high-spurge plot (n = 11) experienced the highest nest success (0.745, χ2 = 13.2, df = 2, P \u3c 0.01). There were no significant differences between successful and unsuccessful nests or between nests and nearby paired sites with respect to number of spurge stems/m2 or percent cover of spurge. However there were significant differences for other measured vegetational features. Thus, based on these data, most birds appeared to show little response to leafy spurge per se. Birds may choose microhabitats based more on characteristics of vegetation structure (e.g. ground cover, vegetation height, vertical density, litter depth) than on particular plant species. Circumstantial evidence suggests that spurge may even provide benefits for certain species through foraging opportunities and nest protection. Assuming spurge can alter vegetation structure to the detriment of grassland birds, infestation may not be high enough over much of the SNG to show a strong negative effect on bird community parameters. Other factors may obscure relationships between bird densities and spurge infestation including strong avian preferences for other vegetation characteristics, cattle grazing intensity, and habitat productivity. We surveyed the breeding bird communities of the five major habitat types (grassland, sedge meadow, wetland, savanna, and woodland) of the SNG. Grasslands contained the greatest number of total species (47), but species richness/point and species diversity/point were not significantly different among habitat types (F = 1.33, P = 0.29; F = 0.65, P 0.63, respectively). The most abundant species on grassland survey points was the Western Meadowlark (47.5 birds/100 ha). The Red-winged Blackbird was the most abundant species on sedge meadow and wetland survey points (88.5 and 382.2 birds/100 ha, respectively). Ground foragers were the most abundant guild on savanna and woodland points (236.6 and 229.3 birds/100 ha, respectively). The complex interspersion among habitat patches, combined with the relatively broad range of habitat preferences and flexibility displayed by many bird species probably lead to the observed patterns of species overlap among communities

Optimizing cardiovascular and chemopreventive benefits of aspirin: what role for the proton-pump inhibitors?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75584/1/j.1365-2036.2004.02347.x.pd

The Cystic Duct Remnant: An Unusual Case of a Biliary Intraluminal Filling Defect

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72892/1/j.1572-0241.1988.tb06086.x.pd

The clinical and economic impact of alternative staging strategies for adenocarcinoma of the pancreas

Several innovative imaging modalities, including endoscopic ultrasound, have increased the number of available preoperative staging methods in patients with adenocarcinoma of the pancreas. Our goal was to estimate the clinical outcomes and cost-effectiveness of alternative staging strategies for pancreatic adenocarcinoma. METHODS : Decision analysis was used to simulate alternative staging strategies. Cost inputs were based on Medicare reimbursements; clinical inputs were obtained from the available literature. Model endpoints of interest were cost per curative resection and appropriateness of treatment allocation based on pathological stage. RESULTS : Endoscopic ultrasound followed by laparoscopy yielded the lowest cost per curative resection ($37,600) and minimized the number of unnecessary surgical explorations (5.4 per 100 patients staged). Requiring angiographic confirmation when endoscopic ultrasound demonstrated an unresectable tumor yielded an intermediate cost-effectiveness ratio and virtually eliminated the risk of overstaging. Laparoscopy alone maximized the resection rate, but each additional resection would cost approximately$2 million relative to a strategy employing both endoscopic ultrasound and angiography. CONCLUSIONS : Staging strategies incorporating endoscopic ultrasound may improve treatment allocation and are cost-effective relative to angiography-based strategies. A staging protocol that does not incorporate an imaging modality to detect vascular invasion dramatically increases the cost per additional curative resection compared with more comprehensive staging protocols.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74623/1/j.1572-0241.2000.02191.x.pd

Effect of Naproxen on Gastroesophageal Reflux and Esophageal Function: A Randomized, Double-Blind, Placebo-Controlled Study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75450/1/j.1572-0241.1995.tb09312.x.pd

Helicobacter pylori test-and-treat intervention compared to usual care in primary care patients with suspected peptic ulcer disease in the United States

The Helicobacter pylori ( H. pylori ) “test-and-treat” strategy in uninvestigated dyspepsia is an effective alternative to prompt endoscopy. Our aims were to determine whether the combination of an educational session and availability of office-based H. pylori testing (test-and-treat intervention [TTI]) increases use of the test-and-treat strategy by primary care practitioners and whether it improves patient outcomes. Methods : We conducted a 1-yr prospective trial of patients with suspected peptic ulcer disease in six primary care centers, three with TTI and three designated as usual care controls (UCC). Results : H. pylori testing was performed in 81% of 54 TTI patients and in 49% of 39 UCC patients ( p = 0.004). TTI and UCC patients had similar gastroenterology referral rates (24% vs 33%, p = 0.33), endoscopy or upper GI radiography rates (30% vs 31%, p = 0.91), and primary care visits per patient (3.1 ± 2.8 vs 3.1 ± 2.6, p = 0.92). TTI patients were less likely than UCC patients to receive repeated antisecretory medication prescriptions (35% vs 66%, p = 0.003). Symptomatic status at 1 yr and satisfaction with medical care did not differ between groups. Median (and interquartile range) annualized disease-related expenditures per patient were $454 ($162–932) for TTI and $576 ($327–1435) for UCC patients ( p = 0.17). Conclusions : The combination of an educational session and availability of office-based H. pylori testing may increase acceptance of the test-and-treat strategy by primary care providers. It remains to be determined whether increased use of the test-and-treat strategy yields significant improvements in clinical and economic outcomes compared to usual care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74830/1/j.1572-0241.2002.07118.x.pd

Change in convergence and accommodation after two weeks of eye exercises in typical young adults

Abstract: Introduction Although eye exercises appear to help heterophoria, convergence insufficiency and intermittent strabismus, true treatment effects can be confounded by placebo, practice and encouragement factors. This study assessed objective changes in vergence and accommodation responses in typical naïve young adults after two weeks of exercises compared to control conditions to assess the extent of treatment effects occur above other factors. Methods 156 asymptomatic young adults were randomly assigned to 6 exercise groups or 2 no-treatment groups. Treatment targeted i) accommodation, ii)vergence, iii) both, iv) convergence>accommodation, v)accommodation>convergence, or vi) a placebo. All were re-tested under identical conditions, except for the second control group who were additionally encouraged during testing. Objective accommodation and vergence were assessed to a range of targets moving in depth containing combinations of blur, disparity and proximity/looming cues. Results Response gain improved more for less naturalistic targets where more improvement was possible. Convergence exercises improved vergence for near across all targets (P=.035). Mean accommodation changed similarly,but non-significantly. No other treatment group differed significantly from the non-encouraged control group, while encouraging effort produced significantly increased vergence (P=.004) and accommodation (P=.005) gains in the other control group. Conclusions True treatment effects were small, only significantly better after vergence exercises to a non-accommodative target, and were rarely related to response they were designed to improve. Exercising accommodation without convergence made no difference to accommodation to cues containing detail. Additional effort improved objective responses the most, so should be controlled carefully in research, and considered when auditing treatment

Photodetector Development for the Wheel Abrasion Experiment on the Sojourner Microrover of the Mars Pathfinder Mission

On-board the Mars Pathfinder spacecraft, launched in December of 1996, is a small roving vehicle named Sojourner. On Sojourner is an experiment to determine the abrasive characteristics of the Martian surface, called the Wheel Abrasion Experiment (WAE). The experiment works as follows: one of the wheels of the rover has a strip of black anodized aluminum bonded to the tread. The aluminum strip has thin coatings of aluminum, nickel and platinum deposited in patches. There are five (5) patches or samples of each metal, and the patches range in thickness from 200 A to 1000 A. The different metals were chosen for their differing hardness and their environmental stability. As the wheel is spun in the Martian soil, the thin patches of metal are abraded away, exposing the black anodization. The abrasion is monitored by measuring the amount of light reflected off of the samples. A photodetector was developed for this purpose, and that is the subject of this paper