Search

The results from a cross-national study comparing calculus performance of students at East China Normal University (ECNU) in Shanghai and students at the University of Michigan before and after their first university calculus course are presented. Overall, ECNU significantly outperformed Michigan on both the pre- and post-tests, but the Michigan students showed a larger gain and normalized gain, and hence narrowed the gap. ECNU's superior performance was especially striking on the subset of problems requiring only a pre-calculus background. On those, Michigan's post-test scores were below ECNU's pre-test scores and, indeed, ECNU's higher performance on both the overall pre-test and overall post-test is attributable to its success on these problems.

Estimates of the number of successfully breeding adults (NS) in a population can predict levels of recruitment. However, assessments of NS are often difficult to obtain because encounters with adults are limited due to life‐history characteristics, low abundance or other constraints associated with access to critical habitats. Alternatively, efforts to sample individuals at earlier ontogenetic stages can be more tractable, resulting in more comprehensive samples.To estimate NS, we describe, evaluate and apply two nonparametric species richness estimators to information associated with genetic pedigree reconstruction. Simulations compared bias and precision associated with Chao and Jackknife methods when estimating NS. We also evaluated NS estimation sensitivity to two sources of variation associated with species reproductive ecology (variance in reproductive success and sex ratio skew) and genetic pedigree assignment error. Finally, the application of our novel method was demonstrated in two different species and systems (Chinook Salmon in Oregon, USA and Lake Sturgeon in Michigan, USA).We found unbiased NS estimates were generated across a broad range of offspring sample sizes using the Chao method. Empirical results corroborated simulation‐based expectations and highlighted applications where parents and offspring are sampled, and when only offspring are sampled.When offspring sample sizes are adequate and pedigree reconstruction errors are low, the combination of established methods from community ecology and genetic pedigree reconstruction provides an accurate alternative method to estimate NS that can facilitate population assessments. [ABSTRACT FROM AUTHOR]

Aquatic habitat has been extensively altered throughout the Laurentian Great Lakes to increase navigation connectivity. In particular, the St. Marys River, a Great Lakes connecting channel, lost >50% of its historic rapids habitat over the past century. In 2016, the natural flow was restored to the Little Rapids area of the St. Marys River. The goal of our study was to evaluate physical and ecological responses to the restoration of the Little Rapids area. Extensive habitat and biological data were collected prior to restoration (2013 and 2014), and after restoration (2017 and 2018). Measured parameters included total suspended solids, current velocity, benthic macroinvertebrates, and larval, juvenile, and adult fishes. Total suspended solids stayed low (<4 mg/L) following restoration, with the exception of a single construction‐related event. Pre‐restoration data indicated that all measured velocities were below the target flow rate of 0.24 m/s, whereas 70% of the measured habitat was above the target flow post‐restoration. Abundance and richness of benthic macroinvertebrates were reduced following restoration (>90% reduction). We observed a 45% increase in richness of larval fish 2 years after restoration and a 131% increase in catch per unit effort. For adult fishes, the proportion of individuals with a preference for fast‐moving waters increased from 1.5 to 45% in the restored area, and from 7 to 15% upstream of the restored area; a similar response was observed for lithophilic spawners. The physical and biological conditions of the Little Rapids improved and resembled conditions typical of rapids habitat extent in other areas of the river and other systems. [ABSTRACT FROM AUTHOR]

BurbotLota lotaare a key demersal piscivore across the Laurentian Great Lakes whose populations have declined by about 90% in recent decades. Larval Burbot typically hatch in the early spring and rely on abundant crustacean zooplankton prey. We examined the stomach contents of larval Burbot from inshore (≤15 m) and offshore sites (37 and 91 m) in northern Lake Huron, Michigan. Concurrent zooplankton vertical tows at the same sites showed that the prey community was dominated by calanoid copepods, dreissenid mussel veligers, and rotifers. Burbot consumed mostly cyclopoid copepods, followed by copepod nauplii and calanoid copepods. Chesson's index of selectivity was calculated and compared among sites and months for individual Burbot. According to this index, larval Burbot exhibited positive selection for cyclopoid copepods and copepod nauplii and negative selection for calanoid copepods, cladocerans, rotifers, and dreissenid veligers. This selectivity was consistent across sites and throughout the sampling period. Burbot displayed little variation in their prey preferences during the larval stage, which suggests that the recent shifts in zooplankton abundance due to the invasion of the predatory zooplankterBythotrephes longimanusand competition from invasive Rainbow SmeltOsmerus mordaxcould negatively impact larval Burbot populations. Received September 7, 2012; accepted March 14, 2013 [ABSTRACT FROM AUTHOR]

1. Oligotrophic lakes are generally dominated by calanoid copepods because of their competitive advantage over cladocerans at low prey densities. Planktivory also can alter zooplankton community structure. We sought to understand the role of planktivory in driving recent changes to the zooplankton community of Lake Huron, a large oligotrophic lake on the border of Canada and the United States. We tested the hypothesis that excessive predation by fish (rainbow smelt Osmerus mordax, bloater Coregonus hoyi) and invertebrates ( Mysis relicta, Bythotrephes longimanus) had driven observed declines in cladoceran and cyclopoid copepod biomass between 2002 and 2007. 2. We used a field sampling and bioenergetics modelling approach to generate estimates of daily consumption by planktivores at two 91-m depth sites in northern Lake Huron, U.S.A., for each month, May-October 2007. Daily consumption was compared to daily zooplankton production. 3. Bythotrephes was the dominant planktivore and estimated to have eaten 78% of all zooplankton consumed. Bythotrephes consumption exceeded total zooplankton production between July and October. Mysis consumed 19% of all the zooplankton consumed and exceeded zooplankton production in October. Consumption by fish was relatively unimportant - eating only 3% of all zooplankton consumed. 4. Because Bythotrephes was so important, we explored other consumption estimation methods that predict lower Bythotrephes consumption. Under this scenario, Mysis was the most important planktivore, and Bythotrephes consumption exceeded zooplankton production only in August. 5. Our results provide no support for the hypothesis that excessive fish consumption directly contributed to the decline of cladocerans and cyclopoid copepods in Lake Huron. Rather, they highlight the importance of invertebrate planktivores in structuring zooplankton communities, especially for those foods webs that have both Bythotrephes and Mysis. Together, these species occupy the epi-, meta- and hypolimnion, leaving limited refuge for zooplankton prey. [ABSTRACT FROM AUTHOR]

The article offers information about court procedure related to mediation and offer of judgment rules in the U.S. Topics include Federal Rule of Civil Procedure 68, state judgment rules similar to the federal model in states such as Minnesota and Michigan, and proposed changes to federal rules regarding judgments and mediation.

Describes the work being done at the Grand Valley State University in Allendale, Michigan to address the lack of mathematical preparation by prospective mathematics teachers. Need of prospective mathematics teachers for mathematics courses that will develop their understanding of mathematical concepts that they will teach; Overview of the university's project and its goals; Inclusion of grades kindergarten-12 activities in college-level mathematics courses.

Focuses on the findings of clinical diagnosis of cases related to localized constricting lesions of the colon which are presented during the Clinical X-ray Staff Conferences on the Colon in Grand Rapids, Michigan in 1953. Fundamental problem in evaluation constricting lesions of the colon; Factors that led a radiologist to consider a lesion as carcinoma in a patient in a postradiation fibrosis condition; Results of a physical examination done on a woman complaining of abdominal pain and loss of appetite.

American and Japanese overnight deprived tobacco smokers were compared with respect to expired CO, plasma nicotine and cotinine, and red cell carboxyhemoglobin. The participants were 51 of 59 American and 55 of 86 Japanese cigarette smokers of mixed gender who met similar strict criteria. Female and male American tobacco smokers were similar in mean age, number of cigarettes smoked per day, machine-rated nicotine and tar yield per cigarette and per 24 h plasma cotinine, calculated previous 24 h nicotine dose, and exhaled CO. Only mean plasma nicotine levels were significantly higher in American females. American and Japanese female smokers had similar tobacco uptake parameters. American and Japanese male smokers differed; the latter had higher plasma nicotine and lower cotinine levels as well as calculated 24 h dose of nicotine and lower exhaled CO. Japanese females and males were similar in all tobacco smoke uptake parameters. When the two racial groups were compared, irrespective of gender, the only statistically significant differences were lower mean exhaled CO levels and percent COHb in the Japanese. It is concluded that Japanese males inhale cigarettes in moderation compared to Americans. The results are discussed in relation to known ethnic, social, and genetic differences in CYP2A6 gene polymorphism.

Previous analyses have implied diminished efficacy of angiotensin converting enzyme inhibitors (ACEI), and equivalent or enhanced efficacy of beta-blockers (BB), in African Americans (AA) with congestive heart failure (CHF), when compared to placebo. These results may have been influenced by lead-time bias, in that AA may not have been entered into the older ACEI trials until late in their CHF course. Our goal was to use a prospective cohort study of 29,686 CHF patients within a single health system to examine the impact on AA mortality of administering ACEI and BB within the first year of CHF diagnosis. Pharmacy claims from 1995-1998 were available for 3353 newly diagnosed CHF patients (39.2% AA; N=1317) within the health maintenance organization. Rates of ACEI and BB use were 46.4% and 54.0%; 43.4% and 28.9%; and 40.7% and 18.6%, for Whites, AA, and other races, respectively. The relative risk reductions (RRR) for ACEI were 68.7%, P<.0001; 52.1%, P<.0001; and -36.3%, P=.56, for Whites, AA, and other races, respectively. The RRR for BB were 59.0%, P<.0001; 34.6%, P=.009; and 74.3%, P=.17, for Whites, AA, and other races, respectively. Age- and gender-adjusted survival rates for AA were significantly enhanced in those taking ACEI, BB, or a combination of the two: P<.001, P=.001, and P=.003, respectively. Although we could not control for selection bias, these data suggest that AA benefit from both ACEI and BB when treatment is initiated within the first year of CHF diagnosis. Future, similar analyses other databases should control for the duration of illness to avoid lead-time bias in AA with CHF.

Background: Improved treatment of congestive heart failure (CHF) can slow disease progression, promote clinical stability, and prolong survival., Hypothesis: Patterns in diagnostic test utilization and pharmacotherapy among patients with newly diagnosed heart failure may affect outcomes., Methods: Claims data were analyzed from all diagnostic procedures and prescriptions from 1995 to 1998 in 3,353 patients with heart failure diagnosed within 1 year. Rates of diagnostic testing and categories of drugs prescribed were the main outcome measures. Demographic variables and type of provider were analyzed within a setting whose access to care was controlled., Results: Rates of diagnostic testing with respect to basic, metabolic/endocrine, alternative diagnoses, underlying ischemia, and left ventricular function varied as a function of gender, age, race, and primary versus specialty care provider. Only 4.7% of patients underwent all diagnostics and treatments recommended in current guidelines. However, those patients (27.5%) who underwent an evaluation for ischemic heart disease and were prescribed vasodilators or beta blockers enjoyed the lowest crude mortality., Conclusions: There are multiple opportunities apparent to improve the initial diagnostic and therapeutic care of patients with heart failure. There appears to be an early survival benefit with respect to use of vasodilators and beta blockers within the first year of treatment.