NHTI - Concord's Community College

Declining oxygen concentrations in the deep waters of lakes worldwide pose a pressing environmental and societal challenge. Existing theory suggests that low deep-water dissolved oxygen (DO) concentrations could trigger a positive feedback through which anoxia (i.e., very low DO) during a given summer begets increasingly severe occurrences of anoxia in following summers. Specifically, anoxic conditions can promote nutrient release from sediments, thereby stimulating phytoplankton growth, and subsequent phytoplankton decomposition can fuel heterotrophic respiration, resulting in increased spatial extent and duration of anoxia. However, while the individual relationships in this feedback are well established, to our knowledge, there has not been a systematic analysis within or across lakes that simultaneously demonstrates all of the mechanisms necessary to produce a positive feedback that reinforces anoxia. Here, we compiled data from 656 widespread temperate lakes and reservoirs to analyze the proposed anoxia begets anoxia feedback. Lakes in the dataset span a broad range of surface area (1-126,909 ha), maximum depth (6-370 m), and morphometry, with a median time-series duration of 30 years at each lake. Using linear mixed models, we found support for each of the positive feedback relationships between anoxia, phosphorus concentrations, chlorophyll a concentrations, and oxygen demand across the 656-lake dataset. Likewise, we found further support for these relationships by analyzing time-series data from individual lakes. Our results indicate that the strength of these feedback relationships may vary with lake-specific characteristics: For example, we found that surface phosphorus concentrations were more positively associated with chlorophyll a in high-phosphorus lakes, and oxygen demand had a stronger influence on the extent of anoxia in deep lakes. Taken together, these results support the existence of a positive feedback that could magnify the effects of climate change and other anthropogenic pressures driving the development of anoxia in lakes around the world.

Abstract The use of the 1–4 grading scale is gaining popularity as schools transition to competency‐based education. However, independent interpretations and percentage conversions have led to general confusion and sometimes outright rejection of competency‐based assessment. The first step to establish clear communication is to anchor the existing four‐point GPA scale in cognitive performance, which provides a strong framework for improved student engagement. Applied research into the learning brain is shifting classroom expectations to actively engage learners with stimulating cognitive challenges, such as synthesis and creative transfer. When the cognitive performance curve is consistently applied in the development of assessment rubrics, educators will provide stronger analytical feedback through meaningful common grades.

Transcultural nursing practices for terminally ill patients. To examine several criticisms of transcultural nursing theory in end-of-life care. Published literature and interviews with nurses. Nurses often encounter barriers that impede their ability to provide ideal end-of-life care.

This study assessed the predictive validity of the Risk and Promise Profile© 1 with a diverse sample of 542 two-year and four-year older college students at six educational institutions. The profile is a seventy-eight-item, self-report, paper and pencil questionnaire that can be used to outline a profile of personal and social influences that are related to persistence. Hierarchical multiple regression and ANOVA indicate that the profile explains significant portions of the variance associated with academic success. The results also suggest that different measures are related to the success of Caucasian students and African-American students. Further, the study suggests that race per se should not be used to identify students “at risk.” Instead, combinations of personal and social measures are more appropriate predictors of academic performance.

The purpose of this study was to determine if a relationship exists between participation in a therapeutic riding program and improvement in self-concept. Using a One Group Pre and Post Test design...

The lack of scientific data which accurately addresses the evaluation/success verification question in the treatment of alcoholism is being raised. The willingness of providers to guarantee treatment outcome would assure the public of the providers' belief in the efficacy of their work; in addition, it would create a database to support such claims.

Particulate size distributions were obtained in the effluent gases from three steam generating boilers of a power station employing mechanical, steam, and air systems for heavy fuel atomization. Samples were obtained with an eight-stage cascade impactor. The air atomized burner produced the lowest particulate loading, the greatest percentage of particulates by weight in the submicron range, and particulates with the lowest combustible content.