College of Southern Nevada

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

This study evaluated norms for fine motor dexterity skills on elementary school children of ages 5 through 10 and conducted reliability and validity stud ies utilizing the Nine-hole Peg Test. The sample included 826 students in 10 elementary schools. Moderately high test-retest reliability (rs = .81 and .79) and high interrater agreement (rs > .99) were obtained. Older students had shorter completion time that measured fine motor dexterity than younger students. Significant sex differences were found in completion time, but only for the dominant hand. Correlations of -.80 and -.74 between the scores on the Nine hole Peg Test and Purdue Pegboard Test at all tested ages indicated adequate concurrent validity of the measures and a significant difference in test scores between regular and special education groups provided further evidence of construct validity. The findings supported the Nine-hole Peg Test as an effective screening tool for fine motor dexterity of school-age children.

For several millennia, stem extracts of Ephedra (Ephedraceae, Gnetales) have been used as folk medicines in both the Old and New World. Some species were used in treatments of questionable efficacy for venereal disease in North America during the last century. Many Eurasian species produce phenylethylamine alkaloids, mostly ephedrine and pseudoephedrine, that interact with adrenergic receptors in the mammalian sympathetic nervous system. Asian Ephedra have been used recently in the clandestine manufacture of a street drug, methamphetamine. Although ephedrine alkaloids are not detectable in New World species of Ephedra, together with Asian species they contain other nitrogen-containing secondary metabolites with known neuropharmacological activity. Many mesic and particularly xeric species worldwide accumulate substantial amounts of quinoline-2-carboxylic acids, or kynurenates, in their aerial parts. Many species of Ephedra accumulate cyclopropyl amino acid analogues of glutamate and proline in their stems and roots, and particularly in the seed endosperm. Mesic species synthesize substantial amounts of three L-2-(carboxycyclopropyl)glycine stereomers rarely seen in nature. A cyclopropyl analogue of proline with known antimicrobial activity, cis-3,4-methanoproline, is found in large amounts in the stems and seeds of many Ephedra species. The ability to synthesize cyclopropyl amino acids may be an ancestral feature in the taxon. The natural function in the taxon of these three groups of secondary compounds remains to be established.

Multiple curricular approaches are being used to teach cultural competency to nursing students in the United States in accordance with accrediting board standards. As nurse educators are searching for evidence based teaching practices, this article reviews the most commonly current teaching methods being used. Although a variety of methods are being implemented, little empirical evidence exists to suggest any one methodology for teaching cultural competency for nursing students produces significantly better outcomes. The use of clinical experiences, standardized patients and immersion experiences have produced the most favorable results which increase student awareness, knowledge and confidence in working with ethnically diverse patients.

A general population sample of bite marks in wax is used to demonstrate mathematically the individuality of the human dentition. The general principles of probability are discussed and applied to the analysis of teeth using a precise method of measurement. The unique nature of the human dentition is confirmed.

The decision tree method has grown fast in the past two decades and its performance in classification is promising. The tree-based ensemble algorithms have been used to improve the performance of an individual tree. In this study, we compared four basic ensemble methods, that is, bagging tree, random forest, AdaBoost tree and AdaBoost random tree in terms of the tree size, ensemble size, band selection (BS), random feature selection, classification accuracy and efficiency in ecological zone classification in Clark County, Nevada, through multi-temporal multi-source remote-sensing data. Furthermore, two BS schemes based on feature importance of the bagging tree and AdaBoost tree were also considered and compared. We conclude that random forest or AdaBoost random tree can achieve accuracies at least as high as bagging tree or AdaBoost tree with higher efficiency; and although bagging tree and random forest can be more efficient, AdaBoost tree and AdaBoost random tree can provide a significantly higher accuracy. All ensemble methods provided significantly higher accuracies than the single decision tree. Finally, our results showed that the classification accuracy could increase dramatically by combining multi-temporal and multi-source data set.

Over three field seasons between 2007 and 2012, we excavated three caves—Mota, Tuwatey, and Gulo—situated at an average elevation of 2,084 m above sea level in the cool and moist Boreda Gamo Highlands of southwestern Ethiopia. Anthropogenic deposits in these caves date from the Middle to Late Holocene (ca. 6000 to 100 BP) and provide excellent preservation of material culture, fauna, flora, and human skeletal remains from which to investigate changes in technologies and habitat use over the last several thousand years. Here, we present results and interpretations, suggesting ways in which Holocene communities of the Boreda Gamo Highlands constructed new landscapes and technologies in their transition from hunting and gathering to an agropastoral way of life.

The Monterrey metropolitan area (MMA) is the third greatest urban area and the second largest economic city of Mexico. More than four million people living in this megacity use groundwater for drinking, industrial and household purposes. Thus, major ion and trace element content were assessed in order to investigate the main hydrochemical properties of groundwater and determine if groundwater of the area poses a threat to the MMA population. Hierarchical cluster analysis using all the groundwater chemical data showed five groups of water. The first two groups were classified as recharge waters (Ca-HCO3) coming from the foothills of mountain belts. The third group was also of Ca-HCO3 water type flowing through lutites and limestones. Transition zone waters of group four (Ca-HCO3-SO4) flow through the valley of Monterrey, whereas discharge waters of group 5 (Ca-SO4) were found toward the north and northeast of the MMA. Principal component analysis performed in groundwater data indicates four principal components (PCs). PC1 included major ions Si, Co, Se, and Zn, suggesting that these are derived by rock weathering. Other trace elements such as As, Mo, Mn, and U are coupled in PC2 because they show redox-sensitive properties. PC3 indicates that Pb and Cu could be the less mobile elements in groundwater. Although groundwater supplied to MMA showed a high-quality, high mineralized waters of group 5 have NO3 − concentrations higher than the maximum value proposed by international guidelines and SO4 2−, NO3 −, and total dissolved solid concentrations higher than the maximum levels allowed by the Mexican normative.

Environmental conditions which define boundaries for biofilm production could provide useful ecological information for biofilm models. A practical use of defined conditions could be applied to the high-level nuclear waste repository at Yucca Mountain. Data for temperature and humidity conditions indicate that decreases in relative humidity or increased temperature severely affect biofilm formation on three candidate canister metals.

Cataracts, one of the leading causes of preventable blindness worldwide, refers to lens degradation that is characterized by clouding, with consequent blurry vision. As life expectancies improve, the number of people affected with cataracts is predicted to increase worldwide, especially in low-income nations with limited access to surgery. Although cataract surgery is considered safe, it is associated with some complications such as retinal detachment, warranting a search for cheap, pharmacological alternatives to the management of this ocular disease. The lens is richly endowed with a complex system of non-enzymatic and enzymatic antioxidants which scavenge reactive oxygen species to preserve lens proteins. Depletion and/or failure in this primary antioxidant defense system contributes to the damage observed in lenticular molecules and their repair mechanisms, ultimately causing cataracts. Several attempts have been made to counteract experimentally induced cataract using in vitro, ex vivo, and in vivo techniques. The majority of the anti-cataract compounds tested, including plant extracts and naturally-occurring compounds, lies in their antioxidant and/or free radical scavenging and/or anti-inflammatory propensity. In addition to providing an overview of the pathophysiology of cataracts, this review focuses on the role of various categories of natural and synthetic compounds on experimentally-induced cataracts.

The purpose of this paper is to study two notions of stochastic comparisons of non-negative random variables via ratios that are determined by their Laplace transforms. Some interpretations of the new orders are given, and various properties of them are derived. The relationships to other stochastic orders are also studied. Finally, some applications in reliability theory are described.

Abstract This study compared the impact of proctoring on the final course grades of community college students enrolled in distance education mathematics courses. The goal was to determine whether distance education students who are evaluated entirely online, in environments that are not proctored, receive grades that differ from distance education students who take proctored exams. In an analysis of 850 grades from a variety of distance education mathematics courses, 406 were given to students who were evaluated in a proctored environment, and the remaining 444 were a result of assessment that was conducted entirely in the online setting and was not proctored. Statistical analysis revealed no significant difference between the grades that were earned in any of the individual courses. Also, no significant difference was found when the grades of the 406 students who took exams in person were compared with the 444 who were assessed entirely in an unsupervised online environment.

Let X 1 , X 2 ,… be a sequence of independent random variables and let N be a positive integer-valued random variable which is independent of the X i . In this paper we obtain some stochastic comparison results involving min { X 1 , X 2 , …, X N ) and max{ X 1 , X 2 ,…, X N } .

Multispecies interbreeding networks, or syngameons, have been increasingly reported in natural systems. However, the formation, structure, and maintenance of syngameons have received little attention. Through gene flow, syngameons can increase genetic diversity, facilitate the colonization of new environments, and contribute to hybrid speciation. In this study, we evaluated the history, patterns, and consequences of hybridization in a pinyon pine syngameon using morphological and genomic data to assess genetic structure, demographic history, and geographic and climatic data to determine niche differentiation. We demonstrated that Pinus edulis, a dominant species in the Southwestern US and a barometer of climate change, is a core participant in the syngameon, involved in the formation of two drought-adapted hybrid lineages including the parapatric and taxonomically controversial fallax-type. We found that species remain morphologically and genetically distinct at range cores, maintaining species boundaries while undergoing extensive gene flow in areas of sympatry at range peripheries. Our study shows that sequential hybridization may have caused relatively rapid speciation and facilitated the colonization of different niches, resulting in the rapid formation of two new lineages. Participation in the syngameon may allow adaptive traits to be introgressed across species barriers and provide the changes needed to survive future climate scenarios.

Soil compaction from human trampling, biking, and off-road motor vehicle traffic was quantitatively investigated in a blackbrush ( Coleogyne ramosissima ) shrubland in Kyle Canyon of the Spring Mountains in southern Nevada. A significant difference was detected in soil compaction, bulk density, and percent pore space at a particular frequency of visits in each of 4 disturbance types. On average a single vehicle pass was equivalent to 10 human footprints. Ten and 100 footprints were equivalent to 1 motorcycle pass and 10 vehicle passes, respectively. Soil compaction is a product of increased bulk density and decreased pore space. The degree of soil compaction is a function of disturbance type and visit frequency when examining these 2 factors independently. However, interactive effects of disturbance type and visit frequency on soil bulk density, compaction, and percent pore space were not significantly different. The greatest effects occurred during the first few passes, with changes per pass decreasing as the number of passes increased in all 4 trails. Results of this study suggest that the effects of hiking and biking slowly increase over time relative to the effects of motor vehicle traffic in the Coleogyne shrubland of Kyle Canyon in southern Nevada.

We examine issues involving science which have been contested in recent public debate. These “contested science” issues include human evolution, stem-cell research, and climate change. We find that few respondents evince consistently skeptical attitudes toward science issues, and that religious variables are generally strong predictors of attitudes toward individual issues. Furthermore, and contrary to analyses of elite discourse, partisan identification is not generally predictive of attitudes toward contested scientific issues.

Microorganisms, implicated in microbiologically influenced corrosion, were isolated from the deep subsurface at Yucca Mountain. Corrosion rates of iron-oxidizing, sulfate-reducing, and exopolysaccharide (EPS)-producing bacteria were examined in constructed electrochemical corrosion cells for periods up to 109 days. The test system consisted of a 1020 carbon steel (CS) coupon immersed in soft R2A agar prepared with simulated groundwater. A 1% potassium chloride (KCl) bridge was used to connect the test to a reference calomel electrode and a potential was applied with a platinum counter electrode. The corrosion process was measured by polarization resistance methodology. Average corrosion rates were measured in milli-inches per year (mpy) against time. Purified cultures of EPS-producing bacteria and enrichment cultures of iron-oxidizing and sulfate-reducing bacteria were tested separately and in various combinations. An uninoculated control cell was prepared to assess abiotic corrosion. The corrosion rates peaked at 35 days at 1.2 mpy (control), 2.3 mpy (iron-oxidizing bacteria), 3.30 mpy (sulfate-reducing bacteria), and 2.8 mpy (EPS-producing bacteria) before stabilizing. Various microbial combinations demonstrated higher corrosion rates (3.1 mpy to 4.8 mpy) than single groups and peaked at 30 days. The results indicate that Yucca Mountain microorganisms, alone and in combination, are capable of causing corrosion of 1020 CS. Upon completion of these experiments, phospholipid fatty acid analysis detected all of the bacterial groups inoculated into the individual test systems, suggesting that biofilm development had occurred. The examination of mineralized biofilms on the CS surface with light microscopy and scanning electron microscopy/energy-dispersive x-ray analysis (SEM/EDXA) demonstrated that all of the bacterial groups promoted a generalized corrosion process; however, the corrosion experiments containing SRB were particularly effective in biofilm development and pitting.

We conducted a three-year study to describe the ecology and behavior of the Midget Faded Rattlesnake, Crotalus organus concolor. We encountered 426 and telemetered 50 C. o. concolor between 2000 and 2002. We found that their primary diet was lizards (associated with rock outcrops), though they will consume small mammals and birds. They den in aggregations, although in low numbers when compared to other subspecies. Movements and activity ranges were among the largest reported for rattlesnakes. Minimum convex polygon area was 117.8 ha for males, 63.9 ha for nongravid females, and 4.8 ha for gravid females. Mean distances traveled per year were 2122.0 m for males, 1956.0 m for nongravid females, and 296.7 m for gravid and postpartum females. Following emergence from hibernation, they spent several weeks shedding, often in aggregations before migration, and migrations occurred in early summer. Most snakes made straight-line movements to and from discrete summer activity ranges where short, multidirectional movements ensued, although others made multidirectional movements throughout the active season. We observed mating behavior between 21 July and 12 August. Gravid females gave birth during the third week of August. Mean clutch size was 4.17 (range 2–7). We found that the sex ratio was skewed favoring females 1:1.24, and they were sexually dimorphic in size (males SVL = 44.1 cm; females SVL = 40.8 cm). Our data further illustrate the diversity within the large group of Western Rattlesnakes (Crotalus viridis).

Background: Noncommunicable diseases (NCDs) are one of the major global health challenges in developed countries and are rapidly increasing globally. Perception of self-efficacy is important for complex activities and long-term changes in health behavior. This study aimed to determine whether self-efficacy mediates the effect of individual beliefs (perceived severity, susceptibility, benefits and barriers) among informal settlement residents’ health behavior in relation to the prevention and management of NCDs. Methods: A cross-sectional survey was conducted using a closed-ended questionnaire among informal settlement residents in Diepsloot, Johannesburg. The proposed model was tested using structural equation modeling (AMOS software). Results: A total of 2,277 participants were interviewed during this survey, consisting of 1,236 (54.3%) females, with the majority of them aged between 20 and 29 years. All constructs in the questionnaire had a good reliability with a Cronbach’s alpha of >0.7. Perceived benefits and perceived barriers were the strongest predictors of self-efficacy, with the highest beta values of 0.14 and 0.15, respectively. Once associated with perceived self-efficacy, the direct effect of perceived susceptibility and perceived benefits on health behavior was statistically nonsignificant ( P =0.0894 and P =0.2839, respectively). Perceived benefits and perceived susceptibility were totally mediated by self-efficacy. The indirect effects of perceived severity and perceived barriers (through self-efficacy) on health behavior were significant. Thus, perceived severity and perceived barriers were partially mediated by self-efficacy. Conclusion: Perceived susceptibility and perceived benefits did not affect health behavior unless associated with self-efficacy. In contrast, individual perception of the seriousness of NCDs and perceived barriers might still have a direct influence on health behavior even if the person does not feel able to prevent NCDs. However, this influence would be more significant when perceived severity and perceived barriers of NCDs are associated with self-efficacy. Keywords: perceptions, Diepsloot township, health belief model, noncommunicable diseases, perceived susceptibility, perceived barriers

Most universities now offer a plethora of on-campus courses for students to choose from. However, many students are not able to take campus-based courses due to distance or timetabling limitations. An important option for such students has always been distance education. This paper focuses on the use of multimedia delivery technologies and their effect on how distance education is received and used by students. It discusses the creation, delivery and evaluation of an online version of an existing campus-based module. A quantitative comparison of the two methods of course delivery has been made and the results are then discussed in terms of examination performance and attrition. Confirming the initial hypothesis, no significant differences were found.