An Analytical Study of Ozone Feedbacks on Kelvin and Rossby–Gravity Waves: Effects on the QBO

An equatorial beta-plane model of the middle atmosphere is used to analytically examine the effects of radiative cooling and ozone heating on the spatial and temporal evolution of the quasi-biennial oscillation (QBO). Under the assumption that the diabatic heating is weak and the background fields of wind, temperature, and ozone are slowly varying, a perturbation analysis yields expressions describing the vertical spatial modulation of Kelvin and Rossby–gravity waves in the presence of ozone. These expressions show that wave-induced changes in the diabatic heating arising from the advection of basic-state ozone reduce the local radiative damping rate by up to 15% below 35 km. In a one-dimensional model of the QBO, eddy ozone heating increases the amplitude of the zonal wind QBO by 1–2 m s−1 and increases the oscillation period by about two months. The significance of these results to the observed QBO is discussed

Isosorbide dinitrate-hydralazine combination therapy in African Americans with heart failure

Despite significant improvement in therapy and management, heart failure remains a worrisome disease state that is especially problematic in special populations. African Americans suffer a disproportionately higher prevalence of heart failure when compared to other populations. It has been recently demonstrated that vasodilator therapy using the combination of isosorbide dinitrate (ISDN) and hydralazine (HYD) as an adjunct to background evidence-based therapy appears to display the strongest signal of benefit in reducing mortality and morbidity in the African American population. Through review of the retrospective and more recent prospective data, we will focus on the benefit of ISDN-HYD as adjunctive therapy for use in African Americans with systolic heart failure on concomitant appropriate evidence based therapy. This review also closely examines some of the potential contributions to endothelial dysfunction in African Americans, and the relationship of vascular homeostasis and nitric oxide. The role of oxidative stress in left ventricular dysfunction will also be explored as a reduction of oxidative stress offers particular promise in the management of heart failure. Although neurohormonal blockade has been responsible for notable event reductions in patients with systolic heart failure, the addition of ISDN-HYD, vasodilator therapy that enhances nitric oxide and reduces oxidative stress, further improves quality of life and survival in African American patients with heart failure. These findings strongly imply that nitric oxide enhancement and/or oxidative stress reduction may be important new therapeutic directions in the management of heart failure

What Explained Nonprofit Organizations’ Satisfaction with Volunteer Retention During the COVID-19 Pandemic?

The purpose of this quantitative study was to investigate nonprofit organizations’ satisfaction with volunteer retention during the COVID-19 pandemic. The participants were 74 nonprofit organizations’ leaders who participated in the online survey. The response rate was 10.6%. We found that the overall mean score for satisfaction with organizational retention of volunteers during the COVID-19 pandemic was 3.50 (SD = .98), and the importance of volunteer management practices was 3.52 (SD = .96). Most nonprofit organizations were proactive (38.8%) and reacted promptly (52.2%) while addressing the organizations’ response to the pandemic. Approximately 10.3% of the variation in satisfaction with organizational retention of volunteers during the COVID-19 pandemic could be explained by the importance of volunteer management practices and organizational response to the COVID-19 pandemic. However, within the final model, only one factor was a significant predictor of satisfaction with organizational retention of volunteers during the COVID-19 pandemic, namely, organizational response to the COVID-19 pandemic (β = -.304; p = .014). Recommendations for future research discussed. Implications for volunteer management and leadership studies faculty, University Extension educators, human resources practitioners, and local nonprofit organizations’ leaders are also presented

Red light camera enforcements in Missouri City, Texas

Discusses the advantages and disadvantages of installing red light cameras

Creative Science Through Inquiry: Improving Teacher Self-Efficacy and Outcome Expectancy Through Adaptable, Mystery-Based Professional Development

Teacher self-efficacy is an important contributor to student outcomes, school climate and teacher retention. Outcome expectancy, a construct studied more commonly in health- and behaviour-related fields, may also positively impact school-related outcomes. Research shows that professional development can increase teacher confidence, but few studies have considered this connection for science-focused professional development, specifically. Our study assesses the impact of a science-focused, mystery-based professional development workshop for upper-elementary to high-school teachers. The hands-on, collaborative nature of this workshop allowed for generalisability to classrooms of various ability levels. Using the Science Teaching Efficacy Belief Instrument-A (STEBI-A) as a measure of science-teaching self-efficacy and outcome expectancy, we found that participants’ self-reported self-efficacy and outcome expectancy significantly increased (p < .001 for each) over the course of the two-week workshop. This outcome is especially relevant to schools and districts interested in improving student outcomes, school climate and teacher retention rates

History of contaminant inputs into Lake Mead derived from sediment cores

Assessing the changes in contaminant inputs (both organic and inorganic) over time is important in determining sources and sinks of these inputs. Variations in contaminant input were assessed in four sediment cores taken in 1998 from three different parts of Lake Mead (two from Las Vegas Bay and one from Overton Arm and Virgin Basin). Sediments were analyzed for major and trace elements, radionuclides, and organic compounds. Anthropogenic contaminant concentrations are greatest in Las Vegas Bay reflecting inputs from the Las Vegas urban area, although concentrations are low compared to sediment quality guidelines and to other USA lakes. One exception to this pattern was higher mercury concentrations in the Virgin Basin core. The Virgin Basin core is in the main body of the reservoir and is influenced by the hydrology of the Colorado River, which changed after completion of Glen Canyon Dam. Major- and trace-elements in the core show pronounced shifts in the early 1960s and, in many cases, gradually return to concentrations more typical of pre-1960s by the 1980s and 1990s, after the filling of Lake Powell upstream. The Overton Arm is the sub-basin least effected by anthropogenic contaminant inputs. Cores from Las Vegas Bay taken in 2007 were analyzed for emerging contaminants and although data are still preliminary, detections of musk fragrances have been found only in the upper 10 – 15 cm of the core, indicating that these compounds either degrade with time or have only been accumulating for the past 10 – 20 years

Feasibility of utilizing the 200-inch Hale telescope as a deep-space optical receiver

Capturing the very faint optical communications signals expected from the Mars Laser Communication Demonstration (MLCD) experiment to fly aboard the Mars Telecommunications Orbiter (MTO) in 2009 requires a sensitive receiver placed at the focus of a large collecting aperture. For the purpose of demonstrating the potential of deep-space optical communication, it makes sense to employ a large astronomical telescope as a temporary receiver. Because of its large collecting aperture, its reputation as a well-run instrument, and its relative convenience, the 200-inch Hale Telescope on Palomar Mountain is being considered as a demonstration optical 'antenna' for the experiment. However, use of the telescope in this manner presents unique challenges to be overcome, the greatest of which is pointing the telescope and maintaining the communication link to within a few degrees of the Sun. This paper presents our candidate approaches for adapting the Hale telescope to meet the demonstration requirements, modifications to the facilities and infrastructure, the derivation of requirements for baffles and filters to meet the near-Sun pointing objectives, and initial data on the potential of candidate modifications to meet the requirements

An atypical receiver domain controls the dynamic polar localization of the Myxococcus xanthus social motility protein FrzS

The Myxococcus xanthus FrzS protein transits from pole-to-pole within the cell, accumulating at the pole that defines the direction of movement in social (S) motility. Here we show using atomic-resolution crystallography and NMR that the FrzS receiver domain (RD) displays the conserved switch Tyr102 in an unusual conformation, lacks the conserved Asp phosphorylation site, and fails to bind Mg2+ or the phosphoryl analogue, Mg2+·BeF3. Mutation of Asp55, closest to the canonical site of RD phosphorylation, showed no motility phenotype in vivo, demonstrating that phosphorylation at this site is not necessary for domain function. In contrast, the Tyr102Ala and His92Phe substitutions on the canonical output face of the FrzS RD abolished S-motility in vivo. Single-cell fluorescence microscopy measurements revealed a striking mislocalization of these mutant FrzS proteins to the trailing cell pole in vivo. The crystal structures of the mutants suggested that the observed conformation of Tyr102 in the wild-type FrzS RD is not sufficient for function. These results support the model that FrzS contains a novel ‘pseudo-receiver domain’ whose function requires recognition of the RD output face but not Asp phosphorylation

Speech Facilitates the Categorization of Motions in 9-Month-Old Infants

Two experiments were used to investigate the influence of both native and non-native speech on the categorization of a set of an object’s motions by 9-month-olds. In Experiment 1, infants were habituated to a set of three object motions and tested with familiar and novel motions. Results of Experiment 1 show that infants were more likely to categorize the motion stimuli if they listened to either the native or non-native speech during the categorization process than if they listened to music or heard nothing at all. Results of Experiment 2 show that discrimination of the motions was not impaired by the presence of the labeling phrases. These results are consistent with a number of findings that report a unique influence of labels on categorization of static objects in infancy and extend those findings to categorization of motions