5,638 research outputs found
Larra bicolor Fabricius (Hymenoptera: Crabronidae): its distribution throughout Florida
We document the presence of Larra bicolor Fabricius (Hymenoptera: Crabronidae) in 46 of Florida's 67 counties. The species is represented by two stocks. The first (released in 1981) originated in Pará, Brazil, but was obtained from Puerto Rico, and became established in Broward County in southern Florida. The second (released in 1988) originated in Santa Cruz de la Sierra, Bolivia, and became established in Alachua County in northern Florida. The Bolivian stock, aided by additional satellite releases from Alachua County, is now widely distributed. The species probably occupies all counties in central and northern Florida, but may yet be absent from some southern counties. Introduction was made for classical biological control of invasive mole crickets
Pretend Play and Creativity in Preschool-Aged Children: Associations and Brief Intervention
Cognitive and affective processes in play have related to measures of creativity in school-aged children. In a previous examination of these play processes in preschool-aged children with the Affect in Play Scale-Preschool version, cognitive and affective play processes related to divergent thinking. One goal of the current study was to replicate this finding and examine the relationship between pretend play and storytelling creativity in preschoolers. A second goal was to test the effectiveness of a brief play intervention. Adult-led play interventions have effectively improved play skills and related developmental skills for children with documented play deficits. However, there is a need for an empirically-based, brief play intervention for typically developing preschool-aged children. A pilot study found medium to large effect sizes for increased play skills for an intervention with preschool-aged children and their parents. The current study aimed to examine the effectiveness of the intervention without parent involvement.
Forty-one typically developing children (ages 4-6 years) participated. Pretend play, divergent thinking, and creative storytelling were assessed at baseline and outcome. Children were randomly assigned to the play skills intervention, which received three 20-30 minute individual play sessions, or the active control. At baseline, results were that cognitive and affective play processes related to divergent thinking and creative storytelling. The play intervention did not significantly improve pretend play skills or creativity in the intervention group compared to the control group. Reasons for the nonsignfiicant findings for the intervention, suggestions for future refinement of the intervention, and implications for childhood development are discussed
Application and development of zero-valent iron (ZVI) for groundwater and wastewater treatment
Zero-valent iron has been used for more than 130 years for water treatment. It is based on redox reactions as well as on sorption to the corrosion products of iron. It is successfully applied for the removal of metals and organic pollutants from groundwater and wastewater. There are different variations how zero-valent iron can be used, especially (i) permeable reactive barriers, (ii) fluidized bed reactors and (iii) nanoscale zero-valent iron. Permeable reactive barriers are used for in situ treatment of groundwater in trench-like constructions or in a funnel and gate system. Their advantages are low maintenance cost, inexpensive construction and prevention of excavation wastes, and their disadvantages are surface passivation and clogging of pores by corrosion products. Zero-valent iron nanoparticles are injected directly in contaminated soil or groundwater. Their advantages are a higher reactivity than coarse-grained zero-valent iron and their mobility in the subsurface to reach the contaminated areas. However, they also have some major disadvantages like fast ageing in the system, phytotoxicity, agglomeration during migration and high costs. The latest development is a fluidized bed process (“ferrodecont process”) which avoids the passivation and clogging observed in permeable reactive barriers as well as the high costs and toxicity issues of nanoscale zero-valent iron. First results of this technology for Cr(VI) and organically contaminated groundwaters and metal removal from industrial wastewaters are highly promising
Assessment of Buffet Forcing Function Development Process Using Unsteady Pressure Sensitive Paint
A wind tunnel test was conducted at the Ames Unitary Plan Wind Tunnel to characterize the transonic buffet environment of a generic launch vehicle forebody. The test examined a highly instrumented version of the Coe and Nute Model 11 test article first tested in the 1960s. One of the measurement techniques used during this test was unsteady pressure sensitive paint (uPSP) developed at the Arnold Engineering Development Complex. This optical measurement technique measured fluctuating pressures at over 300,000 locations on the surface of the model. The high spatial density of these measurements provided an opportunity to examine in depth the assumptions underpinning the development of buffet forcing functions (BFFs) used in the development of the Space Launch System vehicle. The comparison of discrete-measurement-based BFFs to BFFs developed by continuous surface pressure integration indicates that the current BFF development approach under predicts low frequency content of the BFFs while over predicting high frequency content. Coherence-based adjustments employed to reduce over prediction in the surface integration of discrete pressure measurements contribute to the inaccuracy of the BFFs and their implementation should be reevaluated
Replication confers β cell immaturity.
Pancreatic β cells are highly specialized to regulate systemic glucose levels by secreting insulin. In adults, increase in β-cell mass is limited due to brakes on cell replication. In contrast, proliferation is robust in neonatal β cells that are functionally immature as defined by a lower set point for glucose-stimulated insulin secretion. Here we show that β-cell proliferation and immaturity are linked by tuning expression of physiologically relevant, non-oncogenic levels of c-Myc. Adult β cells induced to replicate adopt gene expression and metabolic profiles resembling those of immature neonatal β that proliferate readily. We directly demonstrate that priming insulin-producing cells to enter the cell cycle promotes a functionally immature phenotype. We suggest that there exists a balance between mature functionality and the ability to expand, as the phenotypic state of the β cell reverts to a less functional one in response to proliferative cues
Ares Launch Vehicle Transonic Buffet Testing and Analysis Techniques
It is necessary to define the launch vehicle buffet loads to ensure that structural components and vehicle subsystems possess adequate strength, stress, and fatigue margins when the vehicle structural dynamic response to buffet forcing functions are considered. In order to obtain these forcing functions, the accepted method is to perform wind-tunnel testing of a rigid model instrumented with hundreds of unsteady pressure transducers designed to measure the buffet environment across the desired frequency range. The buffet wind-tunnel test program for the Ares Crew Launch Vehicle employed 3.5 percent scale rigid models of the Ares I and Ares I-X launch vehicles instrumented with 256 unsteady pressure transducers each. These models were tested at transonic conditions at the Transonic Dynamics Tunnel at NASA Langley Research Center. The ultimate deliverable of the Ares buffet test program are buffet forcing functions (BFFs) derived from integrating the measured fluctuating pressures on the rigid wind-tunnel models. These BFFs are then used as input to a multi-mode structural analysis to determine the vehicle response to buffet and the resulting buffet loads and accelerations. This paper discusses the development of the Ares I and I-X rigid buffet model test programs from the standpoint of model design, instrumentation system design, test implementation, data analysis techniques to yield final products, and presents normalized sectional buffet forcing function root-mean-squared levels
Analysis of a Transonic Alternating Flow Phenomenon Observed During Ares Crew Launch Vehicle Wind Tunnel Tests
A transonic wind tunnel test of the Ares I-X Rigid Buffet Model (RBM) identified a Mach number regime where unusually large buffet loads are present. A subsequent investigation identified the cause of these loads to be an alternating flow phenomenon at the Crew Module-Service Module junction. The conical design of the Ares I-X Crew Module and the cylindrical design of the Service Module exposes the vehicle to unsteady pressure loads due to the sudden transition from separated to attached flow about the cone-cylinder junction with increasing Mach number. For locally transonic conditions at this junction, the flow randomly fluctuates back and forth between a subsonic separated flow and a supersonic attached flow. These fluctuations produce a square-wave like pattern in the pressure time histories which, upon integration result in large amplitude, impulsive buffet loads. Subsequent testing of the Ares I RBM found much lower buffet loads since the evolved Ares I design includes an ogive fairing that covers the Crew Module-Service Module junction, thereby making the vehicle less susceptible to the onset of alternating flow. An analysis of the alternating flow separation and attachment phenomenon indicates that the phenomenon is most severe at low angles of attack and exacerbated by the presence of vehicle protuberances. A launch vehicle may experience either a single or, at most, a few impulsive loads since it is constantly accelerating during ascent rather than dwelling at constant flow conditions in a wind tunnel. A comparison of a wind-tunnel-test-data-derived impulsive load to flight-test-data-derived load indicates a significant over-prediction in the magnitude and duration of the buffet loa
Treatment of Sleep Problems in Young Children: A Case Series Report of a Cognitive-Behavioral Play Intervention
Sleep problems and bedtime resistance are common in young children. Treatment is critical because sleep problems typically persist, and insufficient sleep is related to worse outcomes. Current behavioral treatments do not work directly with the child to reduce anxiety and distress at bedtime. Cognitive-behavioral play therapy is a treatment approach designed to teach coping skills to young children by combining cognitive-behavioral therapy with pretend play, a developmentally-appropriate intervention mode. The current case series examined the effectiveness of adding a brief cognitive-behavioral play intervention (CBPI) to parent behavior management for young children with sleep difficulties. Four children (4-6 years) received three 20-30 minute individual sessions during which the child played out stories with an advanced graduate student therapist (first author, K.F.) about a child coping with sleep problems. Each child’s parent also received a 30-minute sleep information session. Three parents returned questionnaires post-treatment. As expected, all three parents reported improvements in their child’s sleep habits, sleep anxiety, and general fears. All three parents also reported a high level of satisfaction with the treatment. These preliminary results suggest that the CBPI may be effective for decreasing anxiety and child distress when added to behavioral treatment, thus increasing the breadth of treatment approaches available for young children with sleep problems. These results are promising, although a randomized study is needed to further refine the intervention and establish the efficacy of a CBPI for treatment of sleep problems in young children
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