10,364 research outputs found
Theoretical Studies of Several Small-Ring Precursors to (+)-JQ1
We present the results of DFT(B3LYP) calculations on several precursors to (+)-JQ1 using an accurate basis set, including a report of conformational analysis, thermochemistry, optimized geometries and electrostatic potentials, and calculated IR and Raman spectra. Species include (I)1H-1,4-diazepin-2(3H)-imine, (II) 9H-[1,2,4]triazolo[4,3-a][1,4]diazepine, (III) 6H-thieno[3,2-f][1,2,4]triazolo[4,3a][1,4]diazepine, and (IV) 4-(4-chlorophenyl)-6H-thieno[3,2f][1,2,4]triazolo[4,3-a][1,4]diazepine. Studies are also reported on monobrominated (II)-(IV) substituted at the chiral center of the seven member ring, including a comparison of the energetics of equatorial versus axial bromination of the parent precursor. Implications with regard to the larger structure of (+)-JQ1 are discussed
Changes in Soil pH Caused by Heavy Nitrogen Fertilization
Ammonium nitrate, ammonium phosphate, ammonium sulfate, urea and anhydrous ammonia leave acid residues, thus tending to make the soils more acid. The degree to which soil pH may be affected and the persistence of such changes for a silt loam soil is shown in the table below. The same amounts of phosphorus and potash were applied to all plots, and the different amounts of nitrogen were supplied from ammonium nitrate. Burley tobacco was the crop grown and the data are for 1963, which was the second consecutive year for the fertilizer treatments. (These were experimental plots and the high treatments are not recommended for burley production.
Community Violence and Trauma: The Influence of Child Abuse, Bullying, and Intimate Partner Violence
Community violence exposure is associated with a myriad of physical and mental health problems and adjustment difficulties (Fowler, Tompsett, Braciszewski, Jacques-Tiura & Baltes, 2009; Senn, Walsh & Carey, 2016 ; Voisin, Chen, Fullilove & Jacobson, 2015). However, the research that investigates the adult mental health consequences of community violence exposure within the context of other potentially traumatic events is still emerging (Walling, Eriksson, Putman & Foy, 2011; Kennedy, Bybee & Greeson, 2014 ). This dissertation responds to this gap in the literature. This study investigated the interrelationships among violence exposures in community, school, family and intimate relationships and PTSD symptoms. The study also examined whether child abuse, intimate partner violence and school bullying moderated the relationship between community violence exposure and PTSD. The researcher collected data from 499 undergraduate students using a demographic questionnaire, the Trauma Symptom Checklist -40 (Briere & Runtz, 1989), the Survey of Exposure to Community Violence (SECV; Richters & Saltzman, 1990), the Retrospective Bully Questionnaire (RBQ; Schäfer, et al,2004), the Composite Abuse Scale (Hegarty, Bush, Sheehan, 2005) and the Early Trauma Inventory-Self Report (ETI-SR; Bremner, Bolus & Mayer, 2007). Bivariate correlations revealed significant, positive correlations between PTSD and community violence exposure (r =.264, p \u3c .01), school bullying (r = .242, p \u3c .01), intimate partner violence (r = .327, p \u3c .01) and child abuse (r = .292, p \u3c .01). Community violence, child abuse, intimate partner violence and school bully significantly predicted the variance in PTSD symptoms. The study found that child abuse, intimate partner violence and school bullying scores were (β = -.000, t (216) = -.027, p \u3e.01) not substantial moderators for the relationship between community violence and PTSD with this sample F(211) = 8.067, p \u3c .01, R2 = .192 ) . Demographic differences in PTSD symptoms and community violence exposure were observed
Many-Impurity Effects in Fourier Transform Scanning Tunneling Spectroscopy
Fourier transform scanning tunneling spectroscopy (FTSTS) is a useful
technique for extracting details of the momentum-resolved electronic band
structure from inhomogeneities in the local density of states due to
disorder-related quasiparticle scattering. To a large extent, current
understanding of FTSTS is based on models of Friedel oscillations near isolated
impurities. Here, a framework for understanding many-impurity effects is
developed based on a systematic treatment of the variance Delta rho^2(q,omega)
of the Fourier transformed local density of states rho(q,\omega). One important
consequence of this work is a demonstration that the poor signal-to-noise ratio
inherent in rho(q,omega) due to randomness in impurity positions can be
eliminated by configuration averaging Delta rho^2(q,omega). Furthermore, we
develop a diagrammatic perturbation theory for Delta rho^2(q,omega) and show
that an important bulk quantity, the mean-free-path, can be extracted from
FTSTS experiments.Comment: 7 pages, 5 figures. A version of the paper with high resolution,
colour figures is available at
http://www.trentu.ca/physics/batkinson/FTSTS.ps.gz minor revisions in
response to refree report + figure 5 is modifie
Yield and Value of Burley 21 Tobacco as Influenced by Nitrogen Nutrition, Suckering Practice, and Harvest Date
An experiment was conducted in the field during 1966 on Maury silt loam soil to obtain information of the effects of agronomic factors on yield and value of Burley 21 tobacco . Ammonium nitrate fertilizer at varying rates, and concentrated super-phosphate and potassium sulfate at constant rates , were broadcast and disked in after plowing and before transplanting. All plots received irrigation water (sprinkler system) to supplement rainfall when soil moisture dropped below 60% of available moisture-holding capacity. Sucker control practices utilized were (a) no topping - no suckering, (b) topping - no suckering, (c) topping - hand suckering, and (d) topping - MH-30. Half of the tobacco was harvested early (about 1 week prior to maturity) and half late (1 week past maturity) . However, N fertilizer at the 400 lb/ acre N rate delayed maturity about 2 weeks beyond that for tobacco treated at the 100 and 200 N rates . Thus all the early harvests were made 1 week prior to maturity, the 100- and 200-lb N treated plots 2 weeks later, and the 400-lb N plots 4 weeks after the early harvest
Transport and Fate of River Discharge on the Continental Shelf of the Southeastern United States
We have analyzed 8 years of wind and salinity data from a frontal zone in a region of the inner continental shelf off the southeastern United States. The changes in low‐salinity water stored in the frontal zone have been parameterized by analyzing the monthly rate of change in freshwater content. When the rate of change in freshwater content was negative, we interpreted this as a loss of low‐salinity water from the frontal zone. When this parameter was compared with seasonally averaged alongshore wind stress, the rate of loss was independent of the alongshore wind stress magnitude until threshold of about 0.1 dyne cm−2 was reached. Above the threshold there was a clear relationship between northward alongshore wind stress and rate of loss of freshwater from the inner shelf. Experimental evidence suggests that horizontal currents in the inner‐shelf frontal zone have cyclonic shear with increasing depth. When wind stress is northward and offshore, near‐surface low‐salinity water is transported offshore by Ekman transport while near‐bottom high‐salinity water is transported shoreward
Visual control of action in step descent
Visual guidance of forwards, sideways, and upwards stepping has been investigated, but there is little knowledge about the visuomotor processes underlying stepping down actions. In this study we investigated the visual control of a single vertical step. We measured which aspects of the stepping down movement scaled with visual information about step height, and how this visual control varied with binocular versus monocular vision. Subjects stepped down a single step of variable and unpredictable height. Several kinematic measures were extracted including a new measure, “kneedrop”. This describes a transition in the movement of the lower leg, which occurs at a point proportional to step height. In a within-subjects design, measurements were made with either full vision, monocular vision, or no vision. Subjects scaled kneedrop relative to step height with vision, but this scaling was significantly impaired in monocular and no vision conditions. The study establishes a kinematic marker of visually controlled scaling in single-step locomotion which will allow further study of the visuomotor control processes involved in stepping dow
Visually guided step descent in children with Williams Syndrome
Individuals with Williams syndrome (WS) have impairments in visuospatial tasks and in manual visuomotor control, consistent with parietal and cerebellar abnormalities. Here we examined whether individuals with WS also have difficulties in visually controlling whole-body movements. We investigated visual control of stepping down at a change of level in children with WS (5–16-year-olds), who descended a single step while their movement was kinematically recorded. On each trial step height was set unpredictably, so that visual information was necessary to perceive the step depth and position the legs appropriately before landing. Kinematic measures established that children with WS did not use visual information to slow the leg at an appropriate point during the step. This pattern contrasts with that observed in typically developing 3- and 4-year-old children, implying severe impairment in whole-body visuomotor control in WS. For children with WS, performance was not significantly predicted by low-level visual or balance problems, but improved significantly with verbal age. The results suggest some plasticity and development in WS whole-body control. These data clearly show that visuospatial and visuomotor deficits in WS extend to the locomotor domain. Taken together with evidence for parietal and cerebellar abnormalities in WS, these results also provide new evidence for the role of these circuits in the visual control of whole-body movement
The Effect of Nitrogen Rate and Method of Sucker Control on Dry Matter Accumulation in Different Plant Parts of Burley 21 Tobacco
Earlier research has shown that higher leaf yields of burley tobacco result from topping and controlling sucker (axillary bud) growth. Suckering practices which provide the greatest degree of sucker control generally result in highest leaf yields . Chemically suckering with maleic hydrazide (MH-30) and other chemicals provides for a higher degree of control than most hand sucker ing practices although hand sucker ing at frequent intervals may produce leaf yields comparable to those from use of maleic hydrazide. High leaf yields resulting from a high degree of sucker control has been attributed to the elimination of the use of photosynthate to produce suckers
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