Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to HH 110

Collimated supersonic flows in laboratory experiments behave in a similar manner to astrophysical jets provided that radiation, viscosity, and thermal conductivity are unimportant in the laboratory jets, and that the experimental and astrophysical jets share similar dimensionless parameters such as the Mach number and the ratio of the density between the jet and the ambient medium. Laboratory jets can be studied for a variety of initial conditions, arbitrary viewing angles, and different times, attributes especially helpful for interpreting astronomical images where the viewing angle and initial conditions are fixed and the time domain is limited. Experiments are also a powerful way to test numerical fluid codes in a parameter range where the codes must perform well. In this paper we combine images from a series of laboratory experiments of deflected supersonic jets with numerical simulations and new spectral observations of an astrophysical example, the young stellar jet HH 110. The experiments provide key insights into how deflected jets evolve in 3-D, particularly within working surfaces where multiple subsonic shells and filaments form, and along the interface where shocked jet material penetrates into and destroys the obstacle along its path. The experiments also underscore the importance of the viewing angle in determining what an observer will see. The simulations match the experiments so well that we can use the simulated velocity maps to compare the dynamics in the experiment with those implied by the astronomical spectra. The experiments support a model where the observed shock structures in HH 110 form as a result of a pulsed driving source rather than from weak shocks that may arise in the supersonic shear layer between the Mach disk and bow shock of the jet's working surface.Comment: Full resolution figures available at http://sparky.rice.edu/~hartigan/pub.html To appear in Ap

Using geothermal mine water energy for food production in Leeds

Using geothermal energy from unused coal mines for food production in vertical farms or glasshouses may increase food resilience in a low carbon way. An action plan to establish a pilot in Leeds was developed with stakeholders. There is an opportunity for Leeds to spearhead this approach for the UK and internationally

Nonprofit governance: Improving performance in troubled economic times

Nonprofit management is currently pressured to perform effectively in a weak economy. Yet, nonprofit governance continues to suffer from unclear conceptions of the division of labor between board of directors and executive directors. This online survey of 114 executive directors aims to provide clarification and recommendations for social administration

Physiological genetics of aluminum tolerance in the wheat cultivar Atlas 66

Aluminum toxicity limits wheat (Triticum aestivum L.) production on acidic soils. The wheat cultivar Atlas 66 reportedly may have both more than one Al tolerance gene and more than one Al tolerance mechanism. The purpose of this study was to identify the Al tolerance mechanisms conferred by the individual Atlas 66 Al tolerance genes present in near-isogenic lines (NILs) of the cv. Century and Chisholm ('Century-T' and 'Chisholm-T'). Seedling hydroponic culture analysis revealed that the NILs were not as Al tolerant, nor were they able to exclude Al from root apices as effectively as Atlas 66. Al-inducible malate release from root apices was significantly higher in the NILs compared with the recurrent parents, but less than that observed in Atlas 66. In contrast, root phosphate release was significantly lower than previously reported in Atlas 66, with no major differences observed among lines. These results indicate that the Atlas 66 Al tolerance gene present in each NIL acts by increasing Al-inducible malate release from root tips, but confers only a portion of the Al tolerance of Atlas 66 in both instances. Thus, differences in Al tolerance between the NILs and Atlas 66 can be attributed to malate release differences, and not differential phosphate release. Further, these results indicate that genetic variation at more than one locus underlies the malate- mediated Al tolerance differences in Atlas 66, when compared with Century and Chisholm. The Atlas 66 alleles for these loci have not been introgressed into the NILs.Peer reviewedPlant and Soil Science

Developing autonomous learning in first year university students using perspectives from positive psychology

Autonomous learning is a commonly occurring learning outcome from university study, and it is argued that students require confidence in their own abilities to achieve this. Using approaches from positive psychology, this study aimed to develop confidence in first‐year university students to facilitate autonomous learning. Psychological character strengths were assessed in 214 students on day one at university. Two weeks later their top three strengths were given to them in study skills modules as part of a psycho‐educational intervention designed to increase their self‐efficacy and self‐esteem. The impact of the intervention was assessed against a control group of 40 students who had not received the intervention. The results suggested that students were more confident after the intervention, and that levels of autonomous learning increased significantly compared to the controls. Character strengths were found to be associated with self‐efficacy, self‐esteem and autonomous learning in ways that were theoretically meaningful

Colloquium on Solid State Devices

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Kinetics of isothermal and non-isothermal precipitation in an Al-6at%Si alloy

A novel theory which describes the progress of a thermally activated reaction under isothermal and linear heating conditions is presented. It incorporates nucleation, growth and impingement and takes account of temperaturedependent solubility. The model generally fits very well to isothermal calorimetry and differential scanning calorimetry data on precipitation in an Al-6 at.% Si alloy. Analysis of the data shows that two processes occur in this precipitation reaction: growth of large Si particles and growth of pre-existing small nuclei. Determination of the sizes of Si precipitates by transmission electron microscopy indicates that interfacial energy contributions are small and have a negligible influence on solubilit

Structure of the TPR Domain of AIP: Lack of Client Protein Interaction with the C-Terminal alpha-7 Helix of the TPR Domain of AIP Is Sufficient for Pituitary Adenoma Predisposition

PMCID: PMC3534021This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Contributions of leaf rust resistance and awns to agronomic and grain quality performance in winter wheat

Wheat (Triticum aestivum L.) cultivars grown in the Great Plains usually bear awned spikes for their putative value to grain yield and quality. Awnletted cultivars are generally limited to forage-only systems. We hypothesized that an awnletted type would be more acceptable to grain producers if flag leaf senescence is delayed by protection against leaf rust (caused by Puccinia triticina Erikss.), the principal foliar disease affecting wheat production in the southern Great Plains. In field experiments under moderate levels of leaf rust infection, our objective was to estimate the effects of awns and leaf rust resistance according to the action and interaction of genes controlling these traits. Our analysis focused on agronomic and quality attributes previously shown to be influenced by these genes. Experimental lines were developed from crosses between leaf rust-susceptible (awnletted or awned) near-isolines of 'Century' and two leaf rust-resistant, awned backcrossed-derived lines with Lr41 or Lr42 from Triticum tauschii (Coss.) Schmal. For most attributes, genes controlling awns and rust resistance acted additively but with unequal effects. For the average effects of Lr41 and Lr42, grain yield increased by 63 and 26%, test weight increased by 5 and 3%, and kernel weight increased by 14 and 9%. Averaged across resistant and susceptible types for each gene, awns increased yield by 6.2 and 0%, increased test weight by 1.7% (either Lr gene source), and increased kernel weight by 6 and 4%. Rust resistance was more effective in compensating for the absence of awns than awns were in compensating for the lack of rust resistance. Leaf rust resistance improved milling quality by increasing flour yield and kernel diameter, independent of the presence or absence of awns. The development of awnletted cultivars with acceptable grain yield potential and quality appears achievable, but their utility in a grain-only production system will be limited without leaf rust resistance.Peer reviewedPlant and Soil SciencesEntomology and Plant Patholog

Phenotypic microarrays suggest Escherichia coli ST131 is not a metabolically distinct lineage of extra-intestinal pathogenic E. coli

Extraintestinal pathogenic E. coli (ExPEC) are the major aetiological agent of urinary tract infections (UTIs) in humans. The emergence of the CTX-M producing clone E. coli ST131 represents a major challenge to public health worldwide. A recent study on the metabolic potential of E. coli isolates demonstrated an association between the E. coli ST131 clone and enhanced utilisation of a panel of metabolic substrates. The studies presented here investigated the metabolic potential of ST131 and other major ExPEC ST isolates using 120 API test reagents and found that ST131 isolates demonstrated a lower metabolic activity for 5 of 120 biochemical tests in comparison to non-ST131 ExPEC isolates. Furthermore, comparative phenotypic microarray analysis showed a lack of specific metabolic profile for ST131 isolates countering the suggestion that these bacteria are metabolically fitter and therefore more successful human pathogens