Synthesis between leadership behaviours and principal–agent theory

‘Initiating structure’ and ‘consideration’ have long stood as broad dimensions of leadership behaviour. Recent theory and meta-analyses suggest a continued role for such constructs. However, this study asserts that initiating structure is best composed of two sub-constructs, namely a leadership focus on directing and controlling subordinate task behaviours versus a focus on outcomes. Ignoring this dualism has previously rendered initiating structure too broad a construct to facilitate meaningful hypotheses, and statistically the weaker of the constructs. This study uses principal–agent theory to support this split in theory, and presents initial structural equation modelling (SEM) tests to illustrate the superiority of a two-part initiating structure construct. Thereafter, a large number of research propositions are explored using the new dimensions, as well as two interesting case contexts. This respecification allows for propositions more in line with prior empirical findings, and finer examinations of relationships.Key words: initiating structure, consideration, agency theory, principal–agent theor

Interactions between the gastrointestinal tract, kidney, and the liver in the regulation of body phosphate balance

Inorganic phosphate (Pi) is an essential element that fuels vital processes in the body. To date, there is discord regarding the mechanisms of Pi regulation and the proportion of transport attributed to active (sodium-driven), paracellular, or uncharacterized transcellular pathways. The present studies address this by comparing Pi transport in different segments of the intestine using in vitro, in situ, and ex vivo techniques. Potential Pi signalling between the intestine, kidney, and liver was also investigated using intestinal perfusion and in vivo renal clearance surgeries. Regional differences in intestinal Pi transport were investigated using the in situ closed-loop, in vitro everted sleeve, and ex vivo intestinal perfusion techniques. These studies highlighted measured Pi transport discrepancies between methods, confirmed the jejunum as the site of highest Pi transport ability in the GI tract, and also revealed that the distal colon transported a significant amount of Pi both in vitro and in situ. An intestinal perfusion technique never applied to studies of Pi transport also exposed a concentrated amount of Pi transported directly across the rat intestinal epithelium. Renal Pi clearance surgeries investigated a proposed Pi sensing mechanism between the small intestine and the kidney in which a high duodenal Pi load triggered rapid phosphaturia. Present data show no phosphaturia after a physiological 10mM Pi duodenal instillation. In contrast with previously published data, a high Pi load into the duodenum increased plasma Pi and parathyroid hormone (PTH) levels resulting in correlated phosphaturia. The role of the liver in Pi transport was investigated by removing the liver following instillation of 1, 5, 10, and 15mM 32P coupled Pi buffer into the jejunum. Data show a steady increase of Pi accumulated in the liver, which correlated with increased Pi concentration instilled into the jejunum. Between 10 and 15mM however, the Pi in the liver reached saturation, suggesting that the liver may only store physiological concentrations of Pi. Sodium-dependency of Pi uptake by the liver was also not apparent until 15mM Pi, in contrast with sodium-dependent Pi transport by the intestine at all four concentrations. This finding suggests a separate mechanism of liver Pi transport at this supraphysiological Pi concentration

Growth characteristics and productivity of tall fescue new variety ‘Purumi’ in South Korea

A new tall fescue variety (Festuca arundinacea Schreb.) named ‘Purumi’ was developed by the National Institute of Animal Science, Rural Development Administration, South Korea from 1999 to 2007. For synthetic seed  production of this new variety, 5 superior clones: EFa9108, EFa0010, EFa0020, EFa0108 and EFa0202 were selected and polycrossed. The agronomic growth characteristics and forage production capability of the seeds were studied at Cheonan from 2004 to 2005, and regional trials were conducted in Cheonan, Pyungchang, Jeju and Jinju from 2008 to 2010. Purumi showed enhanced winter hardiness, disease resistance, and regrowth ability as compared to Fawn. The dry matter yield of Purumi was about 5.6% (16.821 kg/ha) higher than that of Fawn. However, the  nutritive value of both varieties was similar. Since this new variety of tall fescue, Purumi has been developed and distributed with its most  remarkable adaptability for Korean climates and superior value as a livestock feed, it is expected to play an important role in restoration of the pasture industry in Korea.Key words: Tall fescue, Purumi, variety, forage, grassland

Direct observation of delithiation as the origin of analog memristance in LixNbO2

The discovery of analog LixNbO2 memristors revealed a promising new memristive mechanism wherein the diffusion of Li+ rather than O2- ions enables precise control of the resistive states. However, directly correlating lithium concentration with changes to the electronic structure in active layers remains a challenge and is required to truly understand the underlying physics. Chemically delithiated single crystals of LiNbO2 present a model system for correlating lithium variation with spectroscopic signatures from operando soft x-ray spectroscopy studies of device active layers. Using electronic structure modeling of the x-ray spectroscopy of LixNbO2 single crystals, we demonstrate that the intrinsic memristive behavior in LixNbO2 active layers results from field-induced degenerate p-type doping. We show that electrical operation of LixNbO2-based memristors is viable even at marginal Li deficiency and that the analog memristive switching occurs well before the system is fully metallic. This study serves as a benchmark for material synthesis and characterization of future LixNbO2-based memristor devices and suggests that valence change switching is a scalable alternative that circumvents the electroforming typically required for filamentary-based memristors

High frequency plant regeneration from mature seedderived callus of Italian ryegrass (Lolium multiflorum) cultivars

In the present study, we have developed a high-frequency plant regeneration system for Italian ryegrass via callus culture using mature seeds as explants. Optimal embryogenic callus induction was found to occur in MS medium containing 5 mg l-1 2,4-D, 0.5 mg l-1 BA, 500 mg l-1 L-proline, 1 g l-1 casein hydrolysate, 30 g l-1 sucrose, 7 mg l-1 AgNO3, 2 mg l-1 CuSO4 and solidified with 3 g l-1 Gelrite. The highest regeneration rate was obtained in MS medium containing 1 mg l-1 2,4-D, 5 mg l-1 BA, 500 mg l-1 L-proline, 1 g l-1 casein hydrolysate, 1 mg l-1 thiamine-HCl, 30 g l-1 sucrose, 7 mg l-1 AgNO3, 2 mg l-1 CuSO4 and solidified with 3 g l-1 Gelrite. By using the most effective treatment determined for each parameter, the highest rates of embryogenic callus formation (48.9%) and regeneration (47.6%) were obtained with the Hwasan 101 cultivar. The overall plant regeneration rates of the examined cultivars ranged from 7.5 to 23.2%. Thus, optimization of regeneration frequency using mature seeds as explant material may offer a simple and efficient protocol for Italian ryegrass that may improve molecular breeding of this species

Mom-I don't want to hear it: Brain response to maternal praise and criticism in adolescents with major depressive disorder

Recent research has implicated altered neural response to interpersonal feedback as an important factor in adolescent depression, with existing studies focusing on responses to feedback from virtual peers. We investigated whether depressed adolescents differed from healthy youth in neural response to social evaluative feedback from mothers. During neuroimaging, twenty adolescents in a current episode of major depressive disorder (MDD) and 28 healthy controls listened to previously recorded audio clips of their own mothers' praise, criticism and neutral comments. Whole-brain voxelwise analyses revealed that MDD youth, unlike controls, exhibited increased neural response to critical relative to neutral clips in the parahippocampal gyrus, an area involved in episodic memory encoding and retrieval. Depressed adolescents also showed a blunted response to maternal praise clips relative to neutral clips in the parahippocampal gyrus, as well as areas involved in reward and self-referential processing (i.e. Ventromedial prefrontal cortex, precuneus, and thalamus/caudate). Findings suggest that maternal criticism may be more strongly encoded or more strongly activated during memory retrieval related to previous autobiographical instances of negative feedback from mothers in depressed youth compared to healthy youth. Furthermore, depressed adolescents may fail to process the reward value and self-relevance of maternal praise

Impact on sales of adding a smaller serving size of beer and cider in licensed premises: an A-B-A reversal design

Background: Smaller serving sizes of alcoholic drinks could reduce alcohol consumption across populations thereby lowering the risk of many diseases. The effect of modifying the available range of serving sizes of beer and cider in a real-world setting has yet to be studied. The current study assessed the impact on beer and cider sales of adding a serving size of draught beer and cider (2/3 pint) that was between the current smallest (1/2 pint) and largest (1 pint) standard serving sizes. Methods: Twenty-two licensed premises in England consented to taking part in the study. The study used an ABA reversal design, set over three 4-weekly periods, with A representing the non-intervention periods, during which standard serving sizes were served and B the intervention period when a 2/3 pint serving size of draught beer and cider was added to the existing range, along with smaller 1/2 pint and larger 1 pint serving sizes. The primary outcome was the daily volume of beer and cider sold, extracted from sales data. Results: Fourteen premises started the study, of which thirteen completed it. Twelve of those did so per protocol and were included in the primary analysis. After adjusting for pre-specified covariates, the intervention did not have a significant effect on the volume of beer and cider sold per day (3.14 ml; 95%CIs -2.29 to 8.58; p = 0.257). Conclusions: In licensed premises, there was no evidence that adding a smaller serving size for draught beer and cider (2/3 pint) when the smallest (1/2 pint) and largest (1 pint) sizes were still available, affected the volume of beer and cider sold. Studies are warranted to assess the impact of removing the largest serving size. Trial registration: ISRCTN: https://doi.org/10.1186/ISRCTN33169631 (08/09/2021), OSF: https://osf.io/xkgdb/ (08/09/2021)

Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L.) grown at four international field sites

Peer reviewedPublisher PD