Herbicides for Trefoil Seedings?

Birdsfoot trefoil is an important legume in many parts of Iowa for improving permanent pastures. No other pasture legume now available compares with birdsfoot trefoil in its ability to withstand continuous grazing. Once established, stands may be expected to furnish high-quality pasture for many years

Torsional motion of the chromophore catechol following the absorption of ultraviolet light

The ability to probe energy flow in molecules, following the absorption of ultraviolet light, is crucial to unraveling photophysical phenomena. Here we excite a coherent superposition of vibrational states in the first excited electronic state (S1) in catechol, resulting in a vibrational wave packet. The observed quantum beats, assigned to superpositions of the low-frequency, and strongly mixed, O–H torsional mode τ2, elegantly demonstrate how changes in geometry upon photoionization from the S1 state to the ground state of the cation (D0) enables one to probe energy flow at the very early stages of photoexcitation in this biological chromophore

Towards Understanding Photodegradation Pathways in Lignins:The Role of Intramolecular Hydrogen Bonding in Excited States

The photoinduced dynamics of the lignin building blocks syringol, guaiacol, and phenol were studied using time-resolved ion yield spectroscopy and velocity map ion imaging. Following irradiation of syringol and guaiacol with a broad-band femtosecond ultraviolet laser pulse, a coherent superposition of out-of-plane OH torsion and/or OMe torsion/flapping motions is created in the first excited 1ππ* (S1) state, resulting in a vibrational wavepacket, which is probed by virtue of a dramatic nonplanar → planar geometry change upon photoionization from S1 to the ground state of the cation (D0). Any similar quantum beat pattern is absent in phenol. In syringol, the nonplanar geometry in S1 is pronounced enough to reduce the degree of intramolecular H bonding (between OH and OMe groups), enabling H atom elimination from the OH group. For guaiacol, H bonding is preserved after excitation, despite the nonplanar geometry in S1, and prevents O–H bond fission. This behavior affects the propensities for forming undesired phenoxyl radical sites in these three lignin chromophores and provides important insight into their relative “photostabilities” within the larger biopolymer

The Effect of Obesity on Nocturnal Blood Pressure Patterns

Abnormal nocturnal blood pressure (BP) during sleep is considered an indication of many cardio­vascular diseases.[1] For healthy individuals, noc­turnal BP drops 5-10% on ambulatory BP monitor­ing (ABPM). Individuals with abnormal nocturnal BP are classified in three distinct ways: (1) an ab­sence of BP drop, (2) a lack of typical nocturnal dip (LND), or (3) a rise of BP at night (RBPN).[3] In this study, we examine a potential correlation between obesity and abnormal nocturnal BP and the impact of weight loss on nocturnal BP patterns. For our study, we recruited 30 individuals with LND, 30 with RBPN, and 20 with normal nocturnal BP (control) and placed them all on a prescribed DASH diet previously demonstrated to improve daytime BP.[9] Baseline ABPM readings and body mass index (BMI) measurements for each individ­ual were compared before and after two months of dieting. After two months on the DASH diet, the control group had the lowest BMI followed by the LND group and the RBPN group. These results demonstrate a linear correlation between BMI and nocturnal BP. Individuals who lost less than 5% of their original weight experienced a 3% increase in BP at night. Those who lost more than 5% weight experienced a 8.5% decrease in BP nocturnally, effectively restoring their healthy nocturnal BP pat­tern. Thus, obesity may contribute to nocturnal BP abnormalities, and weight loss may improve this condition.Une pression artérielle (PA) nocturne anormale durant le sommeil est considérée un indicateur de nombreuses maladies cardiovasculaires.[1] Chez les personnes saines, la PA nocturne diminue de façon physiologique d’environ 5-10 % mesurée grâce au moniteur ambulatoire de pression artérielle (MAPA). Les personnes ayant une PA nocturne anormale sont classées de trois façons distinctes: 1) une absence d’une diminution de PA, 2) un manque de « dipping » nocturne typique (MDN), ou 3) une augmentation de la PA durant la nuit (APAN).[3] Dans cette étude, nous examinons la possibilité d’une corrélation entre l’obésité et la PA nocturne anormale et l’impact d’une perte de poids sur les motifs de la PA nocturne. Pour notre étude, nous avons recruté 30 individus avec MDN, 30 avec APAN, et 20 individus avec une PA nocturne normale (groupes contrôle), et les avons mis sur le régime DASH qui a précédemment dé­montré une amélioration de PA durant la journée.[9] Des mesures de base avec MAPA ainsi que des mesures d’indice de masse corporelle (IMC) furent prises pour chaque individu, et par la suite utilisées afin de les comparer avec les mesures de MAPA et d’IMC suites aux deux mois du régime. Après avoir suivi le régime DASH pendant une durée de deux mois, le groupe contrôle avait la plus faible IMC suivie par le groupe du MDN, et le groupe APAN eu le plus haut IMC global. Ces résultats démontrent une relation linéaire entre l’IMC et des anomalies de PA nocturnes. Les individus qui ont perdus <5 % de poids ont su voir une augmentation de PA d’un taux de 3 % la nuit. Ceux qui ont perdu ≥ 5 % de poids ont eu une diminution de leur PA de 8,5% la nuit ce qui rétablit un motif sains de PA nocturne. Par con­séquent, conformément à cette étude on peut con­clure que l’obésité contribue à des anormalités de la PA nocturne, et la perte de poids peut améliorer cette conditions

Implementing skill acquisition research in high performance sport: Reflecting on the importance of autonomy-support for successful collaboration

Perceptual-cognitive-motor skills, such as visual anticipation, are pivotal for superior performance in sport. However, there are only a limited number of skill acquisition specialists working with coaches to develop these skills in athletes. The purpose of this paper is to present a brief reflection on the use of psychological strategies to create an autonomy-supportive environment to embed a skill acquisition research project in high-performance sport. The research project was conducted with the Australian national field hockey high-performance unit and investigated individual differences in expert goalkeepers’ visual anticipation. The paper first discusses the role of a skill acquisition specialist, how they collaborate with coaches and athletes, and barriers to collaboration. The paper then outlines how psychological strategies can be used to create an autonomy-supportive environment to build a relationship and establish a research collaboration with a team. Further, the paper discusses the importance of continually involving coaches and athletes in the research process to facilitate their engagement and self-determined motivation to complete the project. By applying psychological strategies to create an autonomy-supportive environment, sports scientists may have greater success in overcoming the many barriers to conduct research in an elite sport setting, with the outcomes highly valuable for athlete development

A Randomised, Blinded, Placebo-Controlled, Dose Escalation Study of the Tolerability and Efficacy of Filgrastim for Haemopoietic Stem Cell Mobilisation in Patients With Severe Active Rheumatoid Arthritis

Autologous haemopoietic stem cell transplantation (HSCT) represents a potential therapy for severe rheumatoid arthritis (RA). As a prelude to clinical trails, the safety and efficacy of haemopoietic stem cell (HSC) mobilisation required investigation as colony-stimulating factors (CSFs) have been reported to flare RA. A double-blind, randomised placebo-controlled dose escalation study was performed. Two cohorts of eight patients fulfilling strict eligibility criteria for severe active RA (age median 40 years, range 24-60 years; median disease duration 10.5 years, range 2-18 years) received filgrastim (r-Hu-methionyl granulocyte(G)-(SF) at 5 and 10 microg/kg/day, randomised in a 5:3 ratio with placebo. Patients were unblinded on the fifth day of treatment and those randomised to filgrastim underwent cell harvesting (leukapheresis) daily until 2 X 10^6/kg CD34+ cells (haemopoietic stem and progenitor cells) were obtained. Patients were assessed by clinical and laboratory parameters before, during and after filgrastim administration. RA flare was defined as an increase of 30% or more in two of the following parameters: tender joint count, swollen joint count or pain score. Efficacy was assessed by quantitation of CD34+ cells and CFU-GM. One patient in the 5 microg/kg/day group and two patients in the 10 microg/kg/day group fulfilled criteria for RA flare, although this did not preclude successful stem cell collection. Median changes in swollen and tender joint counts were not supportive of filgrastim consistently causing exacerbation of disease, but administration of filgrastim at 10 microg/kg/day was associated with rises in median C-reactive protein and median rheumatoid factor compared with placebo. Other adverse events were well recognised for filgrastim and included bone pain (80%) and increases in alkaline phosphatase (four-fold) and lactate dehydrogenase (two-fold). With respect to efficacy, filgrastim at 10 microg/kg/day was more efficient with all patients (n = 5) achieving target CD34+ cell counts with a single leukapheresis (median = 2.8, range = 2.3-4.8 X 10^6/kg, median CFU-GM = 22.1, range = 4.2-102.9 X 10^4/kg), whereas 1-3 leukaphereses were necessary to achieve the target yield using 5 microg/kg/day. We conclude that filgrastim may be administered to patients with severe active RA for effective stem cell mobilisation. Flare of RA occurs in a minority of patients and is more likely with 10 than 5 microg/kg/day. However, on balance, 10 microg/kg/day remains the dose of choice in view of more efficient CD34+ cell mobilisation

Intramolecular thiomaleimide [2+2] photocycloadditions: stereoselective control for disulfide stapling and observation of excited state intermediates by transient absorption spectroscopy

Thiomaleimides undergo efficient intermolecular [2 + 2] photocycloaddition reactions and offer applications from photochemical peptide stapling to polymer crosslinking; however, the reactions are limited to the formation of the exo head-to-head isomers. Herein, we present an intramolecular variation which completely reverses the stereochemical outcome of this photoreaction, quantitatively generating endo adducts which minimise the structural disturbance of the disulfide staple and afford a 10-fold increase in quantum yield. We demonstrate the application of this reaction on a protein scaffold, using light to confer thiol stability to an antibody fragment conjugate. To understand more about this intriguing class of [2 + 2] photocycloadditions, we have used transient absorption spectroscopy (electronic and vibrational) to study the excited states involved. The initially formed S2 (π1π*) excited state is observed to decay to the S1 (n1π*) state before intersystem crossing to a triplet state. An accelerated intramolecular C–C bond formation provides evidence to explain the increased efficiency of the reaction, and the impact of the various excited states on the carbonyl vibrational modes is discussed

Pulmonary availability of isotretinoin in rats after inhalation of a powder aerosol

Repeated oral administration of chemopreventive retinoids such as isotretinoin over extended periods of time is associated with intolerable systemic toxicity. Here isotretinoin was formulated as a powder aerosol, and its delivery to the lungs of rats was studied with the aim to explore the possibility of minimizing adverse effects associated with its oral administration. Rats received isotretinoin orally (0.5, 1 or 10 mg kg–1) or by inhalation (theoretical dose ~1 or ~10 mg kg–1) in a nose-only inhalation chamber. Isotretinoin was quantitated by high-pressure liquid chromatography in plasma and lung tissue. The ratios of mean area of concentration-vs-time curve (AUC) values in the lungs over mean AUCs in the plasma for isotretinoin following single or repeated aerosol exposure surpassed those determined for the oral route by factors of between two (single low-dose) and five (single high-dose). Similarly, the equivalent ratios for the maximal peak concentrations in lungs and plasma obtained after aerosol exposure consistently exceeded those seen after oral administration, suggesting that lungs were exposed to higher isotretinoin concentrations after aerosol inhalation than after oral administration of similar doses. Repeated high doses of isotretinoin by inhalation resulted in moderate loss of body weight, but microscopic investigation of ten tissues including lung and oesophagus did not detect any significant aerosol-induced damage. The results suggest that administration of isotretinoin via powder aerosol inhalation is probably superior to its application via the oral route in terms of achieving efficacious drug concentrations in the lungs. © 2000 Cancer Research Campaig

Strong and auxiliary forms of the semi-Lagrangian method for incompressible flows

We present a review of the semi-Lagrangian method for advection-diusion and incompressible Navier-Stokes equations discretized with high-order methods. In particular, we compare the strong form where the departure points are computed directly via backwards integration with the auxiliary form where an auxiliary advection equation is solved instead; the latter is also referred to as Operator Integration Factor Splitting (OIFS) scheme. For intermediate size of time steps the auxiliary form is preferrable but for large time steps only the strong form is stable