Recent history of corporate audit committees

This article explores factors in the financial, legal and social environments that have significantly influenced the development of corporate audit committees. Particular emphasis is given to the actions of the Securities and Exchange Commission and the American Institute of Certified Public Accountants

Ice-crystal traces imply ephemeral freezing in early Permian equatorial Pangea

Delicate impressions in lacustrine strata of the lower Permian (lower Cisuralian) Usclas Formation record ephemeral freezing in equatorial Pangea. These sediments accumulated in the paleoequatorial and intramontane Lodève Basin (southern Massif Central, France) during peak icehouse conditions of the Late Paleozoic Ice Age. Experimental replication of these features supports the interpretation that they are ice-crystal molds. Evidence for films of ice in marginal-lacustrine sediment at such low latitudes and inferred low to moderate altitudes (1–2 km) calls for a reevaluation of climate conditions in eastern equatorial Pangea. Ephemeral freezing implies either cold tropical temperatures (~5 °C cooler than the Last Glacial Maximum) and/or lapse rates that exceeded those of the Last Glacial Maximum. Extreme continentality of the Lodève Basin would have amplified seasonality, albeit the climatic forcing(s) necessary to have promoted cold temperatures in equatorial Pangea remain enigmatic

Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine

The 9-azabicyclo[3.3.1]nonane ring system is present in several insect- and plant-derived alkaloids. (−)-Adaline (1) and (+)-euphococcinine (2), found in secretions of Coccinelid beetles, and (+)-N-methyleuphococcinine (3), isolated from the Colorado blue spruce Picea pungens, are members of this alkaloid family. Their unique bicyclic system with a quaternary stereocenter, and the potent biological activity exerted by these homotropane alkaloids, make them attractive synthetic targets. This work aims briefly to review the chemical ecology of Adalia bipunctata and the recent methodologies to obtain adaline (1), euphococcinine (2), and N-methyleuphococcinine (3)

Disruption of host-seeking behaviour by the salmon louse,Lepeophtheirus salmonis,using botanically derived repellents

The potential for developing botanically derived natural products as novel feed-through repellents for disrupting settlement of the salmon louse, Lepeophtheirus salmonis (Caligidae) upon farmed Atlantic salmon, Salmo salar, was investigated using an established laboratory vertical Y-tube behavioural bioassay for assessing copepodid behaviour. Responses to artificial sea water conditioned with the odour of salmon, or to the known salmon-derived kairomone component, α-isophorone, in admixture with selected botanical materials previously known to interfere with invertebrate arthropod host location were recorded. Materials included oils extracted from garlic, Allium sativum (Amaryllidaceae), rosemary, Rosmarinus officinalis (Lamiaceae), lavender, Lavandula angustifolia (Lamiaceae), and bog myrtle, Myrica gale (Myricaceae), and individual components (diallyl sulphide and diallyl disulphide from garlic; allyl, propyl, butyl, 4-pentenyl and 2-phenylethyl isothiocyanate from plants in the Brassica genus). Removal of attraction to salmon-conditioned water (SCW) or α-isophorone was observed when listed materials were presented at extremely low parts per trillion (ppt), that is picograms per litre or 10−12 level. Significant masking of attraction to SCW was observed at a level of 10 ppt for diallyl disulphide and diallyl sulphide, and allyl isothiocyanate and butyl isothiocyanate. The potential of very low concentrations of masking compounds to disrupt Le. salmonis copepodid settlement on a host fish has been demonstrated in vitro

Mixed Matrix Carbon Molecular Sieve and Alumina (CMS-Al₂O₃) Membranes

This work shows mixed matrix inorganic membranes prepared by the vacuum-assisted impregnation method, where phenolic resin precursors filled the pore of a-alumina substrates. Upon carbonisation, the phenolic resin decomposed into several fragments derived from the backbone of the resin matrix. The final stages of decomposition (>650 degrees C) led to a formation of carbon molecular sieve (CMS) structures, reaching the lowest average pore sizes of similar to 5 angstrom at carbonisation temperatures of 700 degrees C. The combination of vacuum-assisted impregnation and carbonisation led to the formation of mixed matrix of CMS and a-alumina particles (CMS-Al2O3) in a single membrane. These membranes were tested for pervaporative desalination and gave very high water fluxes of up to 25 kg m(-2) h(-1) for seawater (NaCl 3.5 wt%) at 75 degrees C. Salt rejection was also very high varying between 93-99% depending on temperature and feed salt concentration. Interestingly, the water fluxes remained almost constant and were not affected as feed salt concentration increased from 0.3, 1 and 3.5 wt%

Routine exercise-based cardiac rehabilitation does not increase aerobic fitness: A CARE CR study

Background Recent evidence suggests that routine exercise-based cardiac rehabilitation (CR) may not lead to a substantial increase in estimated peak oxygen uptake (V̇O2peak). This could reduce the potential benefits of CR and explain why CR no longer improves patient survival in recent studies. We aimed to determine whether routine exercise-based CR increases V̇O2peak using gold-standard maximal cardiopulmonary exercise testing (CPET), and to quantify the exercise training stimulus which might be insufficient in patients undertaking CR. Methods We studied the effects of a routine, twice weekly, exercise-based CR programme for eight weeks (intervention group) compared with abstention from supervised exercise training (control group) in patients with coronary heart disease. The primary outcome was V̇O2peak measured using CPET. We also measured changes in body composition using dual X-ray absorptiometry, carotid intima-media thickness, hs-CRP and N-terminal pro B-type natriuretic peptide at baseline, 10 weeks and one year. We also calculated the Calibre 5-year all-cause mortality risk score. Results Seventy patients (age 63.1 SD10.0 years; BMI 29.2 SD4.0 kg·m−2; 86% male) were recruited (n = 48 intervention; n = 22 controls). The mean aerobic exercise training duration was 23 min per training session, and the mean exercise training intensity was 45.9% of heart rate reserve. V̇O2peak was 23·3 ml·kg-1·min−1 at baseline, and there were no changes in V̇O2peak between groups at any time point. The intervention had no effect on any of the secondary endpoints. Conclusion Routine CR does not lead to an increase in V̇O2peak and is unlikely to improve long-term outcomes

Priming of production in maize of volatile organic defence compounds by the natural plant activator cis- jasmone

cis-Jasmone (CJ) is a natural plant product that activates defence against herbivores in model and crop plants. In this study, we investigated whether CJ could prime defence in maize, Zea mays, against the leafhopper, Cicadulina storeyi, responsible for the transmission of maize streak virus (MSV). Priming occurs when a pre-treatment, in this case CJ, increases the potency and speed of a defence response upon subsequent attack on the plant. Here, we tested insect responses to plant volatile organic compounds (VOCs) using a Y-tube olfactometer bioassay. Our initial experiments showed that, in this system, there was no significant response of the herbivore to CJ itself and no difference in response to VOCs collected from unexposed plants compared to CJ exposed plants, both without insects. VOCs were then collected from C. storeyi-infested maize seedlings with and without CJ pre-treatment. The bioassay revealed a significant preference by this pest for VOCs from infested seedlings without the CJ pre-treatment. A timed series of VOC collections and bioassays showed that the effect was strongest in the first 22 h of insect infestation, i.e. before the insects had themselves induced a change in VOC emission. Chemical analysis showed that treatment of maize seedlings with CJ, followed by exposure to C. storeyi, led to a significant increase in emission of the defensive sesquiterpenes (E)-(1R,9S)-caryophyllene, (E)-α-bergamotene, (E)-β-farnesene and (E)-4,8-dimethyl-1,3,7-nonatriene, known to act as herbivore repellents. The chemical analysis explains the behavioural effects observed in the olfactometer, as the CJ treatment caused plants to emit a blend of VOCs comprising more of the repellent components in the first 22 h of insect infestation than control plants. The speed and potency of VOC emission was increased by the CJ pre-treatment. This is the first indication that CJ can prime plants for enhanced production of defensive VOCs antagonist towards herbivores