BRACKEN (Pteridium aquilinum (L.) Kuhn) STAND CHARACTERISATION ON THE NORTH YORK MOORS: A STUDY OF THE RHIZOME AND FROND SYSTEM WITH REGARD TO A LARGE SCALE CONTROL PROGRAMME

Merged with duplicate record 10026.1/777 on 15.02.2017 by CS (TIS)Large-scale rhizome sampling on the North York Moors together with an assessment of published bracken sampling protocols concluded that small-scale sampling of the rhizome system is inadequate to describe upland bracken stands accurately. It is also concluded that the frond cannot be used as an indicator of the rhizome system before or after treatment to achieve bracken control. An improved sampling strategy is proposed which increases the reliability of data collected and the validity of any conclusions drawn form such data. The structure of bracken rhizome systems, from separate stands on the North York Moors, were found to be distinct from one another and demonstrated intrinsic variation which could affect a differential response to control. The most important components of the rhizome system, when considering chemical control using asulam are: the number of buds likely to remain viable afterwards; the rhizome biomass which may effect herbicide dilution; and the origin of frond production which may affect herbicide distribution. The effect of asulam was to cause severe localised damage to buds and apices detectable one year after treatment but the rhizome dry weight remained unaffected. In one instance asulam appeared to have a stimulatory effect on bracken by breaking bud dormancy, this was related to the characteristics of the stand before treatment. It is recommended that the use of asulam is restricted to pioneer or building stands which have a high number of active buds in relation to dormant buds, and a low rhizome dry weight. Crushing bracken once a year effected a temporary reduction in rhizome dry weight, and an increase in frond number (which could improve asulam absorption). A combination of crushing and asulam reduced both bud number and rhizome dry weight and was thus the most successful treatment studied for reduction of bracken vigour. In particular, stands adjacent to valued plant communities should be targeted for control. It is suggested that bilberry could be used as a buffer zone between heather and invading bracken. The use of large-scale bracken control programmes in upland regions was questioned due to the apparent ineffectiveness of asulam on the rhizome system, and the difficulty of implementing a programme of successful follow-up and after-care management. A broad classification of upland bracken, based on the rhizome, was recognised, and general models of selective bracken control suggested, by evaluation of the rhizome system with regard to the number of dormant and active buds, and the rhizome dry weight.The North York Moors National Par

MP 2012-02

Final report to BP.The Prudhoe Bay oil fields, Alaska were discovered in 1968, and commercial production commenced in 1977 with the completion of the Trans-Alaska Pipeline. Oil production has been declining since 1989, although additional exploratory drilling continues. Support facilities for oil production are built on permafrost soils that surface-thaw in summer to form extensive wetlands composed of moist meadows, sedge marshes, moist sedge-dwarf shrub tundra, grass marshes, small ponds and lakes (Walker and Acevedo 1987). To prevent thawing and subsidence of subsurface, ice-rich soils, gravel pads, 2m (6 ft) or more thickness have been built to support drilling sites as well as roads, airstrips and building pads (Kidd et al. 2006). As well sites are decommissioned, the gravel is wholly or partially removed resulting in the need for site rehabilitation and/or restoration to support wetland plants and, in some instances, enhance wildlife habitat (McKendrick 1991, Jorgenson and Joyce 1994, Kidd et al. 2004, 2006). Since the 1970s, methods to revegetate arctic wetlands have included a variety of planting techniques, seed treatments, seeding with native and non-native species (mostly grasses), and fertilizer applications (Chapin and Chapin 1980; Bishop and Chapin 1989, Jorgenson 1988, Kidd and Rossow 1998, Kidd et al. 2004, 2006, Maslen and Kershaw 1989, McKendrick 1987, 1991, 2000, McKendrick et al. 1980, McKendrick and Mitchell 1978, Mitchell et al. 1974). Treatments also have included sprigging and plug transplantation (Kidd et al. 2004, 2006), surface manipulation (Streever et al. 2003), as well as natural re-colonization (Ebersole 1987, Schwarzenbach 1996). These methods have been partially successful. The gravelly soils often are dry, nutrient-poor, and have a higher pH and lower organic matter content than surrounding soils, so natural recolonization does not occur readily (Bishop and Chapin 1989, Jorgenson and Joyce 1994). Methods such as sprigging and plug transplanting are slow, labor intensive and expensive compared to direct seeding. Fertilization, especially with phosphorus, is recommended for long-term survival of plants grown on gravelly sandy soils (BP Exploration and McKendrick 2004). Two common species in the arctic coastal wetlands are water sedge, Carex aquatilis Wahlenb. and cotton sedge, Eriophorum angustifolium Honck. Carex aquatilis in particular forms large populations that spread vegetatively by rhizomes and often dominate these wetland environments (Shaver and Billings 1975). Despite their abundance, these species have not been considered for revegetation because of poor seed germination and inadequate information on seed development and viability (Dr. William Streever, BP Alaska, pers. comm.). Both Carex and Eriophorum in arctic environments produce abundant seeds, but seed viability and germination often is low and highly variable among years and locations (Archibold 1984, Billings and Mooney 1968, Ebersole 1989, Gartner et al. 1983). Germination recommendations for both species vary by location and have included an array of pretreatments such as light, alternating temperatures, cold stratification, scarification, and high and low temperature dry storage (Amen 1966, Billings and Mooney 1960, Bliss 1958, Hunt and Moore 2003, Johnson et al. 1965, Phillips 1954 and Steinfeld 2001). The purpose of this project was to explore methods of seed germination of Carex aquatilis and Eriophorum angustifolium, to learn the conditions for germination and dormancy control mechanisms, and identify seed treatments that might enhance germination for eventual use in direct-seeding or plug production for arctic wetland revegetation

Two Classes of cAMP Analogs Which Are Selective for the Two Different cAMP-Binding Sites of Type II Protein Kinase Demonstrate Synergism When Added Together to Intact Adipocytes

Twenty-five cyclic nucleotide analogs were tested individually to act as lipolytic agents and to activate adipocyte protein kinase. The lipolytic potency of individual analogs correlated better with their K(a) for protein kinase and their lipophilicity rather than with either parameters alone. Some of the most potent lipolytic analogs had high I50 values for the particulate low K(m) cAMP phosphodiesterase suggesting that their effect was not due to raising endogenous cAMP levels through inhibition of phosphodiesterase. The most potent lipolytic analogs contained a thio moiety at the C-8 or C-6 position. These analogs exhibited concave upward dose-response curves. At high concentrations some analogs were as effective as optimal concentrations of epinephrine in stimulating glycerol release. The regulatory subunit of protein kinase has two different intrachain cAMP-binding sites and cAMP analogs modified at the C-8 position (C-8 analogs) are generally selective for Site 1 and analogs modified at the C-6 position (C-6 analogs) are generally selective for Site 2 (Rannels, S.R., and Corbin, J.D. (1980) J. Biol. Chem. 255, 7085-7088). Thus, C-8 and C-6 analogs were tested in combination to stimulate lipolysis in intact adipocytes and to activate protein kinase in vitro. Each process was stimulated synergistically by a combination of a C-6 and C-8 analog. Two C-8 analogs or two C-6 analogs added together did not cause synergism of either process. For both lipolysis and protein kinase activation, C-8 thio analogs acted more synergistically than C-8 amino analogs when incubated in combination with C-6 analogs, a characteristic of type II protein kinase. It is concluded that the observed synergism of lipolysis is due to binding of cAMP analogs to both intrachain sites and that it is the type II protein kinase isozyme which is responsible for the lipolytic response

The theory and simulation of relativistic electron beam transport in the ion‐focused regime

Several recent experiments involving relativistic electron beam (REB) transport in plasma channels show two density regimes for efficient transport; a low‐density regime known as the ion‐focused regime (IFR) and a high‐pressure regime. The results obtained in this paper use three separate models to explain the dependency of REB transport efficiency on the plasma density in the IFR. Conditions for efficient beam transport are determined by examining equilibrium solutions of the Vlasov–Maxwell equations under conditions relevant to IFR transport. The dynamic force balance required for efficient IFR transport is studied using the particle‐in‐cell (PIC) method. These simulations provide new insight into the transient beam front physics as well as the dynamic approach to IFR equilibrium. Nonlinear solutions to the beam envelope are constructed to explain oscillations in the beam envelope observed in the PIC simulations but not contained in the Vlasov equilibrium analysis. A test particle analysis is also developed as a method to visualize equilibrium solutions of the Vlasov equation. This not only provides further insight into the transport mechanism but also illustrates the connections between the three theories used to describe IFR transport. Separately these models provide valuable information about transverse beam confinement; together they provide a clear physical understanding of REB transport in the IFR.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70203/2/PFBPEI-4-5-1332-1.pd

Customised broadband metamaterial absorbers for arbitrary polarisation

This paper shows that customised broadband absorption of electromagnetic waves having arbitrary polarisation is possible by use of lossy cut-wire (CW) metamaterials. These useful features are confirmed by numerical simulations in which different lengths of CW pairs are combined as one periodic metamaterial unit and placed near to a perfect electric conductor (PEC). So far metamaterial absorbers have exhibited some interesting features, which are not available from conventional absorbers, e.g. straightforward adjustment of electromagnetic properties and size reduction. The paper shows how with proper design a broad range of absorber characteristics may be obtained.Comment: 12 pages, 5 figures, submitted to Optics Expres

Longitudinally and circumferentially directed movements of the left ventricle studied by cardiovascular magnetic resonance phase contrast velocity mapping

OBJECTIVE: Using high resolution cardiovascular magnetic resonance (CMR), we aimed to detect new details of left ventricular (LV) systolic and diastolic function, to explain the twisting and longitudinal movements of the left ventricle. METHODS: Using CMR phase contrast velocity mapping (also called Tissue Phase Mapping) regional wall motion patterns and longitudinally and circumferentially directed movements of the left ventricle were studied using a high temporal resolution technique in healthy male subjects (n = 14, age 23 +/- 3 years). RESULTS: Previously undescribed systolic and diastolic motion patterns were obtained for left ventricular segments (based on the AHA segmental) and for basal, mid and apical segments. The summation of segmental motion results in a complex pattern of ventricular twisting and longitudinal motion in the normal human heart which underlies systolic and diastolic function. As viewed from the apex, the entire LV initially rotates in a counter-clockwise direction at the beginning of ventricular systole, followed by opposing clockwise rotation of the base and counter-clockwise rotation at the apex, resulting in ventricular torsion. Simultaneously, as the entire LV moves in an apical direction during systole, the base and apex move towards each other, with little net apical displacement. The reverse of these motion patterns occur in diastole. CONCLUSION: Left ventricular function may be a consequence of the relative orientations and moments of torque of the sub-epicardial relative to the sub-endocardial myocyte layers, with influence from tethering of the heart to adjacent structures and the directional forces associated with blood flow. Understanding the complex mechanics of the left ventricle is vital to enable these techniques to be used for the evaluation of cardiac pathology

A pilot study of an intergenerational program for people in residential aged care with cognitive impairment and children from a co-located early learning centre during COVID-19

Intergenerational programs in residential aged care may improve well-being and combat loneliness and social isolation in older people with cognitive impairment. This pilot study investigated the effects of a semi-structured intergenerational group, including children from a co-located early learning centre and people living in residential aged care with cognitive impairment. This 9-week study used a mixed methods pre- and post-program design. Sessions were designed and delivered once per week by Occupational Therapists and took into account residents’ interests and children’s developmental needs and interests, identified in pre-program interviews. Nine older people with cognitive impairment and 13 children participated. The program was well attended despite disruptions and complications caused by COVID-19 and weather conditions. Older people valued the opportunity to engage with the children. Children were observed to gain confidence in communicating and forming friendships with older people with different levels of ability. There did not appear to be any change in loneliness or neuropsychiatric symptoms. The intergenerational program benefited participants and received strong support from family members and staff of the early learning centre and aged care home