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The flat oyster Ostrea edulis has declined significantly in European waters since the 1850s as a result of anthropogenic activity. Ostrea edulis was designated a UK Biodiversity Action Plan Species and Habitat in 1995, and as a Feature of Conservation Importance (FOCI) within the UK Marine & Coastal Access Act 2009. To promote the recovery of oyster beds, a greater understanding of its abundance and distribution is required. Distribution of O. edulis across the proposed Blackwater, Crouch, Roach and Colne MCZ in Essex was determined between 2008 and 2012. Ostrea edulis were present in four estuary zones; with highest sample abundance in the Blackwater and Ray Sand zones. Size structure of populations varied, with the Ray Sand and Colne zones showing a significant lack of individuals with shell height <39 mm. Ostrea edulis occurred in highest number on shell substratum, followed by silty sediments. There were no significant associations between O. edulis abundance or size structure with water column Chl a, suspended solids, oxygen, nitrate or ammonium concentrations, temperature or pH. Highest abundance and most equitable population shell-size distribution for O. edulis were located within, or adjacent to, actively managed aquaculture zones. This suggests that traditional seabed management contributed to the maintenance or recovery of the species of conservation concern. Demonstration that the Essex estuaries were a stronghold for Ostrea edulis in the southern North sea area led to the designation of the Blackwater, Crouch, Roach and Colne estuaries Marine Conservation Zone in 2013.
The rocky shores of New Zealand (NZ) and Australia provide many interesting comparisons in their intertidal species and structuring processes. Both countries are in the biogeographic realm of temperate Australasia and share many common species and closely related taxa. Here we review similarities and contrasts in communities and structuring processes, especially involving grazing invertebrates and macroalgae. We consider the similarity of the structure of intertidal shores of NZ and south-eastern Australia, a suite of important trophic interactions within and between regions, the utility of local-scale experiments in understanding large-scale processes and how we might better plan for and manage our coasts. The major comparisons are between warm-temperate areas of northern NZ and New South Wales, and the cooler areas of southern NZ and south-eastern Australia. In the quest for ‘ecosystem’-level understanding, which perforce involves large-scale events, there is an increasing tendency to minimise or ignore the hard-won insights gained from well-structured experiments across multiple sites. Because all large-scale effects must be manifested at local sites, it is incumbent on us to determine what scales up or down, and the caveats that make comparisons across biogeographic regions challenging. Here, we discuss these issues using austral shores as models.
Intertidal biofilms are a diverse mixture of bacteria, algae as well as sporelings of macroalgae embedded in a polysaccharid matrix. As the primary colonisers of newly formed surfaces, biofilms undergo a succession of different microbe assemblage until the mature state is reached. A biofilm can act as primary producers and as such recycle nutrients in a habitat. It will influence macrobiota by providing a food source or sending out cues to settlers. Biofilms themselves will be controlled by these settlers. This interaction between bottom-up and top-down plays a crucial part for the functioning of the rocky shore ecosystems. However, the diversity of biolfilms as well as it nature to react quickly to environmental changes makes identification and quantification of the individual compounds a difficult task. Subsequently, the understanding of biofilms in general and intertidal, rocky shore microbe assemblages has always tied to techniques and methods available at the time of study. This chapter focusses on the techniques that have greatly contributed to increasing knowledge of biofilms and discusses their findings. Nonetheless, newly developed methods promise to further this knowledge of the ecological role of biofilms on rocky coastlines.
Adolescents’ peer networks provide an important context that can contribute to increases in antisocial behavior. By a process called deviancy training, peers can both model and reinforce these behaviors, thereby conveying group norms about the acceptability of such behaviors. This research examined the relationship between the proportion of adolescents’ peers who exchanged antisocial text messages and externalizing behaviors during high school. In Study 1, parent-, teacher-, and self-reports of rule-breaking and aggression were collected for a sample of adolescents (n = 167, 80 girls; 22.2% Black, 51.5% Caucasian, 18.7% Hispanic) during the summers before and after 9th grade. Total text frequency, frequency of antisocial texts, and the proportion of the peer network who exchanged antisocial messages were examined as predictors of antisocial behavior. The proportion of peers who exchanged antisocial texts significantly predicted rule-breaking, but not aggression. Study 2 examined the direction of the relationship documented in Study 1 more thoroughly. Externalizing behaviors at 9th, 10th, and 11th grade were evaluated as predictors of the proportion of the peer network that exchanged texts about antisocial topics (n = 205, 98 girls; 22.4% Black, 53.7% Caucasian, 16.9% Hispanic). Externalizing behaviors predicted the proportion of adolescents’ peer network that exchanged antisocial texts in each of the subsequent years, but this proportion of the peer network exchanging antisocial communication did not predict subsequent externalizing behaviors. The findings suggest that the extent to which antisocial communication permeates the peer group is a selection effect.
X-ray microscopy is a field that has developed rapidly in recent years. Two different approaches have been used. Zone plates have been employed to produce focussed beams with sizes as low as 0.07 pm for x-ray energies below 1 keV. Images of biological materials and elemental maps for major and minor low Z have been produced using above and below absorption edge differences. At higher energies collimators and focussing mirrors have been used to make small diameter beams for excitation of characteristic K— or L-x rays of all elements in the periodic
Recent advances in techniques to generate static ultra-high pressure (>100 GPa) in the diamond anvil cell have significantly enhanced our understanding of the properties of solids under these extreme conditions. In order to characterize the structure of solids at these pressures, X-ray diffraction using synchrotron radiation has become an invaluable tool. Since the highest pressures are attained at the expense of sample volume (~ 100 μm3) , it is best to use the intense radiation available from a synchrotron to study the very small samples used in ultra-high pressure studies. Even with the intense x-ray beams currently available, it is still often desirable to focus the x-ray beam to increase the available flux. We have developed a focusing system which uses multilayer coated spherical mirrors. With this system, intense x-ray beams with sizes smaller than 10 μm by 10 μm can be achieved at a synchrotron radiation beamline. Previously, we used the focusing system for x-ray microprobe experiments.
To determine the effectiveness of vestibular rehabilitation using the Wii Fit balance platform, in adults with dizziness.
A single-site prospective clinical trial was conducted in a university hospital in the UK. Forty patients with dizziness, who would normally be candidates for vestibular rehabilitation, were identified and considered as potential participants. Participants were randomised into either the treatment group (the Wii Fit group) or the control group (standard customised vestibular rehabilitation protocol). Participants were assessed over a 16-week period using several balance and quality of life questionnaires.
Both exercise regimes resulted in a reduction of dizziness and an improvement in quality of life scores over time, but no statistically significant difference between the two interventions was identified.
This pilot study demonstrated that use of the Wii Fit balance platform resulted in a statistically significant improvement in balance function and quality of life. Furthermore, outcomes were comparable to a similar group of individuals following a standard customised vestibular rehabilitation protocol. The study provides useful information to inform the design and execution of a larger clinical trial.
Two studies consisting of six field experiments each were conducted at three locations in southwestern Ontario, Canada, in 2014 and 2015 to evaluate the possible antagonism when dicamba was added to quizalofop-p-ethyl or clethodim for the control of volunteer glyphosate-resistant (GR) corn. At 4 wk after application (WAA), quizalofop-p-ethyl at 24, 30, or 36 g ai ha−1 provided 88, 94, and 95% control of volunteer GR corn, respectively. The addition of dicamba at 300 or 600 g ae ha−1 to quizalofop-p-ethyl (24 g ha−1) reduced the activity of quizalofop-p-ethyl on volunteer GR corn by 12 and 20%. At 4 WAA, clethodim at 30, 37.5, and 45 g ai ha−1 provided 85, 91, and 95% control of volunteer GR corn, respectively. The addition of dicamba at 300 or 600 g ha−1 to clethodim (30 g ha−1) resulted in antagonism, causing a reduction in volunteer GR corn by 12 and 11%, respectively. In general, there was greater antagonism when the high rate of dicamba was tank-mixed with the lower rate of the graminicide. There was no antagonistic effect on soybean yield by tank-mixing dicamba with either graminicide at all rates evaluated. Based on these results, volunteer GR corn can be controlled effectively by increasing the rate of the graminicide when tankmixed with dicamba.
We present the results of measurements of 26Al and 10Be produced in situ in 12 samples of Libyan Desert Glass by cosmic rays during the last ten million years. Based on the variability of the concentrations of 10Be and of the 26Al/10Be ratios we measured, we conclude that individual fragments of glass have experienced different exposure histories, implying several major redistributions of the glass within the past 106 years. The 26Al and 10Be concentrations are inconsistent with the theoretical estimates of the rates of in situ production. We estimate minimum production rates of 70 atoms g-1 yr-1 and 10 atoms g-1 yr-1 for 26Al and 10Be, respectively, produced in quartz at sea level between 60–90° latitude. Despite the present uncertainty in the rates of production, we feel that these results show clearly the effectiveness of in situ produced 26Al and 10Be in studying earth-surface processes.
The Neoselachii are a monophyletic group including all of the extant sharks and rays. They underwent rapid diversification throughout the Jurassic and Cretaceous, going from low-diversity assemblages of members of extinct orders in the Late Triassic to diverse assemblages containing representatives of most extant clades by the end of the Cretaceous. The known fossil record of Mesozoic neoselachians is composed largely of isolated teeth, with articulated skeletal remains being known from a limited number of sites. The small tooth size of a large proportion of neoselachians, including almost all taxa in existence prior to the mid Cretaceous, led to very poor representation in older publications. Their state of knowledge has improved dramatically since 1970 with the increased use of bulk sampling for isolated dental remains. Despite this, the high proportion of Lazarus taxa from some stages suggests that the state of knowledge is still intermittent. Increase in assemblage diversity throughout the Jurassic and Cretaceous suggests that radiation events resulted in real and dramatic increases in diversity, and that the perceived diversification is not an artifact of poor knowledge. Cladogenesis inferred from the fossil record typically compares more favorably with divergence predicted from molecular analysis, where Batoidea form a discrete basal clade, than with divergence predicted from morphological analysis, where Batoidea are considered a derived crown group within the Squalea. The timing of diversification events is discussed in light of the known fossil record, cladistically generated divergence times, and the paleoenvironmental distribution of faunas.
Lysergic acid diethylamide (LSD) is a potent serotonergic hallucinogen or psychedelic that modulates consciousness in a marked and novel way. This study sought to examine the acute and mid-term psychological effects of LSD in a controlled study.
A total of 20 healthy volunteers participated in this within-subjects study. Participants received LSD (75 µg, intravenously) on one occasion and placebo (saline, intravenously) on another, in a balanced order, with at least 2 weeks separating sessions. Acute subjective effects were measured using the Altered States of Consciousness questionnaire and the Psychotomimetic States Inventory (PSI). A measure of optimism (the Revised Life Orientation Test), the Revised NEO Personality Inventory, and the Peter's Delusions Inventory were issued at baseline and 2 weeks after each session.
LSD produced robust psychological effects; including heightened mood but also high scores on the PSI, an index of psychosis-like symptoms. Increased optimism and trait openness were observed 2 weeks after LSD (and not placebo) and there were no changes in delusional thinking.
The present findings reinforce the view that psychedelics elicit psychosis-like symptoms acutely yet improve psychological wellbeing in the mid to long term. It is proposed that acute alterations in mood are secondary to a more fundamental modulation in the quality of cognition, and that increased cognitive flexibility subsequent to serotonin 2A receptor (5-HT2AR) stimulation promotes emotional lability during intoxication and leaves a residue of ‘loosened cognition’ in the mid to long term that is conducive to improved psychological wellbeing.
Glancing incidence telescopes of the kind first described by Wolter have now been physically realized, so that it is now possible to obtain high resolution images of celestial objects at all wavelengths greater than about 3 Å. In this paper we shall describe two such instruments: the GSFC-MSFC X-ray telescope for the Apollo telescope mount uses Wolter type 1 optics and is capable of forming images of the sun in the 8–70 Å region with spatial resolution of the order of one arc second. The GSFC extreme ultraviolet spectroheliometer for OSO H uses type 2 optics and can obtain images of the Sun in spectral lines in the 170–400 Å region with a spatial resolution of about ten arc seconds. Theoretical (ray trace) and laboratory data on these systems will be presented.
Osteoarthritis (OA) is a common condition expected to be the fourth leading cause of disability by the year 2020. Treatment with non-steroidal anti-inflammatory drugs is problematic in older adults (>75 years) where the presence of comorbidities is more prevalent. Exercise has been recommended irrespective of age and comorbidity. The purpose of this project was to develop a combined exercise and self-management intervention to help older adults with OA to manage their comorbidities.
Literature reviews were conducted to inform the development of an intervention followed by a pilot study to assess feasibility and test outcome measures. Participant interviews and session observation were used to evaluate the pilot study.
Evidence from the literature reviews suggested that a combined intervention consisting of behavioural change/self-management education and exercise was the most appropriate. Each component was developed and then tested as a combined package in a pilot study which comprised 12 sessions delivered over six weeks. Four males and six females aged between 75 and 92 years took part. The average attendance was 89%. Most participants reported some benefit and satisfaction with the programme along with changes in physical ability. The majority of participants continued with some form of exercise at three months.
The intervention was well received and has encouraged 80% of participants to continue exercising after the programme. The small but positive changes seen in comorbidities, benefit of the intervention, satisfaction and general health are promising. Randomised controlled trial evidence of effectiveness and cost effectiveness is needed before such interventions can be recommended.
This investigation examined the relation between developmental trajectories jointly estimated for social and physical aggression and adjustment problems at age 14. Teachers provided ratings of children's social and physical aggression in Grades 3, 4, 5, 6, and 7 for a sample of 255 children (131 girls, 21% African American, 52% European American, 21% Mexican American). Participants, parents, and teachers completed measures of the adolescent's adjustment to assess internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. Results showed that membership in a high and rising trajectory group predicted rule-breaking behaviors and borderline personality features. Membership in a high desister group predicted internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. The findings suggest that although low levels of social and physical aggression may not bode poorly for adjustment, individuals engaging in high levels of social and physical aggression in middle childhood may be at greatest risk for adolescent psychopathology, whether they increase or desist in their aggression through early adolescence.
Pressure vessels often have notches or other stress concentrations present. Considering further that pressure vessels are nearly always subjected to some cyclic loading, fatigue cracking at notches is an important problem. The objective here is to describe some fatigue life testing and analysis which was performed with notched specimens in order to determine the effects of notch overload on fatigue life of pressure vessels.
A series of sputtered as-prepared and annealed Ge/C multilayer structures with periods ranging from 2 to 8 nm has been studied with high resolution transmission electron microscopy (HRTEM), x-ray scattering, and stress measurement techniques. Ge/C multilayers have potential applications as normal incidence reflective mirrors near 4.4 nm wavelength. The reflectivity and stress in these structures depend on the microstructural evolution of the component layers. The as-prepared structure of both Ge and C layers appear amorphous from TEM imaging and diffraction. Annealing at 500°C for 60 minutes leads to crystallization of the Ge layers. As the phase diagram indicates, no carbide compound has been found. X-ray scattering reveals that the multilayer period expands by as much as 10% after annealing. Both TEM images and x-ray profiles suggest that the layer structures remain well-defined upon annealing. In-situ stress-temperature measurements directly show the Ge/C multilayer microstructure evolution path. X-ray measurements show that the structures with periods near 2 nm undergo a significant improvement on optical performance with annealing. The physical mechanisms that may have caused the optical enhancement are discussed. Correlation of the stress evolution in the multilayers and in individual layers during annealing, and their relationships to the microstructures and optical properties are examined.
Multilayer (ML) structures composed of Mo-Be, Ru-Be and Rh-Be with bilayer periods of - 6 nm have been grown using dc magnetron sputter deposition. The ML microstructure has been characterized using x-ray diffraction and high-resolution transmission electron microscopy, and the normal incidence reflectivity has been measured at soft x-ray wavelengths.
In many applications, x-ray mulhilayer mirrors are exposed to high peak fluxes of x-rays with subsequent damage to the mirror. Mirror damage is a particularly severe problem with the use of multilayers as cavity optics for short wavelength x-ray lasers. Intense optical and x-ray radiation, from the x-ray laser plasma amplifier, often damages the multilayer mirror on time scales of hundreds of picoseconds. The phenomenon of multilayer mirror damage by pulsed xray emission has been studied using short duration (500 psec) bursts of soft x-rays from a laser produced gold plasma. The results of the experiments will be compared with some simple models and the possibility of increasing the damage thresholds of short wavelength multilayer mirrors will be discussed.
We investigate here for the first time GaN and AIGaN films by using x-ray photoemission spectromicroscopy. As compared to conventional x-ray photoemission spectroscopy (XPS), spectromicroscopy can provide spatially resolved information on the chemical composition of the sample surface. The experimental results where obtained by using MAXIMUM, a scanning photoemission microscope installed on 12.0 undulator beamline at the Advanced Light Source (ALS), Berkelely, allowing for a spatial resolution of 100 nm. We investigate here GaN and AlGaN thin films grown on sapphire substrate by metalorganic chemical vapor deposition (MOCVD). The results clearly indicate the great potential of spectromicroscopy in investigating chemical inhomogeneity, inpurities and localization in GaN and AlGaN thin films.
X-ray absorption and glancing angle reflectivity measurements in the energy range of the Nitrogen K-edge and Gallium M2,3 edges are reported. Linear muffin-tin orbital band-structure and spectral function calculations are used to interpret the data. Polarization effects are evidenced for the N-K-edge spectra by comparing X-ray reflectivity in s- and p-polarized light.