Tentacular diversity in deep-sea deposit-feeding holothurians: implications for biodiversity in the deep sea

The tentacles of deep-sea holothurians show a wide range of morphological diversity. The present paper examines gross tentacle morphology in surface deposit feeding holothurians from a range of bathymetric depths. Species studied included the elasipods: Oneirophanta mutabilis, Psychropotes longicauda and Benthogone rosea and the aspidochirotids: Paroriza prouhoi, Pseudostichopus sp., Bathyplotes natans and Paroriza pallens. The sympatric abyssal species Oneirophanta mutabilis, Psychropotes longicauda and Pseudostichopus sp. show subtle differences in diet and the structure and filling patterns of the gut that suggest differences in feeding strategies which may represent one mechanism to overcome competition for food resources in an environment where nutrient resources are considered to be, at least periodically, limiting. Interspecific differences in tentacle functional morphology and digestive strategies, which reflects taxonomic diversity could be explained in terms of Sanders'; Stability–Time Hypothesis. Since different tentacle types will turn over sediments to different extents, their impact on sedimentary communities will be enormous so that high diversity in meiofaunal communities may be explained most simply by Dayton and Hessler's Biological Disturbance Hypothesis.

Does the freshwater pearl mussel, Margaritifera margaritifera L., face extinction in Northern Ireland?

1. Until recently the status of Margaritifera margaritifera L. in Northern Ireland was not well documented. This paper presents the results of field surveys conducted in 1990/'91 and in 1996 at over 200 sites covering all major river systems in Northern Ireland. 2.Margaritifera populations in Northern Ireland were recorded at just 20 sites mainly located in the west of the province. Formerly many rivers supported vast numbers of mussels but anecdotal evidence points to periods of major declines in mussel populations since the turn of the century. 3. The absence of mussels smaller than 30 mm in length at most sites suggests very little or no recruitment during the past decade. During the surveys, deteriorating water quality, habitat disturbance and pearl fishing were recorded and are the major causes of the decline of the freshwater pearl mussel in Northern Ireland. 4. Unless the above problems are alleviated in the very near future, M.margaritifera will probably become extinct in Northern Ireland. © 1998 John Wiley & Sons, Ltd.

Faithful nonclassicality indicators and extremal quantum correlations in two-qubit states

The state disturbance induced by locally measuring a quantum system yields a signature of nonclassical correlations beyond entanglement. Here, we present a detailed study of such correlations for two-qubit mixed states. To overcome the asymmetry of quantum discord and the unfaithfulness of measurement-induced disturbance (severely overestimating quantum correlations), we propose an ameliorated measurement-induced disturbance as nonclassicality indicator, optimized over joint local measurements, and we derive its closed expression for relevant two-qubit states. We study its analytical relation with discord, and characterize the maximally quantum-correlated mixed states, that simultaneously extremize both quantifiers at given von Neumann entropy: among all two-qubit states, these states possess the most robust quantum correlations against noise.

Quality of food consumed by over wintering pale-bellied Brent geese Branta bernicla hrota and wigeon Anas penelope

The seasonal selection of food by pale-bellied Brent geese and wigeon on Strangford Lough was analysed with respect to nutritive quality. Both species selected food plants to maximise nutrition. In wigeon, food selection may also have been affected by the intolerance of this species to disturbance, forcing many individuals to feed in secondary habitats. Minerals do not seem to affect food selection, with most plant species in the diet providing a sufficiently balanced complement of nutrients. It is concluded that interspecific differences in food selection and reaction to human disturbance may have contributed to the decline in numbers of wigeon in Strangford Lough while numbers of Brent geese have been maintained. Some implications are discussed and recommendations for management are proposed.

Behaviour of Brent geese Branta bernicla hrota and wigeon Anas penelope feeding on intertidal Zostera spp

Mixed flocks of pale-bellied Brent geese (Branta bernicla hrota) and wigeon (Anas penelope L.) feeding on intertidal Zostera spp were studied during October 1993 with respect to tidal position, feeding method and duration, and competitive: interactions within and between species. Owing to many disturbance incidents affecting the use of the site by wildfowl, only complete data on flow tides were presented. Brent geese fed over a greater period of the tidal cycle than wigeon. Differences in feeding methods indicated that Brent geese exploited the rhizomes, which are energetically more profitable than the shoot on which wigeon fed. Aggressive interactions were recorded within species but there were no records of aggression between species. More subtle competition for space, however, may have occurred during feeding. Brent geese could reach Zostera spp For a short period after increasing depth of water prevented access by wigeon. However, individual wigeon were observed foraging near feeding Brent geese, picking up the scraps oi material discarded by the latter, and small numbers of wigeon may benefit from the presence of the geese. These benefits for some individual wigeon are not considered to compensate for the disadvantages to the latter species population as a whole in feeding on poorer-quality food for a shorter period of the tidal cycle. This disadvantage is likely to have contributed to the decline in the wigeon population on Strangford Lough, Co. Down, while numbers of Brent geese have been maintained at a high level.

Altered endothelin-1 induced contraction and second messenger generation in bovine retinal microvascular pericytes cultured in high glucose medium.

The effect of simulated hyperglycaemia on bovine retinal pericytes was studied following culture of these cells for 10 days under normal (5 mmol/l) and elevated (25 mmol/l) glucose conditions in the absence of endothelial cells. Pericytes cultured under high ambient glucose exhibited both a delayed and reduced contractile response following stimulation with endothelin-1. Stimulation with 10(-7) mol/l endothelin-1 for 30 s caused significant contraction in cells grown in both 5 mmol/l and 25 mmol/l glucose. The former also contracted significantly with 10(-8) mol/l endothelin-1. Further, at all concentrations tested, statistical comparison of the time course of contraction showed a significant difference (p 0.1) between bovine retinal pericytes grown for 10 days under normo- or hyperglycaemic conditions, it became apparent that the altered contractility in bovine retinal pericytes following culture in high glucose must be due to post-binding intracellular disturbance(s). Indeed, both basal and 15 s post-stimulation with 10(-8) mol/l endothelin-1, levels of inositol trisphosphate were significantly reduced (p

Assessment of sample quality in soft clay using shear wave velocity and suction measurements

The characterisation of soils for civil engineering purposes depends on removing sufficiently high-quality samples from the ground. Accurate evaluation of sample quality is therefore important if reliable design parameters are to be determined. This paper describes the use of unconfined shear wave velocity (V _s) and suction (u _r) measurements to assess sample quality rapidly in soft clay. Samples of varying quality from three well-characterised soft clay sites are initially assessed using conventional techniques, and their results compared with V _s and u _r measurements performed on the same samples. It is observed that the quality of samples indicated by these measurements is very similar to those inferred from traditional disturbance measures, with V _s being the more reliable indicator. A tentative empirically derived criterion, based on samples tested in this project, is proposed to quantify sample disturbance combining both V _s and u _r measurements. Further work using this criterion on different materials is important so as to test its usefulness.

Gastric emptying in patients with flatulent dyspepsia, with and without gallbladder disease

It has been suggested that the symptoms of flatulent dyspepsia are caused by a functional disturbance of the upper gastrointestinal tract. The aim of this study was to investigate delayed gastric emptying as the basis of symptoms in patients with and without gallbladder disease and after cholecystectomy. There were 13 dyspeptic patients with gallbladder disease, 12 with normal gallbladders, and 13 post-cholecystectomy patients. Gastric emptying was measured by means of a 99mTc-labelled scrambled egg meal and external scintillation counter. The rate of emptying in the symptomatic groups was compared with that in 24 asymptomatic normal control subjects and 12 non-dyspeptic patients with gallbladder disease. Delayed gastric emptying tended to occur in patients with gallbladder disease with and without dyspepsia and was not specifically associated with symptoms.

Assessing the extent to which temporal changes in waterbird community composition are driven by either local, regional or global factors.

1. Lough Neagh and Lough Beg Special Protection Area (SPA, hereafter Lough Neagh) is an important non-estuarine site in Britain and Ireland for overwintering wildfowl. Multivariate analysis of the winter counts showed a state-shift in the waterbird community following winter 2000/2001, mostly due to rapid declines in abundance (46–57% declines in the mean mid-winter January counts between 1993–2000 and 2002–2009) of members of the diving duck guild (pochard Aythya ferina, tufted duck Aythya fuligula and goldeneye Bucephala clangula) and coot (Fulica atra), a submerged macrophyte feeder.
2. Only pochard showed correlations between declines at Lough Neagh and those of overall species flyway population indices to suggest that global changes could contribute to declines at the site. However, indices from the Republic of Ireland showed no overall decline in the rest of Ireland. Tufted duck indices at the site were inversely related to indices in Great Britain. Lough Neagh goldeneye indices were positively correlated with indices in the Republic of Ireland and Great Britain, suggesting that short-stopping could contribute to declines at the site. Coot declines at Lough Neagh did not correlate with trends elsewhere, suggesting local factors involved in the decline.
3. These analyses indicate that although there are potentially different explanations for the dramatic declines in these four waterbird species at this site, the simultaneous nature of the declines across two feeding guilds strongly
suggest that local factors (such as loss of submerged macrophytes and benthic invertebrates) were involved. An assessment of the food supply, local disturbance and other factors at Lough Neagh is required to find an explanation for the observed adverse trends in wintering numbers of the affected species.
4. This study highlights the potential of waterbird community structure to reflect the status of aquatic systems, but confirms the need to establish site-specific factors responsible for the observed changes in abundance of key waterbird species at a site.

Using vulnerability performance indicators to attain food supply chain robustness

High effectiveness and leanness of modern supply chains (SCs) increase their vulnerability, i.e. susceptibility to disturbances reflected in non-robust SC performances. Both the SC management literature and SC professionals indicate the need for the development of SC vulnerability assessment tools. In this article, a new method for vulnerability assessment, the VULA method, is presented. The VULA method helps to identify how much a company would underperform on a specific Key Performance Indicator in the case of a disturbance, how often this would happen and how long it would last. It ultimately informs the decision about whether process redesign is appropriate and what kind of redesign strategies should be used in order to increase the SC's robustness. The applicability of the VULA method is demonstrated in the context of a meat SC using discrete-event simulation to conduct the performance analysis.

Vegetation changes and human settlement of Easter Island during the last millennia: a multiproxy study of the Lake Raraku sediments

Earlier palynological studies of lake sediments from Easter Island suggest that the island underwent a recent and abrupt replacement of palm-dominated forests by grasslands, interpreted as a deforestation by indigenous people. However, the available evidence is inconclusive due to the existence of extended hiatuses and ambiguous chronological frameworks in most of the sedimentary sequences studied. This has given rise to an ongoing debate about the timing and causes of the assumed ecological degradation and cultural breakdown. Our multiproxy study of a core recovered from Lake Raraku highlights the vegetation dynamics and environmental shifts in the catchment and its surroundings during the late Holocene. The sequence contains shorter hiatuses than in previously recovered cores and provides a more continuous history of environmental changes. The results show a long, gradual and stepped landscape shift from palm-dominated forests to grasslands. This change started c. 450 BC and lasted about two thousand years. The presence of Verbena litoralis, a common weed, which is associated with human activities in the pollen record, the significant correlation between shifts in charcoal influx, and the dominant pollen types suggest human disturbance of the vegetation. Therefore, human settlement on the island occurred c. 450 BC, some 1500 years earlier than is assumed. Climate variability also exerted a major influence on environmental changes. Two sedimentary gaps in the record are interpreted as periods of droughts that could have prevented peat growth and favoured its erosion during the Medieval Climate Anomaly and the Little Ice Age, respectively. At c. AD 1200, the water table rose and the former Raraku mire turned into a shallow lake, suggesting higher precipitation/evaporation rates coeval with a cooler and wetter Pan-Pacific AD 1300 event. Pollen and diatom records show large vegetation changes due to human activities c. AD 1200. Other recent vegetation changes also due to human activities entail the introduction of taxa (e.g. Psidium guajava, Eucalyptus sp.) and the disappearance of indigenous plants such as Sophora toromiro during the two last centuries. Although the evidence is not conclusive, the American origin of V. litoralis re-opens the debate about the possible role of Amerindians in the human colonisation of Easter Island.

Visual outcomes in the subfoveal radiotherapy study:A randomized controlled trial of teletherapy for age-related macular degeneration

Objective: To determine whether teletherapy with 6-mV photons can reduce visual loss in patients with subfoveal choroidal neovascularization in age-related macular degeneration. Design: A multicenter, single-masked, randomized controlled trial of 12 Gy of external beam radiation therapy delivered to the macula of an affected eye vs observation only. Setting: Three United Kingdom-based hospital units. Participants: Patients with age-related macular degeneration, aged 60 years and older, who had subfoveal choroidal neovascularization and a visual acuity of 20/200 (logMAR 1.0) or better. Methods: Two hundred three patients were randomly assigned to radiotherapy or observation. Treatment was undertaken at designated radiotherapy centers, and patients assigned to the treatment group received a total dosage of 12 Gy of 6-mV photons in 6 fractions. Follow-up was scheduled at 3, 6, 12, and 24 months. After excluding protocol violators, the data from 199 patients were analyzed. Main Outcome Measures: The primary outcome measure was mean loss of distance visual acuity in the study eye at 12 and 24 months. Other outcome variables analyzed were near visual acuity and contrast sensitivity. The proportions of patients losing 3 or more or 6 or more lines of distance and near acuity and 0.3 or more or 0.6 or more log units of contrast sensitivity at each follow-up were also analyzed. Results: At all time points, mean distance visual acuity was better in the radiotherapy-treated group than in the control group, but the differences did not reach statistical significance. At 24 months, analysis of the proportions of patients with loss of 3 or more (moderate) (P=.08) or 6 or more (severe) (P=.29) lines of distance vision showed that fewer treated patients had severe losses, but there was no statistically significant difference between groups. For near visual acuity, although there was no evidence of treatment benefit at 12 and 24 months, a significant difference in favor of treatment was present at 6 months (P=.048). When analyzed by the proportions of patients losing 3 lines of contrast sensitivity, there was a significant difference in favor of treatment at 24 months (P=.02). No adverse retinal effects were observed during the study, but transient disturbance of the precorneal tear film was noted in treated patients. Conclusion: The results of the present trial do not support the routine clinical use of external beam radiation therapy in subjects with subfoveal choroidal neovascularization in age-related macular degeneration.

A ten year retrospective audit of clinical psychology referrals within a paediatric CF team

Objective: This retrospective audit was undertaken to explore the nature of referrals made by the paediatric CF team to the Clinical Psychologist over a period of 10 years. The aim of the audit was to identify patterns or trends related to difficulties referred by the team.
Methods: A database consisting of all referrals received over a ten year period from 2001-2010 was created. A coding template was then created by KR and AC, which allowed for the categorisation of referrals into three main themes: Mood disturbance; CF related events; and non-CF related events. The same coding template was used to categorise referrals to the adult CF service. Descriptive statistics were used to interpret the data.
Results: Over the ten year period, 106 young people with CF were referred to psychology, representing 266 referrals. On average, a referral was made every two weeks. The most common reason for referral was for CF related events (i.e. adherence, living everyday life with CF). Referrals were found to increase with age. Both genders were equally likely to be referred, with females being re-referred most frequently, indicating increased psychological morbidity. The majority of referrals (79%) were repeat referrals, indicating that psychology input is focused upon a small number of young people but over a period of time. In a typical year (09-10), only 16% of all young people with CF were able to access psychology services. Conclusion: This audit identified patterns related to inequality of access, gender differences, and the identification of common concerns across age groups. The audit also highlighted areas where early intervention and training efforts could be targeted.

A ten year audit of clinical psychology referrals in the regional Adult Cystic Fibrosis Unit in Northern Ireland

Objectives: A retrospective audit was conducted into Clinical Psychology referrals made by the adult cystic fibrosis (CF) team over a ten year period from 2001-2010. The aim of the audit was to examine the psychological difficulties referred to Clinical Psychology and identify any trends.
Methods: A database of all referrals received over a ten year period was created. A coding template was created by KR and AC which allowed for the categorisation of referrals into three main themes: Mood disturbance, CF related events and non-CF related events. The same coding template was used to categorise referrals to the children’s CF service. Descriptive statistics were used to interpret the data.
Results: In 2009/10, 11% of the adult CF population in Northern Ireland were referred to Clinical Psychology. In the past 10 years there were 200 referrals and 105 adults who accessed Clinical Psychology services. The majority of referrals (67%) were re-referrals (range 2-7). More females were referred and they were also more likely to be referred repeatedly The main reason for referral was anxiety. Depression, adherence and end of life/transplant issues also accounted for a large proportion of referrals. A small proportion of referrals were due to non CF related events. There were age and gender differences in the reasons for referral.
Conclusion: A minority of CF patients attending the regional unit were referred to Clinical Psychology. Those who accessed the services appear to be at increased risk of psychological morbidity as re-referral rates are high. The gender difference in referral and re-referral rates may reflect a difference in psychological morbidity or males not accessing services.

Myotonic dystrophy mimicking bilateral internuclear ophthalmoplegia

Myotonic dystrophy is a disorder with frequent ophthalmologic features. A 44-year-old black male with myotonic dystrophy is described. The patient displays a previously unreported type of motility disturbance in myotonic dystrophy in which there is an apparent limitation of motility that simulates a bilateral internuclear ophthalmoplegia. Myotonic dystrophy may be considered as another possible cause of pseudo-internuclear ophthalmoplegia.