Impact of biodiversity loss on production in complex marine food webs mitigated by prey-release

Public concern over biodiversity loss is often rationalized as a threat to ecosystem functioning, but biodiversity-ecosystem functioning (BEF) relations are hard to empirically quantify at large scales. We use a realistic marine food-web model, resolving species over five trophic levels, to study how total fish production changes with species richness. This complex model predicts that BEF relations, on average, follow simple Michaelis-Menten curves when species are randomly deleted. These are shaped mainly by release of fish from predation, rather than the release from competition expected from simpler communities. Ordering species deletions by decreasing body mass or trophic level, representing 'fishing down the food web', accentuates prey-release effects and results in unimodal relationships. In contrast, simultaneous unselective harvesting diminishes these effects and produces an almost linear BEF relation, with maximum multispecies fisheries yield at approximate to 40% of initial species richness. These findings have important implications for the valuation of marine biodiversity.

PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

PTF11iqb was initially classified as a TypeIIn event caught very early after explosion. It showed narrow Wolf-Rayet (WR) spectral features on day 2, but the narrow emission weakened quickly and the spectrum morphed to resemble those of Types II-L and II-P. At late times, Halpha emission exhibited a complex, multipeaked profile reminiscent of SN1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN~1998S, although with weaker interaction with circumstellar material (CSM) at early times, and stronger CSM interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for weak CSM interaction added to the light curve of a normal SN~II-P. This plateau requires that the progenitor had an extended H envelope like a red supergiant, consistent with the slow progenitor wind speed indicated by narrow emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum --- meaning that the presence of such WR features in an early SN spectrum does not necessarily indicate a WR-like progenitor. [abridged] Overall, PTF11iqb bridges SNe~IIn with weaker pre-SN mass loss seen in SNe II-L and II-P, implying a continuum between these types.

Computing probable maximum loss in catastrophe reinsurance portfolios on multi-core and many-core architectures

In the reinsurance market, the risks natural catastrophes pose to portfolios of properties must be quantified, so that they can be priced, and insurance offered. The analysis of such risks at a portfolio level requires a simulation of up to 800 000 trials with an average of 1000 catastrophic events per trial. This is sufficient to capture risk for a global multi-peril reinsurance portfolio covering a range of perils including earthquake, hurricane, tornado, hail, severe thunderstorm, wind storm, storm surge and riverine flooding, and wildfire. Such simulations are both computation and data intensive, making the application of high-performance computing techniques desirable.

In this paper, we explore the design and implementation of portfolio risk analysis on both multi-core and many-core computing platforms. Given a portfolio of property catastrophe insurance treaties, key risk measures, such as probable maximum loss, are computed by taking both primary and secondary uncertainties into account. Primary uncertainty is associated with whether or not an event occurs in a simulated year, while secondary uncertainty captures the uncertainty in the level of loss due to the use of simplified physical models and limitations in the available data. A combination of fast lookup structures, multi-threading and careful hand tuning of numerical operations is required to achieve good performance. Experimental results are reported for multi-core processors and systems using NVIDIA graphics processing unit and Intel Phi many-core accelerators.

Methodological variations in estimating apparent progressive visual field loss in clinical trials of glaucoma treatment.

OBJECTIVES:

To compare methods to estimate the incidence of visual field progression used by 3 large randomized trials of glaucoma treatment by applying these methods to a common data set of annually obtained visual field measurements of patients with glaucoma followed up for an average of 6 years.

METHODS:

The methods used by the Advanced Glaucoma Intervention Study (AGIS), the Collaborative Initial Glaucoma Treatment Study (CIGTS), and the Early Manifest Glaucoma Treatment study (EMGT) were applied to 67 eyes of 56 patients with glaucoma enrolled in a 10-year natural history study of glaucoma using Program 30-2 of the Humphrey Field Analyzer (Humphrey Instruments, San Leandro, Calif). The incidence of apparent visual field progression was estimated for each method. Extent of agreement between the methods was calculated, and time to apparent progression was compared.

RESULTS:

The proportion of patients progressing was 11%, 22%, and 23% with AGIS, CIGTS, and EMGT methods, respectively. Clinical assessment identified 23% of patients who progressed, but only half of these were also identified by CIGTS or EMGT methods. The CIGTS and the EMGT had comparable incidence rates, but only half of those identified by 1 method were also identified by the other.

CONCLUSIONS:

The EMGT and CIGTS methods produced rates of apparent progression that were twice those of the AGIS method. Although EMGT, CIGTS, and clinical assessment rates were comparable, they did not identify the same patients as having had field progression.

Traffic gap judgment in people with significant peripheral field loss.

PURPOSE: Subjects with significant peripheral field loss (PFL) self report difficulty in street crossing. In this study, we compared the traffic gap judgment ability of fully sighted and PFL subjects to determine whether accuracy in identifying crossable gaps was adversely affected because of field loss. Moreover, we explored the contribution of visual and nonvisual factors to traffic gap judgment ability. METHODS: Eight subjects with significant PFL as a result of advanced retinitis pigmentosa or glaucoma with binocular visual field <20 degrees and five age-matched normals (NV) were recruited. All subjects were required to judge when they perceived it was safe to cross at a 2-way 4-lane street while they stood on the curb. Eye movements were recorded by an eye tracker as the subjects performed the decision task. Movies of the eye-on-scene were made offline and fixation patterns were classified into either relevant or irrelevant. Subjects' street-crossing behavior, habitual approach to street crossing, and perceived difficulties were assessed. RESULTS: Compared with normal vision (NV) subjects, the PFL subjects identified 12% fewer crossable gaps while making 23% more errors by identifying a gap as crossable when it was too short (p < 0.05). The differences in traffic gap judgment ability of the PFL subjects might be explained by the significantly smaller fixation area (p = 0.006) and fewer fixations distributed to the relevant tasks (p = 0.001). The subjects' habitual approach to street crossing and perceived difficulties in street crossing (r > 0.60) were significantly correlated with traffic gap judgment performance. CONCLUSIONS: As a consequence of significant field loss, limited visual information about the traffic environment can be acquired, resulting in significantly reduced performance in judging safe crossable gaps. This poor traffic gap judgment ability in the PFL subjects raises important concerns for their safety when attempting to cross the street.

Endothelial cell loss and surgically induced astigmatism after sutureless large-incision manual cataract extraction (SLIMCE).

OBJECTIVES:

To describe a modified manual cataract extraction technique, sutureless large-incision manual cataract extraction (SLIMCE), and to report its clinical outcomes.

METHODS:

Case notes of 50 consecutive patients with cataract surgery performed using the SLIMCE technique were retrospectively reviewed. Clinical outcomes 3 months after surgery were analyzed, including postoperative uncorrected visual acuity, best-corrected visual acuity, intraoperative and postoperative complications, endothelial cell loss, and surgically induced astigmatism using the vector analysis method.

RESULTS:

At the 3-month follow-up, all 50 patients had postoperative best-corrected visual acuity of at least 20/60, and 37 patients (74%) had visual acuity of at least 20/30. Uncorrected visual acuity was at least 20/68 in 28 patients (56%) and was between 20/80 and 20/200 in 22 patients (44%). No significant intraoperative complications were encountered, and sutureless wounds were achieved in all but 2 patients. At the 3-month follow-up, endothelial cell loss was 3.9%, and the mean surgically induced astigmatism was 0.69 diopter.

CONCLUSIONS:

SLIMCE is a safe and effective manual cataract extraction technique with low rates of surgically induced astigmatism and endothelial cell loss. In view of its low cost, SLIMCE may have a potential role in reducing cataract blindness in developing countries.

Forced Displacement, Suffering and the Aesthetics of Loss

This article investigates how artists have addressed shocking experiences of displacement in different political contexts. Drawing on the notion of ‘the aesthetics of loss’ (Köstlin, 2010), it examines and compares the different aims, desires and strategies that have shaped the histories and social lives of paintings, memorial statues, installations and other artefacts. The analysis identifies a mode of artistic engagement with the sense of a ‘loss of homeland’ that has been commonly felt amongst Sudeten German expellees, namely the production and framing of visual images as markers of collective trauma. These aesthetics of loss are contrasted with the approach taken by the Dutch artist Sophie Ernst in her project entitled HOME. Working with displaced people from Pakistan, India, Palestine, Israel and Iraq, she created a mnemonic space to stimulate a more individualistic, exploratory engagement with the loss of home, which aimed, in part, to elicit interpersonal empathy. To simply oppose these two modes of aesthetic engagement, however, would ignore the ways in which artefacts are drawn into different discursive, affective and spatial formations. This article argues for the need to expose such dynamic processes of framing and reframing by focusing on the processual aspects of aestheticisation with attention to the perspective of loss.

Addiction to Runx1 is partially attenuated by loss of p53 in the Eµ-Myc lymphoma model

The Runx genes function as dominant oncogenes that collaborate potently with Myc or loss of p53 to induce lymphoma when over-expressed. Here we examined the requirement for basal Runx1 activity for tumor maintenance in the Eµ-Myc model of Burkitt's lymphoma. While normal Runx1fl/fl lymphoid cells permit mono-allelic deletion, primary Eµ-Myc lymphomas showed selection for retention of both alleles and attempts to enforce deletion in vivo led to compensatory expansion of p53null blasts retaining Runx1. Surprisingly, Runx1 could be excised completely from established Eµ-Myc lymphoma cell lines in vitro without obvious effects on cell phenotype. Established lines lacked functional p53, and were sensitive to death induced by introduction of a temperature-sensitive p53 (Val135) allele. Transcriptome analysis of Runx1-deleted cells revealed a gene signature associated with lymphoid proliferation, survival and differentiation, and included strong de-repression of recombination-activating (Rag) genes, an observation that was mirrored in a panel of human acute leukemias where RUNX1 and RAG1,2 mRNA expression were negatively correlated. Notably, despite their continued growth and tumorigenic potential, Runx1null lymphoma cells displayed impaired proliferation and markedly increased sensitivity to DNA damage and dexamethasone-induced apoptosis, validating Runx1 function as a potential therapeutic target in Myc-driven lymphomas regardless of their p53 status.

Capture and loss of electron by MeV ions penetrating through liquid spray:Formation of negative ion and neutral atom beams

Charge changing processes of MeV ions penetrating through liquid spray is confirmed to be abundant source of various energetic negative ion and neutral atom beams its generic nature is demonstrated.

Hydrological and photochemical influence on dynamics of estuarine bacteria

Os estuários são ecossistemas complexos, onde os processos físicos, químicos e biológicos estão intimamente ligados. A dinâmica bacteriana num estuário reflete a interação e a elevada variação temporal e espacial desses processos. Este trabalho teve como objetivo elucidar as interações entre os processos físicos, fotoquímicos e microbiológicos no sistema estuarino da Ria de Aveiro (Portugal). Para tal, foi realizada uma abordagem inicial no campo, durante a qual as comunidades bacterianas na coluna de água foram caracterizadas em termos de abundância e atividade ao longo de 2 anos. O estudo foi realizado em dois locais distintos, escolhidos por tipificarem as características marinhas e salobras do estuário. Estes locais possuem diferentes hidrodinâmicas, influências fluviais e, quantidade e composição de matéria orgânica. Numa perspectiva mecanicista, foram realizadas simulações laboratoriais no sentido de elucidar a resposta das bactérias à matéria orgânica foto-transformada. As comunidades bacterianas no estuário adaptam-se a diferentes regimes de água doce, desenvolvendo padrões de abundância e atividade distintos nas zonas marinha e salobra. Os elevados caudais dos rios induzem estratificação vertical na zona marinha, promovendo o fluxo de fitoplâncton do mar para o estuário, do bacterioplâncton do estuário para o mar, e estimulam a importação de bactérias aderentes a partículas na zona salobra. O transporte advectivo e os processos de ressuspensão contribuem para aumentar 3 vezes o número de bactérias aderentes a partículas durante os períodos de intensas descargas fluviais. Adicionalmente, a atividade bacteriana no estuário é controlada pela concentração de azoto inerente à variações de água doce. O fornecimento de azoto em associação com a fonte dos substratos bacterianos induzem alterações significativas na produtividade. O padrão de variação vertical de comunidades bacterianas foi distinto nas duas zonas do estuário. Na zona marinha, as bactérias na microcamada superficial (SML) apresentaram taxas de hidrólise mais elevadas, mas menores taxas de incorporação de monómeros e produção de biomassa que na água subjacente (UW), enquanto na zona salobra, as taxas de hidrólise e incorporação foram similares nos dois compartimentos, mas a produtividade foi significativamente mais elevada na SML. Apesar da abundância bacteriana ter sido semelhante na SML e UW, a fração de células aderentes a partículas foi significativamente maior na SML (2-3 vezes), em ambas as zonas do estuário. A integração dos resultados microbiológicos com as variáveis ambientais e hidrológicos mostraram que fortes correntes na zona marinha promovem a mistura vertical, inibindo o estabelecimento de uma comunidade bacteriana na SML distinta da UW. Em contraste, na zona de água salobra, a menor velocidades das correntes fornece as condições adequadas ao aumento da atividade bacteriana na SML. Características específicas do local, tais como a hidrodinâmica e as fontes e composição da matéria orgânica, conduzem também a diferentes graus de enriquecimento superficial de matéria orgânica e inorgânica, influenciando a sua transformação. Em geral, o ambiente da SML estuarina favorece a hidrólise de polímeros, mas inibe a utilização de monómeros, comparativamente com água subjacente. No entanto, as diferenças entre as duas comunidades tendem a atenuar-se com o aumento da atividade heterotrófica na zona salobra. A matéria orgânica dissolvida cromófora (CDOM) das duas zonas do estuário possui diferentes características espectrais, com maior aromaticidade e peso molecular médio (HMW) na zona de água salobra, em comparação com a zona marinha. Nesta zona, a abundância bacteriana correlacionou-se com a350 e a254, sugerindo uma contribuição indireta das bactéria para HMW CDOM. A irradiação do DOM resultou numa diminuição dos valores de a254 e a350, e, em um aumento do declive S275-295 e dos rácios E2:E3 (a250/a365) e SR. No entanto, a extensão de transformações foto-induzidas e as respostas microbianas são dependentes das características iniciais CDOM, inferidas a partir das suas propriedades ópticas. A dinâmica estuarina influencia claramente as atividades heterotróficas e a distribuição dos microorganismos na coluna de água. A entrada de água doce influencia a dinâmica e os principais reguladores das comunidades bacterianas no estuário. Os processos fotoquímicos e microbianos produzem alterações nas propriedades ópticas da CDOM e a combinação desses processos determina o resultado global e o destino da CDOM nos sistemas estuarinos com influência na produtividade nas áreas costeiras adjacente.

Loss of Aggressiveness of Phytophthora cinnamomi (Beta-Cinnamomin Silenced Strain) in the Infection of Castanea sativa

Several forest species are severely affected by Phytophthora cinnamomi. The contribution of this oomycete to forest decline and dieback has been broadly reported. In particular, it is consensual that it is the causal agent of ink disease in Castanea sativa. It has been associated with the severe decline of Quercus species, namely the Q. suber and Q. ilex dieback in Portugal and Spain, and has been responsible for the infection of numerous native species and crops. This pathogen persists in the soil or on plant material in the form of chlamydospores allowing the infection of living root tissues when environmental conditions are favorable. © Microscopy Society of America 2012.

Effect of high CO2 and ocean acidification on photosynthesis and response to oxidative stress in seagrasses

Climate change scenarios comprise significant modifications of the marine realm, notably ocean acidification and temperature increase, both direct consequences of the rising atmospheric CO2 concentration. These changes are likely to impact marine organisms and ecosystems, namely the valuable seagrass-dominated coastal habitats. The main objective of this thesis was to evaluate the photosynthetic and antioxidant responses of seagrasses to climate change, considering CO2, temperature and light as key drivers of these processes. The methodologies used to determine global antioxidant capacity and antioxidant enzymatic activity in seagrasses were optimized for the species Cymodocea nodosa and Posidonia oceanica, revealing identical defence mechanisms to those found in terrestrial plants. The detailed analysis and identification of photosynthetic pigments in Halophila ovalis, H.stipulacea, Zostera noltii, Z marina, Z. capricorni, Cymodocea nodosa and Posidonia oceanica, sampled across different climatic zones and depths, also revealed a similarity with terrestrial plants, both in carotenoid composition and in the pigment-based photoprotection mechanisms. Cymodocea nodosa plants from Ria Formosa were submitted to the combined effect of potentially stressful light and temperature ranges and showed considerable physiological tolerance, due to the combination of changes in the antioxidant system, activation of the VAZ cycle and accumulation of leaf soluble sugars, thus preventing the onset of oxidative stress. Cymodocea nodosa plants living in a naturally acidified environment near submarine volcanic vents in Vulcano Island (Italy) showed to be under oxidative stress despite the enhancement of the antioxidant capacity, phenolics concentration and carotenoids. Posidonia oceanica leaves loaded with epiphytes showed a significant increase in oxidative stress, despite the increase of antioxidant responses and the allocation of energetic resources to these protection mechanisms. Globally, the results show that seagrasses are physiologically able to deal with potentially stressful conditions from different origins, being plastic enough to avoid stress in many situations and to actively promote ulterior defence and repair mechanisms when under effective oxidative stress.

Loss of Par3 leads to aberrant divisions and faster mitotic progression in differentiating primary murine keratinocytes

Dissertação de Mestrado, Oncobiologia: Mecanismos Moleculares do Cancro, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

AB1258­HPR pilot study: does a mediterranean diet­based weight loss programme improve health outcomes in overweight older women with knee osteoarthritis?

Osteoarthritis (OA) is one of the leading causes of pain and disability among older adults, particularly women. Pain and mobility disability are major consequences of knee OA which and can interfere with the functional autonomy of elderly and thus, making it difficult to perform activities of daily living. Evidence suggests that obesity is strongly linked to knee OA and that non­pharmacological therapy should be based on physical activity and weight loss in case of overweight and obesity. A positive relationship between adherence to the Mediterranean diet and health outcomes has been widely discussed in scientific literature, including its potential benefits in weight loss.

Best Practice for Providing Social Care and Support to People Living with Concurrent Sight Loss and Dementia: Professional Perspectives

Purpose-Approximately 100,000 people in the UK aged 75 and over have concurrent dementia and sight loss, but current understanding of their experiences, needs and preferences is limited. The purpose of this paper is to report on a research project that explored the provision of social care and support for older people with both conditions. Design/methodology/approach-The project was a collaboration between the universities of York, Worcester, Bournemouth and Cambridge, supported by the Thomas Pocklington Trust and the Housing and Dementia Research Consortium. Data for this paper were drawn from focus groups held in 2013 involving 47 professionals across the dementia, sight loss and housing sectors. Findings-Thematic analysis identified five main barriers to providing high-quality, cost-effective social care and support: time constraints; financial limitations; insufficient professional knowledge; a lack of joint working; and inconsistency of services. The requirements of dementia and sight loss often conflict, which can limit the usefulness of equipment, aids and adaptations. Support and information needs to address individual needs and preferences. Research limitations/implications-Unless professionals consider dementia and sight loss together, they are unlikely to think about the impact of both conditions and the potential of their own services to provide effective support for individuals and their informal carers. Failing to consider both conditions together can also limit the availability and accessibility of social care and support services. This paper is based on input from a small sample of self-selecting professionals across three geographical regions of England. More research is needed in this area. Practical implications-There are growing numbers of people living with concurrent dementia and sight loss, many of whom wish to remain living in their own homes. There is limited awareness of the experiences and needs of this group and limited provision of appropriate services aids/adaptations. A range of measures should be implemented in order to support independence and well-being for people living with both conditions and their family carers. These include increased awareness, improved assessment, more training and greater joint working. Social implications-People living with dementia or sight loss are at high risk of social isolation, increasingly so for those with both conditions. Services that take an inclusive approach to both conditions can provide crucial opportunities for social interaction. Extra care housing has the potential to provide a supportive, community-based environment that can help residents to maintain social contact. Originality/value-This paper adds much-needed evidence to the limited existing literature, and reflects the views of diverse professionals across housing, health and social care