Hepatic artery thrombosis following pediatric liver transplantation: Assessment of blood flow measurement in allografts

The purpose of this study was to define parameters which could be predictive of hepatic artery thrombosis, which continues to be a major complicating factor in pediatric liver transplantation. The hepatic blood flow of 14 pediatric liver patients (15 grafts) who weighted less than 15 kg was measured electromagnetically during orthotopic liver transplantation. The results of blood flow determination and the clinical data in 7 patients (8 grafts) who developed hepatic artery thrombosis were compared with those of 7 control patients. All patients with a hepatic arterial flow of less than 60 ml/min developed hepatic artery thrombosis (4/8 vs. 0/7; p < 0.05), and the patients with hepatic artery thrombosis exhibited higher total hepatic and portal vein flow per 100 gram of liver tissue (262 vs. 136 ml/min; p < 0.001 and 222 vs. 80 ml/min; p < 0.025, respectively) as well as longer cold preservation time (384 vs. 326 min; p < 0.025). The results of our study suggest that hepatic arterial flows of less than 60 ml/min are critical for the development of hepatic artery thrombosis, and that portal venous overflow and increased preservation times may contribute to the development of hepatic artery thrombosis

OKT3 and viral disease in pediatric liver transplant recipients

Seventy-four consecutive pediatric liver transplant recipients were reviewed to assess the effect of the monoclonal anti-T-lymphocyte antibody OKT3 on subsequent viral infection (9 patients were excluded due to postoperative demise during the 1st week). Twenty-two patients received OKT3 in addition to standard cyclosporine-prednisone immunosuppression for either steroid-resistant acute rejection (18) or to facilitate reduction of cyclosporine due to severe renal impairment (4). Invasive infections were diagnosed by histology or culture in tissue biopsies or bronchoalveolar lavage specimens. The overall incidence of viral infection was 58%, half of which was due to cytomegalovirus (CMV). Invasive viral disease was associated with increased mortality (37% vs. 3% p = 0.001). Viral-related deaths were due to CMV (5), disseminated adenovirus (3), disseminated enterovirus (1) and respiratory syncytial viral pneumonia (1). The use of OKT3 was associated with increased viral disease (59% vs. 33% p = 0.04) and invasive primary CMV disease (58% vs. 19% p = 0.04). Trends were observed toward increased overall viral infection (73% vs. 51% p = 0.08), primary CMV infection (58% vs. 25% p = 0.08) and overall mortality (27% vs. 9% p = 0.08) following OKT3 therapy. We conclude that pediatric liver transplant recipients who require OKT3 therapy may be at increased risk for invasive viral disease and especially invasive primary CMV disease

The Ctf18 RFC-like complex positions yeast telomeres but does not specify their replication time

Peer reviewedPreprin

Methods for biogeochemical studies of sea ice: The state of the art, caveats, and recommendations

AbstractOver the past two decades, with recognition that the ocean’s sea-ice cover is neither insensitive to climate change nor a barrier to light and matter, research in sea-ice biogeochemistry has accelerated significantly, bringing together a multi-disciplinary community from a variety of fields. This disciplinary diversity has contributed a wide range of methodological techniques and approaches to sea-ice studies, complicating comparisons of the results and the development of conceptual and numerical models to describe the important biogeochemical processes occurring in sea ice. Almost all chemical elements, compounds, and biogeochemical processes relevant to Earth system science are measured in sea ice, with published methods available for determining biomass, pigments, net community production, primary production, bacterial activity, macronutrients, numerous natural and anthropogenic organic compounds, trace elements, reactive and inert gases, sulfur species, the carbon dioxide system parameters, stable isotopes, and water-ice-atmosphere fluxes of gases, liquids, and solids. For most of these measurements, multiple sampling and processing techniques are available, but to date there has been little intercomparison or intercalibration between methods. In addition, researchers collect different types of ancillary data and document their samples differently, further confounding comparisons between studies. These problems are compounded by the heterogeneity of sea ice, in which even adjacent cores can have dramatically different biogeochemical compositions. We recommend that, in future investigations, researchers design their programs based on nested sampling patterns, collect a core suite of ancillary measurements, and employ a standard approach for sample identification and documentation. In addition, intercalibration exercises are most critically needed for measurements of biomass, primary production, nutrients, dissolved and particulate organic matter (including exopolymers), the CO2 system, air-ice gas fluxes, and aerosol production. We also encourage the development of in situ probes robust enough for long-term deployment in sea ice, particularly for biological parameters, the CO2 system, and other gases.This manuscript is a product of SCOR working group 140 on Biogeochemical Exchange Processes at Sea-Ice Interfaces (BEPSII); we thank BEPSII chairs Jacqueline Stefels and Nadja Steiner and SCOR executive director Ed Urban for their practical and moral support of this endeavour. This manuscript was first conceived at an EU COST Action 735 workshop held in Amsterdam in April 2011; in addition to COST 735, we thank the other participants of the “methods” break-out group at that meeting, namely Gerhard Dieckmann, Christoph Garbe, and Claire Hughes. Our editors, Steve Ackley and Jody Deming, and our reviewers, Mats Granskog and two anonymous reviewers, provided invaluable advice that not only identified and helped fill in some gaps, but also suggested additional ways to make what is by nature a rather dry subject (methods) at least a bit more interesting and accessible. We also thank the librarians at the Institute of Ocean Sciences for their unflagging efforts to track down the more obscure references we required. Finally, and most importantly, we thank everyone who has braved the unknown and made the new measurements that have helped build sea-ice biogeochemistry into the robust and exciting field it has become.This is the final published article, originally published in Elementa: Science of the Anthropocene, 3: 000038, doi: 10.12952/journal.elementa.00003

The Structure and Evolution of Stars: Introductory Remarks

In this introductory chapter of the Special Issue entitled ‘The Structure and Evolution of Stars’, we highlight the recent major progress made in our understanding of the physics that governs stellar interiors. In so doing, we combine insight from observations, 1D evolutionary modelling and 2D + 3D rotating (magneto)hydrodynamical simulations. Therefore, a complete and compelling picture of the necessary ingredients in state-of-the-art stellar structure theory and areas in which improvementsstillneedtobemadearecontextualised. Additionally, the over-arching perspective linking all the themes of subsequent chapters is presented

Bacterial diversity in snow on North Pole ice floes

The microbial abundance and diversity in snow on ice floes at three sites near the North Pole was assessed using quantitative PCR and 454 pyrosequencing. Abundance of 16S rRNA genes in the samples ranged between 43 and 248 gene copies per millilitre of melted snow. A total of 291,331 sequences were obtained through 454 pyrosequencing of 16S rRNA genes, resulting in 984 OTUs at 97 % identity. Two sites were dominated by Cyanobacteria (72 and 61 %, respectively), including chloroplasts. The third site differed by consisting of 95 % Proteobacteria. Principal component analysis showed that the three sites clustered together when compared to the underlying environments of sea ice and ocean water. The Shannon indices ranged from 2.226 to 3.758, and the Chao1 indices showed species richness between 293 and 353 for the three samples. The relatively low abundances and diversity found in the samples indicate a lower rate of microbial input to this snow habitat compared to snow in the proximity of terrestrial and anthropogenic sources of microorganisms. The differences in species composition and diversity between the sites show that apparently similar snow habitats contain a large variation in biodiversity, although the differences were smaller than the differences to the underlying environment. The results support the idea that a globally distributed community exists in snow and that the global snow community can in part be attributed to microbial input from the atmosphere. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00792-014-0660-y) contains supplementary material, which is available to authorized users

7 Scoping review of homonymous hemianopia in childhood

Cerebral visual impairment (CVI) encompasses a heterogeneous group of disorders and a spectrum of types of visual impairments. Research is needed to characterise the different forms of CVI and identify the specific needs of these groups to inform individualised patient care. Homonymous hemianopia (HH) is a definable visual field defect that affect some children with CVI. As part of a new research programme, we conducted a scoping review of the literature on HH in children and young people to map current knowledge and identify evidence gaps.We used the PRISMA extension for Scoping Reviews methodology. Multiple online databases were searched using terms associated with 'homonymous hemianopia' and 'children'. This yielded 1588 papers which were screened by two reviewers. Of these 1001 were excluded at abstract screen and a further 415 excluded after full text review, with full text unavailable for 15. Data were extracted and charted from 157 studies and additional grey literature.Interim analysis shows reported studies are predominantly from high income countries with a paucity of higher-level evidence, and a preponderance of case reports. Most papers reported causative pathology and diagnosis of HH. There was minimal attention to or evidence relating to intervention. Child-specific grey literature on HH was limited.This review collates the current evidence-base for HH in children. It demonstrates the important evidence-gap relating to intervention in these cases that would help inform more individualised care. Similar scoping reviews may be prove useful in assessing the evidence relating to other definable groups within the CVI umbrella

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Creating Creative Technologists: playing with(in) education

Since the industrial revolution, the organization of knowledge into distinct scientific, technical or creative categories has resulted in educational systems designed to produce and validate particular occupations. The methods by which students are exposed to different kinds of knowledge are critical in creating and reproducing individual, professional or cultural identities. (“I am an Engineer. You are an Artist”). The emergence of more open, creative and socialised technologies generates challenges for discipline-based education. At the same time, the term “Creative Technologies” also suggests a new occupational category (“I am a Creative Technologist”). This chapter presents a case-study of an evolving ‘anti-disciplinary’ project-based degree that challenges traditional degree structures to stimulate new forms of connective, imaginative and explorative learning, and to equip students to respond to a changing world. Learning is conceived as an emergent process; self-managed by students through critique and open peer review. We focus on ‘playfulness’ as a methodology for achieving multi-modal learning across the boundaries of art, design, computer science, engineering, games and entrepreneurship. In this new cultural moment, playfulness also re-frames the institutional identities of teacher and learner in response to new expectations for learning

Use of wild bird surveillance, human case data and GIS spatial analysis for predicting spatial distributions of West Nile Virus in Greece

West Nile Virus (WNV) is the causative agent of a vector-borne, zoonotic disease with a worldwide distribution. Recent expansion and introduction of WNV into new areas, including southern Europe, has been associated with severe disease in humans and equids, and has increased concerns regarding the need to prevent and control future WNV outbreaks. Since 2010, 524 confirmed human cases of the disease have been reported in Greece with greater than 10% mortality. Infected mosquitoes, wild birds, equids, and chickens have been detected and associated with human disease. The aim of our study was to establish a monitoring system with wild birds and reported human cases data using Geographical Information System (GIS). Potential distribution of WNV was modelled by combining wild bird serological surveillance data with environmental factors (e.g. elevation, slope, land use, vegetation density, temperature, precipitation indices, and population density). Local factors including areas of low altitude and proximity to water were important predictors of appearance of both human and wild bird cases (Odds Ratio = 1,001 95%CI = 0,723–1,386). Using GIS analysis, the identified risk factors were applied across Greece identifying the northern part of Greece (Macedonia, Thrace) western Greece and a number of Greek islands as being at highest risk of future outbreaks. The results of the analysis were evaluated and confirmed using the 161 reported human cases of the 2012 outbreak predicting correctly (Odds = 130/31 = 4,194 95%CI = 2,841–6,189) and more areas were identified for potential dispersion in the following years. Our approach verified that WNV risk can be modelled in a fast cost-effective way indicating high risk areas where prevention measures should be implemented in order to reduce the disease incidence