bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of low dose CT angiography in the follow-up after endovascular aneurysm repair of abdominal aorta
Authors: Macchi Monica , Floridi Chiara , Strocchi Sabina , Fontana Federico , Mangini Monica , Piacentino Filippo , Duka Ejona , Donati Alberto V , Fugazzola Carlo
Published: December 2014

Background

Computed tomography angiography (CTA) is the most employed modality in the follow-up after endovascular aneurysm repair (EVAR) of abdominal aorta (AA); repeated standard controls expose patients to a high cumulative radiation dose (RD).

Purpose

To compare image quality and RD between 100 kV and 120 kV protocols in the same group of patients, previously treated with EVAR.

Material and Methods

Thirty patients, who had performed a previous CTA at 120 kV, underwent a low dose CTA with the same 64-detector machine. Images were evaluated qualitatively and quantitatively. The influence of body mass index (BMI), considering three groups of patients (normal weight, overweight, and obese) was also assessed. RD values (volume CT dose index and effective dose) were calculated.

Results

The mean qualitative score at 100 kV was worse than that at 120 kV, but the difference was not statistically significant and in all cases the image quality was satisfactory. At 100 kV the vessels mean attenuation value was significantly higher; signal-to-noise ratio significantly lower; contrast-to-noise ratio lower, but the difference was not significant. Regarding BMI, the difference in the qualitative score was significant in the obese group, but not in the other two groups; of the quantitative parameters only the signal-to-noise ratio presented a significant difference in the obese group. The average CTDIvol was reduced by 22% and the mean effective dose by 36% with the 100 kV protocol compared to the 120 kV protocol. Both differences were significant.

Conclusion

The 100 kV protocol allowed a consistent RD reduction, maintaining a satisfactory image quality in all patients.
Relationship between tumour angiogenesis and expression of cyclo-oxygenase-2 and vascular endothelial growth factor-A in human renal cell carcinoma
Authors: Yang Sheng , Gao Qin , Jiang Wei
Published: December 2014

Objective

*These authors contributed equally to this work. To study the relationship between tumour angiogenesis and expression of cyclo-oxygenase ( COX)-2 and vascular endothelial growth factor ( VEGF)-A in human renal cell carcinoma.

Methods

Archival samples of primary human renal cell carcinoma tissue and surrounding normal renal tissue (control samples) obtained from patients diagnosed with renal cell carcinoma were analysed for COX-2 and VEGF-A expression by immunohistochemistry using specific monoclonal antibodies. Tumour microvasculature was examined using factor VIII-related antigen antibody staining.

Results

A total of 33 renal cell carcinoma and 12 control renal tissue specimens were included. COX-2 and VEGF-A genes were overexpressed in tumour specimens compared with normal epithelia. A significant correlation was found between COX-2 and VEGF-A expression. Microvessel density was found to be increased in tumour tissues that expressed COX-2 and VEGF-A.

Conclusion

Microvessel density was increased in tumour tissues that expressed COX-2 and VEGF-A, suggesting that COX-2 and VEGF-A are related to tumour angiogenesis in human renal cell carcinoma.
Distinguishing Intestinal Lymphoma From Inflammatory Bowel Disease in Canine Duodenal Endoscopic Biopsy Samples
Authors: Carrasco V. , Rodríguez-Bertos A. , Rodríguez-Franco F. , Wise A. G. , Maes R. , Mullaney T. , Kiupel M.
Published: December 2014

Inflammatory bowel disease (IBD) and intestinal lymphoma are intestinal disorders in dogs, both causing similar chronic digestive signs, although with a different prognosis and different treatment requirements. Differentiation between these 2 conditions is based on histopathologic evaluation of intestinal biopsies. However, an accurate diagnosis is often difficult based on histology alone, especially when only endoscopic biopsies are available to differentiate IBD from enteropathy-associated T-cell lymphoma (EATL) type 2, a small cell lymphoma. The purpose of this study was to evaluate the utility of histopathology; immunohistochemistry (IHC) for CD3, CD20, and Ki-67; and polymerase chain reaction (PCR) for antigen receptor rearrangement (T-cell clonality) in the differential diagnosis of severe IBD vs intestinal lymphoma. Endoscopic biopsies from 32 dogs with severe IBD or intestinal lymphoma were evaluated. The original diagnosis was based on microscopic examination of hematoxylin and eosin (HE)–stained sections alone followed by a second evaluation using morphology in association with IHC for CD3 and CD20 and a third evaluation using PCR for clonality. Our results show that, in contrast to feline intestinal lymphomas, 6 of 8 canine small intestinal lymphomas were EATL type 1 (large cell) lymphomas. EATL type 2 was uncommon. Regardless, in dogs, intraepithelial lymphocytes were not an important diagnostic feature to differentiate IBD from EATL as confirmed by PCR. EATL type 1 had a significantly higher Ki-67 index than did EATL type 2 or IBD cases. Based on the results of this study, a stepwise diagnostic approach using histology as the first step, followed by immunophenotyping and determining the Ki67 index and finally PCR for clonality, improves the accuracy of distinguishing intestinal lymphoma from IBD in dogs.
Vitamin C Depletion in Prenatal Guinea Pigs as a Model of Lissencephaly Type II
Authors: Čapo I. , Hinić N. , Lalošević D. , Vučković N. , Stilinović N. , Marković J. , Sekulić S.
Published: December 2014

Humans and guinea pigs are unable to produce vitamin C, with deficiency resulting in a well-known disorder of collagen synthesis. Pial basement membrane structure preservation is essential in the proper migration of neurons. In our study, intrauterine deprivation of vitamin C in guinea pig fetuses led to a collagen synthesis disorder, weakness, and finally a breach of pial basement membrane. We found excessive migration of the external germinal layer cells into the subarachnoid space of the cerebellum through defects in the pial basement membrane. The changes ranged from focal rupture of pial basement membranes to their complete disintegration. The loss of proper folia formation resulted in macroscopically visible flattening of the cerebellar surface. Different grades of dysplastic changes in the folia of the cerebellar cortex were observed in 2 experimental groups assigned different limits to mark the time of commencement and duration of vitamin C deprivation. The most severe form of dysplastic changes was characterized by marked irregularity of the cerebellar cortex similar to that in lissencephaly type II. Thus, prenatal vitamin C deficiency represents a novel animal model to study the effects of collagen synthesis on development of breaches in the pial basement membrane, disordered migration of neurons, dysplasia of cerebellar cortex, and the pathogenesis of lissencephaly.
“It Felt Good but Weird at the Same Time”
Authors: Vasilenko Sara A. , Maas Megan K. , Lefkowitz Eva S.
Published: December 2014

Although sexual behavior is multidimensional, little research has focused on the experience of nonintercourse behaviors for adolescents and emerging adults. This article uses open-ended coded data from a longitudinal study of college students ( N = 346; M age = 18.5, 52% female, 27% Hispanic/Latino [HL], 25% non-HL European American, 23% non-HL Asian American, 16% non-HL African American, 9% non-HL multiracial) to examine what emotional responses emerging adults report about their first experiences of six sexual behaviors. The four most common emotional reactions were happy, excited, fearful, and indifferent. Descriptions were largely positive, although mixed reactions were relatively common and emotional reactions varied by behavior. Results suggest the importance of including multiple types of sexual behaviors, as well as their possible positive and negative outcomes, in sexuality education programs.
Leadership in an Asian American Community in the South
Authors: Weng Suzie S.
Published: December 2014

Despite the development of culturally sensitive practices and ethnic-specific services for non-dominant groups, Asian Americans continue to underutilize social services. The underutilization is a reminder that multiple barriers still exist in preventing the historically invisible members of the Asian American population from improving their well-being. If Asian Americans are not using formalized services, they are likely turning to their own informal supports, of which little is known, for meeting their needs. Using a grounded theory approach, this article explores the leaders and their roles in the development of an informal support network in an Asian American community in the southern region of the United States. The theory developed in this study indicates cultural influences affecting leaders and their ethnic identity, which then informs identification of needs and the helping process in the development of the informal support network. The article concludes with implications.
Deformation measurements in welded plates based on close-range photogrammetry
Authors: Chen Bai-Qiao , Soares C Guedes
Published: December 2014

A global approach for measuring weld-induced deformations in plated structures is presented in this article. Three-dimensional deformation models of butt-welded plates were obtained before and after three welding tests by using close-range photogrammetry to generate the displacement field from sets of digital images. The procedure was validated against direct measurements of the deformations. A polynomial equation was found to be the best fitting to the surface of a butt-welded plate. Based on the modified Fourier series, a proposed function to represent complex surface was validated. A comparative study on the sampling element size was also included.
Discussing measurement criteria and competitive strategies of green suppliers from a green law perspective
Authors: Tsai Sang-Bing , Saito Riga , Lin Yi-Chuan , Chen Quan , Zhou Jie
Published: December 2014

Green suppliers form an active and independent green production management system that complies with green manufacturing regulations, eliminates bottlenecks and difficulties encountered by enterprises related to the requirements of green products, and enhances enterprises’ green competitiveness. Previous studies on competitive indices and strategies of green suppliers have generally had two limitations. First, most studies have assumed that competitive indices are independent of one another and are not causally related. Second, several studies have assumed that the weights of the evaluation indices are identical. To overcome these two limitations, this study integrated simultaneous importance-performance analysis and decision-making trial-and-evaluation laboratory methods and proposed a simultaneous importance-performance analysis–decision-making trial-and-evaluation laboratory model. In this study, simultaneous importance-performance analysis was used to explore the green performance and competitive situations of a case company and its competitors. Subsequently, decision-making trial-and-evaluation laboratory was used to calculate the degrees of influence that the competitive indices of green supplier regarding green performance exhibited on each other and to investigate the causal relationships among the competitive indices. Finally, competitive green supplier strategies for the case company were proposed. The results indicated that the method developed in this study not only provides theoretical contributions but also can be applied to businesses.
Modeling and prototype experiment of a six-DOF parallel micro-manipulator with nano-scale accuracy
Authors: Dong Yi , Gao Feng , Yue Yi
Published: December 2014

This paper presents a high-accurate micro-manipulator featured with monolithic compliant structure, orthogonally arranged parallel mechanism and piezoelectric (PZT) actuation. 6-SPS mechanism is employed to provide six degrees of freedom (DOF), including three linear translations and three rotations. The kinematics and stiffness of the micro-manipulator is studied first in this paper. Then, the relationship between PZT nominal displacement and the end pose is derived. Aiming at achieving trajectories with nano-scale accuracy, a two-step strategy is proposed. Finite element analysis (FEA) is conducted to verify the kinematics and stiffness model. Finally, in order to demonstrate the performance of the micro-manipulator, experiments of typical trajectories are carried out. The experimental result shows that the proposed micro-manipulator is capable of achieving trajectories with nano-scale accuracy.
Simulation of hydrodynamic lubrication between cage pockets and rollers in cylindrical roller bearings
Authors: Ma Fangbo , Jiang Fengyuan , An Qi
Published: December 2014

A calculating model for roller-pocket rotation and mechanics analysis is established to investigate the hydrodynamic lubrication between rollers and straight-sided cage pockets in a cylindrical roller bearing. An algorithm for calculating roller-pocket oil film pressure and film thickness is developed. Hydrodynamic lubrication simulation of the roller-pocket clearances is carried out. Effects of inner ring rotation speed, cage angular acceleration, roller profile and cage geometry on roller-pocket oil film performance are numerically studied. Some regular curves and conclusions are obtained and analyzed.
Fluctuation prediction of machining accuracy for multi-axis machine tool based on stochastic process theory
Authors: Cheng Qiang , Feng Qiunan , Liu Zhifeng , Gu Peihua , Cai Ligang
Published: December 2014

Geometric error has significant influence on the processing results and reduces machining accuracy. Machine tool geometric errors can be interpreted as a deterministic value with an uncertain fluctuation of probabilistic distribution. Although, the uncertain fluctuation can not be compensated, it has extremely profound significance on the precision and ultra-precision machining to reduce the fluctuation range of machining accuracy as far as possible. In this paper, a typical 3-axis machine tool with high precision is selected and the fluctuations in machining accuracy are studied. The volumetric error modeling of machine tool is established by multi-body system (MBS) theory, which describes the topological structure of MBS in a simple and convenient matrix form. Based on the volumetric error model, the equivalent components of the errors for the three axes are established by reducing error terms. Then, the fluctuations of equivalent errors and the machining accuracy in working planes are depicted and predicted using the theory of stochastic process, whose range should be controlled within a certain confidence interval. Furthermore, the critical geometric errors that have significant influence on the machining accuracy fluctuation are identified. Based on the analysis results, some improvement in the machine tool parts introduced and the results for the modified machine show that the prediction allow for reduction in errors for the precision and ultra-precision machining.
Succession of pitfall-trapped insects and arachnids on eight Norwegian glacier forelands along an altitudinal gradient: Patterns and models
Authors: Vater Amber E , Matthews John A
Published: December 2014

Invertebrate primary succession based on pitfall traps is described in eight glacier-foreland chronosequences across a major geo-ecological gradient in the Jotunheimen and Jostedalsbreen subregions of southern Norway. Regional (predominantly altitudinal) and local environmental gradients are shown to be effective influences on the nature and rate of colonization and succession at both species- and community-levels of analysis. Inclusion of flying taxa identified only to higher taxonomic units had little effect on the species-level results for epigeal taxa because the flying taxa were found more-or-less evenly throughout each chronosequence. A relatively large number of pioneer taxa colonize within <20 years of deglacierization in the alpine zone (46–61% of taxa, compared with 22–43% in the subalpine and boreal zones) and contribute to a relatively simple, two-stage succession. Later colonizers are proportionately more important in the subalpine and boreal zones where a three-stage succession results in several divergent late-successional trajectories conditioned by local exposure and moisture differences. The Pioneer Persistence Index (PPI), which measures the percentage of pioneer taxa that persist into the mature stage of succession, is consistently high (65–86%), while the Pioneer Importance Index (PII), which measures the percentage of the taxa at the mature stage that comprise the persistent pioneer element, is higher in the Jotunheimen chronosequences (49–52%) than those of Jostedalsbreen (21–45%). Results support the addition and persistence model of succession, which is seen as being driven primarily by the individualistic behaviour of highly mobile (mainly carnivorous) species that apparently exhibit low dependence on the vegetation succession. Although this model differs substantially from models of primary plant succession, a relatively small element of replacement change increases with decreasing altitude. This contributes to a more complex community structure in subalpine and boreal zones and is attributed to greater biotic interaction, involving not only predators but also an increasing number of herbivores and omnivores.
South to north: Contrasting late-glacial and early-Holocene climate changes and vegetation responses between south and north Norway
Authors: Birks Hilary H
Published: December 2014

Norway shows south–north climate and vegetation gradients today. Were there similar gradients during the late-glacial and early Holocene, 14,700–9000 years ago? A comparison was made along a south–north transect in Norway of plant-macrofossil reconstructions of past vegetation changes and independent summer temperature records derived from parallel chironomid data (C-Tjul). Three lake sites were selected with sediment cores with good chronological control. The importance of soil moisture is reflected by the reconstructed vegetation in relation to the temperature regime. Besides climate drivers, how important were intrinsic succession and competition in influencing vegetation patterns? Were migration delays significant, why and by how much? Oceanic climate in the late-glacial in south-west Norway resulted in snow-bed vegetation and glacier development in the Younger Dryas (YD). In contrast, the north was arid and continental, even into the early Holocene. Overall, temperatures were about 2°C colder than in the south. The YD impact differed markedly between south and north Norway. In the south, cooling at c. 12,700 cal. yr BP was swift and marked by strong responses. In the north, there was no impact at the chronological start of the YD, but cooling occurred later about 12,450 cal. yr BP together with increased aridity. During the early Holocene, temperature and oceanicity increased progressively northwards as the North Atlantic Current became established. Birch woodland developed in the south about 660 years after the start of the Holocene, after about 1000 years on Andøya, and after about 1450 years in northernmost Norway. However, the 590 year lag in the south after C-Tjul reached 11°C, the limiting temperature for tree-birch growth, decreased to 400 years in the north, as the birch tree-line kept pace with temperature rise. In the far north, a thermal maximum of 1°C above today’s mean July temperature and parallel vegetation development were recorded from 10,100 to 9370 cal. yr BP. On Andøya, temperatures exceeded present values by 1°C after 9700 cal. yr BP. There was no detectable period of above modern temperatures further south before 9000 cal. yr BP.
Diatom-based evidence of regional aridity during the mid-Holocene period in boreal lakes from northwest Ontario (Canada)
Authors: Karmakar Moumita , Laird Kathleen R , Cumming Brian F
Published: December 2014

Boreal regions and their freshwater ecosystems may be susceptible to future climate change under projected warmer conditions. Northwest Ontario is a boreal region adjacent to the climatically sensitive prairie-forest ecotone (PFE). Pollen records spanning the Holocene from near the Manitoba/Ontario border to lakes up to ~300 km east of the PFE indicate a warmer and possibly wetter mid-Holocene period across northwest Ontario from ~8000 to 4500 cal. yr BP. To date, only one Holocene-scale record of changes in effective moisture, as indicated through diatom-inferred changes in lake level (Experimental Lakes Area (ELA) Lake 239), is available from this region. Our study expands the regional context of Holocene climate changes, with the analysis of diatom assemblages in sediment cores from two additional lakes, which span a distance of over 200 km across the present-day boreal forest, from 80 km west of ELA Lake 239 to ~150 km to the northeast. In cores from both lakes, benthic taxa predominate in the early-to-mid-Holocene period, with a low abundance of planktonic taxa, suggesting lower lake levels by ~2–5 m. Increases in the abundance of planktonic taxa to >50% occurred in both lakes beginning ~4500–4000 cal. yr BP suggesting positive water balance over the last 4000 years in comparison with the mid-Holocene period. This new evidence supports a regional mid-Holocene period of aridity, with reduced water levels across the boreal region of northwest Ontario. If future climate change results in lower effective moisture, then conditions could become similar to the mid-Holocene period aridity, leading to real challenges for the management of water resources across the region.
Trees tracking a warmer climate: The Holocene range shift of hazel (Corylus avellana) in northern Europe
Authors: Seppä Heikki , Schurgers Guy , Miller Paul A , Bjune Anne E , Giesecke Thomas , Kühl Norbert , Renssen Hans , Salonen J Sakari
Published: December 2014

Palaeoecological records provide a rich source of information to explore how plant distribution ranges respond to climate changes, but their use is complicated by the fact that, especially when based on pollen data, they are often spatially too inaccurate to reliably determine past range limits. To solve this problem, we focus on hazel ( Corylus avellana), a tree species with large and heavy fruits (nuts), which provide firm evidence of the local occurrence of species in the past. We combine the fossil nut records of hazel from Fennoscandia, map its maximum distribution range during the Holocene thermal maximum (HTM) and compare the fossil record with the Holocene hazel range shift as simulated by the LPJ-GUESS dynamic vegetation model. The results show that the current northern range limit of hazel in central and eastern Fennoscandia is constrained by too short growing seasons and too long and cold winters and demonstrate that the species responded to the HTM warming of about 2.5°C (relative to the present) by shifting its range limit up to 63–64°N, reached a rough equilibrium with the HTM climatic conditions and retreated from there to about 60°N during the last 4000 years in response to the late-Holocene cooling. Thus, the projected future warming of about 2.5°C would reverse the long-term southward retraction of species’ northern range limit in Europe and is likely to lead to hazel being a common, regeneratively reproductive species up to 63–64°N. In addition to the accuracy of the projected warming, the likelihood of this scenario will depend on inter-specific competition with other tree taxa and the potential of hazel to migrate and its population to grow in balance with the warming. In general, the range dynamics from the HTM to the present suggest a tight climatic control over hazel’s range limit in Fennoscandia.
The magnetic record of inorganic fly ash deposition in lake sediments and ombrotrophic peats
Authors: Oldfield Frank , Gedye Sharon A , Hunt Andrew , Jones Jennifer M , Jones Mervyn DH , Richardson Nigel
Published: December 2014

Interest in identifying a geological marker signifying the starting point for the Anthropocene has prompted an exploration of the stratigraphic record of inorganic particulates generated by industrial activities. Magnetic measurements of recent lake sediments and ombrotrophic peats are here used to reconstruct the history of deposition of inorganic fly-ash spheres resulting mainly from solid fuel combustion and metal smelting. The chronologies used have been based on moss-increment counting, radioisotope dating and pollen analysis. The sites come from the United Kingdom, Scandinavia and North America. In several cases where detailed chronologies of both fly-ash deposition and local industry can be compared, the sequence of concentration-linked magnetic measurements appears to capture accurately the record of industrial development despite incontrovertible evidence from other peat-based records for some selective dissolution of magnetic minerals. The dates at which magnetic concentration increases begin range from the 16th century in the peat profiles around the head of Morecambe Bay, South Cumbria, in North-West England where early iron manufacture using charcoal-fuelled bloomery hearths is well documented, to the mid-20th century at the remotest sites in Arctic Scandinavia. The lake sediment profiles used here come mainly from the United Kingdom and, in most cases, they date increases to the late 19th century or the first decades of the 20th century. Any attempt to use the magnetic record of fly-ash deposition in lake sediments and/or peats to mark the date chosen as the onset of the Anthropocene would require careful choice of site location and archive, bearing in mind the issue of selective magnetic mineral dissolution.
Air pollutant contamination and acidification of surface waters in the North York Moors, UK: Multi-proxy evidence from the sediments of a moorland pool
Authors: Battarbee Richard W , Turner Simon , Yang Handong , Rose Neil L , Smyntek Peter M , Reimer Paula J , Oldfield Frank , Jones Vivienne J , Flower Roger J , Roe Kevin , Shilland Ewan , Blaauw Maarten
Published: December 2014

Despite the extensive geographical range of palaeolimnological studies designed to assess the extent of surface water acidification in the United Kingdom during the 1980s, little attention was paid to the status of surface waters in the North York Moors (NYM). In this paper, we present sediment core data from a moorland pool in the NYM that provide a record of air pollution contamination and surface water acidification. The 41-cm-long core was divided into three lithostratigraphic units. The lower two comprise peaty soils and peats, respectively, that date to between approximately 8080 and 6740 cal. BP. The uppermost unit comprises peaty lake muds dating from between approximately ad 1790 and the present day (ad 2006). The lower two units contain pollen dominated by forest taxa, whereas the uppermost unit contains pollen indicative of open landscape conditions similar to those of the present. Heavy metal, spheroidal carbonaceous particle, mineral magnetics and stable isotope analysis of the upper sediments show clear evidence of contamination by air pollutants derived from fossil-fuel combustion over the last c. 150 years, and diatom analysis indicates that the naturally acidic pool became more acidic during the 20th century. We conclude that the exceptionally acidic surface waters of the pool at present (pH =  c. 4.1) are the result of a long history of air pollution and not because of naturally acidic local conditions. We argue that the highly acidic surface waters elsewhere in the NYM are similarly acidified and that the lack of evidence of significant recovery from acidification, despite major reductions in the emissions of acidic gases that have taken place over the last c. 30 years, indicates the continuing influence of pollutant sulphur stored in catchment peats, a legacy of over 150 years of acid deposition.
Stacking of discontinuous regional palaeoclimate records: Chironomid-based summer temperatures from the Alpine region
Authors: Heiri Oliver , Ilyashuk Boris , Millet Laurent , Samartin Stéphanie , Lotter André F
Published: December 2014

Since multi-site reconstructions are less affected by site-specific climatic effects and artefacts, regional palaeotemperature reconstructions based on a number of sites can provide more robust estimates of centennial- to millennial-scale temperature trends than individual, site-specific records. Furthermore, reconstructions based on multiple records are necessary for developing continuous climate records over time scales longer than covered by individual sequences. Here, we present a procedure for developing such reconstructions based on relatively short (centuries to millennia), discontinuously sampled records as are typically developed when using biotic proxies in lake sediments for temperature reconstruction. The approach includes an altitudinal correction of temperatures, an interpolation of individual records to equal time intervals, a stacking procedure for sections of the interval of interest that have the same records available, as well as a splicing procedure to link the individual stacked records into a continuous reconstruction. Variations in the final, stacked and spliced reconstruction are driven by variations in the individual records, whereas the absolute temperature values are determined by the stacked segment based on the largest number of records. With numerical simulations based on the NGRIP δ18O record, we demonstrate that the interpolation and stacking procedure provides an approximation of a smoothed palaeoclimate record if based on a sufficient number of discontinuously sampled records. Finally, we provide an example of a stacked and spliced palaeotemperature reconstruction 15000–90 calibrated 14C yr BP based on six chironomid records from the northern and central Swiss Alps and eastern France to discuss the potential and limitations of this approach.
Climate and abrupt vegetation change in Northern Europe since the last deglaciation
Authors: Seddon Alistair WR , Macias-Fauria Marc , Willis Kathy J
Published: December 2014

A long-standing question in palaeoecology has been to determine the importance of climate driving vegetation change since the last deglaciation. Here, we investigate the local-to-regional dynamics of vegetation change during the Lateglacial and the Holocene in Northern Europe. We extracted sites from the European Pollen Database and used the squared-chord distance (SCD) dissimilarity metric to identify time periods of high pollen assemblage turnover representing periods of abrupt vegetation change. In addition, a set of generalized additive mixed models were applied to investigate the underlying dynamics of two periods of higher rates of turnover: the Younger Dryas–early Holocene transition (YD-EH; 11.6–9.0 kyr) and early–middle Holocene (EMH; 9.0–6.0 kyr). Results revealed a high frequency of turnover events between 12.75–11.5, 10.75–11, 10.25–10, 7.75–7.25, 3.25–3.0 and 1.75–.25 kyr. Furthermore, there was a strong linear relationship between pollen assemblage turnover and large directional temperature changes during the abrupt climate changes of the Lateglacial–early Holocene transition. In contrast, patterns of turnover during the Holocene were generally site-specific and during the EMH, we found evidence that the vegetation response was non-linear and highly variable across and between regions. Our results have implications for understanding the relationship between threshold dynamics and the amplitude of an extrinsic forcing. Across the Lateglacial–early Holocene boundary, the rate and magnitude of temperature change were large enough to override any site-specific thresholds, resulting in large assemblage turnovers. In contrast, during the Holocene, the vegetation response was mediated by intrinsic factors, which resulted in varying turnover rates between regions. The next research challenge is to attempt to determine whether it is possible to appreciate the velocity and rate of change that is necessary to result in these different responses and whether this rate is the same across biomes.
Long-term successional changes in peatlands of the Hudson Bay Lowlands, Canada inferred from the ecological dynamics of multiple proxies
Authors: Hargan Kathryn E , Rühland Kathleen M , Paterson Andrew M , Holmquist James , MacDonald Glen M , Bunbury Joan , Finkelstein Sarah A , Smol John P
Published: December 2014

Peatlands in northern Ontario, Canada, archive multiple biological indicators, including macrofossils, algae, testate amoebae, and pollen. These proxies can provide insights concerning the timing and nature of long-term climatic and environmental changes. The Hudson Bay Lowlands (HBL) of central Canada contain one of Earth’s largest continuous peatland complexes, and thus comprehensive spatial and temporal studies are needed to understand the implications of climate change on carbon cycling. Diatom assemblages were examined in three cores retrieved from ombrotrophic bogs across two Canadian terrestrial ecozones. Comparisons were made with testate amoebae and macrofossil data previously analyzed from these cores, as well as with regional pollen records from surrounding peatlands. From ~2000 to ~600 cal. BP, changes in diatom composition likely reflect hydrosere succession within the peatland, including fluctuations in connectivity to the water table and pH changes. From ~600 cal. BP to present, the synchronous timing of changes in diatoms and testate amoebae are tracking drying conditions and subsequent microhabitat variations that occur within bogs. It is possible that diatoms are tracking subtle changes in the stability of peat microforms including bog hollows and hummocks, highlighting their sensitivity to small chemical change, whereas testate amoebae are tracking the lowering of a peatland water table and subsequent drying of the peatland. The use of multiple proxies provides a more holistic approach to interpreting past ecological succession and responses to climate within peatlands. When present and well preserved, diatoms can be applied to track drying conditions in bogs, in terms of both hydrosere succession and present climatic change.
John Birks: Pioneer in quantitative palaeoecology
Authors: Battarbee Richard W , Lamb Henry , Bennett Keith , Edwards Mary , Bjune Anne E , Kaland Peter E , Berglund Björn E , Lotter André F , Seppä Heikki , Willis Kathy J , Herzschuh Ulrike , Birks Hilary H
Published: December 2014

We describe the career of John Birks as a pioneering scientist who has, over a career spanning five decades, transformed palaeoecology from a largely descriptive to a rigorous quantitative science relevant to contemporary questions in ecology and environmental change. We review his influence on students and colleagues not only at Cambridge and Bergen Universities, his places of primary employment, but also on individuals and research groups in Europe and North America. We also introduce the collection of papers that we have assembled in his honour. The papers are written by his former students and close colleagues and span many of the areas of palaeoecology to which John himself has made major contributions. These include the relationship between ecology and palaeoecology, late-glacial and Holocene palaeoecology, ecological succession, climate change and vegetation history, the role of palaeoecological techniques in reconstructing and understanding the impact of human activity on terrestrial and freshwater ecosystems and numerical analysis of multivariate palaeoecological data.
Early summer temperatures reconstructed from black pine (Pinus nigra Arnold) tree-ring widths from Albania
Authors: Levanič Tom , Poljanšek Simon , Toromani Elvin
Published: December 2014

The first regional chronology of black pine ( Pinus nigra Arnold) from Albania, its response to climate and a 428-year long reconstruction of June–July temperatures for the 1583–2010 period are presented. Samples were collected at five locations from the north to the south of Albania. We constructed a 552-year long Pinus nigra chronology with sufficient sample depth for potential climate reconstruction from 1583 to 2010 (428 years). Response to precipitation was significant only for July of the current year (0.23), while a clear temperature response to the May–August period was identified, with July having by far the highest correlation (−0.47). When combined, June–July temperatures had the highest correlation of all tested combinations ( r = −0.63), explaining almost 40% of the tree-ring width variability. The test of the climate signal temporal stability using a 31-year running correlation highlighted the very stable relationship between tree-ring indices and June–July temperatures. The spatial extent of the regional Pinus nigra chronology tested, using a field correlation function, showed very high spatial correlation over a large part of the Balkan Peninsula and even southern Italy. Based on high explained variance between tree-ring indices and June–July temperatures and significant values of reduction of error (RE) and coefficient of efficiency statistics (CE; 0.62 and 0.25 in the calibration period), a linear model was developed, with June–July temperatures reconstructed for the 1583–2010 period. Our reconstruction and identified extreme years were compared with various temperature, drought and precipitation reconstructions from nearby regions, as well as data from documentary archives. We confirmed a high degree of similarity of our reconstruction with other reconstructions and documentary data.
Simultaneous presentation of acute disseminated encephalomyelitis (ADEM) and systemic lupus erythematosus (SLE) after enteroviral infection: can ADEM present as the first manifestation of SLE?
Authors: Kim J-M , Son C-N , Chang H W , Kim S-H
Published: December 2014

Central Nervous System (CNS) involvement of Systemic Lupus Erythematosus (SLE) includes a broad range of neuropsychiatric syndromes. Acute Disseminated Encephalomyelitis (ADEM) is a demyelinating CNS disorder characterized by encephalopathy and multifocal lesions predominantly involving the white matter on brain magnetic resonance imaging. ADEM associated with SLE has been only rarely reported. We report an unusual case of a 17-year-old girl who developed ADEM after enteroviral infection as the first manifestation of SLE. The authors emphasize that the patient’s illness was preceded by enteroviral infection and that ADEM occurred before any other symptoms of SLE, which makes this case unique.
Right or duty of information
Authors: Nunes Sofia RT , Rego Guilhermina , Nunes Rui
Published: December 2014

Background:

The theoretical framework of Jϋrgen Habermas suggests that effective communication requires competent participants with an objective attitude that complies with the rules and worlds designated as objective, social and subjective. This situation determines communicative action, which stimulates the search for mutual understanding and results in a process of interaction that promotes self-determination.

Objectives:

In this study, the discharge letters of patients with myocardial infarction were explored regarding the provision of information. The patient’s right to information and the duty of informing were analysed according to the perspective of Jϋrgen Habermas.

Research design:

This was a cross-sectional analysis (from a broader longitudinal study) of all discharge letters that were directly related to nursing interventions regarding the provision of information to 106 patients. In this major study, the difficulties faced by patients who experienced a myocardial infarction and the changes in their lifestyles were analysed based on the type of information received.

Ethical considerations:

The hospital Ethics Committee approved the study, which complied with ethical principles and required informed consent.

Findings:

In the nursing letters, interventions related to the provision of information were conducted at an average of 3.59 interventions per patient. For 8.5% of the patients, however, no interventions related to the provision of information were performed. The most common area of information during hospitalisation was related to the management of signs and symptoms and applied to 90.6% patients.

Discussion:

The nursing interventions did not cover patient education, transition processes or awareness of the disease. Thus, the right to information can be questioned.

Conclusion:

Information is a right, and communication is extremely important. Health professionals should be aware of this importance regarding both care management and the satisfaction guarantee. The sharing of information by health professionals based on their competency is essential for patients to exercise their right to self-determination and decision-making.
Psychosocial determinants of nurses’ intention to practise euthanasia in palliative care
Authors: Lavoie Mireille , Godin Gaston , Vézina-Im Lydi-Anne , Blondeau Danielle , Martineau Isabelle , Roy Louis
Published: December 2014

Background:

Most studies on euthanasia fail to explain the intentions of health professionals when faced with performing euthanasia and are atheoretical.

Research objective:

The purpose of this study was to identify the psychosocial determinants of nurses’ intention to practise euthanasia in palliative care if it were legalised.

Research design:

A cross-sectional study using a validated anonymous questionnaire based on an extended version of the Theory of Planned Behaviour.

Participants and research context:

A random sample of 445 nurses from the province of Quebec, Canada, was selected for participation in the study.

Ethical considerations:

The study was reviewed and approved by the Ethics Committee of the Centre hospitalier universitaire de Québec.

Findings:

The response rate was 44.2% and the mean score for intention was 4.61 ± 1.90 (range: 1–7). The determinants of intention were the subjective (odds ratio = 3.08; 95% confidence interval: 1.50–6.35) and moral (odds ratio = 2.95; 95% confidence interval: 1.58–5.49) norms. Specific beliefs which could discriminate nurses according to their level of intention were identified.

Discussion:

Overall, nurses have a slightly positive intention to practise euthanasia. Their family approval seems particularly important and also the approval of their medical colleagues. Nurses’ moral norm was related to beneficence, an ethical principle.

Conclusion:

To our knowledge, this is the first study to identify nurses’ motivations to practise euthanasia in palliative care using a validated psychosocial theory. It also has the distinction of identifying the ethical principles underlying nurses’ moral norm and intention.
Nurses’ perceptions and practice of physical restraint in China
Authors: Jiang Hui , Li Chen , Gu Yan , He Yanan
Published: December 2014

Background:

There is controversy concerning the use of physical restraint. Despite this controversy, some nurses still consider the application of physical restraint unavoidable for some of their clients.

Aim:

Identify the perceptions and practice of physical restraint in China.

Research design:

This was a descriptive study that combined qualitative interviews with a quantitative cross-sectional survey.

Participants:

A total of 18 nurses were interviewed and 330 nurses were surveyed.

Ethical considerations:

Approval of the study was obtained from the hospital ethics committee. Permission to conduct the study was obtained from the director of nursing. Participants were assured that their participation is voluntary.

Results:

Physical restraint was commonly used to protect patients’ safety. Naturally, intensive care unit nurses used physical restraint much more frequently than general medical/surgical ward nurses ( p < 0.01). In addition, night shift nurses tended to use physical restraint more frequently.

Conclusion:

Nursing managers should be aware of the role nurses play in the use of physical restraint. In-service training regarding the proper use of physical restraint should be strengthened and nurse staffing levels should be improved in order to minimize the use of physical restraint in China.
Values in nursing students and professionals
Authors: Jiménez-López F Rosa , Roales-Nieto Jesus Gil , Seco Guillermo Vallejo , Preciado Juan
Published: December 2014

Background:

Many studies have explored personal values in nursing, but none has assessed whether the predictions made by the theory of intergenerational value change are true for the different generations of nursing professionals and students. This theory predicts a shift in those personal values held by younger generations towards ones focussed on self-expression.

Research question:

The purpose of the study was to identify intergenerational differences in personal values among nursing professionals and nursing students and to determine whether generational value profiles fit the predictions made by the theory.

Research design:

An exploratory comparative design with a cross-sectional survey method was used.

Participants and research context:

Participants were recruited from four public hospitals and 10 Primary Care Centres in medium-size cities in Spain. A sample of 589 nurses and 2295 nursing students participated in the study. An open survey method was used to collect data that were classified grouping reported values into categories following a method of value lexicon construction and analysed by contingency tables with Pearson’s χ2 and standardized residuals.

Ethical considerations:

Approval to conduct the study was obtained from the Deans of the nursing schools and the Directors of Nursing of the institutions. Anonymity was guaranteed, participation was voluntary and participants were informed of the purpose of the study.

Findings:

The results can be synthesized in two age-related trends in the reporting of values among three groups of participants. First, among younger nurses and students, some nursing core values (e.g. ethical and professional) decreased in importance, while other values centred on social relationships and personal well-being increased.

Discussion and Conclusion:

This study shows intergenerational change in personal values among both nursing students and young nursing professionals. Findings suggest the need to pay more attention to value training and professional socialization during the schooling period.