Comparison of freehand-navigated and aiming device-navigated targeting of liver lesions

BACKGROUND Accurate needle placement is crucial for the success of percutaneous radiological needle interventions. We compared three guiding methods using an optical-based navigation system: freehand, using a stereotactic aiming device and active depth control, and using a stereotactic aiming device and passive depth control. METHODS For each method, 25 punctures were performed on a non-rigid phantom. Five 1 mm metal screws were used as targets. Time requirements were recorded, and target positioning errors (TPE) were measured on control scans as the distance between needle tip and target. RESULTS Time requirements were reduced using the aiming device and passive depth control. The Euclidian TPE was similar for each method (4.6 ± 1.2-4.9 ± 1.7 mm). However, the lateral component was significantly lower when an aiming device was used (2.3 ± 1.3-2.8 ± 1.6 mm with an aiming device vs 4.2 ± 2.0 mm without). DISCUSSION Using an aiming device may increase the lateral accuracy of navigated needle insertion.

Bioavailability of silver nanoparticles and ions: from a chemical and biochemical perspective

Owing to their antimicrobial properties, silver nanoparticles (NPs) are the most commonly used engineered nanomaterial for use in a wide array of consumer and medical applications. Many discussions are currently ongoing as to whether or not exposure of silver NPs to the ecosystem (i.e. plants and animals) may be conceived as harmful or not. Metallic silver, if released into the environment, can undergo chemical and biochemical conversion which strongly influence its availability towards any biological system. During this process, in the presence of moisture, silver can be oxidized resulting in the release of silver ions. To date, it is still debatable as to whether any biological impact of nanosized silver is relative to either its size, or to its ionic constitution. The aim of this review therefore is to provide a comprehensive, interdisciplinary overview--for biologists, chemists, toxicologists as well as physicists--regarding the production of silver NPs, its (as well as in their ionic form) chemical and biochemical behaviours towards/within a multitude of relative and realistic biological environments and also how such interactions may be correlated across a plethora of different biological organisms.

Climate refugia: joint inference from fossil records, species distribution models and phylogeography

Climate refugia, locations where taxa survive periods of regionally adverse climate, are thought to be critical for maintaining biodiversity through the glacial–interglacial climate changes of the Quaternary. A critical research need is to better integrate and reconcile the three major lines of evidence used to infer the existence of past refugia – fossil records, species distribution models and phylogeographic surveys – in order to characterize the complex spatiotemporal trajectories of species and populations in and out of refugia. Here we review the complementary strengths, limitations and new advances for these three approaches. We provide case studies to illustrate their combined application, and point the way towards new opportunities for synthesizing these disparate lines of evidence. Case studies with European beech, Qinghai spruce and Douglas-fir illustrate how the combination of these three approaches successfully resolves complex species histories not attainable from any one approach. Promising new statistical techniques can capitalize on the strengths of each method and provide a robust quantitative reconstruction of species history. Studying past refugia can help identify contemporary refugia and clarify their conservation significance, in particular by elucidating the fine-scale processes and the particular geographic locations that buffer species against rapidly changing climate.

Individual group efficacy beliefs and performance motivation: A mediational approach

Introduction: According to the theoretical model of Cranach, Ochsenbein, and Valach (1986) understanding group actions needs consideration of aspects at both the group level and the level of individual members. For example individual action units constituting group actions are motivated at the individual level while potentially being affected by characteristics of the group. Theoretically, group efficacy beliefs could be a part of this motivational process as they are an individual’s cognitive contents about group-level abilities to perform well in a specific task. Positive relations between group level efficacy-beliefs and group performance have been reported and Bandura and Locke (2003) argue that this relationship is being mediated by motivational processes and goal setting. The aims of this study were a) to examine the effects of group characteristics on individual performance motivation and b) to test if those are mediated by individual group efficacy beliefs. Methods: Forty-seven students (M=22.83 years, SD=2.83, 34% women) of the university of Berne participated in this scenario based experiment. Data were collected on two collection points. Subjects were provided information about fictive team members with whom they had to perform a group triathlon. Three values (low, medium, high) of the other team members’ abilities to perform in their parts of the triathlon (swimming and biking respectively) were combined in a 3x3 full factorial design (Anderson, 1982) yielding nine groups. Subjects were asked how confident they were that the teams would perform well in the task (individual group efficacy beliefs), and to provide information about their motivation to perform at their best in the respective group contexts (performance motivation). Multilevel modeling (Mplus) was used to estimate the effects of the factors swim and bike, and the context-varying covariate individual group efficacy beliefs on performance motivation. Further analyses were undertaken to test if the effects of group contexts on performance motivation are mediated by individual group efficacy beliefs. Results: Significant effects were reported for both the group characteristics (βswim = 7.86; βbike = 8.57; both p < .001) and the individual group efficacy beliefs (βigeb; .40, p < .001) on performance motivation. The subsequent mediation model indicated that the effects of group characteristics on performance motivation were partly mediated by the individual group efficacy beliefs of the subjects with significant mediation effects for both factors swim and bike. Discussion/Conclusion: The results of the study provide further support for the motivational character of efficacy beliefs and point out a mechanism by which team characteristics influence performance relevant factors at the level of individual team members. The study indicates that high team abilities lead to augmented performance motivation, adding a psychological advantage to teams already high on task relevant abilities. Future investigations will be aiming at possibilities to keep individual performance motivation high in groups with low task relevant abilities. One possibility could be the formulation of individual task goals. References: Anderson, N. H. (1982). Methods of information integration theory. New York: Academic Press. Bandura, A. & Locke, E. A. (2003). Negative self-efficacy and goal effects revisited. Journal of Applied Psychology, 88, 87-99. Cranach, M. von, Ochsenbein, G. & Valach, L. (1986). The group as a self-active system: Outline of a theory of group action. European Journal of Social Psychology, 16, 193-229.

There is more than "more is up": Hand and foot responses reverse the vertical association of number magnitudes

Recent research in cognitive sciences shows a growing interest in spatial-numerical associations. The horizontal SNARC (spatial-numerical association of response codes) effect is defined by faster left-sided responses to small numbers and faster right-sided responses to large numbers in a parity judgment task. In this study we investigated whether there is also a SNARC effect for upper and lower responses. The grounded cognition approach suggests that the universal experience of "more is up" serves as a robust frame of reference for vertical number representation. In line with this view, lower hand responses to small numbers were faster than to large numbers (Experiment 1). Interestingly, the vertical SNARC effect reversed when the lower responses were given by foot instead of the hand (Experiments 2, 3, and 4). We found faster upper (hand) responses to small numbers and faster lower (foot) responses to large numbers. Additional experiments showed that spatial factors cannot account for the reversal of the vertical SNARC effect (Experiments 4 and 5). Our results question the view of "more is up" as a robust frame of reference for spatial-numerical associations. We discuss our results within a hierarchical framework of numerical cognition and point to a possible link between effectors and number representation.

Effects of colostrum versus formula feeding on hepatic glucocorticoid and α1- and β2-adrenergic receptors in neonatal calves and their effect on glucose and lipid metabolism

Neonatal energy metabolism in calves has to adapt to extrauterine life and depends on colostrum feeding. The adrenergic and glucocorticoid systems are involved in postnatal maturation of pathways related to energy metabolism and calves show elevated plasma concentrations of cortisol and catecholamines during perinatal life. We tested the hypothesis that hepatic glucocorticoid receptors (GR) and α₁- and β₂-adrenergic receptors (AR) in neonatal calves are involved in adaptation of postnatal energy metabolism and that respective binding capacities depend on colostrum feeding. Calves were fed colostrum (CF; n=7) or a milk-based formula (FF; n=7) with similar nutrient content up to d 4 of life. Blood samples were taken daily before feeding and 2h after feeding on d 4 of life to measure metabolites and hormones related to energy metabolism in blood plasma. Liver tissue was obtained 2 h after feeding on d 4 to measure hepatic fat content and binding capacity of AR and GR. Maximal binding capacity and binding affinity were calculated by saturation binding assays using [(3)H]-prazosin and [(3)H]-CGP-12177 for determination of α₁- and β₂-AR and [(3)H]-dexamethasone for determination of GR in liver. Additional liver samples were taken to measure mRNA abundance of AR and GR, and of key enzymes related to hepatic glucose and lipid metabolism. Plasma concentrations of albumin, triacylglycerides, insulin-like growth factor I, leptin, and thyroid hormones changed until d 4 and all these variables except leptin and thyroid hormones responded to feed intake on d 4. Diet effects were determined for albumin, insulin-like growth factor I, leptin, and thyroid hormones. Binding capacity for GR was greater and for α₁-AR tended to be greater in CF than in FF calves. Binding affinities were in the same range for each receptor type. Gene expression of α₁-AR (ADRA1) tended to be lower in CF than FF calves. Binding capacity of GR was related to parameters of glucose and lipid metabolism, whereas β₂-AR binding capacity was negatively associated with glucose metabolism. In conclusion, our results indicate a dependence of GR and α₁-AR on milk feeding immediately after birth and point to an involvement of hepatic GR and AR in postnatal adaptation of glucose and lipid metabolism in calves.

Electoral and Financial Bookkeeping: A Comparison of Pre-Electoral Pledges on Public Spending and the Outcome of Post-Electoral Budget Debates

In the wake of the financial crisis, budgetary discipline has taken centre stage in politics. More than ever a country's budget mirrors the true policy preferences of the legislative majority beyond all political discourse and cheap talk. The paper sheds light on mandate fulfilment in the field of public spending and fiscal policy in general. Based on previous work on pledge fulfilment in Switzerland the paper compares publicised pre-electoral statements of MPs on public spending and the development of the public finances with their post-electoral legislative behaviour during budget debates and votes. The findings of the paper confirm the results of the aforementioned earlier studies and point to the potential of budgetary statements for future mandate fulfilment research.

Developmental oestrogen exposure differentially modulates IGF-I and TNF-α expression levels in immune organs of Yersinia ruckeri-challenged young adult rainbow trout (Oncorhynchus mykiss).

Intensified aquaculture has strong impact on fish health by stress and infectious diseases and has stimulated the interest in the orchestration of cytokines and growth factors, particularly their influence by environmental factors, however, only scarce data are available on the GH/IGF-system, central physiological system for development and tissue shaping. Most recently, the capability of the host to cope with tissue damage has been postulated as critical for survival. Thus, the present study assessed the combined impacts of estrogens and bacterial infection on the insulin-like growth factors (IGF) and tumor-necrosis factor (TNF)-α. Juvenile rainbow trout were exposed to 2 different concentrations of 17β-estradiol (E2) and infected with Yersinia ruckeri. Gene expressions of IGF-I, IGF-II and TNF-α were measured in liver, head kidney and spleen and all 4 estrogen receptors (ERα1, ERα2, ERβ1 and ERβ2) known in rainbow trout were measured in liver. After 5 weeks of E2 treatment, hepatic up-regulation of ERα1 and ERα2, but down-regulation of ERß1 and ERß2 were observed in those groups receiving E2-enriched food. In liver, the results further indicate a suppressive effect of Yersinia-infection regardless of E2-treatment on day 3, but not of E2-treatment on IGF-I whilst TNF-α gene expression was not influenced by Yersinia-infection but was reduced after 5 weeks of E2-treatment. In spleen, the results show a stimulatory effect of Yersinia-infection, but not of E2-treatment on both, IGF-I and TNF-α gene expressions. In head kidney, E2 strongly suppressed both, IGF-I and TNF-α. To summarise, the treatment effects were tissue- and treatment-specific and point to a relevant role of IGF-I in infection.

Metabolic and hormonal response to intermittent high-intensity and continuous moderate intensity exercise in individuals with type 1 diabetes: a randomised crossover study.

AIMS/HYPOTHESIS To investigate exercise-related fuel metabolism in intermittent high-intensity (IHE) and continuous moderate intensity (CONT) exercise in individuals with type 1 diabetes mellitus. METHODS In a prospective randomised open-label cross-over trial twelve male individuals with well-controlled type 1 diabetes underwent a 90 min iso-energetic cycling session at 50% maximal oxygen consumption ([Formula: see text]), with (IHE) or without (CONT) interspersed 10 s sprints every 10 min without insulin adaptation. Euglycaemia was maintained using oral (13)C-labelled glucose. (13)C Magnetic resonance spectroscopy (MRS) served to quantify hepatocellular and intramyocellular glycogen. Measurements of glucose kinetics (stable isotopes), hormones and metabolites complemented the investigation. RESULTS Glucose and insulin levels were comparable between interventions. Exogenous glucose requirements during the last 30 min of exercise were significantly lower in IHE (p = 0.02). Hepatic glucose output did not differ significantly between interventions, but glucose disposal was significantly lower in IHE (p < 0.05). There was no significant difference in glycogen consumption. Growth hormone, catecholamine and lactate levels were significantly higher in IHE (p < 0.05). CONCLUSIONS/INTERPRETATION IHE in individuals with type 1 diabetes without insulin adaptation reduced exogenous glucose requirements compared with CONT. The difference was not related to increased hepatic glucose output, nor to enhanced muscle glycogen utilisation, but to decreased glucose uptake. The lower glucose disposal in IHE implies a shift towards consumption of alternative substrates. These findings indicate a high flexibility of exercise-related fuel metabolism in type 1 diabetes, and point towards a novel and potentially beneficial role of IHE in these individuals. TRIAL REGISTRATION ClinicalTrials.gov NCT02068638 FUNDING: Swiss National Science Foundation (grant number 320030_149321/) and R&A Scherbarth Foundation (Switzerland).

Concomitant Mycobacterium tuberculosis infection and type 2 diabetes: A descriptive model with global health implications

The type 2 diabetes (diabetes) pandemic is recognized as a threat to tuberculosis (TB) control worldwide. This secondary data analysis project estimated the contribution of diabetes to TB in a binational community on the Texas-Mexico border where both diseases occur. Newly-diagnosed TB patients > 20 years of age were prospectively enrolled at Texas-Mexico border clinics between January 2006 and November 2008. Upon enrollment, information regarding social, demographic, and medical risks for TB was collected at interview, including self-reported diabetes. In addition, self-reported diabetes was supported by blood-confirmation according to guidelines published by the American Diabetes Association (ADA). For this project, data was compared to existing statistics for TB incidence and diabetes prevalence from the corresponding general populations of each study site to estimate the relative and attributable risks of diabetes to TB. In concordance with historical sociodemographic data provided for TB patients with self-reported diabetes, our TB patients with diabetes also lacked the risk factors traditionally associated with TB (alcohol abuse, drug abuse, history of incarceration, and HIV infection); instead, the majority of our TB patients with diabetes were characterized by overweight/obesity, chronic hyperglycemia, and older median age. In addition, diabetes prevalence among our TB patients was significantly higher than in the corresponding general populations. Findings of this study will help accurately characterize TB patients with diabetes, thus aiding in the timely recognition and diagnosis of TB in a population not traditionally viewed as at-risk. We provide epidemiological and biological evidence that diabetes continues to be an increasingly important risk factor for TB.^

Geochemistry and mineralogy of Eocene-Oligocene sediments of IODP Hole 302-M0002A

In 2004, Integrated Ocean Drilling Program Expedition 302 (Arctic Coring Expedition, ACEX) to the Lomonosov Ridge drilled the first Central Arctic Ocean sediment record reaching the uppermost Cretaceous (~430 m composite depth). While the Neogene part of the record is characterized by grayish-yellowish siliciclastic material, the Paleogene part is dominated by biosiliceous black shale-type sediments. The lithological transition between Paleogene and Neogene deposits was initially interpreted as a single sedimentological unconformity (hiatus) of ~26 Ma duration, separating Eocene from Miocene strata. More recently, however, continuous sedimentation on Lomonosov Ridge throughout the Cenozoic was proclaimed, questioning the existence of a hiatus. In this context, we studied the elemental and mineralogical sediment composition around the Paleogene-Neogene transition at high resolution to reconstruct variations in the depositional regime (e.g. wave/current activity, detrital provenance, and bottom water redox conditions). Already below the hiatus, mineralogical and geochemical proxies imply drastic changes in sediment provenance and/or weathering intensity in the hinterland, and point to the existence of another, earlier gap in the sediment record. The sediments directly overlying the hiatus (the Zebra interval) are characterized by pronounced and abrupt compositional changes that suggest repeated erosion and re-deposition of material. Regarding redox conditions, euxinic bottom waters prevailed at the Eocene Lomonosov Ridge, and became even more severe directly before the hiatus. With detrital sedimentation rates decreasing, authigenic trace metals were highly enriched in the sediment. This continuous authigenic trace metal enrichment under persistent euxinia implies that the Arctic trace metal pool was renewed continuously by water mass exchange with the world ocean, so the Eocene Arctic Ocean was not fully restricted. Above the hiatus, extreme positive Ce anomalies are clear signs of a periodically well-oxygenated water column, but redox conditions were highly variable during deposition of the Zebra interval. Significant Mn enrichments only occur above the Zebra interval, documenting the Miocene establishment of stable oxic conditions in the Arctic Ocean. In summary, extreme and abrupt changes in geochemistry and mineralogy across the studied sediment section do not suggest continuous sedimentation at the Lomonosov Ridge around the Eocene-Miocene transition, but imply repeated periods of very low sedimentation rates and/or erosion.

(Table T1) Coral taxa and their ecological significance in ODP Site 194-1196 and Hole 194-1199A sediments

The Southern Marion Plateau (SMP) represents a vertical stacking of Miocene carbonate platform deposits. Two sites (1196 and 1199) were drilled on top of this plateau, penetrating a 663-m carbonate succession of bioclastic and reefal sedimentary bodies. The study focuses on the least dolomitized 410-m-thick upper part of the succession, which is middle to late Miocene in age. Sedimentological and paleontological studies were conducted at both sites in order to propose a paleoenvironmental model and its evolution through the Miocene age. Six main microfacies of possible environmental significance were defined using statistical multivariate analyses, based on the recognition and point counting of 24 biogenic components. Depositional environment reconstructions are proposed as well as the biosedimentary and the environmental evolution regarding seismic architectures, stratigraphy, biosedimentology, and microfacies analysis. The SMP platform mainly results from a vertical stacking of lens-shaped bodies in homoclinal to distally steepened ramp settings.

"Porque no habrá obra" : El archivo en la escritura de María Moreno

A partir del año 2001 con la publicación de A tontas y a locas la escritora y periodista María Moreno da una inflexión clave a su producción escritural redireccionándola de manera contundente hacia el trabajo con el archivo propio de materiales periodísticos hasta entonces inéditos en libro. El presente artículo explora de qué manera este trabajo con el archivo propio tanto moviliza una reapropiación de la crónica y un "aprovechamiento" del nuevo estatus del que goza el género como así también, alimenta un posicionamiento estético y ético enfrentado al valor de la "obra" literaria. Ambos procesos se encuentran estrechamente vinculados entre sí y a su vez entraman las reflexiones que la cronista produce desde los años '80 en relación a una escritura femenina, la cual, según Moreno, para intervenir efectivamente en el campo cultural debe primero desarmar los cotos expresivos que se le imponen

Carbonate and Aluminium accumulation in the central equatorial Pacific Ocean

We examined the flux of Al to sediment accumulating beneath the zone of elevated productivity in the central equatorial Pacific Ocean, along a surface sediment transect at 135°W as well as downcore for a 650 kyr record at 1.3°N, 133.6°W. Across the surface transect, a pronounced, broadly equatorially symmetric increase in Al accumulation is observed, relative to Ti, with Al/Ti ratios reaching values 3-4 times that of potential detrital sources. The profile parallels biogenic accumulation and the modeled flux of particulate 234Th, suggesting rapid and preferential adsorptive removal of Al from seawater by settling biogenic particles. Normative calculations confirm that most Al is unsupported by the terrigenous fraction. The observed distributions are consistent with previous observations of the relative and absolute behavior of Al and Ti in seawater, and we can construct a reasonable mass balance between the amount of seawater-sourced Al retained in the sediment and the amount of seawater Al available in the overlying column. The close tie between Al/Ti and biogenic accumulation (as opposed to concentration) emphasizes that biogenic sedimentary Al/Ti responds to removal-transport phenomena and not bulk sediment composition. Thus, in these sediments dominated by the biogenic component, the bulk Al/Ti ratio reflects biogenic particle flux, and by extension, productivity of the overlying seawater. The downcore profile of Al/Ti at 1.3°N displays marked increases during glacial episodes, similar to that observed across the surface transect, from a background value near Al/Ti of average upper crust. The excursions in Al/Ti are stratigraphically coincident with maxima in both bulk and CaCO3 accumulation and the excess Al appears to not be preferentially affiliated with opaline or organic phases. Consistent with the similar behavioral removal of Al and 234Th, the latter of which responds to the total particle flux, the Al flux reflects carbonate accumulation only because carbonate comprises the dominant flux in these particular deposits. These results collectively indicate that (1) Al in biogenic sediment and settling biogenic particles is strongly affected by a component adsorbed from seawater. Therefore, the common tenet that Al is dominantly associated with terrestrial particulate matter, and the subsequent use of Al distributions to calculate the abundance and flux of terrestrial material in settling particles and sediment, needs to be reevaluated. (2) The Al/Ti ratio in biogenic sediment can be used to trace the productivity of the overlying water, providing a powerful new paleochemical tool to investigate oceanic response to climatic variation. (3) The close correlation between the Al/Ti productivity signal and carbonate maxima downcore at 1.3°N suggests that the sedimentary carbonate maxima in the central equatorial Pacific Ocean record increased productivity during glacial episodes.

"Porque no habrá obra" : El archivo en la escritura de María Moreno

A partir del año 2001 con la publicación de A tontas y a locas la escritora y periodista María Moreno da una inflexión clave a su producción escritural redireccionándola de manera contundente hacia el trabajo con el archivo propio de materiales periodísticos hasta entonces inéditos en libro. El presente artículo explora de qué manera este trabajo con el archivo propio tanto moviliza una reapropiación de la crónica y un "aprovechamiento" del nuevo estatus del que goza el género como así también, alimenta un posicionamiento estético y ético enfrentado al valor de la "obra" literaria. Ambos procesos se encuentran estrechamente vinculados entre sí y a su vez entraman las reflexiones que la cronista produce desde los años '80 en relación a una escritura femenina, la cual, según Moreno, para intervenir efectivamente en el campo cultural debe primero desarmar los cotos expresivos que se le imponen