Cryotherapy of Liver Tumours–A Practical Guide

The use of cryotherapy for the treatment of some unresectable liver tumours has been clearly established as a therapeutic option. Intra-operative ultrasound has enhanced the process by enabling the surgeon to identify hepatic lesions and to allow visualisation of the freezing process to ensure that the cryolesion will include the tumour mass. The purpose of this paper is to provide a practical guide to surgeons who wish to perform cryotherapy of liver tumours. Patient selection and anaesthetic considerations are important. The surgeon should be able to deal with the complications of cryotherapy, particularly the intra-operative haemorrhage which may arise from cracking of the hepatic parenchyma as the iceball thaws. Follow-up is based on tumour marker assay and imaging of the liver and repeat cryotherapy can be considered for selected cases

Nitrous oxide emission from highland winter wheat field after long-term fertilization

Nitrous oxide (N<sub>2</sub>O) is an important greenhouse gas. N<sub>2</sub>O emissions from soils vary with fertilization and cropping practices. The response of N<sub>2</sub>O emission to fertilization of agricultural soils plays an important role in global N<sub>2</sub>O emission. The objective of this study was to assess the seasonal pattern of N<sub>2</sub>O fluxes and the annual N<sub>2</sub>O emissions from a rain-fed winter wheat (<i>Triticum aestivum</i> L.) field in the Loess Plateau of China. A static flux chamber method was used to measure soil N<sub>2</sub>O fluxes from 2006 to 2008. The study included 5 treatments with 3 replications in a randomized complete block design. Prior to initiating N<sub>2</sub>O measurements the treatments had received the same fertilization for 22 years. The fertilizer treatments were unfertilized control (CK), manure (M), nitrogen (N), nitrogen + phosphorus (NP), and nitrogen + phosphorus + manure (NPM). Soil N<sub>2</sub>O fluxes in the highland winter wheat field were highly variable temporally and thus were fertilization dependent. The highest fluxes occurred in the warmer and wetter seasons. Relative to CK, m slightly increased N<sub>2</sub>O flux while N, NP and NPM treatments significantly increased N<sub>2</sub>O fluxes. The fertilizer induced increase in N<sub>2</sub>O flux occurred mainly in the first 30 days after fertilization. The increases were smaller in the relatively warm and dry year than in the cold and wet year. Combining phosphorous and/or manure with mineral N fertilizer partly offset the nitrogen fertilizer induced increase in N<sub>2</sub>O flux. N<sub>2</sub>O fluxes at the seedling stage were mainly controlled by nitrogen fertilization, while fluxes at other plant growth stages were influenced by plant and environmental conditions. The cumulative N<sub>2</sub>O emissions were always higher in the fertilized treatments than in the non-fertilized treatment (CK). Mineral and manure nitrogen fertilizer enhanced N<sub>2</sub>O emissions in wetter years compared to dryer years. Phosphorous fertilizer offset 0.50 and 1.26 kg N<sub>2</sub>O-N ha<sup>−1</sup> increases, while manure + phosphorous offset 0.43 and 1.04 kg N<sub>2</sub>O-N ha<sup>−1</sup> increases by N fertilizer for the two observation years. Our results suggested that the contribution of single N fertilizer on N<sub>2</sub>O emission was larger than that of NP and NPM and that manure and phosphorous had important roles in offsetting mineral N fertilizer induced N<sub>2</sub>O emissions. Relative to agricultural production and N<sub>2</sub>O emission, manure fertilization (M) should be recommended while single N fertilization (N) should be avoided for the highland winter wheat due to the higher biomass and grain yield and lower N<sub>2</sub>O flux and annual emission in m than in N

Evaluation of a new, perforated heat flux plate design

Accurate measurement of heat flux is essential to optimize structural and process design and to improve understanding of energy transfer in natural systems. Laboratory and field experiments evaluated the performance of a new, perforated heat flux plate designed to reduce flow distortion for environmental applications. Laboratory tests involving dry and saturated sand showed that performance of the new CAPTEC plate is comparable to a solid, standard REBS plate. Very low thermal gradients may have however led to poor performance of the CAPTEC plate in saturated sand. Water infiltration and redistribution experiments using clayey and sandy soils showed an apparent reduced disruption of liquid water and vapour in the soil surrounding the CAPTEC plate as compared to solid Hukseflux and standard REBS plates. Surface area of REBS plate, though smaller than that of CAPTEC, did not lead to any significantly improved evaporation, due to perforations on CAPTEC plate. Field tests in a loam soil indicated that the CAPTEC plates were durable and produced daily total flux values within ~ 0.15 MJ m− 2 of independent estimates

The Three-Magnon Contribution to the Spin Correlation Function in Integer-Spin Antiferromagnetic Chains

The exact form factor for the O(3) non-linear sigma model is used to predict the three-magnon contribution to the spin correlation function, S(q,w), near wavevector q=pi in an integer spin, one-dimensional antiferromagnet. The three-magnon contribution is extrememly broad and extremely weak; the integrated intensity is <2% of the single-magnon contribution.Comment: 4 pages, 1 figur

Integrating evidence, politics and society: a methodology for the science–policy interface

There is currently intense debate over expertise, evidence and ‘post-truth’ politics, and how this is influencing policy formulation and implementation. In this article, we put forward a methodology for evidence-based policy making intended as a way of helping navigate this web of complexity. Starting from the premise of why it is so crucial that policies to meet major global challenges use scientific evidence, we discuss the socio-political difficulties and complexities that hinder this process. We discuss the necessity of embracing a broader view of what constitutes evidence—science and the evaluation of scientific evidence cannot be divorced from the political, cultural and social debate that inevitably and justifiably surrounds these major issues. As a pre-requisite for effective policy making, we propose a methodology that fully integrates scientific investigation with political debate and social discourse. We describe a rigorous process of mapping, analysis, visualisation and sharing of evidence, constructed from integrating science and social science data. This would then be followed by transparent evidence evaluation, combining independent assessment to test the validity and completeness of the evidence with deliberation to discover how the evidence is perceived, misunderstood or ignored. We outline the opportunities and the problems derived from the use of digital communications, including social media, in this methodology, and emphasise the power of creative and innovative evidence visualisation and sharing in shaping policy

Dependence of the Energy Spectrum of UHE Cosmic Rays on the Latitude of an Extensive Air Shower Array

Several energy spectra of cosmic rays with energies E_0 \geq 10^17 eV measured at the Yakutsk EAS, AGASA, Haverah Park, HiRes, Auger, and SUGAR arrays are considered. It is shown that the fairly good mutual agreement of the spectrum shapes can be achieved if the energy of each spectrum is multiplied by a factor K specific for each spectrum. These factors exhibit a pronounced dependence on the latitude of the above-mentioned arrays.Comment: 4 pages, 4 figure

Late Holocene Paleoecology of Southeastern Iowa: Development of Riparian Vegetation at Nichols Marsh

Pollen, vascular plant and bryophyte macrofossils from peat and silt deposits that filled an oxbow lake near Nichols, Iowa provide a 2500- year record of wetland succession and of upland habitats. Radiocarbon dates of 2320 ± 90 yr B. P. (BETA 12514) near the base and 1260 ±70 yr B.P. (BETA-12513) midway up one section, and 1050 ±70 (BETA 12515) in another provide chronologic control. The pollen diagram indicates substantial changes in local wetland habitats, but less change in upland vegetation in the last 2500 years. Plant macrofossils record changes from a deep to a shallow oxbow lake during the first few hundred years after the meander was cut off. About 1600 yr B.P. marsh vegetation began to encroach as the lake filled with sediment. A somewhat weedy marsh that existed from about 1400 to 900 yr B. P., developed into a rich mire that persisted until the 1840\u27s, when Europeans began cultivating the upland areas. A rise of ragweed pollen (from 7 to 25%) documents the beginning of cultivation in the area, and is accompanied by a sudden increase in diversity and in numbers and taxa of weedy species on the marsh. The presence of abundant charcoal and macrofossils of such prairie taxa as Amorpha and Petalosteinum imply warmer conditions from about 1400 to 900 B. P.; their absence and the appearance of the bryophyte Meesia suggest cooler conditions during the last thousand years

Time-like flows of energy-momentum and particle trajectories for the Klein-Gordon equation

The Klein-Gordon equation is interpreted in the de Broglie-Bohm manner as a single-particle relativistic quantum mechanical equation that defines unique time-like particle trajectories. The particle trajectories are determined by the conserved flow of the intrinsic energy density which can be derived from the specification of the Klein-Gordon energy-momentum tensor in an Einstein-Riemann space. The approach is illustrated by application to the simple single-particle phenomena associated with square potentials.Comment: 14 pages, 11 figure

Microturbulence studies in RFX-mod

Present-days Reversed Field Pinches (RFPs) are characterized by quasi-laminar magnetic configurations in their core, whose boundaries feature sharp internal transport barriers, in analogy with tokamaks and stellarators. The abatement of magnetic chaos leads to the reduction of associated particle and heat transport along wandering field lines. At the same time, the growth of steep temperature gradients may trigger drift microinstabilities. In this work we summarize the work recently done in the RFP RFX-mod in order to assess the existence and the impact upon transport of such electrostatic and electromagnetic microinstabilities as Ion Temperature Gradient (ITG), Trapped Electron Modes (TEM) and microtearing modes.Comment: Work presented at the 2010 Varenna workshop "Theory of Fusion Plasmas". To appear in Journal of Physics Conference Serie