bluuebunny/crossref_metadata_2025 huggingface dataset:
Reducing the incidence of post‐hepatectomy hepatic complications by preoperatively applying parameters predictive of liver function
Authors: Nanashima Atsushi , Tobinaga Syuuichi , Abo Takafumi , Nonaka Takashi , Takeshita Hiroaki , Hidaka Shigekazu , Sawai Terumitsu , Nagayasu Takeshi
Published: April 2010

Background/purpose

To prevent or reduce hepatic complications after hepatectomy, it is important to employ preoperative predictive parameters and to determine the indications for hepatectomy. In the present study, we evaluated risk parameters in patients who underwent hepatectomy between 1994 and 2003, and selected three parameters to modify the surgical indications. Using these indications before surgery in patients who underwent hepatectomy between 2004 and 2008, we compared the prevalences of postoperative complications in the the two groups of patients.

Methods

We examined 250 consecutive patients who underwent hepatectomy for liver disease [149 in 1994–2003 (termed the early period) and 101 in 2004 to 2008 (termed the later period)].

Results

In the early period, uncontrolled ascites was observed in 55 patients and hepatic failure was observed in 15 of the 149 patients. Multivariate analysis identified volume of the resected liver (≥50%), intraoperative blood loss (≥1500 ml), prothrombin activity (<70%), hyaluronic acid level (≥200 ng/ml), and LHL15 (hepatic uptake ratio of technetium‐99m galactosyl human serum albumin (99mTc‐GSA) (<0.85) as risk factors; the latter three parameters were evaluated as predictors of outcome. From 2004, we used these three parameters, in addition to the indocyanine green retention rate at 15 min (ICGR15), as criteria for indications for hepatectomy. Despite the lower prevalence of normal liver in the later period, comparisons showed decreases in the rates of uncontrolled ascites (23 vs. 37%,p = 0.03), hepatic failure (4 vs. 10%,p = 0.12), and hepatic complications (25 vs. 44%,p = 0.003) in patients in the later period compared with these rates in the previous period.

Conclusions

The use of prothrombin activity, and levels of hyaluronic acid and LHL15, as parameters of functional liver reserve in the selection of candidates for surgery reduced the incidence of hepatic complications after hepatectomy.
What Facilitates or Impedes Family Communication Following Genetic Testing for Cancer Risk? A Systematic Review and Meta‐Synthesis of Primary Qualitative Research
Authors: Chivers Seymour Kim , Addington‐Hall Julia , Lucassen Anneke M. , Foster Claire L.
Published: April 2010

To systematically review and meta‐synthesise primary qualitative research findings regarding family communication following genetic testing of cancer risk, in order to inform development of effective interventions. Systematic searches of CINAHL, Embase, Medline, British Nursing Index and PsycINFO databases were undertaken and relevant studies identified using strict criteria. The selected primary qualitative studies were appraised for quality and relevance by three independent researchers and then synthesized using a “Framework” approach. Fourteen (4.3%) studies met the inclusion criteria. The following factors influenced family communication following genetic testing for late‐onset hereditary cancer: the informant's feelings about informing relatives about genetic testing; the perceived relevance of the information to other family members and their anticipated reactions; the “closeness” of relationships within the family; family rules and patterns (e.g., who is best placed to share information with whom); finding the right time and level of disclosure; and the supportive role of heath care professionals. The themes identified in this review could provide practitioners with a useful framework for discussing family communication with those undergoing genetic testing. This framework focuses on helping health care professionals to facilitate family communication. The next step will be the development of an intervention to directly support people in talking to their relatives.
Treatment of femoral fractures in children: Is titanium elastic nailing an improvement over hip spica casting?
Authors: Saseendar S. , Menon J. , Patro D. K.
Published: April 2010

Purpose

The purpose of the study was to assess the validity of surgical interference with elastic nailing in treating pediatric femur fractures in comparison with the traditional treatment method—hip spica casting.

Methods

Sixteen consecutive femur fractures in children 5–15 years of age were recruited prospectively over 13 months. An equal number of age-matched children treated by spica casting were recruited retrospectively. Subtrochanteric, supracondylar femur fractures were excluded.

Results

Fracture union occurred earlier in the surgical group (6 weeks) than in the spica group (8 weeks) ( P = 0.001). Spica casting caused higher coronal plane angulation ( P = 0.001), higher rotational malalignment ( P < 0.001), higher limb length discrepancy at 1-year follow-up ( P < 0.001), longer duration of immobilization ( P < 0.001), later full weight-bearing ( P < 0.001), and greater absence from school ( P < 0.001). Flynn outcome scores were better with titanium elastic nailing than with hip spica casting.

Conclusion

Titanium elastic nailing led to better outcomes compared to hip spica casting in terms of earlier union, lower rates of malunion, shorter rehabilitation milestones, and better functional outcome scores.
Influence of cochlear implantation on peripheral vestibular receptor function
Authors: Krause Eike , Louza Julia P.R. , Wechtenbruch Juliane , Gürkov Robert
Published: April 2010

Objective

The objectives of this study were 1) to assess the influence of a cochlear implantation on peripheral vestibular receptor function in the inner ear in the implant and in the nonimplant side, and 2) to analyze a possible correlation with resulting vertigo symptoms.

Study Design

Prospective clinical study.

Setting

Cochlear implant center at tertiary referral hospital.

Subjects and Methods

A total of 32 patients, aged 15 to 83 years, undergoing cochlear implantation were assessed pre‐ and postoperatively for caloric horizontal semicircular canal response and vestibular‐evoked myogenic potentials of the sacculus, and postoperatively for subjective vertigo symptoms. Patients with vertigo were compared with patients without symptoms with regard to the findings of the vestibular function tests.

Results

Cochlear implantation represents a significant risk factor for horizontal semicircular canal impairment (P < 0.001) and sacculus impairment (P = 0.047) in the implanted ear. In eight of 16 patients with preoperatively preserved caloric response, this response was decreased postoperatively. Before surgery, 14 of 30 patients had regular vestibular‐evoked myogenic responses. Two months after implantation, six patients had a new loss and another six showed depression of sacculus function on vestibular‐evoked myogenic potentials testing. The impaired vestibular function did not correlate with vertigo symptoms. Function on the contralateral side remains unaffected (P > 0.05).

Conclusion

Cochlear implantation is a relevant risk factor for damage of peripheral vestibular receptor function. Therefore, preservation not only of residual hearing function but also of vestibular function should be aimed for, by using minimally invasive surgical techniques.
Development of a decision support tool to evaluate the financial implications of cull cow finishing under different feeding strategies
Authors: MINCHIN W. , O'DONOVAN M. , BUCKLEY F. , KENNY D. A. , SHALLOO L.
Published: April 2010

The objective of the current study was to develop, validate and describe a decision support system (DSS) to evaluate cull dairy cow finishing strategies. The DSS was developed within a Microsoft Excel framework. The purpose of a DSS is to assist the process of making accurate and repeatable calculations, assisting the decision on which cull cow finishing strategy is most profitable under individual farm circumstances. The model was based on data from two evaluation experiments including eight finishing strategies in total: ad libitum grass silage (GS); GS+3 kg concentrate (GS+3); GS+6 kg concentrate (GS+6); GS+9 kg concentrate (GS+9); ad libitum grass silage prior to ad libitum spring grass (GS+G); 0·75 grass silage and 0·25 straw prior to ad libitum spring grass (GS+S) and finally grass silage plus 6 kg concentrate dry matter (DM)/cow/day and milked twice daily prior to ad libitum spring grass (EXTLAC). Stochastic budgeting was included in the model to account for variability in key input and output variables on the overall profitability of various finishing strategies. The stochastic input and output variables included in the model were initial carcass value, feed strategy, concentrate cost and final carcass value. Net profit per cow was selected as the output distribution. The mean net profit per cow with the GS, GS+3, GS+6, GS+9, GS+G, GS+S and EXTLAC was €85·3, €73·7, €95·6, €58·5, €158·8 and €186·8 and €283·0, respectively. Profitability for the EXTLAC strategy was stochastically dominant to all other strategies evaluated meaning a higher level of profit and a lower level of risk is associated with the EXTLAC strategy. The optimal strategy of cull cow beef production depends greatly on the prevailing economic environment, purchase and sale price, milk price, feed costs, housing and labour.
Vibroplasty involving direct coupling of the floating mass transducer to the oval window niche
Authors: Zehlicke T , Dahl R , Just T , Pau H-W
Published: April 2010

Objective:

To demonstrate the technique and clinical application of vibroplasty in which the floating mass transducer component of the Vibrant Soundbridge implant is coupled directly to the oval window niche, in patients with a mobile stapes footplate but a malformed or destroyed stapes suprastructure.

Methods:

The underlying concept was to create a soft tissue casing for the floating mass transducer, while also firmly connecting the transducer to a small, solid cartilage ‘plunger’ attached to the stapes footplate. This was realised by removing almost all the cartilage from a larger piece of cartilage–perichondrium, leaving only a tiny cartilage island about half a millimetre in diameter, attached to a much wider ‘blanket’ of perichondrium.

Results:

By coupling the floating mass transducer directly to the oval window niche, patients' speech understanding was improved. Post-operative aided thresholds of 30–40 dB HL were achieved by all patients.

Conclusions:

In patients with mixed hearing loss combined with a destroyed stapes suprastructure but a mobile stapes footplate, we describe the coupling of the floating mass transducer component of a Vibrant Soundbridge to the stapes footplate, as an alternative to coupling to the round window.
Short note: Strict unwraps make worker/wrapper fusion totally correct
Authors: GAMMIE PETER
Published: April 2010

The worker/wrapper transformation is a general way of changing the type of a recursive definition, usually applied with an eye to increasing algorithmic efficiency. This note identifies an infelicity in the program transformations presented by Gill & Hutton (The worker/wrapper transformation, J. Funct. Program., vol. 19, 2009, pp. 227–251) and proposes a new totally correct worker/wrapper fusion rule.
Key Parameters Affecting Quantitative Analysis of STEM-EDS Spectrum Images
Authors: Parish Chad M. , Brewer Luke N.
Published: April 2010

In this article, we use simulated and experimental data to explore how three operator-controllable parameters—(1) signal level, (2) detector resolution, and (3) number of factors chosen for analysis—affect quantitative analyses of scanning transmission electron microscopy–energy dispersive X-ray spectroscopy spectrum images processed by principal component analysis (PCA). We find that improvements in both signal level and detector resolution improve the precision of quantitative analyses, but that signal level is the most important. We also find that if the rank of the PCA solution is not chosen properly, it may be possible to improperly fit the underlying data and degrade the accuracy of results. Additionally, precision is degraded in the case when too many factors are included in the model.
TETRAVALENT s-TRANSITIVE GRAPHS OF ORDER TWICE A PRIME POWER
Authors: ZHOU JIN-XIN , FENG YAN-QUAN
Published: April 2010

A graph is s-transitive if its automorphism group acts transitively on s-arcs but not on (s+1)-arcs in the graph. Let X be a connected tetravalent s-transitive graph of order twice a prime power. In this paper it is shown that s=1,2,3 or 4. Furthermore, if s=2, then X is a normal cover of one of the following graphs: the 4-cube, the complete graph of order 5, the complete bipartite graph K5,5 minus a 1-factor, or K7,7 minus a point-hyperplane incidence graph of the three-dimensional projective geometry PG(2,2); if s=3, then X is a normal cover of the complete bipartite graph of order 4; if s=4, then X is a normal cover of the point-hyperplane incidence graph of the three-dimensional projective geometry PG(2,3). As an application, we classify the tetravalent s-transitive graphs of order 2p2 for prime p.
Location and spatial shape of electron beams in Io's wake
Authors: Jacobsen S. , Saur J. , Neubauer F. M. , Bonfond B. , Gérard J.‐C. , Grodent D.
Published: April 2010

The Galileo spacecraft observed energetic field‐aligned electron beams very close to Io during several flybys. We apply a three‐dimensional magnetohydrodynamic (MHD) model of the far‐field Io‐Jupiter interaction to simulate for the first time the location and spatial shape of field‐aligned electron beams. Io continuously generates MHD waves by disturbing the Jovian magnetoplasm. Currents carried by Alfvén waves propagate predominantly along the magnetic field lines. As the number of charge carriers decreases along the travel path, electrons are accelerated toward Jupiter. These energetic electrons precipitate into the Jovian ionosphere, visible as prominent Io footprint emission. Electrons are also accelerated toward Io and form the equatorial beams observed by the Galileo spacecraft. Unlike the beam formation, the position and spatial structure of these beams have not been addressed in detail before. We use a 3‐D MHD model with initial conditions corresponding to the individual Galileo flyby and determine the spatial morphology of the beams in Io's orbital plane. Our results for the beam locations are in good agreement with the Galileo Energetic Particle Detector observations. We find that the ratio of the one‐way travel time of the Alfvén wave from Io to Jupiter and the convection time of the plasma past the obstacle controls the location of the beam. This leads to the conclusion that at other satellites with other plasma environments, the electrons might not be close to the satellite but can be shifted significantly downstream along its plasma wake. Thus, the future search for electron beams near a satellite should be further extended to the wake region.
Relativistic electron scattering by electromagnetic ion cyclotron fluctuations: Test particle simulations
Authors: Liu Kaijun , Lemons Don S. , Winske Dan , Gary S. Peter
Published: April 2010

Relativistic electron scattering by electromagnetic ion cyclotron (EMIC) fluctuations is studied using test particle computations coupled to the results of a hybrid simulation code. The enhanced EMIC fluctuations are derived from a 1‐D, self‐consistent hybrid simulation model and are due to the growth of the Alfvén cyclotron instability driven by the ion temperature anisotropy, Ti⊥ > Ti∥ (where the subscripts ⊥ and ∥ refer to directions perpendicular and parallel to the background magnetic field, respectively), in a magnetized, homogeneous, collisionless plasma with a single ion species. The test particle computations follow the motion of relativistic test electrons in the input EMIC fluctuations. The time evolution of the mean square pitch angle change of the test electrons is calculated and used to determine the pitch angle diffusion coefficient. Finally, the results are compared with quasi‐linear diffusion theory. The diffusion coefficients given by the test particle computations agree with the ones from quasi‐linear theory very well except for large‐amplitude waves (δB/B0 ≥ 0.03 in the case presented, where δB is the wave magnetic field amplitude and B0 is the background magnetic field) when the weak turbulence approximation in quasi‐linear theory breaks down. Quasi‐linear theory overestimates the pitch angle diffusion coefficient for large‐amplitude waves and may, consequently, overestimate the pitch angle diffusion of relativistic electrons in the radiation belts at high L values.
Solar proxies pertaining to empirical ionospheric total electron content models
Authors: Maruyama Takashi
Published: April 2010

Solar proxies and indices exhibiting extreme ultraviolet (EUV) irradiance that affects the ionospheric total electron content (TEC) were examined through training an artificial neural network (ANN). A TEC database was constructed from a dense GPS receiver network over Japan from April 1997 to March 2008, covering an entire 11 year solar activity period. In empirical models of upper atmospheric parameters, such as the International Reference Ionosphere model and the Mass Spectrometer and Incoherent Scatter thermospheric model, the 10.7 cm solar radio flux (F10.7) or the sunspot number (R) is used as a proxy for determining the solar activity. In the present study, ANN training for predicting TEC as a target parameter was done by including new solar proxies/indices in the input space that were based on direct measurements of solar EUV/UV flux, SOHO_SEM26–34 (the integrated 26–34 nm EUV emission), and Mg II cwr (the core‐to‐wing ratio of Mg II 280 nm line), as well as the traditional indices F10.7 and R. Root mean square errors (RMSEs) of TEC were compared after the training was completed using a variety of combinations of solar proxies. When a single proxy was used, SOHO_SEM26–34 yielded the smallest RMSE, or it was the best proxy for modeling ionospheric TEC. Further, general improvements were obtained by combining different types of proxies and short‐ and long‐term means of them. The best combination was the 3 day smoothed daily, 7 day and 27 day backward mean values of Mg II cwr, SOHO_SEM26–34, and the 10.7 cm radio flux.
Micromechanics of cataclastic pore collapse in limestone
Authors: Zhu Wei , Baud Patrick , Wong Teng‐fong
Published: April 2010

The analysis of compactant failure in carbonate formations hinges upon a fundamental understanding of the mechanics of inelastic compaction. Microstructural observations indicate that pore collapse in a limestone initiates at the larger pores, and microcracking dominates the deformation in the periphery of a collapsed pore. To capture these micromechanical processes, we developed a model treating the limestone as a dual porosity medium, with the total porosity partitioned between macroporosity and microporosity. The representative volume element is made up of a large pore which is surrounded by an effective medium containing the microporosity. Cataclastic yielding of this effective medium obeys the Mohr‐Coulomb or Drucker‐Prager criterion, with failure parameters dependent on porosity and pore size. An analytic approximation was derived for the unconfined compressive strength associated with failure due to the propagation and coalescence of pore‐emanated cracks. For hydrostatic loading, identical theoretical results for the pore collapse pressure were obtained using the Mohr‐Coulomb or Drucker‐Prager criterion. For nonhydrostatic loading, the stress state at the onset of shear‐enhanced compaction was predicted to fall on a linear cap according to the Mohr‐Coulomb criterion. In contrast, nonlinear caps in qualitative agreement with laboratory data were predicted using the Drucker‐Prager criterion. Our micromechanical model implies that the effective medium is significantly stronger and relatively pressure‐insensitive in comparison to the bulk sample.
An analysis of the effects of swell and surface roughness spectra on microwave backscatter from the ocean
Authors: Hwang Paul A. , Plant William J.
Published: April 2010

The spectrum of ocean surface roughness is significantly modified by the presence of background long waves not generated by local wind. Active radar scattering and passive microwave emission from the ocean surface are therefore modified by swell conditions. Here we investigate predictions of the normalized radar cross section (NRCS) of the sea by a multiscale radar scattering model using four different spectral functions, one of which accounts for swell effects. Variations in predicted NRCS using the different spectral functions are quantified. As a result, the effect of swell on microwave backscatter can be separated from uncertainty due to the form of the spectrum without swell. The tilting effects of swell are also examined, and their effect on backscatter is calculated using the model. We find that changes in the ocean surface roughness spectrum due to swell reduce the wind speed dependence of the NRCS at low and moderate incidence angles while tilting effects produce changes in both the incidence angle and wind speed behavior of the NRCS. In general C band NRCS measurements are better explained by the multiscale model and less sensitive to choice of roughness spectral model than are Ku band NRCS values.
Seasonal evolution of upper‐ocean horizontal structure and the remnant mixed layer
Authors: Cole Sylvia T. , Rudnick Daniel L. , Colosi John A.
Published: April 2010

We discuss the seasonal evolution of upper‐ocean thermohaline structure at small horizontal scales. The upper 350 m of a 1000 km long section in the subtropical North Pacific was observed in winter, spring, and summer with 3–14 km horizontal resolution. Four vertical regions had distinct density and salinity structure: the mixed layer, remnant mixed layer, high‐stratification layer, and permanent thermocline. The remnant mixed layer consists of water from the winter mixed layer left over after restratification. The remnant mixed layer was most similar to the mixed layer in winter and spring, and most similar to the high‐stratification layer below in summer. The high‐stratification layer had elevated stratification that varied seasonally. The permanent thermocline varied little seasonally and was horizontally and vertically uniform in comparison. In all seasons, density ratios showed that mixed‐layer θ‐S differences tended to compensate in density with the strongest tendency toward compensation in winter. Density ratios were temperature dominated in the remnant mixed layer consistent with salt‐fingering. Salinity anomalies were largest at the surface and decayed with depth in all seasons. Spectra of isopycnal depth and θ‐S anomalies along isopycnals are compared between the three seasons and four vertical layers. Isopycnal depth variance at 30–46 km wavelengths decreased from winter to spring to summer by a factor of 2–10 in stratified regions. By treating salinity anomalies as a tracer, the effective isopycnal diffusivity in the remnant mixed layer was estimated to be 1.4 m2 s−1 over 30–46 km wavelengths.
On the mystery of the perennial carbon dioxide cap at the south pole of Mars
Authors: Guo Xin , Richardson Mark Ian , Soto Alejandro , Toigo Anthony
Published: April 2010

A perennial ice cap has long been observed near the south pole of Mars. The surface of this cap is predominantly composed of carbon dioxide ice. The retention of a CO2 ice cap results from the surface energy balance of the latent heat, solar radiation, surface emission, subsurface conduction, and atmospheric sensible heat. While models conventionally treat surface CO2 ice using constant ice albedos and emissivities, such an approach fails to predict the existence of a perennial cap. Here we explore the role of the insolation‐dependent ice albedo, which agrees well with Viking, Mars Global Surveyor, and Mars Express albedo observations. Using a simple parameterization within a general circulation model, in which the albedo of CO2 ice responds linearly to the incident solar insolation, we are able to predict the existence of a perennial CO2 cap at the observed latitude and only in the southern hemisphere. Further experiments with different total CO2 inventories, planetary obliquities, and surface boundary conditions suggest that the location of the residual cap may exchange hemispheres favoring the pole with the highest peak insolation.
Estimation of tropical forest height and biomass dynamics using lidar remote sensing at La Selva, Costa Rica
Authors: Dubayah R. O. , Sheldon S. L. , Clark D. B. , Hofton M. A. , Blair J. B. , Hurtt G. C. , Chazdon R. L.
Published: April 2010

In this paper we present the results of an experiment to measure forest structure and biomass dynamics over the tropical forests of La Selva Biological Station in Costa Rica using a medium resolution lidar. Our main objective was to observe changes in forest canopy height, related height metrics, and biomass, and from these map sources and sinks of carbon across the landscape. The Laser Vegetation Imaging Sensor (LVIS) measured canopy structure over La Selva in 1998 and again in 2005. Changes in waveform metrics were related to field‐derived changes in estimated aboveground biomass from a series of old growth and secondary forest plots. Pairwise comparisons of nearly coincident lidar footprints between years showed canopy top height changes that coincided with expected changes based on land cover types. Old growth forests had a net loss in height of −0.33 m, while secondary forests had net gain of 2.08 m. Multiple linear regression was used to relate lidar metrics with biomass changes for combined old growth and secondary forest plots, giving an r2 of 0.65 and an RSE of 10.5 Mg/ha, but both parametric and bootstrapped confidence intervals were wide, suggesting weaker model performance. The plot level relationships were then used to map biomass changes across La Selva using LVIS at a 1 ha scale. The spatial patterns of biomass changes matched expected patterns given the distribution of land cover types at La Selva, with secondary forests showing a gain of 25 Mg/ha and old growth forests showing little change (2 Mg/ha). Prediction intervals were calculated to assess uncertainty for each 1 ha cell to ascertain whether the data and methods used could confidently estimate the sign (source or sink) of the biomass changes. The resulting map showed most of the old growth areas as neutral (no net biomass change), with widely scattered and isolated sources and sinks. Secondary forests in contrast were mostly sinks or neutral, but were never sources. By quantifying both the magnitude of biomass changes and the sensitivity of lidar to detect them, this work will help inform the formulation of future space missions focused on biomass dynamics, such as NASA's Deformation Ecosystem Structure and Dynamics of Ice mission.
Role of stormflow in reducing N retention in a suburban forested watershed, western Japan
Authors: Chiwa Masaaki , Maruno Ryoko , Ide Jun'ichiro , Miyano Takeaki , Higashi Naoko , Otsuki Kyoichi
Published: April 2010

To evaluate the role of stormflow in reducing N retention in forested watersheds, we investigated the inorganic N budget of a Japanese suburban forested watershed for 4 years where the proportion of direct flow to precipitation is considerably high (mean is 33%; range is 25–42%). Soil net N mineralization and net nitrification were also measured at middle and lower positions of a slope within the watershed to evaluate nitrate (NO3−) pool size. Annual mean N deposition via throughfall plus stemflow was 15.5 kg N ha−1 yr−1 (13.6–17.1 kg N ha−1 yr−1), which exceeded the threshold value to potentially induce N leaching from forested watersheds. Net nitrification at the middle position was comparable with the lower position. This suggests that the NO3− rich area is large, which could be partly caused by comparable soil moisture conditions with the lower position due to rising groundwater levels during storm events. Annual mean N export was 10.4 kg N ha−1 yr−1 (7.8–12.5 kg N ha−1 yr−1), and subsequent N retention was distinctly low 33% (12–53%). Stormflow accounted for more than 80% of total annual N export. Furthermore, N retention was lower (12 and 27%) in years with higher proportions of direct flow than in years with lower proportions (36 and 53%). Therefore, stormflow is a significant factor in reducing N retention in forested watersheds. The effect of stormflow observation on the comparison of N budgets in other watersheds with different climate and/or hydrologic conditions is discussed.
Variations in free‐phase gases in peat landforms determined by ground‐penetrating radar
Authors: Parsekian Andrew D. , Slater Lee , Comas Xavier , Glaser Paul H.
Published: April 2010

The spatial variability of biogenic gas produced by methanogenic archaea is difficult to assess within saturated peat soils and is often poorly quantified. This study uses ground‐penetrating radar to noninvasively estimate the vertical distribution of biogenic free‐phase gas (FPG) in two distinct peat landform types in the Glacial Lake Agassiz Peatland, Minnesota: a near‐crest bog and a midslope lawn (i.e., both as defined by surface vegetation communities). Ground‐penetrating radar velocities retrieved from common midpoint surveys were modeled using the Complex Refractive Index Model to estimate free‐phase gas volumes along one‐dimensional vertical profiles. Near‐crest bog landforms are characterized by vertical variability in gas content with accumulations along the peat column up to 24% by volume of FPG localized within the deep peat (e.g., 2–4 m depth). Midslope lawn sites show lower total volumes (up to 12% free‐phase gas) and less variability that result in a more even free‐phase gas distribution throughout the vertical profile. High‐resolution data also suggests the presence of thinner layers (<1 m) containing up to 40% free‐phase gas at a near‐crest site. Our results suggest that spatial distribution of free‐phase gas along the peat column may vary in the Glacial Lake Agassiz Peatlands depending on peat landform. Statistical analysis supports vertical variability of ground‐penetrating radar velocity data with a 95% confidence limit. Our results could potentially be upscaled using surface vegetation communities to estimate landscape‐scale gas storage potential in peat landforms.
PtrA is required for coordinate regulation of gene expression during phosphate stress in a marine Synechococcus
Authors: Ostrowski Martin , Mazard Sophie , Tetu Sasha G , Phillippy Katherine , Johnson Aaron , Palenik Brian , Paulsen Ian T , Scanlan Dave J
Published: April 2010

Previous microarray analyses have shown a key role for the two-component system PhoBR (SYNW0947, SYNW0948) in the regulation of P transport and metabolism in the marine cyanobacterium Synechococcus sp. WH8102. However, there is some evidence that another regulator, SYNW1019 (PtrA), probably under the control of PhoBR, is involved in the response to P depletion. PtrA is a member of the cAMP receptor protein transcriptional regulator family that shows homology to NtcA, the global nitrogen regulator in cyanobacteria. To define the role of this regulator, we constructed a mutant by insertional inactivation and compared the physiology of wild-type Synechcococcus sp. WH8102 with the ptrA mutant under P-replete and P-stress conditions. In response to P stress the ptrA mutant failed to upregulate phosphatase activity. Microarrays and quantitative RT-PCR indicate that a subset of the Pho regulon is controlled by PtrA, including two phosphatases, a predicted phytase and a gene of unknown function psip1 (SYNW0165), all of which are highly upregulated during P limitation. Electrophoretic mobility shift assays indicate binding of overexpressed PtrA to promoter sequences upstream of the induced genes. This work suggests a two-tiered response to P depletion in this strain, the first being PhoB-dependent induction of high-affinity PO4 transporters, and the second the PtrA-dependent induction of phosphatases for scavenging organic P. The levels of numerous other transcripts are also directly or indirectly influenced by PtrA, including those involved in cell-surface modification, metal uptake, photosynthesis, stress responses and other metabolic processes, which may indicate a wider role for PtrA in cellular regulation in marine picocyanobacteria.
Effects of soil type and farm management on soil ecological functional genes and microbial activities
Authors: Reeve Jennifer R , Schadt Christopher W , Carpenter-Boggs Lynne , Kang Sanghoon , Zhou Jizhong , Reganold John P
Published: April 2010

Relationships between soil microbial diversity and soil function are the subject of much debate. Process-level analyses have shown that microbial function varies with soil type and responds to soil management. However, such measurements cannot determine the role of community structure and diversity in soil function. The goal of this study was to investigate the role of gene frequency and diversity, measured by microarray analysis, on soil processes. The study was conducted in an agro-ecosystem characterized by contrasting management practices and soil types. Eight pairs of adjacent commercial organic and conventional strawberry fields were matched for soil type, strawberry variety, and all other environmental conditions. Soil physical, chemical and biological analyses were conducted including functional gene microarrays (FGA). Soil physical and chemical characteristics were primarily determined by soil textural type (coarse vs fine-textured), but biological and FGA measures were more influenced by management (organic vs conventional). Organically managed soils consistently showed greater functional activity as well as FGA signal intensity (SI) and diversity. Overall FGA SI and diversity were correlated to total soil microbial biomass. Functional gene group SI and/or diversity were correlated to related soil chemical and biological measures such as microbial biomass, cellulose, dehydrogenase, ammonium and sulfur. Management was the dominant determinant of soil biology as measured by microbial gene frequency and diversity, which paralleled measured microbial processes.
BMI Independently Predicts Younger Age at Hip and Knee Replacement
Authors: Gandhi Rajiv , Wasserstein David , Razak Fahad , Davey J. Roderick , Mahomed Nizar N.
Published: April 2010

Obesity has been identified as a risk factor for the development of hip and knee osteoarthritis (OA) and may play a role in exacerbating existing disease. Therefore, we hypothesized that obese patients would present for hip and knee replacement surgery at a younger age than nonobese patients. From our registry, we performed a cross‐sectional study of 841 hip and 804 knee replacement patients. Patients were categorized by BMI ≤25 kg/m2, 25.1–29.9 kg/m2, 30–34.9 kg/m2, and ≥35 kg/m2. Linear regression modeling was used to examine the relationship between BMI and age at surgery. Hip and knee replacement patients' mean age at surgery was 7.1 and 7.9 years younger, respectively, if their BMI was ≥35 kg/m2 when compared to patients with a BMI ≤25 kg/m2 (P = 0.002). BMI was a significant independent (of gender, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, surgeon, and comorbidity) predictor of age at knee replacement (P < 0.05). WOMAC scores were significantly worse preoperatively in patients with a BMI ≥35 kg/m2 compared to those with a BMI ≤25 kg/m2 (P < 0.05). Our study indicates that obese patients, especially those with a BMI ≥35 kg/m2, presented for and underwent joint replacement surgery at a younger age as compared to nonobese patients.
Cognitive Biases to Healthy and Unhealthy Food Words Predict Change in BMI
Authors: Calitri Raff , Pothos Emmanuel M. , Tapper Katy , Brunstrom Jeffrey M. , Rogers Peter J.
Published: April 2010

The current study explored the predictive value of cognitive biases to food cues (assessed by emotional Stroop and dot probe tasks) on weight change over a 1‐year period. This was a longitudinal study with undergraduate students (N = 102) living in shared student accommodation. After controlling for the effects of variables associated with weight (e.g., physical activity, stress, restrained eating, external eating, and emotional eating), no effects of cognitive bias were found with the dot probe. However, for the emotional Stroop, cognitive bias to unhealthy foods predicted an increase in BMI whereas cognitive bias to healthy foods was associated with a decrease in BMI. Results parallel findings in substance abuse research; cognitive biases appear to predict behavior change. Accordingly, future research should consider strategies for attentional retraining, encouraging individuals to reorient attention away from unhealthy eating cues.
Biological Pathway‐Based Genome‐Wide Association Analysis Identified the Vasoactive Intestinal Peptide (VIP) Pathway Important for Obesity
Authors: Liu Yong‐Jun , Guo Yan‐Fang , Zhang Li‐Shu , Pei Yu‐Fang , Yu Na , Yu Ping , Papasian Christopher J , Deng Hong‐Wen
Published: April 2010

Recent genome‐wide association (GWA) studies have identified a number of novel genes/variants predisposing to obesity. However, most GWA studies have focused on individual single‐nucleotide polymorphism (SNPs)/genes with a strong statistical association with a phenotypic trait without considering potential biological interplay of the tested genes. In this study, we performed biological pathway‐based GWA analysis for BMI and body fat mass. We used individual level genotype data generated from 1,000 unrelated US whites that were genotyped for ∼500,000 SNPs. Statistical analysis of pathways was performed using a modification of the Gene Set Enrichment Algorithm. A total of 963 pathways extracted from the BioCarta, Kyoto Encyclopedia of Genes and Genomes (KEGG), Ambion GeneAssist, and Gene Ontology (GO) databases were analyzed. Among all of the pathways analyzed, the vasoactive intestinal peptide (VIP) pathway was most strongly associated with fat mass (nominal P = 0.0009) and was the third most strongly associated pathway with BMI (nominal P = 0.0006). After multiple testing correction, the VIP pathway achieved false‐discovery rate (FDR) q values of 0.042 and 0.120 for fat mass and BMI, respectively. Our study is the first to demonstrate that the VIP pathway may play an important role in development of obesity. The study also highlights the importance of pathway‐based GWA analysis in identification of additional genes/variants for complex human diseases.
The Evolution of Food Technology, Novel Foods, and the Psychology of Novel Food ‘Acceptance’
Authors: Frewer Lynn , Fischer Arnout
Published: April 2010

Chapter 2 presents an interesting and detailed analysis of the psychology behind our choice of foods, and provides an explanation as to why our reactions to “rationally” presented evidence does not always align with the expectations of scientists and policy makers. It appears that our sensitivity to the use of new technologies in producing our food is particularly heightened, and despite the intuitive appeal of all the benefits offered by nanotechnology, the new technology will not receive our automatic acceptance. The chapter also discusses the challenges for the food processing sector and the potential approaches that could be used to assess and inform attitudes. It is evident that effective research and development strategies for this new technology will need to encompass the consumer psychology if this technology is to fulfil its potential. Public engagement and informed dialogue are the key if we are to avoid the furore that has dogged the introduction of other new technologies in recent years such as food irradiation or genetic modification (GM).
Potential Benefits and Market Drivers for Nanotechnology Applications in the Food Sector
Authors: Kampers Frans W. H.
Published: April 2010

This chapter presents a broad overview of the likely benefits that nanotechnologies can bring to the consumer, and discusses the main drivers for the new technological innovations that are likely to revolutionise the food sector. It analyses the role of nanotechnologies in meeting the global challenges that have placed increasing demands on the agri-food sector, in terms of provision of a sustainable supply of food for the growing world population, whilst maintaining food safety and quality, and enhancing the crucial role of food in preventive healthcare. It highlights the various positive aspects of nanotechnology applications in everyday food products, which are aimed at benefiting the consumer, for example in terms of healthy, affordable, and tasteful food products. Nanotechnologies will also enable a reduction in food waste by extending the shelf life of food products, and will cater for different lifestyles and individual needs of the consumer. The chapter concludes that, to benefit from the new developments, consumers need to develop a trust in the applications, and that the new technological advancements must be aimed at addressing the needs and aspirations of the consumers, and not for the benefit of the industry alone.
Potential Risks of Nanofood to Consumers
Authors: Bouwmeester Hans , Marvin Hans J. P.
Published: April 2010

The field of nanotechnologies is rapidly developing and applications can be found throughout the entire food production chain. This is expected to lead to many new products with new and exciting features that are not feasible using conventional production processes. Although the obvious beneficial effects of the application of nanotechnologies are well recognized, the potential human and environmental impacts of engineered nanomaterials have so far received little attention. As nanotechnologies are likely to be used in food production more and more in the future, this raises the question of consumer exposure to nanofood. This chapter presents a review of scientific issues that need to be addressed in order to perform a robust safety assessment of the use of nanotechnologies in food production. One of the main issues to be addressed includes development of validated analytical tools for characterisation of nanomaterials in food. This is essentially needed to enable assessment of consumer exposure. Furthermore, fundamental knowledge on the biokinetics and interaction of nanomaterials at both organism and cellular levels needs to be generated. Only with this knowledge can a reliable assessment of the potential hazards be made. Integrating this knowledge in the established risk analysis paradigm is a prerequisite for the sustainable development of nano foods, which will also need consumer acceptance of the new applications in food production.
Selenium controls the sex-specific immune response and selenoprotein expression during the acute-phase response in mice
Authors: Stoedter Mette , Renko Kostja , Hög Antonia , Schomburg Lutz
Published: April 2010

Selenium modifies inflammatory reactions in rodents and humans. The liver controls metabolism and transport of selenium via hepatically-derived SEPP (selenoprotein P). Intracellular SEPS (selenoprotein S) modifies endoplasmic-reticulum function and immune-cell activity. Polymorphisms in SEPS have been associated with cytokine levels and inflammatory diseases in a subset of clinical studies. In the present study, we hypothesized that sex and selenium represent decisive parameters controlling the immune response and regulation of SEPS expression in vivo. Male and female mice fed a selenium-poor diet were supplemented or not with selenite for 3 days and injected with saline or LPS (lipopolysaccharide) 24 h before analysis. Selenium supplementation mitigated the LPS-induced rise in circulating cytokines in male mice. Serum SepP and selenium concentrations decreased in response to LPS, whereas hepatic SepS was specifically up-regulated despite declining selenium concentrations in the liver. Hepatic SepS induction was mainly controlled by post-transcriptional mechanisms and attributed to hepatocytes by analysing transgenic mice. Notably, selenium supplementation was essential for an optimal SepS induction. We conclude that selenoprotein biosynthesis becomes redirected in hepatocytes during the acute-phase response at the expense of dispensable selenoproteins (e.g. SepP) and in favour of SepS expression, thereby causing declining serum selenium and improving liver function. The selenium status and sex control SepS expression and modify cytokine response patterns in serum, which might explain contradictory results on associations of SEPS genotype and inflammatory diseases in clinical studies.
Glial fibrillary acidic protein is elevated in the lysosomal storage disease classical late-infantile neuronal ceroid lipofuscinosis, but is not a component of the storage material
Authors: Xu Su , Sleat David E. , Jadot Michel , Lobel Peter
Published: April 2010

Classical late-infantile neuronal ceroid lipofuscinosis (LINCL) is a fatal neurodegenerative disease of children caused by mutations in TPP1, the gene encoding the lysosomal protease tripeptidyl peptidase 1. LINCL is characterized by lysosomal accumulation of storage material of which only a single protein component, subunit c of mitochondrial ATP synthase, has been well established to date. Identification of other protein constituents of the storage material could provide useful insights into the pathophysiology of disease and the natural substrates for TPP1. We have therefore initiated a proteomic analysis of storage material in brain from a LINCL mouse model. One protein, GFAP (glial fibrillary acidic protein), was found to be elevated in the LINCL mice compared with normal controls in both isolated storage bodies and a lysosome-enriched subcellular fraction that contains storage material. To determine whether GFAP accumulates within the lysosome in LINCL, we examined its intracellular distribution using subcellular fractionation and morphological methods. These experiments demonstrate that GFAP is not a component of the storage material in LINCL, suggesting that reports of GFAP storage in other NCLs may need to be re-examined. A number of other proteins were elevated in the storage material and/or lysosome-enriched fraction from the LINCL mice, but it remains unclear whether these proteins are true constituents of the storage material or, like GFAP, whether they associate with this material upon purification.
Tumour escape mechanisms and their therapeutic implications in combination tumour therapy
Authors: Bhutia Sujit K. , Mallick Sanjaya K. , Maiti Tapas K.
Published: April 2010

Most tumours arise from a single normal cell through a sequential evolutionary process of mutation and selection. Tumours are initiated by escaping non‐immune surveillance, which includes defective DNA repair, epigenetic gene alternation, resistance to apoptosis and loss of intercellular contact inhibition. Tumour cells harbour mutations in a number of critical genes that provide selective advantages at various stages during the evolution of the tumour. The tumour cells that circumvent the tumour suppressor mechanisms of the non‐immune surveillance process are edited by the immune system, resulting in the selection of a resistant tumour variant. The selection of the tumour cell is further shaped by its interactions with cells and other factors in its microenvironment. Tumour evolution is thought to adhere to Darwinian principles by escaping both non‐immune (intrinsic) and immune (extrinsic) responses against self‐altered tumour cells. At end‐stage, tumours have escaped both non‐immune and immune surveillance with increased threshold of apoptosis. Combination therapy has been proposed, by exploring the non‐immune and immune suppressive nature of the tumour, and has been found to have a therapeutic efficiency on tumour regression as compared with monotherapies. The combination of immunotherapy and other different modalities, especially vaccines, with conventional anticancer therapies with optimized dosage and scheduling can offer synergistic antitumour effects. Here, we focus on the mechanism of tumour evolution and its implication in combination therapy.