bluuebunny/crossref_metadata_2025 huggingface dataset:
Ginsenoside Composition and Antiproliferative Activities of Explosively Puffed Ginseng (Panax ginseng C.A. Meyer)
Authors: Yoon Sung‐Ran , Lee Gee‐Dong , Park Jung‐Hyun , Lee In‐Seon , Kwon Joong‐Ho
Published: May 2010

ABSTRACT:  The puffing process was evaluated as an alternative to the steaming process for producing a biologically more active ginseng product, like red ginseng, from raw ginseng. A puffing treatment of dried raw ginseng roots induced an overall increase in crude saponin content. As puffing pressure increased, the content of ginsenoside Re, Rg1, Rb1, Rc, and Rb2 decreased, while ginsenoside Rg3 increased significantly as compared to raw ginseng. The content of ginsenoside Rg3 in puffed ginseng at a pressure of 490 kPa was similar to that of red ginseng. Cancer cell lines (HeLa, MCF‐7, and HepG2) showed that antiproliferative effects of saponin extract of puffed ginseng increased with an increase in puffing pressure. Ginseng explosively puffed at 490 kPa had similar saponin constituents and antiproliferative effects as those of red ginseng.

Practical Application: The puffing process could provide an alternative mean to produce functional ginseng products, along with a reduction in processing time as compared to traditional red ginseng processing by steam.
Effect of Thawing and Cold Storage on Frozen Chicken Thigh Meat Quality by High‐Voltage Electrostatic Field
Authors: Hsieh Chang‐Wei , Lai Cheng‐Hung , Ho Wai‐Jane , Huang Su‐Chen , Ko Wen‐Ching
Published: May 2010

ABSTRACT:  One of the most popular issues in electrostatic biology is the effects of a high‐voltage electrostatic field (HVEF) on the thawing of chicken thigh meat. In this study, chicken thigh meat was treated with HVEF (E‐group), and compared to samples stored in a common refrigerator (R‐group), to investigate how HVEF affects chicken thigh meat quality after thawing at low temperature storage (−3 and 4 °C). The results showed that there were no significant differences in biochemical and microorganism indices at −3 °C. However, the HVEF can significantly shorten thawing time for frozen chicken thigh meat at −3 °C. After thawing chicken thigh meat and storing at 4 °C, the total viable counts reached the Intl. Commission on Microbiological Specification for Foods limit of 107 CFU/g on the 6 and 8 d for the R‐ and E‐group, respectively. On the 8th d, the volatile basic nitrogen had increased from 11.24 mg/100 g to 21.9 mg/100 g for the E‐group and 39.9 mg/100 g for the R‐group, respectively. The biochemical and microorganism indices also indicated that the E‐group treatment yielded better results on thawing than the R‐group treatment. The application of this model has the potential to keep products fresh.
Dehydration of Pollock Skin Prior to Gelatin Production
Authors: Bower Cindy K. , Avena‐Bustillos Roberto J. , Hietala Katie A. , Bilbao‐Sainz Cristina , Olsen Carl W. , McHugh Tara H.
Published: May 2010

ABSTRACT:  Alaska pollock (Theragra chalcogramma) is the U.S.A.'s largest commercial fishery, with an annual catch of over 1 million tons. During pollock processing, the skins are discarded or made into fish meal, despite their value for gelatin production. The absence of gelatin‐processing facilities in Alaska necessitates drying of the skins before transport to decrease the moisture content, but conventional hot‐air drying is expensive. This study evaluated a less energy‐intensive technology, the use of desiccants for reducing water weight in pollock skins prior to shipment. To ensure that the functional properties of gelatin obtained from dried pollock skins were not affected during desiccation, gelatins were prepared from each skin‐drying treatment and compared with gelatin extracted from air‐dried pollock skins. None of the desiccation treatments decreased the gel strength of pollock skin gelatin, nor were there major differences in gelling temperature or viscosity among the gelatin solutions. This suggests that pollock skins can be economically stabilized for transport to a gelatin‐processing facility through the use of regenerable desiccants that are already common in the food industry.

Practical Application: Pollock skins destined for gelatin production can be stabilized using chemical desiccants prior to shipment. The dehydration process does not harm the functional properties of gelatin, such as gel strength, gelling temperature, and viscosity. This research suggests that fish skins can be economically stabilized for transport to a gelatin‐processing facility through the use of regenerable desiccants that are already common in the food industry.
On the Effect of Tastant Excluded Fillers on Sweetness and Saltiness of a Model Food
Authors: Goh S.M. , Leroux B. , Groeneschild C.A.G. , Busch J.L.H.C.
Published: May 2010

ABSTRACT:  In this study, the effect on taste due to the addition of air bubbles to a water‐based gel was investigated. The gel phase contained either sucrose to give a sweet taste or sodium chloride to give a salty taste. For the sweet gels, taste intensities were evaluated for samples with different volume fractions of the air bubbles (up to 40%, v/v) and different concentrations of the sucrose. For the salty gels, samples were evaluated at 40% volume fraction of air bubbles. It was found that a reduction of the sodium chloride or sucrose by the same weight percentage as the volume fraction of the air bubbles in the samples gave equal taste perception as the nontastant‐reduced samples. Moreover, saltiness and sweetness perception were clearly enhanced at 40% volume fractions of air bubbles if the sodium chloride or sucrose was not reduced. Thus, the overall tastes of the samples appeared to depend mainly on the concentration levels of the salt or the sucrose in the aqueous phase irrespective of the volume fraction of the air bubbles. However, the air bubbles were found to change the texture and appearance of the samples. It has been demonstrated that the inclusion of air bubbles offers scope for the reduction of sodium chloride or sucrose in food products.
In Vitro and In Vivo Metabolism of the Radiolytic Compound 2‐Dodecylcyclobutanone
Authors: Hijaz Faraj , Shrestha Tej B. , Bossman Stefan H. , Hussain Faris , Smith J. Scott
Published: May 2010

ABSTRACT:  Our knowledge about the metabolism of alkylcyclobutanones (2‐ACBs) is limited, and the lack of literature on the metabolism of 2‐ACBs causes consumers to doubt the safety of irradiated foods. The objectives of this study were to evaluate the metabolism of 2‐dodecylcyclobutanone (2‐DCB) and identify any possible metabolite. The 2‐DCB was mixed with rat S9 (postmitochondrial supernatant fraction) and β‐nicotinamide adenine dinucleotide phosphate (NADPH) in phosphate buffer (pH 7.4) and incubated for 2 h at 37 °C. Then, the incubation mixture was mixed with sodium sulfate and extracted with n‐hexane by using a Soxhlet apparatus. The hexane extract was concentrated under nitrogen and injected into the gas chromatography‐mass spectrometry (GC‐MS) machine running in selective ion monitoring mode (SIM) to measure 2‐DCB concentration. The hexane extract from the in vitro and in vivo studies was also derivatized with a silylation reagent and injected into a GC‐MS running in full scan mode. The average percentage of 2‐DCB recovered from the test incubations was 23%, compared with 50% from the controls. The GC‐MS chromatograms of the derivatized samples showed a unique peak in the in vitro test incubations and in the hexane extract of the rat feces that were given 2‐DCB. This peak was later identified as 2‐doecylcyclobutanol.
Thermal Stability of Tagatose in Solution
Authors: Luecke Katherine J. , Bell Leonard N.
Published: May 2010

ABSTRACT:  Tagatose, a monosaccharide similar to fructose, has been shown to behave as a prebiotic. To deliver this prebiotic benefit, tagatose must not degrade during the processing of foods and beverages. The objective of this study was to evaluate the thermal stability of tagatose in solutions. Tagatose solutions were prepared in 0.02 and 0.1 M phosphate and citrate buffers at pHs 3 and 7, which were then held at 60, 70, and 80 °C. Pseudo‐1st‐order rate constants for tagatose degradation were determined. In citrate and phosphate buffers at pH 3, minimal tagatose was lost and slight browning was observed. At pH 7, tagatose degradation rates were enhanced. Degradation was faster in phosphate buffer than citrate buffer. Higher buffer concentrations also increased the degradation rate constants. Enhanced browning accompanied tagatose degradation in all buffer solutions at pH 7. Using the activation energies for tagatose degradation, less than 0.5% and 0.02% tagatose would be lost under basic vat and HTST pasteurization conditions, respectively. Although tagatose does breakdown at elevated temperatures, the amount of tagatose lost during typical thermal processing conditions would be virtually negligible.

Practical Application: Tagatose degradation occurs minimally during pasteurization, which may allow for its incorporation into beverages as a prebiotic.
Recovery of Sediment Characteristics in Moraine, Headwater Streams of Northern Minnesota After Forest Harvest1
Authors: Merten Eric C. , Hemstad Nathaniel A. , Kolka Randall K. , Newman Raymond M. , Verry Elon S. , Vondracek Bruce
Published: May 2010

Merten, Eric C., Nathaniel A. Hemstad, Randall K. Kolka, Raymond M. Newman, Elon S. Verry, and Bruce Vondracek, 2010. Recovery of Sediment Characteristics in Moraine, Headwater Streams of Northern Minnesota After Forest Harvest. Journal of the American Water Resources Association (JAWRA) 46(4): 733‐743. DOI: 10.1111/j.1752‐1688.2010.00445.x

Abstract:  We investigated the recovery of sediment characteristics in four moraine, headwater streams in north‐central Minnesota after forest harvest. We examined changes in fine sediment levels from 1997 (preharvest) to 2007 (10 years postharvest) at study plots with upland clear felling and riparian thinning, using canopy cover, proportion of unstable banks, surficial fine substrates, residual pool depth, and streambed depth of refusal as response variables. Basin‐scale year effects were significant (p < 0.001) for all responses when evaluated by repeated‐measures ANOVAs. Throughout the study area, unstable banks increased for several years postharvest, coinciding with an increase in windthrow and fine sediment. Increased unstable banks may have been caused by forest harvest equipment, increased windthrow and exposure of rootwads, or increased discharge and bank scour. Fine sediment in the channels did not recover by summer 2007, even though canopy cover and unstable banks had returned to 1997 levels. After several storm events in fall 2007, 10 years after the initial sediment input, fine sediment was flushed from the channels and returned to 1997 levels. Although our study design did not discern the source of the initial sediment inputs (e.g., forest harvest, road crossings, other natural causes), we have shown that moraine, headwater streams can require an extended period (up to 10 years) and enabling event (e.g., high storm flows) to recover from large inputs of fine sediment.
Magnesian anorthositic granulites in lunar meteorites Allan Hills A81005 and Dhofar 309: Geochemistry and global significance
Authors: TREIMAN Allan H. , MALOY Amy K. , SHEARER Charles K. , GROSS Juliane
Published: May 2010

Abstract– Fragments of magnesian anorthositic granulite are found in the lunar highlands meteorites Allan Hills (ALH) A81005 and Dhofar (Dho) 309. Five analyzed clasts of meteoritic magnesian anorthositic granulite have Mg′ [molar Mg/(Mg + Fe)] = 81–87; FeO ≈ 5% wt; Al2O3 ≈ 22% wt; rare earth elements abundances ≈ 0.5–2 × CI (except Eu ≈ 10 × CI); and low Ni and Co in a non‐chondritic ratio. The clasts have nearly identical chemical compositions, even though their host meteorites formed at different places on the Moon. These magnesian anorthositic granulites are distinct from other highlands materials in their unique combination of mineral proportions, Mg′, REE abundances and patterns, Ti/Sm ratio, and Sc/Sm ratio. Their Mg′ is too high for a close relationship to ferroan anorthosites, or to have formed as flotation cumulates from the lunar magma ocean. Compositions of these magnesian anorthositic granulites cannot be modeled as mixtures of, or fractionates from, known lunar rocks. However, compositions of lunar highlands meteorites can be represented as mixtures of magnesian anorthositic granulite, ferroan anorthosite, mare basalt, and KREEP. Meteoritic magnesian anorthositic granulite is a good candidate for the magnesian highlands component inferred from Apollo highland impactites: magnesian, feldspathic, and REE‐poor. Bulk compositions of meteorite magnesian anorthositic granulites are comparable to those inferred for parts of the lunar farside (the Feldspathic Highlands Terrane): ∼4.5 wt% FeO; ∼28 wt% Al2O3; and Th <1 ppm. Thus, magnesian anorthositic granulite may be a widespread and abundant component of the lunar highlands.
An ATPase for a Kinase
Authors: Gough Nancy R.
Published: May 2010

By promoting an inhibitory autophosphorylation event, the ATPase XP24 decreases immune responses mediated by the XA21 pattern recognition receptor.
Signal to Slow Down
Authors: Gough Nancy R.
Published: May 2010

By bringing the Rap1 effector RapL to the membrane, the adaptor SKAP1 promotes adhesion, allowing activated T cell receptors to decrease T cell motility.
Light Structures
Authors: Vinson Valda
Published: May 2010

Fleeting molecular events are observed as light illuminates chlorophyll to initiate photosynthesis.
Science Signaling
Podcast: 4 May 2010
Authors: Eng Christina H. , Abraham Robert T. , VanHook Annalisa M.
Published: May 2010

Ammonia induces autophagy, which may help cancer cells survive stressful conditions.
A Rapid Antimicrobial Susceptibility Test for
Bacillus anthracis
Authors: Weigel Linda M. , Sue David , Michel Pierre A. , Kitchel Brandon , Pillai Segaran P.
Published: May 2010

An effective public health response to a deliberate release of
Bacillus anthracis
will require a rapid distribution of antimicrobial agents for postexposure prophylaxis and treatment. However, conventional antimicrobial susceptibility testing for
B. anthracis
requires a 16- to 20-h incubation period. To reduce this time, we have combined a modified broth microdilution (BMD) susceptibility testing method with real-time quantitative PCR (qPCR). The growth or inhibition of growth of
B. anthracis
cells incubated in 2-fold dilutions of ciprofloxacin (CIP) (0.015 to 16 μg/ml) or doxycycline (DOX) (0.06 to 64 μg/ml) was determined by comparing the fluorescence threshold cycle (

C
T

) generated by target amplification from cells incubated with each drug concentration with the

C
T

of the no-drug (positive growth) control. This Δ

C
T

readily differentiated susceptible and nonsusceptible strains. Among susceptible strains, the median Δ

C
T

values were ≥7.51 cycles for CIP and ≥7.08 cycles for DOX when drug concentrations were at or above the CLSI breakpoint for susceptibility. For CIP- and DOX-nonsusceptible strains, the Δ

C
T

was <1.0 cycle at the breakpoint for susceptibility. When evaluated with 14 genetically and geographically diverse strains of
B. anthracis
, the rapid method provided the same susceptibility results as conventional methods but required less than 6 h, significantly decreasing the time required for the selection and distribution of appropriate medical countermeasures.
Minimal Removal of Raltegravir by Hemodialysis in HIV-Infected Patients with End-Stage Renal Disease
Authors: Moltó José , Sanz-Moreno José , Valle Marta , Cedeño Samandhy , Bonal Jordi , Bouarich Hanane , Clotet Bonaventura
Published: May 2010

Little is known about raltegravir removal by hemodialysis in patients with end-stage renal disease (ESRD). We therefore measured raltegravir concentrations in plasma in pre- and postdialyzer blood samples from 2 ESRD HIV-infected patients. The hemodialysis extraction ratio and raltegravir hemodialysis clearance were 5.5% and 9.1 ml/min in patient 1 and 9.5% and 19.1 ml/min in patient 2, respectively. Our results suggest minimal raltegravir removal by hemodialysis with no specific raltegravir dosage adjustments required in HIV-infected patients undergoing hemodialysis.
Syndecan-Fc Hybrid Molecule as a PotentIn VitroMicrobicidal Anti-HIV-1 Agent
Authors: Bobardt Michael D. , Chatterji Udayan , Schaffer Lana , de Witte Lot , Gallay Philippe A.
Published: May 2010

In the absence of a vaccine, there is an urgent need for the development of safe and effective topical microbicides to prevent the sexual transmission of human immunodeficiency virus type 1 (HIV-1). In this study, we proposed to develop a novel class of microbicides using syndecan as the antiviral agent. Specifically, we generated a soluble syndecan-Fc hybrid molecule by fusing the ectodomain of syndecan-1 to the Fc domain of a human IgG. We then tested the syndecan-Fc hybrid molecule for variousin vitromicrobicidal anti-HIV-1 properties. Remarkably, the syndecan-Fc hybrid molecule possesses multiple attractive microbicidal properties: (i) it blocks HIV-1 infection of primary targets including T cells, macrophages, and dendritic cells (DC); (ii) it exhibits a broad range of antiviral activity against primary HIV-1 isolates, multidrug resistant HIV-1 isolates, HIV-2, and simian immunodeficiency virus (SIV); (iii) it prevents transmigration of HIV-1 through human primary genital epithelial cells; (iv) it prevents HIV-1 transfer from dendritic cells to CD4+T cells; (v) it is potent when added 2 h prior to addition of HIV-1 to target cells; (vi) it is potent at a low pH; (vii) it blocks HIV-1 infectivity when diluted in genital fluids; and (viii) it prevents herpes simplex virus infection. The heparan sulfate chains of the syndecan-Fc hybrid molecule are absolutely required for HIV-1 neutralization. Several lines of evidence suggest that the highly conserved Arg298 in the V3 region of gp120 serves as the locus for the syndecan-Fc hybrid molecule neutralization. In conclusion, this study suggests that the syndecan-Fc hybrid molecule represents the prototype of a new generation of microbicidal agents that may have promise for HIV-1 prevention.
Observational and cost analysis of the implementation of breast cancer sentinel node intraoperative molecular diagnosis
Authors: Cutress R I , McDowell A , Gabriel F G , Gill J , Jeffrey M J , Agrawal A , Wise M , Raftery J , Cree I A , Yiangou C
Published: May 2010

Background

Accurate intraoperative sentinel lymph node (SLN) assessment enables axillary clearance to be completed immediately in node-positive breast cancer patients. This article reports a study of the introduction of intraoperative molecular SLN analysis in routine clinical practice in the Portsmouth Breast Care Centre.

Design

There was prospective analysis of 254 consecutive patients who underwent SLN biopsy in a single centre. Nodes were sectioned at 2 mm intervals and alternate slices were analysed using a CE-marked assay for mammaglobin (MG) and cytokeratin 19 (CK19). Remaining slices of node were sent for histological analysis, which included CK19 immunohistochemistry. While the assay was being carried out, the surgeon performed the breast tumour resection. The cost per patient was estimated retrospectively and the cost effects on the hospital and primary care trust for a typical service were also estimated.

Results

A total of 491 SLNs from 254 patients were evaluated. The intraoperative assay showed positivity of SLNs for metastatic cells in 78 patients. There was 100% detection of macrometastases within sentinel nodes analysed by GeneSearch. Overall concordance between histological status, including micrometastases and GeneSearch analysis, was 95% (sensitivity 96%, specificity 95%). The cost per procedure was increased for wide local excision with SLN biopsy and intraoperative assessment compared with other models, but fewer procedures were carried out.

Conclusion

Intraoperative assessment of SLNs in breast cancer using a molecular assay is a safe, acceptable and accurate technique that allows a reduction in the frequency of delayed axillary clearance surgery. Take-up of this method may be hampered by perverse incentives operating within healthcare funding.
Justifying terminal care by ‘retrospective quality-adjusted life-years’
Authors: Cowley Christopher
Published: May 2010

A lot of medical procedures can be justified in terms of the number of quality-adjusted life-years (QALYs) they can be expected to generate; that is, the number of extra years that the procedure will provide, with the quality of life during those extra years factored in. QALYs are a crude tool, but good enough for many decisions. Notoriously, however, they cannot justify spending any money on terminal care (and indeed on older people in general). In this paper I suggest a different way of construing ‘quality’ (as meaningfulness rather than physical comfort) and ‘life’ (as both backward-looking and forward-looking), so that the terminal patient's efforts to find meaning in his life could in principle generate plenty of ‘retrospective QALYs’ to justify funding.
Evaluating end of life practices in ten Brazilian paediatric and adult intensive care units
Authors: Piva Jefferson , Lago Patrícia , Othero Jairo , Garcia Pedro Celiny , Fiori Renato , Fiori Humberto , Borges Luiz Alexandre , Dias Fernando S
Published: May 2010

Objective

To evaluate the modes of death and treatment offered in the last 24 h of life to patients dying in 10 Brazilian intensive care units (ICUs) over a period of 2 years.

Design and setting

Cross-sectional, multicentre, retrospective study based on medical chart review. The medical records of all patients that died in seven paediatric and three adult ICUs belonging to university and tertiary hospitals over a period of 2 years were included. Deaths in the first 24 h of admission to the ICU and brain death were excluded.

Intervention

Two intensive care fellows of each ICU were trained in fulfilling a standard protocol (κ=0.9) to record demographic data and all medical management provided in the last 48 h of life. The Student t test, Mann–Whitney U test, χ2test and RR were used for data comparison.

Measurements and main results

1053 medical charts were included (59.4% adult patients). Life support limitation was more frequent in the adult group (86% vs 43.5%; p<0.001). A ‘do not resuscitate’ order was the most common life support limitation in both groups (75% and 66%), whereas withholding/withdrawing were more frequent in the paediatric group (33.9% vs 24.9%; p=0.02). The life support limitation was rarely reported in the medical chart in both groups (52.6% and 33.7%) with scarce family involvement in the decision making process (23.0% vs 8.7%; p<0.001).

Conclusion

Life support limitation decision making in Brazilian ICUs is predominantly centred on the medical perspective with scarce participation of the family, and consequently several non-coherent medical interventions are observed in patients with life support limitation.
Effect of cold temperature on the rate of natural attenuation of benzene, toluene, ethylbenzene, and the three isomers of xylene (BTEX)
Authors: Ulrich Ania C. , Tappenden Kristen , Armstrong James , Biggar Kevin W.
Published: May 2010

The impact of cold temperatures on natural attenuation rates is poorly understood and compounded by the lack of published data, particularly under field conditions. This paper presents a collection of data from monitoring and remediation projects completed at cold temperatures. The data set was compiled from 55 studies under anaerobic conditions (46 field and nine laboratory) from sites where groundwater temperatures are typically less than 15 °C. By normalizing the data to +5 and +10 °C, the scatter in rates for BTEX degradation in groundwater was reduced by 33% to 66%. In an attempt to address the paucity of data on natural attenuation rates under cold temperatures, this study has compiled and normalized 101 anaerobic BTEX natural attenuation rates. Eleven of the 55 studies and 43 of the 101 rates presented in this study have not been previously published. Additionally, this study has compiled, for each site, relevant contaminant and hydrogeological information that can be reviewed to choose appropriate rates for preliminary site analysis.
Particle damage observed in ring shear tests on sands
Authors: Sadrekarimi Abouzar , Olson Scott M.
Published: May 2010

In this paper, particle damage of three test sands with different mineralogical compositions is studied using stress–displacement response measured in ring shear tests, particle-size distributions of the original sand prior to shear and from the shear band after shear, and by examining particle shape changes determined by scanning electron microscope. Particle damage during shearing produced a wider particle-size distribution, and damage typically continued until the normal stress was small (about 28 kPa) in constant volume ring shear tests and the internal stresses were distributed among sufficient particle contacts such that damage practically ceased. The dominant damage mechanism (typically either particle abrasion and shearing-off asperities or particle splitting) depended strongly on the soil response (i.e., contraction or dilation), particle hardness, and particle-size distribution, but both mechanisms produced particles that were more angular and rougher than the original sand particles. The magnitude of particle damage observed in the ring shear tests was influenced by the consolidation normal stress, shear displacement, particle mineralogy, particle-size distribution, drainage conditions, and soil fabric (in constant volume tests). Lastly, the influence of particle damage on engineering properties including hydraulic conductivity, liquefaction resistance, stress–strain response, friction angle, and critical state are briefly discussed.
Effect of grain shape and angularity on the undrained response of fine sands
Authors: Tsomokos A. , Georgiannou V. N.
Published: May 2010

The objective of this paper is to discuss the effect of grain shape and angularity on the undrained behaviour of sands. Four fine to medium (D50= 0.15–0.29 mm) and uniform sands were examined. These sands have similar and (or) identical grading curves, but differ with respect to the angularity of their grains. Under the electron scanning microscope two sands have rounded grains and the other two have subangular to angular grains. For sands with rounded grains, evidence of undrained behaviour undergoing systematic weakening (shear stress reduction after a transient peak deviator stress) is provided by torsional hollow cylinder tests. However, sands with the same grading curve and void ratio, but angular grains, show stable response with a continuous increase in strength after a transient peak. A small variation in the sand gradation, i.e., D50= 0.22 ± 0.07 mm, does not appear to alter the pattern of undrained response described earlier, with the angular sand (D50= 0.15) exhibiting stable response to shear and the rounded sands (D50= 0.22 and 0.29) having unstable response to shear. The stiffness characteristics of the sands are also presented. Triaxial compression tests were performed to confirm the pattern of response observed under torsional testing.
Mechanical response of highly gap-graded mixtures of waste rock and tailings. Part I: Monotonic shear response
Authors: Khalili Ali , Wijewickreme Dharma , Wilson G. Ward
Published: May 2010

The idea of mixing mine tailings and waste rock to form “paste rock” prior to disposal is now receiving significant attention from the point of view of sustainable mine waste management practices. This approach has been viewed as a favourable alternative to traditional methods of mine waste disposal because paste rock has the potential to overcome deficiencies (e.g., acid rock drainage and liquefaction-induced failures) associated with traditional methods. To advance the current limited knowledge, a laboratory research program was undertaken to study the mechanical response of paste rock. Testing was undertaken on paste rock specimens prepared so that the tailings would “just fill” the void spaces within the waste rock particle skeleton. The findings suggest that the material is unlikely to experience flow deformation under monotonic shear loading conditions, at least up to the tested initial effective confining stress conditions of 400 kPa. The monotonic shear response of paste rock was found to be similar to that of rock-only material; this finding is in agreement with previous observations from one-dimensional consolidation testing where it had been shown that the rock particle skeleton would carry almost 90% of the externally applied stress on a given paste rock mass.
Comparisons between field- and LiDAR-based measures of stand structural complexity
Authors: Kane Van R. , McGaughey Robert J. , Bakker Jonathan D. , Gersonde Rolf F. , Lutz James A. , Franklin Jerry F.
Published: May 2010

Forest structure, as measured by the physical arrangement of trees and their crowns, is a fundamental attribute of forest ecosystems that changes as forests progress through suc;cessional stages. We examined whether LiDAR data could be used to directly assess the successional stage of forests by determining the degree to which the LiDAR data would show the same relative ranking of structural development among sites as would traditional field measurements. We sampled 94 primary and secondary sites (19–93, 223–350, and 600 years old) from three conifer forest zones in western Washington state, USA, in the field and with small-footprint, discrete return LiDAR. Seven sets of LiDAR metrics were tested to measure canopy structure. Ordinations using the of LiDAR 95th percentile height, rumple, and canopy density metrics had the strongest correlations with ordinations using two sets of field metrics (Procrustes R = 0.72 and 0.78) and a combined set of LiDAR and field metrics (Procrustes R = 0.95). These results suggest that LiDAR can accurately characterize forest successional stage where field measurements are not available. This has important implications for enabling basic and applied studies of forest structure at stand to landscape scales.
QUANTUM DIRECT COMMUNICATION BASED ON QUANTUM SEARCH ALGORITHM
Authors: WANG CHUAN , HAO LIANG , SONG SI YU , LONG GUI LU
Published: May 2010

Quantum direct communications, including deterministic secure quantum communication and quantum secure direct communication protocol using two-qubit quantum search algorithm are proposed in this paper. Secret messages are encoded by two-qubit unitary operations and exchanged by the two communication parties directly. We discussed the security of the protocol under intercept-resend attack and individual attack. We found that the protocols are secure against eavesdropping attacks.
Tight failure detection bounds on atomic object implementations
Authors: Delporte-Gallet Carole , Fauconnier Hugues , Guerraoui Rachid
Published: May 2010

This article determines the weakest failure detectors to implement shared atomic objects in a distributed system with crash-prone processes. We first determine the weakest failure detector for the basic register object. We then use that to determine the weakest failure detector for all popular atomic objects including test-and-set, fetch-and-add, queue, consensus and compare-and-swap, which we show is the same.
Set constraints with projections
Authors: Pacholski Witold Charatonik Leszek
Published: May 2010

Set constraints form a constraint system where variables range over the domain of sets of trees. They give a natural formalism for many problems in program analysis. Syntactically, set constraints are conjunctions of inclusions between expressions built over variables, constructors (constants and function symbols from a given signature) and a choice of set operators that defines the specific class of set constraints. In this article, we are interested in the class of
set constraints with projections
, which is the class with all Boolean operators (union, intersection and complement) and
projections
that in program analysis directly correspond to type destructors. We prove that the problem of existence of a solution of a system of set constraints with projections is in NEXPTIME, and thus that it is NEXPTIME-complete.
Setwise and filtered gibbs samplers for teletraffic analysis
Authors: Andrew Lachlan L. H. , Qian Guoqi , Vázquez-Abad Felisa J.
Published: May 2010

A setwise Gibbs sampler (SGS) method is developed to simulate stationary distributions and performance measures of network occupancy of Baskett-Chandy-Muntz-Palacios (BCMP) telecommunication models. It overcomes the simulation difficulty encountered in applying the standard Gibbs sampler to closed BCMP networks with constant occupancy constraints. We show Markov chains induced by SGS converge to the target stationary distributions. This article also investigates the filtered Gibbs sampler (FGS) as an efficient method for estimating various network performance measures. It shows that FGS's efficiency is considerable, but may be improperly overestimated. A more conservative performance estimator is then presented.
CDNsim
Authors: Stamos Konstantinos , Pallis George , Vakali Athena , Katsaros Dimitrios , Sidiropoulos Antonis , Manolopoulos Yannis
Published: May 2010

Content distribution networks (CDNs) have gained considerable attention in the past few years. Hence there is need for developing frameworks for carrying out CDN simulations. In this article we present a modeling and simulation framework for CDNs, called CDNsim. CDNsim has been designated to provide a realistic simulation for CDNs, simulating the surrogate servers, the TCP/IP protocol, and the main CDN functions. The main advantages of this tool are its high performance, its extensibility, and its user interface, which is used to configure its parameters. CDNsim provides an automated environment for conducting experiments and extracting client, server, and network statistics. The purpose of CDNsim is to be used as a testbed for CDN evaluation and experimentation. This is quite useful to both the research community (to experiment with new CDN data management techniques), and for CDN developers (to evaluate profits on prior certain CDN installations).
Comments on “an integrated efficient solution for computing frequent and top-k elements in data streams”
Authors: Liu Hongyan , Wang Xiaoyu , Yang Yinghui
Published: May 2010

We investigate a well-known algorithm,
Space-Saving
[Metwally et al. 2006], which has been proven efficient and effective at mining frequent elements in data streams. We discovered an error in one of the theorems in Metwally et al. [2006]. Experiments are conducted to illustrate the error.
A hardware/software framework for instruction and data scratchpad memory allocation
Authors: Chen Zhong-Ho , Su Alvin W. Y.
Published: May 2010

Previous researches show that a scratchpad memory device consumed less energy than a cache device with the same capacity. In this article, we locate the scratchpad memory (SPM) in the top level of the memory hierarchy to reduce the energy consumption. To take the advantage of a SPM, we address two issues of utilizing a SPM. First, the program's locality should be improved. The second issue is SPM management. To tackle these two issues, we present a hardware/software framework for dynamically allocating both instructions and data in SPM. The software flow could be divided into three phases: locality improving, locality extraction, and runtime SPM management. Without modifying the original compiler and the source code, we improve the locality of a program. An optimization algorithm is proposed to extract the SPM allocations. At runtime, an SPM management program is employed. In hardware, an address translation logic (ATL) is proposed to reduce the overhead of SPM management.

The results show that the proposed framework can reduce energy delay product (EDP) by 63%, on average, when compared with the traditional cache architecture. The reduction in EDP is contributed by properly allocating both instructions and data in SPM. By allocating only instructions in SPM, the EDPs are reduced by 45%, on average. By allocating only data in SPM, the EDPs are reduced by 14%, on average.
Chameleon
Authors: Woo Dong Hyuk , Fryman Joshua B. , Knies Allan D. , Lee Hsien-Hsin S.
Published: May 2010

Heterogeneous multicore processors have emerged as an energy- and area-efficient architectural solution to improving performance for domain-specific applications such as those with a plethora of data-level parallelism. These processors typically contain a large number of small, compute-centric cores for acceleration while keeping one or two high-performance ILP cores on the die to guarantee single-thread performance. Although a major portion of the transistors are occupied by the acceleration cores, these resources will sit idle when running unparallelized legacy codes or the sequential part of an application. To address this underutilization issue, in this article, we introduce Chameleon, a flexible heterogeneous multicore architecture to virtualize these resources for enhancing memory performance when running sequential programs. The Chameleon architecture can dynamically virtualize the idle acceleration cores into a last-level cache, a data prefetcher, or a hybrid between these two techniques. In addition, Chameleon can operate in an adaptive mode that dynamically configures the acceleration cores between the hybrid mode and the prefetch-only mode by monitoring the effectiveness of the Chameleon cache mode. In our evaluation with SPEC2006 benchmark suite, different levels of performance improvements were achieved in different modes for different applications. In the case of the adaptive mode, Chameleon improves the performance of SPECint06 and SPECfp06 by 31% and 15%, on average. When considering only memory-intensive applications, Chameleon improves the system performance by 50% and 26% for SPECint06 and SPECfp06, respectively.
Evolution in Action: Plants Resistant to Herbicides
Authors: Powles Stephen B. , Yu Qin
Published: May 2010

Modern herbicides make major contributions to global food production by easily removing weeds and substituting for destructive soil cultivation. However, persistent herbicide selection of huge weed numbers across vast areas can result in the rapid evolution of herbicide resistance. Herbicides target specific enzymes, and mutations are selected that confer resistance-endowing amino acid substitutions, decreasing herbicide binding. Where herbicides bind within an enzyme catalytic site very few mutations give resistance while conserving enzyme functionality. Where herbicides bind away from a catalytic site many resistance-endowing mutations may evolve. Increasingly, resistance evolves due to mechanisms limiting herbicide reaching target sites. Especially threatening are herbicide-degrading cytochrome P450 enzymes able to detoxify existing, new, and even herbicides yet to be discovered. Global weed species are accumulating resistance mechanisms, displaying multiple resistance across many herbicides and posing a great challenge to herbicide sustainability in world agriculture. Fascinating genetic issues associated with resistance evolution remain to be investigated, especially the possibility of herbicide stress unleashing epigenetic gene expression. Understanding resistance and building sustainable solutions to herbicide resistance evolution are necessary and worthy challenges.
Abscisic Acid: Emergence of a Core Signaling Network
Authors: Cutler Sean R. , Rodriguez Pedro L. , Finkelstein Ruth R. , Abrams Suzanne R.
Published: May 2010

Abscisic acid (ABA) regulates numerous developmental processes and adaptive stress responses in plants. Many ABA signaling components have been identified, but their interconnections and a consensus on the structure of the ABA signaling network have eluded researchers. Recently, several advances have led to the identification of ABA receptors and their three-dimensional structures, and an understanding of how key regulatory phosphatase and kinase activities are controlled by ABA. A new model for ABA action has been proposed and validated, in which the soluble PYR/PYL/RCAR receptors function at the apex of a negative regulatory pathway to directly regulate PP2C phosphatases, which in turn directly regulate SnRK2 kinases. This model unifies many previously defined signaling components and highlights the importance of future work focused on defining the direct targets of SnRK2s and PP2Cs, dissecting the mechanisms of hormone interactions (i.e., cross talk) and defining connections between this new negative regulatory pathway and other factors implicated in ABA signaling.
Quantitation in Mass-Spectrometry-Based Proteomics
Authors: Schulze Waltraud X. , Usadel Björn
Published: May 2010

Mass-spectrometry-based proteomics, the large-scale analysis of proteins by mass spectrometry, has emerged as a new technology over the last decade and become routine in many plant biology laboratories. While early work consisted merely of listing proteins identified in a given organ or under different conditions of interest, there is a growing need to apply comparative and quantitative proteomics strategies toward gaining novel insights into functional aspects of plant proteins and their dynamics. However, during the transition from qualitative to quantitative protein analysis, the potential and challenges will be tightly coupled. Several strategies for differential proteomics that involve stable isotopes or label-free comparisons and their statistical assessment are possible, each having specific strengths and limitations. Furthermore, incomplete proteome coverage and restricted dynamic range still impose the strongest limitations to data throughput and precise quantitative analysis. This review gives an overview of the current state of the art in differential proteomics and possible strategies in data processing.
Metal Hyperaccumulation in Plants
Authors: Krämer Ute
Published: May 2010

During the history of life on Earth, tectonic and climatic change repeatedly generated large territories that were virtually devoid of life and exhibited harsh environmental conditions. The ability of a few specialist pioneer plants to colonize such hostile environments was thus of paramount ecological importance for the continuous maintenance of primary production over time. Yet, we know very little about how extreme traits evolve and function in plants. Recent breakthroughs have given first insights into the molecular basis underlying the complex extreme model trait of metal hyperaccumulation and associated metal hypertolerance. This review gives an introduction into the hyperaccumulator research field and its history; provides an overview of hyperaccumulator germplasm; describes the state of the art of our understanding of the physiological, molecular, and genetic basis underlying metal hyperaccumulation and its evolution; and highlights future research needs and opportunities.
Genetic and Molecular Bases of Rice Yield
Authors: Xing Yongzhong , Zhang Qifa
Published: May 2010

Grain yield in rice is a complex trait multiplicatively determined by its three component traits: number of panicles, number of grains per panicle, and grain weight; all of which are typical quantitative traits. The developments in genome mapping, sequencing, and functional genomic research have provided powerful tools for investigating the genetic and molecular bases of these quantitative traits. Dissection of the genetic bases of the yield traits based on molecular marker linkage maps resolved hundreds of quantitative trait loci (QTLs) for these traits. Mutant analyses and map-based cloning of QTLs have identified a large number of genes required for the basic processes underlying the initiation and development of tillers and panicles, as well as genes controlling numbers and sizes of grains and panicles. Molecular characterization of these genes has greatly advanced the mechanistic understanding of the regulation of these rice yield traits. These findings have significant implications in crop genetic improvement.
Computational Morphodynamics: A Modeling Framework to Understand Plant Growth
Authors: Chickarmane Vijay , Roeder Adrienne H.K. , Tarr Paul T. , Cunha Alexandre , Tobin Cory , Meyerowitz Elliot M.
Published: May 2010

Computational morphodynamics utilizes computer modeling to understand the development of living organisms over space and time. Results from biological experiments are used to construct accurate and predictive models of growth. These models are then used to make novel predictions that provide further insight into the processes involved, which can be tested experimentally to either confirm or rule out the validity of the computational models. This review highlights two fundamental challenges: (a) to understand the feedback between mechanics of growth and chemical or molecular signaling, and (b) to design models that span and integrate single cell behavior with tissue development. We review different approaches to model plant growth and discuss a variety of model types that can be implemented to demonstrate how the interplay between computational modeling and experimentation can be used to explore the morphodynamics of plant development.
The Regulation of Gene Expression Required for C4Photosynthesis
Authors: Hibberd Julian M. , Covshoff Sarah
Published: May 2010

C4photosynthesis is normally associated with the compartmentation of photosynthesis between mesophyll (M) and bundle sheath (BS) cells. The mechanisms regulating the differential accumulation of photosynthesis proteins in these specialized cells are fundamental to our understanding of how C4photosynthesis operates. Cell-specific accumulation of proteins in M or BS can be mediated by posttranscriptional processes and translational efficiency as well as by differences in transcription. Individual genes are likely regulated at multiple levels. Although cis-elements have been associated with cell-specific expression in C4leaves, there has been little progress in identifying trans-factors. When C4photosynthesis genes from C4species are placed in closely related C3species, they are often expressed in a manner faithful to the C4cycle. Next-generation sequencing and comprehensive analysis of the extent to which genes from C4species are expressed in M or BS cells of C3plants should provide insight into how the C4pathway is regulated and evolved.
Structure and Function of Plant Photoreceptors
Authors: Möglich Andreas , Yang Xiaojing , Ayers Rebecca A. , Moffat Keith
Published: May 2010

Signaling photoreceptors use the information contained in the absorption of a photon to modulate biological activity in plants and a wide range of organisms. The fundamental—and as yet imperfectly answered—question is, how is this achieved at the molecular level? We adopt the perspective of biophysicists interested in light-dependent signal transduction in nature and the three-dimensional structures that underpin signaling. Six classes of photoreceptors are known: light-oxygen-voltage (LOV) sensors, xanthopsins, phytochromes, blue-light sensors using flavin adenine dinucleotide (BLUF), cryptochromes, and rhodopsins. All are water-soluble proteins except rhodopsins, which are integral membrane proteins; all are based on a modular architecture except cryptochromes and rhodopsins; and each displays a distinct, light-dependent chemical process based on the photochemistry of their nonprotein chromophore, such as isomerization about a double bond (xanthopsins, phytochromes, and rhodopsins), formation or rupture of a covalent bond (LOV sensors), or electron transfer (BLUF sensors and cryptochromes).