bluuebunny/crossref_metadata_2025 huggingface dataset:
PR65, the HEAT-repeat scaffold of phosphatase PP2A, is an elastic connector that links force and catalysis
Authors: Grinthal Alison , Adamovic Ivana , Weiner Beth , Karplus Martin , Kleckner Nancy
Published: January 2010

PR65 is the two-layered (α-α solenoid) HEAT-repeat (Huntingtin, elongation factor 3, a subunit of protein phosphatase 2A, PI3 kinase target of rapamycin 1) scaffold of protein phosphatase PP2A. Molecular dynamics simulations predict that, at forces expected in living systems, PR65 undergoes (visco-)elastic deformations in response to pulling/pushing on its ends. At lower forces, smooth global flexural and torsional changes occur via even redistribution of stress along the hydrophobic core of the molecule. At intermediate forces, helix–helix separation along one layer (“fracturing”) leads to global relaxation plus loss of contact in the other layer to unstack the affected units. Fracture sites are determined by unusual sequences in contiguous interhelix turns. Normal mode analysis of the heterotrimeric PP2A enzyme reveals that its ambient conformational fluctuations are dominated by elastic deformations of PR65, which introduce a mechanical linkage between the separately bound regulatory and catalytic subunits. PR65-dominated fluctuations of PP2A have the effect of opening and closing the enzyme’s substrate binding/catalysis interface, as well as altering the positions of certain catalytic residues. These results suggest that substrate binding/catalysis are sensitive to mechanical force. Force could be imposed from the outside (e.g., in PP2A’s response to spindle tension) or arise spontaneously (e.g., in PP2A’s interaction with unstructured proteins such as Tau, a microtubule-associated Alzheimer’s-implicated protein). The presented example supports the view that conformation and function of protein complexes can be modulated by mechanical energy inputs, as well as by chemical energy inputs from ligand binding. Given that helical-repeat proteins are involved in many cellular processes, the findings also encourage the view that mechanical forces may be of widespread importance.
Kenneth Yamada: Exploring the paths of cell migration
Authors: Short Ben
Published: January 2010

The intrepid Yamada has made many discoveries while mapping out cell adhesion and motility.
Immunomodulation of voltage-dependent K+ channels in macrophages: molecular and biophysical consequences
Authors: Villalonga Núria , David Miren , Bielanska Joanna , Vicente Rubén , Comes Núria , Valenzuela Carmen , Felipe Antonio
Published: January 2010

Voltage-dependent potassium (Kv) channels play a pivotal role in the modulation of macrophage physiology. Macrophages are professional antigen-presenting cells and produce inflammatory and immunoactive substances that modulate the immune response. Blockage of Kv channels by specific antagonists decreases macrophage cytokine production and inhibits proliferation. Numerous pharmacological agents exert their effects on specific target cells by modifying the activity of their plasma membrane ion channels. Investigation of the mechanisms involved in the regulation of potassium ion conduction is, therefore, essential to the understanding of potassium channel functions in the immune response to infection and inflammation. Here, we demonstrate that the biophysical properties of voltage-dependent K+ currents are modified upon activation or immunosuppression in macrophages. This regulation is in accordance with changes in the molecular characteristics of the heterotetrameric Kv1.3/Kv1.5 channels, which generate the main Kv in macrophages. An increase in K+ current amplitude in lipopolysaccharide-activated macrophages is characterized by a faster C-type inactivation, a greater percentage of cumulative inactivation, and a more effective margatoxin (MgTx) inhibition than control cells. These biophysical parameters are related to an increase in Kv1.3 subunits in the Kv1.3/Kv1.5 hybrid channel. In contrast, dexamethasone decreased the C-type inactivation, the cumulative inactivation, and the sensitivity to MgTx concomitantly with a decrease in Kv1.3 expression. Neither of these treatments apparently altered the expression of Kv1.5. Our results demonstrate that the immunomodulation of macrophages triggers molecular and biophysical consequences in Kv1.3/Kv1.5 hybrid channels by altering the subunit stoichiometry.
Is High Consumption of Antibiotics Associated with Clostridium difficile Polymerase Chain Reaction–Ribotype 027 Infections in France?
Authors: Birgand Gabriel , Miliani Katiuska , Carbonne Anne , Astagneau Pascal
Published: January 2010

We compared antibiotic consumption between hospitals affected by a strain of Clostridium difficile designated as polymerase chain reaction–ribotype 027 (CD-027) and those unaffected during an outbreak in northern France. The mean consumption of several β-lactams, amikacin, and fluoroquinolones was high in affected hospitals (P<.05). However, only levofloxacin and imipenem remained associated with emerging CD-027 in the multivariate analysis, suggesting that those antibiotics should be better targeted by prevention campaigns.
Rapid formation of electric field profiles in repetitively pulsed high-voltage high-pressure nanosecond discharges
Authors: Ito Tsuyohito , Kobayashi Kazunobu , Czarnetzki Uwe , Hamaguchi Satoshi
Published: January 2010

Rapid formation of electric field profiles has been observed directly for the first time in nanosecond narrow-gap parallel-plate discharges at near-atmospheric pressure. The plasmas examined here are of hydrogen, and the field measurement is based on coherent Raman scattering (CRS) by hydrogen molecules. Combined with the observation of spatio-temporal light emission profiles by a high speed camera, it has been found that the rapid formation of a high-voltage thin cathode sheath is accompanied by fast propagation of an ionization front from a region near the anode. Unlike well-known parallel-plate discharges at low pressure, the discharge formation process at high pressure is almost entirely driven by electron dynamics as ions and neutral species are nearly immobile during the rapid process.
Highly sensitive measurements of the energy transferred during plasma sputter deposition of metals
Authors: Bedra L , Thomann A L , Semmar N , Dussart R , Mathias J
Published: January 2010

This work reports results obtained from heat flux measurements performed during the deposition of metallic thin films by low-pressure plasma sputtering. It introduces a sensitive diagnostic, which allows us to perform such measurements directly during the process and to follow in real-time mechanisms involved in the plasma/surface interaction. Although quantitative results are provided and discussed, the main scope of this paper is a qualitative study of the sputter-deposition process via the energy flux transfers. The diagnostic developed for energy flux measurements is presented and the versatility of the experimental apparatus is described. Results on the study of the deposition of Pt (and Fe) thin films demonstrate a good reproducibility of the measurements and the ability to separate the energetic contribution of the main plasma (∼300 mW cm−2) from the deposition process contribution (2 to 23 mW cm−2). The influence of gas pressure, plasma power and target bias voltage on the energy transferred to the silicon substrate is also studied.
ITER ICRF antenna analysis and optimization using the TOPICA code
Authors: Milanesio D. , Maggiora R.
Published: January 2010

This paper documents the complete analysis and optimization of the ITER ion cyclotron range of frequency (ICRF) launcher using the TOPICA code, carried out in the frame of EFDA design activities.

The possibility to simulate the detailed geometry of an ICRF antenna in front of a realistic plasma description and to obtain the antenna input parameters and the radiated near electric field distribution is of paramount importance to evaluate and predict the overall system performances.

Upon starting from a reference geometry, we pursued a detailed electrical optimization of the IC launcher and we came out with a final geometry showing a remarkable increase in terms of power coupled to plasma. The optimization procedure involved the modification of different parts of the antenna, such as the horizontal septa, the coaxial cables, the coax-to-feeder transitions, the feeders, the strap and the grounding.

Eventually, the optimized geometry has been the object of a comprehensive analysis, varying the working frequency, the plasma conditions and the poloidal and toroidal phasings between the feeding cables. The performances of the antenna have been appreciated not only in terms of input parameters or power coupled to plasma, but also by means of power spectra and with the evaluation of the RF potentials.
Heterofunctionalization catalysis with organometallic complexes of calcium, strontium and barium
Authors: Barrett Anthony G. M. , Crimmin Mark R. , Hill Michael S. , Procopiou Panayiotis A.
Published: January 2010

Despite the routine employment of Grignard reagents and Hauser bases as stoichiometric carbanion reagents in organic and inorganic synthesis, a defined reaction chemistry encompassing the heavier elements of Group II (M = Ca, Sr and Ba) has, until recently, remained unreported. This article provides details of the recent progress in heavier Group II catalysed small molecule transformations mediated by well-defined heteroleptic and homoleptic complexes of the form LMX or MX
2
; where L is a mono-anionic ligand and X is a reactive σ-bonded substituent. The intra- and intermolecular heterofunctionalization (hydroamination, hydrophosphination, hydrosilylation and hydrogenation) of alkenes, alkynes, dienes, carbodiimides, isocyanates and ketones is discussed.
A comparison of the effectiveness of dexmedetomidine versus propofol target‐controlled infusion for sedation during fibreoptic nasotracheal intubation
Authors: Tsai C.‐J. , Chu K.‐S. , Chen T.‐I. , Lu D. V. , Wang H.‐M. , Lu I.‐C.
Published: January 2010

Fibreoptic intubation is a valuable modality for airway management. This study aimed to compare the effectiveness of dexmedetomidine vs target controlled propofol infusion in providing sedation during fibreoptic intubation. Forty patients with anticipated difficult airways and due to undergo tracheal intubation for elective surgery were enrolled and randomly allocated into the dexmedetomidine group (1.0 μg.kg−1 over 10 min) (n = 20) or the propofol target controlled infusion group (n = 20). Intubating conditions and patient tolerance as graded by a scoring system were evaluated as primary outcomes. Intubation was successful in all patients. Satisfactory intubating conditions were found in both groups (19/20 in each group). The median (IOR [range]) comfort score was 2 (1–2 [1–4]) in the dexmedetomidine group and 3 (2–4 [2–5]) in the propofol group (p = 0.027), favouring the former. The dexmedetomidine group experienced fewer airway events and less heart rate response to intubation than the propofol group (p < 0.003 and p = 0.007, respectively). Both dexmedetomidine and propofol target‐controlled infusion are effective for fibreoptic intubation. Dexmedetomidine allows better tolerance, more stable haemodynamic status and preserves a patent airway.
The use of sugammadex in a patient with myasthenia gravis
Authors: Unterbuchner C. , Fink H. , Blobner M.
Published: January 2010

Myasthenia gravis, affecting neuromuscular transmission, leads to a large variability in sensitivity to depolarising and non‐depolarising neuromuscular blocking drugs. We report the successful use of the modified μ‐cyclodextrin sugammadex in a myasthenic patient to reverse a rocuronium‐induced deep level of neuromuscular block. After spontaneous neuromuscular recovery of T2 (second twitch of the train‐of‐four series), we administered 2 mg.kg−1 of sugammadex intravenously, reversing neuromuscular blockade to a train‐of‐four ratio (T4/T1) > 90% within 210 s. Sugammadex, in combination with objective neuromuscular monitoring, can be used to reverse rocuronium‐induced neuromuscular blockade in patients with myasthenia gravis, thereby avoiding the need for reversal with acetylcholinesterase inhibitors.
Growth patterns during childhood and the relationship with acylation‐stimulating protein
Authors: Leunissen R. W. J. , Gao Y. , Cianflone K. , Stijnen T. , Hokken‐Koelega A. C. S.
Published: January 2010

Background/Objectives  Acylation‐stimulating protein (ASP) is an adipose tissue‐derived hormone, which stimulates glucose and free fatty acid (FFA) uptake into adipocytes. Changes in ASP metabolism are associated with alterations in lipid metabolism. As postnatal catch‐up growth has been associated with dyslipidaemia in later life, we investigated the association between ASP and birth size, adult size and different growth patterns during childhood.

Methods  The associations were investigated by multiple regression analyses in 285 young adults, aged 18–24. Subsequently, differences in ASP were analysed in four clinically relevant subgroups, young adults either born small for gestational age with short stature (SGA‐S) or with catch‐up growth (SGA‐CU), or born appropriate for gestational age with idiopathic short stature (ISS) or with normal stature (controls).

Results  Weight gain during childhood, particularly fat accumulation, was positively related to ASP levels in early adulthood, independent of birth size, age and gender. Foetal growth, reflected by birth size, was not related to ASP levels. Between the subgroups, no differences in ASP were found, but SGA‐CU and ISS subjects had significantly higher levels of FFA.

Conclusion  Exaggerated weight gain during childhood, but not foetal growth, contributes to alterations in ASP metabolism, which may be associated with impaired FFA uptake and delayed triglycerides clearance. Therefore, exaggerated weight gain during childhood should be prevented.
AFLP reveals cryptic population structure in migratory European red admirals (Vanessa atalanta)
Authors: BRATTSTRÖM OSKAR , ÅKESSON SUSANNE , BENSCH STAFFAN
Published: January 2010

1. The genetic differentiation in a migratory butterfly, the red admiral (Vanessa atalanta), was investigated to discern patterns of migratory routes used across Europe. AFLP profiles showed significant differences between almost all sampled locations, but there was no clear pattern of isolation‐by‐distance.

2. Using the software STRUCTURE 2.2, we found two distinct genotype clusters present in different frequencies at all study sites. The frequencies of these genotypic clusters varied significantly between years within the same site. Remarkably few individuals were of mixed ancestry, indicating that some isolating mechanisms are present. Twenty‐seven mtDNA haplotypes were identified but they showed no geographic structure, nor were they related to either of the two genotype clusters identified in the AFLP data.

3. Most field observations of migrating red admirals suggest a regular north–south migration pattern in Europe. Our data indicate both long‐distance migration and a more variable pattern in orientation, since the composition of the two genotypic clusters shows dramatic variation between sites and years in the northern part of the distribution range.
Photoperiod affects compensating developmental rate across latitudes in the damselflyLestes sponsa
Authors: ŚNIEGULA SZYMON , JOHANSSON FRANK
Published: January 2010

1. Although there is a great deal of theoretical and empirical data about the life history responses of time constraints in organisms, little is known about the latitude‐compensating mechanism that enables northern populations' developmental rates to compensate for latitude. To investigate the importance of photoperiod on development, offspring of the obligatory univoltine damselflyLestes sponsafrom two populations at different latitudes (53°N and 63°N) were raised in a common laboratory environment at both northern and southern photoperiods that corresponded to the sites of collection.

2. Egg development time was shorter under northern photoperiod regimes for both populations. However, the northern latitude population showed a higher phenotypic plasticity response to photoperiod compared with the southern latitude population, suggesting a genetic difference in egg development time in response to photoperiod.

3. Larvae from both latitudes expressed shorter larval development time and faster growth rates under northern photoperiod regimes. There was no difference in phenotypic plastic response between northern and southern latitude populations with regard to development time.

4. Data on field collected adults showed that adult sizes decreased with an increase in latitude. This adult size difference was a genetically fixed trait, as the same size difference between populations was also found when larvae were reared in the laboratory.

5. The results suggest phenotypic plasticity responses in life history traits to photoperiod, but also genetic differences between north and south latitude populations in response to photoperiod, which indicates the presence of a latitudinal compensating mechanism that is triggered by a photoperiod.
Permeability of receptive fig fruits and its effects on the re‐emergence behaviour of pollinators
Authors: HAO‐YUAN HU , LI‐MING NIU , GUANG‐CHANG MA , YUE‐GUAN FU , ZHENG‐QIANG PENG , DA‐WEI HUANG
Published: January 2010

1. Figs and pollinating fig wasps provide a model system for studying mutualism. The permeability of the syconium changes during receptivity or between seasons, which may affect the behaviour of pollinators. Fig fruits are permeable during receptivity, and in some species, pollinators can enter and re‐emerge after oviposition/pollination. We studied the relationship between fig permeability and pollinator re‐emergence behaviour with a functional dioecious fig, Ficus hispida and the obligate pollinator Ceratosolen solmsi marchali.

2. The relationship reflects the interaction of figs and pollinators in the mutualism and also the conflicts of interests between the two partners: figs benefit from the enclosed fig fruits which have low permeability, but pollinators benefit from their re‐emergence behaviour, which requires high fig permeability.

3. The results showed that at the end of receptivity, the permeability of fig fruits lowered rapidly with changes to the ostiole structures, and re‐emergence rate was low, with more re‐emerging pollinators trapped in the ostiolar bracts. Our results also showed that in the rainy season, the length of receptivity was shorter and fig permeability was lower. The re‐emergence rates were also lower than those in the dry season. The results elucidated that figs' interests dominated in the conflicts between fig and pollinating wasp.

4. Based on a new criteria which employed the classification of pollinators found dead in the ostiolar bracts and which involved a survey of 6 monoecious and 12 dioecious fig species, we found that re‐emergence behaviour was prevalent among fig species, and was more prevalent in functional dioecious figs than monoecious ones.
Weedbeds and big bugs: the importance of scale in detecting the influence of nutrients and predation on macroinvertebrates in plant‐dominated shallow lakes
Authors: BERESFORD ANGELA L. , JONES J. IWAN
Published: January 2010

1. The scale of investigations influences the interpretation of results. Here, we investigate the influence of fish and nutrients on biotic communities in shallow lakes, using studies at two different scales: (i) within‐lake experimental manipulation and (ii) comparative, among‐lake relationships.

2. At both scales, fish predation had an overriding influence on macroinvertebrates; fish reduced macroinvertebrate biomass and altered community composition. Prey selection appeared to be size based. Fish influenced zooplankton abundance and light penetration through the water column also, but there was no indication that fish caused increased resuspension of sediment.

3. There were effects of nutrients at both scales, but these effects differed with the scale of the investigation. Nutrients increased phytoplankton and periphyton at the within‐lake scale, and were associated with increased periphyton at the among‐lake scale. No significant effect of nutrients on macroinvertebrates was observed at the within‐lake scale. However, at the among‐lake scale, nutrients positively influenced the biomass and density of macroinvertebrates, and ameliorated the effect of fish on macroinvertebrates.

4. Increased prey availability at higher nutrient concentrations would be expected to cause changes in the fish community. However, at the among‐lake scale, differences were not apparent in fish biomass among lakes with different nutrient conditions, suggesting that stochastic events influence the fish community in these small and relatively isolated shallow lakes.

5. The intensity of predation by fish significantly influences macroinvertebrate community structure of shallow lakes, but nutrients also play a role. The scale of investigation influences the ability to detect the influence of nutrients on the different components of shallow lake communities, particularly for longer lived organisms such as macroinvertebrates, where the response takes longer to manifest.
Growth patterns of a stream vertebrate differ between urban and forested catchments
Authors: BARRETT KYLE , HELMS BRIAN S. , SAMORAY STEPHEN T. , GUYER C.
Published: January 2010

1. Urban development results in the decline of amphibian density and species richness. A logical next step towards understanding why urbanisation negatively impacts amphibians is to track species‐specific demographic responses to urbanisation.

2. We monitored growth of two‐lined salamander (Eurycea cirrigera Green) larvae over two complete cohorts (2006 and 2007) in nine western Georgia, U.S.A. streams.

3. We found that salamanders in streams surrounded by urbanised and developing catchments hatched at the same size as their reference‐stream counterparts, but achieved larger sizes within the first few months of growth. We evaluated the effect of four variables that correlate with the urban‐forest gradient and found that elevated temperatures in the urban environment, coupled with decreased intraspecific competition because of lower survivorship in these same habitats, were two of the most likely explanations for increased growth rates.

4. Such an increase in growth of surviving larvae may maintain population viability in urban areas where it has been shown survival is difficult because of increased in‐channel flow during flood events. Because larvae that do survive in urban streams undergo metamorphosis at large sizes, they may recoup a component of fitness (i.e. increased adult survivorship and reproduction) through growth.
Fining of red wines with gluten or yeast extract protein
Authors: Iturmendi Nerea , Durán Daniel , Marín‐Arroyo Mª Remedios
Published: January 2010

Due to a growing interest in alternatives to substitute gelatin as clarifying agent, this work investigates the use of yeast extracts and glutens. Physico‐chemical characteristics of proteins were analysed. Fining experiments were carried out on young red wines. Turbidity reduction, lees volume and effects on polyphenolic content and colour characteristics were determined. The results indicated that glutens and yeast extracts turbidity reduction is comparable to gelatin. Lees production was considerably reduced by non‐animal proteins: yeast extracts produced 44%, wheat glutens 60% and maize gluten 92% less than gelatin. Lees volume is highly correlated (R = −0.720) with the absolute superficial charge density value (SCD) and with the pI (0.936) when clarifier was used in combination with bentonite. Treatments with glutens reduced less the polyphenolic content (between 0.6 and 8.7 units) than gelatin did. There were slight differences on the modification of colour intensity.
A novel photochromic time–temperature indicator to support cold chain management
Authors: Kreyenschmidt Judith , Christiansen Henning , Hübner Antonia , Raab V. , Petersen Brigitte
Published: January 2010

A detailed investigation of the behaviour of a new printable photochromic time–temperature indicator (TTI) was conducted to characterise its properties under specific temperature conditions and to analyse the influence of ultra violet (UV) light irradiation (activation) on the discolouration process. The reproducibility of the charging process and the discolouration process of the TTI were analysed. For different charging times the calculated activation energies based on the Arrhenius model ranged from 23.2 to 25.3 kcal mol−1 depending on the UV light irradiation (charging time). A quality contour diagram was established to define the appropriate charging time for different kinds of products. Due to the possibility of defining the shelf life of a TTI by different charging times, this novel TTI constitutes a reliable tool to monitor the cold chains of a broad range of food products on their way from production to consumption.
Antioxidant and antimicrobial activity of pomegranate peel extract improves the shelf life of chicken products
Authors: Kanatt Sweetie R. , Chander Ramesh , Sharma Arun
Published: January 2010

The antioxidant and antimicrobial potential of pomegranate peel and seed extract was investigated. Pomegranate peel extract (PE) showed excellent antioxidant activity while the seed extract (PS) did not have any significant activity. The IC50 value of PE for 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging was 4.9 μg mL–1 while that of Butylated hydroxy toluene was 21.2 μg mL–1, indicating that it was a stronger antioxidant. The efficacy of PE in scavenging hydroxyl and superoxide anion radical was also very high. It also had good reducing power and iron chelation capacity. PE showed good antimicrobial activity against Staphylococcus aureus and Bacillus cereus having minimum inhibitory concentration of 0.01%. Pseudomonas could be inhibited at a higher concentration of 0.1% while it was ineffective against Escherichia coli and S. typhimurium. Addition of PE to popular chicken meat products enhanced its shelf life by 2–3 weeks during chilled storage. PE was also effective in controlling oxidative rancidity in these chicken products.
Effects of off‐vine bunches shading and cryomaceration on free and glycosilated flavours of Malvasia delle Lipari wine
Authors: Piombino Paola , Genovese Alessandro , Gambuti Angelita , Lamorte Simona Antonella , Lisanti Maria Tiziana , Moio Luigi
Published: January 2010

This study evaluated the impact on free and bound volatiles of Malvasia delle Lipari passito wine of two transformation variables at different stages of the winemaking process: different sun exposures of post‐harvested grapes during drying and pre‐fermentative cryomaceration. Wine volatiles were analysed by solid‐phase extraction/GC‐MS (gas‐chromatography/mass spectrometry) and odour by sensory descriptive analysis. The off‐vine bunches dried in shaded conditions (MLsh wine) and juice cryomaceration (6 °C, 12 h) of the dried grapes (MLc wine), both significantly affected the volatiles of Malvasia delle Lipari traditionally produced (MLs wine). The MLsh wine was richest (67%) in free volatiles. Total bound terpenoids had a higher level in the MLsh wine (20%). Total free volatiles of the cryomacerated wine (MLc) were higher (45%) than those of MLs. Total bound volatiles were 36% higher in the cryomacerated sample. Sensory analysis showed that compositional differences of the wine volatiles reflected on their odour character.
Effects of different nitric oxide application on quality of kiwifruit during 20 °C storage
Authors: Zhu Shuhua , Sun Lina , Zhou Jie
Published: January 2010

The effects of fumigating with 0, 10, 20, 30 μL L−1 nitric oxide (NO) gas and dipping in 0.5, 1.0 and 2.0 μmol L−1 NO aqueous solution on quality of kiwifruit (Actinidia Chinensis Planch cv Xuxiang) during storage at 20 °C were evaluated. It was found that fumigating with 20 μL L−1 NO gas and dipping in 1.0 μmol L−1 NO aqueous solution delayed firmness lost and increased SSC/TA ratios of kiwifruits. In comparison with the kiwifruits fumigated with 20 μL L−1 NO, the kiwifruits dipped in 1.0 μmol L−1 NO solution had slower ethylene production, lower contents of soluble solids and malondialdehyde (MDA), higher contents of vitamin C and E, but no significant difference existed in chlorophyll contents. The results suggested that dipping kiwifruits in 1.0 μmol L−1 NO aqueous solution was more effective in maintaining kiwifruits quality during 20 °C storage.
A novel spectrophotometric method for quantitative determination of lactulose in food industries
Authors: Zhang Zhong , Wang He , Yang Ruijin , Jiang Xiaoyan
Published: January 2010

A sensitive and simple spectrophotometric method for quantification of lactulose without interference from aldoses was developed. The method was based on hydrolysis of lactulose under acidic conditions. The hydrolysed product reacts with cysteine hydrochloride‐tryptophon reagent, giving an absorption peak at 518 nm. By following the conditions optimised in this paper, the absorbance value generated by lactose or galactose was far less than that of lactulose of the same amount, suggesting that the interference from aldoses for determination of lactulose could be neglected. The calibration curve was linear in the range of 5–25 μg mL−1 with a correlation coefficient of 0.999. The limit of detection of lactulose at 518 nm was 0.58 μg mL−1. The variation between the results for lactulose (18 μg mL−1) was 1.02%. These facts revealed that the method can be recommended for the quantitative determination of lactulose in case of syrups, biological fluids or dairy products.
Screening of phytochemicals in fresh lamb meat patties stored in modified atmosphere packs: influence on selected meat quality characteristics
Authors: Andrés Nieto Ava Isabel , O’Grady Michael N. , Gutierrez Juan Ignacio , Kerry Joseph P.
Published: January 2010

This study was carried out to determine the antioxidant activity of phytochemicals and plant extracts in fresh lamb patties. Quality indices such as colour (Hunter L* a* b*), lipid oxidation (TBARS) and pH were measured over an 8‐day storage period. Resveratrol, citroflavan‐3‐ol, olive leaf extract and Echinacea purpurea were added to raw minced M. longissimus dorsi lamb patties, at concentrations ranging from 0–400 mg kg−1 lamb meat, stored in high oxygen modified atmospheres packs (75% O2:25% CO2) for up to 8 days at 4 °C. The pH of the lamb meat was not significantly affected by the addition of the phytochemicals and plant extracts examined (P > 0.05). Resveratrol and citroflavan‐3‐ol decreased (P < 0.05) lipid oxidation in raw lamb patties during storage and increased a* values (P < 0.05), relative to controls. By contrast, olive leaf extract and Echinacea purpurea did not exhibit antioxidant activity or promote higher a* values relative to controls. Results obtained demonstrate potential for the development of functional meats using plant extracts such as resveratrol and citroflavan‐3‐ol.
Effect of chill storage under different icing conditions on sensory and physical properties of canned farmed salmon (Oncorhynchus kisutch)
Authors: Rodríguez Alicia , Carriles Nicolás , Aubourg Santiago P.
Published: January 2010

This work focuses the sensory and physical properties of canned farmed coho salmon (Oncorhynchus kisutch); the effect of flake ice and slurry ice as previous slaughter and chilling conditions was studied. Hydrolytic chemical changes related to sensory and physical properties were also evaluated in canned salmon. Thermal treatment led to a canned muscle showing higher firmness, lower cohesivity and colour changes (higher L* and b* values; lower a* values); filling oils showed higher turbidity scores and lower L*, a* and b* values than starting oil. Additionally, oxidised and putrid odour development in canned muscle and filling oil was low. However, previous icing condition and time (up to 9 days) provided no changes in canned muscle and filling oil, except for an increasing oxidised odour and turbidity in filling oil with chilling time. Meantime, free fatty acid formation and K value were markedly affected by previous icing system and time.
Screening of medium composition for the free radical‐scavenging properties by Antrodia cinnamomea
Authors: Yang Ching‐Ting , Kuo Jong‐Tar , Lin En‐Shyh
Published: January 2010

The effects of nutritional conditions on the scavenging capacity on superoxide anion radical and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical of ethanolic extracts from filtrates of Antrodia cinnamomea were investigated in shake‐flask cultures. Culture medium significantly affected inhibition of superoxide anion generation and DPPH free radical scavenging activity. In contrast, both scavenging capabilities on superoxide anion radical and DPPH free radical were found to be greatly affected by varying the carbon source, the nitrogen source, the growth factors or the trace elements. The maximal inhibition of superoxide anion generation could be obtained when the culture medium compositions were: xylose, ammonium oxalate, nicotinic acid, NaH2PO4 and CuSO4; while a maximal DPPH free radical scavenging activity could be achieved when the medium composition setting as: fructose, peptone, nicotinic acid, KH2PO4 and CaCl2 (the scavenging effects on superoxide anion radical and DPPH free radical were increased to 96.3 ± 0.3% and 29.0 ± 1.0%, respectively). We proved that controlling the culturing conditions and modifying the composition of the medium can dramatically enhance the scavenging ability on superoxide anion radical and DPPH free radical of A. cinnamomea.
Effects of harvest time on the quality attributes of processed and non‐processed tomato varieties
Authors: Akbudak Bulent
Published: January 2010

This study examines physicochemical changes in newly developed and existing tomato varieties at different levels of maturity. Serum viscosity is an important factor in the selection of tomato varieties for processing. Most of the attributes indicative of quality for fresh and paste tomatoes occurred at a less mature stage and declined with maturity. The canned varieties ‘H9888,’‘H8892’ and ‘H9780’ had a greater ascorbic acid content and antioxidant capacity. The highest lycopene contents were found in the varieties ‘H9888,’‘CXD254,’‘CXD222’ and ‘H9780’. Total soluble solids levels increased with maturity. The highest acidity values occurred in canned ‘Shasta’, ‘CXD254’ and ‘H9780’ varieties. Mid‐ and late‐season varieties harvested at an early stage produced thicker pastes with greater serum viscosity and acidity than tomatoes harvested at other points in the ripening process. The best results were obtained from canned samples of ‘H9888,’‘CXD254’ and ‘H9780.’
Quality changes of fish burgers prepared from deep flounder (Pseudorhombus elevatus Ogilby, 1912) with and without coating during frozen storage (−18 °C)
Authors: Mahmoudzadeh Maryam , Motallebi Abbasali , Hosseini Hedayat , Khaksar Ramin , Ahmadi Hamed , Jenab Ehsan , Shahraz Farzaneh , Kamran Manijeh
Published: January 2010

In the present study, chemical and sensory qualities of fish burgers prepared from deep flounder (Pseudorhombus elevatus Ogilby, 1912) with and without coating (Group A and Group B, respectively) or batter and breading materials were determined during frozen storage at −18 °C for 5 months. According the statistical results, Total volatile base nitrogen of two groups increased significantly (P < 0.05) but a significant decrease (P < 0.05) was observed at the third month for Group A. Thiobarbituric acid value of Group A decreased significantly (P < 0.05) with the storage time from 1.01 to 0.22, whereas a significant increase (P < 0.05) was observed for Group B from 0.15 to 0.62 at the end of storage time. There were significant differences of pH in either the Group A or Group B between the beginning and end of the storage periods (P < 0.05). Parameters of colour, texture, taste and general acceptability for two groups decreased (P < 0.05) but Group B indicated better scores than Group A at the end of the storage period.
Viscoelastic properties and pasting characteristics of fermented maize: influence of the addition of malted cereals
Authors: Afoakwa Emmanuel Ohene , Adjonu Randy , Asomaning Justice
Published: January 2010

Investigations were conducted on the viscoelastic properties and pasting characteristics of fermented maize with malted cereals and their suitability for infant feeding. A 3 × 3 × 2 factorial experimental design with malting time, cereal malt concentration and cereal type was used. Maize, millet, and sorghum malts were added to fermented maize to reducing its bulk density. Samples were analysed for their viscoelastic properties and pasting characteristics using Brabender Viscoamylograph. Sorghum malt in comparison to millet and maize malts was not effective in terms of lowering the hot and cold paste viscosities of the fermented maize. Maize and millet malts liquefied the dough considerably during both the hot and cold paste viscosities. The effect of 4‐day malted millet was most pronounced whilst the highest activity of maize malt was observed with the 3‐day malted flours. The addition of maize and millet malts to fermented maize were most effective in lowering the viscoelastic properties of the resulting porridges.
Antimicrobial and antioxidant activity of crude onion (Allium cepa, L.) extracts
Authors: Santas Jonathan , Almajano María Pilar , Carbó Rosa
Published: January 2010

Antioxidant and antimicrobial activity of the ethyl acetate and water subfractions of methanolic extracts of three Spanish onion varieties were assayed. Flavonoids were mainly present in ethyl acetate subfraction being 34.92 ± 0.75, 7.95 ± 0.16, 0.38 ± 0.01 μmol of rutin eq. g−1 D.W. and its antioxidant capacity was 74.86 ± 1.77, 24.59 ± 0.67, 4.55 ± 0.44 μmol Trolox g−1 D.W. of Grano de Oro, Fuentes de Ebro and Calçot de Valls varieties, respectively. The antimicrobial activity of flavonol standards and onion extracts was evaluated against some food spoiler microorganisms. Quercetin and kaempferol were inhibitory against gram positive bacteria such as Bacillus cereus, Staphylococcus aureus, Microcroccus luteus and Listeria monocytogenes. Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa were less sensible to the antimicrobial effect of both flavonol standards and Candida albicans was totally resistant. Among the onion extracts tested only ethyl acetate subfraction showed antimicrobial inhibition.
Mobile guide system using problem‐solving strategy for museum learning: a sequential learning behavioural pattern analysis
Authors: Sung Y.‐T. , Hou H.‐T. , Liu C.‐K. , Chang K.‐E.
Published: January 2010

Mobile devices have been increasingly utilized in informal learning because of their high degree of portability; mobile guide systems (or electronic guidebooks) have also been adopted in museum learning, including those that combine learning strategies and the general audio–visual guide systems. To gain a deeper understanding of the features and limitations of these guide systems in a museum‐learning context and also to provide new designs that better guide learners in interacting with peers and exhibitions, in‐depth exploration of learners' actual visits and analyses of their behavioural patterns is crucial. This study was based on empirical observation and analysis of the learning behaviours (recorded on video) of 65 elementary‐school students who were placed into three groups: mobile guide with problem‐solving strategy, audio–visual mobile guide and paper‐based learning‐sheet guide. By coding and analysing the video and conducting sequential analysis and frequency analysis of learning‐related discussion content, behavioural interaction patterns were determined by which the features and limitations of the different types of guides were compared. Among the findings, it was discovered that the students in the problem‐solving mobile guide group showed a higher level of two‐way interactions with their peers and the exhibits, as well as more learning‐related discussions. Relevant suggestions for teachers, researchers and guide‐systems developers are also given.
Demographic effects of extreme weather events on a short‐lived calcareous grassland species: stochastic life table response experiments
Authors: Davison Raziel , Jacquemyn Hans , Adriaens Dries , Honnay Olivier , De Kroon Hans , Tuljapurkar Shripad
Published: January 2010

1. Life table response experiment (LTRE) analyses have been widely used to examine the sources of differences in the long‐term deterministic growth rate (r = log λ) of stage‐structured populations that live in spatially distinct habitats or under distinct experimental conditions. However, existing methods for LTRE analysis ignore the fact that persistent temporal variation in matrix elements results in a long‐term stochastic growth rate (a = log λs) that is different from the deterministic growth rate (r) and thus do not take into account environmental stochasticity.

2. Here, we develop a stochastic extension of LTRE methods that can be used to compare stochastic growth rates among populations that differ in the observed variability of their matrix elements over time. We illustrate our method with actual data and explore a range of questions that may be addressed with these new tools. Specifically, we investigate how variability in weather conditions affected the population dynamics of the short‐lived perennial plant species Anthyllis vulneraria and examine how differences in stochastic growth rates (a) are determined by contributions of mean matrix elements and variability in matrix elements.

3. We find that, consistent with the life history of the species, differences in mean fertility and growth made the largest contribution to differences in a, whereas in terms of variability fertility made the largest contribution in most populations. However, we also find that in all populations, the magnitude of the total contribution of mean matrix elements outweighed that of variability. Finally, increasing soil depth significantly lowered contributions of variability in matrix elements, but it was not related to contributions of differences in mean matrix elements.

4.
Synthesis. Stochastic life table response experiment analysis described here provides the first systematic way of incorporating observed differences in temporal variability into the comparison of natural populations. A key finding from this study is that populations occurring on relatively deeper soils were better buffered against climatic variation than populations occurring on shallow soils. We expect this new approach to analyse temporal variability to prove especially useful in the analysis of natural populations experiencing environmental change.
Keeping plant shrinkage in the demographic loop
Authors: Salguero‐Gómez Roberto , Casper Brenda B.
Published: January 2010

1. Plant demographers using matrix tools have paid special attention to vital rates of reproduction, growth and survival. The demographic implications of plants regressing in size, or shrinking, have been overlooked. Shrinkage has either been ignored during demographic censuses or lumped with other demographic processes such as stasis or growth under the assumption that they have similar demographic effects.

2. We carried out a comparative prospective analysis using classical vital rate elasticities in size‐based projection matrices of 80 herbaceous perennial species. We analysed the correlations of the elasticities of each demographic vital rate with the demographic life‐history traits (life span, population growth rate, etc.).

3. We also conducted a comparative loop analysis to understand the effects of shrinkage on demographic parameters linked to size plasticity. We classified loops into ‘recruitment’ (growth that contributes to reproduction), ‘size plasticity’ (where individuals fluctuate in size) and ‘size rigidity’ (no change in size class), and used them as the basis to explain ecological characteristics of the species.

4. Our results with classical vital rates demonstrate that considering shrinkage as a separate vital rate increases our understanding of factors that contribute to demographic equilibrium (e.g. minimized departure from population growth rate at equilibrium) and buffering (e.g. higher speed of recovery after disturbance), and to reproductive strategies (e.g. mean age of parents of offspring).

5. The loop analysis results support the findings with vital rate analyses and also reveal new patterns: high growth rates are not exclusively dominated by high elasticities of recruitment, but also by size‐plastic loops, and long‐lived species experience a marginal increase in the demographic importance of size plasticity.

6.

Synthesis. This study illustrates the necessity for exploring individual demographic vital rates, as opposed to grouping them, to advance our understanding of how different biological processes affect population dynamics. Shrinkage is demographically important because it aids in demographic buffering, increases survival and is related to maintenance–reproduction trade‐offs. However, shrinkage cannot be fully explored only with traditional elasticity approaches; because shrinkage for some species is a fundamental plastic trait, its importance is more appropriately captured with loop analyses.
Difference in genes between a high virulence strain G4 and a low virulence strain G18 of Flavobacterium columnare by using suppression subtractive hybridization
Authors: Li N , Zhang J , Zhang L Q , Nie P
Published: January 2010

Flavobacterium columnare is the causative agent of columnaris disease. Different genetic groups of F. columnare show to some extent different degrees of virulence. To identify genetic differences between the high virulence strain G4 and the low virulence strain G18 of F. columnare, suppression subtractive hybridization was used. A total of 46 genes were identified from the virulent strain G4, 35 of which showed some degree of homology with known proteins and can be classified into 11 categories: DNA replication or recombination proteins, inorganic ion transport proteins, outer membrane proteins, enterotoxin, binding proteins, YD repeat proteins, transposase, chaperon, signal transduction‐related proteins, regulatory proteins, metabolism‐related proteins. Several putative virulence factors identified in other bacteria could also be identified in the virulent strain G4, such as ferrous iron transport protein, TonB‐dependent receptor, transposases, as well as ABC transporter permease protein. The flanking region of a putative transposase ISFclI was analysed, and a putative Rhs element was located at the downstream of the putative transposase. The analysis of isfclI gene in 24 strains of F. columnare isolated in China revealed that 11 strains have isfclI, and all the strains from Zhaoqing, Anhui and Qingjiang have isfclI.