bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability of α‐Linolenic Acid and Secoisolariciresinol Diglucoside in Flaxseed‐Fortified Macaroni
Authors: Hall Clifford A. , Manthey Frank A. , Lee Robert E. , Niehaus Mary
Published: February 2009

Research was conducted to determine the stability of secoisolariciresinol diglucoside (SDG) and α‐linolenic acid (ALA) in flaxseed‐fortified macaroni. Macaroni was fortified with whole ground flaxseed (GWF) at levels of 10% to 20% and then dried under low temperature (LT, 40°C), high temperature (HT, 70°C), or ultrahigh temperature (UHT, 90°C). Macaroni was also fortified with 15% ground hull (GHF) or steam‐treated whole ground flaxseed (GSWF) and dried under UHT. The dried macaroni was stored for 32 wk under ambient conditions. Approximately 80% to 95% of the SDG was recovered, indicating that SDG was stable during the 32‐wk storage period. Total lipid and ALA levels in all flaxseed macaroni treatments remained unchanged throughout the 32‐wk storage. This observation was consistent across the drying conditions and flaxseed addition levels. Conjugated diene (CD) values indicated that macaroni fortified with GWF did not oxidize significantly during the 32‐wk storage for the macaroni dried under HT or UHT. However, a significant increase (P <0.05) in CD values for macaroni containing 10% and 20% flaxseed and dried using LT was observed at the 32‐wk storage period. Headspace volatile concentrations did increase over the storage period for macaroni containing GWF, but the increase was not significant. Significant increases (P < 0.05) in oxidation were found by 24 wk in GHF‐ and GSWF‐fortified macaroni. GWF macaroni dried at UHT, HT, or LT could be used as a way to improve our dietary consumption of ALA and SDG. However, use of steam as a method to inactivate unwanted enzyme activity is not recommended.
Detection of Fecal Contamination on Cantaloupes Using Hyperspectral Fluorescence Imagery
Authors: Vargas Angela M. , Kim Moon S. , Tao Yang , Lefcourt Alan M. , Chen Yud‐Ren , LUO Yaguang , SONG Yoonseok , Buchanan Robert
Published: February 2009

To determine whether detection of fecal contamination on cantaloupes is possible using fluorescence imaging, hyperspectral images of cantaloupes artificially contaminated with a range of diluted bovine feces were acquired from 425 to 774 nm in responses to ultraviolet‐A (320 to 400 nm) excitation. Evaluation of images at emission peak wavelengths indicated that 675 nm exhibited the greatest contrast between feces contaminated and untreated surface areas. Two‐band ratios compared with the single‐band images enhanced the contrast between the feces contaminated spots and untreated cantaloupe surfaces. The 595/655‐nm, 655/520‐nm, and 555/655‐nm ratio images provided relatively high detection rates ranging from 79% to 96% across all feces dilutions. However, both single band and ratio methods showed a number of false positives caused by such features as scarred tissues on cantaloupes. Principal component analysis (PCA) was performed using the entire hyperspectral images data; 2nd and 5th principal component (PC) image exhibited differential responses between feces spots and false positives. The combined use of the 2 PC images demonstrated the detection of feces spots (for example, minimum level of 16‐μg/mL dry fecal matter) with minimal false positives. Based on the PC weighing coefficients, the dominant wavelengths were 465, 487, 531, 607, 643, and 688 nm. This research demonstrated the potential of multispectral‐based fluorescence imaging for online applications for detection of fecal contamination on cantaloupes.
Effects of High Pressure on Texture and Microstructure of Sea Bass (Dicentrarchus labrax L.) Fillets
Authors: Chéret Romuald , Chapleau Nicolas , Delbarre‐Ladrat Christine , Verrez‐Bagnis Véronique , Lamballerie Marie de
Published: February 2009

High pressure is an innovative non‐thermal food‐preservation technology. We studied the effect of high‐pressure treatment up to 500 MPa for 5 min on physical characteristics of sea bass fillets after 0, 7, and 14 d of refrigerated storage. Color results exhibited an increase of lightness and a slight change of hue, which might be imperceptible in cooked fish. High‐pressure treatment induced a decrease of exudation and water‐holding capacity. Pressure treatment above 300 MPa provoked higher fish hardness after storage than in untreated sample, proving the ability of high pressure to improve textural quality of chilled, stored fish fillet. These assessments were corroborated with microstructure observations. We showed that high‐pressure treatment at 500 MPa allowed, after 7 d of storage, a total aerobic count equivalent to that of untreated fresh fish fillet to be obtained. Thus, high pressure might be considered to be a technology able to improve safety and textural quality of fresh fish fillets.
Effect of Near‐infrared Radiation and Jet Impingement Heat Transfer on Crust Formation of Bread
Authors: Olsson E.E.M. , Trägårdh A.C. , Ahrné L.M.
Published: February 2009

Rapid heat transfer methods can be used to speed up the baking process and create new product properties. This study investigates the effect of air jet impingement and infrared radiation (alone or in combination) on crust formation of par‐baked baguettes during post‐baking. The parameters investigated are crust color, crust thickness, total water loss, and heating time. The results show that infrared radiation and jet impingement, as compared with heating in a conventional household oven, increased the rate of color development of the crust and shortened the heating time. The fastest color development was obtained by combining infrared and impingement heating. The water loss rate was increased due to the high heat transfer rate, but the total water loss was reduced because of the shorter heating time. Crust thickness was most dependent on heating time and crust temperature. In general, the crust was thinner for infrared‐heated baguettes.
Production of Cocoa Butter Microcapsules Using an Electrospray Process
Authors: Bocanegra Rodrigo , Gaonkar Anikumar G. , Barrero Antonio , Loscertales Ignacio G. , Pechack David , Marquez Manuel
Published: February 2009

An experimental approach to the production of cocoa butter microcapsules containing an aqueous solution or an oil‐in‐water emulsion via electrified coaxial jets is presented here. Recently, a new method to generate nano‐micrometric coaxial jets has been reported. These coaxial jets are generated by electrohydrodynamic forces with diameters that range from hundreds of nanometers to tens of microns. The controlled break‐up of the jets gives rise to an aerosol of compound droplets in which an outer liquid coats an inner one. This technique has turned out to be an effective method to encapsulate aqueous‐based food ingredients such as flavors, aromas, enzymes, salts, minerals, and vitamins in the micrometric range with relatively high monodispersity and controllable geometrical parameters of the capsules such as thickness of the shell or number of inner cores in the capsules.
Retail Shelf‐Life of Pork Dipped in Organic Acid before Modified Atmosphere or Vacuum Packaging
Authors: Huang Nai‐Yun , Ho Chung‐Ping , McMillin Kenneth W.
Published: February 2009

Modified atmosphere packaging (MAP) is increasingly popular for meat, but raw, chilled pork in vacuum or anoxic environments has a purple color. The retail shelf‐life of pork chops dipped in 500 ppm ascorbic acid, 250 ppm citric acid, or no acid dip and stored at 1 °C before simulated retail display in MAP with gas exchange or air‐permeable packaging after vacuum pouch storage was determined. The 80% N2:20% CO2 in MAP was exchanged with 80% O2:20% CO2, and chops were removed from vacuum packages and overwrapped with permeable film (VP‐PVC) on the 7th day before simulated retail display at 4 °C. Shelf‐life traits were determined at 1, 7, 8, 10, 12, and 14 d postpackaging. The pH values changed with time, but returned to post‐dipped, prepackaged levels at the end of simulated retail storage. Weight loss of chops increased (P < 0.05) in VP‐PVC compared with MAP. The a* values increased (P < 0.05) and L* and b* values decreased during simulated retail display, with higher L*, a*, and b* color values for chops in MAP than VP‐PVC. Log numbers of psychrotrophic microorganisms were higher (P < 0.05) on VP‐PVC samples than for chops in MAP on days 12 and 14. Psychrotrophic counts on ascorbic acid‐treated samples were decreased compared with citric acid or no dipping on pork during simulated retail display. Pork chops in MAP with gas exchange had lighter and redder color, increased weight retention, decreased psychrotrophic counts, and increased lipid oxidation compared with conventional vacuum and overwrap packaging systems.
Resistance of Lactobacillus casei KCTC 3260 to Reactive Oxygen Species (ROS): Role for a Metal Ion Chelating Effect
Authors: Lee Jeongmin , Hwang Kwon‐Tack , Chung Min‐Young , Cho Dong‐Hyeok , Park Chang‐Soo
Published: February 2009

The antioxidative capacity of 4 Lactobacillus strains, isolated from a milk product, was evaluated by measuring total antioxidative ability (TAA) and resistance to reactive oxygen species (ROS). Both intact cells and intracellular cell‐free extracts of Lactobacillus casei KCTC 3260 demonstrated the highest antioxidative activity and inhibited lipid peroxidation by 46.2% and 72.9%, respectively. To evaluate the resistance of 4 Lactobacillus strains to ROS, we tested the survival under conditions of 1 mM hydrogen peroxide, 0.4 mM hydroxyl radicals, and 10 mM paraquat‐induced superoxide anions. L. casei KCTC 3260 was viable even after 8 h in the presence of 1 mM hydrogen peroxide and after 7 h in 0.4 mM hydroxyl radicals. Moreover, this strain was not influenced by superoxide anions, indicating that it has resistance to superoxide anions. To define the antioxidative mechanism, superoxide dismutase (SOD) and metal ion chelating activity were determined. All tested strains did not possess detectable SOD activity except Lactobacillus rhamnosus GG, but L. casei KCTC 3260 had the higher level of chelating activity for both Fe2+ and Cu2+ ions at 10.6 ppm and 21.8 ppm, respectively. These results suggested that the antioxidative capacity of L. casei KCTC 3260 may be caused by chelating metal ions instead of SOD activation.
Methods for Detecting Botulinum Toxin with Applicability to Screening Foods Against Biological Terrorist Attacks
Authors: Scarlatos Amber , Welt Bruce A. , Cooper Brian Y. , Archer Douglas , DeMarse Thomas , Chau Khe V.
Published: February 2009

Seven serologically related, but antigenically different, botulinum toxins (BoNTs) have been identified including types A, B, C, D, E, F, and G. The bacterium Clostridium botulinum along with some strains of Clostridium baratti and Clostridium butyricum are known to produce botulinum toxins responsible for 4 forms of botulism poisoning including food‐borne botulism, inhalation botulism, wound botulism, and infant botulism. Botulism toxins consist of a heavy chain (100 kDa), responsible for binding to target cells, and a light chain (50 kDa) responsible for catalytic protein cleaving activity. Light chain has been identified as a zinc endopeptidase that cleaves proteins forming the synaptic vesicle docking and fusion complex (Simpson 1996; Lacy and Stevens 1997). The standard for detection of BoNT toxins is the mouse bioassay, which is able to detect as little as 0.02 ng of toxin. Strengths of the mouse bioassay include conceptual simplicity and sensitivity. While the non‐selectivity of the mouse bioassay enables it to detect any BoNT serotype, additional neutralization assays are necessary to determine serotype. Other limitations of the mouse bioassay include expense, expertise related to maintaining mouse‐rearing facilities, and time, because as much as 4 d may be required to obtain results (Hallis and others 1996; Witcome and others 1999). Several attempts to replace the mouse bioassay have been made. Methods that have been developed and hold promise for future replacement of the mouse bioassay include mass spectroscopy, immunoassays, polymerase chain reaction (PCR) assays, and assays based upon protease activities of BoNTs. Currently, no single assay appears to be capable of replacing the broadly applicable mouse bioassay.
Silicon Content of Italian Mineral Waters and Its Contribution to Daily Intake
Authors: Giammarioli Stefania , Mosca Maurizio , Sanzini Elisabetta
Published: February 2009

Dietary intake is the main source of silicon for humans. The essentiality of silicon for man has not been clearly established, and no suitable data are available for the establishment of a tolerable upper intake level. Recently, a few cases of silica stones in subjects not ingesting trisilicate antacid have been reported, as well as 1 case of renal silica calculi in a 10‐mo‐old boy, ascribed to the silicate‐rich mineral water used to dilute milk. The purpose of this study was to collect extensive data on the silicon content of mineral water that could be combined with data on different foods to study the overall intake of silicon in the diet and to evaluate the potential risk associated with a high intake of this element. Results relating to 207 brands of mineral water show a low silicon concentration (<10 mg/L) in 77% of samples, with the highest levels (>25 mg/L) occurring primarily in water from volcanic areas. The contribution of mineral water to the total consumption of silicon was calculated, considering both the average intake of water by the Italian population and the recommended intake. When the estimated daily intake with solid foods and other beverages was added, the intake was in the range of 45 to 69 mg/d for a consumption of 700 mL of water and 48 to 99 mg/d for a consumption of 1500 mL of water. These values are near or above the upper limit of the typical dietary intake of 20 to 50 mg silicon/d, which is regarded as unlikely to cause adverse effects. The assumption of silicon by newborns deserves particular attention, in view of their special sensitivity and of a reported case of urinary silica calculi in an infant. The levels of silicon we found never reached the value found in the case described.
Formula Optimization of a Low‐fat Food System Containing Whey Protein Isolate‐ Xanthan Gum Complexes as Fat Replacer
Authors: Laneuville Sandra I. , Paquin Paul , Turgeon Sylvie L.
Published: February 2009

Whey protein isolate‐xanthan gum complexes (WPXC) have the potential to significantly reduce fat use in various products. However, their stability and functionality have not been extensively studied, particularly in neutral pH products. The objective of this study was to evaluate WPXC as a fat replacer in cake frostings and sandwich cookie fillings with reduced‐fat content (160 or 80 g/kg fat). Response surface methodology was used to analyze the effect of WPXC on the viscosity and textural response attributes of samples and to optimize the low‐fat formulations. It was found that WPXC had a positive effect (P > 0.001), providing acceptable viscosity and texture attributes to the low‐fat samples. A significant moisture‐WPXC interaction (P > 0.001) revealed that the optimum moisture‐WPXC ratio varied, depending on the targeted texture. This ratio was about 8:1 for cake frostings and about 5:1 for sandwich cookie fillings. Optimal formulations were found, and samples meeting the desirability specifications presented textural and melting profiles similar to those of the control products. However, for the production of sandwich cookie fillings, the use of other ingredients (for example humectants and emulsifiers) must be considered to maintain a low water activity (Aw) and prevent moisture migration to the cookie shell.
Hypocholesterolemic Action of Fermented Brown Rice Supplement in Cholesterol‐Fed Rats: Cholesterol‐lowering Action of Fermented Brown Rice
Authors: Hee Seung , Park Baek Soojin , Lee Hyeon Gyu
Published: February 2009

Fermented rice products have been implicated in vascular injury and atherosclerosis in recent animal and human studies. In the current study, whether consumption of differently processed brown rice diets may change the cholesterol metabolism was evaluated in male Spraque Dawley (SD) rats after 28 d of treatment with diets containing 1% cholesterol. The experimental diets include corn starch alone as control diet (CO) or a diet containing a 50% substitute of CO; uncooked brown rice (UB), cooked brown rice (CB), lactic acid bacteria (LAB), brown rice mixed with LAB (BLAB), and fermented‐brown rice by LAB (FB), respectively. Among them, FB group elicited significantly lower levels of plasma and hepatic triglycerides, plasma total cholesterol, low‐density lipoprotein cholesterol (LDL‐C), and very low‐density lipoprotein cholesterol (VLDL‐C) by 33% to 50%, whereas higher levels of HDL‐C were elicited by 227% compared with the CO group (P < 0.05). These amelioration action on lipid profile in FB group appeared to correspondent to the higher excretions of fecal weight, triglyceride (TG), total cholesterol (TC), and bile acid (P < 0.05). Furthermore, sensory properties such as flavor liking, taste liking, and overall acceptability of the diet were significantly improved by the addition of fermented brown rice. Conclusively, fermented‐brown rice may have a potent cholesterol‐lowering benefits with sensory quality improvement of the diet.
Simultaneous Optimization of a Multi‐response System by Desirability Function Analysis of Boondi‐making: A Case Study
Authors: Ravi Ramasamy , Susheelamma N.S.
Published: February 2009

Response surface methodology (RSM) was used to investigate the influence of 3 important independent processing variables–batter concentration (36% to 44%), frying temperature (160 °C to 200 °C), frying time (180 to 300 s)–on the various quality characteristics of the fried chickpea batter balls calledboondi. Instrumental color parametersL,a b, and tan‐1(b/a), oil content, and sensory attributes like color, oily appearance, uniformity of boondi, crumbliness, and overall quality (OQ) were measured and used as response variables. The effects of the processing variables of frying were studied by adopting a standard Central Composite Rotatable (CCR) experimental design. The response variables were fitted to predictive quadratic polynomial models using multiple regression. Applying the desirability function analysis (DFA), optimal‐quality boondi was obtained with a maximum overall quality score of 12.7 on a 15‐cm quantitative descriptive analysis (QDA) scale, when the batter concentration, frying temperature, and frying time were 40.4%, 182 °C, and 240 s, respectively.
Determination of Sensory Thresholds of Selected Calcium Salts and Formulation of Calcium‐fortified Pocket‐type Flat Bread
Authors: Ziadeh Ghada , Shadarevian Sossy , Malek Amal , Khalil Joanna , Haddad Tharwat , Haddad John , Toufeili Imad
Published: February 2009

Pita bread loaves were prepared from flours fortified with calcium carbonate, calcium sulfate, and tricalcium dicitrate at 8 ascending levels to provide ranges of 800 to 2500, 700 to 1500, and 400 to 2000 mg of added Ca/100 g flour, respectively. The detection thresholds of calcium salts in pita bread were determined by the 3‐alter‐native forced choice (3‐AFC) test and construction of dose‐response curves. Detection thresholds determined by calculating geometric mean of individual best estimate thresholds, using criterion of 50%‐above‐chance and probit analysis of 3‐AFC data, were in the middle region of calcium concentrations. Analysis of dose‐response curves yielded values for thresholds outside the range of surveyed calcium concentrations. The detection threshold of CaSO4(2724 mg/100 g) in pita bread was significantly higher (P < 0.01) than those of calcium carbonate (1984 mg/100 g) and tricalcium dicitrate (2132 mg/100 g). Calcium‐fortified pita bread was similar (P<0.01) to its regular counterpart when formulated to contain 1254.6, 1772.5, or 1155 mg/100 g of CaCO3, CaSO4, or tricalcium dicitrate, respectively. At the indicated levels of fortification, calcium‐fortified pita bread is expected to provide between 61% and 126.5% of the recommended daily intake for calcium for Middle Eastern populations.
Labeling of Vanilla Type Affects Consumer Perception of Vanilla Ice Cream
Authors: Parker April R. , Penfield Marjorie P.
Published: February 2009

The effects of labeling vanilla type on consumer liking of vanilla ice cream were evaluated. Three experiments with 144 to 150 panelists using 4 commercial ice creams were done where the samples were initially not labeled with the type of vanilla flavoring, then labeled, and finally labeled either correctly or incorrectly. Three experiments (116 to 150 panelists) then were conducted similarly for 3 laboratory‐made ice creams. When the 4 commercial samples were not labeled, a natural vanilla‐flavored sample was liked less (P < 0.05) than mixed‐flavored samples overall; when labeled, the naturally flavored and 1 of the mixed‐flavor ice creams were liked equally overall (P > 0.05). Products labeled “natural” (correctly or incorrectly) were liked more (P < 0.05) overall than products with other labels. When laboratory‐made ice creams (natural, artificial, mixed flavored) were evaluated, the labeled, naturally flavored sample was liked more than the unlabeled sample overall; when labeled, the artificially flavored ice cream was liked less than the unlabeled sample. Labeling was shown to affect consumer liking.
Production of an Isoflavone Concentrate from Red Clover Flowers
Authors: Xu Lei , Kumar Ashwani , Lamb Karen , Layton Linda
Published: February 2009

Red clover flowers are a rich source of isoflavones in the forms of biochanin A, formononetin, genistein, and genistin. A simple process was developed to recover isoflavones from red clover flowers as a nutraceutical product. Isoflavones were 1st extracted in alkaline water and insoluble polyvinylpolypyrrolidone (PVP) was then added to the extract for adsorbing isoflavones. The adsorbed isoflavones were subsequently eluted with ethanol and dried. The main steps of this process were optimized for the product yield and quality. The final product was an isoflavone concentrate, containing more than 20 wt% isoflavones, which represented a recovery of greater than 50% of the total isoflavone amount in red clover flowers.
Behavioural phenotype in Börjeson‐Forssman‐Lehmann syndrome
Authors: De Winter C. F. , Van Dijk F. , Stolker J. J. , Hennekam R. C. M.
Published: February 2009

Background  Börjeson‐Forssman‐Lehmann syndrome (BFLs) is an X‐linked inherited disorder characterised by unusual facial features, abnormal fat distribution and intellectual disability. As many genetically determined disorders are characterised not only by physical features but also by specific behaviour, we studied whether a specific behavioural phenotype exists in BFLs.

Methods  We studied in detail the behaviour of four molecularly proven BFLs patients, and reviewed available literature on BFLs specifically for behavioural characteristics.

Results  Behaviour in persons with BFLs is in general friendly, but can be challenging with externalising and thrill‐seeking features. Social skills are good. However, variation among patients is wide. Three patients from a single family showed expressed hypersexual behaviour. This was not present in other patients.

Conclusion  In BFLs a specific behavioural phenotype exists and in behaviour general is challenging besides a friendly habit. Within single families more problematic behaviour may occur. Further behavioural and molecular analysis of a larger group of patients is warranted to determine whether a genotype‐behavioural phenotype correlation exists.
Differential expression of a virulence factor in pathogenic and non‐pathogenic mycobacteria
Authors: Houben Edith N. G. , Walburger Anne , Ferrari Giorgio , Nguyen Liem , Thompson Charles J. , Miess Christian , Vogel Guido , Mueller Bernd , Pieters Jean
Published: February 2009

The pathogenicity of mycobacterial infections depends on virulence factors that mediate survival inside host macrophages. These virulence factors are generally believed to be specific for pathogenic species and absent or mutated in non‐pathogenic strains. The serine/threonine protein kinase G (PknG) mediates survival of mycobacteria within macrophages by blocking lysosomal delivery. Here we describe a gene of the non‐pathogenic species Mycobacterium smegmatis that is 78% identical with pknG of Mycobacterium tuberculosis and M. bovis bacillus Calmette–Guérin (BCG). When cloned into expression vectors, the M. smegmatis pknG orthologue produced an active kinase and performed the same function as its M. bovis BCG counterpart in intracellular survival. In addition, similar levels of pknG transcripts were found in M. bovis BCG and M. smegmatis. However, virtually no translation product of chromosomal pknG could be detected in M. smegmatis both after in vitro growth and after macrophage infection. This lack of efficient translation was shown to be caused by regulatory elements in the upstream region of the M. smegmatis gene. The data reveal dramatically increased translational efficiency of a virulence gene in a pathogenic mycobacterium compared with a non‐pathogenic mycobacterium suggesting that changes in expression levels may underlie evolution of pknG and other pathogenicity genes in mycobacterium.
A novel mechanism for translation initiation operates in haloarchaea
Authors: Hering Oliver , Brenneis Mariam , Beer Jürgen , Suess Beatrix , Soppa Jörg
Published: February 2009

Four different mechanisms for translation initiation are known, i.e. one prokaryotic mechanism involving a Shine–Dalgarno sequence, two eukaryotic mechanisms relying on ribosomal scanning or internal ribosomal entry sites, and one mechanism acting on leaderless transcripts. Recently it was reported that the majority of haloarchaeal transcripts is leaderless and that most leadered transcripts are devoid of a Shine–Dalgarno sequence, excluding the operation of a ‘bacterial‐like’ initiation mechanism. Therefore, the current study concentrated on elucidating whether a ‘eukaryotic‐like’ scanning mechanism might operate instead. GUG and UUG were efficiently used as start codons on leadered transcripts in vivo, in contrast to initiation on leaderless transcripts (and leadered eukaryotic transcripts). Deleted versions of the 5′‐UTR initiated translation very inefficiently. Introduction of additional upstream AUGs did not influence the initiation efficiency at internal start codons. An additional in‐frame AUG at the 5′‐end led to the simultaneous usage of two start sites on the same message. A stable stem‐loop structure at the 5′‐end inhibited only initiation at the first AUG, but did not influence usage of the internal AUG. Taken together, operation of a scanning mechanism was excluded and the results indicate that a novel mechanism for translation initiation operates at least in haloarchaea.
Structural basis for autoinhibition and activation of Auto, a virulence‐associated peptidoglycan hydrolase of Listeria monocytogenes
Authors: Bublitz Maike , Polle Lilia , Holland Christin , Heinz Dirk W. , Nimtz Manfred , Schubert Wolf‐Dieter
Published: February 2009

During a bacterial infection, each successive step is orchestrated by a dedicated set of virulence factors. In Gram‐positive bacteria, the presentation or release of such factors is crucially dependent on the continual remodelling of the cell wall. We have investigated the autolysin or peptidoglycan hydrolase Auto (Lmo1076) from the human pathogen Listeria monocytogenes to structurally and biochemically underpin its role in host cell invasion. We demonstrate that Auto is an N‐acetylglucosaminidase, that it is autoinhibited when newly secreted but activated by proteolytic cleavage, that it has an acidic pH optimum and that it preferentially cleaves acetylated over de‐acetylated peptidoglycan. The crystal structure of Auto, the first for glycoside hydrolase family 73, and the first for a listerial autolysin, indicates that autoinhibition is due to an N‐terminal α‐helix unique to Auto that physically blocks the substrate‐binding cleft. We identify Glu122 and Glu156 as the two catalytically essential carboxylate groups. The physical properties of Auto as well as its localization to lipoteichoic acid by its four C‐terminal GW modules imply cell wall degradation by Auto to be highly co‐ordinated. Its spatio‐temporally controlled activation and localized activity in an acidified environment indicate that it facilitates remodelling of the cell wall and may be involved in co‐ordinating the release of virulence factors at specific stages of an infection.
Rrp1, a cyclic‐di‐GMP‐producing response regulator, is an important regulator of Borrelia burgdorferi core cellular functions
Authors: Rogers Elizabeth A. , Terekhova Darya , Zhang Hong‐Ming , Hovis Kelley M. , Schwartz Ira , Marconi Richard T.
Published: February 2009

Two‐component systems (TCS) are universal among bacteria and play critical roles in gene regulation. Our understanding of the contributions of TCS in the biology of the Borrelia is just now beginning to develop. Borrelia burgdorferi, a causative agent of Lyme disease, harbours a TCS comprised of open reading frames (ORFs) BB0419 and BB0420. BB0419 encodes a response regulator designated Rrp1, and BB0420 encodes a hybrid histidine kinase–response regulator designated Hpk1. Rrp1, which contains a conserved GGDEF domain, undergoes phosphorylation and produces the secondary messenger, cyclic diguanylate (c‐di‐GMP), a critical signaling molecule in numerous organisms. However, the regulatory role of the Rrp1–Hpk1 TCS and c‐di‐GMP signaling in Borrelia biology are unexplored. In this study, the distribution, conservation, expression and potential global regulatory capability of Rrp1 were assessed. rrp1 was found to be universal and highly conserved among isolates, co‐transcribed with hpk1, constitutively expressed during in vitro cultivation, and significantly upregulated upon tick feeding. Allelic exchange replacement and microarray analyses revealed that the Rrp1 regulon consists of a large number of genes encoded by the core Borrelia genome (linear chromosome, linear plasmid 54 and circular plasmid 26) that encode for proteins involved in central metabolic processes and virulence mechanisms including immune evasion.
Spinocerebellar ataxia type 6 (SCA6): neurodegeneration goes beyond the known brain predilection sites
Authors: Gierga K. , Schelhaas H. J. , Brunt E. R. , Seidel K. , Scherzed W. , Egensperger R. , De Vos R. A. I. , Den Dunnen W. , Ippel P. F. , Petrasch‐Parwez E. , Deller T. , Schöls L. , Rüb U.
Published: February 2009

Aims: Spinocerebellar ataxia type 6 (SCA6) is a late onset autosomal dominantly inherited ataxic disorder, which belongs to the group of CAG repeat, or polyglutamine, diseases. Although, it has long been regarded as a ‘pure’ cerebellar disease, recent clinical studies have demonstrated disease signs challenging the view that neurodegeneration in SCA6 is confined to the well‐known lesions in the cerebellum and inferior olive.Methods: We performed a systematic pathoanatomical study throughout the brains of three clinically diagnosed and genetically confirmed SCA6 patients.Results: This study confirmed that brain damage in SCA6 goes beyond the known brain predilection sites. In all of the SCA6 patients studied loss of cerebellar Purkinje cells and absence of morphologically intact layer V giant Betz pyramidal cells in the primary motor cortex, as well as widespread degeneration of brainstem nuclei was present. Additional damage to the deep cerebellar nuclei was observed in two of three SCA6 patients.Conclusions: In view of the known functional role of affected central nervous grey components it is likely that their degeneration at least in part is responsible for the occurrence of a variety of SCA6 disease symptoms.
Fc‐receptors and immunity to malaria: from models to vaccines
Authors: PLEASS R. J.
Published: February 2009

The complexity and number of antigens (Ags) seen during an immune response has hampered the development of malaria vaccines. Antibodies (Abs) play an important role in immunity to malaria and their passive administration is effective at controlling the disease. Abs represent approximately 25% of all proteins undergoing clinical trials, and these ‘smart biologicals’ have undergone a major revival with the realization that Abs lie at the interface between innate and adaptive immunity. At least 18 Abs have FDA approval for clinical use and approximately 150 are in clinical trials, the majority for the treatment of cancer, allograft rejection or autoimmune disease. Despite these triumphs none are in development for malaria, principally because they are perceived as being too expensive for a disease mainly afflicting poor and marginalized populations. Although unlikely, at least in the foreseeable future, that Ab‐based prophylaxis will be made available to the millions of people at risk from malaria, they may be incorporated into current vaccine approaches, since Abs act as correlates of protection in studies aimed at defining the best Ags to include in vaccines. Abs may also form the basis for novel vaccination strategies by targeting Ags to appropriate antigen presenting cells. Therefore, to develop the most efficacious vaccines it will be necessary to fully understand which Abs and Fc‐receptors (FcRs) are best engaged for a positive outcome.
A complementary role for ELF3 and TFL1 in the regulation of flowering time by ambient temperature
Authors: Strasser Bárbara , Alvarez Mariano J. , Califano Andrea , Cerdán Pablo D.
Published: February 2009

Plants regulate their time to flowering by gathering information from the environment. Photoperiod and temperature are among the most important environmental variables. Sub‐optimal, but not near‐freezing, temperatures regulate flowering through the thermosensory pathway, which overlaps with the autonomous pathway. Here we show that ambient temperature regulates flowering by two genetically distinguishable pathways, one requiring TFL1 and another requiring ELF3. The delay in flowering time observed at lower temperatures was partially suppressed in single elf3 and tfl1 mutants, whereas double elf3 tfl1 mutants were insensitive to temperature. tfl1 mutations abolished the temperature response in cryptochrome mutants that are deficient in photoperiod perception, but not in phyB mutants, which have a constitutive photoperiodic response. In contrast to tfl1, elf3 mutations were able to suppress the temperature response in phyB mutants, but not in cryptochrome mutants. Gene expression profiles revealed that the tfl1 and elf3 effects are due to the activation of different sets of genes, and identified CCA1 and SOC1/AGL20 as being important cross‐talk points. Finally, genome‐wide gene expression analysis strongly suggests a general and complementary role for ELF3 and TFL1 in temperature signalling.
CIPK6, a CBL‐interacting protein kinase is required for development and salt tolerance in plants
Authors: Tripathi Vineeta , Parasuraman Boominathan , Laxmi Ashverya , Chattopadhyay Debasis
Published: February 2009

Calcineurin B‐like proteins (CBL) and CBL‐interacting protein kinases (CIPK) mediate plant responses to a variety of external stresses. Here we report that Arabidopsis CIPK6 is also required for the growth and development of plants. Phenotype of tobacco plants ectopically expressing a homologous gene (CaCIPK6) from the leguminous plant chickpea (Cicer arietinum) indicated its functional conservation. A lesion inAtCIPK6 significantly reduced shoot‐to‐root and root basipetal auxin transport, and the plants exhibited developmental defects such as fused cotyledons, swollen hypocotyls and compromised lateral root formation, in conjunction with reduced expression of a number of genes involved in auxin transport and abiotic stress response. The Arabidopsis mutant was more sensitive to salt stress compared to wild‐type, while overexpression of a constitutively active mutant of CaCIPK6 promoted salt tolerance in transgenic tobacco. Furthermore, tobacco seedlings expressing the constitutively active mutant of CaCIPK6 showed a developed root system, increased basipetal auxin transport and hypersensitivity to auxin. Our results provide evidence for involvement of a CIPK in auxin transport and consequently in root development, as well as in the salt‐stress response, by regulating the expression of genes.
Early production of thymic stromal lymphopoietin precedes infiltration of dendritic cells expressing its receptor in allergen‐induced late phase cutaneous responses in atopic subjects
Authors: Corrigan C. J. , Jayaratnam A. , Wang Y. , Liu Y. , De Waal Malefyt R. , Meng Q. , Kay A. B. , Phipps S. , Lee T. H. , Ying S.
Published: February 2009

Background:  Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)‐7‐like cytokine that triggers dendritic cell‐mediated T helper (Th)2 inflammatory responses through a receptor consisting of a heterodimer of the IL‐7 receptor alpha (IL‐7Rα) chain and the TSLP receptor (TSLPR), which resembles the cytokine receptor common gamma chain. Dendritic cells activated by TSLP prime development of CD4+ T cells into Th2 cells contributing to the pathogenesis of allergic inflammation. We hypothesized that allergen exposure induces expression of TSLP and results in recruitment of TSLPR bearing cells in the cutaneous allergen‐induced late‐phase reaction (LPR) in atopic subjects.

Methods:  Skin biopsies were obtained from atopic subjects (n = 9) at various times after cutaneous allergen challenge. In situ hybridization and immunohistochemistry were used to determine TSLP mRNA expression and to measure infiltration of TSLPR+ DC in skin LPR. RT‐PCR and flow cytometry were employed to analyse TSLPR expression on isolated blood DC.

Results:  Allergen‐induced skin TSLP expression occurred as early as 1 h after allergen challenge, whereas TSLPR+ and CD11c+ cells infiltrated relatively late (24–48 h). The majority of TSLPR+ cells were DC co‐expressing blood DC antigen‐1 (BDCA‐1) or BDCA‐2. Freshly isolated blood DC expressed both TSLPR and IL‐7Rα chains. Maturation and stimulation with TSLP or polyriboinosinic–polyribocytidylic acid in vitro upregulated the expression of both TSLPR and IL‐7Rα chains in DC but not in chemoattractant receptor‐homologous molecule expressed on Th2 cells+ CD4+ T cells.

Conclusion:  The data suggest that TSLP plays a role in augmenting, through DC recruitment and activation, the development of Th2‐type T cells in allergic inflammation.
Genetic diversity of Swiss sheep breeds in the focus of conservation research
Authors: Glowatzki‐Mullis M.‐L. , Muntwyler J. , Bäumle E. , Gaillard C.
Published: February 2009

There is constant pressure to improve evaluation of animal genetic resources in order to prevent their erosion. Maintaining the integrity of livestock species as well as their genetic diversity is of paramount interest for long‐term agricultural policies. One major use of DNA techniques in conservation is to reveal genetic diversity within and between populations. Forty‐one microsatellites were analysed to assess genetic diversity in nine Swiss sheep breeds and to measure the loss of the overall diversity when one breed would become extinct. The expected heterozygosities varied from 0.65 to 0.74 and 10.8% of the total genetic diversity can be explained by the variation among breeds. Based on the proportion of shared alleles, each of the nine breeds were clearly defined in their own cluster in the neighbour‐joining tree describing the relationships among the breeds. Bayesian clustering methods assign individuals to groups based on their genetic similarity and infer the number of populations. In STRUCTURE, this approach pooled the Valais Blacknose and the Valais Red. With BAPS method the two Valais sheep breeds could be separated. Caballero & Toro approach (2002) was used to calculate the loss or gain of genetic diversity when each of the breeds would be removed from the set. The changes in diversity based on between‐breed variation ranged from −12.2% (Valais Blacknose) to 0% (Swiss Black Brown Mountain and Mirror Sheep); based on within‐breed diversity the removal of a breed could also produce an increase in diversity (−0.6% to + 0.6%). Allelic richness ranged from 4.9 (Valais Red) to 6.7 (Brown Headed Meat sheep and Red Engadine Sheep). Breed conservation decisions cannot be limited to genetic diversity alone. In Switzerland, conservation goals are embedded in the desire to carry the cultural legacy over to future generations.
Identifiability of parameters and behaviour of MCMC chains: a case study using the reaction norm model
Authors: Shariati M.M. , Korsgaard I.R. , Sorensen D.
Published: February 2009

Markov chain Monte Carlo (MCMC) enables fitting complex hierarchical models that may adequately reflect the process of data generation. Some of these models may contain more parameters than can be uniquely inferred from the distribution of the data, causing non‐identifiability. The reaction norm model with unknown covariates (RNUC) is a model in which unknown environmental effects can be inferred jointly with the remaining parameters. The problem of identifiability of parameters at the level of the likelihood and the associated behaviour of MCMC chains were discussed using the RNUC as an example. It was shown theoretically that when environmental effects (covariates) are considered as random effects, estimable functions of the fixed effects, (co)variance components and genetic effects are identifiable as well as the environmental effects. When the environmental effects are treated as fixed and there are other fixed factors in the model, the contrasts involving environmental effects, the variance of environmental sensitivities (genetic slopes) and the residual variance are the only identifiable parameters. These different identifiability scenarios were generated by changing the formulation of the model and the structure of the data and the models were then implemented via MCMC. The output of MCMC sampling schemes was interpreted in the light of the theoretical findings. The erratic behaviour of the MCMC chains was shown to be associated with identifiability problems in the likelihood, despite propriety of posterior distributions, achieved by arbitrarily chosen uniform (bounded) priors. In some cases, very long chains were needed before the pattern of behaviour of the chain may signal the existence of problems. The paper serves as a warning concerning the implementation of complex models where identifiability problems can be difficult to detect a priori. We conclude that it would be good practice to experiment with a proposed model and to understand its features before embarking on a full MCMC implementation.
Biology and host specificity of Aulacobaris fallax (Coleoptera: Curculionidae), a potential biological control agent for dyer’s woad, Isatis tinctoria (Brassicaceae) in North America
Authors: Gerber E. , Cortat G. , Hinz H. L.
Published: February 2009

Dyer’s woad, Isatis tinctoria, a plant of Eurasian origin is a problematic weed in western North America against which a classical biological weed control programme was initiated in 2004. Three European insect species were selected as candidate agents to control this invasive species, including the root‐mining weevil Aulacobaris fallax. To determine its suitability as an agent, the biology and host specificity of A. fallax were studied in outdoor plots and in the field between 2004 and 2006 in its native European range. Aulacobaris fallax is a univoltine species that lays its eggs from March to August into leaf stalks and roots of dyer’s woad. Larvae mine and pupate in the roots and adults emerge from August to October. Up to 62% of the dyer’s woad plants at the field sites investigated were attacked by this weevil. In no‐choice host‐specificity tests, A. fallax attacked 16 out of 39 species and varieties within the Family Brassicaceae. Twelve of these are native to North America. In subsequent multiple‐choice tests, seven species, all native to North America, suffered a similar level of attack as dyer’s woad, while none of the European species were attacked. Our results demonstrate the importance of including test plant species that have not co‐evolved with the respective candidate agent. In sum, we conclude that the risk of non‐target effects is too high for A. fallax to be considered as a biological control agent for dyer’s woad in the United States.
Are the palms Washingtonia filifera and Chamaerops humilis suitable hosts for the red palm weevil, Rhynchophorus ferrugineus (Col. Curculionidae)?
Authors: Dembilio Ó. , Jacas J. A. , Llácer E.
Published: February 2009

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is a widely distributed pest which has recently become the major pest of palms in the Mediterranean Basin. This weevil has been recorded on 19 different palm species, however, the host status of Washingtonia filifera and Chamaerops humilis remains unclear. The present study was carried out to check whether these species had either antixenotic or antibiotic mechanisms of resistance against this pest. Our results show that both W. filifera and C. humilis are resistant to R. ferrugineus. Resistance in W. filifera is based on antibiosis whereas in C. humilis resistance is based on antixenosis.
Differential maturation of circadian rhythms in clock gene proteins in the suprachiasmatic nucleus and the pars tuberalis during mouse ontogeny
Authors: Ansari Nariman , Agathagelidis Manuel , Lee Choogon , Korf Horst‐Werner , Von Gall Charlotte
Published: February 2009

Circadian rhythms of many body functions in mammals are controlled by a master pacemaker, residing in the hypothalamic suprachiasmatic nucleus (SCN), which synchronises peripheral oscillators. The SCN and peripheral oscillators share several components of the molecular clockwork and comprise transcriptional activators (BMAL1 and CLOCK/NPAS2) and inhibitors (mPER1/2 and mCRY1/2). Here we compared the ontogenetic maturation of the clockwork in the SCN and pars tuberalis (PT). The PT is a peripheral oscillator that strongly depends on rhythmic melatonin signals. Immunoreactions for clock gene proteins were determined in the SCN and PT at four different timepoints during four differential stages of mouse ontogeny: foetal (embryonic day 18), newborn (2‐day‐old), infantile (10‐day‐old), and adult. In the foetal SCN, levels of immunoreactions of all clock proteins were significantly lower than adult levels except for BMAL1. In the newborn SCN the clock protein immunoreactions had not yet reached adult levels, but the infantile SCN showed similar levels of immunoreactions as the adult. In contrast, immunoreactions for all clock gene proteins in the foetal PT were as intense as in newborn, infantile and adult, and showed the same phase. As the foetal pineal gland is not yet capable of rhythmic melatonin production, the rhythms in clock gene proteins in the foetal PT are presumably dependent on the maternal melatonin signal. Thus, our data provide the first evidence that maternal melatonin is important for establishing and maintaining circadian rhythms in a foetal peripheral oscillator.
Musical experience and neural efficiency – effects of training on subcortical processing of vocal expressions of emotion
Authors: Strait Dana L. , Kraus Nina , Skoe Erika , Ashley Richard
Published: February 2009

Musicians exhibit enhanced perception of emotion in speech, although the biological foundations for this advantage remain unconfirmed. In order to gain a better understanding for the influences of musical experience on neural processing of emotionally salient sounds, we recorded brainstem potentials to affective human vocal sounds. Musicians showed enhanced time‐domain response magnitude to the most spectrally complex portion of the stimulus and decreased magnitude to the more periodic, less complex portion. Enhanced phase‐locking to stimulus periodicity was likewise seen in musicians’ responses to the complex portion. These results suggest that auditory expertise engenders both enhancement and efficiency of subcortical neural responses that are intricately connected with acoustic features important for the communication of emotional states. Our findings provide the first biological evidence for behavioral observations indicating that musical training enhances the perception of vocally expressed emotion in addition to establishing a subcortical role in the auditory processing of emotional cues.