bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF INFORMATION RELATED TO FAT CONTENT AND TASTE ON CONSUMER RESPONSES TO A REDUCED‐FAT FRANKFURTER AND A REDUCED‐FAT CHOCOLATE BAR
Authors: KÄHKÖNEN PÄIVI , HAKANPÄÄ PIRJO , TUORILA HELY
Published: May 2007

The effects of product information on responses to frankfurter sausages and chocolate bars were studied by comparing sensory and hedonic ratings in two conditions: blind tasting and tasting with information present. Furthermore, the effect of information alone was investigated by having the subjects rate the expected sensory and hedonic intensities of the products on the basis of packages with different claims. Three groups of subjects were tested by giving them different information: The basic group (no added claims, n=31), the reduced‐fat group (products claimed to have reduced‐fat, n=29) and the flavorful group (products claimed to have full meat/chocolate flavor, n=31). Product information increased the rated pleasantness of the frankfurter in all three information groups compared to the blind ratings. The information did not affect the pleasantness of the chocolate bars. The expected attribute intensities of the frankfurters and chocolates were rated lower by the reduced‐fat group than by the other groups. Overall, the effect of product information was more clearly seen in ratings of sensory attributes than in pleasantness ratings.
INSTRUMENTAL AND SENSORY ANALYSIS OF VOLATILE AROMA OF COOKED RICE
Authors: YAU N.J.N. , LIU T.T.
Published: May 2007

The objective of this study was to compare the differences in aroma of cooked rice samples. The rice aroma of four popular rice varieties in Taiwan (TC 189, TNu 70, TNu 67 and TC Sen 10) at different temperatures (18C, 25C and 60C) were analyzed by GC‐MS system (using headspace capture collection) and evaluated by trained and naive panels. The GC‐MS results indicated that the composition of the volatile components of rice was complicated and no single volatile compound contributed to the characteristics of rice aroma. Fourteen attributes were developed using modified quantitative descriptive analysis and evaluated with line scaling method. The 60C samples were higher in hot‐steam‐bread aroma, corn aroma, corn‐leaf aroma and brown‐rice aroma, while the 18C samples were higher in cold‐steam‐bread aroma and fermented‐sour aroma. Compared to the other varieties, the TC Sen 10 was uniquely higher in plastic aroma, sulfur aroma and gasoline aroma. As expected, hedonic results showed that naive panelists preferred the overall aroma perception of the 60C samples. The relationship between the volatile compounds and descriptive attributes is discussed.
COMPARISON OF MONADIC AND SIMULTANEOUS SAMPLE PRESENTATION MODES IN A DESCRIPTIVE ANALYSIS OF MILK CHOCOLATE
Authors: MAZZUCCHELLI ROSSELLA , GUINARD JEAN‐XAVIER
Published: May 2007

Monadic (one sample served at a time, and all attributes rated for that sample) and simultaneous multiple (4 samples served together, and attributes rated one at a time across samples) presentation and evaluation procedures were compared in terms of descriptive profile generated, panel performance (ability to discriminate, reproducibility, concept alignment) and session duration, in a descriptive analysis of 9 milk chocolate samples by a panel of 18 trained judges. The sensory profiles obtained with the two presentation modes were very similar (as assessed by spider web and principal component plots). Time‐wise, the simultaneous presentation procedure took significantly longer to complete (p<0.001). Judges discriminated slightly better and were more reproducible with the simultaneous presentation mode, but quality of concept alignment did not differ between the two procedures. We conclude each method has its advantages and limitations, and choice of presentation procedure should be based on the type of descriptive analysis carried out and the time frame available.
EFFECT OF PASTEURIZATION ON THE SENSORY CHARACTERISTICS OF A EWE'S‐MILK CHEESE
Authors: MENDIA C. , IBAÑEZ F.C. , TORRE P. , BARCINA Y.
Published: May 2007

The present study examined the effect of two different processing technologies in the manufacture of a ewe's‐milk cheese. Two batches were manufactured, one from raw milk, the other from pasteurized milk. A starter culture consisting of Lactococcus lactis subsp. lactis var. diacetylactis and Lactobacillus casei subsp. casei was added to both batches. Descriptive analysis of the sensory characteristics was carried out for the two cheese batches at two different ripening times (90 and 180 days).

Statistical analysis revealed differences both between the two batches and between the ripening times considered. The cheeses made from the raw milk were firmer, with a more characteristic odor, taste, and aftertaste. The cheeses made from the pasteurized milk were creamier with a sweeter odor and taste and a more bitter aftertaste. Irrespective of the cheese batch, at 180 days all the cheese samples were firmer and grainier with a more characteristic taste and aftertaste as well as a spicier taste and aftertaste.
EFFECT OF FREEZING AND FROZEN STORAGE ON THE SENSORIAL CHARACTERISTICS OF LOS PEDROCHES, A SPANISH EWE CHEESE
Authors: TEJADA L. , GÓMEZ R. , VIOQUE M. , SÁNCHEZ E. , MATA C. , FERNÁNDEZ‐SALGUERO J.
Published: May 2007

The aim of the present work was to study the sensorial characteristics of Los Pedroches cheese after freezing, monitoring the effects of the speed and time of frozen storage. Changes were observed in the hardness, creaminess and eyes of cheeses after 3‐months frozen storage. The paste hardened, becoming less creamy, and the number and size of the eyes decreased substantially. However, these attributes remained unchanged during storage periods of up to 9 months. Odor, flavor intensity, acidity and grainy were modified as a consequence of frozen storage. The speed of the freezing process only affected the grainy of the cheese; this was greater in slowly‐frozen cheeses.
VARIABILITY IN HEDONICS: INDICATIONS OF WORLD‐WIDE SENSORY AND COGNITIVE PREFERENCE SEGMENTATION
Authors: MOSKOWITZ HOWARD R. , BERNSTEIN RICHARD
Published: May 2007

This paper approaches inter‐individual differences in the hedonics of food products as an indication of the existence of different groups of people with different likes and dislikes. Rather than considering the differences as an unpleasant fact of nature, to be ignored, the paper shows how these differences point to segments of consumers in the population. These segments enable the product developer to create different types of food products, in order to satisfy the different tastes. The paper, presenting an algorithm for segmentation of individuals into different groups, results from three studies with foods, and the extension of the particular segmentation algorithm into concepts (with three additional studies). The paper presents both new data and results from previously published research. These data are presented in a case history format.
THE INFLUENCE OF SOLUTION VISCOSITY AND DIFFERENT VISCOSIFYING AGENTS ON APPLE JUICE FLAVOR
Authors: WALKER SHANE , PRESCOTT JOHN
Published: May 2007

Viscosifying agents are used in foods as thickeners to produce improved mouthfeel and as stabilizers to prevent settling out of particulate matter. While viscosifying agents are also known to influence the sensory profile of the products in which they are used, previous studies have examined the effects of viscosifying agents at levels that are not typical of those used in foods. The current study used a descriptive analysis panel to examine the effects of both viscosity and viscosifying agent on the sensory properties of apple juice using three viscosifying agents (carboxymethylcellulose, xanthan and pectin) at levels of usage similar to those recommended for drink products. Gas chromatography‐flame ionization detection and gas chromatography‐mass spectrometry were conducted on the samples to relate alteration in physico‐chemical parameters to changes in sensory profile. Results from the descriptive panel showed that increasing viscosity tended to decrease some aspects of flavor intensity (sourness and cooked apple odor). Individual viscosifying agents were shown to have specific effects on odor and flavor attributes, e.g. pectin enhanced cereal odor. Gas chromatography‐flame ionization detection and mass spectrometry suggested that this effect was related to isopropyl alcohol contributed by the pectin in solution. Pectin also suppressed honey odor and flavor, lemon odor and cooked apple flavor.
DETERMINATION OF THE SENSORY ATTRIBUTES OF WHEAT SOURDOUGH BREAD 1
Authors: LOTONG VARAPHA , IV EDGAR CHAMBERS , CHAMBERS DELORES H.
Published: May 2007

A lexicon for describing the flavor of wheat sourdough bread (WSB) was developed. A highly trained, descriptive sensory panel identified, defined, and referenced 32 flavor attributes for WSB. To determine the flavor characteristics of WSB, 37 samples were selected or prepared to represent a wide range of both commercial and laboratory variations. Crust and crumb of sourdough bread had different flavor properties; thus, they were evaluated separately. Twenty six attributes described the characteristics of sourdough bread crumb, and 28 attributes described the characteristics of crust. Some attributes were found in most or all samples, but many attributes were found in only one or a few samples. All 37 samples had distinctly different flavor attributes and intensities in both crumb and crust samples. The principal components analysis for crumb and crust indicated that the number of attributes could not be reduced into a smaller set of components that completely described the wide range of breads used in this study. However, reducing the number of attributes measured might be possible when only a few WSB samples are evaluated.
CHILDREN'S PERCEPTIONS OF AND PREFERENCES FOR VEGETABLES IN THE WEST OF SCOTLAND: THE ROLE OF DEMOGRAPHIC FACTORS
Authors: BAXTER IRENE A. , SCHRÖDER MONIKA J.A. , BOWER JOHN A.
Published: May 2007

Forty‐four Glaswegian 8‐10 year old children participated in this study to measure their perceptions of common vegetables. North Glasgow was selected as the locale because it contains the areas with Scotland's lowest and highest fruit and vegetable intakes. The impact of socioeconomic status upon the children's perceptions and preferences was examined, as were age, gender and frequency of vegetable consumption. The repertory grid method was used to elicit the perceptual data. Personal attributes were scored on a 10‐cm linear scale, alongside a scale to measure the children's liking for the vegetables. Generalized Procrustes analysis and Preference Mapping were used to analyze the data. Sensory characteristics (especially texture and appearance) and the context of consumption were found to influence perceptions and preferences of vegetables. Socioeconomic background influenced perceptions, while self‐reported consumption was significantly affected by social background, age and gender.
THRESHOLDS AND SUPRATHRESHOLD INTENSITY FUNCTIONS FOR CAPSAICIN IN OIL AND AQUEOUS BASED CARRIERS
Authors: LAWLESS HARRY T. , HARTONO CAROLINE , HERNANDEZ SUSANA
Published: May 2007

Thresholds and responses to capsaicin in oil‐ and water‐based model systems were compared. Thresholds were measured among 23 individuals using an ascending forced choice method of limits. Detection thresholds were 11.75 (± 1.31) mg/L in oil and 0.31 (± 0.03) mg/L in water. A horizontal labeled magnitude scale was used to obtain suprathreshold scaling functions in corn and soybean oils and in water systems using an emulsifier (polysorbate) or alcohol to solvate the capsaicin. In the water‐based systems, capsaicin ranged from weak to very strong ratings over a range of 0.3 to 10 mg/L while the same perceptual range was achieved in oil over a range of 10 to 316 mg/L. Nonconsumers of hot/spicy foods generally had higher thresholds and higher suprathreshold responses in oil systems. Differences between user groups were less pronounced in water‐based stimuli.
ALTERATION OF THE SENSORY PERCEPTION OF THE MUDDY/EARTHY ODORANT 2‐METHYLISOBORNEOL IN CHANNEL CATFISH ICTALURUS PUNCTATUS FILLET TISSUES BY ADDITION OF SEASONINGS
Authors: BETT K.L. , INGRAM D.A. , GRIMM C.C. , VINYARD B.T. , BOYETTE K.D.C. , DIONIGI C.P.
Published: May 2007

Commercial production of catfish requires frequent feeding, which contributes to effusive microbial blooms in ponds. Microbial production of the muddy metabolite 2‐methylisoborneol (MIB) can reduce fish flavor quality. Although commercial seasonings may be added to fillets, little information is available concerning the sensory interaction of seasonings and MIB. The replicate sensory evaluation of catfish fillet samples containing either 1.0 or 10.0 ppb chemically‐synthesized MIB conducted under controlled conditions indicated a more frequent acceptance of fish as on‐flavored in samples treated with a “ lemon‐pepper” commercial seasoning preparation than either untreated samples or those treated with a “ cajun‐spice” seasoning blend. In addition, experimentation conducted with fish containing MIB from biological sources within the production pond, indicated a similar reduction in MIB flavor of lemon‐pepper‐treated samples. Although a 4‐terpenol co‐eluted with MIB from lemon‐pepper treated samples subjected to gas chromatography mass spectroscopy, the compound(s) in the lemon‐pepper preparation that interfere with the perception of MIB was (were) not identified.
MARGARINE: THE DRIVERS OF LIKING AND IMAGE
Authors: MOSKOWITZ HOWARD R.
Published: May 2007

This paper presents a study of the attributes of margarine, showing the depth of information about consumer perceptions and drivers of liking that emerges from a detailed analysis of relations among attributes. The paper develops three sets of analyses to understand relations among attributes: principal components analysis in order to identify basic dimensions of perception, linear functions relating overall liking to attribute liking or to image ratings in order to identify drivers of liking, and quadratic functions that relate overall liking or image ratings to sensory attribute levels in order to identify optimal sensory levels and to create sensory preference segments. The analyses show how consumer data can generate learning about the consumer perceptions on the one hand, and guidance for product development.
RICE EXTERNAL PREFERENCE MAPPING FOR ASIAN CONSUMERS LIVING IN THE UNITED STATES
Authors: MEULLENET J.‐F. , GRIFFIN V.K. , CARSON K. , DAVIS G. , DAVIS S. , GROSS J. , HANKINS J.A. , SAILER E. , SITAKALIN C. , SUWANSRI S. , CAICEDO A.L. VASQUEZ
Published: May 2007

Twenty‐one rice samples covering examples of aromatic, long and medium grain, instant, and parboiled products were evaluated by a group of 120 Asian consumers, currently living in the United States and by a professionally trained sensory panel. Results showed that imported Thai Jasmine rice was preferred by this group of Asian consumers over every other rice tested including domestically grown Jasmine rice. The most important acceptance factors for Asian consumers were cooked rice appearance and aroma. Predictive models of rice overall acceptance were evaluated using descriptive sensory evaluation data (i.e. including appearance, flavor and texture attributes). These models allowed the identification of sensory characteristics most important to rice acceptance by this consumer group. This information could be useful to rice breeders to select for specific sensory characteristics expected by Asian consumers.
INTERACTION OF ASTRINGENCY AND TASTE CHARACTERISTICS1
Authors: BRANNAN G.D. , SETSER C.S. , KEMP K.E.
Published: May 2007

The perception of astringency and basic taste in mixtures and their interaction effects were investigated by two procedures. In Experiment 1, focused and nonfocused testing procedures were compared using mixtures of low and high concentrations of alum and basic taste solutions. Both procedures yielded taste and astringency intensities that were modality‐dependent. Nonfocused testing was used in Experiment 2 to investigate the interactions of astringent phenolic (tannic acid) and nonphenolic (alum) compounds with each basic taste. Sweetness of sucrose increased with increased concentration with or without alum or tannin present. Changes in salty, bitter, and sour taste intensities were modality‐dependent. Astringency either remained unchanged or decreased with the addition of sucrose, sodium chloride, citric acid, or caffeine depending upon the taste concentration. Bitterness of tannin and alum at high concentrations was suppressed by the addition of sucrose, sodium chloride, or citric acid; sourness also decreased in the presence of sucrose or sodium chloride as well as a high level of caffeine.
CHEESE HARDNESS ASSESSMENT BY EXPERTS AND UNTRAINED JUDGES
Authors: GONZÁLEZ REMEDIOS , BENEDITO JOSÆ , CÁRCEL JUAN A. , MULET ANTONIO
Published: May 2007

Although expert assessment of food characteristics is recognized as a key step in product development, the use of consumer based measurements is sometimes recommended as an equivalent to the experts. From cognitive psychology, support of the role of perceptual learning is found in some instances, although this could not be relevant in others. To address this point performance analysis of experts and untrained panelists in cheese texture evaluation was carried out. Neither the untrained panelists nor the experts were familiar with either the scales or the kind of cheese. The same Cheddar cheese was given to 44 untrained subjects in three trials to assess hardness. The results showed that their judgment has a 29% average random error variance; the interrater reliability being low. The same experiment gave a random error variance of 2% for three highly skilled judges (experts). The difference in variance was linked to training. Untrained panelists also showed an adaptation error. Nevertheless, there was no significant difference between the average ratings of both groups, whether untrained or experts.
EXACT BETA‐BINOMIAL TABLES FOR SMALL EXPERIMENTS
Authors: BI JIAN , ENNIS DANIEL M.
Published: May 2007

Exact tables calculated directly from the probability function of a beta‐binomial distribution are provided for replicated difference and preference tests. The tables can be used for small experiments when the numbers of replications and trials are not more than five.
EFFECTS OF FORGETTING ON VARIOUS PROTOCOLS FOR CATEGORY AND LINE SCALES OF INTENSITY
Authors: LEE HAE‐JIN , KIM KWANG‐OK , O'MAHONY MICHAEL
Published: May 2007

Judges rated the intensity of NaCl solutions and orange drinks of varying sweetness using category scales and line scales. They performed under four response conditions that varied in reliance on memory: (1) verbal response (2) written response with no retasting and the response sheet removed (3) written response with a single response sheet which allowed past scores to be reviewed and amended but with no retasting (4) the same as ‘3’ but with retasting. Discrimination errors decreased from conditions ‘1’ through ‘4’ indicating how allowing judges to ‘refresh the memory’ improved discrimination. The cognitive processes involved in rating and consequences for scaling protocols and the experimental design for descriptive analysis are discussed in the light of these findings.
HEDONIC R‐INDEX MEASUREMENT OF TEMPERATURE PREFERENCES FOR DRINKING BLACK COFFEE
Authors: PIPATSATTAYANUWONG S. , LEE H.S. , LAU S. , O'MAHONY M.
Published: May 2007

R‐index measures were obtained from judges who ranked black coffees for preferred drinking temperature. Preferred temperatures were above thermal pain and thermal damage thresholds. The least preferred temperature was below the oral thermal pain threshold. Similar results were obtained with a ranking for temperatures that judges felt were most likely to be served in a coffee shop. Observations of customers in coffee shops indicated that they began sipping coffee at similar high temperatures.
DISCREPANCY BETWEEN THE EXPECTED AND ACTUAL ACCEPTABILITY OF MEAT PRODUCTS, EGGS AND FISH: THE CASE OF OLDER CONSUMERS
Authors: ROUSSET S. , JOLIVET P.
Published: May 2007

Expected acceptability and actually taste acceptability of meat and other foods were determined in elderly subjects. Subjects gave an acceptability score, followed by a free description of the strong and weak points, first from memory during an interview and then after tasting each food. Taste acceptabilities of lamb, fish, poultry, veal and pork were similar to those expected during the interview. Significant discrepancies between observed and expected acceptability were found for beef, processed pork, eggs and rabbit meat. Beef was described as “ tough” after tasting while it was expected as being “ tender” in the interview; processed pork was associated with “ good quality” and “ good texture” during tasting whereas, “ too fatty” with no strong points were expected in the interview; rabbit was criticized for “ dry texture” more often in the interview than after tasting; eggs were popular for their “ soft texture” and “ good taste” but associated with “ too fatty” and “ bad quality” in the interview. The expected acceptability of processed pork, eggs and rabbit seemed to be governed by negative images of fatness or dryness and that of beef by a positive image of “ tenderness”, which related poorly with tasting experience.
MATCHING RESULTS OF TWO INDEPENDENT HIGHLY TRAINED SENSORY PANELS USING DIFFERENT DESCRIPTIVE ANALYSIS METHODS1
Authors: LOTONG VARAPHA , CHAMBERS DELORES H. , DUS CLARE , IV EDGAR CHAMBERS , CIVILLE GAIL V.
Published: May 2007

Two independent, highly trained panels separately conducted descriptive analysis of orange juices using different descriptive analysis methods and sets of samples. Lexicons were developed independently. One panel evaluated 23 orange juice products and identified and referenced 24 attributes. The other panel evaluated 17 products and identified 17 attributes for testing. Though not identical, the lexicons developed by both panels were similar overall. To compare the sensory space of the product category, Principal Component Analysis (PCA) and sensory maps were developed separately for each panel. The comparison showed that the underlying sample spaces obtained from both panels were comparable in many ways. Key flavor characteristics for the same types of orange juice products were described similarly by both panels. These data indicate that the process of using highly trained panels that define attributes and use reference standards for descriptive sensory analysis can give objective and comparable information for a product category across different panels.
DETERMINATION OF THE SENSORY ATTRIBUTES OF DRIED MILK POWDERS AND DAIRY INGREDIENTS
Authors: DRAKE M.A. , KARAGUL‐YUCEER Y. , CADWALLADER K.R. , CIVILLE G.V. , TONG P.S.
Published: May 2007

A standardized descriptive language for skim milk powder and dried dairy ingredients was developed. The lexicon was initially identified from a large sample set of dried dairy ingredients (138). A highly trained descriptive panel (n = 14) refined terms and identified references. Dried dairy ingredients (36) were then evaluated using the developed language. Twenty‐one descriptors were identified for dried dairy ingredients. Seventeen flavors and tastes were identified in skim milk powders (27) with nine flavors/tastes observed in all skim milk powders. Dried dairy ingredients were differentiated using the language (P<0.05). There were flavors common to all dried dairy ingredients while other flavors were specific to particular products.
PERCEIVED EATING DIFFICULTIES AND PREFERENCES FOR VARIOUS TEXTURES OF RAW AND COOKED CARROTS IN YOUNG AND ELDERLY SUBJECTS
Authors: ROININEN KATARIINA , FILLION LAURENCE , KILCAST DAVID , LÄHTEENMÄKI LIISA
Published: May 2007

The aim of the study was to determine how those texture attributes that elderly people find difficult to eat are related to their preferences for different modifications of carrot textures. This study was conducted with same methods in Finland and in the United Kingdom (UK). Trained sensory panels in both countries described sensory profiles of a range of carrot samples with same glossary of texture terms. The texture of carrot samples was manipulated using different preparation and cooking methods. Based on the Principal Component Analysis (PCA), boiled and puréed samples were perceived as soft, wet, pulpy and smooth, whereas raw samples were dry, brittle, rough, crispy and crunchy. Two age groups were used for the consumer tests: a young adult group aged 23 to 40 years, mean 32 (Finland) and 33 (UK) and an elderly group aged over 60 years, mean 75 (Finland) and 76 (UK). Both the elderly and young adult respondents considered samples as difficult to eat if they needed a long chewing time, were crunchy, hard, brittle, dry, rough or sharp, such as raw slices and coarsely grated samples. On the other hand, slimy, wet, smooth, soft and pulpy samples, such as boiled carrots and purée, were considered as easy‐to‐eat. The young adults liked more difficult textures such as rough, crispy, crunchy and hard than did the elderly respondents, but the easiest textures were not liked by either age group. Subjects with dental deficiencies liked easier textures more than those fully dentate.
COMPARISON OF SENSORY PROFILES DONE BY TRAINED AND UNTRAINED JURIES: METHODOLOGY AND RESULTS
Authors: HUSSON F. , PAGÈS J.
Published: May 2007

We compare the sensory profiles of six dark chocolates done by two types of juries: some trained juries and an untrained jury. Six laboratories, each one made up of 10 to 15 judges, are regarded as trained juries since the assessors were well trained before the evaluation of the products. The second type of jury is composed of only one panel of 29 untrained assessors and this jury is named the untrained jury. Fourteen attributes were evaluated and analyses of variance have been carried out by attribute to compare the sensory profiles of the six chocolates done by the trained juries and by the untrained jury. These analyses of variance show that the two types of juries give similar sensory profiles and that the few differences are mainly due to different ways of using the scale.
Disinhibition of perifornical hypothalamic neurones activates noradrenergic neurones and blocks pontine carbachol‐induced REM sleep‐like episodes in rats
Authors: Lu Jackie W. , Fenik Victor B. , Branconi Jennifer L. , Mann Graziella L. , Rukhadze Irma , Kubin Leszek
Published: May 2007

Studies in behaving animals suggest that neurones located in the perifornical (PF) region of the posterior hypothalamus promote wakefulness and suppress sleep. Among such cells are those that synthesize the excitatory peptides, orexins (ORX). Lack of ORX, or their receptors, is associated with narcolepsy/cataplexy, a disorder characterized by an increased pressure for rapid eye movement (REM) sleep. We used anaesthetized rats in which pontine microinjections of a cholinergic agonist, carbachol, can repeatedly elicit REM sleep‐like episodes to test whether activation of PF cells induced by antagonism of endogenous, GABAA receptor‐mediated, inhibition suppresses the ability of the brainstem to generate REM sleep‐like state. Microinjections of the GABAA receptor antagonist, bicuculline (20 nl, 1 mm), into the PF region elicited cortical and hippocampal activation, increased the respiratory rate and hypoglossal nerve activity, induced c‐fos expression in ORX and other PF neurones, and increased c‐fos expression in pontine A7 and other noradrenergic neurones. The ability of pontine carbachol to elicit any cortical, hippocampal or brainstem component of the REM sleep‐like response was abolished during the period of bicuculline‐induced activation. The activating and REM sleep‐suppressing effect of PF bicuculline was not attenuated by systemic administration of the ORX type 1 receptor antagonist, SB334867. Thus, activation of PF neurones that are endogenously inhibited by GABAA receptors is sufficient to turn off the brainstem REM sleep‐generating network; the effect is, at least in part, due to activation of pontine noradrenergic neurones, but is not mediated by ORX type 1 receptors. A malfunction of the pathway that originates in GABAA receptor‐expressing PF neurones may cause narcolepsy/cataplexy.
Mechanical influences on skeletal muscle vascular tone in humans: insight into contraction‐induced rapid vasodilatation
Authors: Kirby Brett S. , Carlson Rick E. , Markwald Rachel R. , Voyles Wyatt F. , Dinenno Frank A.
Published: May 2007

We tested the hypothesis that mechanical deformation of forearm blood vessels via acute increases in extravascular pressure elicits rapid vasodilatation in humans. In healthy adults, we measured forearm blood flow (Doppler ultrasound) and calculated forearm vascular conductance (FVC) responses to whole forearm compressions and isometric muscle contractions with the arm above heart level. We used several experimental protocols to gain insight into how mechanical factors contribute to contraction‐induced rapid vasodilatation. The findings from the present study clearly indicate that acute increases in extravascular pressure (200 mmHg for 2 s) elicit a significant rapid vasodilatation in the human forearm (peak ΔFVC∼155%). Brief, 6 s sustained compressions evoked the greatest vasodilatation (ΔFVC∼260%), whereas the responses to single (2 s) and repeated compressions (five repeated 2 s compressions) were not significantly different (ΔFVC∼155%versus∼115%, respectively). This mechanically induced vasodilatation peaks within 1–2 cardiac cycles, and thus is dissociated from the temporal pattern normally observed in response to brief muscle contractions (∼4–7 cardiac cycles). A non‐linear relation was found between graded increases in extravascular pressure and both the immediate and peak rapid vasodilatory response, such that the responses increased sharply from 25 to 100 mmHg, with no significant further dilatation until 300 mmHg (maximal ΔFVC∼185%). This was in contrast to the linear intensity‐dependent relation observed with muscle contractions. Our collective findings indicate that mechanical influences contribute largely to the immediate vasodilatation (first cardiac cycle) observed in response to a brief, single contraction. However, it is clear that there are additional mechanisms related to muscle activation that continue to cause and sustain vasodilatation for several more cardiac cycles after contraction. Additionally, the potential contribution of mechanical influences to the total contraction‐induced hyperaemia appears greatest for low to moderate intensity single muscle contractions, and this contribution becomes less significant for sustained and repeated contractions. Nevertheless, this mechanically induced vasodilatation could serve as a feedforward mechanism to increase muscle blood flow at the onset of exercise, as well as in response to changes in contraction intensity, prior to alterations in local vasodilating substances that influence vascular tone.
Characterization of flow and mixing regimes within the ileum of the brushtail possum using residence time distribution analysis with simultaneous spatio‐temporal mapping
Authors: Janssen P. W. M. , Lentle R. G. , Asvarujanon P. , Chambers P. , Stafford K. J. , Hemar Y.
Published: May 2007

We studied the flow and mixing regimes in isolated segments of the terminal ileum of brushtail possums during spontaneous circumferential and longitudinal contractions under conditions that allowed backflow and compared them with those of inactive segments. Residence time distributions (RTDs) were determined by perfusion with two probes of different rheological properties to which an inert dye marker was added. Ileal segment volume and oscillatory flow during the period of RTD determination were derived from spatiotemporal maps. High viscosity guar gum solution generated RTDs characteristic of laminar flow in inactive ileal segments which confirmed that no slip was occurring at the mucosal layer. In active segments, motility and consequent oscillatory flow imparted significant additional axial dispersion to the flow patterns of both probes. Mixing occurred episodically during periods when intestinal volume was reduced and onflow was augmented by peristalsis, which may prevent the establishment of steady state conditions. Marker concentration rose more steeply when active ileal segments were being perfused with a probe of similar viscosity to normal digesta than with low viscosity Earle's/Hepes solution, each being subject to similar levels of oscillatory flow. This indicated that a coarser mixing regime prevailed and that absorption of nutrients from viscous digesta would rely to a greater degree on molecular diffusion.
Genetically manipulated mice: a powerful tool with unsuspected caveats
Authors: Matthaei Klaus I.
Published: May 2007

Although genetic manipulations in mice have provided a powerful tool for investigating gene function in vivo, recent studies have uncovered a number of developmental phenomena that complicate the attribution of phenotype to the specific genetic change. A more realistic approach has been to modulate gene expression and function in a temporal and tissue‐specific manner. The most common of these methods, the CreLoxP and tetracycline response systems, are surveyed here and their recently identified shortcomings discussed, along with a less well known system based on the E. coli lac operon and modified for use in mammals. The potential for further complications in interpretation due to hitherto unexpected epigenetic effects involving transfer of RNA or protein in oocytes or sperm is also explored. Given these problems we reiterate the necessity for the use of completely reversible methods that will allow each experimental group of animals to act as their own control. Using these methods with a number of specific modifications to eliminate non‐specific effects from random insertion sites and inducer molecules, the full potential of genetic manipulation studies should be realized.
Marine Growth Colonization Process in Guinea Gulf: Data Analysis
Authors: Boukinda Mbadinga Morgan L. , Schoefs Franck , Quiniou-Ramus Valerie , Birades Michel , Garretta Raymond
Published: May 2007

Colonization process of marine growth increasingly arouses the interest of the oil industry because engineering design or reassessment of platforms requires forecasting of biological fouling specific to the area where they are located. Numerous publications related to marine growth on installations of North Sea, Gulf of Mexico, or oil sites in other parts of the world tried to answer the need to supply more quantitative data on biological fouling. Unfortunately, there is a lack of qualitative and quantitative published data in the Gulf of Guinea, where biological fouling has a significant impact on cost of structural inspection and maintenance because of the importance of colonization due to favorable environmental parameters (warmer temperature of seawater, intense action of the waves generating a mixing of the nutritive elements, strong light, etc.). This paper is dedicated to bridge that gap and describe ecosystem dynamics of marine growth in the Gulf of Guinea. We describe patterns of development for dominant types of biofouling in the region. Analyses of evolution and related kinetics parameters are carried out to give main trends of colonization process. Predictive models of marine growth development and their statistical parameters are proposed for reassessment and engineering design.
Discrepancy between published Laplace difference equations on cylindrical dielectrics
Authors: Pinto Fabrizio
Published: May 2007

The problem of two unequal electrodes within a shielding cavity in the presence of a dielectric partially filling the gap is treated by means of overrelaxation methods in the axisymmetric case. A discrepancy in the literature concerning the boundary equation between two dielectrics is resolved and the difference equation for the dielectric corner point is obtained by means of Gauss’ law. Some numerical results are described.
Critical dipoles in one, two, and three dimensions
Authors: Connolly Kevin , Griffiths David J.
Published: May 2007

The Schrödinger equation for a point charge in the field of a stationary electric dipole admits bound states only when the dipole moment exceeds a certain critical value. It is not hard to see why this might be the case, but it is surprisingly difficult to calculate the critical dipole moment. The analogous problem should be simpler in one and two dimensions, but a general theorem forbids critical moments in one dimension, and explicit calculation shows that there is no critical moment in two dimensions.
Second Born approximation and Coulomb scattering
Authors: Holstein Barry R.
Published: May 2007

We examine the problem of calculating higher order contributions to the Coulomb scattering amplitude. To make contact with the well known result, it is necessary to modify the conventional definition of the scattering amplitude.
Introduction to modes and their designation in circular and elliptical fibers
Authors: Kumar Deepak , Choudhury P. K.
Published: May 2007

Some basic ideas are presented to clarify the concept of modes in optical fibers. We describe the formation of modes and the indexing schemes in circular and elliptical core fibers.
Berry’s phase through the path integral formulation
Authors: Alves M. A. , Thomaz M. T.
Published: May 2007

We study the evolution of a quantum system under adiabatic conditions using the path integral formulation. We obtain the Berry phase for systems with nondegenerate and degenerate energy spectra and recover well-known results. We also present a simple derivation of the adiabatic theorem.
An experiment on the Rayleigh instability of charged liquid drops
Authors: Fong Chee Sheng , Black Nathan D. , Kiefer Peter A. , Shaw Raymond A.
Published: May 2007

We describe a simple experiment to observe the fission of an electrically charged liquid droplet. Rayleigh charge instability occurs when the electrostatic repulsion of charges on the surface of a droplet overcomes the droplet surface tension and tears the droplet apart. The experiment requires a low-power laser, simple optics, a CCD camera, and a quadrupole trap, which can be constructed using widely available and relatively straightforward instructions. The experiment was performed primarily by undergraduates as part of their senior research projects and can be implemented readily in an advanced undergraduate physics laboratory course.
An efficient system for markerless gene replacement applicable in a wide variety of enterobacterial species
Authors: White A P , Allen-Vercoe E , Jones B W , DeVinney R , Kay W W , Surette M G
Published: May 2007

We describe an improved allelic-exchange method for generating unmarked mutations and chromosomal DNA alterations in enterobacterial species. Initially developed for use in Salmonella enterica, we have refined the method in terms of time, simplicity, and efficiency. We have extended its use into related bacterial species that are more recalcitrant to genetic manipulations, including enterohemorrhagic and enteropathogenic Escherichia coli and Vibrio parahaemolyticus. Data from over 50 experiments are presented including gene inactivations, site-directed mutagenesis, and promoter exchanges. In each case, desired mutations were identified by polymerase chain reaction screening typically from as few as 10–20 colonies up to a maximum of 300 colonies. The method does not require antibiotic nor nutritional markers in target genes and works efficiently in wild-type strains, obviating the need for specialized hosts or genetic systems. The use is simple, requiring basic laboratory materials, and represents an alternative to existing methods for gene manipulation in the Enterobacteriaceae.Key words: allelic exchange, temperature-sensitive plasmids.
Characterization and control of endophytic bacterial contaminants in in vitro cultures ofPiperspp.,Taxus baccatasubsp.wallichiana, andWithania somnifera
Authors: Kulkarni Anjali A , Kelkar S M , Watve M G , Krishnamurthy K V
Published: May 2007

Bacterial contamination is a serious problem that causes severe loss of in vitro grown cultures of a number of plants. This problem becomes even more acute if the bacterial contamination is of endophytic origin. In such cases, identification and characterization of the contaminants is essential for achieving specific control of the contaminants through selective use of antibiotic agents, especially if the routinely used contamination control methods practiced elsewhere in tissue culture studies are ineffective. Such is the case with the bacterial contamination observed in the present study. The five endophytic bacteria associated with Piper nigrum and Piper colubrinum, four endophytic bacteria associated with Taxus baccata subsp. wallichiana, two endophytic bacteria associated with Withania somnifera, and two bacteria common to all these plant species were isolated and characterized based on morphological and biochemical tests. Their taxonomic positions based on similarity indices were determined. A control strategy against these bacteria has been developed based on bacteriostatic or bactericidal actions of 12 antibiotics at three different concentrations by solid and liquid antibiogramme assays.Key words: antibiotics, endophytic bacterial contamination, identification, Piper nigrum, Piper colubrinum, Taxus baccata subsp. wallichiana, Withania somnifera.
The effect of Penicillium fungi on plant growth and phosphorus mobilization in neutral to alkaline soils from southern Australia
Authors: Wakelin S A , Gupta V V.S.R. , Harvey P R , Ryder M H
Published: May 2007

The phosphate solubilizing fungi Penicillium radicum, Penicillium bilaiae (strain RS7B-SD1), and an unidentified Penicillium sp. designated strain KC6-W2 were tested for their ability to increase the growth and phosphorus (P) nutrition of wheat, medic, and lentil in three soils of neutral to alkaline pH reaction. The strongest plant growth promoting (PGP) strain was Penicillium sp. KC6-W2, which stimulated significant increases in shoot growth and dry mass in seven of the nine experiments conducted. Levels of PGP by Penicillium sp. KC6-W2 ranged from 6.6% to 19% and were associated with increased uptake of P to the shoot. The PGP properties of Penicillium sp. KC6-W2 were evident on each of the three different plant species and soil types, a level of reliability not observed in other strains tested. Inoculation of seed with P. radicum increased lentil growth by 5.5% (P < 0.05) in soil from Tarlee but did not affect plant growth in the eight other experiments. Inoculation of plant seed with P. bilaiae RS7B-SD1 resulted in significant PGP in two of the nine experiments conducted. However, when significant, stimulation of PGP by P. bilaiae RS7B-SD1 was strong and resulted in increases in medic dry matter (19%) and lentil shoot dry matter (15%). A soil microcosm experiment investigated the effect of Penicillium fungi on cycling of soil P. Penicillium bilaiae RS7B-SD1 was the only fungus to significantly increase HCO3-extractable P (23% increase; P < 0.05). Production of phosphatase enzymes was not associated with increased HCO3-extractable P. Addition of carbon in the form of ryegrass seed significantly increased microbial respiration and movement of P to the microbial biomass (P < 0.05), but these parameters were irrespective of Penicillium treatment. This work has established the potential for use of Penicillium inoculants to increase plant growth on alkaline soils in Australia. The role of Penicillium fungi in plant P uptake and soil P cycling requires further exploration.Key words: Penicillium, phosphorus, plant growth promotion, phosphatase, rhizobia.
Decoloration of Amaranth by the white-rot fungusTrametes versicolor. Part II. Verification study
Authors: Gavril Mihaela , Hodson Peter V.
Published: May 2007

The involvement of lignin peroxidase (LiP) in the decoloration of the mono-azo substituted napthalenic dye Amaranth was investigated with pure enzymes and whole cultures of Trametes versicolor. The verification study confirmed that LiP has a direct influence on the initial decoloration rate and showed that another enzyme, which does not need hydrogen peroxide to function and is not a laccase, also plays a role during decoloration. These results confirm the results of a previous statistical analysis. Furthermore, the fungal mycelium affects the performance of the decoloration process.
Studies on uroporphyrinogen decarboxylase fromChlorella kessleri(Trebouxiophyceae, Chlorophyta)
Authors: Juárez Angela B. , Aldonatti Carmen , Vigna María S. , Ríos de Molina María del C.
Published: May 2007

Uroporphyrinogen decarboxylase (UroD) (EC 4.1.1.37) is an enzyme from the tetrapyrrole biosynthetic pathway, in which chlorophyll is the main final product in algae. This is the first time that a study on UroD activity has been performed in a green alga ( Chlorella ). We isolated and partially purified the enzyme from a Chlorella kessleri (Trebouxiophyceae, Chlorophyta) strain (Copahue, Neuquén, Argentina), and describe for the first time some of its properties. In C. kessleri, the decarboxylation of uroporphyrinogen III occurs in two stages, via 7 COOH and then 6 and 5 COOH intermediates, with the decarboxylation of the 7 COOH compound being the rate-limiting step for the reaction. Cultures in the exponential growth phase showed the highest specific activity values. The most suitable conditions to measure UroD activity in C. kessleri were as follows: 0.23–0.3 mg protein/mL, ?6–8 μmol/L uroporphyrinogen III, and 20 min incubation time. Gel filtration chromatography and Western blot assays indicated that UroD from C. kessleri is a dimer of approximately 90 kDa formed by species of lower molecular mass, which conserves enzymatic activity.
Role of chitinase and β-1,3-glucanase activities produced by a fluorescent pseudomonad and in vitro inhibition ofPhytophthora capsiciandRhizoctonia solani
Authors: Arora Naveen Kumar , Kim Min Jeong , Kang Sun Chul , Maheshwari Dinesh Kumar
Published: May 2007

A study was conducted to investigate the possibility of involvement of chitinase and β-1,3-glucanase of an antagonistic fluorescent Pseudomonas in growth suppression of phytopathogenic fungi, Phytophthora capsici and Rhizoctonia solani . Fluorescent Pseudomonas isolates GRC3and GRC4were screened for their antifungal potential against phytopathogenic fungi by using dual culture technique both on solid and liquid media. The percent inhibition was calculated. Various parameters were monitored for optimization of enzyme activities by fluorescent Pseudomonas GRC3. The involvement of chitinases, β-1,3-glucanases, and antifungal metabolites of nonenzymatic nature was correlated with the inhibition of P. capsici and R. solani. The results provide evidence for antibiosis as a mechanism for antagonism. The study also confirms that multiple mechanisms are involved in suppressing phytopathogens as evidenced by the involvement of chitinase and β-1,3-glucanase in inhibition of R. solani but not P. capsici by isolate GRC3.
Mycoplasmal membrane protein p37 promotes malignant changes in mammalian cells
Authors: Liu Wenbin , Ren Tingting , Jiang Beihai , Gong Manman , Shou Chengchao
Published: May 2007

Evidence of Mycoplasma hyorhinis infection in human gastric cancer tissues has been found in previous work. In this study, we demonstrate that the expression of p37, a membrane lipoprotein of M. hyorhinis, in mammalian cells induces antisenescence, enhances clonogenicity in soft agar, and co-operates with human epidermal growth factor receptor-related 2 to inhibit cell adhesion. Conversely, truncated p37 protein, with the first 28 amino acids deleted from its N terminal, promotes cell senescence. Taken together, our findings suggest that p37 promotes malignant changes in mammalian cells. With the identification of this molecular component, which is responsible for mycoplasma malignancy-promoting activity, it is possible that a better understanding of the relationship between M. hyorhinis infection and human gastric cancers will lead to novel diagnostics and therapeutics.