bluuebunny/crossref_metadata_2025 huggingface dataset:
Parasitic diseases and immunodeficiencies
Authors: AMBROISE-THOMAS P.
Published: June 2007

In the last two decades, major immunodeficiency syndromes have strongly influenced medical parasitology. Some animal parasitoses, once unknown in human medicine, have become zoonotic and sometimes anthroponotic. In other cases, the clinical evolution of human parasitoses has been severely aggravated and/or modified in immunodeficient patients especially in toxoplasmosis, cryptosporidiosis, leishmaniasis, strongyloidiasis and scabies. The parasites implicated are varied (protozoa, helminths and even Acaridae) but have in common the capacity to reproduce in or on the human host. These immunodeficiency syndromes are often related to AIDS but other major immunodepressions, such as post-therapeutically in organ transplantation, may also be responsible and raise difficult problems for prevention. The immunological mechanisms involved are not always well understood. In addition, genetic predisposition factors, gradually becoming better-understood in parasites and man, complete and complicate our understanding of the immunological mechanisms.
Heterologous immunity revisited
Authors: CLARK I. A.
Published: June 2007

Heterologous immunity, or protection by one invading organism against another across phylogenetic divides, has been recognised for decades. It was initially thought to operate largely through enhancement of phagocytosis, but this explanation became untenable when it was realised it worked extremely well against intraerythrocytic protozoa and killed them while they were free in the circulation. Clearly a soluble mediator was called for. This review summarises the logic that arose from this observation, which led to a wider appreciation of the roles of pro-inflammatory cytokines, and then nitric oxide, in the host's response against invaders, as well as the ability of these mediators to harm the host itself if they are generated too enthusiastically. This has led to a discernable pattern across heterologous immunity as a whole, and its lessons influence a range of areas, including vaccine development.
Use of an optimality model to solve the immunological puzzle of concomitant infection
Authors: GRAHAM A. L.
Published: June 2007

Immunological data indicate that different subsets of T-helper cells work best against different types of infection. Concomitant infection of a host may thus impose either conflicting or synergistic immune response requirements, depending upon the extent to which the component optimal immune responses differ. Drawing upon empirically-determined optimal responses to single-species infections, an optimality model is here used to generate testable hypotheses for optimal responses to concomitant infection. The model is based upon the principle that the joint immune response will minimize divergence from each of the optima for single-species infections, but that it will also be weighted by the importance of mounting the correct response against each infectious organism. The model thus predicts a weighted average response as the optimal response to concomitant infection. Data on concomitant infection of murine hosts by the parasitesSchistosoma mansoniandToxoplasma gondiiwill provide the first test of the optimality model. If the weighted average hypothesis holds true, then there are no emergent immunological properties of concomitant infections and we may be able to understand immune responses to concomitant infection directly via our understanding of single-species infections.
Dialect areas and dialect continua
Authors: Heeringa Wilbert , Nerbonne John
Published: June 2007

The organizing concept behind dialect variation is still seen
predominantly as the areas within which similar varieties are
spoken. The opposing view—that dialects are organized
in a continuum without sharp boundaries—is likewise popular.
This article introduces a new element into the discussion, which
is the opportunity to view dialectal differences in the aggregate.
We employ a dialectometric technique that provides an additive
measure of pronunciation difference: the (aggregate) pronunciation
distance. This allows us to determine how much of the linguistic
variation is accounted for by geography. In our sample of 27
Dutch towns and villages, the variation ranges between 65% and
81%, which lends credence to the continuum view. The borders
of well-established dialect areas nonetheless show large deviations
from the expected aggregate pronunciation distance. We pay
particular attention to a puzzle concerning the subjective
perception of continua introduced by Chambers and Trudgill (1998):
a traveller walking in a straight line from village to village
notices successive small changes, but seldom, if ever, observes
large differences. This sounds like a justification of the
continuum view, but there is an added twist. Might the traveller
be misled by the perspective of most recent memory? We use the
Chambers–Trudgill puzzle to organize our argument at several
points.
Verifying Visual Properties in Sentence Verification Facilitates Picture Recognition Memory
Authors: Pecher Diane , Zanolie Kiki , Zeelenberg René
Published: June 2007

Abstract. According to the perceptual symbols theory ( Barsalou, 1999 ), sensorimotor simulations underlie the representation of concepts. We investigated whether recognition memory for pictures of concepts was facilitated by earlier representation of visual properties of those concepts. During study, concept names (e.g., apple) were presented in a property verification task with a visual property (e.g., shiny) or with a nonvisual property (e.g., tart). Delayed picture recognition memory was better if the concept name had been presented with a visual property than if it had been presented with a nonvisual property. These results indicate that modality-specific simulations are used for concept representation.
Are Primary-School-Aged Children Experts in Spatial Associate Learning?
Authors: Jansen-Osmann Petra , Heil Martin
Published: June 2007

Abstract. In two experiments (Experiment 1: N = 180, Experiment 2: N = 150), we investigated the anecdotal observation that school age children are assumed to be experts in spatial associate learning. In the first experiment, second graders, sixth graders, and adults learned the associations between 32 pictures and either a position or a word. 16 pictures had each to be associated with one position in a 4-by-4 grid of squares (spatial condition); the other 16 pictures had each to be associated to one of 16 monosyllabic words (verbal condition). After a 3 min distractor interval the associated position or word had to be retrieved with the pictures as cues. In Experiment 2, the results were replicated in principle with modifications in the experimental details. Performance improvement as a function of age turned out to be substantially larger in the verbal condition compared to the spatial one. The results are traced back to the idea that spatial associate learning is a cognitive function maturating early during life span.
A climatological study of evapotranspiration and moisture stress across the continental United States based on thermal remote sensing: 2. Surface moisture climatology
Authors: Anderson Martha C. , Norman John M. , Mecikalski John R. , Otkin Jason A. , Kustas William P.
Published: June 2007

Robust satellite‐derived moisture stress indices will be beneficial to operational drought monitoring, both in the United States and globally. Using thermal infrared imagery from the Geostationary Operational Environmental Satellites (GOES) and vegetation information from the Moderate Resolution Imaging Spectrometer (MODIS), a fully automated inverse model of Atmosphere‐Land Exchange (ALEXI) has been used to model daily evapotranspiration and surface moisture stress over a 10‐km resolution grid covering the continental United States. Examining monthly clear‐sky composites for April–October 2002–2004, the ALEXI evaporative stress index (ESI) shows good spatial and temporal correlation with the Palmer drought index but at considerably higher spatial resolution. The ESI also compares well to anomalies in monthly precipitation fields, demonstrating that surface moisture has an identifiable thermal signature that can be detected from space, even under dense vegetation cover. Simple empirical thermal drought indices like the vegetation health index do not account for important forcings on surface temperature, such as available energy and atmospheric conditions, and can therefore generate spurious drought detections under certain circumstances. Surface energy balance inherently incorporates these forcings, constraining ESI response in both energy‐ and water‐limited situations. The surface flux modeling techniques described here have demonstrated skill in identifying areas subject to soil moisture stress on the basis of the thermal land surface signature, without requiring information regarding antecedent rainfall. ALEXI therefore may have potential for operational drought monitoring in countries lacking well‐established precipitation measurement networks.
Source evaluation of aerosols measured during the Indian Ocean Experiment using combined chemical transport and back trajectory modeling
Authors: Verma S. , Venkataraman C. , Boucher O. , Ramachandran S.
Published: June 2007

This work presents an analysis of aerosol measurements made during the Oceanographic Research Vessel Sagar Kanya cruise of January–March 1999, in the Indian Ocean Experiment intensive field phase (INDOEX‐IFP), with regard to the aerosol chemical constituents and identification of source regions of their origin. This is done through a hybrid approach which uses an Eulerian forward transport calculation in a general circulation model (GCM) with region‐tagged emissions along with an analysis of Lagrangian back trajectories and emission inventory information, for overlapping time periods. Back trajectory analysis showed that the ship was mainly influenced by air masses from the Indo‐Gangetic plain, central India, or south India during the early part of its cruise with the GCM‐predicted aerosol species composed of mainly sulfate and organic matter, whereas dust species dominated during its cruise in late February and early March over the Arabian Sea when the ship was influenced by air masses from Africa‐west Asia or northwest India. However, a typical clean marine aerosol dominated by sea salt was encountered during February when the ship cruised in the tropical Indian Ocean and was mostly influenced by marine air masses. The high aerosol optical depth was due to roughly equal parts of organic matter and sulfate. Region‐tagged GCM estimates showed the presence of distinct transport at surface and higher layers for, e.g., DOY 56–61 and 65–70, indicating strong signals of emissions of black carbon, organic matter, and sulfate originating in central and northwest India, whereas elevated transport channels of black carbon and organic matter from Africa‐west Asia. This is consistent with the back trajectory analysis and in corroboration with INDOEX measurement studies which observed different aerosol properties from aircraft and ship attributed to different transport pathways in surface and elevated flows. However, back trajectory analysis is not sufficient to evaluate the major source regions contributing to the transported aerosol. The fractional contribution of a source region also depended upon the emission flux from the region and its proximity to the receptor domain.
Biomass burning and pollution aerosol over North America: Organic components and their influence on spectral optical properties and humidification response
Authors: Clarke A. , McNaughton C. , Kapustin V. , Shinozuka Y. , Howell S. , Dibb J. , Zhou J. , Anderson B. , Brekhovskikh V. , Turner H. , Pinkerton M.
Published: June 2007

Thermal analysis of aerosol size distributions provided size resolved volatility up to temperatures of 400°C during extensive flights over North America (NA) for the INTEX/ICARTT experiment in summer 2004. Biomass burning and pollution plumes identified from trace gas measurements were evaluated for their aerosol physiochemical and optical signatures. Measurements of soluble ionic mass and refractory black carbon (BC) mass, inferred from light absorption, were combined with volatility to identify organic carbon at 400°C (VolatileOC) and the residual or refractory organic carbon, RefractoryOC. This approach characterized distinct constituent mass fractions present in biomass burning and pollution plumes every 5–10 min. Biomass burning, pollution and dust aerosol could be stratified by their combined spectral scattering and absorption properties. The “nonplume” regional aerosol exhibited properties dominated by pollution characteristics near the surface and biomass burning aloft. VolatileOC included most water‐soluble organic carbon. RefractoryOC dominated enhanced shortwave absorption in plumes from Alaskan and Canadian forest fires. The mass absorption efficiency of this RefractoryOC was about 0.63 m2 g−1 at 470 nm and 0.09 m2 g−1 at 530 nm. Concurrent measurements of the humidity dependence of scattering, γ, revealed the OC component to be only weakly hygroscopic resulting in a general decrease in γ with increasing OC mass fractions. Under ambient humidity conditions, the systematic relations between physiochemical properties and γ lead to a well‐constrained dependency on the absorption per unit dry mass for these plume types that may be used to challenge remotely sensed and modeled optical properties.
Can overshooting convection dehydrate the tropical tropopause layer?
Authors: Jensen E. J. , Ackerman A. S. , Smith J. A.
Published: June 2007

A numerical model is used to investigate the potential for irreversible dehydration near the tropical tropopause caused by overshooting deep convection. We show that convective updrafts overshooting the cold point tropopause can generate extremely cold, dry air within the updrafts. However, the updrafts contain sufficient mass in small (≤20 μm radius) ice crystals that do not sediment out of the short‐lived overshoots, such that when the overshoots collapse and warm back to the ambient temperature, these small crystals sublimate and rehydrate the air, resulting in no irreversible dehydration. Despite maximizing crystal size (and fall speed) by assuming low aerosol concentrations and using large ice‐ice collection efficiencies, we find no evidence to support the hypothesis that overshooting convection can dehydrate the tropical tropopause layer (TTL) when it is initially ice subsaturated. Only when the TTL is initially supersaturated with respect to ice do we find that deep convection can draw down the humidity, as vapor in excess of saturation condenses on the ice crystals. The overall impact of deep convection on the TTL water vapor budget depends on the climatology of TTL relative humidity in convective regions.
Molecular architecture of the human GINS complex
Authors: Boskovic Jasminka , Coloma Javier , Aparicio Tomás , Zhou Min , Robinson Carol V , Méndez Juan , Montoya Guillermo
Published: June 2007

Chromosomal DNA replication is strictly regulated through a sequence of steps that involve many macromolecular protein complexes. One of these is the GINS complex, which is required for initiation and elongation phases in eukaryotic DNA replication. The GINS complex consists of four paralogous subunits. At the G1/S transition, GINS is recruited to the origins of replication where it assembles with cell‐division cycle protein (Cdc)45 and the minichromosome maintenance mutant (MCM)2–7 to form the Cdc45/Mcm2–7/GINS (CMG) complex, the presumed replicative helicase. We isolated the human GINS complex and have shown that it can bind to DNA. By using single‐particle electron microscopy and three‐dimensional reconstruction, we obtained a medium‐resolution volume of the human GINS complex, which shows a horseshoe shape. Analysis of the protein interactions using mass spectrometry and monoclonal antibody mapping shows the subunit organization within the GINS complex. The structure and DNA‐binding data suggest how GINS could interact with DNA and also its possible role in the CMG helicase complex.
Presenilin/γ-secretase-dependent processing of β-amyloid precursor protein regulates EGF receptor expression
Authors: Zhang Yun-wu , Wang Ruishan , Liu Qiang , Zhang Han , Liao Francesca-Fang , Xu Huaxi
Published: June 2007

Presenilins (PS, PS1/PS2) are necessary for the proteolytic activity of γ-secretase, which cleaves multiple type I transmembrane proteins including Alzheimer's β-amyloid precursor protein (APP), Notch, ErbB4, etc. Cleavage by PS/γ-secretase releases the intracellular domain (ICD) of its substrates. Notch ICD translocates into the nucleus to regulate expression of genes important for development. However, the patho/physiological role of other ICDs, especially APP ICD (AICD), in regulating gene expression remains controversial because evidence supporting this functionality stems mainly from studies performed under supraphysiological conditions. EGF receptor (EGFR) is up-regulated in a wide variety of tumors and hence is a target for cancer therapeutics. Abnormal expression/activation of EGFR contributes to keratinocytic carcinomas, and mice with reduced
PS
dosages have been shown to develop skin tumors. Here we demonstrate that the levels of PS and EGFR in the skin tumors of
PS1
+/−
/
PS2
−/−
mice and the brains of
PS1/2
conditional double knockout mice are inversely correlated. Deficiency in PS/γ-secretase activity or APP expression results in a significant increase of EGFR in fibroblasts. Importantly, we show that AICD mediates transcriptional regulation of
EGFR
. Furthermore, we provide
in vivo
evidence demonstrating direct binding of endogenous AICD to the
EGFR
promoter. Our results indicate an important role of PS/γ-secretase-generated APP metabolite AICD in gene transcription and in EGFR-mediated tumorigenesis.
Radiocarbon and DNA evidence for a pre-Columbian introduction of Polynesian chickens to Chile
Authors: Storey Alice A. , Ramírez José Miguel , Quiroz Daniel , Burley David V. , Addison David J. , Walter Richard , Anderson Atholl J. , Hunt Terry L. , Athens J. Stephen , Huynen Leon , Matisoo-Smith Elizabeth A.
Published: June 2007

Two issues long debated among Pacific and American prehistorians are (
i
) whether there was a pre-Columbian introduction of chicken (
Gallus gallus
) to the Americas and (
ii
) whether Polynesian contact with South America might be identified archaeologically, through the recovery of remains of unquestionable Polynesian origin. We present a radiocarbon date and an ancient DNA sequence from a single chicken bone recovered from the archaeological site of El Arenal-1, on the Arauco Peninsula, Chile. These results not only provide firm evidence for the pre-Columbian introduction of chickens to the Americas, but strongly suggest that it was a Polynesian introduction.
Age Shall not Weary Them: Mental Health in the Middle-Aged and the Elderly
Authors: Trollor Julian N. , Anderson Tracy M. , Sachdev Perminder S. , Brodaty Henry , Andrews Gavin
Published: June 2007

Objective: The prevalence of mental disorders in the elderly is disputed. The debate in this area can be informed by data from large population surveys that contain sufficient elderly participants. The aim of the present paper was to provide the first direct comparison of the prevalence and demographic correlates of ICD-10 anxiety and affective disorders in the middle-aged and the elderly.

Method: The 12 month prevalence and demographic correlates of affective and anxiety disorders were compared in a community sample of middle-aged and elderly Australian residents who took part in the Australian National Mental Health and Well-being Survey (NMHWS).

Results: One in seven middle-aged participants and one in 16 elderly participants experienced symptoms consistent with any anxiety or affective disorder in the preceding 12 months. Compared to the middle-aged participants, the elderly had lower rates for most affective and anxiety disorders, and for the combined presence of any disorder. Demographic correlates of mental disorder, especially marital status, were different for the two groups.

Conclusions: Community-dwelling elderly in Australia have lower rates of mental disorder compared to the middle-aged. Differences in demographic correlates between groups support the notion that the determinants of mental disorder in the elderly differ substantially from those in middle age.
Microwave‐Assisted Rapid Modification of Zein by Octenyl Succinic Anhydride
Authors: Biswas Atanu , Sessa David J. , Lawton John W. , Gordon Sherald H. , Willett J. L.
Published: June 2007

Corn is one of the most important food and industrial crops in the United States. Zein constitutes about half of the endosperm proteins in corn. Potential applications of zein include use in fibers, adhesives, inks, cosmetics, textiles, and chewing gum. Recently, attempts have been made to utilize zein for food coatings and biodegradable materials. The new applications of zein require it to be resistant to water. Thus, we are interested in new routes for chemical modification of zein (Biswas et al, unpublished). 2‐Octenyl succinic anhydride (OSA) is extensively used in modifying food starches. Our objective was to take advantage of OSA hydophobicity, flexibility, and compatibility with nonpolar groups and incorporate OSA onto zein. This OSA‐modified zein would possess the best of both OSA and zein. A zein solution in dimethyl formamide (DMF) was reacted with various levels of OSA to give modified zein. In a microwave reactor, the reactions proceeded tremendously fast and they were over in 5 min. The anhydride group of OSA reacted with the hydroxyl/amine group of zein to form ester/amide of zein. The reaction of OSA‐modified zein was confirmed by proton nuclear magnetic resonance (NMR) and IR spectroscopy. The preliminary evaluation showed that zein and OSA‐modified zein had comparable mechanical properties.
French Bread Loaf Volume Variations and Digital Image Analysis of Crumb Grain Changes Induced by the Minor Components of Wheat Flour
Authors: Rouillé J. , Valle G. Della , Devaux M. F. , Marion D. , Dubreil L.
Published: June 2007

A standard quality flour for French breadmaking was fractionated by extraction of water‐soluble components (6% db) and by defatting (<1%db) to study the impact of soluble components and lipids on bread quality in terms of loaf specific volume (vs) and crumb structure. Addition of puroindolines (<0.2%) was also tested. Crumb cell structure was assessed by digital image analysis (DIA) according to erosion‐dilation and closing treatments. The fraction of cells area with size <1 mm (%d<1) was defined as an index of fineness of crumb structure. Both DIA procedures allowed differentiation of crumb structures obtained by various formulations and, in the range of composition modifications tested, variations by a factor of 2 of both criteria (vs and %d1) were obtained. Soluble fraction increased vs and decreased fineness. Defatting and adding puroindolines increased fineness with no effect on vs. The possible role of molecular components of each flour fraction was discussed in terms of rheological and foaming properties. DIA methods and flour recipes tested in this work offer a valuable tool for further studies on the processing‐structure‐properties relationships of French bread dough and crumb.
Impact of Cultivar and Environment on Size Characteristics of Wheat Proteins Using Asymmetrical Flow Field‐Flow Fractionation and Multi‐Angle Laser Light Scattering
Authors: Lemelin E. , Aussenac T. , Violleau F. , Salvo L. , Lein V.
Published: June 2007

The use of multi‐angle laser light scattering (MALLS) in conjunction with asymmetrical flow field‐flow fractionation (A‐FFFF) was investigated for the determination of the molecular weight distribution (MWD) of wheat proteins. The wheat flour proteins were dissolved by sonication in 0.1M sodium phosphate (pH 6.9) containing 2% SDS. The results presented make it evident that efficient separation and size characterization of monomeric (M < 105 g/mol) and polymeric protein (105 ≤ M < 108 g/mol) wheat proteins can be achieved with A‐FFFF/MALLS/UV in a single run. Therefore, this method appears to be able to detect significant modifications of MWD of wheat protein, whatever the factor inducing these alterations (i.e., genetic or environmental) and whatever the nature of these alterations (i.e., monomeric‐to‐polymeric ratio or MWD of polymeric protein). In the present study, we have indeed demonstrated that the MWD of wheat proteins can be altered from one cultivar to another in three main ways: by changing the relative amounts of monomeric and polymeric proteins, by changing the MWD of polymeric protein, and then by changing both the monomeric‐to‐polymeric ratio and the MWD of polymeric protein.
Quality Characteristics of Yellow Alkaline Noodles Enriched with Hull‐less Barley Flour
Authors: Hatcher D. W. , Lagasse S. , Dexter J. E. , Rossnagel B. , Izydorczyk M.
Published: June 2007

Roller milled flours from eight genotypes of hull‐less barley (HB) with normal, waxy, zero amylose waxy (ZAW), and high amylose (HA) starch were incorporated at 20 and 40% (w/w) with a 60% extraction Canada Prairie Spring White (CPSW, cv. AC Vista) wheat flour to evaluate their suitability as a blend for yellow alkaline noodles (YAN). The barley flour supplemented noodles were prepared using conventional equipment. Noodles containing 40% HB flour required less work input than the corresponding 20% blend noodles due to a higher water absorption at the elevated level of HB flour addition, which probably caused them to soften. The addition of any HB flour at either level to the CPSW flour resulted in significantly decreased brightness (L*) and yellowness (b*), elevated redness (a*), concomitant with a significantly greater number of specks per unit area of noodle sheet compared with the control flour. The addition of 40% HB flour to YAN decreased cook time and cooking losses. Noodle firmness, as determined by maximum cutting stress (MCS), was significantly increased by the addition of 40% HB flour. Noodle chewiness, as determined by the texture profile analysis (TPA), was affected by the type of starch in the barley samples; the addition of waxy and ZAW HB flour decreased chewiness, whereas normal and HA HB flour increased chewiness of composite noodles.
Mechanical and Physicochemical Characterization of Vitreous and Mealy Durum Wheat Endosperm
Authors: Samson M.‐F. , Mabille F. , Chéret R. , Abécassis J. , Morel M.‐H.
Published: June 2007

The mechanical, physical, and biochemical characteristics of mealy and vitreous endosperm were investigated. Endosperm were obtained from four durum wheat cultivars grown under different nitrogen fertilization designs. The textural properties and the density of the endosperm were measured on hand‐shaped parallelepiped endosperm samples. Endosperm protein content and composition and also gliadin composition were investigated by HPLC. Mechanical tests showed that mealy and vitreous endosperm differed in hardness and vitreousness. Vitreousness increased with nitrogen fertilization supply whereas there was no variation among the different cultivars. Hardness seemed to be linked to genotype and insensitive to nitrogen supply. From this result, we concluded that hardness and vitreousness are not related. Endosperm protein content and gliadin‐to‐glutenin ratio were related to nitrogen supply and increased especially when nitrogen supply was applied at flowering. At the same time, endosperm vitreousness increased. Further biochemical analyses were performed on 270 kernels, mealy or vitreous, hand‐picked from 148 different crops. Results showed that protein content of vitreous endosperm exceeded 9.7% in >90% of the cases. The glia/glu ratio was a less accurate predictor of kernel vitreousness, indicating that, by itself, it cannot account for the change in kernel vitreousness. Endosperm vitreous texture would rise above a threshold content of 9.7% protein within the endosperm.
Utilization of Hydroxypropylated Waxy Rice and Corn Starches in Korean Waxy Rice Cake to Retard Retrogradation
Authors: Han Jung‐Ah , Lee Bok‐Hee , Lim Wang Jin , Lim Seung‐Taik
Published: June 2007

A traditional waxy rice gel cake in Korea, Injulmi, was prepared with hydroxypropylated waxy rice and corn starches (molar substitutions 0.13 and 0.11, respectively), and the textural and retrogradation characteristics of the cake were compared with a conventional cake made of waxy rice flour. In the pasting viscogram, hydroxypropylated starches exhibited reduced pasting temperatures, but increased peak viscosities compared with the unmodified starches. Under differential scanning calorimetry, the Tg′ and ice melting enthalpy of the starch gel cakes were reduced by hydroxypropylation, which indicated that the modified starches had higher water‐holding capacity than the unmodified starches. The degree of retrogradation, as measured by the hardness of the gel cake and the melting enthalpy, was significantly reduced by hydroxypropylation and hydroxypropylated waxy rice starch was more effective in retarding the retrogradation than hydroxypropylated waxy corn starch
Effect of Different Enzymes on the Textural Stability of Shelf‐Stable Bread
Authors: Barrett Ann H. , Marando Gina , Leung Henry , Kaletunç Gönül
Published: June 2007

Three enzyme systems (2 amylase‐based and 1 protease‐based) were tested in shelf‐stable bread to determine effectiveness in preserving texture during storage for eight weeks. Each enzyme was tested in formulations without glycerol or with 6% glycerol. Bread samples were analyzed to determine physical properties (crumb density, crust‐to‐crumb ratio, rate of moisture distribution from crumb to crust), mechanical properties (modulus, and a parameter [C1] describing resistance to high levels of deformation obtained by fitting stress‐strain data to a three‐parameter function), and thermal properties (thermal stability and enthalpy of transitions) as a function of storage time. Mechanical properties were further analyzed to predict asymptotic firmness. Bread firmness after storage as evaluated in terms of modulus and C1 were lower in all enzyme‐added systems, the effect of protease being the most significant. Enzymes had less effect on glycerol‐containing systems with no apparent trend. The breads had complex thermal behavior and exhibited multiple transitions. Both amylase preparations in the presence of glycerol reduced the amount of starch recrystallization.
Rapid Quality Assessment of Wheat Cultivars Registered in Poland Using the 2‐g Mixograph and Multivariate Statistical Analysis
Authors: Dobraszczyk B. J. , Salmanowicz B. P. , Ługowska B. , Chełkowski J.
Published: June 2007

Baking and 2‐g mixograph analyses were performed for 55 cultivars (19 spring and 36 winter wheat) from various quality classes from the 2002 harvest in Poland. An instrumented 2‐g direct‐drive mixograph was used to study the mixing characteristics of the wheat cultivars. A number of parameters were extracted automatically from each mixograph trace and correlated with baking volume and flour quality parameters (protein content and high molecular weight glutenin subunit [HMW‐GS] composition by SDS‐PAGE) using multiple linear regression statistical analysis. Principal component analysis of the mixograph data discriminated between four flour quality classes, and predictions of baking volume were obtained using several selected mixograph parameters, chosen using a best subsets regression routine, giving R2 values of 0.862–0.866. In particular, three new spring wheat strains (CHD 502a‐c) recently registered in Poland were highly discriminated and predicted to give high baking volume on the basis of two mixograph parameters: peak bandwidth and 10‐min bandwidth.
Accumulation of γ‐Aminobutyric Acid in Giant‐Embryo Rice Grain in Relation to Glutamate Decarboxylase Activity and Its Gene Expression During Water Soaking
Authors: Liu L. L. , Zhai H. Q. , Wan J.‐M.
Published: June 2007

Glutamate decarboxylase (GAD) is the rate‐limiting enzyme for γ‐aminobutyric acid (GABA) synthesis. However, the relationship of GABA accumulation, GAD activity, and its gene expression in rice grain during water soaking is unknown yet. We assessed the role of GAD activity and its gene expression to GABA accumulation after the rice grain was soaked in water for 0, 1, 2, 4, 8, 16, and 32 hr. The results showed a continuous accumulation of GABA in steeped embryo, embryo‐less brown rice, and complete brown rice, respectively. Among them, embryo of brown rice had the maximal accumulation. The activity of GAD was gradually increasing during water soaking, and the enzyme activity was significantly higher in the embryo than in either the embryo‐less brown rice or whole brown rice. The results further indicated that the activity of GAD was markedly stimulated by 0.5 mmol/L of Ca2+, whereas it was almost completely inhibited by 1 mmol/L of Hg2+. Accordingly, the content of GABA in embryo paralleled the activity of GAD treated with Ca2+ or Hg2+. To measure the expression of three GAD homologous genes in steeped rice grain, a RT‐PCR method was developed using the housekeeping gene Actin as the control. Gene expression studies demonstrated differential expression patterns of the three GAD transcripts: OsGAD1, 2 and 3 in brown rice. These results suggested that the accumulation of GABA in rice grain could be attributed to the increase of OsGAD transcripts.
Granule‐Bound Starch Synthase I (GBSSI) in Quinoa (Chenopodium quinoa Willd.) and Its Relationship to Amylose Content
Authors: Lindeboom N. , Chang P. R. , Tyler R. T. , Chibbar R. N.
Published: June 2007

The amylose concentration in starch from 16 quinoa (Chenopodium quinoa Willd.) genotypes grown under identical conditions was 4–20%. Based on the amylose content, a selection of six genotypes was made. Starch granule‐bound proteins were extracted from six genotypes and analyzed using denaturing gel electrophoresis. Two major polypeptides with apparent molecular masses of 56 and 62 kDa were present in all genotypes. Both were identified as granule‐bound starch synthase I (GBSSI) using immunoblot analysis and internal peptide sequencing. The content of the two GBSSI isoforms in starch granules from the six genotypes, as determined by densiometry of the peptide bands, was positively correlated with the concentration of amylose in starch from mature seed. Starch synthase activity in developing seed was positively correlated to starch concentration in seed and amylose concentration in starch during seed development.
Evaluation of Operating Conditions for Surface Lipid Extraction from Rice Using a Soxtec System
Authors: Matsler A. L. , Siebenmorgen T. J.
Published: June 2007

The degree of milling (DOM) of rice is a measure of how well the germ and bran layers are removed from the surface of rice kernels during milling. Because the majority of rice kernel lipids are found on the surface, measuring the surface lipid content (SLC) of rice after milling may be one way to quantify the DOM of rice. While there are several methods to measure the lipid content (LC) of rice, there is not an established standard method for determining the SLC of milled rice. The objective of this study was to evaluate the primary operating variables of a Soxtec apparatus in measuring the SLC of milled rice. This was accomplished by varying the preextraction drying, boiling, rinsing, and postextraction drying durations, as well as the solvent used for extraction, to achieve the maximum extraction of lipids from rice. Experiments were performed on stored Oryza sativa L. ‘Cypress’ and ‘Bengal’ rice milled for 10, 30, and 60 sec. Results showed that durations of 1 hr of preextraction, 20 min of boiling, 30 min of rinsing, and 30 min of postextraction drying provided the maximum lipid extraction from milled head rice with petroleum ether. Of the three solvents tested, petroleum ether, and ethyl ether yielded similar extraction results.
Microbial Transglutaminase as a Tool to Restore the Functionality of Gluten from Insect‐Damaged Wheat
Authors: Bonet A. , Caballero P. A. , Gómez M. , Rosell C. M.
Published: June 2007

In some wheat‐growing countries, considerable quantities of commercial wheat are rendered unusable in standard baking because of preharvest damage of the grain by protease‐injecting bugs. In the present study, we studied the ability of transglutaminase (TG) treatment of damaged wheat flour to return the functionality of the gluten network. To confirm the TG cross‐linking, the degree of protein hydrolysis, the amount of free thiol groups, and the electrophoresis properties of glutenin subunits were determined. The effectiveness of the TG treatment on insect‐damaged wheat was analyzed by measuring the dough mixing behavior and the gluten quality. A decrease in the degree of hydrolysis (or free amino groups), a reduction in thiol group concentration, and a decrease of extractable high molecular weight glutenin subunits (HMW‐GS) (measured by high‐performance capillary electrophoresis) confirmed the protein cross‐linking catalyzed by TG, the simultaneous formation of disulfide bonds by the proximity of the cross‐linked polypeptide chains, and the formation of aggregates of high molecular weight. The TG treatment of the damaged wheat flour led to a recovery of the consistograph parameters and gluten index value, and the covalent nature of the bonds ensured the stability of the protein changes.
Effect of Composition of Feed Model Systems on Pellet Quality: A Mixture Experimental Approach. II
Authors: Cavalcanti Walker B. , Behnke Keith C.
Published: June 2007

The quality of pelleted feeds is dependent on several variables among which formulation is recognized as having the heaviest influence. An experiment was conducted to investigate the functional properties of feed ingredient components when these ingredients were blended at different proportions on the physical quality of pelleted feeds as measured by the pellet durability index (PDI). Thirteen treatments consisting of different inclusion levels of corn, soybean meal, and soybean oil were designed and a total of 18 batches manufactured, processed, and tested for PDI. Three‐dimensional plots were used to depict the relationships between composition of the formulations and PDI. Results showed only a weak dependence of the response on the starch levels in the formulas and the degree of starch gelatinization. Protein, especially from soybean meal, had a positive effect on PDI, whereas a strong negative effect was observed following fat inclusion in the mixer at levels >6.5%. Empirical equations devised by multiple regression analysis adequately predicted PDI of verification batches.
Alkaline‐Carbonate Noodles from Hard Winter Wheat Flours Varying in Protein, Swelling Power, and Polyphenol Oxidase Activity
Authors: Zhao L. F. , Seib P. A.
Published: June 2007

The effects of wheat protein and starch on yellow‐alkaline noodles have not been fully clarified. Twenty‐four hard winter wheats with varying protein, hot‐water swelling power (SP95), and polyphenol oxidase (PPO) activity were milled into long‐patent and short‐patent flours. Protein, SP95, and PPO activity in the 48 flours were 8.2–12.9%, 16.2–24.1 g/g, and 80–157 ΔA480/mg of protein/min, respectively. Lightness of raw noodles declined with increasing protein and PPO levels but yellowness decreased and then increased. Tensile force to break the cooked noodles was positively correlated with SP95 and protein. Compression (50%) force of noodles made from flour with high SP95 ≈21 g/g, averaged ≈20% below those made from low SP95 ≈17 g/g of flour. Compression force was measured in the long dimension of a single noodle strand using a rectangular probe. The instrumental measurements suggest that alkaline noodles made from a single‐null partial‐waxy wheat with medium SP95 ≈19.9 g/g will have a tender bite and a cohesive texture compared with those from a low SP95 wheat with a hard bite and fracturable texture. Furthermore, alkaline noodles from a double‐null partial‐waxy wheat with high SP95 will have an extra soft bite unless flour protein is above ≈12.5%. Hard‐white, dual‐purpose wheat should have a low level of PPO and, depending on the preferred noodle‐eating texture, a low to medium SP95 level. Such wheats with medium protein levels (11–12%) are well suited for alkaline noodles because of improved color and surface smoothness, whereas the same wheats with 12–13% protein are well suited for bread. Wheats with medium SP95 also reduce cooking loss and increase cooked yield.
Studies of Partial Amino Acid Sequences of γ‐40k Secalins of Rye
Authors: Gellrich Claudia , Schieberle Peter , Wieser Herbert
Published: June 2007

Though γ‐40k secalins are a major protein type within rye storage proteins, total amino acid sequences are not as well known as the gluten proteins of wheat. Well‐reputed structural features such as amino acid compositions and molecular masses indicated a close relationship between γ‐40k secalins and γ‐gliadins of wheat, but the degree of homology of amino acid sequences and the positions of intramolecular disulfide bonds are unknown. Therefore, two major components of γ‐40k secalins (R1, R2) were analyzed for partial amino acid sequences. The R1 and R2, derivatized with 4‐vinylpyridine, were isolated from the prolamin fraction of rye cultivar Danko by means of a two‐step RP‐HPLC on C18 silica gel. The proteins were digested in parallel with trypsin and thermolysin, and the partial hydrolyzates were separated by RP‐HPLC. Simultaneous measurement of UV absorbance at 210 and 254 nm allowed the detection of all peptides eluted as well as the specific detection of pyridylethylated cysteine peptides. Isolated peptides were characterized by sequence analysis, and in parts by mass spectrometry, and assigned to known sequences of γ‐gliadins. The results demonstrated that the N‐terminal domain of R1 and R2 remained undigested after tryptic hydrolysis; they were in agreement with the N‐terminal domain of γ‐gliadins in their molecular masses and in the absence of cysteine residues. Most of the isolated peptides originated from the C‐terminal domains, they covered 83% (R1) and 77% (R2), respectively, of the C‐terminal domain of a known γ‐gliadin (clone pW1020). Comparison of R1 and R2 revealed differences only in a few sequence positions. The degree of homology between the C‐terminal domains present in γ‐40k secalins and γ‐gliadins was ≈85%. All eight cysteine residues of γ‐gliadins were found in R1 and R2 sequences. Remarkably, sequences close to corresponding cysteine residues were identical for γ‐40k secalins and γ‐gliadins. Therefore, it can be assumed that the positions of intramolecular disulfide links are homologous.
Effect of Microwave Heating of Kafirin on the Functional Properties of Kafirin Films
Authors: Byaruhanga Yusuf B. , Erasmus Corinda , Taylor John R. N.
Published: June 2007

To improve the functional properties of cast kafirin films, dry kafirin, extracted with an aqueous ethanol‐based solvent at 70°C, was microwave‐heated. No effect on film tensile properties was found. Two strategies were employed to improve the effect of microwaving: extraction of kafirin using an aqueous tert‐butanol‐based solvent at ambient temperature to minimize temperature‐induced denaturation and wetting the kafirin to increase its dielectric properties. Microwave heating this kafirin to 90 or 96°C and holding for 1–2 min more than doubled maximum tensile strength and Young's modulus, and decreased strain by about one‐third compared with films made from nonmicrowaved kafirin. Film water vapor permeability was reduced by at least one‐third. Digestibility of microwaved kafirin and films was also substantially decreased, and film biodegradability was slowed slightly. Microwave heating gave a film microstructure with fewer and smaller size pores. SDS‐PAGE showed microwave‐induced intermolecular cross‐linking of the kafirin monomers, which was possibly responsible for the modification of film properties. Microwave heating of kafirin can be used to modify kafirin film properties, but the kafirin must be microwaved wet and be as close as possible to its native state.
SME‐Arrhenius Model for WSI of Rice Flour in a Twin‐Screw Extruder
Authors: Lei Hanwu , Fulcher R. Gary , Ruan Roger , van Lengerich Bernhard
Published: June 2007

We have modeled a rice extrusion process focusing specifically on the starch gelatinization and water solubility index (WSI) as a function of extrusion system and process parameters. Using a twin‐screw extruder, we examined in detail the effect of screw speed (350–580 rpm), barrel temperature, different screw configurations, and moisture content of rice flour on both extrusion system parameters (product temperature, specific mechanical energy [SME], and residence time distribution [RTD]) and extrudate characteristics (expansion, density, WSI, and water absorption index [WAI]). Changes in WSI were monitored to reveal a relationship between the reaction kinetics during extrusion and WSI. Reaction kinetics models were developed to predict WSI during extrusion. WSI followed a pseudo first‐order reaction kinetics model. It became apparent that the rate constant is a function of both temperature and SME. We have developed an adaptation of the kinetic model based on the Arrhenius equation that shows better correlations with SME and distinguishes data from different screw configurations. This adaptation of the model improved predictability of WSI, thereby linking the extrusion conditions with the extruded product properties.
Classifying Paddy Rice by Morphological and Color Features Using Machine Vision
Authors: Liu Chang‐Chun , Shaw Jai‐Tsung , Poong Keen‐Yik , Hong Mei‐Chu , Shen Ming‐Lai
Published: June 2007

From five paddy rice cultivars grown in Taiwan and harvested in the summers of 1997, 1998, and 1999, five calibrated models were established by backpropagation neural network program through different morphological and color features selection for classifying paddy rice harvested in the summer of 2000. With 60 features, the average classification rates of Model 1 and Model 5 were 92 and 99.8%, respectively. With the most effective 50 features, by loading in the first principal component, the average classification rate of Model 2 was 90.0%. With 35 features selected from the correlation coefficient matrix, the average classification rate of Model 3 was 91.0%. With the most effective 20 features of area, area/perimeter, 48th width, shape factor, maximum length/maximum width, average intensity of blue, maximum length, average intensity of green, 47th width, 50th width, average intensity of red, 1st width, 19th width, 5th width, 6th width, 29th width, perimeter, 46th width, 42nd width, and 4th width based on the contribution of the training model, the average classification rate of Model 4 was 91.8% and would be recommended for classifying five paddy rice cultivars of set trading prices because it required fewer features and held a stable classification rate.