bluuebunny/crossref_metadata_2025 huggingface dataset:
New confidence bounds for QT studies
Authors: Boos Dennis D. , Hoffman David , Kringle Robert , Zhang Ji
Published: February 2007

The proposed guidelines for the assessment of the effect of new pharmaceutical agents on the QT interval (beginning of QRS complex to end of T wave on the electrocardiogram) are based on the maximum of a series over time of simple one‐sided 95 per cent upper confidence bounds. This procedure is typically very conservative as a procedure for obtaining a 95 per cent bound for the maximum of the population parameters. This paper proposes new bounds for the maximum, both analytical and bootstrap‐based, that are lower but still achieve correct coverage in the context of crossover and parallel designs for the most realistic portions of the parameter space. Copyright © 2007 John Wiley & Sons, Ltd.
Assessment of sediment toxicity during anaerobic biodegradation of vegetable oil using Microtox® and Hyalella azteca bioassays
Authors: Li Zhengkai , Lee Kenneth , Cobanli Susan E. , King Thomas , Wrenn Brian A. , Doe Kenneth G. , Jackman Paula M. , Venosa Albert D.
Published: February 2007

The potential ecological impacts of anaerobic degradation of vegetable oil on freshwater sediments were investigated. Sediment toxicity was evaluated using two regulatory biotests: the Microtox® Solid Phase Test and an amphipod (Hyalella azteca) bioassay. The results of the Microtox test showed that the toxicity of the vegetable‐oil‐contaminated sediments (about 17–33 g oil/kg dry sediments) increased after 2 weeks incubation and then decreased to near background levels after incubation for 8 weeks under anaerobic conditions. The amphipod toxicity bioassay showed that the toxicity of fresh contaminated sediments decreased over time and returned to background levels within 8 weeks. These results suggest that the impact of vegetable oils on organisms within sediments may be limited. To account for the significance of environmental conditions, additional studies over a wide range of incubation conditions (e.g., temperature, nutrient concentration) and other test organisms at various trophic levels are recommended for both acute and chronic toxicity assessment. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 1–8, 2007.
Phosphate regulates uranium(VI) toxicity to Lemna gibba L. G3
Authors: Mkandawire Martin , Vogel Kerstin , Taubert Barbara , Dudel E. Gert
Published: February 2007

The influence of phosphate on the toxicity of uranium to Lemna gibba G3 was tested in semicontinuous culture with synthetic mine water developed as an analogue of surface water of two abandoned uranium mining and ore processing sites in Saxony, Germany. Six concentrations of uranium were investigated under five different supply regimes of PO43− at constant pH (7.0 ± 0.5) and alkalinity (7.0 ± 1.6 mg L−1 total CO32−). The results showed significant inhibition of specific growth rates in cultures exposed to the highest uranium concentrations (3500 and 7000 μg U L−1) at lowest PO43− supply of 0.01 mg L−1. An increase of phosphate concentration from 0.01 to 8.0 mg L−1 resulted in an increase of EC50 from 0.9 ± 0.2 to 7.4 ± 1.9 mg L−1 (significant with Student's t test, P > 0.05). The accumulation of uranium in L. gibba increased exponentially with the increase in uranium concentration in cultures with 0.01 and 0.14 mg PO43− L−1. Accumulation also increased significantly when PO43− supply was increased from 0.14 to 1.36 mg PO43− L−1 for all uranium concentrations. However, as the supply of PO43− gradually increased from 1.36 to 8.0 mg PO43− L−1, uranium bioaccumulation increased slightly but insignificantly before leveling off. Uranium speciation modeling with PhreeqC geochemical code predicted increases in the proportions of uranyl phosphate species when PO43− concentrations increase in the media. Most of these uranyl phosphate species have a high probability of precipitation [saturation indices (SI) > 0.93]. Therefore, the alleviation of uranium toxicity to L. gibba with phosphates is due to interactions among components of the media, mainly uranyl and phosphate which results in precipitation. Consequently, bioavailable fractions of uranium to L. gibba are reduced. This might explain lack of consistent EC50 values for uranium to most aquatic organisms. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 9–16, 2007.
Effects of dietary boron on cervical cytopathology and on micronucleus frequency in exfoliated buccal cells
Authors: Korkmaz Mehmet , Uzgören Engin , Bakırdere Sezgin , Aydın Fırat , Ataman O. Yavuz
Published: February 2007

Recent evidence indicates that boron and borates may have anticarcinogenic properties. In this study, we have investigated the incidence of adverse cytological findings in cervical smears and the micronucleus (MN) frequency in women living in boron‐rich and boron‐poor regions. Cervical smears were prepared from 1059 women with low socioeconomic status; 472 of the women lived in relatively boron‐rich rural areas, while 587 lived in relatively boron‐poor regions. The average and standard deviation values for the age of the women screened with the cervical Pap smear test were 41.55 ± 8.38. The mean dietary intake of boron was 8.41 mg/day for women from the boron‐rich regions, and 1.26 mg/day for women living in the boron‐poor regions (P < 0.0001). Women from the boron‐rich regions had no cytopathological indications of cervical cancer, while there were cytopathological findings for 15 women from the boron‐poor areas (χ2 = 10.473, P < 0.05). Sixty women, 30 from each region, were chosen for evaluating MN frequencies in exfoliated buccal cells. MN frequencies for women from the boron‐rich and boron‐poor regions were not significantly different (t = −0.294, P > 0.05). Also, there were no significant correlations between age and MN frequency for women from both the boron‐rich (r = 0.133, P = 0.48, P > 0.05) and boron‐poor (r = −0.033, P = 0.861, P > 0.05) regions. The results suggest that ingestion of boron in the drinking water decreases the incidence of cervical cancer‐related histopathological findings. There was no correlation between the pathological findings from the cervical smears and buccal cell MN frequency suggesting that the two study populations were exposed equally to gentotoxic agents. Nonetheless, cervical cancer‐related histopathological findings should be validated by other researchers. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 17–25, 2007.
Occurrence of the cyanobacterial toxin cylindrospermopsin in northeast Germany
Authors: Fastner Jutta , Rücker Jacqueline , Stüken Anke , Preußel Karina , Nixdorf Brigitte , Chorus Ingrid , Köhler Antje , Wiedner Claudia
Published: February 2007

The frequent occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in the (sub)tropics has been largely associated with cyanobacteria of the order Nostocales of tropical origin, in particular Cylindrospermopsis raciborskii. C. raciborskii is currently observed to spread northwards into temperate climatic zones. In addition, further cyanobacteria of the order Nostocales typically inhabiting water bodies in temperate regions are being identified as CYN‐producers. Therefore, data on the distribution of CYN in temperate regions are necessary for a first assessment of potential risks due to CYN in water used for drinking and recreation. A total of 127 lakes situated in the north‐eastern part of Germany were investigated in 2004 for the presence of the toxin CYN and the phytoplankton composition. The toxin could be detected in half of the lakes (n = 63) and in half of 165 samples (n = 88). Concentrations reached up to 73.2 μg CYN/g DW. CYN thus proved more widely distributed than previously demonstrated. The analyses of phytoplankton data suggest Aphanizomenon sp. and Anabaena sp. as important CYN producers in Germany, and confirm recent findings of Aphanizomenon flos‐aquae as CYN‐producing species frequently inhabiting water bodies in temperate climatic regions. The data shown here suggest that CYN may be an important cyanobacterial toxin in German water bodies and that further data are needed to assess this. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 26–32, 2007.
Toxicity of the quinalphos metabolite 2‐hydroxyquinoxaline: Growth inhibition, induction of oxidative stress, and genotoxicity in test organisms
Authors: Riediger Sonja , Behrends Andreas , Croll Björn , Vega‐Naredo Ignacio , Hänig Nils , Poeggeler Burkhard , Böker Jutta , Grube Sascha , Gipp Juliane , Coto‐Montes Ana , Haldar Chandana , Hardeland Rüdiger
Published: February 2007

The quinalphos metabolite 2‐hydroxyquinoxaline (HQO), previously shown to photocatalytically destroy antioxidant vitamins and biogenic amines in vitro, was tested for toxicity in several small aquatic organisms and for mutagenicity in Salmonella typhimurium. In the rotifer Philodina acuticornis, HQO caused the disappearance of large individuals and increased hydroperoxide concentration. The latter effect was not only observed in animals kept in a light/dark cycle, but also in constant darkness, indicating that HQO can assume a reactive state and/or form reactive intermediates under the influence of either light or redox‐active metabolites, in particular, free radicals. Cell proliferation was inhibited in the ciliate Paramecium bursaria. In the dinoflagellate Lingulodinium polyedrum, which allows early detection of cellular stress on the basis of bioluminescence measurements, strong rises in light emission became apparent on the 2nd day of exposure to HQO and continued until cells died between 12 and 18 days of treatment. Oxidative damage of protein by HQO was demonstrated by measuring protein carbonyl in L. polyedrumin vivo as well as in light‐exposed bovine serum albumin in vitro. In an Ames test of mutagenicity, HQO proved to be genotoxic in both light‐ and dark‐exposed bacteria. HQO appears as a source of secondary quinalphos toxicity, which deserves further attention. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 33–43, 2007.
Early pregnancy failure induced by dibutyltin dichloride in mice
Authors: Ema Makoto , Fujii Sakiko , Ikka Tsuguo , Matsumoto Mariko , Hirose Akihiko , Kamata Eiichi
Published: February 2007

In this study, we examined the adverse effects of dibutyltin on initiation and maintenance of pregnancy after maternal administration during early pregnancy in mice. Following successful mating, female ICR mice were given dibutyltin dichloride (DBTCl) at 0, 7.6, 15.2, or 30.4 mg/kg bw/day by gastric intubation on days 0–3 or days 4–7 of pregnancy. Female mice were sacrificed on day 18 of pregnancy, and the pregnancy outcome was determined. After administration of DBTCl on days 0–3, the rate of nonpregnant females and the incidence of preimplantation embryonic loss were significantly increased at 30.4 mg/kg bw/day. The incidences of postimplantation embryonic loss in females given DBTCl on days 0–3 at 15.2 mg/kg and higher and on days 4–7 at 7.6 mg/kg bw/day and higher were increased. No increase in the incidence of fetuses with external malformations was observed after the administration of DBTCl on days 0–3 or days 4–7. A decline in the serum progesterone levels was detected in mice given DBTCl at 30.4 mg/kg bw/day on days 0–3 or days 4–7 of pregnancy. The data show that DBTCl adversely affects the initiation and maintenance of pregnancy when administered during early pregnancy in mice and suggest that the decline in serum progesterone levels is responsible for pregnancy failure. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 44–52, 2007.
Alteration of monoamine concentrations in the brain of medaka, Oryzias latipes, exposed to tributyltin
Authors: Nakayama Kei , Oshima Yuji , Tachibana Tetsuya , Furuse Mitsuhiro , Honjo Tsuneo
Published: February 2007

We measured the concentrations of monoamines in the brain of Japanese medaka, Oryzias latipes, exposed to tributyltin (TBT). Fish were exposed to 0, 1, 5, 25, or 125 μg g−1 of TBT via the diet for 21 days. After the administration period, six males and six females in each treatment group were dissected and their brains were collected. The following monoamines were analyzed: dopamine (DA), norepinephrine (NE), epinephrine (E), and 5‐hydroxytryptamine (5‐HT). The metabolites of DA, 3,4‐dihydroxyphenylacetic acid and homovanilic acid, and the metabolite of 5‐HT, 5‐hydroxyindolacetic acid were also analyzed. The concentration of DA in the brain of male medaka and the concentrations of 5‐HT and NE in the female brains were significantly decreased by exposure to 125 μg TBT g−1. The concentrations of 5‐HT and NE in males and of DA in females were slightly decreased by 125 μg g−1 of TBT, although the differences were not statistically significant. The present study demonstrates that TBT alters monoamine concentrations in the brain of medaka. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 53–57, 2007.
Diesel exhaust particles disturb gene expression in mouse testis
Authors: Mori Tetsuya , Watanuki Taro , Kashiwagura Tadashi
Published: February 2007

Inhalation of diesel exhaust particles (DEP) has been found to reduce sperm production. There is a possibility that DEP exposure elicits changes in gene expression in testis. To identify the alteration of gene expression resulting from DEP exposure, we constructed subtracted cDNA libraries from mouse testis using the suppression subtractive hybridization method. We isolated 16 candidate clones whose expression levels changed after exposure. Some of these candidates were highly similar to known testis‐specific genes. Some of the clones also seemed to correlate with spermatogenesis. Northern blot analysis revealed that DEP exposure changed the expression levels of several clones in a dose‐dependent manner. For example, the expression of clone R8, which was very similar to human XRRA1, increased by 2.3‐fold in testis after DEP exposure. On the other hand, the expressions of long‐chain acyl‐CoA synthetase 6 (Acsl6) and serine/threonine kinase 35 reduced by 0.3‐fold. These results indicated that some constituents of DEP alter gene expression in the testis. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 58–63, 2007.
A rapid microbiotest for the detection of cyanobacterial toxins
Authors: Törökné Andrea , Vasdinnyei Rita , Asztalos B. Mária
Published: February 2007

Cyanobacteria occur widely in lakes, reservoirs, ponds, and slow flowing rivers. Many species are known to produce toxins (cyanotoxins), a number of which are of concern for health. Cyanotoxins vary in chemical structure and may be found intracellular or released into water. There is not only a wide variation in the toxicity of known cyanotoxins but a substantial number of toxins have to date not been identified chemically. Chemical analysis of cyanotoxins is nowadays not used for routine monitoring because it is time consuming, it requires specialized equipment and expertise, and is hence expensive. There is hence an urgent need for rapid tests in surface waters to detect cyanobacterial toxins because of the need for safe drinking water and safe natural bathing waters, which may be burdened by cyanobacterial blooms or scums. Previous investigations have already shown that larvae of the anostracan crustacean Thamnocephalus platyurus are quite sensitive to neurotoxic and hepatotoxic cyanotoxins. The present paper reports on the sensitivity comparison of the (1 h) Rapidtoxkit (based on a sublethal endpoint) and the (24 h) Thamnotoxkit microbiotest (based on mortality). Both assays make use of larvae of T. platyurus. The Rapidtoxkit is a new microbiotest that determines the decrease of ingestion of colored particles by the crustacean larvae, which are stressed by a short exposure to toxicants. Fifteen cyanobacterial samples composed of laboratory strains and natural bloom samples were tested by both microbiotests. All samples were also analyzed concurrently by HPLC for microcystins and cylindrospermopsin. The correlation coefficient between the two microbiotests (r = 0.82) showed the very good correspondence between the sublethal and the lethal effects. No known toxins could be detected in some samples, although the latter were found highly toxic to the test organisms in both bioassays. These results point to the presence of unknown toxin(s) produced by some cyanobacteria such as e.g., the Cylindrospermopsis raciborskii strain isolated from Lake Balaton in Hungary. This comparative study clearly showed that the 1 h Rapidtoxkit is an attractive rapid alternative to the Thamnotoxkit microbiotest. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 64–68, 2007.
Accumulation of nodularin in sediments, mussels, and fish from the Gulf of Gdańsk, southern Baltic Sea
Authors: Mazur‐Marzec Hanna , Tymińska Anna , Szafranek Janusz , Pliński Marcin
Published: February 2007

In the Gulf of Gdańsk, as in other parts of the Baltic Sea, toxic blooms of Nodularia spumigena are an annual phenomenon. In the present work, the accumulation of nodularin (NOD), a cyanobacterial pentapeptide hepatotoxin, in sediments, blue mussels, and flounders from the Gulf of Gdańsk was studied by enzyme‐linked immunosorbent assay (ELISA). In the surface layers of the sediments NOD concentration ranged from 2.3 ng/g dry weight (dw) several months after cyanobacterial bloom to 75 ng/g dw during the bloom. The highest toxin content in mussels was 139 ng/g dw. In two sampling stations situated in the coastal waters of the Gulf of Gdańsk the concentrations of NOD in sediments and mussels were significantly lower than those measured in the Gulf of Finland. In sediments and mussels collected in the Gulf of Gdańsk, the toxin was also detected in March when N. spumigena did not occur. In flounder, NOD accumulated in the liver (489 ng/g dw), guts (21 ng/g dw), and gonads (21 ng/g dw). Hybride quadrupole‐time‐of‐flight liquid chromatography/mass spectrometry/mass spectrometry (TOF‐LC/MS/MS) confirmed the presence of NOD in sediment, mussel, and fish samples. Additionally, other NOD analogues, ([DMAdda3]NOD and [dhb5]NOD), were detected in sediments and mussel tissue. No NOD conjugates with reduced glutathione or cysteine were found in fish and mussels. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 101–111, 2007.
1H NMR spectra of methylcitric acid in urine
Authors: Krawczyk H. , Gradowska W.
Published: February 2007

Methylcitric acid (3‐carboxy‐3‐hydroxy‐2‐methyl‐pentanedioic acid; MCA) is elevated in body fluids of patients with propionic acidaemia (PA; McKusick: 232000, 232050), methylmalonic aciduria (MMA; McKusick: 251000, 251120) and multiple carboxylase deficiency (McKusick: 253260, 253270). MCA molecule has two stereogenic centers so that it can occur in the form of four stereoisomers. Only two stereoisomers of MCA, (2S, 3S) and (2R, 3S), were found in human urine. They have different spectra and can be easily distinguished. We performed measurements of 1H, 13C NMR and gs‐HMQC (gradient‐selected Heteronuclear Multiple Quantum Coherence) on the samples of unprocessed urine of 6 patients suffering from propionic acidaemia and methylmalonic aciduria and identified the protons of MCA diastereoisomers, 3‐hydroxypropionic acid and methylmalonic acid.

Having used NMR spectroscopy to identify stereoisomers of MCA in urine, we can conclude that this technique gives the possibility of analysing MCA diastereoisomers in body fluids.
Bayesian Risk Assessment in Genetic Testing for Autosomal Dominant Disorders with Age‐Dependent Penetrance
Authors: Ogino Shuji , Wilson Robert B. , Gold Bert , Flodman Pamela
Published: February 2007

Risk assessment is an essential component of genetic counseling and testing, and the accuracy of risk assessment is critical for decision making by consultands. However, it has been shown that genetic risk calculations may have high error rates in practice. Risk calculations for autosomal dominant disorders are frequently complicated by age‐dependent penetrance and sensitivities of less than 100% in genetic testing. We provide methods of risk calculation for prototypical pedigrees of a family at risk for an autosomal dominant disorder with age‐dependent penetrance. Our risk calculations include scenarios in which the sensitivity of genetic testing is less than 100%, and in which the sensitivity of genetic testing varies for different family members at risk. Our Bayesian methods permit autosomal dominant disease probabilities to be calculated accurately, taking into account all relevant information. Our methods are particularly useful for hereditary cancer syndromes, in which genetic testing can seldom achieve 100% sensitivity. Our methods can be applied to many different scenarios, including those where the sensitivity of genetic testing varies for different family members at risk.
What Is It Like To Be in the Minority? Ethnic and Gender Diversity in the Genetic Counseling Profession
Authors: Schoonveld K. Cheri , Veach Patricia McCarthy , LeRoy Bonnie S.
Published: February 2007

Increasingly, the genetic counseling profession is recognizing the need for greater ethnic and gender diversity. Recruitment and retention efforts may be enhanced by better understanding of the experience of individuals considered to be underrepresented in the profession. In this qualitative study, 8 genetic counseling students and 7 practicing genetic counselors who were ethnic minority and/or male participated in semi‐structured telephone interviews regarding how they were introduced to the field, perceived career supports and barriers, their experiences within training programs and the field, and suggestions for increasing diversity. Introduction to the field tended to be late and accidental. There were several career supports (e.g., field combines science and helping others) and barriers (e.g., lack of information about the field). Participant experiences, although primarily positive, included instances of passive, unintentional discrimination; and there were internal and external pressures to be diversity experts and positive representatives of their group. Participants reported positively impacting colleagues’ cultural competency and offering a different presence within clinical settings. Suggestions for increasing diversity and research recommendations are given.
Improving Service Evaluation in Clinical Genetics: Identifying Effects of Genetic Diseases on Individuals and Families
Authors: McAllister Marion , Payne Katherine , Nicholls Stuart , MacLeod Rhona , Donnai Dian , Davies Linda M.
Published: February 2007

Outcome measurement in clinical genetics is challenging. Outcome attributes used currently have been developed by service providers or adapted from measures used in other areas of healthcare. Many of the ‘patients’ in clinical genetics are healthy but at risk of developing or transmitting a condition. Usually no pharmacological or surgical treatment is offered, although information‐giving is an objective of most consultations. We argue that services should be evaluated on the basis of how well they alleviate the effects of disease, from a patient perspective. This paper describes a qualitative study using seven focus groups with health professionals, patients and patient representatives. Social and emotional effects of genetics diseases were identified. Some differences emerged between the effects identified by health professionals and those identified by patients. These findings will be used to inform the evaluation of existing outcome measures and develop robust measures of outcome for clinical genetics services.
Cancer Genetic Counseling: Communication and Counselees’ Post‐Visit Satisfaction, Cognitions, Anxiety, and Needs Fulfillment
Authors: Pieterse Arwen H. , van Dulmen Alexandra M. , Beemer Frits A. , Bensing Jozien M. , Ausems Margreet G. E. M.
Published: February 2007

Little is known about the relation between communication during cancer genetic counseling and outcome. We assessed associations between counselor‐counselee communication and counselee satisfaction, cognitions, anxiety, and fulfillment of major needs, corrected for pre‐visit levels as appropriate. In total 171 consecutive new counselees, mainly referred for breast or colon cancer, received pre‐ and post‐visit questionnaires assessing needs/fulfillment, knowledge, perceived control (PPC), anxiety (STAI), and satisfaction. Initial visits were videotaped and counselor eye gaze was recorded. Verbal communication was rated by Roter Interaction Analysis System (RIAS). Asking more medical questions was associated with lower satisfaction levels. Receiving more medical information was related to higher correct knowledge scores, higher reported fulfillment of some needs, and unrelated to perceptions of control. Receiving more psychosocial information and longer counselor eye gaze were related to higher anxiety scores. Longer visits were related to higher correct knowledge scores. Providing medical information appears the most powerful communication aspect to increase counselee satisfaction and address needs. More research is needed on how to address adequately (emotional) needs and increase feelings of control.
Attitudes Toward Fragile X Mutation Carrier Testing from Women Identified in a General Population Survey
Authors: Anido Aimee , Carlson Lisa M. , Sherman Stephanie L.
Published: February 2007

Fragile X syndrome is primarily due to a CGG repeat expansion found in the FMR1 X‐linked gene. In a previous study, we conducted focus groups with women to assess their attitudes towards fragile X carrier screening. In this follow‐up study, we conducted in‐depth interviews of general population reproductive‐age women who were identified as carriers. We explored their attitudes toward testing for carrier status of the fragile X mutation. These women underwent screening primarily to participate in a research project rather than in search of a diagnosis for specific symptoms. As such, these women were wholly unprepared for positive carrier results. Their responses about their results and carrier screening, in many cases, were being worked out over the course of the interview itself. The most salient finding of this work is the apparent lack of relevance of carrier status to these women. Many expressed that although the information could be relevant in the future, it is not relevant at this stage of their lives in terms of family planning (either with respect to having unaffected offspring or to premature ovarian failure) and personal relationships. Although issues of abortion seemed prominent in the focus groups, we found that carrier status did not have an apparent effect on women's attitudes about termination. We hypothesize this may be related to the fact that women had not processed their new carrier status and had not related it to previously‐formed personal opinions. The findings of this work have significant implications for genetic counseling and population screening. Genetic counselors should be mindful that general population women may not recognize the immediate importance of their carrier status even when literature is provided and discussed prior to providing a sample. As part of comprehensive genetic counseling, counselors should identify the reproductive life stage of the woman receiving the new information and help her identify when this information would be more meaningful in her life. Counselors can assist in setting up a personalized road map with specific types of services that will be more applicable to the woman as her carrier status becomes more relevant.
A Pearson-Type-VII Item Response Model for Assessing Person Fluctuation
Authors: Ferrando Pere J.
Published: February 2007

Using Lumsden’s Thurstonian fluctuation model as a starting point, this paper attempts to develop a unidimensional item response theory model intended for binary personality items. Under some additional assumptions, a new model is obtained in which the item characteristic curves are defined by a cumulative Pearson-Type-VII distribution, and the person response curves are two-parameter normal ogives. Procedures for fitting the new model are proposed. Furthermore, the relations between individual fluctuation and scalability are discussed, and a scalability index based on the new model is proposed. All the developments in this paper are illustrated using two empirical examples.
A Unified Nonparametric IRT Model for d-Dimensional Psychological Test Data (d-ISOP)
Authors: Scheiblechner Hartmann
Published: February 2007

The (univariate) isotonic psychometric (ISOP) model (Scheiblechner, 1995) is a nonparametric IRT model for dichotomous and polytomous (rating scale) psychological test data. A weak subject independence axiom W1 postulates that the subjects are ordered in the same way except for ties (i.e., similarly or isotonically) by all items of a psychological test. A weak item independence axiom W2 postulates that the order of the items is similar for all subjects. Local independence (LI or W3) is assumed in all models. With these axioms, sample-free unidimensional ordinal measurements of items and subjects become feasible. A cancellation axiom (Co) gives, as a result, the additive isotonic psychometric (ADISOP) model and interval scales for subjects and items, and an independence axiom (W4) gives the completely additive isotonic psychometric (CADISOP) model with an interval scale for the response variable (Scheiblechner, 1999). The d-ISOP, d-ADISOP, and d-CADISOP models are generalizations to d-dimensional dependent variables (e.g., speed and accuracy of response).
Interaction Between Al‐δ Layered Sodium Disilicate and Surfactant
Authors: Dong Jinxiang , Li Liping , Xu Hong , Li Jinping
Published: February 2007

This paper investigated the interaction of Al‐δ‐Na2Si2O5with surfactants (LAS, AOS, K12 and AEO‐9) under condition approximating the detergent spray drying process. Al‐δ‐Na2Si2O5and the interaction samples were characterized by XRD, TG, FT‐IR and Ca2+ion binding capacity. The experimental results showed that Al‐δ‐Na2Si2O5might remain as δ phase after interacting with LAS. Al‐δ‐Na2Si2O5had changed to a mixed phase of δ phase and kanemite after interacting with K12 (or AEO‐9, AOS). LAS provides protection for the Al‐δ‐Na2Si2O5structure and K12 also provides protection to Al‐δ‐Na2Si2O5though it changed to a mixed phase when/msur/msolidwas equal to 2:1:3. Themsur/mδwas equal to 0.5, interaction time was 60 min, temperature was 60 ± 2°C and the relative crystallinity of the above samples were 28 and 26% higher than that of blank (the sample without surfactant under the same experimental conditions), respectively. AEO‐9 provided no obvious protection for the Al‐δ‐Na2Si2O5structure. AOS had destructive effect to the crystal structure of Al‐δ‐Na2Si2O5with δ phase relative crystallinity 10% lower than that of the blank under the same experiment condition.
Enhancing Vitamin E in Oilseeds: Unraveling Tocopherol and Tocotrienol Biosynthesis
Authors: Hunter Sarah C. , Cahoon Edgar B.
Published: February 2007

Naturally occurring vitamin E, comprised of four forms each of tocopherols and tocotrienols, are synthesized solely by photosynthetic organisms and function primarily as antioxidants. These different forms vary in their biological availability and in their physiological and chemical activities. Tocopherols and tocotrienols play important roles in the oxidative stability of vegetable oils and in the nutritional quality of crop plants for human and livestock diets. The isolation of genes for nearly all the steps in tocopherol and tocotrienol biosynthesis has facilitated efforts to alter metabolic flux through these pathways in plant cells. Herein we review the recent work done in the field, focusing on branch points and metabolic engineering to enhance and alter vitamin E content and composition in oilseed crops.
Tocopherol Content and Profile of Soybean: Genotypic Variability and Correlation Studies
Authors: Rani Anita , Kumar Vineet , Verma Sandeep K. , Shakya Arvind K. , Chauhan G. S.
Published: February 2007

Plant seed oils, including soybean seed oil, represent the major source of naturally derived tocopherols, the antioxidant molecules that act as free radical quenchers preventing lipid peroxidation in biological systems and vegetable oil products. All four isomers of tocopherols, i.e. α, β, γ, δ tocopherols that exist in nature are found in soybean seeds. The biological activity and the contribution of these isomers in improving the oxidative stability of vegetable oil are in reverse order. Because of the nutritive value and the importance for oil stability, enhancement of tocopherol content, through breeding programs, in soybean seeds has become a new and an important objective. Genotypic variability, which is the basis of every breeding program, is scarcely reported for tocopherol content and profile in soybean seeds. In the present investigation, the tocopherol content and profile in seed samples of 66 genotypes of Indian soybean were determined. The ratios observed between the lowest and the highest values for α, β, γ, δ, total tocopherol content were 1:13.6, 1:10.4, 1:7.5, 1:9.1, 1:7.9, respectively. The mean contents for α, β, γ, δ and total tocopherols were 269, 40, 855, 241 and 1,405 μg/g of oil, respectively. Total tocopherol content was the highest in ‘Co Soya2’ followed by ‘Ankur’. Concentration of α‐tocopherol was the highest (27%) in ‘Ankur’ followed by ‘MACS124’ (26%) whereas gamma tocopherol concentration was the highest (69%) in ‘VLS1’ and ‘PK327’ followed by ‘MACS13’ (67%). In view of the fact that levels of unsaturated fatty acids, apart from tocopherols, also determine the oxidative stability of vegetable oils, the relationship of four isomers of tocopherols with each other as well as with different unsaturated fatty acids and oil content was also investigated in the present study. All the four isomers of tocopherols exhibited highly significant correlations with each other (p < 0.001) whereas γ‐tocopherol and total tocopherol content showed a significant relationship with linoleic acid (p < 0.05).
Editorial
Authors: NAYLOR ROBERT E. L. , WISEMAN JULIAN
Published: February 2007

The Editorial Board of the Journal of Agricultural Science has been keen to develop the Journal as it enters its second century of publication. Our first innovation was a series of Centenary Reviews. These proved so popular with authors that we were able to publish these over 2005 and 2006, reflecting the first volume of the journal in 1905/06. However, we are keen to develop the Journal still further. We traditionally publish the Proceedings of the Agricultural Modellers' Group (Vol. 144, pp. 449–465), and this year we have expanded this to Proceedings of the Second Meeting of the European Association of Operational Research Societies (EURO) working group on Operational Research in Agriculture and Forest Management (Vol. 144, pp. 467–472). The Senior Editors will be happy to consider suggestions for additional meeting reports (email Bob Naylor (reln@abdn.ac.uk) for crop and soil science subjects or Julian Wiseman (julian.wiseman@nottingham.ac.uk) for animal science topics).
Development of primers for detecting dominant yeasts in smear-ripened cheeses
Authors: Gente Stéphanie , Larpin Sandra , Cholet Orianne , Guéguen Micheline , Vernoux Jean-Paul , Desmasures Nathalie
Published: February 2007

PCR primers were developed for the specific detection of Clavispora lusitaniae, Debaryomyces hansenii var hansenii, Geotrichum candidum, Kluyveromyces lactis and K. marxianus and Yarrowia lipolytica, yeast species commonly found on the surface of smear cheese. Forty eight representative strains frequently found in smear cheeses or taxonomically related to the target yeasts were used as templates, to validate the designed primers. The specific and selective detection of these yeasts was effective in situ, in Livarot smear, without yeast isolation and culture and was comparable with data obtained with a conventional method. The primers described here have thus potential for PCR studies applied to cheese. It should also be possible to use some of these primers with other substrates.
Conjugated linoleic acid (CLA) effects on pups growth, milk composition and lipogenic enzymes in lactating rats
Authors: Hayashi Amanda Aparecida , de Medeiros Sérgio Raposo , Hojaij Carvalho Marina , Duarte Lanna Dante Pazzanese
Published: February 2007

Conjugated linoleic acid (CLA) has a range of biological properties, including effects on lipid metabolism, milk and body composition in animals. This study investigated the effects of dietary CLA on lactating rats and development of the suckling pups. Dams were fed either a control diet or the same diet supplemented with 25 g/kg of a fat supplement containing 540 g CLA/kg (final concentration of 13·5 g CLA/kg diet) from parturition to the 15th day post-partum. The CLA mixture used in this study contained the following isomers (per 100 g): cis-9, trans-11 (24 g); cis-10, trans-12 (35 g); cis-8, trans-10 (15 g); cis-11, trans-13 (17 g) and others (9 g). On d 15 post partum, CLA supplementation reduced milk fat content by 33% and pup growth by 21%. The milk fatty acid profile, with decreased content of short and medium chain acids, suggests CLA inhibition was more pronounced for de novo lipid synthesis. Consistent with these results, activities of fatty acid synthase, glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were reduced by CLA treatment in the mammary gland and liver. In contrast, the activity of NADP-malate dehydrogenase was unchanged.
Metabolism of phenylalanine and biosynthesis of styrene in Penicillium camemberti
Authors: Pagot Yves , Belin Jean-Marc , Husson Florence , Spinnler Henry-Eric
Published: February 2007

The occurrence of styrene in food may be an important aroma defect (celluloid odour), even at very low concentrations (Miltz et al. 1980) causing consumer rejection and is therefore a problem for the food industry. We examined the biosynthetic pathway leading to styrene formation by Penicillium camemberti using labelled compounds. As styrene is strongly hydrophobic and volatile, we first had to develop a continuous extraction process. Using resins XAD2 it was reasonable to suspect phenylalanine (Phe) as the precursor. The addition of Phe marked with 13C on the ring provokes the accumulation of labelled styrene. The enzyme activities involved were also tentatively measured. Styrene appears to be synthesized from phenylalanine by phenylalanine ammonia-lyase activity followed by a decarboxylation catalysed by a cinnamic acid decarboxylase.
Disruption and reassociation of casein micelles during high pressure treatment: influence of whey proteins
Authors: Huppertz Thom , de Kruif Cornelis G
Published: February 2007

In the study presented in this article, the influence of added α-lactalbumin and β-lactoglobulin on the changes that occur in casein micelles at 250 and 300 MPa were investigated by in-situ measurement of light transmission. Light transmission of a serum protein-free casein micelle suspension initially increased with increasing treatment time, indicating disruption of micelles, but prolonged holding of micelles at high pressure partially reversed HP-induced increases in light transmission, suggesting reformation of micellar particles of colloidal dimensions. The presence of α-la and/or β-lg did not influence the rate and extent of micellar disruption and the rate and extent of reformation of casein particles. These data indicate that reformation of casein particles during prolonged HP treatment occurs as a result of a solvent-mediated association of the micellar fragments. During the final stages of reformation, κ-casein, with or without denatured whey proteins attached, associates on the surface of the reformed particle to provide steric stabilisation.
Controlled production of camembert-type cheeses: Part III role of the ripening microflora on free fatty acid concentrations
Authors: Leclercq-Perlat Marie-Noëlle , Corrieu Georges , Spinnler Henry-Eric
Published: February 2007

Phenomena generating FFAs, important flavour precursors, are significant in cheese ripening. In Camembert-like cheeses, it was intended to establish the relationships between the dynamics of FFA concentrations changes and the succession of ripening microflora during ripening. Experimental Camembert-type cheeses were prepared in duplicate from pasteurised milk inoculated with Kluyveromyces lactis, Geotrichum candidum, Penicillium camemberti, and Brevibacterium aurantiacum under aseptic conditions. For each cheese and each cheesy medium, concentrations of FFAs with odd-numbered carbons, except for 9[ratio ]0 and 13[ratio ]0, did not change over time. For long-chain FFAs, concentrations varied with the given cheese part (rind or core). K. lactis produced only short or medium-chain FFAs during its growth and had a minor influence on caproic, caprylic, capric, and lauric acids in comparison with G. candidum, the most lipolytic of the strains used here. It generated all short or medium-chain FFAs (4[ratio ]0–12[ratio ]0) during its exponential and slowdown growth periods and only long-chain ones (14[ratio ]0–18[ratio ]0) during its stationary phase. Pen. camemberti produced more long-chain FFAs (14[ratio ]0–18[ratio ]0) during its sporulation. Brev. aurantiacum did not generate any FFAs. The evidence of links between specific FFAs and the growth of a given microorganism is shown.
Effect of Minerals on Casein Micelle Stability of Cows' Milk
Authors: Tsioulpas Alexandros , Lewis Michael J , Grandison Alistair S
Published: February 2007

The effects of minerals on casein micelle stability of individual cows' milk, throughout a complete lactation, were investigated. Calcium and calcium ions, magnesium, phosphorus, sodium, potassium and citrate contents were analysed, together with the following physical properties of milk; pH, ethanol stability, rennet clotting time and coagulum firmness. There was an inverse non-linear relationship between free calcium ion concentration and ethanol stability (ES; r=0·84). Rennet coagulation time showed a weaker relationship with free calcium ion concentration (r=0·44) but a stronger relationship with pH (r=0·66). In addition, samples containing higher amounts of free calcium ions produced a firmer gel. Citrate in natural samples acts as a stabilizing factor, as it slightly improves milk stability. Potassium, on the other hand, exhibited a negative correlation, but only with rennet clotting time (r=−0·52). Throughout lactation the average values were; free Ca2+ concentration 1·88 mM, pH 6·63, ES 83·2% and clotting time 13·6 min. The equilibrium relationship between pH and free Ca2+ concentration was investigated by adjusting milk pH from 5·9 to 7·1, using acid and alkali. There was a good inverse linear relationship between pH and log (free Ca2+) for individual milk samples, with a gradient of −0·62 and a standard deviation of 0·042.
Proteolysis and texture of hard ewes' milk cheese during ripening as affected by somatic cell counts
Authors: Revilla Isabel , Rodríguez-Nogales Jose Manuel , Vivar-Quintana Ana M
Published: February 2007

Ewes' milk samples with low (<500000 ml−1), medium (1000000–1500000 ml−1) and high (>2500000 ml−1) somatic cell counts (SCC) were used to manufacture hard ewes' cheese using the Zamorano cheese manufacturing protocol. Cheeses that had been ripened for 1, 2 and 3 months were used to obtain isoelectric ovine casein that was analysed by capillary electrophoresis. The texture of the cheeses during ripening was determined instrumentally using the Warner-Bratzler maximum shear force and assessed for sensory qualities by consumers using hedonic tests. The study revealed that the pH value and the lactose content of the milk were affected by high SCC and that the coagulation properties were dependent on the somatic cell content. The protein and moisture contents of the cheeses were unaffected by SCC but a significant increase of pH with ripening time were observed in high-SCC cheeses. The results also pointed to a significant increase in proteolysis related to SCC levels, showing that intact casein, both αs1 and β-casein, decreased as the SCC of milk increased, and that the proteolytic fragments, mainly I-αs1, increased with SCC levels. Significant differences in texture were found among the samples, the cheeses made with high levels of SCC being significantly less compact at each ripening time. The differences in texture were detected by the consumers, who reported defects in cheeses made with high levels of SCC. Indeed, high SCC cheeses were significantly less well accepted.
Formation of oligosaccharides in skim milk fermented with mixed dahi cultures, Lactococcus lactis ssp diacetylactis and probiotic strains of lactobacilli
Authors: Yadav Hariom , Jain Shalini , Sinha Pushpalata Ravindra
Published: February 2007

Milk fermented with mixed dahi cultures NCDC167, Lactococcus lactis ssp diacetylactis NCDC60 and two probiotic strains; Lactobacillus acidophilus NCDC14 and Lb. casei NCDC19 were evaluated after fermentation (14 h) and during 8 d storage at 7 °C. The β-galactosidase activity was found to increase after fermentation leading to the hydrolysis of lactose and production of glucose, galactose and oligosaccharides; that subsequently decreased during storage. The viable counts of lactococci and lactobacilli decreased during storage yet remained >106 cfu/ml after storage. The results of present study indicate that all the selected cultures have ability to produce oligosaccharides (prebiotics) due to transgalactosidal and lactose hydrolysis activities of β-galactosidase. The cultures developed an active synbiotic formula by maintaining sufficient probiotic viable counts to exert health benefits to the consumers.
Characterization of the fetuin-binding fraction ofNeospora caninumtachyzoites and its potential involvement in host-parasite interactions
Authors: VONLAUFEN N. , NAGULESWARAN A. , GIANINAZZI C. , HEMPHILL A.
Published: February 2007

Terminal sialic acid residues on surface-associated glycoconjugates mediate host cell interactions of many pathogens. Addition of sialic acid-rich fetuin enhanced, and the presence of the sialidiase inhibitor 2-deoxy-2,3-dehydro-N-acetylneuraminic acid reduced, the physical interaction ofNeospora caninumtachyzoites and bradyzoites with Vero cell monolayers. Thus,Neosporaextracts were subjected to fetuin-agarose affinity chromatography in order to isolate components potentially interacting with sialic acid residues. SDS-PAGE and silver staining of the fetuin binding fraction revealed the presence of a single protein band of ∼65 kDa, subsequently named NcFBP (Neospora caninumfetuin-binding protein), which was localized at the apical tip of the tachyzoites and was continuously released into the surrounding medium in a temperature-independent manner. NcFBP readily interacted with Vero cells and bound to chondroitin sulfate A and C, and anti-NcFBP antibodies interfered in tachyzoite adhesion to host cell monolayers. In additon, analysis of the fetuin binding fraction by gelatin substrate zymography was performed, and demonstrated the presence of two bands of 96 and 140 kDa exhibiting metalloprotease-activity. The metalloprotease activity readily degraded glycosylated proteins such as fetuin and bovine immunoglobulin G heavy chain, whereas non-glycosylated proteins such as bovine serum albumin and immunoglobulin G light chain were not affected. These findings suggest that the fetuin-binding fraction ofNeospora caninumtachyzoites contains components that could be potentially involved in host-parasite interactions.