Assessment of the genetic stability of GMOs with a detailed examination of MON810 using Scorpion probes

For the cultivation and maintenance of seeds, genetic mutations have to be avoided as much as possible. According to the Directive 2001/18/EC, genetic stability has to be proven for the approval of GMOs [1]. The investigation of genetic stability can be performed with various methods, but Southern blots are most commonly used. In this study, a different method, a real-time PCR involving Scorpion primer, was developed for the analysis of DNA rearrangements in GMOs. The advantage of this method is that already small changes in sequence can be detected. In addition, large numbers of samples can be tested at once in a single PCR run. Possible alterations in the region of the Scorpion primer can be detected by differences in the real-time PCR plots. The sequence that was analysed contained 130 nucleotides. The sensitivity of Scorpion primers to measure genetic stability was verified in experiments with plasmids that had only minor sequence alterations in the target region. Such small differences led to a total reduction of the fluorescence signal, even in heterozygous samples where the unaltered template was present as well. Scorpion primers were then used to investigate the transgenic sequences of 567 individual seeds of MON810 for maize at the 5′ and the 3′ region of the insert. In combination with SYBR green, the screening procedure allowed a selection of samples for further analysis. If a sample showed low fluorescence with the Scorpion primer but a normal amplification with SYBR green, then the integrity of the insert was checked by sequencing. The results, however, gave no indication of a mutation or rearrangement of MON810 seeds. In additional experiments, the reliability of the method was studied by determining several parameters that are required for a validation, e.g., specificity, cross-reactivity, dynamic range, correlation of the template concentration and the corresponding Ct values, PCR efficiency, relative repeatability standard deviation (RSDr) relative reproducibility standard deviation (RSDR).     

Increased serum serotonin improves parturient calcium homeostasis in dairy cows

Hypocalcemia in dairy cows is caused by the sudden increase in calcium demand by the mammary gland for milk production at the onset of lactation. Serotonin (5-HT) is a key factor for calcium homeostasis, modulating calcium concentration in blood. Therefore, it is hypothesized that administration of 5-hydroxy-l-tryptophan (5-HTP), a 5-HT precursor, can increase 5-HT concentrations in blood and, in turn, induce an increase in blood calcium concentration. In this study, 20 Holstein dairy cows were randomly assigned to 2 experimental groups. Both groups received a daily i.v. infusion of 1 L of either 0.9% NaCl (C group; n = 10) or 0.9% NaCl containing 1 mg of 5-HTP/kg of BW (5-HTP group, n = 10). Infusions started d 10 before the estimated parturition and ceased the day of parturition, resulting in at least 4 d of infusion (8.37 ± 0.74 d of infusion). Until parturition, blood samples were collected every morning before the infusions, after parturition samples were taken daily until d 7, and a final sample was collected on d 30. Milk yield was recorded during this period. No differences between groups were observed for blood glucose, magnesium, and β-hydroxybutyrate. Cows receiving the 5-HTP infusion showed an increase in fatty acid concentrations from d ?3 to ?1 before parturition. Serum 5-HT concentrations were increased at d ?4 related to parturition until d 5 postpartum in the 5-HTP group compared with the C group. In addition, cows from the 5-HTP group had increased 5-HT concentrations in colostrum, but not in mature milk, on d 7 postpartum. Serum calcium concentrations decreased in both groups around parturition; however, calcium remained higher in the 5-HTP group than in controls, with a significant difference between groups on d 1 (1.62 ± 0.08 vs. 1.93 ± 0.09 mmol/L in control and 5-HTP groups, respectively) and d 2 (1.83 ± 0.06 vs. 2.07 ± 0.07 mmol/L in control and 5-HTP groups, respectively). Additionally, colostrum yield (first milking) was lower in the 5-HTP group compared with the C group, but without consequences on colostrum IgG concentrations. Milk yield did not differ between groups during the rest of the experiment. The study data were consistent with the concept that infusion of 5-HTP to dairy cows increases blood 5-HT concentrations, which in turn is a significant regulatory component in the chain of effectors that affect calcium status around parturition, hence the occurrence of clinical or subclinical hypocalcemia.     

Development and validation of a novel real-time PCR method for the detection of celery (Apium graveolens) in food

The paper presents a novel real-time PCR method allowing the detection of traces of celery (Apium graveolens) in complex food matrices. The method is based on the amplification of a sequence of the gene coding for the Apium graveolens NADPH-dependent mannose-6-phosphate reductase. It allows the detection of three commonly used celery varieties, celery roots (Apium graveolens var. rapaceum), celery stalks (Apium graveolens var. dulce) and leaf celery (Apium graveolens var. secalinum) and does not show any cross-reactivity with 64 biological species, including ten members of the Apiaceae family. The limit of detection, determined by analysing serially diluted celery extracts, is 10 pg celery DNA for all three celery varieties. In spiked model sausages, the LOD is 0.005% celery. The real-time PCR method was applied to 26 commercial food products. Celery DNA was found in one out of ten samples without any information about the presence of celery.     

Erfahrungen bei der Anwendung der neuen DIN 1052 mit Vergleichen zur Vorgängernorm

Mit Einführung der neuen DIN 1052 kommen nun auch im Holzbau das semiprobabilistische Sicherheitskonzept sowie neue Bemessungsregeln und zum Teil erheblich abgeminderte Festigkeitswerte im Vergleich zur alten Norm zur Anwendung. Um die Auswirkungen der niedrigeren Querdruckfestigkeiten aufzuzeigen, werden Vergleichsrechnungen am Beispiel einer eingespannten Stütze und eines Einfeldträgers durchgeführt und einige kritische Anmerkungen zu den in vielen Fällen erforderlichen Verstärkungsmaßnahmen gemacht. Bei Holzbalkendecken wird dargestellt, dass die neu aufgenommenen Empfehlungen zum Schwingungsnachweis die erforderliche Konstruktionshöhe bestimmen und damit Holzbalkendecken für größere Spannweiten unwirtschaftlich werden. Insgesamt zeigt sich bei Anwendung der neuen DIN 1052, dass der Planungsaufwand gegenüber der alten Norm erheblich anwächst. Experience in application of the new German code DIN 1052 in comparison with the previous standard. With the new German code DIN 1052 the semi‐probabilistic safety concept has been introduced for timber constructions as well as new design procedures and to some extent considerably reduced strength properties in comparison to the previous standard. For illustration of the impact of the low lateral pressure strength comparative calculations are performed using a clamped column and a simply supported beam and some critical comments are given for strengthening measurements required in many cases. For timber beam ceilings it is shown that the new recommendations for vibration control govern the required construction height und make such constructions inefficient for longer span lengths. In general, the complexity applying the new DIN 1052 is considerably higher than designing on the basis of the previous standard.     

Bulk high-entropy hexaborides

For the first time, a group of CaB₆-typed cubic rare earth high-entropy hexaborides have been successfully fabricated into dense bulk pellets (>98.5 % in relative densities). The specimens are prepared from elemental precursors via in-situ metal-boron reactive spark plasma sintering. The sintered bulk pellets are determined to be single-phase without any detectable oxides or other secondary phases. The homogenous elemental distributions have been confirmed at both microscale and nanoscale. The Vickers microhardness are measured to be 16?18 GPa at a standard indentation load of 9.8 N. The nanoindentation hardness and Young’s moduli have been measured to be 19?22 GPa and 190?250 GPa, respectively, by nanoindentation test using a maximum load of 500 mN. The material work functions are determined to be 3.7–4.0 eV by ultraviolet photoelectron spectroscopy characterizations, which are significantly higher than that of LaB₆.     

Role of Conserved Residues and F322 in the Extracellular Vestibule of the Rat P2X7 Receptor in Its Expression,Function and Dye Uptake Ability

Activation of the P2X7 receptor results in the opening of a large pore that plays a role in immune responses, apoptosis, and many other physiological and pathological processes. Here, we investigated the role of conserved and unique residues in the extracellular vestibule connecting the agonist-binding domain with the transmembrane domain of rat P2X7 receptor. We found that all residues that are conserved among the P2X receptor subtypes respond to alanine mutagenesis with an inhibition (Y51, Q52, and G323) or a significant decrease (K49, G326, K327, and F328) of 2′,3′-O-(benzoyl-4-benzoyl)-ATP (BzATP)-induced current and permeability to ethidium bromide, while the nonconserved residue (F322), which is also present in P2X4 receptor, responds with a 10-fold higher sensitivity to BzATP, much slower deactivation kinetics, and a higher propensity to form the large dye-permeable pore. We examined the membrane expression of conserved mutants and found that Y51, Q52, G323, and F328 play a role in the trafficking of the receptor to the plasma membrane, while K49 controls receptor responsiveness to agonists. Finally, we studied the importance of the physicochemical properties of these residues and observed that the K49R, F322Y, F322W, and F322L mutants significantly reversed the receptor function, indicating that positively charged and large hydrophobic residues are important at positions 49 and 322, respectively. These results show that clusters of conserved residues above the transmembrane domain 1 (K49–Y51–Q52) and transmembrane domain 2 (G326–K327–F328) are important for receptor structure, membrane expression, and channel gating and that the nonconserved residue (F322) at the top of the extracellular vestibule is involved in hydrophobic inter-subunit interaction which stabilizes the closed state of the P2X7 receptor channel.     

Work-family spillover and life satisfaction among professional psychologists.

How do the professional lives of psychologists influence their personal and family lives? Data from 485 psychologists who responded to a survey on professional and family life were analyzed to examine work-to-family spillover, life satisfaction, and family support. Respondents reported a significantly higher incidence of positive spillover, termed family enhancers, than negative spillover, termed family stressors. The low incidence of family stressors suggested that stresses associated with the professional work of psychology do not routinely spill over into professionals' family lives. Both positive and negative spillover, however, played significant roles in mediating the relationship between work and family domains. On the positive side, a sense of personal accomplishment at work was associated with increased family enhancers, which appeared to lead to greater family support and life satisfaction. On the negative side, emotional exhaustion at work was associated with more family stressors, which appeared to lead to less family support and life satisfaction. The implications of these findings for training and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensor Geometry and Sampling Methods for Space-Variant Image Processing

: Space-variant imaging sensors have many advantages over conventional raster imaging sensors. They provide a large field of view for a given pixel count while maintaining a high resolution at the centre of the field of view and, in addition, produce a mapping that is scale and rotation invariant. The effectiveness of the sensor depends greatly upon the geometry used and the sampling methods employed. In this paper, we define a sensor geometry and introduce an ideal weighted sampling method, where the pixels in the image lying at the intersection of sensor cells, are subdivided into smaller sub-pixels, and an interpolation method using a variable width interpolation mask, whose size varies exponentially with the size and shape of the cells in the sensor array. We compare the computational requirements of these methods, and show that they are scale and rotation invariant, when the image is scaled or rotated about its centre, giving the sensor a functionality similar to that provided by the retinal mapping present in the mammalian retina. These results illustrate the advantages that can be obtained in real-time tracking applications in computer vision, where computational and memory requirements need to be kept to a minimum. Received: 29 August 2001, Received in revised form: 15 January 2002, Accepted: 15 January 2002 ID="A1" Correspondence and offprint requests to: R. Young, School of Engineering and Information Technology, University of Sussex, Brighton, Sussex BN1 9QT, UK. Email: r.c.d.young@sussex.co.uk     

Anytime similarity measures for faster alignment

Image alignment refers to finding the best transformation from a fixed reference image to a new image of a scene. This process is often optimizing a similarity measure between images, computed based on the image data. However, in time-critical applications state-of-the-art methods for computing similarity are too slow. Instead of using all the image data to compute similarity, one could use only a subset of pixels to improve the speed, but often this comes at the cost of reduced accuracy. These kinds of tradeoffs between the amount of computation and the accuracy of the result have been addressed in the field of real-time artificial intelligence as deliberation control problems. We propose that the optimization of a similarity measure is a natural application domain for deliberation control using the anytime algorithm framework. In this paper, we present anytime versions for the computation of two common image similarity measures: mean squared difference and mutual information. Off-line, we learn a performance profile specific to each measure, which is then used on-line to select the appropriate amount of pixels to process at each optimization step. When tested against existing techniques, our method achieves comparable quality and robustness with significantly less computation.     

Work Setting and Burnout Among Professional Psychologists.

How does work setting relate to burnout among professional psychologists? Five hundred and seventy-one doctoral psychologists responded to a survey about professional activities, work environment, and burnout. Solo and group independent practitioners reported a greater sense of personal accomplishment than agency respondents. However, women experienced higher levels of emotional exhaustion in agency settings than in either solo or group independent practice, whereas men experienced higher exhaustion in group independent practice. Overall, greater emotional exhaustion was associated with less control over work activities, working more hours, spending more time on administrative tasks and paperwork, seeing more managed care clients and fewer direct pay clients, and having to deal with more negative client behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)