Do bright-light shock exposures during breaks reduce subjective sleepiness in night workers?

Sleep and Biological Rhythms - Night work has many harmful effects on the health, efficiency and safety of workers. This study evaluates the effects of bright-light exposure (BL) on subjective...     

Prevalence and detection of metallo-β-lactamase (MBL)-producingPseudomonas aeruginosa strains from clinical isolates in Iran

Of the 126 isolates obtained from clinical specimens, seventy strains were selected because of resistance or reduced susceptibilities to imipenem and/or ceftazidime. Screening for detection of MBL-producing strains was performed in latter isolates by the Etest MBL strips. Isolates that were positive to Etest MBL strips were analysed by PCR. PCR was performed with specific DNA probes for detection of genes coding IMP or VIM enzymes and positive controls (MBL-producing strains). Finally, eight isolates ofPseudomonas aeruginosa were detected to carry a bla_VIM gene.     

Variation of nitrogenase activity, photosynthesis and pigmentation of the cyanobacterium Fischerella ambigua strain FS18 under different irradiance and pH values

Summary Our objective was to evaluate the physiological response of Fischerella ambigua FS18 to the combined influence of pH (5, 7 and 9) and light intensity (3 and 300 μmol photon m⁻² s⁻¹). Growth rates were similar at pH 9 and pH 7. There was no growth at pH 5. Increasing light intensity did not have any considerable influence on growth rates. Chlorophyll concentration was higher at pH 7 at all light intensities. Chlorophyll concentration decreased with increasing light intensity from 3 to 300 μmol photon m⁻² s⁻¹. Synthesis of the phycobiliproteins (PBP), phycocyanin (PC) and allophycocyanin (APC) had the highest rate in pH 7. Increasing irradiance decreased the concentrations of all PBPs. The light-saturated photosynthetic rate was clearly higher at high light intensity. With respect to nitrogenase activity, the highest rate was at pH 9 and 300 μmol photon m⁻² s⁻¹. Irradiance did not affect significantly this activity at pH 7. This cyanobacterium seems to be alkalophilic with maximum nitrogenase activity and photosynthesis at pH 9. It can also adapt its photosynthetic apparatus to the variable factors that are found in rice fields.     

New species of Dzhulfian (Late Permian) ammonoids from the Hambast Formation of Central Iran

New ammonoid species of the genus Araxoceras (A. abarquense sp. nov. and A. iranense sp. nov.) are described from the Early Dzhulfian (Early Wuchiapingian) beds of the Hambast Formation of Central Iran (Abade). The data on the distribution of Paraceltites (Paraceltites sp.) and Vedioceras (V. umbonovarum Ruzhencev), for the first time discovered in the Dzhulfian beds of Abade, and of Eoaraxoceras are provided. The correlation of the Late Permian assemblages of ammonoids of Iran and Transcaucasia is amended.     

Nostoc muscorum: a regioselective biocatalyst for 17-carbonyl reduction of androst-4-en-3,17-dione and androst-1,4-dien-3,17-dione

Nostoc muscorum PTCC 1636 was examined for its ability to convert androst-4-en-3,17-dione (AD) and androst-1,4-dien-3,17-dione (ADD) to their 17-hydroxy related derivatives in BG-11 medium. Bioconversion procedures were carried out at 25 °C without shaking. The metabolites obtained were purified using chromatographic methods and characterized as testosterone and 1-dehydrotestosterone on the basis of their spectroscopic features. In both cases, the bioreaction characteristics observed were 17-carbonyl reduction.     

Fine needle aspiration biopsy for preoperative workup of pancreatic cystic neoplasms: report of 4 cases

BACKGROUND: Cystic neoplasms of the pancreas comprise a pathologically heterogeneous group of lesions that usually present with similar, nonspecific clinical features. Based on the diagnosis, treatment varies from watchful observation of the lesion to total surgical resection of the pancreas. Therefore the importance of a precise and accurate diagnosis on fine needle aspiration (FNA) biopsy cannot be overemphasized from the patient management standpoint. There is debate regarding the accuracy of FNA diagnosis of cystic lesions of the pancreas. We report 4 cases and review the literature to explore and highlight the cytologic findings and diagnostic pitfalls that may help the cytopathologist accurately distinguish mucinous cystic neoplasm (MCN), intraductal papillary mucinous neoplasm (IPMN), serous cystadenoma (SCA) and ductal adenocarcinoma (DAC). CASES: We present 4 cases of patients with abdominal masses who underwent either computed tomography (CT)-guided or endoscopic ultrasound (EUS)-guided FNA biopsy as preoperative workup. Based on the cytologic diagnosis, the patients underwent surgery. CONCLUSION: Our cases illustrate the cytologic criteria that help the cytopathologist distinguish among MCN, IPMN, SCA and DAC. Correlation with clinical and radiologic findings is strongly advocated for accurate diagnosis. We describe the diagnostic pitfalls frequently encountered in these cases and how to avoid them.     

Cell-free protein synthesis of perdeuterated proteins for NMR studies

Cell-free protein synthesis protocols for uniformly deuterated proteins typically yield low, non-uniform deuteration levels. This paper introduces an E. coli cell-extract, D-S30, which enables efficient production of proteins with high deuteration levels for all non-labile hydrogen atom positions. Potential applications of the new protocol may include production of proteins with selective isotope-labeling of selected amino acid residues on a perdeuterated background for studies of enzyme active sites or for ligand screening in drug discovery projects, as well as the synthesis of perdeuterated polypeptides for NMR spectroscopy with large supra-molecular structures. As an illustration, it is demonstrated that the 800-kDa chaperonine GroEL synthesized with the D-S30 cell-free system had a uniform deuteration level of about 95% and assembled into its biologically active oligomeric form.     

Introgression of a major QTL from an inferior into a superior population using genomic selection

Background

Selection schemes aiming at introgressing genetic material from a donor into a recipient line may be performed by backcross-breeding programs combined with selection to preserve the favourable characteristics of the donor population. This stochastic simulation study investigated whether genomic selection can be effective in preserving a major quantitative trait locus (QTL) allele from a donor line during the backcrossing phase.

Methods

In a simulation study, two fish populations were generated: a recipient line selected for a production trait and a donor line characterized by an enhanced level of disease resistance. Both traits were polygenic, but one major QTL affecting disease resistance was segregating only within the donor line. Backcrossing was combined with three types of selection (for total merit index) among the crossbred individuals: classical selection, genomic selection using genome-wide dense marker maps, and gene-assisted genomic selection. It was assumed that production could be observed directly on the selection candidates, while disease resistance had to be inferred from tested sibs of the selection candidates.

Results

Classical selection was inefficient in preserving the target QTL through the backcrossing phase. In contrast, genomic selection (without specific knowledge of the target QTL) was usually effective in preserving the target QTL, and had higher genetic response to selection, especially for disease resistance. Compared with pure genomic selection, gene-assisted selection had an advantage with respect to disease resistance (28–40% increase in genetic gain) and acted as an extra precaution against loss of the target QTL. However, for total merit index the advantage of gene-assisted genomic selection over genomic selection was lower (4–5% increase in genetic gain).

Conclusion

Substantial differences between introgression programs using classical and genomic selection were observed, and the former was generally inferior with respect to both genetic gain and the ability to preserve the target QTL. Combining genomic selection with gene-assisted selection for the target QTL acted as an extra precaution against loss of the target QTL and gave additional genetic gain for disease resistance. However, the effect on total merit index was limited.