Coffee Stirrers and Drinking Straws as Disposable Spatulas

While metal spatulas are damaged through everyday use and become discolored and corroded by chemical exposure, drinking straws are inexpensive and disposable, reducing the risk of cross contamination during laboratory experiments. Drinking straws are also useful because they come in a variety of sizes; narrow sample containers such as NMR and EPR tubes can easily be filled using small diameter coffee stirrers, while bulk material can be transferred using larger drinking straws. Several types of drinking straws and coffee stirrers were cut at various angles and the amount of material picked up in a single scoop was massed thirty times. Standard deviations of the thirty measurements per straw indicate that approximately the same amount of material will be scooped each time by the same operator

The impact of classroom environment on student learning

Classroom environment is a concern among almost all educators. This thesis discusses the four major factors of classroom environment: physical environment, time and instructional management, behavior management, and teacher effectiveness. A goal of this study is to contribute to teacher knowledge about how classroom environments impact student learning. A resource center and a first grade classroom were observed and the teachers of both classes were asked to complete a self-evaluation of their classroom\u27s environment. Both teachers were found to have classroom environments that were conducive to learning

Preferential use of the perchlorate over the nitrate in the respiratory processes mediated by the Bacterium Azospira sp. OGA 24

Here we report the results obtained for a strain isolated from a polluted site and classified as Azospira sp. OGA 24. The capability of OGA 24 to utilize perchlorate and nitrate and the regulation of pathways were investigated by growth kinetic studies and analysis of messenger RNA (mRNA) expression of the genes of perchlorate reductase alpha subunit (pcrA), chlorite dismutase (cld), and periplasmic nitrate reductase large subunit (napA). In aerobic conditions and in a minimal medium containing 10 mM acetate as carbon source, 5.6 ± 0.34 mmol L-1 perchlorate or 9.7 ± 0.22 mmol L-1 nitrate were efficiently reduced during the growth with 10 mM of either perchlorate or nitrate. In anaerobiosis, napA was completely inhibited in the presence of perchlorate as the only electron acceptor, pcrA was barely detectable in nitrate-reducing conditions. The cell growth kinetics were in accordance with expression data, indicating a separation of nitrate and perchlorate respiration pathways. In the presence of both compounds, anaerobic nitrate consumption was reduced to 50% (4.9 ± 0.4 vs. 9.8 ± 0.15 mmol L-1 without perchlorate), while that of perchlorate was not affected (7.2 ± 0.5 vs. 6.9 ± 0.6 mmol L-1 without nitrate). Expression analysis confirmed the negative effect of perchlorate on nitrate respiration. Based on sequence analysis of the considered genes and 16S ribosomal gene (rDNA), the taxonomic position of Azospira sp. OGA 24 in the perchlorate respiring bacteria (PRB) group was further defined by classifying it in the oryzae species. The respiratory characteristics of OGA 24 strain make it very attractive in terms of potential applications in the bioremediation of environments exposed to perchlorate salts

Serum or Plasma (and Which Plasma), That Is the Question

Blood derivatives are the biofluids of choice formetabolomic clinical studies since blood can be collected with lowinvasiveness and is rich in biological information. However, the choiceof the blood collection tubes has an undeniable impact on the plasmaand serum metabolic content. Here, we compared the metabolomicand lipoprotein profiles of blood samples collected at the same timeand place from six healthy volunteers but using different collectiontubes (each enrolled volunteer provided multiple blood samples at adistance of a few weeks/months): citrate plasma, EDTA plasma, andserum tubes. All samples were analyzed via nuclear magnetic resonancespectroscopy. Several metabolites showed statistically significantalterations among the three blood matrices, and also metabolites'correlations were shown to be affected. The effects of blood collectiontubes on the lipoproteins'profiles are relevant too, but less marked. Overcoming the issue associated with different blood collectiontubes is pivotal to scale metabolomics and lipoprotein analysis at the level of epidemiological studies based on samples frommulticenter cohorts. We propose a statistical solution, based on regression, that is shown to be efficient in reducing the alterationsinduced by the different collection tubes for both the metabolomic and lipoprotein profile

Iron Binding in the Ferroxidase Site of Human Mitochondrial Ferritin

Ferritins are nanocage proteins that store iron ions in their central cavity as hydrated ferric oxide biominerals. In mammals, further the L (light) and H (heavy) chains constituting cytoplasmic maxi-ferritins, an additional type of ferritin has been identified, the mitochondrial ferritin (MTF). Human MTF (hMTF) is a functional homopolymeric H-like ferritin performing the ferroxidase activity in its ferroxidase site (FS), in which Fe(II) is oxidized to Fe(III) in the presence of dioxygen. To better investigate its ferroxidase properties, here we performed time-lapse X-ray crystallography analysis of hMTF, providing structural evidence of how iron ions interact with hMTF and of their binding to the FS. Transient iron binding sites, populating the pathway along the cage from the iron entry channel to the catalytic center, were also identified. Furthermore, our kinetic data at variable iron loads indicate that the catalytic iron oxidation reaction occurs via a diferric peroxo intermediate followed by the formation of ferric-oxo species, with significant differences with respect to human H-type ferritin

Acute Dacryocystitis with Empyema of the Lacrimal Sac: Is Immediate Endoscopic Dacryocystorhinostomy Justified?

Objectives. To evaluate the efficacy of endoscopic dacryocystorhinostomy (Endo-DCR) in the treatment of acute dacryocystitis with lacrimal sac empyema (ADLSE). Design. Case series with chart review. Setting. Academic tertiary center. Patients. The study included 26 consecutive patients who underwent Endo-DCR for ADLSE between August 2005 and December 2013. Main Outcome Measures. The success of the procedure was defined as complete complaint relief and DCR patency. Data on the time from referral to surgery, postoperative complications, and revision surgery are also reported. Results. The present patient series included 4 males (15.4%) and 22 females (84.6%) (mean age, 66 years). The mean time between referral and surgery was 0.88 days and the mean follow-up time was 29 months. All patients showed immediate relief from symptoms, with no ADLSE recurrences. Complete success was achieved in 25 (96.2%) cases; the only failure was in a patient who had previously undergone radioiodine treatment. In this case, revision Endo-DCR was not successful. The only perioperative complication (3.8%) was epistaxis in a patient who required revision surgery under general anesthesia. The definitive success rate was 96.2% after primary and revision surgery. Conclusions. Endo-DCR enables rapid resolution of ADLSE with a very high success rate. Immediate surgery may reduce the risk of skin fistulization and/or orbital complications. DCR shrinkage and lacrimal obstruction are unlikely with Endo-DCR since the procedure is performed on an enlarged sac. The main advantage of Endo-DCR, compared with external DCR, is the absence of a skin incision in an inflamed and infected field

A dynamic link between H/ACA snoRNP components and cytoplasmic stress granules

Many cell stressors block protein translation, inducing formation of cytoplasmic aggregates. These aggregates, named stress granules (SGs), are composed by translationally stalled ribonucleoproteins and their assembly strongly contributes to cell survival. Composition and dynamics of SGs are thus important starting points for identifying critical factors of the stress response. In the present study we link components of the H/ACA snoRNP complexes, highly concentrated in the nucleoli and the Cajal bodies, to SG composition. H/ACA snoRNPs are composed by a core of four highly conserved proteins -dyskerin, Nhp2, Nop10 and Gar1- and are involved in several fundamental processes, including ribosome biogenesis, RNA pseudouridylation, stabilization of small nucleolar RNAs and telomere maintenance. By taking advantage of cells overexpressing a dyskerin splice variant undergoing a dynamic intracellular trafficking, we were able to show that H/ACA snoRNP components can participate in SG formation, this way contributing to the stress response and perhaps transducing signals from the nucleus to the cytoplasm. Collectively, our results show for the first time that H/ACA snoRNP proteins can have additional non-nuclear functions, either independently or interacting with each other, thus further strengthening the close relationship linking nucleolus to SG composition