Phylogeny and age of cockroaches: a reanalysis of mitogenomes with selective fossil calibrations

In spite of big data and new techniques, the phylogeny and timing of cockroaches remain in dispute. Apart from sequencing more species, an alternative way to improve the phylogenetic inference and time estimation is to improve the quality of data, calibrations and analytical procedure. This study emphasizes the completeness of data, the reliability of genes (judged via alignment ambiguity and substitution saturation), and the justification for fossil calibrations. Based on published mitochondrial genomes, the Bayesian phylogeny of cockroaches and termites is recovered as: Corydiinae + (((Cryptocercidae + Isoptera) + ((Anaplectidae + Lamproblattidae) + (Tryonicidae + Blattidae))) + (Pseudophyllodromiinae + (Ectobiinae + (Blattellinae + Blaberidae)))). With two fossil calibrations, namely, Valditermes brenanae and Piniblattella yixianensis, this study dates the crown Dictyoptera to early Jurassic, and crown Blattodea to middle Jurassic. Using the ambiguous ‘roachoid’ fossils to calibrate Dictyoptera+sister pushes these times back to Permian and Triassic. This study also shows that appropriate fossil calibrations are rarer than considered in previous studies.

Bicyklo[4.4.0]dekan. Metoda oznaczania w powietrzu na stanowiskach pracy

Bicyclo[4.4.0]decane (BCD), also known as decalin, is a colorless liquid with the scent of camphor, menthol and naphthalene. This substance can be fatal if swallowed or entered a respiratory tract. It can cause severe skin burns and eye damage, and is toxic if inhaled. The aim of this study was to develop a method for determining BCD in workplace air, which will allow the determination of its concentrations at the level of 5 mg/m3 . The method was based on adsorption of BCD vapors on activated carbon, desorption with acetone solution in carbon disulfide and chromatographic analysis of the obtained solution. The study was performed with a gas chromatograph (GC) with a flame ionization detector (FID) equipped with a DB-VRX capillary column (60 m × 0.25 mm, 1.4 µm). The method was validated in accordance with the requirements of Standard No. EN 482. The method allows the determination BCD in workplace air in the concentration range 5–200 mg/m3 . The method for determining BCD has been recorded in the form of an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Akrylonitryl. Metoda oznaczania w powietrzu na stanowiskach pracy Anna Jeżewska, Agnieszka Woźnica

Acrylonitrile (AN) is highly flammable, colorless liquid with an unpleasant odor. Acrylonitrile is used in industry to produce polyacrylonitrile (PAN) and its copolymers. Acrylonitrile can cause cancer. The aim of this study was to develop a method for determining acrylonitrile in workplace air which will allow determination of its concentrations at the level of 0.1 mg/m3 . The method was based on adsorption of acrylonitrile vapors on activated carbon, desorption with acetone solution in carbon disulfide and chromatographic analysis of the obtained solution. The study was performed using a gas chromatograph (GC) with a flame ionization detector (FID) equipped with a DB-VRX capillary column (60 m × 0.25 mm, 1.4 µm). The method was validated in accordance with the requirements of Standard No. EN 482. The method allows the determination of acrylonitrile in workplace air at the concentration range from 0.1 to 2 mg/m3. The method for determining acrylonitrile has been recorded in the form of an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Związki manganu, niklu i żelaza. Metoda oznaczania w powietrzu na stanowiskach pracy

The aim of this study was to develop and validate a method for determining of inhalable and respirable fraction of compounds of manganese, nickel and iron in workplace air. The method is based on passing the tested air through a filter from the cellulose ester mixture placed in a specific sampler. The filter mineralizes in concentrated nitric acid (V) and makes a solution for analysis in diluted nitric acid (V). The use of different dilutions of the sample solution after mineralization makes it possible to use the ranges of standard curves for the determination of substances as manganese, nickel and iron. The addition of lanthanum salt (correction buffer) prevents the occurrence of chemical interference, the use of deuterium lamp eliminates background interference. The developed method enables the determination of selected substances in the air of the working environment in the concentration ranges corresponding to the range from 0.1 to 2 MACs values and also enables the determination of nickel and its compounds in the inhalable fraction for the currently proposed new value of the maximum permissible concentration. The developed method has been validated in accordance with the requirements of Standard No. PN-EN 482 and good validation results were obtained. The method can be used for assessing occupational exposure to compounds of manganese, nickel and iron and associated risk to workers’ health. The developed method of determining compounds of manganese, nickel and iron has been recorded as an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Mineral Composition of Dietary Supplements-Analytical and Chemometric Approach

There is a lack of data on the actual composition and effectiveness of beetroot-based dietary supplements. The research aimed to determine the profile of 22 elements (Na, K, Ca, Mg, P, Fe, As, Se, Zn, Cu, Ag, Co, Ni, Mo, Al, Mn, Sr, Cr, Ba, Li, Pb, Cd) in beetroot and its supplements by the microwave plasma atomic emission spectrometry (MP-AES) method. The analytical procedure was optimised and validated. The composition of both groups was compared, assessing compliance with the recommended daily doses for the chosen elements, and the health risk was estimated. Furthermore, chemometric analysis was applied. Beetroots constituted a significant source of elements, especially K, Na, Mg, Ca, P, in contrast to supplements which contained their negligible amounts except from iron-enriched products which provided notable amounts of Fe (38.3–88% of the Recommended Dietary Allowance for an adult male from 19 to 75 years old). Some products were significantly contaminated with toxic elements (As, Cd). Factor and cluster analyses were helpful in the differentiation of beetroot and its supplements in view of their type (vegetable, supplement, iron-enriched supplement), origin, type of cultivation (conventional, organic), and form (capsule, tablet) based on their mineral composition. The obtained results indicate the need for more stringent control of supplements, as they may pose a significant health risk to consumers.

Nonlinear structures: soliton, shocklike and explosive waves in quantum semiconductor plasma

The properties and conditions for the appearance of some nonlinear waves in a three-dimensional semiconductor plasma are discussed, by studying the described plasma fluid system with quantum gradient forces and degraded pressures. Our analytical procedure is built on the reductive perturbation theory to obtain the Kadomtsev-Petvashvili equation for the fluid model and solving it using the direct integration method and the Bäcklund transform. Through different solution methods we got different nonlinear solutions describing different pulse profiles such as soliton, kink and explosive pulses. This model can be used to identify the potential disturbances in a semiconductor plasma.

Physicochemical, Functional and Pasting Properties of Garri Fortified with Soybean Flour

Aim: This study evaluated the physicochemical, functional and pasting properties of garri fortified with soybean flour. Methodology: Soybean flour was incorporated into the garri prior to garrification at a ratio of 10, 20, 30, 40 and 50% for samples A, B, C, D and E respectively. Sample without soybean flour served as control. Standard analytical procedure was used in the evaluation of all six samples. Results: The pH and titratable acidity (TTA) of the samples varied respectively, from 4.59 - 6.48 and 0.08 - 0.17 % lactic acid. There was significant (P<0.05) decrease in pH with increase in soybean flour, while the reverse was the case for TTA. Swelling power, bulk density and water absorption capacity of the soybean fortified garri ranged from 8.74 - 17.81%, 0.60 - 0.80 g/ml and 13.44 – 19.43 % respectively. Control sample (100% garri) had hydrogen cyanide (HCN) content of 1.50 mg HCN/100g while samples with soybean flour had no detectable levels. Peak viscosity, trough, breakdown, final viscosity and setback varied significantly (P<0.05) from 101.19 - 399.44, 90.92 - 320.19, 10.28 - 79.25, 123.19 - 451.50 and 32.28 - 131.31 RVU respectively. Peak time and pasting temperatures ranged from 5.18 – 6.34 min and 74.28 – 92.88 oC. Conclusion: The study revealed that a good quality garri can be produced with the incorporation of soybean flour up to 50%, the garri is safe for consumption as there was no HCN detected, and the decrease in viscosity provides for a soft textured, mouldable garri that is convenient for swallow.

Simple spectrophotometric methods for the determination of amlodipine and atorvastatin in bulk and tablets

Background Simultaneous spectrophotometric determination of samples containing more than one analyte presents analytical challenge; the choice of an analytical procedure is strictly related to the extent of overlapping between the individual absorption peaks of these components; if the absorption peaks are satisfactorily resolved, the determination is not problematic, but if the individual component signals are partly or totally overlapped, then powerful techniques are needed. Combined amlodipine and atorvastatin are typical example where special techniques are needed to resolve bands overlapping. Results Application of multiwavelength regression and absorbance factor methods to the analysis of atorvastatin and amlodipine combination proved to be satisfactorily capable of accurate and precise determination of the two analytes. The two methods recoveries were very close to the expected analytes concentrations, and the precision of the methods was < 2% relative standard deviation. Statistical comparison indicated that there is no significant difference between the assay results obtained by the two method as the calculated t values 0.91 and 1.13 for amlodipine and atorvastatin, respectively, were less than the tabulated t value 2.23 at 95% confidence level. Conclusion The proposed methods are accurate, precise, simple and inexpensive. They can be applied successfully to the analysis of the two drugs in combined dosage form.