St. John’s Wort Herbal Teas – Biological Potential and Chemometric Approach to Quality Control

Plant Foods for Human Nutrition - St. John’s wort has been used for centuries in traditional medicine of many cultures, and nowadays it is well-known as a clinically important antidepressant...     

Thermal shock induction of triploidy in Atlantic cod (Gadus morhua L.)

The effects of thermal treatments on induction of triploidy in Atlantic cod have been investigated. Cold shock [−1.7±0.1°C at 20 min post fertilization (PF) for 2 h] was based on a previously developed protocol, and heat shocks, below the lethal threshold of 24°C, were at 16, 18 or 20°C applied 20, 30 or 40 min PF for 20 min. Cold shock did not affect larval survival and was ineffective for producing triploids (range 0–4%). A heat shock of 20°C at 20 min PF generated the highest percentages (range 66–100%) of triploid larvae at hatching, with survival ranging from 10% to 20% relative to the controls. Lower heat shock temperatures or delayed shocks increased survival but decreased the number of triploids, providing no net gain in triploid yield (range 1–9%). Heat shocks applied later than 20 min PF produced 2–4% tetraploid larvae at hatching. A thermal shock of 20°C initiated at 20 min PF and lasting 20 min proved to be the most generally efficient treatment for induction of triploidy in Atlantic cod.     

Complex multicolor tilings and critical phenomena in tetraphilic liquid crystals

T-shaped molecules with a rod-like aromatic core and a flexible side chain form liquid crystal honeycombs with aromatic cell walls and a cell interior filled with the side chains. Here, we show how the addition of a second chain, incompatible with the first (X-shaped molecules), can form honeycombs with highly complex tiling patterns, with cells of up to five different compositions ("colors") and polygonal shapes. The complexity is caused by the inability of the side chains to separate cleanly because of geometric frustration. Furthermore, a thermoreversible transition was observed between a multicolor (phase-separated) and a single-color (mixed) honeycomb phase. This is analogous to the Curie transition in simple and frustrated ferro- and antiferromagnets; here spin flips are replaced by 180° reorientations of the molecules.     

Initial and residual efficacy of insecticides on different surfaces against rice weevil Sitophilus oryzae (L.)

The aim of the study was to investigate how various types of storage facilities with, e.g., concrete, metal, and plywood surfaces interfere with the activity of different insecticide formulations used for rice weevil Sitophilus oryzae (L.) control: malathion (EC), pirimiphos-methyl (EC), and lambda-cyhalothrin (CS and WP). Initial and residual efficacy were determined in the laboratory. Knockdown data for the initial effects were processed by probit analysis and presented as knockdown time (KDT) parameters with kdt-p lines. Delayed effects were shown as knockdown efficacy (%) determined after 24 h of weevils’ contact with 7-, 14-, 30-, 60-, 90-, 120-, 150-, and 180-day-old deposits on each surface. Malathion (EC) and pirimiphos-methyl (EC) showed the highest initial knockdown efficacy on metal, while it was 3.6 (3.4)- and 4.4 (3.3)-fold lower on concrete and plywood, respectively. Lambda-cyhalothrin (CS and WP) showed the highest initial efficacy on concrete, and slightly lower (1.3 and 2.4) fold on metal and plywood, respectively. Both formulations of lambda-cyhalothrin and malathion on metal, as well as pirimiphos-methyl on plywood were 100 % efficient against S. oryzae 180 days after the treatment. Delayed efficacy of both formulations of lambda-cyhalothrin decreased on plywood after 120 days, and after 180 days the efficacy was 55 %. All insecticides, except lambda-cyhalothrin (CS), expressed low knockdown efficacy on concrete, while the deposit of lambda-cyhalothrin (CS) on concrete was 100 % efficient during 90 days, and after 120, 150, and 180 days the efficacy was 83, 65, and 17 %, respectively.