In this study we investigated how two different approaches to drawing free body diagrams influence the development of students' understanding of Newton's laws including their ability to identify real forces. For this purpose we developed a 12- item two-tier multiple choice survey and conducted a quasi-experiment. This experiment included two groups of first-year physics students from Rijeka (RG) and Split (SG) University. Students from both groups solved mechanics problems for a period of two class hours. The only difference was that RG students used the superposition of forces approach to solving mechanics problems and in SG the decomposition of forces approach has been used. The ANCOVA showed a statistically significant difference in favour of RG, whereby the effect sizes were moderate to large, and largest differences have been observed in the ability of identifying real forces. Students from the control group (SG) more often exhibited the misconception that forces and their components act on a body independently and simultaneously. Our results support the idea that the practice of resolving forces into components may not be the most effective way to develop understanding of Newton's laws and the concept of force.

A connected planar graph is called m-generalized fullerene if two of its faces are m -gons and all other faces are pentagons and hexagons. In this paper we first determine some structural properties of m -generalized fullerenes and then use them to obtain new results on the enumerative aspects of perfect matchings in such graphs. We provide both upper and lower bounds on the number of perfect matchings in m -generalized fullerene graphs and state exact results in some special cases.

Summary The term "nano" refers to nano particle size from 1 to 100 nanometers. The term "nanotechnology" was first introduced by Norio Taniguchi in 1974. Nanotechnology may be used to improve the taste and texture of food and for the production of packaging that maintain fresh product. The primary function of packaging is to maintain the quality and safety of products during transport and storage period, as well as to extend its viability by preventing unwanted effect agents such as microorganisms, chemical contaminants, oxygen, moisture and light. The aim of this paper is to point out the achievements of nanotechnology in terms of food packaging with an overview of polymers that are commonly used in food packaging, as well as strategies to improve the physical properties of polymers, including mechanical strength, thermal stability and barrier to gases. By studing of recently published literature, it was clear that nanomaterials such as nano polymers are trying to replace conventional materials in food packaging. Nanosensors can be used to prove the presence of contaminants, microtoxins and microorganisms in food.

Aplasia cutis congenita (ACC) is a rare inborn lesion, presenting with absence of skin. The etiology is unknown and is probably not attributable to a single cause but to a combination of genetic factors. Multiple causes have been suggested for ACC: syndromes and teratogens, intrauterine infection--varicella zoster virus, herpes simplex virus--fetal exposure to cocaine, heroin, alcohol, or antithyroid drugs. The most common site is the scalp. We report a case with multiple lesions on the trunk, resembling an instance with ACC group 5. This form of ACC occurs in association with the in utero death of a twin or more (in this case triple) fetus. Histological findings are available in very few reports. Therapy options depend on the characteristics of the lesion, but conservative treatment is usually chosen.

The aim of this study was to evaluate the simple reaction time (SRT), the choice reaction time (CRT) and the performance of front crawl swimming at different learning levels. This study had 26 participants of both genders with a mean age of 12.15 years, divided in 2 groups: beginners (G1) and advanced (G2). Reaction time (RT) was assessed by a software that measures the interval between a visual stimulus and response, and the performance of front crawl swimming was measured by a test which allows to evaluate and score the swimming technique. The Student t test for independent samples was used and significance level was set at 5%. Results showed that there was a difference between the 2 groups in SRT (G1 = .341s e G2 = .271s; t = ˗ 3.070; p = .001; TE= 0.60), and CRT Time (G1= .651s e G2= . 492s; t = ˗ 4.016; p = .001; TE= 0.63). A moderate correlation was found between G1 (beginner) and TRE (Advanced) (r = - 0.560, p = 0.046), and G2 (advanced) and TRS (Advanced) (r = - 0.685, p = 0.010). We conclude that TR is important for success in the front crawl performance since its improvement results

Metformin is the most widely used oral anti‐diabetes agent and has considerable benefits over other therapies, yet 20–30% of people develop gastrointestinal side effects, and 5% are unable to tolerate metformin due to the severity of these side effects. The mechanism for gastrointestinal side effects and their considerable inter‐individual variability is unclear. We have recently shown the association between organic cation transporter 1 (OCT1) variants and severe intolerance to metformin in people with Type 2 diabetes. The aim of this study was to explore the association of OCT1 reduced‐function polymorphisms with common metformin‐induced gastrointestinal side effects in Type 2 diabetes.

The paper describes the procedure for parameter tuning of the power system stabilizer, as part of the structure of the automatic voltage regulator of synchronous generator AVR. Parameter tuning is based on a method that uses a mathematical model of synchronous generator on the power system. The parameters of the mathematical model of synchronous generator are determined by identification. Application of the identified mathematical model defines the function of dependence of the characteristics of the voltage regulator of the synchronous generator to the parameters of the controller. Developed method for parameter tuning is tested on the real laboratory system.