PENERAPAN MODEL COOPERATIVE LEARNING DALAM MENINGKATKAN HASIL BELAJAR MATEMATIKA SISWA KELAS VI SDK BHAKTYARSA PADA MATERI OPERASI HITUNG CAMPURAN PECAHAN MELALUI LESSON STUDY

Penelitian ini didasari oleh rendahnya hasil belajar matematika pada materi operasi hitung campuran pecahan yang dialami para peserta didik kelas VI SDK Bhaktyarsa. Berdasarkan hasil pengamatan awal yang dilakukan, dari 33 orang peserta didik, diketahui terdapat 11 orang peserta didik (33%) orang peserta didik yang tuntas, artinya sebanyak 22 orang peserta didik (67%) yang tidak tuntas. Tujuan dari penelitian ini adalah untuk mengetahui adanya peningkatan hasil belajar  matematika setelah menggunakan model pembelajaran cooperative learning pada peserta didik kelas VI SDK Bhaktyarsa. Penelitian ini menggunakana penelitian tindakan kelas berbasis lesson study dengan tahapan perencanaan (plan), pelaksanaan (do), dan refleksi (see). Teknik pengumpulan data dalam penelitian ini menggunakan observasi dan tes. Hasil penelitian pada siklus 1, diketahui terdapat 20 orang peserta didik (61%) yang tuntas, dan pada siklus 2 diketahui terdapat 27 orang peserta didik (82%) yang tuntas. Sehingga hasil penelitian ini dapat disimpulkan bahwa penggunaan model pembelajaran cooperative learning dapat meningkatkan hasil belajar  peserta didik kelas VI A SDK Bhaktyarsa

Human, Animal and Automata Attributions: an Investigation of the Multidimensionality of the Ontologization Process

The ontologization process involves the use of social representation relating to the human–animal binary to classify ingroup and outgroup members. To date, no study has investigated the multidimensional nature (i.e. human, animal and automata) of the ontologizing process via structural equation modelling (SEM). Four hundred and twenty-one Italian participants were asked to attribute 24 positive/negative, human/animal/automata associates to each of three target groups: typical Roma/Chinese/Italian. Results showed that the proposed six-factor model (i.e. positive/negative, human/animal/automata essence) was statistically robust for each of the three groups. The Roma group was animalized by attributing more animal negative associates than any other target group, whereas the Chinese group was mainly given a robot positive essence

Iron (II) citrate complex as a food supplement: Synthesis, characterization and complex stability

Iron deficiency represents a widespread problem for a large part of the population, especially for women, and has received increasing attention in food/supplement research. The contraindications of the iron supplements commercially available (e.g., imbalances in the levels of other essential nutrients, low bioavailability, etc.) led us to search for a possible alternative. In the present work, a rapid and easy method to synthetize a solid iron (II) citrate complex from iron filings and citric acid was developed to serve, eventually, as a food supplement or additive. In order to state its atomic composition and purity, an assortment of analytical techniques was employed (e.g., combustion analysis, thermogravimetry, X-ray diffractometry, UV/Vis spectrophotometry, etc.). Results demonstrate that the synthesized crystalline solid corresponds to the formula FeC6H6O7∙H2O and, by consequence, contains exclusively iron (II), which is an advantage with respect to existing commercial products, because iron (II) is better absorbed than iron (III) (high bioavailability of iron)

Influenza della temperatura di essiccamento sui polifenoli e sulla capacità antiossidante delle susine Stanley

Changes in phenolic content, antioxidant capacity and ascorbic acid in prunes dried at 85°C and 60°C, were studied. Results obtained showed a significant decrease for ascorbic acid. It has to be highlighted that drying at 85°C resulted in keeping the polyphenolic pool and sharply raising the antioxidant activity, while the opposite happened for plums dried at 60°C. Lo studio ha riguardato l'evoluzione dei composti fenolici e dell'attività antiossidante di susine della varietà Stanley in seguito all’essiccamento a due temperature. Sui frutti freschi ed essiccati sono stati analizzati i composti fenolici, l’acido ascorbico e la capacità antiossidante. I risultati ottenuti hanno evidenziato un decremento significativo dell’acido ascorbico nei campioni essiccati. Si evidenzia che l’uso di un’alta temperatura porta ad un mantenimento della componente polifenolica ed a un aumento di oltre 9 volte dell’attività antiossidante in vitro, rispetto ai frutti freschi, mentre nelle susine essiccate a 60°C si ha una diminuzione di entrambi i parametri

Optimization of a rapid QuEChERS sample treatment method for HILIC-MS2 analysis of paralytic shellfish poisoning (PSP) toxins in mussels

A rapid and simple QuEChERS sample treatment was proposed for the development of a selective hydrophilic interaction liquid chromatography-ESI-MS2-based method for the determination of saxitoxins (STXs) in mussel samples. Among different sorbents, ABS Elut-NEXUS phase, composed of polystyrene cross-linked with 50 % divinyl benzene and poly(methyl methacrylate), provided the best results. The effects of experimental parameters, including sorbent amount, vortexing time and centrifugation time were investigated and optimized by experimental design. In particular, regression models and desirability functions were applied to find the experimental conditions providing the highest global extraction response. The method was validated under the optimized conditions; detection and quantification limits in the 3-159 μg/kg and 7-436 μg/kg ranges respectively were obtained, except for C2 for which highest values were calculated due to its low ESI ionization efficiency. Finally, the analysis of twenty-eight mussel samples permitted to detect and quantify some of the investigated STXs, proving the applicability of the devised method

A new catechol-functionalized polyamidoamine as an effective SPION stabilizer

A synthetic strategy was established for decorating and stabilizing superparamagnetic iron oxide nanoparticles (SPIONs) with a zwitterionic linear polyamidoamine (PAA). The strategy was successfully tested with a PAA coded ISA23 previously found endowed with interesting biological properties, such as biocompatibility, degradability in aqueous media and stealth-like properties when injected in test animals. A post-synthetic functionalization with catechol-bearing moieties of a preformed PAA was successfully carried out. ISA23 was obtained by polyaddition reactions of methyl-piperazine and 2,2-bis(acrylamidoacetic) acid. It was functionalized using nitrodopamine and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as coupling agent, to randomly form amide bonds with 17% of ISA23 carboxylic groups (ISA23-ND). SPIONs were prepared by a thermal decomposition synthesis in 1-octadecene with oleic acid, and then transferred in water by two distinct ligand exchange procedures: i) the direct displacement of oleate molecules from SPION surface by ISA23 in a biphasic (n-hexane/water) environment; ii) the two-step method involving an intermediate small molecule, tetramethylammonium hydroxide, used as a transient transfer agent, which was in turn exchanged with ISA23-ND in a second exchange step occurring in water. The two-step procedure provided a SPION@PAA nanocomposite more stable than that obtained by the one-step procedure in the presence of an applied external magnetic field. ATR-FTIR spectroscopy, \u3b6-potential and thermogravimetric analysis (TGA) showed the presence of the ISA23 on the SPION surface. In particular, TGA showed that the ISA23-ND amount on the NPs accounted for 26% of the overall nanocomposite mass. The nanocomposite size was determined by both TEM (21.1\ub12.9 nm) and DLS measurements (hydrodynamic size 100\ub128 nm). SPION@ISA23-ND were re-suspended after lyophilization reverting to their pristine dimensions. The SPION@ISA23-ND adsorption of BSA in water, considered as the first stage of phagocytosis, was very low, suggesting that ISA23 could impart stealthiness to SPION@ISA23-ND. 1H-NMR relaxivity measurements showed an r2 value of 158 s-1 mmol-1 L (vs 100 s-1 mmol-1L for Endorem\uae) at relevant clinical fields for magnetic resonance imaging (from 0.2 to 1.5 T). SPION@ISA23-ND was tested on HeLa cells and their internalization was visualized by reflectance microscopy. Finally, with the aim of prepare a new dual magneto-optical system, a synthetic procedure to decorate SPION@ISA23-ND with a fluorescent dye was devised, even though the emission intensity of the resultant conjugate was lower than expected, possibly due to luminescence quenching caused by the closeness of emitting moieties to the SPION surface