644 research outputs found
Cost efficiency of Italian Commercial Banks: a Stochastic Frontier analysis
During 90’s, the Italian banking system faced a new competitive environment both
widening the dimensional scale and pursuing a rationalization process. Some insights could
be drawn through efficiency analysis by estimation of a stochastic cost frontier for the
period 1993-2004. Benchmark analysis not only highlights the contribution of the main
factors that affect efficiency, but also allows evaluation of efficiency dynamics through
time, determining the presence of technical progress and scale economies. However, such
measure is significant if the sample of firms is homogeneous hence, accounting for
heterogeneity of the units involved is then a goal of our analysi
Pulsed field gel electrophoresis of group A streptococci
Here we describe the protocols to perform PFGE analysis of chromosomal DNA from the bacterial species Streptococcus pyogenes (group A streptococcus, GAS) after digestion with the restriction enzyme SmaI. Large parts of the procedures are suitable for application to DNA digested with other restriction enzymes as well. We have put an effort to present extensions to solve possible limitations to the discriminatory power of the method in the specific case of S. pyogenes
NEXAFS spectroscopy and site-specific fragmentation of N -methylformamide, N,N -dimethylformamide, and N,N -dimethylacetamide
Near-edge X-ray absorption fine-structure (NEXAFS) spectra measured at the C, N, and O K-edges
for three molecules containing the amide moiety, N-methylformamide (HCONHCH3), N,Ndimethylformamide
(HCON(CH3)2), and N,N-dimethylacetamide (CH3CON(CH3)2) are presented.
These molecules have similar structures and differ by the number of methyl groups located at the
molecular ends. The fragmentation of these molecules after resonant excitation at different K-edge
resonances is also investigated, using a 3D-ion imaging time-of-flight spectrometer. A comparison
between the molecules with respect to the relative contributions of the fragments created upon
excitation at distinct resonances reveals site-specific fragmentation. Further information about the
character of the core-excitation and dissociation process is obtained from the angular distributions of
the ion fragments
Literature Review on the Pre-Slaughter Welfare of Italian Heavy Pigs
This work provides a narrative review of the available information on the welfare of Italian heavy pigs in the pre-slaughter phase (transport, lairage, and stunning). The meat from these pigs is used for specific PDO (Protected Designation of Origin) products, and the production rules for these specialties require higher body weight (160–170 kg) and age (in general more than 9 months) at slaughter than in most other countries. This may lead to specific behavioral and physiological needs of pigs. The present paper summarizes the main research findings and knowledge gaps for each of the pre-slaughter phases. Studies are presented according to the four principles of the Welfare Quality assessment protocol (good feeding, good housing, good health, and appropriate behavior). The results of the literature review indicate a lack of knowledge on several aspects. Most of studies were carried out in a single slaughterhouse, making it difficult to identify risk factors and confounding effects. Moreover, animal-based measures were assessed using different protocols, reducing the possibility of comparison across studies. These findings may serve as a basis for the development of specific research studies and policies aimed at enhancing the animal welfare level and the ethical attributes of this renowned production, also in accordance with consumers’ expectations
Antimicrobial Activity of Single And Combined Extracts of Medicinal Plants From Cameroon
Selected Cameroonian plants have been investigated for their antifungal and antibacterial activity
against five species: four bacteria, namely S. aureus, S. pyogenes, S. mutans, Pseudomonas aeruginosa and the
yeast C. albicans. The solvents used for plant extraction were either ethanol or water. The in vitro antimicrobial
activity was performed by disk diffusion and microdilution method. The aqueous extracts showed no activity
whereas the ethanolic extracts showed a significant antibacterial activity, which may be associated to the high
content in tannins shown by some of the extracts. In conclusion, this work adds to the accumulating evidences
supporting the development of new alternatives to antibiotics based on the use of natural products
Single photon thermal ionization of C60
We report on experiments which show that C60 can ionize in an indirect, quasi-thermal boiloff process
after absorption of a single photon. The process involves a large number of incoherently excited valence
electrons and yields electron spectra with a Boltzmann distribution with temperatures exceeding 10^4 K.
It is expected to be present for other molecules and clusters with a comparatively large number of valence
electrons. The astrophysical consequences are briefly discussed
Molecular cloning and biochemical characterization of Xaa-Pro dipeptidyl-peptidase from Streptococcus mutans and its inhibition by anti-human DPP IV drugs
Streptococcus mutans harbours an intracellular, human DPP IV-analogous enzyme Xaa-Pro dipeptidyl-peptidase (EC 3.4.14.11). According to previous reports, an extracellular isozyme in S. gordonii and S. suis has been associated with virulence. Speculating that even an intracellular form may aid in virulence of S. mutans, we have tried to purify, characterize and evaluate enzyme inhibition by specific inhibitors. The native enzyme was partially purified by ion-exchange and gel filtration chromatography. Owing to low yield, the enzyme was overexpressed in Lactococcus lactis and purified by affinity chromatography. The recombinant enzyme (rSm-XPDAP) had a specific activity of 1070 U mg-1, while the Vmax and Km were 7 μM min-1 and 89 ± 7 μM (n = 3), respectively. The serine protease inhibitor phenylmethylsulphonyl fluoride and a DPP IV-specific inhibitor diprotin A proved to be active against rSm-XPDAP. As a novel approach, the evaluation of the effect of anti-human DPP IV (AHD) drugs on rSm-XPDAP activity found saxagliptin to be effective to some extent (Ki = 129 ± 16 μM), which may lead to the synthesis and development of a new class of antimicrobial agents
In Vitro Anti-Helicobacter Pylori and Antioxidant Activities of Plants used in Algerian Traditional Medicine for Gastrointestinal Disorders
It has been recognized that gastric colonization with Helicobacter pylori (H. pylori) induces a risk of developing ulcer disease and gastric cancer. The interest of this research relates for the first time to the study of the Anti-Helicobacter pylori activities of three medicinal plants methanolic extracts, namely Allium sativum, Allium cepa and Foeniculum vulgare. The activity of the methanolic extracts was assessed against two strains of H. pylori (SAN158 and 26659) by the disc diffusion method on Muller Hinton agar. The content of phenolic compounds (TPC) was determined by the Folin-Ciocalteu test and the antioxidant activity was evaluated through the FRAP method (Ferric reducing antioxidant power). All plants extract were inhibitory towards both strains, with F. vulgare’s showing the strongest activity. The highest TPC, along with the best antioxidant capacity, was exhibited by the F. vulgare methanolic extract (1.44 mg GAE (gallic acid equivalents) / g ± 0.2 and 0.009 mg EAA (ascorbic acid equivalent) / g ± 0.001, respectively). This study showed that Allium sativum, Allium cepa and Foeniculum vulgare bioactive substances may be effective against Helicobacter pylori
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