431 research outputs found
What Determines the Economic Links among Organic Farmers? Empirical Evidence from Argentina
Farming and consumers` decisions are affected by markets globalizations, products differentiation, agricultural industrialization at the retail level and new organizational forms. The linkages among farmers emerge as a viable strategy to compete in this new context. Producers must develop skills to maintain market positioning and access to high value added niches. In Argentina, organic production has been an alternative for farmers to increase revenues, since the nineties, due to the major demand of developed countries and the price premiums. The objective of the paper is to investigate the extent to which Argentinian organic producers operate in an associated way and which the determinants of these linkages are. A count model regression is used to estimate the links among producers. The extent to which producers choose to operate in an associated way is mainly determined by the number of marketing channels used by the farmers, processing activities carried out, public support received, the scale of the farm and the kind of goods produced. This study may contribute to understand farmers` decisions about association. The issue is particularly relevant to policy makers in developing countries where associations are promoted due to the emerging role of the social capital in the rural development policies design.Horizontal Links, Organic producers, Count Model, Farm Management, D7, C21,
Cluster of legionnaires’ disease in an Italian prison
Background: Legionella pneumophila (Lp) is the most common etiologic agent causing Legionnaires’ Disease (LD). Water systems offer the best growth conditions for Lp and support its spread by producing aerosols. From 2015 to 2017, the Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis of Palermo monitored the presence of Lp in nine prisons in Western Sicily. During this investigation, we compared Lp isolates from environmental samples in a prison located in Palermo with isolates from two prisoners in the same prison. Methods: We collected 93 water samples from nine Sicilian prisons and the bronchoalveolar lavages (BALs) of two prisoners considered cases of LD. These samples were processed following the procedures described in the Italian Guidelines for the Prevention and Control of Legionellosis of 2015. Then, genotyping was performed on 19 Lp colonies (17 from water samples and 2 from clinical samples) using the Sequence-Based Typing (SBT) method, according to European Study Group for Legionella Infections (ESGLI) protocols. Results: Lp serogroup (sg) 6 was the most prevalent serogroup isolated from the prisons analyzed (40%), followed by Lp sg 1 (16%). Most of all, in four penitentiary institutions, we detected a high concentration of Lp >104 Colony Forming Unit/Liter (CFU/L). The environmental molecular investigation found the following Sequence Types (STs) in Lp sg 6: ST 93, ST 292, ST 461, ST 728, ST 1317 and ST 1362, while most of the isolates in sg 1 belonged to ST 1. We also found a new ST that has since been assigned the number 2451 in the ESGLI-SBT database. From the several Lp sg 1 colonies isolated from the two BALs, we identified ST 2451. Conclusions: In this article, we described the results obtained from environmental and epidemiological investigations of Lp isolated from prisons in Western Sicily. Furthermore, we reported the first cluster of Legionnaires’ in an Italian prison and the molecular typing of Lp sg 1 from one prison’s water system and two BALs, identified the source of the contamination, and discovered a new ST
A portable shield for a neutron howitzer used for instructional and research purposes
The article of record as published may be found at http://dx.doi.org/10.1016/j.apradiso.2015.05.011Neutron howitzers are routinely used in universities to activate samples for instructional laboratory experiments on radioactivity. They are also a convenient source of neutrons and gammas for research purposes, but they must be used with caution. This paper describes the modeling, design, construction, and testing of a portable, economical shield for a 1.0 Curie neutron howitzer. The Monte Carlo N Particle Transport Code (MCNP5) has been used to model the 239PuBe source and the howitzer and to design the external neutron and gamma shield
Synthesis and Antibacterial Activity of Mono- and Bi-Cationic Pyridinium 1,2,4-Oxadiazoles and Triazoles
One of the main causes of mortality in humans continues to be infectious diseases. Scientists are searching for new alternatives due to the fast increase in resistance of some harmful bacteria to the frontline antibiotics. To effectively treat pathogenic infections, it is crucial to design antibiotics that can prevent the development of pathogenic resistance. For this purpose, a set of 39 quaternary pyridinium and bis-pyridinium salts with different lengths of side alkyl or fluorinated chains, heterocyclic spacers, and counter ions were tested on diverse reference bacterial ATCC (American Type Culture Collection) strains, such as S. aureus and E. coli. Subsequently, 6 out of the 39 pyridinium salts showing relevant MIC (Minimum Inhibitory Concentration) values were tested on clinically isolated, resistant strains of S. aureus, S. epidermids, S. haemolyticus, K. pneumoniae, A. baumannii, and P. aeruginosa. Additional tests have been performed to assess if the minimum concentration detected through MIC assay may limit the growth of biofilms
Dificultades en el aprendizaje, inclusión cultural y autoexpectativas académicas: una propuesta de orientación e intervención educativa
HELICOBACTER PYLORI AND EPSTEIN\u2013BARR CO-INFECTION IN GASTRIC DISEASE
The incidence of gastrointestinal diseases and in particular gastric cancer (GC) is high worldwide. Over the last few years, numerous studies have speculated that Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV) can be correlated with gastric cancerogenesis.
Virulence factors of H. pylori can contribute to the variability of clinical outcomes: among the most important virulence factors is the pathogenicity island (CagPAI), vacA and oipA gene. EBV infection usually persists in B cells and induces an inflammatory reaction in cooperation with H. pylori. In Sicily, H. pylori and EBV infections are particularly prevalent, and to our knowledge no study has addressed this yet. The aim of our study was to examine the association of H. pylori and EBV infection in patients with gastric diseases in Sicily. Gastric biopsies were collected from 24 adult patients with chronic gastritis active (CGA) and from 24 adult patients without any gastric disease (NGD) who underwent upper gastrointestinal endoscopy. H. pylori infection was diagnosed by PCR for ureaseA gene while EBV-DNA was detected by Real time PCR for region Bam HI-W. Moreoever, we investigated the presence of CagPaI and the status of vacA and oipA genes. Percentage of resistance to Clarithromycin of H. pylori was evaluated also. We established that H. pylori and EBV infection was present in 42% of patients, while dual infection with H. pylori and EBV-DNA was present in 54% of the patients with CGA. In patients with NGD we found that H. pylori and EBV infection was present in 46% and in 21% of patients respectively, while co-infection was present in 33% of patients. CagPAI was present in only 20% of patients with GCA and in 9% of patients with NGD. As regards vacA alleles, s2i2m2 were predominant, present in 80% and 82% of patients with CGA and NGD respectively. The status \u201cON\u201d of oipA gene was present in the same percentage. Finally, we found that 38% of patients positive for H. pylori infection showed resistance to Clarithromycin. In our study, there was a strong association between the simultaneous presence of H. pylori and EBV infection in patients with CGA compared to patients with NGD. Furthermore, our data confirmed the high percentage of resistance among H. pylori strains circulating in Sicily, underlining the importance of establishing a therapy that is effective in eradicating them and reducing the frequency of coinfections and evolution towards gastric cancerogenesi
High prevalence to resistance of clarithromycin in Helicobacter pylori strains isolated in Sicily .
Eficácia in vitro de extratos vegetais no controle do carrapato Rhipicephalus (Boophilus) microplus.
O carrapato do boi, Rhipicephalus (Boophilus) microplus (Canestrini, 1887), principal ectoparasita dos bovinos nas regiões tropicais e subtropicas, é responsável por diversas perdas econômicas na bovinocultura, dentre as quais temos, perda de peso e depreciação do couro, transmissão de hemoparasitas, espoliação sanguínea e elevados custos ao seu controle. O uso indiscriminado de produtos químicos para o controle desse ectoparasita tem levado ao desenvolvimento de resistência aos princípios químicos, além dos danos ambientais. Diante dessas circunstâncias, os fitoterápicos têm sido avaliados como um método de controle alternativo, visto que, dependendo da espécie vegetal, podem promover desenvolvimento lento da resistência, têm baixo custo e são biodegradáveis, não causando danos ao meio ambiente. O objetivo deste trabalho foi avaliar a eficácia in vitro de seis extratos vegetais em diferentes concentrações sobre fêmeas ingurgitadas (teleóginas) de R. microplus
Phosphorylation and Activation of the Plasma Membrane Na+/H+ Exchanger (NHE1) during Osmotic Cell Shrinkage
The Na+/H+ Exchanger isoform 1 (NHE1) is a highly versatile, broadly distributed and precisely controlled transport protein that mediates volume and pH regulation in most cell types. NHE1 phosphorylation contributes to Na+/H+ exchange activity in response to phorbol esters, growth factors or protein phosphatase inhibitors, but has not been observed during activation by osmotic cell shrinkage (OCS). We examined the role of NHE1 phosphorylation during activation by OCS, using an ideal model system, the Amphiuma tridactylum red blood cell (atRBC). Na+/H+ exchange in atRBCs is mediated by an NHE1 homolog (atNHE1) that is 79% identical to human NHE1 at the amino acid level. NHE1 activity in atRBCs is exceptionally robust in that transport activity can increase more than 2 orders of magnitude from rest to full activation. Michaelis-Menten transport kinetics indicates that either OCS or treatment with the phosphatase inhibitor calyculin-A (CLA) increase Na+ transport capacity without affecting transport affinity (Km = 44 mM) in atRBCs. CLA and OCS act non-additively to activate atNHE1, indicating convergent, phosphorylation-dependent signaling in atNHE1 activation. In situ 32P labeling and immunoprecipitation demonstrates that the net phosphorylation of atNHE1 is increased 4-fold during OCS coinciding with a more than 2-order increase in Na+ transport activity. This is the first reported evidence of increased NHE1 phosphorylation during OCS in any vertebrate cell type. Finally, liquid chromatography and mass spectrometry (LC-MS/MS) analysis of atNHE1 immunoprecipitated from atRBC membranes reveals 9 phosphorylated serine/threonine residues, suggesting that activation of atNHE1 involves multiple phosphorylation and/or dephosphorylation events
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