170,819 research outputs found
À la découverte de Mayotte. Spiteri, J.-C. (dir.), 1994, Découvrons Mayotte, Paris : Hatier
No full textGay Jean-Christophe. À la découverte de Mayotte. Spiteri, J.-C. (dir.), 1994, Découvrons Mayotte, Paris : Hatier. In: Mappemonde 64, 2001/4. p. 13
Aza-Michael Reaction: Mono- versus Bis-Addition Product
No full textThe aza-Michael reaction is one of the most important reactions in modern organic synthesis since a carbon-nitrogen bond is formed during the reaction.1 Primary amines add to electron poor alkenes that are susceptible to nucleophilic attach to give secondary and tertiary products. The first product formed, the secondary derivative, is a result of a mono-addition reaction. The mono-adduct can react further to give the tertiary derivative.
In this study, the aza-Michael reactions between primary amines and propenoates (Scheme 1) were investigated under environmentally-friendly solventless conditions2 in order to obtain the mono-adduct or the bis-adduct. The reaction conditions were altered so as to maximise the yields of the desired product.
Preliminary results will be presented
Landmark Recognition and Mental Route Navigation Disorders in Patients with Imagery Neglect and Perceptual Neglect
No full textThe complex relationship between perceptual neglect and imagery neglect is still not completely understand because, at least in part, these disorders depend on are associated with, different neural systems and can be dissociated even in the same patient (Beschin, Basso, & Della Sala, 2000). Recent studies show that imagery neglect affects specific mechanisms underlying human orientation. In particular, it impairs the ability to manipulate mental representations of the environment and thus prevents the use of previous navigational experience (see for instance Guariglia et al., 2005; Piccardi, 2009; Guariglia & Piccardi, 2010). In this study, we compared the route learning and delayed recall task performance of imagery neglect patients with pure perceptual neglect patients, patients with no neglect and healthy participants. They had to learn a circular pathway in an unexplored area of the hospital; it included 13 landmarks and five turning points (three on the right and two on the left). During the learning phase, the participants explored the pathway three times with the examiner, who pointed out the landmarks. At the end of this phase, the participants performed two different tasks: a) Landmark Recognition Task and b) Navigational Questions. The first task included 26 pictures of landmarks (13 target pictures and 13 fillers) located along the pathway that the participants had to recognize. Fillers were the same type of stimuli as the target, but with different characteristics (e.g., two different doors). The second, delayed recall task consisted of 30 questions investigating the participants' ability to recall a learned pathway and the landmarks encountered along the way. We assessed 23 right brain-damaged patients (4 patients with pure perceptual neglect, 8 patients with imagery neglect and 11 patients without neglect) and 17 healthy participants matched for age and education. Our results showed that only patients with imagery neglect had a pervasive disorder in recognizing landmarks met along the route and in mentally navigating the previously learned pathway. Specifically, they were unable to answer navigational questions investigating their mental representation of the pathway. Differently, perceptual neglect patients were able to recognize landmarks as well as answer navigational questions in spite of their exploration disorder. Right brain-damaged patients without neglect showed no deficit on the tasks. In summary, only the imagery neglect patients were unable to build or retrieve a mental representation of the new environment and, thus, failed in performing these tasks. In fact, results showed they were deficient in using a cognitive map of the environment. It is still unknown whether the deficit observed in imagery neglect patients is due to difficulty in building a mental map, recalling it from memory or using it during navigation, leaving unknown the exact point in which the navigational process is compromised
Phoenician maritime pioneering and Punic expansion: Reconstructing trade and dietary patterns
No full textSession organized by Debono-Spiteri, Salazar García & Vell
Interferon-gamma downregulates the rhinovirus induced expression of intercellular adhesion molecule-1 (ICAM-1) on human airway epithelial cells
No full textHuman rhinoviruses (HRV) are a major cause of upper respiratory tract infections in man, and can exacerbate existing pulmonary disease. The major group of HRV attach to ICAM-1, which is expressed on nasal and bronchial epithelial cells. To study the influence of biological mediators on ICAM-1 expression, and consequently HRV attachment and infection, we compared the effects of various cytokines, alone and in combination, on ICAM-1 expression by an uninfected and HRV-infected bronchial epithelial cell line H292. Cytokines known to be released soon after viral infection, such as tumour necrosis factor-alpha (TNF-alpha), IL-1beta and the chemokine IL-8 increase ICAM-1 expression on uninfected cells. Epithelial cells infected with live HRV-14 displayed marked up-regulation of ICAM-1 compared with baseline. TNF-alpha further enhanced the HRV-induced increase in ICAM-1 expression on epithelial cells, peaking at day 4 after infection, whilst IL-8 exhibited a steady increase in ICAM-1 expression over 14 days. In contrast, IFN-gamma, a known Th1 antiviral lymphokine, whilst increasing the level of ICAM-1 on uninfected cells, induced a significant persistent down-regulation of ICAM-1 expression on HRV-infected epithelial cells. With combinations of TNF-alpha and IFN-gamma, ICAM-1 expression on HRV-infected cells was reduced to basal levels. The effects of IFN-gamma were paralleled by a reduction in viral titres. Our in vitro model has provided useful insights into the early pathogenic events of HRV infection at the level of the host cell-virus interaction. Our data confirm that biological mediators play a crucial role in the pathogenesis as well as the course of HRV infection which is modulated by the types, and time kinetics of inflammatory cytokines in the immediate microenvironment
Egg proteome: the protein and carotenoids characteristics deriving from laying hens reared in different housing systems and under different environmental conditions
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Landmark Recognition and Mental Route Navigation Disorders in Patients with Imagery Neglect and Perceptual Neglect
Full text linkThe complex relationship between perceptual neglect and imagery neglect is still not completely understand because, at least in part, these disorders depend on are associated with, different neural systems and can be dissociated even in the same patient (Beschin, Basso, & Della Sala, 2000).
Recent studies show that imagery neglect affects specific mechanisms underlying human orientation. In particular, it impairs the ability to manipulate mental representations of the environment and thus prevents the use of previous navigational experience (see for instance Guariglia et al., 2005; Piccardi, 2009; Guariglia & Piccardi, 2010).
In this study, we compared the route learning and delayed recall task performance of imagery neglect patients with pure perceptual neglect patients, patients with no neglect and healthy participants.
They had to learn a circular pathway in an unexplored area of the hospital; it included 13 landmarks and five turning points (three on the right and two on the left). During the learning phase, the participants explored the pathway three times with the examiner, who pointed out the landmarks. At the end of this phase, the participants performed two different tasks: a) Landmark Recognition Task and b) Navigational Questions. The first task included 26 pictures of landmarks (13 target pictures and 13 fillers) located along the pathway that the participants had to recognize. Fillers were the same type of stimuli as the target, but with different characteristics (e.g., two different doors). The second, delayed recall task consisted of 30 questions investigating the participants’ ability to recall a learned pathway and the landmarks encountered along the way.
We assessed 23 right brain-damaged patients (4 patients with pure perceptual neglect, 8 patients with imagery neglect and 11 patients without neglect) and 17 healthy participants matched for age and education.
Our results showed that only patients with imagery neglect had a pervasive disorder in recognizing landmarks met along the route and in mentally navigating the previously learned pathway. Specifically, they were unable to answer navigational questions investigating their mental representation of the pathway. Differently, perceptual neglect patients were able to recognize landmarks as well as answer navigational questions in spite of their exploration disorder. Right brain-damaged patients without neglect showed no deficit on the tasks.
In summary, only the imagery neglect patients were unable to build or retrieve a mental representation of the new environment and, thus, failed in performing these tasks. In fact, results showed they were deficient in using a cognitive map of the environment. It is still unknown whether the deficit observed in imagery neglect patients is due to difficulty in building a mental map, recalling it from memory or using it during navigation, leaving unknown the exact point in which the navigational process is compromised
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
The life-course transitions of young women in a Maltese context.
Full text linkThis study analyzed how a cohort of eight young women who underwent certain difficulties whilst at secondary school experienced their transition from secondary school to either work or further education. It explores changes in their perception of events and happenings that they classified as significant to them, and the influence that these changes of perception had on their evolving life-course. While not formally classified as emotionally or behaviorally challenged, all the participants in this study claimed to have had varying depths of difficulty when at secondary school, some alleging that they had been classified as troublesome by their teachers and others claiming to have seen themselves as disruptive in classroom settings. The study was informed by the participants' voices about how they saw their transitions being forged and has a phenomenological focus
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