Del mineral al frontal romànic: aplicació dels pigments minerals en pintura romànica al Berguedà

Treball de recerca realitzat per una alumna d’ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l’any 2008. L’objectiu principal ha estat fer una reproducció a escala d’un frontal del romànic berguedà emprant pigments minerals. Sobre la base d’una recerca bibliogràfica exhaustiva, s’ha realitzat primer una aproximació teòrica amb l’objectiu de poder estudiar els pigments minerals des de diversos punts de vista: el científic, explicant la física, química i geologia del color; i l’artístic, explicant l’evolució dels pigments al llarg de la història de l’art –especialment en el Romànic català -. Paral•lelament, els estudis experimentals es van estructurar en quatre apartats: localització i recol•lecció de minerals, obtenció del pigment, elaboració de la pintura i reproducció del frontal romànic de Sant Andreu de Sagàs. Per tal de comprendre millor el procediment d’elaboració del frontal se’n va confeccionar un altre que es va dividir en quatre parts, corresponents als diferents passos que s’havien de seguir. El treball realitzat mostra que les dues grans branques del saber, l’art i la ciència, es troben íntimament relacionades. A més ha demostrat que gran part dels pigments que s’utilitzaven per elaborar les pintures romàniques del Berguedà provenien de l’entorn més directe, però en cas necessari s’utilitzaven minerals importats de terres llunyanes, com el cinabri. Les pintures elaborades amb pigments minerals tenen un alt valor afegit, ja que requereixen tot un procés de preparació molt llarg i laboriós.

Acute infantile encephalopathy predominantly affecting the frontal lobe (AIEF): A European case.

Acute infantile encephalopathy predominantly affecting the frontal lobes (AIEF) has been described as a new entity, based on MRI findings (acute abnormal diffusion-weighted imaging signals in the frontal lobes followed by atrophy) and exclusion of other acute encephalopathies. Patients present with acute onset of fever, status epilepticus, and coma. Different causal mechanisms have been suggested such as localized viral infection, toxic insult due to cytokines, or postictal damage. Only children of Japanese descent have been described. We report the case of a Caucasian girl whose history and MRI findings were similar to the Japanese cases. She had a massive regression with verbal apraxia, while cognitive development was less affected; she initially presented with a cluster of complex partial seizures (and not convulsive status epilepticus), making epileptic or post anoxic-ischemic sequelae highly unlikely. The place of this proposed entity among other recently described acute encephalopathies with abnormal diffusion on MRI is discussed.

Dead-End Jobs or Career Opportunities? Advancement opportunities in call centers

Employment in call centers has grown significantly throughout the world over the past 15 years. In debates about the quality of these new jobs, there are few studies that specifically address promotion opportunities. Using a survey of over 2400 call centers in 16 countries, this paper documents levels and analyzes factors shaping promotions in call centers, and discusses implications for promotions in the service sector generally. On average, less than 10% of call center agents are promoted in any year--5.7% promoted internally to the call center, and 4% promoted elsewhere in the business. Firms that have more complex labor processes and require agents to have higher levels of firm-specific knowledge tend to also have greater promotion opportunities, which might be expected. There are also unexpected findings, including that increased autonomy in the workplace often provides a ‘substitute' to advancement opportunities, and that unionization is associated with fewer advancement opportunities within call centers, though more advancement opportunities to other parts of the business. Key words: promotions, service industries, call centers.

Spontaneous subconjunctival orbital fat prolapse: presentation of four cases

BACKGROUND: Subconjunctival orbital fat prolapse is a benign entity characterized by orbital fat herniation through a dehiscence in Tenon's capsule, usually between the superior and lateral recti muscles. It is often associated with ocular trauma or surgery, although spontaneous cases have also been reported with a predilection for obese individuals. PATIENTS AND METHODS: A retrospective study of four subconjunctival orbital-fat prolapse cases with no history of ocular surgery or trauma was performed. A trans-conjunctival surgical approach with Tenon's capsule repair was offered to all subjects. Differential diagnosis is discussed. RESULTS: The diagnosis of subconjunctival orbital fat prolapse was confirmed in all cases by histopathological examination. Functional and aesthetic postoperative results were excellent, with no recurrences during follow-up, for all cases. CONCLUSIONS: Although rare, subconjunctival orbital fat prolapse should be recognized. Surgical management offers excellent results.

Migraineurs without aura show microstructural abnormalities in the cerebellum and frontal lobe.

The involvement of the cerebellum in migraine pathophysiology is not well understood. We used a biparametric approach at high-field MRI (3 T) to assess the structural integrity of the cerebellum in 15 migraineurs with aura (MWA), 23 migraineurs without aura (MWoA), and 20 healthy controls (HC). High-resolution T1 relaxation maps were acquired together with magnetization transfer images in order to probe microstructural and myelin integrity. Clusterwise analysis was performed on T1 and magnetization transfer ratio (MTR) maps of the cerebellum of MWA, MWoA, and HC using an ANOVA and a non-parametric clusterwise permutation F test, with age and gender as covariates and correction for familywise error rate. In addition, mean MTR and T1 in frontal regions known to be highly connected to the cerebellum were computed. Clusterwise comparison among groups showed a cluster of lower MTR in the right Crus I of MWoA patients vs. HC and MWA subjects (p = 0.04). Univariate and bivariate analysis on T1 and MTR contrasts showed that MWoA patients had longer T1 and lower MTR in the right and left pars orbitalis compared to MWA (p < 0.01 and 0.05, respectively), but no differences were found with HC. Lower MTR and longer T1 point at a loss of macromolecules and/or micro-edema in Crus I and pars orbitalis in MWoA patients vs. HC and vs. MWA. The pathophysiological implications of these findings are discussed in light of recent literature.

Reversible acquired epileptic frontal syndrome and CSWS suppression in a child with congenital hemiparesis treated by hemispherotomy.

A boy with a right congenital hemiparesis due to a left pre-natal middle cerebral artery infarct developed focal epilepsy at 33 months and then an insidious and subsequently more rapid, massive cognitive and behavioural regression with a frontal syndrome between the ages of 4 and 5 years with continuous spike-waves during sleep (CSWS) on the EEG. Both the epilepsy and the CSWS were immediately suppressed by hemispherotomy at the age of 5 years and 4 months. A behavioural-cognitive follow-up prior to hemispherotomy, an per-operative EEG and corticography and serial post-operative neuropsychological assessments were performed until the age of 11 years. The spread of the epileptic activity to the "healthy" frontal region was the cause of the reversible frontal syndrome. A later gradual long-term but incomplete cognitive recovery, with moderate mental disability was documented. This outcome is probably explained by another facet of the epilepsy, namely the structural effects of prolonged epileptic discharges in rapidly developing cerebral networks which are, at the same time undergoing the reorganization imposed by a unilateral early hemispheric lesion. Group studies on the outcome of children before and after hemispherectomy using only single IQ measures, pre- and post-operatively, may miss particular epileptic cognitive dysfunctions as they are likely to be different from case to case. Such detailed and rarely available complementary clinical and EEG data obtained in a single case at different time periods in relation to the epilepsy, including per-operative electrophysiological findings, may help to understand the different cognitive deficits and recovery profiles and the limits of full cognitive recovery.

Further characterization of the executive memory impairment following frontal lobe lesions.

In this article we describe a 41-year-old man who, following an operation to repair a ruptured anterior communicating artery aneurysm, manifested the "hallmark" features of a dysexecutive memory impairment. Of particular note was the patient's apparently normal level of recognition memory but impaired recall on tasks matched for difficulty in control subjects. However, further testing revealed that the patient's recognition memory was not normal under all circumstances. Implications of these data for the interpretation and further investigation of the dysexecutive deficit are discussed.

Reversible acquired epileptic frontal syndrome and CSWS suppression in a child with congenital hemiparesis treated by hemispherotomy

Rapport de synthèse : Cette thèse a étudié en détail le cas d'un enfant souffrant d'une hémiplégie congénitale sur un infarctus prénatal étendu qui a développé une forme particulière d'épilepsie, le syndrome des pointes ondes continues du sommeil (POCS), associé à une régression mentale massive. Les caractéristiques de cette détérioration pointaient vers un dysfonctionnement de type frontal. Une chirurgie de l'épilepsie (hémisphérotomie) a, non seulement, permis la guérison de l'épilepsie mais une récupération rapide sur le plan comportemental et cognitif, suivie d'une reprise plus lente du développement, avec finalement à l'âge de 11 ans un niveau de déficience intellectuelle modérée. L'intérêt de cette étude réside dans le fait que l'enfant a pu être suivi prospectivement entre l'âge de 4.5 ans et 11 ans par des enregistrements électro-encéphalographiques (EEG) ainsi que des tests neuropsychologiques et des questionnaires de comportements sériés, permettant de comparer les périodes pré-, péri- et postopératoires, ce qui est rarement réalisable. Un enregistrement EEG de surface a même pu être effectué durant l'opération sur l'hémisphère non lésé, permettant de documenter l'arrêt des décharges épileptiformes généralisées dès la fin de l'intervention. L'hypothèse que nous avons- souhaité démontrer est que la régression comportementale et cognitive présentée par l'enfant après une période de développement précoce presque normale (retard de langage) était de nature épileptique : nous l'expliquons par la propagation de l'activité électrique anormale à partir de la lésion de l'hémisphère gauche vers les régions préservées, en particulier frontales bilatérales. L'hémisphérotomie a permis une récupération rapide en déconnectant l'hémisphère gauche lésé et épileptogène de l'hémisphère sain, qui a ainsi pu reprendre les fonctions cognitives les plus importantes. Les progrès plus lents par la suite et l'absence de rattrapage au delà d'un niveau de déficience mentale modérée sont plus difficiles à expliquer: on postule ici un effet de l'épilepsie sur le développement de réseaux neuronaux de l'hémisphère initialement non lésé, réseaux qui sont à la fois à un stade précoce de leur maturation et en cours de réorganisation suite à la lésion prénatale. La littérature sur les déficits cognitifs avant et après hemisphérotomie s'est surtout préoccupée du langage et de sa récupération possible. À notre connaissance, notre étude est la première à documenter la réversibilité d'une détérioration mentale avec les caractéristiques d'un syndrome frontal après hémisphérotomie. La chirurgie de l'épilepsie a offert ici une occasion unique de documenter le rôle de l'activité épileptique dans la régression cognitive puisqu'en interrompant brusquement la propagation de l'activité électrique anormale, on a pu comparer la dynamique du développement avant et après l'intervention. La mise en relation des multiples examens cliniques et EEG pratiqués chez un seul enfant sur plusieurs années a permis d'obtenir des informations importantes dans la compréhension des troubles cognitifs et du comportement associés aux épilepsies focales réfractaires. ABSTRACT : A boy with a right congenital hemiparesis due to a left pre-natal middle cerebral artery infarct developed focal epilepsy at 33 months and then an insidious and subsequently more rapid, massive cognitive and behavioural regression with a frontal syndrome between the ages of 4 and 5 years with continuous spike-waves during sleep (CSWS) on the EEG. Both the epilepsy and the CSWS were immediately suppressed by hemispherotomy at the age of 5 years and 4months. A behavioural-cognitive follow-up prior to hemispheratomy, an per-operative EEG and corticography and serial post-operative neuropsychological assessments were performed until the age of 11 years. The spread of the epileptic activity to the "healthy" frontal region was the cause of the reversible frontal syndrome. A later gradual long-term but incomplete cognitive recovery, with moderate mental disability was documented. T9ris outcome is probably explained by another facet of the epilepsy, namely the structural effects of prolonged epileptic dischazges in rapidly developing cerebral networks which are, at the same time undergoing the reorganization imposed by a unilateral early hemispheric lesion. Group studies on the outcome of children before and after hemispherectomy using only single IQ measures, pre- and postoperatively, may miss particular epileptic cognitive dysfunctions as they are likely to be different from case to case. Such detailed and rarely available complementary clinical and EEG data obtained in a single case at different time periods in relation to the epilepsy, including peroperative electrophysiological findings, may help to understand the different cognitive deficits and recovery profiles and the limits of full cognitive recovery.

Paranasal sinuses in children: size evaluation of maxillary, sphenoid, and frontal sinuses by magnetic resonance imaging and proposal of volume index percentile curves.

Our objective was to establish the age-related 3D size of maxillary, sphenoid, and frontal sinuses. A total of 179 magnetic resonance imaging (MRI) of children under 17 years (76 females, 103 males) were included and sinuses were measured in the three axes. Maxillary sinuses measured at birth (mean+/-standard deviation) 7.3+/-2.7 mm length (or antero-posterior)/4.0+/-0.9 mm height (or cranio-caudal)/2.7+/-0.8 mm width (or transverse). At 16 years old, maxillary sinus measured 38.8+/-3.5 mm/36.3+/-6.2 mm/27.5+/-4.2 mm. Sphenoid sinus pneumatization starts in the third year of life after conversion from red to fatty marrow with mean values of 5.8+/-1.4 mm/8.0+/-2.3 mm/5.8+/-1.0 mm. Pneumatization progresses gradually to reach at 16 years 23.0+/-4.5 mm/22.6+/-5.8 mm/12.8+/-3.1 mm. Frontal sinuses present a wide variation in size and most of the time are not valuable with routine head MRI techniques. They are not aerated before the age of 6 years. Frontal sinuses dimensions at 16 years were 12.8+/-5.0 mm/21.9+/-8.4 mm/24.5+/-13.3 mm. A sinus volume index (SVI) of maxillary and sphenoid sinus was computed using a simplified ellipsoid volume formula, and a table with SVI according to age with percentile variations is proposed for easy clinical application. Percentile curves of maxillary and sphenoid sinuses are presented to provide a basis for objective determination of sinus size and volume during development. These data are applicable to other techniques such as conventional X-ray and CT scan.

Neuronal and nonneuronal quantitative BACE immunocytochemical expression in the entorhinohippocampal and frontal regions in Alzheimer's disease.

In this study, we quantitatively investigated the expression of beta-site amyloid precursor protein cleaving enzyme (BACE) in the entorhinohippocampal and frontal cortex of Alzheimer's disease (AD) and old control subjects. The semiquantitative estimation indicated that the intensity of BACE overall immunoreactivity did not differ significantly between AD and controls, but that a significantly stronger staining was observed in the hippocampal regions CA3-4 compared to other regions in both AD patients and controls. The quantitative estimation confirmed that the number of BACE-positive neuronal profiles was not significantly decreased in AD. However, some degeneration of BACE-positive profiles was attested by the colocalization of neurons expressing BACE and exhibiting neurofibrillary tangles (NFT), as well as by a decrease in the surface area of BACE-positive profiles. In addition, BACE immunocytochemical expression was observed in and around senile plaques (SP), as well as in reactive astrocytes. BACE-immunoreactive astrocytes were localized in the vicinity or close to the plaques and their number was significantly increased in AD entorhinal cortex. The higher amount of beta-amyloid SP and NFT in AD was not correlated with an increase in BACE immunoreactivity. Taken together, these data accent that AD progression does not require an increased neuronal BACE protein level, but suggest an active role of BACE in immunoreactive astrocytes. Moreover, the strong expression in controls and regions less vulnerable to AD puts forward the probable existence of alternate BACE functions.

Thorax, pelvis and hip pattern in the frontal plane during walking in unilateral transtibial amputees: biomechanical analysis.

BACKGROUND Lower limb amputees exhibit postural control deficits during standing which can affect their walking ability. OBJECTIVES The primary purpose of the present study was to analyze the thorax, pelvis, and hip kinematics and the hip internal moment in the frontal plane during gait in subjects with Unilateral Transtibial Amputation (UTA). METHOD The participants included 25 people with UTA and 25 non-amputees as control subjects. Gait analysis was performed using the Vicon(r) Motion System. We analyzed the motion of the thorax, pelvis, and hip (kinematics) as well as the hip internal moment in the frontal plane. RESULTS The second peak of the hip abductor moment was significantly lower on the prosthetic side than on the sound side (p=.01) and the control side (right: p=.01; left: p=.01). During middle stance, the opposite side of the pelvis was higher on the prosthetic side compared to the control side (right: p=.01: left: p=.01). CONCLUSIONS The joint internal moment at the hip in the frontal plane was lower on the prosthetic side than on the sound side or the control side. Thorax and pelvis kinematics were altered during the stance phase on the prosthetic side, presumably because there are mechanisms which affect postural control during walking.