Orbital frustration at the origin of the magnetic behavior in LiNiO2

We report on the ESR, magnetization and magnetic susceptibility measurements performed over a large temperature range, from 1.5 to 750 K, on high-quality stoichiometric LiNiO2. We find that this compound displays two distinct temperature regions where its magnetic behavior is anomalous. With the help of a statistical model based on the Kugel'-Khomskii Hamiltonian, we show that below T_of ~ 400 K, an orbitally-frustrated state characteristic of the triangular lattice is established. This then gives a solution to the long-standing controversial problem of the magnetic behavior in LiNiO2.Comment: 5 pages, 5 figures, RevTex, accepted in PR

La gestion sociale urbaine dans les pays en développement : rapport de fin de recherche mai 1993

Les réflexions proposées ici représentent une étape dans une recherche menée par une équipe du laboratoire TMU sur le thème de "la gestion sociale urbaine dans les pays en développement" ; elle privilégie dans le champ global de la gestion urbaine la dimension sociale, en la considérant comme mécanisme de régulation des rapports sociaux urbains, et comme système de contrôle des populations urbaines. La recherche s'appuie sur l'observation et l'analyse des pratiques des gestionnaires et de celles des citadins, à partir de deux entrées : la régularisation foncière, technique de gestion du sol urbain, mais aussi mode de régulation des rapports sociaux en ville, et la gestion urbaine partagée des services urbains. C'est autour de ces deux axes que s'est tenue une journée de réflexion en mai 1992, qui a permis de mieux cerner les possibilitiés et les limites de la gestion sociale urbaine à son niveau le plus approprié, celui des collectivités territoriales locales. (Résumé d'auteur

Recovery of adrenal insufficiency is frequent after adjuvant mitotane therapy in patients with adrenocortical carcinoma

Mitotane is a steroidogenesis inhibitor and adrenolytic drug used for treatment of adrenocortical cancer (ACC). Mitotane therapy causes adrenal insufficiency requiring glucocorticoid replacement in all patients. However, it is unclear whether chronic therapy with mitotane induces complete destruction of zona fasciculata and whether hypothalamic-pituitary-adrenal (HPA) axis can recover after treatment cessation. Our objective was to assess the HPA axis recovery in a cohort of patients after cessation of adjuvant mitotane therapy for ACC. We retrospectively reviewed patient files with stage I-II-III ACC in two referral centers in Canada and Italy. Data on demographics, tumor characteristics, hormonal profile, and HPA axis were collected. Data from 23 patients with pathologically proven ACC treated with adjuvant mitotane for a minimum of two years were analyzed. Eight patients were males and 15 were females and the median age was 41 years old (range 18 to 73). After mitotane cessation, 18/23 (78.3%) patients achieved a complete HPA axis recovery while 3/23 (13.0%) were unable to tolerate glucocorticoid withdrawal despite having normal hormonal test values and 2/23 (8.7%) never achieved recovery. The mean time interval between mitotane cessation and HPA axis recovery was 2.7 years. A high proportion of patients achieved HPA axis recovery following cessation of mitotane adjuvant therapy. However, complete recovery was often delayed up to 2.5 years and regular assessment of the hormonal profile is required

Consensus guidelines on the construct validity of rodent models of restless legs syndrome.

Our understanding of the causes and natural course of restless legs syndrome (RLS) is incomplete. The lack of objective diagnostic biomarkers remains a challenge for clinical research and for the development of valid animal models. As a task force of preclinical and clinical scientists, we have previously defined face validity parameters for rodent models of RLS. In this article, we establish new guidelines for the construct validity of RLS rodent models. To do so, we first determined and agreed on the risk, and triggering factors and pathophysiological mechanisms that influence RLS expressivity. We then selected 20 items considered to have sufficient support in the literature, which we grouped by sex and genetic factors, iron-related mechanisms, electrophysiological mechanisms, dopaminergic mechanisms, exposure to medications active in the central nervous system, and others. These factors and biological mechanisms were then translated into rodent bioequivalents deemed to be most appropriate for a rodent model of RLS. We also identified parameters by which to assess and quantify these bioequivalents. Investigating these factors, both individually and in combination, will help to identify their specific roles in the expression of rodent RLS-like phenotypes, which should provide significant translational implications for the diagnosis and treatment of RLS

Psychosocial correlates of depression and anxiety in the United Arab Emirates during the COVID-19 pandemic

The impact of the COVID-19 pandemic on mental health is likely to be significant. Identifying vulnerable groups during the pandemic is essential for targeting psychological support, and in preparation for any second wave or future pandemic. Vulnerable groups are likely to vary across different societies; therefore, research needs to be conducted at a national and international level. This online survey explored generalized anxiety and depression symptoms in a community sample of adults (N = 1,039) in the United Arab Emirates (UAE) between April 8th and April 22nd, 2020. Respondents completed symptom measures of depression (PHQ8) and generalized anxiety (GAD7), along with psychosocial and demographic variables that might potentially influence such symptoms. Bivariate and multivariate associations were calculated for the main study variables. Levels of anxiety and depression were notably higher than those reported in previous (pre-pandemic) national studies. Similar variables were statistically significantly associated with both depression and anxiety, most notably younger age, being female, having a history of mental health problems, self or loved ones testing positive for COVID-19, and having high levels of COVID-related anxiety and economic threat. Sections of the UAE population experienced relatively high levels of depression and anxiety symptoms during the early stages of the pandemic. Several COVID-related and psychosocial variables were associated with heightened symptomatology. Identifying such vulnerable groups can help inform the public mental health response to the current and future pandemics

(B)ordering South of Lebanon: Hizbullah’s identity building strategy

International audienceThis paper examines the importance of the Lebanese southern borderland area in the political strategy of Hizbullah's identity building. It highlights how Hizbullah succeeded in its quest to become a major political player in Lebanon by using South Lebanon. The main hypothesis is that this borderland area has been ordered and bordered by Hizbullah to create a common identity among the Lebanese Shi'i population based on a Shi'i religious involvement and the " duty " of armed resistance against Israel. To support this idea, I will rely on a theoretical framework articulating space and identity building and will refer to concepts provided by Middle Eastern studies. In the first part of the paper, I will discuss the conditions of the emergence of the group of solidarity and how it articulates to the religious Shi'i ideology. Then, I will highlight the " lebanonization " process Hizbullah undertaken at the end of the civil war and how during the 1990s it transformed the South into a sanctuary. Finally, I will show how Hizbullah enforced the national legitimacy of its social, political and military actions before targeting the state apparatus

A novel population of cholinergic neurons in the macaque spinal dorsal horn of potential clinical relevance for pain therapy.

Endogenous acetylcholine (ACh) is a well-known modulator of nociceptive transmission in the spinal cord of rodents. It arises mainly from a sparse population of cholinergic interneurons located in the dorsal horn of the spinal cord. This population was thought to be absent from the spinal cord of monkey, what might suggest that spinal ACh would not be a relevant clinical target for pain therapy. In humans, however, pain responses can be modulated by spinal ACh, as evidenced by the increasingly used analgesic procedure (for postoperative and labor patients) consisting of the epidural injection of the acetylcholinesterase inhibitor neostigmine. The source and target of this ACh remain yet to be elucidated. In this study, we used an immunolabeling for choline acetyltransferase to demonstrate, for the first time, the presence of a plexus of cholinergic fibers in laminae II-III of the dorsal horn of the macaque monkey. Moreover, we show the presence of numerous cholinergic cell bodies within the same laminae and compared their density and morphological properties with those previously described in rodents. An electron microscopy analysis demonstrates that cholinergic boutons are presynaptic to dorsal horn neurons as well as to the terminals of sensory primary afferents, suggesting that they are likely to modulate incoming somatosensory information. Our data suggest that this newly identified dorsal horn cholinergic system in monkeys is the source of the ACh involved in the analgesic effects of epidural neostigmine and could be more specifically targeted for novel therapeutic strategies for pain management in humans.journal articleresearch support, non-u.s. gov't2013 Feb 27importe

Dysphagia in multiple system atrophy consensus statement on diagnosis, prognosis and treatment

Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a combination of autonomic failure plus cerebellar syndrome and/or parkinsonism. Dysphagia is a frequent and disabling symptom in MSA and its occurrence within 5 years of motor onset is an additional diagnostic feature. Dysphagia can lead to aspiration pneumonia, a recognized cause of death in MSA. Guidelines for diagnosis and management of dysphagia in MSA are lacking. An International Consensus Conference among experts with methodological support was convened in Bologna to reach consensus statements for the diagnosis, prognosis, and treatment of dysphagia in MSA. Abnormalities of the oral and pharyngeal phases of swallowing, esophageal dysfunction and aspiration occur in MSA and worsen as the disease progresses. According to the consensus, dysphagia should be investigated through available screening questionnaires and clinical and instrumental assessment (videofluoroscopic study or fiberoptic endoscopic evaluation of swallowing and manometry) at the time of MSA diagnosis and periodically thereafter. There is evidence that dysphagia is associated with poor survival in MSA, however effective treatments for dysphagia are lacking. Compensatory strategies like diet modification, swallowing maneuvers and head postures should be applied and botulinum toxin injection may be effective in specific conditions. Percutaneous endoscopic gastrostomy may be performed when there is a severe risk of malnutrition and pulmonary complications, but its impact on survival is undetermined. Several research gaps and unmet needs for research involving diagnosis, prognosis, and treatment were identified

Thermodiffusion in multicomponent n-alkane mixtures

Compositional grading within a mixture has a strong impact on the evaluation of the pre-exploitation distribution of hydrocarbons in underground layers and sediments. Thermodiffusion, which leads to a partial diffusive separation of species in a mixture due to the geothermal gradient, is thought to play an important role in determining the distribution of species in a reservoir. However, despite recent progress, thermodiffusion is still difficult to measure and model in multicomponent mixtures. In this work, we report on experimental investigations of the thermodiffusion of multicomponent n-alkane mixtures at pressure above 30 MPa. The experiments have been conducted in space onboard the Shi Jian 10 spacecraft so as to isolate the studied phenomena from convection. For the two exploitable cells, containing a ternary liquid mixture and a condensate gas, measurements have shown that the lightest and heaviest species had a tendency to migrate, relatively to the rest of the species, to the hot and cold region, respectively. These trends have been confirmed by molecular dynamics simulations. The measured condensate gas data have been used to quantify the influence of thermodiffusion on the initial fluid distribution of an idealised one dimension reservoir. The results obtained indicate that thermodiffusion tends to noticeably counteract the influence of gravitational segregation on the vertical distribution of species, which could result in an unstable fluid column. This confirms that, in oil and gas reservoirs, the availability of thermodiffusion data for multicomponent mixtures is crucial for a correct evaluation of the initial state fluid distribution