Interplay between an Absorbing Phase Transition and Synchronization in a Driven Granular System.

Absorbing phase transitions (APTs) are widespread in nonequilibrium systems, spanning condensed matter, epidemics, earthquakes, ecology, and chemical reactions. APTs feature an absorbing state in which the system becomes entrapped, along with a transition, either continuous or discontinuous, to an active state. Understanding which physical mechanisms determine the order of these transitions represents a challenging open problem in nonequilibrium statistical mechanics. Here, by numerical simulations and mean-field analysis, we show that a quasi-2D vibrofluidized granular system exhibits a novel form of APT. The absorbing phase is observed in the horizontal dynamics below a critical packing fraction, and can be continuous or discontinuous based on the emergent degree of synchronization in the vertical motion. Our results provide a direct representation of a feasible experimental scenario, showcasing a surprising interplay between dynamic phase transition and synchronization.

Enhancing (quasi-)long-range order in a two-dimensional driven crystal.

It has been recently shown that 2D systems can exhibit crystalline phases with long-range translational order showcasing a striking violation of the Hohenberg-Mermin-Wagner (HMW) theorem, which is valid at equilibrium. This is made possible by athermal driving mechanisms that inject energy into the system without exciting long wavelength modes of the density field, thereby inducing hyperuniformity. However, as thermal fluctuations are superimposed on the non-equilibrium driving, long-range translational order is inevitably lost. Here, we discuss the possibility of exploiting non-equilibrium effects to suppress arbitrarily large density fluctuations even when a global thermal bath is coupled to the system. We introduce a model of a harmonic crystal driven both by a global thermal bath and by a momentum conserving noise, where the typical observables related to density fluctuations and long-range translational order can be analytically derived and put in relation. This model allows us to rationalize the violation of the HMW theorem observed in previous studies through the prediction of large-wavelength phonons, which thermalize at a vanishing effective temperature when the global bath is switched off. The conceptual framework introduced through this theory is then applied to numerical simulations of a hard-disk solid in contact with a thermal bath and driven out-of-equilibrium by active collisions. Our numerical analysis demonstrates how varying driving and dissipative parameters can lead to an arbitrary enhancement of the quasi-long-range order in the system regardless of the applied global noise amplitude. Finally, we outline a possible experimental procedure to apply our results to a realistic granular system.

Modified telehealth for care of chronic wounds during the Coronavirus disease 2019 pandemic: A rapid literature review of alternative care modalities.

Due to the changes in delivering medical care during the Coronavirus disease 2019 (COVID-19) pandemic, such as the heavy reliance on telehealth, it is worth exploring if this is suitable when treating complex wounds. A literature rapid review was performed to explore the existing evidence around alternative service delivery modalities. While there are organisations that have successful telehealth systems and infrastructure, for services that do not already widely use telehealth it is difficult to implement a standardised system in the current state of emergency. The evidence reviewed demonstrates that telehealth appears to currently have a limited place in chronic wound management; therefore, standardisation on determining suitability in conjunction with evaluation of telehealth during this period is needed to shape implementation of telehealth systems in the future.

[Therapeutic perspectives in the treatment of chronic subjective tinnitus]. / Perspectives thérapeutiques dans la prise en charge de l'acouphène subjectif chronique.

There are no effective therapies for the treatment of chronic subjective tinnitus. The present study aims to compare two therapeutic approaches: Tinnitus Retraining Therapy (TRT) and a Biopsychosocial Approach (BPS). Results show no difference in evolution of tinnitus' perception between the beginning of the study and after 12 months of treatment in both treatment groups. Important anxiety could be a factor contributed towards the abandonment or ineffectiveness of treatments. Patients with more biopsychosocial comorbidities are more receptive to therapies. The practicioners therefore must assess specific needs, comorbidities and biopsychosocial profiles of patients suffering from tinnitus.

[An update on bone anchored hearing aids]. / Appareils auditifs à ancrage osseux.

Hearing loss represents a hidden handicapwith various repercussions on development and social life. In the majority of cases, classical hearing aids address most hearing losses. However, the enhancement required for severe deafness frequently involves sound distortions which are very uncomfortable for patients. With the advent of bone anchored hearing aids, conductive hearing losses as well as mixed hearing losses are now better rehabilitated. Recently their indications have been expanded to profound to severe sensorineural hearing loss. The emergence of new materials as well as subcutaneous implants has lead to lessen skin complications and has diminished the aesthetic discomfort of this type of hearing devices.

[Vestibular neuritis: treatment and prognosis]. / Névrite vestibulaire: traitement et pronostic.

Vestibular neuritis is a sudden unilateral peripheral vestibular deficit of unknown origin without associated hearing loss. It is the second cause of peripheral vertigo after Benign Paroxysmal Positional Vertigo (BPPV). The etiology remains unclear and some treatments are still controversial. The prognosis is good. The differential diagnosis of the disease mainly includes an acute vertigo of central origin. This article summarizes the management and prognosis of vestibular neuritis.

[Surgical treatment of benign paroxysmal positional vertigo]. / Traitement chirurgical du vertige positionnel paroxystique bénin.

Benign paroxysmal positional vertigo (BPPV) is a common disorder that presents to the general practitioner. This condition represents one of the most common causes of peripheral vertigo. The diagnosis is made on clinical grounds. The treatment relies on repositioning maneuvers with relief of symptoms that occur in a few weeks in the majority of the cases. Rarely, patients are incapacitated by persistent or recurrent BPPV despite multiple repositioning maneuvers. In these cases, surgical therapies are available which provide excellent results.

[Indications and results of stereotactic radiosurgery with LINAC for the treatment of acoustic neuromas: preliminary results]. / Indications et résultats du traitement des neurinomes de l'acoustique par radiothérapie stéréotaxique avec LINAC: résultats préliminaires.

INTRODUCTION: Radiosurgery is presently becoming an alternative to microsurgical resection of acoustic neuromas. The interest of radiosurgery consists in its lower morbidity compared to surgery and likely in similar rates of long-term tumor control. The goal of our study was to assess the clinical outcome (hearing preservation and neurological complications) as well as tumor control after low-dose radiosurgery for unilateral acoustic neuromas. MATERIAL AND METHODS: Since April 2002, 22 patients with untreated acoustic neuromas underwent stereotactic radiosurgery using a linear accelerator (LINAC) and a micromultileaf collimator (mMLC, Brain Lab) at a low-dose of 12 Gy. The average age was 56.4 years (range 29-73 years). The treatment volume was 0.03 to 6.04 cm(3) (median 1.85 cm(3)). The median follow-up period was 18 months (range 6-36 months). RESULTS: No morbidity was observed during the treatment. Preservation of a serviceable hearing (classes I and II according to the Gardner-Robertson scale) was achieved in 10 of 14 patients (71%). Radiological tumor growth control was obtained in all patients (100%). Trigeminal neuropathy was observed in two patients. One of these patients also experienced a slight facial weakness. CONCLUSIONS: Low dose radiosurgery provides a low rate of post-therapeutic morbidity and yields the preservation of a serviceable hearing in 70% of cases. Tumor control is observed in all patients, but a longer follow-up period is needed to confirm the stability of the tumor size.

Study of tonotopic brain changes with functional MRI and FDG-PET in a patient with unilateral objective cochlear tinnitus.

We studied possible brain changes with functional MRI (fMRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) in a patient with a rare, high-intensity "objective tinnitus" (high-level SOAEs) in the left ear of 10 years duration, with no associated hearing loss. This is the first case of objective cochlear tinnitus to be investigated with functional neuroimaging. The objective cochlear tinnitus was measured by Spontaneous Otoacoustic Emissions (SOAE) equipment (frequency 9689 Hz, intensity 57 dB SPL) and is clearly audible to anyone standing near the patient. Functional modifications in primary auditory areas and other brain regions were evaluated using 3T and 7T fMRI and FDG-PET. In the fMRI evaluations, a saturation of the auditory cortex at the tinnitus frequency was observed, but the global cortical tonotopic organization remained intact when compared to the results of fMRI of healthy subjects. The FDG-PET showed no evidence of an increase or decrease of activity in the auditory cortices or in the limbic system as compared to normal subjects. In this patient with high-intensity objective cochlear tinnitus, fMRI and FDG-PET showed no significant brain reorganization in auditory areas and/or in the limbic system, as reported in the literature in patients with chronic subjective tinnitus.

[Chronic tinnitus]. / L'acouphène neurosensoriel chronique.

Chronic tinnitus is a frequent symptom in the current medical practice. Patients presenting with chronic tinnitus have to be evaluated by comprehensive examination, including ENT status, audiometry and complete neuro-otological evaluation if required, to exclude an organic cause of tinnitus, as an external--or middle ear lesion, or a retro-cochlear process. Most often, chronic tinnitus is only associated with a sensorineural hearing-loss. Overall, no drug treatment can be proposed. However, the patient needs help and two techniques can be proposed to make the symptom more tolerable: the bio-psycho-social model, with a medical and psychological sustain, and the habituation auditory therapy, using noisers to mask the tinnitus.

[True or false vertigo: a true or false question?]. / "Vrai" ou "faux" vertige: une vraie ou fausse question?

Some practitioners ask on which criteria vertigo can be considered as "true" or "false". The goal of this paper is to explain why such a concept is misleading. Vertigo and imbalance are subjective symptoms caused by many possible factors, somatic or psychologic, which may cause, in turn, psychological distress in some patients. In all cases, the complain is "true", even in case of psychological disorder. To evaluate patients suffering from vertigo, knowledge in anatomy and physiology are necessary as well as knowledge of the interface between neuro-totologic and psychiatric conditions.

Is an increased waist : hip ratio the cause of alcohol-induced hypertension? The AIR94 study.

OBJECTIVE: The mechanisms of alcohol-associated hypertension are not known. We tested the hypothesis that the alcohol-associated increase in blood pressure may be caused in part by an alcohol-induced accumulation of abdominal fat. SUBJECTS AND METHODS: A total of 842 non-smoking men (mean +/- SD age 52 +/- 16 years) attending the air-show AIR94 in Bouchs, Switzerland, volunteered to participate in a cross-sectional study. Four alcohol consumption frequency categories were self-reported, together with weight changes since the age of 20 and during the last 2 years. Blood pressure, body weight, height and the waist : hip ratio were measured. RESULTS: The results showed that 83% of the subjects were alcohol-consumers. Systolic (analysis of variance, P = 0.002) and diastolic (P = 0.009) blood pressure and the waist : hip ratio (P>0.0001) increased with increasing alcohol consumption. The self-judged dietary fat intake increased significantly with increasing alcohol consumption. Weight changes over time were positively associated with alcohol consumption. In a regression model alcohol consumption was the fourth most important contributor to systolic and diastolic blood pressure as well as to an increased abdominal fat mass. CONCLUSION: The alcohol-associated increase in blood pressure may be caused in part by an alcohol-induced accumulation of abdominal fat. Alcohol consumption favours the development of a positive energy balance and thus the abdominal deposition of fat, which is associated with an increased blood pressure. To reduce the risk of a positive energy balance and the abdominal deposition of fat, the intake of alcohol should be minimized and physical activity increased whenever possible.

Cardiac lesions after mediastinal irradiation for Hodgkin's disease.

We analysed the risk of myocardial infarctions in 339 patients with Hodgkin's disease treated with radiotherapy (rt) with or without chemotherapy. A total of 112 patients underwent cardiac testing with echocardiography, rest and exercise electrocardiogram and myocardial scintigraphy. Nearly all patients have been treated with < 2.0 Gy per fraction to the anterior cardiac region. A significantly increased risk of myocardial infarctions or of sudden death has been observed (10 patients). No cardia events have been observed in 215 non-smokers without hypertension and without coronary artery disease (CAD) already present before rt. In the heart study group (112 patients), there were 6 patients with probable or proven CAD. Five of these 6 patients had known risk factors for CAD. Echocardiography showed sclerosis of the aortic and or the mitral valves in 34 patients. Of these patients, 2 had a slight and 1 a moderate aortic stenosis, 5 had a slight and 1 a moderate mitral regurgitation. Evidence for a disturbance of the diastolic function has not been observed. No patient had a clinically relevant pericardial lesion. In patients without risk factors for CAD, there is only a low risk of ischaemic cardiac events after modern mediastinal rt for Hodgkin's disease. Patients should eliminate the known risk factors. There is a high incidence of sclerosis of the mitral and or the aortic valves developing into clinically important lesions in few patients. Decision on the treatment strategy and the rt technique should also involve consideration of the cardiac risk. For routine follow-up, we recommend inclusion of an echocardiography in intervals between 3 and 4 years.

Relationship between self-perceived stress and blood pressure.

OBJECTIVE: The importance of stress in the pathogenesis of essential hypertension is controversial. In this study we wanted to evaluate the relation between self-perceived stress and the blood pressure (BP) in a asymptomatic healthy population. SUBJECTS AND METHODS: A total of 1666 guests (mean +/- s.d. age 50 +/- 16 years) attending the air show AIR94 in Buochs, Switzerland volunteered to participate in a cross-sectional study. Using a self-administered questionnaire and visual analogue scales the individual stress perception and other cardiovascular risk behaviours/factors were assessed. BP, body weight, height, and the waist:hip ratio were measured. RESULTS: Individual stress perception was inversely related with the systolic BP (SBP) (r = -0.12, P < 0.001). The relationship was found in both men and women and was independent of age and/or body weight. No relation was found between the diastolic BP (DBP) and stress perception. Subjects with high normal BP according the JNC V classification showed a lower stress perception than did subjects with normal BP. In a multiple regression model the stress score was fourth most predictive of the SBP after body mass index, waist:hip ratio, and age followed by alcohol and fat intake. CONCLUSION: In this study we found an inverse association between the self-perceived stress and SBP. We suggest that the inverse association between BP and the self-perceived stress reflects a neuroendocrine and biochemical setting characterized by inadequate stress handling associated with a higher fat and alcohol intake and more abdominal fat tissue leading to a higher BP. Our data suggest that stress denial in combination with abdominal obesity, alcohol consumption, and smoking may be proxy for a high stress level.

Localization of static positional nystagmus with the ocular fixation test.

OBJECTIVE: Characteristics of static positional nystagmus (SPN) (i.e., persistency, direction fixed, direction changing) are observed in both peripheral and central disturbances and possess no localizing value for vestibular lesions. Our objective was to investigate whether the ocular fixation test as applied to SPN could assist in localizing vestibular lesions. STUDY DESIGN: A 3-year prospective study that included 43 patients with SPN. METHODS: All patients underwent a standard vestibular test battery and cerebral imaging (7, computed tomography scan; 36, magnetic resonance imaging). The ocular fixation index (OFI) was calculated by the ratio of the mean slow component velocity of SPN (measured with red light-emitting diode fixation) to that measured in darkness, multiplied by 100. An OFI less than 50 was considered normal. RESULTS: In 33 of 35 patients whose OFI was less than 50, the cerebral imaging was normal and a peripheral vestibular lesion was diagnosed (two benign tumors of the fourth ventricle were missed). In all eight patients whose OFI was greater than 50, the cerebral imaging was abnormal and a central vestibular lesion was noted. CONCLUSIONS: These results indicate that the visual suppression of SPN does, indeed, permit the localization of vestibular lesions. The predictive value of the ocular fixation test on the origin of SPN is greater than 94% for peripheral lesions and 100% for central disorders.

Dynamic asymmetry of the vestibulo-ocular reflex in unilateral peripheral vestibular and cochleovestibular loss.

OBJECTIVE: Rotatory tests in the horizontal plane have shown various degrees of vestibulo-ocular reflex (VOR) asymmetry in patients after surgical deafferentation of one labyrinth. The purpose of this work was to characterize dynamic horizontal VOR responses among patients presenting with a unilateral peripheral labyrinthine deficit of nonsurgical origin and to compare results in isolated vestibular loss versus cochleovestibular loss. STUDY DESIGN: This study included 40 patients who presented with an acute, spontaneous unilateral peripheral labyrinthine lesion. Twenty-two patients had vestibular loss alone (without associated hearing impairment) and 18 presented with a cochleovestibular deficit (sudden hearing loss with vertigo). The majority of these patients were part of a long-term protocol to evaluate vestibular compensation. METHODS: All patients underwent both the clockwise test and the counterclockwise rotatory test in the horizontal plane, using brief impulses of moderate intensity. Results were analyzed by a simplified model of vestibular function, allowing a parametric estimation of the response. RESULTS: A weak and transitory horizontal VOR asymmetry was observed in the 22 patients with vestibular loss. However, the 18 patients with cochleovestibular loss demonstrated a more severe and persistent asymmetry. CONCLUSIONS: This study revealed a difference in the dynamic characteristics of the horizontal VOR between patients with vestibular loss and those with cochleovestibular loss. Our results support the presence of an extensive labyrinthine lesion in cochleovestibular deficit that involves the otolith organs. The implications of this involvement on the central mechanisms of otolith-canal interaction are discussed.

Evaluation of the caloric test by combining 3 response parameters.

The slow-phase velocity of nystagmus is one of the most sensitive parameters of vestibular function and is currently the standard for evaluating the caloric test. However, the assessment of this parameter requires recording the response by using nystagmography. The aim of this study was to evaluate whether frequency and duration of the caloric nystagmus, as measured by using a clinical test with Frenzel glasses, could predict the result of the recorded test. The retrospective analysis of 222 caloric test results recorded by means of electronystagmography has shown a good association between the 3 parameters for unilateral weakness. The asymmetry observed in the velocity can be predicted by a combination of frequency and duration. On the other hand, no relationship was observed between the parameters for directional preponderance. These results indicate that a clinical caloric test with frequency and duration as parameters can be used to predict the unilateral weakness, which would be obtained by use of nystagmography. We propose an evaluation of the caloric test on the basis of diagrams combining the 3 response parameters.

[Evaluation of combined neurosurgical and trans-facial excision of extensive rhinosinus tumors infiltrating the anterior skull base]. / Evaluation de l'exérèse combinée neurochirurgicale et transfaciale des tumeurs rhino-sinusales extensives infiltrant la base antérieure du crâne.

Rhino-sinusal tumors are rare, representing approximately 0.3% of all cancers and 3% of tumors of the upper respiratory and digestive tracts. In cases in which the tumor has infiltrated the anterior cranial base, the treatment of choice is a surgical resection by combined neurosurgical and transfacial approach giving the best possible exposition for the excision. The resection is associated with various reconstruction techniques according to the extent of the defect. Sixteen patients with rhino-sinusal tumors extending to the anterior cerebral cavity were operated at the ENT clinic of the CHUV in Lausanne between 1977 and 1997. The transfacial and neurosurgical combined approach is rarely curative (30% 5 years survival rate, 80% local recurrence during follow-up), but is still justified, given that its disabling side-effects are scarce. It offers an acceptable quality of life and prevents complications inherent to the natural development of tumors. Pre- or postoperative radio- and chemotherapy, as well as skull base reconstructions using bone grafts or a micro-anastomosed flap give rise to complications which worsen significantly the overall prognosis and should therefore be avoided as much as possible. Still, this heavy surgery remains indicated, because it prevents the numerous complications of the natural course of the disease and offers an acceptable quality of life with only few side-effects.

[Enantioselectivity in the excretion of glucuronides of carprofen in man, dogs and horses]. / Enantiosélectivité de l'excrétion des glucuronides du carprofène chez l'homme, le chien et le cheval.

After administration of the racemic drug, the stereoselective quantification of the enantiomers of free and conjugated carprofen was performed in human plasma and in plasma, urine and bile of dogs and horses. In humans, the plasma profile of free carprofen and its glucuronides is not stereoselective and the glucuronides excreted in urine are close to a racemate. In dogs and horses on the contrary, the R(-) enantiomer of the free drug is predominant in plasma, while urine and/or bile concentrations of the glucuronides are high in comparison to plasma with a strong selectivity for the S(+) enantiomer. Because glucuronidation of carprofen, as a carboxylic compound, is known to be the major metabolic pathway in most species, interspecies discrepancies in the stereoselective disposition of carprofen seem to be mainly related to the stereoselectivity in the excretion of the glucuronides. Finally, the high plasma concentrations of carprofen glucuronides in human in comparison to other animal species suggest that the former could be specifically subjected to immunological side effects in the time course of treatments by this type of compounds.