Antarctic permafrost degassing in Taylor Valley by extensive soil gas investigation.

Ongoing studies conducted in northern polar regions reveal that permafrost stability plays a key role in the modern carbon cycle as it potentially stores considerable quantities of greenhouse gases. Rapid and recent warming of the Arctic permafrost is resulting in significant greenhouse gas emissions, both from physical and microbial processes. The potential impact of greenhouse gas release from the Antarctic region has not, to date, been investigated. In Antarctica, the McMurdo Dry Valleys comprise 10 % of the ice-free soil surface areas in Antarctica and like the northern polar regions are also warming albeit at a slower rate. The work presented herein examines a comprehensive sample suite of soil gas (e.g., CO2, CH4 and He) concentrations and CO2 flux measurements conducted in Taylor Valley during austral summer 2019/2020. Analytical results reveal the presence of significant concentrations of CO2, CH4 and He (up to 3.44 vol%, 18,447 ppmv and 6.49 ppmv, respectively) at the base of the active layer. When compared with the few previously obtained measurements, we observe increased CO2 flux rates (estimated CO2 emissions in the study area of 21.6 km2 ≈ 15 tons day-1). We suggest that the gas source is connected with the deep brines migrating from inland (potentially from beneath the Antarctic Ice Sheet) towards the coast beneath the permafrost layer. These data provide a baseline for future investigations aimed at monitoring the changing rate of greenhouse gas emissions from Antarctic permafrost, and the potential origin of gases, as the southern polar region warms.

Characteristic retinal atrophy pattern allows differentiation between pediatric MOGAD and MS after a single optic neuritis episode.

BACKGROUND: Optic neuritis (ON) is the most prevalent manifestation of pediatric multiple sclerosis (MSped) and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGADped) in children > 6 years. In this study, we investigated retinal atrophy patterns and diagnostic accuracy of optical coherence tomography (OCT) in differentiating between both diseases after the first ON episode. METHODS: Patients were retrospectively identified in eight tertial referral centers. OCT, VEP and high/low-contrast visual acuity (HCVA/LCVA) have been investigated > 6 months after the first ON. Prevalence of pathological OCT findings was identified based on data of 144 age-matched healthy controls. RESULTS: Thirteen MOGADped (10.7 ± 4.2 years, F:M 8:5, 21 ON eyes) and 21 MSped (14.3 ± 2.4 years, F:M 19:2, 24 ON eyes) patients were recruited. We observed a significantly more profound atrophy of both peripapillary and macular retinal nerve fiber layer in MOGADped compared to MSped (pRNFL global: 68.2 ± 16.9 vs. 89.4 ± 12.3 µm, p < 0.001; mRNFL: 0.12 ± 0.01 vs. 0.14 ± 0.01 mm3, p < 0.001). Neither other macular layers nor P100 latency differed. MOGADped developed global atrophy affecting all peripapillary segments, while MSped displayed predominantly temporal thinning. Nasal pRNFL allowed differentiation between both diseases with the highest diagnostic accuracy (AUC = 0.902, cutoff < 62.5 µm, 90.5% sensitivity and 70.8% specificity for MOGADped). OCT was also substantially more sensitive compared to VEP in identification of ON eyes in MOGAD (pathological findings in 90% vs. 14%, p = 0.016). CONCLUSION: First MOGAD-ON results in a more severe global peripapillary atrophy compared to predominantly temporal thinning in MS-ON. Nasal pRNFL allows differentiation between both diseases with the highest accuracy, supporting the additional diagnostic value of OCT in children with ON.

Geographically weighted regression and geostatistical techniques to construct the geogenic radon potential map of the Lazio region: A methodological proposal for the European Atlas of Natural Radiation.

In many countries, assessment programmes are carried out to identify areas where people may be exposed to high radon levels. These programmes often involve detailed mapping, followed by spatial interpolation and extrapolation of the results based on the correlation of indoor radon values with other parameters (e.g., lithology, permeability and airborne total gamma radiation) to optimise the radon hazard maps at the municipal and/or regional scale. In the present work, Geographical Weighted Regression and geostatistics are used to estimate the Geogenic Radon Potential (GRP) of the Lazio Region, assuming that the radon risk only depends on the geological and environmental characteristics of the study area. A wide geodatabase has been organised including about 8000 samples of soil-gas radon, as well as other proxy variables, such as radium and uranium content of homogeneous geological units, rock permeability, and faults and topography often associated with radon production/migration in the shallow environment. All these data have been processed in a Geographic Information System (GIS) using geospatial analysis and geostatistics to produce base thematic maps in a 1000 m × 1000 m grid format. Global Ordinary Least Squared (OLS) regression and local Geographical Weighted Regression (GWR) have been applied and compared assuming that the relationships between radon activities and the environmental variables are not spatially stationary, but vary locally according to the GRP. The spatial regression model has been elaborated considering soil-gas radon concentrations as the response variable and developing proxy variables as predictors through the use of a training dataset. Then a validation procedure was used to predict soil-gas radon values using a test dataset. Finally, the predicted values were interpolated using the kriging algorithm to obtain the GRP map of the Lazio region. The map shows some high GRP areas corresponding to the volcanic terrains (central-northern sector of Lazio region) and to faulted and fractured carbonate rocks (central-southern and eastern sectors of the Lazio region). This typical local variability of autocorrelated phenomena can only be taken into account by using local methods for spatial data analysis. The constructed GRP map can be a useful tool to implement radon policies at both the national and local levels, providing critical data for land use and planning purposes.

Brainstem manifestations in neuromyelitis optica: a multicenter study of 258 patients.

BACKGROUND: Neuromyelitis optica (NMO) is a severe autoimmune disease of the central nervous system characterized by spinal cord and optic nerve involvement. Brainstem manifestations have recently been described. OBJECTIVE: To evaluate the time of occurrence, the frequency and the characteristics of brainstem symptoms in a cohort of patients with NMO according to the ethnic background and the serologic status for anti-aquaporin-4 antibodies (AQP4-abs). METHODS: We performed a multicenter study of 258 patients with NMO according to the 2006 Wingerchuk criteria and we evaluated prospectively the frequency, the date of onset and the duration of various brainstem signs in this population. RESULTS: Brainstem signs were observed in 81 patients (31.4%). The most frequently observed signs were vomiting (33.1%), hiccups (22.3%), oculomotor dysfunction (19.8%), pruritus (12.4%), followed by hearing loss (2.5%), facial palsy (2.5%), vertigo or vestibular ataxia (1.7%), trigeminal neuralgia (2.5%) and other cranial nerve signs (3.3%). They were inaugural in 44 patients (54.3%). The prevalence was higher in the non-Caucasian population (36.6%) than in the Caucasian population (26%) (p<0.05) and was higher in AQP4-ab-seropositive patients (32.7%) than in seronegative patients (26%) (not significant). CONCLUSIONS: This study confirms the high frequency of brainstem symptoms in NMO with a majority of vomiting and hiccups. The prevalence of these manifestations was higher in the non Caucasian population.

Cavernous malformations of the central nervous system in children: presentation, treatment and outcome of 20 cases.

BACKGROUND: Cavernous malformations (CM) of the central nervous system are vascular malformations responsible for symptoms such as seizures, headache, and neurological deficits: 25% of cases already present in childhood. MATERIAL AND METHODS: Retrospective study including all CMs of the central nervous system in childhood diagnosed in the period 1993-2008 in 3 paediatric hospitals in Switzerland, focusing on clinical manifestations, neuroimaging findings, treatment, and outcome. RESULTS: 20 children (13 females) were diagnosed with CM, with an average age at presentation of 8.5 years (range 7 months-16 years). 17/20 presented with acute haemorrhage, 9/17 with seizures, 5/17 with focal neurological symptoms, and 3/17 with severe headache only. Localisation was supratentorial in 15/20, infratentorial in 2/20, supra- and infratentorial in 2/20, and spinal in 1 child. Five children had multiple CMs. Treatment was conservative in 10 cases and surgery was indicated in 10: for acute haemorrhage in 5; recurrent bleeding in 3; and epilepsy in 2. Follow-up after diagnosis was 0.5 years-10 years (mean 4 years), revealing neurological sequelae in 6 patients. The CM increased in size in 2 cases with an increase in number also in 1 of these. CONCLUSIONS: We confirm that CMs in childhood mainly present with seizures, severe headache, or focal symptoms due to acute haemorrhage. During infancy they may appear as dynamic lesions increasing in size and/or number. The regular application of newer neuroimaging techniques such as susceptibility weighted imaging will detect more lesions but not necessarily resolve problems concerning optimum treatment.

Acute transverse myelitis in Lyme neuroborreliosis.

INTRODUCTION: Acute transverse myelitis (ATM) is a rare disorder (1-8 new cases per million of population per year), with 20% of all cases occurring in patients younger than 18 years of age. Diagnosis requires clinical symptoms and evidence of inflammation within the spinal cord (cerebrospinal fluid and/or magnetic resonance imaging). ATM due to neuroborreliosis typically presents with impressive clinical manifestations. CASE PRESENTATION: Here we present a case of Lyme neuroborreliosis-associated ATM with severe MRI and CSF findings, but surprisingly few clinical manifestations and late conversion of the immunoglobulin G CSF/blood index of Borrelia burgdorferi sensu lato. CONCLUSION: Clinical symptoms and signs of neuroborrelial ATM may be minimal, even in cases with severe involvement of the spine, as shown by imaging studies. The CSF/blood index can be negative in the early stages and does not exclude Lyme neuroborreliosis; if there is strong clinical suspicion of Lyme neuroborreliosis, appropriate treatment should be started and the CSF/blood index repeated to confirm the diagnosis.

Removal of the submaxillary salivary glands first increases and then abolishes the agonistic response of male mice in repeated social encounters.

Adult male mice of the CD-1 strain were sialectomized (bilateral removal of submaxillary salivary glands) under IP Nembutal anesthesia and then individually housed for 5 weeks. Control mice were sham operated. The behaviors of sialectomized and control mice towards untreated, intact, matched opponents were videotaped during the first 10 min of a 20-min social encounter repeated for 10 consecutive days (isolation days 36-46). On the first session, sialectomized mice exhibited significant increases in elements of aggression (attack, bite, offensive sideways, offensive upright, and tail rattling). These behavioral changes significantly decreased over the remaining encounters, while defensive behaviors (defensive upright, oblique, parry, and defensive sideways) and elements of arrested flight increased progressively. The results suggest that sialectomy, perhaps by removing salivary NGF, interferes with the coping response of mice towards repeated agonist challenge from a conspecific.

Substance P effects on intraspecific aggressive behaviour of isolated male mice: an ethopharmacological analysis.

Adult male mice of the Swiss CD1 strain were used to evaluate the effects on isolation-induced aggressive behaviour of a single intravenous administration of substance P (SP; 0.25, 1.0 or 2.5mg/kg dose). All mice were injected 15min before testing (10min videotaped dyadic encounters with an isolated male untreated opponent). Control mice were injected with vehicle. All animals were tested again 24h later in a drug-free state. SP treatment produced a decrease in offensive scores (Attacks and Rattling behaviour), a longer latency to the first Attack episode, and enhanced defensive displays. These effects were reversed 24h later. In no case did SP treatment affect locomotor activity levels or freezing behaviour. A role of SP in the regulation of murine aggressive response is strongly suggested through a direct action of the drug on the central nervous system and specifically on the hypothalamus.

Familiarity with conspecific odor and isolation-induced aggressive behavior in male mice (Mus domesticus).

Male Swiss CD-1 mice (Mus domesticus, n = 60) were isolated for 24 days. In the isolation group mice were exposed to their own odor; in the familiarity group mice were familiarized with pairmates' odor by daily exchange of bedding; and in the unfamiliarity group subjects (exposed) were familiarized with pairmates' odor, whereas the pairmates (nonexposed) were familiarized with odors of other isolated mice. Aggressive behavior was scored during 20-min sessions. Familiarity with the pairmate's odor (familiarity and exposed subgroups) caused an enhancement of aggressive behavior, shown by the highest frequency of tail rattling and offensive upright posture and by a decrease in latency to the 1st attack. Nonexposed subjects showed high values of submissive upright posture, screaming, fleeing, and freezing. The results suggest that dominantlike behavior, acquired in social isolation, may be directed toward a conspecific whose odor is familiar.

Neonatal capsaicin exposure affects isolation-induced aggressive behavior and hypothalamic substance P levels of adult male mice (Mus musculus).

Subcutaneous administration of capsaicin (50 mg/kg) at Postnatal Days 2 and 5 exerted long-term effects on isolation-induced aggressive behavior of adult mice (Mus musculus) of the CD-1 strain. Isolated capsaicin-treated mice (scored during a 10-min session) showed the highest frequency and the longest duration of total attacks, attacks, rattling, and offensive upright posture when compared with nonisolated capsaicin-treated subjects and both isolated and nonisolated vehicle control animals. Hypothalamic Substance P (SP) was assessed by radioimmunoassay. Capsaicin treatment significantly lowered hypothalamic SP content in both isolated and nonisolated mice. Moreover, individual scores of isolated capsaicin-treated subjects showed a significant correlation between SP depletion and expression of offensive upright posture. Isolation per se was revealed to play an important role in depleting SP from the hypothalamus.

An updated role for nerve growth factor in neurobehavioural regulation of adult vertebrates.

Increasing attention has been focused on the role(s) of nerve growth factor (NGF) in neurobehavioural regulations of adult vertebrates. This interest springs from the emerging evidence that NGF is a "regulator" of physiological processes belonging to the three main homeostatic systems: the nervous, immune and endocrine systems. In fact, the spectrum of action of the NGF molecule is not restricted to neuronal cell types (central basal forebrain; peripheral sensory and sympathetic neurons) but extends also to nonneuronal cells. In mice intermale aggressive behaviour enhances serum NGF levels and promotes its synthesis in some hypothalamic areas. Other types of social events are able to cause NGF release, particularly under stress conditions. The achievement of a social role (dominant vs subordinate) is due to a functional loop involving salivary NGF release-->enhanced production of adrenal hormones-->submissive behaviour-->NGF release. In humans, plasma platelet-derived growth factor (PDGF) increases following mental stress. The aim of this review is to give an updated survey on NGF roles in neurobehavioural regulations of adult animals.

NGF decreases isolation-induced aggressive behavior, while increasing adrenal volume, in adult male mice.

Intravenous administration of highly purified murine nerve growth factor (NGF, either 15 or 30 micrograms/subject/day) for six consecutive days to adult male mice of the CD-1 strain markedly influenced a number of items of aggressive behavior induced by 5 weeks of individual housing. Control mice received the same doses of cytochrome c. During a 20-min fighting session on day 7, both NGF-treated groups showed longer Latency to the first Attack, while Total Attacking Time and Aggressive grooming were significantly lower when compared to control animals. Twenty-four h later, adrenals from the NGF- and cytochrome c-treated groups were dissected and analyzed by means of a Vidas Image-Analyzer. NGF administration produced a remarkable dose-dependent increase in both adrenal weight and volume (particularly in the medullary zone), supporting the hypothesis that adrenals represent a possible target for the NGF release from submaxillary salivary glands occurring upon intraspecific fighting.

Capsaicin affects aggressive behavior, but not hot plate responding, of adult male mice.

Adult male mice of albino Swiss-derived CD-1 strain were used to assess the effects of capsaicin (a powerful agent that produces a marked depletion of the undecapeptide substance P) on both intraspecific aggressive behavior (induced by 8 weeks of individual housing) and pain sensitivity. Capsaicin was given SC, 48 h before behavioral testing. Aggressive behavior, scored during a 5-min session under red light, was significantly enhanced by capsaicin treatment (50 or 100 microliters of a 7.5 mg/ml solution). In fact, Total Aggressive Episodes, Attacks, and Upright Offensive Posture were significantly higher in the two capsaicin-treated groups, while Latency to the first Attack was decreased, when compared to both vehicle or unhandled controls. A concomitant decrease in Submissive Postures and Flee was also evident in capsaicin mice. Hot plate testing (55 +/- 0.1 degrees C, cutoff time 30 s), carried out on nonisolated mice, did not reveal any difference among the two capsaicin groups (same doses) and vehicle or unhandled controls.