Amphibole and apatite insights into the evolution and mass balance of Cl and S in magmas associated with porphyry copper deposits

Chlorine and sulfur are of paramount importance for supporting the transport and deposition of ore metals at magmatic–hydrothermal systems such as the Coroccohuayco Fe–Cu–Au porphyry–skarn deposit, Peru. Here, we used recent partitioning models to determine the Cl and S concentration of the melts from the Coroccohuayco magmatic suite using apatite and amphibole chemical analyses. The pre-mineralization gabbrodiorite complex hosts S-poor apatite, while the syn- and post-ore dacitic porphyries host S-rich apatite. Our apatite data on the Coroccohuayco magmatic suite are consistent with an increasing oxygen fugacity (from the gabbrodiorite complex to the porphyries) causing the dominant sulfur species to shift from S2− to S6+ at upper crustal pressure where the magmas were emplaced. We suggest that this change in sulfur speciation could have favored S degassing, rather than its sequestration in magmatic sulfides. Using available partitioning models for apatite from the porphyries, pre-degassing S melt concentration was 20–200 ppm. Estimates of absolute magmatic Cl concentrations using amphibole and apatite gave highly contrasting results. Cl melt concentrations obtained from apatite (0.60 wt% for the gabbrodiorite complex; 0.2–0.3 wt% for the porphyries) seems much more reasonable than those obtained from amphibole which are very low (0.37 wt% for the gabbrodiorite complex; 0.10 wt% for the porphyries). In turn, relative variations of the Cl melt concentrations obtained from amphibole during magma cooling are compatible with previous petrological constraints on the Coroccohuayco magmatic suite. This confirms that the gabbrodioritic magma was initially fluid undersaturated upon emplacement, and that magmatic fluid exsolution of the gabbrodiorite and the pluton rooting the porphyry stocks and dikes were emplaced and degassed at 100–200 MPa. Finally, mass balance constraints on S, Cu and Cl were used to estimate the minimum volume of magma required to form the Coroccohuayco deposit. These three estimates are remarkably consistent among each other (ca. 100 km3) and suggest that the Cl melt concentration is at least as critical as that of Cu and S to form an economic mineralization

Crystallization and partial melting of rhyolite and felsite rocks at Krafla volcano: A comparative approach based on mineral and glass chemistry of natural and experimental products

Rhyolite and felsite cuttings were collected at Krafla volcano during the perforation of the Iceland Deep Drilling Project Well 1 (IDDP-1). The perforation was stopped at a depth of 2100 m due to intersection with a rhyolite magma that intruded the felsite host rock. Rhyolite cuttings are vitrophiric (glass ~95%, RHL) and exhibit a mineral assemblage made of plagioclase + augite + pigeonite + titanomagnetite. Felsite cuttings display evidences of partial melting, responding to variable degrees of quartz + plagioclase + alkali feldspar + augite + titanomagnetite dissolution. The interstitial glass analyzed close to (i.e., FLS1) and far from (i.e., FLS2) the reaction surface of pyroxene from felsite cuttings shows continuous changes between the two end-members. FLS1 is compositionally similar to RHL, showing Na2O + K2O + REE depletions, counterbalanced by MgO + CaO enrichments. Conversely, FLS2 exhibits opposite chemical features. REE-exchange thermobarometric calculations reveal that plagioclase and augite cores from rhyolite and felsite formed under identical conditions, along a thermal path of 940â\u80\u93960 °C. However, in terms of major and trace element concentrations, plagioclase and augite crystal cores are not in equilibrium with the rhyolite magma, suggesting the incorporation of these minerals directly from the host felsite. To better understand the petrogenetic relationship between rhyolite and felsite, two sets of crystallization and partial melting experiments have been carried out at P = 150 MPa and T = 700â\u80\u93950 °C. Rhyolite crystallization experiments (RCE) reproduce the two-pyroxene assemblage of IDDP-1 rhyolite cuttings only at T â\u89¤ 800 °C, when the crystal content (â\u89¥19%) is higher than that observed in the natural rhyolite (~5%). Under such conditions, the RCE glass is much more differentiated (i.e., marked CaO depletion and Eu anomaly) than RHL. On the other hand, felsite partial melting (FPM) experiments show interstitial glass with a bimodal composition (i.e., FPM1 and FPM2) comparable to FLS1 (â\u89\u88RHL) and to FLS2, only at T = 950 °C. This effect has been quantified by fractional crystallization and batch melting modeling, denoting that FLS1 (â\u89\u88RHL) and FLS2 reflect high (â\u89¥70%) and low (â\u89¤8%) degrees of felsite partial melting, respectively. In contrast, modeling RHL by crystal fractionation requires the removal of an amount (~22%) of solid material that is inconsistent with the low crystal content of the natural IDDP-1 rhyolite. It is therefore concluded that natural rhyolite and felsite represent, respectively, the near-liquidus and sub-solidus states of a virtually identical silicic magma, either feeding aphyric to subaphiric rhyolitic eruptions, or solidifying at depth as phaneritic quartzofeldspathic rocks. Felsite lenses from the Krafla substrate may explore variable degrees of remelting and remobilization processes. The intrusion into felsite of a fresh silicic magma from depth may lead to low degrees of partial melting, whereas the persistent heat release from intense basaltic intrusive events at Krafla may be the source of high degrees of felsite partial melting and consequent rejuvenation of the previously solidified silicic magma

Demographical and clinical indices for long-term evolution of patients in vegetative or in minimally conscious state

Objective. To evaluate the prognostic value of demographical, anamnestic, and clinical findings on long-term outcome (up to 36 months) in individuals with severe brain injury in vegetative state (VS) or in minimally conscious state (MCS). Participants. Patients (N = 216) in VS (N = 159) or in MCS (N = 57) consecutively admitted to a neurorehabilitation unit within 1-3 months after severe anoxic (n = 71), vascular (n = 96), or traumatic (n = 49) brain injury. Main outcome. Mortality and improvements in clinical diagnosis at 12, 24, and 36 months after brain injury. Multivariable logistic regression analyses were performed to verify independent relationships of variables collected at study entry with outcome measures. Results. In patients in VS, at the 12-month follow-up, higher level of responsiveness assessed by the Coma Recovery Scale-Revised (CRS-R) total scores at study entry predicted a higher likelihood of both survival and clinical improvement, whereas younger age predicted survival only. At 24 months, female sex and higher CRS-R total scores tended to be associated with clinical improvements. In patients in MCS, younger age and female predicted consciousness recovery at 12 months. Conclusions. Several patients' features easy to collect in rehabilitation setting might help clinicians in prognostication of long-term mortality and clinical evolution of VS and MCS

Psychological distress is associated with altered cognitive functioning in family caregivers of patients with disorders of consciousness

Objectives: To analyse the possible presence of reduced cognitive efficiency in family caregivers of patients with prolonged disorders of consciousness (DOC). Subjects: The participants were 27 caregivers of 25 patients with DOC admitted to the severe brain injury units of the ICS Maugeri, Institutes of Telese Terme and Sciacca, Italy. Methods: We examined cognitive functions such as short- and long-term memory, executive functions and attention by means of standardized tests. We also assessed features of psychological distress such as anxiety, depression, psychophysiological symptoms, prolonged grief disorder, psychological burden and quality of life. All scores on neuropsychological tests were compared with those of the 15 matched control subjects. Results: Enrolled family caregivers showed high frequency of clinically relevant depressive symptoms and anxiety; half of them met the criteria for prolonged grief disorder. Caregivers achieved scores lower than the matched controls on tests for selective attention, verbal fluency and long-term spatial memory. Conclusions: Family caregivers’ burden is associated with a reduced efficiency of selected executive measures and visuospatial learning. These results emphasize the need for appropriate psychological and cognitive supporting therapies for family caregivers of patients with DOC, also considering their delicate involvement in clinical decision-making and in providing care

Demographical and clinical indices for long-term evolution of patients in vegetative or in minimally conscious state

Objective. To evaluate the prognostic value of demographical, anamnestic, and clinical findings on long-term outcome (up to 36 months) in individuals with severe brain injury in vegetative state (VS) or in minimally conscious state (MCS). Participants. Patients (N = 216) in VS (N = 159) or in MCS (N = 57) consecutively admitted to a neurorehabilitation unit within 1-3 months after severe anoxic (n = 71), vascular (n = 96), or traumatic (n = 49) brain injury. Main outcome. Mortality and improvements in clinical diagnosis at 12, 24, and 36 months after brain injury. Multivariable logistic regression analyses were performed to verify independent relationships of variables collected at study entry with outcome measures. Results. In patients in VS, at the 12-month follow-up, higher level of responsiveness assessed by the Coma Recovery Scale-Revised (CRS-R) total scores at study entry predicted a higher likelihood of both survival and clinical improvement, whereas younger age predicted survival only. At 24 months, female sex and higher CRS-R total scores tended to be associated with clinical improvements. In patients in MCS, younger age and female predicted consciousness recovery at 12 months. Conclusions. Several patients' features easy to collect in rehabilitation setting might help clinicians in prognostication of long-term mortality and clinical evolution of VS and MCS

Multi-centric longitudinal study on electrophysiological diagnostic and prognostic markers in prolonged disorders of consciousness

Diagnostic accuracy and reliable assessment of prognosis are challenging in patients in vegetative state (VS) and in minimally conscious state (MCS). This longitudinal multi-centric study aims to identify neurophysiological patterns with diagnostic and prognostic value. 59 patients in VS and 63 in MCS underwent clinical assessment by Coma Recovery Scale-Revised3 and neurophysiological evaluations of EEG background activity and reactivity, somatosensory evoked potential (SEP) and event related potential (ERP) at 63 months after brain-injury. Clinical outcome was evaluated at 6 months post-injury. EEG background activity and reactivity significantly differed between VS and MCS patients (p < .001), whereas the presence of cortical component N20 on SEP and P300 on ERP did not differ between the two groups. Good outcome was significantly more frequent in patients with moderately abnormal to normal EEG background activity than in patients with poor EEG background organization (p = .001), in patients showing EEG reactivity (p < .001) and in patients showing P300 (p = .016). The presence of SEP did not differ significantly between the two prognostic groups. Multimodal clinical and neurophysiological assessment could provide useful diagnostic and prognostic information for disorder of consciousness. This multicentric project calls for international standardization of diagnostic and prognostic procedure

Multicentre registry of brain-injured patients with disorder of consciousness: rationale and preliminary data

Diagnostic accuracy and reliable estimation of clinical evolution are challenging issues in the management of patients with disorders of consciousness (DoC). Longitudinal systematic investigations conducted in large cohorts of patients with DoC could make it possible to identify reliable diagnostic and prognostic markers. On the basis of this consideration, we devised a multicentre prospective registry for patients with DoC admitted to ten intensive rehabilitation units. The registry collects homogeneous and detailed data on patients' demographic and clinical features, neurophysiological and neuroimaging findings, and medical and surgical complications. Here we present the rationale and the design of the registry and the preliminary results obtained in 53 patients with DoC (vegetative state or minimally conscious state) enrolled during the first seven months of the study. Data at 6-month post-injury follow-up were available for 46 of them. This registry could be an important tool for collecting high-quality data through the application of rigorous methods, and it could be used in the routine management of patients with DoC admitted to rehabilitation settings

A brief history of the reception of sartre in Argentina

This chapter is a brief reconstruction of the reception of Jean-Paul Sartre’s work and thought in Argentina from 1930 to 1970. It shows the French writer and philosopher’s early and crucial role in the intellectual history of Argentina by displaying the major milestones of said process. Firstly, it deals with the process of the translation of several of Sartre’s short stories, articles and novels accomplished by literary journal Sur and publishing house Losada. Secondly, it goes over the rigorous academic studies of Being and Nothingness carried out during the 1950s by some members of the so-called ‘existentialist generation’ or ‘generation of 1925’ in the history of Argentinian philosophy, such as Carlos Astrada, Vicente Fatone, Miguel Ángel and Rafael Virasoro. Thirdly, it analyses the influence of Sartre and his magazine Les Temps modernes on the New Argentinian Left in the late 1950s and the 1960s, especially on the young intellectuals who were part of the magazine Contorno. Then, it addresses the impact of Sartre’s Marxist texts published in the 1960s in the philosophical and political debates between members of the New Left. Finally, it explains the decline of Sartre as an intellectual beacon in Argentina due to the rise of rival schools of thought (structuralism in particular), the deterioration of Sartre’s health and the beginning of political persecution and cultural censorship in Argentina because of the imposition of military dictatorships.Fil: Savignano, Alan Patricio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Multi-center observational study on occurrence and related clinical factors of neurogenic heterotopic ossification in patients with disorders of consciousness

Aims: to assess occurrence and clinical correlates of neurogenic heterotopic ossifications (NHO) in patients with prolonged disorder of consciousness (DoC).Design: multi-center cross-sectional observational study.Setting: 23 intensive neurorehabilitation units.Subjects: 287 patients with prolonged disorder of consciousness (DoC; 150 in vegetative state, VS, and 128 in minimally conscious state, MCS) of different etiology (vascular = 125, traumatic = 83, anoxic = 56, others = 14).Main Measures: clinical evidence of NHO confirmed by standard radiological and/or sonographic evaluation; Coma Recovery Scale-Revised; Disability Rating Scale (DRS); Early Rehabilitation Barthel Index; presence of ventilator support, spasticity, bone fractures and paroxysmal sympathetic hyperactivity.Results: 31 patients (11.2%) presented NHO. Univariate analyses showed that NHO was associated with VS diagnosis, traumatic etiology, high DRS category and total score, and high occurrence of limb spasticity and bone fractures. A cluster-corrected binary logistic regression model (excluding spasticity available in a subset of patients) showed that only lower DRS total score and presence of bone fractures were independently associated with NHO.Conclusions: NHO are relatively frequent in patients with DoC, and are independently associated with functional disability, bone fractures and spasticity. These findings contribute to identifying patients with DoC prone to develop NHO and requiring special interventions to improve functional recovery