454 research outputs found
Organic Carbon Burial following the Middle Eocene Climatic Optimum (MECO) in the central - western Tethys
We present trace metal geochemistry and stable isotope records for the middle Eocene Alano di Piave section, NE Italy, deposited during magnetochron C18n in the marginal Tethys Ocean. We identify a 500 kyr long carbon isotope perturbation event we infer to be the middle Eocene Climatic Optimum (MECO) confirming the northern hemisphere expression and global occurrence of MECO. Interpreted peak climatic conditions are followed by the rapid deposition of two organic rich intervals (3\% TOC) and contemporaneous positive C excursions. These two intervals are associated with increases in the concentration of sulphur and redox-sensitive trace metals, and low concentrations of Mn, as well as coupled with the occurrence of pyrite. Together these changes imply low, possibly dysoxic, bottom water O conditions promoting increased organic carbon burial. We hypothesize that this rapid burial of organic carbon lowered global {\it p}CO following the peak warming and returned the climate system to the general Eocene cooling trend
High-diversity larger foraminiferal assemblages calibrated with calcareous nannoplankton biozones in the aftermath of EECO (Collio, Friuli-Venezia Giulia, northeastern Italy)
The Eocene of Collio (easternmost Friuli-Venezia Giulia, northeastern Italy) contains rich larger foraminiferal assemblages mainly dominated by nummulitids of genera Nummulites and Assilina. Herein, we document, by typological and biometric approaches, upper Ypresian to lower Lutetian taxa, dated by an integrated biostratigraphy combining the Shallow Benthic Zones (SBZ) with the nanno- fossil biozones. A total of seven species of Alveolina, 12 species of Assilina and 33 of Nummulites are described (in Appendix A), some of them left in open nomenclature. The larger foraminiferal assemblages indicate that all the collected samples are assignable to SBZ12 and SBZ13 and their high diversity suggests high resilience of these shallow-water taxa after the Early Eocene Climate Optimum warming event. The occurrence of the calcareous nannofossil Blackites inflatus together with Alveolina violae Nummulites friulanus, N. campesinus, N. quasilaevigatus, Assilina maior maior and A. cuvillieri, typical SBZ12 markers, suggests that SBZ12 extends at least to the basal Lutetian, thus the SBZ12/13 boundary occurs in the lowermost Lutetian instead of at the Ypresian/Lutetian transition
Gli istituti scolastici italiani tra rendicontazione e valutazione. Il bilancio sociale come strumento di integrazione tra le due dimensioni?
Attualmente nella letteratura economico-aziendale a livello nazionale ed internazionale i contributi
su accountability, valutazione della performance e rendicontazione sociale degli istituti scolastici
sono relativamente pochi. Questo articolo mira a indagare i temi sopra citati focalizzando
l’attenzione sul Bilancio Sociale nel contesto italiano. In particolare, esso punta a contribuire
alla letteratura analizzando le interdipendenze tra il bilancio sociale e gli altri documenti della
programmazione e (auto)valutazione della scuola, nonché comprendere se esso sia in grado di
concludere adeguatamente il ciclo della performance degli istituti scolastici in Italia. L’articolo
riferisce di una ricerca di tipo qualitativo basata non solo sull’analisi della letteratura e della
normativa vigente, ma anche sullo studio documentale di 31 bilanci sociali di istituti scolastici
italiani secondo la strategia di content analysis
EOCENE STALKED CRINOIDS IN THE GENUS ISSELICRINUS (ECHINODERMATA, CRINOIDEA, ISOCRINIDA) FROM NORTHEASTERN ITALY
Long fragments of isocrinid stalks belonging to the stalked crinoid genus Isselicrinus (Isocrinida, Isselicrininae) were found at Cambrigar, near Ferrara di Monte Baldo (Verona province, northeastern Italy) in the strata called “Harpactocarcinus punctulatus and Pentacrinus diaboli horizon”, traditionally ascribed to the lower Eocene (Ypresian). Morphometric analysis of this material allowed us to identify two distinct species filtering their food at different levels of the water column. The first species, characterized by a mostly pentagonal stalk section, is ascribable to Isselicrinus diaboli (Bayan), a taxon frequently cited from the lower Eocene of northeastern Italy but until now poorly known. The other species has a marked star-shaped stalk section presenting a combination of pedomorphic characters and is ascribed to the new taxon Isselicrinus baldoensis n. sp. A detailed analysis of numerous columnals and pluricolumnals of Isselicrinus diaboli from the type-locality of San Pancrazio near Mossano (Berici Hills, Vicenza province, northeastern Italy) allowed us to propose a revised and more complete diagnosis of this taxon. The particular burial conditions and the ecology of these two species are discussed as well as a reappraisal of the age of the “Harpactocarcinus punctulatus and Pentacrinus diaboli horizon”. Based on new calcareous nannofossil data, and confirmed by the larger foraminiferal assemblages, the isocrinids from Cambrigar are firmly assigned to the Lutetian (middle Eocene). Calcareous nannofossils identified in the matrix of historical hand specimens from the classical locality of San Pancrazio indicate a similar age
A human MMTV-like betaretrovirus linked to breast cancer has been present in humans at least since the Copper Age
The betaretrovirus Mouse Mammary Tumor Virus (MMTV) is the well characterized etiological agent of mammary tumors in mice. In contrast, the etiology of sporadic human breast cancer (BC) is unknown, but accumulating data indicate a possible viral origin also for these malignancies. The presence of MMTVenv-like sequences (MMTVels) in the human salivary glands and saliva supports the latter as possible route of interhuman dissemination. In the absence of the demonstration of a mouse-man transmission of MMTV, we considered the possibility that a cross-species transmission could have occurred in ancient times. Therefore, we investigated MMTVels in the ancient dental calculus, which originates from saliva and is an excellent material for paleovirology. The calculus was collected from 36 ancient human skulls, excluding any possible mouse contamination. MMTV-like sequences were identified in the calculus of 6 individuals dated from the Copper Age to the 17th century. The MMTV-like sequences were compared with known human endogenous betaretroviruses and with animal exogenous betaretroviruses, confirming their exogenous origin and relation to MMTV. These data reveal that a human exogenous betaretrovirus similar to MMTV has existed at least since 4,500 years ago and indirectly support the hypothesis that it could play a role in human breast cancer
Mode and tempo of the Paleocene-Eocene thermal maximum in an expanded section from the Venetian pre-Alps.
The central part of the Piave River valley in the Venetian pre-Alps of NE Italy exposes an expanded and continuous marine sediment
succession that encompasses the Paleocene series and the Paleocene to Eocene transition.
The Paleocene through lowermost Eocenemsuccession is >100 m thick and was depositednat middle to lower bathyal depths in a
hemipelagic, near-continental setting in the central western Tethys. In the Forada section, the Paleocene succession of limestone-marl couplets is sharply interrupted by an ~3.30- m-thick unit of clays and marls (clay marl unit). The very base of this unit represents the biostratigraphic Paleocene-Eocene boundary, and the entire unit coincides with the main carbon isotope excursion of the Paleocene-Eocene thermal maximum event. Concentrations of hematite and biogenic carbonate, δ13C
measurements, and abundance of radiolarians, all oscillate in a cyclical fashion and are interpreted to represent precession cycles. The main excursion interval spans fi ve complete cycles, that is, 105 ± 10 k.y. The overlying carbon isotope recovery interval, which is composed of six distinct limestone-marl couplets, is interpreted to represent six precessional cycles with a duration of 126 ± 12 k.y. The entire carbon isotope excursion interval in Forada has a total duration of ~231 ± 22 k.y., which is 5%–10% longer than previous estimates derived from open ocean sites (210–220 k.y.).
Geochemical proxies for redox conditions
indicate oxygenated conditions before, during, and after the carbon isotope excursion event.
The Forada section exhibits a nonstepped sharp decrease in δ13C (−2.35‰) at the base of the clay marl unit. The hemipelagic, near-continental depositional setting of Forada and the sharply elevated sedimentation rates throughout the clay marl unit argue for continuous rather than interrupted deposition and show that the initial nonstepped carbon isotope shift was not caused by a hiatus. A single sample at the base of the unit lacks biogenic carbonate.
Preservation of carbonate thereafter improves progressively up-section in the clay marl unit, which is consistent with a prodigiously abrupt and rapid acidifi cation of the oceans followed
by a slower, successive deepening of the carbonate compensation depth. Increased sedimentation rates through the clay marl unit
(approximately the main interval of the carbon isotope excursion) are consistent with an intensifi ed hydrological cycle driven by supergreenhouse conditions and enhanced weathering and transport of terrigenous material to this near-continental, hemipelagic environment in the central western Tethys.
The sharp transition in lithology from the clay marl unit to the overlying limestonemarl couplets in the recovery interval and
the coincident shift toward heavier δ13C values suggest that the silicate pump and continental weathering, the cause of the enhanced terrigenous fl ux to Forada, stopped abruptly.
This implies that the source of the light CO2 ceased to be added to the ocean-atmosphere system at the top of the clay marl unit
Hydroclimate variability in the central Mediterranean during MIS 17 interglacial (Middle Pleistocene) highlights timing offset with monsoon activity
Mediterranean climates are characterized by warm, dry summers and mild, rainy winters. Previous studies suggest that over the last 1.36 Myr, Mediterranean winter rainfalls were in phase with the African monsoon. Here we present a high-resolution terrestrial and marine dataset for the Marine Isotope Stage 17 interglacial (Middle Pleistocene) from Southern Italy, showing that precipitation rates and regimes in the central Mediterranean varied independently of the monsoon system. Specifically, events of extreme summer precipitation were promoted by increased regional insolation rates and/or extratropical cyclones, and their magnitude was further enhanced by the advection of cool and humid North Atlantic air during stadials. Our findings provide new information on the short- to mid-term natural hydroclimatic variability of the Mediterranean basin, and offer new critical insights on land–ocean interactions at the regional scale by complementing previous analyses on the displacement of storm tracks toward southern Europe
A Case of Brachymetatarsia From Medieval Sardinia (Italy)
Archaeological excavations carried out in the Medieval village of Geridu (Sardinia) uncovered several burials dating to the late 13th or the first half of 14th century. Among these individuals, the skeleton of an adult female showing a bilateral abnormal shortness of the fourth metatarsal bone was identified. Bilaterality and absence of other skeletal anomalies allow to rule out an acquired aetiology of the disease and to support a diagnosis of congenital brachymetatarsia. Such a rare deformity
has a clinical incidence of 0.02% to 0.05%, with strong predominance of the female gender. To our knowledge, no other cases of brachymetatarsia have been reported in paleopathology so far
Sclerosing bone dysplasia from 16th century Sardinia (Italy): a possible case of Camurati-Engelmann disease
The skeletal remains of a male aged 45–55 years displaying several bone anomalies were unearthed from the Alghero (Sardinia) plague cemetery ‘lo Quarter’, a burial site dating back to the 1582–1583 AD outbreak. The
skeleton, whose stature is about 165 cm, presents a bilateral hyperostosis with increased diameter of the diaphyses of all the long bones of the upper and lower limbs; the metaphyses appear to be involved, while the
epiphyses are spared. Marked thickening of the cranial vault is also evident. Radiological study showed irregular cortical thickening and massive endoperiosteal bone apposition; sclerotic changes are observed in the
diaphysis of some metacarpals. Computed tomography (CT) cross sections of the long bones displayed a thickening of the cortical portion and endoperiosteal bone apposition.
The individual was affected by a sclerosing bone dysplasia, a genetic disease characterized by increased bone density. In differential diagnosis, several sclerosing bone dysplasia, such as hyperostosis corticalis
generalisata, craniodiaphyseal dysplasia, craniometadiaphyseal dysplasia, pachydermoperiostosis and Camurati–Engelmann disease, as well as other disorders characterized by sclerosing manifestations, such
as Erdheim–Chester disease, mehloreostosis and skeletal fluorosis, need to be considered. The anomalies observed in skeleton 2179 fit with the features of Camurati–Engelmann disease, which is the most likely candidate for final diagnosis. It is highly challenging to evaluate how such a condition may have influenced the individual’s lifestyle in terms of development, mobility and quality of life. This individual was probably symptomatic and must have experienced common clinical symptoms, such as pain in the limbs and fatigability. However, the strong development of the muscular insertions and the degenerative changes in the upper
limbs suggest that the mobility problems should not have prevented him from reaching a mature age and from performing essential daily activities.
The presented case is the unique paleopathological evidence of Camurati–Engelmann disease so far diagnosed
Prognóstico de pacientes com tumor de Wilms unilateral no Rio de Janeiro, 1990-2000
OBJECTIVE: To analyze the survival and the main prognostic factors among patients with unilateral Wilms' tumor patients. METHODS: The study cohort included 132 patients with unilateral Wilms' tumor aged under 15 years, who were enrolled in a pediatric oncology service. Survival curves were calculated using the Kaplan-Meier method and the prognostic factors were analyzed using the Cox proportional hazards model. RESULTS: The overall survival rate for five years was 84.6%. The survival probabilities for disease in stages I, II, III and IV stages were: 100%, 94.2%, 83.2% and 31.3%, respectively. The survival rate was 89.4% for patients with favorable histology, 66.7% for focal anaplasia and 40% for diffuse anaplasia. All patients with stage IV disease and diffuse anaplasia died (n=4). All patients with stage I disease, regardless of histology, remained alive at the end of the follow-up period. CONCLUSIONS: Among the variables selected for the final model, only the staging and the histology remained associated with high risk of death risk, while patients aged 24 - 47 months presented better prognosis than the other patients. These results showed the importance of establishing the diagnosis at an early stage, and that the histology is fundamental for guiding the appropriate therapy.OBJETIVO: Analisar a sobrevida e os principais fatores prognósticos entre os pacientes com tumor de Wilms unilateral. MÉTODOS: A coorte de estudo incluiu 132 casos de tumor de Wilms unilateral em menores de 15 anos de idade matriculados em serviço de oncologia pediátrica, de janeiro de 1990 a dezembro de 2000. Curvas de sobrevida foram confeccionadas utilizando-se o método de Kaplan-Meier e fatores prognósticos foram analisados pelo modelo de riscos proporcionais de Cox. RESULTADOS: A estimativa de sobrevida global em cinco anos foi 84,6%. As probabilidades de sobrevida para os estádios I, II, III e IV foram de 100%; 94,2%; 83,2% e 31,3%, respectivamente. A taxa de sobrevida para os pacientes com: histologia favorável foi de 89,4%, para aqueles com anaplasia focal 66,7 % e com anaplasia difusa 40%. Todos os pacientes com doença em estádio IV e anaplasia difusa foram a óbito (n=4). Todos os pacientes com doença em estádio I, independente da histologia, permaneceram vivos até o final do período de seguimento. CONCLUSÕES: Entre as variáveis escolhidas para o modelo final apenas o estadiamento e a histologia permaneceram associados ao elevado risco de óbito enquanto que os casos na faixa etária entre 24 e 47 meses apresentaram melhor prognóstico que os demais. Esses resultados mostram a importância do diagnóstico em fases iniciais da doença e que a histologia é fundamental para orientar a terapia adequada
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