The early Paleogene (56-48 Myr) provides valuable information about the Earth's climate system in an equilibrium high pCO2 world. High ocean temperatures have been reconstructed for this greenhouse period, but land temperature estimates have been cooler than expected. This mismatch between marine and terrestrial temperatures has been difficult to reconcile. Here we present terrestrial temperature estimates from a newly-calibrated brGDGTbased paleothermometer in ancient lignites (fossilized peat). Our results suggest early Paleogene mid-latitude (45-60 degrees paleolatitude) mean annual air temperatures of 23-29 °C (with an uncertainty of ± 4.7 °C), 5-10 °C higher than

Object Lipomas of the spinal cord are often a component of spinal dysraphic states. Nondysraphic intramedullary spinal cord lipomas are rare, and their presentation, in the form of gradually worsening myelopathy, is nonspecific. The authors report on the methods used for diagnosis and treatment in patients presenting with these lesions at their institution, and they review the relevant literature. Methods The authors treated 14 patients who presented with intramedullary lipomas over a period of 12 years. None of these patients had segmentation anomaly or dysraphism of the spine, or any hindbrain anomaly. Admission magnetic resonance images were diagnostic in all patients. All tumors were located dorsally in the spinal cord, the majority of them in the cervicodorsal cord. The lipomas were partially excised with the help of a carbon dioxide laser in all patients in an attempt to preserve neurological function. All patients attained improvement in their sensory and motor symptoms. Conclusions Because these lesions do not have a clear-cut margin, it is vital to preserve neurological function at the time of surgery, even if it entails incomplete resection.

Object Intraventricular meningiomas are rare tumors. The origin of these tumors can be traced to embryological invagination of arachnoid cells into the choroid plexus. The authors analyzed data that they had collected to study the clinicopathological aspects and review the origin, presentation, imaging, and management of these tumors. Methods In this retrospective analysis, the authors describe the cases of 12 patients who had received a diagnosis of intraventricular meningioma and underwent surgery for the tumors. Nine of these patients were men and three were women. Features of neurofibromatosis Type 2 were present in two of the women. Nine of the tumors were located in the lateral ventricles, one was in the third ventricle, and two were in the fourth ventricle. Raised intracranial pressure (ICP) was the universal presentation in all the patients, and the preoperative diagnoses were confirmed on neuroimaging studies. Excision was performed using the parietooccipital (trigonal) approach for lateral ventricle tumors, the transcortical–transventricular route for the third ventricle tumor, and suboccipital craniectomy for fourth ventricle tumors. Postoperatively, one patient died and the others experienced resolution of their symptoms. Histopathological features of these tumors were similar to those seen in meningiomas in other locations. Conclusions Intraventricular meningiomas are slow-growing tumors that become large prior to detection. Although they are commonly seen in the lateral ventricles, they occur in the third and fourth ventricles as well. Presentation is in the form of raised ICP with no localizing features; therefore the diagnosis is based on imaging studies. Hydrocephalus occurs due to obstruction of cerebrospinal fluid pathways. Excision requires planning to avoid eloquent cortex incision. The histopathological features are varied, although most of the tumors in the study were angiomatous meningiomas. These tumors are no different histologically from tumors that are dural in origin. No recurrence has been reported.

Adrenal incidentalomas are adrenal masses discovered incidental to imaging studies performed for reasons unrelated to adrenal pathology. Although most adrenal incidentalomas are non-functioning benign adenomas, their increasing prevalence presents diagnostic and therapeutic challenges. The assessment of adrenal incidentalomas is aimed at deciding whether or not the tumour should be surgically removed. Adrenalectomy is indicated for phaeochromocytoma, other symptomatic hormone-secreting tumours and those with a high risk of malignancy. Biochemical screening for tumour hypersecretion is mandatory in all adrenal incidentalomas, since hormone secreting tumours may be clinically silent. The diagnosis of phaeochromocytoma is of paramount importance because of its life-threatening complications. Non-functioning adrenal incidentalomas need assessment for risk of malignancy, and this is based on the size of the tumour and its imaging characteristics. An observational policy with periodic radiological and biochemical reassessment is pursued in patients with non-functioning incidentalomas with low malignancy risk. The duration and frequency of reassessment remains unclear, as the natural history of adrenal incidentalomas has yet to be clearly defined, and there is a lack of controlled studies comparing surgical intervention with observation. However, the possibility of acquiring autonomous hypersecretion or conversion to malignancy in an incidentaloma diagnosed to be a benign non-functioning lesion is very low, and most patients may be safely discharged after an initial follow-up period of 2 years.

The electronic structure, electrical and dielectric properties of barium stannate, a semiconducting perovskite oxide prepared by solid state ceramic route were studied by employing X-ray photoelectron spectroscopy (XPS), Mössbauer and impedance spectroscopic techniques in the temperature range 77–300 K. X-ray diffraction (XRD) pattern of BaSnO3 confirms the cubic structure. Scanning electron microscopy (SEM) images show high porosity in the sample and the average grain size was found to be about 1.85 µm which corroborates with the particle size obtained through XRD line broadening analysis. Mössbauer spectra, at 298 and 78 K reveal that tin exists mainly in tetravalent, Sn4+ state. XPS study also shows the same results but it indicates the existence of a trace amount of Sn2+. Electrical conductivity and dielectric constant of this system have been measured in the temperature range 298 to 148 K and in the frequency range 10-2 to 106 Hz. Frequency and temperature dependent electrical conductivity/dielectric properties have been used to separate the contributions of grains and grain boundaries to the total observed conductivity and dielectric constant. Orientational polarisation and space charge polarisation contributes to the observed dielectric properties of the system.