Does Commodity Derivatives Function Effectively? A lengthy Discussion

The present work has been designed to intensely investigate the capability of the commodity futures market in achieving the aim of price discovery. Further, the downside of the cash and futures market and transfer of the risk to other markets has also been studied using VaR, and Bivariate EGARCH. The findings of the work point that the metal commodity derivative market helps in the efficient discovery of price in the spot market except for nickel. But, in the case of the agricultural commodities, the spot is found to be leading and thus there is no price discovery except turmeric. On the other hand, the volatility spillover is bidirectional for both agri and metal commodities except copper, where volatility spills only from futures to spot. Further, the effect of negative shock informational bias differs from commodity to commodity, irrespective of metal or agriculture.

Suitable Alternative for Human Cadaver Temporal Bone Dissection: Comparative Micro Ear Anatomy of Cattle, Pig and Sheep with Human

The study was undertaken to compare the micro ear anatomy of three commonly available animal models which are expected to have similar anatomy to human and to find out suitable model among them as an alternative for human cadaver temporal bone dissection. This is an observational study of comparison of micro ear anatomy of the three animal models with human. Decapitated heads of cattle, pig and sheep were collected from slaughter houses, soft tissues along with brain were removed and preserved in commercially available formalin preservative. CT scan was taken for the three specimens and 3D reconstructions were done. Each specimen was subjected to micro dissection and the anatomical features were studied and compared with human. Among the three animal models sheep is found to be an ideal model for a beginner because of ease of exposure of bone, very thin cortical bone, and no cellularity, good exposure of all the middle ear structures and similar interrelations of middle ear structures with human. Pig may not be an ideal model because of abundant fatty soft tissues, thick periosteum very narrow space occupied by the middle ear, difficulty in accessing cellularity small fragile ossicular chain and overhanging facial nerve.

A time of flight mass spectrometer with field free interaction region for low energy charged particle-molecule collision studies

A new design of a linear time of flight mass spectrometer (ToFMS) is implemented that gives nearly field-free interaction region without compromising on the mass resolution. The design addresses problems that would arise in a conventional Wiley-McLaren type of ToFMS: (i) field leakages into the charged particle-molecule interaction region from various components of the mass spectrometer, including that through the high transparency mesh used to obtain evenly distributed electric fields; (ii) complete collection and transportation of the ions produced in the interaction region to the detector, which is essential for high sensitivity and cross section measurements. This ToFMS works over a wide range of masses from H(+) to a few hundred Daltons and would be the most suitable for low energy charged particle-molecule interaction studies. Performance of the ToFMS has been tested by measuring the partial ionization cross sections for electron impact on CF(4).

Intratentorial lipomas with Meckel's cave and cerebellopontine angle extension

An unusual case of bilateral intratentorial lipomas with extension into Meckel's caves and the cerebellopontine angle is described. Surgical and histopathologic correlation demonstrate that the lipoma encased the trigeminal nerve in Meckel's caves. The origin of the lipoma from the anteromedial margins of the tentorium is discussed and correlated with a recently proposed theory for the development of intracranial lipomas.

Adenocarcinoma production in rats administered 1,2-dimethylhydrazine and fed iron salt and guar gum diets

Iron salts supplemented in a basal ratio, were fed to young Sprague-Dawley male rats for prolonged periods and the frequency of colonic adenocarcinomas induced by repeated s.c. injection of 1,2-dimethylhydrazine (DMH) at unit base doses of 9.0 mg/kg, ascertained and compared with the respective controls. In a series employing ferric ammonium citrate (0.46% Fe), in addition to ferrous sulfate (0.11% Fe) and ferric ammonium sulfate (0.12% Fe), DMH injection was started on day 15 and the animals necropsied 22 weeks after the last of 23 doses. The general condition was more involved with the 0.46% Fe diet and the total colonic lesion numbers were in the control range. However, the ferric ammonium sulfate-fed group showed a significant increase in tumors in the distal colon portion. In the second experiment, 15% guar gum as such and in admixture with ferric ammonium sulfate (0.12%) were compared with the respective controls, the first of 20 weekly dosages of DMH being administered on day 28 of the feeding. At 32 weeks following injection 1, the overall lesion differences were not remarkable, but the guar gum ratios engendered decreases in the distal colon tumor frequencies. In general, lesion incidence was extensive, involving 80-100% of the animals per group of the 2 series. Adenocarcinomas occurred in the small intestine and were more prominent in the control and 15% guar gum dietary groups but fewer with the ferric ammonium sulfate supplement.

Bacterial aerosol emission rates from municipal wastewater aeration tanks

In this report we describe the results of a study conducted to determine the rates of bacterial aerosol emission from the surfaces of the aeration tanks of the Metropolitan Water Reclamation District of Greater Chicago John E. Egan Water Reclamation Plant. This study was accomplished by conducting test runs in which Andersen six-stage viable samplers were used to collect bacterial aerosol samples inside a walled tower positioned above an aeration tank liquid surface at the John E. Egan Water Reclamation Plant. The samples were analyzed for standard plate counts (SPC), total coliforms (TC), fecal coliforms, and fecal streptococci. Two methods of calculation were used to estimate the bacterial emission rate. The first method was a conventional stack emission rate calculation method in which the measured air concentration of bacteria was multiplied by the air flow rate emanating from the aeration tanks. The second method was a more empirical method in which an attempt was made to measure all of the bacteria emanating from an isolated area (0.37 m2) of the aeration tank surface over time. The data from six test runs were used to determine bacterial emission rates by both calculation methods. As determined by the conventional calculation method, the average SPC emission rate was 1.61 SPC/m2/s (range, 0.66 to 2.65 SPC/m2/s). As determined by the empirical calculation method, the average SPC emission rate was 2.18 SPC/m2/s (range, 1.25 to 2.66 SPC/m2/s). For TC, the average emission rate was 0.20 TC/m2/s (range, 0.02 to 0.40 TC/m2/s) when the conventional calculation method was used and 0.27 TC/m2/s (range, 0.04 to 0.53 TC/m2/s) when the empirical calculation method was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoid tumor with intradural spinal metastases

A case of spinal intradural metastasis from a carcinoid tumor is reported. The case is of interest due to the rarity of central nervous system involvement by these tumors and the long latency period of the patient's presentation.

Quantitation and pattern of parenchymal lung injury in blunt chest trauma. Diagnostic and therapeutic implications

Sixty-nine patients with nonpenetrating pulmonary trauma were studied by chest computed tomography (CT) within 24 hours of admission. The percentage of air-space filling was quantitated and compared with the requirement for ventilatory support. Pulmonary intraalveolar hemorrhage always is gravity dependent originating at the site of injury. Utilizing CT, the patients' pulmonary status was classified into three separate clinicoradiologic groups: Grade I injury (less than 18% air-space filling, no ventilator support required), Grade II injury (18-28% air-space filling, ventilator support sometimes required), and Grade III injury (greater than 28 air-space filling, ventilator support always required). The CT quantitation correlated with clinical functional studies and was useful in the therapeutic management of nonpenetrating lung injury.

Computed tomography of Toxocara canis endophthalmitis

Many lesions, termed pseudogliomas, may mimic the appearance of retinoblastoma, both clinically and on computed tomography. The appearance of Toxocara canis endophthalmitis on computed tomography is presented. The role of computed tomography in the evaluation of patients presenting with leukokoria is discussed.

Cholesterol granuloma of the petrous apex and sphenoidal sinus: a case report

A case of a cholesterol granuloma located in the petrous apex and eroding into the sphenoidal sinus is reported. Cholesterol granuloma is thought to occur when pneumatized cells in the temporal bone become obstructed. Although usually occurring in the middle ear, it can occur in the petrous apex. The diagnosis and surgical management are discussed.

Regression analysis of total fatty acids from human whole brain according to age and sex

Total fatty acids processed from whole brain samples removed at autopsy from men and women, 26-87 years of age, were esterified, the methyl esters analyzed by gas chromatography, and the respective profiles deduced. In the study of the effect of age and sex in relation to the fatty acid levels, regression analysis was applied to smoothened data to take care of extraneous effects or variables. Toward this end, five age groupings were formed and the regression relationships explored for each group per sex. Generally, the saturated homologs occurred in higher amounts among males of advancing age but decreased with age among females. This effect stemmed from the even-carbon acids. For the unsaturated fatty acids, the reverse behavior appeared evident. For the prominent acids, 16:0 and 18:0, the differences were moderately significant for cases 50 years and older, for 18:2, significance based on either sex was noted with all age groups.

Imaging modalities of craniosynostosis with surgical and pathological correlation

Premature fusion of the sutures of the skull has been extensively analyzed and several diagnostic imaging modalities have been proposed. Radiographic, scintigraphic and computed tomographic features of craniosynostosis have been reported. This study was initiated (a) to determine the value and accuracy of plain skull radiography, skull scintigraphy and cranial CT; and (b) to determine the optimal imaging modality for the evaluation of a clinically suspected craniosynostosis. The study is based on 36 patients with clinical suspicion of craniosynostosis who underwent craniectomy and cranioplasty. One hundred and three sutures were pathologically and/or surgically evaluated. The overall accuracy rate for skull radiography was 89%, skull scintigraphy, 66%, and cranial CT, 94%. Routine skull series are adequate in the majority of cases of craniosynostosis. Skull scintigraphy is less accurate, more costly, and has a limited role in the evaluation of craniosynostosis. Cranial CT should be reserved for those cases in which the findings in the routine skull series are not clearly positive or negative, or in cases of more complex craniofacial anomalies.

Role of computed tomography in symptomatic vertebral hemangiomas

Vertebral hemangioma, although a benign lesion, can result in neurologic deficit. Computed tomography is useful in demonstrating the extension of the hemangioma into the posterior neural arch and epidural space. Computed tomography after intravenous contrast administration is useful in evaluating the vascular nature of the lesion and is a useful technique before surgery or spinal angiography.

Intramedullary canine spinal cord tumor model

The development of a transplantable model brain tumor in the neonatal dog, the adaptation of the tumor to tissue culture, and the successful growth of the tumor in adult mongrel dogs has been adapted to producing similar tumors in the thoracic spinal cord of the adult dog. Ten adult dogs, weighing 4 to 25.4 kg each, were subjected to formal laminectomy. The tumor cell suspension was injected by hand with a Hamilton syringe at two or three sites over a distance of 1 cm; each site received an injection volume to 0.02 to 0.05 cc of the cell suspension after the dura had been opened. Immediately after injection the field was copiously irrigated and the puncture area sealed with a single drop of ethyl cyanoacrylate. Tumor cells for injection were obtained by thawing ampules stored at -195 degrees C in a mixture of 10% dimethyl sulfoxide and RPMI 1640 culture medium. Cells were resuspended in Hank's balanced salt solution and 15% fetal calf serum on ice. Solutions had 90% cell viability, and animals received a dose in the range of 3 to 13 X 10(6) cells. Eight animals developed tumors and became paraparetic on the 9th to 14th postinjection day. Metrizamide myelography in three animals revealed complete blocks; two animals underwent spinal computerized tomography (CT) and demonstrated syringohydromyelia. Histology revealed the tumors to be highly vascular primitive neoplasms that invaded the surrounding cord. This spinal cord tumor model is large enough to be operated on, studied by CT and myelography, and subjected to pharmacological, electrophysiological, and blood flow study.

Vascular studies in the preoperative evaluation of pituitary adenomas before transsphenoidal surgery

The transsphenoidal approach is being increasingly utilized in the surgical treatment of pituitary microadenoma. Even with high-resolution and dynamic computed tomography (CT) scanning, subtle vascular anatomic variants and other vascular anomalies involving the parasellar carotid arteries cannot always be clearly defined. Five cases are described in which evaluation by digital intravenous subtraction angiography or standard carotid arteriography provided useful preoperative information before transsphenoidal surgery. The implications of these findings are discussed.

Intracranial venous aneurysms: vein of Galen and other similar vascular anomalies

Aneurysmal dilatation of the vein of Galen is peculiar to arteriovenous malformation around the midbrain. Similar venous aneurysms may rarely occur in other regions. This paper deals with the radiographic findings in three cases of vascular malformation associated with giant venous aneurysms. The pathophysiology resulting in aneurysmal venous dilatation is discussed based on our material and those previously reported.

Microglioma--unusual computed tomographic appearance and course of neoplasm

Microglioma accounts for 0.8-1.5% of primary brain tumors. Eight cases of primary lymphoma of brain are presented. 50% of the patients demonstrated unusual computed tomographic appearances. These patients were divided into three groups depending on clinical outcome. Survival seems to be related to treatment modality. Longest survival times were in patients treated with radiation alone or radiation following biopsy.

Morphology and dimensions of the thoracic cord by computer-assisted metrizamide myelography

Computed tomographic (CT) measurements of the thoracic spine and its contents were obtained in 33 patients undergoing metrizamide myelography for various spinal disorders. Twenty-eight of these patients had symptoms referable to the cervical or lumbar region and form the basis of this study. Five patients had symptoms referable to the thoracic spine. Sagittal and coronal CT measurements of the thoracic cord and subarachnoid space were obtained in all cases. In addition, macroscopic measurements of the thoracic cord were obtained from 10 autopsies for correlation with the CT findings. The technical aspects of the measurements are discussed; the normal morphology of the thoracic cord and thecal sac is presented; and the metrizamide CT pattern associated with pathologic lesions involving the thoracic cord is analyzed.

CT characteristics of a transplantable canine glioma model: preliminary kinetic analysis

Experimental brain tumors can be produced in dogs through the intracerebral injection of 3 X 10(6) live tumor cells in either neonates or adult animals. Tumors are visible by computed tomography on day 8 postinjection. Most tumors appear as ring lesions with central lucencies and shaggy borders. By postinjection day 12, tumor volumes increase more than 10 times; the cell cycling time is about 1-3 days. The initial doubling time is about 1-2 days and corresponds to the in vitro doubling time of about 24 hr. The use of computed tomography to perform noninvasive kinetic analysis deserves further study. The transplantable canine glioma model would appear to be ideal for this purpose.

Epidermoid tumor of the fourth ventricle: use of metrizamide-computed tomography

This report describes two cases of epidermoid tumor of the fourth ventricle diagnosed with metrizamide computed tomography. They both presented as a low-density lesion in the region of the fourth ventricle on computed tomography. They did not show any enhancement after intravenous injection of contrast medium and had no hydrocephalus. Metrizamide-enhanced computed tomography demonstrated the irregular fourth-ventricular filling defect characteristic of epidermoid tumors.

Interhemispheric intradural cyst

Intracranial intradural cyst represents a rare congenital malformation of the dura. Computed tomography and autopsy findings in a child with a rapid and progressive enlargement of the head indicated the presence of a large interhemispheric cystic mass. A large dural-like interhemispheric cyst was confirmed at autopsy.

Basal ganglia calcification in the neonate

Calcification of the basal ganglia developed following intracranial hemorrhage in a neonate recovering from severe perinatal asphyxia. Cranial computed tomography is useful in demonstrating the anatomic distribution of dystrophic calcification in regions previously involved by hemorrhage. The demonstration of hemorrhage or hemorrhagic infarction with CT may help to verify the association of basal ganglia calcification with birth anoxia.

CT-angiographic correlation in Sturge-Weber syndrome

Sturge-Weber syndrome in its classic form can be easily diagnosed by CT. However, in the absence of the typical gyral calcification, the diagnosis can be missed on CT. Identification of the intracranial angiomatosis and the associated thrombosis, and thus the diagnosis, require angiography. Computed tomographic and angiographic findings in a case of Sturge-Weber syndrome with unusual clinical features is described.

Computed tomographic findings in cerebral sinus and venous thrombosis

Cerebral sinus and venous thrombosis were diagnosed by computed tomography (CT) and subsequently confirmed by other studies in eleven patients. CT revealed normal or small ventricles, hemorrhages, low-density areas, and increased density of dural sinuses and tentorium. CT in combination with appropriate angiographic studies is necessary for diagnosis and confirmation of sinus and venous thrombosis. Proper use of CT can result in decreased morbidity and mortality associated with this condition.

Delayed carotid-cavernous fistula and multiple cranial neuropathy following basal skull fracture

A case of basilar skull fracture associated with palsies of the 3rd through 10th cranial nerves on the ipsilateral side is presented. Three months after the initial injury, despite return of significant ocular movement, proptosis and conjunctival congestion heralded the onset of an ipsilateral carotid-cavernous fistula. Angiography revealed the presence of a carotid-cavernous fistula; however, the ipsilateral carotid artery was occluded in the neck. A single pathophysiological mechanism is proposed to account for this unique series of events.

CT in head trauma: a review

The diagnosis and management of head trauma has changed significantly with the availability of computed tomography. CT not only demonstrates the presence of a mass, but also delineates acute bleed from brain swelling. CT is useful in determining whether the hematoma is intracerebral or extracerebral, as well as its volume, extent, and multiplicity. CT provides the opportunity for noninvasive sequential studies in the management of the patient with severe head trauma. Sequential CT studies have also been useful in understanding the long-term effects of head trauma. CT has eliminated the need for other diagnostic studies in all but the most exceptional situations.

The role and limitation of CT in craniocerebral trauma

CT is being utilized more often in evaluation of craniofacial and craniovertebral trauma. It is far superior to conventional pluri-directional tomography, since not only the complex fracture but also communication with the orbital or cranial contents can be demonstrated. The extend of soft-tissue trauma can also be better evaluated. However, there are limitations in utilizing CT as the sole modality in evaluating craniocerebral trauma. This article deals with the limitations of utilizing CT alone in evaluation of trauma.

Ct in spinal trauma

The radiological evaluation of patients with acute spinal trauma has always been a challenging problem. Multiple radiological procedures are often necessary for complete evaluation of the extent of spinal injury. CT provides an ideal modality whereby accurate assessment of displacement of bony fragments as well as associated spinal cord and nerve root injury can easily be performed, eliminating the need for difficult radiological procedures.

CT findings in multicentric glioblastoma: diagnostic-pathologic correlation

Computerized cranial tomography (CCT) and angiographic findings in three cases of multicentric glioblastoma are reported. Differentiation of multicentric glioblastoma from diffuse metastatic deposits or multiple abscesses can be difficult with CCT. Apart from demonstrating a mass effect in one case and tumor neovascularity in the second case, angiography did not provide additional helpful information. The pathological diagnoses of these lesions were confirmed by biopsy and subsequent autopsy. Pathological differentiation of the multifocal or multicentric nature of the glioblastoma can be made only at autopsy.

Transverse sinus anomaly simulating a meningioma on CT scanning

A rare, anomalously dilated right transverse sinus with involvement of the torcular herophili strongly suggested the appearance of a meningioma on CT scanning. Carotid and vertebral arteriography did not reveal the nature of the abnormality, since there was only faint opacification of the anomalous vessel, which was interpreted as a faint tumor stain. Transjugular venography was necessary to establish this diagnosis. When a similar lesion is encountered on CT scanning and the transverse sinus is not clearly seen on arteriography, venography should be carried out to determine if the appearance is due to occlusion by a mass or, as in this case, anomalous dilatation of the sinus.

Computer assisted tomography in rapidly growing brain tumor

A case of undifferentiated astrocytoma with rapid increase in size of the tumor as documented by sequential computer assisted tomography (CAT) of the head is reported. The case also demonstrates the sensitivity of computer assisted tomography in the detection of intracranial pathology, in the presence of fals localizing neurological findings.

Interhemispheric subdural empyema: neuroradiological diagnosis

A case of subdural empyema situated in the interhemispheric subdural space is described. CT scan is useful in the diagnosis and follow-up of intracranial inflammatory pathology. Selective angiography was helpful in the compartmental localization of the abscess in the interhemispheric subdural space, adjacent to the falx and tentorium by virtue of the hypertrophied tentorial meningeal arteries and vascular displacement. CT scans are also useful in follow-up of cerebral abscess after micropaque barium has been injected into the cavity as in this patient.

Craniopharyngiomas in children: neuroradiological evaluation

Craniopharyngiomas constitute one of the commonest tumors in the sellar and parasellar region in children. Most often total surgical removal is attempted. Prior knowledge of the extent of the tumor and adhesions to adjacent neurovascular structures is thus necessary prior to deciding the type of surgical intervention. This paper deals with the usefulness of multiple neuroradiographic studies in evaluating these bening neoplasms, based on nearly 50 cases of craniopharyngiomas.