Development and application of an urban solar photovoltaic opportunity mapping tool.

A Geospatial Opportunity Mapping (GOMap) tool was created to identify policy unconstrained land in urban cities that is technically feasible for the deployment of solar photovoltaic power stations; and identify buildings with north- or south-facing orientation for the installation of building integrated PV (BIPV). Collaboration with a local Governing authority and a local electricity provider enabled the process to elicit comprehensive policy and technical aspect information respectively that would impact the site selection process. Five policy and four technical aspects are comprised of a total of 36 individual factors displayable by GOMap on a high-resolution city grid with a scoring system implemented to distinguish between factors that encourage or inhibits solar PV deployment. Weightings can be applied, and different scenarios explored including alternative policy changes and infrastructure upgrades. GOMap generates opportunity maps in the form of available land estimates which can be extrapolated by an in-built solar PV model to quantify annual energy generation based on local weather data, array spacing, panel type and array tilt angle. Three scenarios were devised to identify unconstrained land for solar PV deployment with varying levels of policy and technical factor relaxation, and a fourth scenario to identify dwellings for potential BIPV. These scenarios aim to tackle Glasgow City's growing energy demand and fuel poverty issue, the latter of which can supply energy to dwellings categorised as 'hard-to-heat' once heating is electrified due to the Scottish Government's Energy Strategy commitment.

An investigation of Gf-Gc theory in the older adult population: joint factor analysis of the Woodcock-Johnson-Revised and the Detroit Test of Learning Aptitude-Adult.

Researchers and clinicians are increasingly interested in the structure of intelligence among older adults. A joint factor analysis was conducted for 27 subtests of the Woodcock-Johnson Psycho-Educational Battery-Revised and the Detroit Tests of Learning Aptitude-Adult for a sample of 50 persons ranging in age from 55 to 84 years (M=65.16 yr.). The results provide evidence for the latent factors speci fied by Gf-Gc theory in older adults, indicate which Gf-Gc factors are measured by subtests of the two batteries, and illustrate the necessity of cross-battery assessment to identify the full complement of Gf-Gc factors.

Disseminated neuroblastoma in the nude rat. A xenograft model of human malignancy.

BACKGROUND: The overall survival of children with neuroblastoma remains less than 30% due to disease dissemination at the time of diagnosis. An animal model of neuroblastoma, with characteristics similar to those observed clinically in children, would be beneficial to investigations into the diverse biology of this tumor. The purpose of this study was (1) to develop a model of disseminated neuroblastoma in the nude rat by intracardiac injection of neuroblastoma cells derived from cell lines with different N-myc copy numbers; (2) to investigate the effect of age on tumor growth and dissemination; and (3) to assess progression of disease radiologically and correlate with autopsy findings. METHODS: Nude rats (n = 38), 5-13 weeks of age, underwent intracardiac injection of the human neuroblastoma cell lines IMR-32 with amplified N-myc oncogene and SKNSH with 1 N-myc copy. The animals were observed for at least six weeks for the development of tumor. Twelve rodents injected with IMR-32 cells underwent imaging studies including magnetic resonance imaging (MRI), skeletal radiographs, and indium-111(IN-111)-diethylenetriamine penta-acetic acid-D-Phe1-octreotide scintigraphy. Autopsies with standardized microscopic examinations were performed on all animals. RESULTS: Most of the nude rats (95%) developed neuroblastoma following intracardiac injection of neoplastic cells. Disseminated tumor was evident in 66% of animals. Anatomic sites of neuroblastoma growth were similar to those observed clinically in children, including adrenal glands, paraspinal ganglia, bone, bone marrow, and skin, but no tumor was identified in the liver. Disseminated disease occurred in more animals injected with IMR-32 (78% of animals) than with SKNSH cells (34% of animals) (P < 0.05). Tumor spread appeared to be age dependent; only rodents 5-8 weeks old at the time of injection developed disseminated disease when compared with animals 9 weeks of age or older (P < 0.0001). Radioreceptor scintigraphy demonstrated only pericardial tumor; MRI identified pericardial, adrenal gland, and subcutaneous neoplasms; only skeletal radiographs detected neuroblastoma in cortical bone. CONCLUSIONS: (1) Following intracardiac injection of human neuroblastoma cell lines into nude rats, a xenograft model of disseminated disease develops that closely parallels the malignant process in children. (2) Tumor dissemination is associated with the cell line that demonstrates N-myc amplification and with young age of the recipient at the time of injection. (3) Tumor growth and dissemination may be assessed radiologically. (4) This model of human malignancy may offer an opportunity to investigate the pathophysiologic mechanisms underlying tumor development and dissemination in advanced stage neuroblastoma.

MR of head and neck adenopathy in asymptomatic HIV-seropositive men.

PURPOSE: Adenopathy is a well-known component of AIDS-related complex. Our goal was to determine whether asymptomatic HIV-infected persons have characteristic findings of head and neck adenopathy on MR imaging and whether there is an association between the MR findings and the CD4 lymphocyte counts. METHODS: We blindly and retrospectively evaluated the distribution and size of lymphadenopathy seen on screening MR examinations that were performed on 50 asymptomatic HIV-positive male subjects and 50 age-matched HIV-negative control subjects. We also correlated the imaging findings in HIV-seropositive and -seronegative subjects with their CD4 counts. RESULTS: The HIV-positive subjects had a higher incidence of adenopathy compared with the controls. Statistically significant differences were found between the groups in size and number of neck lymph nodes, thickness of the adenoids, size of high, deep cervical-retropharyngeal lymph nodes, and presence of parotid abnormalities. We found a correlation between increasing lymph node size and decreasing CD4 levels. CONCLUSION: We conclude that HIV-positive asymptomatic patients have a high incidence of head and neck abnormalities including lymphadenopathy, and alteration in their CD4 counts not commonly seen in seronegative control subjects.

The extracranial facial nerve: high resolution three-dimensional Fourier transform MR imaging.

PURPOSE: To investigate the use of high-resolution three-dimensional Fourier transform gradient-echo MR in evaluation of the extracranial facial nerve. METHODS: Nine normal subjects and one clinical patient were scanned. Several imaging parameters, including echo time, field-of-view, and the use of Gd-DTPA, were manipulated to determine the optimal technique. Adequate results were obtained in less than 7 minutes acquisition time using a T1-weighted (50/5.3) gradient-echo technique, with a 30 degree flip angle, a 12-cm field of view, 128 x 256 matrix, and 28 or 60 1.0-mm-thick contiguous sections. RESULTS: Gd-DTPA administration was not found useful in identifying the normal extracranial facial nerve. The proximal extracranial facial nerve was seen as a branching low signal intensity tubular structure on 10 to 20 contiguous images in all five volunteers in which this optimal technique was employed. Postprocessing of the images to produce curved oblique planar reconstructed images was useful to display long segments of the facial nerve on a single image. CONCLUSION: Our experience with high resolution three-dimensional Fourier transform MR imaging indicates that it can consistently demonstrate the intraparotid facial nerve on multiple contiguous images.

Magnetic resonance imaging correlates of neuropsychological impairment in multiple sclerosis.

The authors examined whether specific neuropsychological abnormalities in multiple sclerosis (MS) are associated with focal lesion areas detected by MRI. Lesion area, regardless of distribution, correlated with performance on the vast majority of neuropsychological procedures. No significant difference appeared between groups with normal/mild and moderate overall cognitive impairment on any of the MRI measures. However, patients with severe cognitive impairment had greater lesion area, regardless of location, and had significant atrophy of the corpus callosum compared with the other two groups. These results suggest that severe atrophy of the corpus callosum reflects global disease and provides a relatively focal morphological marker of severe cognitive impairment in MS.

Cyclosporine-associated seizures in bone marrow transplant recipients given busulfan and cyclophosphamide preparative therapy.

Five of 182 recipients of allogeneic bone marrow transplants performed between 2/84 and 6/90 developed seizures while receiving cyclosporine and methylprednisolone to prevent acute graft-versus-host disease. All received a radiation-free regimen of busulfan and cyclophosphamide as preparative therapy. Two patients received HLA-mismatched allografts; and three patients received marrow from HLA-identical sibling donors. Two patients had received extensive intrathecal therapy prior to transplantation. All patients were receiving standard prophylactic doses of CsA and MP at the time of onset (median 31 days posttransplantation) of seizures. Three patients had mild-to-moderate hypertension and varying degrees of morphologic evidence of microangiopathic hemolytic anemia. None had unusually low magnesium levels. Cyclosporine levels were not in the toxic range. Cranial magnetic resonance imaging and computed tomography (CT) showed bilateral abnormalities primarily in the posterior temporal, occipital, and parietal lobes. These abnormalities were shown to be transient on sequential MRI exams in two patients. Seizures as well as radiologic abnormalities resolved on stopping CsA and did not recur in 2 patients who subsequently received CsA in lower doses. These findings confirm and expand previous observations of CsA-associated seizures and demonstrate that they occur in allogeneic bone marrow transplant recipients following a radiation-free preparative regimen of busulfan and cyclophosphamide.

Cerebellorubral degeneration after resection of cerebellar dentate nucleus neoplasms: evaluation with MR imaging.

The authors describe the magnetic resonance (MR) findings in seven patients who developed severe cerebellar symptoms and atrophy of the contralateral red nucleus following removal of unilateral neoplasms in the deep nuclei of the cerebellum. For most patients, pre- and postoperative spin-echo MR images were obtained with long repetition times (TRs) at 1.5 T. The long TR images obtained before surgery demonstrated unilateral masses involving the dentate nucleus. Long TR images obtained after surgical resection of the dentate nucleus showed increased signal intensity in all of seven contralateral red nuclei, three of seven ipsilateral superior cerebellar peduncles, and two of seven contralateral inferior olivary nuclei. Three other patients who underwent surgery for cerebellar neoplasms without resection of the dentate nuclei showed no postoperative brain stem changes on MR images. The authors speculate that the changes in the contralateral red nuclei are due to cerebellorubral degeneration (since well-described neural tracts interconnect the dentate nucleus and the contralateral red nucleus). Injury of the dentate nucleus may result in degeneration of distant neural connections.

Gadopentetate dimeglumine-enhanced MR imaging of the musculoskeletal system.

Contrast-enhanced MR imaging with gadopentetate dimeglumine has been used in the evaluation of musculoskeletal disorders only in recent years, and for the most part it is still under investigation. Review of the literature identified potential uses for this technique: (1) in the spine, for differentiation between scar tissue and recurrent disk herniation and for evaluation of epidural tumors; (2) in musculoskeletal tumors, for differentiation between tumor necrosis and peritumoral edema and for characterization and evaluation of tumors before and after treatment; (3) in the joints for delineation of cartilage and tendon tears, with intraarticular injection, and for differentiation between pannus and joint effusion, with IV injection; and (4) for delineation of infectious processes. Further studies are needed to confirm most of these potential indications. It is unlikely that gadopentetate dimeglumine-enhanced MR imaging will become a routine part of musculoskeletal MR imaging, and its use will be reserved for specific circumstances.

Improving diagnostic accuracy of cervical metastases with computed tomography and magnetic resonance imaging.

Elective neck dissection in patients with head and neck cancer continues to be controversial. The management of these patients would be greatly facilitated by improvements in predicting cervical metastases. Recent investigations have suggested that computed tomography and magnetic resonance imaging are more sensitive in detecting cervical metastases than physical examination. The Department of Otolaryngology at the Ohio State University Hospitals, Columbus, undertook a prospective study to compare the preoperative sensitivities of physical examination, computed tomography, and magnetic resonance imaging with pathologic findings in 27 patients undergoing neck dissections for head and neck cancer. The results indicate that computed tomography and magnetic resonance imaging were more sensitive (84% and 92%, respectively) than physical examination (75%), although the results did not achieve statistical significance. The sensitivity of combined computed tomography and magnetic resonance imaging was 90%.

Ligaments of the lateral aspect of the ankle and sinus tarsi: an MR imaging study.

The normal anatomy of the lateral ankle and subtalar ligaments seen at magnetic resonance (MR) imaging was studied in four cadaver ankles. Sixteen ankles of 11 healthy volunteers were imaged with four different MR imaging protocols to optimize technique. The anterior talofibular ligament was identified in 100% of the ankles of the volunteers in the axial plane, the calcaneofibular ligament in 81% of the ankles in the coronal plane, the cervical ligament in 69% of the ankles in the coronal plane and in 88% of the ankles in the sagittal plane, and the talocalcaneal ligament in 56% of the ankles in the coronal plane and in 62% of the ankles in the sagittal plane. It is concluded that thin-section (1-3-mm) MR imaging techniques, especially the one in which data are acquired with three-dimensional Fourier transform, are best for visualization of the ligaments. These techniques may play a role in the evaluation of patients with chronic ankle pain and instability.

Hamsters (Mesocricetus auratus ) use spatial memory in foraging for food to hoard.

We have collected evidence that a hoarding species of rodent, the Syrian golden hamster (Mesocricetus auratus), uses spatial memory in foraging for food to hoard. Before each trial, we baited the same four arms of a modified seven arm radial maze with sunflower seeds. During the trial we gave each hamster 15-min access to the maze and observed its behaviour. Typically their behaviour comprised two phases: Upon entering the maze the hamsters frequently explored the arms of the maze, not eating seeds nor storing seeds in their cheek pouches. This exploration was followed by food gathering. In doing this, the hamsters generally visited the baited arms in succession, placing all the seed that they found in an arm into their cheek pouches. While gathering food, the hamsters seldom revisited depleted arms, suggesting that they remembered the locations of depleted food sites.

Effects of spinal cord lesioning on somatosensory and neurogenic-motor evoked potentials.

Somatosensory (SEPs) and neurogenic-motor evoked potentials (NMEPs) were elicited from 16 hogs and two humans before, during, and after spinal cordotomy, dorsal, or ventral root rhizotomy. Results indicated that SEPs appear to be insensitive to the effects of motor tract lesioning in hogs and humans. In every case of motor paraplegia, SEPs remained unchanged in the presence of abnormal ischiatic/sciatic NMEPs. These results suggest that SEPs are not adequately sensitive to the functional status of the motor system in hogs and humans. Ischiatic/sciatic NMEPs remained unchanged after sensory tract lesioning, suggesting that these NMEPs are insensitive to the functional status of the sensory system. These results suggest that SEPs and NMEPs should be used in combination when monitoring spinal cord function during surgeries that place that structure at risk.

Experimental infections of the musculoskeletal system: evaluation with MR imaging and Tc-99m MDP and Ga-67 scintigraphy.

Acute osteomyelitis, soft-tissue infection, or both were experimentally produced in 38 New Zealand white rabbits, and three-phase technetium-99m methylene diphosphonate, gallium-67, and magnetic resonance (MR) images were obtained 7 or 14 days after infection. There was no significant difference between radionuclide studies and MR images in the detection of osteomyelitis, but MR imaging was significantly more sensitive (100% vs. 69%; P less than .01) in the detection of soft-tissue infection. In addition, cellulitis could not be distinguished from soft-tissue abscess on radionuclide studies, whereas MR imaging was 92% accurate in depicting soft-tissue abscesses. Further research is necessary to determine how to relate these findings to true human clinical situations.

Penile revascularization in the treatment of vasculogenic impotence.

Arterial insufficiency is the most common organic cause of impotence. The diagnosis can be established on a clinical basis through the use of Doppler probe evaluation of the penile pulses, penile blood pressure measuring, and nocturnal penile tumescence monitoring. The diagnosis may be confirmed by internal pudendal arteriography. Through microsurgical arterial revascularization, a 60 percent long-term success rate has been achieved. Two early and two late failures suggest the need for improved patient selection and confirm the progressive nature of the arteriosclerotic process.

Infections of the musculoskeletal system: high-field-strength MR imaging.

Twenty-two patients with clinical findings consistent with osteomyelitis, soft-tissue infection, or both were studied with magnetic resonance (MR) imaging at 1.5 T. Another 15 patients with joint effusion but no clinical or laboratory signs of infection served as controls. Soft-tissue abscesses, osteomyelitis, joint and tendon sheath effusion, and cellulitis were well depicted on MR imaging, allowing the correct diagnosis of presence and extent of infection in all but two cases. MR imaging was as sensitive as technetium-99m methylene diphosphonate bone scintigraphy in demonstrating osteomyelitis and was more specific and more sensitive than other scintigraphic techniques in demonstrating soft-tissue infections, primarily because of its superior spatial resolution. Computed tomography, performed in seven cases, was as accurate as MR imaging in demonstrating bone and soft-tissue infections. Infected and noninfected synovial effusions had the same signal intensity, but associated findings such as soft-tissue fluid collections or osteomyelitis made the distinction possible.

Rheumatoid factor in otitis media with effusion.

Because of the pathologic similarities between rheumatoid arthritis and otitis media with effusion (OME), rheumatoid factor (RF) was measured in 156 human middle ear effusion (MEE) and serum samples from patients with chronic OME. Using a quantitative latex agglutination test, we were able to demonstrate RF in the MEEs of 85% of patients with OME. Demonstrable RF titers were found in only 8% of the patients' serum samples. The titers of mucoid MEE samples were seven times higher than those observed in serous MEE samples. The presence of RF was not related to the age of the patient, the presence of viable bacteria in the MEEs, or history of OME.