Atsushi Shimizu

Seasonal variations of 3.0∼3.8-day ultra-fast Kelvin waves observed with a meteor wind radar and radiosonde in Indonesia

This paper is concerned with observations of the long-term behavior of Kelvin waves with the wave period ranging from 3 to 4 days, which are generally called an ultra-fast Kelvin (UFK) wave. Horizontal wind velocity at 74–110 km altitudes observed with a meteor wind radar (MWR) near Jakarta (6.4°S, 106.7°E) for five years during November 1992 and December 1997 and daily radiosonde profiles in Bandung (6.9°S, 107.6°E) collected between October 1993 and March 1996 and have been analyzed. In the mesosphere and lower thermosphere (MLT) region, the UFK wave activity, defined by the spectral density of zonal wind perturbations at the 3.0–3.8 day period, is strongly enhanced twice a year. An interaction between UFK waves and a semiannual oscillation in the mesosphere (MSAO) can be suggested, although an exact mechanism is uncertain. We also have investigated seasonal variation of 3.0–3.8 day oscillations of zonal winds in the stratosphere, excluding gravity wave components, but, we have not detected an evidence of semiannual periodicity. The UFK wave activity in the MLT region exhibited intraseasonal variations, which showed some correlation with the amplitudes of zonal wind in the troposphere.

Variations in tropical tropopause observed with radiosondes in Indonesia

Characteristics of the tropical tropopause are described using radiosonde observations in Indonesia. Annual cycles of tropopause height are clearly seen and year-to-year variations are also recognized, especially the in the rainy seasons. Over Indonesia, the tropopause is colder and located higher than that over western Pacific. Cross spectral analyses indicates that the minimum temperature and zonal wind velocity at 16.5 km have good coherency in the period of 10–25 days, which suggests that the structure of temperature around the tropopause is mainly controlled by Kelvin waves passing through. On the other hand, the minimum temperature fluctuation with a period of 25–50 days shows a large correlation with precipitable water vapor in the troposphere.

Melting of heat-induced ovalbumin gel by pressure

The effects of pressure on heat-induced gels of ovalbumin were examined. A heat-induced gel containing 7% ovalbumin and 10 mmol/dm3 Na-phosphate buffer, pH 7.0, melted completely with pressure at 600 MPa for 20 min at 20°C. The melted sample gelled again after the pressure ceased. Most of the heat-induced gels of ovalbumin prepared under various conditions (different protein concentrations, ionic strengths, pHs and heating methods) melted partly with pressure at 600 MPa for 20 min at 20°C, and gelled again at atmospheric pressure. However, a heat-induced gel of glycinin and cold-set gels of gelatin or agarose did not melt with pressure at 400–700 MPa for 20 min at 20°C. The pressure denaturation of ovalbumin and the renaturation of heat-denatured ovalbumin caused by pressure were also examined. The pressure denaturation of ovalbumin was partly reversible and heat-denatured ovalbumin renatured somewhat with treatment at 600 MPa for 20 min at pH 7.0 and low ionic strength.

Observations of atmospheric waves in the tropical Pacific with radars and radiosondes

Abstract By an international research consortium between Japan, Indonesia and Australia, we have been operating a meteor wind radar (MWR) near Jakarta (6.4°S, 106.7°E) since November 1992, and a medium frequency (MF) radar in Pontianak (0.03°N, 109.3°E), west Kalimantan, from November 1995, respectively. We also conducted campaign observations with a balloon-borne radiosonde in LAPAN observatories in Watukosek (7.6°S, 112.7°E), Bandung (6.9°S, 107.6°E) and Pontianak since February 1990. In this paper, radar observations of wind fields in the mesosphere and lower thermosphere (MLT) region are used to study equatorial atmosphere dynamics. We first describe the long-term behavior of zonal wind at 70–100 km using the Jakarta MWR data during November 1992 and October 1997. The mesospheric semiannual oscillation (MSAO) is dominant in the equatorial MLT region, whose westward winds were much larger in March–April than in September–October. Moreover, the maximum amplitudes of MSAO showed a clear biennial periodicity. We also discuss characteristics of ultra-fast Kelvin (UFK) waves, having wave period of 3–4 days. A correlative study between the Jakarta MWR and MF radars at Pontianak and Christmas Island (2°N, 158°W) has indicated that the UFK wave propagates eastward at a zonal wavenumber one. We have further analyzed the long-term behavior of the UFK waves in Jakarta, and have found that the wave activity is characterized by strong enhancements twice a year, having a large value in the westward winds of MSAO.

Osteoid Osteoma Can Occur at the Pars Interarticularis of the Lumbar Spine, Leading to Misdiagnosis of Lumbar Spondylolysis

Patient: Male, 18 Final Diagnosis: Osteoid osteoma Symptoms: Low back pain Medication: — Clinical Procedure: Operation Specialty: Orthopedics and Traumatology Objective: Rare disease Background: Osteoid osteomas are benign bone-forming tumors characterized by local inflammation and pain. They are also characterized by a small osteolytic lesion (nidus). Spondylolysis is a defect of the pars interarticularis, which may lead to stress fractures, and is a common cause of low back pain in adolescence. Osteoid osteoma occurs predominantly in the posterior elements of the spine. Magnetic resonance imaging (MRI) signal abnormality suggesting bone marrow edema is a common finding in osteoid osteoma and early-stage spondylolysis without prominent defect. Case Report: An 18-year-old male was suffering from low back pain. He was diagnosed with lumbar spondylolysis on initial MRI and computed tomography (CT). Subsequent thin-slice CT demonstrated a nidus at the pars interarticularis, and variously-sliced MRI could detect widespread bone marrow edema. On the diagnosis of an osteoid osteoma, the nidus and surrounding osteosclerosis were resected. The patient’s pain disappeared after surgery. Conclusions: Osteoid osteoma in the pars interarticularis can be difficult to diagnosis, because MRI and CT findings for osteoid osteoma at the pars interarticularis are similar to those of the lumbar spondylolysis. The possibility of osteoid osteoma should be kept in mind when examining adolescents with low back pain.

Oxycodone Resistance Due to Rifampin Use in an Osteosarcoma Patient with Tuberculosis

Patient: Male, 30 Final Diagnosis: Osteosarcoma Symptoms: Pain Medication: Rifampin • Oxycodone Clinical Procedure: Oxycodone usage Specialty: Oncology Objective: Unusual clinical course Background: Oxycodone is a semisynthetic opioid receptor agonist, and is frequently used for pain control in patients with cancer. Most oxycodone is metabolized by N-demethylation to noroxycodone by CYP3A. Rifampin is a strong inducer of several drug-metabolizing enzymes, including CYP3A. Hence, rifampin-induced CYP3A activity may decrease the effect of oxycodone. Case Report: Osteosarcoma is a highly aggressive primary bone tumor of childhood and adolescence. Here, we report a 30-year-old male with osteosarcoma of the femur with lung metastases in the upper lobe. The lung also contained small, scattered nodular lesions that were identified as tuberculosis. Multi-drug therapy, including rifampin, was administered. The upper-lobe metastatic lesion extended to the brachial plexus and caused severe pain. Over 1000 mg per day of oxycodone was ineffective for pain control. However, morphine was able to control his pain at about one-third the equivalent dose. Conclusions: Our patient demonstrated oxycodone resistance due to rifampin. Chemotherapy may have compromised the patient’s immune system, thus theoretically increasing the risk of tuberculosis. Recognition of the interactions between rifampin and oxycodone is important in this and other cancers. Notably, for patients using high doses of oxycodone to manage severe pain, stopping rifampin may lead to oxycodone overdose.