52 research outputs found
Recommended from our members
Retrievals of Riming and Snow Density From Vertically Pointing Doppler Radars
Retrievals of ice and snow are made from Ka- and W-band zenith-pointing Doppler radars at Hyytiala, Finland, during the snow experiment component of the Biogenic Aerosols: Effects on Clouds and Climate (2014) field campaign. In a novel optimal estimation retrieval, mean Doppler velocity is exploited to retrieve a density factor parameter, which modulates the mass, shape, terminal velocity, and backscatter cross sections of ice particles. In a case study including aggregate snow and graupel we find that snow rate and ensemble mean ice density can be retrieved to within 50% of in situ measurements at the surface using dual-frequency Doppler radar retrievals. While Doppler measurements are essential to the retrieval of particle density, the dual-frequency ratio provides a strong constraint on particle size. The retrieved density factor is strongly correlated with liquid water path, indicating that riming is the primary process by which the density factor is modulated. Using liquid water path as a proxy for riming, profiles classified as unrimed snow, rimed snow, and graupel exhibit distinct features characteristic of aggregation and riming processes, suggesting the potential to make estimates of process rates from these retrievals. We discuss the potential application of the technique to future satellite missions. Plain Language Summary Ground-based radar measurements of ice clouds and snow are used to estimate the size, number, and density of snowflakes. Doppler velocity measurements of particle fall speeds are used to estimate the mass and shape of the snow particles. The properties of snow estimated using radar compare well against measurements of particles at the surface and estimates of the amount of liquid water in the atmosphere; the presence of liquid water relates to the potential for riming, in which snowflakes increase in density and fall speed by collecting and freezing liquid droplets. More accurate estimates of snow density from ground-based and satellite radars help to improve global estimates of precipitation and snow accumulation and the representation of clouds and snow in weather and climate models.Peer reviewe
Quantitative PCR of ear discharge from Indigenous Australian children with acute otitis media with perforation supports a role for Alloiococcus otitidis as a secondary pathogen
Otitis media is endemic in remote Indigenous communities of Australia’s Northern Territory. Alloiococcus otitidis is an outer ear commensal and putative middle ear pathogen that has not previously been described in acute otitis media (AOM) in this population. The aims of this study were to determine the presence, antibiotic susceptibility and bacterial load of A. otitidis in nasopharyngeal and ear discharge swabs collected from Indigenous Australian children with AOM with perforation.Financial support for this study was provided by the Channel 7 Children’s Research Foundation; The Trust Foundation; and the National Health and Medical Research Council (Australia)
Dedifferentiated chondrosarcoma with leukocytosis and elevation of serum G-CSF. A case report
BACKGROUND: G-CSF is known to function as a hematopoietic growth factor and it is known to be responsible for leukocytosis. G-CSF-producing tumors associated with leukocytosis include various types of malignancies. CASE PRESENTATION: We report the case of a 72-year-old man with dedifferentiated chondrosarcoma characterized by dedifferentiated components of malignant fibrous histiocytoma- or osteosarcoma-like features in addition to conventional chondrosarcoma, arising from his pelvic bone. After hemipelvectomy, when local recurrence and metastasis were identified, leukocytosis appeared and an elevated level of serum granulocyte-colony-stimulating factor (G-CSF) was also recognized. The patient died of multiple organ failure 2 months after surgery. Autopsy specimens showed that the histological specimens of the recurrence and metastasis were dedifferentiated components, without any conventional chondrosarcoma components. G-CSF was expressed only in the dedifferentiated components, not in the chondrosarcoma components, immunohistochemically. CONCLUSION: This is the first report of chondrosarcoma, or any other primary bone tumor, with leukocytosis, probably stimulated by tumor-produced G-CSF from the dedifferentiated components
A new method for measuring torsional deformity in scoliosis
<p>Abstract</p> <p>Background</p> <p>The importance of spinal rotational and torsional deformity in the etiology and the management of scoliosis are well-recognized. For measuring the posterior spinal component rotation, Ho's method was reported to be reliable. However, there is no practical method to measure the anterior spinal component rotation. Moreover, there is also no method to quantify the spinal torsional deformity in scoliosis. The goal of this study is to characterize scoliosis and its deformity to hypothesize the etiology and the development of scoliosis, and to establish a new method for the measurement of the vertebral body rotation and spinal torsional deformity in scoliosis using CT scans.</p> <p>Methods</p> <p>Pre-operative CT scans of 25 non-congenital scoliosis patients were recruited and the apical vertebral rotation was measured by a newly developed method and Ho's method. Ho's method adopts the laminae as the rotational landmark. For a new method to measure the apical vertebral rotation, the posterior point just beneath each pedicle was used as a landmark. For quantifying the spinal torsional deformity angle, the rotational angle difference between the two methods was calculated.</p> <p>Results</p> <p>Intraobserver and interobserver reliability analyses showed both methods to be reliable. Apical vertebral rotation revealed 13.9 ± 6.8 (mean ± standard deviation) degrees by the new method and 7.9 ± 6.3 by Ho's method. Right spinal rotation was assigned a positive value. The discrepancy of rotation (6.1 ± 3.9 degrees), meaning that the anterior component rotated more than the posterior component, was considered to express the spinal torsional deformity to the convex side.</p> <p>Conclusions</p> <p>We have developed an easy, reliable and practical method to measure the rotation of the spinal anterior component using a CT scan. Furthermore, we quantified the spinal torsional deformity to the convex side in scoliosis by comparing the rotation between the anterior and posterior components.</p
Sh3pxd2b Mice Are a Model for Craniofacial Dysmorphology and Otitis Media
Craniofacial defects that occur through gene mutation during development increase vulnerability to eustachian tube dysfunction. These defects can lead to an increased incidence of otitis media. We examined the effects of a mutation in the Sh3pxd2b gene (Sh3pxd2bnee) on the progression of otitis media and hearing impairment at various developmental stages. We found that all mice that had the Sh3pxd2bnee mutation went on to develop craniofacial dysmorphologies and subsequently otitis media, by as early as 11 days of age. We found noteworthy changes in cilia and goblet cells of the middle ear mucosa in Sh3pxd2bnee mutant mice using scanning electronic microscopy. By measuring craniofacial dimensions, we determined for the first time in an animal model that this mouse has altered eustachian tube morphology consistent with a more horizontal position of the eustachian tube. All mutants were found to have hearing impairment. Expression of TNF-α and TLR2, which correlates with inflammation in otitis media, was up-regulated in the ears of mutant mice when examined by immunohistochemistry and semi-quantitative RT-PCR. The mouse model with a mutation in the Sh3pxd2b gene (Sh3pxd2bnee) mirrors craniofacial dysmorphology and otitis media in humans
The role of morphine in regulation of cancer cell growth
Morphine is considered the “gold standard” for relieving pain and is currently one of the most effective drugs available clinically for the management of severe pain associated with cancer. In addition to its use in the treatment of pain, morphine appears to be important in the regulation of neoplastic tissue. Although morphine acts directly on the central nervous system to relieve pain, its activities on peripheral tissues are responsible for many of the secondary complications. Therefore, understanding the impact, other than pain control, of morphine on cancer treatment is extremely important. The effect of morphine on tumor growth is still contradictory, as both growth-promoting and growth-inhibiting effects have been observed. Accumulating evidence suggests that morphine can affect proliferation and migration of tumor cells as well as angiogenesis. Various signaling pathways have been suggested to be involved in these extra-analgesic effects of morphine. Suppression of immune system by morphine is an additional complication. This review provides an update on the influence of morphine on the growth and migration potential of tumor cells
- …