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Sample records for dust related sinonasal

  1. Wood-related occupations, wood dust exposure, and sinonasal cancer.

    Science.gov (United States)

    Hayes, R B; Gerin, M; Raatgever, J W; de Bruyn, A

    1986-10-01

    A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941.

  2. Wood dust-related mutational profile of TP53 in intestinal-type sinonasal adenocarcinoma.

    Science.gov (United States)

    Pérez-Escuredo, Jhudit; Martínez, Jorge García; Vivanco, Blanca; Marcos, César Álvarez; Suárez, Carlos; Llorente, José Luis; Hermsen, Mario A

    2012-11-01

    Intestinal-type sinonasal adenocarcinoma represents 8% to 25% of all malignant sinonasal cancer and is etiologically related to occupational exposure to wood dust. Despite its clear etiology, the mechanisms behind the carcinogenic effects of wood dust are unclear. Because it is known that carcinogens can leave specific mutational fingerprints, we aimed to analyze the spectrum of TP53 mutations and to relate the findings to the wood dust etiology of the patients. Forty-four primary tumors were examined for TP53 mutations by direct sequencing. In addition, p53 protein expression was analyzed by immunohistochemistry using a tissue microarray consisting of 92 tumors. We report a frequency of 41% (18/44) TP53 mutations and 72% (66/92) p53 immunopositivity in intestinal-type sinonasal adenocarcinoma, significantly related to wood dust, but not to tobacco etiology. G→A transition (50%, 9/18 cases) was the most common alteration detected, almost exclusively found in nonsmokers, whereas G→T (27%, 5/18 cases) was detected in smokers only. These data point to wood dust exposure as the causal factor in the mutagenesis of TP53, possibly caused by reactive nitrogen species generated through a chronic inflammatory process.

  3. K-ras mutations in sinonasal cancers in relation to wood dust exposure

    DEFF Research Database (Denmark)

    Bornholdt, Jette; Hansen, Johnni; Steiniche, Torben

    2008-01-01

    carefully reviewed pathologically before inclusion. Paraffin embedded tumour samples from 58 adenocarcinomas, 109 squamous cell carcinomas and 7 other carcinomas were analysed for K-ras codon 12, 13 and 61 point mutations by restriction fragment length polymorphisms and direct sequencing. Information...... mutations were suggested to be related to wood dust exposure, but these studies were too limited to detect statistically significant associations. Methods We examined 174 cases of sinonasal cancer diagnosed in Denmark in the period from 1991 to 2001. To ensure uniformity, all histological diagnoses were...... to unexposed [OR = 21.0, CI = 8.0–55.0]. K-ras was mutated in 13% of the adenocarcinomas (seven patients) and in 1% of squamous cell carcinomas (one patient). Of these eight mutations, five mutations were located in the codon 12. The exact sequence change of remaining three could not be identified...

  4. Mutations in TP53 tumor suppressor gene in wood dust-related sinonasal cancer

    DEFF Research Database (Denmark)

    Holmila, Reetta; Bornholdt, Jette; Heikkilä, Pirjo

    2010-01-01

    to wood dust, using capillary electrophoresis single-strand conformation polymorphism analysis and direct sequencing. A significant association between wood-dust exposure and adenocarcinoma histology was observed [adjusted odds ratio (OR) 12.6, 95% confidence interval (CI), 5.0-31.6]. TP53 mutations...

  5. HPV-related Multiphenotypic Sinonasal Carcinoma

    DEFF Research Database (Denmark)

    Bishop, Justin A; Andreasen, Simon; Hang, Jen-Fan

    2017-01-01

    gene fusions were positive. In the 38 cases with follow-up data, (mean follow-up, 42 mo) 14 recurred locally and 2 metastasized (lung, finger). There were no regional lymph node metastases, and no tumor-related deaths. HMSC is a distinct sinonasal neoplasm characterized by myoepithelial differentiation...

  6. Human papillomavirus-related carcinomas of the sinonasal tract.

    Science.gov (United States)

    Bishop, Justin A; Guo, Theresa W; Smith, David F; Wang, Hao; Ogawa, Takenori; Pai, Sara I; Westra, William H

    2013-02-01

    High-risk human papillomavirus (HPV) is an established cause of head and neck carcinomas arising in the oropharynx. The presence of HPV has also been reported in some carcinomas arising in the sinonasal tract, but little is known about their overall incidence or their clinicopathologic profile. The surgical pathology archives of The Johns Hopkins Hospital were searched for all carcinomas arising in the sinonasal tract from 1995 to 2011, and tissue microarrays were constructed. p16 immunohistochemical analysis and DNA in situ hybridization for high-risk types of HPV were performed. Demographic and clinical outcome data were extracted from patient medical records. Of 161 sinonasal carcinomas, 34 (21%) were positive for high-risk HPV DNA, including type 16 (82%), type 31/33 (12%), and type 18 (6%). HPV-positive carcinomas consisted of 28 squamous cell carcinomas and variants (15 nonkeratinizing or partially keratinizing, 4 papillary, 5 adenosquamous, 4 basaloid), 1 small cell carcinoma, 1 sinonasal undifferentiated carcinoma, and 4 carcinomas that were difficult to classify but exhibited adenoid cystic carcinoma-like features. Immunohistochemistry for p16 was positive in 59/161 (37%) cases, and p16 expression strongly correlated with the presence of HPV DNA: 33 of 34 (97%) HPV-positive tumors exhibited high p16 expression, whereas only 26 of 127 (20%) HPV-negative tumors were p16 positive (Pcarcinomas occurred in 19 men and 15 women ranging in age from 33 to 87 years (mean, 54 y). A trend toward improved survival was observed in the HPV-positive group (hazard ratio=0.58, 95% confidence interval [0.26, 1.28]). The presence of high-risk HPV in 21% of sinonasal carcinomas confirms HPV as an important oncologic agent of carcinomas arising in the sinonasal tract. Although nonkeratinizing squamous cell carcinoma is the most common histologic type, there is a wide morphologic spectrum of HPV-related disease that includes a variant that resembles adenoid cystic carcinoma. The

  7. Sinonasal inflammation in COPD

    DEFF Research Database (Denmark)

    Håkansson, Kåre; Konge, Lars; Thomsen, Sf

    2013-01-01

    In this review we demonstrate that patients with chronic obstructive pulmonary disease (COPD) frequently report sinonasal symptoms. Furthermore, we present evidence that smoking on its own can cause nasal disease, and that in COPD patients, nasal inflammation mimics that of the bronchi. All...... this evidence suggests that COPD related sinonasal disease does exist and that smoking on its own rather than systemic inflammation triggers the condition. However, COPD related sinonasal disease remains to be characterized in terms of symptoms and endoscopic findings. In addition, more studies are needed...... to quantify the negative impact of sinonasal symptoms on the quality of life in COPD patients....

  8. Recently described neoplasms of the sinonasal tract.

    Science.gov (United States)

    Bishop, Justin A

    2016-03-01

    Surgical pathology of the sinonasal region (i.e., nasal cavity and the paranasal sinuses) is notoriously difficult, due in part to the remarkable diversity of neoplasms that may be encountered in this area. In addition, a number of neoplasms have been only recently described in the sinonasal tract, further compounding the difficulty for pathologists who are not yet familiar with them. This manuscript will review the clinicopathologic features of some of the recently described sinonasal tumor types: NUT midline carcinoma, HPV-related carcinoma with adenoid cystic-like features, SMARCB1 (INI-1) deficient sinonasal carcinoma, biphenotypic sinonasal sarcoma, and adamantinoma-like Ewing family tumor.

  9. Newly Described Tumor Entities in Sinonasal Tract Pathology.

    Science.gov (United States)

    Bishop, Justin A

    2016-03-01

    Surgical pathology of the sinonasal tract (nasal cavity and paranasal sinuses) is extremely challenging due in part to the tremendous diversity of tumor types that may arise in this region. Compounding the difficulty, a number of new sinonasal tumor entities have been recently described, and pathologists may not yet be familiar with these neoplasms. This manuscript will review the clinicopathologic features of some of the newly described sinonasal tumor types: NUT midline carcinoma, HPV-related carcinoma with adenoid cystic-like features, SMARCB1 (INI-1) deficient sinonasal carcinoma, biphenotypic sinonasal sarcoma, and renal cell-like adenocarcinoma.

  10. Association between septal deviation and sinonasal papilloma.

    Science.gov (United States)

    Nomura, Kazuhiro; Ogawa, Takenori; Sugawara, Mitsuru; Honkura, Yohei; Oshima, Hidetoshi; Arakawa, Kazuya; Oshima, Takeshi; Katori, Yukio

    2013-12-01

    Sinonasal papilloma is a common benign epithelial tumor of the sinonasal tract and accounts for 0.5% to 4% of all nasal tumors. The etiology of sinonasal papilloma remains unclear, although human papilloma virus has been proposed as a major risk factor. Other etiological factors, such as anatomical variations of the nasal cavity, may be related to the pathogenesis of sinonasal papilloma, because deviated nasal septum is seen in patients with chronic rhinosinusitis. We, therefore, investigated the involvement of deviated nasal septum in the development of sinonasal papilloma. Preoperative computed tomography or magnetic resonance imaging findings of 83 patients with sinonasal papilloma were evaluated retrospectively. The side of papilloma and the direction of septal deviation showed a significant correlation. Septum deviated to the intact side in 51 of 83 patients (61.4%) and to the affected side in 18 of 83 patients (21.7%). Straight or S-shaped septum was observed in 14 of 83 patients (16.9%). Even after excluding 27 patients who underwent revision surgery and 15 patients in whom the papilloma touched the concave portion of the nasal septum, the concave side of septal deviation was associated with the development of sinonasal papilloma (p = 0.040). The high incidence of sinonasal papilloma in the concave side may reflect the consequences of the traumatic effects caused by wall shear stress of the high-velocity airflow and the increased chance of inhaling viruses and pollutants. The present study supports the causative role of human papilloma virus and toxic chemicals in the occurrence of sinonasal papilloma.

  11. Atypical sinonasal Schwannomas: a difficult diagnostic challenge.

    Science.gov (United States)

    Jacopo, Galli; Micaela, Imperiali; Italo, Cantore; Luigi, Corina; Larocca, Luigi M; Gaetano, Paludetti

    2009-08-01

    Schwannomas are benign tumours arising from Schwann cells of the peripheral nerve sheath. They are relatively frequent in the head and neck region (25-45%) but rarely involve in the sinonasal tract (4%). The authors outline the diagnostic difficulties and the problems in choosing the best surgical approach in two atypical cases of sinonasal Schwannomas. In the first case reported clinical data, sex and age of the patient, nasal endoscopy and angio-MRI led us to suspect an angiofibroma; therefore, we approached the case without a biopsy performing a preoperative selective embolization followed by an endoscopic resection. In the second case, due to initial visual symptoms and to the ethmoid-orbital compartment involvement, we performed a sinonasal endoscopy and collected a biopsy which resulted to be fundamental in the diagnostic assessment. Tumour excision was then obtained throughout an intracranial/endonasal approach. The two presented cases revealed the presence of cystic Schwannomas. In the first case, diagnosis was made only post-operatively after histological examination. Patients underwent complete surgical excision by means of an endoscopic sinonasal approach, in the second case associated to a left frontal craniotomy. The patients showed no signs of recurrence at a 9 months follow-up. Nasal endoscopy was extremely important in making the diagnosis, allowing an accurate assessment of the tumour extension and a biopsy. The diagnosis of sinonasal Schwannomas remains challenging; sometimes, clinical behaviour and modern imaging may be misleading. The diagnostic and therapeutic importance of sinonasal endoscopy is emphasised in the two presented cases.

  12. Sinonasal inverted papilloma: From diagnosis to treatment.

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    Lisan, Q; Laccourreye, O; Bonfils, P

    2016-11-01

    Inverted papilloma is a rare sinonasal tumor that mainly occurs in adults during the 5th decade. Three characteristics make this tumor very different from other sinonasal tumors: a relatively strong potential for local destruction, high rate of recurrence, and a risk of carcinomatous evolution. Etiology remains little understood, but an association with human papilloma virus has been reported in up to 40% of cases, raising the suspicions of implication in the pathogenesis of inverted papilloma. Treatment of choice is surgery, by endonasal endoscopic or external approach, depending on extension and tumoral characteristics. Follow-up is critical, to diagnose local relapse, which is often early but may also be late. The seriousness of this pathology lies in its association with carcinoma, which may be diagnosed at the outset or at recurrence during follow-up. It is important to diagnose recurrence to enable early treatment, especially in case of associated carcinoma or malignancy. A comprehensive review of the international literature was performed on PubMed and Embase, using the following search-terms: "sinonasal" [All Fields] AND ("papilloma, inverted" [MeSH Terms] OR ("papilloma" [All Fields] AND "inverted" [All Fields]) OR "inverted papilloma" [All Fields] OR ("inverted" [All Fields] AND "papilloma" [All Fields])). We reviewed all articles referring to sinonasal inverted papilloma published up to January 2015. The present article updates the state of knowledge regarding sinonasal inverted papilloma. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Human Papillomavirus-related Carcinoma with Adenoid Cystic-like Features of the Sinonasal Tract

    DEFF Research Database (Denmark)

    Andreasen, Simon; Bishop, J; Hansen, T V O

    2017-01-01

    with adenoid cystic carcinoma (ACC), a rare and aggressive carcinoma originating in the minor salivary glands. Termed HPV-related carcinoma with ACC-like features, only 9 cases have been reported. To clarify the occurrence of these tumours we screened a large material for presence of HPV-related ACC...... as HPV types 33, 35 and 56. All six cases had areas of dysplastic mucosal lining and showed remarkable heterogeneous morphologies. MYB, MYBL1, and NFIB genes were intact and, interestingly, staining for MYB protein was largely negative in contrast to what was found in ACC. One patient experienced a local...

  14. Nasal and sinonasal cancer. Connection with occupational exposures in Denmark, Finland and Sweden

    DEFF Research Database (Denmark)

    Hernberg, S; Westerholm, P; Schultz-Larsen, K

    1983-01-01

    A joint Danish-Finnish-Swedish case-referent investigation was initiated in 1977 in order to study the connection between nasal and sinonasal cancer and various occupational exposures. All new cases of nasal and sinonasal cancer were collected from the national cancer registers (Finland and Swede...... carcinomas. No associations were found for a number of exposures, including agricultural chemicals, textile dust, asbestos, quartz dust, organic solvents and leather work. Possible exposure to formaldehyde was evenly distributed between the cases and referents....

  15. Intensity-Modulated or Proton Radiation Therapy for Sinonasal Malignancy

    Science.gov (United States)

    2017-07-28

    Adenoid Cystic Carcinoma; Squamous Cell Carcinoma; Sinonasal Carcinoma; Sinonasal Undifferentiated Carcinoma; Mucoepidermoid Carcinoma; Schneiderian Carcinoma; Myoepithelial Carcinoma; Esthesioneuroblastoma; Melanoma

  16. Trends in sinonasal cancer in The Netherlands: more squamous cell cancer, less adenocarcinoma. A population-based study 1973-2009

    NARCIS (Netherlands)

    Kuijpens, J.H.; Louwman, M.W.; Peters, R.; Janssens, G.O.R.J.; Burdorf, A.L.; Coebergh, J.W.W.

    2012-01-01

    BACKGROUND: Cancer of the nasal cavity or the paranasal sinuses (sinonasal cancer) is rare. Sinonasal cancer has been associated with various occupational risk factors such as exposure to dust of hard wood and leather. Also, a relationship with smoking habits has been suggested. We studied the long

  17. COX-2 and p53 in human sinonasal cancer

    DEFF Research Database (Denmark)

    Holmila, Reetta; Cyr, Diane; Luce, Danièle

    2008-01-01

    the exposures and p53 accumulation were found; however, the p53 accumulation pattern (p = 0.062 for wood dust exposure) resembled that of COX-2 expression. In summary, our findings show increased COX-2 expression in SNC adenocarcinoma with wood dust exposure, suggesting a role for inflammatory components......The causal role of wood-dust exposure in sinonasal cancer (SNC) has been established in epidemiological studies, but the mechanisms of SNC carcinogenesis are still largely unknown. Increased amounts of COX-2 are found in both premalignant and malignant tissues, and experimental evidence link COX-2......; 41 for p53). Occupational histories and smoking habits were available for majority of the cases. Most of the adenocarcinoma cases with exposure history data had been exposed to wood dust at work in the past (88%, 14/16). For smokers, 63% (12/19) presented with SSC, whereas 64% (7/11) of nonsmokers...

  18. Ice nucleation by soil dusts: relative importance of mineral dust and biogenic components

    Directory of Open Access Journals (Sweden)

    D. O'Sullivan

    2013-08-01

    Full Text Available Agricultural dust emissions have been estimated to contribute around 20% to the global dust burden. In contrast to dusts from arid source regions, the ice-nucleating abilities of which have been relatively well studied, soil dusts from fertile sources often contain a substantial fraction of organic matter. Using an experimental methodology which is sensitive to a wide range of ice nucleation efficiencies, we have characterised the immersion mode ice-nucleating activities of dusts extracted from fertile soils collected at four locations around England. By controlling droplet sizes, which ranged in volume from 10−12 to 10−6 L, we have been able to determine the ice nucleation behaviour of soil dust particles at temperatures ranging from 267 K (−6 °C down to the homogeneous limit of freezing at about 237 K (−36 °C. At temperatures above 258 K (−15 °C we find that the ice-nucleating activity of soil dusts is diminished by heat treatment or digestion with hydrogen peroxide, suggesting that the ice nuclei stem from biogenic components in the soil. However, below 258 K, we find that the ice active site densities tend towards those expected from the mineral components in the soils, suggesting that the inorganic fraction of soil dusts, in particular the K-feldspar fraction, becomes increasingly important in the initiation of the ice phase at lower temperatures. We conclude that although only a relatively minor contributor to the global atmospheric dust burden, the enhanced IN activities of dusts generated from agricultural activities may play an important role in cloud glaciation, particularly at temperatures above 258 K.

  19. [Viral infection of herpes simplex, Epstein-Barr, varicela zoster, human papilloma, cytomegalovirus, or adenovirus are not related to sinonasal adenocarcinomas].

    Science.gov (United States)

    Pérez Escuredo, Jhudit; Llorente, José Luis; Melón, Santiago; de Oña, María; García Martínez, Jorge; Alvarez Marcos, César; Hermsen, Mario

    2007-01-01

    Several types of virus have been implicated in the development of head and neck tumors. However, until now sinonasal adenocarcinomas (ACN) have not been studied. The aim of this study is to screen a series of ACN for the presence of a number of viruses known to play a role in cancer. Viral DNA sequences of herpes simplex virus, Epstein-Barr, varicela zoster, human papilloma, cytomegalovirus, and adenovirus were analysed by PCR in 37 primary ACN. Three tumors (8.1%) were positive for Epstein-Barr virus and 1 case (2.7%) for cytomegalovirus. Viral infections do not seem to play a role in the etiology of ACN.

  20. Current Trends in Sinonasal Imaging.

    Science.gov (United States)

    Huang, Benjamin Y; Senior, Brent A; Castillo, Mauricio

    2015-11-01

    As endoscopic sinus surgery (ESS) has evolved since its introduction to the United States, so has technology for imaging the sinonasal cavities. Although imaging is most frequently performed for evaluating chronic sinusitis refractory to medical therapy, its uses have expanded beyond inflammatory sinus disease. Multidetector Computed Tomography is the current workhorse for both diagnosis and preoperative planning in prospective ESS patients, while MR imaging remains a complementary tool for evaluating suspected tumors or intracranial and orbital complications of rhinosinusitis. In this article, the authors review current trends and potential future directions in the use of these modalities for sinus imaging.

  1. Sinonasal verrucous carcinoma with oral invasion

    Directory of Open Access Journals (Sweden)

    Karthikeya P

    2006-01-01

    Full Text Available Verrucous carcinoma is a rare warty variant of squamous cell carcinoma, most often seen in the oral cavity and larynx. Its occurrence in the sinonasal tract is rare. This tumor constitutes approximately 1% of all sinonasal neoplasms. The clinical presentation and the histopathological features of verrucous carcinoma are a subject of continuous discussion amongst diagnosticians and pathologists. A case with oral and nasal presentation of this tumor is reported here.

  2. Measurements of Finite Dust Temperature Effects in the Dispersion Relation of the Dust Acoustic Wave

    Science.gov (United States)

    Snipes, Erica; Williams, Jeremiah

    2009-04-01

    A dusty plasma is a four-component system composed of ions, electrons, neutral particles and charged microparticles. The presence of these charged microparticles gives rise to new plasma wave modes, including the dust acoustic wave. Recent measurements [1, 2] of the dispersion relationship for the dust acoustic wave in a glow discharge have shown that finite temperature effects are observed at higher values of neutral pressure. Other work [3] has shown that these effects are not observed at lower values of neutral pressure. We present the results of ongoing work examining finite temperature effects in the dispersion relation as a function of neutral pressure. [4pt] [1] E. Thomas, Jr., R. Fisher, and R. L. Merlino, Phys. Plasmas 14, 123701 (2007). [0pt] [2] J. D. Williams, E. Thomas Jr., and L. Marcus, Phys. Plasmas 15, 043704 (2008). [0pt] [3] T. Trottenberg, D. Block, and A. Piel, Phys. Plasmas 13, 042105 (2006).

  3. Effect of wind speed and relative humidity on atmospheric dust concentrations in semi-arid climates.

    Science.gov (United States)

    Csavina, Janae; Field, Jason; Félix, Omar; Corral-Avitia, Alba Y; Sáez, A Eduardo; Betterton, Eric A

    2014-07-15

    Atmospheric particulate have deleterious impacts on human health. Predicting dust and aerosol emission and transport would be helpful to reduce harmful impacts but, despite numerous studies, prediction of dust events and contaminant transport in dust remains challenging. In this work, we show that relative humidity and wind speed are both determinants in atmospheric dust concentration. Observations of atmospheric dust concentrations in Green Valley, AZ, USA, and Juárez, Chihuahua, México, show that PM10 concentrations are not directly correlated with wind speed or relative humidity separately. However, selecting the data for high wind speeds (>4m/s at 10 m elevation), a definite trend is observed between dust concentration and relative humidity: dust concentration increases with relative humidity, reaching a maximum around 25% and it subsequently decreases with relative humidity. Models for dust storm forecasting may be improved by utilizing atmospheric humidity and wind speed as main drivers for dust generation and transport.

  4. Effect of Wind Speed and Relative Humidity on Atmospheric Dust Concentrations in Semi-Arid Climates

    Science.gov (United States)

    Csavina, Janae; Field, Jason; Félix, Omar; Corral-Avitia, Alba Y.; Sáez, A. Eduardo; Betterton, Eric A.

    2014-01-01

    Atmospheric particulate have deleterious impacts on human health. Predicting dust and aerosol emission and transport would be helpful to reduce harmful impacts but, despite numerous studies, prediction of dust events and contaminant transport in dust remains challenging. In this work, we show that relative humidity and wind speed are both determinants in atmospheric dust concentration. Observations of atmospheric dust concentrations in Green Valley, AZ, USA, and Juárez, Chihuahua, México, show that PM10 concentrations are not directly correlated with wind speed or relative humidity separately. However, selecting the data for high wind speeds (> 4 m/s at 10 m elevation), a definite trend is observed between dust concentration and relative humidity: dust concentration increases with relative humidity, reaching a maximum around 25% and it subsequently decreases with relative humidity. Models for dust storm forecasting may be improved by utilizing atmospheric humidity and wind speed as main drivers for dust generation and transport. PMID:24769193

  5. NUT midline carcinomas of the sinonasal tract.

    Science.gov (United States)

    Bishop, Justin A; Westra, William H

    2012-08-01

    NUT midline carcinoma (NMC) is a highly lethal tumor defined by translocations involving the NUT gene on chromosome 15q14. NMC involves midline structures including the sinonasal tract, but its overall incidence at this midline site and its full morphologic profile are largely unknown because sinonasal tumors are not routinely tested for the NUT gene translocation. The recent availability of an immunohistochemical probe for the NUT protein now permits a more complete characterization of sinonasal NMCs. The archival files of The Johns Hopkins Hospital Surgical Pathology were searched for all cases of primary sinonasal carcinomas diagnosed from 1995 to 2011. Tissue microarrays were constructed, and NUT immunohistochemical analysis was performed. All NUT-positive cases underwent a more detailed microscopic and immunohistochemical analysis. Among 151 primary sinonasal carcinomas, only 3 (2%) were NUT positive. NUT positivity was detected in 2 of 13 (15%) carcinomas diagnosed as sinonasal undifferentiated carcinoma and in 1 of 87 (1%) carcinomas diagnosed as squamous cell carcinoma. All occurred in men (26, 33, and 48 y of age). The NMCs grew as nests and sheets of cells with a high mitotic rate and extensive necrosis. Two were entirely undifferentiated, and 1 tumor showed abrupt areas of squamous differentiation. Each case had areas of cell spindling, and 2 were heavily infiltrated by neutrophils. Immunohistochemical staining was observed for cytokeratins (3 of 3), epithelial membrane antigen (3 of 3), p63 (2 of 3), CD34 (1 of 3), and synaptophysin (1 of 3). All patients died of the disease (survival time range, 8 to 16 mo; mean, 12 mo) despite combined surgery and chemoradiation. NMC represents a rare form of primary sinonasal carcinoma, but its incidence is significantly increased in those carcinomas that exhibit an undifferentiated component. Indiscriminant analysis for evidence of the NUT translocation is unwarranted. Instead, NUT analysis can be restricted to

  6. An Empirical Relation between Sodium Absorption and Dust Extinction

    CERN Document Server

    Poznanski, Dovi; Bloom, Joshua S

    2012-01-01

    Dust extinction and reddening are ubiquitous in astronomical observations and are often a major source of systematic uncertainty. We present here a study of the correlation between extinction in the Milky Way and the equivalent width of the NaI D absorption doublet. Our sample includes more than 100 high resolution spectra from the KECK telescopes and nearly a million low resolution spectra from the Sloan Digital Sky Survey (SDSS). We measure the correlation to unprecedented precision, constrain its shape, and derive an empirical relation between these quantities with a dispersion of order 0.15 magnitude in E(B-V). From the shape of the curve of growth we further show that a typical sight line through the Galaxy crosses about three dust clouds. We provide a brief guide on how to best estimate extinction to extragalactic sources such as supernovae, using the NaI D absorption feature, under a variety of circumstances.

  7. Sinonasal adenoid cystic carcinoma following formaldehyde exposure in the operating theatre.

    Science.gov (United States)

    Sandvik, Anniken; Klingen, Tor Audun; Langård, Sverre

    2014-01-01

    We present a case report of an auxiliary nurse who developed an adenoid cystic carcinoma in her left maxillary sinus following occupational exposure to formaldehyde in the operating theatre. Currently, the epidemiological evidence that formaldehyde can cause cancer in humans is considered to be limited. Previous case-control-studies of formaldehyde and sinonasal cancer have mainly investigated subjects who were concomitantly exposed to wood dust, a known risk factor to the development of sinonasal adenocarcinoma of intestinal type. Our case report presents a patient who has developed an adenoid cystic carcinoma following exposure to formaldehyde. We suggest that the occupational physician remains alert to formaldehyde as an occupational hazard among health care workers.

  8. Herschel -ATLAS: revealing dust build-up and decline across gas, dust and stellar mass selected samples - I. Scaling relations

    Science.gov (United States)

    De Vis, P.; Dunne, L.; Maddox, S.; Gomez, H. L.; Clark, C. J. R.; Bauer, A. E.; Viaene, S.; Schofield, S. P.; Baes, M.; Baker, A. J.; Bourne, N.; Driver, S. P.; Dye, S.; Eales, S. A.; Furlanetto, C.; Ivison, R. J.; Robotham, A. S. G.; Rowlands, K.; Smith, D. J. B.; Smith, M. W. L.; Valiante, E.; Wright, A. H.

    2017-02-01

    We present a study of the dust, stars and atomic gas (H I) in an H I-selected sample of local galaxies (z sample reveals a population of very high gas fraction (>80 per cent), low stellar mass sources that appear to be in the earliest stages of their evolution. We compare this sample with dust- and stellar-mass-selected samples to study the dust and gas scaling relations over a wide range of gas fractions (proxy for evolutionary state of a galaxy). The most robust scaling relations for gas and dust are those linked to near-ultraviolet - r (specific star formation rate) and gas fraction; these do not depend on sample selection or environment. At the highest gas fractions, our additional sample shows that the dust content is well below expectations from extrapolating scaling relations for more evolved sources, and dust is not a good tracer of the gas content. The specific dust mass for local galaxies peaks at a gas fraction of ˜75 per cent. The atomic gas depletion time is also longer for high gas fraction galaxies, opposite to the trend found for molecular gas depletion time-scale. We link this trend to the changing efficiency of conversion of H I to H2 as galaxies increase in stellar mass surface density during their evolution. Finally, we show that galaxies start out barely obscured and increase in obscuration as they evolve, yet there is no clear and simple link between obscuration and global galaxy properties.

  9. Sinonasal microbiome sampling: a comparison of techniques.

    Science.gov (United States)

    Bassiouni, Ahmed; Cleland, Edward John; Psaltis, Alkis James; Vreugde, Sarah; Wormald, Peter-John

    2015-01-01

    The role of the sino-nasal microbiome in CRS remains unclear. We hypothesized that the bacteria within mucosal-associated biofilms may be different from the more superficial-lying, free-floating bacteria in the sinuses and that this may impact on the microbiome results obtained. This study investigates whether there is a significant difference in the microbiota of a sinonasal mucosal tissue sample versus a swab sample. Cross-sectional study with paired design. Mucosal biopsy and swab samples were obtained intra-operatively from the ethmoid sinuses of 6 patients with CRS. Extracted DNA was sequenced on a Roche-454 sequencer using 16S-rRNA gene targeted primers. Data were analyzed using QIIME 1.8 software package. At a maximum subsampling depth of 1,100 reads, the mean observed species richness was 33.3 species (30.6 for swab, versus 36 for mucosa; p > 0.05). There was no significant difference in phylogenetic and non-phylogenetic alpha diversity metrics (Faith's PD_Whole_Tree and Shannon's index) between the two sampling methods (p > 0.05). The type of sample also had no significant effect on phylogenetic and non-phylogenetic beta diversity metrics (Unifrac and Bray-Curtis; p > 0.05). We observed no significant difference between the microbiota of mucosal tissue and swab samples. This suggests that less invasive swab samples are representative of the sinonasal mucosa microbiome and can be used for future sinonasal microbiome studies.

  10. The Sino-Nasal Outcome Test 22 validated for Danish patients

    DEFF Research Database (Denmark)

    Lange, Bibi; Thilsing, Trine; Al-kalemji, Abir;

    2011-01-01

    Chronic rhinosinusitis (CRS) is a significant health problem whose incidence and prevalence is rising. It calls into attention consensus about diagnosing, assessing symptoms and treatment of patients with CRS. Therefore, a validated Danish measure of health-related quality of life in sinonasal...

  11. Cost-effectiveness assessment in outpatient sinonasal surgery.

    Science.gov (United States)

    Mortuaire, G; Theis, D; Fackeure, R; Chevalier, D; Gengler, I

    2017-09-15

    To assess the cost-effectiveness of outpatient sinonasal surgery in terms of clinical efficacy and control of expenses. A retrospective study was conducted from January 2014 to January 2016. Patients scheduled for outpatient sinonasal surgery were systematically included. Clinical data were extracted from surgical and anesthesiology computer files. The cost accounting methods applied in our institution were used to evaluate logistic and technical costs. The standardized hospital fees rating system based on hospital stay and severity in diagnosis-related groups (Groupes homogènes de séjours: GHS) was used to estimate institutional revenue. Over 2years, 927 outpatient surgical procedures were performed. The crossover rate to conventional hospital admission was 2.9%. In a day-1 telephone interview, 85% of patients were very satisfied with the procedure. All outpatient cases showed significantly lower costs than estimated for conventional management with overnight admission, while hospital revenue did not differ between the two. This study confirmed the efficacy of outpatient surgery in this indication. Lower costs could allow savings for the health system by readjusting the rating for the procedure. More precise assessment of cost-effectiveness will require more fine-grained studies based on micro costing at hospital level and assessment of impact on conventional surgical activity and post-discharge community care. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Building-related symptoms and inflammatory potency of dust from office buildings

    DEFF Research Database (Denmark)

    Allermann, Leila; Pejtersen, Jan; Gunnarsen, Lars Bo

    2007-01-01

    Abstract The aim was to investigate the association between building-related symptoms (BRS) in office buildings and the inflammatory potency of dust (PD). Furthermore, the association between dust potency and various building characteristics was investigated. Occupants of 22 office buildings...... linear part of the concentration- response curve. Symptoms of the central nervous system (CNS) were associated with the potency of surface dust (OR ¼ 1.4). This association may be due to an association between an index of CNS symptoms and dust potency in offices of 1-6 occupants (OR ¼ 1.5). No single...... symptoms correlated with the potency of surface dust. The PD was not related to single building factors. The inflammatory PD may be used as an integrated proxy measure of biologically active compounds in dust, reflecting health relevant properties of the dust....

  13. Sinonasal Delivery of Resveratrol via Mucoadhesive Nanostructured Microparticles in a Nasal Polyp Mouse Model

    Science.gov (United States)

    Lee, Mingyu; Park, Chun Gwon; Huh, Beom Kang; Kim, Se-Na; Lee, Seung Ho; Khalmuratova, Roza; Park, Jong-Wan; Shin, Hyun-Woo; Choy, Young Bin

    2017-01-01

    Resveratrol (RSV) has been shown to effectively suppress chronic rhinosinusitis with nasal polyps in a mouse model; however, when locally administered to the sinonasal cavity, bolus RSV is limited by low drug bioavailability owing to its low aqueous solubility and relatively rapid clearance from the administration site. To address this limitation, we propose mucoadhesive nanostructured microparticles (PLGA/PEG NM) as a potential carrier for the sinonasal delivery of RSV. In this study, PLGA/PEG NM released RSV in a sustained manner. Owing to the enlarged specific surface area of the nanostructures, PLGA/PEG NM had synergistically enhanced mucoadhesiveness and thus showed improved in vivo retention properties in the sinonasal cavity. Therefore, when tested in a mouse nasal polyp model, PLGA/PEG NM mitigated polyp formation and restored epithelial integrity better than the control treatments. The therapeutic effect was similar at half the dose of PLGA/PEG NM, suggesting improved local bioavailability of RSV in the sinonasal cavity. PMID:28071713

  14. Coal Mine Dust Desquamative Chronic Interstitial Pneumonia: A Precursor of Dust-Related Diffuse Fibrosis and of Emphysema

    Directory of Open Access Journals (Sweden)

    Tomislav M Jelic

    2017-07-01

    Full Text Available Background: Diseases associated with coal mine dust continue to affect coal miners. Elucidation of initial pathological changes as a precursor of coal dust-related diffuse fibrosis and emphysema, may have a role in treatment and prevention. Objective: To identify the precursor of dust-related diffuse fibrosis and emphysema. Methods: Birefringent silica/silicate particles were counted by standard microscope under polarized light in the alveolar macrophages and fibrous tissue in 25 consecutive autopsy cases of complicated coal worker's pneumoconiosis and in 21 patients with tobacco-related respiratory bronchiolitis. Results: Coal miners had 331 birefringent particles/high power field while smokers had 4 (p<0.001. Every coal miner had intra-alveolar macrophages with silica/silicate particles and interstitial fibrosis ranging from minimal to extreme. All coal miners, including those who never smoked, had emphysema. Fibrotic septa of centrilobular emphysema contained numerous silica/silicate particles while only a few were present in adjacent normal lung tissue. In coal miners who smoked, tobacco-associated interstitial fibrosis was replaced by fibrosis caused by silica/silicate particles. Conclusion: The presence of silica/silicate particles and anthracotic pigment-laden macrophages inside the alveoli with various degrees of interstitial fibrosis indicated a new disease: coal mine dust desquamative chronic interstitial pneumonia, a precursor of both dust-related diffuse fibrosis and emphysema. In studied coal miners, fibrosis caused by smoking is insignificant in comparison with fibrosis caused by silica/silicate particles. Counting birefringent particles in the macrophages from bronchioalveolar lavage may help detect coal mine dust desquamative chronic interstitial pneumonia, and may initiate early therapy and preventive measures.

  15. Infant with nasolacrimal sinonasal myxoma: Difusion MRI features

    Directory of Open Access Journals (Sweden)

    Teresa Gross Kelly, MD

    2015-01-01

    Full Text Available We report the imaging features of a rare sinonasal myxoma situated over the right nasolacrimal duct in a 5-month-old male. We emphasize the importance of including sinonasal myxomas in the list of differential diagnostic possibilities when encountering a nasolacrimal gland mass in an infant, and describe the CT and MRI characteristics of this rare entity.

  16. Primary Non-Hodgkin's Malignant Lymphoma of the Sinonasal Tract

    Directory of Open Access Journals (Sweden)

    Nitin Gupta

    2009-09-01

    Full Text Available Primary non-Hodgkin’s lymphomas (NHL of the sinonasal tract are rather uncommon entities. Morphologically and radiographically, sinonasal lymphomas are difficult to distinguish from other malignant neoplasms or non- neoplastic processes. They have a variable presentation from fulminant destructive manifestations to chronic indolent type of disease and may mimic as carcinomas and invasive fungal infection respectively. We report a case of primary NHL involving sinonasal tract in elderly female, which was clinically and radiologically mimicking as sinonasal malignany and was proven as NHL on histological examination and confirmed by immunohistochemistry. A high index of suspicion, appropriate histopathological examination and immunohistochemistry is necessary to differentiate sinonasal lymphomas from other possibilities. Failure to do so may miss the diagnosis and delay appropriate treatment

  17. Building-related symptoms and inflammatory potency of dust from office buildings

    DEFF Research Database (Denmark)

    Allermann, Leila; Pejtersen, Jan; Gunnarsen, Lars Bo

    2007-01-01

    Abstract The aim was to investigate the association between building-related symptoms (BRS) in office buildings and the inflammatory potency of dust (PD). Furthermore, the association between dust potency and various building characteristics was investigated. Occupants of 22 office buildings...... received a retrospective questionnaire about BRS (2301 respondents). Dust was collected from groups of offices and building characteristics were recorded. The potency of a dust sample to induce interleukin-8 (IL-8) secretion from the lung epithelial cell line A549 was measured as the slope of the initial...... linear part of the concentration- response curve. Symptoms of the central nervous system (CNS) were associated with the potency of surface dust (OR ¼ 1.4). This association may be due to an association between an index of CNS symptoms and dust potency in offices of 1-6 occupants (OR ¼ 1.5). No single...

  18. Building-related symptoms and inflammatory potency of dust from office buildings

    DEFF Research Database (Denmark)

    Allermann, L; Pejtersen, J; Gunnarsen, L

    2007-01-01

    UNLABELLED: The aim was to investigate the association between building-related symptoms (BRS) in office buildings and the inflammatory potency of dust (PD). Furthermore, the association between dust potency and various building characteristics was investigated. Occupants of 22 office buildings...... received a retrospective questionnaire about BRS (2301 respondents). Dust was collected from groups of offices and building characteristics were recorded. The potency of a dust sample to induce interleukin-8 (IL-8) secretion from the lung epithelial cell line A549 was measured as the slope of the initial...... linear part of the concentration-response curve. Symptoms of the central nervous system (CNS) were associated with the potency of surface dust (OR = 1.4). This association may be due to an association between an index of CNS symptoms and dust potency in offices of 1-6 occupants (OR = 1.5). No single...

  19. Phosphorus flame retardants in indoor dust and their relation to asthma and allergies of inhabitants.

    Science.gov (United States)

    Araki, A; Saito, I; Kanazawa, A; Morimoto, K; Nakayama, K; Shibata, E; Tanaka, M; Takigawa, T; Yoshimura, T; Chikara, H; Saijo, Y; Kishi, R

    2014-02-01

    Organophosphate esters are used as additives in flame retardants and plasticizers, and they are ubiquitous in the indoor environment. Phosphorus flame retardants (PFRs) are present in residential dust, but few epidemiological studies have assessed their impact on human health. We measured the levels of 11 PFRs in indoor floor dust and multi-surface dust in 182 single-family dwellings in Japan. We evaluated their correlations with asthma and allergies of the inhabitants. Tris(2-butoxyethyl) phosphate was detected in all samples (median value: 580 μg/g in floor dust, 111 μg/g in multi-surface dust). Tris(2-chloro-iso-propyl) phosphate (TCIPP) was detected at 8.69 μg/g in floor dust and 25.8 μg/g in multi-surface dust. After adjustment for potential confounders, significant associations were found between the prevalence of atopic dermatitis and the presence of TCIPP and tris(1,3-dichloro-2-propyl) phosphate in floor dust [per log10 -unit, odds ratio (OR): 2.43 and 1.84, respectively]. Tributyl phosphate was significantly associated with the prevalence of asthma (OR: 2.85 in floor dust, 5.34 in multi-surface dust) and allergic rhinitis (OR: 2.55 in multi-surface dust). PFR levels in Japan were high compared with values reported previously for Europe, Asia-Pacific, and the USA. Higher levels of PFRs in house dust were related to the inhabitants' health status. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Examination of Mechanisms Responsible for Organic Dust-related Diseases: Mediator Release induced by Microorgansims. A review

    DEFF Research Database (Denmark)

    Norn, Svend; Clementsen, Paul; Kristensen, K.S.;

    1994-01-01

    Farmakologi, org. dust-related diseases, bacteria, pathogenic mechanisms, mediator release, entoxins - fungal spores......Farmakologi, org. dust-related diseases, bacteria, pathogenic mechanisms, mediator release, entoxins - fungal spores...

  1. Sinonasal persistence of Pseudomonas aeruginosa after lung transplantation.

    Science.gov (United States)

    Mainz, J G; Hentschel, J; Schien, C; Cramer, N; Pfister, W; Beck, J F; Tümmler, B

    2012-03-01

    We report on two CF patients who received double lung transplantation (LTX) due to Pseudomonas aeruginosa related pulmonary destruction. Prior to LTX we detected P. aeruginosa in nasal lavages (NL) and sputum cultures from both patients. Donor lungs of patient 1 became colonized within four weeks with P. aeruginosa identical in genotype with isolates from his pre-transplant sputum cultures and pre- and post-transplant NL. In contrast, patient 2 remained P. aeruginosa free in lower airway samples (bronchial lavage/sputum) for now up to 30 months, despite persistent detection of P. aeruginosa that was identical in genotype with pre-transplant NL and sputum isolates in NL and even in throat swabs. For prevention of pulmonary re-colonization patient 2 has continuously inhaled Colomycin 1 MIU once daily during the preceding more than 36 months with the novel Pari Sinus™ nebulizer, which in scintigraphic studies was shown to deliver vibrating aerosols into paranasal sinuses, additional to bronchial antibiotic inhalation. Pulmonary colonization of transplanted donor lungs with identical clones previously colonizing the explanted lungs has been described previously and the upper airways were postulated as reservoir for descending colonization. However, this remained speculative, as upper airway sampling which does not belong to current standards, was not performed in these studies. Our report demonstrates persistence of identical P. aeruginosa genotypes in CF upper airways prior to and after LTX underlining risks of descending colonization of transplanted lungs with P. aeruginosa, which increases risks of graft dysfunction. Therefore, we recommend regular assessment of sinonasal colonization prior to and after LTX. Sinonasal inhalation with antimicrobials should be investigated in prospective trials. Copyright © 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  2. Benign Lesions in Mucosa Adjacent to Intestinal-Type Sinonasal Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Blanca Vivanco

    2011-01-01

    Full Text Available Occupational exposure to wood dust is a strong risk factor for the development of intestinal-type sinonasal adenocarcinoma (ITAC; however, knowledge on possible precursor lesions or biomarkers is limited. Fifty-one samples of tumor-adjacent mucosa and 19 control samples of mucosa from the unaffected fossa of ITAC patients were evaluated for histological changes and p53 protein expression. Mild dysplasia was observed in 14%, cuboidal metaplasia in 57%, intestinal metaplasia in 8%, squamous metaplasia in 24%, and cylindrocellular hyperplasia in 53% of cases. P53 immunopositivity was generally weak occurring most frequently in squamous metaplasia. Wood dust etiology did not appear of influence on the histological changes, but p53 showed a tendency for higher positivity. Dysplasia adjacent to tumor was indicative of subsequent development of recurrence. In conclusion, precursor lesions do occur in mucosa adjacent to ITAC. This is clinically important, because it may justify the screening of high-risk individuals such as woodworkers.

  3. Sinonasal epithelial-Myoepithelial carcinoma-A rare entity

    OpenAIRE

    Pradhan, Sultan A.; Khannan, Rajan; Hazarika, Biswajyoti; Desai, Meena

    2007-01-01

    Epithelial-myoepithelial carcinoma is a rare salivary gland tumor. It comprises less than 1% of all salivary gland tumors. It generally arises from the parotid gland. Unusual sites of occurrence include sinonasal tract, lung, trachea, lacrimal gland and breast. Histopathologically epithelial-myoepithelial carcinoma comprises a dual population of ductal and myoepithelial cells. We report an extremely rare case of epithelial-myoepithelial carcinoma occurring in the sinonasal tract of young man.

  4. An Empirical Relation between Sodium Absorption and Dust Extinction

    OpenAIRE

    Poznanski, Dovi; Prochaska, J. Xavier; Bloom, Joshua S.

    2012-01-01

    Dust extinction and reddening are ubiquitous in astronomical observations and are often a major source of systematic uncertainty. We present here a study of the correlation between extinction in the Milky Way and the equivalent width of the NaI D absorption doublet. Our sample includes more than 100 high resolution spectra from the KECK telescopes and nearly a million low resolution spectra from the Sloan Digital Sky Survey (SDSS). We measure the correlation to unprecedented precision, constr...

  5. Physical activity in people with asbestos related pleural disease and dust-related interstitial lung disease: An observational study.

    Science.gov (United States)

    Dale, Marita T; McKeough, Zoe J; Munoz, Phillip A; Corte, Peter; Bye, Peter T P; Alison, Jennifer A

    2015-11-01

    This study aimed to measure the levels of physical activity (PA) in people with dust-related pleural and interstitial lung diseases and to compare these levels of PA to a healthy population. There is limited data on PA in this patient population and no previous studies have compared PA in people with dust-related respiratory diseases to a healthy control group. Participants with a diagnosis of a dust-related respiratory disease including asbestosis and asbestos related pleural disease (ARPD) and a healthy age- and gender-matched population wore the SenseWear(®) Pro3 armband for 9 days. Six-minute walk distance, Medical Outcomes Study 36-item short-form health survey and the Hospital Anxiety and Depression Scale were also measured. Fifty participants were recruited and 46 completed the study; 22 with ARPD, 10 with dust-related interstitial lung disease (ILD) and 14 healthy age-matched participants. The mean (standard deviation) steps/day were 6097 (1939) steps/day for dust-related ILD, 9150 (3392) steps/day for ARPD and 10,630 (3465) steps/day for healthy participants. Compared with the healthy participants, dust-related ILD participants were significantly less active as measured by steps/day ((mean difference 4533 steps/day (95% confidence interval (CI): 1888-7178)) and energy expenditure, ((mean difference 512 calories (95% CI: 196-827)) and spent significantly less time engaging in moderate, vigorous or very vigorous activities (i.e. >3 metabolic equivalents; mean difference 1.2 hours/day (95% CI: 0.4-2.0)). There were no differences in levels of PA between healthy participants and those with ARPD. PA was reduced in people with dust-related ILD but not those with ARPD when compared with healthy age and gender-matched individuals.

  6. Evaluation of variations in sinonasal region with computed tomography

    Institute of Scientific and Technical Information of China (English)

    Ufuk Dasar; Erkan Gokce

    2016-01-01

    AIM: To investigate the frequency of anatomical variations in sinonasal region and association of these variations with mucosal diseases. METHODS: The study included 400 cases(191 female and 209 male) who were considered to have preliminary diagnoses of sinonasal pathology and who had paranasal sinus computed tomography(CT) examination in axial plane. Reformatted CT images were studied in all planes.RESULTS: Age range of the patients was 20-83(mean 40.26 ± 14.85). Most commonly detected anatomical variation was Agger nasi cell(74.8%). There was a significant association between clinoid process pneumatization and protrusion of internal carotid arteries and optic nerves into sphenoid sinus(P < 0.001). Besides,the relationships between pterygoid process pneumatization and protrusion of vidian nerve into sphenoid sinus,and between pneumatization of large sphenoid wing and protrusion of maxillary nerves into sphenoid sinus were also significant(P < 0.001). Uncinate bulla and giant ethmoid bulla were found to be significantly associated with sinonasal mucosal diseases(P = 0.004 and P = 0.002,respectively).CONCLUSION: Sinonasal region has a great number of variations,and some of them have been determined to be associated with sinonasal mucosal disease. It is necessary to know that some of these variations are associated with protrusion of significant structures such as carotid artery or optic nerve into the sinus and care should be observed in surgeries on patients carrying these variations.

  7. Herschel-ATLAS: Revealing dust build-up and decline across gas, dust and stellar mass selected samples: I. Scaling relations

    CERN Document Server

    De Vis, P; Maddox, S; Gomez, H L; Clark, C J R; Bauer, A E; Viaene, S; Schofield, S P; Baes, M; Baker, A J; Bourne, N; Driver, S P; Dye, S; Eales, S A; Furlanetto, C; Ivison, R J; Robotham, A S G; Rowlands, K; Smith, D J B; Smith, M W L; Valiante, E; Wright, A H

    2016-01-01

    We present a study of the dust, stars and atomic gas (HI) in an HI-selected sample of local galaxies (z80 per cent), low stellar mass sources that appear to be in the earliest stages of their evolution. We compare this sample with dust and stellar mass selected samples to study the dust and gas scaling relations over a wide range of gas fraction (proxy for evolutionary state of a galaxy). The most robust scaling relations for gas and dust are those linked to NUV-r (SSFR) and gas fraction, these do not depend on sample selection or environment. At the highest gas fractions, our additional sample shows the dust content is well below expectations from extrapolating scaling relations for more evolved sources, and dust is not a good tracer of the gas content. The specific dust mass for local galaxies peaks at a gas fraction of ~75 per cent. The atomic gas depletion time is also longer for high gas fraction galaxies, opposite to the trend found for molecular gas depletion timescale. We link this trend to the changi...

  8. Chapter 1: Sinonasal anatomy and function.

    Science.gov (United States)

    Dalgorf, Dustin M; Harvey, Richard J

    2013-01-01

    An understanding of paranasal sinus anatomy based on important fixed landmarks rather than variable anatomy is critical to ensure safe and complete surgery. The concept of the paranasal surgical box defines the anatomic limits of dissection. The boundaries of the surgical box include the middle turbinate medially, orbital wall laterally, and skull base superiorly. The "vertical component" of the surgical box defines the boundaries of the frontal recess and includes the middle turbinate and intersinus septum medially, medial orbital wall and orbital roof laterally, nasofrontal beak anteriorly, and skull base and posterior table of frontal sinus posteriorly. The paranasal sinuses are divided into anterior, posterior, and sphenoidal functional cavities based on their distinct drainage pathways into the nose. The ultimate goal of surgery is to create a functional sinus cavity. Application of the paranasal surgical box and its vertical component enables the surgeon to view the limits of dissection with a single position of the endoscope. This will ensure complete dissection of the functional sinonasal compartments and effectively avoid leaving behind disconnected cells from the surgical cavity, mucocele formation, mucous recirculation, overcome obstructive phenomenon and enable maximal delivery of topical therapy in the post-operative setting. This article reviews the structure and function of the nasal cartilages and turbinates. It also describes the concept of the paranasal surgical box, key anatomical landmarks and limits of dissection. Normal anatomy and common variants of normal anatomy are discussed.

  9. Occupational risks of sinonasal cancer in Denmark.

    Science.gov (United States)

    Olsen, J H

    1988-05-01

    A new comprehensive data linkage system for the detailed investigation of occupational cancer has been established in the Danish Cancer Registry, providing employment histories back to 1964. All 382 cases of cancers of the sinonasal cavities diagnosed between 1970 and 1984 and kept on file in this data linkage system were analysed using standardised proportional incidence ratios (SPIR) to screen for industrial high risk areas for these malignancies in Denmark. Excess risks were confirmed among men and women employed in the manufacture of footwear and other leather products and of wooden furniture. No risk significantly above expectancy was observed among wood workers outside the furniture making industry. Excess risks were also seen among men in all areas of basic metal industries (SPIR = 184-562) and in a subset of workers in industries producing metal containers (SPIR = 329-600). Most unexpected were raised risks among employees of both sexes in making cocoa, chocolate, and sugar confectionery (SPIR = 535 for men and 860 for women); these, in combination with the observed risks among female employees in canning and preserving fruits and vegetables (SPIR = 778) and in farming (SPIR = 735) may point to a common aetiology. The obscuring effect of mass significance may, however, be another explanation. The new associations discovered in this large scale linkage study must therefore await further confirmation.

  10. Phthalates, non-phthalate plasticizers and bisphenols in Swedish preschool dust in relation to children's exposure.

    Science.gov (United States)

    Larsson, Kristin; Lindh, Christian H; Jönsson, Bo Ag; Giovanoulis, Georgios; Bibi, Momina; Bottai, Matteo; Bergström, Anna; Berglund, Marika

    2017-03-05

    Children are exposed to a wide range of chemicals in their everyday environments, including the preschool. In this study, we evaluated the levels of phthalates, non-phthalate plasticizers and bisphenols in dust from 100 Swedish preschools and identified important exposure factors in the indoor environment. In addition, children's total exposure to these chemicals was determined by urine analysis to investigate their relation with dust exposure, and to explore the time trends by comparing with children who provided urine fifteen years earlier. The most abundant plasticizers in preschool dust were the phthalates di-isononyl phthalate (DiNP) and di-(2-ethylhexyl) phthalate (DEHP) with geometric mean levels of 450 and 266μg/g dust, respectively, and the non-phthalate plasticizers bis(2-ethylhexyl) terephthalate (DEHT) and diisononylcyclohexane-1,2-dicarboxylate (DiNCH) found at 105 and 73μg/g dust, respectively. The levels of several substitute plasticizers were higher in newer preschools, whereas the levels of the strictly regulated phthalate di-n-butyl phthalate (DnBP) were higher in older preschools. The presence of foam mattresses and PVC flooring in the sampling room were associated with higher levels of DiNP in dust. Children's exposure from preschool dust ingestion was below established health based reference values and the estimated exposure to different phthalates and BPA via preschool dust ingestion accounted for 2-27% of the total exposure. We found significantly lower urinary levels of BPA and metabolites of strictly regulated phthalates, but higher levels of DiNP metabolites, in urine from the children in this study compared to the children who provided urine samples fifteen years earlier.

  11. Morganella morganii in sinonasal region: A rare case report

    Directory of Open Access Journals (Sweden)

    Haşmet Yazıcı

    2013-09-01

    Full Text Available Morganella morganii is a gram negative pathogen andmay cause potentially lethal disease especially in patientswith underlying or immunosuppressive disease. It is commonlyfound in long-term urinary catheter used and immunesystem deficiency patients as nosocomial disease.Involving other systems such as skin, skeletal systemand central nervous system can be seen too. Sporadicoccurrence is rare and can be seen in any system by variouscauses like AIDS, snake bites and poisoning. In thiscase we present sporadic Morganella morganii infectionon sinonasal region with the presence of sinusitis, sinocutaneousfistula, preseptal cellulitis and hard palate defecton 58 year old male diabetic patient. Microbiologicalassessment from open wound and sinuses were reportedas Morganella morganii. To our knowledge, this is the firstcase of sino-nasal Morganella morganii infection with sino-cutaneous fistula, preseptal cellulitis and maxillofacialbone destruction. J Clin Exp Invest 2013; 4 (3: 383-386Key words: Morganella Morganii, sino-nasal fistula, preseptalcellulitis, bone destruction

  12. Tilted Bianchi type I dust fluid cosmological model in general relativity

    Indian Academy of Sciences (India)

    Raj Bali; Keshav Sharma

    2002-03-01

    In this paper, we have investigated a tilted Bianchi type I cosmological model filled with dust of perfect fluid in general relativity. To get a determinate solution, we have assumed a condition = between metric potentials. The physical and geometrical aspects of the model together with singularity in the model are also discussed.

  13. Sinonasal carcinoma presenting as chronic sinusitis and sequential bilateral visual loss

    Directory of Open Access Journals (Sweden)

    Wei-Yu Chiang

    2015-01-01

    Full Text Available Sinonasal undifferentiated carcinoma-related rhinogenic optic neuropathy is rare and may lead to visual loss. To the best of our knowledge, this is the first report of bilateral sequential visual loss induced by this etiology. It is important to differentiate between chronic sinusitis and malignancy on the basis of specific findings on magnetic resonance images. Surgical decompression with multidisciplinary therapy, including steroids, chemotherapy, and radiotherapy, is indicated. However, no visual improvement was noted in this case, emphasizing the rapid disease progression and importance of early diagnosis and treatment.

  14. Cement dust exposure-related emphysema in a construction worker

    Directory of Open Access Journals (Sweden)

    V Karkhanis

    2011-01-01

    Full Text Available Although, smoking is considered the most important predisposing factor in development of emphysema; environmental exposures also play an important role. There have been several studies on work related respiratory symptoms and ventilatory disorders among employees of cement industry. We report a case of cement exposure related emphysema in 75 years old woman construction worker.

  15. SINONASAL MASSES: A CLINICO PATHOLOGICAL STUDY AT TERTIARY CARE CENTRE

    Directory of Open Access Journals (Sweden)

    Manish Kumar

    2014-07-01

    Full Text Available AIMS: To study the demography of sinonasal masses, clinical presentation, histopathological pattern and to correlate clinical findings with histopathology. MATERIALS AND METHODS: The present study entitled "Clinico pathological study of sinonasal masses" was carried out in 100 patients who attended the ENT OPD and inpatients in the Department of Otorhinolaryngology and Head and Neck Surgery, Gajra Raja Medical College, Gwalior (M.P. and associated with J.A. Group of Hospitals, Gwalior (M.P. during the period of July 2011 to June 2013 who were diagnosed as cases of sinonasal masses on the basis of clinical and histopathological examination. RESULTS: 32% patients were in age group 15-24 years, 64% were males. Most significant complaints were nasal obstruction and rhinorrhoea. Among 100 patients, nasal polyps were diagnosed in 83 patients, angiofibroma in 7 patients, septal angioma in 2 patients, rhinosporidiosis in 2 patients and one case each of capillary haemangioma, squamous cell carcinoma, angiosarcoma, transitional cell carcinoma and nasopharyngeal carcinoma was present. CONCLUSION: In the present study of masses in sinonasal cavity, most of the patients presented with trivial nasal symptoms, and there is always a possibility to miss the diagnosis if great care is not taken while examining the patient. The findings must be interpreted in light of great clinical suspicion, and complete ENT examination including radiologic and endoscopic studies.

  16. SMARCB1 (INI-1)-deficient carcinomas of the sinonasal tract.

    Science.gov (United States)

    Bishop, Justin A; Antonescu, Cristina R; Westra, William H

    2014-09-01

    SMARCB1 (INI-1) is a tumor-suppressor gene located on chromosome 22q11.2. Its gene product is ubiquitously expressed in nuclei of all normal tissues. SMARCB1 gene inactivation has been implicated in the pathogenesis of a diverse group of malignant neoplasms that tend to share "rhabdoid" cytomorphology. This group of SMARCB1-deficient tumors is now further expanded by a subset of carcinomas arising in the sinonasal tract. SMARCB1 immunostaining was performed on 142 sinonasal carcinomas. Tumors that showed loss of expression were further characterized for SMARCB1 deletions by fluorescence in situ hybridization. Nine of 142 (6%) primary sinonasal carcinomas showed loss of SMARCB1 expression by immunohistochemistry. Five patients were women, and patients ranged in age from 33 to 78 years (mean 59 y). The SMARCB1-deficient tumors were characterized by nests, sheets, and cords of cells without any histologic evidence of specific (eg, squamous or glandular) differentiation. The tumors comprised varying proportions of basaloid and rhabdoid cells. The SMARCB1-deficient carcinomas had been diagnosed as nonkeratinizing squamous cell carcinomas (n=3), sinonasal undifferentiated carcinomas (n=2), myoepithelial carcinoma (n=2), nonintestinal adenocarcinoma (n=1), and carcinoma, not otherwise specified (n=1). Fluorescence in situ hybridization analysis revealed SMARCB1 deletions in 6 of 8 (75%) carcinomas. The SMARCB1-deficient carcinomas did not harbor human papillomavirus or NUT-1 alterations. Six patients presented with T4 disease, 5 patients developed local recurrences and/or distant metastases, and 4 died of their disease. Inactivation of the SMARCB1 tumor-suppressor gene appears to be involved in the pathogenesis of a subset of sinonasal carcinomas, further expanding the family of SMARCB1-deficient neoplasms and further delineating a bewildering group of poorly/undifferentiated, aggressive carcinomas arising at this site. The ability to detect SMARCB1 loss by

  17. Comparison of Sinonasal Symptoms in Patients with Nasal Septal Deviation and Patients with Chronic Rhinosinusitis

    Directory of Open Access Journals (Sweden)

    Mohammad Naeimi

    2013-01-01

    Full Text Available Introduction: Disorders of the nose and paranasal sinuses are among the most common chronic illnesses. Although considerable progress has been made in the medical and surgical control of these diseases, a large number of questions relating to the diagnosis, evaluation, and treatment of these conditions remain unanswered. The aim of the present study was to evaluate differences in the frequency of symptoms and disease severity in patients with nasal septal deviation (NSD compared with chronic rhinosinusitis (CRS.  Materials and Methods: A total of 156 patients, divided into NSD and CRS groups, were studied in relation to symptoms and disease severity. Patients were selected from those referred to the Ear, Nose, and Throat (ENT Wards of the Imam Reza and Ghaem Hospitals, who had not responded to a variety of treatments. Depending on the type of disease, patients were candidates for either septoplasty or endoscopic sinus surgery. The Rhinosinusitis Symptom Inventory was administered to measure the severity of symptoms, with scores assigned based on the answers given by patients (Likert scale.  Scores were compared between the CRS and NSD groups.  Results: A total of 156 patients (78 with NDS and 78 with CRS entered the study in overall sinonasal symptoms were more prevalent in CRS group. Nasal congestion, runny nose, earache, toothache, and smelling disorder were significantly more common in the CRS group (P0.05.  Conclusion:  Patients with CRS manifested statistically significantly greater sinonasal symptom scores than patients with NSD.

  18. Obscuration in active galactic nuclei: near-infrared luminosity relations and dust colors

    Science.gov (United States)

    Burtscher, L.; Orban de Xivry, G.; Davies, R. I.; Janssen, A.; Lutz, D.; Rosario, D.; Contursi, A.; Genzel, R.; Graciá-Carpio, J.; Lin, M.-Y.; Schnorr-Müller, A.; Sternberg, A.; Sturm, E.; Tacconi, L.

    2015-06-01

    We combine two approaches to isolate the AGN luminosity at near-IR wavelengths and relate the near-IR pure AGN luminosity to other tracers of the AGN. Using integral-field spectroscopic data of an archival sample of 51 local AGNs, we estimate the fraction of non-stellar light by comparing the nuclear equivalent width of the stellar 2.3 μm CO absorption feature with the intrinsic value for each galaxy. We compare this fraction to that derived from a spectral decomposition of the integrated light in the central arcsecond and find them to be consistent with each other. Using our estimates of the near-IR AGN light, we find a strong correlation with presumably isotropic AGN tracers. We show that a significant offset exists between type 1 and type 2 sources in the sense that type 1 sources are 7 (10) times brighter in the near-IR at log lmir{} = 42.5 (log lx{} = 42.5). These offsets only become clear when treating infrared type 1 sources as type 1 AGNs. All AGNs have very red near- to mid-IR dust colors. This, as well as the range of observed near-IR temperatures, can be explained with a simple model with only two free parameters: the obscuration to the hot dust and the ratio between the warm and hot dust areas. We find obscurations of AV^hot = 5 ldots 15 mag for infrared type 1 sources and AV^hot = 15 ldots 35 mag for type 2 sources. The ratio of hot dust to warm dust areas of about 1000 is nicely consistent with the ratio of radii of the respective regions as found by infrared interferometry.

  19. Dermatophytes, related keratinophilic and opportunistic fungi in indoor dust of houses and hospitals

    OpenAIRE

    Singh I; Mishra A; Kushwaha RKS

    2009-01-01

    Dermatophytes, related keratinophilic and opportunistic fungi were isolated from indoor dust samples of 46 hospitals and 47 houses in Kanpur. A total of 19 fungi represented by 11 genera were isolated by the hair-baiting technique from 230 and 235 samples from hospitals and houses respectively. The isolated fungi are Acremonium implicatum (Indian Type Culture Collection) ITCC 5266 , A. strictum (Germplasm Centre for Keratinophilic Fungi) GPCK 1137 , Aphanoascus fulvescens GPCK 1081 , ...

  20. Effects of wood dust:Inflammation, Genotoxicity and Cancer

    DEFF Research Database (Denmark)

    Lange, Jette Bornholdt

    cell line A549 measuring inflammatory and DNA damaging effects. The second part consists of a molecular analysis of the K-ras gene for mutations in the hotspots codons in human sinonasal cancers. Design, calibration and validation of the assays were performed. Cancer at the sinonasal cavities is rare......-malignant symptoms are still poorly understood. Particulate induced inflammation as well as extractives are suggested to be involved in the carcinogenesis. In this thesis wood dust potential to induce DNA damage and inflammation was investigated exposing the human lung epithelial cell line A549 to various species...... of wood dust and endpoints for inflammation and genotoxicity was evaluated. The experiments showed that the different species of wood dust vary in their ability to cause DNA strand breaks and inflammation. There was no apparent correlation between the species potential to initiate inflammation...

  1. A case of giant prolactinoma, initially misdiagnosed as sinonasal neuroendocrine carcinoma

    Directory of Open Access Journals (Sweden)

    Yasaman Mohtasebi, M.D.

    2015-09-01

    Full Text Available Giant prolactinomas are defined as pituitary tumors greater than 4 cm, often associated with very high prolactin level (>1000 ng/mL. They are relatively rare tumors and can present differently from typical prolactinomas. They can be highly invasive, resulting in acute neurological complication at the time of presentation. We present a case of a young woman with giant prolactinoma initially misdiagnosed as sinonasal neuroendocrine carcinoma. The acute presentation of headache, ptosis and impending brain herniation, requiring emergent ventriculostomy and intubation, led to the clinical suspicion of a more sinister diagnosis. Transnasal biopsy of the mass was consistent with sinonasal neuroendocrine carcinoma, and chemotherapy was planned. Laboratory testing, however, revealed an elevated prolactin (27,400 ng/mL, after 1:100 dilution. Re-review of pathology with additional immunohistochemical staining was requested and confirmed the diagnosis of prolactinoma. After 5 months of cabergoline treatment, prolactin level has decreased to 118 ng/mL. There has been a marked reduction in tumor size and an almost complete resolution of neurological symptoms. Given their atypical presentation and potential for sharing common immunohistochemical stains with other neuroendocrine neoplasms, giant prolactinomas extending into the nasal cavity can be misdiagnosed as other neuroendocrine neoplasms which may develop at this site. Accurate diagnosis is imperative to prevent unnecessary surgery and/or radiation and to ensure implementation of dopamine agonist therapy.

  2. Transitional cell carcinoma of the sinonasal tract: A rare entity

    Directory of Open Access Journals (Sweden)

    Madhumita Mondal

    2015-01-01

    Full Text Available Malignant sinonasal carcinomas are a rare entity comprising less than 1% of all cancers and around 3% of all head and neck malignancies seen in humans. Among these 15-20% are transitional cell carcinoma also known as non keratinizing carcinoma of sinonasal tract. We are reporting the case of a 45 years female with history of nasal obstruction and epistaxis. A contrast enhanced computed tomography (CECT was done which showed mucosal thickening in the right nasal cavity. Endoscopy assisted biopsy was taken which revealed non keratinizing carcinoma (transitional type. Very few reported cases of this type of malignancy was found. A possible reason could be multiple synonyms like cylindrical cell carcinoma, Schneiderian carcinoma and transitional cell carcinoma.

  3. The orbital and sinonasal hemangiopericytoma, 2 case reports:

    Directory of Open Access Journals (Sweden)

    Maryam Maghbol

    2016-03-01

    Full Text Available Background & objective: Hemangiopericytoma is an uncommon vascular tumor derived from the pericytes of Zimmermann. . The most common location of the tumor is pelvic retroperitoneum and musculoskeletal system of the lower extremities. It is rarely seen in the head and neck area. In addition, only 0.8% to 3% of all orbital tumors and less than 5 % of primary sinonasal tumors are primary hemangiopericytoma, which demonstrates that the orbital and sinonasal cavities are rare locations for this tumor. Case: 2 cases of primary orbital and sinonasal hemangiopericytoma that were successfully treated through surgery were reported. Conclusion: Hemangiopericytoma is an uncommon vascular tumor which has a potentially malignant behavior. Histopathologic features alone do not predict the biologic behavior of the tumor but the increased cellularity, necrosis, hemorrhage and more than 4 mitotic figures per 10 high power field, may elicit a diagnosis of malignant hemangiopericytoma . The local recurrence and the distant metastasis might also occur with an incomplete excision.  The lung, bone and liver are the most common sites of distant metastasis. Thus, the long-term follow-up is recommended after the surgical removal of the tumor.

  4. Neoadjuvant Chemotherapy in Locally Advanced and Borderline Resectable Nonsquamous Sinonasal Tumors (Esthesioneuroblastoma and Sinonasal Tumor with Neuroendocrine Differentiation

    Directory of Open Access Journals (Sweden)

    Vijay M. Patil

    2016-01-01

    Full Text Available Introduction. Sinonasal tumors are chemotherapy responsive which frequently present in advanced stages making NACT a promising option for improving resection and local control in borderline resectable and locally advanced tumours. Here we reviewed the results of 25 such cases treated with NACT. Materials and Methods. Sinonasal tumor patients treated with NACT were selected for this analysis. These patients received NACT with platinum and etoposide for 2 cycles. Patients who responded and were amenable for gross total resection underwent surgical resection and adjuvant CTRT. Those who responded but were not amenable for resection received radical CTRT. Patients who progressed on NACT received either radical CTRT or palliative radiotherapy. Results. The median age of the cohort was 42 years (IQR 37–47 years. Grades 3-4 toxicity with NACT were seen in 19 patients (76%. The response rate to NACT was 80%. Post-NACT surgery was done in 12 (48% patients and radical chemoradiation in 9 (36% patients. The 2-year progression free survival and overall survival were 75% and 78.5%, respectively. Conclusion. NACT in sinonasal tumours has a response rate of 80%. The protocol of NACT followed by local treatment is associated with improvement in outcomes as compared to our historical cohort.

  5. Inhaled dust and disease

    Energy Technology Data Exchange (ETDEWEB)

    Holt, P.F.

    1987-01-01

    This book discusses the following: the respiratory system; respirable dust; the fate of inhaled dust; translocation and some general effects of inhaled dust; silicosis; experimental research on silica-related disease; natural fibrous silicates; asbestos dust levels and dust sources; asbestos-related diseases - asbestosis, lung cancer, mesothelioma and other diseases, cancers at sites other than lung and pleura; experimental research relating to asbestos-related diseases; asbestos hazard - mineral types and hazardous occupations, neighbourhood and domestic hazard; silicates other than asbestos-man-made mineral fibres, mineral silicates and cement; metals; coal mine dust, industrial carbon and arsenic; natural and synthetic organic substances; dusts that provoke allergic alveolitis; tobacco smoke.

  6. Intestinal-type sinonasal adenocarcinoma with bone metastasis: a case report

    Institute of Scientific and Technical Information of China (English)

    Akhavan A.; Binesh F.; Teimoori S.; Soltani H.R.

    2011-01-01

    Intestinal type adenocarcinoma is a slow growing tumor of sinonasal area, that account for 4% of malignancies of this area. In women it occurs sporadically. This tumor rarely metastasis to other organs. In this article we presented a woman with sinonasal intestinal type adenocarcinoma with optic nerve involvement and multiple bone metastasis.

  7. [Biological effect of wood dust].

    Science.gov (United States)

    Maciejewska, A; Wojtczak, J; Bielichowska-Cybula, G; Domańska, A; Dutkiewicz, J; Mołocznik, A

    1993-01-01

    The biological effect of exposure to wood dust depends on its composition and the content of microorganisms which are an inherent element of the dust. The irritant and allergic effects of wood dust have been recognised for a long time. The allergic effect is caused by the wood dust of subtropical trees, e.g. western red cedar (Thuja plicata), redwood (Sequoia sempervirens), obeche (Triplochiton scleroxylon), cocabolla (Dalbergia retusa) and others. Trees growing in the European climate such as: larch (Larix), walnut (Juglans regia), oak (Quercus), beech (Fagus), pine (Pinus) cause a little less pronounced allergic effect. Occupational exposure to irritative or allergic wood dust may lead to bronchial asthma, rhinitis, alveolitis allergica, DDTS (Organic dust toxic syndrome), bronchitis, allergic dermatitis, conjunctivitis. An increased risk of adenocarcinoma of the sinonasal cavity is an important and serious problem associated with occupational exposure to wood dust. Adenocarcinoma constitutes about half of the total number of cancers induced by wood dust. An increased incidence of the squamous cell cancers can also be observed. The highest risk of cancer applies to workers of the furniture industry, particularly those dealing with machine wood processing, cabinet making and carpentry. The cancer of the upper respiratory tract develops after exposure to many kinds of wood dust. However, the wood dust of oak and beech seems to be most carcinogenic. It is assumed that exposure to wood dust can cause an increased incidence of other cancers, especially lung cancer and Hodgkin's disease. The adverse effects of microorganisms, mainly mould fungi and their metabolic products are manifested by alveolitis allergica and ODTS. These microorganisms can induce aspergillomycosis, bronchial asthma, rhinitis and allergic dermatitis.

  8. The relation between gas and dust in the Taurus Molecular Cloud

    CERN Document Server

    Pineda, Jorge L; Chapman, Nicholas; Snell, Ronald L; Li, Di; Cambresy, Laurent; Brunt, Chris

    2010-01-01

    (abridged) We report a study of the relation between dust and gas over a 100deg^2 area in the Taurus molecular cloud. We compare the H2 column density derived from dust extinction with the CO column density derived from the 12CO and 13CO J= 1-0 lines. We derive the visual extinction from reddening determined from 2MASS data. The comparison is done at an angular size of 200", corresponding to 0.14pc at a distance of 140pc. We find that the relation between visual extinction Av and N(CO) is linear between Av~3 and 10 mag in the region associated with the B213--L1495 filament. In other regions the linear relation is flattened for Av > 4 mag. We find that the presence of temperature gradients in the molecular gas affects the determination of N(CO) by ~30--70% with the largest difference occurring at large column densities. Adding a correction for this effect and accounting for the observed relation between the column density of CO and CO2 ices and Av, we find a linear relationship between the column of carbon mon...

  9. Gyromagnetic factor of rotating disks of electrically charged dust in general relativity

    Science.gov (United States)

    Liu Pynn, Yu-Chun; Macedo, Rodrigo Panosso; Breithaupt, Martin; Palenta, Stefan; Meinel, Reinhard

    2016-11-01

    We calculated the dimensionless gyromagnetic ratio ("g -factor") of self-gravitating, uniformly rotating disks of dust with a constant specific charge ɛ . These disk solutions to the Einstein-Maxwell equations depend on ɛ and a "relativity parameter" γ (0 <γ ≤1 ) up to a scaling parameter. Accordingly, the g -factor is a function g =g (γ ,ɛ ). The Newtonian limit is characterized by γ ≪1 , whereas γ →1 leads to a black-hole limit. The g -factor, for all ɛ , approaches the values g =1 as γ →0 and g =2 as γ →1 .

  10. Gyromagnetic factor of rotating disks of electrically charged dust in general relativity

    CERN Document Server

    Pynn, Yu-Chun; Breithaupt, Martin; Palenta, Stefan; Meinel, Reinhard

    2016-01-01

    We calculated the dimensionless gyromagnetic ratio ("$g$-factor") of self-gravitating, uniformly rotating disks of dust with a constant specific charge $\\epsilon$. These disk solutions to the Einstein-Maxwell equations depend on $\\epsilon$ and a "relativity parameter" $\\gamma$ ($0<\\gamma\\le 1$) up to a scaling parameter. Accordingly, the $g$-factor is a function $g=g(\\gamma,\\epsilon)$. The Newtonian limit is characterized by $\\gamma \\ll 1$, whereas $\\gamma\\to 1$ leads to a black-hole limit. The $g$-factor, for all $\\epsilon$, approaches the values $g=1$ as $\\gamma\\to 0$ and $g=2$ as $\\gamma\\to 1$.

  11. A study on indoor environment contaminants related to dust mite in dwellings of allergic asthma patients and of healthy subjects.

    Science.gov (United States)

    Feng, M; Yang, B; Zhuang, Y J; Yanagi, U; Cheng, X J

    2012-02-01

    This study investigated the pollution of dust mite allergens in the houses of 30 families and their infection to young allergic asthma patients in Shanghai. Medical records, family information, and dust samples were collected from the dwellings of 15 young allergic asthma patients and 15 healthy subjects. Der 1 allergen, which is a common allergen causing allergic asthma, was measured in collected dust samples using the Pharmacia Uni-CAP System. A significant correlation was found between the number of Der 1 allergens collected from floor surfaces and the number of Der 1 allergens collected from bed surfaces. Some factors influencing Der 1 allergen levels were found in this study. Relative humidity in dwellings was found to be most influential to the allergen levels. The findings suggested that traditional reduction methods for coarse particles, such as opening windows and periodic cleaning of beddings, may be effective in removing dust mite allergens.

  12. Dermatophytes, related keratinophilic and opportunistic fungi in indoor dust of houses and hospitals

    Directory of Open Access Journals (Sweden)

    Singh I

    2009-01-01

    Full Text Available Dermatophytes, related keratinophilic and opportunistic fungi were isolated from indoor dust samples of 46 hospitals and 47 houses in Kanpur. A total of 19 fungi represented by 11 genera were isolated by the hair-baiting technique from 230 and 235 samples from hospitals and houses respectively. The isolated fungi are Acremonium implicatum (Indian Type Culture Collection ITCC 5266 , A. strictum (Germplasm Centre for Keratinophilic Fungi GPCK 1137 , Aphanoascus fulvescens GPCK 1081 , Arthroderma simii GPCK 1275 , Chrysosporium queenslandicum ITCC 5270 , C. indicum ITCC 5269 , C. pannicola GPCK 1022 , C. tropicum GPCK 1269 , Ctenomyces serratus ITCC 5267 , Gymnoascus reessii ITCC 5265 , Malbranchea fulva GPCK 1075 , Malbranchea pulchella ITCC 5268 , Micosporum gypseum GPCK 1038 , Microsporum cookei GPCK 2001, M. fulvum GPCK 2002 , Paecilomyces lilacinum GPCK 1080 , Penicillium expansum GPCK 1082, Trichophyton mentagrophytes GPCK 2003 and T. terrestre GPCK 2004. In hospitals, the minimum frequency was of Ctenomyces serratus ITCC 5267 while the maximum frequency was of Arthroderma simii GPCK 1275 . In houses, Chrysosporium queenslandicum ITCC 5270 and C. tropicum GPCK 1269 were with minimum and maximum frequencies respectively. This makes the first report of these fungi with keratinolytic ability in the indoor dust of hospitals and houses.

  13. Dermatophytes, related keratinophilic and opportunistic fungi in indoor dust of houses and hospitals.

    Science.gov (United States)

    Singh, I; Mishra, A; Kushwaha, Rks

    2009-01-01

    Dermatophytes, related keratinophilic and opportunistic fungi were isolated from indoor dust samples of 46 hospitals and 47 houses in Kanpur. A total of 19 fungi represented by 11 genera were isolated by the hair-baiting technique from 230 and 235 samples from hospitals and houses respectively. The isolated fungi are Acremonium implicatum (Indian Type Culture Collection) ITCC 5266, A. strictum (Germplasm Centre for Keratinophilic Fungi) GPCK 1137, Aphanoascus fulvescens GPCK 1081, Arthroderma simii GPCK 1275, Chrysosporium queenslandicum ITCC 5270, C. indicum ITCC 5269, C. pannicola GPCK 1022, C. tropicum GPCK 1269, Ctenomyces serratus ITCC 5267, Gymnoascus reessii ITCC 5265, Malbranchea fulva GPCK 1075, Malbranchea pulchella ITCC 5268, Micosporum gypseum GPCK 1038 , Microsporum cookei GPCK 2001, M. fulvum GPCK 2002, Paecilomyces lilacinum GPCK 1080, Penicillium expansum GPCK 1082, Trichophyton mentagrophytes GPCK 2003 and T. terrestre GPCK 2004. In hospitals, the minimum frequency was of Ctenomyces serratus ITCC 5267 while the maximum frequency was of Arthroderma simii GPCK 1275. In houses, Chrysosporium queenslandicum ITCC 5270 and C. tropicum GPCK 1269 were with minimum and maximum frequencies respectively. This makes the first report of these fungi with keratinolytic ability in the indoor dust of hospitals and houses.

  14. Assessment of the influence of traffic-related particles in urban dust using sequential selective extraction and oral bioaccessibility tests.

    Science.gov (United States)

    Patinha, C; Durães, N; Sousa, P; Dias, A C; Reis, A P; Noack, Y; Ferreira da Silva, E

    2015-08-01

    Urban dust is a heterogeneous mix, where traffic-related particles can combine with soil mineral compounds, forming a unique and site-specific material. These traffic-related particles are usually enriched in potentially harmful elements, enhancing the health risk for population by inhalation or ingestion. Urban dust samples from Estarreja city and traffic-related particles (brake dust and white traffic paint) were studied to understand the relative contribution of the traffic particles in the geochemical behaviour of urban dust and to evaluate the long-term impacts of the metals on an urban environment, as well as the risk to the populations. It was possible to distinguish two groups of urban dust samples according to Cu behaviour: (1) one group with low amounts of fine particles (car brands (with more than 10 years old), composed by coarser wear particles; and (2) another group with greater amounts of fine particles (car brands (with less than 10 years old). The results obtained showed that there is no direct correlation between the geoavailability of metals estimated by sequential selective chemical extraction (SSCE) and the in vitro oral bioaccessibility (UBM) test. Thus, oral bioaccessibility of urban dust is site specific. Geoavailability was greatly dependent on particle size, where the bioaccessibility tended to increase with a reduction in particle diameter. As anthropogenic particles showed high metal concentration and a smaller size than mineral particles, urban dusts are of major concern to the populations' health, since fine particles are easily re-suspended, easily ingested, and show high metal bioaccessibility. In addition, Estarreja is a coastal city often influenced by winds, which favours the re-suspension of small-sized contaminated particles. Even if the risk to the population does not represent an acute case, it should not be overlooked, and this study can serve as baseline study for cities under high traffic influence.

  15. Dispersion relations of externally and thermally excited dust lattice modes in 2D complex plasma crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xuefeng; Cui Jian; Zhang Yuan [School of Mathematical Sciences, Dalian University of Technology, Dalian 116024 (China); Liu Yue [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2012-07-15

    The dispersion relations of the externally and thermally (naturally) excited dust lattice modes (both longitudinal and transverse) in two-dimensional Debye-Yukawa complex plasma crystals are investigated. The dispersion relations are calculated numerically by taking the neutral gas damping effects into account and the numerical results are in agreement with the experimental data given by Nunomura et al.[Phys. Rev. E 65, 066402 (2002)]. It is found that for the mode excited by an external disturbance with a real frequency, the dispersion properties are changed at a critical frequency near where the group velocity of the mode goes to zero. Therefore, the high frequency branch with negative dispersion cannot be reached. In contrast, for the thermally excited mode, the dispersion curve can extend all the way to the negative dispersion region, while a 'cut-off' wave number exists at the long wavelength end of the dispersion in the transverse mode.

  16. Indoor viable dust-bound microfungi in relation to residential characteristics, living habits, and symptoms in atopic and control children.

    Science.gov (United States)

    Wickman, M; Gravesen, S; Nordvall, S L; Pershagen, G; Sundell, J

    1992-03-01

    Floor dust was collected in the wintertime from the homes of 61 children sensitized to house dust mites, 57 children with sensitization to other aeroallergens, and 57 nonatopic control children. The dust was cultivated and microfungal growth was identified microscopically. Indoor humidity was measured, and condensation on windowpanes was registered during 1 winter week. Housing and sociodemographic and symptom data were obtained by a questionnaire. Penicillium, Alternaria, and Cladosporium were the three most common microfungi. The mean total number of colony-forming units per 30 mg of dust was significantly lower in the homes of the two atopic groups than in homes of the control group, which may be a result of allergen-sanitation measures. High colony-forming unit counts appeared to be related to damp housing. Weak associations were found between the occurrence of viable fungi in dust and allergic symptoms among the house dust mite-sensitized children. However, no consistent association between viable mold growth and sensitization to molds was observed. The health implications of indoor fungal exposure still remain unclear.

  17. Sensitivity of transatlantic dust transport to chemical aging and related atmospheric processes

    KAUST Repository

    Abdelkader, Mohamed

    2017-03-20

    We present a sensitivity study on transatlantic dust transport, a process which has many implications for the atmosphere, the ocean and the climate. We investigate the impact of key processes that control the dust outflow, i.e., the emission flux, convection schemes and the chemical aging of mineral dust, by using the EMAC model following Abdelkader et al. (2015). To characterize the dust outflow over the Atlantic Ocean, we distinguish two geographic zones: (i) dust interactions within the Intertropical Convergence Zone (ITCZ), or the dust–ITCZ interaction zone (DIZ), and (ii) the adjacent dust transport over the Atlantic Ocean (DTA) zone. In the latter zone, the dust loading shows a steep and linear gradient westward over the Atlantic Ocean since particle sedimentation is the dominant removal process, whereas in the DIZ zone aerosol–cloud interactions, wet deposition and scavenging processes determine the extent of the dust outflow. Generally, the EMAC simulated dust compares well with CALIPSO observations; however, our reference model configuration tends to overestimate the dust extinction at a lower elevation and underestimates it at a higher elevation. The aerosol optical depth (AOD) over the Caribbean responds to the dust emission flux only when the emitted dust mass is significantly increased over the source region in Africa by a factor of 10. These findings point to the dominant role of dust removal (especially wet deposition) in transatlantic dust transport. Experiments with different convection schemes have indeed revealed that the transatlantic dust transport is more sensitive to the convection scheme than to the dust emission flux parameterization. To study the impact of dust chemical aging, we focus on a major dust outflow in July 2009. We use the calcium cation as a proxy for the overall chemical reactive dust fraction and consider the uptake of major inorganic acids (i.e., H2SO4, HNO3 and HCl) and their anions, i.e., sulfate (SO42−), bisulfate

  18. Radiologic characteristics of sinonasal fungus ball: an analysis of 119 cases

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young-Joon; Kim, Kyubo (Dept. of Otorhinolaryngology, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)); Kim, Jinna (Dept. of Radiology, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)); Lee, Jeung-Gweon; Kim, Chang-Hoon (Dept. of Otorhinolaryngology, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); The Airway Mucus Institute, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)), email: entman@yuhs.ac; Yoon, Joo-Heon (Dept. of Otorhinolaryngology, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); The Airway Mucus Institute, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); Research Center for Human Natural Defense System, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); BK21 Project for Medical Science, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of))

    2011-09-15

    Background. It is important to differentiate sinonasal fungus ball from non-fungal sinusitis and other forms of fungal sinusitis in order to determine the optimal treatment. In particular, a sinonasal fungus ball, a non-invasive fungal sinusitis, can be characterized by radiologic findings before surgery. Purpose. To differentiate a sinonasal fungus ball from other types of sinusitis and determine optimal treatment on the basis of radiologic findings before surgery. Material and Methods. We studied 119 patients with clinically and pathologically proven sinonasal fungus balls. Their condition was evaluated radiologically with contrast-enhanced CT (99 patients), non-contrast CT (18 patients) and/or MRI (17 patients) prior to sinonasal surgery. Results. Calcifications were found in 78 of 116 (67.2%) patients who underwent CT scans for fungus ball. As opposed to non-contrast CT scans, contrast CT scans revealed hyper attenuating fungal ball in 82.8% and enhanced inflamed mucosa in 65.5% of the patients, respectively. On MRI, most sinonasal fungal balls showed iso- or hypointensity on T1-weighted images and marked hypointensity on T2-weighted images. Inflamed mucosal membranes were noted and appeared as hypointense on T1-weighted images (64.7%) and hyperintense on T2-weighted images (88.2%). Conclusion. When there are no calcifications visible on the CT scan, a hyper attenuating fungal ball located in the central area of the sinus with mucosal thickening on enhanced CT scans is an important feature of a non-invasive sinonasal fungus ball. On MRI, a sinonasal fungus ball has typical features of a marked hypointense fungus ball with a hyperintense mucosal membrane in T2-weighted images. A contrast-enhanced CT scan or MRI provides sufficient information for the preoperative differentiation of a sinonasal fungus ball from other forms of sinusitis

  19. Nitric oxide production is stimulated by bitter taste receptors ubiquitously expressed in the sinonasal cavity.

    Science.gov (United States)

    Yan, Carol H; Hahn, Samuel; McMahon, Derek; Bonislawski, David; Kennedy, David W; Adappa, Nithin D; Palmer, James N; Jiang, Peihua; Lee, Robert J; Cohen, Noam A

    2017-03-01

    Bitter taste receptors (T2R) have recently been demonstrated to contribute to sinonasal innate immunity. One T2R, T2R38, regulates mucosal defense against gram-negative organisms through nitric oxide (NO) production, which enhances mucociliary clearance and directly kills bacteria. To determine whether additional T2Rs contribute to this innate defense, we evaluated two other sinonasal T2Rs (T2R4 and T2R16) for regulation of NO production and expression within the human sinonasal cavity. Primary human sinonasal cultures were stimulated with ligands specific to T2R4 and T2R16, colchicine and D-salicin, respectively. Cellular NO production was measured by intracellular 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate fluorescence. For T2R expression mapping, sinonasal tissue was obtained from patients who underwent sinus surgery of the middle turbinate, maxillary sinus, ethmoid sinus, or sphenoid sinus. The expression of T2R4, T2R16, and T2R38 was evaluated by using immunofluorescence with validated antibodies. Similar to T2R38, T2R4 and T2R16 trigger NO production in a dose-dependent manner by using the canonical taste signaling pathway in response to stimulation with their respective ligands. All three receptors were expressed in the cilia of human epithelial cells of all regions in the sinonasal cavity. These three T2Rs signaled through the same NO-mediated antimicrobial pathway and were ubiquitously expressed in the sinonasal epithelium. Additional T2Rs besides T2R38 may play a role in sinonasal immune defense. Mapping of T2R expression demonstrated the potential widespread role of T2Rs in sinonasal defense, whereas the genetics of these T2Rs may contribute to our understanding of specific endotypes of chronic rhinosinusitis and develop into novel therapeutic targets.

  20. Persistent Expression Changes of Fibrosis-Related Genes in the Lung Tissues of Rats Exposed to Lunar Dust Particles

    Science.gov (United States)

    Zhang, Ye; Lam, Chiu-Wing; Scully, Robert R.; Yeshitla, Samrawit A.; Wu, Honglu; Meyers, Valerie; James, John T.

    2014-01-01

    The Moon's surface is covered by a layer of fine, potential reactive dust. Lunar dust contain about 1-2% of very fine respirable dust (less than 3 micrometers). The habitable area of any lunar landing vehicle and outpost would inevitably be contaminated with lunar dust that could pose a health risk. The purpose of the study is to evaluate the toxicity of Apollo moon dust in rodents to assess the health risk of dust exposures to humans. One of the particular interests in the study is to evaluate dust-induced changes of the expression of fibrosis-related genes, and to identify specific signaling pathways involved in lunar dustinduced toxicity. F344 rats were exposed for 4 weeks (6h/d; 5d/wk) in nose-only inhalation chambers to concentrations of 0 (control air), 2.1, 6.8, 21, and 61 milligrams per cubic meters of lunar dust. Five rats per group were euthanized at 1 day, 1 week, 1 month, and 3 months after the last inhalation exposure. The bronchoalveolar lavage fluid (BALF) was collected by lavaging with phosphate-buffered saline (PBS). A zymosan-induced luminolbased chemiluminescence assay was used to assess the activity of BAL cells. The lavaged lung tissue was snap frozen in LN2 and total RNA was isolated using the Qigen RNeasy kit. The expression of 84 fibrosisrelated genes were analyzed using the RT2 Profiler PCR Array technique. The expression of 18 genes of interest were further measured using real-time PCR technique in all the samples. 10 out of 18 genes of interest showed persistently significant expression changes in the local lung tissue exposed to lunar dust, indicating a prolonged proinflammatory response. The expressions of several of these genes were dose- and time-dependent and were significantly correlated with other pathological parameters. The potential signaling pathways and upstream regulators were further analyzed using IPA pathway analysis tool based on the gene expression data. The data presented in this study, for the first time, explore the

  1. A Rare Manifestation of Crohn's Disease: Sinonasal Granulomatosis. Report of a Case and Review of Literature

    Directory of Open Access Journals (Sweden)

    Lilia Baili

    2014-10-01

    Full Text Available Crohn’s disease is a granulomatous inflammatory bowel disease. Its pathologic findings include non-contiguous chronic inflammation and non-caseating granulomas, sometimes with extra-intestinal localizations. Sinonasal manifestations of Crohn’s disease are quite rare and only a few cases have been reported up to date in the worldwide literature. They are characterized by chronic mucosal inflammation, obstruction, bleeding and occasionally septal perforation. We report a case of sinonasal granulomatosis revealing Crohn’s disease in a 22-year-old woman and go over the available literature on sinonasal involvement in Crohn’s disease.

  2. Relating dust, gas and the rate of star formation in M31

    CERN Document Server

    Tabatabaei, F S

    2010-01-01

    We derive distributions of dust temperature and dust opacity across M31 at 45" resolution using the Spitzer data. With the opacity map and a standard dust model we de-redden the Ha emission yielding the first de-reddened Ha map of M31. We compare the emissions from dust, Ha, HI and H2 by means of radial distributions, pixel-to-pixel correlations and wavelet cross-correlations. The dust temperature steeply decreases from 30K near the center to 15K at large radii. The mean dust optical depth at the Ha wavelength along the line of sight is about 0.7. The radial decrease of the dust-to-gas ratio is similar to that of the oxygen abundance. On scales<2kpc, cold dust emission is best correlated with that of neutral gas and warm dust emission with that of ionized gas. Ha emission is slightly better correlated with emission at 70um than at 24um. In the area 6kpc

  3. Malignant triton tumour of the sinonasal tract: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Abdulmajeed Zakzouk

    2014-01-01

    CONCLUSION: Malignant triton tumour is a rare malignancy of the sinonasal tract. Otolaryngologists should be aware of this disease. The optimal treatment should include radical resection of the tumour.

  4. Advances in recurrence and malignant transformation of sinonasal inverted papillomas

    Science.gov (United States)

    Sun, Qingjia; An, Lifeng; Zheng, Jun; Zhu, Dongdong

    2017-01-01

    Sinonasal inverted papilloma (SIP) is a benign tumor of the nasal cavity and sinus. SIP is characterized by aggressive malignant transformation and a high rate of recurrence. Inadequate removal of the tumor during surgery is one of the most significant contributors to SIP recurrence. A growing body of evidence suggests that molecular alteration in SIP, including human papilloma virus infections, single nucleotide polymorphisms of key genes, deregulation of signaling pathways and immunological changes, may lead to SIP occurrence and malignant transformation. However, the extent to which these molecular mechanisms contribute to SIP pathology and transformation remains unclear due to limited research. Further studies are warranted to elucidate the primary dependent factors that contribute to SIP etiology. The present article reviewed risk factors of progression and recurrence of SIP, including outdoor and industrial occupational exposure, smoking, septal deviation, SIP location, recurrent cases, stage of SIP-associated squamous cell carcinoma and choice of surgical method. PMID:28599459

  5. Sinonasal Fungal Infections and Complications: A Pictorial Review

    Directory of Open Access Journals (Sweden)

    Jose Gavito-Higuera

    2016-01-01

    Full Text Available Fungal infections of the nose and paranasal sinuses can be categorized into invasive and non-invasive forms. The clinical presentation and course of the disease is primarily determined by the immune status of the host and can range from harmless or subtle presentations to life threatening complications. Invasive fungal infections are categorized into acute, chronic or chronic granulomatous entities. Immunocompromised patients with poorly controlled diabetes mellitus, HIV and patients receiving chemotherapy or chronic oral corticosteroids are mostly affected. Mycetoma and Allergic Fungal Rhinosinusitis are considered non-invasive forms. Computer tomography is the gold-standard in sinonasal imaging and is complimented by Magnetic resonance imaging (MRI as it is superior in the evaluation of intraorbital and intracranial extensions. The knowledge and identification of the characteristic imaging patterns in invasive - and non- invasive fungal rhinosinusitis is crucial and the radiologist plays an important role in refining the diagnosis to prevent a possible fatal outcome.

  6. CT and MRI of congenital sinonasal ossifying fibroma

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, V. [Inst. of Diagnostic Radiology, Heinrich Heine Univ. Duesseldorf (Germany); Preis, S.; Hassler, W. [Dept. of Pediatrics, Heinrich Heine Univ. Duesseldorf (Germany); Lenard, H.G. [Dept. of Neurosurgery, Municipal Hospitals, Duisburg (Germany)

    1999-07-01

    We report a 9-year-old boy with a sinonasal ossifying fibroma, probably congential, with atypical findings on CT and MRI. CT revealed a soft-tissue density mass in the sphenoethmoidal sinuses, nasal cavity and right maxillary sinus with a few foci of calcification and with remodelling and destruction of the adjacent facial bones. MRI showed high signal on T2- and intermediate signal on T1-weighted images. A thin, partly enhancing outer shell and some nonenhancing septa were visible on contrast-enhanced images. MRI also showed the tumour to extend into the anterior cranial fossa. Subtotal removal was performed. We compare our findings with reports in the literature and discuss the differences from fibrous dysplasia. (orig.)

  7. Profile of TP53 gene mutations in sinonasal cancer

    DEFF Research Database (Denmark)

    Holmila, Reetta; Bornholdt, Jette; Suitiala, Tuula

    2010-01-01

    %) frameshift or nonsense mutations, and 36 (23%) intronic or silent mutations. In coding region, the most common base change detected was C-->T transition (43/125; 34% of base changes in the coding region). G-->T transversions occurred at a frequency of 10% (12/125), which is less than reported in mutation...... not been reported before as frequently mutated in head and neck cancer or human cancer in general. About half of all tumours with TP53 mutations carried more than one mutation. Interestingly, 86% (19/22) of the silent mutations detected had occurred in tumours with multiple mutations.......Genetic alterations underlying the development of the cancer of the nose and paranasal sinuses (sinonasal cancer, SNC), a rare cancer that can be included in the group of head and neck cancers, are still largely unknown. We recently reported that TP53 mutations are a common feature of SNC...

  8. Turbulence-Induced Relative Velocity of Dust Particles III: The Probability Distribution

    CERN Document Server

    Pan, Liubin; Scalo, John

    2014-01-01

    Motivated by its important role in the collisional growth of dust particles in protoplanetary disks, we investigate the probability distribution function (PDF) of the relative velocity of inertial particles suspended in turbulent flows. Using the simulation from our previous work, we compute the relative velocity PDF as a function of the friction timescales, tau_p1 and tau_p2, of two particles of arbitrary sizes. The friction time of particles included in the simulation ranges from 0.1 tau_eta to 54T_L, with tau_eta and T_L the Kolmogorov time and the Lagrangian correlation time of the flow, respectively. The relative velocity PDF is generically non-Gaussian, exhibiting fat tails. For a fixed value of tau_p1, the PDF is the fattest for equal-size particles (tau_p2~tau_p1), and becomes thinner at both tau_p2tau_p1. Defining f as the friction time ratio of the smaller particle to the larger one, we find that, at a given f in 1/2>T_L). These features are successfully explained by the Pan & Padoan model. Usin...

  9. Turbulence-Induced Relative Velocity of Dust Particles I: Identical Particles

    CERN Document Server

    Pan, Liubin

    2013-01-01

    We study the relative velocity of inertial particles suspended in turbulent flows and discuss implications for dust particle collisions in protoplanetay disks. We simulate a weakly compressible turbulent flow at 512^3 and evolve 14 species of particles with different friction timescales, tau_p. The Stoke number, St, of the smallest particles is ~0.1, where St is the ratio of tau_p to the Kolmorgorov timescale, while the largest particles have tau_p =54T_L, where T_L is the flow Lagrangian correlation timescale. We find that the model by Pan & Padoan (PP10) gives satisfactory predictions for the rms relative velocity between identical particles. The model shows that the relative velocity of two same-size particles is determined by the particle memory of the flow velocity difference along their trajectories, and thus depends on the particle pair separation backward in time. We compute the collision kernel accounting for the effect of turbulent clustering. The kernel per unit cross section shows an abrupt ri...

  10. The Herschel Exploitation of Local Galaxy Andromeda (HELGA): IV. Dust scaling relations at sub-kpc resolution

    CERN Document Server

    Viaene, S; Baes, M; Bendo, G J; Blommaert, J A D L; Boquien, M; Boselli, A; Ciesla, L; Cortese, L; De Looze, I; Gear, W K; Gentile, G; Hughes, T M; Jarrett, T; Karczewski, O Ł; Smith, M W L; Spinoglio, L; Tamm, A; Tempel, E; Thilker, D; Verstappen, J

    2014-01-01

    The imprints of dust-starlight interactions are visible in scaling relations between stellar characteristics, star formation parameters and dust properties. We aim to examine dust scaling relations on a sub-kpc resolution in the Andromeda galaxy (M31) by comparing the properties on a local and global scale to other galaxies of the local universe. New Herschel observations are combined with available data from GALEX, SDSS, WISE and Spitzer to construct a dataset covering UV to submm wavelengths. We work at the resolution of the SPIRE $500\\; \\mu$m beam, with pixels corresponding to physical regions of 137 x 608 pc in the galaxy's disk. A panchromatic spectral energy distribution was modelled for each pixel and several dust scaling relations are investigated. We find, on a sub-kpc scale, strong correlations between $M_d/M_\\star$ and NUV-r, and between $M_d/M_\\star$ and $\\mu_\\star$ (the stellar mass surface density). Striking similarities with corresponding relations based on integrated galaxies are found. We dec...

  11. Cancer mortality and wood dust exposure among participants in the American Cancer Society Cancer Prevention Study-II (CPS-II).

    Science.gov (United States)

    Stellman, S D; Demers, P A; Colin, D; Boffetta, P

    1998-09-01

    In 1994, the International Agency for Research on Cancer (IARC) classified wood duct as a human carcinogen, based on very strong evidence of a carcinogenic risk of sino-nasal cancer. Excesses of other cancers, including lung and stomach, have been reported among persons employed in wood industries or occupationally exposed to wood dust, but not as consistently. We investigated such possible associations using the mortality experience of 362,823 men enrolled in the American Cancer Society's Cancer Prevention Study-II in 1982 and followed up for 6 years. Within this group, 45,399 men (12.5%) reported either employment in a wood-related occupation or exposure to wood dust or both. Among woodworkers, a small but significant excess risk was found for all cases of death (RR 1.17 (95% CI 1.11-1.24)) and for total malignancies (RR 1.17 (1.05-1.30)). Among men who reported exposure to wood dust, there was an elevated risk of total mortality (Rr 1.07 (1.03-1.11)), total malignancies (RR 1.08 (1.01-1.15)), and lung cancer (RR 1.17 (1.04-1.31)). Among woodworkers, a significant trend (P = 0.02) of increasing risk of lung cancer with increasing duration of exposure was observed. An unexpected, significantly increased mortality from prostate cancer was observed in both wood-employed and wood-exposed, and a twofold increased risk of fatal brain cancer was seen among the former. Lung cancer mortality was especially high among woodworkers who also reported exposure to asbestos or formaldehyde, and it appears that exposure to these known carcinogens may partly explain the observed increased risks. Excess sino-nasal cancer was not observed, but the number of cases was small.

  12. Environmental and traffic-related parameters affecting road dust composition: A multi-technique approach applied to Venice area (Italy)

    Science.gov (United States)

    Valotto, Gabrio; Rampazzo, Giancarlo; Visin, Flavia; Gonella, Francesco; Cattaruzza, Elti; Glisenti, Antonella; Formenton, Gianni; Tieppo, Paulo

    2015-12-01

    Road dust is a non-exhaust source of atmospheric particulate by re-suspension. It is composed of particles originating from natural sources as well as other non-exhaust source such as tire, brake and asphalt wear. The discrimination between atmospheric particles directly emitted from abrasion process and those related to re-suspension is therefore an open issue, as far as the percentage contribution of non-exhaust emissions is becoming more considerable due also to the recent policy actions and the technological upgrades in the automotive field, focused on the reduction of exhaust emissions. In this paper, road dust collected along the bridge that connects Venice (Italy) to the mainland is characterized with a multi-technique approach in order to determine its composition depending on environmental as well as traffic-related conditions. Six pollutant sources of road dust particles were identified by cluster analysis: brake, railway, tire, asphalt, soil + marine, and mixed combustions. Considering the lack of information on this matrix in this area, this study is intended to provide useful information for future identification of road dust re-suspension source in atmospheric particulate.

  13. Cross-shift changes in FEV1 in relation to wood dust exposure: the implications of different exposure assessment methods

    Science.gov (United States)

    Schlunssen, V; Sigsgaard, T; Schaumburg, I; Kromhout, H

    2004-01-01

    Background: Exposure-response analyses in occupational studies rely on the ability to distinguish workers with regard to exposures of interest. Aims: To evaluate different estimates of current average exposure in an exposure-response analysis on dust exposure and cross-shift decline in FEV1 among woodworkers. Methods: Personal dust samples (n = 2181) as well as data on lung function parameters were available for 1560 woodworkers from 54 furniture industries. The exposure to wood dust for each worker was calculated in eight different ways using individual measurements, group based exposure estimates, a weighted estimate of individual and group based exposure estimates, and predicted values from mixed models. Exposure-response relations on cross-shift changes in FEV1 and exposure estimates were explored. Results: A positive exposure-response relation between average dust exposure and cross-shift FEV1 was shown for non-smokers only and appeared to be most pronounced among pine workers. In general, the highest slope and standard error (SE) was revealed for grouping by a combination of task and factory size, the lowest slope and SE was revealed for estimates based on individual measurements, with the weighted estimate and the predicted values in between. Grouping by quintiles of average exposure for task and factory combinations revealed low slopes and high SE, despite a high contrast. Conclusion: For non-smokers, average dust exposure and cross-shift FEV1 were associated in an exposure dependent manner, especially among pine workers. This study confirms the consequences of using different exposure assessment strategies studying exposure-response relations. It is possible to optimise exposure assessment combining information from individual and group based exposure estimates, for instance by applying predicted values from mixed effects models. PMID:15377768

  14. Obscuration in AGNs: near-infrared luminosity relations and dust colors

    CERN Document Server

    Burtscher, L; Davies, R I; Janssen, A; Lutz, D; Rosario, D; Contursi, A; Genzel, R; Gracia-Carpio, J; Lin, M -Y; Schnorr-Mueller, A; Sternberg, A; Sturm, E; Tacconi, L

    2015-01-01

    We combine two approaches to isolate the AGN luminosity at near-infrared wavelengths and relate the near-IR pure AGN luminosity to other tracers of the AGN. Using integral-field spectroscopic data of an archival sample of 51 local AGNs, we estimate the fraction of non-stellar light by comparing the nuclear equivalent width of the stellar 2.3 micron CO absorption feature with the intrinsic value for each galaxy. We compare this fraction to that derived from a spectral decomposition of the integrated light in the central arc second and find them to be consistent with each other. Using our estimates of the near-IR AGN light, we find a strong correlation with presumably isotropic AGN tracers. We show that a significant offset exists between type 1 and type 2 sources in the sense that type 1 sources are 7 (10) times brighter in the near-IR at log L_MIR = 42.5 (log L_X = 42.5). These offsets only becomes clear when treating infrared type 1 sources as type 1 AGNs. All AGNs have very red near-to-mid-IR dust colors. T...

  15. The Nottingham energy, health and housing study: reducing relative humidity, dust mites and asthma

    Energy Technology Data Exchange (ETDEWEB)

    Pretlove, S.E.C. [South Bank University, London (United Kingdom); Critchley, R. [Health and Housing Group, Nottingham (United Kingdom); Howard, R. [NEA, Nottingham (United Kingdom); Oreszczyn, T. [University College, London (United Kingdom). The Bartlett

    2002-04-01

    This paper describes the Nottingham energy, health and housing study, a project where seven Nottingham City Council households subject to either fuel poverty or heat poverty have been refurbished to improve the internal environmental conditions and therefore the health of the occupants. The main aim was to provide improvements in ventilation, insulation, draughtproofing and heating control in the dwellings. An intervention study was carried out in the seven dwellings where temperature, relative humidity, health, dust mite numbers and ventilation were measured before the introduction of a range of heating, ventilation and insulation improvements. These were then monitored again a year later. The results of the study indicate that with a limited budget, significant improvements have been realized in the comfort levels of the occupants and in their health. Modelling of the environmental conditions and energy consumption in each dwelling has been carried out using the steady-state Condensation Targeter II model. Comparisons between the model predictions and the measured data show that Condensation Targeter II can be used as an effective tool for selecting the most appropriate design modifications for an individual dwelling and can assess the impact that these modifications will have on the energy efficiency of the dwelling and the health of the occupants. (author)

  16. Extranodal sinonasal Rosai-Dorfman disease: a clinical study of 10 cases.

    Science.gov (United States)

    Duan, Hong-Gang; Zheng, Chun-Quan; Wang, De-Hui; Ding, Guo-Qiang; Luo, Ji-Qin; Zang, Chao-Ping; Yu, Chang

    2015-09-01

    Sinonasal Rosai-Dorfman disease (S-RDD) is a rare form of RDD limited to the sinonasal cavity. Multipatient studies of Chinese S-RDD and documentation of its clinical spectrum are rare. This study aimed to identify the clinical profiles of Chinese S-RDD. Medical records of and tissue sections from 10 patients diagnosed with S-RDD between 2007 and 2014 were reviewed. Data on clinical presentations, endoscopy signs, imageological change, treatment and outcome were analyzed. The mean age of five male and five female patients at the first visit was 40.3 years and the mean follow-up period was 58.6 months. Based on the lesion sites, five cases were divided into an anterior sinonasal group, accompanied by symptoms of epistaxis, nasal obstruction and nasal dorsal deformity. Five other cases were divided into a posterior sinonasal group, accompanied by symptoms of hyposmia, epistaxis and nasal obstruction. Endoscopy signs and imageological changes in the anterior group showed diffuse infiltration of the RDD lesion under the septum mucosa, but in the posterior group the RDD lesions often showed as formations on polyps. At the end of follow-up, only one case spontaneously resolved without surgery; two cases in the anterior sinonasal group and three cases in the posterior sinonasal group recurred after endoscopic surgery, but surgery can result in short-term symptomatic control and restoration of function in all cases. S-RDD of the anterior and posterior sinonasal cavity may have different clinical characteristics; endoscopic surgery is effective for short-term symptomatic control and restoration of function for S-RDD.

  17. Climate-related response of dust flux to the central equatorial Pacific over the past 150 kyr

    Science.gov (United States)

    Jacobel, A. W.; McManus, J. F.; Anderson, R. F.; Winckler, G.

    2017-01-01

    High resolution paleoclimate records from low latitudes are critical for understanding the role of the tropics in transmitting and generating feedbacks for high-latitude climate change on glacial-interglacial and millennial timescales. Here we present three new records of 230Thxs,0-normalized 232Th-derived dust fluxes from the central equatorial Pacific spanning the last 150 kyr at millennial-resolution. All three dust flux records share the "sawtooth" pattern characteristic of glacial-interglacial cycles in ice volume, confirming a coherent response to global climate forcing on long timescales. These records permit a detailed examination of millennial variability in tropical dust fluxes related to abrupt perturbations in oceanic and atmospheric circulation. Increases in dust flux in association with at least six of the longest Greenland stadials provide evidence that abrupt, high-latitude climate oscillations influenced the atmospheric aerosol load in the equatorial Pacific, with implications for both direct and indirect effects on the tropical energy balance. Our latitudinal transect of cores captures shifts in the position of the Intertropical Convergence Zone (ITCZ) in response to variations in the interhemispheric thermal gradient associated with cooling in Greenland and bipolar seesaw warming in Antarctica. These observations demonstrate that changes in the energy and hydrologic balance of the tropics were repeated features of the penultimate deglaciation, last glacial inception and last glacial cycle, and highlight the role of the tropical atmosphere as a dynamic and responsive component of Earth's climate system.

  18. Esthesioneuroblastoma, Neuroendocrine Carcinoma, and Sinonasal Undifferentiated Carcinoma: Differentiation in Diagnosis and Treatment

    Science.gov (United States)

    Su, Shirley Y.; Bell, Diana; Hanna, Ehab Y.

    2014-01-01

    Introduction Malignant sinonasal tumors comprise less than 1% of all neoplasms. A wide variety of tumors occurring primarily in this site can present with an undifferentiated or poorly differentiated morphology. Among them are esthesioneuroblastomas, sinonasal undifferentiated carcinomas, and neuroendocrine carcinomas. Objectives We will discuss diagnostic strategies, recent advances in immunohistochemistry and molecular diagnosis, and treatment strategies. Data Synthesis These lesions are diagnostically challenging, and up to 30% of sinonasal malignancies referred to the University of Texas MD Anderson Cancer Center are given a different diagnosis on review of pathology. Correct classification is vital, as these tumors are significantly different in biological behavior and response to treatment. The past decade has witnessed advances in diagnosis and therapeutic modalities leading to improvements in survival. However, the optimal treatment for esthesioneuroblastoma, sinonasal undifferentiated carcinoma, and neuroendocrine carcinoma remain debated. We discuss advances in immunohistochemistry and molecular diagnosis, diagnostic strategies, and treatment selection. Conclusions There are significant differences in prognosis and treatment for esthesioneuroblastoma, neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma. Recent advances have the potential to improve oncologic outcomes but further investigation in needed. PMID:25992139

  19. Positive airway pressure adherence and mask interface in the setting of sinonasal symptoms.

    Science.gov (United States)

    Schell, Amy E; Soose, Ryan J

    2017-10-01

    Despite reports of lower positive pressure adherence rates with oronasal masks, patients with sinonasal problems are often prescribed this interface over a nasal interface. The aim of this study was to characterize the relationship between mask type and therapy adherence in the setting of sinonasal symptoms. Retrospective case series with chart review. We reviewed 328 patients who underwent positive pressure titration between January 2012 and May 2015. Follow-up adherence data were available for 218 patients (66.5%). Multivariate analysis examined whether patients with sinonasal symptoms have improved adherence with oronasal masks compared to nasal or nasal pillow interfaces. At a median follow-up of 95 days, positive pressure adherence in patients with sinonasal symptoms was highest with the nasal pillow interface. When compared with oronasal interfaces, the odds of adequate therapy adherence were >5 times greater with nasal pillow interfaces (odds ratio [OR] = 5.20, 95% confidence interval [CI] = 1.61-16.80, P = .006) and >3 times greater with nasal interfaces (OR = 3.67, 95% CI = 1.20-11.26, P = .02) in these symptomatic patients. The presence of nasal problems does not predict the need for an oronasal mask. Positive pressure adherence rates are higher with nasal and nasal pillow interfaces compared to oronasal masks, even in patients with sinonasal complaints. 4. Laryngoscope, 127:2418-2422, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  20. Incidence of abnormal retropharyngeal lymph nodes in sinonasal malignancies among adults

    Energy Technology Data Exchange (ETDEWEB)

    Sai, Asari; Shimono, Taro; Yamamoto, Akira; Takeshita, Toru; Miki, Yukio [Osaka City University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Osaka (Japan); Ohsawa, Masahiko; Wakasa, Kenichi [Osaka City University Graduate School of Medicine, Department of Diagnostic Pathology, Osaka (Japan)

    2014-12-15

    The aim of this study is to investigate the relationship between abnormal retropharyngeal lymph nodes (RPLNs) and sinonasal malignancies among adults. Magnetic resonance and computed tomography images from 89 patients over 20 years old who were all histopathologically confirmed to have sinonasal malignancies from September 2001 to April 2014 were assessed retrospectively. Abnormal RPLNs were determined as those >5 mm in shortest axis or showing heterogeneous enhancement on axial images. Locations of sinonasal malignancies were categorized using the anterior border of the pterygopalatine fossa as a boundary: (a) anterior lesions, only present anterior to the boundary, or (b) posterior lesions, present or extending posterior to the boundary. Fisher's exact test was used for the analysis of the relationship between frequency of abnormal RPLNs and lesion location. Abnormal RPLNs were present in 13 of 89 patients (15 %), including 6 of 41 squamous cell carcinomas (15 %), 4 of 24 malignant lymphomas (17 %), 3 of 5 olfactory neuroblastomas (60 %), and 0 of 19 others (0 %). Four of the 39 patients (10 %) with anterior lesions showed abnormal RPLNs, compared to 9 of 50 patients (18 %) with posterior lesions. No significant difference in frequency of abnormal RPLNs was apparent between anterior and posterior lesions (P = 0.37). In primary sinonasal malignancies among adults, the highest incidence of abnormal RPLNs was seen with olfactory neuroblastoma. The frequency of abnormal RPLNs was unaffected by the location of sinonasal malignancies among adults. (orig.)

  1. Sinonasal aspergillosis in a British Shorthair cat in the UK

    Directory of Open Access Journals (Sweden)

    Alice Tamborini

    2016-06-01

    Full Text Available Case summary A 13-year-old, castrated male, British Shorthair cat presented for investigation of chronic, intermittent, bilateral epistaxis and stertor. CT revealed severe asymmetric bilateral intranasal involvement with extensive turbinate lysis, increased soft tissue attenuation and lysis of the sphenopalatine bone and cribriform plate. On retroflexed pharyngoscopy, a plaque-like mass occluded the choanae. Rostral rhinoscopic examination revealed extensive loss of nasal turbinates, necrotic tissue and mucosal fungal plaques in the left nasal cavity. The right nasal cavity was less severely affected. The nasal cavities were debrided extensively of plaques and necrotic tissue. Aspergillus fumigatus was isolated on fungal culture, and species identity was confirmed using comparative sequence analysis of the partial β-tubulin gene. On histopathology of nasal biopsies, there was ulcerative lymphoplasmacytic and neutrophilic rhinitis, and fungal hyphae were identified on nasal mucosa, consistent with a non-invasive mycosis. The cat was treated with oral itraconazole after endoscopic debridement, but signs relapsed 4.5 months from diagnosis. Residual left nasal fungal plaques were again debrided endoscopically and oral posaconazole was administered for 6 months. Fourteen months from diagnosis, the cat remains clinically well with mild intermittent left nasal discharge secondary to atrophic rhinitis. Relevance and novel information This is the first case of rhinoscopically confirmed sinonasal aspergillosis to be diagnosed in a cat in the UK. Endoscopic confirmation of resolution of infection is useful in cases where mild nasal discharge persists after treatment.

  2. Wood dust exposure during furniture manufacture--results from an Australian survey and considerations for threshold limit value development.

    Science.gov (United States)

    Pisaniello, D L; Connell, K E; Muriale, L

    1991-11-01

    A survey of time-weighted average (TWA) personal inhalable dust exposures for woodworkers in 15 Australian furniture factories was undertaken. There was significant variation in the individual dust measurements with mean exposures of 3.2, 5.2, and 3.5 mg/m3 for wood machinists, cabinetmakers, and chair framemakers, respectively. Hardwoods, softwoods, and reconstituted woods are used in the industry, but only minor differences in mean exposures or particle size distributions were found for the broad categories. In addition, a modified British Medical Research Council respiratory questionnaire was used to obtain information about work-related symptoms and job activities. Compared with a control group, the woodworkers reported more eye, ear, and nasal problems, with the differences being statistically significant. However, among the woodworkers themselves, with the exception of several nasal symptoms, the prevalences of reported symptoms were poorly correlated with gravimetric measurements of personal dust exposure. The problem of selection bias in cross-sectional studies is discussed. For a mean TWA personal exposure of about 3 mg/m3, hardwood users were more likely to report nasal symptoms than users of reconstituted wood. The question of appropriate exposure standards for woods in general is addressed by reference to those important health effects, besides sino-nasal cancer, that have been investigated. Further exposure guidelines should be formulated for groups of woods that are known to cause a common health effect, such as nasal/respiratory sensitization.

  3. The Briefing Relating to the Construction of Dust-Storm Monitoring, Predicting and Service System

    Institute of Scientific and Technical Information of China (English)

    ChengLei; WangXuechen

    2005-01-01

    Dust-storm is a kind of severe weather, which has comprehensive and significant impacts on socioeconomic development and people's livelihood. Enhancing the abihties of dust-storm monitoring, predicting and service will be of great benefit and the important significance to China and its people. At present, the comprehensive operation on dust-storm monitoring, predicting and service is still in a preliminary phase, the abilities of operation can' t meet the needs of implementing the real-time and quantitative monitoring and providing the efficient service. The implementation of the project of dust-storm monitoring, predicting and service system will greatly improve the service ability and level for tile sustainable development and make a greater contribution to build the better-off society. The first phase project mainly involves monitoring subsystem, predicting, warning and service subsystem; communications and transmission subsystem, etc. In the first phase construction a series of major measures should be taken to address project overall benefits, such as making better use of current monitoring resource, taking into account the standards of data format and project integrative and extensive abilities and so on.

  4. Exposure to house dust phthalates in relation to asthma and allergies in both children and adults.

    Science.gov (United States)

    Ait Bamai, Yu; Shibata, Eiji; Saito, Ikue; Araki, Atsuko; Kanazawa, Ayako; Morimoto, Kanehisa; Nakayama, Kunio; Tanaka, Masatoshi; Takigawa, Tomoko; Yoshimura, Takesumi; Chikara, Hisao; Saijo, Yasuaki; Kishi, Reiko

    2014-07-01

    Although an association between exposure to phthalates in house dust and childhood asthma or allergies has been reported in recent years, there have been no reports of these associations focusing on both adults and children. We aimed to investigate the relationships between phthalate levels in Japanese dwellings and the prevalence of asthma and allergies in both children and adult inhabitants in a cross-sectional study. The levels of seven phthalates in floor dust and multi-surface dust in 156 single-family homes were measured. According to a self-reported questionnaire, the prevalence of bronchial asthma, allergic rhinitis, allergic conjunctivitis, and atopic dermatitis in the 2 years preceding the study was 4.7%, 18.6%, 7.6%, and 10.3%, respectively. After evaluating the interaction effects of age and exposure categories with generalized liner mixed models, interaction effects were obtained for DiNP and bronchial asthma in adults (Pinteraction=0.028) and for DMP and allergic rhinitis in children (Pinteraction=0.015). Although not statistically significant, children had higher ORs of allergic rhinitis for DiNP, allergic conjunctivitis for DEHP, and atopic dermatitis for DiBP and BBzP than adults, and liner associations were observed (Ptrendphthalates levels collected from multi-surfaces. This study suggests that the levels of DMP, DEHP, DiBP, and BBzP in floor dust were associated with the prevalence of allergic rhinitis, conjunctivitis, and atopic dermatitis in children, and children are more vulnerable to phthalate exposure via household floor dust than are adults. The results from this study were shown by cross-sectional nature of the analyses and elaborate assessments for metabolism of phthalates were not considered. Further studies are needed to advance our understanding of phthalate toxicity.

  5. Epidemiology and survival outcomes of sinonasal verrucous carcinoma in the United States.

    Science.gov (United States)

    Alonso, Jose E; Han, Albert Y; Kuan, Edward C; Suh, Jeffrey D; John, Maie A St

    2017-09-02

    Verrucous carcinoma (VC) is a rare, variant of squamous cell carcinoma with benign cytohistopathologic features and a generally favorable prognosis. Epidemiologic and clinical outcomes data are lacking as a result of limited cases of sinonasal VC. To describe the incidence and determinants of survival of patients with verrucous carcinoma of the sinonasal tract between the years of 1973 to 2014 using the Surveillance, Epidemiology, and End Results (SEER) database. The SEER registry was utilized to calculate survival trends for patients with verrucous carcinoma of the sinonasal tract between 1973 and 2014. Patient data then was analyzed with respect to age, sex, race, and treatment modalities (surgery and radiation therapy). Overall survival (OS) and disease-specific survival (DSS) were calculated. A total of 86 cases of VC of the sinonasal tract were identified. The cohort was comprised of 69.8% males. The mean age at diagnosis was 67.4 years. The nasal cavity was the most common primary site (51.2%), followed by the maxillary sinus (40.7%) and nasopharynx (5.8%). The median OS was 97.6 months. 89.5% of cases underwent surgery and 20.9% received both surgery and radiation therapy. Overall survival at 2, 5, and 10 years was 73%, 59%, and 36%, respectively. On multivariate analysis, advanced age (P Verrucous carcinoma of the sinonasal tract is associated with a generally favorable prognosis. Age, primary site, and surgical therapy are independent predictors of OS and DSS, respectively. We present the first population-based analysis of sinonasal VC, thus clarifying the prognosis and reinforcing the management of this malignancy. 4. Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  6. The Type Ia Supernova Color-Magnitude Relation and Host Galaxy Dust: A Simple Hierarchical Bayesian Model

    Science.gov (United States)

    Mandel, Kaisey; Scolnic, Daniel; Shariff, Hikmatali; Foley, Ryan; Kirshner, Robert

    2017-01-01

    Inferring peak optical absolute magnitudes of Type Ia supernovae (SN Ia) from distance-independent measures such as their light curve shapes and colors underpins the evidence for cosmic acceleration. SN Ia with broader, slower declining optical light curves are more luminous (“broader-brighter”) and those with redder colors are dimmer. But the “redder-dimmer” color-luminosity relation widely used in cosmological SN Ia analyses confounds its two separate physical origins. An intrinsic correlation arises from the physics of exploding white dwarfs, while interstellar dust in the host galaxy also makes SN Ia appear dimmer and redder. Conventional SN Ia cosmology analyses currently use a simplistic linear regression of magnitude versus color and light curve shape, which does not model intrinsic SN Ia variations and host galaxy dust as physically distinct effects, resulting in low color-magnitude slopes. We construct a probabilistic generative model for the dusty distribution of extinguished absolute magnitudes and apparent colors as the convolution of an intrinsic SN Ia color-magnitude distribution and a host galaxy dust reddening-extinction distribution. If the intrinsic color-magnitude (MB vs. B-V) slope βint differs from the host galaxy dust law RB, this convolution results in a specific curve of mean extinguished absolute magnitude vs. apparent color. The derivative of this curve smoothly transitions from βint in the blue tail to RB in the red tail of the apparent color distribution. The conventional linear fit approximates this effective curve near the average apparent color, resulting in an apparent slope βapp between βint and RB. We incorporate these effects into a hierarchical Bayesian statistical model for SN Ia light curve measurements, and analyze a dataset of SALT2 optical light curve fits of 277 nearby SN Ia at z < 0.10. The conventional linear fit obtains βapp ≈ 3. Our model finds a βint = 2.2 ± 0.3 and a distinct dust law of RB = 3.7 ± 0

  7. Sinonasal myospherulosis and paraffin retention cysts suggested by CT: report of a case.

    Science.gov (United States)

    Coulier, Bruno; Desgain, Olivier; Gielen, Isabelle

    2012-06-01

    Sinonasal myospherulosis is a foreign body reaction to lipid material used on nasal packing at the conclusion of paranasal sinus surgery. Rare cases have been sporadically reported. We report a case found in a 79-year-old female 8 months after functional endoscopic sinus surgery during which sinus cavities had been packed with gauze coated with Terra-Cortril (a paraffin-based tetracycline/steroid ointment). The preoperative diagnosis was suggested during CT of the paranasal sinuses by the presence of macroscopic paraffin retention cysts having a characteristic fat density. To our knowledge, our case represents the first report of sinonasal myospherulosis suggested by CT.

  8. Bianchi Type-I bulk viscous fluid string dust magnetized cosmological model in general relativity

    Indian Academy of Sciences (India)

    Raj Bali; Anjali

    2004-09-01

    Bianchi Type-I magnetized bulk viscous fluid string dust cosmological model is investigated. To get a determinate model, we have assumed the conditions and = constant where is the shear, the expansion in the model and the coefficient of bulk viscosity. The behaviour of the model in the presence and absence of magnetic field together with physical and geometrical aspects of the model are also discussed.

  9. Mulberry hypertrophy and accompanying sinonasal pathologies: A review of 68 cases.

    Science.gov (United States)

    Akduman, Davut; Haksever, Mehmet; Yanilmaz, Muhammed; Solmaz, Fevzi

    2016-08-01

    Mulberry hypertrophy occasionally coexists with sinonasal pathologies. There are very few reports in the literature on this clinical entity. We conducted a retrospective study to draw attention to this condition in the context of accompanying sinonasal pathologies. Our study group was made up of 68 patients-51 males and 17 females, aged 13 to 57 years (mean: 34.9)-who had been diagnosed with mulberry hypertrophy and at least one accompanying sinonasal pathology. All patients had a long-standing chronic discharge. Forty-nine of these patients (72.1%) had unilateral mulberry hypertrophy. The most common concomitant pathologies were chronic rhinosinusitis and ostiomeatal complex disease; others included septal deviation, nasal polyposis, allergic rhinitis, and concha bullosa. Thirty-six patients (52.9%) with varying degrees of choanal/nasal obstruction were operated on with endoscopic excision to treat the mulberry hypertrophy. In all, most patients underwent some sort of surgery to treat either the mulberry hypertrophy or the accompanying sinonasal pathology. Based on our findings, we suggest a clinical staging system to serve as a way to standardize management and guide future basic and clinical research.

  10. Schwannoma of the sino-nasal tract: a rare clinico-pathological entity revisited

    Institute of Scientific and Technical Information of China (English)

    Nadia Shirazi; Saurabh Varshney; Meena Harsh; S. S Bisht

    2012-01-01

    Schwannomas are benign neoplasms arising from Schwann cells of the peripheral, cranial and autonomic nerves. We report a case of schwannoma in the sino-nasal tract, a very rare site of tumour origin with unusual pseudoangiomatous histopathological changes, which we came across in a 22 years male with progressive nasal obstruction.

  11. The importance of multimodality therapy in the treatment of sinonasal neuroendocrine carcinoma

    NARCIS (Netherlands)

    van der Laan, Tom P.; Bijl, Hendrik P.; van Hemel, Bettien M.; Plaat, Boudewijn E. C.; Wedman, Jan; van der Laan, Bernard F. A. M.; Halmos, Gyorgy

    2013-01-01

    Sinonasal carcinoma with neuroendocrine differentiation (SCND) is a rare group of tumors known for their aggressive behavior and poor response to treatment. The data in the literature are sparse and cover a wide range of therapeutic approaches over a protracted timeline. Therefore, it is important t

  12. [Influence of anatomic variations of the structures of the middle nasal meatus on sinonasal diseases].

    Science.gov (United States)

    Buljcik-Cupić, Maja M; Savović, Slobodan N; Jovićević, Jasna S

    2008-01-01

    The most common anatomic variations of the structures of the middle nasal meatus are variations of agger nasi cells, variations of the middle turbinate, variations of uncinate process, variations of the ethmoidal bulla, deviations and deformations of nasal septum in the region of the middle nasal meatus, Haller's cell (orbitoethmoidal) and Onodi's cell (sphenoethmoidal cell). In 1997, the Otorhinolaryngology-Head Neck Surgery, Task Force on Chronic Rhinosinusitis defined chronic sinusitis and nasal disease initially by including sinusitis and rhinitis with one term-chronic rhinosinusitis. This was done because it was apparent to many that nasal disoders often affected the sinuses, and vice versa. Also they established baseline parameters, major and minor signs and symptoms, for definition of rhinosinusitis. Two major factors or one major factor and two minor factors constitute a strong history for rhinosinusitis. The following methods were used in the study: 1. Anamnestic data processing about: disease symptoms that were recognized by American Academy for ENT as major and minor criteria in diagnosing nosinusitis; the duration of symptoms; the kind of sinonasal disorder and the secondary disorders. 2. Data processing obtained by anterior/posterior rhinoscopy. 3. Data processing obtained by endoscopic examination. 4. Data processing obtained by CT of paranasal cavities and the nose. The data about anatomic variations were statistically processed by Eives's correlation coefficient that indicates the degree of correlation between sinonasal disorders and anatomic variation. By analyzing the obtained data in the examined patients with sinonasal disorders, anatomic variations were present in over 50% of the patients and are defined by percentage. 1. The deviation of nasal septum in 83.33% patients. 2. The variations of the form of the middle nasal chonha in 58.92% patients. 3. The presence of agger nasi cells in 50% patients. 4. Variations of the form of ethomoidal bulla

  13. Patterns and incidence of sinonasal malignancy with orbital invasion

    Institute of Scientific and Technical Information of China (English)

    CHU Yang; LIU Hong-gang; YU Zhen-kun

    2012-01-01

    Background Sinonasal malignancy with orbital invasion is rare.The objective of the current study was to evaluate the clinical and pathological features,treatment outcomes and survival rates for these malignancies.Methods Ninety-three patients who were treated between 1997 and 2007 were retrospectively reviewed.Age,life style,symptoms,location of lesions,previous occurrences,histological subtypes,and treatment modalities were analyzed.Results Ninety-three patients were evaluated,including 51 men and 42 women:the gender ratio was 1.2 men to 1.0women.The median age was 40.5 years old.The nasal cavity (34.4%),the maxillary sinus (29.0%) and the ethmoid sinus (19.4%) were the most common primary malignant tumor sites.Almost half of the patients,44.1% had squamous cell carcinoma,13.9% had neuroectodermal carcinoma,11.7% had rhabdomyosarcoma,9% had adenocarcinoma and salivary gland-type carcinoma,and 11% had other malignancy.The majority of patients presented with T3/T4 (99%),NO (93.1%),M0 (98%) disease.The distant metastasis rate was 20.9%.The overall survival and disease-free survival rates were 68.1% and 40.9% at three years,respectively.When the overall survival rate was computed according to the epicenter of the original malignant tumor,patients with nasal cavity malignancy and maxillary sinus had the best survival,and patients with ethmoid sinus malignancy had the worse survival (P=0.03).According to their pathology classification,patients with rhabdomyosarcoma had worse overall survival than those with squamous cell carcinoma,or neuroendocrine carcinoma (P <0.001).Squamous cell carcinoma and rhabdomyosarcoma invaded the orbit more often and malignancy of the nasal cavity invaded the orbit more than malignancy of the nasal sinus.Conclusions For nasal orbital tumors early diagnosis is crucial.Orbital exenteration and postoperative rehabilitation should be carefully considered.The current data suggest that surgical resection with

  14. Coplanar VMAT vs. noncoplanar VMAT in the treatment of sinonasal cancer.

    Science.gov (United States)

    Zhong-Hua, Ning; Jing-Ting, Jiang; Xiao-Dong, Li; Jin-Ming, Mu; Jun-Chong, Mo; Jian-Xue, Jin; Ming, Gao; Qi-Lin, Li; Wen-Dong, Gu; Lu-Jun, Chen; Hong-Lei, Pei

    2015-01-01

    Previous studies showed that noncoplanar intensity-modulated radiotherapy (NC-IMRT) for sinonasal cancer is superior to coplanar intensity-modulated radiotherapy (IMRT). Volumetric-modulated arc therapy (VMAT) is a newly introduced treatment modality, and the performance of noncoplanar VMAT for sinonasal cancer has not been well described to date. To compare the dosimetry difference of noncoplanar VMAT (NC-VMAT), coplanar VMAT (co-VMAT), and NC-IMRT for sinonasal cancer. Ten postoperative patients with sinonasal cancer were randomly selected for planning with NC-VMAT, co-VMAT, and NC-IMRT. Two planning target volumes (PTVs) were contoured representing high-risk and low-risk regions set to receive a median absorbed dose (D50%) of 68 Gy and 59 Gy, respectively. The homogeneity index (HI), conformity index (CI), dose-volume histograms (DVHs), and delivery efficiency were all evaluated. Both NC-VMAT and co-VMAT showed superior dose homogeneity and conformity in PTVs compared with NC-IMRT. There was no significant difference between NC-VMAT and co-VMAT in PTV coverage. Both VMAT plans provided a better protection for organs at risk (OARs) than NC-IMRT plans, and NC-VMAT showed a small improvement over co-VMAT in sparing of OARs. For peripheral doses, the doses to breast, thyroid, and larynx in the NC-IMRT plans were significantly higher than those in both VMAT plans. Compared to NC-VMAT, co-VMAT significantly reduced peripheral doses. NC-VMAT and co-VMAT reduced the average delivery time by 63.2 and 64.2%, respectively, in comparison with NC-IMRT. No differences in delivery efficiency were observed between the two VMAT plans. Compared to NC-VMAT, co-VMAT showed similar PTV coverage and comparable OAR sparing but significantly reduced peripheral doses and positioning uncertainty. We propose to give priority to coplanar VMAT in the treatment of sinonasal cancer.

  15. Impact of saline irrigation and topical corticosteroids on the post-surgical sinonasal microbiota

    Science.gov (United States)

    Liu, Cindy M.; Kohanski, Michael A.; Mendiola, Michelle; Soldanova, Katerina; Dwan, Michael G.; Lester, Richard; Nordstrom, Lora; Price, Lance B.; Lane, Andrew P.

    2015-01-01

    Introduction Topical treatments with nasal saline irrigation, topical steroid sprays, or corticosteroid rinses can improve sinonasal symptoms in chronic rhinosinusitis (CRS). However, the impact of these therapies on commensals (Corynebacterium) and on biofilm pathogens associated with CRS (Staphylococcus aureus and Pseudomonas) is not well characterized. Methods Paired nasal and sinus swabs were collected endoscopically from 28 controls and 14 CRS patients with nasal polyposis (CRSwNP) who had not received systemic antibiotics or corticosteroids in the previous eight weeks. Total DNA from swab eluents were extracted and analyzed by 16S rRNA gene-based pyrosequencing. A total 359,077 reads were obtained and classified taxonomically. The association of use of topical therapies with sinonasal microbiota composition was assessed by factor and vector-fitting. The proportional abundances of sinonasal bacteria between topical therapy users and non-users were further compared by two-tailed Kolmogorov-Smirnov test among controls and among CRSwNP participants. Result Nasal saline irrigation, with or without added budesonide, was not associated with significantly distinct sinonasal microbiota composition or significantly decreased Pseudomonas or S. aureus abundances among either controls or CRSwNP participants. Corynebacterium was slightly lower in controls that reported using saline irrigation than those who did not. No significant association was found between nasal saline irrigation and the proportional abundances of Pseudomonas, S. aureus, and Corynebacterium in CRSwNP participants. However, male CRSwNP patients were noted to have significantly higher Corynebacterium proportional abundances than their female counterparts. The use of topical steroid sprays was associated with a distinct microbiota in control subjects, characterized by higher proportional abundances of Dolosigranulum and Simonsiella and a lower proportional abundance of Campylobacter. Conclusion Nasal

  16. [Occupational exposure to wood dust. Health effects and exposure limit values].

    Science.gov (United States)

    Carton, M; Goldberg, M; Luce, D

    2002-04-01

    This article presents a review of the health effects of occupational exposure to wood dusts and of the data that could be used for setting occupational exposure limits for this nuisance. The causal role of wood dust in the onset of sinonasal cancers is solidly established by numerous epidemiological studies, and the magnitude of the risk is particularly high for adenocarcinoma induced by exposure to hardwood dust. However, no current data allows to rule out the carcinogenic role of softwood dusts and, in the view of protecting the health of the workers, it does not seem relevant to distinguish these two types of wood. Various impairments of the lung function have been frequently associated with exposure to both 'allergenic' and 'non-allergenic' wood dusts and may occur at very low concentrations. According to the SUMER 94 and CAREX studies, about 200 000 workers are currently exposed to wood dusts in France (about 1% of the working population between 1990 and 1994). When taking into account full professional careers, the percentage of workers having been occupationally exposed can be estimated to be about 15% for men and 5% for women. Measurements performed in France between 1987 and 2000 show that exposure levels are high, about 50% of the samplings being over 1mg/m(3) (actual TWA in France). Although the studies present limits, particularly for the quantitative assessment of individual exposure levels, it seems that nonmalignant effects are susceptible to arise at the level of 1mg/m(3); a limit value of 0.5mg/m(3) would credibly allow to protect exposed workers from most of the risks of nonmalignant pulmonary effects. However, it is impossible to assure that this value will avoid the induction of sinonasal cancer, even if this level is certainly lower than the levels to which the cases of sinonasal cancers published in the literature were exposed.

  17. Monitoring of heavy metal levels in roadside dusts of Thessaloniki, Greece in relation to motor vehicle traffic density and flow.

    Science.gov (United States)

    Ewen, Caroline; Anagnostopoulou, Maria A; Ward, Neil I

    2009-10-01

    In recent years, the level of heavy metal pollution in urban areas has been of considerable concern. The principal source has been attributed to the motor vehicle and increasing inner city congestion, which has lead to a change and enlargement of transport stop-start zones. These areas of high traffic density are associated with an increased release of heavy metals into the adjacent residential or commercial areas. Seventy-five roadside dust samples were collected throughout the inner city and by-pass motorway areas of Thessaloniki, Northern Greece. Samples were taken from arterial, major and minor roads, as well as the ring road, to compare and contrast the levels of heavy metals, namely Cu, Zn, Cd, Mn and Pb. Flame Atomic Absorption Spectroscopy (FAAS) was developed to quantitatively determine concentrations of both total element and geochemical fractionation, within the two dust particulate fraction sizes congestion/stop-start traffic patterns did influence and have led to increased levels of heavy metal deposition along inner city roads compared to levels observed on the new relief ring road. Dust particulate fraction sizes were only found to show statistically significant differences in cadmium and manganese, at the probability P 0.05 or 95% confidence limit. Road type was seen to have little affect on cadmium and manganese, though lead, copper and zinc were all found to show higher levels on the inner city routes. This can be related back to the wear-and-tear of vehicle components as a result of the stop-start traffic patterns (brake pads etc). Both Pb and Zn have shown to be in chemical forms that are bio available to ecosystems.

  18. Overview on relative importance of house dust ingestion in human exposure to polybrominated diphenyl ethers (PBDEs): International comparison and Korea as a case.

    Science.gov (United States)

    Kim, Seung-Kyu; Kim, Kyoung-Soo; Sang, Hee Hong

    2016-11-15

    Human exposure studies to polybrominated diphenyl ethers (PBDEs) have reached different results about the relative importance of diet intake and house dust ingestion. In the present study, concentrations of PBDEs in Korean house dust (n=15) from geographically different cities were measured, which were in agreement with a previous result, and compared with those for 22 countries of five continents collected from the most recent scientific literature. Compared with other exposure pathways, diet intake was the most important contributor to total PBDEs exposure of Korean adults (i.e., 71% of overall intake). On global comparison, total PBDE levels in house dust differed by two to three orders of magnitude among the countries investigated, with a significant relationship with gross domestic product (GDP). Whereas, dietary daily intakes exhibited a narrow difference within one order of magnitude worldwide and no relationship with GDP. Consequently, the relative importance of major two pathways depended on the contamination extent of PBDEs in house dust, which may be associated with the amount of PBDE products in use. In most countries except for UK and USA, the contribution of house dust ingestion was less important than diet intake in the current and are expected to much more mitigate in the future. However, how fast the effect of regulation will be reflected to house dust and human exposure is necessary to be monitored steadily.

  19. Establishing health standards for indoor foreign proteins related to asthma: Dust mite, cat and cockroach

    Energy Technology Data Exchange (ETDEWEB)

    Platts-Mills, T.A.E.; Chapman, M.D.; Pollart, S.M.; Heymann, P.W.; Luczynska, C.M. (Univ. of Virginia, Charlottesville (United States))

    1990-01-01

    There is no doubt that a large number of individuals become allergic to foreign proteins that are predominantly or exclusively present indoors. In each case this immune response can be demonstrated either by immediate skin test responses or by measuring serum IgE antibodies. It has also been obvious for some time that patients presenting with asthma, perennial rhinitis and atopic dermatitis have an increased prevalence of IgE antibodies to these indoor allergens. More recently several epidemiological surveys have suggested that both mite exposure and IgE antibodies are important risk factors for asthma. The present situation is that assays have been developed capable of measuring the presence of mite, cockroach and cat allergens in house dust. Further clinical studies will be necessary to test the proposed standards for mite allergens and to define risk levels for other allergens.

  20. Smoking, not human papilloma virus infection, is a risk factor for recurrence of sinonasal inverted papilloma.

    Science.gov (United States)

    Roh, Hwan-Jung; Mun, Sue Jean; Cho, Kyu-Sup; Hong, Sung-Lyong

    2016-01-01

    The recurrence rate of sinonasal inverted papillomas (SNIP) is 15-20%. However, few studies have investigated patient-dependent factors related to recurrence of SNIPs. To analyze risk factors, including human papilloma virus (HPV) infection and smoking, as well as other factors, for recurrence of SNIPs. Fifty-four patients who were diagnosed with SNIP and underwent surgery were enrolled: 39 men and 15 women, with the mean age of 54.0 years. Their mean follow-up was 40.6 months. Demographics and information about the history of smoking, previous surgery, tumor extent, follow-up, and recurrence were reviewed retrospectively. Those patients whose tumors were associated with malignant transformation were excluded in this study. HPV detection and genotyping in the tumor specimens were performed with the HPV DNA chip, a polymerase chain reaction-based DNA microarray system. Seven patients (13.0%) had recurrence, with a mean time to recurrence of 39.8 months. Recurrence rates in T1, T2, T3, and T4 of the Krouse staging system were 0% (0/4), 8.3% (2/24), 17.4% (4/23), and 33.3% (1/3), respectively (p > 0.5). Eight patients (14.8%) were positive for HPV DNA. All of these patients belonged to the group without recurrence (p > 0.5). However, recurrence rates according to HPV DNA positivity were not statistically different (0% versus 15.2%). Three (42.9%) in the group with recurrence and four (8.5%) in the group without recurrence were smokers (p < 0.5). Smoking was associated with recurrence of SNIP. However, HPV infection is not a recurrence of SNIP risk factor.

  1. Operational Dust Prediction

    Science.gov (United States)

    Benedetti, Angela; Baldasano, Jose M.; Basart, Sara; Benincasa, Francesco; Boucher, Olivier; Brooks, Malcolm E.; Chen, Jen-Ping; Colarco, Peter R.; Gong, Sunlin; Huneeus, Nicolas; Jones, Luke; Lu, Sarah; Menut, Laurent; Morcrette, Jean-Jacques; Mulcahy, Jane; Nickovic, Slobodan; Garcia-Pando, Carlos P.; Reid, Jeffrey S.; Sekiyama, Thomas T.; Tanaka, Taichu Y.; Terradellas, Enric; Westphal, Douglas L.; Zhang, Xiao-Ye; Zhou, Chun-Hong

    2014-01-01

    Over the last few years, numerical prediction of dust aerosol concentration has become prominent at several research and operational weather centres due to growing interest from diverse stakeholders, such as solar energy plant managers, health professionals, aviation and military authorities and policymakers. Dust prediction in numerical weather prediction-type models faces a number of challenges owing to the complexity of the system. At the centre of the problem is the vast range of scales required to fully account for all of the physical processes related to dust. Another limiting factor is the paucity of suitable dust observations available for model, evaluation and assimilation. This chapter discusses in detail numerical prediction of dust with examples from systems that are currently providing dust forecasts in near real-time or are part of international efforts to establish daily provision of dust forecasts based on multi-model ensembles. The various models are introduced and described along with an overview on the importance of dust prediction activities and a historical perspective. Assimilation and evaluation aspects in dust prediction are also discussed.

  2. Sinonasal Lymphoma Presenting as a Probable Sanctuary Site for Relapsed B Acute Lymphoblastic Leukaemia: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    W. Y. Lim

    2015-01-01

    Full Text Available Sinonasal lymphoma is a non-Hodgkin lymphoma (NHL representing 1.5% of all lymphomas. It presents as an unremitting ulceration with progressive destruction of midline sinonasal and surrounding structures. Poor prognosis warrants early treatment although diagnosis is challenging and frequently delayed. It is usually primary in origin and to our knowledge the sinonasal region has never been reported as a sanctuary site in leukaemia/lymphoma relapse. We present a unique case of B-cell ALL (acute lymphoblastic leukaemia with late relapse to the nasal septum as a sinonasal lymphoblastic lymphoma and with genetic support for this as a sanctuary site.

  3. Ameloblastoma of the Sinonasal Tract: Report of a Case with Clinicopathologic Considerations

    Directory of Open Access Journals (Sweden)

    Maria Grazia Tranchina

    2012-01-01

    Full Text Available Ameloblastomas are locally aggressive jaw tumours with a high propensity for recurrence and are believed to arise from remnants of dental lamina or odontogenic epithelium. Extragnathic ameloblastomas are unusual, and primary sinonasal tract origin is very uncommon with few cases reported in the literature. We herein report a case of primary sinonasal ameloblastoma presented in a 74-year-old male with nasal obstruction, rhinorrhoea, and sinusitis. Nasal endoscopy showed the right nasal cavity completely obstructed by a polypoid lesion attached to the lateral nasal wall. A preoperative CT scan was performed showing a solid lesion, measuring 2 cm in the maximum diameter, extending from the nasopharynx area with obstruction of the ostiomeatal unit and sphenoethmoidal recess into the lateral pharyngeal space, laterally to the parotid, without continuity with maxillary alveola and antrum. The tumour was completely excised endoscopically, and a final diagnosis of ameloblastoma was rendered. At the 12-month followup, there was no evidence of recurrence.

  4. Mortality from myocardial infarction in relation to exposure to vibration and dust among a cohort of iron-ore miners in Sweden.

    Science.gov (United States)

    Björ, Bodil; Burström, Lage; Eriksson, Kåre; Jonsson, Håkan; Nathanaelsson, Lena; Nilsson, Tohr

    2010-03-01

    The aim of this study was to investigate myocardial infarction (MI) mortality in relation to exposure to hand/arm vibration (HAV) and whole body vibration (WBV) as well as exposure to dust among men employed in two Swedish iron-ore mines. This study comprised employed men at two iron-ore mines in Sweden who had been employed for at least 1 year from 1923 up to 1996. The causes of death were obtained from the national cause of death register from 1952 to 2001. Myocardial infarction mortality was obtained by linking personal identification numbers to the national cause of death register. Poisson regression was used for risk estimations on exposure-response relation, and analyses were made on the two age groups 60 years. Relative risks for MI mortality in relation to exposure were significantly increased for exposure (0/>0) to WBV (RR 1.18, 95% CI 1.06 to 1.31) and dust (RR 1.15, 95% CI 1.02 to 1.31), and the results indicated an exposure-response relation for WBV and dust separately. For 60 years and younger, exposure to HAV (0/>0) (RR 1.34, 95% CI 1.03 to 1.74) and WBV (0/>0) (RR 1.39, 95% CI 1.13 to 1.72) increased the risk of MI mortality. An exposure-response was found for HAV and WBV, as the medium and high exposed categories showed significantly increased risk estimates. None of the exposures significantly increased the risk in the group above 60 years. The increased risk estimates for exposure to WBV remained when adjusting for exposure to dust. The results for the working age (< or =60 years) group showed significantly increased MI mortality for univariate exposure to HAV, WBV and dust. We found an association between increased mortality from MI and occupational exposure to WBV, and the risk remained after adjustment for dust exposure.

  5. (18)FDG PET/CT in Routine Surveillance of Asymptomatic Patients following Treatment of Sinonasal Neoplasms.

    Science.gov (United States)

    Workman, Alan D; Glicksman, Jordan T; Parasher, Arjun K; Carey, Ryan M; Brooks, Steven G; Kennedy, David W; Nabavizadeh, Seyed A; Learned, Kim O; Palmer, James N; Adappa, Nithin D

    2017-08-01

    Objective Sinonasal neoplasms have a high rate of recurrence following treatment, and current guidelines support the use of a variety of surveillance techniques. Recent work demonstrates that performance parameters of surveillance modalities may differ with sinonasal tumors in particular when compared with head and neck tumors overall. This study aims to characterize the value of (18)fluorodeoxyglucose ((18)FDG) positron emission tomography/computed tomography (PET/CT) as a screening tool in asymptomatic patients. Study Design Retrospective cohort study. Setting Hospital of the University of Pennsylvania and Pennsylvania hospital. Methods Records of asymptomatic patients without suspicious endoscopy or suspicious imaging other than PET during the first 3 years following definitive treatment for sinonasal malignancy were screened and analyzed for inclusion in the cohort. Disease recurrence was determined by biopsy following suspicious PET evaluation. Results PET/CT scans (n = 111) were performed for 45 disease-free asymptomatic patients with no evidence of disease on endoscopy, and 6.3% were suspicious and prompted biopsy during this period, revealing 3 cases of disease recurrence. Overall specificity for PET/CT alone was 96.3% (95% CI, 90.7%-99.0%), with a negative predictive value of 99% (95% CI, 94.8%-100%). All recurrences were detected between 7 and 12 months, and all patients with true recurrence diagnosed by PET/CT had extrasinonasal involvement of tumor at the time of surgery. Conclusion We examined performance parameters of (18)FDG PET/CT in asymptomatic patients with no evidence of disease on endoscopy during the posttreatment period for sinonasal malignancy. The ability of PET/CT to detect recurrences that may be missed by structural imaging or endoscopy makes it a valuable tool for clinicians.

  6. Long-term sinonasal outcomes of aspirin desensitization in aspirin exacerbated respiratory disease.

    Science.gov (United States)

    Cho, Kyu-Sup; Soudry, Ethan; Psaltis, Alkis J; Nadeau, Kari C; McGhee, Sean A; Nayak, Jayakar V; Hwang, Peter H

    2014-10-01

    This study aimed to assess sinonasal outcomes in patients with aspirin exacerbated respiratory disease (AERD) undergoing aspirin desensitization following endoscopic sinus surgery (ESS). Case series with chart review. University hospital. A retrospective review of sinonasal outcomes was conducted for 30 AERD patients undergoing aspirin desensitization and maintenance therapy following ESS. Sinonasal outcomes were prospectively assessed by the Sinonasal Outcomes Test-22 (SNOT-22) and endoscopic polyp grading system. Data were collected preoperatively, 1 and 4 weeks postsurgery (before desensitization), and 1, 6, 12, 18, 24, and 30 months after aspirin desensitization. Twenty-eight of 30 patients (93.3%) successfully completed aspirin desensitization, whereas 2 of 30 (6.7%) were unable to complete desensitization due to respiratory intolerance. Of the 21 patients who successfully completed a minimum of 24 weeks of follow-up, 20 (95.2%) patients demonstrated sustained endoscopic and symptomatic improvement for a median follow-up period of 33 months. After surgical treatment but before desensitization, patients experienced significant reductions in SNOT-22 and polyp grade scores. In the first 6 months after aspirin desensitization, patients experienced further significant reductions in SNOT-22 scores, whereas polyp grade remained stable. The improvements in symptom endoscopic scores were preserved throughout the follow-up period after desensitization. No patients required additional sinus surgery. One patient had to discontinue aspirin therapy due to gastrointestinal side effects. No other adverse reactions to aspirin were noted. Aspirin desensitization following ESS appears to be a well-tolerated and effective adjunctive therapy for long-term control of nasal polyposis in patients with AERD. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  7. The Olfactory Strip and Its Preservation in Endoscopic Pituitary Surgery Maintains Smell and Sinonasal Function.

    Science.gov (United States)

    Harvey, Richard J; Winder, Mark; Davidson, Andrew; Steel, Tim; Nalavenkata, Sunny; Mrad, Nadine; Bokhari, Ali; Barham, Henry; Knisely, Anna

    2015-12-01

    Background The return of olfaction and of sinonasal function are important end points after pituitary surgery. Opinions differ on the impact of surgery because techniques vary greatly. A modified preservation of the so-called olfactory strip is described that utilizes a small nasoseptal flap and wide exposure. Methods A cohort of patients undergoing pituitary surgery and endoscopic sinonasal tumor surgery were assessed. Patient-reported outcomes (Sino-Nasal Outcome Test [SNOT22] and Nasal Symptom Score [NSS]) were recorded. A global score of sinonasal function and the impact on smell and taste were obtained. Objective smell discrimination testing was performed in the pituitary group with the Smell Identification Test. Outcomes were assessed at baseline and at 6 months. Results Ninety-eight patients, n = 40 pituitary (50.95 ± 15.31 years; 47.5% female) and n = 58 tumor (52.35 ± 18.51 years; 52.5% female) were assessed. For pituitary patients, NSSs were not significantly different pre- and postsurgery (2.75 ± 3.40 versus 3.05 ± 3.03; p = 0.53). SNOT22 scores improved postsurgery (1.02 ± 0.80 versus 0.83 ± 0.70; p = 0.046). Objective smell discrimination scores between baseline and 6 months were similar (31.63 ± 3.49 versus 31.35 ± 4.61; p = 0.68). No difference in change of olfaction was seen compared with controls (Kendall tau-b p = 0.46). Conclusions Preservation of the olfactory strip can provide a low morbidity approach without adversely affecting olfaction and maintaining reconstruction options.

  8. Phthalate concentrations in house dust in relation to autism spectrum disorder and developmental delay in the CHildhood Autism Risks from Genetics and the Environment (CHARGE) study.

    Science.gov (United States)

    Philippat, Claire; Bennett, Deborah H; Krakowiak, Paula; Rose, Melissa; Hwang, Hyun-Min; Hertz-Picciotto, Irva

    2015-06-26

    Phthalates are endocrine-disrupting chemicals that influence thyroid hormones and sex steroids, both critical for brain development. We studied phthalate concentrations in house dust in relation to the risks of developing autism spectrum disorder (ASD) or developmental delay (DD). Participants were a subset of children from the CHARGE (CHildhood Autism Risks from Genetics and the Environment) case-control study. ASD and DD cases were identified through the California Department of Developmental Services system or referrals; general population controls were randomly sampled from state birth files and frequency-matched on age, sex, and broad geographic region to ASD cases. All children (50 ASD, 27 DD, 68 typically developing (TD)) were assessed with Mullen Scales of Early Learning, Vineland Adaptive Behavior Scales (VABS) and Aberrant Behavior Checklist. We measured 5 phthalates in dust collected in the child's home using a high volume small surface sampler. None of the phthalates measured in dust was associated with ASD. After adjustment, we observed greater di(2-ethylhexyl) phthalate (DEHP) and butylbenzyl phthalate (BBzP) concentrations in indoor dust from homes of DD children: Odds ratios (OR) were 2.10 (95% confidence interval (CI); 1.10; 4.09) and 1.40 (95% CI; 0.97; 2.04) for a one-unit increase in the ln-transformed DEHP and BBzP concentrations, respectively. Among TD children, VABS communication, daily living, and adaptive composite standard scores were lower, in association with increased diethyl phthalate (DEP) concentrations in dust. Participants with higher dibutyl phthalate (DBP) concentrations in house dust also trended toward reduced performance on these subscales. Among ASD and DD boys, higher indoor dust concentrations of DEP and DBP were associated with greater hyperactivity-impulsivity and inattention. House dust levels of phthalates were not associated with ASD. The inability to distinguish past from recent exposures in house dust and the fact

  9. CT, MRI, and FDG PET/CT findings of sinonasal sarcoma: Differentiation from squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Ho; Yoon, Dae Young; Baek, Sora; Park, Min Woo; Kwon, Kee Hwan; Rho, Young Soo [Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of)

    2016-07-15

    To evaluate computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT (PET/CT) findings for the differentiation of sinonasal sarcoma from squamous cell carcinoma (SCC). We retrospectively reviewed CT, MRI, and FDG PET/CT results in 20 patients with pathologically proven sinonasal sarcoma (n = 7) and SCC (n = 13). Imaging characteristics of tumors, such as the shape, size, margin, MRI signal intensity, pattern of enhancement, local tumor invasion, and maximum standardized uptake value (SUVmax) were analyzed and compared between sarcoma and SCC. The SUVmax of sarcomas (7.4 ± 2.1) was significantly lower than the SUVmax of the SCCs (14.3 ± 4.5) (p = 0.0013). However, no significant difference in the shape, size, margin, MRI signal intensity, pattern of enhancement, and local tumor invasion was observed between sarcoma and SCC. Although CT and MR imaging features are nonspecific, FDG PET/CT is useful in distinguishing between sinonasal sarcoma and SCC based on the SUVmax value.

  10. Increased expression of fascin associated with malignant transformation of sinonasal inverted papilloma

    Institute of Scientific and Technical Information of China (English)

    WANG An-liu; LIU Hong-gang; ZHANG Yong

    2007-01-01

    Background Fascin, an actin binding protein, usually expressed at a low level in normal epithelium, but is significantly increased in transformed epithelial cells and several common carcinomas. In this study, we examined the expression of fascin by immunohistochemistry in sinonasal epithelium with chronic inflammation (control group), exophytic papilloma(EP), inverted papilloma (IP) with dysplasia and cancerated IP (including carcinoma in situ and invasive squamous cell carcinoma, SCC), and furthermore investigated the relationship between fascin expression and formation of malignant IP.Methods Fascin expression was immunohistochemically detected using monoclonal antibody against fascin in 86paraffin embedded tissues, including 10 cases of sinonasal mucosa with chronic inflammation, 10 of EP, 45 of IP with dysplasia (45 cases were divided into three groups: IP with mild dysplasia, IP with moderate dysplasia, and IP with severe dysplasia, 15 cases each), and 21 of cancerated IP.Results The level of fascin expression was significantly higher in the neoplastic tissue than that in control group. Fascin expression increased gradually with the progression from sinonasal epithelium with chronic inflammation, IP with mild dysplasia, IP with moderate dysplasia, IP with severe dysplasia, to cancerated IP, and significant difference of fascin expression was observed between any two groups of the five.Conclusion Precancerous lesions of IP exhibit elevated levels of fascin that may be associated with carcinogenesis of IP. Fascin may play a role in the formation of IP and EP.

  11. Magnetic Resonance Imaging in the diagnosis and monitoring of sinonasal pathology

    Directory of Open Access Journals (Sweden)

    Rodrigo BLANCO-HERNÁNDEZ

    2016-11-01

    Full Text Available Introduction and objective: Magnetic resonance imaging (MRI is not commonly used as the first technique in the study of sinonasal pathology, it is usually complementary to computed tomography (CT, however it is useful for the assessment of some pathology and response to treatment. Method: Updated review and study of the protocols and the most representative cases carried out in our department during the last 5 years. Results: The main advantages and utilities of MRI in the diagnosis and monitoring of disease sinonasal are explained. The anatomy of the sinuses and nasal cavity through MRI in different planes is explicated. MRI sequences employed are analyzed, the indications of diagnostic imaging technique are shown according to the pathology and the imaging features in MRI are explained for both, inflammatory pathology and paranasal neoplasms. Conclusions: Although MRI is behind the TC in the study of sinonasal pathology is particularly useful for assessing tumor pathology because of its ability to distinguish between different tissues and facilitate the diagnosis extension of neoplasms. In addition MRI is usually the technique of choice for the post-treatment evaluation.

  12. Vibrational mapping of sinonasal lesions by Fourier transform infrared imaging spectroscopy

    Science.gov (United States)

    Giorgini, Elisabetta; Sabbatini, Simona; Conti, Carla; Rubini, Corrado; Rocchetti, Romina; Re, Massimo; Vaccari, Lisa; Mitri, Elisa; Librando, Vito

    2015-12-01

    Fourier transform infrared imaging (FTIRI) is a powerful tool for analyzing biochemical changes in tumoral tissues. The head and neck region is characterized by a great variety of lesions, with different degrees of malignancy, which are often difficult to diagnose. Schneiderian papillomas are sinonasal benign neoplasms arising from the Schneiderian mucosa; they can evolve into malignant tumoral lesions (squamous cell carcinoma). In addition, they can sometimes be confused with the more common inflammatory polyps. Therefore, an early and definitive diagnosis of this pathology is mandatory. Progressing in our research on the study of oral cavity lesions, 15 sections consisting of inflammatory sinonasal polyps, benign Schneiderian papillomas, and sinonasal undifferentiated carcinomas were analyzed using FTIRI. To allow a rigorous description of these pathologies and to gain objective diagnosis, the epithelial layer and the adjacent connective tissue of each section were separately investigated by following a multivariate analysis approach. According to the nature of the lesion, interesting modifications were detected in the average spectra of the different tissue components, above all in the lipid and protein patterns. Specific band-area ratios acting as spectral markers of the different pathologies were also highlighted.

  13. Sinonasal imaging after Caldwell-Luc surgery: MDCT findings of an abandoned procedure in times of functional endoscopic sinus surgery

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Stefan Franz; Peloschek, Philipp; Koelblinger, Claus; Mehrain, Sheida; Krestan, Christian Robert; Czerny, Christian [Department of Radiology, Division of Neuroradiology and Musculoskeletalradiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria)

    2009-04-15

    Background and purpose: Today, functional endoscopic sinus surgery (FESS) is performed in most of the patients with sinonasal inflammatory disease. The postoperative imaging findings of FESS in multidetector computed tomography (MDCT) considerably differ from those of historic Caldwell-Luc (CL) maxillary sinus surgery which is an uncommon procedure today. Thus, the postoperative CL imaging findings may lead to diagnostic confusion and misinterpretation. Therefore, this study explicitly presents the MDCT findings of post-CL patients which have not been described previously. Methods: Twenty-eight patients with clinically suspected sinusitis and documented history of CL-procedure underwent 16 row MDCT (MDCT Mx8000 IDT Philips) with multiplanar reconstructions of the paranasal sinuses in the axial plane. The following parameters were used: 140 kV, 50 mAs; 16 mm x 0.75 mm detector collimation; 1 mm reconstructed slice thickness; 0.5 mm increment. The studies were reconstructed with a bone algorithm (W3000/L600; 1 mm slice thickness) in axial plane and coronal plane (3 mm slice thickness). The images were retrospectively evaluated for the presence of normal surgery-related and pathological findings. Results: Surgery-related imaging characteristics presented as follows: an anterior and a medial bony wall defect and sclerosis and sinus wall thickening were observed in all 28/28 cases (100%). Collaps of the sinus cavity was seen in 26/28 cases (92.9%). Furthermore, inflammatory disease of the operated sinus(es) was found in 23/28 cases (82.1%): 14/28 patients (50%) had inflammatory mucosal thickening of the operated sinus(es) as well as of other sinonasal cavities and 9/28 patients (32.1%) had inflammatory mucosal thickening limited to the operated sinus(es). A postoperative mucocele was depicted in 3/28 cases (10.7%). 2/28 patients (7.1%) showed neither maxillary nor other mucosal swelling. Conclusion: MDCT with multiplanar reconstructions is a precise method to evaluate

  14. Effects of dust storm events on weekly clinic visits related to pulmonary tuberculosis disease in Minqin, China

    Science.gov (United States)

    Wang, Yun; Wang, Ruoyu; Ming, Jing; Liu, Guangxiu; Chen, Tuo; Liu, Xinfeng; Liu, Haixia; Zhen, Yunhe; Cheng, Guodong

    2016-02-01

    Pulmonary tuberculosis (PTB) is a major public health problem in China. Minqin, a Northwest county of China, has a very high number of annual PTB clinic visits and it is also known for its severe dust storms. The epidemic usually begins in February and ends in July, while the dust storms mainly occur throughout spring and early summer, thereby suggesting that there might be a close link between the causative agent of PTB and dust storms. We investigated the general impact of dust storms on PTB over time by analyzing the variation in weekly clinic visits in Minqin during 2005-2012. We used the Mann-Whitney-Pettitt test and a regression model to determine the seasonal periodicity of PTB and dust storms in a time series, as well as assessing the relationships between meteorological variables and weekly PTB clinic visits. After comparing the number of weekly PTB cases in Gansu province with dust storm events, we detected a clear link between the population dynamics of PTB and climate events, i.e., the onset of epidemics and dust storms (defined by an atmospheric index) occurred in almost the same mean week. Thus, particulate matter might be the cause of PTB outbreaks on dust storm days. It is highly likely that the significant decline in annual clinic visits was closely associated with improvements in the local environment, which prevented desertification and decreased the frequency of dust storm events. To the best of our knowledge, this is the first population-based study to provide clear evidence that a PTB epidemic was affected by dust storms in China, which may give insights into the association between this environmental problem and the evolution of epidemic disease.

  15. Sinonasal malignancies with neuroendocrine differentiation: Case series and review of literature

    Directory of Open Access Journals (Sweden)

    Menon Santosh

    2010-01-01

    Full Text Available Primary sinonasal tumors with neuroendocrine differentiation (SCND are uncommon tumors with considerable overlap of histological features. Based on their neuroendocrine differentiation they can be sub categorized into sinonasal undifferentiated carcinoma (SNUC, sinonasal neuroendocrine carcinoma (SNEC, esthesioneuroblastoma (ENB and small cell carcinoma (SmCC. The natural history and biological behavior varies in this group of tumors. Hence the histo-morphological diagnosis coupled with grading/staging is important for the prognostication of these tumors. Aim : To study the clinicopathological characteristics of sinonasal neuroendocrine malignancies at our institute. Material and Methods : We searched our institute′s pathology database for the period from 2002 to 2007, for the four subcategories of sinonasal tumors with neuroendocrine differentiation. Morphological and immunohistochemical features were studied and, grading, staging was done in accordance with standard criteria. The clinical treatment and follow- up data were retrieved from the case files in available cases. Results : A total of 37 cases were retrieved from our database which include 14 cases of SNUC, 14 cases of ENB and nine cases of SNEC. The cases of SNUC were immunopositive for cytokeratin, epithelial membrane antigen and weakly for neuron-specific enolase. SNEC showed strong reactivity with epithelial and neuroendocrine markers whereas ENB demonstrated immunoreactivity to synaptophysisn and chromogranin strongly, with weak to negative expression of epithelial markers. All cases of SNUC and SNEC were of high grade and stage whereas 50% of ENB cases were of grade II but high stage tumors. Most of the SNUC and SNEC patients had been treated with multimodality treatment regimens including upfront chemotherapy followed by surgery and loco- regional radiation. In contrast, ENB patients had undergone surgical extirpation followed by radiation therapy in majority of cases. With

  16. A longitudinal study of sick building syndrome among pupils in relation to microbial components in dust in schools in China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin, E-mail: xinzhang0051@sxu.edu.cn [Research Center for Environmental Science and Engineering, Shanxi University, 030006 Taiyuan (China); Department of Medical Sciences, Uppsala University and University Hospital, 75185 Uppsala (Sweden); Zhao, Zhuohui [Department of Environmental Health, Key Laboratory of Public Health Safety, Ministry of Education, Fudan University, 030002 Shanghai (China); Nordquist, Tobias [Department of Medical Sciences, Uppsala University and University Hospital, 75185 Uppsala (Sweden); Larsson, Lennart; Sebastian, Aleksandra [Department of Laboratory Medicine, Division of Medial Microbiology, University of Lund, 22100 Lund (Sweden); Norback, Dan [Department of Medical Sciences, Uppsala University and University Hospital, 75185 Uppsala (Sweden)

    2011-11-15

    There are few longitudinal studies on sick building syndrome (SBS), which include ocular, nasal, throat, and dermal symptoms, headache, and fatigue. We studied the associations between selected microbial components, fungal DNA, furry pet allergens, and incidence and remission of SBS symptoms in schools in Taiyuan, China. The study was based on a two-year prospective analysis in pupils (N = 1143) in a random sample of schools in China. Settled dust in the classrooms was collected by vacuum cleaning and analyzed for lipopolysaccharide (LPS), muramic acid (MuA), and ergosterol (Erg). Airborne dust was collected in Petri dishes and analyzed for cat and dog allergens and fungal DNA. The relationship between the concentration of allergens and microbial compounds and new onset of SBS was analyzed by multi-level logistic regression. The prevalence of mucosal and general symptoms was 33% and 28%, respectively, at baseline, and increased during follow-up. At baseline, 27% reported at least one symptom that improved when away from school (school-related symptoms). New onset of mucosal symptoms was negatively associated with concentration of MuA, total LPS, and shorter lengths of 3-hydroxy fatty acids from LPS, C14, C16, and C18. Onset of general symptoms was negatively associated with C18 LPS. Onset of school-related symptoms was negatively associated with C16 LPS, but positively associated with total fungal DNA. In general, bacterial compounds (LPS and MuA) seem to protect against the development of mucosal and general symptoms, but fungal exposure measured as fungal DNA could increase the incidence of school-related symptoms. - Highlights: {yields} SBS symptoms increased during the two-year follow-up period in school children in Taiyuan, China {yields} We studied the associations between selected microbial components and incidence and remission of SBS symptoms. {yields} Bacterial compounds (LPS and MuA) seem to protect against the development of mucosal and general symptoms

  17. Influence of house dust mite impermeable covers on health-related quality of life of adult patients with asthma: results of a randomized clinical trial.

    NARCIS (Netherlands)

    Bemt, L. van den; Vries, M.P. de; Cloosterman, S.G.M.; Thoonen, B.P.A.; Muris, J.W.M.; Goossens, M.; Wesseling, G.; Schayck, C.P. van

    2007-01-01

    The aim of this study was to evaluate the effect of house dust mite impermeable covers on asthma-specific health-related quality of life in adult asthmatic patients that were trained in guided self-management. In a 2-year randomized placebo-controlled clinical trial, information on the quality of li

  18. Influence of house dust mite impermeable covers on health-related quality of life of adult patients with asthma: results of a randomized clinical trial.

    NARCIS (Netherlands)

    Bemt, L. van den; Vries, M.P. de; Cloosterman, S.G.M.; Thoonen, B.P.A.; Muris, J.W.M.; Goossens, M.; Wesseling, G.; Schayck, C.P. van

    2007-01-01

    The aim of this study was to evaluate the effect of house dust mite impermeable covers on asthma-specific health-related quality of life in adult asthmatic patients that were trained in guided self-management. In a 2-year randomized placebo-controlled clinical trial, information on the quality of li

  19. Inflammatory potential in relation to the microbial content of settled dust samples collected from moisture damaged and reference schools : Results of HITEA study

    NARCIS (Netherlands)

    Huttunen, Kati; Tirkkonen, Jenni; Täubel, Martin; Krop, Esmeralda; Mikkonen, Santtu; Pekkanen, Juha; Heederik, Dick; Zock, Jan-Paul; Hyvärinen, Anne; Hirvonen, Maija-Riitta

    2016-01-01

    Aiming to identify factors causing the adverse health effects associated with moisture damaged indoor environments, we analyzed immunotoxicological potential of settled dust from moisture damaged and reference schools in relation to their microbiological composition. Mouse RAW264.7 macrophages were

  20. Inflammatory potential in relation to the microbial content of settled dust samples collected from moisture domaged and reference schools: results of HITEA study.

    NARCIS (Netherlands)

    Huttunen, K.; Tirkkonen, J.; Täubel, M.; Krop, E.; Mikkonen, S.; Pekkanen, J.; Heederik, D.; Zock, J.P.; Hyvärinen, A.; Hirvonen, M.R.

    2015-01-01

    Aiming to identify factors causing the adverse health effects associated with moisture-damaged indoor environments, we analyzed immunotoxicological potential of settled dust from moisture-damaged and reference schools in relation to their microbiological composition. Mouse RAW264.7 macrophages were

  1. High-level vancomycin resistant Enterococcus faecium related to humans and pigs found in dust from pig breeding facilities.

    Science.gov (United States)

    Braga, Teresa M; Pomba, Constança; Lopes, M Fátima Silva

    2013-01-25

    Environmental dust from animal breeding facilities was never screened for the presence of enterococci, nor of vancomycin-resistant enterococci (VRE), despite the possibility of being a vehicle of transmission of strains and antibiotic resistance genes between food-producing animals and man. Bio-security measures in pig facilities include disinfection with biocides to avoid the dissemination of opportunistic pathogenic bacteria, namely enterococci and in particular VRE. We thus undertook collection of enterococci and VRE in a representative number of breeding pig facilities in Portugal (n=171) and analyzed their susceptibility to benzalkonium chloride (BC) and chlorhexidine (CHX). A prevalence of 15% of VRE was found, with 6% high-level resistance found, and MIC values for CHX and BC were similar to those commonly found among enterococcal isolates from related environments, 8 μg/ml and 4 μg/ml, respectively. Among the isolated high-level vancomycin resistant Enterococcus faecium carrying the vanA genotype, we found multilocus sequence types closely related to pig and human isolates from European countries and Brazil. These results strongly advise constant surveillance of this environment and its inclusion in future epidemiologic studies on VRE.

  2. Lung function: occupational exposure to wood dust

    Directory of Open Access Journals (Sweden)

    Baran S

    2009-12-01

    Full Text Available Abstract Objectives Occupational exposure to wood dust has been shown to cause several respiratory disorders, such as allergic rhinitis, chronic bronchitis, asthma, sino-nasal adenocarcinoma, and impairment of lung function. The aim of the study was to estimate lung function (in the woodworking industry among workers employed by wood processing, who run the risk of being expose to wood dust. Methods The study concerns a group of 70 workers aged 24-55. All the workers underwent general and laryngological examination. A group of 20 workers, working at the positions where dustiness exceeded TLV (threshold limit value took X-ray of the chest and spirometry. The following parameters were measured: VC, IC, ERV, TV, BF, FEV1, FVC, PEF, MEF25-75, FEV1%FVC, FEV1%VC. The data are presented as means ± SD and the authors applied references values according to ERS guidelines. Results The results show that there was no decline in FEV1 (3.7 ± 0.7 and FVC (4.5 ± 0.8. Normal lung function was defined as FEV1/VC ratio ≥0.7. None of the tested workers had obstructive pattern in spirometry. The mean FEV1%VC was 77.1 ± 10.2. These results suggest that wood dust exposure might not lead to significant pulmonary damage. Conclusions These data do not corroborate that wood dust plays significant role in lung function impairment. Future studies of respiratory health among workers exposed to wood dust are needed.

  3. Turbulence-Induced Relative Velocity of Dust Particles II: The Bidisperse Case

    CERN Document Server

    Pan, Liubin; Scalo, John

    2014-01-01

    We investigate the relative velocity of inertial particles induced by turbulent motions, extending our earlier work on equal-size particles to the bidisperse case for different particles of arbitrary sizes. The model of Pan & Padoan (PP10) shows that the relative velocity between different particles has two contributions, named the generalized shear and acceleration terms, respectively. The generalized shear term represents the particles' memory of the spatial flow velocity difference across the particle distance at given times in the past, while the acceleration term is associated with the temporal flow velocity difference on individual particle trajectories. The latter vanishes for equal-size particles. Using a simulation, we compute the root-mean-square (rms) relative velocity, ^1/2, as a function of the particle friction times, tau_p1 and tau_p2, and show that the prediction of the PP10 model is in satisfactory agreement with the data, confirming the validity of its physical picture. For a given tau_p...

  4. The role of radiotherapy in the management of sinonasal melanoma and its impact on patients and healthcare professionals.

    Science.gov (United States)

    Moore, A

    2014-11-01

    The aim of this paper is discuss the contemporary issues surrounding radiotherapy for sinonasal mucosal melanoma (SNMM). SNMM is a rare disease with a poor prognosis. The particular challenge with regard to radiotherapy for SNMM is that melanoma is a relatively radioresistant tumour in an anatomical site surrounded by important radiosensitive structures. IMRT has been shown to be an effective primary and adjuvant therapy, and is superior to traditional photon radiotherapy techniques. Emerging evidence also supports the role of particle therapy. Protons and carbon ions may provide a superior target dose and less collateral damage than IMRT. Stereotactic radiotherapy has also been used successfully. The introduction of new technology will always be inhibited by financial constraints and concerns about long-term efficacy. The role of the health professional will change commensurate with the introduction of new technology in terms of the knowledge and the clinical skills they must acquire. Working patterns may need to change to manage the competing interests of expanding services and financial cutbacks. In addition to the clinical expertise health professionals provide, they will be charged with the responsibility of finding innovative ways to improve and develop radiotherapy services for SNMM.

  5. Particle size distribution and particle size-related crystalline silica content in granite quarry dust.

    Science.gov (United States)

    Sirianni, Greg; Hosgood, Howard Dean; Slade, Martin D; Borak, Jonathan

    2008-05-01

    Previous studies indicate that the relationship between empirically derived particle counts, particle mass determinations, and particle size-related silica content are not constant within mines or across mine work tasks. To better understand the variability of particle size distributions and variations in silica content by particle size in a granite quarry, exposure surveys were conducted with side-by-side arrays of four closed face cassettes, four cyclones, four personal environmental monitors, and a real-time particle counter. In general, the proportion of silica increased as collected particulate size increased, but samples varied in an inconstant way. Significant differences in particle size distributions were seen depending on the extent of ventilation and the nature and activity of work performed. Such variability raises concerns about the adequacy of silica exposure assessments based on only limited numbers of samples or short-term samples.

  6. Allergies, asthma, and dust

    Science.gov (United States)

    Reactive airway disease - dust; Bronchial asthma - dust; Triggers - dust ... Things that make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are ...

  7. Intensity modulated radiotherapy for sinonasal malignancies with a focus on optic pathway preservation

    Directory of Open Access Journals (Sweden)

    Chi Alexander

    2013-01-01

    Full Text Available Abstract Purpose To assess if intensity-modulated radiotherapy (IMRT can possibly lead to improved local control and lower incidence of vision impairment/blindness in comparison to non-IMRT techniques when treating sinonasal malignancies; what is the most optimal dose constraints for the optic pathway; and the impact of different IMRT strategies on optic pathway sparing in this setting. Methods and materials A literature search in the PubMed databases was conducted in July, 2012. Results Clinical studies on IMRT and 2D/3D (2 dimensional/3 dimensional RT for sinonasal malignancies suggest improved local control and lower incidence of severe vision impairment with IMRT in comparison to non-IMRT techniques. As observed in the non-IMRT studies, blindness due to disease progression may occur despite a lack of severe toxicity possibly due to the difficulty of controlling locally very advanced disease with a dose ≤ 70 Gy. Concurrent chemotherapy’s influence on the the risk of severe optic toxicity after radiotherapy is unclear. A maximum dose of ≤ 54 Gy with conventional fractionation to the optic pathway may decrease the risk of blindness. Increased magnitude of intensity modulation through increasing the number of segments, beams, and using a combination of coplanar and non-coplanar arrangements may help increase dose conformality and optic pathway sparing when IMRT is used. Conclusion IMRT optimized with appropriate strategies may be the treatment of choice for the most optimal local control and optic pathway sparing when treating sinonasal malignancy.

  8. Psychometric evaluation of the Sinonasal Outcome Test-16 and activity impairment assessment in acute bacterial sinusitis.

    Science.gov (United States)

    Quadri, Nuz; Lloyd, Andrew; Keating, Karen N; Nafees, Beenish; Piccirillo, Jay; Wild, Diane

    2013-07-01

    To validate the Sinonasal Outcome Test-16 and Activity Impairment Assessment in patients with acute bacterial sinusitis. Data were used from a phase III clinical trial designed to evaluate the efficacy and safety of moxifloxacin 400 mg once daily for 5 consecutive days in the treatment of acute bacterial sinusitis. The psychometric properties and factor structure of the 2 measures were assessed. Participants were given the measures to self-complete using either a telephone voice response system or a paper-and-pencil format. Three hundred seventy-four patients with acute bacterial sinusitis were used in the analysis. Patients received either a placebo or 400 mg moxifloxacin once daily. Patients were then reviewed at test of cure and follow-up. All analyses were conducted on a combined sample of placebo and active treatment patients. The Sinonasal Outcome Test-16 was associated with minimal missing data at baseline but a higher proportion by test of cure. There was no evidence of floor or ceiling effects and no significant skew. The Activity Impairment Assessment also had low missing data at baseline and no obvious floor or ceiling effects, but the data were not normally distributed. Both measures had good internal consistency. Convergent and divergent validity as well as sensitivity and the minimally important difference are also reported. The measures both have good psychometric properties and are suitable for use with patients with acute bacterial sinusitis. Both instruments are sensitive. The minimal important difference estimates for the Sinonasal Outcome Test-16 are quite high but are similar to estimates reported previously.

  9. Distribution of dust during two dust storms in Iceland

    Science.gov (United States)

    Ösp Magnúsdóttir, Agnes; Dagsson-Waldhauserova, Pavla; Arnalds, Ólafur; Ólafsson, Haraldur

    2017-04-01

    Particulate matter mass concentrations and size fractions of PM1, PM2.5, PM4, PM10, and PM15 measured in transversal horizontal profile of two dust storms in southwestern Iceland are presented. Images from a camera network were used to estimate the visibility and spatial extent of measured dust events. Numerical simulations were used to calculate the total dust flux from the sources as 180,000 and 280,000 tons for each storm. The mean PM15 concentrations inside of the dust plumes varied from 10 to 1600 ?g?m?3 (PM10 = 7 to 583 ?g?m?3). The mean PM1 concentrations were 97-241 ?g?m?3 with a maximum of 261 ?g?m?3 for the first storm. The PM1/PM2.5 ratios of >0.9 and PM1/PM10 ratios of 0.34-0.63 show that suspension of volcanic materials in Iceland causes air pollution with extremely high PM1 concentrations, similar to polluted urban areas in Europe or Asia. Icelandic volcanic dust consists of a higher proportion of submicron particles compared to crustal dust. Both dust storms occurred in relatively densely inhabited areas of Iceland. First results on size partitioning of Icelandic dust presented here should challenge health authorities to enhance research in relation to dust and shows the need for public dust warning systems.

  10. The Role of Robotic Surgery in Sinonasal and Ventral Skull Base Malignancy.

    Science.gov (United States)

    Hachem, Ralph Abi; Rangarajan, Sanjeet; Beer-Furlan, Andre; Prevedello, Daniel; Ozer, Enver; Carrau, Ricardo L

    2017-04-01

    Over the past decade, robotic surgery has gained wide popularity, making a significant impact on multiple surgical specialties. In the head and neck arena, transoral robotic surgery has proven to be safe and associated with acceptable oncological and superior functional outcomes for surgery of the oropharynx, hypopharynx, supraglottis, and glottis; thus, changing the paradigm for the management of tumors in these anatomic locations. Robotic surgery of the ventral skull base is at an early stage of development. In this article reviews the literature discussing the role of robotic surgery in managing sinonasal and ventral skull base malignant lesions.

  11. IMRT for Sinonasal Tumors Minimizes Severe Late Ocular Toxicity and Preserves Disease Control and Survival

    Energy Technology Data Exchange (ETDEWEB)

    Duprez, Frederic, E-mail: frederic.duprez@ugent.be [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Madani, Indira; Morbee, Lieve [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Bonte, Katrien; Deron, Philippe; Domjan, Vilmos [Department of Head and Neck Surgery, Ghent University Hospital, Ghent (Belgium); Boterberg, Tom; De Gersem, Werner; De Neve, Wilfried [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)

    2012-05-01

    Purpose: To report late ocular (primary endpoint) and other toxicity, disease control, and survival (secondary endpoints) after intensity-modulated radiotherapy (IMRT) for sinonasal tumors. Methods and Materials: Between 1998 and 2009, 130 patients with nonmetastatic sinonasal tumors were treated with IMRT at Ghent University Hospital. Prescription doses were 70 Gy (n = 117) and 60-66 Gy (n = 13) at 2 Gy per fraction over 6-7 weeks. Most patients had adenocarcinoma (n = 82) and squamous cell carcinoma (n = 23). One hundred and one (101) patients were treated postoperatively. Of 17 patients with recurrent tumors, 9 were reirradiated. T-stages were T1-2 (n = 39), T3 (n = 21), T4a (n = 38), and T4b (n = 22). Esthesioneuroblastoma was staged as Kadish A, B, and C in 1, 3, and 6 cases, respectively. Results: Median follow-up was 52, range 15-121 months. There was no radiation-induced blindness in 86 patients available for late toxicity assessment ({>=}6 month follow-up). We observed late Grade 3 tearing in 10 patients, which reduced to Grade 1-2 in 5 patients and Grade 3 visual impairment because of radiation-induced ipsilateral retinopathy and neovascular glaucoma in 1 patient. There was no severe dry eye syndrome. The worst grade of late ocular toxicity was Grade 3 (n = 11), Grade 2 (n = 31), Grade 1 (n = 33), and Grade 0 (n = 11). Brain necrosis and osteoradionecrosis occurred in 6 and 1 patients, respectively. Actuarial 5-year local control and overall survival were 59% and 52%, respectively. On multivariate analysis local control was negatively affected by cribriform plate and brain invasion (p = 0.044 and 0.029, respectively) and absence of surgery (p = 0.009); overall survival was negatively affected by cribriform plate and orbit invasion (p = 0.04 and <0.001, respectively) and absence of surgery (p = 0.001). Conclusions: IMRT for sinonasal tumors allowed delivering high doses to targets at minimized ocular toxicity, while maintaining disease control and survival

  12. The Gas-to-Dust Relation in the Dark Cloud L1523 - Observational Evidence for CO Gas Depletion

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Correlation between gas and dust column density has been studied for the dark globule L1523. The 13CO(J= 1→0) emission is used for tracing the gas, and the IR emissions, for tracing the dust constituent. In order to match the beam resolution between the images, a beam de-convolution algorithm based on the Maximum Correlation Method (MCM) was applied on the Infrared Astronomical Satellite (IRAS) data. The morphology of 13CO column density map shows a close correlation to that of 100μm dust optical depth. The distribution of the optical depth at 100 μm follows that of gas column density more closely than does the flux map at either 60 or 100μm. The ratio of the 13CO column density to the 100μm optical depth shows a decreasing trend with increasing dust optical depth in the central part, indicating possible molecular gas condensation onto dust particles. The excessive decrease in the CO column density in the envelope may most probably be due to the photo-dissociation of CO molecules.

  13. House dust mites: a risk factor to be considered for occupational safety or source of work-related allergens.

    Science.gov (United States)

    Saleh, Ahmed Megahed Ahmed; Ali, Hisham Abd El-Raouf; Ahmed, Salwa Abdalla Mohamed; Mohammad, Naema Mahmoud; Morsy, Tosson A

    2013-12-01

    House dust mites (HDM) can be found worldwide where human beings live independent from the climate and are a major source of multiple allergens. Mite allergens sensitize and induce perennial rhinitis, asthma, or atopic dermatitis in a large portion of patients with allergic disease particularly children. There is convincing evidence that avoidance of mite allergen can effectively reduce allergic symptoms. This study examined dust from a military hospital and the private home of some nursing staff. A total of seven species of mites belonging to six genera were recovered. The commonest species was Dermatophagoides farinae followed by D. pteronyssinus and the lowest Laelaps nuttalli. Besides, the 7th mite or Parasitus consanguineous live free on dust as a bio-control agent of mites. The presence of mites in and out doors in a hospital and dwellings of medical personnel pave the way to consider HDM as occupational or nosocomial Allergens.

  14. Correlation of in vivo relative bioavailability to in vitro bioaccessibility for arsenic in household dust from China and its implication for human exposure assessment.

    Science.gov (United States)

    Li, Hong-Bo; Li, Jie; Juhasz, Albert L; Ma, Lena Q

    2014-12-01

    Incidental ingestion of household dust is an important arsenic (As) exposure pathway for children. However, compared to soils, assessment of As relative bioavailability (RBA) in household dust is limited. In this study, As-RBA in 12 household dust samples (7–38 mg kg(–1)) was measured using an in vivo mouse model and compared to As bioaccessibility determined using 4 assays [Solubility Bioaccessibility Research Consortium method (SBRC), in vitro gastrointestinal method (IVG), Deutsches Institut für Normunge.V. method (DIN), and physiologically based extraction test (PBET)]. Arsenic RBA ranged from 21.8 ± 1.6 to 85.6 ± 7.2% with samples containing low Fe and high total organic carbon content having higher As-RBA. Strong in vivo–in vitro correlations (IVIVC) were found between As-RBA and As bioaccessibility for SBRC and DIN (r2 = 0.63–0.85), but weaker ones were obtained for IVG and PBET (r2 = 0.29–0.55). The developed IVIVC for SBRC and DIN were used to calculate As-RBA based on As bioaccessibility for an additional 12 household dust samples. Although As bioaccessibility differed significantly (up to 7.7-fold) based on in vitro methods, predicted As-RBA was less variable (up to 3.0-fold) when calculated using As bioaccessibility data and the corresponding IVIVC. Our data suggested that both SBRC and DIN had potential to assess As bioavailability in household dust samples; however, additional research is needed.

  15. The Type Ia Supernova Color-Magnitude Relation and Host Galaxy Dust: A Simple Hierarchical Bayesian Model

    Science.gov (United States)

    Mandel, Kaisey S.; Scolnic, Daniel M.; Shariff, Hikmatali; Foley, Ryan J.; Kirshner, Robert P.

    2017-06-01

    Conventional Type Ia supernova (SN Ia) cosmology analyses currently use a simplistic linear regression of magnitude versus color and light curve shape, which does not model intrinsic SN Ia variations and host galaxy dust as physically distinct effects, resulting in low color-magnitude slopes. We construct a probabilistic generative model for the dusty distribution of extinguished absolute magnitudes and apparent colors as the convolution of an intrinsic SN Ia color-magnitude distribution and a host galaxy dust reddening-extinction distribution. If the intrinsic color-magnitude (M B versus B - V) slope {β }{int} differs from the host galaxy dust law R B , this convolution results in a specific curve of mean extinguished absolute magnitude versus apparent color. The derivative of this curve smoothly transitions from {β }{int} in the blue tail to R B in the red tail of the apparent color distribution. The conventional linear fit approximates this effective curve near the average apparent color, resulting in an apparent slope {β }{app} between {β }{int} and R B . We incorporate these effects into a hierarchical Bayesian statistical model for SN Ia light curve measurements, and analyze a data set of SALT2 optical light curve fits of 248 nearby SNe Ia at zlinear fit gives {β }{app}≈ 3. Our model finds {β }{int}=2.3+/- 0.3 and a distinct dust law of {R}B=3.8+/- 0.3, consistent with the average for Milky Way dust, while correcting a systematic distance bias of ˜0.10 mag in the tails of the apparent color distribution. Finally, we extend our model to examine the SN Ia luminosity-host mass dependence in terms of intrinsic and dust components.

  16. VARIATIONS OF MID- AND FAR-INFRARED LUMINOSITIES AMONG EARLY-TYPE GALAXIES: RELATION TO STELLAR METALLICITY AND COLD DUST

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, William G.; Brighenti, Fabrizio [University of California Observatories/Lick Observatory, Board of Studies in Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Temi, Pasquale; Amblard, Alexandre, E-mail: mathews@ucolick.org, E-mail: fabrizio.brighenti@unibo.it, E-mail: pasquale.temi@nasa.gov [Astrophysics Branch, NASA/Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States)

    2013-05-01

    The Hubble morphological sequence from early to late galaxies corresponds to an increasing rate of specific star formation. The Hubble sequence also follows a banana-shaped correlation between 24 and 70 {mu}m luminosities, both normalized with the K-band luminosity. We show that this correlation is significantly tightened if galaxies with central active galactic nucleus (AGN) emission are removed, but the cosmic scatter of elliptical galaxies in both 24 and 70 {mu}m luminosities remains significant along the correlation. We find that the 24 {mu}m variation among ellipticals correlates with stellar metallicity, reflecting emission from hot dust in winds from asymptotic giant branch stars of varying metallicity. Infrared surface brightness variations in elliptical galaxies indicate that the K - 24 color profile is U-shaped for reasons that are unclear. In some elliptical galaxies, cold interstellar dust emitting at 70 and 160 {mu}m may arise from recent gas-rich mergers. However, we argue that most of the large range of 70 {mu}m luminosity in elliptical galaxies is due to dust transported from galactic cores by feedback events in (currently IR-quiet) AGNs. Cooler dusty gas naturally accumulates in the cores of elliptical galaxies due to dust-cooled local stellar mass loss and may accrete onto the central black hole, releasing energy. AGN-heated gas can transport dust in cores 5-10 kpc out into the hot gas atmospheres where it radiates extended 70 {mu}m emission but is eventually destroyed by sputtering. This, and some modest star formation, defines a cycle of dust creation and destruction. Elliptical galaxies evidently undergo large transient excursions in the banana plot in times comparable to the sputtering time or AGN duty cycle, 10 Myr. Normally regarded as passive, elliptical galaxies are the most active galaxies in the IR color-color correlation.

  17. Image of Fomalhaut Dust Ring at 350 Microns: The Relative Column Density Map Shows Pericenter-Apocenter Asymmetry

    Science.gov (United States)

    Marsh, K. A.; Velusamy, T.; Dowell, C. D.; Grogan, K.; Beichman, C. A.

    2005-01-01

    We have imaged the circumstellar disk of Fomalhaut at 350 mm wavelength, using SHARC II (Submillimeter High Angular Resolution Camera II) at the Caltech Submillimeter Observatory. The spatial resolution of the raw images (9") has been enhanced by a factor of 3 using the HiRes deconvolution procedure. We find that at this wavelength and signal-to-noise ratio (approx.12), the observed morphology is that of a simple inclined ring (i approx. 70 deg), with little or no other apparent structure--this is the first observation that shows clearly the ring morphology of the disk. We have combined our 350 mm data with Spitzer Space Telescope images at 24, 70, and 160 mm in order to estimate the two-dimensional spatial variation of relative column density ("tau map") using our DISKFIT procedure. The tau map is based on the following physical assumptions: (1) the wavelength variation of opacity is the same throughout the disk, (2) the radial variation of dust temperature is dictated by the energy balance of individual grains in the stellar radiation field, and (3) the vertical scale height of the disk follows a power-law radial variation. The results confirm the ringlike morphology but also show that the geometric center is displaced from the star by about 8 AU and that the ring has an apocentric enhancement of approximately 14% in integrated column density. If we interpret the displacement in terms of elliptical orbital motion due to gravitational perturbation by an unseen planet, then the implied forced eccentricity is 0.06; dynamical modeling then predicts an apocentric density enhancement consistent with that inferred from the tau map.

  18. Respiratory symptoms and cross-shift lung function in relation to cotton dust and endotoxin exposure in textile workers in Nepal: a cross-sectional study

    OpenAIRE

    Paudyal, Priyamvada; Semple, SEAN; Gairhe, Santosh; Steiner, Markus F C; Niven, Rob; Jon G. Ayres

    2015-01-01

    Objectives: Inhalation of a cotton-based particulates has previously been associated with respiratory symptoms and impaired lung function. This study investigates the respiratory health of Nepalese textile workers in relation to dust and endotoxin exposure. Methods: A total of 938 individuals from four sectors (garment, carpet, weaving and recycling) of the textile industry in Kathmandu, Nepal completed a health questionnaire and performed spirometry. A subset (n=384) performed cross-shift sp...

  19. Relative Importance of Dust, Splash, and Sheet/Rill Transport Processes on Off-Highway Vehicle Trails in the Ouachita Mountains

    Science.gov (United States)

    Marion, D.; Phillips, J. D.

    2015-12-01

    Sheet/rill erosion, dust displacement, and vehicle induced splash are the primary sediment transport processes on off-highway vehicle (OHV) trails in the Ouachita Mountains of the central United States. The relative importance of these three processes is assessed by comparing the area affected and the sediment connectivity of each process to affected streams using field data from the Wolf Pen Gap Trail Complex. The occurrence and areal extent of erosion processes were assessed using systematic transect measurements, feature inventories, and visual observation over representative trail segments. Sheet/rill erosion affects the entire denunded surface of the trail system, an area of 2,820 m2 km-1 of trail. Distinct erosion features created by sheet/rill erosion occur 16.3 times per km. Dust transport extends a mean travel distance of 3.7 m off-trail. Dust transport affects both the entire trail area and an additional 6,640 m2 km-1 of off-trail area. In contrast, splash transport was restricted to trail dips, and extends 1.6 m off-trail. Splash transport affects 60 m2 km-1of off-trail area.The impact of trail erosion increases where sediment sources are connected to drainageways. Of 480 sheet/rill erosion features rated, 69.4% had high to very high connectivity to channels. All sampled dips were directly connected to drainage ways. Dust transport affected 99% of dips on one trail side and 90% on both sides. About 80% of the dips had splash transport on one trail side and 42% on both sides.Sheet/rill, dust, and splash transport processes are all important in the Trail Complex, but for different reasons. Sheet/rill erosion affects the entire trail surface, is well connected to area drainageways, but only occurs after rainfall. Dust transport affects the largest area and occurs most often throughout the year, but the sediment is deposited diffusely, and the ratio delivered to the drainage network is relatively low. Splash affects the smallest area and is limited to short

  20. Sinonasal characteristics and quality of life by SNOT-22 in adult patients with cystic fibrosis.

    Science.gov (United States)

    Kang, Suzie Hyeona; Meotti, Camila Degen; Bombardelli, Karine; Piltcher, Otávio Bejzman; de Tarso Roth Dalcin, Paulo

    2017-04-01

    The prevalence of chronic sinus disease in cystic fibrosis (CF) has gradually increased. Sinonasal involvement may have influence on pulmonary exacerbations and can have a negative impact on the quality of life. To evaluate nasal characteristics and quality of life in adult patients with CF; to establish an association and determine the predictors in SNOT-22 questionnaire. Cross- sectional study with prospective data collection was performed to evaluate adult CF patients. Patients underwent clinical evaluation, lung function tests, nasal endoscopy, and paranasal sinuses CT scan. All the patients answered the SNOT-22 questionnaire. A total of 91 patients were allocated, of which, 45.1% were male. Patients were divided into three groups by SNOT-22. A high average age, late age of diagnosis, rhinitis symptoms, and clinical criteria for rhinosinusitis were observed more frequently in patients with high SNOT-22 scores (p life domain. In total score, there was a positive association with age and the presence of P. aeruginosa in sputum. Despite high prevalence of abnormal tomographic findings, patients reported mild intensity of sinonasal symptoms. Advanced age and the presence of P. aeruginosa were associated with higher SNOT-22 scores.

  1. An Extremely Rare Case of Advanced Metastatic Small Cell Neuroendocrine Carcinoma of Sinonasal Tract

    Directory of Open Access Journals (Sweden)

    Yu Yu Thar

    2016-01-01

    Full Text Available Small cell neuroendocrine carcinoma (SNEC is a rare form of malignancy. It mainly presents as bronchogenic neoplasm, and the extrapulmonary form accounts for only 0.1% to 0.4% of all cancers. These extrapulmonary tumors have been described most frequently in the urinary bladder, prostate, esophagus, stomach, colon and rectum, gall bladder, head and neck, cervix, and skin. Primary SNEC of the sinonasal tract is extremely rare with only less than 100 cases reported in the literature. Because of extreme rarity and aggressiveness of the tumor, the management for this entity varies considerably mandating multimodality approach. In this paper, we report a patient presented with left-sided facial swelling, and the histopathologic examination confirmed primary SNEC of left sinonasal tract. The tumor involved multiple paranasal sinuses with invasion into the left orbit and left infratemporal fossa and metastasized to cervical lymph nodes and bone. The patient encountered devastating outcome in spite of optimal medical management and treatment with palliative chemotherapy highlighting the necessity for further research of primary SNEC of head and neck.

  2. Organ preservation with neoadjuvant chemoradiation in patients with orbit invasive sinonasal cancer otherwise requiring extenteration

    Energy Technology Data Exchange (ETDEWEB)

    Amsbaugh, Mark J.; Yusuf, Mehran; Silverman, Craig; Bumpous, Jeffery; Perez, Cesar A.; Potts, Keven; Tennant, Paul; Redman, Rebecca; Dunlap, Neal [University of Louisville, Louisville (United States)

    2016-09-15

    We sought to determine if organ preservation (OP) with neoadjuvant chemoradiation (CRT) was feasible in patients with sinonasal cancer determined to require exenteration. Twenty patients were determined to require exenteration for definitive treatment from 2005 to 2014. Fourteen patients underwent OP and 6 patients received exenteration with adjuvant CRT. Exenteration free survival (EFS), locoregional control (LRC), progression-free survival (PFS), and overall survival (OS) were estimated. Five patients (36%) receiving OP had complete disease response at time of surgery. With a median follow-up of 18.8 months, EFS was 62% at 2 years for patients undergoing OP. At 2 years, there were no significant differences in LRC, PFS or OS (all all p > 0.050) between the groups. Less grade 3 or greater toxicity was seen in patients undergoing OP (p = 0.003). Visual function was preserved in all patients undergoing OP. For patients with sinonasal cancer, OP may avoid exenteration, offering similar disease control and improved toxicity.

  3. Nodal recurrence of sinonasal cancer: does the risk of cervical relapse justify a prophylactic neck treatment?

    Science.gov (United States)

    Mirghani, Haïtham; Hartl, Dana; Mortuaire, Geoffrey; Armas, Gian Luca; Aupérin, Anne; Chevalier, Dominique; Lefebvre, Jean Louis

    2013-04-01

    Sinonasal cancers are rare and no high-level evidence exists to determine their optimal management. Prophylactic neck treatment issue remains controversial. The aim of this study was to analyze the pattern of neck failure and to identify any prognostic factors that may influence neck control. A retrospective review of 155 consecutive patients treated for sinonasal malignancy, without prophylactic neck treatment, between 1995 and 2005 at tertiary cancer center was performed. Demographic, clinical, morphological and pathological parameters were correlated with oncologic outcomes. Eight out of 155 patients (5%) presented initially with neck node metastasis. Complete remission was obtained for 133 patients after treatment completion. During follow up, 16 out of 133 patients (12%) were affected with regional recurrence. Neck failure occurred in 8 out of 51 patients with local failure and in 8 out of 82 patients locally controlled. Isolated nodal failure was observed in 5 patients initially cN0 out of 133 (3.8%) representing 7.3% of all recurrences and 3 of them underwent successful salvage therapy. None of the tested factors were significantly associated with neck control (p>0.05). Lymph node at diagnosis time was significantly and independently associated with poor survival (p=0.0012). Isolated neck relapse, when local control is achieved, is rare and salvage treatment is effective. Routine prophylactic neck treatment has little interest. However, this approach could be profitable to few selected patients, who remain to be defined. Further investigations are needed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Dust, Climate, and Human Health

    Science.gov (United States)

    Maynard, N. G.

    2003-12-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health

  5. Evaluation of workers' exposure to total, respirable and silica dust and the related health symptoms in Senjedak stone quarry, Iran.

    Science.gov (United States)

    Golbabaei, Farideh; Barghi, Mohammad-Ali; Sakhaei, Manouchehr

    2004-01-01

    The present research was conducted in a stone quarry of marble located in northeast of Iran. Time weighted average of total dust, respirable dust, and crystalline silica (alpha-quartz) concentration in workers' breathing zone were monitored by using both gravimetric and XRD methods. The results showed that the employees working in hammer drill process had the highest exposure to the total and respirable dust: 107.9 +/- 8.0 mg/m3, 11.2 +/- 0.77 mg/m3 respectively, while the cutting machine workers had the lowest exposure (9.3 +/- 3.0 mg/m3, 1.8 +/- 0.82 mg/m3). The maximum concentration of a-quartz in total and respirable dust were detected equal to 0.670 +/- 8.49 x 10(-2) and 5.7 x 10(-2) +/- 1.6 x 10(-2) mg/m3 respectively, which belonged to the exposure of the workers of hammer drill process. The prevalence of skin and respiratory symptoms were higher in hammer drill workers, however, respiratory symptoms showed no significant prevalence. Regarding the average age of workers (31.6 +/- 1.9 yr) and average of their work history (3.8 +/- 1.0 yr), these results were predictable.

  6. Meta-analysis of 701 published cases of sinonasal neuroendocrine carcinoma : The importance of differentiation grade in determining treatment strategy

    NARCIS (Netherlands)

    van der Laan, Tom P; Iepsma, René; Witjes, Max J H; van der Laan, Bernard F A M; Plaat, Boudewijn E C; Halmos, Gyorgy B

    2016-01-01

    The aim of this meta-analysis was to provide treatment guidelines for sinonasal neuroendocrine carcinoma (SNC) by combining all available data in the literature. A literature search for all studies concerning SNC was performed against the MEDLINE and EMBASE databases. Available clinical data was nor

  7. Linear and nonlinear excitations in complex plasmas with nonadiabatic dust charge fluctuation and dust size distribution

    Institute of Scientific and Technical Information of China (English)

    Zhang Li-Ping; Xue Ju-Kui; Li Yan-Long

    2011-01-01

    Both linear and nonlinear excitation in dusty plasmas have been investigated including the nonadiabatic dust charge fluctuation and Gaussian size distribution dust particles.A linear dispersion relation and a Korteweg-de VriesBurgers equation governing the dust acoustic shock waves are obtained.The relevance of the instability of wave and the wave evolution to the dust size distribution and nonadiabatic dust charge fluctuation is illustrated both analytically and numerically.The numerical results show that the Gaussian size distribution of dust particles and the nonadiabatic dust charge fluctuation have strong common influence on the propagation of both linear and nonlinear excitations.

  8. SURVEILLANCE OF SINO-NASAL ABNORMALITIES DIAGNOSED BY COMPUTED TOMOGRAPHY SCAN OF PARANASAL SINUSES IN A TEACHING HOSPITAL

    Directory of Open Access Journals (Sweden)

    Saumya Ranjan

    2016-02-01

    Full Text Available Computed tomography, CT scan of Paranasal Sinuses (PNS is the gold standard test in diagnosing sinonasal abnormalities, which has the advantage of being able to show fine anatomic detail in serial tomographic sections, eliminating the gross volume averaging inherent in plain films. AIM To have surveillance of sinonasal abnormalities, from computed tomography CT scan of PNS, in the hospital in one year. MATERIAL AND METHODS Symptomatic patients pertaining to nose and paranasal sinuses were subjected to non-contrast CT scan of PNS by a GE Multi-detector CT scan with 0.6mm slices, for the diagnoses of sinonasal abnormalities from CT scan findings. RESULTS Of 339 patients, the primary radiological diagnoses were 66 Deviated Nasal Septum (DNS, 54 maxillary sinusitis, 47 ethmoid sinusitis, 44 Inferior Turbinate Hypertrophy (ITH, 35 maxillary sinus-mucosal hypertrophy, 28 frontal sinusitis, 20 ethmoidal polyp, 14 antrochoanal polyp, 12 nasal mass, 9 nasopharyngeal mass, 5 concha bullosa, 3 pan-sinusitis and 2 sphenoid sinusitis. There were 190 male and 149 female patients, diagnosed to have cited sinonasal diseases. The age distribution of diseases was: 57 in ≤ 14 years (Paediatric, 155 in 15-39 years (Adults and 127 in the age group of ≥ 40 years (Elderly; 86 cases of sinusitis were associated with anatomical variants, among which deviated nasal septum and inferior turbinate hypertrophy were accountable for 31 cases each. CONCLUSION Deviated Nasal Septum (DNS was the most frequently encountered condition in 19.5% of the total 339 patients. Among the patients of DNS, ITH was the most frequent co-existent abnormality. Maxillary sinusitis was the commonest sinus infection. Deviated nasal septum and inferior turbinate hypertrophy were most common anatomical variants seen in cases of sinusitis. CT scan of PNS is an indispensable diagnostic tool, which assisted in planning and advocating appropriate treatment modalities for sinonasal abnormalities.

  9. Gravimetric dust sampling for control purposes and occupational dust sampling.

    CSIR Research Space (South Africa)

    Unsted, AD

    1997-02-01

    Full Text Available Prior to the introduction of gravimetric dust sampling, konimeters had been used for dust sampling, which was largely for control purposes. Whether or not absolute results were achievable was not an issue since relative results were used to evaluate...

  10. Sinonasal Wegener's granulomatosis: CT characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Benoudiba, F.; Marsot-Dupuch, K.; Rabia, Hadj M.; Lasjaunias, P. [Neuroradiology Department, Bicetre Hospital, 78 rue du General Leclerc, 94275 Le Kremlin Bicetre (France); Cabanne, J. [Department of Internal Medecine, Saint-Antoine Hospital, 184 rue du Faubourg Saint-Antoine, 75012 Paris (France); Bobin, S. [Head and Neck Department, Bicetre Hospital, 78, rue du General Leclerc, 94275 Le Kremlin Bicetre (France)

    2003-02-01

    Wegener's granulomatosis (WG) is a severe and potentially lethal granulomatosis. Even though no specific radiological criteria exist, CT may suggest the correct diagnosis at an early stage. Recent improvement in the prognosis is related to earlier diagnosis, allowing the initiation of efficient and specific treatment before any severe complications occur. We reviewed a series of WG cases in order to establish the CT diagnostic criteria. (orig.)

  11. Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dust

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, C K; Schuepfer, P; Boiteux, P, E-mail: chuynh@hospvd.c [Institute for Work and Health, rue du Bugnon 21, CH-1005 Lausanne (Switzerland)

    2009-02-01

    Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of mug.g{sup -1} or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.

  12. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

    Directory of Open Access Journals (Sweden)

    James D Johnston

    Full Text Available Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr and summer (July-Sept, 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

  13. Variation of Mid and Far-IR Luminosities among Early-Type Galaxies: Relation to Stellar Metallicity and Cold Dust

    CERN Document Server

    Mathews, William G; Brighenti, Fabrizio; Amblard, Alexandre

    2013-01-01

    The Hubble morphological sequence from early to late galaxies corresponds to an increasing rate of specific star formation. The Hubble sequence also follows a banana-shaped correlation between 24 and 70 micron luminosities, both normalized with the K-band luminosity. We show that this correlation is significantly tightened if galaxies with central AGN emission are removed, but the cosmic scatter of elliptical galaxies in both 24 and 70 micron luminosities remains significant along the correlation. We find that the 24 micron variation among ellipticals correlates with stellar metallicity, reflecting emission from hot dust in winds from asymptotic giant branch stars of varying metallicity. Infrared surface brightness variations in elliptical galaxies indicate that the K - 24 color profile is U-shaped for reasons that are unclear. In some elliptical galaxies cold interstellar dust emitting at 70 and 160 microns may arise from recent gas-rich mergers. However, we argue that most of the large range of 70 micron lu...

  14. An Experimental Study on the Structure of Cosmic Dust Aggregates and Their Alignment by Motion Relative to Gas.

    Science.gov (United States)

    Wurm; Blum

    2000-01-20

    We experimentally studied the shape of dust grains grown in a cluster-cluster type of aggregation (CCA) and derived characteristic axial ratios to describe the nonsphericity. CCAs might be described by an axial ratio rhoCCA=rg,max&solm0;rg,min approximately 2.0 in the limit of large aggregates, where rg,min and rg,max describe the minimum and maximum radius of gyration, while small aggregates show a somewhat larger value in their mean axial ratio up to rhoCCA approximately 3.0 but rapidly decrease to the limit rhoCCA approximately 2.0. The axial ratios for large aggregates are in agreement with the general findings of different authors for axial ratios of interstellar dust grains that are generally described by rods or spheroids. Beyond this kind of agreement, our approach does not necessarily require a special shape for individual dust grains but rather offers a physical process to generate nonsphericity. Although the simple shapes might be sufficient for first-order applications and are easier to handle analytically, our results offer a firm ground of special axial ratios for rods or spheroids on a more physical basis apart from any ad hoc assumptions. We also find an alignment of the aggregates during sedimentation in a gas along the drift axis leading to an axial ratio of rhoCCA,align=1.21+/-0.02 with respect to the drift axis and an axis perpendicular to this drift. This result is directly applicable to dust grains in protoplanetary disks and planetary atmospheres.

  15. Influence of house dust mite impermeable covers on health-related quality of life of adult patients with asthma: results of a randomized clinical trial.

    Science.gov (United States)

    van den Bemt, Lisette; de Vries, Marjolein P; Cloosterman, Sonja; Thoonen, Bart; Muris, Jean W M; Goossens, Marielle; Wesseling, Geertjan; van Schayck, Constant P

    2007-12-01

    The aim of this study was to evaluate the effect of house dust mite impermeable covers on asthma-specific health-related quality of life in adult asthmatic patients that were trained in guided self-management. In a 2-year randomized placebo-controlled clinical trial, information on the quality of life was collected. The improvement of Mini Asthma Quality of Life Questionnaire (AQLQ) score in the allergens-avoidance group (0.26) was comparable to the improvement in the placebo group (0.30) and not significant. HDM-impermeable covers for pillows, duvets, and mattresses did not result in improved health-related quality of life.

  16. The bioavailable iron in NEEM ice core related to Asian dust records over the past 110 kyr

    Science.gov (United States)

    Xiao, Cunde

    2016-04-01

    The mineral dust can indirectly affect climate by supplying iron and other essential bioavailable elements into ocean. In this study, we present dissolved iron (DFe) and total dissolved iron (TDFe) concentrations in NEEM ice core over the past 110 kyr B.P. The concentrations of bioavailable reactive element Fe have good positive correlation with the concentrations of dust and Ca2+ in NEEM ice core, while show significantly negative relationship with δ18O and CO2 concentration. The ratios of DFe/TDFe are higher in warm periods (Holocene and last interglacial) than in cold period (LGM), indicating the iron-biological pump effect is more significant in warm periods than that in cold periods, this result may provide a new insight for reevaluating the iron hypothesis over glacial/interglacial periods. Our study also shows that the iron flux changes between NEEM ice core and Asian loess records are good consistent with the northern Hemisphere summer insolation. These results emphasize that the variability of Fe flux is most likely driven by solar radiation and dust in northern hemisphere.

  17. The Type Ia Supernova Color-Magnitude Relation and Host Galaxy Dust: A Simple Hierarchical Bayesian Model

    CERN Document Server

    Mandel, Kaisey S; Shariff, Hikmatali; Foley, Ryan J; Kirshner, Robert P

    2016-01-01

    Conventional Type Ia supernova (SN Ia) cosmology analyses currently use a simplistic linear regression of magnitude versus color and light curve shape, which does not model intrinsic SN Ia variations and host galaxy dust as physically distinct effects, resulting in low color-magnitude slopes. We construct a probabilistic generative model for the distribution of dusty extinguished absolute magnitudes and apparent colors as a convolution of the intrinsic SN Ia color-magnitude distribution and the host galaxy dust reddening-extinction distribution. If the intrinsic color-magnitude (M_B vs. B-V) slope beta_int differs from the host galaxy dust law R_B, this convolution results in a specific curve of mean extinguished absolute magnitude vs. apparent color. The derivative of this curve smoothly transitions from beta_int in the blue tail to R_B in the red tail of the apparent color distribution. The conventional linear fit approximates this effective curve at this transition near the average apparent color, resultin...

  18. Planck intermediate results XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust

    DEFF Research Database (Denmark)

    Adam, R.; Ade, P. A. R.; Aghanim, N.;

    2016-01-01

    The role of the magnetic field in the formation of the filamentary structures observed in the interstellar medium (ISM) is a debated topic owing to the paucity of relevant observations needed to test existing models. The Planck all-sky maps of linearly polarized emission from dust at 353 GHz prov...... in the context of models and MHD simulations, which attempt to describe the respective roles of turbulence, magnetic field, and self-gravity in the formation of structures in the magnetized ISM.......The role of the magnetic field in the formation of the filamentary structures observed in the interstellar medium (ISM) is a debated topic owing to the paucity of relevant observations needed to test existing models. The Planck all-sky maps of linearly polarized emission from dust at 353 GHz...... an algorithm to estimate the orientation of the ridges from the dust intensity map. We use analytical models to account for projection effects. Comparing polarization angles on and off the structures, we estimate the mean ratio between the strengths of the turbulent and mean components of the magnetic field...

  19. Dust Mite Allergy

    Science.gov (United States)

    Dust mite allergy Overview By Mayo Clinic Staff Dust mite allergy is an allergic reaction to tiny bugs that commonly live in house dust. Signs of dust mite allergy include those common to hay fever, such as ...

  20. Optimizing Saharan dust CALIPSO retrievals

    Directory of Open Access Journals (Sweden)

    V. Amiridis

    2013-06-01

    Full Text Available We demonstrate improvements in CALIPSO dust extinction retrievals over North Africa and Europe when corrections are applied regarding the Saharan dust lidar ratio assumption, the separation of dust portion in detected dust mixtures, and the averaging scheme introduced in the Level 3 CALIPSO product. First, a universal, spatially constant lidar ratio of 58 sr instead of 40 sr is applied to individual Level 2 dust-related backscatter products. The resulting aerosol optical depths show an improvement compared with synchronous and co-located AERONET measurements. An absolute bias of the order of −0.03 has been found, improving on the statistically significant biases of the order of −0.10 reported in the literature for the original CALIPSO product. When compared with the MODIS co-located AOD product, the CALIPSO negative bias is even less for the lidar ratio of 58 sr. After introducing the new lidar ratio for the domain studied, we examine potential improvements to the climatological CALIPSO Level 3 extinction product: (1 by introducing a new methodology for the calculation of pure dust extinction from dust mixtures and (2 by applying an averaging scheme that includes zero extinction values for the non-dust aerosol types detected. The scheme is applied at a horizontal spatial resolution of 1° × 1° for ease of comparison with the instantaneous and co-located dust extinction profiles simulated by the BSC-DREAM8b dust model. Comparisons show that the extinction profiles retrieved with the proposed methodology reproduce the well-known model biases per sub-region examined. The very good agreement of the proposed CALIPSO extinction product with respect to AERONET, MODIS and the BSC-DREAM8b dust model, makes this dataset an ideal candidate for the provision of an accurate and robust multi-year dust climatology over North Africa and Europe.

  1. Rhinosporidiosis: A Rare Cause of Proptosis and an Imaging Dilemma for Sinonasal Masses

    Directory of Open Access Journals (Sweden)

    Amit Kumar Dey

    2016-01-01

    Full Text Available Background. Rhinosporidiosis is a common disease entity in tropical countries; however, it can be encountered in other parts of the world as well due to increasing medical tourism. It may mimic other more malignant and vigorous pathologies of the involved part. Case Report. We present a case of a 36-year-old male presenting with proptosis due to involvement of nasolacrimal duct which is rare. We will discuss typical CT and MRI features of the disease which were present in the case. Conclusion. For a surgeon and a radiologist, this is a necessary differential to be kept in mind for sinonasal masses. CT and MRI are invaluable investigations. However, FNAC is confirmatory. Both clinical and radiological aspects are required to reach correct diagnosis.

  2. A study of pulmonary function test among tea garden factory workers in relation to exposure of tea dust

    Directory of Open Access Journals (Sweden)

    Birinchi Kartik Das

    2015-10-01

    Results: The investigator is interested to test whether there were significant differences between parameters of PFT among the study and control group. For this purpose student t test has been applied and significant differences were found in all the parameters of PFT as P < 0.01. Conclusions: Exposure to tea dust affects the lung volumes and flow rates, thereby causing increased prevalence of respiratory, allergic symptoms and significant degree of airway obstruction. [Int J Res Med Sci 2015; 3(10.000: 2686-2693

  3. Planck intermediate results. XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust

    CERN Document Server

    Adam, R; Aghanim, N; Alves, M I R; Arnaud, M; Arzoumanian, D; Ashdown, M; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartolo, N; Battaner, E; Benabed, K; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Bracco, A; Burigana, C; Butler, R C; Calabrese, E; Cardoso, J -F; Catalano, A; Chamballu, A; Chiang, H C; Christensen, P R; Colombi, S; Colombo, L P L; Combet, C; Couchot, F; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Ducout, A; Dupac, X; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Ferrière, K; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Ghosh, T; Giard, M; Gjerløw, E; González-Nuevo, J; Górski, K M; Gregorio, A; Gruppuso, A; Guillet, V; Hansen, F K; Hanson, D; Harrison, D L; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Holmes, W A; Hovest, W; Huffenberger, K M; Hurier, G; Jaffe, A H; Jaffe, T R; Jones, W C; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leonardi, R; Levrier, F; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Mazzotta, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Natoli, P; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Oppermann, N; Oxborrow, C A; Pagano, L; Pajot, F; Paoletti, D; Pasian, F; Perdereau, O; Perotto, L; Perrotta, F; Pettorino, V; Piacentini, F; Piat, M; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Pratt, G W; Prunet, S; Puget, J -L; Rachen, J P; Reach, W T; Reinecke, M; Remazeilles, M; Renault, C; Ristorcelli, I; Rocha, G; Roudier, G; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savini, G; Scott, D; Soler, J D; Spencer, L D; Stolyarov, V; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Wade, L A; Wandelt, B D; Wehus, I K; Wiesemeyer, H; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01

    The role of the magnetic field in the formation of the filamentary structures observed in the interstellar medium (ISM) is a debated topic. The Planck all-sky maps of linearly polarized emission from dust at 353GHz provide the required combination of imaging and statistics to study the correlation between the structures of the Galactic magnetic field and of interstellar matter, both in the diffuse ISM and in molecular clouds. The data reveal structures, or ridges, in the intensity map with counterparts in the Stokes Q and/or U maps. We focus on structures at intermediate and high Galactic latitudes with column density from $10^{20}$ to $10^{22}$ cm$^{-2}$. We measure the magnetic field orientation on the plane of the sky from the polarization data, and present an algorithm to estimate the orientation of the ridges from the dust intensity map. We use analytical models to account for projection effects. Comparing polarization angles on and off the structures, we estimate the mean ratio between the strengths of ...

  4. Propagation of dust-acoustic waves in weakly ionized plasmas with dust-charge fluctuation

    Indian Academy of Sciences (India)

    K K Mondal

    2004-11-01

    For an unmagnetized partially ionized dusty plasma containing electrons, singly charged positive ions, micron-sized massive negatively charged dust grains and a fraction of neutral atoms, dispersion relations for both the dust-ion-acoustic and the dust-acoustic waves have been derived, incorporating dust charge fluctuation. The dispersion relations, under various conditions, have been exhaustively analysed. The explicit expressions for the growth rates have also been derived.

  5. Newton to Einstein — dust to dust

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Michael; Uhlemann, Cora; Haugg, Thomas, E-mail: michael.kopp@physik.lmu.de, E-mail: cora.uhlemann@physik.lmu.de, E-mail: thomas.haugg@physik.lmu.de [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilian University Munich, Theresienstr. 37, Munich, 80333 (Germany)

    2014-03-01

    We investigate the relation between the standard Newtonian equations for a pressureless fluid (dust) and the Einstein equations in a double expansion in small scales and small metric perturbations. We find that parts of the Einstein equations can be rewritten as a closed system of two coupled differential equations for the scalar and transverse vector metric perturbations in Poisson gauge. It is then shown that this system is equivalent to the Newtonian system of continuity and Euler equations. Brustein and Riotto (2011) conjectured the equivalence of these systems in the special case where vector perturbations were neglected. We show that this approach does not lead to the Euler equation but to a physically different one with large deviations already in the 1-loop power spectrum. We show that it is also possible to consistently set to zero the vector perturbations which strongly constrains the allowed initial conditions, in particular excluding Gaussian ones such that inclusion of vector perturbations is inevitable in the cosmological context. In addition we derive nonlinear equations for the gravitational slip and tensor perturbations, thereby extending Newtonian gravity of a dust fluid to account for nonlinear light propagation effects and dust-induced gravitational waves.

  6. Rapid review: sinonasal surgery vs. medical therapy for asthma in patients with chronic rhinosinusitis with or without nasal polyps.

    Science.gov (United States)

    de Bruin, Rick Johan Matthies; Hage, Rene; van der Zaag-Loonen, Hester; van Benthem, Peter Paul Germain

    2016-09-01

    The objective of the study was to compare the effect of sinonasal surgery vs. medical treatment on asthma in patients with chronic rhinosinusitis with or without nasal polyps. We executed a PRISMA guidelines-based systematic search of the following databases: PubMed, CENTRAL, Embase, Scopus and CINAHL. The search ran from database inception until 26 Feb 2014. We included controlled clinical trials comparing surgical intervention with medical intervention in patients with chronic rhinosinusitis with or without nasal polyps. We included only English papers. We used a pre-defined data collection form. Two authors independently assessed study quality. We assessed directness of evidence and risk of bias using pre-defined criteria. Our search yielded 2004 original articles, six of which satisfied our inclusion criteria. One article was excluded from further review because no comparison could be made of the subgroup of operated asthmatic patients versus the non-surgical control group. Only one study used objective pulmonary function measurements in asthmatics undergoing sinonasal surgery and therefore had the highest directness of evidence. Also it had a low risk of bias. Patient characteristics, treatments and outcome measures varied across studies, as did the observed effect. Risk of bias was high in most studies. Patient characteristics, treatment and outcome measurement differed across studies, making a comparison of the effects difficult. There is a risk of publication language bias. There is insufficient evidence either for or against sinonasal surgery for asthma control as compared to medical treatment.

  7. Human thermal perception related to Föhn winds due to Saharan dust outbreaks in Crete Island, Greece

    Science.gov (United States)

    Nastos, P. T.; Bleta, A. G.; Matsangouras, I. T.

    2016-01-01

    Crete Island is located in the southmost border of East Mediterranean basin, facing exacerbating atmospheric conditions (mainly concentrations of particulates) due to Saharan dust outbreaks. It is worth to note that these episodes are more frequent during spring and autumn, when mild biometeorological conditions become intolerable due to the synergy of the so called Föhn winds. Cretan mountains, especially Psiloritis Mt. (summit at 2456 m), are orientated perpendicularly to the southwest air mass flow, generating the Föhn winds. Propagating from the leeward of the mountains, these dry, hot winds have an effect on prevailing biometeorological conditions. While descending to the lowlands on the leeward side of the range, the wind becomes strong, gusty, and desiccating. This wind often lasts less than an hour to several days, with gradual weakening after the first or the second day. Sometimes, it stops very abruptly. In this work, the authors examined and analyzed the abrupt changes of human thermal perception within specific case studies during which Föhn winds appeared in Heraklion city at the leeward of Psiloritis Mt, associated with extreme Saharan dust episodes, observed within the period 2006-2010. In order to verify the development of Föhn winds, Meteorological Terminal Aviation Routine Weather Reports (METARs, meteorological observations every half hour), were acquired from the Heraklion meteorological station installed by the Hellenic National Meteorological Service (HNMS). The biometeorological conditions analyzed are based on human thermal bioclimatic indices such as the Physiologically equivalent temperature (PET) and the Universal Thermal Climate Index (UTCI). METAR recordings of meteorological variables, such as air temperature, vapor pressure, wind speed, and cloudiness, were used as input variables in modeling the aforementioned thermal indices, so that to interpret the grade of the thermo-physiological stress. The PET and UTCI analysis was

  8. Human thermal perception related to Föhn winds due to Saharan dust outbreaks in Crete Island, Greece

    Science.gov (United States)

    Nastos, P. T.; Bleta, A. G.; Matsangouras, I. T.

    2017-05-01

    Crete Island is located in the southmost border of East Mediterranean basin, facing exacerbating atmospheric conditions (mainly concentrations of particulates) due to Saharan dust outbreaks. It is worth to note that these episodes are more frequent during spring and autumn, when mild biometeorological conditions become intolerable due to the synergy of the so called Föhn winds. Cretan mountains, especially Psiloritis Mt. (summit at 2456 m), are orientated perpendicularly to the southwest air mass flow, generating the Föhn winds. Propagating from the leeward of the mountains, these dry, hot winds have an effect on prevailing biometeorological conditions. While descending to the lowlands on the leeward side of the range, the wind becomes strong, gusty, and desiccating. This wind often lasts less than an hour to several days, with gradual weakening after the first or the second day. Sometimes, it stops very abruptly. In this work, the authors examined and analyzed the abrupt changes of human thermal perception within specific case studies during which Föhn winds appeared in Heraklion city at the leeward of Psiloritis Mt, associated with extreme Saharan dust episodes, observed within the period 2006-2010. In order to verify the development of Föhn winds, Meteorological Terminal Aviation Routine Weather Reports (METARs, meteorological observations every half hour), were acquired from the Heraklion meteorological station installed by the Hellenic National Meteorological Service (HNMS). The biometeorological conditions analyzed are based on human thermal bioclimatic indices such as the Physiologically equivalent temperature (PET) and the Universal Thermal Climate Index (UTCI). METAR recordings of meteorological variables, such as air temperature, vapor pressure, wind speed, and cloudiness, were used as input variables in modeling the aforementioned thermal indices, so that to interpret the grade of the thermo-physiological stress. The PET and UTCI analysis was

  9. Reducing aluminum dust explosion hazards: case study of dust inerting in an aluminum buffing operation.

    Science.gov (United States)

    Myers, Timothy J

    2008-11-15

    Metal powders or dusts can represent significant dust explosion hazards in industry, due to their relatively low ignition energy and high explosivity. The hazard is well known in industries that produce or use aluminum powders, but is sometimes not recognized by facilities that produce aluminum dust as a byproduct of bulk aluminum processing. As demonstrated by the 2003 dust explosion at aluminum wheel manufacturer Hayes Lemmerz, facilities that process bulk metals are at risk due to dust generated during machining and finishing operations [U.S. Chemical Safety and Hazard Investigation Board, Investigation Report, Aluminum Dust Explosion Hayes Lemmerz International, Inc., Huntington, Indiana, Report No. 2004-01-I-IN, September 2005]. Previous studies have shown that aluminum dust explosions are more difficult to suppress with flame retardants or inerting agents than dust explosions fueled by other materials such as coal [A.G. Dastidar, P.R. Amyotte, J. Going, K. Chatrathi, Flammability limits of dust-minimum inerting concentrations, Proc. Saf. Progr., 18-1 (1999) 56-63]. In this paper, an inerting method is discussed to reduce the dust explosion hazard of residue created in an aluminum buffing operation as the residue is generated. This technique reduces the dust explosion hazard throughout the buffing process and within the dust collector systems making the process inherently safer. Dust explosion testing results are presented for process dusts produced during trials with varying amounts of flame retardant additives.

  10. Coplanar VMAT vs. noncoplanar VMAT in the treatment of sinonasal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Zhong-Hua; Mu, Jin-Ming; Mo, Jun-Chong; Gao, Ming; Li, Qi-Lin; Gu, Wen-Dong; Pei, Hong-Lei [The Third Affiliated Hospital, Soochow University, Department of Radiation Oncology, Changzhou (China); Jiang, Jing-Ting; Li, Xiao-Dong; Chen, Lu-Jun [The Third Affiliated Hospital, Soochow University, Department of Tumor Biological Treatment, Changzhou (China); Jin, Jian-Xue [Elekta China Co. Ltd, Department of Radiation Physics, Beijing, Chaoyang District (China)

    2014-10-08

    Previous studies showed that noncoplanar intensity-modulated radiotherapy (NC-IMRT) for sinonasal cancer is superior to coplanar intensity-modulated radiotherapy (IMRT). Volumetric-modulated arc therapy (VMAT) is a newly introduced treatment modality, and the performance of noncoplanar VMAT for sinonasal cancer has not been well described to date. To compare the dosimetry difference of noncoplanar VMAT (NC-VMAT), coplanar VMAT (co-VMAT), and NC-IMRT for sinonasal cancer. Ten postoperative patients with sinonasal cancer were randomly selected for planning with NC-VMAT, co-VMAT, and NC-IMRT. Two planning target volumes (PTVs) were contoured representing high-risk and low-risk regions set to receive a median absorbed dose (D{sub 50} {sub %}) of 68 Gy and 59 Gy, respectively. The homogeneity index (HI), conformity index (CI), dose-volume histograms (DVHs), and delivery efficiency were all evaluated. Both NC-VMAT and co-VMAT showed superior dose homogeneity and conformity in PTVs compared with NC-IMRT. There was no significant difference between NC-VMAT and co-VMAT in PTV coverage. Both VMAT plans provided a better protection for organs at risk (OARs) than NC-IMRT plans, and NC-VMAT showed a small improvement over co-VMAT in sparing of OARs. For peripheral doses, the doses to breast, thyroid, and larynx in the NC-IMRT plans were significantly higher than those in both VMAT plans. Compared to NC-VMAT, co-VMAT significantly reduced peripheral doses. NC-VMAT and co-VMAT reduced the average delivery time by 63.2 and 64.2 %, respectively, in comparison with NC-IMRT. No differences in delivery efficiency were observed between the two VMAT plans. Compared to NC-VMAT, co-VMAT showed similar PTV coverage and comparable OAR sparing but significantly reduced peripheral doses and positioning uncertainty. We propose to give priority to coplanar VMAT in the treatment of sinonasal cancer. (orig.) [German] Fruehere Studien zeigten, dass die nichtkoplanare intensive modulierte

  11. Dust in protoplanetary disks: observations*

    Directory of Open Access Journals (Sweden)

    Waters L.B.F.M.

    2015-01-01

    Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

  12. Dust Devil Tracks

    Science.gov (United States)

    Reiss, Dennis; Fenton, Lori; Neakrase, Lynn; Zimmerman, Michael; Statella, Thiago; Whelley, Patrick; Rossi, Angelo Pio; Balme, Matthew

    2016-11-01

    Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth's surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ˜1 m and ˜1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550-850 nm on Mars and around 0.5 % in the wavelength range from 300-1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand

  13. Linear Alkylbenzenesulfonates in indoor Floor Dust

    DEFF Research Database (Denmark)

    Wolkoff, Peder; Madsen, Jørgen Øgaard

    1999-01-01

    The amount of Linear Alkylbenzenesulfonates (LAS) in the particle fraction of floor dust sampled from 7 selected public buildings varied between 34 and 1500 microgram per gram dust, while the contents of the fibre fractions generally were higher with up to 3500 microgram LAS/g dust. The use...... of a cleaning agent with LAS resulted in an increase of the amount of LAS in the floor dust after floor wash relative to just before floor wash. However, the most important source of LAS in the indoor floor dust appears to be residues of detergent in clothing. Thus, a newly washed shirt contained 2960 microgram...

  14. Dust Acoustic Wave Excitation in a Plasma with Warm Dust

    Science.gov (United States)

    Rosenberg, M.; Thomas, E., Jr.; Marcus, L.; Fisher, R.; Williams, J. D.; Merlino, R. L.

    2008-11-01

    Measurements of the dust acoustic wave dispersion relation in dusty plasmas formed in glow discharges at the University of Iowa [1] and Auburn University [2] have shown the importance of finite dust temperature effects. The effect of dust grains with large thermal speeds was taken into account using kinetic theory of the ion-dust streaming instability [3]. The results of analytic and numerical calculations of the dispersion relation based on the kinetic theory will be presented and compared with the experimental results. [1] E. Thomas, Jr., R. Fisher, and R. L. Merlino, Phys. Plasmas 14, 123701 (2007). [2] J. D. Williams, E. Thomas Jr., and L. Marcus, Phys. Plasmas 15, 043704 (2008). [3] M. Rosenberg, E. Thomas Jr., and R. L. Merlino, Phys. Plasmas 15, 073701 (2008).

  15. Nasal Adenocarcinoma in a Horse with Metastasis to Lung, Liver, and Bone and Review of Metastasis in Nine Horses with Sinonasal Tumors

    Directory of Open Access Journals (Sweden)

    Ashley Hanna

    2015-01-01

    Full Text Available Sinonasal neoplasia metastasizing to distant organs is rare in horses. This case report describes the clinical and imaging findings of a horse with sinonasal neoplasia, which had metastasized to the lung, liver, and humerus. Additionally, the prevalence of sinonasal neoplasia and their incidence of distant metastasis among horses that presented to the Oregon State University Veterinary Teaching Hospital (OSU-VTH were estimated. Of 5,558 equine patients who presented to the OSU-VTH in the last nine years, 1.4% were diagnosed with sinonasal disease and 10.3% of these cases had sinonasal neoplasia with only one having confirmed distant metastasis. This case was an eleven-year-old quarter horse which was evaluated due to a history of a right forelimb lameness of three weeks duration. Two and a half months later he presented again, this time for unilateral epistaxis and persistent right forelimb lameness. Radiography of the right elbow noted an increasingly irregular, periosteal response and osteolytic lesion of the right distal humeral condyle. At the time of the second presentation, nasosinal endoscopy identified a lobulated mass in the region of the ethmoid turbinates. Histopathology of this mass revealed an adenocarcinoma of nasal origin with metastasis to the lung, liver, and right humerus.

  16. E ring dust sources: Implications from Cassini's dust measurements

    Science.gov (United States)

    Spahn, Frank; Albers, Nicole; Hörning, Marcel; Kempf, Sascha; Krivov, Alexander V.; Makuch, Martin; Schmidt, Jürgen; Seiß, Martin; Miodrag Sremčević

    2006-08-01

    The Enceladus flybys of the Cassini spacecraft are changing our understanding of the origin and sustainment of Saturn's E ring. Surprisingly, beyond the widely accepted dust production caused by micrometeoroid impacts onto the atmosphereless satellites (the impactor-ejecta process), geophysical activities have been detected at the south pole of Enceladus, providing an additional, efficient dust source. The dust detector data obtained during the flyby E11 are used to identify the amount of dust produced in the impactor-ejecta process and to improve related modeling [Spahn, F., Schmidt, J., Albers, N., Hörning, M., Makuch, M., Seiß, M., Kempf, S., Srama, R., Dikarev, V.V., Helfert, S., Moragas-Klostermeyer, G., Krivov, A.V., Sremčević, M., Tuzzolino, A., Economou, T., Grün, E., 2006. Cassini dust measurements at Enceladus: implications for Saturn's E ring. Science, in press]. With this, we estimate the impact-generated dust contributions of the other E ring satellites and find significant differences in the dust ejection efficiency by two projectile families - the E ring particles (ERPs) and the interplanetary dust particles (IDPs). Together with the Enceladus south-pole source, the ERP impacts play a crucial role in the inner region, whereas the IDP impacts dominate the particle production in the outer E ring, possibly accounting for its large radial extent. Our results can be verified in future Cassini flybys of the E ring satellites. In this way poorly known parameters of the dust particle production in hypervelocity impacts can be constrained by comparison of the data and theory.

  17. TERT promoter mutations in sinonasal malignant melanoma: a study of 49 cases.

    Science.gov (United States)

    Jangard, Mattias; Zebary, Abdlsattar; Ragnarsson-Olding, Boel; Hansson, Johan

    2015-06-01

    Sinonasal malignant melanoma (SNMM) comprises less than 1% of all melanomas and is located in the nasal cavity and the paranasal sinuses. The majority of SNMMs have unknown underlying oncogenic driver mutations. The recent identification of a high frequency of driver mutations in the promoter of the telomerase reverse transcriptase (TERT) gene in cutaneous melanoma led us to investigate whether these mutations also occur in SNMM. Our aim was to determine the TERT promoter mutation frequencies in primary SNMMs. Laser capture microdissection and manual dissection were used to isolate tumour cells from 49 formalin-fixed paraffin-embedded tissues. The tumours were screened for TERT promoter mutations by direct Sanger sequencing. Information on NRAS, BRAF and KIT mutation was available from an earlier study. Overall, 8% (4/49) of SNMMs harboured TERT promoter mutations. One of these mutated tumours had a coexistent NRAS mutation and one had a BRAF mutation. Our findings show that TERT promoter mutations are present in a moderate proportion of SNMM. No conclusion can be drawn on their potential influence on the clinical outcome or tumour progression.

  18. Roles of human papillomavirus infection and stathmin in the pathogenesis of sinonasal inverted papilloma.

    Science.gov (United States)

    Lin, Hai; Lin, Dong; Xiong, Xi-Sheng

    2016-02-01

    The purpose of this study was to investigate roles of human papillomavirus (HPV) infection and stathmin in sinonasal inverted papilloma (SNIP). HPV DNA detection was performed by the fluorescence-based polymerase chain reaction (PCR) method. Stathmin protein expression was investigated by the immunohistochemistry method and mRNA expression of stathmin, Kif2a, and cyclin D1 were assessed by real-time PCR in SNIP and control subjects. The positive rate of HPV DNA detected in SNIP was about 53.6% (15 of 28). Recurrent cases showed a higher rate of HPV infection compared with initial cases and higher Krouse stage (T3 + T4) cases showed higher rate of HPV infection than lower Krouse stage (T1 + T2) cases. Stronger expression of stathmin, Kif2a, and cyclin D1 were observed in SNIP, especially HPV(+) SNIP. HPV infection was closely associated with recurrence and progression of SNIP. Stathmin is a valuable prognostic marker and could be considered as a therapeutic target in patients with SNIP. © 2015 Wiley Periodicals, Inc.

  19. Does human papilloma virus play a role in sinonasal inverted papilloma?

    Science.gov (United States)

    Govindaraj, Satish; Wang, Hailun

    2014-02-01

    Inverted papillomas are a benign sinonasal tumor with a propensity for recurrence and malignant transformation. Although many investigations have been made into the nature of this disease, its etiology and causes for malignant transformation have yet to be fully elucidated. It is the authors' objective to present a review on management of the disease and evaluate the present relationship between human papilloma virus (HPV) and inverted papilloma. A causal relationship between HPV and the pathogenesis and progression of inverted papilloma has been posited since the 1980s. Although widely varied HPV detection rates have been reported, recent studies have noted a substantial increase in both recurrence and malignant transformation in HPV-infected inverted papillomas. However, exact cellular mechanisms by which infection leads to subsequent recurrence and development of carcinoma have yet to be elucidated. Evidence exists suggesting that HPV infection plays a role in the progression of inverted papilloma and confers an increased risk for recurrence and malignant transformation. PCR is the preferred detection method, and fresh or frozen specimens are the ideal source of tissue for evaluation. Although multiple studies have detected an association between HPV and inverted papilloma (both recurrent and malignant transformation), further studies are necessary to elucidate the underlying molecular pathways before an association can be changed to causation.

  20. Prevalence of Human Papilloma Virus in Sinonasal Papilloma in Southern Iranian Population.

    Science.gov (United States)

    Valibeigi, Behnaz; Ashraf, Mohamad Javad; Kerdegari, Narges; Safai, Akbar; Abedi, Elham; Khademi, Bijan; Azarpira, Negar

    2017-06-01

    Sinonasal papilloma (SNP) is a rare benign lesion characterized by high recurrence rate and malignant transformation. This study aimed to investigate the prevalence of human papilloma virus (HPV) infection in these lesions in South of Iran. In this cross sectional retrospective study, a total of 41 patients, 38 SNP and 3 SNP/Squamous cell carcinoma cases, from 2007 to 2014 were studied. Human papilloma virus (HPV) DNA detection was performed by nested PCR method and positive cases were analyzed for high risk HPV-16 and HPV-18. HPV was detected in 31.7%; HPV- 16 in 4.9% and HPV 18 was not detected at all. Dysplastic epithelium was detected in 53% that was not associated with HPV. Three cases were accompanied with malignant transformation that HPV genome was detected in only one case and none of them were positive for HPV16 /18 genomic DNA. Current research suggests that HPV may be involved in the development of SNP. But the high risk HPV is not important in malignant transformation. More studies are needed to elucidate the possible etiologic mechanism between HPV, inverted papilloma, and squamous cell carcinoma.

  1. What causes canine sino-nasal aspergillosis? A molecular approach to species identification.

    Science.gov (United States)

    Talbot, Jessica J; Johnson, Lynelle R; Martin, Patricia; Beatty, Julia A; Sutton, Deanna A; Billen, Frédéric; Halliday, Catriona L; Gibson, Justine S; Kidd, Sarah; Steiner, Jörg M; Ujvari, Beata; Barrs, Vanessa R

    2014-04-01

    On the basis of phenotypic identification methods, Aspergillus fumigatus is reported as the most commonly identified aetiological agent of canine sino-nasal aspergillosis (SNA). However, definitive identification of Aspergillus spp. using phenotypic features alone is unreliable. The aim of this study was to determine the molecular identities of fungal species causing SNA in dogs. Genomic DNA was extracted from 91 fungal isolates from 90 dogs diagnosed with SNA in Australia, the USA and Belgium, and the ITS1-5.8S-ITS2 ribosomal DNA and partial β-tubulin regions were sequenced. Eighty-eight of 91 (96.7%) isolates were identified as A. fumigatus and 3/91 (3.3%) belonged to Aspergillus section Nigri spp. (Aspergillus tubingensis: 2/91; Aspergillus uvarum: 1/91). These findings confirm that A. fumigatus is the most common aetiological agent of canine SNA. This is the first report to document a pathogenic role for A. tubingensis and A. uvarum in dogs. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  2. Bone regeneration after sinonasal mucocele marsupialization: What really happens over time?

    Science.gov (United States)

    Terranova, Paola; Karligkiotis, Apostolos; Digilio, Elena; Basilico, Francesca; Bernardini, Elena; Pistochini, Andrea; Bignami, Maurizio; Castelnuovo, Paolo

    2015-07-01

    To evaluate the necessity of reconstructing the eroded bony boundaries after mucocele marsupialization when the mucoperiosteum has been spared. Retrospective review of 308 patients treated for a sinonasal mucocele. Of these, 116 showed areas of bone reabsorption in their preoperative computed tomography (CT) scan. Of 116 patients showing one or more areas of bone reabsorption who underwent marsupialization of the mucocele, whether using a purely endonasal endoscopic approach or a combined approach, the common factor was that the mucoperiosteum of the paranasal sinus had always been spared and the eroded bone had never been reconstructed. After rigorous selection, 12 adult patients were enrolled to undergo a postoperative CT scan in order to verify what had happened to the eroded bone at least 3 years following the surgical marsupialization of the mucocele. In 66,6% of patients, the postoperative CT scan showed complete self-reconstruction of bone that had previously been eroded by the mucocele. No enophthalmus, meningocele, or other facial deformities were noted in our selection group, despite not having undergone surgical reconstruction of the bone. Even taking into account the small number of patients enrolled in the present study, indications are that there is no need to reconstruct the eroded bone, as would appear from our results that sparing the mucoperiosteum is enough to enable the bone to regenerate. Nevertheless, larger scale studies of the subject are merited. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  3. [A case report of sinonasal tumor: the effect of corrective make up training].

    Science.gov (United States)

    Sugiura, Saiko; Fujimoto, Yasushi; Nakata, Seiichi; Nakashima, Tsutomu

    2006-06-01

    Facial appearance is very important for personal identity, and some patients suffer long-term stress as a result of disfigurement caused by facial nerve paralysis and wounds. The psychological aspect of the disease has important implications for the optimal management of patients. In such cases, while aggressive rehabilitation including cosmetic surgery may be useful, cosmetics are also effective for covering visible signs of the disease. A patient who had undergone an operation for a sinonasal tumor was instructed by an expert beautician in the application of make up to correct her facial imbalance and wounds. The 60-item General Health Questionnaire (GHQ60) and the European quality of life 5 dimensions (EQ-5D) VAS were administered before the first application and one month afterwards. The GHQ60 and EQ-5D VAS scores improved after the make up instruction. We suggest that corrective make up training is an effective measure for reducing the psychological load of patients with head and neck tumors.

  4. Primary step for endoscopic sinonasal tract and anterior skull base robotics

    Directory of Open Access Journals (Sweden)

    Crampette Louis

    2011-12-01

    Full Text Available Introduction: Surgeons have evolved a lot their surgical procedures in sinus surgery and are now able to resect malignant tumors. These progresses are now leading new difficulties like impairing vision (bleeding and LCR flow and necessity of multiple simultaneous tasks. With the aim of designing a new endoscope-holder, primary step was to characterize the surgeon gesture, the kinematics, and the type of man-machine interface acceptable by the surgeon. Methods: We worked on thirteen sinonasal tracts of cadaver heads. Surgical procedures were: opening all the sinuses, the carotid, the sella turcica, the lamina papyracea and the anterior skull base. We used conventional instruments which were instrumented with a force-torque sensor and a navigation system. Then we have experimentally evaluated robots with three different kinematics and two types of man-machine interfaces. Results: We collected enough position and force data as well as kinematics constraints and interface requirements to specify a robot for endoscopic sinus surgery.

  5. Dust Measurements in Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

    2008-04-23

    Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.

  6. Low prevalence of K-RAS, EGF-R and BRAF mutations in sinonasal adenocarcinomas. Implications for anti-EGFR treatments.

    Science.gov (United States)

    Franchi, Alessandro; Innocenti, Duccio Rossi Degli; Palomba, Annarita; Miligi, Lucia; Paiar, Fabiola; Franzese, Ciro; Santucci, Marco

    2014-07-01

    We have previously shown that a subset of sinonasal intestinal-type adenocarcinomas (ITAC) shows activation of the epidermal growth factor-receptor (EGFR) pathway. In this study we examine the status of the EGFR, KRAS and BRAF genes in a series of sinonasal intestinal (ITAC) and non-intestinal type adenocarcinomas (non-ITAC). Eighteen ITACs and 12 non-ITACs were studied immunohistochemically for EGFR expression. Point mutations were analyzed for EGFR exons 19 and 21, KRAS exon 2 and BRAF exon 15 by direct sequencing. Non-ITACs showed significantly higher expression of EGFR (p = 0.015). Mutation analysis revealed one ITAC with EGFR and one ITAC with KRAS mutation, while two non-ITACs presented mutation of BRAF. We conclude that a subset of sinonasal adenocarcinomas shows overexpression of EGFR, while activating mutations of the signaling cascade downstream of EGFR are rare, suggesting that these tumors could be good candidates for anti-EGFR therapies.

  7. Reuyl Crater Dust Avalanches

    Science.gov (United States)

    2002-01-01

    (Released 13 May 2002) The Science The rugged, arcuate rim of the 90 km crater Reuyl dominates this THEMIS image. Reuyl crater is at the southern edge of a region known to be blanketed in thick dust based on its high albedo (brightness) and low thermal inertia values. This thick mantle of dust creates the appearance of snow covered mountains in the image. Like snow accumulation on Earth, Martian dust can become so thick that it eventually slides down the face of steep slopes, creating runaway avalanches of dust. In the center of this image about 1/3 of the way down is evidence of this phenomenon. A few dozen dark streaks can be seen on the bright, sunlit slopes of the crater rim. The narrow streaks extend downslope following the local topography in a manner very similar to snow avalanches on Earth. But unlike their terrestrial counterparts, no accumulation occurs at the bottom. The dust particles are so small that they are easily launched into the thin atmosphere where they remain suspended and ultimately blow away. The apparent darkness of the avalanche scars is due to the presence of relatively dark underlying material that becomes exposed following the passage of the avalanche. Over time, new dust deposition occurs, brightening the scars until they fade into the background. Although dark slope streaks had been observed in Viking mission images, a clear understanding of this dynamic phenomenon wasn't possible until the much higher resolution images from the Mars Global Surveyor MOC camera revealed the details. MOC images also showed that new avalanches have occurred during the time MGS has been in orbit. THEMIS images will allow additional mapping of their distribution and frequency, contributing new insights about Martian dust avalanches. The Story The stiff peaks in this image might remind you of the Alps here on Earth, but they really outline the choppy edge of a large Martian crater over 50 miles wide (seen in the context image at right). While these aren

  8. COMBINED CO AND DUST SCALING RELATIONS OF DEPLETION TIME AND MOLECULAR GAS FRACTIONS WITH COSMIC TIME, SPECIFIC STAR-FORMATION RATE, AND STELLAR MASS

    Energy Technology Data Exchange (ETDEWEB)

    Genzel, R.; Tacconi, L. J.; Lutz, D.; Berta, S.; Burkert, A. [Max-Planck-Institut für Extraterrestrische Physik (MPE), Giessenbachstr., D-85748 Garching (Germany); Saintonge, A. [Department of Physics and Astronomy, University College London, Gower Place, London WC1E 6BT (United Kingdom); Magnelli, B. [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Combes, F. [Observatoire de Paris, LERMA, CNRS, 61 Av. de l' Observatoire, F-75014 Paris (France); García-Burillo, S. [Observatorio Astronómico Nacional-OAN, Observatorio de Madrid, Alfonso XII, 3, 28014 Madrid (Spain); Neri, R.; Boissier, J. [IRAM, 300 Rue de la Piscine, F-38406 St. Martin d' Heres, Grenoble (France); Bolatto, A. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Contini, T.; Boone, F.; Bouché, N. [Institut d' Astrophysique et de Planétologie, Universite de Toulouse, 9 Avenue du Colonel Roche BP 44346, F-31028 Toulouse Cedex 4 (France); Lilly, S.; Carollo, M. [Institute of Astronomy, Department of Physics, Eidgenössische Technische Hochschule, CH-8093 ETH Zürich (Switzerland); Bournaud, F. [Service d' Astrophysique, DAPNIA, CEA/Saclay, F-91191 Gif-sur-Yvette Cedex (France); Colina, L. [CSIC Instituto Estructura Materia, C/Serrano 121, E-28006 Madrid (Spain); Cooper, M. C., E-mail: linda@mpe.mpg.de, E-mail: genzel@mpe.mpg.de [Department of Physics and Astronomy, Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); and others

    2015-02-10

    We combine molecular gas masses inferred from CO emission in 500 star-forming galaxies (SFGs) between z = 0 and 3, from the IRAM-COLDGASS, PHIBSS1/2, and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas depletion timescale (t {sub depl}) and gas to stellar mass ratio (M {sub mol} {sub gas}/M{sub *} ) of SFGs near the star formation ''main-sequence'' with redshift, specific star-formation rate (sSFR), and stellar mass (M{sub *} ). The CO- and dust-based scaling relations agree remarkably well. This suggests that the CO → H{sub 2} mass conversion factor varies little within ±0.6 dex of the main sequence (sSFR(ms, z, M {sub *})), and less than 0.3 dex throughout this redshift range. This study builds on and strengthens the results of earlier work. We find that t {sub depl} scales as (1 + z){sup –0.3} × (sSFR/sSFR(ms, z, M {sub *})){sup –0.5}, with little dependence on M {sub *}. The resulting steep redshift dependence of M {sub mol} {sub gas}/M {sub *} ≈ (1 + z){sup 3} mirrors that of the sSFR and probably reflects the gas supply rate. The decreasing gas fractions at high M{sub *} are driven by the flattening of the SFR-M {sub *} relation. Throughout the probed redshift range a combination of an increasing gas fraction and a decreasing depletion timescale causes a larger sSFR at constant M {sub *}. As a result, galaxy integrated samples of the M {sub mol} {sub gas}-SFR rate relation exhibit a super-linear slope, which increases with the range of sSFR. With these new relations it is now possible to determine M {sub mol} {sub gas} with an accuracy of ±0.1 dex in relative terms, and ±0.2 dex including systematic uncertainties.

  9. Histopathological study of lesions of nose and paranasal sinuses and association of Human Papilloma Virus (HPV with sinonasal papillomas and squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Beigh Ambreen

    2016-06-01

    Full Text Available A variety of non-neoplastic and neoplastic conditions involve the nasal cavity and paranasal sinuses which are commonly encountered in clinical practice. The nose and paranasal sinuses are exposed to a variety of infections, chemically irritating, antigenically stimulating, traumatic and undoubtedly many other influences and consequences of these multifaceted deleterious exposures result in the formation of tumour-like and truly neoplastic conditions. To study histopathological pattern of sinonasal lesions and association of Human Papilloma Virus (HPV with sinonasal papillomas and squamous cell carcinomas. The present study was a hospital based observational study conducted over a period of three years from January, 2010 to January, 2013 in the Department of Pathology, Government Medical College, Srinagar which included 181 cases of non-neoplastic and neoplastic lesions of nasal cavity and paranasal sinuses followed by study of association of HPV with sinonasal papillomas and squamous cell carcinomas by polymerase chain reaction (PCR. Out of total 181 cases, 114 were non-neoplastic and 67 were neoplastic. Out of 67 neoplastic lesions, 46 were benign and 21 were malignant. Nasal polyp was most common among non neoplastic lesions. Inverted sinonasal papilloma was most common benign lesion and squamous cell carcinoma was most common malignant lesion seen. Out of a total of 181 sinonasal lesions 101 (55.8% were present in males and 80 (44.2% were present in females with male to female ratio being 1.26:1. The age range of patients with sinonasal lesions varied from 5-75 years with a mean age being 34.67 (SD±16.58 years. HPV positivity was seen in 4 (13.33% out of 30 cases of inverted papillomas, 3 out of 6 (50% exophytic papillomas tested positive for HPV. Out of 9 squamous cell carcinomas HPV positivity was seen in 2 (22.2% cases. Categorizing the sinonasal lesions according to histopathological features into various types helps us to know the

  10. Nano-metric Dust Particles as a Hardly Detectable Component of the Interplanetary Dust Cloud

    Indian Academy of Sciences (India)

    I. Simonia; Sh. Nabiyev

    2015-09-01

    The present work introduces the hypothesis of existence of a hardly detectable component of the interplanetary dust cloud and demonstrates that such a component is a dust formation consisting of the dust particles of nano-metric dimensions. This work describes the main physical properties of such a kind of nano-dust, and its possible chemical and mineralogical peculiarities proposes new explanations related to reddening of the dynamically cold transneptunian objects on account of scattering their light by nano-dust of the hardly detectable component of the interplanetary dust cloud. We propose the relation for the coefficient of absorption by the nano-dust and provide results of the statistical analysis of the TNO color index–orbital inclinations. We also present a critical assessment of the proposed hypothesis.

  11. Resveratrol enhances airway surface liquid depth in sinonasal epithelium by increasing cystic fibrosis transmembrane conductance regulator open probability.

    Directory of Open Access Journals (Sweden)

    Shaoyan Zhang

    Full Text Available BACKGROUND: Chronic rhinosinusitis engenders enormous morbidity in the general population, and is often refractory to medical intervention. Compounds that augment mucociliary clearance in airway epithelia represent a novel treatment strategy for diseases of mucus stasis. A dominant fluid and electrolyte secretory pathway in the nasal airways is governed by the cystic fibrosis transmembrane conductance regulator (CFTR. The objectives of the present study were to test resveratrol, a strong potentiator of CFTR channel open probability, in preparation for a clinical trial of mucociliary activators in human sinus disease. METHODS: Primary sinonasal epithelial cells, immortalized bronchoepithelial cells (wild type and F508del CFTR, and HEK293 cells expressing exogenous human CFTR were investigated by Ussing chamber as well as patch clamp technique under non-phosphorylating conditions. Effects on airway surface liquid depth were measured using confocal laser scanning microscopy. Impact on CFTR gene expression was measured by quantitative reverse transcriptase polymerase chain reaction. RESULTS: Resveratrol is a robust CFTR channel potentiator in numerous mammalian species. The compound also activated temperature corrected F508del CFTR and enhanced CFTR-dependent chloride secretion in human sinus epithelium ex vivo to an extent comparable to the recently approved CFTR potentiator, ivacaftor. Using inside out patches from apical membranes of murine cells, resveratrol stimulated an ~8 picosiemens chloride channel consistent with CFTR. This observation was confirmed in HEK293 cells expressing exogenous CFTR. Treatment of sinonasal epithelium resulted in a significant increase in airway surface liquid depth (in µm: 8.08+/-1.68 vs. 6.11+/-0.47,control,p<0.05. There was no increase CFTR mRNA. CONCLUSION: Resveratrol is a potent chloride secretagogue from the mucosal surface of sinonasal epithelium, and hydrates airway surface liquid by increasing CFTR

  12. Occupational risk factors for sinonasal cancer: a case-control study in France.

    Science.gov (United States)

    Luce, D; Leclerc, A; Morcet, J F; Casal-Lareo, A; Gérin, M; Brugère, J; Haguenoer, J M; Goldberg, M

    1992-01-01

    A case-control study was conducted in France to examine occupational risk factors for sinonasal cancer; 207 cases and 409 controls were included in the study. Detailed information was collected on occupational history and other potential risk factors for nasal cancer. Results are presented for three histologic types: adenocarcinoma, squamous cell carcinoma, and others. Among males, the risk of adenocarcinoma was significantly elevated for cabinetmakers (odds-ratio = 35.4, 95% confidence interval = 18.1-69.3), carpenters and joiners (OR = 25.2, 95% CI = 14.6-43.6), and wood-working machine operators (OR = 7.4, 95% CI = 3.4-15.8), whereas the odds-ratios were less than 1 for loggers and wood preparation workers. Odds-ratios associated with cabinetmakers (OR = 11.2, 95% CI = 2.7-45.9)) and carpenters and joiners (OR = 5.8, 95% CI = 1.8-18.6) were also significantly elevated for the other-histologic-types category. Significant excesses in risk of squamous cell cancer were noted for "bakers, pastry cooks, grain millers" (OR = 3.9, 1.2-12.8), construction workers (OR = 3.7, 95% CI = 1.7-8.0), and carpenters and joiners having worked for at least 15 years in the wood manufacturing industry (OR = 8.1, 95% CI = 1.3-50.3). Among females, a significant increase in risk of squamous cell carcinoma (OR = 9.5, 95% CI = 1.7-54.1) and a moderate increase in risk of adenocarcinoma (OR = 4.0, 95% CI = 0.7-23.5) was observed for textile workers. Elevated risks of squamous cell cancer were noted for farm workers of both sexes (males: OR = 2.2, 95% CI = 1.1-4.4; females: OR = 4.9, 95% CI = 1.0-24.9).

  13. Survival Outcome of Squamous Cell Carcinoma Arising from Sinonasal Inverted Papilloma

    Institute of Scientific and Technical Information of China (English)

    Qing-Zhuang Liang; De-Zhi Li; Xiao-Lei Wang; Hui Huang; Zhen-Gang Xu; Yue-Huang Wu

    2015-01-01

    Background:Sinonasal inverted papilloma (IP) is a rare benign tumor of the nasal cavities and paranasal sinuses.It is destructive or bone-remodeling,tends to recur after surgical resection,and has a significant malignant potential.The present study aimed to perform a retrospective analysis of patients with squamous cell carcinoma (SCC) arising from IP,including characteristics,survival outcome,and predictors of associated malignancy.Methods:The medical records of 213 patients diagnosed with IP from January 1970 to January 2014 were retrospectively reviewed.Eighty-seven patients were diagnosed with SCC/IP; their clinical characteristics,treatments,and survival outcomes were analyzed.Results:Of the 87 patients with SCC/IP,the 5-and 10-year overall survival outcomes were 39.6% and 31.8%,respectively.Twenty-nine of these patients received surgery and 58 received combined surgery and radiation.Of the patients with stages Ⅲ-Ⅳ,the 5-year survival rate was 30.7% for those treated with surgery only and 39.9% for those given the combination treatment (P =0.849).Factors associated with significantly poor prognosis were advanced-stage,metachronous tumors,or with cranial base and orbit invasion.Age,synchronous or metachronous tumors,and pathological stage were independent risk factors for mortality,shown by multivariate analysis.Conclusion:Patients with SCC/IP had low overall survival outcomes.Advanced age,stage,and metachronous tumors are the main factors affecting prognosis.Treatment planning should consider high-risk factors to improve survival outcome.

  14. House dust mites, our intimate associates.

    Science.gov (United States)

    Nadchatram, M

    2005-06-01

    House dust mites have lived in human contact from time immemorial. Human dander or dead skin constitutes the major organic component of the house dust ecosystem. Because the mites feed on dander, dust mites and human association will continue to co-exist as part of our environment. Efficient house-keeping practice is the best form of control to reduce infestation. However, special precautions are important when individuals are susceptible or sensitive to dust mites. House dust mites are responsible for causing asthma, rhinitis and contact dermatitis. The respiratory allergies are caused by the inhalation of dead or live mites, their faecal matter or other byproducts. Immune factors are of paramount importance in the development of dust related or mite induced respiratory diseases. House dust mites were found in some 1,000 samples of dust taken from approximately 330 dwellings in Peninsular Malaysia and Singapore. Mattresses, carpets, corners of a bedroom, and floor beneath the bed are favourable dust mite habitats. The incriminating species based on studies here and elsewhere, as well as many other species of dust mites of unknown etiological importance are widely distributed in Malaysian homes. Density of dust mites in Malaysia and Singapore is greater than in temperate countries. Prevention and control measures with reference to subjects sensitive to dust mite allergies, including chemical control described in studies conducted in Europe and America are discussed. However, a cost free and most practical way to remove mites, their faecal matter and other products is to resort to sunning the bedding and carpets to kill the living mites, and then beaten and brushed to remove the dust and other components.

  15. Astrophysics of Dust in Cold Clouds

    CERN Document Server

    Draine, B T

    2003-01-01

    Nine lectures reviewing the astrophysics of dust in interstellar clouds. Topics include: (1) Summary of observational evidence concerning interstellar dust: broadband extinction, scattering of starlight, polarization of starlight, spectroscopy of dust, IR and FIR emission, and depletions of grain-forming elements. (2) Optics of interstellar dust grains: dielectric functions of nonconducting and conducting materials, calculational techniques, formulae valid in the Rayleigh limit, Kramers-Kronig relations, microwave emission mechanisms, and X-ray scattering. (3) IR and FIR emission: heating of interstellar dust, including single-photon heating, and resulting IR emission spectrum. (4) Charging of dust grains: collisional charging, photoelectric emission, and resulting charge distribution functions. (5) Dynamics: gas drag, Lorentz force, forces due to anisotropic radiation, and resulting drift velocities. (6) Rotational dynamics: brownian rotation, suprathermal rotation, and effects of starlight torques. (7) Alig...

  16. Simulation of dust statistical characteristics in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, R.D.; Pigarov, A.Yu.; Krasheninnikov, S.I.; Rosenberg, M.; Mendis, D.A. [University of California, San Diego, La Jolla, California, 92093 (United States)

    2008-03-15

    In this work we analyze the size (radius) distribution function of dust particles in tokamak plasmas during a steady state discharge. A relation between the radius distribution function of dust in the plasma and the radius distribution of dust injected from tokamak walls is obtained using a Green's function formalism. Numerical simulations of the dust radius distribution function in a tokamak plasma with the Dust Transport (DUSTT) code are used to obtain the analytical form of the Green's function semi-empirically. It is demonstrated that the Green's function obtained can be used to predict qualitatively the dust size distributions in the tokamak plasmas. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Dust Formation in Milky Way-like Galaxies

    CERN Document Server

    McKinnon, Ryan; Vogelsberger, Mark

    2015-01-01

    We introduce a dust model for cosmological simulations implemented in the moving-mesh code AREPO and present a suite of cosmological hydrodynamical zoom-in simulations to study dust formation within galactic haloes. Our model accounts for the stellar production of dust, accretion of gas-phase metals onto existing grains, destruction of dust through local supernova activity, and dust driven by winds from star-forming regions. We find that accurate stellar and active galactic nuclei feedback is needed to reproduce the observed dust-metallicity relation and that dust growth largely dominates dust destruction. Our simulations predict a dust content of the interstellar medium which is consistent with observed scaling relations at $z = 0$, including scalings between dust-to-gas ratio and metallicity, dust mass and gas mass, dust-to-gas ratio and stellar mass, and dust-to-stellar mass ratio and gas fraction. We find that roughly two-thirds of dust at $z = 0$ originated from Type II supernovae, with the contribution ...

  18. Imaging and Outcomes for a New Entity: Low-Grade Sinonasal Sarcoma with Neural and Myogenic Features

    Science.gov (United States)

    Cannon, Richard B.; Wiggins, Richard H.; Witt, Benjamin L.; Dundar, Yusuf; Johnston, Tawni M.; Hunt, Jason P.

    2017-01-01

    Objectives Low-grade sinonasal sarcoma with neural and myogenic features (LGSSNMF) is a new, rare tumor. Our goal is to describe the imaging characteristics and surgical outcomes of this unique skull base malignancy. Design Retrospective case series. Setting Academic medical center. Participants There were three patients who met inclusion criteria with a confirmed LGSSNMF. Main Outcome Measures Imaging and histopathological characteristics, treatments, survival and recurrence outcomes, complications, morbidity, and mortality. Results Patients presented with diplopia, facial discomfort, a supraorbital mass, and nasal obstruction. Magnetic resonance imaging and computed tomography imaging in all cases showed an enhancing sinonasal mass with associated hyperostotic bone formation that involved the frontal sinus, invaded the lamina papyracea and anterior skull base, and had intracranial extension. One patient underwent a purely endoscopic surgical resection and the second underwent a craniofacial resection, while the last is pending treatment. All patients recovered well, without morbidity or long-term complications, and are currently without evidence of disease (mean follow-up of 2.1 years). One patient recurred after 17 months and underwent a repeat endoscopic skull base and dural resection. Conclusions The surgical outcomes and imaging of this unique, locally aggressive skull base tumor are characterized. PMID:28229035

  19. Mechanical properties of dust collected by dust separators in iron ore sinter plants.

    Science.gov (United States)

    Lanzerstorfer, Christof

    2015-01-01

    The flow-related mechanical properties of dusts from the de-dusting systems of several sinter plants were investigated. The mass median diameters of the dusts were in the range from approximately 3 to 100 µm. Also, the bulk density of the dusts varied in a wide range (approximately 400 to 2300 kg/m³). A good correlation between the bulk density and the mass median diameter for most of the dusts was found. In contrast, the angles of repose did not vary very much, only for the coarsest dust a significantly lower value was measured. The angles of internal friction as well as the wall friction angles were lower for coarse dust and higher for fine dust. The shear tests showed that both angles depend considerably on the stress level. At low stress, the angles decreased significantly with increasing values of stress, whereas at higher stress, the dependence was small or even disappeared. The only exception to this behaviour was shown by the finest dust. The flowability decreased with the particle size. The flowability categories suggested by the three flowability indicators were passable only for the coarser dusts. For the finer dusts, the flowability was overestimated by all flowability indicators.

  20. Experimental Method for Measuring Dust Load on Surfaces in Rooms

    DEFF Research Database (Denmark)

    Lengweiler, Philip; Nielsen, Peter V.; Moser, Alfred

    A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms......, there is a need for better understanding of the mechanism of dust deposition and resuspension. With the presented experimental setup, the dust load on surfaces in a channel can be measured as a function of the environmental and surface conditions and the type of particles under controlled laboratory conditions....

  1. Potential cytotoxicity of water-soluble fraction of dust and particulate matters and relation to metal(loid)s based on three human cell lines.

    Science.gov (United States)

    Huang, Minjuan; Kang, Yuan; Wang, Wei; Chan, Chuen Yu; Wang, Xuemei; Wong, Ming Hung

    2015-09-01

    Hepatocellular liver carcinoma (HepG2), human skin derived keratinocyte (KERTr,) and lung epithelial carcinoma (A549) were employed in MTT assay to evaluate the cytotoxicity of water-soluble fraction of road dust, air-conditioning (AC) filter dust and PM2.5 via ingestion, dermal contact and inhalation. Their effects on cell growth were dependent on exposure time and concentration. The LC20s of PM2.5 for A549 cell were approximately one order of magnitude lower than those of road dust and AC filter dust for KERTr cell and HepG2 cell. The LC20s of aqueous extracts were negatively correlated to the water-soluble metal(loid)s contained in dust coarse particles (KERTr: p=0.004; HepG2: p0.05). Other water-soluble components in dust and PM might cause the cell hazards synergistically or additively with metal(loid)s. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. House dust in seven Danish offices

    Science.gov (United States)

    Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

    estimated to be relatively low. The storage of the bulk dust during the experiment had little effect on the specific biological and chemical composition.

  3. Dust coagulation in ISM

    Science.gov (United States)

    Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

    1989-01-01

    Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

  4. Dust-Acoustic Waves in Strongly Coupled Dusty Plasmas Containing Variable-Charge Impurities

    Institute of Scientific and Technical Information of China (English)

    XIE Bai-Song; HE Kai-Fen; M. Y. Yu

    2000-01-01

    A relatively self-consistent theory of dust-acoustic waves in the strongly coupled dusty plasmas containing variable charge impurities is given. Relevant physical processes such as dust elastic relaxation and dust charge relaxation are taken into account. It is shown that the negative dispersion of dust-acoustic waves due to the strong correlation of dusts is enhanced in the presence of dust-neutral collisions.

  5. Dust grains from the heart of supernovae

    Science.gov (United States)

    Bocchio, Marco; Marassi, Stefania; Schneider, Raffaella; Bianchi, Simone; Limongi, Marco; Chieffi, A.

    2016-06-01

    Dust grains are classically thought to form in the winds of asymptotic giant branch (AGB) stars. However, there is increasing evidence today for dust formation in supernovae (SNe). To establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. We have developed a new code (GRASH_Rev) which follows the newly-formed dust evolution throughout the supernova explosion until the merging of the forward shock with the circumstellar ISM. We have considered four well studied SNe in the Milky Way and Large Magellanic Cloud: SN1987A, CasA, the Crab Nebula, and N49. For all the simulated models, we find good agreement with observations and estimate that between 1 and 8% of the observed mass will survive, leading to a SN dust production rate of (3.9± 3.7)×10^(-4) MM_{⊙})/yr in the Milky Way. This value is one order of magnitude larger than the dust production rate by AGB stars but insufficient to counterbalance the dust destruction by SNe, therefore requiring dust accretion in the gas phase.

  6. Physics of interstellar dust

    CERN Document Server

    Krugel, Endrik

    2002-01-01

    The dielectric permeability; How to evaluate grain cross sections; Very small and very big particles; Case studies of Mie calculus; Particle statistics; The radiative transition probability; Structure and composition of dust; Dust radiation; Dust and its environment; Polarization; Grain alignment; PAHs and spectral features of dust; Radiative transport; Diffuse matter in the Milky Way; Stars and their formation; Emission from young stars. Appendices Mathematical formulae; List of symbols.

  7. Dust-off

    OpenAIRE

    Maycroft, Neil; Cheang, Shu Lea

    2015-01-01

    The fan of a motherboard switches on and off intermittently. It blows household dust, removed from the inside of a computer carcass, into the air. The dust then settles onto the motherboard, to be blown off again. This continual movement of dust is contained in the piece. However, it should remind us that the ceaseless creation and motion of unconfined dust accompanies all stages of the e-waste journey.

  8. Dust-off

    OpenAIRE

    Maycroft, Neil; Cheang, Shu Lea

    2015-01-01

    The fan of a motherboard switches on and off intermittently. It blows household dust, removed from the inside of a computer carcass, into the air. The dust then settles onto the motherboard, to be blown off again. This continual movement of dust is contained in the piece. However, it should remind us that the ceaseless creation and motion of unconfined dust accompanies all stages of the e-waste journey.

  9. Dust in the Universe

    Science.gov (United States)

    Hemenway, Mary Kay; Armosky, Brad J.

    2004-01-01

    Space is seeming less and less like empty space as new discoveries and reexaminations fill in the gaps. And, ingenuity and technology, like the Spitzer Space Telescope, is allowing examination of the far reaches of the Milky Way and beyond. Even dust is getting its due, but not the dust everyone is familiar with. People seldom consider the dust in…

  10. Glacial to Holocene changes in trans-Atlantic Saharan dust transport and dust-climate feedbacks.

    Science.gov (United States)

    Williams, Ross H; McGee, David; Kinsley, Christopher W; Ridley, David A; Hu, Shineng; Fedorov, Alexey; Tal, Irit; Murray, Richard W; deMenocal, Peter B

    2016-11-01

    Saharan mineral dust exported over the tropical North Atlantic is thought to have significant impacts on regional climate and ecosystems, but limited data exist documenting past changes in long-range dust transport. This data gap limits investigations of the role of Saharan dust in past climate change, in particular during the mid-Holocene, when climate models consistently underestimate the intensification of the West African monsoon documented by paleorecords. We present reconstructions of African dust deposition in sediments from the Bahamas and the tropical North Atlantic spanning the last 23,000 years. Both sites show early and mid-Holocene dust fluxes 40 to 50% lower than recent values and maximum dust fluxes during the deglaciation, demonstrating agreement with records from the northwest African margin. These quantitative estimates of trans-Atlantic dust transport offer important constraints on past changes in dust-related radiative and biogeochemical impacts. Using idealized climate model experiments to investigate the response to reductions in Saharan dust's radiative forcing over the tropical North Atlantic, we find that small (0.15°C) dust-related increases in regional sea surface temperatures are sufficient to cause significant northward shifts in the Atlantic Intertropical Convergence Zone, increased precipitation in the western Sahel and Sahara, and reductions in easterly and northeasterly winds over dust source regions. Our results suggest that the amplifying feedback of dust on sea surface temperatures and regional climate may be significant and that accurate simulation of dust's radiative effects is likely essential to improving model representations of past and future precipitation variations in North Africa.

  11. The concentrations of phthalates in settled dust in Bulgarian homes in relation to building characteristic and cleaning habits in the family

    DEFF Research Database (Denmark)

    Kolarik, Barbara; Bornehag, Carl-Gustaf; Naydenov, Kiril Georgiev;

    2008-01-01

    Phthalate esters are chemical compounds with a broad range of applications. Recently, we have shown that significantly higher dust concentration of di(2-ethylhexyl) phthalate (DEHP) was found in Bulgarian homes of children with asthma or allergies compared to healthy children. The concentration...... of DEHP was found to be significantly associated with wheezing in the last 12 months as reported by parents. The objective of the current study was to examine the associations between concentrations of phthalates in settled dust collected in Bulgarian homes and building characteristics and cleaning habits...... habits were collected from parental reports in questionnaires and from inspectors' observations in the homes. Significantly higher concentrations of BBzP, DEHP and DnOP in indoor dust were found in homes where polishing agents were used, compared to homes where such products were not used. The highest...

  12. Collection and analysis of samples for polycyclic aromatic hydrocarbons in dust and other solids related to sealed and unsealed pavement from 10 cities across the United States, 2005-07

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, Barbara J.; Wilson, Jennifer T.; Burbank, Teresa L.

    2008-01-01

    Parking lots and driveways are dominant features of the modern urban landscape, and in the United States, sealcoat is widely used on these surfaces. One of the most widely used types of sealcoat contains refined coal tar; coal-tar-based sealcoat products have a mean polycyclic aromatic hydrocarbon (PAH) concentration of about 5 percent. A previous study reported that parking lots in Austin, Texas, treated with coal-tar sealcoat were a major source of PAH compounds in streams. This report presents methods for and data from the analysis of concentrations of PAH compounds in dust from sealed and unsealed pavement from nine U.S. cities, and concentrations of PAH compounds in other related solid materials (sealcoat surface scrapings, nearby street dust, and nearby soil) from three of those same cities and a 10th city. Dust samples were collected by sweeping dust from areas of several square meters with a soft nylon brush into a dustpan. Some samples were from individual lots or driveways, and some samples consisted of approximately equal amounts of material from three lots. Samples were sieved to remove coarse sand and gravel and analyzed by gas chromatography/mass spectrometry. Concentrations of PAHs vary greatly among samples with total PAH (sigmaPAH), the sum of 12 unsubstituted parent PAHs, ranging from nondetection for all 12 PAHs (several samples from Portland, Oregon, and Seattle, Washington; sigmaPAH of less than 36,000 micrograms per kilogram) to 19,000,000 micrograms per kilogram for a sealcoat scraping sample (Milwaukee, Wisconsin). The largest PAH concentrations in dust are from a driveway sample from suburban Chicago, Illinois (sigmaPAH of 9,600,000 micrograms per kilogram).

  13. Toxicity of lunar dust

    CERN Document Server

    Linnarsson, Dag; Fubini, Bice; Gerde, Per; Karlsson, Lars L; Loftus, David J; Prisk, G Kim; Staufer, Urs; Tranfield, Erin M; van Westrenen, Wim

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of substantial research efforts, lunar dust properties, and therefore lunar dust toxicity may differ substantially. In this contribution, past and ongoing work on dust toxicity is reviewed, and major knowledge gaps that prevent an accurate assessment of lunar dust toxicity are identified. Finally, a range of studies using ground-based, low-gravity, and in situ measurements is recommended to address the identified knowledge gaps. Because none of the curated lunar samples exist in a pristine state that preserves the surface reactive chemical aspects thought to be present on the lunar surface, studies using this material carry with them considerable uncertainty in terms of fidelity. As a consequence, in situ data on lunar dust...

  14. Desert dust hazards: A global review

    Science.gov (United States)

    Middleton, N. J.

    2017-02-01

    Dust storms originate in many of the world's drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones - where dust storms represent a severe form of accelerated soil erosion - the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

  15. Dust processing in photodissociation regions - Mid-IR emission modelling

    CERN Document Server

    Compiegne, M; Verstraete, L; Habart, E

    2008-01-01

    Mid-infrared spectroscopy of dense illuminated ridges (or photodissociation regions, PDRs) suggests dust evolution. Such evolution must be reflected in the gas physical properties through processes like photo-electric heating or H_2 formation. With Spitzer Infrared Spectrograph (IRS) and ISOCAM data, we study the mid-IR emission of closeby, well known PDRs. Focusing on the band and continuum dust emissions, we follow their relative contributions and analyze their variations in terms of abundance of dust populations. In order to disentangle dust evolution and excitation effects, we use a dust emission model that we couple to radiative transfer. Our dust model reproduces extinction and emission of the standard interstellar medium that we represent with diffuse high galactic latitude clouds called Cirrus. We take the properties of dust in Cirrus as a reference to which we compare the dust emission from more excited regions, namely the Horsehead and the reflection nebula NGC 2023 North. We show that in both regio...

  16. Mesospheric dust observations during the MAXIDUSTY campaign

    Science.gov (United States)

    Antonsen, Tarjei; Havnes, Ove; Fredriksen, Åshild; Friedrich, Martin; Sternovsky, Zoltan; Plane, John; Hartquist, Tom; Olsen, Sveinung; Eilertsen, Yngve; Trondsen, Espen; Mann, Ingrid; Hedin, Jonas; Gumbel, Jörg; Moen, Jøran; Latteck, Ralph; Baumgarten, Gerd; Höffner, Josef; Williams, Bifford; Hoppe, Ulf-Peter; Karlberg, Jan-Ove

    2017-04-01

    The MAXIDUSTY rocket payloads, launched from Andøya June 30 and July 8 2016, were equipped with dust impact detectors aiming to characterize mesospheric dust charge state, mass distribution of impact fragments and NLC/PMSE structure. One of the main scientific objectives for the campaign was to confirm that material of meteoric origin is abundant inside the icy mesospheric dust particles. The rockets were launched simultaneously with PMSE and NLC (MAXIDUSTY-1) and PMSE (MAXIDUSTY-1B) respectively, and radar measurements were made coincident with the rocket flight path. We report here on the initial results from the rocket probes and remote soundings, with emphasis on the dust impact detector results. Results from the Multiple Dust Detector (MUDD) confirm that NLC ice particles probably have a relatively high content of meteoric smoke particles with a filling factor of up to several percent. Comparisons of the DUSTY faraday bucket and PMSE show that there is no simple correlation between the two.

  17. Bacterial d-amino acids suppress sinonasal innate immunity through sweet taste receptors in solitary chemosensory cells.

    Science.gov (United States)

    Lee, Robert J; Hariri, Benjamin M; McMahon, Derek B; Chen, Bei; Doghramji, Laurel; Adappa, Nithin D; Palmer, James N; Kennedy, David W; Jiang, Peihua; Margolskee, Robert F; Cohen, Noam A

    2017-09-05

    In the upper respiratory epithelium, bitter and sweet taste receptors present in solitary chemosensory cells influence antimicrobial innate immune defense responses. Whereas activation of bitter taste receptors (T2Rs) stimulates surrounding epithelial cells to release antimicrobial peptides, activation of the sweet taste receptor (T1R) in the same cells inhibits this response. This mechanism is thought to control the magnitude of antimicrobial peptide release based on the sugar content of airway surface liquid. We hypothesized that d-amino acids, which are produced by various bacteria and activate T1R in taste receptor cells in the mouth, may also activate T1R in the airway. We showed that both the T1R2 and T1R3 subunits of the sweet taste receptor (T1R2/3) were present in the same chemosensory cells of primary human sinonasal epithelial cultures. Respiratory isolates of Staphylococcus species, but not Pseudomonas aeruginosa, produced at least two d-amino acids that activate the sweet taste receptor. In addition to inhibiting P. aeruginosa biofilm formation, d-amino acids derived from Staphylococcus inhibited T2R-mediated signaling and defensin secretion in sinonasal cells by activating T1R2/3. d-Amino acid-mediated activation of T1R2/3 also enhanced epithelial cell death during challenge with Staphylococcus aureus in the presence of the bitter receptor-activating compound denatonium benzoate. These data establish a potential mechanism for interkingdom signaling in the airway mediated by bacterial d-amino acids and the mammalian sweet taste receptor in airway chemosensory cells. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  18. Sinonasal inhalation of tobramycin vibrating aerosol in cystic fibrosis patients with upper airway Pseudomonas aeruginosa colonization: results of a randomized, double-blind, placebo-controlled pilot study

    Directory of Open Access Journals (Sweden)

    Mainz JG

    2014-02-01

    Full Text Available Jochen G Mainz,1 Katja Schädlich,1 Claudia Schien,1 Ruth Michl,1 Petra Schelhorn-Neise,2 Assen Koitschev,3 Christiane Koitschev,4 Peter M Keller,5 Joachim Riethmüller,6 Baerbel Wiedemann,7 James F Beck1 1Cystic Fibrosis Centre, Department of Pediatrics, Jena University Hospital, Jena, Germany; 2Otorhinolaryngology Department, Jena University Hospital, Jena, Germany; 3Otorhinolaryngology Department, Klinikum Stuttgart, Germany; 4Otorhinolaryngology Department, University Hospital, Tübingen, Germany; 5Microbiology, Jena University Hospital, Jena, Germany; 6University Hospital, Pediatric CF-Centre, Tübingen, Germany; 7Technical University, Biometrics, Dresden, Germany Rationale: In cystic fibrosis (CF, the paranasal sinuses are sites of first and persistent colonization by pathogens such as Pseudomonas aeruginosa. Pathogens subsequently descend to the lower airways, with P. aeruginosa remaining the primary cause of premature death in patients with the inherited disease. Unlike conventional aerosols, vibrating aerosols applied with the PARI Sinus™ nebulizer deposit drugs into the paranasal sinuses. This trial assessed the effects of vibrating sinonasal inhalation of the antibiotic tobramycin in CF patients positive for P. aeruginosa in nasal lavage. Objectives: To evaluate the effects of sinonasal inhalation of tobramycin on P. aeruginosa quantification in nasal lavage; and on patient quality of life, measured with the Sino-Nasal Outcome Test (SNOT-20, and otologic and renal safety and tolerability. Methods: Patients were randomized to inhalation of tobramycin (80 mg/2 mL or placebo (2 mL isotonic saline once daily (4 minutes/nostril with the PARI Sinus™ nebulizer over 28 days, with all patients eligible for a subsequent course of open-label inhalation of tobramycin for 28 days. Nasal lavage was obtained before starting and 2 days after the end of each treatment period by rinsing each nostril with 10 mL of isotonic saline. Results: Nine

  19. Identifying sources of aeolian mineral dust: Present and past

    Science.gov (United States)

    Muhs, Daniel R; Prospero, Joseph M; Baddock, Matthew C; Gill, Thomas E

    2014-01-01

    glacial periods are likely due to greater production of glaciogenic dust particles from expanded ice sheets and mountain glaciers, but could also include dust inputs from exposed continental and insular shelves now submerged. Future dust sources are difficult to assess, but will likely differ from those of the present because of global warming. Global warming could bring about shifts in dust sources by changes in degree or type of vegetation cover, changes in wind strength, and increases or decreases in the size of water bodies. A major uncertainty in assessing dust sources of the future is related to changes inhuman land use, which could affect land surface cover, particularly due to increased agricultural endeavors and water usage.

  20. 石棉相关产品生产过程粉尘危害与控制对策%Dust hazards and control countermeasures in the process of asbestos-related production

    Institute of Scientific and Technical Information of China (English)

    王勇毅; 姜亢; 郭建中; 李琳

    2012-01-01

    Asbestos was widely used as an important mineral resource with its good performance. Due to asbestos dust generated in the production process of asbestos mining and asbestos-related products could cause serious harm to the physical health of the operating personnel, asbestos was included in the list of toxic substances released by Chinas Ministry of Health. In order to effectively control the health hazards of asbestos dust on workers, this paper based on the extensive research of asbestos mining and production enterprises, the characteristics and the job which could produce dust in the processing of asbestos mining and asbestos product producing were identified, typical work which had serious dust hazard were summarized in the in the processing of asbestos mining and asbestos product producing. Combined with our natural environment, production technology and management level and other factors , the reason why asbestos dust had serious harmful effects was analyzed, recommended countermeasures of controlling the occupational hazards of asbestos dust was proposed, in order to give advices of reducing or eliminate the hazards of asbestos-related production.%作为重要的矿产资源,石棉以其良好的性能得到广泛应用.由于石棉开采和石棉相关产品生产过程中产生的石棉粉尘对作业人员身体健康造成严重损害,石棉被列入我国卫生部发布的高毒物品名录.为有效控制石棉粉尘对作业人员的健康危害,在对我国石棉矿山和相关产品生产企业广泛调研基础上,辨识了石棉矿山开采、石棉制品生产过程存在粉尘危害的作业及特点,分析归纳石棉生产加工典型工序的粉尘危害因素.结合我国自然环境、生产技术和管理水平等因素,研究了我国石棉粉尘危害严重的原因,并提出控制石棉尘粉尘职业危害的建议对策,以期为达到降低或消除石棉相关产品生产企业石棉粉尘危害提供参考.

  1. Mineral dust transport in the Arctic modelled with FLEXPART

    Science.gov (United States)

    Groot Zwaaftink, Christine; Grythe, Henrik; Stohl, Andreas

    2016-04-01

    Aeolian transport of mineral dust is suggested to play an important role in many processes. For instance, mineral aerosols affect the radiation balance of the atmosphere, and mineral deposits influence ice sheet mass balances and terrestrial and ocean ecosystems. While many efforts have been done to model global dust transport, relatively little attention has been given to mineral dust in the Arctic. Even though this region is more remote from the world's major dust sources and dust concentrations may be lower than elsewhere, effects of mineral dust on for instance the radiation balance can be highly relevant. Furthermore, there are substantial local sources of dust in or close to the Arctic (e.g., in Iceland), whose impact on Arctic dust concentrations has not been studied in detail. We therefore aim to estimate contributions of different source regions to mineral dust in the Arctic. We have developed a dust mobilization routine in combination with the Lagrangian dispersion model FLEXPART to make such estimates. The lack of details on soil properties in many areas requires a simple routine for global simulations. However, we have paid special attention to the dust sources on Iceland. The mobilization routine does account for topography, snow cover and soil moisture effects, in addition to meteorological parameters. FLEXPART, driven with operational meteorological data from European Centre for Medium-Range Weather Forecasts, was used to do a three-year global dust simulation for the years 2010 to 2012. We assess the model performance in terms of surface concentration and deposition at several locations spread over the globe. We will discuss how deposition and dust load patterns in the Arctic change throughout seasons based on the source of the dust. Important source regions for mineral dust found in the Arctic are not only the major desert areas, such as the Sahara, but also local bare-soil regions. From our model results, it appears that total dust load in the

  2. [Effect of lunar dust on humans: -lunar dust: regolith-].

    Science.gov (United States)

    Morimoto, Yasuo; Miki, Takeo; Higashi, Toshiaki; Horie, Seichi; Tanaka, Kazunari; Mukai, Chiaki

    2010-09-01

    We reviewed the effect of lunar dust (regolith) on humans by the combination of the hazard/exposure of regolith and microgravity of the moon. With regard to the physicochemical properties of lunar dust, the hazard-related factors are its components, fibrous materials and nanoparticles. Animal exposure studies have been performed using a simulant of lunar dust, and it was speculated that the harmful effects of the simulant lies between those of crystalline silica and titanium dioxide. Fibrous materials may not have a low solubility judging from their components. The nanoparticles in lunar dust may have harmful potentials from the view of the components. As for exposure to regolith, there is a possibility that particles larger than ones in earth (1 gravity) are respirable. In microgravity, 1) the deposition of particles of less than 1 µm in diameter in the human lung did not decrease, 2) the functions of macrophages including phagocytosis were suppressed, 3) pulmonary inflammation was changed. These data on hazard/exposure and microgravity suggest that fine and ultrafine particles in regolith may have potential hazards and risks for humans.

  3. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    Science.gov (United States)

    Lam, Chiu-wing; James, John T.

    2009-01-01

    NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. Because the toxicity of lunar dust is not known, NASA has tasked its toxicology laboratory to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal/intrapharyngeal instillation. This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies are in progress to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated (ground) lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The results from the instillation studies will be useful for choosing exposure concentrations for the animal inhalation study. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The experiment with the simulate will ensure that the study techniques used with actual lunar dust will be successful. The results of instillation and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

  4. Release of monomers from composite dust.

    Science.gov (United States)

    Cokic, S M; Duca, R C; Godderis, L; Hoet, P H; Seo, J W; Van Meerbeek, B; Van Landuyt, K L

    2017-05-01

    Dental personnel are more at risk to develop asthmatic disease, but the exact reason is so far unknown. During abrasive procedures, dental personnel are exposed to nano-sized dust particles released from dental composite. The aim of this study was to investigate whether respirable composite dust may also release monomers. Respirable (composite dust was collected and the release of methacrylate monomers and Bisphenol A (BPA) in water and ethanol was evaluated by liquid chromatography/mass spectroscopy (LC-MS/MS). The dust was ultra-morphologically and chemically analyzed by transmission electron microscopy and energy-dispersive X-ray spectroscopy (TEM-EDS). LC-MS/MS analysis revealed that, irrespective of the type of composite, the respirable fraction of composite dust may release relatively high concentrations of unpolymerized methacrylate monomers, both in water and ethanol. Higher release was observed in ethanol. The endocrine disruptor BPA also emanated from the composite dust particles. TEM showed that most particles were nano-sized, although particle size ranged between 6nm and 5μm with a mode value between 12 and 39nm. Most particles consisted of several filler particles in resin matrix, although single nano-filler particles could also be observed. Elemental analysis by TEM-EDS proved that the particles collected on the filters originated from the dental composites. Theoretically, composite dust may function as a vehicle to transport monomers deeply into the respiratory system. The results of this study may shed another light on the increasing incidence of respiratory disease among dental personnel, and more care should be taken to prevent inhalation of composite dust. Special care should be taken to prevent inhalation of composite dust, as the dust particles may release methacrylate monomers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Model of Image Artifacts from Dust Particles

    Science.gov (United States)

    Willson, Reg

    2008-01-01

    is the shape (typically, circular) of the aperture, and the contribution of the particle to the attenuation factor for a given pixel is the fraction of the cross-sectional area of the collection cone occupied by the particle. Assuming that dust particles do not overlap, the net transmission factor for a given pixel is calculated as one minus the sum of attenuation factors contributed by all dust particles affecting that pixel. In a test, the model was used to synthesize attenuation images for random distributions of dust particles on the front surface of a lens at various relative aperture (F-number) settings. As shown in Figure 2, the attenuation images resembled dust artifacts in real test images recorded while the lens was aimed at a white target.

  6. The Making of a Skull Base Team and the Value of Multidisciplinary Approach in the Management of Sinonasal and Ventral Skull Base Malignancies.

    Science.gov (United States)

    Snyderman, Carl H; Wang, Eric W; Fernandez-Miranda, Juan C; Gardner, Paul A

    2017-02-01

    The management of sinonasal and ventral skull base malignancies is best performed by a team. Although the composition of the team may vary, it is important to have multidisciplinary representation. There are multiple obstacles, both individual and institutional, that must be overcome to develop a highly functioning team. Adequate training is an important part of team-building and can be fostered with surgical telementoring. A quality improvement program should be incorporated into the activities of a skull base team.

  7. 鼻腔、鼻窦内翻性乳头状瘤中G3BP、Stathmin的表达及意义%Expressions and clinical significances of G3BP、Stathmin in sinonasal inverted papilloma

    Institute of Scientific and Technical Information of China (English)

    黄方; 张勇; 黄建强; 黄斯诚

    2011-01-01

    Objective To detect expressions of G3BP and Stathmin in Sinonasal inverted papilloma( NIP) and explore their roles in the development of NIP as well as their interrelationships. Method The immunohistochemical (PV-9000 two-step method) method was used to analyze protein expressions of G3BP and Stathmin in paraffin embedded tissues from 34 cases of sinonasal inverted papilloma, At the same time, expressions of these two proteins was also measured in 20 cases of inferior nasal concha mucosa and 12 cases of nasal squamous cell carcinoma as controls. SPSS13.0 was applied to determine the differences and correlation in the NIP. Results Positive expression rates of Stathmin protein and G3BP protein in sinonasal inverted papilloma were 52.9% and 73.5% , which were significantly higher than those in the inferior nasal concha mucosa ( 0% and 0% ;P 0.05). Stathmin was positively related to expression of G3BP( r, > 0, P < 0. 001). Conclusion Stathmin protein and G3BP protein were highly expressed in sinonasal inverted papilloma. The result indicates that they may be associated with the recur-rence and invasiveness of sinonasal inverted papilloma. Because Stathmin was positively related to expression of G3BP, joint detection of Stathmin and G3BP may be useful in the diagnosis and prognosis of cancer.%目的 检测Stathmin、G3BP蛋白在鼻腔、鼻窦内翻性乳头状瘤(NIP)、下鼻甲黏膜(INCM)及鼻鳞状细胞癌(NSCC)中的表达情况,及其在NIP中可能的作用及相互关系.方法 采用免疫组织化学法(PV-9000二步法)检测G3BP及Stathmin蛋白在34例NIP病理标本蜡块切片中的表达情况,并同时检测20例下鼻甲黏膜以及12例鼻鳞状细胞癌组织标本蜡块切片中两蛋白的表达作为对照,运用SPSS 13.0软件进行统计学分析,观察两指标在不同组织中的表达情况,分析其在NIP中的表达有无相关性.结果 按本实验所采用计数标准,Stathmin、G3BP 蛋白在NIP组织中

  8. Dust pollen distribution on a continental scale and its relation to present-day vegetation along north-south transects in east China

    Institute of Scientific and Technical Information of China (English)

    P.; COUR; D.; DUZER; G.; ROBERT; M.; CALLEJA; C.; BEAUDOUIN

    2007-01-01

    A series of dust pollen samples was collected along N-S transects in east China (18°N to 53°N latitudes). Sample sites extend from the cold-temperate zone in the north to the tropical region in the south. Pollen taxa characterize each region and reflect the natural and devastated vegetation as well as corre- sponding climatic zones. The quantitative pollen data can be used to estimate the spatial distribution of planted and introduced species. Valuable information of human disturbance of the natural forest is evaluated by quantitative comparison between dust pollen and in-situ pollen of protected forest. In addition, percentages of grass pollen vary regularly from north to south that is consistent with spatial distribution of net primary productivity in east China. Among all grasses, Artemisia and the Gramineae carry the clearest signal: their ratio increases northwards and therefore represent a suitable and con- venient tool for palaeoclimate reconstructions.

  9. Dust pollen distribution on a continental scale and its relation to present-day vegetation along north-south transects in east China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zhuo; P. COUR; HUANG CiXuan; D. DUZER; G. ROBERT; M. CALLEJA; C. BEAUDOUIN; DENG Yun; HUANG KangYou

    2007-01-01

    A series of dust pollen samples was collected along N-S transects in east China (18°N to 53°N latitudes). Sample sites extend from the cold-temperate zone in the north to the tropical region in the south. Pollen taxa characterize each region and reflect the natural and devastated vegetation as well as corresponding climatic zones. The quantitative pollen data can be used to estimate the spatial distribution of planted and introduced species. Valuable information of human disturbance of the natural forest is evaluated by quantitative comparison between dust pollen and in-situ pollen of protected forest. In addition, percentages of grass pollen vary regularly from north to south that is consistent with spatial distribution of net primary productivity in east China. Among all grasses, Artemisia and the Gramineae carry the clearest signal: their ratio increases northwards and therefore represent a suitable and convenient tool for palaeoclimate reconstructions.

  10. Stone dusting process advance

    Energy Technology Data Exchange (ETDEWEB)

    Matt Ryan; David Humphreys [Mining Attachments (Qld.) Pty Ltd. (Australia)

    2009-01-15

    The coal mining industry has, for many years, used dry stone dust or calcium carbonate (CaCO{sub 3}) in the prevention of the propagation of coal dust explosions throughout their underground mines in Australia. In the last decade wet stone dusting has been introduced. This is where stone dust and water are mixed together to form a paste like slurry. This mixture is pumped and sprayed on to the underground roadway surfaces. This method solved the contamination of the intake airways but brought with it a new problem known as 'caking'. Caking is the hardened layer that is formed as the stone dust slurry dries. It was proven that this hardened layer compromises the dispersal characteristics of the stone dust and therefore its ability to suppress a coal dust explosion. This project set out to prove a specially formulated, non toxic slurry additive and process that could overcome the caking effect. The slurry additive process combines dry stone dust with water to form a slurry. The slurry is then treated with the additive and compressed air to create a highly vesicular foam like stone dusted surface. The initial testing on a range of additives and the effectiveness in minimising the caking effect of wet dusting were performed at Applied Chemical's research laboratory in Melbourne, Victoria and independently tested at the SGS laboratory in Paget, Queensland. The results from these tests provided the platform to conduct full scale spraying trials at the Queensland Mines Rescue Station and Caledon Coal's Cook Colliery, Blackwater. The project moved into the final stage of completion with the collection of data. The intent was to compare the slurry additive process to dry stone dusting in full-scale methane explosions at the CSIR Kloppersbos explosion facility in Kloppersbos, South Africa.

  11. Variability of Disk Emission in Pre-Main Sequence and Related Stars. II. Variability in the Gas and Dust Emission of the Herbig Fe Star SAO 206462

    CERN Document Server

    Sitko, Michael L; Kimes, Robin L; Beerman, Lori C; Martus, Cameron; Lynch, David K; Russell, Ray W; Grady, Carol A; Schneider, Glenn; Lisse, Carey M; Nuth, Joseph A; Cure, Michel; Henden, Arne A; Kraus, Stefan; Motta, Veronica; Tamura, Motohide; Hornbeck, Jeremy; Williger, Gerard M; Fugazza, Dino

    2011-01-01

    We present thirteen epochs of near-infrared (0.8-5 micron) spectroscopic observations of the pre-transitional, "gapped" disk system in SAO 206462 (=HD 135344B). In all, six gas emission lines (including Br gamma, Pa beta, and the 0.8446 micron line of O I) along with continuum measurements made near the standard J, H, K, and L photometric bands were measured. A mass accretion rate of approximately 2 x 10^-8 solar masses per year was derived from the Br gamma and Pa beta lines. However, the fluxes of these lines varied by a factor of over two during the course of a few months. The continuum also varied, but by only ~30%, and even decreased at a time when the gas emission was increasing. The H I line at 1.083 microns was also found to vary in a manner inconsistent with that of either the hydrogen lines or the dust. Both the gas and dust variabilities indicate significant changes in the region of the inner gas and the inner dust belt that may be common to many young disk systems. If planets are responsible for d...

  12. Subregional inversion of North African dust sources

    Science.gov (United States)

    Escribano, Jerónimo; Boucher, Olivier; Chevallier, Frédéric; Huneeus, Nicolás.

    2016-07-01

    The emission of mineral dust aerosols in arid and semiarid regions is a complex process whose representation in atmospheric models remains crude, due to insufficient knowledge about the aerosol lifting process itself, the lack of global data on soil characteristics, and the impossibility for the models to resolve the fine-scale variability in the wind field that drives some of the dust events. As a result, there are large uncertainties in the total emission flux of mineral dust, its natural variability at various timescales, and the possible contribution from anthropogenic land use changes. This work aims for estimating dust emissions and reduces their uncertainty over the Sahara desert and the Arabian Peninsula—the largest dust source region of the globe. We use a data assimilation approach to constrain dust emission fluxes at a monthly resolution for 18 subregions. The Moderate Resolution Imaging Spectroradiometer satellite-derived aerosol optical depth is assimilated in a regional configuration of a general circulation model coupled to an aerosol model. We describe this data assimilation system and apply it for 1 year, resulting in a total mineral dust emissions flux estimate of 2900 Tg yr-1 over the Sahara desert and the Arabian Peninsula for the year 2006. The analysis field of aerosol optical depth shows an improved fit relative to independent Aerosol Robotic Network measurements as compared to the model prior field.

  13. Dust Sources of Saturn's E Ring

    Science.gov (United States)

    Spahn, F.; Schmidt, J.; Albers, N.; Kempf, S.; Krivov, A. V.; Sremcevic, M.

    The recent detection of a dust plume at Enceladus' south pole sheds new light on the origin of the E ring of Saturn. The particles probably condense from gas vents escaping from a system of cracks covering the south pole that appears unusually hot in the Cassini infrared experiments. The main fraction of the E ring dust is created in these gas vents. Still, significant amounts of dust should originate from grains ejected by hypervelocity impacts of E ring particles (ERPs), or alternatively, of interplanetary dust grains (IDPs) on the Saturnian moons embedded in the E ring. We estimate the contributions of impactor -ejecta created dust at these various satellites in the ring, relative to the production rate of grains in the plume at Enceladus. Furthermore, we compare the amount of dust created by both projectile families - ERPs and IDPs - and predict that one can clearly discriminate between the ejecta raised by either projectile families in the data of the Cassini dust detector (CDA) collected at close flybys with the moons embedded in the E ring.

  14. Respirable dust measured downwind during rock dust application.

    Science.gov (United States)

    Harris, M L; Organiscak, J; Klima, S; Perera, I E

    2017-05-01

    The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

  15. An Overview of Mineral Dust Modeling over East Asia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Siyu; Huang, Jianping; Qian, Yun; Zhao, Chun; Kang, Litai; Yang, Ben; Wang, Yong; Liu, Yuzhi; Yuan, Tiangang; Wang, Tianhe; Ma, Xiaojun; Zhang, Guolong

    2017-08-27

    Dust aerosol, one of the most abundant aerosol species in the atmosphere, has significant impacts on the energy balance and climatic feedback of the Earth system through its influence on solar and terrestrial radiation as well as clouds. East Asia is the one of prominent regions of dust generation. The East Asia dust life cycle and associated radiative and climatic effects are the outstanding science issues in understanding climate change at regional and even global scale. In the past decades, numerous dust models have been developed and applied to comprehend a series of dust-related processes studies, including emission, transport, and deposition, and to understand the effects of dust aerosol on the radiation and climate over East Asian. In this paper, we review the recent achievements and progresses in East Asian dust modeling research and discuss the potential challenges in future studies.

  16. Dust escape from Io

    Science.gov (United States)

    Flandes, Alberto

    2004-08-01

    The Dust ballerina skirt is a set of well defined streams composed of nanometric sized dust particles that escape from the Jovian system and may be accelerated up to >=200 km/s. The source of this dust is Jupiter's moon Io, the most volcanically active body in the Solar system. The escape of dust grains from Jupiter requires first the escape of these grains from Io. This work is basically devoted to explain this escape given that the driving of dust particles to great heights and later injection into the ionosphere of Io may give the particles an equilibrium potential that allow the magnetic field to accelerate them away from Io. The grain sizes obtained through this study match very well to the values required for the particles to escape from the Jovian system.

  17. Galactic dust properties

    Science.gov (United States)

    Paradis, D.

    2011-12-01

    Recent studies have shown evidence for variations in the dust emissivity law with temperature and wavelength. A recent dust emission model, called TLS model (for two-level systems), based on the description of the disordered internal structure of the amorphous dust grains has been developped to interpret observations in the far-infrared/submillimeter (FIR/submm) domain. A recent work focusing on the comparison between data of the diffuse interstellar medium seen by FIRAS-WMAP, as well as Archeops compact sources, with the TLS model allowed us to constrain the model parameters characterizing the general Galactic dust properties. Using the newly available Herschel/Hi-GAL data of the inner Galactic plane, we report a 500 μm emissivity excess in the peripheral parts of the Galactic plane, that can reach up to 20% of the emissivity. Results of the TLS modeling indicate significant changes in the dust properties from the central to peripheral parts of the Galactic plane.

  18. Improved Performance in Differentiating Benign from Malignant Sinonasal Tumors Using Diffusion-weighted Combined with Dynamic Contrast-enhanced Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Xin-Yan Wang

    2015-01-01

    Full Text Available Background: Differentiating benign from malignant sinonsal lesions is essential for treatment planning as well as determining the patient′s prognosis, but the differentiation is often difficult in clinical practice. The study aimed to determine whether the combination of diffusion-weighted (DW and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI can improve the performance in differentiating benign from malignant sinonasal tumors. Methods: This retrospective study included 197 consecutive patients with sinonasal tumors (116 malignant tumors and 81 benign tumors. All patients underwent both DW and DCE-MRI in a 3-T magnetic resonance scanner. Two different settings of b values (0,700 and 0,1000 s/mm 2 and two different strategies of region of interest (ROI including whole slice (WS and partial slice (PS were used to calculate apparent diffusion coefficients (ADCs. A DW parameter with WS ADCs b0,1000 and two DCE-MRI parameters (time intensity curve [TIC] and time to peak enhancement [Tpeak] were finally combined to use in differentiating the benign from the malignant tumors in this study. Results: The mean ADCs of malignant sinonasal tumors (WS ADCs b0,1000 = 1.084 × 10−3 mm 2 /s were significantly lower than those of benign tumors (WS ADCs b0,1000 = 1.617 × 10−3 mm 2 /s, P < 0.001. The accuracy using WS ADCs b0,1000 alone was 83.7% in differentiating the benign from the malignant tumors (85.3% sensitivity, 81.2% specificity, 86.4% positive predictive value [PPV], and 79.5% negative predictive value [NPV]. The accuracy using DCE with Tpeak and TIC alone was 72.1% (69.1% sensitivity, 74.1% specificity, 77.5% PPV, and 65.1% NPV. Using DW-MRI parameter was superior than using DCE parameters in differentiation between benign and malignant sinonasal tumors (P < 0.001. The accuracy was 87.3% (90.5% sensitivity, 82.7% specificity, 88.2% PPV, and 85.9% NPV using DW-MRI combined with DCE-MRI, which was superior than that using DCE

  19. A Comparison Analysis of Chemical Composition of Aerosols in the Dust and Non-Dust Periods in Beijing

    Institute of Scientific and Technical Information of China (English)

    张仁健; 徐永福; 韩志伟

    2004-01-01

    Dust events occurred frequently in Beijing in recent years. In this work, 120 aerosol samples were collected in two typical dust events (21-22 March and 15 May) and a non-dust period in Beijing from March to May 2001. Samples were analyzed for major elemental components by the Proton Induced Xray Emission (PIXE) method. Results show that the enrichment factors of crustal elements such as Mg,Al, and Ti had little differences between the dust period and the non-dust period in Beijing, while the enrichment factors of other elements that have a relation to anthropogenic emissions were very low during the dust period. The results derived by using multivariate factor analysis from the observation data show that the sources such as soil dust, industry, and fuel combustion were among the major contributors to the particles in Beijing.

  20. Customized individual applicators for endocavitary brachytherapy in patients with cancers of the nasal cavity, sinonasal region and nasopharynx.

    Science.gov (United States)

    Kadah, Basel Al; Niewald, Marcus; Papaspyrou, George; Dzierma, Yvonne; Schneider, Mathias; Schick, Bernhard

    2016-06-01

    Brachytherapy has become an established therapeutic regimen for primary, persistent, recurrent and metastatic tumour disease in the head and neck region. This study presents the authors' preliminary experience with intracavitary brachytherapy by means of an individual silicone applicator in the treatment of patients with nasal, sinonasal, orbital and nasopharyngeal cancer. Between January 2001 and January 2013, twenty patients with cancer of the nasal cavity, the paranasal sinuses and nasopharynx underwent surgery and intracavitary brachytherapy with the aid of an individually manufactured silicone applicator in the Department of Otolaryngology, Head and Neck Surgery and in the Department of Radiotherapy and Radiooncology at the Saarland University Medical Center of Homburg, Germany. The tumour was localized in the nasal cavity/paranasal sinuses (15) affecting the orbit twice and the nasopharynx (5). There were 14 patients with squamous cell carcinoma, 2 patients with mixed tumours and one patient with adenocarcinoma, adenoid cystic carcinoma, mucosal melanoma or plasmocytoma. The majority of the patients presented with advanced disease (T3 or T4 tumours). In 18/20 patients, brachytherapy was performed as a boost technique, in the remaining two solely because of a previous radiation series. All surgical interventions were performed endonasally. Three to six weeks after surgery, a cast of the nasal cavity was created under general anaesthesia. Subsequently, an individual brachytherapy silicon applicator with two to four plastic tubes was manufactured. The radiation therapy was applied using the Ir-192 high-dose-rate-afterloading method (total dose 10-20 Gy) in two to five sessions, additionally in 18/20 patients a percutaneous radiotherapy with a total dose of 30-60 Gy was applied. After a mean duration of follow-up of 2 years, 7/20 patients experienced a local progression, 5/19 a regional recurrence in the neck nodes and 4/19 distant metastases. The 2-year

  1. Interactions Between Mineral Dust, Climate, and Ocean Ecosystems

    Science.gov (United States)

    Gasso, Santiago; Grassian, Vicki H.; Miller, Ron L.

    2010-01-01

    Over the past decade, technological improvements in the chemical and physical characterization of dust have provided insights into a number of phenomena that were previously unknown or poorly understood. In addition, models are now incorporating a wider range of physical processes, which will allow us to better quantify the climatic and ecological impacts of dust. For example, some models include the effect of dust on oceanic photosynthesis and thus on atmospheric CO 2 (Friedlingstein et al. 2006). The impact of long-range dust transport, with its multiple forcings and feedbacks, is a relatively new and complex area of research, where input from several disciplines is needed. So far, many of these effects have only been parameterized in models in very simple terms. For example, the representation of dust sources remains a major uncertainty in dust modeling and estimates of the global mass of airborne dust. This is a problem where Earth scientists could make an important contribution, by working with climate scientists to determine the type of environments in which easily erodible soil particles might have accumulated over time. Geologists could also help to identify the predominant mineralogical composition of dust sources, which is crucial for calculating the radiative and chemical effects of dust but is currently known for only a few regions. Understanding how climate and geological processes control source extent and characterizing the mineral content of airborne dust are two of the fascinating challenges in future dust research.

  2. Interactions Between Mineral Dust, Climate, and Ocean Ecosystems

    Science.gov (United States)

    Gasso, Santiago; Grassian, Vicki H.; Miller, Ron L.

    2010-01-01

    Over the past decade, technological improvements in the chemical and physical characterization of dust have provided insights into a number of phenomena that were previously unknown or poorly understood. In addition, models are now incorporating a wider range of physical processes, which will allow us to better quantify the climatic and ecological impacts of dust. For example, some models include the effect of dust on oceanic photosynthesis and thus on atmospheric CO 2 (Friedlingstein et al. 2006). The impact of long-range dust transport, with its multiple forcings and feedbacks, is a relatively new and complex area of research, where input from several disciplines is needed. So far, many of these effects have only been parameterized in models in very simple terms. For example, the representation of dust sources remains a major uncertainty in dust modeling and estimates of the global mass of airborne dust. This is a problem where Earth scientists could make an important contribution, by working with climate scientists to determine the type of environments in which easily erodible soil particles might have accumulated over time. Geologists could also help to identify the predominant mineralogical composition of dust sources, which is crucial for calculating the radiative and chemical effects of dust but is currently known for only a few regions. Understanding how climate and geological processes control source extent and characterizing the mineral content of airborne dust are two of the fascinating challenges in future dust research.

  3. Dust grains from the heart of supernovae

    Science.gov (United States)

    Bocchio, M.; Marassi, S.; Schneider, R.; Bianchi, S.; Limongi, M.; Chieffi, A.

    2016-03-01

    Dust grains are classically thought to form in the winds of asymptotic giant branch (AGB) stars. However, there is increasing evidence today for dust formation in supernovae (SNe). To establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. With this aim, we have developed a new code, GRASH_Rev, that allows following the dynamics of dust grains in the shocked SN ejecta and computing the time evolution of the mass, composition, and size distribution of the grains. We considered four well-studied SNe in the Milky Way and Large Magellanic Cloud: SN 1987A, CasA, the Crab nebula, and N49. These sources have been observed with both Spitzer and Herschel, and the multiwavelength data allow a better assessment the mass of warm and cold dust associated with the ejecta. For each SN, we first identified the best explosion model, using the mass and metallicity of the progenitor star, the mass of 56Ni, the explosion energy, and the circumstellar medium density inferred from the data. We then ran a recently developed dust formation model to compute the properties of freshly formed dust. Starting from these input models, GRASH_Rev self-consistently follows the dynamics of the grains, considering the effects of the forward and reverse shock, and allows predicting the time evolution of the dust mass, composition, and size distribution in the shocked and unshocked regions of the ejecta. All the simulated models aagree well with observations. Our study suggests that SN 1987A is too young for the reverse shock to have affected the dust mass. Hence the observed dust mass of 0.7-0.9 M⊙ in this source can be safely considered as indicative of the mass of freshly formed dust in SN ejecta. Conversely, in the other three SNe, the reverse shock has already destroyed between 10-40% of the

  4. Non-monotonic spatial distribution of the interstellar dust in astrospheres: finite gyroradius effect

    Science.gov (United States)

    Katushkina, O. A.; Alexashov, D. B.; Izmodenov, V. V.; Gvaramadze, V. V.

    2017-02-01

    High-resolution mid-infrared observations of astrospheres show that many of them have filamentary (cirrus-like) structure. Using numerical models of dust dynamics in astrospheres, we suggest that their filamentary structure might be related to specific spatial distribution of the interstellar dust around the stars, caused by a gyrorotation of charged dust grains in the interstellar magnetic field. Our numerical model describes the dust dynamics in astrospheres under an influence of the Lorentz force and assumption of a constant dust charge. Calculations are performed for the dust grains with different sizes separately. It is shown that non-monotonic spatial dust distribution (viewed as filaments) appears for dust grains with the period of gyromotion comparable with the characteristic time-scale of the dust motion in the astrosphere. Numerical modelling demonstrates that the number of filaments depends on charge-to-mass ratio of dust.

  5. Imaging-based dust sensors: equipment and methods

    Science.gov (United States)

    Bonifazi, Giuseppe; Greco, Sonia

    2004-05-01

    Dust detection and control in real time, represent one of the most challenging problem in all those environments where fine and ultrafine airborne particulate solids products are present. The presence of such products can be linked to several factors, often directly related and influenced by the working-production actions performed. Independently from the causes generating dust, airborne contaminants are an occupational problem of increasing interest as they are related to a wide number of diseases. In particular, airborne dusts are well known to be associated with several classical occupational lung diseases, such as the pneumoconiosis, especially at high levels of exposure. Nowadays there is also an increasing interest in other dust related diseases, from the most serious as cancer and asthma, to those related with allergies or irritation and other illnesses, also occurring at lower levels of exposure. Among the different critical factors influencing health risk for airborne dust exposure, mainly four have to be considered, that is: i) nature of the dust resulting from working in terms of presence of specific poisoning material, i.e. free silica, and morphological and morphometrical attributes of particulates constituting airborne dust; ii) size of the particles, iii) duration of exposure time and, finally, iv) airborne dust concentration in the breathing zone where the worker performs his activity. A correct dust detection is not easy, especially if some of the previous mentioned factors, have to be detected and quantified in real time in order to define specific "on-line" control actions aimed to reduce the level of the exposure to dust of the workers, as for example: i) modification of aspirating devices operating condition, change of filtering cleaning sequence, etc. . The more severe are the environmental conditions, in terms of dust presence (in quantity and quality) more difficult is to utilize efficient sampling devices. Detection devices, in fact, tend

  6. Compression Behaviour of Porous Dust Agglomerates

    CERN Document Server

    Seizinger, Alexander; Kley, Wilhelm

    2012-01-01

    The early planetesimal growth proceeds through a sequence of sticking collisions of dust agglomerates. Very uncertain is still the relative velocity regime in which growth rather than destruction can take place. The outcome of a collision depends on the bulk properties of the porous dust agglomerates. Continuum models of dust agglomerates require a set of material parameters that are often difficult to obtain from laboratory experiments. Here, we aim at determining those parameters from ab-initio molecular dynamics simulations. Our goal is to improveon the existing model that describe the interaction of individual monomers. We use a molecular dynamics approach featuring a detailed micro-physical model of the interaction of spherical grains. The model includes normal forces, rolling, twisting and sliding between the dust grains. We present a new treatment of wall-particle interaction that allows us to perform customized simulations that directly correspond to laboratory experiments. We find that the existing i...

  7. The Dust Management Project: Final Report

    Science.gov (United States)

    Hyatt, Mark J.; Straka, Sharon

    2011-01-01

    A return to the Moon to extend human presence, pursue scientific activities, use the Moon to prepare for future human missions to Mars, and expand Earth s economic sphere, will require investment in developing new technologies and capabilities to achieve affordable and sustainable human exploration. From the operational experience gained and lessons learned during the Apollo missions, conducting longterm operations in the lunar environment will be a particular challenge, given the difficulties presented by the unique physical properties and other characteristics of lunar regolith, including dust. The Apollo missions and other lunar explorations have identified significant lunar dust-related problems that will challenge future mission success. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it s potentially harmful effects on exploration systems and human explorers. The Dust Management Project (DMP) is tasked with the evaluation of lunar dust effects, assessment of the resulting risks, and development of mitigation and management strategies and technologies related to Exploration Systems architectures. To this end, the DMP supports the overall goal of the Exploration Technology Development Program (ETDP) of addressing the relevant high priority technology needs of multiple elements within the Constellation Program (CxP) and sister ETDP projects. Project scope, approach, accomplishments, summary of deliverables, and lessons learned are presented.

  8. The dissolution of natural and artificial dusts in glutamic acid

    Science.gov (United States)

    Ling, Zhang; Faqin, Dong; Xiaochun, He

    2015-06-01

    This article describes the characteristics of natural dusts, industrial dusts, and artificial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phases of natural dusts and industrial dusts with high SiO2 and CaO and low K2O and Na2O in the chemical composition. The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 °C) in 32 h was investigated. The potential harm that the dust could lead to in body glutamic acid acidic environment, namely biological activity, is of great importance for revealing the human toxicological mechanism. The changes of pH values and electric conductivity of suspension of those dusts were similar, increased slowly in the first 8 h, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, and Mg was 35.4 to 429 mg/kg, particularly Ca was maximal of 20 to 334 mg/kg. The total amount of dissolved ions of Fe, Zn, Mn, Pb, and Ba was 0.18 to 5.59 mg/kg and in Al and Si was 3.0 to 21.7 mg/kg. The relative solubility order of dusts in glutamic acid is wollastonite > serpentine > sepiolite, the cement plant industrial dusts > natural dusts > power plant industrial dusts. The wollastonite and cement plant industrial dusts have the highest solubility, which also have high content of CaO; this shows that there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and power plant industrial dusts have lowest solubility, which also have high content of SiO2; this shows that there are a higher corrosion-resisting ability and stronger bio-resistibility.

  9. MAPPING DUST THROUGH EMISSION AND ABSORPTION IN NEARBY GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Kreckel, Kathryn; Groves, Brent; Schinnerer, Eva; Meidt, Sharon E.; Tabatabaei, Fatemeh S. [Max Planck Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Johnson, Benjamin D. [Institut d' Astrophysique de Paris, UMR 7095, 98 bis Bvd Arago, F-75014 Paris (France); Aniano, Gonzalo [Institut d' Astrophysique Spatiale (IAS), Batiment 121, Universite Paris-Sud 11 and CNRS (UMR 8617), F-91405 Orsay (France); Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Croxall, Kevin V. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Draine, Bruce T. [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544-1001 (United States); Gordon, Karl D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Crocker, Alison F.; Smith, J. D. T. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Dale, Daniel A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Hunt, Leslie K. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Kennicutt, Robert C., E-mail: kreckel@mpia.de [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2013-07-01

    Dust has long been identified as a barrier to measuring inherent galaxy properties. However, the link between dust and attenuation is not straightforward and depends on both the amount of dust and its distribution. Herschel imaging of nearby galaxies undertaken as part of the KINGFISH project allows us to map the dust as seen in emission with unprecedented sensitivity and {approx}1 kpc resolution. We present here new optical integral field unit spectroscopy for eight of these galaxies that provides complementary 100-200 pc scale maps of the dust attenuation through observation of the reddening in both the Balmer decrement and the stellar continuum. The stellar continuum reddening, which is systematically less than that observed in the Balmer decrement, shows no clear correlation with the dust, suggesting that the distribution of stellar reddening acts as a poor tracer of the overall dust content. The brightest H II regions are observed to be preferentially located in dusty regions, and we do find a correlation between the Balmer line reddening and the dust mass surface density for which we provide an empirical relation. Some of the high-inclination systems in our sample exhibit high extinction, but we also find evidence that unresolved variations in the dust distribution on scales smaller than 500 pc may contribute to the scatter in this relation. We caution against the use of integrated A{sub V} measures to infer global dust properties.

  10. Carbonaceous Components in the Comet Halley Dust

    Science.gov (United States)

    Fomenkova, M. N.; Chang, S.; Mukhin, L. M.

    1994-01-01

    Cometary grains containing large amounts of carbon and/or organic matter (CHON) were discovered by in situ measurements of comet Halley dust composition during VEGA and GIOTTO flyby missions. In this paper, we report the classification of these cometary, grains by means of cluster analysis, discuss the resulting compositional groups, and compare them with substances observed or hypothesized in meteorites, interplanetary dust particles, and the interstellar medium. Grains dominated by carbon and/or organic matter (CHON grains) represent approx. 22% of the total population of measured cometary dust particles. They, usually contain a minor abundance of rock-forming elements as well. Grains having organic material are relatively more abundant in the vicinity of the nucleus than in the outer regions of the coma, which suggests decomposition of the organics in the coma environment. The majority of comet Halley organic particles are multicomponent mixtures of carbon phases and organic compounds. Possibly, the cometary CHON grains may be related to kerogen material of an interstellar origin in carbonaceous meteorites. Pure carbon grains, hydrocarbons and polymers of cyanopolyynes, and multi-carbon monoxides are present in cometary dust as compositionally simple and distinctive components among a variety of others. There is no clear evidence of significant presence of pure formaldehyde or HCN polymers in Halley dust particles. The diversity of types of cometary organic compounds is consistent with the inter-stellar dust model of comets and probably reflects differences in composition of precursor dust. Preservation of this heterogeneity among submicron particles suggest the gentle formation of cometary, nucleus by aggregation of interstellar dust in the protosolar nebula without complete mixing or chemical homogenization at the submicron level.

  11. The dragonfly splint: a new disposable device designed to prevent both medial and lateral turbinate synechiae after sinonasal surgery.

    Science.gov (United States)

    Mantovani, Mario; Rinaldi, Vittorio; Torretta, Sara; Sigismund, Paolo Enrico; Cappadona, Maurizio; Minetti, Andrea; Pignataro, Lorenzo

    2014-03-01

    Periturbinal adhesions are among the most frequent and challenging complications of sinonasal surgery. Endonasal paraseptal splints have proved to be very efficient in preventing "medial synechiae," that is, adhesions located between the medial faces of the middle/inferior turbinates and the septum. However, none of these devices for guiding mucosal healing can prevent "lateral synechiae" (adhesions between the lateral face of the middle turbinate and the lateral nasal wall) inside the middle meatal cleft, which is a very critical area for the physiology of the anterior sinus system. For this reason, if followed by the formation of lateral synechiae, the surgical maneuvers used to treat sinus diseases could paradoxically become a cause of persistent functional impairment and lead to iatrogenic sinusitis or mucocele.We describe our preliminary experience with a new endonasal splint called "Dragonfly" (because of its shape), which has been designed to prevent both medial and lateral postsurgical synechiae. This device has a long lateral wing designed to separate the mucosal surfaces of the middle meatal/ethmoid cavities and prevent adhesions during the postoperative process of healing. The device must be kept in situ for 3 to 4 weeks to permit the re-epithelialization of the internal nasal surfaces. Our experience shows that the splints are well tolerated and highly efficient, preventing both medial and lateral synechiae in 100% of cases. A randomized controlled study has now been started to confirm these positive preliminary findings in a larger patient population.

  12. Mechanisms of metal dusting corrosion

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo

    In this thesis the early stages of metal dusting corrosion is addressed; the development of carbon expanded austenite, C, and the decomposition hereof into carbides. Later stages of metal dusting corrosion are explored by a systematic study of stainless steel foils exposed to metal dusting...... influence of oxygen and carbon on the metal dusting corrosion is explored. The results indicate that exposure to metal dusting conditions have a detrimental effect on the resistance against oxidation and, conversely, that exposure to oxidation has a detrimental effect on the resistance towards metal dusting....... Consequently, a combination of carburizing and oxidizing conditions has a strong mutual catalyzing effect on the metal dusting corrosion....

  13. Composite circumstellar dust grains

    Science.gov (United States)

    Gupta, Ranjan; Vaidya, Dipak B.; Dutta, Rajeshwari

    2016-10-01

    We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5-25 μm. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18 μm. We also study the variation of the absorption of porous silicate grains. We use the absorption efficiencies to calculate the infrared flux at various dust temperatures and compare with the observed infrared emission flux from the circumstellar dust around some M-type and asymptotic giant branch stars obtained from IRAS and a few stars from Spitzer satellite. We interpret the observed data in terms of the circumstellar dust grain sizes, shape, composition and dust temperature.

  14. Composite Circumstellar Dust Grains

    CERN Document Server

    Gupta, Ranjan; Dutta, Rajeshwari

    2016-01-01

    We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5--25$\\rm \\mu m$. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18$\\rm \\mu m$. We also study the variation of the absorption of porous silicate grains. We use the absorption efficiencies to calculate the infrared flux at various dust temperatures and compare with the observed infrared emission flux from the circumstellar dust around some M-Type \\& AGB stars obtained from IRAS and a few stars from Spitzer satellite. We interpret the observed data in terms of the circumstellar dust grain sizes; shape; composition and dust temperature.

  15. Nano Dust Analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a new highly sensitive instrument to confirm the existence of the so-called nano-dust particles, characterize their impact parameters, and...

  16. How relevant are house dust mite-fungal interactions in laboratory culture to the natural dust system?

    Science.gov (United States)

    Hay, D B; Hart, B J; Pearce, R B; Kozakiewicz, Z; Douglas, A E

    1992-11-01

    Both house dust and house dust mites Dermatophagoides pteronyssinus contained a wider range of fungi than laboratory mite cultures. In total, nine species of fungi were isolated from D. pteronyssinus in house dust, and these included three xerophilic species (Eurotium amstelodami, Aspergillus penicillioides and Wallemia sebi) commonly found in laboratory cultures of D. pteronyssinus. It is concluded that mites do interact with a similar range of fungi in natural dust and in laboratory culture, but that the diversity of fungal species in the laboratory is reduced and the density of individual fungal species in culture exceeds that of house dust. In a second experiment, dust samples were incubated at room temperature with 75% relative humidity. The diversity of fungi invariably declined from up to 13 genera to the few species recorded in laboratory culture. This suggests that the dominance of xerophilic fungi in laboratory mite rearings is mediated primarily by low relative humidity, and the exclusion of air-borne spores.

  17. Dust Versus Cosmic Acceleration

    CERN Document Server

    Aguirre, A N

    1999-01-01

    Two groups have recently discovered a statistically significant deviation in the fluxes of high-redshift type Ia supernovae from the predictions of a Friedmann model with zero cosmological constant. This letter argues that bright, dusty, starburst galaxies would preferentially eject a dust component with a shallower opacity curve (hence less reddening) and a higher opacity/mass than the observed galactic dust which is left behind. Such dust could cause the falloff in flux at high-z without violating constraints on reddening or metallicity. The specific model presented is of needle-like dust, which is expected from the theory of crystal growth and has been detected in samples of interstellar dust. Carbon needles with conservative properties can supply the necessary opacity, and would very likely be ejected from galaxies as required. The model is not subject to the arguments given in the literature against grey dust, but may be constrained by future data from supernova searches done at higher redshift, in clust...

  18. Dust grains from the heart of supernovae

    CERN Document Server

    Bocchio, M; Schneider, R; Bianchi, S; Limongi, M; Chieffi, A

    2016-01-01

    Dust grains are classically thought to form in the winds of AGB stars. However, nowadays there is increasing evidence for dust formation in SNe. In order to establish the relative importance of these two classes of stellar sources of dust it is important to know what is the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. With this aim, we have developed a new code, GRASH_Rev, that allows to follow the dynamics of dust grains in the shocked SN ejecta and to compute the time evolution of the mass, composition and size distribution of the grains. We consider four well studied SNe in the Milky Way and LMC: SN 1987a, Cas A, the Crab Nebula, and N49. For all the simulated models, we find good agreement with observations. Our study suggests that SN 1987A is too young for the reverse shock to have affected the dust mass. Conversely, in the other three SNe, the reverse shock has already destroyed between 10 and 40% of the...

  19. Dust grains from the heart of supernovae

    CERN Document Server

    Bocchio, M; Schneider, R; Bianchi, S; Limongi, M; Chieffi, A

    2016-01-01

    Dust grains are classically thought to form in the winds of asymptotic giant branch (AGB) stars. However, there is increasing evidence today for dust formation in supernovae (SNe). To establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. We have developed a new code (GRASH\\_Rev) which follows the newly-formed dust evolution throughout the supernova explosion until the merging of the forward shock with the circumstellar ISM. We have considered four well studied SNe in the Milky Way and Large Magellanic Cloud: SN1987A, CasA, the Crab Nebula, and N49. For all the simulated models, we find good agreement with observations and estimate that between 1 and 8$\\%$ of the observed mass will survive, leading to a SN dust production rate of $(3.9 \\pm 3.7) \\times 10^{-4}$ M$_{\\odot}$yr$^{-1}$ in the Milky Way. This value i...

  20. Modeling Respiratory Toxicity of Authentic Lunar Dust

    Science.gov (United States)

    Santana, Patricia A.; James, John T.; Lam, Chiu-Wing

    2010-01-01

    The lunar expeditions of the Apollo operations from the 60 s and early 70 s have generated awareness about lunar dust exposures and their implication towards future lunar explorations. Critical analyses on the reports from the Apollo crew members suggest that lunar dust is a mild respiratory and ocular irritant. Currently, NASA s space toxicology group is functioning with the Lunar Airborne Dust Toxicity Assessment Group (LADTAG) and the National Institute for Occupational Safety and Health (NIOSH) to investigate and examine toxic effects to the respiratory system of rats in order to establish permissible exposure levels (PELs) for human exposure to lunar dust. In collaboration with the space toxicology group, LADTAG and NIOSH the goal of the present research is to analyze dose-response curves from rat exposures seven and twenty-eight days after intrapharyngeal instillations, and model the response using BenchMark Dose Software (BMDS) from the Environmental Protection Agency (EPA). Via this analysis, the relative toxicities of three types of Apollo 14 lunar dust samples and two control dust samples, titanium dioxide (TiO2) and quartz will be determined. This will be executed for several toxicity endpoints such as cell counts and biochemical markers in bronchoaveolar lavage fluid (BALF) harvested from the rats.

  1. Head and neck region consolidation radiotherapy and prophylactic cranial irradiation with hippocampal avoidance delivered with helical tomotherapy after induction chemotherapy for non-sinonasal neuroendocrine carcinoma of the upper airways

    Directory of Open Access Journals (Sweden)

    Franco Pierfrancesco

    2012-02-01

    Full Text Available Abstract Background Non-sinonasal neuroendocrine carcinomas (NSNECs of the head and neck are considered an unfrequent clinico-pathological entity. Combined modality treatment represents an established therapeutic option for undifferentiated forms where distant metastasis is a common pattern of failure. Methods We report on a case of NSNEC treated with sequential chemo-radiation consisting of 6 cycles of cisplatin and etoposide followed by loco-regional radiation to the head and neck and simultaneous prophylactic cranial irradiation to prevent from intracranial spread, delivered with helical tomotherapy with the 'hippocampal avoidance' technique in order to reduce neuro-cognitive late effects. Results One year after the end of the whole combined modality approach, the patient achieved complete remission, with no treatment-related sub-acute and late effects. Conclusions The present report highlights the importance of multidisciplinary management for NSNECs of the head and neck, as the possibility to achieve substantial cure rates with mild side effects with modern radiotherapy techniques.

  2. The dust content of galaxies from z = 0 to z = 9

    CERN Document Server

    Popping, Gergö; Galametz, Maud

    2016-01-01

    We study the dust content of galaxies from z $=$ 0 to z $=$ 9 in semi-analytic models of galaxy formation that include new recipes to track the production and destruction of dust. We include condensation of dust in stellar ejecta, the growth of dust in the interstellar medium (ISM), the destruction of dust by supernovae and in the hot halo, and dusty winds and inflows. The rate of dust growth in the ISM depends on the metallicity and density of molecular clouds. Our fiducial model reproduces the relation between dust mass and stellar mass from z $=$ 0 to z $=$ 7, the dust-to-gas ratio of local galaxies as a function of stellar mass, the double power law trend between dust-to- gas ratio and gas-phase metallicity, the number density of galaxies with dust masses less than $10^{8.3} M_\\odot$, and the cosmic density of dust at z $=$ 0. The dominant mode of dust formation is dust growth in the ISM, except for galaxies with $M_* < 10^7 M_\\odot$, where condensation of dust in supernova ejecta dominates. The dust-t...

  3. Adjoint inversion modeling of Asian dust emission using lidar observations

    Directory of Open Access Journals (Sweden)

    K. Yumimoto

    2008-06-01

    Full Text Available A four-dimensional variational (4D-Var data assimilation system for a regional dust model (RAMS/CFORS-4DVAR; RC4 is applied to an adjoint inversion of a heavy dust event over eastern Asia during 20 March–4 April 2007. The vertical profiles of the dust extinction coefficients derived from NIES Lidar network are directly assimilated, with validation using observation data. Two experiments assess impacts of observation site selection: Experiment A uses five Japanese observation sites located downwind of dust source regions; Experiment B uses these and two other sites near source regions. Assimilation improves the modeled dust extinction coefficients. Experiment A and Experiment B assimilation results are mutually consistent, indicating that observations of Experiment A distributed over Japan can provide comprehensive information related to dust emission inversion. Time series data of dust AOT calculated using modeled and Lidar dust extinction coefficients improve the model results. At Seoul, Matsue, and Toyama, assimilation reduces the root mean square differences of dust AOT by 35–40%. However, at Beijing and Tsukuba, the RMS differences degrade because of fewer observations during the heavy dust event. Vertical profiles of the dust layer observed by CALIPSO are compared with assimilation results. The dense dust layer was trapped at potential temperatures (θ of 280–300 K and was higher toward the north; the model reproduces those characteristics well. Latitudinal distributions of modeled dust AOT along the CALIPSO orbit paths agree well with those of CALIPSO dust AOT, OMI AI, and MODIS coarse-mode AOT, capturing the latitude at which AOTs and AI have high values. Assimilation results show increased dust emissions over the Gobi Desert and Mongolia; especially for 29–30 March, emission flux is about 10 times greater. Strong dust uplift fluxes over the Gobi Desert and Mongolia cause the heavy dust event. Total optimized dust emissions are 57

  4. Where Do the Sand-Dust Storms Come From?: Conversations with Specialists from the Exploring Sand-Dust Storms Scientific Expedition Team

    Science.gov (United States)

    Shixin, Liu

    2004-01-01

    This article relates the different views from specialists of the scientific expedition team for the exploration of the origin of sand-dust storms. They observed and examined on-site the ecological environment of places of origin for sand-dust storms, and tried to find out causes of sand-dust storm and what harm it can cause in the hope of…

  5. Organophosphate esters in dust samples collected from Danish homes and daycare centers

    DEFF Research Database (Denmark)

    Langer, Sarka; Fredricsson, Malin; Weschler, Charles J.

    2016-01-01

    distribution of organophosphates in indoor dust is quite variable, with higher concentrations in industrialized countries. This trend differs from that for phthalate esters, whose geographic distribution is more homogeneous. Exposure to organophosphates via dust ingestion is relatively low, although...

  6. Oncogene abnormalities in a series of primary melanomas of the sinonasal tract: NRAS mutations and cyclin D1 amplification are more frequent than KIT or BRAF mutations.

    Science.gov (United States)

    Chraybi, Meriem; Abd Alsamad, Issam; Copie-Bergman, Christiane; Baia, Maryse; André, Jocelyne; Dumaz, Nicolas; Ortonne, Nicolas

    2013-09-01

    Primary malignant melanoma of sinonasal tract is a rare but severe form of melanoma. We retrospectively analyzed 17 cases and focused on the histologic presentation and the expression of c-Kit, epidermal growth factor receptor (EGFR), cyclin D1/Bcl-1, PS100, and HMB45 and searched for BRAF, NRAS, and KIT mutations that are known to be associated with melanoma subtypes, together with amplifications of KIT, cyclin D1, cyclin-dependent kinase 4, MDM2, and microphthalmia-associated transcription factor using quantitative polymerase chain reaction. In most cases (78%), an in situ component was evidenced. Invasive components were composed of diffuse areas of rhabdoid, epithelioid, or spindle cells and, in most cases, lacked inflammatory reaction, suggesting that an immune escape phenomenon probably develops when the disease progresses. EGFR was rarely and weakly expressed in the in situ component of 2 cases. None of the investigated case showed BRAF V600E, but 1 had a D594G mutation. NRAS mutations in exon 2 (G12D or G12A) were found in 3 cases (18%), and a KIT mutation in exon 11 (L576P), in 1, whereas c-Kit was expressed at the protein level in half of the cases. Amplifications of cyclin D1 were evidenced in 5 cases, confirmed in 3 by fluorescence in situ hybridization, but this was not always correlated with protein expression, found in 8 patients (62.5%), 3 having no significant amplification. In conclusion, primary malignant melanoma of sinonasal tract is not associated with BRAF V600E mutations. Instead, NRAS or KIT mutations and cyclin D1 amplification can be found in a proportion of cases, suggesting that primary malignant melanoma of sinonasal tract is heterogeneous at the molecular level and should not be sensitive to therapeutic approaches aiming at BRAF.

  7. Dust exposure and pneumoconiosis in a South African pottery. 1. Study objectives and dust exposure.

    Science.gov (United States)

    Rees, D; Cronje, R; du Toit, R S

    1992-07-01

    Dust exposure and pneumoconiosis were investigated in a South African pottery that manufactured wall tiles and bathroom fittings. This paper describes the objectives of the investigation and presents dust measurement data. x Ray diffraction showed that the clays used by the pottery had a high quartz content (range 58%-23%, mean 38%). Exposure to respirable dust was measured for 43 workers and was highest (6.6 mg/m3) in a bathroom fitting fettler. Quartz concentrations in excess of 0.1 mg/m3 were found in all sections of the manufacturing process from slip production to biscuit firing and sorting. The proportion of quartz in the respirable dust of these sections was 24% to 33%. This is higher than is usually reported in English potteries. Four hundred and six (80%) of the 509 workers employed at the pottery were potentially at risk of occupational lung disease. The finding of large numbers of pottery workers exposed to unacceptable dust concentrations is not surprising as poor dust control was found in all six wall tile and sanitary ware factories surveyed by the National Centre for Occupational Health between 1973 and 1989. Dust related occupational disease can be expected in potters for many years to come.

  8. Old supernova dust factory revealed at the Galactic center

    CERN Document Server

    Lau, Ryan M; Morris, Mark R; Li, Zhiyuan; Adams, Joseph D

    2015-01-01

    Dust formation in supernova ejecta is currently the leading candidate to explain the large quantities of dust observed in the distant, early Universe. However, it is unclear whether the ejecta-formed dust can survive the hot interior of the supernova remnant (SNR). We present infrared observations of ~0.02 $M_\\odot$ of warm (~100 K) dust seen near the center of the ~10,000 yr-old Sgr A East SNR at the Galactic center. Our findings signify the detection of dust within an older SNR that is expanding into a relatively dense surrounding medium ($n_e$ ~ 100 $\\mathrm{cm}^{-3}$) and has survived the passage of the reverse shock. The results suggest that supernovae may indeed be the dominant dust production mechanism in the dense environment of early Universe galaxies.

  9. Solar wind collimation of the Jupiter high velocity dust streams

    Science.gov (United States)

    Flandes, A.; Krueger, H.

    2006-12-01

    The dust bursts discovered by the Ulysses dust sensor when approaching Jupiter in 1992 were later confirmed as collimated streams of high velocity (~200 km/s) charged (~5V) dust grains escaping from Jupiter and dominated by the interplanetary Magnetic field (IMF). With Cassini, a similar phenomenon was observed in Saturn. It was demonstrated that the Jovian dust streams are closely related to the solar wind compressed regions, either Corotating interaction regions (CIRs) or Coronal mass ejections (CMEs) ¨Cto a minor extent-. Actually the dust streams seem ultimately to be generated by such events. This can be explained considering that dust grains are accelerated as they gain substantial energy while compressed at the forward and reverse shocks that bound or precede these solar wind regions.

  10. Interstellar and Ejecta Dust in the Cas A Supernova Remnant

    Science.gov (United States)

    Arendt, Richard G.; Dwek, Eli; Kober, Gladys; Rho, Jonghee; Hwang, Una

    2013-01-01

    The ejecta of the Cas A supernova remnant has a complex morphology, consisting of dense fast-moving line emitting knots and diffuse X-ray emitting regions that have encountered the reverse shock, as well as more slowly expanding, unshocked regions of the ejecta. Using the Spitzer 5-35 micron IRS data cube, and Herschel 70, 100, and 160 micron PACS data, we decompose the infrared emission from the remnant into distinct spectral components associated with the different regions of the ejecta. Such decomposition allows the association of different dust species with ejecta layers that underwent distinct nuclear burning histories, and determination of the dust heating mechanisms. Our decomposition identified three characteristic dust spectra. The first, most luminous one, exhibits strong emission features at approx. 9 and 21 micron, and a weaker 12 micron feature, and is closely associated with the ejecta knots that have strong [Ar II] 6.99 micron and [Ar III] 8.99 micron emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low MgO-to-SiO2 ratios. A second, very different dust spectrum that has no indication of any silicate features, is best fit by Al2O3 dust and is found in association with ejecta having strong [Ne II] 12.8 micron and [Ne III] 15.6 micron emission lines. A third characteristic dust spectrum shows features that best matched by magnesium silicates with relatively high MgO-to-SiO2 ratio. This dust is primarily associated with the X-ray emitting shocked ejecta and the shocked interstellar/circumstellar material. All three spectral components include an additional featureless cold dust component of unknown composition. Colder dust of indeterminate composition is associated with [Si II] 34.8 micron emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. The dust mass giving rise to the warm dust component is about approx. 0.1solar M. However, most of the dust mass

  11. Jeans instability of a dusty plasma with dust charge variations

    Energy Technology Data Exchange (ETDEWEB)

    Hakimi Pajouh, H., E-mail: hakimi@alzahra.ac.ir; Afshari, N. [Faculty of Physics, Alzahra University, P. O. Box 19938-93973, Tehran (Iran, Islamic Republic of)

    2015-09-15

    The effect of the dust charge variations on the stability of a self-gravitating dusty plasma has been theoretically investigated. The dispersion relation for the dust-acoustic waves in a self-gravitating dusty plasma is obtained. It is shown that the dust charge variations have significant effects. It increases the growth rate of instability and the instability cutoff wavenumbers. It is found that by increasing the value of the ions temperature and the absolute value of the equilibrium dust charge, the cutoff wavenumber decreases and the stability region is extended.

  12. Obstructive sleep apnea with pulmonary hypertension and cor-pulmonale in an 11-year-old Nigerian boy with sino-nasal non-hodgkin lymphoma

    Directory of Open Access Journals (Sweden)

    Ibrahim Aliyu

    2014-01-01

    Full Text Available Children are predominantly nasal breathers, therefore obstruction of the nasal passage presents early with difficulty in breathing; however, with advance in age they soon adapt to mouth breathing. Chronic upper airway obstruction may result in cardiovascular complications such as pulmonary hypertension, right ventricular heart failure, and also renal disease. Therefore, we report the case of an 11-year-old Nigerian boy who had upper airway obstruction complicated with sleep apnea, pulmonary hypertension and cor-pulmonale resulting from sino-nasal (nasopharyngeal non-Hodgkin lymphoma which is rare in African children

  13. The effect of metallothionein 2A core promoter region single-nucleotide polymorphism on accumulation of toxic metals in sinonasal inverted papilloma tissues

    Energy Technology Data Exchange (ETDEWEB)

    Starska, Katarzyna, E-mail: katarzyna.starska@umed.lodz.pl [I Department of Otolaryngology and Laryngological Oncology, Medical University of Łódź, Kopcinskiego 22, 90-153 Łódź (Poland); Bryś, Magdalena; Forma, Ewa [Department of Cytobiochemistry, University of Łódź, Pomorska 142/143, 90-236 Łódź (Poland); Olszewski, Jurek; Pietkiewicz, Piotr [II Department of Otolaryngology and Laryngological Oncology, Medical University of Łódź, Żeromskiego 113, 90-549 Łódź (Poland); Lewy-Trenda, Iwona; Danilewicz, Marian [Department of Pathology, Medical University of Łódź, Pomorska 251, 92-213 Łódź (Poland); Krześlak, Anna [Department of Cytobiochemistry, University of Łódź, Pomorska 142/143, 90-236 Łódź (Poland)

    2015-06-15

    Metallothioneins (MTs) are intracellular thiol-rich heavy metal-binding proteins which join trace metal ions protecting cells against heavy metal toxicity and regulate metal distribution and donation to various enzymes and transcription factors. The goal of this study was to identify the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene, and to investigate its effect on allele-specific gene expression and Cd, Zn, Cu and Ni content in sinonasal inverted papilloma tissue (IP), with non-cancerous sinonasal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was identified by restriction fragment length polymorphism using 117 IP and 132 NCM. MT2A gene analysis was performed by quantitative real-time PCR. Metal levels were analyzed by flame atomic absorption spectrometry. The frequency of A allele carriage was 99.2% and 100% in IP and NCM, respectively. The G allele carriage was detected in 23.9% of IP and in 12.1% of the NCM samples. As a result, a significant association of − 5 A/G SNP in MT2A gene with mRNA expression in both groups was determined. A significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. A highly significant association was detected between the rs28366003 genotype and Cd and Zn content in IP. Furthermore, significant differences were identified between A/A and A/G genotype with regard to the type of metal contaminant. The Spearman rank correlation results showed the MT2A gene expression and both Cd and Cu levels were negatively correlated. The results obtained in this study suggest that the − 5 A/G SNP in the MT2A gene may have an effect on allele-specific gene expression and toxic metal accumulation in sinonasal inverted papilloma. - Highlights: • MT2A gene expression and metal content in sinonasal inverted papilloma tissues • Association between SNP (rs28366003) and expression of MT2A • Significant

  14. Higher antineutrophil cytoplasmic antibody (C-ANCA) titers are associated with increased overall healthcare use in patients with sinonasal manifestations of granulomatosis with polyangiitis (GPA).

    Science.gov (United States)

    Janisiewicz, Agnieszka M; Klau, Marc H; Keschner, David B; Lehmer, Randy R; Venkat, Kumar V; Medhekar, Swati S; Chang, Parke K; Badran, Karam; Leary, Ryan; Garg, Rohit; Nguyen, Andrew A; Lee, Jivianne T

    2015-01-01

    Granulomatosis with polyangiitis (GPA) is an autoimmune disease characterized by necrotizing granulomatous airway inflammation and vasculitis. Sinonasal involvement occurs in more than 80% cases, with antineutrophil cytoplasmic antibody (C-ANCA) titers used as a marker of disease severity. The purpose of this study was to determine whether C-ANCA levels impact radiographic findings and healthcare use in patients with sinonasal GPA. A retrospective review was performed on GPA patients evaluated in a multidisciplinary rheumatologic/otolaryngologic clinic from 2008 to 2013. Data were collected with respect to age, gender, clinical presentation, C-ANCA titers, Lund-Mackay (LM) scores, surgical interventions, and healthcare use, the latter of which were determined by assessing the number of rheumatology/otolaryngology clinic visits, computed tomography (CT) scans, and email/telephone encounters. A total of 44 patients were identified, 11 male and 33 female. Sinonasal manifestations were evident in 70.4%, with chronic rhinosinusitis (CRS) (41.9%), septal perforation (38.7%), and crusting (32.2%) the most common findings. No significant differences in number of CT scans (p = 0.10) or mean LM scores (p = 0.47) were found between patients with more than or equal to 1:80 and less than 1:80 C-ANCA titers, respectively. However, overall healthcare use was increased in the more than or equal to 1:80 C-ANCA group (n = 28) compared with less than 1:80 (n = 16), with a significantly greater number of rheumatologic/otolaryngologic encounters (mean 121 versus 69.2, p = 0.03) noted. When otolaryngologic healthcare use was specifically examined, the average number of encounters was also higher in more than or equal to 1:80 C-ANCA patients (31.9 versus 22.9), but this difference was not statistically significant (p = 0.16). Sinonasal GPA patients with presenting C-ANCA titers more than or equal to 1:80 demonstrated significantly greater overall healthcare use than their lower C

  15. SMARCB1/INI1-deficient sinonasal carcinoma shows methylation of RASSF1 gene: A clinicopathological, immunohistochemical and molecular genetic study of a recently described entity.

    Science.gov (United States)

    Laco, Jan; Chmelařová, Marcela; Vošmiková, Hana; Sieglová, Kateřina; Bubancová, Ivana; Dundr, Pavel; Němejcová, Kristýna; Michálek, Jaroslav; Čelakovský, Petr; Mottl, Radovan; Sirák, Igor; Vošmik, Milan; Ryška, Aleš

    2017-02-01

    The aim of the study was detailed clinicopathological investigation of SMARCB1/INI1-deficient sinonasal carcinomas, including molecular genetic analysis of mutational status and DNA methylation of selected protooncogenes and tumor suppressor genes by means of next generation sequencing (NGS) and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). A total of 4/56 (7%) cases of SMARCB1/INI1-deficient carcinomas were detected among 56 sinonasal carcinomas diagnosed over a 19year period using immunohistochemical screening. The series comprised 3 males and 1 female, aged 27-76 years (median 64 years). All tumors arose in the nasal cavity. Three neoplasms were diagnosed in advanced stage pT4. During the follow-up period (range 14-111 months (median 72 months)), three tumors recurred locally, but none of the patients developed regional or distant metastases. Ultimately, two patients died due to the tumor. Microscopically, all tumors consisted of infiltrating nests of polygonal basaloid cells with a variable component of rhabdoid cells with eosinophilic cytoplasm. Immunohistochemically, there was almost diffuse expression of cytokeratins (CK), p16, p40 and p63 in all cases, while expression of CK5/6, CK7 and vimentin was only focal or absent. The detection of NUT gave negative results. In three cases, the absence of SMARCB1/INI1 expression was due to deletion of SMARCB1/INI1 gene. Methylation of SMARCB1/INI1 gene was not found. One tumor harbored HPV18 E6/E7 mRNA. All 12 genes (BRAF, BRCA1, BRCA2, KIT, EGFR, KRAS, NRAS, PDGFRA, PIK3CA, PTEN, RET, and ROS1) tested for mutations using NGS were wild-type. Regarding DNA methylation, all four SMARCB1/INI1-deficient tumors showed methylation of RASSF1 gene by means of MS-MLPA. There was a statistically significant difference in RASSF1 gene methylation between SMARCB1/INI1-deficient and SMARCB1/INI1-positive tumors (p=0.0095). All other examined genes (ATM, BRCA1, BRCA2, CADM1, CASP8, CD44, CDKN1B

  16. Distribution of polybrominated diphenyl ethers and dust particle size fractions adherent to skin in indoor dust, Pretoria, South Africa.

    Science.gov (United States)

    Kefeni, Kebede Keterew; Okonkwo, Jonathan O

    2014-03-01

    In order to determine human exposure to the indoor toxicant, selection of dust fraction and understanding dust particle size distribution in settled indoor dust are very important. This study examined the influence of dust particle size on the concentration of polybrominated diphenyl ethers (PBDEs) congeners, assessed the distribution of dust particle size and characterized the main indoor emission sources of PBDEs. Accordingly, the concentrations of PBDE congeners determined in different indoor dust fractions were found to be relatively higher in the order of dust particle size: 45-106 μm>(106-150 μm. The finding shows arbitrary selection of dust fractions for exposure determination may result in wrong conclusions. Statistically significant moderate correlation between the concentration of Σ9PBDEs and organic matter content calculated with respect to the total dust mass was also observed (r=0.55, p=0.001). On average, of total dust particle size <250 μm, 93.4 % (m/m%) of dust fractions was associated with less than 150 μm. Furthermore, of skin adherent dust fractions considered (<150 μm), 86 % (v/v%) is in the range of particle size 9.25-104.7 μm. Electronic materials treated with PBDEs were found the main emission sources of PBDE congeners in indoor environment. Based on concentrations of PBDEs determined and mass of indoor dust observed, 150 μm metallic sieve is adequate for human exposure risk assessment. However, research in this area is very limited and more research is required to generalize the fact.

  17. Characterisation of atmospheric deposited particles during a dust storm in urban areas of Eastern Australia.

    Science.gov (United States)

    Gunawardena, Janaka; Ziyath, Abdul M; Bostrom, Thor E; Bekessy, Lambert K; Ayoko, Godwin A; Egodawatta, Prasanna; Goonetilleke, Ashantha

    2013-09-01

    The characteristics of dust particles deposited during the 2009 dust storm in the Gold Coast and Brisbane regions of Australia are discussed in this paper. The study outcomes provide important knowledge in relation to the potential impacts of dust storm related pollution on ecosystem health in the context that the frequency of dust storms is predicted to increase due to anthropogenic desert surface modifications and climate change impacts. The investigated dust storm contributed a large fraction of fine particles to the environment with an increased amount of total suspended solids, compared to dry deposition under ambient conditions. Although the dust storm passed over forested areas, the organic carbon content in the dust was relatively low. The primary metals present in the dust storm deposition were aluminium, iron and manganese, which are common soil minerals in Australia. The dust storm deposition did not contain significant loads of nickel, cadmium, copper and lead, which are commonly present in the urban environment. Furthermore, the comparison between the ambient and dust storm chromium and zinc loads suggested that these metals were contributed to the dust storm by local anthropogenic sources. The potential ecosystem health impacts of the 2009 dust storm include, increased fine solids deposition on ground surfaces resulting in an enhanced capacity to adsorb toxic pollutants as well as increased aluminium, iron and manganese loads. In contrast, the ecosystem health impacts related to organic carbon and other metals from dust storm atmospheric deposition are not considered to be significant.

  18. Interstellar and ejecta dust in the cas a supernova remnant

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, Richard G. [CRESST, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Dwek, Eli; Kober, Gladys [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Rho, Jeonghee [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Hwang, Una, E-mail: Richard.G.Arendt@nasa.gov [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2014-05-01

    Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant (SNR). Using low-resolution Spitzer IRS spectra (5-35 μm), and broad-band Herschel PACS imaging (70, 100, and 160 μm), we identify characteristic dust spectra, associated with ejecta layers that underwent distinct nuclear burning histories. The most luminous spectrum exhibits strong emission features at ∼9 and 21 μm and is closely associated with ejecta knots with strong Ar emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low Mg to Si ratios. Another dust spectrum is associated with ejecta having strong Ne emission lines. It has no indication of any silicate features and is best fit by Al{sub 2}O{sub 3} dust. A third characteristic dust spectrum shows features that are best matched by magnesium silicates with a relatively high Mg to Si ratio. This dust is primarily associated with the X-ray-emitting shocked ejecta, but it is also evident in regions where shocked interstellar or circumstellar material is expected. However, the identification of dust composition is not unique, and each spectrum includes an additional featureless dust component of unknown composition. Colder dust of indeterminate composition is associated with emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. Most of the dust mass in Cas A is associated with this unidentified cold component, which is ≲ 0.1 M {sub ☉}. The mass of warmer dust is only ∼0.04 M {sub ☉}.

  19. Oblique dust density waves

    Science.gov (United States)

    Piel, Alexander; Arp, Oliver; Menzel, Kristoffer; Klindworth, Markus

    2007-11-01

    We report on experimental observations of dust density waves in a complex (dusty) plasma under microgravity. The plasma is produced in a radio-frequency parallel-plate discharge (argon, p=15Pa, U=65Vpp). Different sizes of dust particles were used (3.4 μm and 6.4μm diameter). The low-frequency (f 11Hz) dust density waves are naturally unstable modes, which are driven by the ion flow in the plasma. Surprisingly, the wave propagation direction is aligned with the ion flow direction in the bulk plasma but becomes oblique at the boundary of the dust cloud with an inclination of 60^o with respect to the plasma boundary. The experimental results are compared with a kinetic model in the electrostatic approximation [1] and a fluid model [2]. Moreover, the role of dust surface waves is discussed. [1] M. Rosenberg, J. Vac. Sci. Technol. A 14, 631 (1996) [2] A. Piel et al, Phys. Rev. Lett. 97, 205009 (2006)

  20. DustPedia: A Definitive Study of Cosmic Dust in the Local Universe

    Science.gov (United States)

    Davies, J. I.; Baes, M.; Bianchi, S.; Jones, A.; Madden, S.; Xilouris, M.; Bocchio, M.; Casasola, V.; Cassara, L.; Clark, C.; De Looze, I.; Evans, R.; Fritz, J.; Galametz, M.; Galliano, F.; Lianou, S.; Mosenkov, A. V.; Smith, M.; Verstocken, S.; Viaene, S.; Vika, M.; Wagle, G.; Ysard, N.

    2017-04-01

    The European Space Agency has invested heavily in two cornerstones missions: Herschel and Planck. The legacy data from these missions provides an unprecedented opportunity to study cosmic dust in galaxies so that we can, for example, answer fundamental questions about the origin of the chemical elements, physical processes in the interstellar medium (ISM), its effect on stellar radiation, its relation to star formation and how this relates to the cosmic far-infrared background. In this paper we describe the DustPedia project, which enables us to develop tools and computer models that will help us relate observed cosmic dust emission to its physical properties (chemical composition, size distribution, and temperature), its origins (evolved stars, supernovae, and growth in the ISM), and the processes that destroy it (high-energy collisions and shock heated gas). To carry out this research, we combine the Herschel/Planck data with that from other sources of data, and provide observations at numerous wavelengths (≤slant 41) across the spectral energy distribution, thus creating the DustPedia database. To maximize our spatial resolution and sensitivity to cosmic dust, we limit our analysis to 4231 local galaxies (venergy distributions (HerBIE) and a state-of-the-art Monte Carlo photon-tracing radiative transfer model (SKIRT). In this, the first of the DustPedia papers, we describe the project objectives, data sets used, and provide an insight into the new scientific methods we plan to implement.

  1. Magnetic susceptibility of dust-loaded leaves as a proxy of traffic-related heavy metal pollution in Kathmandu city, Nepal

    Science.gov (United States)

    Gautam, Pitambar; Blaha, Ulrich; Appel, Erwin

    Dust-loaded tree leaves from Kathmandu have been analyzed for magnetic susceptibility ( χ) and heavy metal (HM) contents. For 221 samples of leaves of cypress (mainly Cupressus corneyana), silky oak ( Grevillea robusta) and bottlebrush ( Callistemon lanceolatus), χ has a range of (0.01-54)×10 -8 m 3 kg -1 with a median of about 10.0×10 -8 m 3 kg -1. Trees situated close to the busy road intersections, near the main bus station and sectors of roads with steep slope yield elevated susceptibility. Chemical analysis of 20 samples of varying susceptibility by atomic absorption spectrometry yields the following maximum HM contents: Fe (1.3 wt%), Mn (281.9 ppm), Zn (195.2 ppm), Cu (41.5 ppm), Pb (38.4 ppm), Ni (8.1 ppm), Cr (6.4 ppm), Co (4.1 ppm) and Cd (1.2 ppm). The logarithmic susceptibility on dry mass basis ( χ) shows significant linear relationship with HM contents: Pearson's correlation coefficient r>0.8 with Zn, Fe, Cr; r>0.7 with Mn, Cu; r>0.6 with Pb, Ni. Magnetic phases are of soft (magnetite/maghemite) and hard (hematite) coercivities. Microscopy of magnetic extracts reveals spherules (mostly of 2-20 μm diameter) originated from vehicle exhausts through the combustion process as well as crystalline grains of lithogenic origin. The dust accumulation in leaves took place mainly after monsoon (beginning of October 2001) till the sampling period (first half of February 2002). Despite the dependence of susceptibility and HM contents on a variety of spatial and temporal factors (amount of particulate matter (PM), efficiency of deposition/removal of PM by wind, precipitation, birds etc.), a significant correlation of susceptibility to HM implies that the former serves as an effective proxy of metallic pollution. Hence, susceptibility-based bio-monitoring technique is recommended as an economic and rapid tool for assessment of environmental pollution in urban areas like Kathmandu.

  2. 'Nuisance Dust' - a Case for Recalibration?

    Science.gov (United States)

    Datson, Hugh; Marker, Brian

    2013-04-01

    time). 'Custom and practice' acceptance criteria for dust samples obtained by mass or soiling techniques have been developed and are widely applied even though they were not necessarily calibrated thoroughly and have not been reviewed recently. Furthermore, as sampling techniques have evolved, criteria developed for one method have been adapted for another. Criteria and limit values have sometimes been based on an insufficient knowledge of sampler characteristics. Ideally, limit values should be calibrated for the locality to take differences in dust density and visibility into account. Work is needed on the definition of criteria and limit values, and sampling practices for coarse dust fractions, followed by discussion of good practices for securing effective monitoring that is proportionate and fit for purpose. With social changes and the evolution of environmental controls since the 1960s, the public perception of 'nuisance dust' has changed and needs to be addressed by reviewing existing thresholds in relation to the range of monitoring devices currently in use.

  3. High Energy Studies of Astrophysical Dust

    Science.gov (United States)

    Corrales, Lia Racquel

    Astrophysical dust---any condensed matter ranging from tens of atoms to micron sized grains---accounts for about one third of the heavy elements produced in stars and disseminated into space. These tiny pollutants are responsible for producing the mottled appearance in the spray of light we call the "Milky Way." However these seemingly inert particles play a strong role in the physics of the interstellar medium, aiding star and planet formation, and perhaps helping to guide galaxy evolution. Most dust grains are transparent to X-ray light, leaving a signature of atomic absorption, but also scattering the light over small angles. Bright X-ray objects serendipitously situated behind large columns of dust and gas provide a unique opportunity to study the dust along the line of sight. I focus primarily on X-ray scattering through dust, which produces a diffuse halo image around a central point source. Such objects have been observed around X-ray bright Galactic binaries and extragalactic objects that happen to shine through the plane of the Milky Way. I use the Chandra X-ray Observatory, a space-based laboratory operated by NASA, which has imaging resolution ideal for studying X-ray scattering halos. I examine several bright X-ray objects with dust-free sight lines to test their viability as templates and develop a parametric model for the Chandra HETG point spread function (PSF). The PSF describes the instrument's imaging response to a point source, an understanding of which is necessary for properly measuring the surface brightness of X-ray scattering halos. I use an HETG observation of Cygnus X-3, one of the brightest objects available in the Chandra archive, to derive a dust grain size distribution. There exist degenerate solutions for the dust scattering halo, but with the aid of Bayesian analytics I am able to apply prior knowledge about the Cyg X-3 sight line to measure the relative abundance of dust in intervening Milky Way spiral arms. I also demonstrate how

  4. Planar dust-acoustic waves in electron-positron-ion-dust plasmas with dust size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-Yan; Zhang, Kai-Biao [Sichuan University of Science and Engineering, Zigong (China)

    2014-06-15

    Nonlinear dust-acoustic solitary waves which are described with a Kortweg-de vries (KdV) equation by using the reductive perturbation method, are investigated in a planar unmagnetized dusty plasma consisting of electrons, positrons, ions and negatively-charged dust particles of different sizes and masses. The effects of the power-law distribution of dust and other plasma parameters on the dust-acoustic solitary waves are studied. Numerical results show that the dust size distribution has a significant influence on the propagation properties of dust-acoustic solitons. The amplitudes of solitary waves in the case of a power-law distribution is observed to be smaller, but the soliton velocity and width are observed to be larger, than those of mono-sized dust grains with an average dust size. Our results indicate that only compressed solitary waves exist in dusty plasma with different dust species. The relevance of the present investigation to interstellar clouds is discussed.

  5. Dust exposure in Finnish foundries.

    Science.gov (United States)

    Siltanen, E; Koponen, M; Kokko, A; Engström, B; Reponen, J

    1976-01-01

    Dust measurements were made in 51 iron, 9 steel, and 8 nonferrous foundries, at which 4,316 foundrymen were working. The sampling lasted at least two entire shifts or work days continuously during various operations in each foundry. The dust samples were collected at fixed sites or in the breathing zones of the workers. The mass concentration was determined by weighing and the respirable dust fraction was separated by liquid sedimentation. The free silica content was determined by X-ray diffraction. In the study a total of 3,188 samples were collected in the foundries and 6,505 determinations were made in the laboratory. The results indicated a definite difference in the dust exposure during various operations. The highest dust exposures were found during furnace, cupola, and pouring ladle repair. During cleaning work, sand mixing, and shake-out operations excessive silica dust concentrations were also measured. The lowest dust concentrations were measured during melting and pouring operations. Moderate dust concentrations were measured during coremaking and molding operations. The results obtained during the same operations of iron and steel foundries were similar. The distribution of the workers into various exposure categories, the content of respirable dust and quartz, the correlation between respirable dust and total dust, and the correlation between respirable silica and total dust concentrations are discussed. Observations concerning dust suppression and control methods are briefly considered.

  6. Analytical Study of Nonlinear Dust Acoustic Waves in Two-Dimensional Dust Plasma with Dust Charge Variation

    Institute of Scientific and Technical Information of China (English)

    LIN Chang; ZHANG Xiu-Lian

    2005-01-01

    The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation.

  7. Effect of industrial dust on some test organisms

    Energy Technology Data Exchange (ETDEWEB)

    Schuck, H.J.

    1974-01-01

    The effect of industrial dust on the growth of Lepidium sativum Cress and on spore germination and germ-tube development of Botrytis cinerea and Fusarium oxysporum was studied. Lepidium sativum was strongly inhibited and in most cases the fungi were stimulated. The effect was related to the species of trees and the district, where the dust-samples were collected.

  8. Dust Devil Days

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 6 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. Dust devils, small cyclonic wind storms, are common in the American Southwest and on Mars. As the dust devil moves across the surface it picks up the loose dust, leaving behind a dark track to mark its passage. These dust devil tracks are in the Argyre Basin. Image information: VIS instrument. Latitude -46.6, Longitude 317.5 East (42.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the

  9. Dust during the Reionization

    CERN Document Server

    Elfgren, E; Elfgren, Erik

    2003-01-01

    The possibility that population III stars have reionized the Universe at redshifts greater than 6 has recently gained momentum with WMAP polarization results. Here we analyse the role of early dust produced by these stars and ejected into the intergalactic medium. We show that this dust, heated by the radiation from the same population III stars, produces a submillimetre excess. The electromagnetic spectrum of this excess is compatible with the FIRAS (Far Infrared Absolute Spectrophotometer) cosmic far infrared background. This spectrum, a Doppler spectrum times the $\

  10. Electrostatic Dust Detection and Removal for ITER

    Energy Technology Data Exchange (ETDEWEB)

    C.H. Skinner; A. Campos; H. Kugel; J. Leisure; A.L. Roquemore; S. Wagner

    2008-09-01

    We present some recent results on two innovative applications of microelectronics technology to dust inventory measurement and dust removal in ITER. A novel device to detect the settling of dust particles on a remote surface has been developed in the laboratory. A circuit board with a grid of two interlocking conductive traces with 25 μm spacing is biased to 30 – 50 V. Carbon particles landing on the energized grid create a transient short circuit. The current flowing through the short circuit creates a voltage pulse that is recorded by standard nuclear counting electronics and the total number of counts is related to the mass of dust impinging on the grid. The particles typically vaporize in a few seconds restoring the previous voltage standoff. Experience on NSTX however, showed that in a tokamak environment it was still possible for large particles or fibers to remain on the grid causing a long term short circuit. We report on the development of a gas puff system that uses helium to clear such particles. Experiments with varying nozzle designs, backing pressures, puff durations, and exit flow orientations have given an optimal configuration that effectively removes particles from an area up to 25 cm² with a single nozzle. In a separate experiment we are developing an advanced circuit grid of three interlocking traces that can generate a miniature electrostatic traveling wave for transporting dust to a suitable exit port. We have fabricated such a 3-pole circuit board with 25 micron insulated traces that operates with voltages up to 200 V. Recent results showed motion of dust particles with the application of only 50 V bias voltage. Such a device could potentially remove dust continuously without dedicated interventions and without loss of machine availability for plasma operations.

  11. Modeling of Plasma Irregularities in Expanding Ionospheric Dust Clouds

    Science.gov (United States)

    Fu, H.; Scales, W.; Mahmoudian, A.; Bordikar, M. R.

    2009-12-01

    Natural dust layers occur in the earth’s mesosphere (50km-85km). Plasma irregularities are associated with these natural dust layers that produce radar echoes. Recently, an Ionospheric sounding rocket experiment was performed to investigate the plasma irregularities in upper atmospheric dust layers. The Charged Aerosol Release Experiment (CARE) uses a rocket payload injection of particles in the ionosphere to determine the mechanisms for enhanced radar scatter from plasma irregularities embedded in artificial dusty plasma in space. A 2-D hybrid computational model is described that may be used to study a variety of irregularities in dusty space plasmas which may lead to radar echoes. In this model, the dust and ions are both treated with Particle-In-Cell method while the dust charge varies with time based on the standard dust Orbit Motion Limited charging model. A stochastic model is adopted to remove particle ions due to the dust charging process. Electrons are treated with a fluid model including the parallel dynamics of magnetic fields. Fourier spectral methods with a predictor-corrector time advance are used to solve it. This numerical model will be used to investigate the electrodynamics and several possible plasma irregularity generation mechanisms after the creation of an artificial dust layer. The first is the dust ion-acoustic instability due to the drift of dust relative to the plasma. The instability saturates by trapping some ions. The effects of dust radius and dust drift velocity on plasma irregularities will be analyzed further. Also, a shear- driven instability in expanding dusty clouds is investigated.

  12. The Dust Management Project: Characterizing Lunar Environments and Dust, Developing Regolith Mitigation Technology and Simulants

    Science.gov (United States)

    Hyatt, Mark J.; Straka, Sharon A.

    2010-01-01

    A return to the Moon to extend human presence, pursue scientific activities, use the Moon to prepare for future human missions to Mars, and expand Earth?s economic sphere, will require investment in developing new technologies and capabilities to achieve affordable and sustainable human exploration. From the operational experience gained and lessons learned during the Apollo missions, conducting long-term operations in the lunar environment will be a particular challenge, given the difficulties presented by the unique physical properties and other characteristics of lunar regolith, including dust. The Apollo missions and other lunar explorations have identified significant lunar dust-related problems that will challenge future mission success. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it?s potentially harmful effects on exploration systems and human explorers. The Dust Management Project (DMP) is tasked with the evaluation of lunar dust effects, assessment of the resulting risks, and development of mitigation and management strategies and technologies related to Exploration Systems architectures. To this end, the DMP supports the overall goal of the Exploration Technology Development Program (ETDP) of addressing the relevant high priority technology needs of multiple elements within the Constellation Program (CxP) and sister ETDP projects. Project scope, plans, and accomplishments will be presented.

  13. Electrostatic Characterization of Lunar Dust

    Science.gov (United States)

    2008-01-01

    To ensure the safety and success of future lunar exploration missions, it is important to measure the toxicity of the lunar dust and its electrostatic properties. The electrostatic properties of lunar dust govern its behavior, from how the dust is deposited in an astronaut s lungs to how it contaminates equipment surfaces. NASA has identified the threat caused by lunar dust as one of the top two problems that need to be solved before returning to the Moon. To understand the electrostatic nature of lunar dust, NASA must answer the following questions: (1) how much charge can accumulate on the dust? (2) how long will the charge remain? and (3) can the dust be removed? These questions can be answered by measuring the electrostatic properties of the dust: its volume resistivity, charge decay, charge-to-mass ratio or chargeability, and dielectric properties.

  14. Dead Zones in protoplanetary disks : accumulation and coagulation of dust

    Science.gov (United States)

    Charnoz, S.; Taillifet, E.

    2011-10-01

    The growth of micronic dust to macroscopical sizes (>meter) in a turbulent protoplanetary disk is still largely debated. In particular the dust coagulation process must go through two barriers imposed by their coupling with the gas: the "meter" barrier due to an efficient radial migration of dust when their Stokes number is about one and the "fragmentation barrier" implied by the critical fragmentation velocity (around cm/s) preventing any further growth of particle when they reach a macroscopic size due to the two fast relative velocities of particles. So, paradoxically, a protoplanetary disks may seem quite a hostile place for dust-growth, despite the frequent detection of exoplanets showing that planetary formation is in fact an efficient process. We then explore a new possibility suggested by the stratified nature of a protoplanetary disk. Protoplanetary disks are expected to harbour nonionized regions in their mid-plane, the so called "dead zone" inside which the gas flow should be laminar. Dust coagulation in these regions could be quite effective and in addition, since they are regions of low diffusivity, they are expected to be able to accumulate efficiently dust. Using hybrid numerical simulations, coupling dustgrowth and dust dynamics, we explore how dust penetrate a dead-zone and how dust coagulate up to macroscopic sizes and compare it to coagulation efficiency in the active layers of the disk, subject to turbulence. Different disk structures will be explored and discussed. Implication for observations by ALMA will be also presented.

  15. The impacts of Middle East dust on Indian summer rainfall

    Science.gov (United States)

    Jin, Q.; Yang, Z. L.; Wei, J.

    2014-12-01

    Using the Weather Research and Forecasting model with online chemistry (WRF-Chem), the impact of Middle East dust aerosols on the Indian summer monsoon rainfall was studied. Eight numerical experiments were conducted to take into account uncertainties related to dust-absorbing properties, various assumptions used in calculating aerosol optical depth (AOD), and various radiation schemes. In order to obtain reasonable dust emission, model-simulated AOD and radiation forcing at the top of the atmosphere were compared with multiple satellite- and surface-based observations. Consistent with observations, modeled results show heavy dust loadings in the Arabian Peninsula and Pakistan, which can be transported through long distance to the Arabian Sea and the Indian Peninsula. By heating the atmosphere in the lower troposphere over the Iranian Plateau, these dust aerosols result in strengthened Indian summer monsoon circulations, which in turn transport more water vapor to the Indian Peninsula. The model shows that northern India becomes wetter during the monsoon season in dust cases than non-dust cases. Further observational analyses show an increasing trend in AOD over the Arabian Peninsula, which corresponds to an increasing trend of rainfall in northern India during summer monsoon seasons from 2000 to 2013. These observed trends of AOD and rainfall are consistent with the model-simulated positive relationship between Middle East dust and Indian summer monsoon rainfall. Our results highlight long-term (decadal) impacts of Middle East dust aerosols on the Indian summer rainfall.

  16. Dust origin in late-type dwarf galaxies: ISM growth vs. type II supernovae

    CERN Document Server

    Zhukovska, Svitlana

    2014-01-01

    We re-evaluate the roles of different dust sources in dust production as a function of metallicity in late-type dwarf galaxies, with the goal of understanding the relation between dust content and metallicity. The dust content ol late-type dwarf galaxies with episodic star formation is studied with a multicomponent model of dust evolution, which includes dust input from AGB stars, type II SNe and dust growth by accretion of atoms in the ISM. Dust growth in the ISM becomes an important dust source in dwarf galaxies, on the timescale of 0.1 - a few Gyrs. It increases the dust-to-gas ratio (DGR) during post-burst evolution, unlike type II SNe, which eject grains to the ISM only during starbursts. Before the dust growth in the ISM overtakes the dust production, AGB stars can be major sources of dust in metal-poor dwarf galaxies. Our models reproduce the relation between the DGR and oxygen abundance, derived from observations of a large sample of dwarf galaxies. The steep decrease in the DGR at low O values is exp...

  17. Identification of the exploatation dust in road dust

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2012-01-01

    Full Text Available The aim of this publication is to determine models of explore dust from vehicle brake systems and the presentationof measurement results of the exploitation dust, which is separate from road dust. The following methods and measuring devices were used: T-01M device, screen analysis, analysis of chemical composition with the use of a scanning microscope with Energy Dispersive x-ray Spectroscopy (EDS analyser. The measurements for identifying this type of dust were conducted on marked sections of roads: motorway, city road and mountain road. The explored dust was distinguished in the following car systems: brakes, clutch plates, tyres and catalytic converters.

  18. Dusting off the Diffuse Interstellar Bands

    CERN Document Server

    Baron, Dalya; Watson, Darach; Yao, Yushu; Prochaska, J Xavier

    2014-01-01

    Using over a million and a half extragalactic spectra we study the properties of the mysterious Diffuse Interstellar Bands (DIBs) in the Milky Way. These data provide us with an unprecedented sampling of the skies at high Galactic-latitude and low dust-column-density. In this first paper we present our method, study the correlation of the equivalent width of 12 DIBs with dust extinction and with a few atomic species, and the distribution of four DIBs over nearly 15,000 square degrees. As previously found, DIBs strengths correlate with extinction and therefore inevitably with each other. However, we find that DIBs can exist even in dust free areas. Furthermore, we find that the DIBs correlation with dust varies significantly over the sky. DIB under- or over-densities, relative to the expectation from dust, are often spread over hundreds of square degrees. These patches are different for the four DIBs, showing that they are unlikely to originate from the same carrier.

  19. Cylindrically symmetric dust spacetime

    CERN Document Server

    Senovilla, J M M; Senovilla, Jose M. M.; Vera, Raul

    2000-01-01

    We present an explicit exact solution of Einstein's equations for an inhomogeneous dust universe with cylindrical symmetry. The spacetime is extremely simple but nonetheless it has new surprising features. The universe is ``closed'' in the sense that the dust expands from a big-bang singularity but recollapses to a big-crunch singularity. In fact, both singularities are connected so that the whole spacetime is ``enclosed'' within a single singularity of general character. The big-bang is not simultaneous for the dust, and in fact the age of the universe as measured by the dust particles depends on the spatial position, an effect due to the inhomogeneity, and their total lifetime has no non-zero lower limit. Part of the big-crunch singularity is naked. The metric depends on a parameter and contains flat spacetime as a non-singular particular case. For appropriate values of the parameter the spacetime is a small perturbation of Minkowski spacetime. This seems to indicate that flat spacetime may be unstable agai...

  20. Cylindrically symmetric dust spacetime

    Science.gov (United States)

    Senovilla, José M. M.

    2000-07-01

    We present an explicit exact solution of Einstein's equations for an inhomogeneous dust universe with cylindrical symmetry. The spacetime is extremely simple but nonetheless it has surprising new features. The universe is `closed' in the sense that the dust expands from a big-bang singularity but recollapses to a big-crunch singularity. In fact, both singularities are connected so that the whole spacetime is `enclosed' within a single singularity of general character. The big-bang is not simultaneous for the dust, and in fact the age of the universe as measured by the dust particles depends on the spatial position, an effect due to the inhomogeneity, and their total lifetime has no non-zero lower limit. Part of the big-crunch singularity is naked. The metric depends on a parameter and contains flat spacetime as a non-singular particular case. For appropriate values of the parameter the spacetime is a small perturbation of Minkowski spacetime. This seems to indicate that flat spacetime may be unstable against some global non-vacuum perturbations.

  1. Left in the Dust

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    NASA's Stardust spacecraft ended its seven-year voyage January 15 after a safe landing on earth, bringing back a capsule of comet particles and samples of interstellar dust that exceeded the loftiest of expectations of mission scientists. The ensuing studies of the cosmic treasure are expected to shed light on the origins of the solar system and earth itself.

  2. Dust devil dynamics

    Science.gov (United States)

    Horton, W.; Miura, H.; Onishchenko, O.; Couedel, L.; Arnas, C.; Escarguel, A.; Benkadda, S.; Fedun, V.

    2016-06-01

    A self-consistent hydrodynamic model for the solar heating-driven onset of a dust devil vortex is derived and analyzed. The toroidal flows and vertical velocity fields are driven by an instability that arises from the inversion of the mass density stratification produced by solar heating of the sandy surface soil. The nonlinear dynamics in the primary temperature gradient-driven vertical airflows drives a secondary toroidal vortex flow through a parametric interaction in the nonlinear structures. While an external tangential shear flow may initiate energy transfer to the toroidal vortex flow, the nonlinear interactions dominate the transfer of vertical-radial flows into a fast toroidal flow. This secondary flow has a vertical vorticity, while the primary thermal gradient-driven flow produces the toroidal vorticity. Simulations for the complex nonlinear structure are carried out with the passive convection of sand as test particles. Triboelectric charging modeling of the dust is used to estimate the charging of the sand particles. Parameters for a Dust Devil laboratory experiment are proposed considering various working gases and dust particle parameters. The nonlinear dynamics of the toroidal flow driven by the temperature gradient is of generic interest for both neutral gases and plasmas.

  3. [Leather dust and systematic research on occupational tumors: the national and regional registry TUNS].

    Science.gov (United States)

    Mensi, Carolina; Sieno, Claudia; Consonni, Dario; Riboldi, Luciano

    2012-01-01

    The sinonasal cancer (SNC) are a rare tumors characterized by high occupational etiologic fraction. For this reason their incidence and etiology can be actively monitored by a dedicated cancer registry. The National Registry of these tumours is situated at the Italian Institute for Occupational Safety and Prevention (ISPESL) and is based on Regional Operating Centres (ROCs). In Lombardy Region the ROC has been established at the end of 2007 with the purpose to make a systematic surveillance and therefore to support in the most suitable way the scientific research and the prevention actions in the high risk working sectors. The aims of this surveillance are: to estimate the regional incidence of SNC, to define different sources of occupational and environmental exposure both known (wood, leather, nickel, chromium) and unknown. The registry collects all the new incident cases of epithelial SNC occurring in residents in Lombardy Region since 01.01.2008. The regional Registry is managed according to National Guidelines. Until January 2010 we received 596 cases of suspected SNC; only 91 (15%) of these were actually incident cases according to the inclusion criteria of the Registry, and they were preferentially adenocarcinoma and squamous carcinoma. In 2008 the regional age-standardized incidence rate of SNC for males and females, respectively, is 0.8 and 0.5 per 100,000. Occupational or environmental exposure to wood or leather dust is ascertained in over the 50% of cases. The occupational exposure to leather dust was duo to work in shoe factories. Our preliminary findings confirm that occupational exposure to wood and leather dusts are the more relevant risk factors for SNC. The study of occupational sectors and job activity in cases without such exposure could suggest new etiologic hypothesis.

  4. [Seasonal Provincial Characteristics of Vertical Distribution of Dust Loadings and Heavy Metals near Surface in City].

    Science.gov (United States)

    Li, Xiao-yan; Zhang, Shu-ting

    2015-06-01

    With the emergence of urban high-rise building, the vertical space of human daily life gradually extended upward. Seasonal characteristics of vertical distribution of dust loadings and heavy metals near surface are remarkable. In this study, we collected dust deposited on the windowsill at different space height (1th-8th floor) from three buildings in Guiyang city during spring, summer, autumn and winter, and analyzed the deposition fluxes of dust and elements including Ca, Fe, Cd, Cr, Cu, Ni, Pb and Zn. The results showed that: the total changing trend of vertical distribution of dust loadings was that the deposition fluxes of dust in winter were the highest, followed by those in spring, and the deposition fluxes of dust in summer were the lowest. The degree of variation on dust loadings dependent on the change of elevation was the highest in winter, followed by that in summer, and was relatively lower in spring and autumn. The effect on dust loadings by seasonal changing was relatively heavier on windowsill on the lower level than on the higher level. The levels of elements were the highest in spring dust, while those in autumn were relatively lower. Among the 8 elements, the variability of Zn in dust related to space time variation was the most obvious, and that of Ca was weaker. The atmospheric inversion condition might be one of the reasons that improved the deposition fluxes of dust and the contents of Ph and Zn in dust during winter and spring.

  5. Seasonal provenance changes in present-day Saharan dust collected in and off Mauritania

    Directory of Open Access Journals (Sweden)

    C. A. Friese

    2017-08-01

    Full Text Available Saharan dust has a crucial influence on the earth climate system and its emission, transport and deposition are intimately related to, e.g., wind speed, precipitation, temperature and vegetation cover. The alteration in the physical and chemical properties of Saharan dust due to environmental changes is often used to reconstruct the climate of the past. However, to better interpret possible climate changes the dust source regions need to be known. By analysing the mineralogical composition of transported or deposited dust, potential dust source areas can be inferred. Summer dust transport off northwest Africa occurs in the Saharan air layer (SAL. In continental dust source areas, dust is also transported in the SAL; however, the predominant dust input occurs from nearby dust sources with the low-level trade winds. Hence, the source regions and related mineralogical tracers differ with season and sampling location. To test this, dust collected in traps onshore and in oceanic sediment traps off Mauritania during 2013 to 2015 was analysed. Meteorological data, particle-size distributions, back-trajectory and mineralogical analyses were compared to derive the dust provenance and dispersal. For the onshore dust samples, the source regions varied according to the seasonal changes in trade-wind direction. Gibbsite and dolomite indicated a Western Saharan and local source during summer, while chlorite, serpentine and rutile indicated a source in Mauritania and Mali during winter. In contrast, for the samples that were collected offshore, dust sources varied according to the seasonal change in the dust transporting air layer. In summer, dust was transported in the SAL from Mauritania, Mali and Libya as indicated by ferroglaucophane and zeolite. In winter, dust was transported with the trades from Western Sahara as indicated by, e.g., fluellite.

  6. Satellite based Observations of Saharan Dust Source Areas - Comparison and Variability

    Science.gov (United States)

    Schepanski, K.; Tegen, I.; Macke, A.

    2012-04-01

    Satellite remote sensing products such as Meteosat Second Generation (MSG) Infra Red (IR) dust index and Ozone Monitoring Instrument (OMI) Aerosol Index (AI) are commonly used to infer dust source areas. We compare two different methods for dust source identification, (1) a "back-tacking" method applied to 4 years of 15-minute MSG IR dust index, and (2) a "frequency" method applied to daily OMI AI and daily MODIS DeepBlue Aerosol Optical Thickness (AOT) data for the same time period. Using the "back-tracking" method, dust source areas are inferred by tracking individual dust plumes back to their place of origin, allowed by the high temporal resolution of the MSG images. OMI AI and MODIS Deep Blue AOT products are available on daily resolution only, which disables for back-tracking of individual dust plumes. Thus, dust source areas are retrieved by relating the frequencies of occurrence of high dust loadings to source areas. The spatial distribution of inferred dust source areas from the two methods shows significant differences. The MSG back-tracking method highlights frequent dust emission from sources within complex terrain, while frequencies of high OMI AI values emphasise topographic basins as important dust source areas. Dust source areas retrieved from DeepBlue AOTs are generally placed further south towards the Sahel region. This study shows that the temporal resolution of satellite dust products is a key issue in retrieving dust source areas. Both, the spatial distribution of dust sources and their annual cycle strongly depend on the acquisition time related to the start of dust emission.

  7. Seasonal provenance changes in present-day Saharan dust collected in and off Mauritania

    Science.gov (United States)

    Friese, Carmen A.; van Hateren, Johannes A.; Vogt, Christoph; Fischer, Gerhard; Stuut, Jan-Berend W.

    2017-08-01

    Saharan dust has a crucial influence on the earth climate system and its emission, transport and deposition are intimately related to, e.g., wind speed, precipitation, temperature and vegetation cover. The alteration in the physical and chemical properties of Saharan dust due to environmental changes is often used to reconstruct the climate of the past. However, to better interpret possible climate changes the dust source regions need to be known. By analysing the mineralogical composition of transported or deposited dust, potential dust source areas can be inferred. Summer dust transport off northwest Africa occurs in the Saharan air layer (SAL). In continental dust source areas, dust is also transported in the SAL; however, the predominant dust input occurs from nearby dust sources with the low-level trade winds. Hence, the source regions and related mineralogical tracers differ with season and sampling location. To test this, dust collected in traps onshore and in oceanic sediment traps off Mauritania during 2013 to 2015 was analysed. Meteorological data, particle-size distributions, back-trajectory and mineralogical analyses were compared to derive the dust provenance and dispersal. For the onshore dust samples, the source regions varied according to the seasonal changes in trade-wind direction. Gibbsite and dolomite indicated a Western Saharan and local source during summer, while chlorite, serpentine and rutile indicated a source in Mauritania and Mali during winter. In contrast, for the samples that were collected offshore, dust sources varied according to the seasonal change in the dust transporting air layer. In summer, dust was transported in the SAL from Mauritania, Mali and Libya as indicated by ferroglaucophane and zeolite. In winter, dust was transported with the trades from Western Sahara as indicated by, e.g., fluellite.

  8. Interstellar Dust Close to the Sun

    CERN Document Server

    Frisch, Priscilla C

    2012-01-01

    The low density interstellar medium (ISM) close to the Sun and inside of the heliosphere provides a unique laboratory for studying interstellar dust grains. Grain characteristics in the nearby ISM are obtained from observations of interstellar gas and dust inside of the heliosphere and the interstellar gas towards nearby stars. Comparison between the gas composition and solar abundances suggests that grains are dominated by olivines and possibly some form of iron oxide. Measurements of the interstellar Ne/O ratio by the Interstellar Boundary Explorer spacecraft indicate that a high fraction of interstellar oxygen in the ISM must be depleted onto dust grains. Local interstellar abundances are consistent with grain destruction in ~150 km/s interstellar shocks, provided that the carbonaceous component is hydrogenated amorphous carbon and carbon abundances are correct. Variations in relative abundances of refractories in gas suggest variations in the history of grain destruction in nearby ISM. The large observed ...

  9. Dust sources and atmospheric circulation in concert controlling Saharan dust emission and transport towards the Western Mediterranean Basin

    Science.gov (United States)

    Schepanski, Kerstin; Mallet, Marc; Heinold, Bernd; Ulrich, Max

    2017-04-01

    Dust transported from north African source regions towards Europe is a ubiquitous phenomenon in the Mediterranean region, a geographic region that is in part densely populated. Besides its impacts on the atmospheric radiation budget, dust suspended in the atmosphere results in reduced air quality, which is generally sensed as a reduction in quality of life. Furthermore, the exposure to dust aerosols enhances the prevalence of respiratory diseases, which reduces the general human wellbeing, and ultimately results in an increased loss of working hours due to illness and hospitalization rates. Characteristics of the atmospheric dust life cycle that determine dust transport will be presented with focus on the ChArMEx special observation period in June and July 2013 using the atmosphere-dust model COSMO-MUSCAT (COSMO: Consortium for Small-scale MOdeling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model). Modes of atmospheric circulation were identified from empirical orthogonal function (EOF) analysis of the geopotential height at 850 hPa for summer 2013 and compared to EOFs calculated from 1979-2015 ERA-Interim reanalysis. Generally, two different phases were identified. They are related to the eastward propagation of the subtropical ridge into the Mediterranean basin, the position of the Saharan heat low, and the predominant Iberian heat low. The relation of these centres of action illustrates a dipole pattern for enhanced (reduced) dust emission fluxes, stronger (weaker) meridional dust transport, and consequent increase (decrease) atmospheric dust concentrations and deposition fluxes. In concert, the results from this study aim at illustrating the relevance of knowing the dust source locations in concert with the atmospheric circulation. Ultimately, this study addresses the question of what is finally transported towards the Mediterranean basin and Europe from which source regions - and fostered by which atmospheric circulation pattern. Outcomes from this study

  10. FINDING WAYS OF RECYCLING DUST OF ARC STEEL FURNACES AT THE BELARUSIAN METALLURGIC PLANT. PART 3. EXPERIMENTS ON BRIQUETTING OF DUST OFARC STEEL FURNACES

    Directory of Open Access Journals (Sweden)

    A. I. Rozhkov

    2015-01-01

    Full Text Available The article gives an overview of the global experience of recycling dust by briquetting. The advantages and disadvantages of recycling dust with its preliminary briquetting are described. Information about experiments on briquetting of dust generated in different organizations of the Belarusian metallurgy plant with various binders is given. Economic calculations were performed on the basis of technical data obtained during the manufacture of prototypes of briquettes. The results of the calculations showedinexpediency of recycling dust briquetting method because of the low iron content in the dust, high cost of binder and a relatively small rate of ecological tax.

  11. Dust processing in elliptical galaxies

    CERN Document Server

    Hirashita, Hiroyuki; Villaume, Alexa; Srinivasan, Sundar

    2015-01-01

    We reconsider the origin and processing of dust in elliptical galaxies. We theoretically formulate the evolution of grain size distribution, taking into account dust supply from asymptotic giant branch (AGB) stars and dust destruction by sputtering in the hot interstellar medium (ISM), whose temperature evolution is treated by including two cooling paths: gas emission and dust emission (i.e. gas cooling and dust cooling). With our new full treatment of grain size distribution, we confirm that dust destruction by sputtering is too efficient to explain the observed dust abundance even if AGB stars continue to supply dust grains, and that, except for the case where the initial dust-to-gas ratio in the hot gas is as high as $\\sim 0.01$, dust cooling is negligible compared with gas cooling. However, we show that, contrary to previous expectations, cooling does not help to protect the dust; rather, the sputtering efficiency is raised by the gas compression as a result of cooling. We additionally consider grain grow...

  12. Some Dust/Ocean Connections - Past, Present, and Future

    Science.gov (United States)

    Duce, R. A.

    2015-12-01

    Atmospheric dust has been the subject of communications for more than 3000 years, since the ancient Chinese book Chronicles Reported on Bamboo Shoots in 1150 BC. Similar reports of hwangsa and woo-tou in ancient Korean and kosa in ancient Japanese literature also indicated major Asian dust events in those areas. Western observers noted dust storms in India and Afghanistan in the early 1800s, while in the 1840s Darwin surmised that Sahara dust could be an important component of marine sedimentation in the North Atlantic. More recent interest has focused on the importance of dust as a source of the nutrients iron and phosphorus in the global ocean and the role of iron as a limiting nutrient in many areas of the surface ocean. While significant progress has been made in the past 25 years in identifying important dust/ocean connections, many issues remain. Included are the relative dearth of long-term measurements of atmospheric dust (and iron and phosphorus) over and deposition to the ocean, especially in the southern hemisphere; comparisons between modeled and measured deposition of dust to the ocean; and the solubility of iron and phosphorus (and thus their availability as nutrients) after the mineral matter enters the ocean. Addressing these problems will certainly help to provide more accurate estimates of the input of dust to the ocean and its impacts. However, future changes in dust emissions in a warmer world as well as changes in the acid/base environment that mineral dust experiences during its transport and deposition as a result of emission controls on atmospheric NOx and SO2 are two facors that may change the input of these nutrients to the ocean and their impacts in the coming years. These and other issues will be reviewed in this paper.

  13. DustPedia - A Definitive Study of Cosmic Dust in the Local Universe

    CERN Document Server

    Davies, J I; Bianchi, S; Jones, A; Madden, S; Xilouris, M; Bocchio, M; Casasola, V; Cassara, L; Clark, C; De Looze, I; Evans, R; Fritz, J; Galametz, M; Galliano, F; Lianou, S; Mosenkov, A V; Smith, M; Verstocken, S; Viaene, S; Vika, M; Wagle, G; Ysard, N

    2016-01-01

    The European Space Agency has invested heavily in two cornerstones missions; Herschel and Planck. The legacy data from these missions provides us with an unprecedented opportunity to study cosmic dust in galaxies so that we can answer fundamental questions about, for example: the origin of the chemical elements, physical processes in the interstellar medium (ISM), its effect on stellar radiation, its relation to star formation and how this relates to the cosmic far infrared background. In this paper we describe the DustPedia project, which is enabling us to develop tools and computer models that will help us relate observed cosmic dust emission to its physical properties (chemical composition, size distribution, temperature), to its origins (evolved stars, super novae, growth in the ISM) and the processes that destroy it (high energy collisions and shock heated gas). To carry out this research we will combine the Herschel/Planck data with that from other sources of data, providing observations at numerous wav...

  14. Lead isotopes and trace metals in dust at Yucca Mountain

    Science.gov (United States)

    Kwak, Loretta; Neymark, Leonid A.; Peterman, Zell E.

    2008-01-01

    Lead (Pb)-isotope compositions and trace-metal concentrations were determined for samples of dust collected from underground and surface locations at and near the proposed radioactive waste repository at Yucca Mountain, Nevada. Rare earth element concentrations in the dust samples from the underground tunnels are similar to those in wholerock samples of the repository host rocks (Miocene Tiva Canyon Tuff and Topopah Spring Tuff), supporting interpretation that the subsurface dust is mainly composed of rock comminuted during tunnel construction. Other trace metals (arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead, antimony, thallium, and zinc) are variably enriched in the subsurface dust samples relative to the average concentrations in the host rocks. Average concentrations of arsenic and lead in dust samples, high concentrations of which can cause corrosion of waste canisters, have enrichment factors from 1.2 to 1.6 and are insignificant relative to the range of concentrations for these metals observed in the host rock samples. Most dust samples from surface sites also are enriched in many of these trace metals relative to average repository host rocks. At least some of these enrichments may be artifacts of sampling. Plotted on a 208Pb/206Pb-207Pb/206Pb graph, Pb-isotope compositions of dust samples from underground sites form a mixing line extending from host-rock Pb-isotope compositions towards compositions of many of the dust samples from surface sites; however, combined Pb concentration and isotope data indicate the presence of a Pbenriched component in the subsurface dust that is not derived from host rock or surface dust and may derive from anthropogenic materials introduced into the underground environment.

  15. Southern Dust Devils

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 9 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. In our final dust devil image we are again looking at the southern hemisphere of Mars. These tracks occur mainly on the northeast side of the topographic ridges. Of course, there are many exceptions, which makes understanding the dynamics that initiate the actual dust devil cyclone difficult. Image information: VIS instrument. Latitude -47.6, Longitude 317.3 East (42.7 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed

  16. Plentiful Dust Devils

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 8 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. These dust devil tracks occur on the northern plains of Mars. The majority of the surface seen in the image has been affected by the passage of dust devils. Image information: VIS instrument. Latitude -54.6, Longitude 79.3 East (280.7 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are

  17. Contribution of Asian dust to atmospheric deposition of radioactive cesium ((137)Cs).

    Science.gov (United States)

    Fukuyama, Taijiro; Fujiwara, Hideshi

    2008-11-01

    Both Asian dust (kosa) transported from the East Asian continent and locally suspended dust near monitoring sites contribute to the observed atmospheric deposition of (137)Cs in Japan. To estimate the relative contribution of these dust phenomena to the total (137)Cs deposition, we monitored weekly deposition of mineral particles and (137)Cs in spring. Deposition of (137)Cs from a single Asian dust event was 62.3 mBq m(-2) and accounted for 67% of the total (137)Cs deposition during the entire monitoring period. Furthermore, we found high (137)Cs specific activity in the Asian dust deposition sample. Although local dust events contributed to (137)Cs deposition, their contribution was considerably smaller than that of Asian dust. We conclude that the primary source of atmospheric (137)Cs in Japan is dust transported from the East Asian continent.

  18. Measurements of Selected Air Pollutants in Danish Homes and Ozone Interaction with Floor Dust

    DEFF Research Database (Denmark)

    Vibenholt, Anni

    and a FLEC on a stainless steel plate without dust (kFLEC). The composition of organic compounds in the dust was analyzed by pressurized liquid extraction and thermal desorption GC-MS before and after ozone exposure. KFLEC was independent of the ozone concentration and the reaction was treated as first order...... in the Field and Laboratory Emission Cell (FLEC) at different ozone concentrations and relative humidities (0, 25, and 50 % RH). One gram of dust was spread on a clean stainless steel plate which was placed in the FLEC. Steady state reaction rate (kDust) at 2.2 ppm ozone was determined for four different floor......Section I: Laboratory studies: Chemical and sorption properties of indoor floor dust in FLEC: Ozone reacts with C-C double bonds in common indoor VOCs and SVOCs contained in indoor dust and may be catalytically degraded on dust surfaces. The reaction between floor dust and ozone was investigated...

  19. Influence of Air Humidity and Water Particles on Dust Control Using Ultrasonic Atomization

    Science.gov (United States)

    Okawa, Hirokazu; Nishi, Kentaro; Shindo, Dai; Kawamura, Youhei

    2012-07-01

    The influence of air humidity and water particles on dust control was examined using ultrasonic atomization at 2.4 MHz, an acrylic box (61 L), and four types of ore dust samples: green tuff (4 µm), green tuff (6 µm), kaolin, and silica. It was clearly demonstrated that ultrasonic atomization was effective in raising humidity rapidly. However, at high relative air humidity, the water particles remained stable in the box without changing to water vapor. Ultrasonic atomization was applied to suppress dust dispersion and 40-95% dust reduction was achieved at 83% relative air humidity. Dust dispersion was more effective with ultrasonic atomization than without.

  20. Sensitivity simulations with direct shortwave radiative forcing by aeolian dust during glacial cycles

    Science.gov (United States)

    Bauer, E.; Ganopolski, A.

    2014-07-01

    Possible feedback effects between aeolian dust, climate and ice sheets are studied for the first time with an Earth system model of intermediate complexity over the late Pleistocene period. Correlations between climate and dust deposition records suggest that aeolian dust potentially plays an important role for the evolution of glacial cycles. Here climatic effects from the dust direct radiative forcing (DRF) caused by absorption and scattering of solar radiation are investigated. Key elements controlling the dust DRF are the atmospheric dust distribution and the absorption-scattering efficiency of dust aerosols. Effective physical parameters in the description of these elements are varied within uncertainty ranges known from available data and detailed model studies. Although the parameters can be reasonably constrained, the simulated dust DRF spans a~wide uncertainty range related to the strong nonlinearity of the Earth system. In our simulations, the dust DRF is highly localized. Medium-range parameters result in negative DRF of several watts per square metre in regions close to major dust sources and negligible values elsewhere. In the case of high absorption efficiency, the local dust DRF can reach positive values and the global mean DRF can be insignificantly small. In the case of low absorption efficiency, the dust DRF can produce a significant global cooling in glacial periods, which leads to a doubling of the maximum glacial ice volume relative to the case with small dust DRF. DRF-induced temperature and precipitation changes can either be attenuated or amplified through a feedback loop involving the dust cycle. The sensitivity experiments suggest that depending on dust optical parameters, dust DRF has the potential to either damp or reinforce glacial-interglacial climate changes.

  1. Potential Dust Emissions from Sources in the Southern Hemisphere.

    Science.gov (United States)

    Bhattachan, A.; D'Odorico, P.; Okin, G. S.

    2014-12-01

    The Southern Hemisphere currently exhibits low levels of atmospheric dust concentrations relative to the Northern Hemisphere. Recent research suggests that dust concentrations could, however, increase as a result of loss of vegetation cover in the Southern Kalahari and the Mallee. Disturbances resulting from grazing and agriculture are identified as such drivers of land use change in these regions. While studies on the importance of atmospheric dust in global-scale processes are abundant, little has been done to locate the potential dust sources in the Southern Hemisphere because potential new sources are by definition inactive and are undetected in satellite images. To this end, using a combination of laboratory experiments and field observations, we assess that the sediments collected from the dunefields in the Southern Kalahari and Mallee can emit substantial amount of dust, are rich in soluble iron and dust from these sources would reach the Southern Ocean. It is suggested that the supply of soluble iron through atmospheric dust deposition limits the productivity of the Southern Ocean. Thus intensification of land use can potentially make these regions an important source of iron given their proximity to the Southern Ocean. This iron-rich dust could stimulate ocean productivity in future as more areas are reactivated as a result of land-use and droughts.

  2. Influence of continuous mining arrangements on respirable dust exposures

    Science.gov (United States)

    Beck, T. W.; Organiscak, J. A.; Pollock, D. E.; Potts, J. D.; Reed, W. R.

    2017-01-01

    In underground continuous mining operations, ventilation, water sprays and machine-mounted flooded-bed scrubbers are the primary means of controlling respirable dust exposures at the working face. Changes in mining arrangements — such as face ventilation configuration, orientation of crosscuts mined in relation to the section ventilation and equipment operator positioning — can have impacts on the ability of dust controls to reduce occupational respirable dust exposures. This study reports and analyzes dust concentrations measured by the Pittsburgh Mining Research Division for remote-controlled continuous mining machine operators as well as haulage operators at 10 U.S. underground mines. The results of these respirable dust surveys show that continuous miner exposures varied little with depth of cut but are significantly higher with exhaust ventilation. Haulage operators experienced elevated concentrations with blowing face ventilation. Elevated dust concentrations were observed for both continuous miner operators and haulage operators when working in crosscuts driven into or counter to the section airflow. Individual cuts are highlighted to demonstrate instances of minimal and excessive dust exposures attributable to particular mining configurations. These findings form the basis for recommendations for lowering face worker respirable dust exposures. PMID:28529441

  3. Silica dust exposure: Effect of filter size to compliance determination

    Science.gov (United States)

    Amran, Suhaily; Latif, Mohd Talib; Khan, Md Firoz; Leman, Abdul Mutalib; Goh, Eric; Jaafar, Shoffian Amin

    2016-11-01

    Monitoring of respirable dust was performed using a set of integrated sampling system consisting of sampling pump attached with filter media and separating device such as cyclone or special cassette. Based on selected method, filter sizes are either 25 mm or 37 mm poly vinyl chloride (PVC) filter. The aim of this study was to compare performance of two types of filter during personal respirable dust sampling for silica dust under field condition. The comparison strategy focused on the final compliance judgment based on both dataset. Eight hour parallel sampling of personal respirable dust exposure was performed among 30 crusher operators at six quarries. Each crusher operator was attached with parallel set of integrated sampling train containing either 25 mm or 37 mm PVC filter. Each set consisted of standard flow SKC sampler, attached with SKC GS3 cyclone and 2 pieces cassette loaded with 5.0 µm of PVC filter. Samples were analyzed by gravimetric technique. Personal respirable dust exposure between the two types of filters indicated significant positive correlation (p arithmetic mean(AM) and geometric mean(GM). In overall we concluded that personal respirable dust exposure either based on 25mm or 37mm PVC filter will give similar compliance determination. Both filters are reliable to be used in respirable dust monitoring for silica dust related exposure.

  4. Laboratory evaluation of the CIP 10 personal dust sampler.

    Science.gov (United States)

    Gero, A; Tomb, T

    1988-06-01

    The "capteur individuel de poussiere" CIP 10 personal dust sampler--developed by the Centre d'Etudes et Recherches de Charbonnages de France (CERCHAR) research organization--is a small, quiet, lightweight unit which samples at a flow rate of 10 L/min. It is a three-stage sampler, using two stages to remove nonrespirable dust particles and one stage to collect the respirable fraction. Airflow through the sampler is induced by the third stage, which is a rotating collector cup that contains a fine grade sponge. Laboratory tests were conducted in a dust chamber using aerosols of Arizona road dust, coal dust and silica dust. Aerosol concentrations measured with the CIP 10 were compared to those measured with the coal mine dust personal sampler unit used in the United States. The results of this study showed that aerosol concentrations measured with the CIP 10 were linearly related to those obtained with the coal mine dust personal sampler. The relationship, however, was dependent on preselector configuration and aerosol characteristics. The collection medium allows some small particles (less than 3 microns) to pass through the sampler without being collected. As much as 13% (by weight) of the aerosol that penetrated through the preseparating stages was exhausted from the sampler.

  5. Dust Quantization and Effects on Agriculture Over Uttar Pradesh, India

    Science.gov (United States)

    Munshi, Pavel; Tiwari, Shubhansh

    2017-01-01

    Dust plays a very important role in the atmosphere and the biosphere. In this communication, the effect of atmospheric dust on the yields of certain crops grown in Uttar Pradesh, India is assessed. Coherent physical and thermodynamic fingerprints of dust parameters such as from Satellite data- KALPANA-1, MODIS, OMI, CALIPSO; Model data- DREAM, HYSPLIT, ECMWF; have been considered to run the APSIM model to derive the impacts. This paper assesses dust as a physical atmospheric phenomenon including its Long Range Transport (LRT) and dispersion along with considerable variations of Aerosol Optical Depths (AODs) over the subcontinent of India. While AODs significantly increase by more dust concentration, the local dispersion of pollutants is a major concern with deposition of atmospheric dust such as sulphates and other chemical constituents that affect agricultural land. An approach in atmospheric physics is also taken to parameterize the model outputs. This communication indicates dust to be a positive factor for the cultivation of certain crops such as wheat, maize in the experimental location. Initial results suggest that LRT dust is a viable counterpart to decrease the concentration of soil acidity and related parameters thus enhancing the vitality of crops.

  6. The burden of revision sinonasal surgery in the UK—data from the Chronic Rhinosinusitis Epidemiology Study (CRES): a cross-sectional study

    Science.gov (United States)

    Philpott, Carl; Hopkins, Claire; Erskine, Sally; Kumar, Nirmal; Robertson, Alasdair; Farboud, Amir; Ahmed, Shahzada; Anari, Shahram; Cathcart, Russell; Khalil, Hisham; Jervis, Paul; Carrie, Sean; Kara, Naveed; Prinsley, Peter; Almeyda, Robert; Mansell, Nicolas; Sunkaraneni, Sankalp; Salam, Mahmoud; Ray, Jaydip; Panesaar, Jaan; Hobson, Jonathan; Clark, Allan; Morris, Steve

    2015-01-01

    Objectives The aim of this study was to investigate the surgical revision rate in patients with chronic rhinosinusitis (CRS) in the UK CRS Epidemiology Study (CRES). Previous evidence from National Sinonasal Audit showed that 1459 patients with CRS demonstrated a surgical revision rate 19.1% at 5 years, with highest rates seen in those with polyps (20.6%). Setting Thirty secondary care centres around the UK. Participants A total of 221 controls and 1249 patients with CRS were recruited to the study including those with polyps (CRSwNPs), without polyps (CRSsNPs) and with allergic fungal rhinosinusitis (AFRS). Interventions Self-administered questionnaire. Primary outcome measure The need for previous sinonasal surgery. Results A total of 651 patients with CRSwNPs, 553 with CRSsNPs and 45 with AFRS were included. A total of 396 (57%) patients with CRSwNPs/AFRS reported having undergone previous endoscopic nasal polypectomy (ENP), of which 182 of the 396 (46%) reported having received more than one operation. The mean number of previous surgeries per patient in the revision group was 3.3 (range 2–30) and a mean duration of time of 10 years since the last procedure. The average length of time since their first operation up to inclusion in the study was 15.5 years (range 0–74). Only 27.9% of all patients reporting a prior ENP had received concurrent endoscopic sinus surgery (ESS; n=102). For comparison, surgical rates in patients with CRSsNPs were significantly lower; 13% of cases specifically reported ESS, and of those only 30% reported multiple procedures (χ2 p<0.001). Conclusions This study demonstrated that there is a high burden of both primary and revision surgery in patients with CRS, worst in those with AFRS and least in those with CRSsNPs. The burden of revision surgery appears unchanged in the decade since the Sinonasal Audit. PMID:25926143

  7. [House dust mite allergy].

    Science.gov (United States)

    Carrard, A; Pichler, C

    2012-04-01

    House dust mites can be found all over the world where human beings live independent from the climate. Proteins from the gastrointestinal tract- almost all known as enzymes - are the allergens which induce chronic allergic diseases. The inhalation of small amounts of allergens on a regular base all night leads to a slow beginning of the disease with chronically stuffed nose and an exercise induced asthma which later on persists. House dust mites grow well in a humid climate - this can be in well isolated dwellings or in the tropical climate - and nourish from human skin dander. Scales are found in mattresses, upholstered furniture and carpets. The clinical picture with slowly aggravating complaints leads quite often to a delayed diagnosis, which is accidently done on the occasion of a wider spectrum of allergy skin testing. The beginning of a medical therapy with topical steroids as nasal spray or inhalation leads to a fast relief of the complaints. Although discussed in extensive controversies in the literature - at least in Switzerland with the cold winter and dry climate - the recommendation of house dust mite avoidance measures is given to patients with good clinical results. The frequent ventilation of the dwelling with cold air in winter time cause a lower indoor humidity. Covering encasings on mattresses, pillow, and duvets reduces the possibility of chronic contact with mite allergens as well as the weekly changing the bed linen. Another option of therapy is the specific immunotherapy with extracts of house dust mites showing good results in children and adults. Using recombinant allergens will show a better quality in diagnostic as well as in therapeutic specific immunotherapy.

  8. A coal dust burner

    Energy Technology Data Exchange (ETDEWEB)

    Vakhrshev, B.M.; Khasnullin, I.G.; Krauze, Ye.G.; Ushakov, Yu.A.; Zinovyev, V.G.

    1982-01-01

    The burner for combustion of coal dust fuel, primarily, in rotating furnaces, contains coaxially disposed pipes, a branch pipe for feeding in the air mixture and a rotating mechanism. The first two pipes are switched in to an air source. The third pipe on the input end has an oblique section and the pipe may be rotated around an axis by a mechanism. The first pipe has ports and it may be moved in an axial direction. By installing the third pipe in the first and second positions, it is possible to direct the dust coming from the branch pipe along the central (the larger part of the dust) or the central pipe, respectively, which makes it possible to regulate the configuration of the torch and its temperature. Hot air is sucked from the furnace through the ports in the perforated first pipe to the mouth of the burner, which makes it possible to intensify combustion. By moving the fifitpipe to the right it is possible to overlap the ports with the projections and to rule out suction of the air. The possibility of regulating combustion in wide ranges makes it possible to reduce the expenditure of fuel by 2 to 3 percent.

  9. Quantifying the anthropogenic dust emission from agricultural land use and desiccation of the Aral Sea in Central Asia

    Science.gov (United States)

    Xi, Xin; Sokolik, Irina N.

    2016-10-01

    A regional dust model system is applied to quantify the anthropogenic dust emission in the post-Soviet Central Asia from 2000 to 2014. Two physically based dust schemes suggest that a proportion of 18.3-32.8% of total dust emissions is contributed by agricultural land use and the desiccation of Aral Sea, whereas a simplified dust scheme yields higher estimates in the range of 49.7-56.5% depending on whether a static or dynamic preferential dust source function is used. The dust schemes also differ greatly in the spatial distribution of anthropogenic dust and the sensitivity to the use of land use intensity in separating natural and human-made source areas, suggesting that the model representation of erosion threshold velocity, especially the role of vegetation, is a key source of model uncertainty in quantifying anthropogenic dust. The relative importance of agriculture and dried Aral Sea bed (Aralkum) differs greatly among the dust schemes. Despite the increased dust from the expansion of Aralkum, there is a negative trend in the anthropogenic dust proportion, indicating a shift of dust emission toward natural source areas. All dust schemes show a decrease in anthropogenic dust in response to land cover changes over agricultural lands.

  10. Dust Properties in HII Regions in M33

    CERN Document Server

    Relano, M; Lisenfeld, U; Verley, S; Hermelo, I; Boquien, M; Albrecht, M; Kramer, C; Braine, J; Perez-Montero, E; De Looze, I; Xilouris, M; Kovacs, A; Staguhn, J

    2016-01-01

    The conversion of the IR emission into star formation rate can be strongly dependent on the physical properties of the dust, which are affected by the environmental conditions where the dust is embedded. We study here the dust properties of a set of HII regions in the Local Group Galaxy M33 presenting different spatial configurations between the stars, gas and dust to understand the dust evolution under different environments. We model the SED of each region using the DustEM tool and obtain the mass relative to hydrogen for Very Small Grains (YVSG), Polycyclic Aromatic Hydrocarbons (YPAH) and Big Grains (YBG). The relative mass of the VSGs (YVSG/YTOT) is a factor of 1.7 higher for HII regions classified as filled and mixed than for regions presenting a shell structure. The enhancement of VSGs within NGC 604 and NGC 595 is correlated to expansive gas structures with velocities greater than 50 km/s. The gas-to-dust ratio derived for the HII regions in our sample exhibits two regimes related to the HI-H2 transit...

  11. Clouds and Dust Storms

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 2 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere. Image information: VIS instrument. Latitude 68.4, Longitude 180 East (180 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote

  12. Impact of mineral dust on nitrate, sulfate, and ozone in transpacific Asian pollution plumes

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2009-11-01

    Full Text Available We use a 3-d global chemical transport model (GEOS-Chem to interpret aircraft observations of nitrate and sulfate partitioning in transpacific dust plumes during the INTEX-B campaign of April–May 2006. The model includes explicit transport of size-resolved mineral dust and its alkalinity, nitrate, and sulfate content. The observations show that particulate nitrate is primarily associated with dust, sulfate is primarily associated with ammonium, and Asian dust remains alkaline across the Pacific. This can be reproduced in the model by using a reactive uptake coefficient for HNO3 on dust (γ(HNO3~10−3 much lower than commonly assumed in models and likely reflecting limitation of uptake by dust dissolution. The model overestimates gas-phase HNO3 by a factor of 2–3, typical of previous model studies; we show that this cannot be corrected by uptake on dust. We find that the fraction of aerosol nitrate on dust in the model increases from ~30% in fresh Asian outflow to 80–90% over the Northeast Pacific, reflecting in part the volatilization of ammonium nitrate and the resulting transfer of nitrate to the dust. Consumption of dust alkalinity by uptake of acid gases in the model is slow relative to the lifetime of dust against deposition, so that dust in general does not acidify. This argues against the hypothesis that dust iron released by acidification could become bio-available upon dust deposition. Observations in INTEX-B show no detectable ozone depletion in Asian dust plumes, consistent with the model. Uptake of HNO3 by dust, suppressing its recycling to NOx, reduces Asian pollution influence on US surface ozone in the model by 10–15% or up to 1 ppb.

  13. High latitude dust pathways from Iceland: implications for aeolian inputs to oceans and cryosphere

    Science.gov (United States)

    Bullard, J. E.; Baddock, M.; Mockford, T.; Thorsteinsson, T.

    2016-12-01

    Recent research has suggested that dust emission from source areas found in the high latitudes (≥50°N and ≥40°S) may contribute at least 5% to the global dust budget. Although this amount is low compared to that from sub-tropical dust sources, the relative impact of dust emission at high latitudes may well be magnified by its regional significance. High latitude regions lie away from the transport corridors of dust from the major sub-tropical dust belt, thus sources at higher latitudes have the potential to be especially important providers of mineral aerosol to (their) proximal cryospheric, terrestrial and marine systems. To examine the distribution of dust from a prominent high latitude dust source, this study employed forward air parcel trajectory modelling over a 20 year period, quantifying dust trajectories from source areas in the north and south of Iceland. The majority of multi-year dust transport studies have relied upon daily-run trajectories over their decadal study periods. This research differs from these because it only analyses trajectories generated when dust was known to be in suspension at the origin, based on meteorological observations. We demonstrate that the potential for Icelandic dust to be transported over the Greenland Ice Sheet is considerably overestimated by generic transport climatologies when compared with those specifically associated with dust. Modeled transport patterns illustrate the strong influence of seasonality as a primary control on dust emission and its transport from Iceland. Snow cover means dust activity is suppressed for a longer duration in the north of Iceland, and while winds are weakest in summer, the delivery of dust to Atlantic and sub-arctic oceans is greatest and broadest in that season. These findings illustrate the influence of drivers unique to high latitude environments, and their importance in understanding the aeolian systems operating there.

  14. Impact of mineral dust on nitrate, sulfate, and ozone in transpacific Asian pollution plumes

    Directory of Open Access Journals (Sweden)

    T. D. Fairlie

    2010-04-01

    Full Text Available We use a 3-D global chemical transport model (GEOS-Chem to interpret aircraft observations of nitrate and sulfate partitioning in transpacific dust plumes during the INTEX-B campaign of April–May 2006. The model includes explicit transport of size-resolved mineral dust and its alkalinity, nitrate, and sulfate content. The observations show that particulate nitrate is primarily associated with dust, sulfate is primarily associated with ammonium, and Asian dust remains alkaline across the Pacific. This can be reproduced in the model by using a reactive uptake coefficient for HNO3 on dust (γ(HNO3 ~10−3 much lower than commonly assumed in models and possibly reflecting limitation of uptake by dust dissolution. The model overestimates gas-phase HNO3 by a factor of 2–3, typical of previous model studies; we show that this cannot be corrected by uptake on dust. We find that the fraction of aerosol nitrate on dust in the model increases from ~30% in fresh Asian outflow to 80–90% over the Northeast Pacific, reflecting in part the volatilization of ammonium nitrate and the resulting transfer of nitrate to the dust. Consumption of dust alkalinity by uptake of acid gases in the model is slow relative to the lifetime of dust against deposition, so that dust does not acidify (at least not in the bulk. This limits the potential for dust iron released by acidification to become bio-available upon dust deposition. Observations in INTEX-B show no detectable ozone depletion in Asian dust plumes, consistent with the model. Uptake of HNO3 by dust, suppressing its recycling to NOx, reduces Asian pollution influence on US surface ozone in the model by 10–15% or up to 1 ppb.

  15. Impact of long-range desert dust transport on hydrometeor formation over coastal East Asia

    Science.gov (United States)

    Zhang, Zhenxi; Zhou, Wen; Wenig, Mark; Yang, Liangui

    2017-01-01

    Model simulations and hydrological reanalysis data for 2007 are applied to investigate the impact of long-range desert dust transport on hydrometeor formation over coastal East Asia. Results are analyzed from Hong Kong and Shanghai, which are two representative coastal cities of East Asia. Long-range desert dust transport impacts mainly spring and summer clouds and precipitation over coastal East Asia. In spring, clouds and precipitation come mainly from large-scale condensation and are impacted mainly by dust from the Gobi, Sahara, and Thar deserts. These desert dusts can participate in the precipitation within and below the clouds. At lower latitudes, the dust particles act mainly as water nuclei. At higher latitudes, they act as both water nuclei and ice nuclei. The effect of Gobi, Sahara, and Thar dust on large-scale clouds and precipitation becomes stronger at higher latitudes. In summer, clouds and precipitation over coastal East Asia come mainly from convection and are impacted mainly by dust from the Taklamakan, Arabian, and Karakum-Kavir deserts. Most Taklamakan dust particles can participate in precipitation within convective clouds as ice nuclei, while Arabian and Karakum-Kavir dust particles participate only as water nuclei in precipitation below the clouds. The effect of Taklamakan dust on convective clouds and precipitation becomes stronger at lower latitudes. Of all the desert dusts, that from the Gobi and Taklamakan deserts has the relatively largest impact. Gobi dust impacts climate change in coastal East Asia by affecting spring water clouds at higher latitudes.

  16. [The research on remote sensing dust aerosol by using split window emissivity].

    Science.gov (United States)

    Xu, Hui; Yu, Tao; Gu, Xing-Fa; Cheng, Tian-Hai; Xie, Dong-Hai; Liu, Qian

    2013-05-01

    Dust aerosol can cause the change in the land surface emissivity in split window by radiative forcing (RF). Firstly, the present paper explained from the microscopic point of view the extinction properties of dust aerosols in the 11 and 12 microm channels, and their influence on the land surface emissivity. Secondly, on April 29, 2011, in the northern region of Inner Mongolia a strong sandstorm outbroke, and based on the analysis of the changes in land surface emissivity, this paper proposed a dust identification method by using the variation of emissivity. At last, the dust identification result was evaluated by the dust monitoring product provided by the National Satellite Meteorological Center. The result shows that under the assumption that the 12 microm emissivity equals to 1, using 11 microm relative emissivity could identify dust cover region effectively, and the 11 microm relative emissivity to a certain extent represented the intensity information of dust aerosol.

  17. ULTRAVIOLET RADIATIVE TRANSFER MODELING OF NEARBY GALAXIES WITH EXTRAPLANAR DUSTS

    Energy Technology Data Exchange (ETDEWEB)

    Shinn, Jong-Ho; Seon, Kwang-Il, E-mail: jhshinn@kasi.re.kr [Korea Astronomy and Space Science Institute, 776 Daeduk-daero, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of)

    2015-12-20

    In order to examine their relation to the host galaxy, the extraplanar dusts of six nearby galaxies are modeled, employing a three-dimensional Monte Carlo radiative transfer code. The targets are from the highly inclined galaxies that show dust-scattered ultraviolet halos, and the archival Galaxy Evolution Explorer FUV band images were fitted with the model. The observed images are generally well-reproduced by two dust layers and one light source layer, whose vertical and radial distributions have exponential profiles. We obtained several important physical parameters, such as star formation rate (SFR{sub UV}), face-on optical depth, and scale-heights. Three galaxies (NGC 891, NGC 3628, and UGC 11794) show clear evidence for the existence of an extraplanar dust layer. However, it is found that the remaining three targets (IC 5249, NGC 24, and NGC 4173) do not necessarily need a thick dust disk to model the ultraviolet (UV) halo, because its contribution is too small and the UV halo may be caused by the wing part of the GALEX point spread function. This indicates that the galaxy samples reported to have UV halos may be contaminated by galaxies with negligible extraplanar (halo) dust. The galaxies showing evidence of an extraplanar dust layer fall within a narrow range on the scatter plots between physical parameters such as SFR{sub UV} and extraplanar dust mass. Several mechanisms that could possibly produce the extraplanar dust are discussed. We also found a hint that the extraplanar dust scale-height might not be much different from the polycyclic aromatic hydrocarbon emission characteristic height.

  18. Cassini Dust Measurements at Enceladus and Implications for the Origin of the E Ring

    Science.gov (United States)

    Spahn, Frank; Schmidt, Jürgen; Albers, Nicole; Hörning, Marcel; Makuch, Martin; Seiß, Martin; Kempf, Sascha; Srama, Ralf; Dikarev, Valeri; Helfert, Stefan; Moragas-Klostermeyer, Georg; Krivov, Alexander V.; Sremčević, Miodrag; Tuzzolino, Anthony J.; Economou, Thanasis; Grün, Eberhard

    2006-03-01

    During Cassini's close flyby of Enceladus on 14 July 2005, the High Rate Detector of the Cosmic Dust Analyzer registered micron-sized dust particles enveloping this satellite. The dust impact rate peaked about 1 minute before the closest approach of the spacecraft to the moon. This asymmetric signature is consistent with a locally enhanced dust production in the south polar region of Enceladus. Other Cassini experiments revealed evidence for geophysical activities near Enceladus' south pole: a high surface temperature and a release of water gas. Production or release of dust particles related to these processes may provide the dominant source of Saturn's E ring.

  19. Recent progress in understanding the behavior of dust in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Krasheninnikov, S I; Pigarov, A Yu; Smirnov, R D; Rosenberg, M; Benson, D J; Mendis, D A; Rudakov, D L; Yu, J H [University of California at San Diego, La Jolla, CA (United States); Tanaka, Y [Kanazawa University, Kanazawa (Japan); Soboleva, T K [ICN, Universidad Nacional Autonoma de Mexico, Mexico D. F. (Mexico); Rognlien, T D [Lawrence Livermore National Laboratory, Livermore, CA (United States); Bray, B D; West, W P [General Atomics, San Diego, CA (United States); Roquemore, A L; Skinner, C H [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Terry, J L; Lipschultz, B; Bader, A; Granetz, R S [PSFC, Massachusetts Institute of Technology, Cambridge, MA (United States); Pitcher, C S [ITER Cadarache Joint Work Site, Cedex (France)] (and others)

    2008-12-15

    It has been known for a long time that microscopic dust appears in plasmas in fusion devices. Recently it was shown that dust can be responsible for the termination of long- discharges. Also, in ITER-scale experiments dust can pose safety problems related to its chemical activity, tritium retention and radioactive content. In particular, the presence of dust in the vacuum chamber of ITER is one of the main concerns of the ITER licensing process. Here we review recent progress in the understanding of different experimental and theoretical aspects of the physics of dust dynamics and transport in fusion plasmas and discuss the remaining issues.

  20. Regional and climatic controls on seasonal dust deposition in the southwestern U.S.

    Science.gov (United States)

    Reheis, M.C.; Urban, F.E.

    2011-01-01

    Vertical dust deposition rates (dust flux) are a complex response to the interaction of seasonal precipitation, wind, changes in plant cover and land use, dust source type, and local vs. distant dust emission in the southwestern U.S. Seasonal dust flux in the Mojave-southern Great Basin (MSGB) deserts, measured from 1999 to 2008, is similar in summer-fall and winter-spring, and antecedent precipitation tends to suppress dust flux in winter-spring. In contrast, dust flux in the eastern Colorado Plateau (ECP) region is much larger in summer-fall than in winter-spring, and twice as large as in the MSGB. ECP dust is related to wind speed, and in the winter-spring to antecedent moisture. Higher summer dust flux in the ECP is likely due to gustier winds and runoff during monsoonal storms when temperature is also higher. Source types in the MSGB and land use in the ECP have important effects on seasonal dust flux. In the MSGB, wet playas produce salt-rich dust during wetter seasons, whereas antecedent and current moisture suppress dust emission from alluvial and dry-playa sources during winter-spring. In the ECP under drought conditions, dust flux at a grazed-and-plowed site increased greatly, and also increased at three annualized, previously grazed sites. Dust fluxes remained relatively consistent at ungrazed and currently grazed sites that have maintained perennial vegetation cover. Under predicted scenarios of future climate change, these results suggest that an increase in summer storms may increase dust flux in both areas, but resultant effects will depend on source type, land use, and vegetation cover. ?? 2011.

  1. Sensitivity simulations with direct radiative forcing by aeolian dust during glacial cycles

    Science.gov (United States)

    Bauer, E.; Ganopolski, A.

    2014-01-01

    Possible feedback effects between aeolian dust, climate and ice sheets are studied for the first time with an Earth system model of intermediate complexity over the late Pleistocene period. Correlations between climate variables and dust deposits suggest that aeolian dust potentially plays an important role for the evolution of glacial cycles. Here climatic effects from the dust direct radiative forcing (DRF) caused by absorption and scattering of solar radiation are investigated. Key factors controlling the dust DRF are the atmospheric dust distribution and the absorption-scattering efficiency of dust aerosols. Effective physical parameters in the description of these factors are varied within uncertainty ranges known from available data and detailed model studies. Although the parameters are reasonably constrained by use of these studies, the simulated dust DRF spans a wide uncertainty range related to nonlinear dependencies. In our simulations, the dust DRF is highly localized. Medium-range parameters result in negative DRF of several W m-2 in regions close to major dust sources and negligible values elsewhere. In case of high absorption efficiency, the local dust DRF can reach positive values and the global mean DRF can be insignificantly small. In case of low absorption efficiency, the dust DRF can produce a significant global cooling in glacial periods which leads to a doubling of the maximum glacial ice volume relative to the case with small dust DRF. DRF-induced temperature and precipitation changes can either be attenuated or amplified through a feedback loop involving the dust cycle. The sensitivity experiments suggest that depending on dust optical parameters the DRF has the potential to either damp or reinforce glacial-interglacial climate changes.

  2. Characterization of dust from blast furnace cast house de-dusting.

    Science.gov (United States)

    Lanzerstorfer, Christof

    2016-12-14

    During casting of liquid iron and slag, a considerable amount of dust is emitted into the cast house of a blast furnace (BF). Usually, this dust is extracted via exhaust hoods and subsequently separated from the ventilation air. In most BFs the cast house dust is recycled. In this study a sample of cast house dust was split by air classification into five size fractions, which were then analysed. Micrographs showed that the dominating particle type in all size fractions is that of single spherical-shaped particles. However, some irregular-shaped particles were also found and in the finest size fraction also some agglomerates were present. Almost spherical particles consisted of Fe and O, while highly irregular-shaped particles consisted of C. The most abundant element was Fe, followed by Ca and C. These elements were distributed relatively uniformly in the size fractions. As, Cd, Cu, K, Pb, S, Sb and Zn were enriched significantly in the fine size fractions. Thus, air classification would be an effective method for improved recycling. By separating a small fraction of fines (about 10-20%), a reduction of the mass of Zn in the coarse dust recycled in the range of 40-55% would be possible.

  3. Quantifying dust plume formation and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa

    KAUST Repository

    Khan, Basit Ali

    2015-01-01

    Dust particles mixed in the free troposphere have longer lifetimes than airborne particles near the surface. Their cumulative radiative impact on earth’s meteorological processes and climate might be significant despite their relatively small contribution to total dust abundance. One example is the elevated dust--laden Saharan Air Layer (SAL) over the equatorial North Atlantic, which cools the sea surface and likely suppresses hurricane activity. To understand the formation mechanisms of SAL, we combine model simulations and dust observations collected during the first stage of the Saharan Mineral Dust Experiment (SAMUM--I), which sampled dust events that extended from Morocco to Portugal, and investigated the spatial distribution and the microphysical, optical, chemical, and radiative properties of Saharan mineral dust. We employed the Weather Research Forecast model coupled with the Chemistry/Aerosol module (WRF--Chem) to reproduce the meteorological environment and spatial and size distributions of dust. The experimental domain covers northwest Africa including the southern Sahara, Morocco and part of the Atlantic Ocean with 5 km horizontal grid spacing and 51 vertical layers. The experiments were run from 20 May to 9 June 2006, covering the period of most intensive dust outbreaks. Comparisons of model results with available airborne and ground--based observations show that WRF--Chem reproduces observed meteorological fields as well as aerosol distribution across the entire region and along the airplane’s tracks. We evaluated several aerosol uplift processes and found that orographic lifting, aerosol transport through the land/sea interface with steep gradients of meteorological characteristics, and interaction of sea breezes with the continental outflow are key mechanisms that form a surface--detached aerosol plume over the ocean. Comparisons of simulated dust size distributions with airplane and ground--based observations are generally good, but suggest

  4. Flying Through Dust From Asteroids

    Science.gov (United States)

    Kohler, Susanna

    2016-11-01

    How can we tell what an asteroid is made of? Until now, weve relied on remote spectral observations, though NASAs recently launched OSIRIS-REx mission may soon change this by landing on an asteroid and returning with a sample.But what if we could learn more about the asteroids near Earth without needing to land on each one? It turns out that we can by flying through their dust.The aerogel dust collector of the Stardust mission. [NASA/JPL/Caltech]Ejected CluesWhen an airless body is impacted by the meteoroids prevalent throughout our solar system, ejecta from the body are flung into the space around it. In the case of small objects like asteroids, their gravitational pull is so weak that most of the ejected material escapes, forming a surrounding cloud of dust.By flying a spacecraft through this cloud, we could perform chemical analysis of the dust, thereby determining the asteroids composition. We could even capture some of the dust during a flyby (for example, by using an aerogel collector like in the Stardust mission) and bring it back home to analyze.So whats the best place to fly a dust-analyzing or -collecting spacecraft? To answer this, we need to know what the typical distribution of dust is around a near-Earth asteroid (NEA) a problem that scientists Jamey Szalay (Southwest Research Institute) and Mihly Hornyi (University of Colorado Boulder) address in a recent study.The colors show the density distribution for dust grains larger than 0.3 m around a body with a 10-km radius. The distribution is asymmetric, with higher densities on the apex side, shown here in the +y direction. [Szalay Hornyi 2016]Moon as a LaboratoryTo determine typical dust distributions around NEAs, Szalay and Hornyi first look at the distribution of dust around our own Moon, caused by the same barrage of meteorites wed expect to impact NEAs. The Moons dust cloud was measured in situ in 2013 and 2014 by the Lunar Dust Experiment (LDEX) on board the Lunar Atmosphere and Dust Environment

  5. House dust mite control measures for asthma: systematic review

    DEFF Research Database (Denmark)

    Gøtzsche, Peter C.; Johansen, Helle Krogh

    2008-01-01

    The major allergen in house dust comes from mites. We performed a systematic review of the randomized trials that had assessed the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma, and had compared active interventions with placebo...... improved (relative risk 1.01, 95% CI 0.80-1.27), asthma symptom scores (standardized mean difference -0.04, 95% CI -0.15 to 0.07) or in medication usage (standardized mean difference -0.06, 95% CI -0.18 to 0.07). Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot...

  6. [Ecological study of Pyroglyphides mites in house dust in the Grenoble area. A qualitative approach and incidence of various parameters: seasons, altitude, temperature and relative dampness in their multiplication].

    Science.gov (United States)

    Lascaud, D

    1978-01-01

    This study concerns the analysis of 70 samples of dust mites taken periodically from 13 sample areas or mattresses at different altitudes. It shows the presence of Pyroglyphid mites in all the mattresses studied. Four species were found: Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei and Dermatophagoides evansi. From a quantitative point of view, the statistical analysis of the results obtained allows the following conclusions to be drawn: -- All the Pyroglyphids (adults and young) undergo seasonal fluctuations at low, middle and high altitude. In the plains and at middle altitude these mites have a seasonal maximum and minimum. At high altitude only the seasonal maximum can be determined. -- The number of Pyroglyphids found is much higher in the plaine than at middle altitude and at middle altitude than at high altitude. The influence of altitude can be demonstrated with certitude. -- The conditions of temperature and relative dampness most favourable to the multiplication of mites are found in the plaine. At middle and high altitude these conditions are only met in summer. In flat country the statistical analysis allows us to show the existance of a correlation between the rate of dampness and the number of Pyroglyphids, and more specially, between the dampness rate and Dermatophagoides farinae, a predominant species at this sampling area. At middle and high altitude such a correlation cannot be shown clearly. At the three altitudes considered, no correlation can be established between the temperature and the number of Pyroglyphid mites found.

  7. Testing the sensitivity of past climates to the indirect effects of dust

    Science.gov (United States)

    Sagoo, Navjit; Storelvmo, Trude

    2017-06-01

    Mineral dust particles are important ice nuclei (IN) and as such indirectly impact Earth's radiative balance via the properties of cold clouds. Using the Community Earth System Model version 1.0.6, and Community Atmosphere Model version 5.1, and a new empirical parameterization for ice nucleation on dust particles, we investigate the radiative forcing induced by dust IN for different dust loadings. Dust emissions are representative of global conditions for the Last Glacial Maximum and the mid-Pliocene Warm Period. Increased dust leads to smaller and more numerous ice crystals in mixed phase clouds, impacting cloud opacity, lifetime, and precipitation. This increases the shortwave cloud radiative forcing, resulting in significant surface temperature cooling and polar amplification—which is underestimated in existing studies relative to paleoclimate archives. Large hydrological changes occur and are linked to an enhanced dynamical response. We conclude that dust indirect effects could potentially have a significant impact on the model-data mismatch that exists for paleoclimates.Plain Language SummaryMineral dust and climate are closely linked, with large fluctuations in dust deposition recorded in geological archives. Dusty conditions are generally associated with cold, glacial periods and low dust with warmer climates. The direct effects of dust on the climate (absorbing and reflecting radiation) are well understood; however, the indirect effects of dust on climate have been overlooked. Dust indirectly impacts the climate through its role as ice nuclei; the presence of dust makes it easier for ice to form in a cloud. We explore the indirect effects of dust in climates with different dust loading from the present by conducting a climate modeling study in which dust are able to act as ice nuclei. Including dust indirect effects increases the sensitivity of our model to changes in dust emission. Increasing dust impacts ice crystal numbers (increased) and size

  8. Regional variability in dust-on-snow processes and impacts in the Upper Colorado River Basin

    Science.gov (United States)

    Skiles, S. McKenzie; Painter, Thomas H.; Belnap, Jayne; Holland, Lacey; Reynolds, Richard; Goldstein, Harland; Lin, J.

    2015-01-01

    Dust deposition onto mountain snow cover in the Upper Colorado River Basin frequently occurs in the spring when wind speeds and dust emission peaks on the nearby Colorado Plateau. Dust loading has increased since the intensive settlement in the western USA in the mid 1880s. The effects of dust-on-snow have been well studied at Senator Beck Basin Study Area (SBBSA) in the San Juan Mountains, CO, the first high-altitude area of contact for predominantly southwesterly winds transporting dust from the southern Colorado Plateau. To capture variability in dust transport from the broader Colorado Plateau and dust deposition across a larger area of the Colorado River water sources, an additional study plot was established in 2009 on Grand Mesa, 150 km to the north of SBBSA in west central, CO. Here, we compare the 4-year (2010–2013) dust source, deposition, and radiative forcing records at Grand Mesa Study Plot (GMSP) and Swamp Angel Study Plot (SASP), SBBSA's subalpine study plot. The study plots have similar site elevations/environments and differ mainly in the amount of dust deposited and ensuing impacts. At SASP, end of year dust concentrations ranged from 0.83 mg g−1 to 4.80 mg g−1, and daily mean spring dust radiative forcing ranged from 50–65 W m−2, advancing melt by 24–49 days. At GMSP, which received 1.0 mg g−1 less dust per season on average, spring radiative forcings of 32–50 W m−2 advanced melt by 15–30 days. Remote sensing imagery showed that observed dust events were frequently associated with dust emission from the southern Colorado Plateau. Dust from these sources generally passed south of GMSP, and back trajectory footprints modelled for observed dust events were commonly more westerly and northerly for GMSP relative to SASP. These factors suggest that although the southern Colorado Plateau contains important dust sources, dust contributions from other dust sources contribute to dust loading in this region

  9. Of data and dust

    CERN Multimedia

    Stephanie Hills

    2016-01-01

    The traditional image of an archive is one of dusty old boxes, books and papers. When your archive is digital, dust spells disaster. An innovative environmental sensor designed and built by a CERN IT specialist has become an essential element in the Laboratory’s data-preservation strategy.   The novel air particle monitoring sensor designed by CERN's Julien Leduc. CERN’s archive holds more than 130 petabytes of data from past and present high-energy physics experiments. Some of it is 40 years old, most of it needs to be kept forever, and all of it is held on tape cartridges (over 20,000 of them). The cartridges are held inside tape libraries with robotic arms that load them into tape drives where they can be read and written. Tape cartridges have many advantages over other data storage media, notably cost and long-term reliability, but topping the list of drawbacks is their vulnerability to contamination from airborne dust particles; a tiny piece of g...

  10. Charged Dust Aggregate Interactions

    Science.gov (United States)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  11. Mining dust filter. Bergbaustaubfilter

    Energy Technology Data Exchange (ETDEWEB)

    Igelbuescher, H.; Hoelter, H.

    1988-12-28

    A dust filter for application underground, whose casing is designed as a transportable unit combinable with further casings and fitted with removable filter pockets. These filter pockets have a frame which seals towards the casing and with the lattices on which the filter cloth is stretched and with spacers holding the said lattices at a distance. Each casing as such has inspection ports that are operationable optionally on either side, and clean and crude gas channels on its upper side. The ends of these channels have coupleable head pieces, so that connection is made easy when casings are arranged in a line. Each crude gas channel is connected to the inside of the casing by means of perforations in the floor of said channel, whereas the clean gas channel, for its part, is in connection with the inside of the casing by means of a channel on the head side of the casing. It is thus possible to create a dust filter having practically any desired output by arranging individual modules in line, in which connection each individual module is reliably transportable on the facilities available below ground, as pre-fabricated above ground. Stable support of the sides of the filter cloths is ensured by the lattice that consists of reciprocally cranked longitudinal and transverse wires. 10 figs.

  12. Sulfur in Cometary Dust

    Science.gov (United States)

    Fomenkova, M. N.

    1997-01-01

    The computer-intensive project consisted of the analysis and synthesis of existing data on composition of comet Halley dust particles. The main objective was to obtain a complete inventory of sulfur containing compounds in the comet Halley dust by building upon the existing classification of organic and inorganic compounds and applying a variety of statistical techniques for cluster and cross-correlational analyses. A student hired for this project wrote and tested the software to perform cluster analysis. The following tasks were carried out: (1) selecting the data from existing database for the proposed project; (2) finding access to a standard library of statistical routines for cluster analysis; (3) reformatting the data as necessary for input into the library routines; (4) performing cluster analysis and constructing hierarchical cluster trees using three methods to define the proximity of clusters; (5) presenting the output results in different formats to facilitate the interpretation of the obtained cluster trees; (6) selecting groups of data points common for all three trees as stable clusters. We have also considered the chemistry of sulfur in inorganic compounds.

  13. Erosion of dust aggregates

    CERN Document Server

    Seizinger, Alexander; Kley, Wilhelm

    2013-01-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple recipes to account for erosion effects. Methods: To study the erosion of dust aggregates we employed a molecular dynamics approach that features a detailed micro-physical model of the interaction of spherical grains. For the first time, the model has been extended by introducing a new visco-elastic damping force which requires a proper calibration. Afterwards, different sample generation methods were used to cover a wide range of aggregate types. Results: The visco-elastic damping force introduced in this work turns out to be crucial to reproduce results obtained from laboratory experiments. After proper calibration, we find that erosion occurs for impact velocities of 5 m/s and above. Though fractal aggregates as ...

  14. Utilization of ultrasonic atomization for dust control in underground mining

    Science.gov (United States)

    Okawa, Hirokazu; Nishi, Kentaro; Kawamura, Youhei; Kato, Takahiro; Sugawara, Katsuyasu

    2017-07-01

    This study examined dust suppression using water particles generated by ultrasonic atomization (2.4 MHz) at low temperature (10 °C). Green tuff (4 µm), green tuff (6 µm), kaolin, and silica were used as dust samples. Even though ultrasonic atomization makes fine water particles, raising relative air humidity immediately was difficult at low temperature. However, remaining water particles that did not change to water vapor contributed to suppression of dust dispersion. Additionally, the effect of water vapor amount (absolute humidity) and water particles generated by ultrasonic atomization on the amount of dust dispersion was investigated using experimental data at temperatures of 10, 20, and 30 °C. Utilization of ultrasound atomization at low temperature has the advantages of low humidity increments in the working space and water particles remaining stable even with low relative air humidity.

  15. Dance into the fire: dust survival inside supernova remnants

    Science.gov (United States)

    Micelotta, Elisabetta R.; Dwek, Eli; Slavin, Jonathan D.

    2016-06-01

    Core collapse supernovae (CCSNe) are important sources of interstellar dust, potentially capable of producing 1 M_{⊙}) of dust in their explosively expelled ejecta. However, unlike other dust sources, the dust has to survive the passage of the reverse shock, generated by the interaction of the supernova blast wave with its surrounding medium. Knowledge of the net amount of dust produced by CCSNe is crucial for understanding the origin and evolution of dust in the local and high-redshift universe. Our goal is to identify the dust destruction mechanisms in the ejecta, and derive the net amount of dust that survives the passage of the reverse shock. To do so, we have developed analytical models for the evolution of a supernova blast wave and of the reverse shock, and the simultaneous processing of the dust inside the cavity of the supernova remnant. We have applied our models to the special case of the clumpy ejecta of the remnant of Cassiopeia A (Cas A), assuming that the dust (silicates and carbon grains) resides in cool oxygen-rich ejecta clumps which are uniformly distributed within the remnant and surrounded by a hot X-ray emitting plasma (smooth ejecta). The passage of the reverse shock through the clumps gives rise to a relative gas-grain motion and also destroys the clumps. While residing in the ejecta clouds, dust is processed via kinetic sputtering, which is terminated either when the grains escape the clumps, or when the clumps are destroyed by the reverse shock. In either case, grain destruction proceeds thereafter by thermal sputtering in the hot shocked smooth ejecta. We find that 12 and 16 percent of silicate and carbon dust, respectively, survive the passage of the reverse shock by the time the shock has reached the center of the remnant. These fractions depend on the morphology of the ejecta and the medium into which the remnant is expanding, as well as the composition and size distribution of the grains that formed in the ejecta. Results will

  16. Uncertainty in modeling dust mass balance and radiative forcing from size parameterization

    Directory of Open Access Journals (Sweden)

    C. Zhao

    2013-07-01

    Full Text Available This study examines the uncertainties in simulating mass balance and radiative forcing of mineral dust due to biases in the dust size parameterization. Simulations are conducted quasi-globally (180° W–180° E and 60° S–70° N using the WRF-Chem model with three different approaches to represent dust size distribution (8-bin, 4-bin, and 3-mode. The biases in the 3-mode or 4-bin approaches against a relatively more accurate 8-bin approach in simulating dust mass balance and radiative forcing are identified. Compared to the 8-bin approach, the 4-bin approach simulates similar but coarser size distributions of dust particles in the atmosphere, while the 3-mode approach retains more fine dust particles but fewer coarse dust particles due to its prescribed σg of each mode. Although the 3-mode approach yields up to 10 days longer dust mass lifetime over the remote oceanic regions than the 8-bin approach, the three size approaches produce similar dust mass lifetime (3.2 days to 3.5 days on quasi-global average, reflecting that the global dust mass lifetime is mainly determined by the dust mass lifetime near the dust source regions. With the same global dust emission (∼6000 Tg yr-1, the 8-bin approach produces a dust mass loading of 39 Tg, while the 4-bin and 3-mode approaches produce 3% (40.2 Tg and 25% (49.1 Tg higher dust mass loading, respectively. The difference in dust mass loading between the 8-bin approach and the 4-bin or 3-mode approaches has large spatial variations, with generally smaller relative difference (-2 and atmospheric warming (0.39∼0.96 W m-2 and in a tremendous difference of a factor of ∼10 in dust TOA cooling (-0.24∼-2.20 W m-2. An uncertainty of a factor of 2 is quantified in dust emission estimation due to the different size parameterizations. This study also highlights the uncertainties in modeling dust mass and number loading, deposition fluxes, and radiative forcing resulting from different size

  17. Measurements of Martian dust devil winds with HiRISE

    Science.gov (United States)

    Choi, D.S.; Dundas, C.M.

    2011-01-01

    We report wind measurements within Martian dust devils observed in plan view from the High Resolution Imaging Science Experiment (HiRISE) orbiting Mars. The central color swath of the HiRISE instrument has three separate charge-coupled devices (CCDs) and color filters that observe the surface in rapid cadence. Active features, such as dust devils, appear in motion when observed by this region of the instrument. Our image animations reveal clear circulatory motion within dust devils that is separate from their translational motion across the Martian surface. Both manual and automated tracking of dust devil clouds reveal tangential winds that approach 20-30 m s -1 in some cases. These winds are sufficient to induce a ???1% decrease in atmospheric pressure within the dust devil core relative to ambient, facilitating dust lifting by reducing the threshold wind speed for particle elevation. Finally, radial velocity profiles constructed from our automated measurements test the Rankine vortex model for dust devil structure. Our profiles successfully reveal the solid body rotation component in the interior, but fail to conclusively illuminate the profile in the outer regions of the vortex. One profile provides evidence for a velocity decrease as a function of r -1/2, instead of r -1, suggestive of surface friction effects. However, other profiles do not support this observation, or do not contain enough measurements to produce meaningful insights. Copyright 2011 by the American Geophysical Union.

  18. Dust accretion and destruction in galaxy groups and clusters

    CERN Document Server

    McGee, Sean L

    2010-01-01

    We examine the dust distribution around a sample of 70,000 low redshift galaxy groups and clusters derived from the Sloan Digital Sky Survey. By correlating spectroscopically identified background quasars with the galaxy groups we obtain the relative colour excess due to dust reddening. We present a significant detection of dust out to a clustercentric distance of 30 Mpc/h in all four independent SDSS colours, consistent with the expectations of weak lensing masses of similar mass halos and excess galaxy counts. The wavelength dependence of this colour excess is consistent with the expectations of a Milky Way dust law with R_V=3.1. Further, we find that the halo mass dependence of the dust content is much smaller than would be expected by a simple scaling, implying that the dust-to-gas ratio of the most massive clusters (~10E14 Msun/h) is ~3% of the local ISM value, while in small groups (~10E12.7 Msun/h) it is ~55% of the local ISM value. We also find that the dust must have a covering fraction on the order ...

  19. Dust fallout in Kuwait city: deposition and characterization.

    Science.gov (United States)

    Al-Awadhi, Jasem M; Alshuaibi, Arafat A

    2013-09-01

    Dust fallouts in Kuwait city was monitored on monthly basis during the period from March 2011 to February 2012 at 10 locations. The results of this study reveal that: (1) monthly dust deposition rates ranged from 0.002 to 0.32 kg/m(2) with average deposition rate of 0.053 kg/m(2) and annual average deposition rate of 0.59 kg/m(2), ranking the first out of 56 dust deposition rates observed throughout the world; (2) on average, about 55.9% of the settled dust have fine to very fine sand fraction sizes, while silt and clay comprise an average of 37.4 and 1.4% of the total sample, respectively; (3) the concentrations for Zn and Mo out of 15 other elements analyzed from the dust were up to 11 times higher than their soil background values in Kuwait, while Pb and Ni were about seven times higher; (4) Mo, Ni, Pb and Zn show maximum enrichment relative to the upper continental crustal component (Mn); (5) Sr, Zr and Zn show highest concretions among all collected samples; and (6) quartz and calcite were the dominant minerals in the dust samples. The distribution of the heavy metals in dust seems to be controlled mainly by the land uses and the volume of traffic emissions.

  20. Results of evaluation of tailing dumps dust intensity

    Directory of Open Access Journals (Sweden)

    Masloboev V. A.

    2016-03-01

    Full Text Available A set of most acceptable and well-known methods of dust intensity evaluation has been defined and tested (dependence of Westphal D. L. et al. and DEAD scheme based on the analysis of exiting approaches (deserts, tailing dumps, etc.. The description of the chosen methods has been given. The determination of dynamic velocity u* and velocity at the height of +10 m above the dusting surface u10 which are necessary to evaluate the dust intensity has been demonstrated. The method is based on two-dimensional numerical model of atmosphere aerodynamics in the area of "tailing dumps of ANOF-2 ‒ the town of Apatity". The study provides calculations of horizontal velocity at the height of +10 m above the dusting surface at the wind speed varying from 5 to 23 m/sec. The work also suggests the results of graphical data processing related to tailing grain size distribution from the surface of the firmly established surface of the tailing dumps of ANOF-2. Comparative analysis has been given and the peculiarities of interval (based on grains sizes dust intensity of the tailing dumps of ANOF-2 have been shown using the dependence of Westphal D. L. et al. and DEAD scheme within the wind speed range. The received values of dust intensity at the lower range limit are close to the "maximum specific dust off" value which is used by project specialists for documentation development

  1. Satellite Observations of Desert Dust-induced Himalayan Snow Darkening

    Science.gov (United States)

    Gautam, Ritesh; Hsu, N. Christina; Lau, William K.-M.; Yasunari, Teppei J.

    2013-01-01

    The optically thick aerosol layer along the southern edge of the Himalaya has been subject of several recent investigations relating to its radiative impacts on the South Asian summer monsoon and regional climate forcing. Prior to the onset of summer monsoon, mineral dust from southwest Asian deserts is transported over the Himalayan foothills on an annual basis. Episodic dust plumes are also advected over the Himalaya, visible as dust-laden snow surface in satellite imagery, particularly in western Himalaya. We examined spectral surface reflectance retrieved from spaceborne MODIS observations that show characteristic reduction in the visible wavelengths (0.47 nm) over western Himalaya, associated with dust-induced solar absorption. Case studies as well as seasonal variations of reflectance indicate a significant gradient across the visible (0.47 nm) to near-infrared (0.86 nm) spectrum (VIS-NIR), during premonsoon period. Enhanced absorption at shorter visible wavelengths and the resulting VIS-NIR gradient is consistent with model calculations of snow reflectance with dust impurity. While the role of black carbon in snow cannot be ruled out, our satellite-based analysis suggests the observed spectral reflectance gradient dominated by dust-induced solar absorption during premonsoon season. From an observational viewpoint, this study underscores the importance of mineral dust deposition toward darkening of the western Himalayan snow cover, with potential implications to accelerated seasonal snowmelt and regional snow albedo feedbacks.

  2. Ground truth of (sub-)micrometre cometary dust – Results of MIDAS onboard Rosetta

    Science.gov (United States)

    Mannel, Thurid; Bentley, Mark; Schmied, Roland; Torkar, Klaus; Jeszenszky, Harald; Romsted, Jens; Levasseur-Regourd, A.; Weber, Iris; Jessberger, Elmar K.; Ehrenfreund, Pascale; Köberl, Christian; Havnes, Ove

    2016-10-01

    The investigation of comet 67P by Rosetta has allowed the comprehensive characterisation of pristine cometary dust particles ejected from the nucleus. Flying alongside the comet at distances as small as a few kilometres, and with a relative velocity of only centimetres per second, the Rosetta payload sampled almost unaltered dust. A key instrument to study this dust was MIDAS (the Micro-Imaging Dust Analysis System), a dedicated atomic force microscope that scanned the surfaces of hundreds of (sub-)micrometre sized particles in 3D with resolutions down to nanometres. This offers the unique opportunity to explore the morphology of smallest cometary dust and expand our current knowledge about cometary material.Here we give an overview of dust collected and analysed by MIDAS and highlight its most important features. These include the ubiquitous agglomerate nature of the dust, which is found at all size scales from the largest (>10 µm) through to the smallest (common cometary origin.

  3. Andromeda's dust

    Energy Technology Data Exchange (ETDEWEB)

    Draine, B. T.; Aniano, G. [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544-1001 (United States); Krause, Oliver; Groves, Brent; Sandstrom, Karin; Klaas, Ulrich; Linz, Hendrik; Rix, Hans-Walter; Schinnerer, Eva; Schmiedeke, Anika; Walter, Fabian [Max-Planck-Institut fur Astronomie, Konigstuhl 17, D-69117 Heidelberg (Germany); Braun, Robert [CSIRO—Astronomy and Space Science, P.O. Box 76, Epping, NWS 1710 (Australia); Leroy, Adam, E-mail: draine@astro.princeton.edu, E-mail: ganiano@ias.u-psud.fr [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)

    2014-01-10

    Spitzer Space Telescope and Herschel Space Observatory imaging of M31 is used, with a physical dust model, to construct maps of dust surface density, dust-to-gas ratio, starlight heating intensity, and polycyclic aromatic hydrocarbon (PAH) abundance, out to R ≈ 25 kpc. The global dust mass is M {sub d} = 5.4 × 10{sup 7} M {sub ☉}, the global dust/H mass ratio is M {sub d}/M {sub H} = 0.0081, and the global PAH abundance is (q {sub PAH}) = 0.039. The dust surface density has an inner ring at R = 5.6 kpc, a maximum at R = 11.2 kpc, and an outer ring at R ≈ 15.1 kpc. The dust/gas ratio varies from M {sub d}/M {sub H} ≈ 0.026 at the center to ∼0.0027 at R ≈ 25 kpc. From the dust/gas ratio, we estimate the interstellar medium metallicity to vary by a factor ∼10, from Z/Z {sub ☉} ≈ 3 at R = 0 to ∼0.3 at R = 25 kpc. The dust heating rate parameter (U) peaks at the center, with (U) ≈ 35, declining to (U) ≈ 0.25 at R = 20 kpc. Within the central kiloparsec, the starlight heating intensity inferred from the dust modeling is close to what is estimated from the stars in the bulge. The PAH abundance reaches a peak q {sub PAH} ≈ 0.045 at R ≈ 11.2 kpc. When allowance is made for the different spectrum of the bulge stars, q {sub PAH} for the dust in the central kiloparsec is similar to the overall value of q {sub PAH} in the disk. The silicate-graphite-PAH dust model used here is generally able to reproduce the observed dust spectral energy distribution across M31, but overpredicts 500 μm emission at R ≈ 2-6 kpc, suggesting that at R = 2-6 kpc, the dust opacity varies more steeply with frequency (with β ≈ 2.3 between 200 and 600 μm) than in the model.

  4. Dust and the Sick Building Syndrome

    DEFF Research Database (Denmark)

    Gyntelberg, Finn; Suadicani, Poul; Wohlfahrt Nielsen, Jan

    1994-01-01

    Farmakologi, bacteria, dust, histamine, disease, gram-negative, indoor climate, sick building syndrome......Farmakologi, bacteria, dust, histamine, disease, gram-negative, indoor climate, sick building syndrome...

  5. PERSPECTIVE: Dust, fertilization and sources

    Science.gov (United States)

    Remer, Lorraine A.

    2006-11-01

    Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory (http://earthobservatory.nasa.gov). Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the

  6. Atmospheric processing of iron carried by mineral dust

    OpenAIRE

    S. Nickovic; A. Vukovic; M. Vujadinovic

    2013-01-01

    Nutrification of the open ocean originates mainly from deposited aerosol in which the bio-avaliable iron is likely to be an important factor. The relatively insoluble iron in dust from arid soils becomes more soluble after atmospheric processing and, through its deposition in the ocean, could contribute to marine primary production. To numerically simulate the atmospheric route of iron from desert sources to sinks in the ocean, we developed a regional atmospheric dust-iron model that included...

  7. Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa

    KAUST Repository

    Khan, Basit Ali

    2015-11-27

    Dust particles mixed in the free troposphere have longer lifetimes than airborne particles near the surface. Their cumulative radiative impact on earth’s meteorological processes and climate might be significant despite their relatively small contribution to total dust abundance. One example is the elevated dust-laden Saharan Air Layer (SAL) over the tropical and subtropical North Atlantic, which cools the sea surface. To understand the formation mechanisms of a dust layer in the free troposphere, this study combines model simulations and dust observations collected during the first stage of the Saharan Mineral Dust Experiment (SAMUM-I), which sampled dust events that extended from Morocco to Portugal, and investigated the spatial distribution and the microphysical, optical, chemical, and radiative properties of Saharan mineral dust. The Weather Research Forecast model coupled with the Chemistry/Aerosol module (WRF-Chem) is employed to reproduce the meteorological environment and spatial and size distributions of dust. The model domain covers northwest Africa and adjacent water with 5 km horizontal grid spacing and 51 vertical layers. The experiments were run from 20 May to 9 June 2006, covering the period of the most intensive dust outbreaks. Comparisons of model results with available airborne and ground-based observations show that WRF-Chem reproduces observed meteorological fields as well as aerosol distribution across the entire region and along the airplane’s tracks. Several mechanisms that cause aerosol entrainment into the free troposphere are evaluated and it is found that orographic lifting, and interaction of sea breeze with the continental outflow are key mechanisms that form a surface-detached aerosol plume over the ocean. The model dust emission scheme is tuned to simultaneously fit the observed total optical depth and the ratio of aerosol optical depths generated by fine and coarse dust modes. Comparisons of simulated dust size distributions with

  8. Dust-acoustic waves and stability in the permeating dust plasma: II. Power-law distributions

    CERN Document Server

    Gong, Jingyu; Du, Jiulin

    2012-01-01

    The dust-acoustic waves and their stability driven by a flowing dust plasma when it cross through a static (target) dust plasma (the so-called permeating dust plasma) are investigated when the components of the dust plasma obey the power-law q-distributions in nonextensive statistics. The frequency, the growth rate and the stability condition of the dust-acoustic waves are derived under this physical situation, which express the effects of the nonextensivity as well as the flowing dust plasma velocity on the dust-acoustic waves in this dust plasma. The numerical results illustrate some new characteristics of the dust-acoustic waves, which are different from those in the permeating dust plasma when the plasma components are the Maxwellian distribution. In addition, we show that the flowing dust plasma velocity has a significant effect on the dust-acoustic waves in the permeating dust plasma with the power-law q-distribution.

  9. Dust Composition in Climate Models: Current Status and Prospects

    Science.gov (United States)

    Pérez García-Pando, C.; Miller, R. L.; Perlwitz, J. P.; Kok, J. F.; Scanza, R.; Mahowald, N. M.

    2015-12-01

    Mineral dust created by wind erosion of soil particles is the dominant aerosol by mass in the atmosphere. It exerts significant effects on radiative fluxes, clouds, ocean biogeochemistry, and human health. Models that predict the lifecycle of mineral dust aerosols generally assume a globally uniform mineral composition. However, this simplification limits our understanding of the role of dust in the Earth system, since the effects of dust strongly depend on the particles' physical and chemical properties, which vary with their mineral composition. Hence, not only a detailed understanding of the processes determining the dust emission flux is needed, but also information about its size dependent mineral composition. Determining the mineral composition of dust aerosols is complicated. The largest uncertainty derives from the current atlases of soil mineral composition. These atlases provide global estimates of soil mineral fractions, but they are based upon massive extrapolation of a limited number of soil samples assuming that mineral composition is related to soil type. This disregards the potentially large variability of soil properties within each defined soil type. In addition, the analysis of these soil samples is based on wet sieving, a technique that breaks the aggregates found in the undisturbed parent soil. During wind erosion, these aggregates are subject to partial fragmentation, which generates differences on the size distribution and composition between the undisturbed parent soil and the emitted dust aerosols. We review recent progress on the representation of the mineral and chemical composition of dust in climate models. We discuss extensions of brittle fragmentation theory to prescribe the emitted size-resolved dust composition, and we identify key processes and uncertainties based upon model simulations and an unprecedented compilation of observations.

  10. Increase in African dust flux at the onset of commercial agriculture in the Sahel region.

    Science.gov (United States)

    Mulitza, Stefan; Heslop, David; Pittauerova, Daniela; Fischer, Helmut W; Meyer, Inka; Stuut, Jan-Berend; Zabel, Matthias; Mollenhauer, Gesine; Collins, James A; Kuhnert, Henning; Schulz, Michael

    2010-07-01

    The Sahara Desert is the largest source of mineral dust in the world. Emissions of African dust increased sharply in the early 1970s (ref. 2), a change that has been attributed mainly to drought in the Sahara/Sahel region caused by changes in the global distribution of sea surface temperature. The human contribution to land degradation and dust mobilization in this region remains poorly understood, owing to the paucity of data that would allow the identification of long-term trends in desertification. Direct measurements of airborne African dust concentrations only became available in the mid-1960s from a station on Barbados and subsequently from satellite imagery since the late 1970s: they do not cover the onset of commercial agriculture in the Sahel region approximately 170 years ago. Here we construct a 3,200-year record of dust deposition off northwest Africa by investigating the chemistry and grain-size distribution of terrigenous sediments deposited at a marine site located directly under the West African dust plume. With the help of our dust record and a proxy record for West African precipitation we find that, on the century scale, dust deposition is related to precipitation in tropical West Africa until the seventeenth century. At the beginning of the nineteenth century, a sharp increase in dust deposition parallels the advent of commercial agriculture in the Sahel region. Our findings suggest that human-induced dust emissions from the Sahel region have contributed to the atmospheric dust load for about 200 years.

  11. Modeling of atmospheric iron processing carried by mineral dust and its deposition to ocean

    Science.gov (United States)

    Nickovic, Slobodan; Vukovic, Ana; Vujadinovic, Mirjam

    2014-05-01

    Relatively insoluble iron in dust originating from desert soils increases its solubility after Fe carried by mineral dust is chemically processed by the atmosphere. After dust is deposited deposition to the ocean, soluble Fe as a nutrient could enhance the marine primary production. The atmospheric dust cycle is driven by the atmospheric processes often of smaller, meso-scales. The soil mineralogy of dust emitted from sources determines also how much Fe in the aerosol will be finding. Once Fe is exposed to the atmospheric processes, the atmospheric radiation, clouds and polluted air will chemically affect the iron in dust. Global dust-iron models, having typical horizontal resolutions of 100-300 km which are mostly used to numerically simulate the fate of iron in the atmosphere can provide rather global picture of the dust and iron transport, but not details. Such models often introduce simplistic approximation on the Fe content in dust-productive soils. To simulate the Fe processing we instead implemented a high resolution regional atmospheric dust-iron model with detailed 1km global map for the geographic distribution of Fe content in soil. We also introduced a parameterization of the Fe processing caused by dust mineralogy, cloud processes and solar radiation. We will present results from simulation experiments in order to explore the model capability to reproduce major observed patterns of deposited Fe into the Atlantic cruises.

  12. Dust acoustic solitary and shock excitations in a Thomas-Fermi magnetoplasma

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Z.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Ali, S. [National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)

    2014-07-15

    The linear and nonlinear properties of dust-acoustic waves are investigated in a collisionless Thomas-Fermi magnetoplasma, whose constituents are electrons, ions, and negatively charged dust particles. At dust time scale, the electron and ion number densities follow the Thomas-Fermi distribution, whereas the dust component is described by the classical fluid equations. A linear dispersion relation is analyzed to show that the wave frequencies associated with the upper and lower modes are enhanced with the variation of dust concentration. The effect of the latter is seen more strongly on the upper mode as compared to the lower mode. For nonlinear analysis, we obtain magnetized Korteweg-de Vries (KdV) and Zakharov-Kuznetsov (ZK) equations involving the dust-acoustic solitary waves in the framework of reductive perturbation technique. Furthermore, the shock wave excitations are also studied by allowing dissipation effects in the model, leading to the Korteweg-de Vries-Burgers (KdVB) and ZKB equations. The analysis reveals that the dust-acoustic solitary and shock excitations in a Thomas-Fermi plasma are strongly influenced by the plasma parameters, e.g., dust concentration, dust temperature, obliqueness, magnetic field strength, and dust fluid viscosity. The present results should be important for understanding the solitary and shock excitations in the environments of white dwarfs or supernova, where dust particles can exist.

  13. Saharan dust deposition in the Carpathian Basin and its possible effects on interglacial soil formation

    Science.gov (United States)

    Varga, György; Cserháti, Csaba; Kovács, János; Szalai, Zoltán

    2016-09-01

    Several hundred tons of windblown dust material are lifted into the atmosphere and are transported every year from Saharan dust source areas towards Europe having an important climatic and other environmental effect also on distant areas. According to the systematic observations of modern Saharan dust events, it can be stated that dust deflated from North African source areas is a significant constituent of the atmosphere of the Carpathian Basin and Saharan dust deposition events are identifiable several times in a year. Dust episodes are connected to distinct meteorological situations, which are also the determining factors of the different kinds of depositional mechanisms. By using the adjusted values of dust deposition simulations of numerical models, the annual Saharan dust flux can be set into the range of 3.2-5.4 g/m2/y. Based on the results of past mass accumulation rates calculated from stratigraphic and sedimentary data of loess-paleosol sequences, the relative contribution of Saharan dust to interglacial paleosol material was quantified. According to these calculations, North African exotic dust material can represent 20-30% of clay and fine silt-sized soil components of interglacial paleosols in the Carpathian Basin. The syngenetic contribution of external aeolian dust material is capable to modify physicochemical properties of soils and hereby the paleoclimatic interpretation of these pedogene stratigraphic units.

  14. Saharan dust, climate variability, and asthma in Grenada, the Caribbean

    Science.gov (United States)

    Akpinar-Elci, Muge; Martin, Francis E.; Behr, Joshua G.; Diaz, Rafael

    2015-11-01

    Saharan dust is transported across the Atlantic and interacts with the Caribbean seasonal climatic conditions, becoming respirable and contributing to asthma presentments at the emergency department. This study investigated the relationships among dust, climatic variables, and asthma-related visits to the emergency room in Grenada. All asthma visits to the emergency room ( n = 4411) over 5 years (2001-2005) were compared to the dust cover and climatic variables for the corresponding period. Variation in asthma was associated with change in dust concentration ( R 2 = 0.036, p cultures, population sizes, industrialization level, and economies. Therefore, different than from the studies in Trinidad and Barbados, Grenada is a non-industrialized low-income small island without major industrialized air pollution addition; asthma visits were inversely related to mean sea level pressure ( R 2 = 0.123, p = 0.006) and positively correlated with relative humidity ( R 2 = 0.593, p = 0.85). Saharan dust in conjunction with seasonal humidity allows for inhalable particulate matter that exacerbates asthma among residents in the Caribbean island of Grenada. These findings contribute evidence suggesting a broader public health impact from Saharan dust. Thus, this research may inform strategic planning of resource allocation among the Caribbean public health agencies.

  15. Coal mine dust as a benchmark for standards for other poorly soluble dusts. Partial Position Report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Cowie, H.A.; Soutar, C.A. [Institute of Occupational Medicine, Edinburgh (United Kingdom)

    2006-08-15

    An extensive programme of research provides the legacy of an atypically comprehensive database on the respiratory health and exposure experienced by thousands of coalminers, collected at intervals during their working life. The development of generic standards for poorly soluble dusts would be greatly aided if health risks quantified for coal dust were a good surrogate for those of other low toxicity dusts. The authors compared the published effects of low toxicity mineral dust exposures on lung function (FEV1) in four occupational groups (talc workers, coal miners, PVC workers and heavy clay workers), with some additional investigation of respiratory symptoms, standardising units and refitting comparable regression models where necessary. Coalminers and talc workers had similar exposure levels on average. PVC workers had lower average exposure levels, but this may have been due, at least in part, to an underestimation of cumulative dust exposure in this population. Coalminers showed a decline of 0.19 standardised units of FEV1 for each 100 units increase in dust exposure, 0.26 standardised units in talc workers and 0.66 units in PVC workers. Relative risks of reporting symptoms were very similar for coalminers and heavy clay workers, but could not be calculated for talc or PVC workers. Allowing for possible underestimation of the PVC exposures, these risks of respiratory ill health were clearly of the same orders of magnitude in the occupations studied. Further more detailed cross- sectional or longitudinal analyses on the coalminers' data sets are thus likely to be informative about risks of dusty exposures in other industries. 11 refs., 4 tabs.

  16. Climatic controls on the interannual to decadal variability in Saudi Arabian dust activity: Toward the development of a seasonal dust prediction model

    Science.gov (United States)

    Yu, Yan; Notaro, Michael; Liu, Zhengyu; Wang, Fuyao; Alkolibi, Fahad; Fadda, Eyad; Bakhrjy, Fawzieh

    2015-03-01

    The observed climatic controls on springtime and summertime Saudi Arabian dust activities during 1975-2012 are analyzed, leading to development of a seasonal dust prediction model. According to empirical orthogonal function analysis, dust storm frequency exhibits a dominantly homogeneous pattern across Saudi Arabia, with distinct interannual and decadal variability. The previously identified positive trend in remotely sensed aerosol optical depth since 2000 is shown to be a segment of the decadal oscillation in dust activity, according to long-duration station record. Regression and correlation analyses reveal that the interannual variability in Saudi Arabian dust storm frequency is regulated by springtime rainfall across the Arabian Peninsula and summertime Shamal wind intensity. The key drivers of Saudi Arabian dust storm variability are identified. Winter-to-spring La Niña enhances subsequent spring dust activity by decreasing rainfall across the country's primary dust source region, the Rub' al Khali Desert. A relatively cool tropical Indian Ocean favors frequent summer dust storms by producing an anomalously anticyclonic circulation over the central Arabian Peninsula, which enhances the Shamal wind. Decadal variability in Saudi Arabian dust storm frequency is associated with North African rainfall and Sahel vegetation, which regulate African dust emissions and transport to Saudi Arabia. Mediterranean sea surface temperatures (SSTs) also regulate decadal dust variability, likely through their influence on Sahel rainfall and Shamal intensity. Using antecedent-accumulated rainfall over the Arabian Peninsula and North Africa, and Mediterranean SSTs, as low-frequency predictors, and tropical eastern Pacific and tropical Indian Ocean SSTs as high-frequency predictors, Saudi Arabia's seasonal dust activity is well predicted.

  17. Emphysema and dust exposure in a group of coal workers

    Energy Technology Data Exchange (ETDEWEB)

    Ruckley, V.A.; Gauld, S.J.; Chapman, J.S.; Davis, J.M.; Douglas, A.N.; Fernie, J.M.; Jacobsen, M.; Lamb, D.

    1984-04-01

    The lungs of 450 coal miners who had been studied previously in a long-term epidemiologic project at 24 British mines have been examined post-mortem for signs of dust-related fibrosis and emphysema. Reliable estimates of cumulative (working-life) exposures to respirable mine dust were available for 342 of the men. The relative frequency of emphysema increased with age at death, and both panacinar and centriacinar emphysema occurred more frequently in smokers than in nonsmokers. The proportion of subjects with any emphysema was 47% in 92 men with no palpable dust lesions, 65% in 183 with small, simple pneumoconiotic lesions, and 83% in 175 miners with massive fibrosis (PMF). The chance of finding centriacinar emphysema in those with PMF increased significantly with increasing exposure to coal dust in life (p less than 0.025). A similar but less convincing relationship was found in those with simple pneumoconiosis (p less than 0.11), but in both groups, increasing amounts of ash with a given exposure to coal reduced the probability of finding centriacinar emphysema. The occurrence of centriacinar emphysema was associated also with increasing amounts of dust retained in the lungs. A preliminary exploration of this association did not support the hypothesis that emphysematous lungs clear dust less efficiently. We conclude that the association observed between exposure to respirable coal dust and emphysema in coal miners indicates a causal relationship. However, because it can be demonstrated only for men whose lungs show some dust-related fibrosis, it is suggested that the extent and nature of such fibrosis may be a crucial factor in determining the presence of centriacinar emphysema.

  18. Intraseasonal variability and atmospheric controls on daily dust occurrence frequency over the central and western Sahara during the boreal summer

    Science.gov (United States)

    Ashpole, Ian; Washington, Richard

    2013-12-01

    classify satellite-derived maps of daily dust occurrence frequency over the central and western Sahara (CWS) during the boreal summer in order to identify typical patterns using the neural network based system of self-organized maps. Resulting dust states vary in terms of the frequency of dust occurrence and its location. The most commonly occurring dust states are those of relatively low dust detection frequency. On days with relatively high dust occurrence, dust tends to favor either a location close to the Algeria-Mali-Niger border triple point (TP) or further to the northwest across the western half of the Mali-Algeria border (MAB). States in which dust is detected at both locations simultaneously are rare. There is a distinct intraseasonal progression in preferred dust location from the TP in the early season to the MAB later in the season. The evolution of dust states reveals a one-way transition from dust at the TP to dust at the MAB and then to reduced daily dust occurrence frequency. There is a distinct degree of interannual variability in the occurrence frequency of the different states, dominated by the extremes of high and low dust detection frequency. Analysis of climatological composites demonstrates that monsoon surges into the Saharan heat low are associated with days of high dust detection frequency, while a strong Harmattan into the CWS is linked to days with less frequent dust presence. The CWS atmospheric dust budget for June-August is thus strongly linked to the dynamics of the West African monsoon.

  19. Dust-to-metal ratios in damped Lyman-α absorbers. Fresh clues to the origins of dust and optical extinction towards γ-ray bursts

    Science.gov (United States)

    De Cia, A.; Ledoux, C.; Savaglio, S.; Schady, P.; Vreeswijk, P. M.

    2013-12-01

    Motivated by the anomalous dust-to-metal ratios derived in the literature for γ-ray burst (GRB) damped Lyman-α absorbers (DLAs), we measure these ratios using the dust-depletion pattern observed in UV/optical afterglow spectra associated with the interstellar medium (ISM) at the GRB host-galaxy redshifts. Our sample consists of 20 GRB absorbers and a comparison sample of 72 DLAs toward quasars (QSOs) with redshift 1.2 extinction AV increases steeply with the column density of iron in dust, N(Fe)dust, calculated from relative metal abundances, confirming that dust extinction is mostly occurring in the host galaxy ISM. Most GRB-DLAs display log N(Fe)dust > 14.7, above which several QSO-DLAs reveal molecular hydrogen, making GRB-DLAs promising candidates for molecular detection and study.

  20. Dust ablation in Pluto's atmosphere

    Science.gov (United States)

    Horanyi, Mihaly; Poppe, Andrew; Sternovsky, Zoltan

    2016-04-01

    Based on measurements by dust detectors onboard the Pioneer 10/11 and New Horizons spacecraft the total production rate of dust particles born in the Edgeworth Kuiper Belt (EKB) has been be estimated to be on the order of 5 ṡ 103 kg/s in the approximate size range of 1 - 10 μm. Dust particles are produced by collisions between EKB objects and their bombardment by both interplanetary and interstellar dust particles. Dust particles of EKB origin, in general, migrate towards the Sun due to Poynting-Robertson drag but their distributions are further sculpted by mean-motion resonances as they first approach the orbit of Neptune and later the other planets, as well as mutual collisions. Subsequently, Jupiter will eject the vast majority of them before they reach the inner solar system. The expected mass influx into Pluto atmosphere is on the order of 200 kg/day, and the arrival speed of the incoming particles is on the order of 3 - 4 km/s. We have followed the ablation history as function of speed and size of dust particles in Pluto's atmosphere, and found that volatile rich particles can fully sublimate due to drag heating and deposit their mass in narrow layers. This deposition might promote the formation of the haze layers observed by the New Horizons spacecraft. This talk will explore the constraints on the composition of the dust particles by comparing the altitude of the deposition layers to the observed haze layers.

  1. Evolution of dust and molecular hydrogen in the Magellanic System

    CERN Document Server

    Yozin, Cameron

    2014-01-01

    We investigate the evolution of the interstellar medium (ISM) in self-consistent, chemodynamical simulations of the Magellanic Clouds (MCs) during their recent (z<0.3) past. An explicit modelling of dust and molecular hydrogen lifecycles enables the comparison of our models against the observed properties of the ISM, including elemental depletion from the gas-phase. Combining this model with a tidal-dominated paradigm for the formation for the Magellanic Stream and Bridge, we reproduce the age-metallicity relations, long gas depletion timescales, and presently observed dust and molecular hydrogen masses of the MCs to within their respective uncertainties. We find that these models' enrichment depends sensitively on the processing of dust within the ISM and the dynamical influence of external tides/stellar bars. The ratio of characteristic dust destruction timescales in our SMC and LMC models, a governing parameter of our models' evolution, is consistent with estimates based on observed supernova (SN) rates...

  2. The changing role of dust in biogeochemical cycling

    Science.gov (United States)

    Neff, J. C.; Reynolds, R. L.; Farmer, G. L.; Reheis, M.

    2007-12-01

    Dust emission and deposition have the potential to deplete and enrich ecosystems of mineral resources essential to life. In many parts of the world, and particularly in semi-arid settings, wind erosion of soils and the subsequent long-distance transport and deposition of mineral aerosols play a basic role in soil composition and processes, including the production of essential plant nutrients through weathering. Although the long-term role of dust in the development of soils is reasonably well understood, the effects of recent dust emission and deposition on ecosystems are not. Recent work on ecosystems around the world has highlighted the fundamental importance of contemporary wind erosion and dust deposition in biogeochemical cycling. In the western U.S., studies of Sr and Nd isotopes, elemental concentrations, and magnetic properties elucidate the role of dust in recent soil development and soil loss by wind erosion related to land-use change. In the arid landscapes in and around Canyonlands National Park (Utah), these techniques provide insight into the development of soils in stable settings where human activities have been minimal but the loss of soil in areas affected by grazing and recreational activities. In stable settings of the central Colorado Plateau (Utah), dust deposition is responsible for a large proportion (as much as 20 percent) of surface soil mass and elemental content. In contrast, wind erosion is responsible for large losses of nutrients and surface soil of nearby, closely similar geomorphic settings disturbed by human activity. In the San Juan Mountains (Colorado) downwind of the Colorado Plateau, Nd and Sr isotopes in dust and lake sediments provide evidence for large increases in dust deposition during the 19th and 20th century compared to records from the middle to late Holocene. The recent enhancement in dust deposition is also responsible for increased loading of many elements, including essential nutrients that may influence

  3. The cosmic dust analyser onboard cassini: ten years of discoveries

    Science.gov (United States)

    Srama, R.; Kempf, S.; Moragas-Klostermeyer, G.; Altobelli, N.; Auer, S.; Beckmann, U.; Bugiel, S.; Burton, M.; Economomou, T.; Fechtig, H.; Fiege, K.; Green, S. F.; Grande, M.; Havnes, O.; Hillier, J. K.; Helfert, S.; Horanyi, M.; Hsu, S.; Igenbergs, E.; Jessberger, E. K.; Johnson, T. V.; Khalisi, E.; Krüger, H.; Matt, G.; Mocker, A.; Lamy, P.; Linkert, G.; Lura, F.; Möhlmann, D.; Morfill, G. E.; Otto, K.; Postberg, F.; Roy, M.; Schmidt, J.; Schwehm, G. H.; Spahn, F.; Sterken, V.; Svestka, J.; Tschernjawski, V.; Grün, E.; Röser, H.-P.

    2011-12-01

    The interplanetary space probe Cassini/Huygens reached Saturn in July 2004 after 7 years of cruise phase. The German cosmic dust analyser (CDA) was developed under the leadership of the Max Planck Institute for Nuclear Physics in Heidelberg under the support of the DLR e.V. This instrument measures the interplanetary, interstellar and planetary dust in our solar system since 1999 and provided unique discoveries. In 1999, CDA detected interstellar dust in the inner solar system followed by the detection of electrical charges of interplanetary dust grains during the cruise phase between Earth and Jupiter. The instrument determined the composition of interplanetary dust and the nanometre-sized dust streams originating from Jupiter's moon Io. During the approach to Saturn in 2004, similar streams of submicron grains with speeds in the order of 100 km/s were detected from Saturn's inner and outer ring system and are released to the interplanetary magnetic field. Since 2004 CDA measured more than one million dust impacts characterising the dust environment of Saturn. The instrument is one of the three experiments which discovered the active ice geysers located at the south pole of Saturn's moon Enceladus in 2005. Later, a detailed compositional analysis of the water ice grains in Saturn's E ring system led to the discovery of large reservoirs of liquid water (oceans) below the icy crust of Enceladus. Finally, the determination of the dust-magnetosphere interaction and the discovery of the extended E ring (at least twice as large as predicted) allowed the definition of a dynamical dust model of Saturn's E ring describing the observed properties. This paper summarizes the discoveries of a 10-year story of success based on reliable measurements with the most advanced dust detector flown in space until today. This paper focuses on cruise results and findings achieved at Saturn with a focus on flux and density measurements. CDA discoveries related to the detailed dust stream

  4. Dust tracking techniques applied to the STARDUST facility: First results

    Energy Technology Data Exchange (ETDEWEB)

    Malizia, A., E-mail: malizia@ing.uniroma2.it [Associazione EURATOM-ENEA, Department of Industrial Engineering, University of Rome “Tor Vergata”, Via del Politecnico 1, 00133 Rome (Italy); Camplani, M. [Grupo de Tratamiento de Imágenes, E.T.S.I de Telecomunicación, Universidad Politécnica de Madrid (Spain); Gelfusa, M. [Associazione EURATOM-ENEA, Department of Industrial Engineering, University of Rome “Tor Vergata”, Via del Politecnico 1, 00133 Rome (Italy); Lupelli, I. [Associazione EURATOM-ENEA, Department of Industrial Engineering, University of Rome “Tor Vergata”, Via del Politecnico 1, 00133 Rome (Italy); EURATOM/CCFE Association, Culham Science Centre, Abingdon (United Kingdom); Richetta, M.; Antonelli, L.; Conetta, F.; Scarpellini, D.; Carestia, M.; Peluso, E.; Bellecci, C. [Associazione EURATOM-ENEA, Department of Industrial Engineering, University of Rome “Tor Vergata”, Via del Politecnico 1, 00133 Rome (Italy); Salgado, L. [Grupo de Tratamiento de Imágenes, E.T.S.I de Telecomunicación, Universidad Politécnica de Madrid (Spain); Video Processing and Understanding Laboratory, Universidad Autónoma de Madrid (Spain); Gaudio, P. [Associazione EURATOM-ENEA, Department of Industrial Engineering, University of Rome “Tor Vergata”, Via del Politecnico 1, 00133 Rome (Italy)

    2014-10-15

    Highlights: •Use of an experimental facility, STARDUST, to analyze the dust resuspension problem inside the tokamak in case of loss of vacuum accident. •PIV technique implementation to track the dust during a LOVA reproduction inside STARDUST. •Data imaging techniques to analyze dust velocity field: first results and data discussion. -- Abstract: An important issue related to future nuclear fusion reactors fueled with deuterium and tritium is the creation of large amounts of dust due to several mechanisms (disruptions, ELMs and VDEs). The dust size expected in nuclear fusion experiments (such as ITER) is in the order of microns (between 0.1 and 1000 μm). Almost the total amount of this dust remains in the vacuum vessel (VV). This radiological dust can re-suspend in case of LOVA (loss of vacuum accident) and these phenomena can cause explosions and serious damages to the health of the operators and to the integrity of the device. The authors have developed a facility, STARDUST, in order to reproduce the thermo fluid-dynamic conditions comparable to those expected inside the VV of the next generation of experiments such as ITER in case of LOVA. The dust used inside the STARDUST facility presents particle sizes and physical characteristics comparable with those that created inside the VV of nuclear fusion experiments. In this facility an experimental campaign has been conducted with the purpose of tracking the dust re-suspended at low pressurization rates (comparable to those expected in case of LOVA in ITER and suggested by the General Safety and Security Report ITER-GSSR) using a fast camera with a frame rate from 1000 to 10,000 images per second. The velocity fields of the mobilized dust are derived from the imaging of a two-dimensional slice of the flow illuminated by optically adapted laser beam. The aim of this work is to demonstrate the possibility of dust tracking by means of image processing with the objective of determining the velocity field values

  5. Full-sky, High-resolution Maps of Interstellar Dust

    Science.gov (United States)

    Meisner, Aaron Michael

    We present full-sky, high-resolution maps of interstellar dust based on data from the Wide-field Infrared Survey Explorer (WISE) and Planck missions. We describe our custom processing of the entire WISE 12 micron All-Sky imaging data set, and present the resulting 15 arcsecond resolution, full-sky map of diffuse Galactic dust emission, free of compact sources and other contaminating artifacts. Our derived 12 micron dust map offers angular resolution far superior to that of all other existing full-sky, infrared dust emission maps, revealing a wealth of small-scale filamentary structure. We also apply the Finkbeiner et al. (1999) two-component thermal dust emission model to the Planck HFI maps. We derive full-sky 6.1 arcminute resolution maps of dust optical depth and temperature by fitting this two-component model to Planck 217-857 GHz along with DIRBE/IRAS 100 micron data. In doing so, we obtain the first ever full-sky 100-3000 GHz Planck-based thermal dust emission model, as well as a dust temperature correction with ~10 times enhanced angular resolution relative to DIRBE-based temperature maps. Analyzing the joint Planck/DIRBE dust spectrum, we show that two-component models provide a better fit to the 100-3000 GHz emission than do single-MBB models, though by a lesser margin than found by Finkbeiner et al. (1999) based on FIRAS and DIRBE. We find that, in diffuse sky regions, our two-component 100-217 GHz predictions are on average accurate to within 2.2%, while extrapolating the Planck Collaboration (2013) single-MBB model systematically underpredicts emission by 18.8% at 100 GHz, 12.6% at 143 GHz and 7.9% at 217 GHz. We calibrate our two-component optical depth to reddening, and compare with reddening estimates based on stellar spectra. We find the dominant systematic problems in our temperature/reddening maps to be zodiacal light on large angular scales and the cosmic infrared background anisotropy on small angular scales. Future work will focus on combining

  6. The climatology of dust aerosol over the arabian peninsula

    Directory of Open Access Journals (Sweden)

    A. Shalaby

    2015-01-01

    Full Text Available Dust storms are considered to be a natural hazard over the Arabian Peninsula, since they occur all year round with maximum intensity and frequency in Spring and Summer. The Regional Climate Model version 4 (RegCM4 has been used to study the climatology of atmospheric dust over the Arabian Peninsula from 1999 to 2012. This relatively long simulation period samples the meteorological conditions that determine the climatology of mineral dust aerosols over the Arabian Peninsula. The modeled Aerosol Optical Depth (AOD has been compared against ground-based observations of three Aerosol Robotic Network (AERONET stations that are distributed over the Arabian Peninsula and daily space based observations from the Multi-angle Imaging SpectroRadiometer (MISR, the Moderate resolution Imaging SpectroRadimeter (MODIS and Ozone Monitoring Instrument (OMI. The large scale atmospheric circulation and the land surface response that lead to dust uplifting have been analyzed. While the modeled AOD shows that the dust season extends from March to August with two pronounced maxima, one over the northern Arabian Peninsula in March with AOD equal to 0.4 and one over the southern Arabian Peninsula in July with AOD equal to 0.7, the observations show that the dust season extends from April to August with two pronounced maxima, one over the northern Arabian Peninsula in April with AOD equal to 0.5 and one over the southern Arabian Peninsula in July with AOD equal to 0.5. In spring a high pressure dominates the Arabian Peninsula and is responsible for advecting dust from southern and western part of the Arabian Peninsula to northern and eastern part of the Peninsula. Also, fast developed cyclones in northern Arabian Peninsula are responsible for producing strong dust storms over Iraq and Kuwait. However, in summer the main driver of the surface dust emission is the strong northerly wind ("Shamal" that transport dust from the northern Arabian Peninsula toward south parallel

  7. Lunar Dust Mitigation Technology Development

    Science.gov (United States)

    Hyatt, Mark J.; Deluane, Paul B.

    2008-01-01

    NASA s plans for implementing the Vision for Space Exploration include returning to the moon as a stepping stone for further exploration of Mars, and beyond. Dust on the lunar surface has a ubiquitous presence which must be explicitly addressed during upcoming human lunar exploration missions. While the operational challenges attributable to dust during the Apollo missions did not prove critical, the comparatively long duration of impending missions presents a different challenge. Near term plans to revisit the moon places a primary emphasis on characterization and mitigation of lunar dust. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it s potentially harmful effects on exploration systems. This paper presents the current perspective and implementation of dust knowledge management and integration, and mitigation technology development activities within NASA s Exploration Technology Development Program. This work is presented within the context of the Constellation Program s Integrated Lunar Dust Management Strategy. The Lunar Dust Mitigation Technology Development project has been implemented within the ETDP. Project scope and plans will be presented, along with a a perspective on lessons learned from Apollo and forensics engineering studies of Apollo hardware. This paper further outlines the scientific basis for lunar dust behavior, it s characteristics and potential effects, and surveys several potential strategies for its control and mitigation both for lunar surface operations and within the working volumes of a lunar outpost.

  8. Fight against noise and dusts emissions

    Energy Technology Data Exchange (ETDEWEB)

    Babel, M.

    1996-06-01

    Quarries and most of the industrial mineral transformation plants belong to the French nomenclature of classified installations for environment protection (rubrics 2510 to 2542). According to their impact on the environment, these installations are subjected to the declaration procedures or authorizations from the July 19, 1976 law, which stipulates the use of adequate procedures to ensure the protection of environment especially against dusts and noise emissions in the neighborhood. The extractive industries (mines and quarries) belong to a different legal and workers protection regime, but its finality is similar. This paper describes the general rules of both legal frames and more particularly the legal aspects relative to healthiness and dusts and noise nuisances in the extractive industries. (J.S.). 1 tab.

  9. Comprometimento órbito-craniano por tumores malignos sinonasais: estudo por tomografia computadorizada Sinonasal malignant tumors involvement of the orbit and skull: a computed tomography study

    Directory of Open Access Journals (Sweden)

    Ana Célia Baptista

    2002-10-01

    Full Text Available Tumores malignos das cavidades sinonasais são raros e freqüentemente diagnosticados em estágio avançado da doença. A extensão destes tumores para locais críticos como a órbita e o crânio gera dificuldades no tratamento destas lesões. Dez pacientes com neoplasia maligna sinonasal, sem qualquer tratamento prévio e com evidência radiológica de extensão órbito-craniana, foram estudados por tomografia computadorizada. Dos dez tumores, cinco (50% foram neoplasias epiteliais, tendo sido a mais comum o carcinoma epidermóide (três casos. O sítio de origem tumoral mais comum foi o seio etmoidal, em quatro pacientes (40%, seguido pelo seio maxilar (30% e pela fossa nasal (30%. Dezesseis órbitas foram comprometidas, já que seis pacientes (60% apresentaram acometimento orbitário tumoral bilateral. Os tumores se estenderam mais freqüentemente para as órbitas através de erosão da parede medial e do soalho orbitários. A maioria das órbitas teve todos os compartimentos acometidos. Extensão dos tumores para a cavidade craniana foi mais comum através do teto etmoidal (70% e teto orbitário (30%. A fossa craniana anterior foi acometida em oito casos (80%, seguida pela fossa craniana média (40% e pelo lobo frontal (excluindo-se a fossa anterior (30%. Trinta e sete regiões da face foram acometidas pelos dez tumores, excluindo-se o sítio de origem da neoplasia e a região órbito-craniana, corroborando a grande extensão loco-regional do tumor no momento do diagnóstico.Malignant tumors of the sinonasal cavities are rare and often diagnosed late in the course of the disease. These tumors can extend into regions such as the orbit and brain, where treatment is difficult. Ten patients with nontreated sinonasal malignant neoplasms and radiological evidence of tumor extension into the orbit and brain were studied with computed tomography. Five (50% tumors were epithelial neoplasms whereas squamous cell carcinoma was the most common type (3

  10. Dust Storms: Why Are Dust Storms a Concern?

    Science.gov (United States)

    ... Radon Solvents Styrene Sulfur Dioxide Toluene Uranium Volatile Organic Compounds (VOCs) For Educators Introduction Tox Town-Based Curriculum Units / Science Club Careers in Environmental Health, Chemistry, and Toxicology More Resources Dust Storms en español ...

  11. Dust reddening in star-forming galaxies

    CERN Document Server

    Xiao, Ting; Wang, Huiyuan; Zhou, Hongyan; Lu, HongLin; Dong, Xiaobo

    2011-01-01

    We present empirical relations between the global dust reddening and other physical galaxy properties including the Halpha luminosity, Halpha surface brightness, metallicity and axial ratio for star-forming disc galaxies. The study is based on a large sample of ~22 000 well-defined star-forming galaxies selected from the Sloan Digital Sky Survey (SDSS). The reddening parameterized by color excess E(B-V) is derived from the Balmer decrement. Besides the dependency of reddening on Halpha luminosity / surface brightness and gas phase metallicity, it is also correlated with the galaxy inclination, in the sense that edge-on galaxies are more attenuated than face-on galaxies at a give intrinsic luminosity. In light of these correlations, we present the empirical formulae of E(B-V) as a function of these galaxy properties, with a scatter of only 0.07 mag. The empirical relation can be reproduced if most dust attenuation to the HII region is due to diffuse background dust distributing in a disc thicker than that of H...

  12. Long-term dust aerosol production from natural sources in Iceland.

    Science.gov (United States)

    Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur

    2017-02-01

    Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland is volcanic sandy deserts. Not only do natural emissions from these sources influenced by strong winds affect regional air quality in Iceland ("Reykjavik haze"), but dust particles are transported over the Atlantic ocean and Arctic Ocean >1000 km at times. The aim of this paper is to place Icelandic dust production area into international perspective, present long-term frequency of dust storm events in northeast Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in northeast Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the northeastern erosion area, indicating extreme dust plume activity and erosion within the northeastern deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and Aeolian transport during dust/volcanic ash storms in Iceland, which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust may contribute to the Arctic air pollution.

  13. Comparison of coarse coal dust sampling techniques in a laboratory-simulated longwall section.

    Science.gov (United States)

    Patts, Justin R; Barone, Teresa L

    2017-05-01

    Airborne coal dust generated during mining can deposit and accumulate on mine surfaces, presenting a dust explosion hazard. When assessing dust hazard mitigation strategies for airborne dust reduction, sampling is done in high-velocity ventilation air, which is used to purge the mining face and gallery tunnel. In this environment, the sampler inlet velocity should be matched to the air stream velocity (isokinetic sampling) to prevent oversampling of coarse dust at low sampler-to-air velocity ratios. Low velocity ratios are often encountered when using low flow rate, personal sampling pumps commonly used in underground mines. In this study, with a goal of employing mine-ready equipment, a personal sampler was adapted for area sampling of coarse coal dust in high-velocity ventilation air. This was done by adapting an isokinetic nozzle to the inlet of an Institute of Occupational Medicine (Edinburgh, Scotland) sampling cassette (IOM). Collected dust masses were compared for the modified IOM isokinetic sampler (IOM-MOD), the IOM without the isokinetic nozzle, and a conventional dust sampling cassette without the cyclone on the inlet. All samplers were operated at a flow rate typical of personal sampling pumps: 2 L/min. To ensure differences between collected masses that could be attributed to sampler design and were not influenced by artifacts from dust concentration gradients, relatively uniform and repeatable dust concentrations were demonstrated in the sampling zone of the National Institute for Occupational Safety and Health experimental mine gallery. Consistent with isokinetic theory, greater differences between isokinetic and non-isokinetic sampled masses were found for larger dust volume-size distributions and higher ventilation air velocities. Since isokinetic sampling is conventionally used to determine total dust concentration, and isokinetic sampling made a difference in collected masses, the results suggest when sampling for coarse coal dust the IOM-MOD may

  14. Where are the Dust Tori of Mars? - A Possible Role of Stochastic Effects

    Science.gov (United States)

    Makuch, M.; Brilliantov, N. V.; Spahn, F.; Krivov, A. V.

    2005-08-01

    Dust tori around Mars were predicted theoretically several decades ago, but still escape direct detection. On the base of our recent analytical and numerical studies we re-assess expected properties of the dust belts. In addition to deterministic models developed before we investigate the influence of stochastic effects on the dynamics, lifetimes of particles, and configuration of the dust tori. There exist various sources of stochasticity. For instance, we consider the influence of solar radiation on an ensemble of differently-shaped dust particles. Following the ergodic hypothesis, the dynamics of a single dust grain exposed to fluctuating radiation mimics the stochastic evolution of the whole ensemble. Further, we study the action of the planetary shadow on the dynamics of dust particles, a perturbation which turns out to be stochastic. Additional stochastic perturbations of deterministic dust trajectories are expected to be caused by different material properties of the dust grains, fluctuations of the solar wind, and the related magnetic field. As a result the fluctuating forces cause a diffusion of the dust configuration whose related fluxes can be estimated from our numerical experiments. This effect leads to a decrease of the expected optical depth of the tori, which is mainly determined by the strength of the stochastic force. We will provide estimates for the latter resulting in a diffusion coefficient. This will give new information about change of the configuration and lifetimes of the Martian dust-tori.

  15. A Diversity of Dust In Oort Cloud Comets

    Science.gov (United States)

    Kelley, Michael S.; Woodward, Charles E.; Harker, David Emerson; Wooden, Diane H.; Sitko, Michael L.; Yang, Bin; Russell, Ray W.

    2016-10-01

    Oort cloud comet nuclei, especially their interiors, have remained cool enough to retain highly volatile molecules such as CO2, CO, and CH4. At these low temperatures the composition of comet dust remains stable. Thus, observations of comet dust may reveal information on cometary origins, including dust formation processes and the spatial distribution of refractory materials in the early outer Solar System. We examine IRTF/BASS, IRTF/MIRSI, Gemini/T-ReCS, and VLT/VISIR mid-infrared spectra of six Oort cloud comets: C/2004 Q2 (Machholz), C/2009 P1 (Garradd), C/2011 L4 (Pan-STARRS), C/2012 F6 (Lemmon), C/2013 US10 (Catalina) (from Woodward et al. in prep.), and C/2014 Q1 (Pan-STARRS). The shapes of their 10-μm silicate bands are similar, trapezoidal with a crystalline silicate peak at 11.2 to 11.3 μm. However, there are some differences on the short-wavelength end of the spectrum, and the relative strengths of the silicate bands vary from 12% to 45% above the pseudo continuum. These variations are due to dust grain size, porosity, and composition. We fit each spectrum with our comet dust thermal model to quantify the relative amounts of the major dust species: "amorphous" silicates, crystalline silicates, and low albedo (e.g., carbonaceous) dust. These results are presented, and comapred to other Oort cloud comets already modeled in the literature in order to better understand the distribution of dust in the comet formation zone.This research was supported by NASA's Planetary Astronomy Program grant NNX13AH67G and at The Aerospace Corporation by the Independent Research and Development program.

  16. [Causation, prevention and treatment of dust explosion].

    Science.gov (United States)

    Dong, Maolong; Jia, Wenbin; Wang, Hongtao; Han, Fei; Li, Xiao-Qiang; Hu, Dahai

    2014-10-01

    With the development of industrial technology, dust explosion accidents have increased, causing serious losses of people's lives and property. With the development of economy, we should lay further emphasis on causation, prevention, and treatment of dust explosion. This article summarizes the background, mechanism, prevention, and treatment of dust explosion, which may provide some professional knowledge and reference for the treatment of dust explosion.

  17. Reply to Comment by Xu et al. on "Sr-Nd isotope composition and clay mineral assemblages in eolian dust from the central Philippine Sea over the last 600 kyr: Implications for the transport mechanism of Asian dust" by Seo et al.

    Science.gov (United States)

    Seo, Inah; Lee, Yong Il; Yoo, Chan Min; Kim, Hyung Jeek; Hyeong, Kiseong

    2016-12-01

    Against Xu et al. (2016), who argued that East Asian Desert (EAD) dust that traveled on East Asian Winter Monsoon winds dominates over Central Asian Desert (CAD) dust in the Philippine Sea with presentation of additional data, we reconfirm Seo et al.'s (2014) conclusion that CAD dust carried on the Prevailing Westerlies and Trade Winds dominates over EAD dust in overall dust budget of the central Philippine Sea. The relative contribution of dust from EADs and CADs using clay mineral composition should be evaluated with elimination of mineralogical contribution from the volcanic end-member which is enriched in kaolinite and overestimate the contribution of EAD dust.

  18. Modeling Dust Evolution in Galaxies with a Multiphase, Inhomogeneous ISM

    Science.gov (United States)

    Zhukovska, Svitlana; Dobbs, Clare; Jenkins, Edward B.; Klessen, Ralf S.

    2016-11-01

    We develop a model of dust evolution in a multiphase, inhomogeneous interstellar medium (ISM) using hydrodynamical simulations of giant molecular clouds in a Milky Way-like spiral galaxy. We improve the treatment of dust growth by accretion in the ISM to investigate the role of the temperature-dependent sticking coefficient and ion-grain interactions. From detailed observational data on the gas-phase Si abundances [{{Si}}{gas}/{{H}}] measured in the local Galaxy, we derive a relation between the average [{{Si}}{gas}/{{H}}] and the local gas density n({{H}}) that we use as a critical constraint for the models. This relation requires a sticking coefficient that decreases with the gas temperature. The relation predicted by the models reproduces the slope of -0.5 for the observed relation in cold clouds, which is steeper than that for the warm medium and is explained by dust growth. We find that growth occurs in the cold medium for all adopted values of the minimum grain size a min from 1 to 5 nm. For the classical cutoff of {a}\\min =5 {nm}, the Coulomb repulsion results in slower accretion and higher [{{Si}}{gas}/{{H}}] than the observed values. For {a}\\min ≲ 3 {nm}, the Coulomb interactions enhance the growth rate, steepen the slope of the [{{Si}}{gas}/{{H}}]-n({{H}}) relation, and provide a better match to observations. The rates of dust re-formation in the ISM by far exceed the rates of dust production by stellar sources. After the initial 140 Myr, the cycle of matter in and out of dust reaches a steady state, in which the dust growth balances the destruction on a similar timescale of 350 Myr.

  19. Levy dusts, Mittag-Leffler statistics, mass fractal lacunarity, and perceived dimension

    Energy Technology Data Exchange (ETDEWEB)

    Blumenfeld, R. [Theoretical Division and CNLS, Mail Stop B262, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mandelbrot, B.B. [Mathematics Department, Yale University, New Haven, Connecticut 06520-8283 (United States)

    1997-07-01

    We study the Levy dusts on the line on two accounts: the fluctuations around the average power law that characterizes the mass-radius relation for self-similar fractals, and the statistics of the intervals between strides along the logarithmic axis (their tail distribution is related to the dust`s fractal dimension). The Levy dusts are suggested as a yardstick of neutral lacunarity, against which non-neutral lacunarity can be measured objectively. A notion of perceived dimension is introduced. We conclude with an application of the Mittag-Leffler statistics to a nonlinear electrical network. {copyright} {ital 1997} {ital The American Physical Society}

  20. A numerical study on dust devils with implications to global dust budget estimates

    Science.gov (United States)

    The estimates of the contribution of dust devils (DDs) to the global dust budget have large uncertainties because the dust emission mechanisms in DDs are not yet well understood. In this study, a large-eddy simulation model coupled with a dust scheme is used to investigate DD dust entrainment. DDs a...

  1. Dust exposure in indoor climbing halls.

    Science.gov (United States)

    Weinbruch, Stephan; Dirsch, Thomas; Ebert, Martin; Hofmann, Heiko; Kandler, Konrad

    2008-05-01

    The use of hydrated magnesium carbonate hydroxide (magnesia alba) for drying the hands is a strong source for particulate matter in indoor climbing halls. Particle mass concentrations (PM10, PM2.5 and PM1) were measured with an optical particle counter in 9 indoor climbing halls and in 5 sports halls. Mean values for PM10 in indoor climbing halls are generally on the order of 200-500 microg m(-3). For periods of high activity, which last for several hours, PM10 values between 1000 and 4000 microg m(-3) were observed. PM(2.5) is on the order of 30-100 microg m(-3) and reaches values up to 500 microg m(-3), if many users are present. In sports halls, the mass concentrations are usually much lower (PM10 sport in which magnesia alba is also used) similar dust concentrations as for indoor climbing were observed. The size distribution and the total particle number concentration (3.7 nm-10 microm electrical mobility diameter) were determined in one climbing hall by an electrical aerosol spectrometer. The highest number concentrations were between 8000 and 12 000 cm(-3), indicating that the use of magnesia alba is no strong source for ultrafine particles. Scanning electron microscopy and energy-dispersive X-ray microanalysis revealed that virtually all particles are hydrated magnesium carbonate hydroxide. In-situ experiments in an environmental scanning electron microscope showed that the particles do not dissolve at relative humidities up to 100%. Thus, it is concluded that solid particles of magnesia alba are airborne and have the potential to deposit in the human respiratory tract. The particle mass concentrations in indoor climbing halls are much higher than those reported for schools and reach, in many cases, levels which are observed for industrial occupations. The observed dust concentrations are below the current occupational exposure limits in Germany of 3 and 10 mg m(-3) for respirable and inhalable dust. However, the dust concentrations exceed the German guide

  2. Characteristics of 14C and 13C of carbonate aerosols in dust storm events in China

    Science.gov (United States)

    Chen, Bing; Jie, Dongmei; Shi, Meinan; Gao, Pan; Shen, Zhenxing; Uchida, Masao; Zhou, Liping; Liu, Kexin; Hu, Ke; Kitagawa, Hiroyuki

    2015-10-01

    In contrast with its decrease in western China deserts, the dust storm event in eastern China, Korea, and Japan shows an increase in frequency. Although the drylands in northeastern China have been recognized as an important dust source, the relative contributions of dust transport from the drylands and deserts are inconclusive, thus the quantification of dust storm sources in downwind area remains a challenge. We measured the 14C and 13C contents in carbonates of dust samples from six sites in China, which were collected for the duration of dust storm events in drylands, deserts, and urban areas. The δ13C of the dryland dust samples considerably varied in a range of - 9.7 to - 5.0‰, which partly overlapped the desert dust carbonate δ13C ranges. The 14C content of the dryland dust carbonates showed a narrow range of 60.9 ± 4.0 (as an average and 1 SD of five samples) percent modern carbon (pMC), indicating the enrichment of modern carbonate. Dust samples in desert regions contained relatively aged carbonates with the depleting 14C showing of 28.8 ± 3.3 pMC. After the long-range transport of the western China desert dust plume, the carbonates collected at the southern China remained the depletion of 14C (33.5 ± 5.3 pMC) as in the desert regions. On the other hand, the samples of dust storm events at the urban areas of eastern China showed an enrichment of 14C contents (46.2 ± 5.0 pMC, n = 7), which might be explained by the stronger contribution of modern-carbonate-rich dryland dust.

  3. Loess and Eolian Dust Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past environment derived from Loess and Eolian dust (silt-sized material deposited on the Earth surface by the surface winds. Parameter keywords describe...

  4. Surface System Dust Mitigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will perform a detailed examination of dust mitigation and tolerance strategies for connections and mechanisms to be employed on the lunar...

  5. Dust Evolution in Protoplanetary Disks

    CERN Document Server

    Testi, Leonardo; Ricci, Luca; Andrews, Sean; Blum, Juergen; Carpenter, John; Dominik, Carsten; Isella, Andrea; Natta, Antonella; Williams, Jonathan; Wilner, David

    2014-01-01

    (abridged) In the core accretion scenario for the formation of planetary rocky cores, the first step toward planet formation is the growth of dust grains into larger and larger aggregates and eventually planetesimals. Although dust grains are thought to grow from the submicron sizes typical of interstellar dust to micron size particles in the dense regions of molecular clouds and cores, the growth from micron size particles to pebbles and kilometre size bodies must occur in protoplanetary disks. This step in the formation of planetary systems is the last stage of solids evolution that can be observed directly in young extrasolar systems. In this chapter we review the constraints on the physics of grain-grain collisions as they have emerged from laboratory experiments and numerical computations. We then review the current theoretical understanding of the global processes governing the evolution of solids in protoplanetary disks, including dust settling, growth, and radial transport. The predicted observational...

  6. Wormhole shadows in rotating dust

    Science.gov (United States)

    Ohgami, Takayuki; Sakai, Nobuyuki

    2016-09-01

    As an extension of our previous work, which investigated the shadows of the Ellis wormhole surrounded by nonrotating dust, in this paper we study wormhole shadows in a rotating dust flow. First, we derive steady-state solutions of slowly rotating dust surrounding the wormhole by solving relativistic Euler equations. Solving null geodesic equations and radiation transfer equations, we investigate the images of the wormhole surrounded by dust for the above steady-state solutions. Because the Ellis wormhole spacetime possesses unstable circular orbits of photons, a bright ring appears in the image, just as in Schwarzschild spacetime. The bright ring looks distorted due to rotation. Aside from the bright ring, there appear weakly luminous complex patterns by the emission from the other side of the throat. These structure could be detected by high-resolution very-long-baseline-interferometry observations in the near future.

  7. Automated Classification of Stratospheric Dust

    Science.gov (United States)

    Bell, S. W.; Lasue, J.; Stepinski, T.

    2010-03-01

    We have applied data mining techniques to the JSC Cosmic Dust Catalog Volume 16 cluster particles. We have demonstrated a technique capable of reproducing the separation between cosmic and contaminant particles.

  8. Dust Evolution in Protoplanetary Disks

    Science.gov (United States)

    Testi, L.; Birnstiel, T.; Ricci, L.; Andrews, S.; Blum, J.; Carpenter, J.; Dominik, C.; Isella, A.; Natta, A.; Williams, J. P.; Wilner, D. J.

    In the core-accretion scenario for the formation of planetary rocky cores, the first step toward planet formation is the growth of dust grains into larger and larger aggregates and eventually planetesimals. Although dust grains are thought to grow up to micrometer-sized particles in the dense regions of molecular clouds, the growth to pebbles and kilometer-sized bodies must occur at the high densities within protoplanetary disks. This critical step is the last stage of solids evolution that can be observed directly in extrasolar systems before the appearance of large planetary-sized bodies. In this chapter we review the constraints on the physics of grain-grain collisions as they have emerged from laboratory experiments and numerical computations. We then review the current theoretical understanding of the global processes governing the evolution of solids in protoplanetary disks, including dust settling, growth, and radial transport. The predicted observational signatures of these processes are summarized. We briefly discuss grain growth in molecular cloud cores and in collapsing envelopes of protostars, as these likely provide the initial conditions for the dust in protoplanetary disks. We then review the observational constraints on grain growth in disks from millimeter surveys, as well as the very recent evidence for radial variations of the dust properties in disks. We also include a brief discussion on the small end of the grain size distribution and dust settling as derived from optical, near-, and mid-infrared observations. Results are discussed in the context of global dust-evolution models; in particular, we focus on the emerging evidence for a very efficient early growth of grains and the radial distribution of maximum grain sizes as the result of growth barriers. We also highlight the limits of the current models of dust evolution in disks, including the need to slow the radial drift of grains to overcome the migration/fragmentation barrier.

  9. Dust vortex flows in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, P.K

    2002-12-30

    Coherent nonlinear structures in the form of dust vortex flows have been observed in unmagnetized laboratory dusty plasmas. Our objective here is show that the dynamics of such dust vortices is governed by a modified Navier-Stokes equation (MNSE) and that the stationary solutions of the MNSE can be represented as monopolar as well as a row of identical Stuart and a row of counter-rotating vortices.

  10. Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition

    OpenAIRE

    Moore, J. Keith; Doney, Scott C.; Lindsay, Keith; Mahowald, Natalie; Michaels, Anthony F.

    2011-01-01

    A global ocean biogeochemical model is used to quantify the sensitivity of marine biogeochemistry and air–sea CO2 exchange to variations in dust deposition over decadal timescales. Estimates of dust deposition generated under four climate states provide a large range in total deposition with spatially realistic patterns; transient ocean model experiments are conducted by applying a step-function change in deposition from a current climate control. Relative to current conditions, higher dust d...

  11. Generalized polarization force acting on dust grains in a dusty plasma

    Science.gov (United States)

    Bentabet, Karima; Mayout, Saliha; Tribeche, Mouloud

    2017-01-01

    The polarization force acting on dust particles in a dusty plasma is revisited within the theoretical framework of the Tsallis statistical mechanics. The generalized nonextensive polarization force expression is derived. As application, the modifications arising in the propagation of dust-acoustic solitary waves, and dust sheath formation are analyzed. Our results should be of wide relevance to explain and interpret the sheath formation and its structure in nonequilibrium plasmas related process such as surface treatments and ion implantation.

  12. Dust in the Interplanetary Medium

    CERN Document Server

    Mann, Ingrid; Meyer-Vernet, Nicole; Zaslavsky, Arnaud; Lamy, Herve

    2010-01-01

    The mass density of dust particles that form from asteroids and comets in the interplanetary medium of the solar system is, near 1 AU, comparable to the mass density of the solar wind. It is mainly contained in particles of micrometer size and larger. Dust and larger objects are destroyed by collisions and sublimation and hence feed heavy ions into the solar wind and the solar corona. Small dust particles are present in large number and as a result of their large charge to mass ratio deflected by electromagnetic forces in the solar wind. For nano dust particles of sizes 1 - 10 nm, recent calculations show trapping near the Sun and outside from about 0.15 AU ejection with velocities close to solar wind velocity. The fluxes of ejected nano dust are detected near 1AU with the plasma wave instrument onboard the STEREO spacecraft. Though such electric signals have been observed during dust impacts before, the interpretation depends on several different parameters and data analysis is still in progress.

  13. Uranium mill ore dust characterization

    Energy Technology Data Exchange (ETDEWEB)

    Knuth, R.H.; George, A.C.

    1980-11-01

    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 ..mu..m with a median diameter of 11 ..mu..m. The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  14. New house dust collection system and its use in a study of asthma in dust mite sensitive children in Raleigh, North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, A.B.; Beck, M.A.; Henry, M.M.; Barnes, D.M.; Henderson, F.W.

    1993-01-01

    A prototype dust collection system, the House Dust Vacuum One (HDVI), was designed for use in a study to investigate the relationship between house dust mite antigen levels and the presence of asthma in dust mite sensitive children. The HDVI was designed for the collection of dust samples from all potentially relevant domestic substrates, with the primary sampling objective being the retrieval at least 100 mg of sample material. During the winter of 1991-92, dust samples were collected from six different microenvironments in the homes of 49 dust mite sensitive children living in the Raleigh, NC metropolitan area. In addition to the standard antigen immunoassay, the performance of the HDVI was assessed by conducting side by side comparison tests using two alternative antigen collection systems. Microenvironmental antigen concentrations were found to be lognormally distributed within the test homes and within each microenvironment. With the relatively large quantity of sample material collected and the ease with which the HDVI was able to collect samples from a wide variety of substrates, the new unit was determined to be well suited for surface dust and dust mite antigen collection studies.

  15. High Proportions of Sub-micron Particulate Matter in Icelandic Dust Storms in 2015

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur; Magnusdottir, Agnes

    2017-04-01

    in situ measurements at the dust source in 2013 revealed extremely high number concentrations of submicron particles, specifically in the size range 0.3-0.337 μm. The PM2.5/PM10 ratios of mass concentrations seem to be lower at the dust sources that in some distance from the sources as measured in 2015. Common dust storms in Iceland are of several hundred thousand tons of magnitude from relatively well defined main dust sources. Numerical simulations were used calculate the total dust flux from the sources as 180,000 - 280,000 tons in this study. The mean PM1 (PM10) concentrations inside of the dust plumes varied from 97 to 241 µg m-3 (PM10 = 158 to 583 µg m-3). The extent of moderate dust events was calculated as 2.450 km2 to 4.220 km2 of the land area suggesting the regional scale of the events. Dust plumes reported here passed the most densely inhabited areas of Iceland, health risk warnings for the general public were, however, not issued. The data provided stresses the need for such warning system and is an important step towards its development.

  16. The Cosmic DUNE dust astronomy mission

    Science.gov (United States)

    Grun, E.; Srama, R.; Cosmic Dune Team

    A dust astronomy mission aims at the simultaneous measurement of the origin and the chemical composition of individual dust grains in space. Interstellar dust traversing the solar system constitutes the galactic solid phase of matter from which stars and planetary systems form. Interplanetary dust, from comets and asteroids, represents remnant material from bodies at different stages of early solar system evolution. Thus, studies of interstellar and interplanetary dust with Cosmic DUNE (Cosmic Dust Near Earth) will provide a comparison between the composition of the interstellar medium and primitive planetary objects. Cosmic DUNE will prepare the way for effective collection in near-Earth space of interstellar and interplanetary dust for subsequent return to Earth and analysis in laboratories. Cosmic DUNE establishes the next logical step beyond NASA's Stardust mission, with four major advancements in cosmic dust research: (1) Analysis of the elemental and isotopic composition of individual cosmic dust grains, (2) determination of the size distribution of interstellar dust, (3) characterization of the interstellar dust flow through the planetary system, and (4) analysis of interplanetary dust of cometary and asteroidal origin. This mission goal will be reached with novel dust instrumentation. A dust telescope trajectory sensor has been developed which is capable of obtaining precision trajectories of sub-micron sized particles in space. A new high mass resolution dust analyzer of 0.1m2 impact area can cope with the low fluxes expected in interplanetary space. Cosmic DUNE will be proposed to ESA in response to its upcoming call for mission ideas.

  17. Escape mechanisms of dust in Io

    Science.gov (United States)

    Flandes, A.

    The injection of material into the jovian magnetosphere through Io's volcanic activity makes possible the formation of structures such as the plasma torus and the dust ballerina skirt. Io's high temperature volcanism produces spectacular plumes, but even the tallest plumes, as those of Pelen Patera, will not produce enough energy to defeat the gravitational attraction of Io. The fact is that dust escapes from Io, which implies that a second mechanism is acting on the grains. Grains brought to the top of the highest plumes by the volcanic forces are still under Io's gravitational pull, but need only a minimum charge (~10-1 4 C) so that the Lorentz force due to the Jovian magnetic field equilibrates this attraction. In the volcanic vents, the escape velocity of the ejected material and its own density produces enough collisions to create charges. On top of the highest plumes (~500km) charged grains are exposed to the plasma torus that co-rotates rigidly with Jupiter and, due to the relative velocity among Io and the torus, the grains will be dragged away from Io. As it is well known, these dust grains will also be dragged away from Jupiter.

  18. Dust impact signals on the wind spacecraft

    Science.gov (United States)

    Kellogg, P. J.; Goetz, K.; Monson, S. J.

    2016-02-01

    We analyze waveforms recorded by the Time Domain Sampler of the WAVES experiment on Wind which are similar to impulsive waveforms observed by the S/WAVES experiment on STEREO. These have been interpreted as dust impacts by Meyer-Vernet et al. and M. L. Kaiser and K. Goetz and extensively analyzed by Zaslavsky et al. The mechanism for coupling the emission to the antennas to produce an electrical signal is still not well understood, however. One suggested mechanism for coupling of the impact to the antenna is that the spacecraft body changes potential with respect to the surrounding plasma but the antennas do not (the body mechanism). Another class of mechanisms, with several forms, is that the charge of the emitted cloud interacts with the antennas. The Wind data show that both are operating. The time domain shapes of the dust pulses are highly variable but we have little understanding of what provides these shapes. One feature of the STEREO data has been interpreted as impacts from high velocity nanoparticles entrained by the solar wind. We have not found evidence for fast nanodust in the Wind data. An appreciable fraction of the impacts observed on Wind is consistent with interstellar dust. The impact rates do not follow a Poisson distribution, expected for random independent events, and this is interpreted as bunching. We have not succeeded in relating this bunching to known meteor showers, and they do not repeat from 1 year to the next. The data suggest bunching by fields in the heliosphere.

  19. Determinants of wood dust exposure in the Danish furniture industry.

    Science.gov (United States)

    Mikkelsen, Anders B; Schlunssen, Vivi; Sigsgaard, Torben; Schaumburg, Inger

    2002-11-01

    This paper investigates the relation between wood dust exposure in the furniture industry and occupational hygiene variables. During the winter 1997-98 54 factories were visited and 2362 personal, passive inhalable dust samples were obtained; the geometric mean was 0.95 mg/m(3) and the geometric standard deviation was 2.08. In a first measuring round 1685 dust concentrations were obtained. For some of the workers repeated measurements were carried out 1 (351) and 2 weeks (326) after the first measurement. Hygiene variables like job, exhaust ventilation, cleaning procedures, etc., were documented. A multivariate analysis based on mixed effects models was used with hygiene variables being fixed effects and worker, machine, department and factory being random effects. A modified stepwise strategy of model making was adopted taking into account the hierarchically structured variables and making possible the exclusion of non-influential random as well as fixed effects. For woodworking, the following determinants of exposure increase the dust concentration: manual and automatic sanding and use of compressed air with fully automatic and semi-automatic machines and for cleaning of work pieces. Decreased dust exposure resulted from the use of compressed air with manual machines, working at fully automatic or semi-automatic machines, functioning exhaust ventilation, work on the night shift, daily cleaning of rooms, cleaning of work pieces with a brush, vacuum cleaning of machines, supplementary fresh air intake and safety representative elected within the last 2 yr. For handling and assembling, increased exposure results from work at automatic machines and presence of wood dust on the workpieces. Work on the evening shift, supplementary fresh air intake, work in a chair factory and special cleaning staff produced decreased exposure to wood dust. The implications of the results for the prevention of wood dust exposure are discussed.

  20. HTGR Dust Safety Issues and Needs for Research and Development

    Energy Technology Data Exchange (ETDEWEB)

    Paul W. Humrickhouse

    2011-06-01

    This report presents a summary of high temperature gas-cooled reactor dust safety issues. It draws upon a literature review and the proceedings of the Very High Temperature Reactor Dust Assessment Meeting held in Rockville, MD in March 2011 to identify and prioritize the phenomena and issues that characterize the effect of carbonaceous dust on high temperature reactor safety. It reflects the work and input of approximately 40 participants from the U.S. Department of Energy and its National Labs, the U.S. Nuclear Regulatory Commission, industry, academia, and international nuclear research organizations on the topics of dust generation and characterization, transport, fission product interactions, and chemical reactions. The meeting was organized by the Idaho National Laboratory under the auspices of the Next Generation Nuclear Plant Project, with support from the U.S. Nuclear Regulatory Commission. Information gleaned from the report and related meetings will be used to enhance the fuel, graphite, and methods technical program plans that guide research and development under the Next Generation Nuclear Plant Project. Based on meeting discussions and presentations, major research and development needs include: generating adsorption isotherms for fission products that display an affinity for dust, investigating the formation and properties of carbonaceous crust on the inside of high temperature reactor coolant pipes, and confirming the predominant source of dust as abrasion between fuel spheres and the fuel handling system.

  1. Interplanetary dust. [survey of last four years' research

    Science.gov (United States)

    Brownlee, D. E.

    1979-01-01

    Progress in the study of interplanetary dust during the past four years is reviewed. Attention is given to determinations of the relative contributions of interstellar dust grains, collisional debris from the asteroid belt and short-period comets to the interplanetary dust cloud. Effects of radiation pressure and collisions on particle dynamics are discussed, noting the discovery of the variation of the orbital parameters of dust particles at 1 AU with size and in situ measurements of dust density between 0.3 and 5 AU by the Helios and Pioneer spacecraft. The interpretation of the zodiacal light as produced by porous absorbing particles 10 to 100 microns in size is noted, and measurements of the Doppler shift, light-producing-particle density, UV spectrum, photometric axis and angular scattering function of the zodiacal light are reported. Results of analyses of lunar rock microcraters as to micrometeoroid density, flux rate, size distribution and composition are indicated and interplanetary dust particles collected from the stratosphere are discussed. Findings concerning the composition of fragile meteoroid types found as cosmic spherules in deep sea sediments are also presented.

  2. Climate, not conflict, explains extreme Middle East dust storm

    Science.gov (United States)

    Parolari, Anthony J.; Li, Dan; Bou-Zeid, Elie; Katul, Gabriel G.; Assouline, Shmuel

    2016-11-01

    The recent dust storm in the Middle East (Sepember 2015) was publicized in the media as a sign of an impending ‘Dust Bowl.’ Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation cover was high in 2015 relative to the prior drought and conflict periods, suggesting that agricultural activity was not diminished during that year, thus negating the media narrative. Instead, meteorological simulations using the Weather Research and Forecasting (WRF) model show that the storm was associated with a cyclone and ‘Shamal’ winds, typical for dust storm generation in this region, that were immediately followed by an unusual wind reversal at low levels that spread dust west to the Mediterranean Coast. These unusual meteorological conditions were aided by a significant reduction in the critical shear stress due to extreme dry and hot conditions, thereby enhancing dust availability for erosion during this storm. Concluding, unusual aridity, combined with unique synoptic weather patterns, enhanced dust emission and westward long-range transport across the region, thus generating the extreme storm.

  3. Estimating Children's Soil/Dust Ingestion Rates through ...

    Science.gov (United States)

    Background: Soil/dust ingestion rates are important variables in assessing children’s health risks in contaminated environments. Current estimates are based largely on soil tracer methodology, which is limited by analytical uncertainty, small sample size, and short study duration. Objectives: The objective was to estimate site-specific soil/dust ingestion rates through reevaluation of the lead absorption dose–response relationship using new bioavailability data from the Bunker Hill Mining and Metallurgical Complex Superfund Site (BHSS) in Idaho, USA. Methods: The U.S. Environmental Protection Agency (EPA) in vitro bioavailability methodology was applied to archived BHSS soil and dust samples. Using age-specific biokinetic slope factors, we related bioavailable lead from these sources to children’s blood lead levels (BLLs) monitored during cleanup from 1988 through 2002. Quantitative regression analyses and exposure assessment guidance were used to develop candidate soil/dust source partition scenarios estimating lead intake, allowing estimation of age-specific soil/dust ingestion rates. These ingestion rate and bioavailability estimates were simultaneously applied to the U.S. EPA Integrated Exposure Uptake Biokinetic Model for Lead in Children to determine those combinations best approximating observed BLLs. Results: Absolute soil and house dust bioavailability averaged 33% (SD ± 4%) and 28% (SD ± 6%), respectively. Estimated BHSS age-specific soil/du

  4. An overview of mineral dust modeling over East Asia

    Science.gov (United States)

    Chen, Siyu; Huang, Jianping; Qian, Yun; Zhao, Chun; Kang, Litai; Yang, Ben; Wang, Yong; Liu, Yuzhi; Yuan, Tiangang; Wang, Tianhe; Ma, Xiaojun; Zhang, Guolong

    2017-08-01

    East Asian dust (EAD) exerts considerable impacts on the energy balance and climate/climate change of the earth system through its influence on solar and terrestrial radiation, cloud properties, and precipitation efficiency. Providing an accurate description of the life cycle and climate effects of EAD is therefore critical to better understanding of climate change and socioeconomic development in East Asia and even worldwide. Dust modeling has undergone substantial development since the late 1990s, associated with improved understanding of the role of EAD in the earth system. Here, we review the achievements and progress made in recent decades in terms of dust modeling research, including dust emissions, long-range transport, radiative forcing (RF), and climate effects of dust particles over East Asia. Numerous efforts in dust/EAD modeling have been directed towards furnishing more sophisticated physical and chemical processes into the models on higher spatial resolutions. Meanwhile, more systematic observations and more advanced retrieval methods for instruments that address EAD related science issues have made it possible to evaluate model results and quantify the role of EAD in the earth system, and to further reduce the uncertainties in EAD simulations. Though much progress has been made, large discrepancies and knowledge gaps still exist among EAD simulations. The deficiencies and limitations that pertain to the performance of the EAD simulations referred to in the present study are also discussed.

  5. Effective dust control systems on concrete dowel drilling machinery.

    Science.gov (United States)

    Echt, Alan S; Sanderson, Wayne T; Mead, Kenneth R; Feng, H Amy; Farwick, Daniel R; Farwick, Dawn Ramsey

    2016-09-01

    Rotary-type percussion dowel drilling machines, which drill horizontal holes in concrete pavement, have been documented to produce respirable crystalline silica concentrations above recommended exposure criteria. This places operators at potential risk for developing health effects from exposure. United States manufacturers of these machines offer optional dust control systems. The effectiveness of the dust control systems to reduce respirable dust concentrations on two types of drilling machines was evaluated under controlled conditions with the machines operating inside large tent structures in an effort to eliminate secondary exposure sources not related to the dowel-drilling operation. Area air samples were collected at breathing zone height at three locations around each machine. Through equal numbers of sampling rounds with the control systems randomly selected to be on or off, the control systems were found to significantly reduce respirable dust concentrations from a geometric mean of 54 mg per cubic meter to 3.0 mg per cubic meter on one machine and 57 mg per cubic meter to 5.3 mg per cubic meter on the other machine. This research shows that the dust control systems can dramatically reduce respirable dust concentrations by over 90% under controlled conditions. However, these systems need to be evaluated under actual work conditions to determine their effectiveness in reducing worker exposures to crystalline silica below hazardous levels.

  6. Modelling Dust Evolution in Galaxies with a Multiphase, Inhomogeneous ISM

    CERN Document Server

    Zhukovska, Svitlana; Jenkins, Edward B; Klessen, Ralf

    2016-01-01

    We develop a model of dust evolution in a multiphase, inhomogeneous ISM including dust growth and destruction processes. The physical conditions for grain evolution are taken from hydrodynamical simulations of giant molecular clouds in a Milky Way-like spiral galaxy. We improve the treatment of dust growth by accretion in the ISM to investigate the role of the temperature-dependent sticking coefficient and ion-grain interactions. From detailed observational data on the gas-phase Si abundances [Si/H]_{gas} measured in the local Galaxy, we derive a relation between the average [Si/H]_{gas} and the local gas density n(H) which we use as a critical constraint for the models. This relation requires a sticking coefficient that decreases with the gas temperature. The synthetic relation constructed from the spatial dust distribution reproduces the slope of -0.5 of the observed relation in cold clouds. This slope is steeper than that for the warm medium and is explained by the dust growth. We find that it occurs for a...

  7. Some considerations on velocity vector accuracy in dust trajectory analysis

    Science.gov (United States)

    Jackson, A. A.; Zook, Herbert A.

    1994-01-01

    The relative contributions of comets and asteroids to the reservoir of dust in the interplanetary medium is not known. There are direct observations of dust released from comets and there is evidence to associate the IRAS dust bands with possible collisions of asteroids in the main belt. A means towards sorting out the parent sources has been proposed in the establishment of a dust collector in orbit about the Earth. The purpose of such a facility would be to collect not only cosmic dust particles intact but also the state vectors, as they arrive at the detector, the idea being that one may combine analytical laboratory analysis of the physics and chemistry of the captured particles with orbital data in order to help distinguish between bodies and identify parent bodies. The theoretical study of dust particle orbits in the solar system takes on greatly more importance if we use collected trajectory data. The orbital motion of dust when radiation and forces alone are acting is well understood. When gravitational forces due to the planets are included, the motion can become quite complex. In order to characterize the orbits of particles as they crossed the Earth's orbits, a study of the long-time dust orbital evolution was undertaken. We have considered various parameters associated with these dust orbits to see if one may in a general way discriminate between particles evolved from comets and asteroids. We proceed in this study as we have done previously. That is, we considered the dust particles as ideal black bodies, of density 1 gm/cc, spherical, with radii 10-100 microns. Particles of this size are affected by radiation forces, photon pressure, and Poynting-Robertson drag. Account was also taken of solar wind drag, which amounts to about 30 percent of the Poynting-Robertson drag negligible. The gravitational forces due to the planets are included, unlike in our previous study; the planetary orbits are those of true n-body interaction so that the possibility of

  8. Global impact of mineral dust on cloud droplet number concentration

    Science.gov (United States)

    Karydis, Vlassis A.; Tsimpidi, Alexandra P.; Bacer, Sara; Pozzer, Andrea; Nenes, Athanasios; Lelieveld, Jos

    2017-05-01

    formation from the relatively smaller anthropogenic particles (e.g., CDNC decreases by 10 % over southern Europe and 20 % over northeastern Asia by applying adsorption theory). The global average CDNC decreases by 10 % by considering adsorption activation, while changes are negligible when accounting for the mineral dust chemistry. Sensitivity simulations indicate that CDNC is also sensitive to the mineral dust mass and inherent hydrophilicity, and not to the chemical composition of the emitted dust.

  9. Ice Nucleation Activity of Various Agricultural Soil Dust Aerosol Particles

    Science.gov (United States)

    Schiebel, Thea; Höhler, Kristina; Funk, Roger; Hill, Thomas C. J.; Levin, Ezra J. T.; Nadolny, Jens; Steinke, Isabelle; Suski, Kaitlyn J.; Ullrich, Romy; Wagner, Robert; Weber, Ines; DeMott, Paul J.; Möhler, Ottmar

    2016-04-01

    Recent investigations at the cloud simulation chamber AIDA (Aerosol Interactions and Dynamics in the Atmosphere) suggest that agricultural soil dust has an ice nucleation ability that is enhanced up to a factor of 10 compared to desert dust, especially at temperatures above -26 °C (Steinke et al., in preparation for submission). This enhancement might be caused by the contribution of very ice-active biological particles. In addition, soil dust aerosol particles often contain a considerably higher amount of organic matter compared to desert dust particles. To test agricultural soil dust as a source of ice nucleating particles, especially for ice formation in warm clouds, we conducted a series of laboratory measurements with different soil dust samples to extend the existing AIDA dataset. The AIDA has a volume of 84 m3 and operates under atmospherically relevant conditions over wide ranges of temperature, pressure and humidity. By controlled adiabatic expansions, the ascent of an air parcel in the troposphere can be simulated. As a supplement to the AIDA facility, we use the INKA (Ice Nucleation Instrument of the KArlsruhe Institute of Technology) continuous flow diffusion chamber based on the design by Rogers (1988) to expose the sampled aerosol particles to a continuously increasing saturation ratio by keeping the aerosol temperature constant. For our experiments, soil dust was dry dispersed into the AIDA vessel. First, fast saturation ratio scans at different temperatures were performed with INKA, sampling soil dust aerosol particles directly from the AIDA vessel. Then, we conducted the AIDA expansion experiment starting at a preset temperature. The combination of these two different methods provides a robust data set on the temperature-dependent ice activity of various agriculture soil dust aerosol particles with a special focus on relatively high temperatures. In addition, to extend the data set, we investigated the role of biological and organic matter in more

  10. Effect of Dust Storms on the Atmospheric Microbiome in the Eastern Mediterranean.

    Science.gov (United States)

    Mazar, Yinon; Cytryn, Eddie; Erel, Yigal; Rudich, Yinon

    2016-04-19

    We evaluated the impact of Saharan dust storms on the local airborne microbiome in a city in the Eastern Mediterranean area. Samples of particles with diameter less than 10 μm were collected during two spring seasons on both dusty and nondusty days. DNA was extracted, and partial 16S rRNA gene amplicons were sequenced using the Illumina platform. Bioinformatic analysis showed the effect of dust events on the diversity of the atmospheric microbiome. The relative abundance of desert soil-associated bacteria increased during dust events, while the relative abundance of anthropogenic-influenced taxa decreased. Quantitative polymerase chain reaction measurements of selected clinically significant antibiotic resistance genes (ARGs) showed that their relative abundance decreased during dust events. The ARG profiles on dust-free days were similar to those in aerosol collected in a poultry house, suggesting a strong agricultural influence on the local ambient profiles. We conclude that dust storms enrich the ambient airborne microbiome with new soil-derived bacteria that disappear as the dust settles, suggesting that the bacteria are transported attached to the dust particles. Dust storms do not seem to be an important vector for transport of probed ARGs.

  11. Prediction of the treatment outcome using intravoxel incoherent motion and diffusional kurtosis imaging in nasal or sinonasal squamous cell carcinoma patients

    Energy Technology Data Exchange (ETDEWEB)

    Fujima, Noriyuki; Yoshida, Daisuke; Tsukahara, Akiko; Shimizu, Yukie; Kudo, Kohsuke [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, Sapporo, Hokkaido (Japan); Sakashita, Tomohiro; Homma, Akihiro [Hokkaido University Graduate School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Sapporo (Japan); Tha, Khin Khin; Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Department of Radiation Medicine, Sapporo (Japan); Global Institution for Collaborative Research and Education, The Global Station for Quantum Medical Science and Engineering, Sapporo (Japan)

    2017-03-15

    To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) and diffusional kurtosis imaging (DKI) parameters in nasal or sinonasal squamous cell carcinoma (SCC) patients to determine local control/failure. Twenty-eight patients were evaluated. MR acquisition used single-shot spin-echo EPI with 12 b-values. Quantitative parameters (mean value, 25th, 50th and 75th percentiles) of IVIM (perfusion fraction f, pseudo-diffusion coefficient D*, and true-diffusion coefficient D), DKI (kurtosis value K, kurtosis corrected diffusion coefficient D{sub k}) and apparent diffusion coefficient (ADC) were calculated. Parameter values at both the pretreatment and early-treatment period, and the percentage change between these two periods were obtained. Multivariate logistic regression analysis: the percentage changes of D (mean, 25th, 50th, 75th), K (mean, 50th, 75th), Dk (mean, 25th, 50th), and ADC (mean, 25th, 50th) were predictors of local control. ROC curve analysis: the parameter with the highest accuracy = the percentage change of D value with the histogram 25th percentile (0.93 diagnostic accuracy). Multivariate Cox regression analyses: the percentage changes of D (mean, 25th, 50th), K (mean, 50th, 75th), Dk (mean, 25th, 50th) and ADC (mean, 25th, 50th) are predictors. IVIM and DKI parameters, especially the D-value's histogram 25th percentile, are useful for predicting local control. (orig.)

  12. Estimation of high altitude Martian dust parameters

    Science.gov (United States)

    Pabari, Jayesh; Bhalodi, Pinali

    2016-07-01

    Dust devils are known to occur near the Martian surface mostly during the mid of Southern hemisphere summer and they play vital role in deciding background dust opacity in the atmosphere. The second source of high altitude Martian dust could be due to the secondary ejecta caused by impacts on Martian Moons, Phobos and Deimos. Also, the surfaces of the Moons are charged positively due to ultraviolet rays from the Sun and negatively due to space plasma currents. Such surface charging may cause fine grains to be levitated, which can easily escape the Moons. It is expected that the escaping dust form dust rings within the orbits of the Moons and therefore also around the Mars. One more possible source of high altitude Martian dust is interplanetary in nature. Due to continuous supply of the dust from various sources and also due to a kind of feedback mechanism existing between the ring or tori and the sources, the dust rings or tori can sustain over a period of time. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, it is mystery how dust has reached to such high altitudes. Estimation of dust parameters before-hand is necessary to design an instrument for the detection of high altitude Martian dust from a future orbiter. In this work, we have studied the dust supply rate responsible primarily for the formation of dust ring or tori, the life time of dust particles around the Mars, the dust number density as well as the effect of solar radiation pressure and Martian oblateness on dust dynamics. The results presented in this paper may be useful to space scientists for understanding the scenario and designing an orbiter based instrument to measure the dust surrounding the Mars for solving the mystery. The further work is underway.

  13. The Paleozoic Dust Bowl: Dust Deposition in Tropical Western Pangaea (Midcontinent U.S.) at the Terminus of the Late Paleozoic Ice Age

    Science.gov (United States)

    Soreghan, G. S.; Heavens, N. G.; Benison, K. C.; Soreghan, M. J.; Mahowald, N. M.; Foster, T.; Zambito, J.; Sweet, A.; Kane, M.

    2012-12-01

    Atmospheric dust is well recognized and studied as both an archive and agent of climate change in Earth's relatively recent past. Archives of past dust include loess deposits and dust recovered from ocean- and ice-cores. Dust remains poorly known in Earth's past prior to the Cenozoic, but is increasingly recognized in the form of paleo-loess deposits, and (epeiric) marine strata that accumulated isolated from fluvio-deltaic influx. Here, we report on the growing recognition of voluminous dust deposits preserved in the Permian record of the U.S. Midcontinent (western tropical Pangaea). Fine-grained redbeds predominate in Permian strata throughout the U.S. Midcontinent, but notably in a swath extending from Oklahoma through South Dakota. These units consist predominantly of red mudstone and siltstone in commonly massive units, but sedimentary structures and bedding that signal aqueous processes (e.g. laminations, ripples) have led most to infer deltaic or tidal deposition. The absence of channel systems to deliver the sediment, as well as the predominantly massive and laterally continuous character and the uniform fine grain size signal wind transport, implying that these units record sustained dust deposition overprinted at times by sub-aqueous deposition in lakes, including ephemeral saline and acid lakes that led to evaporite cementation. Detrital zircon geochronology indicates that much of the dust originated in the relatively distant Appalachian-Ouachita orogenic systems, which formed part of the central Pangaean mountains (CPM), the collisional zone that sutured the supercontinent. Within the Anadarko basin of Oklahoma, Permian redbeds record >2 km of predominantly dust deposition, some of the thickest dust deposits yet documented in Earth's record. Yet the tropical setting is remarkably non-uniformitarian, as much Quaternary loess occurs in mid- to high-latitude regions, commonly linked to glacial genesis. We are currently investigating with both data and

  14. Circumplanetary dust dynamics : application to Martian dust tori and Enceladus dust plumes

    OpenAIRE

    Makuch, Martin

    2007-01-01

    Our Solar system contains a large amount of dust, containing valuable information about our close cosmic environment. If created in a planet's system, the particles stay predominantly in its vicinity and can form extended dust envelopes, tori or rings around them. A fascinating example of these complexes are Saturnian rings containing a wide range of particles sizes from house-size objects in the main rings up to micron-sized grains constituting the E ring. Other example are ring systems in g...

  15. MEDUSA (Martian Environmental DUst Systematic Analyser)

    Science.gov (United States)

    Battaglia, R.; Colangeli, L.; della Corte, V.; Esposito, F.; Ferrini, G.; Mazzotta Epifani, E.; Palomba, E.; Palumbo, P.; Panizza, A.; Rotundi, A.

    2003-04-01

    ) onboard the Mars Global Surveyor. Seasonal variations in the column abundance are due to the combined effect of exchange of H_2O between atmosphere and water reservoirs (i.e. polar caps, regolith) and atmospheric transport. Despite the low absolute water content (0.03% by volume), relative humidity can exceed 100% leading to frosting phenomena, thanks to low Martian temperatures. The typical value of the pressure at surface, close to the triple point value of water phase diagram, makes the persistence of liquid water at the surface of Mars highly improbable. This means that the water is probably present exclusively in gaseous and solid states, at the surface level. Attempts to use space-born and earth-based observations to estimate quantitatively surface and near-surface sources and sinks of water vapour have had good but also partial success. Most important questions that appear from the present knowledge is how the water vapour atmospheric circulation occurs and how to explain the difference in the hemispheric and seasonal behaviour of the water vapour. Despite TES results showed that a percentage of hemispheric "asymmetry" of the seasonal vapour abundance was probably due to the presence of two dust storms during MAWD observations, an evident difference remains partially unexplained. In this context, it is extremely important to study the role of the different contributions to the production of atmospheric vapour from the main reservoirs and to the formation of water ice clouds most probably catalysed by the atmospheric dust. At present, no in situ measurement of water vapour content was performed yet. We discuss the possibility of using a new concept instrument for extraterrestrial planetary environments, based on the past experience acquired for dust monitoring in space and on Earth and new possible technologies for space applications. MEDUSA (Martian Environmental Dust Analyser) project is a multisensor and multistage instrument based on an optical detector of dust

  16. Discernible rhythm in the spatio/temporal distributions of transatlantic dust

    Directory of Open Access Journals (Sweden)

    Y. Ben-Ami

    2011-08-01

    Full Text Available The differences in North African dust emission regions and transport routes, between the boreal winter and summer are thoroughly documented. Here we re-examine the spatial and temporal characteristics of dust transport over the tropical and subtropical North Atlantic Ocean, using 10 years of satellite data, in order to determine better the different dust transport periods and their characteristics. We see a robust annual triplet: a discernible rhythm of "transatlantic dust weather".

    The proposed annual partition is composed of two heavy loading periods, associated here with a northern-route period and southern-route period, and one clean, light-loading period, accompanied by unusually low average optical depth of dust. The two dusty periods are quite different in character: their duration, transport routes, characteristic aerosol loading and frequency of pronounced dust episodes.

    The southern route period lasts about ~4 months, from the end of November to end of March. It is characterized by a relatively steady southern positioning, low frequency of dust events, low background values and high variance in dust loading. The northern-route period lasts ~6.5 months, from the end of March to mid October, and is associated with a steady drift northward of ~0.1 latitude day−1, reaching ~1500 km north of the southern route. The northern period is characterized by higher frequency of dust events, higher (and variable background and smaller variance in dust loading. It is less episodic than the southern period.

    Transitions between the periods are brief. Separation between the southern and northern periods is marked by northward latitudinal shift in dust transport and by moderate reduction in the overall dust loading. The second transition between the northern and southern periods commences with an abrupt reduction in dust loading (thereby initiating the clean period and rapid shift southward of ~0.2 latitude day

  17. Satellite-based Dust Source Identification over North Africa: Diurnal Cycle, Meteorological Controls, and Interannual Variability

    Science.gov (United States)

    Schepanski, Kerstin; Tegen, Ina; Macke, Andreas

    2010-05-01

    Mineral dust aerosol emitted from arid and semi-arid areas impacts on the weather and climate system by affecting e.g. radiation fluxes and nutrient cycles. To estimate the effect of dust aerosol, detailed knowledge on the spatio-temporal distribution of active dust sources is necessary. For a better representation of dust-related processes in numerical models and climate change projections the knowledge on the natural variability of dust source activity has to be improved. As dust sources are mostly located over remote areas satellite observations are suitable for identifying active dust sources. The accuracy of dust source identification using such an indirect method is limited by the temporal resolution and the ambiguities of the retrieval. Here, a data set on the spatial (1°x1°) and temporal (3-hourly) distribution of dust source activations (DSA) over North Africa is compiled by analyzing 15-minute Meteosat Second Generation (MSG) infra-red (IR) dust index images since March 2006. The index is designed using radiances measured by the Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) on-board MSG at 8.7 µm, 10.8 µm and 12.0 µm which are converted to brightness temperatures (BTs). To strengthen the dust signal, differences of BTs are used to compute RGB-composite images. This newly data set providing information on the diurnal cycle of dust emission has been used (1) to identify most active dust source areas, and (2) to investigate on the temporal distribution of DSAs. Over the Sahara Desert 65% of dust sources become active during 06-09 UTC pointing towards an important role of the break-down of the nocturnal low-level jet (LLJ) for dust mobilization besides other meteorological features like density currents, haboobs, and cyclones. Furthermore the role of the nocturnal LLJs for dust mobilization over the Sahara is investigated by weather observations and a regional modeling study. Four years of DSA observations indicate an interannual variability in

  18. An Observational and Numerical Study on the Topographic Influence on Dust Transport in East Asia

    Institute of Scientific and Technical Information of China (English)

    JIANG Xuegong; CHEN Shoujun

    2009-01-01

    Based on observations and numerical simulations, the topographic impacts on dust transport in East Asia were studied. Two regions frequently attacked by dust storms have been confirmed: one is the western part of Inner Mongolia and the southern Mongolia (namely the Mongolia Plateau), and the other is the Tarim Basin.The most frequent dust storm occurrence area within the first region appears in its hinterland while that of the second one lies in its southern boundary. Moreover, the region from the northeastern edge of the Tibetan Plateau (TP) to the Loess Plateau is attacked by dust storms second frequently. The dust storms frequently occurring over the Mongolia Plateau are related not only to the abundant sand and dust sources, but also to the special topographic conditions of East Asia. The most significant factor that influences the dust storms forming in the hinterland of the Mongolia Plateau is the canyon low level jet (CLLJ), which dominates around the southern areas of the Altay-Sayan Mountains with an east-west direction in the beginning of its formation, and is accompanied by significantly enhanced surface wind afterwards. Due to the obstructive effects of the CLLJ, a lot of dust particles carried by the southward down-slope cold air mass would pile up over the southern slope of the Sayan Mountains. Meanwhile, uneven surface conditions are favorable for the dust particles to go up into the upper atmosphere. With the dust particles piling up continuously, a dust layer is formed in the troposphere and can be recognized as a "dust accumulating container", which provides abundant dust particles to be transported later to the downstream areas. Additionally, the topographic features of East Asia also exert a great influence on dust transport. Generally, the easterly CLLJ enhances the easterly dust transport. The down-slope air current over the southern Sayan Mountains and the air flow surrounding the TP near its northeastern edge enhance the southward dust

  19. PROPERTIES AND SPATIAL DISTRIBUTION OF DUST EMISSION IN THE CRAB NEBULA

    Energy Technology Data Exchange (ETDEWEB)

    Temim, Tea; Sonneborn, George; Dwek, Eli; Arendt, Richard G. [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gehrz, Robert D. [Minnesota Institute for Astrophysics, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States); Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Roellig, Thomas L., E-mail: tea.temim@nasa.gov [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-1000 (United States)

    2012-07-01

    Recent infrared (IR) observations of freshly formed dust in supernova remnants have yielded significantly lower dust masses than predicted by theoretical models and measured from high-redshift observations. The Crab Nebula's pulsar wind is thought to be sweeping up freshly formed supernova (SN) dust along with the ejected gas. The evidence for this dust was found in the form of an IR excess in the integrated spectrum of the Crab and in extinction against the synchrotron nebula that revealed the presence of dust in the filament cores. We present the first spatially resolved emission spectra of dust in the Crab Nebula acquired with the Infrared Spectrograph on board the Spitzer Space Telescope. The IR spectra are dominated by synchrotron emission and show forbidden line emission from S, Si, Ne, Ar, O, Fe, and Ni. We derived a synchrotron spectral map from the 3.6 and 4.5 {mu}m images, and subtracted this contribution from our data to produce a map of the residual continuum emission from dust. The dust emission appears to be concentrated along the ejecta filaments and is well described by an amorphous carbon or silicate grain compositions. We find a dust temperature of 55 {+-} 4 K for silicates and 60 {+-} 7 K for carbon grains. The total estimated dust mass is (1.2-12) Multiplication-Sign 10{sup -3} M{sub Sun }, well below the theoretical dust yield predicted for a core-collapse supernova. Our grain heating model implies that the dust grain radii are relatively small, unlike what is expected for dust grains formed in a Type IIP SN.

  20. Milky Way Tomography IV: Dissecting Dust

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Michael; /Washington U., Seattle, Astron. Dept. /Rutgers U., Piscataway; Ivezic, Zeljko; /Washington U., Seattle, Astron. Dept.; Sesar, Branimir; /Caltech; Juric, Mario; /Harvard U., Phys. Dept.; Schlafly, Edward F.; /Harvard-Smithsonian Ctr. Astrophys.; Bellovary, Jillian; /Michigan U.; Finkbeiner, Douglas; /Harvard-Smithsonian Ctr. Astrophys.; Vrbanec, Dijana; /Zagreb U.; Beers, Timothy C.; /Natl. Solar Observ., Tucson; Brooks, Keira J.; /Washington U., Seattle, Astron. Dept.; Schneider, Donald P.; /Penn State U. /Washington U., Seattle, Astron. Dept.

    2011-11-01

    intrinsic scatter of R{sub V} in the regions probed by SEGUE stripes is {approx} 0.2. We introduce a method for efficient selection of candidate red giant stars in the disk, dubbed 'dusty parallax relation', which utilizes a correlation between distance and the extinction along the line of sight. We make these best-fit parameters, as well as all the input SDSS and 2MASS data, publicly available in a user-friendly format. These data can be used for studies of stellar number density distribution, the distribution of dust properties, for selecting sources whose SED differs from SEDs for high-latitude main sequence stars, and for estimating distances to dust clouds and, in turn, to molecular gas clouds.

  1. IDIS Small Bodies and Dust Node

    Science.gov (United States)

    de Sanctis, M. C.; Capria, M. T.; Carraro, F.; Fonte, S.; Giacomini, L.; Turrini, D.

    2009-04-01

    The EuroPlaNet information service provides access to lists of researchers, laboratories and data archives relevant to many aspects of planetary and space physics. Information can be accessed through EuroPlaNet website or, for advanced searches, via web-services available at the different thematic nodes. The goal of IDIS is to provide easy-to-use access to resources like people, laboratories, modeling activities and data archives related to planetary sciences. The development of IDIS is an international effort started under the European Commission's 6th Framework Programme and which will expand its capabilities during the 7th Framework Programme, as part of the Capacities Specific Programme/Research Infrastructures. IDIS is complemented by a set of other EuroPlaNet web-services maintained under the responsibility of separate institutions. Each activity maintains its own web-portal with cross-links pointing to the other elements of EuroPlaNet. General access is provided via the EuroPlaNet Homepage. IDIS is not a repository of original data but rather supports the access to various data sources. The final goal of IDIS is to provide Virtual Observatory tools for the access to data from laboratory measurements and ground- and spaced-based observations to modeling results, allowing the combination of as divergent data sources as feasible. IDIS is built around four scientific nodes located in different European countries. Each node deals with a subset of the disciplines related to planetary sciences and, working in cooperation with international experts in these fields, provides a wealth of information to the international planetary science community. The EuroPlaNet IDIS thematic node "Small Bodies and Dust Node" is hosted by the Istituto di Fisica dello Spazio Interplanetario and is established in close cooperation with the Istituto di Astrofisica Spaziale. Both these institutes are part of the Istituto Nazionale di Astrofisica (INAF). The IDIS Small Bodies and Dust

  2. Dust emissions from unpaved roads on the Colorado Plateau

    Science.gov (United States)

    Duniway, M.; Flagg, C.; Belnap, J.

    2013-12-01

    On the Colorado Plateau, elevated levels of aeolian dust have become a major land management and policy concern due to its influence on climate, weather, terrestrial ecosystem dynamics, landscape development and fertility, melting of snow and ice, air quality, and human health. Most desert soil surfaces are stabilized by plants, rocks, and/or physical or biological soil crusts, but once disturbed, sediment production from these surfaces can increase dramatically. Road development and use is a common surface disturbing activity in the region. The extent and density of roads and road networks is rapidly increasing due to continued energy exploration, infrastructure development, and off-highway recreation activities. Though it is well known that unpaved roads produce dust, the relative contribution of dust from existing roads or the implications of future road development to regional dust loading is unknown. To address this need, we have initiated a multifaceted research effort to evaluating dust emissions from unpaved roads regionally. At 34 sites arranged across various road surfaces and soil textures in southeastern Utah, we are: 1) monitoring dust emissions, local wind conditions, and vehicle traffic and 2) evaluating fugitive dust potential using a portable wind tunnel and measuring road characteristics that affect dust production. We will then 3) develop a GIS-based model that integrates results from 1 & 2 to estimate potential dust contributions from current and future scenarios of regional road development. Passive, horizontal sediment traps were installed at three distances downwind from the road edge. One control trap was placed upwind of the samplers to account for local, non-road dust emissions. An electronic vehicle counter and anemometer were also installed at monitoring sites. Dust samples were collected every three months at fixed heights, 15 cm up to 100 cm above the soil surface, from March 2010 to the present. Threshold friction velocities (TFV

  3. Experiment study on the propagation laws of gas and coal dust explosion in coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Rong-jun Si; Run-zhi Li; Lei Wang; Zi-ke Wu [China Coal Research Institute, Chongqing (China). Chongqing Research Institute

    2009-09-15

    An experiment of gas and coal dust explosion propagation in a single laneway was carried out in a large experimental roadway that is nearly the same with actual environment and geometry conditions. In the experiment, the time when the gas and coal dust explosion flame reaches test points has a logarithmic function relation with the test point distances. The explosion flame propagation velocity rises rapidly in the foreside of the coal dust segment and then decreases. The length of the flame area is about 2 times that of the original coal dust accumulation area. Shock wave pressure comes down to the rock bottom in the coal dust segment, then reaches a maximum peak rapidly and decreases. The theoretical basis of the research and assemble of across or explosion is supplied by the experiment conclusion. Compared with gas explosion, the force and destruction degree of a gas and coal dust explosion is much larger. 3 refs., 6 figs., 3 tabs.

  4. The dust morphology of the elliptical Galaxy M86 with SPIRE

    CERN Document Server

    Gomez, H L; Cortese, L; Smith, M W L; Boselli, A; Ciesla, L; Bendo, G J; Pohlen, M; Alighieri, S di Serego; Auld, R; Barlow, M J; Bock, J J; Bradford, M; Buat, V; Castro-Rodriguez, N; Chanial, P; Charlot, S; Clements, D L; Cooray, A; Cormier, D; Davies, J I; Dwek, E; Eales, S; Elbaz, D; Galametz, M; Galliano, F; Gear, W K; Glenn, J; Griffin, M; Hony, S; Isaak, K G; Levenson, L R; Lu, N; Madden, S; O'Halloran, B; Okumura, K; Oliver, S; Page, M J; Panuzzo, P; Papageorgiou, A; Parkin, T J; Perez-Fournon, I; Rangwala, N; Rigby, E E; Roussel, H; Rykala, A; Sacchi, N; Sauvage, M; Schirm, M R P; Schulz, B; Spinoglio, L; Srinivasan, S; Stevens, J A; Symeonidis, M; Trichas, M; Vaccari, M; Vigroux, L; Wilson, C D; Wozniak, H; Wright, G S; Zeilinger, W W

    2010-01-01

    We present Herschel-SPIRE observations at 250-500um of the giant elliptical galaxy M86 and examine the distribution of the resolved cold dust emission and its relation with other galactic tracers. The SPIRE images reveal three dust components: emission from the central region; a dust lane extending north-south; and a bright emission feature 10kpc to the south-east. We estimate that approximately 10^6 solar masses of dust is spatially coincident with atomic and ionized hydrogen, originating from stripped material from the nearby spiral NGC4438 due to recent tidal interact