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Sample records for occult hepadnavirus infection

  1. Serological and molecular evidence of hepadnavirus infection in swine

    Yasmine R Vieira

    2015-02-01

    Full Text Available [b]Introduction and objective[/b]. Recently, investigations in a swine herd identified evidence of the existence of a novel member of the Hepadnavirus family endemic in swine. The aim of this study was to investigate the serological and molecular markers of Hepadnavirus circulation in Brazilian domestic swine and wild boar herds, and to evaluate the identity with HBV and other Hepadnaviruses reported previously. [b]Materials and methods[/b]. For the study, 376 swine were screened for hepatitis B virus serological markers. Analyses were performed in serum samples using commercial enzyme-linked immunosorbent assay (ELISA kits (DiaSorin® for anti-HBc, HBsAg and anti-HBs. Reactive and undetermined swine serum samples were selected to perform DNA viral extraction (QIAamp DNA Mini Kit, Qiagen®, partial genome amplification and genome sequencing. [b]Results[/b]. From 376 swine samples analysed, 28 (7.45% were reactive to anti-HBc, 3 (0.80% to HBsAg and 6 (1.6% to anti-HBs. Besides, more 17 (4.52% swine samples analyzed were classified in the grey zone of the EIA test to anti-HBc and 2 (0.53% to HBsAg. From 49 samples molecularly analyzed after serological trial, 4 samples showed a positive result for the qualitative PCR for Hepadnavirus. Phylogenetic reconstruction using partial genome sequencing (360 bp of 3 samples showed similarity with HBV with 90.8–96.3% of identity. [b]Conclusions.[/b] Serological and molecular data showed evidence of the circulation of a virus similar to hepatitis B virus in swine.

  2. Occult hepatitis B infection: an evolutionary scenario

    Lukashov Vladimir V

    2008-12-01

    Full Text Available Abstract Background Occult or latent hepatitis B virus (HBV infection is defined as infection with detectable HBV DNA and undetectable surface antigen (HBsAg in patients' blood. The cause of an overt HBV infection becoming an occult one is unknown. To gain insight into the mechanism of the development of occult infection, we compared the full-length HBV genome from a blood donor carrying an occult infection (d4 with global genotype D genomes. Results The phylogenetic analysis of polymerase, core and X protein sequences did not distinguish d4 from other genotype D strains. Yet, d4 surface protein formed the evolutionary outgroup relative to all other genotype D strains. Its evolutionary branch was the only one where accumulation of substitutions suggests positive selection (dN/dS = 1.3787. Many of these substitutiions accumulated specifically in regions encoding the core/surface protein interface, as revealed in a 3D-modeled protein complex. We identified a novel RNA splicing event (deleting nucleotides 2986-202 that abolishes surface protein gene expression without affecting polymerase, core and X-protein related functions. Genotype D strains differ in their ability to perform this 2986-202 splicing. Strains prone to 2986-202 splicing constitute a separate clade in a phylogenetic tree of genotype D HBVs. A single substitution (G173T that is associated with clade membership alters the local RNA secondary structure and is proposed to affect splicing efficiency at the 202 acceptor site. Conclusion We propose an evolutionary scenario for occult HBV infection, in which 2986-202 splicing generates intracellular virus particles devoid of surface protein, which subsequently accumulates mutations due to relaxation of coding constraints. Such viruses are deficient of autonomous propagation and cannot leave the host cell until it is lysed.

  3. Fecal Occult Blood Test and Gastrointestinal Parasitic Infection

    Majed H. Wakid

    2010-01-01

    Full Text Available Stool specimens of 1238 workers in western region of Saudi Arabia were examined for infection with intestinal parasites and for fecal occult blood (FOB to investigate the possibility that enteroparasites correlate to occult intestinal bleeding. Direct smears and formal ether techniques were used for detection of diagnostic stages of intestinal parasites. A commercially available guaiac test was used to detect fecal occult blood. 47.01% of the workers were infected with intestinal parasites including eight helminthes species and eight protozoan species. The results provided no significant evidence (P-value=0.143 that intestinal parasitic infection is in association with positive guaiac FOB test.

  4. Diagnostic strategy for occult hepatitis B virus infection

    Ocana, Sara; Casas, Maria Luisa; Buhigas, Ingrid; Lledo, Jose Luis

    2011-01-01

    In 2008, the European Association for the study of the liver (EASL) defined occult hepatitis B virus infection (OBI) as the “presence of hepatitis B virus (HBV) DNA in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing hepatitis B surface antigen (HBsAg) negative by currently available assays”. Several aspects of occult HBV infection are still poorly understood, including the definition itself and a standardized approach for laboratory-based detection, which is the purpose of this review. The clinical significance of OBI has not yet been established; however, in terms of public health, the clinical importance arises from the risk of HBV transmission. Consequently, it is important to detect high-risk groups for occult HBV infection to prevent transmission. The main issue is, perhaps, to identify the target population for screening OBI. Viremia is very low or undetectable in occult HBV infection, even when the most sensitive methods are used, and the detection of the viral DNA reservoir in hepatocytes would provide the best evaluation of occult HBV prevalence in a defined set of patients. However, this diagnostic approach is obviously unsuitable: blood detection of occult hepatitis B requires assays of the highest sensitivity and specificity with a lower limit of detection < 10 IU/mL for HBV DNA and < 0.1 ng/mL for HBsAg. PMID:21472120

  5. A Novel Hepadnavirus Identified in an Immunocompromised Domestic Cat in Australia

    Mahdis Aghazadeh

    2018-05-01

    Full Text Available High-throughput transcriptome sequencing allows for the unbiased detection of viruses in host tissues. The application of this technique to immunosuppressed animals facilitates the detection of viruses that might otherwise be excluded or contained in immunocompetent individuals. To identify potential viral pathogens infecting domestic cats we performed high-throughput transcriptome sequencing of tissues from cats infected with feline immunodeficiency virus (FIV. A novel member of the Hepadnaviridae, tentatively named domestic cat hepadnavirus, was discovered in a lymphoma sample and its complete 3187 bp genome characterized. Phylogenetic analysis placed the domestic cat hepadnavirus as a divergent member of mammalian orthohepadnaviruses that exhibits no close relationship to any other virus. DNA extracted from whole blood from pet cats was positive for the novel hepadnavirus by PCR in 6 of 60 (10% FIV-infected cats and 2 of 63 (3.2% FIV-uninfected cats. The higher prevalence of hepadnavirus viraemia detected in FIV-infected cats mirrors that seen in human immunodeficiency virus-infected humans coinfected with hepatitis B virus. In summary, we report the first hepadnavirus infection in a carnivore and the first in a companion animal. The natural history, epidemiology and pathogenic potential of domestic cat hepadnavirus merits additional investigation.

  6. Detection of occult HBV infection by nested PCR assay among ...

    Occult hepatitis B virus infection (OBI) has been reported among patients with chronic hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). This study aimed to evaluate the prevalence of OBI in chronic hepatitis C patients with and without hepatocellular carcinoma. A total of 40 chronic hepatitis C patients ...

  7. Occult hepatitis B virus infection in immunocompromised patients

    Ruth Nogueira Cordeiro Moraes Jardim

    Full Text Available Occult hepatitis B infection is characterized by hepatitis B virus (HBV DNA in the serum in the absence of hepatitis B surface antigen (HBsAg. We assessed occult HBV infection prevalence in two groups of immunocompromised patients (maintenance hemodialysis patients and HIV-positive patients presenting HBsAg-negative and anti-HBc positive serological patterns, co-infected or not by HCV. Thirty-four hemodialysis anti-HIV negative patients, 159 HIV-positive patients and 150 blood donors who were anti-HBc positive (control group were selected. HBV-DNA was detected by nested-PCR. Occult hepatitis B infection was not observed in the hemodialysis patients group but was found in 5% of the HIV-patients and in 4% of the blood donors. Immunosuppression in HIV positive patients was not a determining factor for occult HBV infection. In addition, no significant relationship between HBV-DNA and HCV co-infection in the HIV-positive patient group was found. A lack of significant associations was also observed between positivity for HBV-DNA and CD4 count, viral load and previous lamivudine treatment in these HIV-positive patients.

  8. Occult HBV infection in HIV-infected adults and evaluation of pooled NAT for HBV.

    Dinesha, T R; Boobalan, J; Sivamalar, S; Subashini, D; Solomon, S S; Murugavel, K G; Balakrishnan, P; Smith, D M; Saravanan, S

    2018-01-06

    The study aimed to determine the prevalence of occult hepatitis B virus infection among HIV-infected persons and to evaluate the use of a pooling strategy to detect occult HBV infection in the setting of HIV infection. Five hundred and two HIV-positive individuals were tested for HBV, occult HBV and hepatitis C and D with serologic and nucleic acid testing (NAT). We also evaluated a pooled NAT strategy for screening occult HBV infection among the HIV-positive individuals. The prevalence of HBV infection among HIV-positive individuals was 32 (6.4%), and occult HBV prevalence was 10%. The pooling HBV NAT had a sensitivity of 66.7% and specificity of 100%, compared to HBV DNA NAT of individual samples. In conclusion, this study found a high prevalence of occult HBV infection among our HIV-infected population. We also demonstrated that pooled HBV NAT is highly specific, moderately sensitive and cost-effective. As conventional HBV viral load assays are expensive in resource-limited settings such as India, pooled HBV DNA NAT might be a good way for detecting occult HBV infection and will reduce HBV-associated complications. © 2018 John Wiley & Sons Ltd.

  9. Multiple surface antigen mutations in five blood donors with occult hepatitis B virus infection

    Zaaijer, H. L.; Torres, P.; Ontañón, A.; Ponte, L. González; Koppelman, M. H. G. M.; Lelie, P. N.; Hemert, F. J. van; Boot, H. J.

    2008-01-01

    Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA while the HBV surface antigen (HBsAg) remains undetectable. The HBV genomes in five asymptomatic blood donors with occult HBV infection and low viremia ( <10 to 1,000 HBV DNA copies/mL, genotype D) were studied. An

  10. Occult hepatitis B infection and transfusion-transmission risk.

    Candotti, D; Boizeau, L; Laperche, S

    2017-09-01

    Advances in serology and viral nucleic acid testing (NAT) over the last decades significantly reduced the risk of transfusion-transmitted hepatitis B virus (HBV). The combination of HBsAg testing and NAT efficiently prevents the majority of HBV transmission. However, a specific residual risk remains associated with extremely low viral DNA levels in blood donors with occult HBV infection (OBI) that are intermittently or not detectable even by highly sensitive individual donation (ID) NAT. Studies have reported HBV transfusion-transmission with blood components from donors with OBI that contained low amount of viruses (transfusion-transmission seems to depend on a combination of several factors including the volume of plasma associated with the infected blood components transfused, the anti-HBV immune status of both recipient and donor, and possibly the viral fitness of the infecting HBV strain. Models based on clinical and experimental evidences estimate a residual transmission risk of 3-14% associated with OBI donations testing HBsAg and ID-NAT non-reactive. Anti-HBc testing has the potential to improve further blood safety but it may also compromise blood availability in settings with medium/high HBV prevalence. Pathogen reduction procedures might be considered. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Extensive diversity and evolution of hepadnaviruses in bats in China.

    Nie, Fang-Yuan; Lin, Xian-Dan; Hao, Zong-Yu; Chen, Xiao-Nan; Wang, Zhao-Xiao; Wang, Miao-Ruo; Wu, Jun; Wang, Hong-Wei; Zhao, Guoqiang; Ma, Runlin Z; Holmes, Edward C; Zhang, Yong-Zhen

    2018-01-15

    To better understand the evolution of hepadnaviruses, we sampled bats from Guizhou, Henan and Zhejiang provinces, China, and rodents from Zhejiang province. Genetically diverse hepadnaviruses were identified in a broad range of bat species, with an overall prevalence of 13.3%. In contrast, no rodent hepadnaviruses were identified. The newly discovered bat hepadnaviruses fell into two distinct phylogenetic groups. The viruses within the first group exhibited high diversity, with some closely related to viruses previously identified in Yunnan province. Strikingly, the newly discovered viruses sampled from Jiyuan city in the second phylogenetic group were most closely related to those found in bats from West Africa, suggestive of a long-term association between bats and hepadnaviruses. A co-phylogenetic analysis revealed frequent cross-species transmission among bats from different species, genera, and families. Overall, these data suggest that there are likely few barriers to the cross-species transmission of bat hepadnaviruses. Copyright © 2017. Published by Elsevier Inc.

  12. Occult hepatitis B infection in children with chronic liver disease.

    Srivastava, Anshu; Mathias, Amrita; Yachha, Surender K; Aggarwal, Rakesh

    2015-04-01

    Occult hepatitis B infection (OBI) may adversely affect the outcome of patients with chronic liver disease (CLD). There are no data on OBI and CLD in children. This study determined the prevalence and effect of OBI in HBsAg-negative CLD children. CLD children were prospectively evaluated with a demographic, clinical, and investigative proforma. All HBsAg-negative CLD cases were tested for exposure to hepatitis B (total anti-HBc, anti-HBs). Serum hepatitis B virus DNA was measured in exposed (total anti-HBc positive) patients. A total of 115 HBsAg-negative CLD children (59 boys, age 9.0±3.6 years) were enrolled. The etiology of CLD was known in 94 cases and 21 children had cryptogenic CLD. Of these, 45 (39.1%) had evidence of HBV exposure (23 total anti-HBc positive, 17 total anti-HBc and anti-HBs positive, five only anti-HBs positive without previous vaccination). The anti-HBc-positive children had a higher Child's score than the anti-HBc-negative children [11 (5-13) vs. 7 (5-13); P=0.00]. A total of 4/45 children had seropositive OBI with serum HBV DNA of 8, 36, 133, and 156 IU/ml, respectively. The proportion of total anti-HBc positivity (8/21 vs. 32/94; P=0.8) and OBI (2/21 vs. 2/94; P=0.1) was similar in cryptogenic CLD and known cause CLD. Seropositive OBI is infrequent in Indian children with CLD. The prevalence is similar in cryptogenic and CLD of known etiology.

  13. Prevalence of occult hepatitis B virus infection in haemodialysis patients from central Greece

    Mina, Paraskevi; Georgiadou, Sarah P; Rizos, Christos; Dalekos, George N; Rigopoulou, Eirini I

    2010-01-01

    AIM: To assess the hepatitis B virus (HBV)-DNA and the prevalence of occult HBV infection in end-stage renal failure (ESRF) patients from Central Greece. METHODS: Sera from 366 ESRF patients attending five out of six dialysis units from Central Greece were investigated for HBV-DNA by real-time polymerase chain reaction. Only serum samples with repeatedly detectable HBV-DNA were considered positive. IgG antibodies to hepatitis C virus (anti-HCV) were tested by a third generation enzyme linked immunosorbent assay (ELISA), while IgG antibodies to hepatitis E virus (anti-HEV) were tested by two commercially available ELISAs. RESULTS: HBV-DNA was detected in 15/366 patients (4.1%) and HBsAg in 20/366 (5.5%). The prevalence of occult HBV infection was 0.9% (3/346 HBsAg-negative patients). Occult HBV was not associated with a specific marker of HBV infection or anti-HCV or anti-HEV reactivity. There was no significant difference in HBV-DNA titres, demographic and biochemical features, between patients with occult HBV infection and those with HBsAg-positive chronic HBV infection. CONCLUSION: In central Greece, 4% of ESRF patients had detectable HBV-DNA, though in this setting, the prevalence of occult HBV seems to be very low (0.9%). PMID:20066742

  14. Prevalence of occult hepatitis C virus infection in the Iranian patients with human immunodeficiency virus infection.

    Bokharaei-Salim, Farah; Keyvani, Hossein; Esghaei, Maryam; Zare-Karizi, Shohreh; Dermenaki-Farahani, Sahar-Sadat; Hesami-Zadeh, Khashayar; Fakhim, Shahin

    2016-11-01

    Occult hepatitis C virus (HCV) infection is a new form of chronic HCV infection described by the presence of the genomic HCV-RNA in liver biopsy and/or peripheral blood mononuclear cell (PBMC) samples, and undetectable levels or absence of HCV-RNA and in the absence or presence of anti HCV antibodies in the plasma specimens. The aim of the present study was to evaluate the occurrence of occult HCV infection (OCI) among Iranian subjects infected with human immunodeficiency virus (HIV) using RT-nested PCR. From March 2014 until April 2015, 109 Iranian patients with established HIV infection were enrolled in this cross-sectional study. After extraction of viral RNA from the plasma and PBMC samples, HCV-RNA status was examined by RT-nested PCR using primers from the 5'-NTR. HCV genotyping was conducted using RFLP analysis. For the confirmation of HCV genotyping by RFLP method, the PCR products were sequenced. Of the 109 patients, 50 were positive for antibodies against HCV. The HCV-RNA was detected in PBMC specimens in 6 (10.2%) out of the total 59 patients negative for anti-HCV Abs and undetectable plasma HCV-RNA and also from 4 (8.0%) out of the total 50 patients positive for anti-HCV Abs and undetectable plasma HCV-RNA. HCV genotyping analysis showed that 6 (60.0%) patients were infected with HCV subtype 3a, 3 (30.0%) were infected with HCV subtype 1a and 1 (10.0%) patient was infected with HCV subtype 1b. This study revealed the incidence of OCI (9.2%) in HIV-infected Iranian patients. Hence, designing prospective studies focusing on the detection of OCI in these patients would provide more information. J. Med. Virol. 88:1960-1966, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Infectivity of blood products from donors with occult hepatitis B virus infection

    Allain, Jean-Pierre; Mihaljevic, Ivanka; Gonzalez-Fraile, Maria Isabel

    2013-01-01

    BACKGROUND: Occult hepatitis B virus (HBV) infection (OBI) is identified in 1:1000 to 1:50,000 European blood donations. This study intended to determine the infectivity of blood products from OBI donors. STUDY DESIGN AND METHODS: Recipients of previous donations from OBI donors were investigated...... blood cells [RBCs], p Donor and recipient strains sequence homology of at least 99% confirmed transfusion-transmitted infection in 10 cases and excluded it in one case. CONCLUSION: Blood...... through lookback (systematic retrieval of recipients) or traceback (triggered by clinical cases). Serologic and genomic studies were undertaken on consenting donors and recipients. Multiple variables potentially affecting infectivity were examined. RESULTS: A total of 45 of 105 (42.9%) donor...

  16. Characterization of a novel hepadnavirus in the white sucker (Catostomus commersonii) from the Great Lakes Region of the USA

    Hahn, Cassidy M.; Iwanowicz, Luke R.; Cornman, Robert S.; Conway, Carla M.; Winton, James R.; Blazer, Vicki S.

    2015-01-01

    The white sucker Catostomus commersonii is a freshwater teleost often utilized as a resident sentinel. Here, we sequenced the full genome of a hepatitis B-like virus that infects white suckers from the Great Lakes Region of the USA. Dideoxysequencing confirmed the white sucker hepatitis B virus (WSHBV) has a circular genome (3542 bp) with the prototypical codon organization of hepadnaviruses. Electron microscopy demonstrated that complete virions of approximately 40 nm were present in the plasma of infected fish. Compared to avi- and orthohepadnaviruses, sequence conservation of the core, polymerase and surface proteins was low and ranged from 16-27% at the amino acid level. An X protein homologue common to the orthohepadnaviruses was not present. The WSHBV genome included an atypical, presumptively non-coding region absent in previously described hepadnaviruses. Phylogenetic analyses confirmed WSHBV as distinct from previously documented hepadnaviruses. The level of divergence in protein sequences between WSHBV other hepadnaviruses, and the identification of an HBV-like sequence in an African cichlid provide evidence that a novel genus of the family Hepadnaviridae may need to be established that includes these hepatitis B-like viruses in fishes. Viral transcription was observed in 9.5% (16 of 169) of white suckers evaluated. The prevalence of hepatic tumors in these fish was 4.9%, of which only 2.4% were positive for both virus and hepatic tumors. These results are not sufficient to draw inferences regarding the association of WSHBV and carcinogenesis in white sucker.

  17. Endogenous hepadnaviruses, bornaviruses and circoviruses in snakes.

    Gilbert, C; Meik, J M; Dashevsky, D; Card, D C; Castoe, T A; Schaack, S

    2014-09-22

    We report the discovery of endogenous viral elements (EVEs) from Hepadnaviridae, Bornaviridae and Circoviridae in the speckled rattlesnake, Crotalus mitchellii, the first viperid snake for which a draft whole genome sequence assembly is available. Analysis of the draft assembly reveals genome fragments from the three virus families were inserted into the genome of this snake over the past 50 Myr. Cross-species PCR screening of orthologous loci and computational scanning of the python and king cobra genomes reveals that circoviruses integrated most recently (within the last approx. 10 Myr), whereas bornaviruses and hepadnaviruses integrated at least approximately 13 and approximately 50 Ma, respectively. This is, to our knowledge, the first report of circo-, borna- and hepadnaviruses in snakes and the first characterization of non-retroviral EVEs in non-avian reptiles. Our study provides a window into the historical dynamics of viruses in these host lineages and shows that their evolution involved multiple host-switches between mammals and reptiles. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  18. Naturally occurring mutations in large surface genes related to occult infection of hepatitis B virus genotype C.

    Hong Kim

    Full Text Available Molecular mechanisms related to occult hepatitis B virus (HBV infection, particularly those based on genotype C infection, have rarely been determined thus far in the ongoing efforts to determine infection mechanisms. Therefore, we aim to elucidate the mutation patterns in the surface open reading frame (S ORF underlying occult infections of HBV genotype C in the present study. Nested PCRs were applied to 624 HBV surface antigen (HBsAg negative Korean subjects. Cloning and sequencing of the S ORF gene was applied to 41 occult cases and 40 control chronic carriers. Forty-one (6.6% of the 624 Korean adults with HBsAg-negative serostatus were found to be positive for DNA according to nested PCR tests. Mutation frequencies in the three regions labeled here as preS1, preS2, and S were significantly higher in the occult subjects compared to the carriers in all cases. A total of two types of deletions, preS1 deletions in the start codon and preS2 deletions as well as nine types of point mutations were significantly implicated in the occult infection cases. Mutations within the "a" determinant region in HBsAg were found more frequently in the occult subjects than in the carriers. Mutations leading to premature termination of S ORF were found in 16 occult subjects (39.0% but only in one subject from among the carriers (2.5%. In conclusion, our data suggest that preS deletions, the premature termination of S ORF, and "a" determinant mutations are associated with occult infections of HBV genotype C among a HBsAg-negative population. The novel mutation patterns related to occult infection introduced in the present study can help to broaden our understanding of HBV occult infections.

  19. [Prevalence of occult hepatitis B virus infection and its phylogenetic features among mother-teenager pairs].

    Dong, Xiao-lian; Yao, Qing-qing; Wang, Xue-cai; Xu, Hai-tao; Wang, Xiao-li; Chen, Sheng-yu; Tang, Zhi-feng; Zheng, Ying-Jie

    2013-03-01

    Prevalence of occult hepatitis B virus (HBV) infection (OBI) was investigated in a paired mother-teenager population and HBV S gene variation including overt and occult HBV, was determined. A follow-up study based on an initial survey of 135 mother-teenager pairs was carried out through collection of questionnaires and blood samples HBsAg were detected by ELISA method, viral load by PCR amplification and HBV S gene by phylogenetic analysis. 102 pairs of subjects were followed-up. Blood samples from 94 mothers and 101 children were collected. OBI prevalence in mothers was 10.0% (6/60), significantly higher than 2.0% (2/101) in teenagers. Medians of viral load were 399.9 IU/ml and 247.6 IU/ml in overt and occult HBV strains, but without significant difference. 1 occult HBV strain belonged to genotype B with serotype adw while the other 7 were genotype C with serotype adr. 15 of the overt HBV strains belonged to genotype B with serotype adw and the other 8 were genotype C with serotype adr. Proportions of genotype-C strains were significantly higher in occult HBV strains than in overt HBV strains. OBI was seen in teenage-mother population.

  20. Significance of occult hbv infection in patients with chronic hepatitis c

    Anwar, W.; Sarwar, M.; Saif, M.; Hussain, A.B.; Tariq, W.Z.

    2006-01-01

    Objective: To determine the frequency of occurrence of occult Hepatitis B infection in chronic hepatitis C patients and its impact (if any) on the effectivity of standard chronic hepatitis C treatment. Design: Quasi-experimental study. Place and Duration of Study: The study was conducted at the Department of Medicine, Military Hospital, Rawalpindi, and Virology Department, Armed Forces Institute of Pathology, Rawalpindi, for a period of nine months from January 2003 to September 2003. Patients and Methods: This study was conducted on 30 HBsAg negative patients with chronic hepatitis C liver disease who were receiving combination therapy with interferon and ribavirin. Occult hepatitis B infection was assessed by carrying out HBV DNA by polymerase chain reaction (PCR) in the sera of these patients. Markers of previous hepatitis B infection Le; anti-HBs and total anti-HBc antibodies were also tested. Response to treatment for hepatitis C (with interferon and ribavirin) was assessed at the end of six months of therapy by measuring ALT levels and HCV RNA by PCR in the serum. Results: In our study only one patient (3.33%) was found to be harbouring HBV DNA in the serum detectable by PCR, with markers of previous HBV infection (both anti HBc antibodies and anti HBs antibodies were positive). A total 14 patients (46.67%) had markers of previous HBV infection, while 16 patients (53.33%) had no such sero markers. Twenty five out of 30 patients (83.33%) responded to treatment and 5 (16.66%) turned out to be non-responders. The single case of occult hepatitis B detected in this study responded to hepatitis C treatment. Conclusion: Occult hepatitis B is not a common occurrence in chronic hepatitis C patients and it did not alter the outcome of treatment for hepatitis C in our study. (author)

  1. HBV vaccination of HCV-infected patients with occult HBV infection and anti-HBc-positive blood donors

    J.S.F. Pereira

    2006-04-01

    Full Text Available Anti-HBc positivity is a frequent cause of donation rejection at blood banks. Hepatitis B virus (HBV infection may also occur in HBsAg-negative patients, a situation denoted occult infection. Similarly, very low levels of HBV-DNA have also been found in the sera of patients with chronic hepatitis C virus (HCV infection, even in the absence of serum HBsAg. Initially we searched for HBV-DNA in serum of 100 blood donors and 50 HCV-infected patients who were HBsAg negative/anti-HBc positive by nested-PCR and by an HBV monitor commercial test for HBV-DNA. Anti-HBs seroconversion rates were measured in 100 blood donors and in 22 patients with chronic HCV infection after HBV vaccination to determine if the HBV vaccination could eliminate an occult HBV infection in these individuals. Occult HBV infection was detected in proportionally fewer blood donors (6/100 = 6% than chronic hepatitis C patients (12/50 = 24% (P 0.05. All subjects who were HBV-DNA(+ before the first dose of HBV vaccine (D1, became HBV-DNA(- after D1, D2, and D3. Among 22 HCV-positive patients, 10 HBV-DNA(+ and 12 HBV-DNA(-, seroconversion was observed in 9/10 (90% HBV-DNA(+ and in 9/12 (75% HBV-DNA(- subjects (P > 0.05. The disappearance of HBV-DNA in the majority of vaccinated patients suggests that residual HBV can be eliminated in patients with occult infection.

  2. Characterization of a Novel Hepadnavirus in the White Sucker (Catostomus commersonii) from the Great Lakes Region of the United States.

    Hahn, Cassidy M; Iwanowicz, Luke R; Cornman, Robert S; Conway, Carla M; Winton, James R; Blazer, Vicki S

    2015-12-01

    The white sucker Catostomus commersonii is a freshwater teleost often utilized as a resident sentinel. Here, we sequenced the full genome of a hepatitis B-like virus that infects white suckers from the Great Lakes Region of the United States. Dideoxy sequencing confirmed that the white sucker hepatitis B virus (WSHBV) has a circular genome (3,542 bp) with the prototypical codon organization of hepadnaviruses. Electron microscopy demonstrated that complete virions of approximately 40 nm were present in the plasma of infected fish. Compared to avi- and orthohepadnaviruses, sequence conservation of the core, polymerase, and surface proteins was low and ranged from 16 to 27% at the amino acid level. An X protein homologue common to the orthohepadnaviruses was not present. The WSHBV genome included an atypical, presumptively noncoding region absent in previously described hepadnaviruses. Phylogenetic analyses confirmed WSHBV as distinct from previously documented hepadnaviruses. The level of divergence in protein sequences between WSHBV and other hepadnaviruses and the identification of an HBV-like sequence in an African cichlid provide evidence that a novel genus of the family Hepadnaviridae may need to be established that includes these hepatitis B-like viruses in fishes. Viral transcription was observed in 9.5% (16 of 169) of white suckers evaluated. The prevalence of hepatic tumors in these fish was 4.9%, and only 2.4% of fish were positive for both virus and hepatic tumors. These results are not sufficient to draw inferences regarding the association of WSHBV and carcinogenesis in white sucker. We report the first full-length genome of a hepadnavirus from fishes. Phylogenetic analysis of this genome indicates divergence from genomes of previously described hepadnaviruses from mammalian and avian hosts and supports the creation of a novel genus. The discovery of this novel virus may better our understanding of the evolutionary history of hepatitis B-like viruses of

  3. Prediction of occult hepatitis B virus infection in liver transplant donors through hepatitis B virus blood markers.

    Tandoi, Francesco; Caviglia, Gian Paolo; Pittaluga, Fabrizia; Abate, Maria Lorena; Smedile, Antonina; Romagnoli, Renato; Salizzoni, Mauro

    2014-11-01

    Occult hepatitis B virus infection is defined as detectable HBV-DNA in liver of HBsAg-negative individuals, with or without detectable serum HBV-DNA. In deceased liver donors, results of tissue analysis cannot be obtained prior to allocation for liver transplantation. we investigated prevalence and predictability of occult hepatitis B using blood markers of viral exposure/infection in deceased liver donors. In 50 consecutive HBsAg-negative/anti-HBc-positive and 20 age-matched HBsAg-negative/anti-HBc-negative donors, a nested-PCR assay was employed in liver biopsies for diagnosis of occult hepatitis B according to Taormina criteria. All donors were characterized for plasma HBV-DNA and serum anti-HBs/anti-HBe. In liver tissue, occult hepatitis B was present in 30/50 anti-HBc-positive (60%) and in 0/20 anti-HBc-negative donors (pdonors with detectable HBV-DNA in plasma (n=5) or anti-HBs>1,000 mIU/mL (n=5) eventually showed occult infection, i.e, 10/30 occult hepatitis B-positive donors which could have been identified prior to transplantation. In the remaining 40 anti-HBc-positive donors, probability of occult infection was 62% for anti-HBe-positive and/or anti-HBs ≥ 58 mIU/mL; 29% for anti-HBe-negative and anti-HBsdonors, combining anti-HBc with other blood markers of hepatitis B exposure/infection allows to predict occult hepatitis B with certainty and speed in one third of cases. These findings might help refine the allocation of livers from anti-HBc-positive donors. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  4. Detection of occult HBV infection by nested PCR assay among ...

    Shereen E. Taha

    2013-07-10

    Jul 10, 2013 ... or produce S proteins with aberrant epitopes which are not de- tected by conventional ... Inclusion criteria were: an age of 18 years or over, proven HCV infection based on viral load ...... Revista da Sociedade · Brasileira de ...

  5. Prevalence, risk factors, and impact of isolated antibody to hepatitis B core antigen and occult hepatitis B virus infection in HIV-1-infected pregnant women.

    Khamduang, Woottichai; Ngo-Giang-Huong, Nicole; Gaudy-Graffin, Catherine; Jourdain, Gonzague; Suwankornsakul, Weerapong; Jarupanich, Tapnarong; Chalermpolprapa, Veeradate; Nanta, Sirisak; Puarattana-Aroonkorn, Noossara; Tonmat, Sakchai; Lallemant, Marc; Goudeau, Alain; Sirirungsi, Wasna

    2013-06-01

    Prevalence and risk factors for isolated antibody to hepatitis B core antigen (anti-HBc) and occult hepatitis B virus (HBV) infection are not well known in human immunodeficiency virus type 1 (HIV-1)-infected pregnant women. It is unclear if women with occult infections are at risk of transmitting HBV to their infants. HIV-1-infected and HBV surface antigen (HBsAg)-negative pregnant women were tested for antibody to HBsAg (anti-HBs) and anti-HBc using enzyme immunoassay. Women with isolated anti-HBc were assessed for occult HBV infection, defined as HBV DNA levels >15 IU/mL, using the Abbott RealTime HBV DNA assay. Infants born to women with isolated anti-HBc and detectable HBV DNA were tested at 4 months of age for HBV DNA. Logistic regression analysis was used to identify factors associated with isolated anti-HBc and occult HBV infection. Among 1812 HIV-infected pregnant women, 1682 were HBsAg negative. Fourteen percent (95% confidence interval [CI], 12%-15%) of HBsAg-negative women had an isolated anti-HBc that was independently associated with low CD4 count, age >35 years, birth in northern Thailand, and positive anti-hepatitis C virus serology. Occult HBV infection was identified in 24% (95% CI, 18%-30%) of women with isolated anti-HBc, representing 2.6% (95% CI, 1.9%-3.5%) of HIV-1-infected pregnant women, and was inversely associated with HIV RNA levels. None of the women with isolated anti-HBc and occult HBV infection transmitted HBV to their infants. HIV-1-infected pregnant women with isolated anti-HBc and occult HBV infection have very low HBV DNA levels and are thus at very low risk to transmit HBV to their infants.

  6. Utility of the serum C-reactive protein for detection of occult bacterial infection in children.

    Isaacman, Daniel J; Burke, Bonnie L

    2002-09-01

    To assess the utility of serum C-reactive protein (CRP) as a screen for occult bacterial infection in children. Febrile children ages 3 to 36 months who visited an urban children's hospital emergency department and received a complete blood cell count and blood culture as part of their evaluation were prospectively enrolled from February 2, 2000, through May 30, 2001. Informed consent was obtained for the withdrawal of an additional 1-mL aliquot of blood for use in CRP evaluation. Logistic regression and receiver operator characteristic (ROC) curves were modeled for each predictor to identify optimal test values, and were compared using likelihood ratio tests. Two hundred fifty-six patients were included in the analysis, with a median age of 15.3 months (range, 3.1-35.2 months) and median temperature at triage 40.0 degrees C (range, 39.0 degrees C-41.3 degrees C). Twenty-nine (11.3%) cases of occult bacterial infection (OBI) were identified, including 17 cases of pneumonia, 9 cases of urinary tract infection, and 3 cases of bacteremia. The median white blood cell count in this data set was 12.9 x 10(3)/ micro L [corrected] (range, 3.6-39.1 x10(3)/ micro L) [corrected], the median absolute neutrophil count (ANC) was 7.12 x 10(3)/L [corrected] (range, 0.56-28.16 x10(3)/L) [corrected], and the median CRP level was 1.7 mg/dL (range, 0.2-43.3 mg/dL). The optimal cut-off point for CRP in this data set (4.4 mg/dL) achieved a sensitivity of 63% and a specificity of 81% for detection of OBI in this population. Comparing models using cut-off values from individual laboratory predictors (ANC, white blood cell count, and CRP) that maximized sensitivity and specificity revealed that a model using an ANC of 10.6 x10(3)/L [corrected] (sensitivity, 69%; specificity, 79%) was the best predictive model. Adding CRP to the model insignificantly increased sensitivity to 79%, while significantly decreasing specificity to 50%. Active monitoring of emergency department blood cultures

  7. Genomic variability associated with the presence of occult hepatitis B virus in HIV co-infected individuals

    Martin, C. M.; Welge, J. A.; Shire, N. J.; Rouster, S. D.; Shata, M. T.; Sherman, K. E.; Blackard, J. T.

    2009-01-01

    Occult hepatitis B virus (O-HBV) infection is characterized by the presence of HBV DNA without detectable hepatitis B surface antigen (HBV DNA+/HBsAg−) in the serum. Although O-HBV is more prevalent during HBV/HIV co-infection, analysis of HBV mutations in co-infected patients is limited. In this preliminary study, HBV PreSurface (PreS) and surface (S) regions were amplified from 33 HIV-positive patient serum samples − 27 chronic HBV (C-HBV) and six O-HBV infections. HBV genotype was determin...

  8. Early detection of Haemonchus contortus infection in sheep using three different faecal occult blood tests

    A.V. Rodríguez

    2015-07-01

    Full Text Available Haemonchus contortus is a blood-sucking parasite causing the presence of faecal occult blood (FOB. The objective was to study three different FOB tests in order to have a new indicator of H. contortus infection in sheep that could be included in the genetic evaluation system as an alternative selection criterion to faecal worm egg count (FEC. A total of 29 Corriedale lambs were experimentally infected with 10.000 larvae of H. contortus. Stool samples were recorded for FEC and FOB tests (Hexagon, Hematest® and Multistix®, blood for packed cell volume (PCV, haemoglobin, white and red blood cell count (RBC, and FAMACHA© for scoring anaemia. At the end of the experiment lambs were slaughtered to worm burden count. Field infection was achieved in 309 Merino lambs under natural parasite challenge. FEC data were normalized through logarithmic transformation (LnFEC. Pearson correlation was estimated to examine the relationship between all traits. The three tests were able to detect the presence of FOB at day 11. FEC, PCV and RBC decreased to sub-normal values from day 18. FAMACHA© score 3 was considered to be indicative of anaemia. Most of the correlations were of high magnitude, with the exception of Multistix® test that was moderately correlated with haematological parameters, LnFEC and FEC. In field infection, most samples were negative to FOB tests and the correlations were lower than those calculated under experimental infection. In conclusion, FOB tests were able to detect haemonchosis earlier than FEC under high experimental parasite challenge. However, they were not able to detect FOB under natural mixed parasite challenge. FAMACHA© and PCV demonstrated to be good indicators of Haemonchosis, having moderate to high correlations with FEC.

  9. Clinical experience with 111In tropolonate leucocytes in the detection of occult infection

    Wraight, E.P.

    1988-01-01

    Over a period of 3 years, 275 scans were performed in 233 patients with suspected occult sepsis. A firm diagnosis was ultimately established in 160 cases. 81 sites of infection were correctly identified and there were 77 true negative studies. There were 4 false negative and 7 false positive studies, most of which were due to misinterpreting bowel activity as sepsis and vice versa. In 56 cases CT scans were performed within a few days of the leucocyte study. There was good agreement between the findings. Comparison was possible with ultrasound in 81 cases. In 15 of these ultrasound failed to detect infection in the abdomen which was demonstrated by 111 In leucocytes, suggesting that ultrasound is much less sensitive in this situation. The overall accuracy of 111 In leucocyte scanning in this series was 93,5%. The predictive value of a positive result was 92% and of a negative one 95%. The need for serial images to distinguish bowel activity (colitis or swallowed activity) from paracolic sepsis is emphasised. (orig.)

  10. Occult hepatitis B virus infection is not associated with disease progression of chronic hepatitis C virus infection.

    Cho, Junhyeon; Lee, Sang Soo; Choi, Yun Suk; Jeon, Yejoo; Chung, Jung Wha; Baeg, Joo Yeong; Si, Won Keun; Jang, Eun Sun; Kim, Jin-Wook; Jeong, Sook-Hyang

    2016-11-14

    To clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma (HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus (HCV) infection. This prospective cohort study enrolled 174 patients with chronic HCV infection (chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or more different viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome. The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively ( P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase > 40 IU/L, Child-Pugh score and sustained virologic response (SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development. The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans.

  11. Hepatitis B virus infection in human immunodeficiency virus infected southern African adults: occult or overt--that is the question.

    Trevor G Bell

    Full Text Available Hepatitis B virus (HBV and human immunodeficiency virus (HIV share transmission routes and are endemic in sub-Saharan Africa. The objective of the present study was to use the Taormina definition of occult HBV infection, together with stringent amplification conditions, to determine the prevalence and characteristics of HBV infection in antiretroviral treatment (ART-naïve HIV(+ve adults in a rural cohort in South Africa. The presence of HBV serological markers was determined by enzyme linked immunoassay (ELISA tests. HBV DNA-positivity was determined by polymerase chain reaction (PCR of at least two of three different regions of the HBV genome. HBV viral loads were determined by real-time PCR. Liver fibrosis was determined using the aspartate aminotransferase-to-platelet ratio index. Of the 298 participants, 231 (77.5% showed at least one HBV marker, with 53.7% HBV DNA(-ve (resolved and 23.8% HBV DNA(+ve (current [8.7% HBsAg(+ve: 15.1% HBsAg(-ve]. Only the total number of sexual partners distinguished HBV DNA(+ve and HBV DNA(-ve participants, implicating sexual transmission of HBV and/or HIV. It is plausible that sexual transmission of HBV and/or HIV may result in a new HBV infection, superinfection and re-activation as a consequence of immunesuppression. Three HBsAg(-ve HBV DNA(+ve participants had HBV viral loads <200 IU/ml and were therefore true occult HBV infections. The majority of HBsAg(-ve HBV DNA(+ve participants did not differ from HBsAg(+ve HBV DNA(+ve (overt participants in terms of HBV viral loads, ALT levels or frequency of liver fibrosis. Close to a quarter of HIV(+ve participants were HBV DNA(+ve, of which the majority were HBsAg(-ve and were only detected using nucleic acid testing. Detection of HBsAg(-ve HBV DNA(+ve subjects is advisable considering they were clinically indistinguishable from HBsAg(+ve HBV DNA(+ve individuals and should not be overlooked, especially if lamivudine is included in the ART.

  12. In vitro and in vivo infectivity and pathogenicity of the lymphoid cell-derived woodchuck hepatitis virus.

    Lew, Y Y; Michalak, T I

    2001-02-01

    Woodchuck hepatitis virus (WHV) and human hepatitis B virus are closely related, highly hepatotropic mammalian DNA viruses that also replicate in the lymphatic system. The infectivity and pathogenicity of hepadnaviruses propagating in lymphoid cells are under debate. In this study, hepato- and lymphotropism of WHV produced by naturally infected lymphoid cells was examined in specifically established woodchuck hepatocyte and lymphoid cell cultures and coculture systems, and virus pathogenicity was tested in susceptible animals. Applying PCR-based assays discriminating between the total pool of WHV genomes and covalently closed circular DNA (cccDNA), combined with enzymatic elimination of extracellular viral sequences potentially associated with the cell surface, our study documents that virus replicating in woodchuck lymphoid cells is infectious to homologous hepatocytes and lymphoid cells in vitro. The productive replication of WHV from lymphoid cells in cultured hepatocytes was evidenced by the appearance of virus-specific DNA, cccDNA, and antigens, transmissibility of the virus through multiple passages in hepatocyte cultures, and the ability of the passaged virus to infect virus-naive animals. The data also revealed that WHV from lymphoid cells can initiate classical acute viral hepatitis in susceptible animals, albeit small quantities (approximately 10(3) virions) caused immunovirologically undetectable (occult) WHV infection that engaged the lymphatic system but not the liver. Our results provide direct in vitro and in vivo evidence that lymphoid cells in the infected host support propagation of infectious hepadnavirus that has the potential to induce hepatitis. They also emphasize a principal role of the lymphatic system in the maintenance and dissemination of hepadnavirus infection, particularly when infection is induced by low virus doses.

  13. Infective endocarditis detected by 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography in a patient with occult infection

    Chia-Lu Yeh

    2011-11-01

    Full Text Available Integrated 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG PET/CT has been clinically used to detect infectious lesions. We present a case with pyrexia and bacteremia of unknown origin. Whole body FDG PET/CT was arranged to look for an occult source of infection and it revealed a focal lesion with increased FDG uptake in the mitral valve area. Under suspicion of infective endocarditis, transthoracic echocardiography was repeated and then the presence of linear vegetation over the calcified mitral annulus was confirmed. Ultimately, definite infective endocarditis was diagnosed according to the Duke criteria. The patient recovered after the antibiotic therapy. In our case, FDG PET/CT can help to localize the exact site of occult infection, thereby guiding additional testing and facilitating timely definitive diagnosis and therapy.

  14. Patterns of hepatitis B virus infection in Brazilian human immunodeficiency virus infected patients: high prevalence of occult infection and low frequency of lamivudine resistant mutations

    Michel VF Sucupira

    2006-09-01

    Full Text Available Hepatitis B virus (HBV molecular profiles were determined for 44 patients who were infected with human immunodeficiency virus (HIV type 1 and had antibodies to the hepatitis B core antigen (anti-HBc, with and without other HBV serological markers. In this population, 70% of the patients were under lamivudine treatment as a component of antiretroviral therapy. HBV DNA was detected in 14 (32% patients. Eight out of 12 (67% HBsAg positive samples, 3/10 (30% anti-HBc only samples, and 3/22 (14% anti-HBs positive samples were HBV DNA positive. HBV DNA loads, measured by real time polymerase chain reaction, were much higher in the HBsAg positive patients (mean, 2.5 × 10(9 copies/ml than in the negative ones (HBV occult infection; mean, 2.7 × 10(5 copies/ml. Nine out of the 14 HBV DNA positive patients were under lamivudine treatment. Lamivudine resistant mutations in the polymerase gene were detected in only three patients, all of them belonging to the subgroup of five HBsAg positive, HBV DNA positive patients. A low mean HBV load (2.7 × 10(5 copies/ml and an absence of lamivudine resistant mutations were observed among the cases of HBV occult infection.

  15. Occult Hepatitis B Virus infection in ART-Naive HIV-Infected Patients seen at a Tertiary Care Centre in North India

    Singh Sarman

    2010-03-01

    Full Text Available Abstract Background Co-infections of hepatitis B and C viruses are frequent with HIV due to shared routes of transmission. In most of the tertiary care health settings, HIV reactive patients are routinely tested for HBsAg and anti-HCV antibodies to rule out these co-infections. However, using the routine serological markers one can only detect active HBV infection while the occult HBV infection may be missed. There is insufficient data from India on HIV-HBV co-infection and even scarce on occult HBV infection in this group. Methods We estimated the burden of HBV infection in patients who were tested positive for HIV at a tertiary care centre in north India. We also attempted to determine the prevalence and clinical characteristics of occult HBV infection among these treatment-naïve patients and compare their demographic features with other HIV patients. During a period of 6 years between January 2002 to December 2007, 837 HIV positive patients (631 males and 206 females (M: F :: 3.06:1 were tested for serological markers of HBV (HBsAg and HCV (anti-HCV antibodies infections in our laboratory. For comparison 1000 apparently healthy, HIV-negative organ donors were also included in the study. Data on demographics, sexual behaviour, medical history, laboratory tests including the serum ALT and CD4 count of these patients were recorded. A sub-group of 53 HBsAg negative samples from HIV positive patients were assessed for anti-HBs, anti-HBc total (IgG+IgM and HBV-DNA using a highly sensitive qualitative PCR and analysed retrospectively. Results Overall, 7.28% of HIV positive patients showed presence of HBsAg as compared to 1.4% in the HIV negative control group. The prevalence of HBsAg was higher (8.55% in males than females (3.39%. The study revealed that occult HBV infection with detectable HBV-DNA was prevalent in 24.5% of patients positive for anti-HBc antibodies; being 45.5% in HBsAg negative patients. Most importantly the occult infection was

  16. Molecular analysis of hepatitis B virus (HBV in an HIV co-infected patient with reactivation of occult HBV infection following discontinuation of lamivudine-including antiretroviral therapy

    Costantini Andrea

    2011-11-01

    Full Text Available Abstract Background Occult hepatitis B virus (HBV infection (OBI is characterized by HBV DNA persistence even though the pattern of serological markers indicates an otherwise resolved HBV infection. Although OBI is usually clinically silent, immunocompromised patients may experience reactivation of the liver disease. Case presentation We report the case of an individual with human immunodeficiency virus (HIV infection and anti-HBV core antibody positivity, who experienced severe HBV reactivation after discontinuation of lamivudine-including antiretroviral therapy (ART. HBV sequencing analysis showed a hepatitis B surface antigen escape mutant whose presence in an earlier sample excluded reinfection. Molecular sequencing showed some differences between two isolates collected at a 9-year interval, indicating HBV evolution. Resumption of ART containing an emtricitabine/tenofovir combination allowed control of plasma HBV DNA, which fell to undetectable levels. Conclusion This case stresses the ability of HBV to evolve continuously, even during occult infection, and the effectiveness of ART in controlling OBI reactivation in HIV-infected individuals.

  17. Novel Electron Spin Resonance-Enzyme Immunosorbent Assay for Detecting Occult Hepatitis B Infection in HCV Chronic Liver Disease

    Hala Badawi

    2017-11-01

    Full Text Available Background: Hepatitis B virus infection in patients who lack detectable hepatitis B surface antigen (HBsAg is called occult hepatitis B infection (OHB. The very low level of HBV genome may hamper its detection by molecular techniques. Recently, a highly sensitive EIA utilizing a novel modified electron spin resonance (ESR technique (modified ESR-EIA was developed to detect HBsAg by measuring stabilized nitroxide radicals. Aim: to detect occult HBV infection, using ESR-EIA among HCV-related chronic liver disease (CLD Egyptian patients who were seronegative for HBsAg by standard EIA. Methods: The study was conducted on two periods of time; in 1st period, 72 inpatients in Tropical Medicine Department of TBRI, were enrolled in the study. They were divided into two groups; 44 seropositive anti-HCV patients (Group I, 28 seronegative anti-HCV patients (Group II. Sera were subjected to virological assays for HBsAg, HBeAg, anti-HBc IgM, anti-HBc IgG, anti-HBs, anti-HCV and HCV RNA. We also examined serum HBV DNA by polymerase chain reaction (PCR technique and real-time detection polymerase chain reaction (RTD-PCR. In the 2nd period; modified ESR-EIA was applied on 32 TBRI inpatients, 23 in Tropical Medicine Department (Group I and 9 from hemodialysis unit (Group II with HCV-related CLD. Results: OHB was detected in 18.1% and 86.9% of our patients in 2002 and 2006 respectively. In phase 1, there was a higher detection rate among HCV patients in Group I (25% than Group II (7%, with higher prevalence (52.4% in patients with positive HCV RNA in Group I versus those with negative HCV viremia (8% in Group II. HBV DNA by either PCR or RTD-PCR was negative in all patients of both groups as the HBV viral load of the samples were below detectable level of the methods used; less than 100 copies/ml. None of 9 hemodialysis patients were positive for OHB. Conclusion: The newly developed quantitative ESR-EIA technique represents a great evolution for screening and

  18. Occult HBV infection status among chronic hepatitis C and hemodialysis patients in Northeastern Egypt: regional and national overview.

    Mandour, Mohamed; Nemr, Nader; Shehata, Atef; Kishk, Rania; Badran, Dahlia; Hawass, Nashaat

    2015-01-01

    Occult hepatitis B infection (OBI) is considered to be one of the major risks for patients suffering from end-stage renal disease (ESRD) on regular hemodialysis (HD) and patients with chronic hepatitis C virus (HCV) infection. This study compared the prevalence of OBI among these two high-risk groups in the Suez Canal region, Northeastern Egypt, to obtain a better national overview of the magnitude of OBI in this region. Serum samples were collected from 165 HD patients and 210 chronic HCV-infected patients. Anti-HCV antibody, hepatitis B surface antigen (HBsAg), total hepatitis B core (anti-HBc) antibody, and hepatitis B surface antibody (anti-HBs) were detected by enzyme-linked immunosorbent assay (ELISA). HCV RNA was detected using a quantitative real-time RT-PCR assay, and HBV was detected using a nested PCR. All patients were negative for HBsAg. A total of 49.1% and 25.2% of the patients in the HD and HCV groups, respectively, were anti-HBc-positive. In addition, more anti-HBs-positive patients were detected in the HD group compared to the HCV group (52.1% and 11.4%, respectively). Three cases were positive for HBV DNA in the HD group, while eighteen positive cases were detected in the HCV group. Both study groups showed significant differences in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level as well as anti-HBc, anti-HBs and HBV-DNA positivity. OBI was more prevalent among chronic HCV patients than HD patients in the Suez Canal region, Egypt, with rates of 8.5% and 1.8%, respectively. However, more precise assessment of this infection requires regular patient follow-up using HBV DNA detection methods.

  19. Investigation of occult hepatitis B virus infection in anti-hbc positive patients from a liver clinic.

    Martinez, Maria Carmela; Kok, Chee Choy; Baleriola, Cristina; Robertson, Peter; Rawlinson, William D

    2015-01-01

    Occult hepatitis B infection (OBI) is manifested by presence of very low levels (Hepatitis B viral DNA (HBV DNA) in the blood and the liver while exhibiting undetectable HBV surface antigen (HBsAg). The molecular mechanisms underlying this occurrence are still not completely understood. This study investigated the prevalence of OBI in a high-risk Australian population and compared the HBV S gene sequences of our cohort with reference sequences. Serum from HBV DNA positive, HBsAg negative, and hepatitis B core antibody (anti-HBc) positive patients (study cohort) were obtained from samples tested at SEALS Serology Laboratory using the Abbott Architect, as part of screening and diagnostic testing. From a total of 228,108 samples reviewed, 1,451 patients were tested for all three OBI markers. Only 10 patients (0.69%) out of the 1,451 patients were found to fit the selection criteria for OBI. Sequence analysis of the HBV S gene from 5 suspected OBI infected patients showed increased sequence variability in the 'a' epitope of the major hydrophilic region compared to reference sequences. In addition, a total of eight consistent nucleotide substitutions resulting in seven amino acid changes were observed, and three patients had truncated S gene sequence. These mutations appeared to be stable and may result in alterations in HBsAg conformation. These may negatively impact the affinity of hepatitis B surface antibody (anti-HBs) and may explain the false negative results in serological HBV diagnosis. These changes may also enable the virus to persist in the liver by evading immune surveillance. Further studies on a bigger cohort are required to determine whether these amino acid variations have been acquired in the process of immune escape and serve as markers of OBI.

  20. Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia.

    Julio Cesar Rendon

    Full Text Available Hepatitis B virus (HBV occult infection (OBI is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease.Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia. Samples obtained from patients who were negative for the surface antigen of HBV (n = 50 were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique.In five cases out of 50 patients (10% the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3, genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X.This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12 described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis.

  1. Hepatitis B virus infection among first-time blood donors in Italy: prevalence and correlates between serological patterns and occult infection.

    Romanò, Luisa; Velati, Claudio; Cambiè, Giuseppe; Fomiatti, Laura; Galli, Claudio; Zanetti, Alessandro Remo

    2013-04-01

    A prospective, 1-year study was performed among Italian first-time, volunteer blood donors, who account for 12% of all donations, in order to assess the frequency and serological patterns of hepatitis B virus infection and the presence of occult infection. Consecutive donors (n=31,190) from 21 blood transfusion centres, from age classes not subjected to universal HBV vaccination, were tested for HBsAg and anti-HBc by commercial immunoassays. Other HBV serological markers were searched for and qualitative and quantitative assessments of HBV-DNA were made in HBsAg and/or anti-HBc-positive individuals. Of the 31,190 donors studied, 100 (0.32%) were positive for both HBsAg and anti-HBc, 2 for HBsAg (0.01%) alone, and 2,593 (8.3%) for anti-HBc. Of these last, 86.7% were also positive for anti-HBs (with or without anti-HBe), 2.9% were positive for anti-HBe without anti-HBs and 10.4% had no other HBV markers (anti-HBc alone). A general north-south increasing gradient of HBV prevalence was observed. Circulating HBV-DNA was found in 96.8% of HBsAg-positive subjects as compared to 0.55% (12/2,186) of anti-HBc-positive/HBsAg-negative subjects, with higher frequencies among anti-HBs-negative than among anti-HBs-positive ones (1.68% vs. 0.37%; p blood donors is much lower than in the past. The presence of occult infections in this group was confirmed (frequency: 1 in 2,599), supporting the hypothesis of long-term persistence of HBV infection after clearance of HBsAg. HBsAg and nucleic acid amplification testing for blood screening and vaccination against HBV are crucial in order to further reduce the risk of transfusion-transmitted HBV towards zero.

  2. Plasma Viral miRNAs Indicate a High Prevalence of Occult Viral Infections

    Enrique Fuentes-Mattei

    2017-06-01

    Full Text Available Prevalence of Kaposi sarcoma-associated herpesvirus (KSHV/HHV-8 varies greatly in different populations. We hypothesized that the actual prevalence of KSHV/HHV8 infection in humans is underestimated by the currently available serological tests. We analyzed four independent patient cohorts with post-surgical or post-chemotherapy sepsis, chronic lymphocytic leukemia and post-surgical patients with abdominal surgical interventions. Levels of specific KSHV-encoded miRNAs were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR, and KSHV/HHV-8 IgG were measured by immunoassay. We also measured specific miRNAs from Epstein Barr Virus (EBV, a virus closely related to KSHV/HHV-8, and determined the EBV serological status by ELISA for Epstein-Barr nuclear antigen 1 (EBNA-1 IgG. Finally, we identified the viral miRNAs by in situ hybridization (ISH in bone marrow cells. In training/validation settings using independent multi-institutional cohorts of 300 plasma samples, we identified in 78.50% of the samples detectable expression of at least one of the three tested KSHV-miRNAs by RT-qPCR, while only 27.57% of samples were found to be seropositive for KSHV/HHV-8 IgG (P < 0.001. The prevalence of KSHV infection based on miRNAs qPCR is significantly higher than the prevalence determined by seropositivity, and this is more obvious for immuno-depressed patients. Plasma viral miRNAs quantification proved that EBV infection is ubiquitous. Measurement of viral miRNAs by qPCR has the potential to become the “gold” standard method to detect certain viral infections in clinical practice.

  3. Prevalence of genotype D in chronic liver disease patients with occult HBV infection in northern region of India

    Meher Rizvi

    2014-01-01

    Full Text Available Background: Etiology of nearly 30% cases of chronic viral hepatitis remains undetected. Occult HBV infection (OBI has emerged as an important clinical entity in this scenario. Apart from prevalence and clinical outcome of OBI patients genotype was determined in northern region of India. Materials and Methods: A total of 847 patients with chronic liver disease (CLD were screened for common viral etiologies and others serological markers of HBV. Amplification of surface, precore and polymerase genes of HBV was performed in patients negative for other etiologies. Genotyping and sequencing of the precore region was performed for OBI cases. Results: Twenty-nine (7.61% cases of OBI were identifiedof which 9 had chronic liver disease (CHD, 11 liver cirrhosis (LC and 9 hepatocellular carcinoma (HCC. Majority of OBI cases were detected by amplification of surface gene 26 (89.6%, followed by pre-core gene 12 (41.3%. Their liver functions tests were significantly deranged in comparison to overt HBV cases. IgG anti HBc was present in 8 (27.6% OBI cases. Mutation was observed in 8 (32% in pre-core region at nt. 1896 of overt HBV cases. Genotype D was the predominant genotype. In conclusion: OBI in our study was characterized by predominance of genotype D and more severe clinical and biochemical profile in comparison to overt HBV. IgG anti HBc positivity could be utilized as a marker of OBI. We recommend use of sensitive nested PCR for diagnosis of OBI, amplifying at least surface and precore gene.

  4. Detection of occult hepatitis B and window period infection among blood donors by individual donation nucleic acid testing in a tertiary care center in South India.

    Keechilot, Cinzia S; Shenoy, Veena; Kumar, Anil; Biswas, Lalitha; Vijayrajratnam, Sukhithasri; Dinesh, Kavitha; Nair, Prem

    With the introduction of highly sensitive hepatitis B surface antigen immunoassay, transfusion associated HBV infection have reduced drastically but they still tend to occur due to blood donors with occult hepatitis B infection (OBI) and window period (WP) infection. Sera from, 24338 healthy voluntary blood donors were screened for HBsAg, HIV and HCV antibody using Vitros Enhanced Chemiluminescent Immunoassay. The median age of the donor population was 30 (range 18-54) with male preponderance (98%). All serologically negative samples were screened by nucleic acid testing (NAT) for viral DNA and RNA. NAT-positive samples were subjected to discriminatory NAT for HBV, HCV, and HIV and all samples positive for HBV DNA were tested for anti-HBc, anti-HBs, HBeAg. Viral load was determined using artus HBV RG PCR Kit. Of the 24,338 donors screened, 99.81% (24292/24338) were HBsAg negative of which NAT was positive for HBV DNA in 0.0205% (5/24292) donors. Four NAT positive donors had viral load of <200 IU/ml making them true cases of OBI. One NAT positive donor was negative for all antibodies making it a case of WP infection. Among OBI donors, 75% (3/4) were immune and all were negative for HBeAg. Precise HBV viral load could not be determined in all (5/5) NAT positive donors due to viral loads below the detection limit of the artus HBV RG PCR Kit. The overall incidence of OBI and WP infections was found to be low at 1 in 6503 and 1 in 24214 donations, respectively. More studies are needed to determine the actual burden of WP infections in Indian blood donors.

  5. Molecular and serological detection of occult hepatitis B virus ...

    Background: Occult hepatitis B infections are becoming a major global threat, but the available data on its prevalence in various parts of the world are often divergent. Objective: This study aimed to detect occult hepatitis B virus in hepatitis B surface antigen-negative serum using anti-HBc as a marker of previous infection.

  6. Occult HCV Infection (OCI) Diagnosis in Cirrhotic and Non-cirrhotic Naïve Patients by Intra-PBMC Nested Viral RNA PCR.

    Abd Alla, Mohamed Darwish Ahmed; Elibiary, Saleh Ahmed; Wu, George Y; El-Awady, Mostafa Kamel

    2017-12-28

    Background and Aims: Occult HCV infections (OCIs) include IgG antibody seronegative cryptogenic (COCIs), as well as seropositive secondary naïve (SNOCIs) and experienced (SEOCIs) cases. We used peripheral-blood-mononuclear-cell (PBMC)-PCR to evaluate COCIs and SNOCIs prevalence, serum HCV spontaneous disappearance (SCSD) in naïve cirrhotics and non-cirrhotics, intra-PBMC HCV-RNA strands in relation to cirrhosis density in naïve non-viremia cases, and HCV-RNA seroconversion after 1 year of solitary naïve intra-PBMC infection. Methods: The anti-HCV IgG antibody-positive naïve-patients ( n = 785) were classified into viremic ( n = 673) and non-viremic [ n = 112, including non-cirrhotics ( n = 55) and cirrhotics ( n = 57)], and 62 controls without evidence of HCV-infection. Controls and post-HCV non-viremia cases ( n = 62+112 = 174) were submitted to hepatic Fibroscan-Elastography evaluation. All subjects ( n = 847) were screened for intra-PBMC HCV-RNA sense and antisense strands by nested-PCR. Results: Naïve-OCI cases (4.84%) that were diagnosed by PBMC-PCR significantly raised the total numbers of HCV-infection to 714 ( p = 0.01). The percent positivity of SNOCIs (34.82%) was significantly higher than for asymptomatic-COCIs (3.125%, p = 0.0001). Comparing PBMC-PCR with single-step-reverse-transcription (SRT)-PCR for identification of SCSD in naïve IgG antibody-positive non-viremia patients ( n = 112) revealed a decline in SCSD prevalence by PBMC-PCR (from 14.27% to 9.3%), regardless of presence of hepatic cirrhosis ( p = 0.03). SCSD was found to be higher by PBMC-PCR in non-cirrhotics compared to cirrhotics ( p = 0.0001), with an insignificant difference when using SRT-PCR ( p = 0.45). Intra-PBMC HCV-RNA infection was significantly more frequent in cirrhotics compared to both non-cirrhotics and controls ( p < 0.0005). An increased hepatic fibrosis density was recognized in intra-PBMC HCV-RNA infection with sense ( p = 0.0001) or antisense strand ( p = 0

  7. Low occurrence of HBsAg but high frequency of transient occult HBV infection in vaccinated and HBIG-administered infants born to HBsAg positive mothers.

    Zhou, Shan; Li, Tingting; Allain, Jean-Pierre; Zhou, Bin; Zhang, Yuming; Zhong, Mei; Fu, Yongshui; Li, Chengyao

    2017-12-01

    The status of chronic and occult HBV infection (OBI) in neonatal hepatitis B vaccine and immunoglobulin (HBIG) vaccinated infants born to HBsAg+ mothers was investigated at a major hospital in China. Seventy-seven and 15 blood samples were collected in first or second follow-up detection from the vaccinated babies aged 3-36 months born to 43 HBsAg+ or plus 25 HBeAg+ mothers. HBV infection was analyzed between the paired baby and mother by serology and DNA analysis. Among 77 children born to 68 HBsAg+ mothers, 3.9% (3/77) were HBsAg+, and 36.4% (28/77) were HBV DNA+/HBsAg- (OBIs) by a single PCR, respectively. Thirteen of 28 HBV DNA+/HBsAg- samples were conformed by two PCRs or S sequence, which accounted for 16.9% (13/77) of children. Three HBsAg+ and six OBIs were genotyped in consistent with their mother's HBV strains. Of 77 babies' blood samples, anti-HBs reactivity varied slightly according to age groups, while passively transmitted anti-HBc reactivity declined from 100% high reactivity at age 3-5 months to mostly negative at age ≥12 months. Babies with apparent OBI had higher levels of anti-HBc and lower levels of anti-HBs than those without OBI but all eight OBI babies with second follow-up samples became HBV DNA negative beyond 1 year of age. The vaccinated infants born to HBsAg+ mothers presented the low rate of HBsAg occurrence as vaccination failure and high frequency of viral persistence in the form of transient OBIs since no evidence of active HBV infection occurred beyond 1 year of age. © 2017 Wiley Periodicals, Inc.

  8. Methicillin-Resistant Staphylococcus aureus Infections: A Comprehensive Review and a Plastic Surgeon's Approach to the Occult Sites.

    Hunter, Cedric; Rosenfield, Lorne; Silverstein, Elena; Petrou-Zeniou, Panayiota

    2016-08-01

    Up to 20 percent of the general population is persistently colonized with Staphylococcus aureus, and 1 to 3 percent of the population is colonized with community-acquired methicillin-resistant S. aureus. Currently, the knowledge of methicillin-resistant Staphylococcus aureus carriage sites other than the nose, and their effect on surgical site infections in cosmetic surgery, is lacking. A comprehensive literature review using the PubMed database to analyze prevalence, anatomical carrier sites, current screening and decontamination protocols and guidelines, and methicillin-resistant S. aureus in cosmetic surgery was performed. The senior author's (L.R.) methicillin-resistant S. aureus infection experience and prevention protocols were also reviewed. Nasal swabs detect only 50.5 percent of methicillin-resistant S. aureus colonization, and broad screening has noted the presence of methicillin-resistant S. aureus in the ear canal and umbilicus. Decolonization protocols within the orthopedic and cardiothoracic surgery literature have reduced rates of methicillin-resistant S. aureus surgical-site infections. There are no decolonization guidelines for plastic surgeons. Since instituting their decolonization protocol, the authors have had no cases of methicillin-resistant S. aureus infection in nearly 1000 cosmetic surgery procedures. There are very limited, if any, Level I or II data regarding methicillin-resistant S. aureus screening and decolonization. As the sequelae of a surgical-site infection can be disastrous, expert opinions recommend that plastic surgeons vigorously address methicillin-resistant S. aureus colonization and infection. The authors have developed and recommend a simple decolonization protocol that includes treatment of the umbilicus, ear canal, and nares to limit surgical-site infection and improve surgical outcomes.

  9. Comparison of fecal occult blood tests for colorectal cancer screening in an Alaska Native population with high prevalence of Helicobacter pylori infection, 2008-2012.

    Redwood, Diana; Provost, Ellen; Asay, Elvin; Roberts, Diana; Haverkamp, Donald; Perdue, David; Bruce, Michael G; Sacco, Frank; Espey, David

    2014-04-10

    Alaska Native colorectal cancer (CRC) incidence and mortality rates are the highest of any ethnic/racial group in the United States. CRC screening using guaiac-based fecal occult blood tests (gFOBT) are not recommended for Alaska Native people because of false-positive results associated with a high prevalence of Helicobacter pylori-associated hemorrhagic gastritis. This study evaluated whether the newer immunochemical FOBT (iFOBT) resulted in a lower false-positive rate and higher specificity for detecting advanced colorectal neoplasia than gFOBT in a population with elevated prevalence of H. pylori infection. We used a population-based sample of 304 asymptomatic Alaska Native adults aged 40 years or older undergoing screening or surveillance colonoscopy (April 2008-January 2012). Specificity differed significantly (P < .001) between gFOBT (76%; 95% CI, 71%-81%) and iFOBT (92%; 95% CI, 89%-96%). Among H. pylori-positive participants (54%), specificity of iFOBT was even higher (93% vs 69%). Overall, sensitivity did not differ significantly (P = .73) between gFOBT (29%) and iFOBT (36%). Positive predictive value was 11% for gFOBT and 32% for iFOBT. The iFOBT had a significantly higher specificity than gFOBT, especially in participants with current H. pylori infection. The iFOBT represents a potential strategy for expanding CRC screening among Alaska Native and other populations with elevated prevalence of H. pylori, especially where access to screening endoscopy is limited.

  10. Occult Hepatitis B Virus in Gezira State Sudan | Gasmelseed ...

    Background: Occult hepatitis B infection (OBI) is simply defined as serologically undetectable hepatitis B surface antigen (HBsAg-ve), despite the presence of circulating HBV DNA. Objective: The aim of this study was to determine the prevalence of occult HBV among Screened HBsAg subjects in Gezira State, Sudan.

  11. Quantitation of HBV cccDNA in anti-HBc-positive liver donors by droplet digital PCR: a new tool to detect occult infection.

    Caviglia, Gian Paolo; Abate, Maria Lorena; Tandoi, Francesco; Ciancio, Alessia; Amoroso, Antonio; Salizzoni, Mauro; Saracco, Giorgio Maria; Rizzetto, Mario; Romagnoli, Renato; Smedile, Antonina

    2018-04-02

    The accurate diagnosis of occult HBV infection (OBI) requires the demonstration of HBV DNA in liver biopsies of HBsAg-negative subjects. However, in clinical practice a latent OBI is deduced by the finding of the antibody to the HB-core antigen (anti-HBc). We investigated the true prevalence of OBI and the molecular features of intrahepatic HBV in anti-HBc-positive subjects. The livers of 100 transplant donors (median age 68.2 years; 64 males, 36 females) positive for anti-HBc at standard serologic testing, were examined for total HBV DNA by nested-PCR and for the HBV covalently closed circular DNA (HBV cccDNA) with an in-house droplet digital PCR assay (ddPCR) (Linearity: R 2 = 0.9998; lower limit of quantitation and detection of 2.4 and 0.8 copies/10 5 cells, respectively). A true OBI status was found in 52% (52/100) of the subjects and cccDNA was found in 52% (27/52) of the OBI-positive, with a median 13 copies/10 5 cells (95% confidence interval 5-25). Using an assay specific for anti-HBc of IgG class, the median antibody level was significantly higher in HBV cccDNA-positive than negative donors (5.7 [3.6-9.7] vs. 17.0 [7.0-39.2] COI, p = 0.007). By multivariate analysis, an anti-HBc IgG value above a 4.4 cut-off index (COI) was associated with the finding of intrahepatic HBV cccDNA (OR = 8.516, p = 0.009); a lower value ruled out its presence with a negative predictive value of 94.6%. With a new in-house ddPCR-based method, intrahepatic HBV cccDNA was detectable in quantifiable levels in about half of the OBI cases examined. The titer of anti-HBc IgG may be a useful surrogate to predict the risk of OBI reactivation in immunosuppressed patients. The covalently closed circular DNA (cccDNA) form of the Hepatitis B virus (HBV) sustains the persistence of the virus even after decades of resolution of the florid infection (Occult HBV infection=OBI). In the present study we developed an highly sensitive method based on droplet digital PCR technology for the detection

  12. Limitations in the use of indium-111-oxine-labeled leucocytes for the diagnosis of occult infection in children

    Haentjens, M.; Piepsz, A.; Perlmutter-Cremer, N.; Schell-Frederick, E.; Fruehling, J.

    1987-02-01

    Fifteen children underwent scintigraphy with indium 111 (/sup 111/In)-labeled white blood cells (WBC) for the detection of a local suppuration. The procedure generally contributed to a correct diagnosis. False negative results were observed in 5 children, but in two of them positive foci were also present. The missed lesions were 2 liver abscesses, 1 lung abscess, foci of osteomyelitis and 1 pericarditis. Two cases of chronic granulomatous disease are presented in which increased leucocyte accumulation was not observed in proven instances of infection.

  13. Measurement of stellar occultations

    Eberle, Andreas

    2008-09-01

    Whenever an asteroid occults a star, we have the opportunity to study that asteroid in great detail. As frequently shown in the past, amateur astronomers1 have the necessary equipment to measure such events successfully2. Combined with the dense net of amateur observatories and online coordination tools3 for movable stations, they can create fine grids to detect even small bodies. The analysis of these events gives us the possibility to receive high precision astrometry data, to determine the asteroids size and shape (and therefore its albedo), and even to collect information on the star itself.4 While usually a set of several light curves is required to do so, a single recording5 of (10734) Wieck's occultation of HIP 22157 on 2008 Feb 08 was sufficient to retrieve the necessary data6. 1 Observation campaigns are organized by the International Occultation Timing Association (IOTA), http://www.iota-es.de/ 2 for results see e.g. euraster.net by E. Frappa, http://www.euraster.net/ 3 Occult Watcher by H. Pavlov, http://www.hristopavlov.net/OccultWatcher/OccultWatcher.html 4 see K. Miyashita's analysis of the observation of the occultation of TYC 1886-01206-1 by Kalliope and Linus, http://www005.upp.so-net.ne.jp/k miyash/occ02/kalliope/doublestar en.html 5 recording obtained by H. Michels, MPC Station Code 240 6 using Limovie by K. Miyashita

  14. Bats carry pathogenic hepadnaviruses antigenically related to hepatitis B virus and capable of infecting human hepatocytes

    Drexler, J. F.; Geipel, A.; König, A.; Corman, V. M.; Van Riel, D.; Leijten, L. M.; Bremer, C. M.; Rasche, A.; Cottontail, V. M.; Maganga, G. D.; Schlegel, M.; Müller, M. A.; Adam, A.; Klose, S. M.; Borges Carneiro, A. J.; Stöcker, A.; Franke, C. R.; Gloza-Rausch, F.; Geyer, J.; Annan, A.; Adu-Sarkodie, Y.; Oppong, S.; Binger, T.; Vallo, Peter; Tschapka, M.; Ulrich, R. G.; Gerlich, W. H.; Leroy, E.; Kuiken, T.; Glebe, D.; Drosten, C.

    2013-01-01

    Roč. 110, č. 40 (2013), s. 16151-16156 ISSN 0027-8424 Institutional support: RVO:68081766 Keywords : Evolution * Zoonosis * Virome * Metagenomics * Reverse genetics Subject RIV: EG - Zoology Impact factor: 9.809, year: 2013

  15. Occult spinal dysraphism

    paediatricians, paediatric neurosurgeons, urologists, orthopaedic surgeons, occupational ... Occult spinal dysraphism refers to a diverse group of congenital abnormalities resulting from varying degrees of disordered neuro- embryogenesis. Several terms have .... can image the whole spine. T1-weighted sagittal and axial ...

  16. Occult Macular Dystrophy

    Işıl Sayman Muslubaş

    2016-04-01

    Full Text Available Occult macular dystrophy is an inherited macular dystrophy characterized by a progressive decline of bilateral visual acuity with normal fundus appearance, fluorescein angiogram and full-field electroretinogram. This case report presents a 20-year-old female patient with bilateral progressive decline of visual acuity for six years. Her visual acuity was 3-4/10 in both eyes. Anterior segment and fundus examination, fluorescein angiogram and full-field electroretinogram were normal. She could read all Ishihara pseudoisochromatic plates. Fundus autofluorescence imaging was normal. There was a mild central hyporeflectance on fundus infrared reflectance imaging in both eyes. Reduced foveal thickness and alterations of the photoreceptor inner and outer segment junction were observed by optical coherence tomography in both eyes. Central scotoma was also found by microperimetry and reduced central response was revealed by multifocal electroretinogram in both eyes. These findings are consistent with the clinical characteristics of occult macular dystrophy

  17. Occult carbon monoxide poisoning.

    Kirkpatrick, J N

    1987-01-01

    A syndrome of headache, fatigue, dizziness, paresthesias, chest pain, palpitations and visual disturbances was associated with chronic occult carbon monoxide exposure in 26 patients in a primary care setting. A causal association was supported by finding a source of carbon monoxide in a patient's home, workplace or vehicle; results of screening tests that ruled out other illnesses; an abnormally high carboxyhemoglobin level in 11 of 14 patients tested, and abatement or resolution of symptoms when the source of carbon monoxide was removed. Exposed household pets provided an important clue to the diagnosis in some cases. Recurrent occult carbon monoxide poisoning may be a frequently overlooked cause of persistent or recurrent headache, fatigue, dizziness, paresthesias, abdominal pain, diarrhea and unusual spells.

  18. Occult Carbon Monoxide Poisoning

    Kirkpatrick, John N.

    1987-01-01

    A syndrome of headache, fatigue, dizziness, paresthesias, chest pain, palpitations and visual disturbances was associated with chronic occult carbon monoxide exposure in 26 patients in a primary care setting. A causal association was supported by finding a source of carbon monoxide in a patient's home, workplace or vehicle; results of screening tests that ruled out other illnesses; an abnormally high carboxyhemoglobin level in 11 of 14 patients tested, and abatement or resolution of symptoms ...

  19. Occult pneumothorax, revisited

    Mangar Devanand; Abdelmalak Hany; Omar Hesham R; Rashad Rania; Helal Engy; Camporesi Enrico M

    2010-01-01

    Abstract Pneumothorax is a recognized cause of preventable death following chest wall trauma where a simple intervention can be life saving. In cases of trauma patients where cervical spine immobilization is mandatory, supine AP chest radiograph is the most practical initial study. It is however not as sensitive as CT chest for early detection of a pneumothorax. "Occult" pneumothorax is an accepted definition of an existing but usually a clinically and radiologically silent disturbance that i...

  20. GAMBARAN RADIOLOGIS PADA OCCULT PNEUMOTHORAKS

    Putu Aditha Satya Putra

    2013-02-01

    Full Text Available Pneumothorax is a recognized cause of death in chest wall trauma. Radiological examination is the key factor to establish the existence of a pneumothorax. Occult pneumothorax is pneumothorax that undiagnosed clinically and with thoracic x-ray, but it can be tolerated while other more urgent trauma. Occult pneumothorax can be detected by CT (Computed tomography. Occult pneumothorax may progress to tension pneumothorax in certain circumstances. Missing in diagnosed pneumothorax will cause death. This literature will discuss radiological examination for diagnosing, early detection, and management of occult pneumothorax. If thoracic x-ray examination did not reveal the occult pneumothorax, it can be dangerous if existence of pneumothorax was not known. In this case, the examination of thoracic CT-Scan is gold standard for determining the presence of occult pneumothorax and can provide appropriate care.

  1. GAMBARAN RADIOLOGIS PADA OCCULT PNEUMOTHORAKS

    Putu Aditha Satya Putra; Nyoman Srie Laksminingsih

    2013-01-01

    Pneumothorax is a recognized cause of death in chest wall trauma. Radiological examination is the key factor to establish the existence of a pneumothorax. Occult pneumothorax is pneumothorax that undiagnosed clinically and with thoracic x-ray, but it can be tolerated while other more urgent trauma. Occult pneumothorax can be detected by CT (Computed tomography). Occult pneumothorax may progress to tension pneumothorax in certain circumstances. Missing in diagnosed pneumothorax will cause deat...

  2. Neurogenic bladder from occult herpes zoster.

    Rothrock, J F; Walicke, P A; Swenson, M R

    1986-11-01

    Active infection with herpes zoster may cause acute urinary retention, especially when it involves sacral dermatomes. Although frank retention usually develops days to weeks after eruption of the typical rash, bladder incompetence infrequently develops first, raising concern over other, more ominous etiologies. In the case presented, rash appearance was delayed until six weeks after the initial onset of urinary retention, a much longer interval than previously reported. Occult herpes zoster infection should be considered in patients presenting with an acute neurogenic bladder of obscure cause.

  3. Beamsteerable GNSS Radio Occultation ASIC

    National Aeronautics and Space Administration — We will develop an integrated RF ASIC to enable high quality radio occultation (RO) weather observations using the Global Navigations System Satellite (GNSS)...

  4. Evaluation of clinical sensitivity and specificity of hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency Virus-1 by cobas MPX: Detection of occult HBV infection in an HBV-endemic area.

    Ha, Jihye; Park, Younhee; Kim, Hyon-Suk

    2017-11-01

    Transfusion-transmitted infectious diseases remain a major concern for blood safety, particularly with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Nucleic acid testing (NAT) in donor screening shortens the serologically negative window period and reduces virus transmission. The cobas MPX (Roche Molecular Systems, Inc., Branchburg, New Jersey) is a recently developed multiplex qualitative PCR system that enables the simultaneous detection of HBV, HCV, and HIV with improved sensitivity and throughput using cobas 6800 and 8800 instruments. The aim of this study was to conduct an evaluation of the clinical sensitivity and specificity of cobas MPX detection of HBV, HCV, and HIV in clinical specimens. Among samples referred for HBV, HCV, and HIV-1 quantification at Severance Hospital, Yonsei University College of Medicine, positive samples were selected to evaluate sensitivity. A total of 843 samples was tested using both cobas MPX and COBAS AmpliPrep/COBAS TaqMan Tests for HBV, HCV, and HIV-1 using the cobas 8800 system and a COBAS TaqMan 96 analyzer, respectively. Samples that showed discrepancies were confirmed by nested PCR. The cobas MPX achieved excellent sensitivity and specificity for the detection of HBV, HCV, and HIV-1 in clinical samples. We found that the lower limit of detection (LOD) of blood screening by NAT actually improves clinical sensitivity, and occult HBV infection prevalence among healthy employees of the hospital was rather high. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Characteristics of atopic children with pandemic H1N1 influenza viral infection: pandemic H1N1 influenza reveals 'occult' asthma of childhood.

    Hasegawa, Shunji; Hirano, Reiji; Hashimoto, Kunio; Haneda, Yasuhiro; Shirabe, Komei; Ichiyama, Takashi

    2011-02-01

    The number of human cases of pandemic H1N1 influenza viral infection has increased in Japan since April 2009, as it has worldwide. This virus is widespread in the Yamaguchi prefecture in western Japan, where most infected children exhibited respiratory symptoms. Bronchial asthma is thought to be one of the risk factors that exacerbate respiratory symptoms of pandemic H1N1-infected patients, but the pathogenesis remains unclear. We retrospectively investigated the records of 33 children with pandemic H1N1 influenza viral infection who were admitted to our hospital between October and December 2009 and analyzed their clinical features. The percentage of children with asthma attack, with or without abnormal findings on chest radiographs (pneumonia, atelectasis, etc.), caused by pandemic H1N1 influenza infection was significantly higher than that of children with asthma attack and 2008-2009 seasonal influenza infection. Of the 33 children in our study, 22 (66.7%) experienced an asthma attack. Among these children, 20 (90.9%) did not receive long-term management for bronchial asthma, whereas 7 (31.8%) were not diagnosed with bronchial asthma and had experienced their first asthma attack. However, the severity of the attack did not correlate with the severity of the pulmonary complications of pandemic H1N1 influenza viral infection. The pandemic H1N1 influenza virus greatly increases the risk of lower respiratory tract complications such as asthma attack, pneumonia, and atelectasis, when compared to the seasonal influenza virus. Furthermore, our results suggest that pandemic H1N1 influenza viral infection can easily induce a severe asthma attack, pneumonia, and atelectasis in atopic children without any history of either an asthma attack or asthma treatment. © 2011 John Wiley & Sons A/S.

  6. Potent inhibition of late stages of hepadnavirus replication by a modified cell penetrating peptide

    Abdul, Fabien; Ndeboko, Bénédicte; Buronfosse, Thierry

    2012-01-01

    Cationic cell-penetrating peptides (CPPs) and their lipid domain-conjugates (CatLip) are agents for the delivery of (uncharged) biologically active molecules into the cell. Using infection and transfection assays we surprisingly discovered that CatLip peptides were able to inhibit replication...... by confocal laser scanning microscopy indicating severe structural changes of preS/S. Sucrose gradient analysis of supernatants from Deca-(Arg)8-treated cells showed unaffected naked viral nucleocapsids release, which was concomitant with a complete arrest of virion and surface protein-containing subviral...

  7. Occult Phenomena in Sherlock Holmes the Movie

    NAMAZCARRA, CHRIESHER

    2014-01-01

    Keywords: Occult phenomena, Sherlock Holmes, movie. Lately, it is not difficult for people to find occult practices. There are many television programs and movie which air mystical programme aggressively to raise the rating and attract the viewers. A movie that raise occultism theme is Sherlock Holmes, the Movie. This movie tells about the struggle of detective Sherlock Holmes to fight the black magic power of Lord Blackwood.To carry out the study, the theories of Occultism such as the secrec...

  8. Detection of occult hepatitis B virus among chronic hepatitis C patients

    Background: Concurrent infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are increasingly recognized in patients with chronic hepatitis. In Egypt, the last decade showed a remarkable decline in HBV infection associated with remarkable rise in HCV infection. The probable impact of occult HBV in patients ...

  9. Progress on the occulter experiment at Princeton

    Cady, Eric; Balasubramanian, Kunjithapatham; Carr, Michael; Dickie, Matthew; Echternach, Pierre; Groff, Tyler; Kasdin, Jeremy; Laftchiev, Christian; McElwain, Michael; Sirbu, Dan; Vanderbei, Robert; White, Victor

    2009-08-01

    An occulter is used in conjunction with a separate telescope to suppress the light of a distant star. To demonstrate the performance of this system, we are building an occulter experiment in the laboratory at Princeton. This experiment will use an etched silicon mask as the occulter, with some modifications to try to improve the performance. The occulter is illuminated by a diverging laser beam to reduce the aberrations from the optics before the occulter. We present the progress of this experiment and expectations for future work.

  10. Current management of occult bacteremia in infants

    Eduardo Mekitarian Filho

    2015-11-01

    Full Text Available Objectives: To summarize the main clinical entities associated with fever without source (FWS in infants, as well as the clinical management of children with occult bacteremia, emphasizing laboratory tests and empirical antibiotics. Sources: A non-systematic review was conducted in the following databases – PubMed, EMBASE, and SciELO, between 2006 and 2015. Summary of the findings: The prevalence of occult bacteremia has been decreasing dramatically in the past few years, due to conjugated vaccination against Streptococcus pneumoniae and Neisseria meningitidis. Additionally, fewer requests for complete blood count and blood cultures have been made for children older than 3 months presenting with FWS. Urinary tract infection is the most prevalent bacterial infection in children with FWS. Some known algorithms, such as Boston and Rochester, can guide the initial risk stratification for occult bacteremia in febrile infants younger than 3 months. Conclusions: There is no single algorithm to estimate the risk of occult bacteremia in febrile infants, but pediatricians should strongly consider outpatient management in fully vaccinated infants older than 3 months with FWS and good general status. Updated data about the incidence of occult bacteremia in this environment after conjugated vaccination are needed. Resumo: Objetivos: Listar as principais entidades clínicas associadas a quadros de febre sem sinais localizatórios (FSSL em lactentes, bem como o manejo dos casos de bacteremia oculta com ênfase na avaliação laboratorial e na antibioticoterapia empírica. Fonte dos dados: Foi realizada revisão não sistemática da literatura nas bases de dados PubMed, EMBASE e Scielo no período de 2006 a 2015. Síntese dos dados: A ocorrência de bacteremia oculta vem diminuindo sensivelmente em lactentes com FSSL, principalmente devido à introdução da vacinação conjugada contra Streptococcus pneumoniae e Neisseria meningitidis nos últimos anos

  11. Radioimmune localization of occult carcinoma

    Duda, R.B.; Zimmer, A.M.; Rosen, S.T.; Gilyon, K.A.; Webber, D.; Spies, S.; Spies, W.; Merchant, B.

    1990-01-01

    Patients with a rising serum carcinoembryonic antigen level and no clinical or roentgenographic evidence of recurrent or metastatic cancer present a treatment dilemma. Eleven such patients, 10 with a previously treated colorectal carcinoma and 1 with a previously treated breast carcinoma, received an injection of the anticarcinoembryonic antigen monoclonal antibody ZCE-025 labeled with the radioisotope indium 111. Nuclear scintigraphy was performed on days 3 and 5 through 7 to detect potential sites of tumor recurrence. The monoclonal antibody scan accurately predicted the presence or absence of occult malignancy in 7 (64%) patients. Second-look laparotomy confirmed the monoclonal antibody scan results in the patients with colorectal cancer, and magnetic resonance imaging confirmed metastatic breast cancer. This study demonstrates that In-ZCE-025 can localize occult carcinoma and may assist the surgeon in facilitating the operative exploration. In-ZCE-025 assisted in the initiation of adjuvant therapy for the patient with breast cancer

  12. Aplastic crisis in occult hereditary spherocytosis caused by human parvovirus (HPV B19).

    Rappaport, E S; Quick, G; Ransom, D; Helbert, B; Frankel, L S

    1989-02-01

    We have reported a case of aplastic crisis occurring in an 11-year-old black boy with occult hereditary spherocytosis. An etiologic diagnosis of human parvovirus (HPV) B19 infection was confirmed serologically. The Coulter Model S + IV proved useful for both diagnosis and treatment monitoring through serial histograms. The relationship of HPV infection and aplastic crisis is discussed.

  13. OCCULT POWER AND AFRICA'S SOCIO-ECONOMIC PROBLEMS ...

    Dr Ike

    people believe in the existence of occult powers and this belief affects their ... make use of occult powers to solve their problems. For example, ... existence and influence of paranormal and occult powers, argues that ..... and friends.

  14. Occultations for probing atmosphere and climate

    Foelsche, Ulrich; Steiner, Andrea

    2004-01-01

    Use of occultation methodology for observing the Earth's atmosphere and climate has become so broad as to comprise solar, lunar, stellar, navigation and satellite­ crosslink occultation methods. The atmospheric parameters obtained extend from the fundamental variables temperature, density, pressure, water vapor, and ozone via a multitude of trace gas species to particulate species such as aerosols and cloud liquid water. Ionospheric electron density is sensed as well. The methods all share the key properties of self-calibration, high accuracy and vertical resolution, global coverage, and (if using radio signals) all-weather capability. Occultation data are thus of high value in a wide range of fields including climate monitoring and research, atmospheric physics and chemistry, operational meteorology, and other fields such as space weather and planetary science. This wide area of variants and uses of the occultation method has led to a diversi­ fication of the occultation-related scientific community into a...

  15. Sociology of religion and the occult revival

    Lennart Ejerfeldt

    1975-01-01

    Full Text Available The "new" that makes the cults of the occult revival to "new religions" of the Western world, is their recently increased social significance. Historically most of modern occultism is anything but new. From the research and theorizing about the occult revival we have picked up some main themes. The first is the social diffusion of the new occultism. In this field, we find some studies of superstition, especially astrology. These illuminate the differences in social connotation between the consumers of superstition and the followers of institutional religion. Secondly the study of the occult revival has made valuable contributions to the conceptualizing of "cult" and the cultic phenomenon. Thirdly, we will look upon the connection between the occult revival and the counter-culture. The problem of the rise of cults as a symptom of socio-cultural change will be briefly discussed with reference to Bell's thesis of "the disjuntion of culture and social structure". Lastly, we proffer some reflections on the occult revival and the new spiritual trends in the churches, which so sharply contrast with the theology and churchmanship of the sixties.

  16. Occult hepatitis B virus among the patients with abnormal alanine transaminase.

    Makvandi, Manoochehr; Neisi, Niloofar; Khalafkhany, Davod; Makvandi, Kamyar; Hajiani, Eskandar; Shayesteh, Ali Akbar; Masjedi Zadeh, Abdolrahim; Sina, Amir Hosein; Hamidifard, Mojtaba; Rasti, Mojtaba; Aryan, Ehsan; Ahmadi, Kambiz; Yad Yad, Mohammad Jafar

    2014-08-01

    The occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the sera or in the liver biopsy and the absence of hepatitis B surface antigen (HBsAg) by serological test. The current study aimed to evaluate the occult HBV infection by polymerase chain reaction (PCR) and determine HBV genotyping among the patients with abnormal alanine transaminase (ALT) in Ahvaz city, Iran. The sera of 120 patients, 54 (45%) females and 66 (55%) males, with abnormal ALT 40-152 IU were collected. All the patients were negative for HBsAg for more than one year. The patients` sera were tested by PCR using primers specified for the S region of HBV. Then the positive PCR products were sequenced to determine HBV genotyping and phylogenic tree. Of these 120 subjects, 12 (10%) patients including 6 (5%) males and 6 (5%) females were found positive for HBV DNA by PCR, which indicated the presence of occult HBV infection among these patients. The sequencing results revealed that genotype D was predominant with sub-genotyping D1 among OBI patients. Occult hepatitis B infection is remarkably prevalent in Ahvaz, Iran, and should be considered as a potential risk factor for the transmission of Hepatitis B Virus throughout the community by the carriers.

  17. Occult Hepatitis B Virus Among the Patients With Abnormal Alanine Transaminase

    Makvandi, Manoochehr; Neisi, Niloofar; Khalafkhany, Davod; Makvandi, Kamyar; Hajiani, Eskandar; Shayesteh, Ali Akbar; Masjedi Zadeh, Abdolrahim; Sina, Amir Hosein; Hamidifard, Mojtaba; Rasti, Mojtaba; Aryan, Ehsan; Ahmadi, Kambiz; Yad Yad, Mohammad Jafar

    2014-01-01

    Background: The occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the sera or in the liver biopsy and the absence of hepatitis B surface antigen (HBsAg) by serological test. Objectives: The current study aimed to evaluate the occult HBV infection by polymerase chain reaction (PCR) and determine HBV genotyping among the patients with abnormal alanine transaminase (ALT) in Ahvaz city, Iran. Patients and Methods: The sera of 120 patients, 54 (45%) females and 66 (55%) males, with abnormal ALT 40-152 IU were collected. All the patients were negative for HBsAg for more than one year. The patients` sera were tested by PCR using primers specified for the S region of HBV. Then the positive PCR products were sequenced to determine HBV genotyping and phylogenic tree. Results: Of these 120 subjects, 12 (10%) patients including 6 (5%) males and 6 (5%) females were found positive for HBV DNA by PCR, which indicated the presence of occult HBV infection among these patients. The sequencing results revealed that genotype D was predominant with sub-genotyping D1 among OBI patients. Conclusions: Occult hepatitis B infection is remarkably prevalent in Ahvaz, Iran, and should be considered as a potential risk factor for the transmission of Hepatitis B Virus throughout the community by the carriers. PMID:25485052

  18. Reflective Occultation Mask for Evaluation of Occulter Designs for Planet Finding

    Hagopian, John; Lyon, Richard; Shiri, Shahram; Roman, Patrick

    2011-01-01

    Advanced formation flying occulter designs utilize a large occulter mask flying in formation with an imaging telescope to block and null starlight to allow imaging of faint planets in exosolar systems. A paper describes the utilization of subscale reflective occultation masks to evaluate formation flying occulter designs. The use of a reflective mask allows mounting of the occulter by conventional means and simplifies the test configuration. The innovation alters the test set-up to allow mounting of the mask using standard techniques to eliminate the problems associated with a standard configuration. The modified configuration uses a reflective set-up whereby the star simulator reflects off of a reflective occulting mask and into an evaluation telescope. Since the mask is sized to capture all rays required for the imaging test, it can be mounted directly to a supporting fixture without interfering with the beam. Functionally, the reflective occultation mask reflects light from the star simulator instead of transmitting it, with a highly absorptive carbon nanotube layer simulating the occulter blocking mask. A subscale telescope images the star source and companion dim source that represents a planet. The primary advantage of this is that the occulter can be mounted conventionally instead of using diffractive wires or magnetic levitation.

  19. McDonald's and the Occult.

    Singer, Barry

    1979-01-01

    Discusses "occult" and "paranormal" literature which is often mistaken for nonfiction. Suggests that most publishers are unwilling to publish scientific perspectives on the paranormal because such writings would be unmarketable. Journal availability: see SO 507 190. (KC)

  20. Optical performance of the New Worlds Occulter

    Arenberg, Jonathan W.; Lo, Amy S.; Glassman, Tiffany M.; Cash, Webster

    2007-04-01

    The New Worlds Observer (NWO) is a multiple spacecraft mission that is capable of detecting and characterizing extra-solar planets and planetary systems. NWO consists of an external occulter and a generic space telescope, flying in tandem. The external occulter has specific requirements on its shape and size, while the telescope needs no special modification beyond that required to do high-quality astrophysical observations. The occulter is a petal-shaped, opaque screen that creates a high-suppression shadow large enough to accommodate the telescope. This article reports on the optical performance of the novel New Worlds occulter design. It also introduces two new aspects of its optical performance which enhance the detectability of extra-solar planets. We also include a brief discussion of the buildability and the tolerances of the occulter. It is also shown that an occulter design can be found for any set of science requirements. We show that NWO is a viable mission concept for the study of extra-solar planets. To cite this article: J.W. Arenberg et al., C. R. Physique 8 (2007).

  1. Occult hepatitis B virus coinfection in HIV-positive African migrants to the UK: a point prevalence study.

    Chadwick, D; Doyle, T; Ellis, S; Price, D; Abbas, I; Valappil, M; Geretti, A M

    2014-03-01

    Occult (surface antigen-negative/DNA-positive) hepatitis B virus (HBV) infection is common in areas of the world where HBV is endemic. The main objectives of this study were to determine the prevalence of occult HBV infection in HIV-infected African migrants to the UK and to determine factors associated with occult coinfection. This anonymized point-prevalence study identified Africans attending three HIV clinics, focussing on patients naïve to antiretroviral therapy (ART). Stored blood samples were tested for HBV DNA. Prevalence was calculated in the entire cohort, as well as in subpopulations. Risk factors for occult HBV coinfection were identified using logistic regression analysis. Among 335 HIV-positive African migrants, the prevalence of occult HBV coinfection was 4.5% [95% confidence interval (CI) 2.8-7.4%] overall, and 6.5% (95% CI 3.9-10.6%) and 0.8% (95% CI 0.2-4.6%) in ART-naïve and ART-experienced patients, respectively. Among ART-naïve anti-HBV core (anti-HBc)-positive patients, the prevalence was 16.4% (95% CI 8.3-25.6%). The strongest predictor of occult coinfection was anti-HBc positivity [odds ratio (OR) 7.4; 95% CI 2.0-27.6]. Median HBV DNA and ALT levels were 54 IU/mL [interquartile range (IQR) 33-513 IU/mL] and 22 U/L (IQR 13-27 U/L), respectively. Occult HBV coinfection remains under-diagnosed in African HIV-infected patients in the UK. Given the range of HBV DNA levels observed, further studies are warranted to determine its clinical significance and to guide screening strategies and ART selection in these patients. © 2013 British HIV Association.

  2. Oligometastasis as a predictor for occult disease.

    Kendal, Wayne S

    2014-05-01

    Oligometastasis can be defined as a state of limited metastases that is potentially amenable to ablative local therapy; the success of such therapy depends on whether or not additional occult metastases exist. A model is presented here to predict occult metastases given detectable oligometastases. Predictions were based on Bayes' theorem, in conjunction with descriptions of the statistical distributions for the sizes and numbers of hematogenous metastases. The background probability for occult metastases in individuals with oligometastases increased markedly with relatively minor increases in metastatic potential. With each additional metastasis detected the chance of further occult metastases increased. These latter increases were incremental and proportionately smaller with the more metastatic tumors. Long disease free intervals had a major effect to decrease in the probability of further occult disease. Demonstration of oligometastases depends heavily upon the sensitivity of radiological imaging techniques, where the proportion of detectable metastases relates to the position of the distribution of metastasis growth times with respect to the detection threshold. Given the limitations of radiological methods, and the possibility that the oligometastases detected may be the only disease, an aggressive approach appears indicated. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Boundary diffraction wave integrals for diffraction modeling of external occulters

    Cady, E.

    2012-01-01

    An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional light into this region, and a challenge of modeling an occulter system is to accurately and quickly...

  4. ORIGINAL ARTICLES HBV/HIV co-infection: The dynamics of HBV ...

    B virus (HBV) exposure, and an estimated 400 million are chronically infected.1 ... transplantation, cancer and HIV/AIDS might induce reactivation of occult HBV with ... productive infection.7-9 Occult HBV infection refers to the presence of HBV DNA without ... CD4+ cell count of <200 cells/µl in patients infected with HIV.

  5. Strong scintillations during atmospheric occultations Theoretical intensity spectra. [radio scattering during spacecraft occultations by planetary atmospheres

    Hinson, D. P.

    1986-01-01

    Each of the two Voyager spacecraft launched in 1977 has completed a reconnaissance of the Jovian and Saturnian systems. In connection with occultation experiments, strong scintillations were observed. Further theoretical work is required before these scintillations can be interpreted. The present study is, therefore, concerned with the derivation of a theory for strong scattering during atmospheric occultation experiments, taking into account as fundamental quantity of interest the spatial spectrum (or spectral density) of intensity fluctuations. Attention is given to a theory for intensity spectra, and numerical calculations. The new formula derived for Phi-i accounts for strong scattering of electromagnetic waves during atmospheric occultations.

  6. First results from stellar occultations in the "GAIA era"

    Benedetti-Rossi, G.; Vieira-Martins, R.; Sicardy, B.

    2017-09-01

    Stellar occultation is a powerful technique to study distant solar system bodies. It allows high angular resolution of the occulting body from the analysis of a light curve acquired with high temporal resolution with uncertainties comparable as probes. In the "GAIA era", stellar occultations is now able to obtain even more impressive results such as the presence of atmosphere, rings and topographic features.

  7. Occult spondyloarthritis in inflammatory bowel disease.

    Bandinelli, Francesca; Manetti, Mirko; Ibba-Manneschi, Lidia

    2016-02-01

    Spondyloarthritis (SpA) is a frequent extra-intestinal manifestation in patients with inflammatory bowel disease (IBD), although its real diffusion is commonly considered underestimated. Abnormalities in the microbioma and genetic predisposition have been implicated in the link between bowel and joint inflammation. Otherwise, up to date, pathogenetic mechanisms are still largely unknown and the exact influence of the bowel activity on rheumatic manifestations is not clearly explained. Due to evidence-based results of clinical studies, the interest on clinically asymptomatic SpA in IBD patients increased in the last few years. Actually, occult enthesitis and sacroiliitis are discovered in high percentages of IBD patients by different imaging techniques, mainly enthesis ultrasound (US) and sacroiliac joint X-ray examinations. Several diagnostic approaches and biomarkers have been proposed in an attempt to correctly classify and diagnose clinically occult joint manifestations and to define clusters of risk for patient screening, although definitive results are still lacking. The correct recognition of occult SpA in IBD requires an integrated multidisciplinary approach in order to identify common diagnostic and therapeutic strategies. The use of inexpensive and rapid imaging techniques, such as US and X-ray, should be routinely included in daily clinical practice and trials to correctly evaluate occult SpA, thus preventing future disability and worsening of quality of life in IBD patients.

  8. Occult diaphragmatic injuries caused by stab wounds.

    Leppäniemi, Ari; Haapiainen, Reijo

    2003-10-01

    Missed diaphragmatic perforation caused by penetrating trauma can lead to subsequent strangulation of a hollow viscus, which has prompted the use of invasive diagnostic procedures to exclude occult diaphragmatic injuries in asymptomatic, high-risk patients. The objective of this study was to determine the incidence of occult diaphragmatic injuries caused by stab wounds of the lower chest and upper abdomen, and to examine the natural history and consequences of missed diaphragmatic injuries. On the basis of patient data from two previous randomized studies from our institution, a retrospective analysis was performed on 97 patients treated for anterior stab wounds located between the nipple line, the umbilical level, and the posterior axillary lines not having indications for immediate surgical exploration. The patients were divided into two groups on the basis of their initial randomized management (open or laparoscopic exploration vs. expectant observation). In the exploration group (n = 47), four diaphragmatic injuries (9%) were detected (three left-sided and one right-sided). Excluding patients with associated injuries requiring surgical repair, the incidence of occult diaphragmatic injuries was 3 of 43 (7%). In the observation group (n = 50), there were two patients (4%) with delayed presentation of missed left-sided diaphragmatic injury 2 and 23 months later, respectively. Both injuries resulted from stab wounds of the left flank and presented with herniation of the stomach or small bowel and colon. The overall incidence of occult diaphragmatic injuries in left-sided thoracoabdominal stab wounds was 4 of 24 (17%), and was much lower after stab wounds of left epigastrium (0%), right lower chest (0%), and right epigastrium (4%). In asymptomatic patients with anterior or flank stab wounds of the lower chest or upper abdominal area, the risk of an occult diaphragmatic injury is approximately 7% which, if undetected, is associated with a high risk of subsequent

  9. Occult HBV among Anti-HBc Alone: Mutation Analysis of an HBV Surface Gene and Pre-S Gene.

    Kim, Myeong Hee; Kang, So Young; Lee, Woo In

    2017-05-01

    The aim of this study is to investigate the molecular characteristics of occult hepatitis B virus (HBV) infection in 'anti-HBc alone' subjects. Twenty-four patients with 'anti-HBc alone' and 20 control patients diagnosed with HBV were analyzed regarding S and pre-S gene mutations. All specimens were analyzed for HBs Ag, anti-HBc, and anti-HBs. For specimens with an anti-HBc alone, quantitative analysis of HBV DNA, as well as sequencing and mutation analysis of S and pre-S genes, were performed. A total 24 were analyzed for the S gene, and 14 were analyzed for the pre-S gene through sequencing. A total of 20 control patients were analyzed for S and pre-S gene simultaneously. Nineteen point mutations of the major hydrophilic region were found in six of 24 patients. Among them, three mutations, S114T, P127S/T, M133T, were detected in common. Only one mutation was found in five subjects of the control group; this mutation was not found in the occult HBV infection group, however. Pre-S mutations were detected in 10 patients, and mutations of site aa58-aa100 were detected in 9 patients. A mutation on D114E was simultaneously detected. Although five mutations from the control group were found at the same location (aa58-aa100), no mutations of occult HBV infection were detected. The prevalence of occult HBV infection is not low among 'anti-HBc alone' subjects. Variable mutations in the S gene and pre-S gene were associated with the occurrence of occult HBV infection. Further larger scale studies are required to determine the significance of newly detected mutations. © Copyright: Yonsei University College of Medicine 2017

  10. Occult fractures of the knee: tomographic evaluation

    Apple, J.S.; Martinez, S.; Allen, N.B.; Caldwell, D.S.; Rice, J.R.

    1983-01-01

    Seven adults with painful effusions of the knee were examined for occult fractures using pluridirectional tomograph in the coronal and lateral planes. Six patients (ages 50 to 82 years) were osteopenic and gave histories ranging from none to mild trauma; one 26-year-old man was not osteopenic and had severe trauma. In all cases, routine radiographs were interpreted as negative, but tomography demonstrated a fracture. Five fractures were subchondral. Bone scans in 2 patients were positive. The authors conclude that osteopenic patients with a painful effusion of the knee should be considered to have an occult fracture. While bone scans may be helpful, tomography is recommended as the procedure of choice to define the location and extent of the fracture

  11. Paraneoplastic retinopathy associated with occult bladder cancer

    Nivean, M; Muttuvelu, Danson V; Afzelius, Pia Maria Tullia

    2016-01-01

    (ERG), serology including serum antibodies for CAR, and positron emission tomography-computed tomography (PET-CT) scan. The patient was diagnosed with bladder carcinoma revealed by PET-CT. Timely recognition of this entity may be crucial for an increased patient survival thus adult onset progressive...... photoreceptor dysfunction, confirmed by ERG, should alert to a possible remote effect of known or occult malignancy. In the latter, PET-CT may be exploited as a powerful diagnostic tool....

  12. Results from occultations by minor planets

    Taylor, G.E.

    1982-01-01

    Since the minor planets are believed to consist of primordial matter dating from the time of the formation of the solar system there is great interest in determining their composition. It is therefore necessary to calculate their densities, for which we need accurate masses and sizes. On the rare occasions when a minor planet occults a star, timed observations of the event from a number of observing sites enable an accurate size of the minor planet to be determined. (Auth.)

  13. ASTEROID SIZING BY RADIOGALAXY OCCULTATION AT 5 GHZ

    Lehtinen, K.; Muinonen, K.; Poutanen, M. [Finnish Geospatial Research Institute FGI, Geodeetinrinne 2, FI-02430 Masala (Finland); Bach, U. [Max-Planck-Institut für Radioastronomie, Radioobservatorium Effelsberg, Max-Planck-Str. 28, D-53902 Bad Münstereifel-Effelsberg (Germany); Petrov, L., E-mail: kimmo.lehtinen@nls.fi [Astrogeo Center, Falls Church, VA 22043 (United States)

    2016-05-10

    Stellar occultations by asteroids observed at visual wavelengths have been an important tool for studying the size and shape of asteroids and for revising the orbital parameters of asteroids. At radio frequencies, a shadow of an asteroid on the Earth is dominated by diffraction effects. Here, we show, for the first time, that a single observation of an occultation of a compact radio source at a frequency of 5 GHz can be used to derive the effective size of the occulting object and to derive the distance between the observer and the center of the occultation path on the Earth. The derived diameter of the occulting object, asteroid (115) Thyra, is 75 ± 6 km. The observed occultation profile shows features that cannot be explained by diffraction of a single asteroid.

  14. OCCULTISM AND MEDIUMSHIP IN FERNANDO PESSOA

    Alisson Diêgo Dias de Medeiros

    2016-03-01

    Full Text Available This work is the result of a research on the influence that the occultism had on the work of the Portuguese poet Fernando Pessoa. To delimitate the study, we selected papers of Fernando Pessoa, which  suggested that the poet considered himself medium, and hence influenced his work, building his depersonalization. This work presents, thus, as main objectiveto analyze personal papers of Fernando Pessoa, whose outstanding characteristic is the presence of occultism and the supposed mediumship defended by him in response to non-literary and heteronymic manifestations. To this end, I focused on specific objectives, which are: a to study the speech of Fernando Pessoa on his supposed mediumship / occultism b to analyze specific texts that are, for the poet, mediumistic manifestations c to study excerpts from a set of personal letters in which Fernando Pessoa suggested being a medium. It is true that this dissertation will address many discussions already made by scholars and specialists in Fernando Pessoa, but we consider the possibility to deepen issues and contribute to the critical fortune of the poet.

  15. Ultrasound detection of nonpalpable mammographically occult malignancy

    Simpson, W.L.; Hermann, G.; Rausch, D.R.; Sherman, J.; Feig, S.A.; Bleiweiss, I.J.; Jaffer, S.

    2008-01-01

    To evaluate the prevalence of occult malignancy with screening breast ultrasound. All ultrasound-guided core needle breast biopsies performed between January 1, 1999, and June 30, 2001, were retrospectively reviewed. Lesions were identified during screening breast ultrasound in high-risk women with no mammographic or palpable abnormality in either breast, a unilateral mammographic or palpable abnormality in the contralateral breast, or a unilateral mammographic or palpable abnormality in a different quadrant of the same breast. All ultrasound-detected lesions were histologically verified. Six hundred and fifty-two women with a mean age of 49 years underwent 698 biopsies during the study period. Three hundred and forty-nine of these lesions were detected at screening breast ultrasound. Out of 349, 11 (3.2%) had a mammographically and clinically occult malignancy. Nine cancers were found in women with no mammographic or palpable abnormality. Two cancers were found in the same breast as the mammographic or palpable abnormality. None were found in the breast contralateral to a palpable or mammographic abnormality. Screening breast ultrasound of high-risk women has a similar detection rate for occult carcinoma as screening mammography, but has a low positive predictive value in cases where biopsy is performed. (author)

  16. OCCULT-ORSER complete conversational user-language translator

    Ramapriyan, H. K.; Young, K.

    1981-01-01

    Translator program (OCCULT) assists non-computer-oriented users in setting up and submitting jobs for complex ORSER system. ORSER is collection of image processing programs for analyzing remotely sensed data. OCCULT is designed for those who would like to use ORSER but cannot justify acquiring and maintaining necessary proficiency in Remote Job Entry Language, Job Control Language, and control-card formats. OCCULT is written in FORTRAN IV and OS Assembler for interactive execution.

  17. The prevalence of visible and/or occult blood on anesthesia and monitoring equipment.

    Perry, S M; Monaghan, W P

    2001-02-01

    The Occupational Safety and Health Administration (OSHA) and the Centers for Disease Control and Prevention (CDC) have attempted to stop the spread of blood-borne pathogens by issuing several recommendations and regulations. However, unless healthcare workers comply with these standards, they are not effective. In the anesthesia care environment, the anesthetist is responsible for ensuring that the equipment is clean, and disinfected, before use. We studied the prevalence of visible and occult blood on 6 types of anesthesia and monitoring equipment identified as ready for use in 28 operating suites, in 2 facilities. The sample consisted of 336 observations of the 6 types of equipment. The equipment was inspected for visible blood and then tested for occult blood using a 3-stage phenolphthalein test. Of the 336 observations, 110 (32.7%), were positive for occult blood with only 6 showing visible blood. The presence of blood on this equipment may be in direct violation of the OSHA Blood-borne Pathogen Standard and the infection control guidelines of the American Association of Nurse Anesthetists. Furthermore, the presence of blood on this equipment may increase the risk for nosocomial and occupational exposure to viral and bacterial pathogens. Recommendations were made to decrease the risks from this contamination by redesigning equipment, increasing the use of disposable equipment, and ensuring compliance with effective infection control practices.

  18. Prevalence of occult inflammatory bowel disease in ankylosing spondylitis.

    Costello, P B; Alea, J A; Kennedy, A C; McCluskey, R T; Green, F A

    1980-10-01

    Fifty-five patients with ankylosing spondylitis and 16 control patients matched for sex and age were examined for evidence of occult inflammatory bowel disease. In all patients evaluation included history and physical examination, barium enema, sigmoidoscopy, and rectal biopsy. The results of this study suggest that there is no increased prevalence of occult inflammatory bowel disease in patients with ankylosing spondylitis.

  19. 21 CFR 864.6550 - Occult blood test.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Occult blood test. 864.6550 Section 864.6550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test. (a...

  20. Radio Occultation Bending Angle Anomalies During Tropical Cyclones

    Biondi, Riccardo; Neubert, Torsten; Syndergaard, Stig

    signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC), we show that the bending angle anomaly of a GPS radio occultation signal is typically larger...

  1. Esophageal Metastasis From Occult Lung Cancer

    Po-Kuei Hsu

    2010-06-01

    Full Text Available A 66-year-old man with dysphagia was found to have a poorly differentiated esophageal carcinoma by incision biopsy. Following esophagectomy, reconstruction with a gastric tube was performed. Pathological examination and immunohisto-chemistry showed infiltration of adenocarcinoma cells with positive thyroid transcription factor 1-staining in the submucosal layer, which indicated metastatic esophageal carcinoma. Although no pulmonary lesion could be visualized by imaging or bronchoscopy, pulmonary origin was highly suspected as a result of positive thyroid transcription factor 1-staining. To the best of our knowledge, this is the first reported case of metastatic esophageal carcinoma from occult lung cancer (AJCC TNM stage TX.

  2. Lunar occultation observations of the Crab Nebula

    Maloney, F.P.

    1977-01-01

    Three lunar of occultations of the Crab Nebula were observed, two at 114 MHz and one at 26.3 MHz, during the 1974 series of events. The higher frequency observations were deconvolved of diffraction effects to yield four strip integrated brightness profiles of the Nebula, with an effective resolution of 30 arc-seconds. These four profiles were Fourier inverted and cleaned of sidelobe structure to synthesize a two-dimensional map of the Nebula. At 114 MHz, the Nebula is composed of a broad envelope of emission which contains several smaller sources. The attenuation of the low radio frequency radiation by the thermal hydrogen in the filaments is considered as a possible mechanism to explain these new data. The 26.3 MHz observations indicate the presence of a bright, localized source containing greater than 80% of the flux of the Nebula. The position of the source is confined by the data to a narrow strip centered at the pulsar position. Both sets of data are compared with past occultation observations

  3. CT detection of occult pneumothorax in head trauma

    Tocino, I.M.; Miller, M.H.; Frederick, P.R.; Bahr, A.L.; Thomas, F.

    1984-01-01

    A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneuomothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia

  4. CT detection of occult pneumothorax in head trauma

    Tocino, I.M.; Miller, M.H.; Frederick, P.R.; Bahr, A.L.; Thomas, F.

    1984-11-01

    A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneuomothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia.

  5. Profiling Saturn's rings by radio occultation

    Marouf, E.A.; Tyler, G.L.; Rosen, P.A.

    1986-01-01

    The development of reconstruction algorithms that correct for diffraction effects in radio occultation measurements is described. The reciprocal Fresnel transform relationship between the complex amplitude of the observed coherent signal and the complex microwave transmittance of the rings is derived using the Huygens-Fresnel formulation of the diffraction problem. The effects of the finite data segment width, the uncertainties in the Fresnel scale, systematic phase errors in the kernel of the inverse transform, reference oscillator instabilities, and random noise measurements on the resolution of the reconstructed transmittance are analyzed. Examples of reconstructed opacity profiles for some regions of Saturn's rings derived by applying the reconstruction theory to Voyager 1 at Saturn data are presented. 35 references

  6. Diagnosis of occult abdominal abscesses using radioisotopes

    Koch, B.; Schroth, H.J.; Wolf, N.; Wilhelm, H.; Universitaet des Saarlandes, Homburg/Saar

    1983-01-01

    Occult intraperitoneal abscesses are difficult to localize and dispose of. Therefore, a method of examination is needed that is specific, can be used at any time, is not expensive, and yields early results within 2-3 h. This seems possible with a new method of examination. sup(99m)Tc-Sn-colloid was used to label autologous polymorphonuclear leukocytes which, when reinjected, emigrate to the site of the suspected abscess. Standard scintigraphy localizes the labeled inflammatory cells. Scans were performed in 57 surgical patients with good results. 23 (40,4%) patients had true negative results; 28 (49,1%) scans represented intraperitoneal abscesses; 5 (8,8%) scans demonstrated true positive extraperitoneal inflammations. Only 1 (1,7%) scan was false positive. (orig.) [de

  7. Atmospheric stability index using radio occultation refractivity profiles

    A new stability index based on atmospheric refractivity at ∼500 hPa level and surface measurements of temperature ... able at different heights rather than pressure levels. However ..... the radio occultation technique being a limb sound-.

  8. Characterization and evolution of distant planetary atmospheres using stellar occultations

    Young, L. A.

    2008-09-01

    Ground-based or near-Earth (e.g., HST) stellar occultations of every atmosphere in our solar system has been observed: Venus, Mars, Jupiter, Saturn, Titan, Uranus, Neptune, Triton, and Pluto [1]. These observations probe the atmospheres at roughly 0.1 to 100 microbar. I will talk about three aspects of stellar occultations: one-dimensional vertical profiles of the atmosphere, two- or three-dimensional atmospheric states, and the time evolution of atmosphere. In all three, I will draw on recent observations, with an emphasis on Pluto. Occultations are particularly important for the study of Pluto's atmosphere, which is impossible to study with imaging, and extremely difficult to study with spectroscopy. It was discovered by stellar occultation in 1988 [2]. No subsequent Pluto occultations were observed until two events in 2002 [3]. Pluto is now crossing the galactic plane, and there have been several additional occultations observed since 2006. These include a high signal-to-noise observation from the Anglo Australian Observatory in 2006 [4] (Fig 1), densely spaced visible and infrared observations of Pluto's upper atmosphere from telescopes in the US and Mexico in March, 2007 [5] (Fig. 2), and a dualwavelength central flash observation from Mt. John in July, 2007 [6] (Fig 3). The flux from a star occulted by an atmosphere diminishes primarily due to the increase in refraction with depth in the atmosphere, defocusing the starlight, although absorption and tangential focusing can also contribute. Because the atmospheric density, to first order, follows an exponential, it is feasible to derive a characteristic pressure and temperature from isothermal fits to even low-quality occultation light curves. Higher quality light curves allow fits with more flexible models, or light curve inversions that derive temperatures limited by the resolution of the data. These allow the derivation of one-dimensional profiles of temperature and pressure vs. altitude, which are critical

  9. UARS Halogen Occultation Experiment (HALOE) Level 2 V001

    National Aeronautics and Space Administration — The HALOE home page on the WWW is http://haloe.gats-inc.com/home/index.php The Halogen Occultation Experiment (HALOE) on NASA's Upper Atmosphere Research Satellite...

  10. Photoreceptor atrophy in acute zonal occult outer retinopathy

    Zibrandtsen, N.; Munch, I.C.; Klemp, K.

    2006-01-01

    Purpose: To assess retinal morphology in acute zonal occult outer retinopathy (AZOOR). Methods: Three patients with a normal ophthalmoscopic fundus appearance, a history of photopsia, and visual field loss compatible with AZOOR were examined using optical coherence tomography, automated perimetry...

  11. Possible occultation by Pluto from US East Coast

    Waagen, Elizabeth O.

    2012-06-01

    We have been asked to help disseminate the news of a possible occultation by Pluto visible to observers on the US East coast. Although the AAVSO does not ordinarily issue announcements of upcoming occultations, in this case the object is Pluto and the NASA New Horizons mission (http://www.nasa.gov/mission_pages/newhorizons/main/index.html) will be visiting Pluto in 2015. The information below has been supplied by Dr. Leslie Young (Southwest Research Institute), who is coordinating this observing campaign on Pluto. Dr. Young is also Deputy Project Scientist for the New Horizons mission. ALERT: Possible Pluto occultation Wednesday night (2012/06/14 03:28 UT) from US East coast. CONTACT: Leslie Young (layoung@boulder.swri.edu; work: 303-546-6057; skype: drpluto). Also see our planning pages in progress at http://wiki.boulder.swri.edu/mediawiki/index.php/2012-06-14_Pluto_occultation. Pluto's thin, nitrogen atmosphere is in vapor-pressure equilibrium with the surface ice, and changes seasonally. We've seen it double since 1988, and now we measure its pressure once or twice a year. The technique we use is stellar occultation, when a star passes behind Pluto's atmosphere. The atmosphere defocuses the starlight. By the timing of the fading of the star, we measure the pressure and temperature in Pluto's atmosphere at ~10 km resolution. MORE INFORMATION: See http://wiki.boulder.swri.edu/mediawiki/index.php/2012-06-14_Pluto_occultation.

  12. Occult pneumomediastinum in blunt chest trauma: clinical significance.

    Rezende-Neto, J B; Hoffmann, J; Al Mahroos, M; Tien, H; Hsee, L C; Spencer Netto, F; Speers, V; Rizoli, S B

    2010-01-01

    Thoracic injuries are potentially responsible for 25% of all trauma deaths. Chest X-ray is commonly used to screen patients with chest injury. However, the use of computed tomography (CT) scan for primary screening is increasing, particularly for blunt trauma. CT scans are more sensitive than chest X-ray in detecting intra-thoracic abnormalities such as pneumothoraces and pneumomediastinums. Pneumomediastinum detected by chest X-ray or "overt pneumomediastinum", raises the concern of possible aerodigestive tract injuries. In contrast, there is scarce information on the clinical significance of pneumomediastinum diagnosed by CT scan only or "occult pneumomediastinum". Therefore we investigated the clinical consequences of occult pneumomediastinum in our blunt trauma population. A 2-year retrospective chart review of all blunt chest trauma patients with initial chest CT scan admitted to a level I trauma centre. Data extracted from the medical records include; demographics, occult, overt, or no pneumomediastinum, the presence of intra-thoracic aerodigestive tract injuries (trachea, bronchus, and/or esophagus), mechanism and severity of injury, endotracheal intubation, chest thoracostomy, operations and radiological reports by an attending radiologist. All patients with intra-thoracic aerodigestive tract injuries from 1994 to 2004 were also investigated. Of 897 patients who met the inclusion criteria 839 (93.5%) had no pneumomediastinum. Five patients (0.6%) had overt pneumomediastinum and 53 patients (5.9%) had occult pneumomediastinum. Patients with occult pneumomediastinum had significantly higher ISS and AIS chest (pchest thoracostomy tube was more common (ppneumothorax. None of the patients with occult pneumomediastinum had aerodigestive tract injuries (95%CI 0-0.06). Follow up CT scan of patients with occult pneumomediastinum showed complete resolution in all cases, in average 3 h after the initial exam. Occult pneumomediastinum occurred in approximately 6% of

  13. Right upper-quadrant pain in a patient with drug abuse, secondary syphilis and occult hepatitis B virus.

    Fielding, Cory M; Angulo, Paul

    2014-01-01

    To describe the etiology of hepatitis and identify occult hepatitis B virus (HBV) infection. A 40-year-old man presented with severe abdominal pain and jaundice, a history of acute HBV infection that had cleared as well as the use of acetaminophen, methamphetamine, buprenorphine and marijuana. He admitted to having had unprotected sex with multiple partners of both genders. A thorough skin examination revealed papulosquamous lesions on his penis, scrotum, upper and lower extremities and feet. Transaminases and bilirubin were elevated. His rapid plasma reagin was reactive, and hepatitis serologies showed occult HBV. Liver biopsy showed severe hepatitis, but the stains for hepatitis B surface antigen and hepatitis B core antigen were negative. The pathological findings were highly indicative of drug-induced hepatitis without evidence of chronic hepatitis, reactivation of HBV or syphilitic hepatitis. With supportive management and abstinence from drugs, his condition improved. This case describes a patient with multiple potential causes for hepatitis and highlights the importance of obtaining a detailed social history. Further, one should consider the presence of occult HBV and recognize the serologic pattern. © 2014 S. Karger AG, Basel.

  14. Greater trochanteric fracture with occult intertrochanteric extension.

    Reiter, Michael; O'Brien, Seth D; Bui-Mansfield, Liem T; Alderete, Joseph

    2013-10-01

    Proximal femoral fractures are frequently encountered in the emergency department (ED). Prompt diagnosis is paramount as delay will exacerbate the already poor outcomes associated with these injuries. In cases where radiography is negative but clinical suspicion remains high, magnetic resonance imaging (MRI) is the study of choice as it has the capability to depict fractures which are occult on other imaging modalities. Awareness of a particular subset of proximal femoral fractures, namely greater trochanteric fractures, is vital for both radiologists and clinicians since it has been well documented that they invariably have an intertrochanteric component which may require surgical management. The detection of intertrochanteric or cervical extension of greater trochanteric fractures has been described utilizing MRI but is underestimated with both computed tomography (CT) and bone scan. Therefore, if MRI is unavailable or contraindicated, the diagnosis of an isolated greater trochanteric fracture should be met with caution. The importance of avoiding this potential pitfall is demonstrated in the following case of an elderly woman with hip pain and CT demonstrating an isolated greater trochanteric fracture who subsequently returned to the ED with a displaced intertrochanteric fracture.

  15. Visible and occult microscopic lesions of endometriosis

    Khaleque Newaz Khan

    2014-11-01

    Full Text Available Endometriosis is a multifactorial disease mostly affecting women of reproductive age and is associated with chronic pelvic pain and infertility. Even after 300 years, most of the literature claims that pathogenesis and/or pathophysiology of endometriosis is still elusive. Recurrence of pain and lesion continues to occur after effective medical or surgical therapies. Once generated within the pelvis due to retrograde entry of menstrual debris, peritoneal endometriotic lesions time-dependently change their color appearance resulting from certain biochemical change within lesions. A variable pattern of endometriotic lesions within the pelvis can be detected by laparoscopy as visible peritoneal endometriosis. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by the innate immune system in the pelvic microenvironment by their interaction with endometrial cells and immune cells. Even with the careful eyes of an expert surgeon, we may sometimes miss detecting peritoneal lesion within the peritoneal cavity or deep into the peritoneum. In such a case, random collection of normal peritoneum may carry the possibility to identify some hidden endometriotic lesions by microscopy and these lesions can be named as occult (invisible microscopic endometriosis (OME. Here, we discuss the color appearance of peritoneal lesions and activity of these lesions by analysis of a panel of activity markers. Finally we discuss our recent findings on OME, their biological and clinical significance, and try to make a possible link in the origin between visible endometriosis and OME.

  16. Celestial shadows eclipses, transits, and occultations

    Westfall, John

    2015-01-01

    Much of what is known about the universe comes from the study of celestial shadows—eclipses, transits, and occultations.  The most dramatic are total eclipses of the Sun, which constitute one of the most dramatic and awe-inspiring events of nature.  Though once a source of consternation or dread, solar eclipses now lead thousands of amateur astronomers and eclipse-chasers to travel to remote points on the globe to savor their beauty and the adrenaline-rush of experiencing totality, and were long the only source of information about the hauntingly beautiful chromosphere and corona of the Sun.   Long before Columbus, the curved shadow of the Earth on the Moon during a lunar eclipse revealed that we inhabit a round world. The rare and wonderful transits of Venus, which occur as it passes between the Earth and the Sun, inspired eighteenth century expeditions to measure the distance from the Earth to the Sun, while the recent transits of 2004 and 2012 were the most widely observed ever--and still produced re...

  17. Infection,

    1980-10-16

    characteristic in severe gram-negative sepsis. Hypertriglyceridemia results from an increase in hepatic synthesis in combination with diminished activity of...induced stress, and tissue repair (1). The magnitude and type of nutritional losses caused by an infection reflect both the severity and duration of an... several functional forms of nutrient loss must be anticipated. Functional losses are defined as the within-body losses of nutrients due to infection

  18. Recent progress on external occulter technology for imaging exosolar planets

    Kasdin, N. J.; Vanderbei, R. J.; Sirbu, D.; Samuels, J.; Shaklan, S.; Lisman, D.; Thomson, M.; Cady, E.; Martin, S.

    Imaging planets orbiting nearby stars requires a system for suppressing the host starlight by at least ten orders of magnitude. One such approach uses an external occulter, a satellite flying far from the telescope and employing a large screen, or starshade, to suppress the incoming starlight. This trades the added complexity of building the precisely shaped starshade and flying it in formation against simplifications in the telescope since extremely precise wavefront control is no longer necessary. Much progress has been made recently in designing, testing and manufacturing starshade technology. In this paper we describe the design of starshades and report on recent accomplishments in manufacturing and measuring a prototype occulter petal as part of NASA's first Technology Development for Exoplanet Missions (TDEM) program. We demonstrate that the as-built petal is consistent with a full-size occulter achieving better than 10-10 contrast. We also discuss laboratory testing at the Princeton Occulter Testbed. These experiments use sub-scale, long-distance beam propagation to verify the diffraction analysis associated with occulter starlight suppression. We demonstrate roughly 10-10 suppression in the laboratory and discuss the important challenges and limitations.

  19. Crosslink Radio Occultation for the Remote Sensing of Planetary Atmospheres

    Mannucci, A. J.; Ao, C. O.; Asmar, S.; Edwards, C. D.; Kahan, D. S.; Paik, M.; Pi, X.; Williamson, W.

    2015-12-01

    Radio occultation utilizing deep space telecommunication signals has been used with great success in the profiling of planetary atmospheres and ionospheres since the 1960s. A shortcoming of this technique, however, is the limited temporal and spatial sampling that it provides. We consider a different approach where radio occultation measurements are taken between two spacecraft orbiting an extra-terrestrial body. Such "crosslink" radio occultations between the Global Positioning System satellites and low-earth orbiting spacecraft have been routinely acquired to provide global observations of the Earth's atmosphere and ionosphere that are used for weather forecast, climate analysis, and space weather applications. The feasibility of applying this concept to other planets has recently been demonstrated for the first time, where crosslink occultation measurements have been acquired between the Mars Odyssey and Mars Reconnaissance Orbiter spacecraft. These measurements leverage the proximity link telecommunication payloads on each orbiter, which are nominally used to provide relay communication and navigation services to Mars landers and rovers. In this presentation, we will describe the Mars crosslink experiments and the corresponding data analysis in detail. In addition, we will discuss how the crosslink occultation concepts can be effectively applied in future space exploration missions.

  20. [Occultism, parapsychology and the esoteric from the perspective of psychopathology].

    Scharfetter, C

    1998-10-01

    The concepts and main themes of occultism, parapsychology and esoterics are set in comparison to religion, spirituality, mysticism. The cultural relativity of these concepts is emphasised. Occultism means dealing with phenomena, processes, and/or powers which are not accessible to "normal perception". The manipulation of such powers is effected via (white, black, grey) magic. Parapsychology, in its popular sense, deals with occult phenomena, whereas scientific parapsychology investigates them empirically. Esoterics is a complex of beliefs within a hermetic tradition about occult processes and about desting after death. Transpersonal psychology deals with these issues while calling them "spiritual". Effects of paranormal experiences and actions on the side of the actor as well as the adept are discussed: personality types, interpersonal effects, crises and psychoses (mediumistic psychoses). The concept of dissociation of subpersonalities (subselves) appears to be a viable perspective to explain these phenomena. In mediumistic psychoses, the splitting of non-ego parts of the psyche leads to a manifestation of schizophrenic symptoms. Dangers for mental health are an ego inflation by self-attribution of "superhuman" power. A personality disposition for parapsychological perception and/or action may be seen in schizotypia and similar near-psychotic "personalities up the border". Adepts of occultism may present with a "false self" in the sense of Winnicott.

  1. David Levy's Guide to Eclipses, Transits, and Occultations

    Levy, David H.

    2010-08-01

    Introduction; Part I. The Magic and History of Eclipses: 1. Shakespeare, King Lear, and the Great Eclipse of 1605; 2. Three centuries later: Einstein, relativity, and the solar eclipse of 1919; 3. What causes solar and lunar eclipses; Part II. Observing Solar Eclipses: 4. Safety considerations; 5. What to expect during a partial eclipse; 6. Annular eclipses and what to see in them; 7. Total eclipse of the Sun: introduction to the magic; 8. The onset: temperature drop, Baily's Beads, Diamond Ring; 9. Totality: Corona, Prominences, Chromosphere, and surrounding area; 10. Photographing and imaging a solar eclipse; Part III. Observing Lunar Eclipses: 11. Don't forget the penumbral eclipses!; 12. Partial lunar eclipses; 13. Total lunar eclipses; 14. Photographing and imaging lunar eclipses; Part IV. Occultations: 15. When the Moon occults a star; Part V. Transits: 16. When planets cross the Sun; Part VI. My Favorite Eclipses: 17. A personal canon of eclipses, occultations, and transits I have seen; Appendices; Index.

  2. Operation of the Radio Occultation Mission in KOMPSAT-5

    Mansoo Choi

    2010-12-01

    Full Text Available Korea multi-purpose satellite-5 (KOMPSAT-5 is a low earth orbit (LEO satellite scheduled to be launched in 2010. To satisfy the precision orbit determination (POD requirement for a high resolution synthetic aperture radar image of KOMPSAT-5, KOMPSAT-5 has atmosphere occultation POD (AOPOD system which consists of a space-borne dual frequency global positioning system (GPS receiver and a laser retro reflector array. A space-borne dual frequency GPS receiver on a LEO satellite provides position data for the POD and radio occultation data for scientific applications. This paper describes an overview of AOPOD system and operation concepts of the radio occultation mission in KOMPSAT-5. We showed AOPOD system satisfies the requirements of KOMPSAT-5 in performance and stability.

  3. Categorizing the Occult: Vodun, Sorcery and Religious Beliefs In Benin

    Strandsbjerg, Camilla

    2011-01-01

    In everyday life in Benin as well as in academic research on the topic, the terms of vodun, witchcraft and the occult are often used in a non distinct way covering quite similar phenomena while at the same time referring to different kinds of beliefs and practices. The problem of understanding...... confronted with this difficulty. Both because the vodun, as a recognized religion in the country - equal to Islam and Christianity - , plays an important role in society as well as in individual life, but also because all area of social life are on one level or another influenced by beliefs and practices...... characterized as witchcraft or occult. Reflecting upon earlier research and particularly on the choice of terminology of the occult in writing on religion and political change in Benin (PhD thesis 2008), this paper seeks to clarify some of the epistemological, academic and historical reasons that have formed...

  4. The stellar occultation by the dwarf planet Haumea

    Santos-Sanz, Pablo; Ortiz, Jose Luis; Sicardy, Bruno; Rossi, Gustavo; Berard, Diane; Morales, Nicolas; Duffard, Rene; Braga-Ribas, Felipe; Hopp, Ulrich; Ries, Christoph; Nascimbeni, Valerio; Marzari, Francesco; Granata, Valentina; Pál, András; Kiss, Csaba; Pribulla, Theodor; Milan Komzík, Richard; Hornoch, Kamil; Pravec, Petr; Bacci, Paolo; Maestripieri, Martina; Nerli, Luca; Mazzei, Leonardo; Bachini, Mauro; Martinelli, Fabio; Succi, Giacomo; Ciabattari, Fabrizio; Mikuz, Herman; Carbognani, Albino; Gaehrken, Bernd; Mottola, Stefano; Hellmich, Stephan; Rommel, Flavia; Fernández-Valenzuela, Estela; Campo Bagatin, Adriano; Haumea occultation international Collaboration: https://cloud.iaa.csic.es/public.php?service=files&t=d9276f8ab1a316cef13bee28bef75add

    2017-10-01

    The dwarf planet Haumea is a very peculiar Trans-Neptunian Object (TNO) with unique and exotic characteristics. It is currently classified as one of the five dwarf planets of the solar system, and it is the only one for which size, shape, albedo, density and other basic properties were not accurately known. To solve that we predicted an occultation of the star GaiaDR1 1233009038221203584 by Haumea and organized observations within the expected shadow path. Medium/large telescopes were needed to record the occultation with enough signal to noise ratio because the occulted star is of similar brightness as Haumea (R~17.7 mag). We will report results derived from this successful stellar occultation by Haumea on 2017 January 21st. The occultation was positive from 12 telescopes at 10 observing stations in Europe: the Asiago Observatory 1.8m telescope (Italy), the Mount Agliale Observatory 0.5m telescope (Italy), the Lajatico Astronomical Centre 0.5m telescope (Italy), the S.Marcello Pistoiese Observatory 0.6m telescope (Italy), the Crni Vrh Observatory 0.6m telescope (Slovenia), the Ondrejov Observatory 0.65m telescope (Czech Republic), the Bavarian Public Observatory 0.81m telescope (Germany), the Konkoly Observatory 1m and 0.6m telescopes (Hungary), the Skalnate Pleso Observatory 1.3m telescope (Slovakia), and the Wendelstein Observatory 2m and 0.4m telescopes (Germany). This is the occultation by a TNO with the largest number of chords ever recorded.Part of this work has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 687378.

  5. Exploring small bodies in the outer solar system with stellar occultations

    Elliot, Jim L.; Dunham, Edward W.; Olkin, C. B.

    1995-01-01

    Stellar occultation observations probe the atmospheric structure and extinction of outer solar system bodies with a spatial resolution of a few kilometers, and an airborne platform allows the observation of occultations by small bodies that are not visible from fixed telescopes. Results from occultations by Triton, Pluto, and Chiron observed with KAO are discussed, and future directions for this program are presented.

  6. Predictions of stellar occultations by TNOs/Centaurs using Gaia

    Desmars, Josselin; Camargo, Julio; Berard, Diane; Sicardy, Bruno; Leiva, Rodrigo; Vieira-Martins, Roberto; Braga-Ribas, Felipe; Assafin, Marcelo; Rossi, Gustavo; Chariklo occultations Team, Rio Group, Lucky Star Occultation Team, Granada Occultation Team

    2017-10-01

    Stellar occultations are the unique technique from the ground to access physical parameters of the distant solar system objects, such as the measure of the size and the shape at kilometric level, the detection of tenuous atmospheres (few nanobars), and the investigation of close vicinity (satellites, rings, jets).Predictions of stellar occultations require accurate positions of the star and the object.The Gaia DR1 catalog now allows to get stellar position to the milliarcsecond (mas) level. The main uncertainty in the prediction remains in the position of the object (tens to hundreds of mas).Now, we take advantage of the NIMA method for the orbit determination that uses the most recent observations reduced by the Gaia DR1 catalog and the astrometric positions derived from previous positive occultations.Up to now, we have detected nearly 50 positive occultations for about 20 objects that provide astrometric positions of the object at the time of the occultation. The uncertainty of these positions only depends on the uncertainty on the position of the occulted stars, which is a few mas with the Gaia DR1 catalog. The main limitation is now on the proper motion of the star which is only given for bright stars in the Tycho-Gaia Astrometric Solution. This limitation will be solved with the publicationof the Gaia DR2 expected on April 2018 giving proper motions and parallaxes for the Gaia stars. Until this date, we use hybrid stellar catalogs (UCAC5, HSOY) that provide proper motions derived from Gaia DR1 and another stellar catalog.Recently, the Gaia team presented a release of three preliminary Gaia DR2 stellar positions involved in the occultations by Chariklo (22 June and 23 July 2017) and by Triton (5 October 2017).Taking the case of Chariklo as an illustration, we will present a comparison between the proper motions of DR2 and the other catalogs and we will show how the Gaia DR2 will lead to a mas level precision in the orbit and in the prediction of stellar

  7. Presentation of Axillary Metastases from Occult Breast Carcinoma

    Xin Wang

    2007-01-01

    Axillary presentation from occult breast cancer is uncommon and continues to be a diagnostic and therapeutic challenge to physicians.Once the diagnosis of adenocarcinoma metastatic to an axillary lymph node has been confirmed,a preoperative workup should be done.The current experience is based on several relatively small retrospective reviews and case reports.It is difficult to determine the best management of occult breast cancer.However,treatmenl of axillary Iymph node dissection is recommended for local control and complete staging information.Treatment of breast should be a choice between breast conservation with whole-breast radiotherapy and mastectomy.Adjuvant systemic treatment should be offered.

  8. Detection of occult abscesses with 111In-labeled leukocytes

    Martin, W.R.; Gurevich, N.; Goris, M.L.; McDougall, I.R.

    1979-01-01

    Clinicians are frequently faced with the problem of a patient in whom they suspect an occult abscess. In such a situation, there may be no clinical signs to localize the site of the abscess and often extensive investigations do not provide additional useful information. This report illustrates the efficacy of autologous leukocytes labeled with 111 In oxine in detecting the site and extent of occult abscesses in two patients. The technique of in vitro lebeling of leukocytes is simple and has been mastered by all of our nuclear medicine technologists

  9. [Identification of occult disseminated tumor cells by recombinant herpes simplex virus expressing GFP (HSV(GFP))].

    Han, Xiang-ping; Shi, Gui-lan; Wang, Cheng-feng; Li, Jie; Zhang, Jian-wei; Zhang, Yu; Zhang, Shu-ren; Liu, Bin-lei

    2012-12-01

    To develop a novel rapid protocol for the detection of occult disseminated tumor cells by a recombinant herpes simplex virus expressing GFP (HSV(GFP)). Tumor cells of seven cell lines were exposed to HSV(GFP) and then examined for GFP expression by fluorescence microscopy. Various numbers of tumor cells (10, 100, 1000, 10 000) were mixed into 2 ml human whole blood, separated with lymphocytes separation medium, exposed to HSV(GFP), incubated at 37°C for 6 - 24 h and then counted for the number of green cells under the fluorescence microscope. Some clinical samples including peripheral blood, pleural effusion, ascites, spinal fluid from tumor-bearing patients were screened using this protocol in parallel with routine cytological examination. HSV(GFP) was able to infect all 7 tumor cell lines indicating that the HSV(GFP) can be used to detect different types of tumor cells. The detection sensitivity was 10 cancer cells in 2 ml whole blood. In the clinical samples, there were 4/15 positive by routine cytological examination but 11/15 positive by HSV(GFP), indicating a higher sensitivity of this new protocol. Recombinant herpes simplex virus-mediated green fluorescence is a simple and sensitive technique for the identification of occult disseminated cancer cells including circulating tumor cells (CTCs).

  10. Occult Radiographically Evident Port-Site Hernia After Robot-Assisted Urologic Surgery: Incidence and Risk Factors.

    Christie, Matthew C; Manger, Jules P; Khiyami, Abdulaziz M; Ornan, Afshan A; Wheeler, Karen M; Schenkman, Noah S

    2016-01-01

    Laparoscopic trocar-site hernias (TSH) are rare, with a reported incidence of 1% or less. The incidence of occult radiographically evident hernias has not been described after robot-assisted urologic surgery. We evaluated the incidence and risk factors of this problem. A single-institution retrospective review of robot-assisted urologic surgery was performed from April 2009 to December 2012. Patients with preoperative and postoperative CT were included for analysis. Imaging was reviewed by two radiologists and one urologist. One hundred four cases were identified, including 60 partial nephrectomy, 38 prostatectomy, and 6 cystectomy. Mean age was 58 years and mean body mass index (BMI) was 29 kg/m(2). The cohort was 77% male. Ten total hernias were identified by CT in 8 patients, 2 of which were clinically evident hernias. Excluding these two hernias, occult port-site hernias were identified radiographically in seven patients. Per-patient incidence of occult TSH was 6.7% (7/104), and per-port incidence was 1.4% (8/564). All hernias were midline and 30% contained bowel. Eight of the 10 occurred at 12 mm sites (p = 0.0065) and 3 of the 10 occurred at extended incisions. Age, gender, BMI, smoking status, diabetes mellitus, immunosuppressive drug therapy, ASA score, procedure, blood loss, prior abdominal surgery, and history of hernia were not significant risk factors. Specimen size >40 g (p = 0.024) and wound infection (p = 0.0052) were significant risk factors. While the incidence of clinically evident port-site hernia remains low in robot-assisted urologic surgery, the incidence of CT-detected occult hernia was 6.7% in this series. These occurred most often in sites extended for specimen extraction and at larger port sites. This suggests more attention should be paid to fascial closure at these sites.

  11. Molecular and serological detection of occult hepatitis B virus ...

    hepatitis B surface antigen-negative blood donors in Malaysia. ... Objective: This study aimed to detect occult hepatitis B virus in hepatitis B surface .... of the standard HBV-positive serum and the detection ... in general population ranges from 1.5 to 9.8% but report- .... Putra, Malaysia for their financial support of this research.

  12. Occult hepatitis B among Iranian hepatitis C patients

    Ahmad shavakhi

    2009-02-01

    Full Text Available

    • BACKGROUND: Occult hepatitis B is defined as presence of HBV DNA in tissue or serum without hepatitis B surface antigen. The aim of this study is to determine frequency of occult hepatitis B among hepatitis C patients in Tehran and compare the route of transmission and liver enzymes between positive and negative HBV DNA patients.
    • METHODS: In a cross sectional study, serum of 103 hepatitis C cases (79.6% men and 20.4% women were analyzed for s, x and core genes via a nested polymerase chain reaction technique.
    • RESULTS: HBV DNA was detectable in serum of 20 patients (19.4%. No significant difference in age, sex and route of transmission were seen in HBV DNA positive and negative patients. In HBV DNA positive and negative groups, mean of AST was 73, 47 (p < 0.05 and mean of ALT was 76 and 36 respectively (p < 0.05.
    • CONCLUSION: Occult hepatitis B was observed in a considerable number of hepatitis C patients in Tehran. It was associated with elevation in liver enzyme but was not related to route of transmission.
    • KEY WORD: Occult hepatitis B, hepatitis C, cirrhosis.

  13. Occult spontaneous lateral intrasphenoidal encephalocele: A rare presentation

    Shahina Bano

    2013-01-01

    Full Text Available Basal encephaloceles are extremely rare congenital malformations. Advanced cross-sectional imaging modalities like computed tomography and magnetic resonance imaging are necessary for diagnosing the asymptomatic, occult basal encephalocele and planning the surgical approach. We present an interesting case of clinically silent right-sided lateral intrasphenoidal encephalocele through a large bony defect.

  14. Occurrence of occult CSF leaks during standard FESS procedures.

    Bucher, S; Kugler, A; Probst, E; Epprecht, L; Stadler, R S; Holzmann, D; Soyka, M B

    2018-03-18

    To determine the incidence of occult cerebrospinal fluid leaks (CSF) after functional endoscopic sinus surgery (FESS) and to evaluate the diagnostic performance of beta2-transferrin in blood-contaminated conditions. Prospective cohort study. An analysis of 57 intraoperative samples using hydrogel 6 beta2-transferrin assay after FESS was undertaken. In case of CSF positive samples and continuing rhinorrhea, reanalysis after more than 1 year was conducted. In-vivo analysis of a primary spontaneous CSF leak sample took place to verify difficulties in detecting beta2-transferrin in blood-contaminated settings. Own titrations were performed to evaluate detection limits of CSF by beta2-transferrin and beta-trace protein assays in these settings. An incidence of 13% for occult CSF leaks after FESS was found. In blood-contaminated conditions, routine beta2-transferrin assays showed low sensitivity. In over 1 year follow-up, all samples were negative for CSF and none of them developed clinical relevant CSF leaks or meningitis. Occult and clinically irrelevant CSF leaks do occur in a significant proportion of patients during and shortly after FESS. Intra- and postoperatively, routine beta2-transferrin assays show low sensitivity. They should not be used in these settings. The clinical course of patients with occult CSF leaks indicated possibility of an uneventful follow-up.

  15. Pluto-Charon Stellar Occultation Candidates: 1990-1995

    Dunham, E. W.; McDonald, S. W.; Elliot, J. L.

    1991-01-01

    We have carried out a search to identify stars that might be occulted by Pluto or Charon during the period 1990-1995 and part of 1996. This search was made with an unfiltered CCD camera operated in the strip scanning mode, and it reaches an R magnitude of approximately 17.5-about 1.5 mag fainter than previous searches. Circumstances for each of the 162 potential occultations are given, including an approximate R magnitude of the star, which allows estimation of the signal-to-noise ratio (S/N) for observation of each occultation. The faintest stars in our list would yield an S/N of about 20 for a 1 S integration when observed with a CCD detector on an 8 m telescope under a dark sky. Our astrometric precision (+/- 0.2 arcsec, with larger systematic errors possible for individual cases) is insufficient to serve as a final prediction for these potential occultations, but is sufficient to identify stars deserving of further, more accurate, astrometric observations. Statistically, we expect about 32 of these events to be observable somewhere on Earth. The number of events actually observed will be substantially smaller because of clouds and the sparse distribution of large telescopes. Finder charts for each of the 91 stars involved are presented.

  16. Radio occultation bending angle anomalies during tropical cyclones

    Biondi, Riccardo; Neubert, Torsten; Syndergaard, S.

    2011-01-01

    -located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock...

  17. Past and future of radio occultation studies of planetary atmospheres

    Eshleman, Von R.; Hinson, David P.; Tyler, G. Leonard; Lindal, Gunnar F.

    1987-01-01

    Measurements of radio waves that have propagated through planetary atmospheres have provided exploratory results on atmospheric constituents, structure, dynamics, and ionization for Venus, Mars, Titan, Jupiter, Saturn, and Uranus. Highlights of past results are reviewed in order to define and illustrate the potential of occultation and related radio studies in future planetary missions.

  18. A method to detect occult pneumothorax with chest radiography.

    Matsumoto, Shokei; Kishikawa, Masanobu; Hayakawa, Koichi; Narumi, Atsushi; Matsunami, Katsutoshi; Kitano, Mitsuhide

    2011-04-01

    Small pneumothoraces are often not visible on supine screening chest radiographs because they develop anteriorly to the lung. These pneumothoraces are termed occult. Occult pneumothoraces account for an astonishingly high 52% to 63% of all traumatic pneumothoraces. A 19-year-old obese woman was involved in a head-on car accident. The admission anteroposterior chest radiographs were unremarkable. Because of the presence of right chest tenderness and an abrasion, we suspected the presence of a pneumothorax. Thus, we decided to take a supine oblique chest radiograph of the right side of the thorax, which clearly revealed a visceral pleural line, consistent with a diagnosis of traumatic pneumothorax. A pneumothorax may be present when a supine chest radiograph reveals either an apparent deepening of the costophrenic angle (the "deep sulcus sign") or the presence of 2 diaphragm-lung interfaces (the "double diaphragm sign"). However, in practice, supine chest radiographs have poor sensitivity for occult pneumothoraces. Oblique chest radiograph is a useful and fast screening tool that should be considered for cases of blunt chest trauma, especially when transport of critically ill patients to the computed tomographic suite is dangerous or when imminent transfer to another hospital is being arranged and early diagnosis of an occult pneumothorax is essential. Copyright © 2010 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

  19. Occult Metabolic Bone Disease in Chronic Pancreatitis | Hari Kumar ...

    Background: Chronic pancreatitis (CP) leads to malabsorption and metabolic bone disease (MBD). Alcoholic CP (ACP) and tropical CP (TCP) are the two common types of CP. Objective: We investigated the presence of occult MBD in patients with CP and compared the same between ACP and TCP. Materials and Methods: ...

  20. Precise pointing knowledge for SCIAMACHY solar occultation measurements

    K. Bramstedt

    2012-11-01

    Full Text Available We present a method to precisely determine the viewing direction for solar occultation instruments from scans over the solar disk. Basic idea is the fit of the maximum intensity during the scan, which corresponds to the center of the solar disk in the scanning direction. We apply this method to the solar occultation measurements of the satellite instrument SCIAMACHY, which scans the Sun in elevation direction. The achieved mean precision is 0.46 mdeg, which corresponds to an tangent height error of about 26 m for individual occultation sequences. The deviation of the derived elevation angle from the geolocation information given along with the product has a seasonal cycle with an amplitude of 2.26 mdeg, which is in tangent height an amplitude of about 127 m. The mean elevation angle offset is −4.41 mdeg (249 m. SCIAMACHY's sun follower device controls the azimuth viewing direction during the occultation measurements. The derived mean azimuth direction has an standard error of 0.65 mdeg, which is about 36 m in horizontal direction at the tangent point. We observe also a seasonal cycle of the azimuth mispointing with an amplitude of 2.3 mdeg, which is slightly increasing with time. The almost constant mean offset is 88 mdeg, which is about 5.0 km horizontal offset at the tangent point.

  1. Sensing Water Vapon via Spacecraft Radio Occultation Observations

    Kursinski, E. Robert; Hajj, George A.

    2000-01-01

    The radio occultation technique has been used to characterize planetary atmospheres since the 1960's spanning atmospheric pressures from 16 microbars to several bars. In 1988, the use of GPS signals to make occultation observations of Earth's atmosphere was realized by Tom Yunck and Gunnar Lindal at JPL. In the GPS to low-Earth-orbiter limb- viewing occultation geometry, Fresnel diffraction yield a unique combination of high vertical resolution of 100 m to 1 km at long wavelengths (approx. 20 cm) insensitive to particulate scattering which allows routine limb sounding from the lower mesosphere through the troposphere. A single orbiting GPS/GLONASS receiver can observe - 1000 to 1400 daily occultations providing as many daily, high vertical resolution soundings as the present global radiosonde network, but with far more evenly distributed, global coverage. The occultations yield profiles of refractivity as a function of height. In the cold, dry conditions of the upper troposphere and above (T less than 240 K), profiles of density, pressure (geopotential), and temperature can be derived. Given additional temperature information, water vapor can be derived in the midddle and lower troposphere with a unique combination of vertical resolution, global distribution and insensitivity to clouds and precipitation to an accuracy of approx. 0.2 g/kg. At low latitudes, moisture profiles will be accurate to 1-5% within the convective boundary layer and better than 20% below 6 to 7 km. Accuracies of climatological averages should be approx. 0. 1 g/kg limited by the biases in the temperature estimates. To use refractivity to constrain water vapor, knowledge of temperature is required. The simplest approach is to use the temperature field from an analysis such as the 6 hour ECMWF global analysis interpolated to the locations of each occultation. A better approach is to combine the temperature and moisture fields from such an analysis with the occultation refractivity in a weighting

  2. Occult Pneumothoraces in Acute Trauma Patients

    Chad Berryman

    2012-12-01

    Full Text Available Introduction: Many traumatic pneumothoraces (PTX are not seen on initial chest radiograph (CR(occult PTX but are detected only on computed tomography (CT. Although CR remains the first toolfor detecting PTX, most trauma patients with significant thoracoabdominal injuries will receive both CTand CR. The primary objective of this study was to retrospectively determine the effectiveness of CR fordetecting PTX in trauma patients. Our hypotheses were that CR is a sensitive indicator of PTX on CT,that chest pain and shortness of breath are good predictors of PTX on CR, and that we could determineother predictors of PTX on CR.Methods: All trauma patients presenting to our Level I trauma center with a CT-diagnosed PTX over a2-year period who had both a CR and a chest CT were included. The CT reading was considered thegold standard for PTX diagnosis. Electronic medical records were searched using key words fordiagnoses, symptoms, demographics, and radiologic results. We recorded the official radiologistreadings for both CR and CT (positive or negative and the size of the PTX on CT (large, moderate,small, or tiny. The outcome variable was dichotomized based on presence or absence of PTXdetected on CR. Descriptive statistics and v2 tests were used for univariate analysis. A regressionanalysis was performed to determine characteristics predictive of a PTX on CR, and 1 variable wasadded to the model for every 10 positive CRs. With equal-size groups, this study has the power of 80%to detect a 10% absolute difference in single predictors of PTX on CR with 45 subjects in each group.Results: There were 134 CT-documented PTXs included in the study. Mean age was 42, and 74%were men. For 66 (49% patients, PTX was detected on CR (sensitivity¼50%. The CR detected 30%of small PTX, 35% of moderate PTX, and 33% of large PTX. Comparing patients with and without PTXon CR, there were no significant differences in shortness of breath or chest pain. There no

  3. Occult pneumothoraces in acute trauma patients.

    Ernst, Amy A; McIntyre, William A; Weiss, Steven J; Berryman, Chad

    2012-11-01

    Many traumatic pneumothoraces (PTX) are not seen on initial chest radiograph (CR) (occult PTX) but are detected only on computed tomography (CT). Although CR remains the first tool for detecting PTX, most trauma patients with significant thoracoabdominal injuries will receive both CT and CR. The primary objective of this study was to retrospectively determine the effectiveness of CR for detecting PTX in trauma patients. Our hypotheses were that CR is a sensitive indicator of PTX on CT, that chest pain and shortness of breath are good predictors of PTX on CR, and that we could determine other predictors of PTX on CR. All trauma patients presenting to our Level I trauma center with a CT-diagnosed PTX over a 2-year period who had both a CR and a chest CT were included. The CT reading was considered the gold standard for PTX diagnosis. Electronic medical records were searched using key words for diagnoses, symptoms, demographics, and radiologic results. We recorded the official radiologist readings for both CR and CT (positive or negative) and the size of the PTX on CT (large, moderate, small, or tiny). The outcome variable was dichotomized based on presence or absence of PTX detected on CR. Descriptive statistics and χ(2) tests were used for univariate analysis. A regression analysis was performed to determine characteristics predictive of a PTX on CR, and 1 variable was added to the model for every 10 positive CRs. With equal-size groups, this study has the power of 80% to detect a 10% absolute difference in single predictors of PTX on CR with 45 subjects in each group. There were 134 CT-documented PTXs included in the study. Mean age was 42, and 74% were men. For 66 (49%) patients, PTX was detected on CR (sensitivity = 50%). The CR detected 30% of small PTX, 35% of moderate PTX, and 33% of large PTX. Comparing patients with and without PTX on CR, there were no significant differences in shortness of breath or chest pain. There no relationships between PTX detected

  4. Detection and identification of occult HBV in blood donors in Taiwan using a commercial, multiplex, multi-dye nucleic acid amplification technology screening test.

    Lin, K T; Chang, C L; Tsai, M H; Lin, K S; Saldanha, J; Hung, C M

    2014-02-01

    The ability of a new generation commercial, multiplex, multi-dye test from Roche, the cobas TaqScreen MPX test, version 2.0, to detect and identify occult HBV infections was evaluated using routine donor samples from Kaohsiung Blood Bank, Taiwan. A total of 5973 samples were tested by nucleic acid amplification technology (NAT); 5898 in pools of six, 66 in pools of less than six and nine samples individually. NAT-reactive samples were retested with alternative NAT tests, and follow-up samples from the donors were tested individually by NAT and for all the HBV serological markers. Eight NAT-only-reactive donors were identified, and follow-up samples were obtained from six of the donors. The results indicated that all eight donors had an occult HBV infection with viral loads <12 IU/ml. The cobas(®) TaqScreen MPX test, version 2.0, has an advantage over the current Roche blood screening test, the cobas TaqScreen MPX test, for screening donations in countries with a high prevalence of occult HBV infections since the uncertainty associated with identifying samples with very low viremia is removed by the ability of the test to identify the viral target in samples that are reactive with the cobas TaqScreen MPX test, version 2.0. © 2013 International Society of Blood Transfusion.

  5. Error analysis for mesospheric temperature profiling by absorptive occultation sensors

    M. J. Rieder

    Full Text Available An error analysis for mesospheric profiles retrieved from absorptive occultation data has been performed, starting with realistic error assumptions as would apply to intensity data collected by available high-precision UV photodiode sensors. Propagation of statistical errors was investigated through the complete retrieval chain from measured intensity profiles to atmospheric density, pressure, and temperature profiles. We assumed unbiased errors as the occultation method is essentially self-calibrating and straight-line propagation of occulted signals as we focus on heights of 50–100 km, where refractive bending of the sensed radiation is negligible. Throughout the analysis the errors were characterized at each retrieval step by their mean profile, their covariance matrix and their probability density function (pdf. This furnishes, compared to a variance-only estimation, a much improved insight into the error propagation mechanism. We applied the procedure to a baseline analysis of the performance of a recently proposed solar UV occultation sensor (SMAS – Sun Monitor and Atmospheric Sounder and provide, using a reasonable exponential atmospheric model as background, results on error standard deviations and error correlation functions of density, pressure, and temperature profiles. Two different sensor photodiode assumptions are discussed, respectively, diamond diodes (DD with 0.03% and silicon diodes (SD with 0.1% (unattenuated intensity measurement noise at 10 Hz sampling rate. A factor-of-2 margin was applied to these noise values in order to roughly account for unmodeled cross section uncertainties. Within the entire height domain (50–100 km we find temperature to be retrieved to better than 0.3 K (DD / 1 K (SD accuracy, respectively, at 2 km height resolution. The results indicate that absorptive occultations acquired by a SMAS-type sensor could provide mesospheric profiles of fundamental variables such as temperature with

  6. Error analysis for mesospheric temperature profiling by absorptive occultation sensors

    M. J. Rieder

    2001-01-01

    Full Text Available An error analysis for mesospheric profiles retrieved from absorptive occultation data has been performed, starting with realistic error assumptions as would apply to intensity data collected by available high-precision UV photodiode sensors. Propagation of statistical errors was investigated through the complete retrieval chain from measured intensity profiles to atmospheric density, pressure, and temperature profiles. We assumed unbiased errors as the occultation method is essentially self-calibrating and straight-line propagation of occulted signals as we focus on heights of 50–100 km, where refractive bending of the sensed radiation is negligible. Throughout the analysis the errors were characterized at each retrieval step by their mean profile, their covariance matrix and their probability density function (pdf. This furnishes, compared to a variance-only estimation, a much improved insight into the error propagation mechanism. We applied the procedure to a baseline analysis of the performance of a recently proposed solar UV occultation sensor (SMAS – Sun Monitor and Atmospheric Sounder and provide, using a reasonable exponential atmospheric model as background, results on error standard deviations and error correlation functions of density, pressure, and temperature profiles. Two different sensor photodiode assumptions are discussed, respectively, diamond diodes (DD with 0.03% and silicon diodes (SD with 0.1% (unattenuated intensity measurement noise at 10 Hz sampling rate. A factor-of-2 margin was applied to these noise values in order to roughly account for unmodeled cross section uncertainties. Within the entire height domain (50–100 km we find temperature to be retrieved to better than 0.3 K (DD / 1 K (SD accuracy, respectively, at 2 km height resolution. The results indicate that absorptive occultations acquired by a SMAS-type sensor could provide mesospheric profiles of fundamental variables such as temperature with

  7. Digital solar edge tracker for the Halogen Occultation Experiment

    Mauldin, L. E., III; Moore, A. S.; Stump, C. W.; Mayo, L. S.

    1987-01-01

    The optical and electronic design of the Halogen Occultation Experiment (Haloe) elevation sun sensor is described. The Haloe instrument is a gas-correlation radiometer now being developed at NASA Langley for the Upper Atmosphere Research Satellite. The system uses a Galilean telescope to form a solar image on a linear silicon photodiode array. The array is a self-scanned monolithic CCD. The addresses of both solar edges imaged on the array are used by the control/pointing system to scan the Haloe science instantaneous field of view (IFOV) across the vertical solar diameter during instrument calibration and then to maintain the science IFOV 4 arcmin below the top edge during the science data occultation event. Vertical resolution of 16 arcsec and a radiometric dynamic range of 100 are achieved at the 700-nm operating wavelength. The design provides for loss of individual photodiode elements without loss of angular tracking capability.

  8. Sensitivity of GPS occultation to the stratopause height

    Schrøder, Thomas Morville; Ao, Chi; de la Torre Juárez, Manuel

    2007-01-01

    We scrutinize temperature profiles collected with radio occultation measurement for an imprint of the stratopause. In the retrieval step that integrates bending angle data to atmospheric refractivity, the falloff toward infinite altitude is constrained in a boundary condition with statistical opt...... rate, not isothermal conditions. Keeping the model seed for temperature conversion to subsequent retrieval steps eliminates external information from the deconvolved refractivity. It will help argue for radio occultation as independent vehicle for climate monitoring....... height gradient. On the basis of noise free simulation using a climatology covering all latitudes, seasons, and hours and on the basis of validation against data collected with weather balloons, laser imaging, and limb sounding, we find that adaptation to the fluctuating stratopause is crucial...

  9. Dusty Dwarfs Galaxies Occulting A Bright Background Spiral

    Holwerda, Benne

    2017-08-01

    The role of dust in shaping the spectral energy distributions of low mass disk galaxies remains poorly understood. Recent results from the Herschel Space Observatory imply that dwarf galaxies contain large amounts of cool (T 20K) dust, coupled with very modest optical extinctions. These seemingly contradictory conclusions may be resolved if dwarfs harbor a variety of dust geometries, e.g., dust at larger galactocentric radii or in quiescent dark clumps. We propose HST observations of six truly occulting dwarf galaxies drawn from the Galaxy Zoo catalog of silhouetted galaxy pairs. Confirmed, true occulting dwarfs are rare as most low-mass disks in overlap are either close satellites or do not have a confirmed redshift. Dwarf occulters are the key to determining the spatial extent of dust, the small scale structure introduced by turbulence, and the prevailing dust attenuation law. The recent spectroscopic confirmation of bona-fide low mass occulting dwarfs offers an opportunity to map dust in these with HST. What is the role of dust in the SED of these dwarf disk galaxies? With shorter feedback scales, how does star-formation affect their morphology and dust composition, as revealed from their attenuation curve? The resolution of HST allows us to map the dust disks down to the fine scale structure of molecular clouds and multi-wavelength imaging maps the attenuation curve and hence dust composition in these disks. We therefore ask for 2 orbits on each of 6 dwarf galaxies in F275W, F475W, F606W, F814W and F125W to map dust from UV to NIR to constrain the attenuation curve.

  10. A variational regularization of Abel transform for GPS radio occultation

    T.-K. Wee

    2018-01-01

    In the Global Positioning System (GPS) radio occultation (RO) technique, the inverse Abel transform of measured bending angle (Abel inversion, hereafter AI) is the standard means of deriving the refractivity. While concise and straightforward to apply, the AI accumulates and propagates the measurement error downward. The measurement error propagation is detrimental to the refractivity in lower altitudes. In particular, it builds up negative refractivity bias in the tropical ...

  11. [Occult pneumothorax: Does it take drain before elective surgery?].

    Bensghir, M; Moutaoukil, M; Meziane, M; Jaafari, A; Hemmaoui, B; Haimeur, C

    2016-08-01

    Pneumothorax occult is defined by the presence of a non-visible to standard asymptomatic pneumothorax and pulmonary diagnosed only by X-ray computed tomography. The presence of this type of pneumothorax before planned surgery is a rare situation. What to do remains non-consensual. Through two clinic cases and a literature review, the authors discuss the modalities of management of this entity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Implementation of immunochemical faecal occult blood test in general practice

    Juul, Jakob Søgaard; Bro, Flemming; Hornung, Nete

    2016-01-01

    anvendelsen af immunochemical faecal occult blood test (iFOBT) i almen praksis. iFOBT detekterer humant globin i fæces og indikerer gastrointestinal blødning. Studiet udgør en del af et ph.d.-studie, der bidrager med ny viden til at optimere udredningen af patienter med tarmkræft. Der er et stort behov...

  13. [Results of conservative treatment in patients with occult pneumothorax].

    Llaquet Bayo, Heura; Montmany Vioque, Sandra; Rebasa, Pere; Navarro Soto, Salvador

    2016-04-01

    An occult pneumothorax is found in 2-15% trauma patients. Observation (without tube thoracostomy) in these patients presents still some controversies in the clinical practice. The objective of the study is to evaluate the efficacy and the adverse effects when observation is performed. A retrospective observational study was undertaken in our center (university hospital level II). Data was obtained from a database with prospective registration. A total of 1087 trauma patients admitted in the intensive care unit from 2006 to 2013 were included. In this period, 126 patients with occult pneumothorax were identified, 73 patients (58%) underwent immediate tube thoracostomy and 53 patients (42%) were observed. Nine patients (12%) failed observation and required tube thoracostomy for pneumothorax progression or hemothorax. No patient developed a tension pneumothorax or experienced another adverse event related to the absence of tube thoracostomy. Of the observed patients 16 were under positive pressure ventilation, in this group 3 patients (19%) failed observation. There were no differences in mortality, hospital length of stay or intensive care length of stay between the observed and non-observed group. Observation is a safe treatment in occult pneumothorax, even in pressure positive ventilated patients. Copyright © 2014 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Lunar occultation observation of μ Sgr: A progress report

    Jatmiko, A. T. P. [Bosscha Observatory, Institut Teknologi Bandung (Indonesia); Puannandra, G. P.; Hapsari, R. D.; Putri, R. A.; Arifin, Z. M.; Haans, G. K.; Hadiputrawan, I. P. W. [Bosscha Observatory, Institut Teknologi Bandung, Indonesia and Astronomy Study Program, Institut Teknologi Bandung (Indonesia)

    2014-03-24

    Lunar Occultation (LO) is an event where limb of the Moon passing over a particular heavenly bodies such as stars, asteroids, or planets. In other words, during the event, stars, asteroids and planets are occulted by the Moon. When occulted objects contact the lunar limb, there will be a diffraction fringe(s) which can be measured photometrically, until the signal vanishes into noise. This event will give us a valuable information about binarities (of stars) and/or angular diameters estimation (of stars, planets, asteroids) in milliarcsecond resolution, by fitting with theoretical LO pattern. CCDs are common for LO observation because of its fast read out, and recently are developed for sub-meter class telescope. In this paper, our LO observation attempt of μ Sgr and its progress report are presented. The observation was conducted on July 30{sup th}, 2012 at Bosscha Observatory, Indonesia, using 45cm f/12 GOTO telescope combined with ST-9 XE CCD camera and Bessel B filter. We used drift-scan method to obtain light curve of the star as it was disappearing behind Moon's dark limb. Our goal is to detect binarity (or multiplicity) of this particular object.

  15. Pediatric Sepsis Secondary to an Occult Dental Abscess: A Case Report.

    Holmberg, Peter; Hellmich, Thomas; Homme, James

    2017-05-01

    In general, hematogenous spread of bacteria in children is uncommon. Bacteremia, however, is a known complication of dental procedures and severe caries, but is infrequently associated with primary, asymptomatic, non-procedural-related, dentoalveolar infection. The patient is a 7-year-old previously healthy boy who presented to the Emergency Department (ED) with "fever, mottling, and shaking chills." In the ED, he appeared systemically ill with fever, mottling, delayed capillary refill, and rigors. Physical examination by three different physicians failed to reveal any focus of infection. Laboratory evaluation, including blood cultures, was obtained. The patient later developed unilateral facial swelling and pain, and a dentoalveolar abscess was found. He was started on antibiotics, underwent pulpectomy and eventually, extraction, prior to improvement in symptoms. Blood cultures grew two separate anaerobic bacteria (Veillonella and Lactobacillus). This is, to our knowledge, one of the first reported cases of pediatric sepsis with two different anaerobic organisms secondary to occult dentoalveolar abscess in a pediatric patient. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is imperative for emergency physicians to recognize the possibility of pediatric sepsis in the setting of acute maxillary or mandibular pain, as well as in patients for whom no clear focus of infection can be found. This is particularly important for those who appear ill at presentation or meet systemic inflammatory response syndrome criteria and would benefit from further laboratory evaluation, including blood cultures, and possibly antibiotic therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Developing an Optical Lunar Occultation Measurement Reduction System for Observations at Kaau Observatory

    Malawi, Abdulrahman A.

    2013-06-01

    We present here a detailed explanation of the reduction method that we use to determine the angular diameters of the stars occulted by the dark limb of the moon. This is a main part of the lunar occultation observation program running at King Abdul Aziz University observatory since late 1993. The process is based on the least square model fitting method of analyzing occultation data, first introduced by Nather et al. (Astron. J. 75:963, 1970).

  17. Lunar occultation of Saturn. IV - Astrometric results from observations of the satellites

    Dunham, D. W.; Elliot, J. L.

    1978-01-01

    The method of determining local lunar limb slopes, and the consequent time scale needed for diameter studies, from accurate occultation timings at two nearby telescopes is described. Results for photoelectric observations made at Mauna Kea Observatory during the occultation of Saturn's satellites on March 30, 1974, are discussed. Analysis of all observations of occultations of Saturn's satellites during 1974 indicates possible errors in the ephemerides of Saturn and its satellites.

  18. Diagnostic accuracy of oblique chest radiograph for occult pneumothorax: comparison with ultrasonography

    Matsumoto, Shokei; Sekine, Kazuhiko; Funabiki, Tomohiro; Orita, Tomohiko; Shimizu, Masayuki; Hayashida, Kei; Kazamaki, Taku; Suzuki, Tatsuya; Kishikawa, Masanobu; Yamazaki, Motoyasu; Kitano, Mitsuhide

    2016-01-01

    Backgraound An occult pneumothorax is a pneumothorax that is not seen on a supine chest X-ray but is detected by computed tomography scanning. However, critical patients are difficult to transport to the computed tomography suite. We previously reported a method to detect occult pneumothorax using oblique chest radiography (OXR). Several authors have also reported that ultrasonography is an effective technique for detecting occult pneumothorax. The aim of this study was to evaluate the useful...

  19. New Avian Hepadnavirus in Palaeognathous Bird, Germany

    Jo, Wendy K; Pfankuche, Vanessa M; Petersen, Henning; Frei, Samuel; Kummrow, Maya; Lorenzen, Stephan; Ludlow, Martin; Metzger, Julia; Baumgärtner, Wolfgang; Osterhaus, Albert; van der Vries, Erhard

    2017-01-01

    In 2015, we identified an avian hepatitis B virus associated with hepatitis in a group of captive elegant-crested tinamous (Eudromia elegans) in Germany. The full-length genome of this virus shares <76% sequence identity with other avihepadnaviruses. The virus may therefore be considered a new

  20. [Management of occult malformations at the lateral skull base].

    Bryson, E; Draf, W; Hofmann, E; Bockmühl, U

    2005-12-01

    Occult malformations of the lateral skull base are rare anomalies, but can cause severe complications such as recurrent meningitis. Therefore, they need to be precisely delineated and sufficient surgical closure is mandatory. Between 1986 and 2004 twenty patients (10 children and 10 adults) with occult malformations at the lateral skull base were treated surgically at the ENT-Department of the Hospital Fulda gAG. Of these 3 Mondini-malformations, 11 defects of the tegmen tympani or the mastoidal roof, 2 dural lesions to the posterior fossa and 4 malformations within the pyramidal apex have been found. Four patients have had multiple anomalies. Routing symptom was in all cases at least one previous meningitis. Radiological diagnostics included high-resolution computed tomography (CT) and magnetic resonance imaging (MRI) as well as CT- or MR-cisternography. Depending on type and localisation of the defect the following surgical algorithm was carried out: The trans-mastoidal approach was used in all cases of Mondini-malformation (including obliteration of the ear), in case of lesions to the posterior fossa as well as partly in anomalies at the tegmen tympani and mastoidal roof, respectively. Defects of the pyramidal apex should be explored via the trans-mastoidal way if the lesion is located caudally to the inner auditory canal (IAC), whereas the trans-temporal approach should be used if the lesion is situated ventral to the IAC and dorso-medially to the internal carotid artery (ICA). The trans-temporal approach was also performed in large defects of the tegmen tympani and mastoidal roof as well as in recurrences. In all cases of recurrent meningitis caused by agents of the upper airway tract the basic principle should be to search for occult skull base malformations radiologically as well as by sodium fluorescein endoscopy as long as the anomaly is detected.

  1. A 2017 stellar occultation by Orcus/Vanth

    Sickafoose, Amanda A.; Bosh, Amanda S.; Levine, Stephen; Zuluaga, Carlos A.; Genade, Anja; Schindler, Karsten; Lister, Tim; Person, Michael J.

    2017-10-01

    (90482) Orcus is a large trans-Neptunian object (TNO) of diameter ~900 km, located in the 3:2 orbital resonance with Neptune. This plutino has a satellite, Vanth, approximately 280 km in diameter. Vanth orbits roughly 9000 km from Orcus in a ~9.5-day period. This system is particularly interesting, as Orcus falls between the small, spectrally-bland TNOs and the large TNOs having spectra rich in volatile features, while Vanth might have resulted from either collision or capture.A stellar occultation by Orcus was predicted to occur on 07 March 2017. Observations were made from five sites: the 0.6-m Astronomical Telescope of the University of Stuttgart (ATUS) at Sierra Remote Observatories (SRO), California; Las Cumbres Observatory’s 1-m telescope (ELP) at McDonald Observatory, Fort Davis, Texas; NASA’s 3-m InfraRed Telescope Facility (IRTF) on Mauna Kea, Hawaii; the 4.1-m Southern Astrophysical Research telescope (SOAR) on Cerro Pachón, Chile; and the 0.6-m Southeastern Association for Research in Astronomy telescope (SARA-CT) at Cerro Tololo, Chile. High-speed, visible-wavelength images were taken at all sites, in addition to simultaneous K-band images at the IRTF. A solid-body occultation was observed at both ELP and the IRTF. Offset midtimes and incompatible light ratios suggest that two different stars were occulted by two different bodies, likely Orcus and Vanth. See Bosh et al. this conference for details of the astrometry for the event. Here, we present results from the observations, including light curves, size and albedo estimates, and upper limits on a possible atmosphere.

  2. External occulter edge scattering control using metamaterials for exoplanet detection

    Bendek, Eduardo A.; Sirbu, Dan; Liu, Zhaowei; Martin, Stefan; Lu, Dylan

    2015-09-01

    Direct imaging of earth-like exoplanets in the Habitable Zone of sun-like stars requires image contrast of ~10^10 at angular separations of around a hundred milliarcseconds. One approach for achieving this performance is to fly a starshade at a long distance in front of the telescope, shading the telescope from the direct starlight, but allowing planets around the star to be seen. The starshade is positioned so that sunlight falls on the surface away from the telescope, so the sun does not directly illuminate it. However, sunlight scattered from the starshade edge can enter the telescope, raising the background light level and potentially preventing the starshade from delivering the required contrast. As a result, starshade edge design has been identified as one of the highest priority technology gaps for external occulter missions in the NASAs Exoplanet Exploration Program Technology Plan 2013. To reduce the sunlight edge scatter to an acceptable level, the edge Radius Of Curvature (ROC) should be 1μm or less (commercial razor blades have ROC of a few hundred nanometer). This poses a challenging manufacturing requirement and may make the occulter difficult to handle. In this paper we propose an alternative approach to controlling the edge scattering by applying a flexible metamaterial to the occulter edge. Metamaterials are artificially structured materials, which have been designed to display properties not found in natural materials. Metamaterials can be designed to direct the scatter at planned incident angles away from the space telescope, thereby directly decreasing the contaminating background light. Reduction of the background light translates into shorter integration time to characterize a target planet and therefore improves the efficiency of the observations. As an additional benefit, metamaterials also have potential to produce increased tolerance to edge defects.

  3. Trio of Stellar Occultations by Pluto One Year Prior to New Horizons’ Arrival

    2016-04-02

    stellar signal, both with 20 s exposures with our frame-transfer Portable Occultation, Eclipse, and Transit System. Since Pluto had a geocentric velocity...and for New Horizons’s 2015 approach . For the July 31 event, though for our atmospheric studies we are glad to have detected the occultation of this

  4. Combined parathyroid adenoma and an occult papillary carcinoma

    Meshikhes, Abdul-Wahid N.; Al-Saihati, Basima A.; Butt, Mohammad S.

    2004-01-01

    Although the pathological association of thyroid and parathyroid disease is common, the association of both parathyroid adenoma and thyroid cancer is rare. We report here a case of a 45-year-old saudi women who diagnosed to have primary hyperparathyrodism due to single parathyroid adenoma as confirmed biochemically and radiologically. At operation, the adenoma was found to be an intrathyroid and therefore a thyroid lobectomy was performed. Histology of the excised lobe revealed in addition to the intrathyroid parathyroid adenoma a concurrent occult thyroid papillary carcinoma. The interesting association is discussed based on a literature review. (author)

  5. MR imaging of occult fractures of the knee

    Mink, J.H.; Deutsch, A.L.

    1988-01-01

    The authors encountered 65 radiographically occult fractures that they classified into five types. Bone bruises were a result of direct trauma or were associated with ligamentous injury. They were characterized by geographic foci of decreased signal on short repetition time (TR), short echo time (TE) sequences. Stress fractures were linear or globular foci of low signal on short TR, short TE sequences. Osteochondral fractures were displaced or impacted types; the latter were often associated with an anterior cruciate ligament tear. Tibial fractures were minimally displaced, vertically oriented fractures extending into the plateaus. Femoral fractures were Y-shaped, extending across the supracondylar region

  6. Laser fluorescence bronchoscope for localization of occult lung tumors

    Profio, A.E.; Doiron, D.R.; King, E.G.

    1979-01-01

    A system for imaging occult bronchogenic carcinoma by the fluorescence of previously-injected, tumor-specific compound hematoporphyrin-derivative has been assembled and successfully used to locate a tumor l mm thick. The violet excitation source is a krypton ion laser coupled to fused quartz fiber light conductor. An electrostatic image intensifier attached to a standard flexible fiberoptic bronchoscope provides a bright image even at relatively low irradiance. A red secondary filter rejects most reflected background and autofluorescence. Sensitivity and contrast capability of the system should permit detection of a tumor less than 0.1 mm thick

  7. Occult microscopic endometriosis: undetectable by laparoscopy in normal peritoneum.

    Khan, Khaleque Newaz; Fujishita, Akira; Kitajima, Michio; Hiraki, Koichi; Nakashima, Masahiro; Masuzaki, Hideaki

    2014-03-01

    Is there any occurrence of hidden (occult) endometriotic lesions in normal peritoneum of women with and without visible endometriosis? We detected a slightly higher occurrence of occult microscopic endometriosis (OME) in normal peritoneum of women with visible endometriosis than in control women. Based on a small number of cases, the concept of invisible microscopic endometriosis in visually normal peritoneum has been reported for more than a decade but there is controversy regarding their tissue activity and clinical significance. This case-controlled research study was conducted with prospectively collected normal peritoneal samples from 151 women with and 62 women without visible endometriosis. Normal peritoneal biopsy specimens from different pelvic sites of were collected during laparoscopy. A histological search of all peritoneal biopsy specimens for the detection of invisible endometriosis was done by immunoreaction to Ber-EP4 (epithelial cell marker), CD10 (stromal cell marker) and Calretinin (mesothelial cell marker). Tissue expression of estrogen/progesterone receptors (ER/PR) and cell proliferation marker, Ki-67, was performed by immunohistochemistry to identify tissue activity. Three different patterns of OME were detected based on (I) the presence of typical gland/stroma, (II) reactive hyperplastic change of endometrioid epithelial cells with surrounding stroma and (III) single-layered epithelium-lined cystic lesions with surrounding stroma. A higher tendency toward the occurrence of OME was found in women with visible endometriosis (15.2%, 23/151) compared with control women (6.4%, 4/62) (P = 0.06, χ(2) test). The epithelial cells and/or stromal cells of OME lesions were immunoreactive to Ber-EP4 and CD10 but not reactive to Calretinin. ER and PR expression was observed in all patterns of OME lesions. Ki-67 index was significantly higher in pattern I/II OME lesions than in pattern III OME lesions (Pendometriosis due to the presence of adhesions in

  8. Significance of mammographic signs in clinically occult disease

    Waal, J.C. de; Steil, B.; Baltzer, J.; Vaillant, W.; Zander, J.

    1987-10-01

    The significance of various radiographic signs in 183 patients with clinically occult breast disease is described. 30.6% hat a carcinoma of the breast or a carcinoma in situ. The radiological features have varying predictive values and there is variation in the incidence of lymph node metastases. It is considered useful to classify the radiological appearances under the headings of round foci, star-shaped opacities, diffuse opacities, opacities with calcification and groups of micro-calcification. Despite the early diagnosis, 24% of patients already had lymph node metastases.

  9. Occult lung malignancy presenting with finger pain: a case report

    Embley Matthew A

    2008-12-01

    Full Text Available Abstract Introduction Lung cancer is currently one of the most common malignancies in the world. Early detection is an important prognostic factor. Unfortunately, initial symptoms may be vague and a substantial proportion of cases present with the effects of metastases. Case presentation We discuss a case of occult lung malignancy in a 61-year-old man. The only symptom at presentation was pain in the right ring finger due to metastasis from the lung primary. Conclusion This case highlights the need for vigilance when a patient presents with unusual or unexplained symptoms, especially if they have known risk factors for cancer.

  10. James Webb Space Telescope Observations of Stellar Occultations by Solar System Bodies and Rings

    Santos-Sanz, P.; French, R. G.; Pinilla-Alonso, N.; Stansberry, J.; Lin, Z-Y.; Zhang, Z-W.; Vilenius, E.; Mueller, Th.; Ortiz, J. L.; Braga-Ribas, F.; hide

    2016-01-01

    In this paper, we investigate the opportunities provided by the James Webb Space Telescope (JWST) for significant scientific advances in the study of Solar System bodies and rings using stellar occultations. The strengths and weaknesses of the stellar occultation technique are evaluated in light of JWST's unique capabilities. We identify several possible JWST occultation events by minor bodies and rings and evaluate their potential scientific value. These predictions depend critically on accurate a priori knowledge of the orbit of JWST near the Sun–Earth Lagrange point 2 (L2). We also explore the possibility of serendipitous stellar occultations by very small minor bodies as a byproduct of other JWST observing programs. Finally, to optimize the potential scientific return of stellar occultation observations, we identify several characteristics of JWST's orbit and instrumentation that should be taken into account during JWST's development.

  11. Wave propagation simulation of radio occultations based on ECMWF refractivity profiles

    von Benzon, Hans-Henrik; Høeg, Per

    2015-01-01

    This paper describes a complete radio occultation simulation environment, including realistic refractivity profiles, wave propagation modeling, instrument modeling, and bending angle retrieval. The wave propagator is used to simulate radio occultation measurements. The radio waves are propagated...... of radio occultations. The output from the wave propagator simulator is used as input to a Full Spectrum Inversion retrieval module which calculates geophysical parameters. These parameters can be compared to the ECMWF atmospheric profiles. The comparison can be used to reveal system errors and get...... a better understanding of the physics. The wave propagation simulations will in this paper also be compared to real measurements. These radio occultations have been exposed to the same atmospheric conditions as the radio occultations simulated by the wave propagator. This comparison reveals that precise...

  12. A rare case of occult abdominal tuberculosis with Poncet′s disease mimicking Adult onset Still′s disease

    Isha Sood

    2015-01-01

    Full Text Available A 50-year-old female presented with fever, symmetrical arthralgias, rash, painful oral ulcerations and alopecia since 8 weeks. Examination showed mild hepatospleenomegaly. Investigations revealed leucocytosis, neutrophilia, elevated sedimentation rate and raised ferritin levels (3850 ng/ml. Computerized tomography (CT abdomen showed hepatospleenomegaly, mild ascitis and mild bilateral pleural-effusion. After ruling out occult infections, tuberculosis, malignancies and autoimmune diseases by appropriate investigations, and due to raised ferritin levels, adult onset stills disease (AOSD was diagnosed. Patient responded to oral steroids initially, but after 7 days developed severe abdominal pain. Repeat CT showed multiple enlarged, necrotic and matted retroperitoneal lymph nodes with caseating granuloma on histopathology suggesting tuberculosis. Patient was given four-drug anti-tubercular treatment and she improved. Thus our patient of occult abdominal tuberculosis with reactive arthritis (Poncet′s disease presented with hyperferritinemia mimicking AOSD. We postulate that extreme hyperferritinemia can be seen in tuberculosis and tuberculosis must be conclusively ruled out before diagnosing AOSD in tropics.

  13. PREVALENCE OF OCCULT DEPRESSION IN ELDERLY WITH CHRONIC CO - MORBIDS

    Sachin

    2015-02-01

    Full Text Available BACKGROUND: Growth in elderly population has led to an increase in age related diseases and mainly depression which is affecting the quality of life. Depression is more prevalent amongst elderly individuals with medical illnesses and emerging public health problem leading to increased morbidity and disability worldwide. AIMS AND OBJE CTIVES: To assess the prevalence of occult depression in elderly patients with chronic co - morbid medical conditions. MATERIALS AND METHODS: It was a cross - sectional study conducted in tertiary hospital. Total 100 elderly patients with underlying chronic me dical illnesses were included. Depression in study population was assessed by geriatric depression scale and analyzed. RESULT: Out of 100 patients 23(23% had depression. Females 12/39(30.76% were affected more than males 11/61 (18.03%. Depression was mo re prevalent among patients with 3 or more co - morbid conditions (45.4% as compared to <3 (11.9%. CONCLUSION: Elderly patients with multiple chronic medical illnesses may have associated occult depression. Screening of these patients for depression couple d with appropriate psychiatric referral should be an integral part of Geriatric service

  14. Fluctuations of radio occultation signals in sounding the Earth's atmosphere

    V. Kan

    2018-02-01

    Full Text Available We discuss the relationships that link the observed fluctuation spectra of the amplitude and phase of signals used for the radio occultation sounding of the Earth's atmosphere, with the spectra of atmospheric inhomogeneities. Our analysis employs the approximation of the phase screen and of weak fluctuations. We make our estimates for the following characteristic inhomogeneity types: (1 the isotropic Kolmogorov turbulence and (2 the anisotropic saturated internal gravity waves. We obtain the expressions for the variances of the amplitude and phase fluctuations of radio occultation signals as well as their estimates for the typical parameters of inhomogeneity models. From the GPS/MET observations, we evaluate the spectra of the amplitude and phase fluctuations in the altitude interval from 4 to 25 km in the middle and polar latitudes. As indicated by theoretical and experimental estimates, the main contribution into the radio signal fluctuations comes from the internal gravity waves. The influence of the Kolmogorov turbulence is negligible. We derive simple relationships that link the parameters of internal gravity waves and the statistical characteristics of the radio signal fluctuations. These results may serve as the basis for the global monitoring of the wave activity in the stratosphere and upper troposphere.

  15. Progress in turbulence detection via GNSS occultation data

    L. B. Cornman

    2012-04-01

    Full Text Available The increased availability of radio occultation (RO data offers the ability to detect and study turbulence in the Earth's atmosphere. An analysis of how RO data can be used to determine the strength and location of turbulent regions is presented. This includes the derivation of a model for the power spectrum of the log-amplitude and phase fluctuations of the permittivity (or index of refraction field. The bulk of the paper is then concerned with the estimation of the model parameters. Parameter estimators are introduced and some of their statistical properties are studied. These estimators are then applied to simulated log-amplitude RO signals. This includes the analysis of global statistics derived from a large number of realizations, as well as case studies that illustrate various specific aspects of the problem. Improvements to the basic estimation methods are discussed, and their beneficial properties are illustrated. The estimation techniques are then applied to real occultation data. Only two cases are presented, but they illustrate some of the salient features inherent in real data.

  16. Influence of Ionospheric Weather on GNSS Radio Occultation Signals

    Yue, X.; Schreiner, W. S.; Pedatella, N. M.; Kuo, Y. H.

    2016-12-01

    Transient loss of lock (LOL) is one of the key space weather effects on the Global Navigation Satellite System (GNSS). Based on the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) observations during 2007-2011, we have analyzed the signal cycle slip (CS) occurrence comprehensively and its correlation to the ionospheric weather phenomena such as sporadic E (Es), equatorial F region irregularity (EFI), and the ionospheric equatorial ionization anomaly (EIA). The high vertical resolution of RO observations enables us to distinguish the CS resulting from different ionospheric layers clearly on a global scale. In the E layer, the CS is dominated by the Es occurrence, while in the F layer, the CS is mainly related to the EIA and EFI at low and equatorial latitudes. In the polar region, the CS is primarily related to polar cap electron density gradients. The overall average CS (> 6 cycles) occurrence is 23% per occultation, with the E (50-150 km) and F (150-600 km) layers contributing 8.3% and 14.7%, respectively. Awareness of the effect of the ionospheric weather on the CS of the low-Earth-orbit (LEO)-based GNSS signal could be beneficial to a variety of applications, including the LEO-based GNSS data processing and the corresponding hardware/firmware design.

  17. Occulting Light Concentrators in Liquid Scintillator Neutrino Detectors

    Buizza Avanzini, Margherita; Cabrera, Anatael; Dusini, Stefano; Grassi, Marco; He, Miao; Wu, Wenjie

    2017-09-01

    The experimental efforts characterizing the era of precision neutrino physics revolve around collecting high-statistics neutrino samples and attaining an excellent energy and position resolution. Next generation liquid-based neutrino detectors, such as JUNO, HyperKamiokande, etc, share the use of a large target mass, and the need of pushing light collection to the edge for maximal calorimetric information. Achieving high light collection implies considerable costs, especially when considering detector masses of several kt. A traditional strategy to maximize the effective photo-coverage with the minimum number of PMTs relies on Light Concentrators (LC), such as Winston Cones. In this paper, the authors introduce a novel concept called Occulting Light Concentrators (OLC), whereby a traditional LC gets tailored to a conventional PMT, by taking into account its single-photoelectron collection efficiency profile and thus occulting the worst performing portion of the photocathode. Thus, the OLC shape optimization takes into account not only the optical interface of the PMT, but also the maximization of the PMT detection performances. The light collection uniformity across the detector is another advantage of the OLC system. By considering the case of JUNO, we will show OLC capabilities in terms of light collection and energy resolution.

  18. Image guidance improves localization of sonographically occult colorectal liver metastases

    Leung, Universe; Simpson, Amber L.; Adams, Lauryn B.; Jarnagin, William R.; Miga, Michael I.; Kingham, T. Peter

    2015-03-01

    Assessing the therapeutic benefit of surgical navigation systems is a challenging problem in image-guided surgery. The exact clinical indications for patients that may benefit from these systems is not always clear, particularly for abdominal surgery where image-guidance systems have failed to take hold in the same way as orthopedic and neurosurgical applications. We report interim analysis of a prospective clinical trial for localizing small colorectal liver metastases using the Explorer system (Path Finder Technologies, Nashville, TN). Colorectal liver metastases are small lesions that can be difficult to identify with conventional intraoperative ultrasound due to echogeneity changes in the liver as a result of chemotherapy and other preoperative treatments. Interim analysis with eighteen patients shows that 9 of 15 (60%) of these occult lesions could be detected with image guidance. Image guidance changed intraoperative management in 3 (17%) cases. These results suggest that image guidance is a promising tool for localization of small occult liver metastases and that the indications for image-guided surgery are expanding.

  19. 'Trick', 'manipulation' and 'farce': Albert Moll's critique of occultism.

    Wolffram, Heather

    2012-04-01

    In July 1925, the psychiatrist Albert Moll appeared before the district court in Berlin-Schöneberg charged with having defamed the medium Maria Vollhardt (alias Rudloff) in his 1924 book Der Spiritismus [Spiritism]. Supported by some of Berlin's most prominent occultists, the plaintiff--the medium's husband--argued that Moll's use of terms such as 'trick', 'manipulation' and 'farce' in reference to Vollhardt's phenomena had been libellous. In the three-part trial that followed, however, Moll's putative affront to the medium--of which he was eventually acquitted--was overshadowed, on the one hand, by a debate over the scientific status of parapsychology, and on the other, by the question of who--parapsychologists, occultists, psychiatrists or jurists--was entitled to claim epistemic authority over the occult. This paper will use the Rudloff-Moll trial as a means of examining Moll's critique of occultism, not only as it stood in the mid-1920s, but also as it had developed since the 1880s. It will also provide insight into the views of Germany's occultists and parapsychologists, who argued that their legitimate bid for scientific credibility was hindered by Dunkelmänner [obscurantists] such as Albert Moll.

  20. Advanced Electrocardiography Can Identify Occult Cardiomyopathy in Doberman Pinschers

    Spiljak, M.; Petric, A. Domanjko; Wilberg, M.; Olsen, L. H.; Stepancic, A.; Schlegel, T. T.; Starc, V.

    2011-01-01

    Recently, multiple advanced resting electrocardiographic (A-ECG) techniques have improved the diagnostic value of short-duration ECG in detection of dilated cardiomyopathy (DCM) in humans. This study investigated whether 12-lead A-ECG recordings could accurately identify the occult phase of DCM in dogs. Short-duration (3-5 min) high-fidelity 12-lead ECG recordings were obtained from 31 privately-owned, clinically healthy Doberman Pinschers (5.4 +/- 1.7 years, 11/20 males/females). Dogs were divided into 2 groups: 1) 19 healthy dogs with normal echocardiographic M-mode measurements: left ventricular internal diameter in diastole (LVIDd . 47mm) and in systole (LVIDs . 38mm) and normal 24-hour ECG recordings (100 VPCs/24h; 1/12 dogs had only abnormal 24-hour ECG recordings (>100 VPCs/24h). ECG recordings were evaluated via custom software programs to calculate multiple parameters of high-frequency (HF) QRS ECG, heart rate variability, QT variability, waveform complexity and 3-D ECG. Student's t-tests determined 19 ECG parameters that were significantly different (P canine DCM as five selected ECG parameters can with reasonable accuracy identify occult DCM in Doberman Pinschers. Future extensive clinical studies need to clarify if 12-lead A-ECG could be useful as an additional screening test for canine DCM.

  1. Ex Luna Scientia: The Lunar Occultation Explorer (LOX)

    Miller, Richard

    2017-01-01

    The Lunar Occultation Explorer (LOX) is a next-generation mission concept that provides new capabilities for time-domain astrophysics and established the Moon as a platform for nuclear astrophysics. Performance requirements are driven by Type-Ia supernova (SNeIa) science goals that seek to revel details of these profoundly radioactive objects, including their diversity. Primary science objectives include, but are not limited to, probing the fundamental thermonuclear physics processes, performing a census of progenitors and their explosion mechanisms, and evaluating the environmental conditions and intrinsic systematics of these enigmatic objects. LOX provides new capabilities for all-sky, continuous monitoring in the MeV regime (0.1-10 MeV) by leveraging the Lunar Occultation Technique (LOT). Key benefits of the LOX/LOT approach include maximizing the ratio of sensitive-to-total deployed mass, low implementation risk, and demonstrated operational simplicity that leverages extensive experience with planetary orbital geochemistry investigations; LOX also enables long-term monitoring of MeV gamma-ray sources, a critical capability for SNeIa science. Proof-of-principle efforts validated all aspects of the mission using previously deployed lunar science assets, and led to the first high-energy gamma-ray source detected at the Moon. LOX mission performance, development progress, and expectations for science investigations will be presented.

  2. The ionosphere of Europa from Galileo radio occultations

    Kliore, A. J.; Hinson, D. P.; Flasar, F. M.; Nagy, A. F.; Cravens, T. E.

    1997-01-01

    The Galileo spacecraft performed six radio occultation observations of Jupiter's Galilean satellite Europa during its tour of the jovian system. In five of the six instances, these occultations revealed the presence of a tenuous ionosphere on Europa, with an average maximum electron density of nearly 10(4) per cubic centimeter near the surface and a plasma scale height of about 240 +/- 40 kilometers from the surface to 300 kilometers and of 440 +/- 60 kilometers above 300 kilometers. Such an ionosphere could be produced by solar photoionization and jovian magnetospheric particle impact in an atmosphere having a surface density of about 10(8) electrons per cubic centimeter. If this atmosphere is composed primarily of O2, then the principal ion is O2+ and the neutral atmosphere temperature implied by the 240-kilometer scale height is about 600 kelvin. If it is composed of H2O, the principal ion is H3O+ and the neutral temperature is about 340 kelvin. In either case, these temperatures are much higher than those observed on Europa's surface, and an external heating source from the jovian magnetosphere is required.

  3. Waves in the Martian Atmosphere: Results from MGS Radio Occultations

    Flasar, F. M.; Hinson, D. P.; Tyler, G. L.

    1999-01-01

    Temperatures retrieved from Mars Global Surveyor radio occultations have been searched for evidence of waves. Emphasis has been on the initial series of occultations between 29 deg N and 64 deg S, obtained during the early martian southern summer, L(sub s) = 264 deg - 308 deg. The profiles exhibit an undulatory behavior that is suggestive of vertically propagating waves. wavelengths approximately 10 km are often dominant, but structure on smaller scales is evident. The undulatory structure is most pronounced between latitudes 29 deg N and 10 deg S, usually in regions of "interesting" topography, e.g., in the Tharsis region and near the edge of Syrtis Major. Several temperature profiles, particularly within 30 deg of the equator, exhibit lapse rates that locally become superadiabatic near the 0.4-mbar level or at higher altitudes. This implies that the waves are "breaking" and depositing horizontal momentum into the atmosphere. Such a deposition may play an important role in modulating the atmospheric winds, and characterizing the spatial and temporal distribution of these momentum transfers can provide important clues to understanding how the global circulation is maintained.

  4. The floating cardiac fat pad-sign of occult pneumothorax.

    Kaufman, Claire; Bokhari, S A Jamal

    2016-08-01

    Pneumothoraces are a possible sequela of chest trauma with potential morbidity and mortality if not recognized and treated promptly. A portable supine chest radiograph is frequently the first radiologic study performed in the setting of trauma. While large pneumothoraces can be readily recognized on these radiographs, smaller pneumothoraces are missed in up to 15 % of trauma patients. There are many radiographic signs of occult pneumothoraces, and we are presenting a new radiographic sign of occult pneumothorax. The floating cardiac fat pad sign occurs when pleural air collects anteriorly and superiorly in the most non-dependent portion of the chest lifting the pericardial fat pad off the diaphragm. Lung markings are still seen surrounding the pericardial fat pad due to the inflated lower lobe of the lung resting dependently. Rapid and accurate identification of pneumothoraces is critical but often difficult on chest radiographs. Although there are many existing radiographic signs for identification of pneumothorax, prospective identification of small pneumothoraces is still relatively poor. Here, we describe an additional sign which aides in the detection of pneumothoraces, the floating cardiac fat pad. When present, this should prompt further evaluation with chest CT or upright chest radiograph.

  5. Diffraction-based analysis of tunnel size for a scaled external occulter testbed

    Sirbu, Dan; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2016-07-01

    For performance verification of an external occulter mask (also called a starshade), scaled testbeds have been developed to measure the suppression of the occulter shadow in the pupil plane and contrast in the image plane. For occulter experiments the scaling is typically performed by maintaining an equivalent Fresnel number. The original Princeton occulter testbed was oversized with respect to both input beam and shadow propagation to limit any diffraction effects due to finite testbed enclosure edges; however, to operate at realistic space-mission equivalent Fresnel numbers an extended testbed is currently under construction. With the longer propagation distances involved, diffraction effects due to the edge of the tunnel must now be considered in the experiment design. Here, we present a diffraction-based model of two separate tunnel effects. First, we consider the effect of tunnel-edge induced diffraction ringing upstream from the occulter mask. Second, we consider the diffraction effect due to clipping of the output shadow by the tunnel downstream from the occulter mask. These calculations are performed for a representative point design relevant to the new Princeton occulter experiment, but we also present an analytical relation that can be used for other propagation distances.

  6. Noninvasive Prenatal Testing and Incidental Detection of Occult Maternal Malignancies.

    Bianchi, Diana W; Chudova, Darya; Sehnert, Amy J; Bhatt, Sucheta; Murray, Kathryn; Prosen, Tracy L; Garber, Judy E; Wilkins-Haug, Louise; Vora, Neeta L; Warsof, Stephen; Goldberg, James; Ziainia, Tina; Halks-Miller, Meredith

    2015-07-14

    Understanding the relationship between aneuploidy detection on noninvasive prenatal testing (NIPT) and occult maternal malignancies may explain results that are discordant with the fetal karyotype and improve maternal clinical care. To evaluate massively parallel sequencing data for patterns of copy-number variations that might prospectively identify occult maternal malignancies. Case series identified from 125,426 samples submitted between February 15, 2012, and September 30, 2014, from asymptomatic pregnant women who underwent plasma cell-free DNA sequencing for clinical prenatal aneuploidy screening. Analyses were conducted in a clinical laboratory that performs DNA sequencing. Among the clinical samples, abnormal results were detected in 3757 (3%); these were reported to the ordering physician with recommendations for further evaluation. NIPT for fetal aneuploidy screening (chromosomes 13, 18, 21, X, and Y). Detailed genome-wide bioinformatics analysis was performed on available sequencing data from 8 of 10 women with known cancers. Genome-wide copy-number changes in the original NIPT samples and in subsequent serial samples from individual patients when available are reported. Copy-number changes detected in NIPT sequencing data in the known cancer cases were compared with the types of aneuploidies detected in the overall cohort. From a cohort of 125,426 NIPT results, 3757 (3%) were positive for 1 or more aneuploidies involving chromosomes 13, 18, 21, X, or Y. From this set of 3757 samples, 10 cases of maternal cancer were identified. Detailed clinical and sequencing data were obtained in 8. Maternal cancers most frequently occurred with the rare NIPT finding of more than 1 aneuploidy detected (7 known cancers among 39 cases of multiple aneuploidies by NIPT, 18% [95% CI, 7.5%-33.5%]). All 8 cases that underwent further bioinformatics analysis showed unique patterns of nonspecific copy-number gains and losses across multiple chromosomes. In 1 case, blood was

  7. [Occult rupture of the spleen in a patient with infectious mononucleosis].

    Bonsignore, A; Grillone, G; Soliera, M; Fiumara, F; Pettinato, M; Calarco, G; Angiò, L G; Licursi, M

    2010-03-01

    Rupture of the spleen can be secondary to abdominal traumas (usually closed trauma) or spontaneous, can interest an organ normal or with morphological alterations secondary to various pathologies. Among the diseases responsible of occult rupture, infectious diseases are the most frequent and, among these, infectious mononucleosis, that is complicated with splenic rupture in 0.5% of the cases, with 30% of mortality. P.M., 16 years old female, admitted with acute abdomen, progressive anaemia and incipient cardiovascular instability, associated with suggestive clinical diagnosis of infectious mononucleosis, confirmed by serological findings and histological examination. Because of the imaging of subcapsular splenic haematoma, probably ruptured and with peritoneal bleeding we opt for emergency laparotomy intraoperative findings allows to splenectomy. Splenic rupture in infectious mononucleosis often presents as left hypochondrial pain, rare in uncomplicated cases; its occurrence in a patient with a recent diagnosis of infectious mononucleosis or with clinical or laboratory features suggestive of acute EBV infection, should always be investigated with an urgent abdominal ultrasound scan or CT. This approach is mandatory when hypochondrial pain is associated with pain referred to the left shoulder (Kehr's sign), peritoneal irritation and haemodynamic instability. Patients with splenic rupture in infectious mononucleosis generally undergo emergency splenectomy.

  8. First light of an external occulter testbed at flight Fresnel numbers

    Kim, Yunjong; Sirbu, Dan; Hu, Mia; Kasdin, Jeremy; Vanderbei, Robert J.; Harness, Anthony; Shaklan, Stuart

    2017-01-01

    Many approaches have been suggested over the last couple of decades for imaging Earth-like planets. One of the main candidates for creating high-contrast for future Earth-like planets detection is an external occulter. The external occulter is a spacecraft flown along the line-of-sight of a space telescope to suppress starlight and enable high-contrast direct imaging of exoplanets. The occulter is typically tens of meters in diameter and the separation from the telescope is of the order of tens of thousands of kilometers. Optical testing of a full-scale external occulter on the ground is impossible because of the long separations. Therefore, laboratory verification of occulter designs is necessary to validate the optical models used to design and predict occulter performance. At Princeton, we have designed and built a testbed that allows verification of scaled occulter designs whose suppressed shadow is mathematically identical to that of space occulters. The goal of this experiment is to demonstrate a pupil plane suppression of better than 1e-9 with a corresponding image plane contrast of better than 1e-11. The occulter testbed uses a 77.2 m optical propagation distance to realize the flight Fresnel number of 14.5. The scaled mask is placed at 27.2 m from the artificial source and the camera is located 50.0 m from the scaled mask. We will use an etched silicon mask, manufactured by the Microdevices Lab(MDL) of the Jet Propulsion Laboratory(JPL), as the occulter. Based on conversations with MDL, we expect that 0.5 μm feature size is an achievable resolution in the mask manufacturing process and is therefore likely the indicator of the best possible performance. The occulter is illuminated by a diverging laser beam to reduce the aberrations from the optics before the occulter. Here, we present first light result of a sample design operating at a flight Fresnel number and the experimental setup of the testbed. We compare the experimental results with simulations

  9. Influence of misalignments on the performance of externally occulted solar coronagraphs. Application to PROBA-3/ASPIICS

    Shestov, S. V.; Zhukov, A. N.

    2018-05-01

    Context. The ASPIICS instrument is a novel externally occulted coronagraph that will be launched on board the PROBA-3 mission of the European Space Agency. The external occulter will be placed on one satellite 150 m ahead of the second satellite that will carry an optical instrument. During 6 h out of 19.38 h of orbit, the satellites will fly in a precise (accuracy around a few millimeters) formation, constituting a giant externally occulted coronagraph. The large distance between the external occulter and the primary objective will allow observations of the white-light solar corona starting from extremely low heights 1.1R⊙. Aims: We intend to analyze influence of shifts of the satellites and misalignments of optical elements on the ASPIICS performance in terms of diffracted light. Based on the quantitative influence of misalignments on diffracted light, we provide a recipe for choosing the size of the internal occulter (IO) to achieve a trade-off between the minimal height of observations and sustainability to possible misalignments. Methods: We considered different types of misalignments and analyzed their influence from optical and computational points of view. We implemented a numerical model of the diffracted light and its propagation through the optical system and computed intensities of diffracted light throughout the instrument. Our numerical approach is based on a model from the literature that considered the axisymmetrical case. Here we extend the model to include nonsymmetrical cases and possible misalignments. Results: The numerical computations fully confirm the main properties of the diffracted light that we obtained from semi-analytical consideration. We obtain that relative influences of various misalignments are significantly different. We show that the internal occulter with RIO = 1.694 mm = 1.1R⊙ is large enough to compensate possible misalignments expected to occur in PROBA-3/ASPIICS. Besides that we show that apodizing the edge of the

  10. Heparin as a pharmacologic intervention to induce positive scintiscan in occult gastrointestinal bleeding

    Chaudhuri, T.K.; Brantly, M.

    1984-01-01

    The value of using heparin as a pharmacologic intervention to induce a positive scintiscan was studied in a patient with chronic occult gastrointestinal bleeding. When all standard diagnostic tests (upper and lower gastrointestinal series, upper and lower endoscopy, and conventional noninterventional Tc-99m RBC imaging) fail to detect and localize gastrointestinal bleeding in a patient who has definite clinical evidence (guaiac positive stool and dropping hemoglobin, hematocrit) of chronic occult gastrointestinal oozing, heparin may be used (with proper precaution) as a last resort to aid in the scintigraphic detection and localization of chronic occult gastrointestinal bleeding

  11. A duck hepatitis B virus strain with a knockout mutation in the putative X ORF shows similar infectivity and in vivo growth characteristics to wild-type virus

    Meier, P.; Scougall, C.A.; Will, H.; Burrell, C.J.; Jilbert, A.R.

    2003-01-01

    Hepadnaviruses including human hepatitis B virus (HBV) and duck hepatitis B virus (DHBV) express X proteins, HBx and DHBx, respectively. Both HBx and DHBx are transcriptional activators and modulate cellular signaling in in vitro assays. To test whether the DHBx protein plays a role in virus infection, we compared the in vivo infectivity and growth characteristics of a DHBV3 strain with a stop codon in the X-like ORF (DHBV3-X-K.O.) to those of the wild-type DHBV3 strain. Here we report that the two strains showed no significant difference in (i) their ability to induce infection that resulted in stable viraemia measured by serum surface antigen (DHBsAg) and DHBV DNA, and detection of viral proteins and replicative DNA intermediates in the liver; (ii) the rate of spread of infection in liver and extrahepatic sites after low-dose virus inoculation; and (iii) the ability to produce transient or persistent infection under balanced age/dose conditions designed to detect small differences between the strains. Thus, none of the infection parameters assayed were detectably affected by the X-ORF knockout mutation, raising the question whether DHBx expression plays a physiological role during in vivo infection with wild-type DHBV

  12. Acute Zonal Occult Outer Retinopathy with Atypical Findings

    Dimitrios Karagiannis

    2014-01-01

    Full Text Available Background. To report a case of acute zonal occult outer retinopathy (AZOOR with atypical electrophysiology findings. Case Presentation. A 23-year-old-female presented with visual acuity deterioration in her right eye accompanied by photopsia bilaterally. Corrected distance visual acuity at presentation was 20/50 in the right eye and 20/20 in the left eye. Fundus examination was unremarkable. Visual field (VF testing revealed a large scotoma. Pattern and full-field electroretinograms (PERG and ERG revealed macular involvement associated with generalized retinal dysfunction. Electrooculogram (EOG light rise and the Arden ratio were within normal limits bilaterally. The patient was diagnosed with AZOOR due to clinical findings, visual field defect, and ERG findings. Conclusion. This is a case of AZOOR with characteristic VF defects and clinical symptoms presenting with atypical EOG findings.

  13. Radiosensitive orbital metastasis as presentation of occult colonic adenocarcinoma.

    Ludmir, Ethan B; McCall, Shannon J; Czito, Brian G; Palta, Manisha

    2014-09-19

    An 82-year-old man presented with progressive right frontal headaches. The patient's history was significant for benign polyps on surveillance colonoscopy 2 years prior, without high-grade dysplasia or carcinoma. MRI revealed an enhancing lesion arising within the superomedial aspect of the right orbit. Lesion biopsy demonstrated histological appearance and immunophenotype suggestive of colonic adenocarcinoma. Staging positron emission tomography/CT showed visceral metastases and diffuse activity in the posterior rectosigmoid, consistent with metastatic colon cancer. Treatment of the orbital lesion with external beam radiotherapy to 30 Gy resulted in significant palliation of the patient's headaches. The patient expired 2 months following treatment completion due to disease progression. Orbital metastasis as the initial presentation of an occult colorectal primary lesion is exceedingly rare, and occurred in this patient despite surveillance colonoscopy. Radiotherapy remains an efficacious modality for treatment of orbital metastases. 2014 BMJ Publishing Group Ltd.

  14. Lunar occultations for gamma-ray source measurements

    Koch, David G.; Hughes, E. B.; Nolan, Patrick L.

    1990-01-01

    The unambiguous association of discrete gamma-ray sources with objects radiating at other wavelengths, the separation of discrete sources from the extended emission within the Galaxy, the mapping of gamma-ray emission from nearby galaxies and the measurement of structure within a discrete source cannot presently be accomplished at gamma-ray energies. In the past, the detection processes used in high-energy gamma-ray astronomy have not allowed for good angular resolution. This problem can be overcome by placing gamma-ray detectors on the moon and using the horizon as an occulting edge to achieve arcsec resolution. For purposes of discussion, this concept is examined for gamma rays above 100 MeV for which pair production dominates the detection process and locally-generated nuclear gamma rays do not contribute to the background.

  15. Management of occult stress urinary incontinence with prolapse surgery.

    Al-Mandeel, H; Al-Badr, A

    2013-08-01

    Pelvic organ prolapse (POP) and stress urinary incontinence (SUI), are two common health-related conditions, each affecting up to 50% women worldwide. Stress urinary incontinence only observed after the reduction of co-existent prolapse is called occult SUI (OSUI), and is found in up to 80% of women with advanced POP. Although there is no consensus on how to diagnose OSUI, there are several reported methods to better diagnose. Counseling symptomatically continent women with POP concerning the potential risk for developing SUI postoperatively cannot be overstated. Evidence suggests that positive OSUI in symptomatically continent women who are planning to have POP repair is associated with a high risk of POSUI, furthermore, adding continence procedure is found to reduce postoperative SUI. Therefore, adding continence surgery at the time of POP surgery in patients who are found to have OSUI preoperatively is advocated.

  16. Adolescent Occultism and the Philosophy of Things in Three Novels

    Samuel Finegan

    2015-11-01

    Full Text Available Shirley Jackson’s 1962 We Have Always Lived in the Castle, Iain Banks’s 1984 The Wasp Factory and Sonya Hartnett’s 2009 Butterfly are novels separated not only by decades, but by distance being produced in the United States, Scotland and Australia respectively. Despite this, each of these texts depicts a young adult in a mimetically recognisable world struggling to reconcile their intuitive occultism with that world. The mediation of magic through assemblages of charged objects creates a philosophy of things – modelling in intuitive and narrative terms the essence and nature of objects familiar from the philosophies of Martin Heidegger and Walter Benjamin. As such, the supernaturalism of Iain Banks, Shirley Jackson and Sonya Hartnett’s narratives implicates their readers – breaking the boundaries of fiction to comment on the material world itself, not through analogy or metaphor but through direct modelling of the potential power and worth of things.

  17. Radiographically Occult and Subtle Fractures: A Pictorial Review

    Jarraya, M.; Hayashi, D.; Roemer, F.W.; Crema, M.D.; Conlin, J.; Marra, M.D.; Guermazi, A.; Roemer, F.W.; Crema, M.D.; Diaz, L.; Conlin, J.; Jomaah, N.

    2013-01-01

    Radiographically occult and subtle fractures are a diagnostic challenge. They may be divided into (1) high energy trauma fracture, (2) fatigue fracture from cyclical and sustained mechanical stress, and (3) insufficiency fracture occurring in weakened bone (e.g., in osteoporosis and post radiotherapy). Independently of the cause, the initial radiographic examination can be negative either because the findings seem normal or are too subtle. Early detection of these fractures is crucial to explain the patients symptoms and prevent further complications. Advanced imaging tools such as computed tomography, magnetic resonance imaging, and scintigraphy are highly valuable in this context. Our aim is to raise the awareness of radiologists and clinicians in these cases by presenting illustrative cases and a discussion of the relevant literature.

  18. Small Spacecraft Constellation Concept for Mars Atmospheric Radio Occultations

    Asmar, S. W.; Mannucci, A. J.; Ao, C. O.; Kobayashi, M. M.; Lazio, J.; Marinan, A.; Massone, G.; McCandless, S. E.; Preston, R. A.; Seubert, J.; Williamson, W.

    2017-12-01

    First demonstrated in 1965 when Mariner IV flew by Mars and determined the salient features of its atmosphere, radio occultation experiments have been carried out on numerous planetary missions with great discoveries. These experiments utilize the now classic configuration of a signal from a single planetary spacecraft to Earth receiving stations, where the science data are acquired. The Earth science community advanced the technique to utilizing a constellation of spacecraft with the radio occultation links between the spacecraft, enabled by the infrastructure of the Global Positioning System. With the advent of small and less costly spacecraft, such as planetary CubeSats and other variations, such as the anticipated innovative Mars Cube One mission, crosslinks among small spacecraft can be used to study other planets in the near future. Advantages of this type of experiment include significantly greater geographical coverage, which could reach global coverage over a few weeks with a small number of spacecraft. Repeatability of the global coverage can lead to examining temperature-pressure profiles and ionospheric electron density profiles, on daily, seasonal, annual, or other time scales of interest. The higher signal-to-noise ratio for inter-satellite links, compared to a link to Earth, decreases the design demands on the instrumentation (smaller antennas and transmitters, etc.). After an actual Mars crosslink demonstration, this concept has been in development using Mars as a possible target. Scientific objectives, delivery methods, operational scenarios and end-to-end configuration have been documented. Science objectives include determining the state and variability of the lower Martian atmosphere, which has been an identified as a high priority objective by the Mars Exploration Program Analysis Group, particularly as it relates to entry, descent, and landing and ascent for future crewed and robotic missions. This paper will present the latest research on the

  19. The prototype cameras for trans-Neptunian automatic occultation survey

    Wang, Shiang-Yu; Ling, Hung-Hsu; Hu, Yen-Sang; Geary, John C.; Chang, Yin-Chang; Chen, Hsin-Yo; Amato, Stephen M.; Huang, Pin-Jie; Pratlong, Jerome; Szentgyorgyi, Andrew; Lehner, Matthew; Norton, Timothy; Jorden, Paul

    2016-08-01

    The Transneptunian Automated Occultation Survey (TAOS II) is a three robotic telescope project to detect the stellar occultation events generated by TransNeptunian Objects (TNOs). TAOS II project aims to monitor about 10000 stars simultaneously at 20Hz to enable statistically significant event rate. The TAOS II camera is designed to cover the 1.7 degrees diameter field of view of the 1.3m telescope with 10 mosaic 4.5k×2k CMOS sensors. The new CMOS sensor (CIS 113) has a back illumination thinned structure and high sensitivity to provide similar performance to that of the back-illumination thinned CCDs. Due to the requirements of high performance and high speed, the development of the new CMOS sensor is still in progress. Before the science arrays are delivered, a prototype camera is developed to help on the commissioning of the robotic telescope system. The prototype camera uses the small format e2v CIS 107 device but with the same dewar and also the similar control electronics as the TAOS II science camera. The sensors, mounted on a single Invar plate, are cooled to the operation temperature of about 200K as the science array by a cryogenic cooler. The Invar plate is connected to the dewar body through a supporting ring with three G10 bipods. The control electronics consists of analog part and a Xilinx FPGA based digital circuit. One FPGA is needed to control and process the signal from a CMOS sensor for 20Hz region of interests (ROI) readout.

  20. Between occultism and drama. Henrik Ibsen and Aleister Crowley

    Giuliano D' Amico

    2015-02-01

    Full Text Available The article investigates the references to the works of Henrik Ibsen that the writer and occultist Aleister Crowley scattered in his writings around the turn of the 20th century, in the early phase of his career as a writer and occultist. Crowley’s reading of Ibsen has a marked a socio-political bent, especially in his interpretation of the work of the Norwegian playwright as an act of rebellion against the bourgeois (and for Crowley, Victorian system of values. Also, such view is enriched by a spiritual and individualistic interpretation of Ibsen as an “Artist”, i.e., in the light of Crowley’s occult doctrine, Thelema, of an individual who has found his own “Will” and can inspire others to do so. Such social and spiritual interpretations of Ibsen on Crowley’s part found their literary realization in his one-act play The Mother’s Tragedy (1899. The article claims that Crowley’s reading of Ibsen can give some new insight in the mechanisms of reception of the Norwegian playwright, by opening up for a reading of some of his plays within an occult discourse. Also, it is an occasion to treat Crowley – a figure that was constantly present in the European cultural and literary life of the last decade of the 19th century and of the first five decades of the 20th – with a different attitude than the irony and disdain to which he is often exposed.

  1. Mapping Pluto's Temperature Distribution Through Twenty Years of Stellar Occultations

    Zangari, Amanda; Binzel, R. P.; Person, M. J.

    2012-10-01

    Multi-chord, high signal-to-noise Pluto occultations have been observed several times over the past two decades, including events in 1988, 2002, 2006, 2007, 2010 and 2011 (Elliot et al. 1989, 2003, 2007; Person et al. 2008, 2010, 2011). We fit separate immersion and emersion occultation light-curve models to each of the individual light curves obtained from these efforts. Asymmetries in the light curves result in the half-light temperatures for opposite sides of a single chord to differ by up to 20 Kelvin in the largest case. The temperature difference for each chord is consistent using both isothermal (b=0) and non-isothermal (e.g. b=-2.2) models based on the methodology described by Elliot & Young (1992). We examine the relationship between the location of immersion and emersion points on Pluto and these temperatures at the half-light radius and will present results for correlations between these location/temperature data and surface composition maps, Pluto geometry, and accumulated insolation patterns. This work was supported by NASA Planetary Astronomy Grant to MIT (NNX10AB27G), and NSF Astronomy and Astrophysics Grant to MIT (0707609). The authors would like to acknowledge the late Professor James L. Elliot for his efforts in beginning this work. References: Elliot, J. L., Dunham, E. W., Bosh, A. S., et al. 1989, Icarus, 77,148 Elliot, J. L., Ates, A., Babcock, B. A., et al. 2003, Nature, 424,165 Elliot, J. L., Person, M. J., Gulbis, A. A. S., et al. 2007, AJ, 134, 1 Elliot, J. L., & Young, L. A. 1992, AJ, 103, 991. Person, M. J., Elliot, J. L., Gulbis, A. A. S., et al. 2008, AJ, 136, 1510 Person, M. J., Elliot, J. L., Bosh, A. S., et al. 2010, Bulletin of the American Astronomical Society, 42, 983 Person, M. J., Dunham, E. W., Bida, T., et al. 2011, EPSC-DPS Joint Meeting 2011, 1374.

  2. Magellan radio occultation measurements of atmospheric waves on Venus

    Hinson, David P.; Jenkins, J. M.

    1995-01-01

    Radio occultation experiments were conducted at Venus on three consecutive orbits of the Magellan spacecraft in October 1991. Each occultation occurred over the same topography (67 deg N, 127 deg E) and at the same local time (22 hr 5 min), but the data are sensitive to zonal variations because the atmosphere rotates significantly during one orbit. Through comparisons between observations and predictions of standard wave theory, we have demonstrated that small-scale oscillations in retrieved temperature profiles as well as scintillations in received signal intensity are caused by a spectrum of vertically propagating internal gravity waves. There is a strong similarity between the intensity scintillations observed here and previous measurements, which pertain to a wide range of locations and experiment dates. This implies that the same basic phenomenon underlies all the observations and hence that gravity waves are a persistent, global feature of Venus' atmosphere. We obtained a fairly complete characterization of a gravity wave that appears above the middle cloud in temperature measurements on all three orbits. The amplitude and vertical wavelength are about 4 K and 2.5 km respectively, at 65 km. A model for radiative damping implies that the wave intrinsic frequency is approximately 2 x 10(exp 4) rad/sec, the corresponding ratio between horizontal and vertical wavelengths is approximately 100. The wave is nearly stationary relative to the surface or the Sun. Radiative attenuation limits the wave amplitude at altitudes above approximately 65 km, leading to wave drag on the mean zonal winds of about +0.4 m/sec per day (eastward). The sign, magnitude, and location of this forcing suggest a possible role in explaining the decrease with height in the zonal wind speed that is believed to occur above the cloud tops. Temperature oscillations with larger vertical wavelengths (5-10 km) were also observed on all three orbits, but we are able unable to interpret these

  3. Fecal Occult Blood Test (FOBT): MedlinePlus Lab Test Information

    ... caused by a variety of conditions, including: Polyps Hemorrhoids Diverticulosis Ulcers Colitis , a type of inflammatory bowel ... on a fecal occult blood test include ulcers, hemorrhoids, polyps, and benign tumors. If your test results ...

  4. Observations of Hot-Jupiter occultations combining Spitzer and Kepler photometry

    Knutson H.

    2011-02-01

    Full Text Available We present the status of an ongoing program which aim at measuring occultations by their parent stars of transiting hot giant exoplanets discovered recently by Kepler. The observations are obtained in the near infrared with WarmSpitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of measuring the mid-occultation times and the relative occultation depths in each band-passes. Our measurements of occultations depths in the Kepler bandpass is turned into the determination of the optical geometric albedo Ag in this wavelength domain. The brightness temperatures of these planets are deduced from the infrared observations. We combine the optical and near infrared planetary emergent fluxes to obtain broad band emergent spectra of individual planet. We finally compare these spectra to hot Jupiter atmospheric models in order broadly distinguishing these atmospheres between different classes of models.

  5. Parapsychology on the couch: the psychology of occult belief in Germany, c. 1870-1939.

    Wolffram, Heather

    2006-01-01

    This article considers the attempts of academic psychologists and critical occultists in Germany during the late nineteenth and early twentieth centuries to construct a psychology of occult belief. While they claimed that the purpose of this new subdiscipline was to help evaluate the work of occult researchers, the emergence of a psychology of occult belief in Germany served primarily to pathologize parapsychology and its practitioners. Not to be outdone, however, parapsychologists argued that their adversaries suffered from a morbid inability to accept the reality of the paranormal. Unable to resolve through experimental means the dispute over who should be allowed to mold the public's understanding of the occult, both sides resorted to defaming their opponent. (c) 2006 Wiley Periodicals, Inc.

  6. Metastatic Squamous Neck Cancer with Occult Primary Treatment (PDQ®)—Health Professional Version

    Metastatic squamous neck cancer with occult primary treatment options include surgery, radiation therapy or a combination of both. Get detailed information about newly diagnosed or recurrent metastatic squamous neck cancer in this summary for clinicians.

  7. Metastatic Squamous Neck Cancer with Occult Primary Treatment (PDQ®)—Patient Version

    Metastatic squamous neck cancer with occult primary (unknown primary) treatment options include surgery, radiation therapy, or a combination of both. Learn more about the diagnosis and treatment of these tumors in this expert-reviewed summary.

  8. Low-Cost Small Satellite Atmospheric Rotating Solar Occultation Imager (ROI)

    National Aeronautics and Space Administration — Utilizing a unique, new occultation technique involving imaging, the ROI concept will meet or exceed the quality of SAGE measurements at a small fraction of the...

  9. Prevalence of Visible and Occult Blood on the Surfaces of Fiberoptic Bronchoscopes

    McKamey, Jeffrey

    2000-01-01

    .... This study was conducted to determine if current cleaning, disinfection and sterilization procedures used at one medical center was adequate to remove visible and occult blood from fiberoptic bronchoscopes...

  10. Detection of an occult transclival cerebrospinal fluid fistula by CT and MRI

    Schick, B.; Brors, D.; Draf, W.; Goedecke, A.; Prescher, A.

    1998-01-01

    We describe an unusual occult transclival cerebrospinal fluid (CSF) fistula to the sphenoid sinus demonstrated by MRI. CT was performed because of a posterior cerebral infarct caused by cardiac arrhythmia. Axial sections showed fluid in the sphenoid sinus. High-resolution scans revealed a bony defect 3 mm in diameter of the posterior wall of the sphenoid sinus, and MRI showed a transclival CSF fistula. This occult lesion was confirmed by surgery and duraplasty was successfully performed via an endonasal approach. (orig.)

  11. A prospective evaluation of occult disorders in obstructed defecation using the 'iceberg diagram'.

    Pescatori, M; Spyrou, M; Pulvirenti d'Urso, A

    2007-06-01

    Surgical treatment of constipation and obstructed defecation (OD) carries frequent recurrences, as OD is an 'iceberg syndrome' characterized by 'underwater rocks' or occult diseases which may affect the outcome of surgery. The aim of this study was to evaluate occult disorders, in order to alert the clinician of these and minimize failures. One hundred consecutive constipated patients with OD symptoms, 81 women, median age 52 years, underwent perineal examination, proctoscopy, anorectal manometry and anal/vaginal ultrasound (US). Anorectal physiology and imaging tests were also carried out when indicated, as well as psychological and urogynaecological consultations. Symptoms were graded using a modified 1-20 constipation score. Both evident (e.g. rectocele) and occult (e.g. anismus) diseases were prospectively evaluated using a novel 'iceberg diagram'. The type of treatment, whether conservative or surgical, was also recorded. Fifty-four (54%) patients had both mucosal prolapse and rectocele. All patients had at least two occult OD-related diseases, 66 patients had at least three of them: anxiety-depression, anismus and rectal hyposensation were the most frequent (66%, 44% and 33%, respectively). The median constipation score was 11 (range 2-20), the median number of 'occult disorders' was 5 (range 2-8). Conservative treatment was carried out in most cases. Surgery was carried out in 14 (14%) patients. The novel 'iceberg diagram' allowed the adequate evaluation of OD-related occult diseases and better selection of patients for treatment. Most were managed conservatively, and only a minority were treated by surgery.

  12. Scaled model guidelines for solar coronagraphs' external occulters with an optimized shape.

    Landini, Federico; Baccani, Cristian; Schweitzer, Hagen; Asoubar, Daniel; Romoli, Marco; Taccola, Matteo; Focardi, Mauro; Pancrazzi, Maurizio; Fineschi, Silvano

    2017-12-01

    One of the major challenges faced by externally occulted solar coronagraphs is the suppression of the light diffracted by the occulter edge. It is a contribution to the stray light that overwhelms the coronal signal on the focal plane and must be reduced by modifying the geometrical shape of the occulter. There is a rich literature, mostly experimental, on the appropriate choice of the most suitable shape. The problem arises when huge coronagraphs, such as those in formation flight, shall be tested in a laboratory. A recent contribution [Opt. Lett.41, 757 (2016)OPLEDP0146-959210.1364/OL.41.000757] provides the guidelines for scaling the geometry and replicate in the laboratory the flight diffraction pattern as produced by the whole solar disk and a flight occulter but leaves the conclusion on the occulter scale law somehow unjustified. This paper provides the numerical support for validating that conclusion and presents the first-ever simulation of the diffraction behind an occulter with an optimized shape along the optical axis with the solar disk as a source. This paper, together with Opt. Lett.41, 757 (2016)OPLEDP0146-959210.1364/OL.41.000757, aims at constituting a complete guide for scaling the coronagraphs' geometry.

  13. Early detection of Haemonchus contortus infection in sheep using ...

    Haemonchus contortus is a blood-sucking parasite causing the presence of faecal occult blood (FOB). The objective was to study three different FOB tests in order to have a new indicator of H. contortus infection in sheep that could be included in the genetic evaluation system as an alternative selection criterion to faecal ...

  14. Extent and kinetics of recovery of occult spinal cord injury

    Ang, K. Kian; Jiang, G.-L.; Feng Yan; Stephens, L. Clifton; Tucker, Susan L.; Price, Roger E.

    2001-01-01

    Purpose: To obtain clinically useful quantitative data on the extent and kinetics of recovery of occult radiation injury in primate spinal cord, after a commonly administered elective radiation dose of 44 Gy, given in about 2 Gy per fraction. Methods and Materials: A group of 56 rhesus monkeys was assigned to receive two radiation courses to the cervical and upper thoracic spinal cord, given in 2.2 Gy per fraction. The dose of the initial course was 44 Gy in all monkeys. Reirradiation dose was 57.2 Gy, given after 1-year (n 16) or 2-year (n = 20) intervals, or 66 Gy, given after 2-year (n = 4) or 3-year (n = 14) intervals. Two animals developed intramedullary tumors before reirradiation and, therefore, did not receive a second course. The study endpoint was myeloparesis, manifesting predominantly as lower extremity weakness and decrease in balance, occurring within 2.5 years after reirradiation, complemented by histologic examination of the spinal cord. The data obtained were analyzed along with data from a previous study addressing single-course tolerance, and data from a preliminary study of reirradiation tolerance. Results: Only 4 of 45 monkeys completing the required observation period (2-2.5 years after reirradiation, 3-5.5 years total) developed myeloparesis. The data revealed a substantial recovery of occult injury induced by 44 Gy within the first year, and suggested additional recovery between 1 and 3 years. Fitting the data with a model, assuming that all (single course and reirradiation) dose-response curves were parallel, yielded recovery estimates of 33.6 Gy (76%), 37.6 Gy (85%), and 44.6 Gy (101%) of the initial dose, after 1, 2, and 3 years, respectively, at the 5% incidence (D 5 ) level. The most conservative estimate, using a model in which it was assumed that there was no recovery between 1 and 3 years following initial irradiation and that the combined reirradiation curve was not necessarily parallel to the single-course curve, still showed an

  15. Differential gene expression analysis of in vitro duck hepatitis B virus infected primary duck hepatocyte cultures

    Issac Aneesh

    2011-07-01

    Full Text Available Abstract Background The human hepatitis B virus (HBV, a member of the hepadna viridae, causes acute or chronic hepatitis B, and hepatocellular carcinoma (HCC. The duck hepatitis B virus (DHBV infection, a dependable and reproducible model for hepadna viral studies, does not result in HCC unlike chronic HBV infection. Information on differential gene expression in DHBV infection might help to compare corresponding changes during HBV infection, and to delineate the reasons for this difference. Findings A subtractive hybridization cDNA library screening of in vitro DHBV infected, cultured primary duck hepatocytes (PDH identified cDNAs of 42 up-regulated and 36 down-regulated genes coding for proteins associated with signal transduction, cellular respiration, transcription, translation, ubiquitin/proteasome pathway, apoptosis, and membrane and cytoskeletal organization. Those coding for both novel as well as previously reported proteins in HBV/DHBV infection were present in the library. An inverse modulation of the cDNAs of ten proteins, reported to play role in human HCC, such as that of Y-box binding protein1, Platelet-activating factor acetylhydrolase isoform 1B, ribosomal protein L35a, Ferritin, α-enolase, Acid α-glucosidase and Caspase 3, copper-zinc superoxide dismutase (CuZnSOD, Filamin and Pyruvate dehydrogenase, was also observed in this in vitro study. Conclusions The present study identified cDNAs of a number of genes that are differentially modulated in in vitro DHBV infection of primary duck hepatocytes. Further correlation of this differential gene expression in in vivo infection models would be valuable to understand the little known aspects of the hepadnavirus biology.

  16. Detection of Occult Erythrocytic Membrane Damages upon Pharmacological Exposures

    P. Yu. Alekseyeva

    2007-01-01

    Full Text Available Blood administration of pharmaceuticals may cause occult effects of these agents on erythrocytic membranes. These effects may damage and cause additional membrane defects, but may strengthen. The type and degree of the effects of an agent were detected by calibrated irreversible electroporation with a pulsed electric field (PEF. The paper considers the erythrocytic membranous effects of a wide concentration range of agents used in anesthesiology, such as esmerone, tracrium, and mar-caine-adrenaline. Under the action of PEF and esmerone at the normal concentration N, the rate of erythrocytic hemolysis increased by several times as compared with the control. The similar effect also occurred when esmerone was added at the concentration C=10N. Tracrium exerted a fixing effect on erythrocytic membranes. Upon a combined exposure to PEF and tracrium in the normal concentration C=N; erythrocytic hemolysis was slow. So was with the concentration C=10N. The rate of hemolysis of the red blood cells subjected to a combined action of marcaine adrenaline at the normal concentration C=N and even at the concentration C=10N and PEF was comparable with the hemolytic rate of the reference suspension. 

  17. Exploring atmospheric blocking with GPS radio occultation observations

    L. Brunner

    2016-04-01

    Full Text Available Atmospheric blocking has been closely investigated in recent years due to its impact on weather and climate, such as heat waves, droughts, and flooding. We use, for the first time, satellite-based observations from Global Positioning System (GPS radio occultation (RO and explore their ability to resolve blocking in order to potentially open up new avenues complementing models and reanalyses. RO delivers globally available and vertically highly resolved profiles of atmospheric variables such as temperature and geopotential height (GPH. Applying a standard blocking detection algorithm, we find that RO data robustly capture blocking as demonstrated for two well-known blocking events over Russia in summer 2010 and over Greenland in late winter 2013. During blocking episodes, vertically resolved GPH gradients show a distinct anomalous behavior compared to climatological conditions up to 300 hPa and sometimes even further up into the tropopause. The accompanying increase in GPH of up to 300 m in the upper troposphere yields a pronounced tropopause height increase. Corresponding temperatures rise up to 10 K in the middle and lower troposphere. These results demonstrate the feasibility and potential of RO to detect and resolve blocking and in particular to explore the vertical structure of the atmosphere during blocking episodes. This new observation-based view is available globally at the same quality so that blocking in the Southern Hemisphere can also be studied with the same reliability as in the Northern Hemisphere.

  18. Occult radiological effects of lipomatosis of the lumbosacral plexus

    Mahan, Mark A. [Barrow Neurological Institute, Phoenix, AZ (United States); Howe, B.M.; Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Spinner, Robert J. [Mayo Clinic, Department of Neurosurgery, Rochester, MN (United States); Mayo Clinic, Department of Orthopedics, Rochester, MN (United States); Mayo Clinic, Rochester, MN (United States)

    2014-07-15

    Lipomatosis of nerve (LN) is a condition of massive peripheral nerve enlargement frequently associated with hypertrophy within the distribution of the nerve, and most commonly affecting the distal limbs. We sought to understand if LN of the lumbosacral plexus would be associated with the trophic effects of LN on surrounding tissue within the pelvis, which may be clinically occult, but present on MRI. Fifty-one cases of LN, confirmed by pathology or pathognomonic appearance on MRI, were reviewed. Patients with LN of the sciatic nerve were investigated for radiological signs suggestive of overgrowth. Five patients had involvement of the sciatic nerve, 4 of whom had MR imaging of the pelvis. Three patients had LN involving the lumbosacral plexus, and one patient had isolated involvement of the sciatic nerve. All patients with involvement of the lumbosacral plexus demonstrated previously unrecognized evidence of nerve territory overgrowth in the pelvis, including: LN, profound adipose proliferation, muscle atrophy and fatty infiltration, and bone hypertrophy and ankylosis. The patient with LN involving the intrapelvic sciatic nerve, but not the lumbosacral plexus did not demonstrate any radiological evidence of pelvic overgrowth. LN is broader in anatomical reach than previously understood. Proximal plexal innervation may be involved, with a consequent effect on axial skeleton and intrapelvic structures. (orig.)

  19. Cassini-VIMS at Jupiter: Solar occultation measurements using Io

    Formisano, V.; D'Aversa, E.; Bellucci, G.; Baines, K.H.; Bibring, J.-P.; Brown, R.H.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2003-01-01

    We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a "miffor" for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing tecnique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. ?? 2003 Elsevier Inc. All rights reserved.

  20. Ectoparasites of the occult bat, Myotis occultus (Chiroptera: Vespertilionidae)

    Valdez, Ernest W.; Ritzi, Christopher M.; Whitaker, John O.

    2009-01-01

    Only a single previous study has examined ectoparasites of the occult bat (Myotis occultus), from which only 2 species of fleas were identified. For our study, we examined 202 individuals, 52 fresh hosts and 150 museum specimens, from New Mexico and southern Colorado for ectoparasites. We recorded 2158 ectoparasites, 634 from fresh hosts and 1524 from museum specimens. Ectoparasites belonged to 10 families and 13 genera of insect or acari and represent new host and locality records. In general, ectoparasites collected from fresh hosts and museum specimens were represented by 4 major species of mite: Macronyssus crosbyi, Alabidocarpus calcaratus, Acanthophthirius lucifugus, and Alabidocarpus nr. eptesicus. From our study, we found fresh hosts to have significantly greater prevalence values for Myodopsylla gentilis (flea), Chiroptonyssus robustipes (mite), and Leptotrombidium myotis (chigger), whereas museum specimens had significantly greater prevalence values for A. calcaratus(mite) and A. nr. eptesicus (mite). There were no significant differences between prevalence values for 4 mites including M. crosbyi, A. lucifugus, Pteracarus nr. minutus, and Cryptonyssussp. Our study represents the only extensive study of ectoparasites on M. occultus and provides evidence for the importance of examining fresh hosts and museum specimens in future ectoparasite studies.

  1. MRI of occult sacral insufficiency fractures following radiotherapy

    Mammone, J.F.; Schweitzer, M.E.

    1995-01-01

    Following radiation therapy, marrow abnormalities noted on magnetic resonance imaging (MRI) are frequent and may mimic metastases. Specific radiotherapy changes are usually easily identifiable; however, traumatic lesions cause more interpretive difficulties. We assessed the incidence and MRI characteristics of insufficiency fractures in this population. During a 5-year span (1987-1991), 546 patients received pelvic radiotherapy for primary malignancies. MRI was performed in 25 of these patients at least 3 months after treatment. The mean dose in this group was 53 Gy. These MRI scans were retrospectively reviewed for the appearance of the sacrum with particular attention to the presence of insufficiency fractures. This was correlated with clinical course and scintigraphic findings. Presumed insufficiency fractures on MRI paralleled the sacral side of the sacroiliac joint, enhanced with Gd-DTPA, were most prominent or initially seen anteriorly, and had ill-defined margins on all imaging sequences. The incidence of occult sacral insufficiency fractures was at least 20%. Insufficiency fractures of the sacrum in the post-radiotherapy patient are a relatively frequent occurrence which can mimic metastases. Consideration of this phenomenon and knowledge of differential features may avoid overdiagnosis of osseous metastases. (orig.)

  2. Atmospheric diurnal variations observed with GPS radio occultation soundings

    F. Xie

    2010-07-01

    Full Text Available The diurnal variation, driven by solar forcing, is a fundamental mode in the Earth's weather and climate system. Radio occultation (RO measurements from the six COSMIC satellites (Constellation Observing System for Meteorology, Ionosphere and Climate provide nearly uniform global coverage with high vertical resolution, all-weather and diurnal sampling capability. This paper analyzes the diurnal variations of temperature and refractivity from three-year (2007–2009 COSMIC RO measurements in the troposphere and stratosphere between 30° S and 30° N. The RO observations reveal both propagating and trapped vertical structures of diurnal variations, including transition regions near the tropopause where data with high vertical resolution are critical. In the tropics the diurnal amplitude in refractivity shows the minimum around 14 km and increases to a local maximum around 32 km in the stratosphere. The upward propagating component of the migrating diurnal tides in the tropics is clearly captured by the GPS RO measurements, which show a downward progression in phase from stratopause to the upper troposphere with a vertical wavelength of about 25 km. At ~32 km the seasonal variation of the tidal amplitude maximizes at the opposite side of the equator relative to the solar forcing. The vertical structure of tidal amplitude shows strong seasonal variations and becomes asymmetric along the equator and tilted toward the summer hemisphere in the solstice months. Such asymmetry becomes less prominent in equinox months.

  3. Assimilation of GNSS radio occultation observations in GRAPES

    Liu, Y.; Xue, J.

    2014-07-01

    This paper reviews the development of the global navigation satellite system (GNSS) radio occultation (RO) observations assimilation in the Global/Regional Assimilation and PrEdiction System (GRAPES) of China Meteorological Administration, including the choice of data to assimilate, the data quality control, the observation operator, the tuning of observation error, and the results of the observation impact experiments. The results indicate that RO data have a significantly positive effect on analysis and forecast at all ranges in GRAPES not only in the Southern Hemisphere where conventional observations are lacking but also in the Northern Hemisphere where data are rich. It is noted that a relatively simple assimilation and forecast system in which only the conventional and RO observation are assimilated still has analysis and forecast skill even after nine months integration, and the analysis difference between both hemispheres is gradually reduced with height when compared with NCEP (National Centers for Enviromental Prediction) analysis. Finally, as a result of the new onboard payload of the Chinese FengYun-3 (FY-3) satellites, the research status of the RO of FY-3 satellites is also presented.

  4. Information content in reflected signals during GPS Radio Occultation observations

    Aparicio, Josep M.; Cardellach, Estel; Rodríguez, Hilda

    2018-04-01

    The possibility of extracting useful information about the state of the lower troposphere from the surface reflections that are often detected during GPS radio occultations (GPSRO) is explored. The clarity of the reflection is quantified, and can be related to properties of the surface and the low troposphere. The reflected signal is often clear enough to show good phase coherence, and can be tracked and processed as an extension of direct non-reflected GPSRO atmospheric profiles. A profile of bending angle vs. impact parameter can be obtained for these reflected signals, characterized by impact parameters that are below the apparent horizon, and that is a continuation at low altitude of the standard non-reflected bending angle profile. If there were no reflection, these would correspond to tangent altitudes below the local surface, and in particular below the local mean sea level. A forward operator is presented, for the evaluation of the bending angle of reflected GPSRO signals, given atmospheric properties as described by a numerical weather prediction system. The operator is an extension, at lower impact parameters, of standard bending angle operators, and reproduces both the direct and reflected sections of the measured profile. It can be applied to the assimilation of the reflected section of the profile as supplementary data to the direct section. Although the principle is also applicable over land, this paper is focused on ocean cases, where the topographic height of the reflecting surface, the sea level, is better known a priori.

  5. SOLAR OCCULTATION BY TITAN MEASURED BY CASSINI/UVIS

    Capalbo, Fernando J.; Benilan, Yves [Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), UMR 7583 du CNRS, Universites Paris Est Creteil (UPEC) and Paris Diderot - UPD, 61 avenue du General de Gaulle, 94010 Creteil Cedex (France); Yelle, Roger V.; Koskinen, Tommi T.; Sandel, Bill R. [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States); Holsclaw, Gregory M.; McClintock, William E., E-mail: fernando.capalbo@lisa.u-pec.fr [Laboratory for Atmospheric and Space Physics, University of Colorado, 3665 Discovery Drive, Boulder, CO 80303 (United States)

    2013-04-01

    We present the first published analysis of a solar occultation by Titan's atmosphere measured by the Ultraviolet Imaging Spectrograph on board Cassini. The data were measured during flyby T53 in 2009 April and correspond to latitudes between 21 Degree-Sign and 28 Degree-Sign south. The analysis utilizes the absorption of two solar emission lines (584 A and 630 A) in the ionization continuum of the N{sub 2} absorption cross section and solar emission lines around 1085 A where absorption is due to CH{sub 4}. The measured transmission at these wavelengths provides a direct estimate of the N{sub 2} and CH{sub 4} column densities along the line of sight from the spacecraft to the Sun, which we inverted to obtain the number densities. The high signal-to-noise ratio of the data allowed us to retrieve density profiles in the altitude range 1120-1400 km for nitrogen and 850-1300 km for methane. We find an N{sub 2} scale height of {approx}76 km and a temperature of {approx}153 K. Our results are in general agreement with those from previous work, although there are some differences. Particularly, our profiles agree, considering uncertainties, with the density profiles derived from the Voyager 1 Ultraviolet Spectrograph data, and with in situ measurements by the Ion Neutral Mass Spectrometer with revised calibration.

  6. The value of MR imaging of PDFASAT sequence in the diagnosis of extremities occult fractures

    Lu Lingquan; Xu Mingshen; Wu Qianzhi; Mao Chunnan; Wang Shuzi; Zhou Xingfan; Wang Liping

    2004-01-01

    Objective: To investigate the value of MR imaging of proton density weighted-fat saturated (PDFASAT) sequence in detecting the occult fracture of extremities. Methods: Thirty-one patients with acute trauma were studied using radiography and MR imaging within 45 days. MR sequences included FSE T 1 WI, T 2 WI, and PDFASAT. 21 occult fractures occurred in the knee joint, 6 in the hip joint, 1 in the elbow joint, 2 in the shoulder, and 1 in the ankle. Results: All 31 cases had normal radiographic results. 10 cases with proximal fibula, 4 with proximal tibia and 7 with femur condyle occult fractures were found in 21 knee joint acute trauma cases. 2 cases with intertrochanteric, 2 with femoral neck and 2 with cotyle occult fractures were found in 6 hip joint trauma cases. 2 proximal humerus occult fractures were found in 2 shoulder cases. 1 distal humerus and 1 distal fibula occult fracture was found in elbow and ankle cases. MR imaging demonstrated irregular linear low signal in the subcortical region on both T 1 WI and T 2 WI, and high signal changes around low signal were seen on T 2 WI in some cases. The high signal in PDFASAT sequence was more remarkable and wider than that on both T 1 WI and T 2 WI. Conclusion: MR imaging could determine the diagnosis of acute and chronic occult fractures. MRI should be the next choice when plain films fail to reveal suspected fractures in setting of suggestive symptoms and positive physical examination. PDFASAT would be the best effective sequence among the T 1 WI, T 2 WI, and PDFASAT. (author)

  7. Occult Amebic Liver Abscess as Cause of Extensive Inferior Vena Cava and Hepatic Vein Thrombosis.

    Martin, Leslie; Burute, Nishigandha; Haider, Ehsan; Serrano, Pablo E; O'Shea, Timothy; Siegal, Deborah

    2017-10-01

    The most common extraintestinal complication of Entamoeba histolytica is amebic liver abscess (ALA). Hepatic vein and inferior vena cava (IVC) thrombosis are rare but well-documented complications of ALA, typically attributed to mechanical compression and inflammation associated with a large abscess. We present a case of a previously healthy 43-year-old Canadian man presenting with constitutional symptoms and right upper quadrant abdominal pain. He was found to have thrombophlebitis of the IVC, accessory right hepatic vein, and bilateral iliac veins. Extensive investigations for thrombophilia were negative. Magnetic resonance imaging of the liver demonstrated a 3.2-cm focal area of parenchymal abnormality that was reported as presumptive hepatocellular carcinoma, and a 1.9-cm lesion in the caudate lobe with diffusion restriction and peripheral rim enhancement. Despite multiple biopsy attempts, a histopathological diagnosis was not achieved. Abdominal pain and fever 4 months later prompted repeat ultrasound demonstrating a 10.4- × 12.0-cm rim-enhancing fluid attenuation lesion felt to represent a liver abscess. Thick dark "chocolate brown" drainage from the lesion and positive serology for E. histolytica confirmed the diagnosis of ALA acquired from a previous trip to Cuba. The patient was started on treatment with metronidazole and paromomycin and repeat abdominal ultrasound demonstrated resolution of the abscess. This case is the first to demonstrate extensive IVC thrombosis secondary to a relatively small occult ALA and emphasizes the thrombogenic potential of ALA. Amebic infection should be considered as a rare cause of IVC thrombosis in the correct clinical context.

  8. Recurring sets of recurring starspot occultations on exoplanet host Qatar-2

    Močnik, T.; Southworth, J.; Hellier, C.

    2017-10-01

    We announce the detection of recurring sets of recurring starspot occultation events in the short-cadence K2 light curve of Qatar-2, a K dwarf star transited every 1.34 d by a hot Jupiter. In total, we detect 34 individual starspot occultation events, caused by five different starspots, occulted in up to five consecutive transits or after a full stellar rotation. The longest recurring set of recurring starspot occultations spans over three stellar rotations, setting a lower limit for the longest starspot lifetime of 58 d. Starspot analysis provided a robust stellar rotational period measurement of 18.0 ± 0.2 d and indicates that the system is aligned, having a sky-projected obliquity of 0° ± 8°. A pronounced rotational modulation in the light curve has a period of 18.2 ± 1.6 d, in agreement with the rotational period derived from the starspot occultations. We tentatively detect an ellipsoidal modulation in the phase curve, with a semi-amplitude of 18 ppm, but cannot exclude the possibility that this is the result of red noise or imperfect removal of the rotational modulation. We detect no transit-timing and transit-duration variations with upper limits of 15 s and 1 min, respectively. We also reject any additional transiting planets with transit depths above 280 ppm in the orbital period region 0.5-30 d.

  9. Retrieval of Electron Density Profile for KOMPSAT-5 GPS Radio Occultation

    Woo-Kyoung Lee

    2007-12-01

    Full Text Available The AOPOD (Atmosphere Occultation and Precision Orbit Determination system, the secondary payload of KOMPSAT (KOrea Multi-Purpose SATellite-5 scheduled to be launched in 2010, shall provide GPS radio occultation data. In this paper, we simulated the GPS radio occultation characteristic of KOMPSAT-5 and retrieved electron density profiles using KROPS (KASI Radio Occultation Processing Software. The electron density retrieved from CHAMP (CHAllenging Minisatellite Payload GPS radio occultation data on June 20, 2004 was compared with IRI (International Reference Ionosphere - 2001, PLP (Planar Langmuir Probe, and ionosonde measurements. When the result was compared with ionosonde measurements, the discrepancies were 5 km on the F_2 peak height (hmF_2 and 3×10^{10} el/m^3 on the electron density of the F_2 peak height (NmF_2. By comparing with the Langmuir Probe measurements of CHAMP satellite (PLP, both agrees with 1.6×10^{11} el/m^3 at the height of 365.6 km.

  10. [Surgical Diagnosis and Treatment of Primary Hyperthyroidism Complicated with Occult Thyroid Carcinoma].

    Wu, Xin; Yu, Jian-chun; Kang, Wei-ming; Ma, Zhi-qiang; Ye, Xin

    2015-08-01

    To evaluate the surgical diagnosis and treatment of primary hyperthyroidism complicated with occult thyroid carcinoma. Data of 51 cases of primary hyperthyroidism complicated with occult thyroid carcinoma admitted during January 2004 to November 2014 were analyzed retrospectively. The incidence of occult thyroid carcinoma was 5.03% in hyperthyroidism,and 47 cases (92.16%) were female. The preoperative diagnosis of all these 51 cases was primary hyperthyroidism and 11 cases were diagnosed thyroid carcinoma at the same time;25 cases were diagnosed thyroid carcinoma by frozen section and the remaining 26 cases were diagnosed by postoperative pathology. Finally,26 cases underwent subtotal thyroidectomy,4 cases underwent total thyroidectomy, and 21 cases underwent total thyroidectomy with lymphadenectomy. The tumor size ranged from 0.1 to 1.0 cm [mean:(0.63 ± 0.35) cm]. The lesions were less than or equal to 0.5 cm in 28 cases (54.9%). The follow-up lasted from 1 to 121 months [mean:(28.6 ± 22.7)months] in 43 patients,and all of them survived. Primary hyperthyroidism complicated with occult thyroid carcinoma is commonly found in female patients. Preoperative diagnosis is difficult. Ultrasound is the major examining method. Frozen section can increase the detection rate. The postoperative prognosis of hyperthyroidism complicated with occult thyroid carcinoma is satisfactory.

  11. Outcome of Concurrent Occult Hemothorax and Pneumothorax in Trauma Patients Who Required Assisted Ventilation

    Ismail Mahmood

    2015-01-01

    Full Text Available Background. The management and outcomes of occult hemopneumothorax in blunt trauma patients who required mechanical ventilation are not well studied. We aimed to study patients with occult hemopneumothorax on mechanical ventilation who could be carefully managed without tube thoracostomy. Methods. Chest trauma patients with occult hemopneumothorax who were on mechanical ventilation were prospectively evaluated. The presence of hemopneumothorax was confirmed by CT scanning. Hospital length of stay, complications, and outcome were recorded. Results. A total of 56 chest trauma patients with occult hemopneumothorax who were on ventilatory support were included with a mean age of 36 ± 13 years. Hemopneumothorax was managed conservatively in 72% cases and 28% underwent tube thoracostomy as indicated. 29% of patients developed pneumonia, 16% had Acute Respiratory Distress Syndrome (ARDS, and 7% died. Thickness of hemothorax, duration of mechanical ventilation, and development of ARDS were significantly associated with tube thoracostomy in comparison to no-chest tube group. Conclusions. The majority of occult hemopneumothorax can be carefully managed without tube thoracostomy in patients who required positive pressure ventilation. Tube thoracotomy could be restricted to those who had evidence of increase in the size of the hemothorax or pneumothorax on follow-up chest radiographs or developed respiratory compromise.

  12. Disparities in the receipt of fecal occult blood test versus endoscopy among Filipino American immigrants.

    Maxwell, Annette E; Danao, Leda L; Crespi, Catherine M; Antonio, Cynthia; Garcia, Gabriel M; Bastani, Roshan

    2008-08-01

    This report examines disparities associated with the type of colorectal screening test, fecal occult blood test versus endoscopy, within a particular racial/ethnic group, Filipino American immigrants. Between July 2005 and October 2006, Filipino Americans aged 50 to 75 years from 31 community organizations in Los Angeles completed a 15-minute survey in English (65%) or Filipino (35%). Of the 487 respondents included in this analysis, 257 (53%) had never received any type of colorectal cancer screening. Among the 230 subjects who had ever received a routine screening test, 78 had fecal occult blood test only (16% of the total sample), and 152 had endoscopy with or without fecal occult blood test (31% of the total sample). After controlling for access to care and key demographic variables in a multivariate analysis, only two characteristics distinguished between respondents who had fecal occult blood test only versus those who had endoscopy: acculturation, assessed by percent lifetime in the United States and language of interview, and income. Our data suggest a two-tier system, fecal occult blood test for less acculturated Filipino Americans with lower income versus endoscopy for Filipino immigrants with higher levels of acculturation and income. The disparity persists after adjusting for access to care. Instead of treating minority groups as monolithic, differences within groups need to be examined so that interventions can be appropriately targeted.

  13. Optimization of the occulter for the Solar Orbiter/METIS coronagraph

    Landini, Federico; Vivès, Sébastien; Romoli, Marco; Guillon, Christophe; Pancrazzi, Maurizio; Escolle, Clement; Focardi, Mauro; Antonucci, Ester; Fineschi, Silvano; Naletto, Giampiero; Nicolini, Gianalfredo; Nicolosi, Piergiorgio; Spadaro, Daniele

    2012-09-01

    METIS (Multi Element Telescope for Imaging and Spectroscopy investigation), selected to fly aboard the Solar Orbiter ESA/NASA mission, is conceived to perform imaging (in visible, UV and EUV) and spectroscopy (in EUV) of the solar corona, by means of an integrated instrument suite located on a single optical bench and sharing the same aperture on the satellite heat shield. As every coronagraph, METIS is highly demanding in terms of stray light suppression. Coronagraphs history teaches that a particular attention must be dedicated to the occulter optimization. The METIS occulting system is of particular interest due to its innovative concept. In order to meet the strict thermal requirements of Solar Orbiter, METIS optical design has been optimized by moving the entrance pupil at the level of the external occulter on the S/C thermal shield, thus reducing the size of the external aperture. The scheme is based on an inverted external-occulter (IEO). The IEO consists of a circular aperture on the Solar Orbiter thermal shield. A spherical mirror rejects back the disk-light through the IEO. A breadboard of the occulting assembly (BOA) has been manufactured in order to perform stray light tests in front of two solar simulators (in Marseille, France and in Torino, Italy). A first measurement campaign has been carried on at the Laboratoire d'Astrophysique de Marseille. In this paper we describe the BOA design, the laboratory set-up and the preliminary results.

  14. Anti-hepatitis B core antigen testing with detection and characterization of occult hepatitis B virus by an in-house nucleic acid testing among blood donors in Behrampur, Ganjam, Orissa in southeastern India: implications for transfusion

    Panigrahi Rajesh

    2010-08-01

    Full Text Available Abstract Background Occult hepatitis B virus (HBV infection might transmit viremic units into the public blood supply if only hepatitis B surface antigen (HBsAg testing is used for donor screening. Our aim was to evaluate the prevalence of occult HBV infection among the HBsAg negative/antiHBc positive donations from a highly HIV prevalent region of India. Methods A total of 729 HBsAg negative donor units were included in this study. Surface gene and precore region were amplified by in house nucleic acid test (NAT for detection of occult HBV infection and surface gene was analyzed after direct sequencing. Results A total of 220 (30.1% HBsAg negative donors were antiHBc positive, of them 66 (30% were HBV DNA positive by NAT. HBV DNA positivity among 164 antiHBc only group, was 27.1% and among 40 antiHBs positive group was 30.0%. HBV/D (93.3% was predominant and prevalence of both HBV/C and HBV/A was 3.3%. Single or multiple amino acids substitutions were found in 95% samples. Conclusion Thus, a considerable number of HBV infected donors remain undiagnosed, if only HBsAg is used for screening. Addition of antiHBc testing for donor screening, although will lead to rejection of a large number of donor units, will definitely eliminate HBV infected donations and help in reducing HBV transmission with its potential consequences, especially among the immunocompromised population. The HBV genetic diversity found in this donor population are in accordance with other parts of India.

  15. Anti-hepatitis B core antigen testing with detection and characterization of occult hepatitis B virus by an in-house nucleic acid testing among blood donors in Behrampur, Ganjam, Orissa in southeastern India: implications for transfusion.

    Panigrahi, Rajesh; Biswas, Avik; Datta, Sibnarayan; Banerjee, Arup; Chandra, Partha K; Mahapatra, Pradip K; Patnaik, Bharat; Chakrabarti, Sekhar; Chakravarty, Runu

    2010-08-27

    Occult hepatitis B virus (HBV) infection might transmit viremic units into the public blood supply if only hepatitis B surface antigen (HBsAg) testing is used for donor screening. Our aim was to evaluate the prevalence of occult HBV infection among the HBsAg negative/antiHBc positive donations from a highly HIV prevalent region of India. A total of 729 HBsAg negative donor units were included in this study. Surface gene and precore region were amplified by in house nucleic acid test (NAT) for detection of occult HBV infection and surface gene was analyzed after direct sequencing. A total of 220 (30.1%) HBsAg negative donors were antiHBc positive, of them 66 (30%) were HBV DNA positive by NAT. HBV DNA positivity among 164 antiHBc only group, was 27.1% and among 40 antiHBs positive group was 30.0%. HBV/D (93.3%) was predominant and prevalence of both HBV/C and HBV/A was 3.3%. Single or multiple amino acids substitutions were found in 95% samples. Thus, a considerable number of HBV infected donors remain undiagnosed, if only HBsAg is used for screening. Addition of antiHBc testing for donor screening, although will lead to rejection of a large number of donor units, will definitely eliminate HBV infected donations and help in reducing HBV transmission with its potential consequences, especially among the immunocompromised population. The HBV genetic diversity found in this donor population are in accordance with other parts of India.

  16. The Return of Congenital Rickets, Are We Missing Occult Cases?

    Elidrissy, Abdelwahab T H

    2016-09-01

    Congenital rickets is the term given to fetus born with clinical features of rickets, but those born with biochemical evidence of rickets without obvious clinical features still can be considered occult congenital rickets. Some of the affected babies with this disease have the intrauterine rachitic environment, but a calcium trans-placental pump prevents the fetus from having clinical features of rickets. They may present with hypocalcemia few days after birth or later with more florid features of rickets. Congenital rickets cases born with florid features reported over the last 40 years are few and can be divided into two groups. The first due to severe maternal osteomalacia in which their bones were so decalcified to have enough calcium to be pumped to their fetus. Another group in which newborn babies were hypocalcemic due to other maternal diseases as malabsorption, celiac disease, pre-eclampsia, and prematurity. All inherited rickets cases per se, or as part of other syndromes can be considered congenital rickets. Most cases seen in our region are due to maternal vitamin D deficiency with symptoms becoming obvious when the infants are breastfed, or may present with hypocalcemic convulsions or craniotabes. This is a review of congenital rickets with the aim of shedding light on this potentially acute disease that needs more attention and awareness in the neonatal period to avoid rare serious complications as cardiomyopathy or myelofibrosis and the complications of hypocalcemic convulsions. Congenital rickets cases seen simulate a tip of an ice-burg and its prevention is an important issue, especially with the tremendous urbanization with tall buildings living in sun-deprived flats as the commonest type of residence leading to the increasing incidence of maternal osteomalacia and rickets.

  17. Clues to occult cancer in patients with ischemic stroke.

    Suk Jae Kim

    Full Text Available BACKGROUND: We hypothesized that hidden malignancy could be detected in patients with cryptogenic stroke without active cancer when they showed the distinctive characteristics of cancer-related stroke. METHODS AND FINDINGS: Among 2,562 consecutive patients with acute ischemic stroke, patients with cryptogenic stroke were analyzed and categorized into two groups according to the presence of active cancer: cryptogenic stroke with active cancer (cancer-related stroke, CA-stroke group and without active cancer (CR-stroke group. Patients with active lung cancer without stroke were also recruited for comparison purposes (CA-control. Clinical factors, lesion patterns on diffusion-weighted MRI (DWI, and laboratory findings were analyzed among groups. A total of 348 patients with cryptogenic stroke were enrolled in this study. Among them, 71 (20.4% patients had active cancer at the time of stroke. The D-dimer levels were significantly higher in patients with CA-stroke than those with CR-stroke or CA-control (both p<0.001. Regarding lesion patterns, patients with CA-stroke mostly had multiple lesions in multiple vascular territories, while more than 80% of patients with CR-stroke had single/multiple lesions in a single vascular territory (P<0.001. D-dimer levels (OR 1.11 per 1 µg/mL increase; 95% CI 1.06-1.15; P<0.001 and DWI lesion patterns (OR 7.13; 95% CI 3.42-14.87; P<0.001 were independently associated with CA-stroke. Workup for hidden malignancy was performed during hospitalization in 10 patients who showed elevated D-dimer levels and multiple infarcts involving multiple vascular territories but had no known cancer, and it revealed hidden malignancies in all the patients. CONCLUSION: Patients with CA-stroke have distinctive D-dimer levels and lesion patterns. These characteristics can serve as clues to occult cancer in patients with cryptogenic stroke.

  18. Clinical presentations and MRI findings of angiographically occult vascular malformations

    Kida, Yoshihisa; Kobayashi, Tatsuya; Tanaka, Takayuki; Oyama, Hirofumi; Iwakoshi, Takayasu

    1994-01-01

    Various clinical features as well as MRI findings of AOVM (angiographically occult vascular malformation) were studied. Amongst out patients, since January 1988, there have been 30 cases of symptomatic AOVM (20 males, 10 females) including 4 cases with multiple lesions. The age ranged from 3 to 60 years of age, with a mean of 33.4 years. The locations of symptomatic lesions were in the cerebral hemisphere (15), the thalamus (4), the brain stem (8) and in the cerebellum (3). The initial presentations of these 30 cases were either by hemorrhage (18), convulsive seizure (9) or by progressive neurological deficits (3). The initial presentation was not related to the patient's age and the size of the lesion, but apparently related to the location of AOVM. Most of the lesions in the cerebral hemisphere presented seizures, but all of the lesions in the thalamus, the brain stem and the cerebellum disclosed hemorrhage as an initial presentation. In fact it was noticed that brain stem lesions tend to cause repetitive hemorrhage in a relatively short period. AOVM lesions were clearly visualized with T2-weighted MRI images, consisting of high intensity cores with surrounding low intensity rims. Most of the symptomatic lesions were partially enhanced by Gd-DTPA with varied intensity. Dynamic changes in size and enhancement pattern on MRI were occasionally seen, usually accompanied with episodes such as hemorrhage or neurological deterioration. Although AOVMs were angiographically negative some strands indicating draining veins were observed on MRI in several cases. In contrast, none of the nonsymptomatic lesions (22 lesions) demonstrated enhancement effects with Gd-DTPA. (author)

  19. TWENTY-FIVE SUBARCSECOND BINARIES DISCOVERED BY LUNAR OCCULTATIONS

    Richichi, A. [National Astronomical Research Institute of Thailand, 191 Siriphanich Bldg., Huay Kaew Rd., Suthep, Muang, Chiang Mai 50200 (Thailand); Fors, O. [Departament Astronomia i Meteorologia and Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (UB/IEEC), Marti i Franques 1, E-08028 Barcelona (Spain); Cusano, F. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Moerchen, M., E-mail: andrea4work@gmail.com [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

    2013-09-15

    We report on 25 subarcsecond binaries, detected for the first time by means of lunar occultations in the near-infrared (near-IR) as part of a long-term program using the ISAAC instrument at the ESO Very Large Telescope. The primaries have magnitudes in the range K = 3.8-10.4, and the companions in the range K = 6.4-12.1. The magnitude differences have a median value of 2.8, with the largest being 5.4. The projected separations are in the range 6-748 mas and with a median of 18 mas, or about three times less than the diffraction limit of the telescope. Among our binary detections are a pre-main-sequence star and an enigmatic Mira-like variable previously suspected to have a companion. Additionally, we quote an accurate first-time near-IR detection of a previously known wider binary. We discuss our findings on an individual basis as far as made possible by the available literature, and we examine them from a statistical point of view. We derive a typical frequency of binarity among field stars of Almost-Equal-To 10%, in the resolution and sensitivity range afforded by the technique ( Almost-Equal-To 0.''003 to Almost-Equal-To 0.''5, and K Almost-Equal-To 12 mag, respectively). This is in line with previous results using the same technique but we point out interesting differences that we can trace up to sensitivity, time sampling, and average distance of the targets. Finally, we discuss the prospects for further follow-up studies.

  20. Occult carcinoma discovered after simple hysterectomy treated with postoperative radiotherapy

    Crane, Christopher H.; Schneider, Bernard F.

    1999-01-01

    Purpose: Treatment of patients with occult carcinoma of the cervix discovered after simple hysterectomy is controversial. The purpose of this review is to examine our results with postoperative radiotherapy and to compare them to similar reports and to reports of treatment with radical parametrectomy. Methods and Materials: Between November 1979 and April:, 18 patients were treated with radiotherapy at the University of Virginia for invasive carcinoma of the cervix discovered after simple hysterectomy. Simple hysterectomy was performed in all 18 patients for a variety of indications. After surgery gross residual carcinoma remained in four patients; and microscopic disease was present at the surgical margins in two patients. The remaining patients had no evidence of residual disease. All 18 patients had postoperative radiotherapy with or without brachytherapy. The endpoints for this study were local control, survival, and treatment-related toxicity. Actuarial rates were calculated using the Life method. Results: Median follow-up for all 18 patients was 42 months (range 2-202 months). Both the 5 and the 10-year actuarial local control rates were 88%. Five and 10-year actuarial overall survival rates were both 93%. Two patients had both local and distant cancer recurrences. There were no recurrences among the six patients treated with external beam alone. The remaining patients are all alive without evidence of disease, including two patients who had gross residual disease after surgery, and one patient with both microscopic positive margin and a positive lymph node (the only patient to undergo lymph node sampling). There was no severe acute morbidity and only one patient had severe late morbidity. Conclusions: Invasive carcinoma found after simple hysterectomy may be treated safely and effectively with postoperative radiotherapy. Patients with known residual disease following surgery do poorly with either radiotherapy or reoperation, but treatment with radiotherapy

  1. [MRI findings and pathological features of occult breast cancer].

    Zhang, J J; Yang, X T; Du, X S; Zhang, J X; Hou, L N; Niu, J L

    2018-01-23

    Objective: To investigate the magnetic resonance imaging (MRI) findings and clinicopathological features of primary lesions in patients with occult breast cancer (OBC). Methods: The imaging reports from the Breast Imaging Reporting and Data System in 2013 were retrospectively analyzed to investigate the morphology and the time signal intensity curve (TIC) of breast lesions in patients with OBC. The clinical and pathological characteristics of these patients were also included. Results: A total of 34 patients were enrolled. Among these patients, 24 patients underwent modified radical mastectomy and 18 of them had primary breast carcinoma in pathological sections. MRI detected 17 cases of primary lesions, including six masse lesions with a diameter of 0.6-1.2 cm (average 0.9 cm), and 11 non-mass lesions with four linear distributions, three segmental distributions, three focal distributions, and one regions distribution. Five patients had TIC typeⅠprimary lesions, ten had TIC type Ⅱ primary lesions, and two had TIC type Ⅲ primary lesions. Among all 34 cases, 23 of them had complete results of immunohistochemistry: 11 estrogen receptor (ER) positive lesions (47.8%), tenprogesterone receptor (PR) positive lesions (43.5%), seven human epidermal growth factor receptor 2 (HER-2) positive lesions (30.4%), and 20high expression(>14%) of Ki-67 (87.0%). The proportion of type luminal A was 4.3%, type luminal B was 43.5%, triple negative breast cancer (TNBC) was 30.4%, and HER-2 over expression accounted for 21.7%. Conclusions: The primary lesions of OBC usually manifested as small mass lesions, or focal, linear or segmental distribution of non-mass lesions. The positive rate of ER and PR was low, but the positive rate of HER-2 and the proliferation index of Ki-67 was high. Type luminal B is the most common molecular subtype.

  2. Waves in Saturn's rings probed by radio occultation

    Rosen, P.A.

    1989-01-01

    Thirty wave features, observed in 3.6 and 13 cm-wavelength optical depth profiles of Saturn's rings obtained by Voyager 1 radio occultation, are analyzed individually and comparatively. Many are the signature of spiral density waves and bending waves excited by gravitational resonances with Saturn's satellites. A new technique for locating waveform extrema, which fits a sinusoid to each half cycle of wave data, quantifies the wavelength variation across a feature. Fitting dispersion models to the derived wavelengths provides new estimates of ambient surface mass density σ in each wave region. For fourteen weak density waves in Ring A, modelling of the waveform near resonance with linear density wave theory gives independent estimates of σ, as well as reliable estimates of resonance location. Measurements of wave amplitude damping give an upper bound for ring thickness 2H, where H is the ring scale height. In the wave regions studied, Rings A, B, and C have 30 approx-lt σ approx-lt 70, σ approx-gt 65, and σ ∼ 1 g/cm 2 , respectively. Mass loading estimates from waveform modelling are 20 to 40% larger than dispersion-derived values, suggesting accumulation of mass in the wave regions. The average offset of derived wave location from theoretical resonance is about 1 km. Model waveforms of overlapping waves excited by the satellites Janus and Epimethenus agree well with observed morphologies in the linear region near resonance. In Ring C, dispersion analysis indicates that the most prominent wave feature, previously unidentified, is a one-armed spiral wave

  3. Lowest-order average effect of turbulence on atmospheric profiles derived from radio occultation

    Eshleman, V.R.; Haugstad, B.S.

    1977-01-01

    Turbulence in planetary atmospheres and ionospheres causes changes in angles of refraction of radio waves used in occultation experiments. Atmospheric temperature and pressure profiles, and ionospheric electron concentration profiles, derived from radio occultation measurements of Doppler frequency contain errors due to such angular offsets. The lowest-order average errors are derived from a geometrical-optics treatment of the radio-wave phase advance caused by the addition of uniform turbulence to an initially homogeneous medium. It is concluded that the average profile errors are small and that precise Doppler frequency measurements at two or more wavelengths could be used to help determine characteristics of the turbulence, as well as accuracy limits and possible correction terms for the profiles. However, a more detailed study of both frequency and intensity characteristics in radio and optical occultation measurements of turbulent planetary atmospheres and ionospheres is required to realize the full potential of such measurements

  4. An integration time adaptive control method for atmospheric composition detection of occultation

    Ding, Lin; Hou, Shuai; Yu, Fei; Liu, Cheng; Li, Chao; Zhe, Lin

    2018-01-01

    When sun is used as the light source for atmospheric composition detection, it is necessary to image sun for accurate identification and stable tracking. In the course of 180 second of the occultation, the magnitude of sun light intensity through the atmosphere changes greatly. It is nearly 1100 times illumination change between the maximum atmospheric and the minimum atmospheric. And the process of light change is so severe that 2.9 times per second of light change can be reached. Therefore, it is difficult to control the integration time of sun image camera. In this paper, a novel adaptive integration time control method for occultation is presented. In this method, with the distribution of gray value in the image as the reference variable, and the concepts of speed integral PID control, the integration time adaptive control problem of high frequency imaging. The large dynamic range integration time automatic control in the occultation can be achieved.

  5. Magnetic field orientations in Saturn's upper ionosphere inferred from Voyager radio occultations

    Hinson, D. P.

    1984-01-01

    The radio scintillations observed during occultations of Voyagers 1 and 2 by Saturn are analyzed to determine the morphology of plasma irregularities and hence the magnetic field orientation in Saturn's upper atmosphere. The measurement techniques, the weak scattering theory, and the method used to relate the observed radio scintillations to physical properties of the ionospheric irregularities are briefly described. Results on the spatial characteristics of the irregularities are presented, and the magnetic field orientation in Saturn's ionosphere is inferred. Although the occultation measurements generally confirm the accuracy of the Saturnian magnetic field model of Connerney et al. (1982), it is found that a small adjustment of the coefficients in that model's zonal harmonic expansion would remove the discrepancy between the model predictions and the measurements. A strategy for obtaining improved measurements of Saturn's magnetic field from radio occultation observations of scintillations and Faraday rotation using an orbiting spacecraft is briefly discussed.

  6. Helios-1 Faraday rotation experiment - Results and interpretations of the solar occultations in 1975

    Volland, H.; Bird, M. K.; Levy, G. S.; Stelzried, C. T.; Seidel, B. L.

    1977-01-01

    The first of two solar occultations of the satellite Helios-1 in 1975 occurred in April when the satellite's ray path approached the west limb of the sun to a minimum distance of 1.63 solar radii. The second occultation took place in late August/early September when Helios-1 was totally eclipsed by the photosphere. Measurements of the polarization angle of the linearly polarized telemetry signal were performed with automatic tracking polarimeters at the 64 m Goldstone Tracking Station in California and also at the 100 m radio telescope in Effelsberg, West Germany. The coronal Faraday rotation as a function of the solar offset for both occultations is shown in graphs. The theoretical significance of the observations is investigated.

  7. Do X-ray-occult fractures play a role in chronic pain following a whiplash injury?

    Hertzum-Larsen, Rasmus; Petersen, Henrik; Kasch, Helge

    2014-01-01

    symptoms following an MVA was invited to have a cervical SPECT shortly post injury and again 6 months later. Associations between occult fractures and pain levels at baseline, 6 and 12 months of follow-up were analyzed. Eighty-eight patients had baseline SPECT performed at median 15 days (range 3-28) post......Whiplash trauma in motor vehicle accidents (MVA) may involve various painful soft tissue damages, but weeks/months later a minority of victims still suffers from various long-lasting and disabling symptoms, whiplash-associated disorders (WAD). The etiology is currently unknown, but X......-ray-occult fractures may be one cause in some cases. The purpose of this prospective study was to examine the association between occult fractures, as seen on bone single photon emission computed tomography (SPECT), with neck-, head- and arm pain. An inception cohort of 107 patients presenting with acute whiplash...

  8. Occult Pelvic Lymph Node Involvement in Bladder Cancer: Implications for Definitive Radiation

    Goldsmith, Benjamin; Baumann, Brian C.; He, Jiwei; Tucker, Kai; Bekelman, Justin; Deville, Curtiland; Vapiwala, Neha [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Vaughn, David; Keefe, Stephen M. [Department of Medical Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Guzzo, Thomas; Malkowicz, S. Bruce [Department of Urology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Christodouleas, John P., E-mail: christojo@uphs.upenn.edu [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2014-03-01

    Purpose: To inform radiation treatment planning for clinically staged, node-negative bladder cancer patients by identifying clinical factors associated with the presence and location of occult pathologic pelvic lymph nodes. Methods and Materials: The records of patients with clinically staged T1-T4N0 urothelial carcinoma of the bladder undergoing radical cystectomy and pelvic lymphadenectomy at a single institution were reviewed. Logistic regression was used to evaluate associations between preoperative clinical variables and occult pathologic pelvic or common iliac lymph nodes. Percentages of patient with involved lymph node regions entirely encompassed within whole bladder (perivesicular nodal region), small pelvic (perivesicular, obturator, internal iliac, and external iliac nodal regions), and extended pelvic clinical target volume (CTV) (small pelvic CTV plus common iliac regions) were calculated. Results: Among 315 eligible patients, 81 (26%) were found to have involved pelvic lymph nodes at the time of surgery, with 38 (12%) having involved common iliac lymph nodes. Risk of occult pathologically involved lymph nodes did not vary with clinical T stage. On multivariate analysis, the presence of lymphovascular invasion (LVI) on preoperative biopsy was significantly associated with occult pelvic nodal involvement (odds ratio 3.740, 95% confidence interval 1.865-7.499, P<.001) and marginally associated with occult common iliac nodal involvement (odds ratio 2.307, 95% confidence interval 0.978-5.441, P=.056). The percentages of patients with involved lymph node regions entirely encompassed by whole bladder, small pelvic, and extended pelvic CTVs varied with clinical risk factors, ranging from 85.4%, 95.1%, and 100% in non-muscle-invasive patients to 44.7%, 71.1%, and 94.8% in patients with muscle-invasive disease and biopsy LVI. Conclusions: Occult pelvic lymph node rates are substantial for all clinical subgroups, especially patients with LVI on biopsy. Extended

  9. Detection of an occult transclival cerebrospinal fluid fistula by CT and MRI

    Schick, B.; Brors, D.; Draf, W. [Department of Ear, Nose and Throat Diseases, Head, Neck and Facial Plastic Surgery, Marburg Univ. (Germany); Goedecke, A. [Department of Radiology, Academic Teaching Hospital, Fulda (Germany); Prescher, A. [Department of Anatomy and Embryology, University Medical School, RWTH, Aachen (Germany)

    1998-12-01

    We describe an unusual occult transclival cerebrospinal fluid (CSF) fistula to the sphenoid sinus demonstrated by MRI. CT was performed because of a posterior cerebral infarct caused by cardiac arrhythmia. Axial sections showed fluid in the sphenoid sinus. High-resolution scans revealed a bony defect 3 mm in diameter of the posterior wall of the sphenoid sinus, and MRI showed a transclival CSF fistula. This occult lesion was confirmed by surgery and duraplasty was successfully performed via an endonasal approach. (orig.) With 3 figs., 19 refs.

  10. Occult Invasive Lobular Carcinoma of Breast Detected by Stomach Metastasis: A Case Report

    KIm, So Jung; Jung, Hae Kyoung; Ko, Kyung Hee; Yoon, Jung Hyun

    2012-01-01

    Gastric metastasis from primary breast cancer is a rare phenomenon that is more prevalent in the invasive lobular type of breast cancer. We describe a very rare case of occult invasive lobular cancer of the breast detected by the initial presentation of gastric metastasis in a patient without a history of breast cancer. A 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) which showed increased FDG uptake in the stomach, abdominal mesentery and the right breast, and played pivotal roles in the detection of occult primary breast cancer and a diagnosis of gastric metastasis as an ancillary method for obtaining histological results and immunohistochemical stains.

  11. Occult injuries of the femoral neck in osteoporosis of aged patients

    Reichelt, H.G.

    1985-01-01

    Fractures of the femoral neck in elderly patients are often a complication in osteoporosis. Diagnosis of fractures with displacement and compression of fragments is quite easy. The negative radiograph in old patients complaining of hip pain is generally considered a characteristic feature of presensile osteoporotic pain. Clinical examples present patients with hip pain caused by occult injuries of the femoral neck. They should be regarded as imminent fractures and adequately treated. Bone scan is very helpful in the early detection of such occult osteroporotic injuries. (orig.) [de

  12. Occult Invasive Lobular Carcinoma of Breast Detected by Stomach Metastasis: A Case Report

    KIm, So Jung; Jung, Hae Kyoung; Ko, Kyung Hee; Yoon, Jung Hyun [Dept. of Radiology, Bundang CHA general Hospital, CHA University College of Medicine, Seongnam (Korea, Republic of)

    2012-02-15

    Gastric metastasis from primary breast cancer is a rare phenomenon that is more prevalent in the invasive lobular type of breast cancer. We describe a very rare case of occult invasive lobular cancer of the breast detected by the initial presentation of gastric metastasis in a patient without a history of breast cancer. A 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) which showed increased FDG uptake in the stomach, abdominal mesentery and the right breast, and played pivotal roles in the detection of occult primary breast cancer and a diagnosis of gastric metastasis as an ancillary method for obtaining histological results and immunohistochemical stains.

  13. Titan's Surface Composition from Cassini VIMS Solar Occultation Observations

    McCord, Thomas; Hayne, Paul; Sotin, Christophe

    2013-04-01

    Titan's surface is obscured by a thick absorbing and scattering atmosphere, allowing direct observation of the surface within only a few spectral win-dows in the near-infrared, complicating efforts to identify and map geologi-cally important materials using remote sensing IR spectroscopy. We there-fore investigate the atmosphere's infrared transmission with direct measure-ments using Titan's occultation of the Sun as well as Titan's reflectance measured at differing illumination and observation angles observed by Cas-sini's Visual and Infrared Mapping Spectrometer (VIMS). We use two im-portant spectral windows: the 2.7-2.8-mm "double window" and the broad 5-mm window. By estimating atmospheric attenuation within these windows, we seek an empirical correction factor that can be applied to VIMS meas-urements to estimate the true surface reflectance and map inferred composi-tional variations. Applying the empirical corrections, we correct the VIMS data for the viewing geometry-dependent atmospheric effects to derive the 5-µm reflectance and 2.8/2.7-µm reflectance ratio. We then compare the cor-rected reflectances to compounds proposed to exist on Titan's surface. We propose a simple correction to VIMS Titan data to account for atmospheric attenuation and diffuse scattering in the 5-mm and 2.7-2.8 mm windows, generally applicable for airmass water ice for the majority of the low-to-mid latitude area covered by VIMS measurements. Four compositional units are defined and mapped on Titan's surface based on the positions of data clusters in 5-mm vs. 2.8/2.7-mm scatter plots; a simple ternary mixture of H2O, hydrocarbons and CO2 might explain the reflectance properties of these surface units. The vast equatorial "dune seas" are compositionally very homogeneous, perhaps suggesting transport and mixing of particles over very large distances and/or and very consistent formation process and source material. The composi-tional branch characterizing Tui Regio and Hotei Regio is

  14. A variational regularization of Abel transform for GPS radio occultation

    T.-K. Wee

    2018-04-01

    Full Text Available In the Global Positioning System (GPS radio occultation (RO technique, the inverse Abel transform of measured bending angle (Abel inversion, hereafter AI is the standard means of deriving the refractivity. While concise and straightforward to apply, the AI accumulates and propagates the measurement error downward. The measurement error propagation is detrimental to the refractivity in lower altitudes. In particular, it builds up negative refractivity bias in the tropical lower troposphere. An alternative to AI is the numerical inversion of the forward Abel transform, which does not incur the integration of error-possessing measurement and thus precludes the error propagation. The variational regularization (VR proposed in this study approximates the inversion of the forward Abel transform by an optimization problem in which the regularized solution describes the measurement as closely as possible within the measurement's considered accuracy. The optimization problem is then solved iteratively by means of the adjoint technique. VR is formulated with error covariance matrices, which permit a rigorous incorporation of prior information on measurement error characteristics and the solution's desired behavior into the regularization. VR holds the control variable in the measurement space to take advantage of the posterior height determination and to negate the measurement error due to the mismodeling of the refractional radius. The advantages of having the solution and the measurement in the same space are elaborated using a purposely corrupted synthetic sounding with a known true solution. The competency of VR relative to AI is validated with a large number of actual RO soundings. The comparison to nearby radiosonde observations shows that VR attains considerably smaller random and systematic errors compared to AI. A noteworthy finding is that in the heights and areas that the measurement bias is supposedly small, VR follows AI very closely in the

  15. A variational regularization of Abel transform for GPS radio occultation

    Wee, Tae-Kwon

    2018-04-01

    In the Global Positioning System (GPS) radio occultation (RO) technique, the inverse Abel transform of measured bending angle (Abel inversion, hereafter AI) is the standard means of deriving the refractivity. While concise and straightforward to apply, the AI accumulates and propagates the measurement error downward. The measurement error propagation is detrimental to the refractivity in lower altitudes. In particular, it builds up negative refractivity bias in the tropical lower troposphere. An alternative to AI is the numerical inversion of the forward Abel transform, which does not incur the integration of error-possessing measurement and thus precludes the error propagation. The variational regularization (VR) proposed in this study approximates the inversion of the forward Abel transform by an optimization problem in which the regularized solution describes the measurement as closely as possible within the measurement's considered accuracy. The optimization problem is then solved iteratively by means of the adjoint technique. VR is formulated with error covariance matrices, which permit a rigorous incorporation of prior information on measurement error characteristics and the solution's desired behavior into the regularization. VR holds the control variable in the measurement space to take advantage of the posterior height determination and to negate the measurement error due to the mismodeling of the refractional radius. The advantages of having the solution and the measurement in the same space are elaborated using a purposely corrupted synthetic sounding with a known true solution. The competency of VR relative to AI is validated with a large number of actual RO soundings. The comparison to nearby radiosonde observations shows that VR attains considerably smaller random and systematic errors compared to AI. A noteworthy finding is that in the heights and areas that the measurement bias is supposedly small, VR follows AI very closely in the mean refractivity

  16. Impact of occult hepatitis B virus infection on antiviral therapy in ...

    Gamal El Din Ahmed Elsawaf

    2015-01-07

    Jan 7, 2015 ... in the serum of patients who are negative for HBsAg. The presence ... positive. The frequency of HBV-DNA positive HCV patients has a statistically significant associa- ..... not affect the outcome of therapy at weeks 12 and 24.

  17. Serologically silent, occult equine infectious anemia virus (EIAV) infections in horses.

    Ricotti, Sonia; Garcia, Maria Inés; Veaute, Carolina; Bailat, Alejandra; Lucca, Eduardo; Cook, R Frank; Cook, Sheila J; Soutullo, Adriana

    2016-05-01

    Molecular and serological techniques for Equine Infectious Anemia Virus (EIAV) diagnosis were compared using samples from 59 clinically normal horses stabled on five farms in the Santa Fe Province of Argentina. Of these 26 (44.1%) were positive in official AGID tests and/or gp45/gp90-based ELISA. Surprisingly 18 of the 33 seronegative horses were positive in a PCR against viral sequences encoding gp45 (PCR-positive/AGID-negative) with all but one remaining EIAV-antibody negative throughout a two year observation period. The gp45 PCR results are supported by fact that 7/18 of these horses were positive in the Office International des Epizooties (OIE) recommended EIAV gag gene specific PCR plus 2 of this 7 also reacted in a PCR directed predominantly against the 5' untranslated region of the viral genome. Furthermore sufficient quantities of serum were available from 8 of these horses to verify their seronegative status in sensitive Western Blot tests and demonstrate by ELISA the absence of EIAV-specific antibodies was not attributable to abnormalities in total IgG concentration. Studies involving 7 of the PCR-positive/AGID-negative horses to measure lymphocyte proliferation in the presence of PHA showed no significant differences between this group and control animals. In addition, lymphocytes from 2 of these 7 horses responded to peptides derived from gp90 and gp45. Together these results demonstrate that apparently clinically normal horses with no gross signs of immunodeficiency in terms of total IgG concentration or T helper-cell function can remain seronegative for at least 24 months while harboring EIAV specific nucleic acid sequences. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Treatment for occult hepatocellular carcinoma: does it offer survival advantages over symptom-driven treatment?

    Kim, Kwang Min; Kim, Jiyu; Sinn, Dong Hyun; Kim, Hye Seung; Kim, Kyunga; Kang, Wonseok; Gwak, Geum-Youn; Paik, Yong-Han; Choi, Moon Seok; Lee, Joon Hyeok; Koh, Kwang Cheol; Paik, Seung Woon

    2018-04-03

    In order to claim a benefit of screen-based diagnosis for asymptomatic individuals, treatment of occult disease needs to offer survival advantages compared to the treatment of symptomatic disease, yet information on this issue is scarce with regard to hepatocellular carcinoma (HCC) screening. A total of 3353 treatment-naïve, consecutive, newly diagnosed HCC patients [age: 57.9 ± 10.3, male: 2,689 (80.2%), hepatitis B virus: 2555 (76.2%)], diagnosed between 2010 and 2013 were analyzed. Data on the mode of detection was prospectively collected at the time of HCC diagnosis and was used to group patients into occult or symptomatic cases. Overall, 643 (19.2%) patients were symptomatic cases. The proportion of patients undergoing resection, radiofrequency ablation or transplantation were lower in symptomatic cases than occult cases (20.8 vs. 56.2%, p offered a survival benefit to patients over symptomatic cases. These data support screening practices for asymptomatic individuals to diagnose occult HCC.

  19. Endoscopic Follow-Up of Positive Fecal Occult Blood Testing in the Ontario FOBT Project

    Lawrence Paszat

    2007-01-01

    Full Text Available BACKGROUND: The Ontario FOBT Project is a pilot study of fecal occult blood testing (FOBT for colorectal cancer screening conducted among age-eligible volunteers (50 to 75 years in 12 of 37 public health regions in Ontario.

  20. First Ionospheric Results From the MAVEN Radio Occultation Science Experiment (ROSE)

    Withers, Paul; Felici, M.; Mendillo, M.; Moore, L.; Narvaez, C.; Vogt, M. F.; Jakosky, B. M.

    2018-05-01

    Radio occultation observations of the ionosphere of Mars can span the full vertical extent of the ionosphere, in contrast to in situ measurements that rarely sample the main region of the ionosphere. However, most existing radio occultation electron density profiles from Mars were acquired without clear context for the solar forcing or magnetospheric conditions, which presents challenges for the interpretation of these profiles. Here we present 48 ionospheric electron density profiles acquired by the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) Radio Occultation Science Experiment (ROSE) from 5 July 2016 to 27 June 2017 at solar zenith angles of 54° to 101°. Latitude coverage is excellent, and comprehensive context for the interpretation of these profiles is provided by other MAVEN instruments. The profiles show a 9-km increase in ionospheric peak altitude in January 2017 that is associated with a lower atmospheric dust storm, variations in electron densities in the M1 layer that cannot be explained by variations in the solar soft X-ray flux, and topside electron densities that are larger in strongly magnetized regions than in weakly magnetized regions. MAVEN Radio Occultation Science Experiment electron density profiles are publicly available on the NASA Planetary Data System.

  1. Lunar occultation of the Galactic center at 2.2 microns

    Adams, D. J.; Becklin, E. E.; Jameson, R. F.; Longmore, A. J.; Sandqvist, Aa.; Valentijn, E.

    1988-01-01

    Results of the lunar occultation of IRS 16 on 1986 September 11 are reported. Sixty percent of the observed flux in a 6arcsec.5 beam comes from four discrete sources. Three sources are unresolved pointlike objects (<0arcsec.05) and are assumed to be individual stars. The fourth object is well

  2. Post traumatic urinary extravasation in occult urinary obstruction: Report of three cases

    Jyoti Bothra

    2016-01-01

    Full Text Available Urinary extravastion after blunt abdominal trauma is seen often and generally treated conservatively. However a blunt renal trauma causing huge amount of extravasations and symptoms disproportionate to the severity of trauma should alarm the surgeon towards an underlying occult renal pathology usually an obstruction. In this case series, we share three such experiences and their management.

  3. Earlier stages of colorectal cancer detected with immunochemical faecal occult blood tests

    van Rossum, L. G. M.; van Rijn, A. F.; van Munster, I. P.; Jansen, J. B. M. J.; Fockens, P.; Laheij, R. J. F.; Dekker, E.

    2009-01-01

    Background: The aim of colorectal cancer screening is to improve prognosis by the detection of early cancer and precursor stages. We compared the stage distribution of asymptomatic colorectal cancer patients detected by a positive immunochemical or guaiac-based faecal occult blood test (FOBT) with

  4. Clinical relevance of occult tumor cells in lymph nodes from gastric cancer patients.

    Doekhie, F.S.; Mesker, W.H.; Krieken, J.H.J.M. van; Kok, N.F.; Hartgrink, H.H.; Kranenbarg, E.K.; Putter, H.; Kuppen, P.J.; Tanke, H.J.; Tollenaar, R.A.E.M.; Velde, C.J. van de

    2005-01-01

    The current method for staging in gastric cancer is not sufficient as even after a complete primary tumor resection, patients with node-negative gastric cancer suffer from disease recurrence. In this study, the relation between disease recurrence and the presence of occult tumor cells (OTC) in lymph

  5. Design and Verification of External Occulters for Direct Imaging of Extrasolar Planets

    Cady, Eric

    2011-01-01

    An occulter is an optical element which is placed in front of the telescope to block most of the light from a star before it reaches the optics inside, without blocking the planet.In our case, we use two spacecraft ying in formation: First has its edge shaped to cancel the starlight Second is the telescope which images the star and planet

  6. Inappropriate use of the faecal occult blood test in a university hospital in the Netherlands

    van Rijn, Anne F.; Stroobants, An K.; Deutekom, Marije; Lauppe, Corinne; Sturk, Auguste; Bossuyt, Patrick M. M.; Fockens, Paul; Dekker, Evelien

    2012-01-01

    Objectives Although all international guidelines state that there is no indication to perform a faecal occult blood test (FOBT) in symptomatic patients, we believe the test is frequently used as a diagnostic test. The objective of this study was to investigate whether the current guidelines for FOBT

  7. Tropical cyclone cloud‐top height and vertical temperature structure detection using GPS radio occultation measurements

    Biondi, Riccardo; Ho, Shu‐Peng; Randel, William

    2013-01-01

    The accurate determination of tropical cyclone (TC) cloud-top height and its vertical thermal structure using the GPS radio occultation (RO) technique is demonstrated in this study. Cloud-top heights are determined by using the bending angle anomaly and the temperature anomaly profiles during...

  8. Indeling occulte tumorcellen in de lymfklieren bij patiënten met darmkanker onvoldoende betrouwbaar

    van der Zaag, E. S.; Welling, L.; Peters, H. M.; van de Vijver, M. J.; Bemelman, W. A.; Buskens, C. J.

    2011-01-01

    OBJECTIVE: To assess interobserver agreement between pathologists in judging photographs of lymph node preparations of occult tumour cells of patients with colon cancer. DESIGN: Descriptive and comparative study of interobserver variability. METHODS: All lymph nodes of 82 pN0 patients with colon

  9. GPS radio occultation technique for measurement of the atmosphere above tropical cyclones

    Biondi, Riccardo; Neubert, Torsten; Syndergaard, Stig

    2009-01-01

    Water vapour transport to the upper troposphere (UT) and lower stratosphere (LS) by deep convective storms affects the radiation balance of the atmosphere and has been proposed as an important component of climate change. The aim of the work presented here is to understand if the GPS Radio Occult...... 2008 and reached a maximum intensity of Category 3....

  10. Estimation and evaluation of COSMIC radio occultation excess phase using undifferenced measurements

    Xia, Pengfei; Ye, Shirong; Jiang, Kecai; Chen, Dezhong

    2017-05-01

    In the GPS radio occultation technique, the atmospheric excess phase (AEP) can be used to derive the refractivity, which is an important quantity in numerical weather prediction. The AEP is conventionally estimated based on GPS double-difference or single-difference techniques. These two techniques, however, rely on the reference data in the data processing, increasing the complexity of computation. In this study, an undifferenced (ND) processing strategy is proposed to estimate the AEP. To begin with, we use PANDA (Positioning and Navigation Data Analyst) software to perform the precise orbit determination (POD) for the purpose of acquiring the position and velocity of the mass centre of the COSMIC (The Constellation Observing System for Meteorology, Ionosphere and Climate) satellites and the corresponding receiver clock offset. The bending angles, refractivity and dry temperature profiles are derived from the estimated AEP using Radio Occultation Processing Package (ROPP) software. The ND method is validated by the COSMIC products in typical rising and setting occultation events. Results indicate that rms (root mean square) errors of relative refractivity differences between undifferenced and atmospheric profiles (atmPrf) provided by UCAR/CDAAC (University Corporation for Atmospheric Research/COSMIC Data Analysis and Archive Centre) are better than 4 and 3 % in rising and setting occultation events respectively. In addition, we also compare the relative refractivity bias between ND-derived methods and atmPrf profiles of globally distributed 200 COSMIC occultation events on 12 December 2013. The statistical results indicate that the average rms relative refractivity deviation between ND-derived and COSMIC profiles is better than 2 % in the rising occultation event and better than 1.7 % in the setting occultation event. Moreover, the observed COSMIC refractivity profiles from ND processing strategy are further validated using European Centre for Medium

  11. Sizes of the Smallest Particles at Saturn Ring Edges from Diffraction in UVIS Stellar Occultations

    Eckert, S.; Colwell, J. E.; Becker, T. M.; Esposito, L. W.

    2017-12-01

    Cassini's Ultraviolet Imaging Spectrograph (UVIS) has observed more than 150 ring stellar occultations since its arrival at Saturn in 2004. We use stellar occultation data from the UVIS High Speed Photometer (HSP) to identify diffraction signals at ring edges caused by small particles diffracting light into the detector and consequently increasing the signal above that of the unocculted star. The shape of a diffraction signal is indicative of the particle size distribution at the ring edge, which may be a dynamically perturbed region. Becker et al. (2015 Icarus doi:10.1016/j.icarus.2015.11.001) analyzed diffraction signals at the outer edge of the A Ring and the edges of the Encke Gap. We apply the Becker et al. (2015) model to the outer edge of the B Ring as well as the edges of ringlets within the C Ring and Cassini Division. In addition, we analyze diffraction signatures at the A Ring outer edge in 2 new occultations. The best-fit model signals to these occultations are consistent with the findings of Becker et al. (2015) who found an average minimum particle size amin =4.5 mm and average power law slope q=3.2. At the B Ring outer edge, we detect a diffraction signal in 10 of 28 occultations in which the diffraction signal would be observable according to our criteria for star brightness and observation geometry. We find a mean amin =11 mm and a mean q=3.0. At both edges of the so-called "Strange" ringlet (R6) we find a mean amin = 20 mm and mean q values of 3.0 and 2.8 at the inner and outer edges, respectively. In contrast, we do not observe any clear diffraction signals at either edge of the wider Huygens ringlet. This could imply an absence of cm-scale or smaller particles and indicates that collisions here may be less vigorous than at the other ring edges analyzed in this study. We detect diffraction in a small fraction ( 10%) of occultations at 3 ringlets within the Cassini Division: the Herschel ringlet, the Laplace ringlet, and the Barnard ringlet. We

  12. Partially Transparent Petaled Mask/Occulter for Visible-Range Spectrum

    Shiri, Ron Shahram; Wasylkiwskyj, Wasyl

    2013-01-01

    The presence of the Poisson Spot, also known as the spot of Arago, has been known since the 18th century. This spot is the consequence of constructive interference of light diffracted by the edge of the obstacle where the central position can be determined by symmetry of the object. More recently, many NASA missions require the suppression of this spot in the visible range. For instance, the exoplanetary missions involving space telescopes require telescopes to image the planetary bodies orbiting central stars. For this purpose, the starlight needs to be suppressed by several orders of magnitude in order to image the reflected light from the orbiting planet. For the Earth-like planets, this suppression needs to be at least ten orders of magnitude. One of the common methods of suppression involves sharp binary petaled occulters envisioned to be placed many thousands of miles away from the telescope blocking the starlight. The suppression of the Poisson Spot by binary sharp petal tips can be problematic when the thickness of the tips becomes smaller than the wavelength of the incident beam. First they are difficult to manufacture and also it invalidates the laws of physical optics. The proposed partially transparent petaled masks/occulters compensate for this sharpness with transparency along the surface of the petals. Depending on the geometry of the problem, this transparency can be customized such that only a small region of the petal is transparent and the remaining of the surface is opaque. This feature allows easy fabrication of this type of occultation device either as a mask or occulter. A partially transparent petaled mask/ occulter has been designed for the visible spectrum range. The mask/occulter can suppress the intensity along the optical axis up to ten orders of magnitude. The design process can tailor the mask shape, number of petals, and transparency level to the near-field and farfield diffraction region. The mask/occulter can be used in space

  13. Histopathological Parameters predicting Occult Nodal Metastases in Tongue Carcinoma Cases: An Indian Perspective.

    Jacob, Tina Elizabeth; Malathi, N; Rajan, Sharada T; Augustine, Dominic; Manish, N; Patil, Shankargouda

    2016-01-01

    It is a well-established fact that in squamous cell carcinoma cases, the presence of lymph node metastases decreased the 5-year survival rate by 50% and also caused the recurrence of the primary tumor with development of distant metastases. Till date, the predictive factors for occult cervical lymph nodes metastases in cases of tongue squamous cell carcinoma remain inconclusive. Therefore, it is imperative to identify patients who are at the greatest risk for occult cervical metastases. This study was thus performed with the aim to identify various histopathologic parameters of the primary tumor that predict occult nodal metastases. The clinicopathologic features of 56 cases of lateral tongue squamous cell carcinoma with cT1NoMo/cT2NoMo as the stage and without prior radiotherapy or chemotherapy were considered. The surgical excision of primary tumor was followed by elective neck dissection. The glossectomy specimen along with the neck nodes were fixed in formalin and 5 urn thick sections were obtained. The hematoxylin & eosin stained sections were then subjected to microscopic examination. The primary tumor characteristics that were analyzed include tumor grade, invading front, depth of tumor, lymphovascular invasion, perineural invasion and inflammatory response. The nodes were examined for possible metastases using hematoxylin & eosin followed by cytokeratin immunohistochemistry. A total of 12 cases were found with positive occult nodal metastases. On performing univariate analysis, the histopathologic parameters that were found to be statistically significant were lymphovascular invasion (p = 0.004) and perineural invasion (p = 0.003) along with a cut-off depth of infiltration more than 5 mm (p = 0.01). Histopathologic assessment of the primary tumor specimen therefore continues to provide information that is central to guide clinical management, particularly in cases of occult nodal metastases. Clinical significance The study highlights the importance of

  14. Occult pneumothorax in trauma patients: should this be sought in the focused assessment with sonography for trauma examination?

    Tam, Michael M K

    2005-01-01

    At present, CT scan is the gold standard for detecting occult traumatic pneumothorax not apparent on supine chest X-ray radiograph. Recently there were suggestions to expand focused assessment with sonography for trauma (FAST) to include thoracic ultrasound for detecting pneumothorax. The aim of the present study is to determine the incidence of occult pneumothorax (as shown by CT) in the subgroup of trauma patients undergoing FAST. Review of all trauma patients with FAST done from 1 June 2001 to 31 October 2002. Incidence of occult pneumothorax as diagnosed by CT was determined. Patients were not counted as having true occult pneumothorax if they had chest drains inserted before arrival or imaging studies. Selected clinical findings were tested for association with occult pneumothorax. In total, 143 patients underwent FAST, of whom 137 (95.8%) had chest X-ray examination performed. Of the 137 patients 59 required CT abdomen and/or thorax. Occult pneumothorax was found in three patients (2.1%). A history of thorax and/or abdominal injury plus one or more of: (i) mechanisms potentially causing major trauma; (ii) abnormal chest examination; and (iii) chest X-ray radiograph abnormality in the absence of pneumothorax, was significantly associated with the presence of occult pneumothorax (P = 0.03, Fisher's exact test; sensitivity: 100%; specificity: 71%; likelihood ratio: 3.42). The incidence of occult pneumothorax in the subgroup of trauma patients undergoing FAST is low. It implies that routine screening for its presence by adding thoracic ultrasound to FAST is unnecessary. Identifying those at risk of occult pneumothorax for further investigation appeared feasible.

  15. Stellar Occultations by TNOs and Centaurs: first results in the “Gaia era”

    Rossi, Gustavo; Vieira-Martins, Roberto; Sicardy, Bruno; Ortiz, Jose Luis; Rio Group, Lucky Star Occultation Team, Granada Occultation Team

    2017-10-01

    After the first release of the GAIA catalog (in September/2016), stellar positions are now known with unprecedented accuracy, reaching values of the order of milliarcseconds. This improvement reflected into a stunning accuracy on the astrometry of moving objects, such as TNOs. Unfortunately, Gaia stars proper motions will be only available on the second data release (DR2) next year, so there is still a need to use hybrid stellar catalogs for occultation predictions until then. Despite that, stellar occultations predictions are now much more accurate, and the biggest uncertainties comes mainly from the object ephemerides. This issue will be overcome by large surveys such as the LSST, which will provide positions for the known TNOs and it is expected to increase the number of known TNOs by nearly 40,000, with an unprecedent amount of acquired information.This huge amount of data also poses a new era in stellar occultations: predictions will be very accurate and the participation of professional astronomers, laboratories, and the amateur community will be crucial to observe the predicted events; observation campaigns will need to be selected according to a specific scientific purpose such as the probability to detect rings or archs around a body, the presence of atmosphere or even the detection of topographic features; the development of softwares capable of reducing the data more efficiently and an easier method to coordinate observation campaigns are needed.Here we present some impressive results obtained from predictions and observed occultations in 2017 (among them we have Pluto, Chariklo and Haumea), the problems we are starting to face in the beginning of the “Gaia era” and the future challenges of stellar occultation.

  16. Theoretical performance of serrated external occulters for solar coronagraphy. Application to ASPIICS

    Rougeot, R.; Aime, C.

    2018-04-01

    Context. This study is made in the context of the future solar coronagraph ASPIICS of the ESA formation-flying mission Proba-3. Aims: In the context of solar coronagraphy, we provide a comparative study of the theoretical performance of serrated (or toothed) external occulters by varying the number and size of the teeth, which we compare to the sharp-edged and apodized disks. The tooth height is small (a few centimeters), to avoid hindering the observation of the solar corona near the limb. We first analyze the diffraction pattern produced by such occulters. In a second step, we compute the umbra profile by integration over the Sun. Methods: We explored a few methods to compute the diffraction pattern. Two of them were implemented. The first is based on 2D fast Fourier transformation (FFT) routines and a multiplication by the Fresnel filter of the form exp(-iπλzu2). Simple rules were derived and discussed to set the sampling conditions. The Maggi-Rubinowicz representation is then proposed as an alternative method, and is proven to be very efficient for this study. Results: Serrated occulters tend to create a two-level intensity pattern, the inner being the darker, which perfectly matches a previously reported geometrical prediction. The diffraction in this central region is lower by two to four orders of magnitude when compared to the sharp-edged disk. The achieved umbra level at the center ranges from 10-4 to below 10-7, depending on the geometry of the teeth. Conclusions: Our study shows that serrated occulters can achieve a high rejection and can almost reach the performance of the apodized disk when very many teeth are used. We prove that shaped occulters must be preferred to simple disks in solar and stellar coronagraphy.

  17. Predictive factors of occult neck metastasis in patients with oral squamous cell carcinoma

    Renato Fortes Bittar

    Full Text Available ABSTRACT INTRODUCTION: It is well established that cervical lymph node metastasis is the most important prognostic factor in patients with oral squamous cell carcinoma of the upper aerodigestive tract. The definition of parameters and classifications that could separate patients in groups of low, intermediate and high-risk is being attempted for several years. OBJECTIVE: The objective of this study was to determine possible predictive factors related to the occurrence of occult cervical lymph node metastasis through the analysis of histopathological reports of surgical specimens obtained after oral squamous cell carcinoma resection and selective neck dissections of patients initially classified as N0. METHODS: This was a primary, retrospective, observational, case-control study. Histopathological reports were reviewed to determine if some findings were related to the occurrence of occult lymph node metastasis. The events analyzed were oral cavity subsites, pT-stage, muscular infiltration, desmoplasia, vascular emboli, perineural infiltration, tumor thickness and compromised margins. RESULTS: Occult cervical metastasis accounted for 19.10 percent of the cases. Desmoplasia, perineural infiltration, tumor thickness and pT4a stage are predictive factors of occult neck metastasis (p-value = 0.0488, 0.0326, 0.0395, 0.0488, respectively. CONCLUSION: The accurate definition of predictive factors of occult cervical metastasis may guide the selection of patients that should be referred to radiotherapy, avoiding the unnecessary exposure of low-risk patients to radiation and allowing a better regional control of the disease in those of moderate or high risk.

  18. Occult HBV reactivation induced by ibrutinib treatment: a case report.

    de Jésus Ngoma, Patrick; Kabamba, Benoît; Dahlqvist, Geraldine; Sempoux, Christine; Lanthier, Nicolas; Shindano, Tony; Van Den Neste, Eric; Horsmans, Yves

    2015-12-01

    Ibrutinib is a small molecule that has been recently developped for the treatment of B cell malignancies. Common side effects are diarrhoea, nausea, fatigue, infections, neutropenia and thrombocytopenia. Here we report the first case of Hepatitis B virus reactivation in a 80 years old chronic lymphocytic leukaemia patient receiving ibrutinib, suggesting that such treatment must be associated with HBV screening. © Acta Gastro-Enterologica Belgica.

  19. Amplification and protein overexpression of cyclin D1: Predictor of occult nodal metastasis in early oral cancer.

    Noorlag, Rob; Boeve, Koos; Witjes, Max J H; Koole, Ronald; Peeters, Ton L M; Schuuring, Ed; Willems, Stefan M; van Es, Robert J J

    2017-02-01

    Accurate nodal staging is pivotal for treatment planning in early (stage I-II) oral cancer. Unfortunately, current imaging modalities lack sensitivity to detect occult nodal metastases. Chromosomal region 11q13, including genes CCND1, Fas-associated death domain (FADD), and CTTN, is often amplified in oral cancer with nodal metastases. However, evidence in predicting occult nodal metastases is limited. In 158 patients with early tongue and floor of mouth (FOM) squamous cell carcinomas, both CCND1 amplification and cyclin D1, FADD, and cortactin protein expression were correlated with occult nodal metastases. CCND1 amplification and cyclin D1 expression correlated with occult nodal metastases. Cyclin D1 expression was validated in an independent multicenter cohort, confirming the correlation with occult nodal metastases in early FOM cancers. Cyclin D1 is a predictive biomarker for occult nodal metastases in early FOM cancers. Prospective research on biopsy material should confirm these results before implementing its use in routine clinical practice. © 2016 Wiley Periodicals, Inc. Head Neck 39: 326-333, 2017. © 2016 Wiley Periodicals, Inc.

  20. Retrieval of temperature and pressure using broadband solar occultation: SOFIE approach and results

    B. T. Marshall

    2011-05-01

    Full Text Available Measurement of atmospheric temperature as a function of pressure, T(P, is key to understanding many atmospheric processes and a prerequisite for retrieving gas mixing ratios and other parameters from solar occultation measurements. This paper gives a brief overview of the solar occultation measurement technique followed by a detailed discussion of the mechanisms that make the measurement sensitive to temperature. Methods for retrieving T(P using both broadband transmittance and refraction are discussed. Investigations using measurements of broadband transmittance in two CO2 absorption bands (the 4.3 and 2.7 μm bands and refractive bending are then presented. These investigations include sensitivity studies, simulated retrieval studies, and examples from SOFIE.

  1. Observing Tropospheric Water Vapor by Radio Occultation using the Global Positioning System

    Kursinski, E. R.; Hajj, G. A.; Hardy, K. R.; Romans, L. J.; Schofield, J. T.

    1995-01-01

    Given the importance of water vapor to weather, climate and hydrology, global humidity observations from satellites are critical. At low latitudes, radio occultation observations of Earth's atmosphere using the Global Positioning System (GPS) satellites allow water vapor profiles to be retrieved with accuracies of 10 to 20% below 6 to 7 km altitude and approx. 5% or better within the boundary layer. GPS observations provide a unique combination of accuracy, vertical resolution (less than or equal to 1 km) and insensitivity to cloud and aerosol particles that is well suited to observations of the lower troposphere. These characteristics combined with the inherent stability of radio occultation observations make it an excellent candidate for the measurement of long term trends.

  2. Photometry of occultation candidate stars. I - Uranus 1985 and Saturn 1985-1991

    French, L. M.; Morales, G.; Dalton, A. S.; Klavetter, J. J.; Conner, S. R.

    1985-01-01

    Photometric observations of five stars to be occulted by the rings around Uranus are presented. The four stars to be occulted by Saturn or its rings during the period 1985-1991 were also observed. The observations were carried out with a CCD detector attached to the Kitt Peak McGraw-Hill 1.30-m telescope. Landolt standards of widely ranging V-I color indices were used to determine the extinction coefficients, transformation coefficients, and zero points of the stars. Mean extinction coefficients are given for each night of observation. K magnitudes for each star were estimated on the basis of the results of Johnson (1967). The complete photometric data set is given in a series of tables.

  3. Lunar occultation of Saturn. II - The normal reflectance of Rhea, Titan, and Iapetus

    Elliot, J. L.; Dunham, E. W.; Veverka, J.; Goguen, J.

    1978-01-01

    An inversion procedure to obtain the reflectance of the central region of a satellite's disk from lunar occultation data is presented. The scheme assumes that the limb darkening of the satellite depends only on the radial distance from the center of the disk. Given this assumption, normal reflectances can be derived that are essentially independent of the limb darkening and the diameter of the satellite. The procedure has been applied to our observations of the March 1974 lunar occultation of Tethys, Dione, Rhea, Titan, and Iapetus. In the V passband we derive the following normal reflectances: Rhea (0.97 plus or minus 0.20), Titan (0.24 plus or minus 0.03), Iapetus, bright face (0.60 plus or minus 0.14). For Tethys and Dione the values derived have large uncertainties, but are consistent with our result for Rhea.

  4. The Taiwanese-American occultation survey project stellar variability. III. Detection of 58 new variable stars

    Ishioka, R.; Wang, S.-Y.; Zhang, Z.-W.; Lehner, M. J.; Cook, K. H.; King, S.-K.; Lee, T.; Marshall, S. L.; Schwamb, M. E.; Wang, J.-H.; Wen, C.-Y. [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Alcock, C.; Protopapas, P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Axelrod, T. [Steward Observatory, 933 North Cherry Avenue, Room N204, Tucson, AZ 85721 (United States); Bianco, F. B. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Byun, Y.-I. [Department of Astronomy and University Observatory, Yonsei University, 134 Shinchon, Seoul 120-749 (Korea, Republic of); Chen, W. P.; Ngeow, C.-C. [Institute of Astronomy, National Central University, No. 300, Jhongda Road, Jhongli City, Taoyuan County 320, Taiwan (China); Kim, D.-W. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Rice, J. A., E-mail: ishioka@asiaa.sinica.edu.tw [Department of Statistics, University of California Berkeley, 367 Evans Hall, Berkeley, CA 94720 (United States)

    2014-04-01

    The Taiwanese-American Occultation Survey project is designed for the detection of stellar occultations by small-size Kuiper Belt Objects, and it has monitored selected fields along the ecliptic plane by using four telescopes with a 3 deg{sup 2} field of view on the sky since 2005. We have analyzed data accumulated during 2005-2012 to detect variable stars. Sixteen fields with observations of more than 100 epochs were examined. We recovered 85 variables among a total of 158 known variable stars in these 16 fields. Most of the unrecovered variables are located in the fields observed less frequently. We also detected 58 variable stars which are not listed in the International Variable Star Index of the American Association of Variable Star Observers. These variable stars are classified as 3 RR Lyrae, 4 Cepheid, 1 δ Scuti, 5 Mira, 15 semi-regular, and 27 eclipsing binaries based on the periodicity and the profile of the light curves.

  5. Helicobacter pylori infection and serum ferritin

    Berg, Gabriele; Bode, G; Blettner, M

    2001-01-01

    OBJECTIVE: Helicobacter pylori may possibly affect the iron metabolism by occult bleeding, impaired absorption of non-hem iron, and by scavenging hem iron or ferritin, as some studies have suggested. The aim of this study was to analyze the association between H. pylori infection and serum ferritin...... in 1987/1988. The examination included a detailed questionnaire on medical history and lifestyle factors, a 7-day food record, and blood samples. Infection with H. pylori was measured serologically by ELISA and Westernblot. RESULTS: In total, 39.2% of 1806 persons aged 18 to 89 yr included in the study...... were H. pylori positive, of whom 57.6% had an infection with a CagA-positive H. pylori strain. Age- and sex-adjusted geometric mean of ferritin was 54.5 microg/dl among H. pylori-infected compared with 63.8 microg/dl among uninfected persons. A multiple linear regression model with log...

  6. Incidence of occult leiomyosarcoma in presumed morcellation cases: a database study.

    Rodriguez, Ana M; Asoglu, Mehmet R; Sak, Muhammet Erdal; Tan, Alai; Borahay, Mostafa A; Kilic, Gokhan S

    2016-02-01

    Our objective was to estimate the incidence of uterine leiomyosarcoma in patients with leiomyomas following laparoscopic supracervical hysterectomy and myomectomy procedures. For this study, we analyzed records of 13,964 women aged 25-64 years who underwent laparoscopic supracervical hysterectomies or myomectomies for leiomyomas from 2002 to 2011 using Clinformatics DataMart. Patient records were divided into two groups: history of laparoscopic supracervical hysterectomy and history of myomectomy. Subjects were tracked to identify diagnosis of leiomyosarcoma within 1 year of the procedure. We analyzed data from the 25-39, 40-49, and 50-64 age brackets. Evidence was obtained from a cohort study from national private insurance claims in the US. Our results showed the incidence of occult leiomyosarcoma developing within 1 year following supracervical hysterectomy using a laparoscopic-assisted approach are 9.8, 10.7, and 33.4 per 10,000 for the 25-39, 40-49, and 50-64 age brackets, respectively; the overall incidence rate is 13.1 per 10,000. The incidence rate of occult leiomyosarcoma developing within 1 year following myomectomy using a laparoscopic-assisted approach are 0.0, 33.8, and 90.1 per 10,000 for the 25-39, 40-49, and 50-64 age brackets, respectively; the overall incidence rate is 17.3 per 10,000. Our analysis shows the overall risk of being diagnosed with occult leiomyosarcoma is 12.9 per 10,000 in laparoscopic-assisted supracervical hysterectomy and myomectomy for patients younger than 49. There is no evidence of occult leiomyosarcoma 1 year after operation for patients younger than 40 who underwent laparoscopic myomectomy. Copyright © 2015. Published by Elsevier Ireland Ltd.

  7. The occult nature of intramedullary spinal cord metastases from renal cell carcinoma.

    Zakaria, Zaitun

    2012-01-01

    Renal cell carcinomas (RCC) are characterised by a tendency to metastasise widely, often while remaining occult. Intramedullary spinal cord metastases (ISCM) from RCC may be the presenting feature of the disease or present at any time in the disease course. This case report discusses an ISCM from RCC which became manifested at the time of resection of the primary tumour. We review the literature published on ISCM from RCC from 1990 to date comparing disease characteristics and presentations.

  8. High prevalence of occult left heart disease in scleroderma-pulmonary hypertension.

    Fox, Benjamin D; Shimony, Avi; Langleben, David; Hirsch, Andrew; Rudski, Lawrence; Schlesinger, Robert; Eisenberg, Mark J; Joyal, Dominique; Hudson, Marie; Boutet, Kim; Serban, Alexandrina; Masetto, Ariel; Baron, Murray

    2013-10-01

    Our study aimed to determine the prevalence of occult left-heart disease in patients with scleroderma and pulmonary hypertension. In patients with pulmonary hypertension (mean pulmonary artery pressure (mean PAP)≥25 mmHg), differentiation between pre- and post-capillary pulmonary hypertension has been made according to pulmonary artery wedge pressure (PAWP) less than or more than 15 mmHg, respectively. We performed a retrospective chart review of 107 scleroderma patients. All patients with suspected pulmonary hypertension had routine right or left heart catheterisation with left ventricular end-diastolic pressure (LVEDP) measurement pre-/post-fluid challenge. We extracted demographic, haemodynamic and echocardiographic data. Patients were classified into one of four groups: haemodynamically normal (mean PAP15 mmHg); occult PVH (mean PAP≥25 mmHg, PAWP≤15 mmHg, LVEDP>15 mmHg before or after fluid challenge); and pulmonary arterial hypertension (PAH) (mean PAP≥25 mmHg, PAWP≤15 mmHg and LVEDP≤15 mmHg before or after fluid challenge). 53 out of 107 patients had pulmonary hypertension. Based on the PAWP-based definition, 29 out of 53 had PAH and 24 out of 53 had PVH. After considering the resting and post-fluid-challenge LVEDP, 11 PAH patients were reclassified as occult PVH. The occult PVH group was haemodynamically, echocardiographically and demographically closer to the PVH group than the PAH group. PVH had high prevalence in our scleroderma-pulmonary hypertension population. Distinguishing PAH from PVH with only PAWP may result in some PVH patients being misclassified as having PAH.

  9. Outcome of early detection and radiotherapy for occult spinal cord compression

    Venkitaraman, Ramachandran; Barbachano, Yolanda; Dearnaley, David P.; Parker, Christopher C.; Khoo, Vincent; Huddart, Robert A.; Eeles, Rosalind; Horwich, Alan; Aslam Sohaib, S.

    2007-01-01

    Retrospective analysis in 150 patients with metastatic prostate cancer was conducted to determine whether early detection with MRI spine and treatment of clinically occult spinal cord compromise (SCC) facilitate preservation of neurologic function. Our results suggest that prophylactic radiotherapy for patients with back pain or radiological SCC without neurologic deficit may facilitate preservation of neurologic function. Thus MRI surveillance for SCC may be important for prostate cancer patients with bone metastases

  10. Anemia and thrombocytopenia as initial symptoms of occult breast cancer with bone marrow metastasis

    Liu, Lulu; Zhang, Jingjing; Chen, Mingtai; Ren, Saisai; Liu, Haihui; Zhang, Hao

    2017-01-01

    Abstract Rationale: Occult breast cancer (OBC) is a rare type of breast cancer without any symptoms in the breast and is often presented with initial symptoms of axillary lymph node metastasis or other metastases. The low incidence rates of OBC make it a great challenge to diagnose and cure. Patient concerns: Our case was a 58-year-old female affected by dizziness and fatigue for nearly a month. Blood tests revealed anemia and thrombocytopenia, and pathological results of a bone marrow biopsy...

  11. Efficacy of benazepril hydrochloride to delay the progression of occult dilated cardiomyopathy in Doberman Pinschers.

    O'Grady, M R; O'Sullivan, M L; Minors, S L; Horne, R

    2009-01-01

    Angiotensin converting enzyme inhibitors (ACEIs) are recommended in people to treat asymptomatic (occult) dilated cardiomyopathy (DCM). Efficacy of therapy in occult DCM in dogs is unknown. ACEIs, specifically benazepril hydrochloride (BH), will delay the onset of overt DCM in Doberman Pinschers. Ninety-one Doberman Pinschers were studied, 57 dogs received BH, and 34 dogs no ACEI. Retrospective study of the medical records of all Doberman Pinschers with occult DCM that received BH or no ACEI between April 1989 and February 2003. Two criteria of left ventricular enlargement were used for enrollment: one independent of body weight (BW) (C1) and the other indexed to BW (C2). Cox proportional hazards analyses were used to identify variables associated with the onset of overt DCM. On univariate analysis the median time to onset of overt DCM was significantly longer for the benazepril group (for C1: 425 days for BH, 95% confidence interval [CI] 264-625 days; 339 days for no ACEI, CI 172-453 days, P= .02; for C2: 454 days for BH, CI 264-628 days; 356 days for no ACEI, CI 181-547 days, P= .02). The hazard ratio (HR) (benazepril/no ACEI) was 0.57, CI 0.35-0.94, P= .03 for C1; HR = 0.56, CI 0.34-0.93, P= .02 for C2. On multivariate analysis, BH significantly delayed onset of overt DCM (HR [benazepril/no ACEI] = 0.45, CI 0.26-0.78, P < .01, for C1; HR = 0.36, CI 0.21-0.63, P < .01, for C2). BH in particular and ACEIs in general might delay the progression of occult DCM. Prospective studies are warranted to test this theory.

  12. Thermal structure of intense convective clouds derived from GPS radio occultations

    Biondi, Riccardo; Randel, W. J.; Ho, S. -P.

    2012-01-01

    Thermal structure associated with deep convective clouds is investigated using Global Positioning System (GPS) radio occultation measurements. GPS data are insensitive to the presence of clouds, and provide high vertical resolution and high accuracy measurements to identify associated temperature...... behavior. Deep convective systems are identified using International Satellite Cloud Climatology Project (ISCCP) satellite data, and cloud tops are accurately measured using Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO) lidar observations; we focus on 53 cases of near-coincident GPS...

  13. Thermal structure of intense convective clouds derived from GPS radio occultations

    Biondi, Riccardo; Randel, W. J.; Ho, S.-P.

    2011-01-01

    Thermal structure associated with deep convective clouds is investigated using Global Positioning System (GPS) radio occultation measurements. GPS data are insensitive to the presence of clouds, and provide high vertical resolution and high accuracy measurements to identify associated temperature...... behavior. Deep convective systems are identified using International Satellite Cloud Climatology Project (ISCCP) satellite data, and cloud tops are accurately measured using Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO) lidar observations; we focus on 53 cases of near-coincident GPS...

  14. The use of MRI and CT in Imaging Occult Hip Fractures

    Obadă B.

    2014-11-01

    Full Text Available Diagnosis of hip fractures is particularly important due to the high dependence on the integrity of this structure for people to function in their daily lives. Left unrecognized, patients face increasing morbidity and mortality as time from the original injury lengthens. A delay of just 2 days in surgical treatment for an acute hip fracture doubles mortality. In addition, an unrecognized non-displaced fracture may displace, requiring surgery of much higher risk. This may be part of the reason that the most frequent lawsuit against Emergency Physicians is for missed orthopedic injury. We reviewed the use of MRI and CT for occult hip fractures (OHF detection at a major urban trauma unit. Our study is a retrospective review. Inclusion criteria: all patients presenting to the Emergency Clinical Hospital of Constanta with a suspected, posttraumatic, occult hip fracture, over a 5 years period were included. All patients had negative initial radiographs and underwent further imaging with either CT or MRI. A total of 185 cases meeting the inclusion criteria were identified. 72 occult hip fractures were detected with both imaging modalities. Although MRI certainly enables greater image detail, in our experience both modalities are able to provide satisfactory fracture characterization. The choice of imaging should be determined by availability and indication. MRI provides superior imaging of soft tissue but is less sensitive for degenerative changes in presence of bone edema.

  15. Verify Occulter Deployment Tolerances as Part of NASA's Technology Development for Exoplanet Missions

    Kasdin, N. J.; Shaklan, S.; Lisman, D.; Thomson, M.; Webb, D.; Cady, E.; Marks, G. W.; Lo, A.

    2013-01-01

    In support of NASA's Exoplanet Exploration Program and the Technology Development for Exoplanet Missions (TDEM), we recently completed a 2 year study of the manufacturability and metrology of starshade petals. An external occult is a satellite employing a large screen, or starshade, that flies in formation with a spaceborne telescope to provide the starlight suppression needed for detecting and characterizing exoplanets. Among the advantages of using an occulter are the broadband allowed for characterization and the removal of light before entering the observatory, greatly relaxing the requirements on the telescope and instrument. This poster presents the results of our successful first TDEM that demonstrated an occulter petal could be built and measured to an accuracy consistent with close to 10^-10 contrast. We also present the progress in our second TDEM to demonstrate the next critical technology milestone: precision deployment of the central truss and petals to the necessary accuracy. We have completed manufacture of four sub-scale petals and a central hub to fit with an existing deployable truss. We show the plans for repeated stow and deploy tests of the assembly and the metrology to confirm that each deploy repeatably meets the absolute positioning requirements of the petals (better than 1.0 mm).

  16. Verifying occulter deployment tolerances as part of NASA's technology development for exoplanet missions

    Kasdin, N. J.; Lisman, D.; Shaklan, S.; Thomson, M.; Webb, D.; Cady, E.; Marks, G. W.; Lo, A.

    2013-09-01

    An external occulter is a satellite employing a large screen, or starshade, that flies in formation with a spaceborne telescope to provide the starlight suppression needed for detecting and characterizing exoplanets. Among the advantages of using an occulter are the broadband allowed for characterization and the removal of light before entering the observatory, greatly relaxing the requirements on the telescope and instrument. In support of NASA's Exoplanet Exploration Program and the Technology Development for Exoplanet Missions (TDEM), we recently completed a 2 year study of the manufacturability and metrology of starshade petals. In this paper we review the results of that successful first TDEM which demonstrated an occulter petal could be built and measured to an accuracy consistent with close to 10-10 contrast. We then present the results of our second TDEM to demonstrate the next critical technology milestone: precision deployment of the central truss and petals to the necessary accuracy. We show the deployment of an existing deployable truss outfitted with four sub-scale petals and a custom designed central hub.

  17. The Centaur Chariklo and its rings system from stellar occultations in 2017

    Leiva, Rodrigo; Sicardy, Bruno; Camargo, Julio; Ortiz, Jose Luis; Berard, Diane; Desmars, Josselin; Chariklo Occultations Team; Rio Group; Lucky Star Occultation Team; Granada Occultation Team

    2017-10-01

    A stellar occultation in June 3, 2013 revealed the presence of a dense ring system around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 2014). Subsequent analysis of occultation data and long-term photometric variations indicate that Chariklo's body is elongated (Leiva et al. 2017, submitted) and that the main ring exhibits significant longitudinal variations of the radial width (Bérard et al. 2017, in press). We report three multi-chord high-quality stellar occultation by Chariklo on April 9, 2017 and June 22, 2017 from Namibia, and July 23 2017 from South America. The analysis of this new data set is underway, but preliminary results are consistent with triaxial ellipsoidal models. From this analysis we will:-present refined models for the size and shape of Chariklo's main body andevaluate the heights and slopes of its topographic features.-give constraints on the longitudinal width variations of Chariklo's rings andexplore the possibility to obtain the rings apsidal precession rate.Chariklo's shape and topography have strong consequences on the dynamics of the rings through Lindblad-type resonances between mean motion of the ring particles and the spin of the main body, while the rings precession rate gives constraints on the dynamical oblateness of the main body.**Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ ERC Grant Agreement n 669416 ”LUCKY STAR”).

  18. First lunar occultation results from the 2.4 m Thai national telescope equipped with ULTRASPEC

    Richichi, A.; Irawati, P.; Soonthornthum, B. [National Astronomical Research Institute of Thailand, 191 Siriphanich Building, Huay Kaew Road, Suthep, Muang, Chiang Mai 50200 (Thailand); Dhillon, V. S. [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom); Marsh, T. R., E-mail: andrea4work@gmail.com [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom)

    2014-11-01

    The recently inaugurated 2.4 m Thai National Telescope (TNT) is equipped with, among other instruments, the ULTRASPEC low-noise, frame-transfer EMCCD camera. At the end of its first official observing season, we report on the use of this facility to record high time resolution imaging using small detector subarrays with a sampling as fast as several 10{sup 2} Hz. In particular, we have recorded lunar occultations of several stars that represent the first contribution to this area of research made from Southeast Asia with a telescope of this class. Among the results, we discuss an accurate measurement of α Cnc, which has been reported previously as a suspected close binary. Attempts by several authors to resolve this star have so far met with a lack of unambiguous confirmation. With our observation we are able to place stringent limits on the projected angular separation (<0.''003) and brightness (Δm > 5) of a putative companion. We also present a measurement of the binary HR 7072, which extends considerably the time coverage available for its yet undetermined orbit. We discuss our precise determination of the flux ratio and projected separation in the context of other available data. We conclude by providing an estimate of the performance of ULTRASPEC at TNT for lunar occultation work. This facility can help to extend the lunar occultation technique in a geographical area where no comparable resources were available until now.

  19. Astrometry of the Orcus/Vanth occultation on UT 7 March 2017

    Bosh, Amanda S.; Zuluaga, Carlos; Levine, Stephen; Sickafoose, Amanda A.; Genade, Anja; Schindler, Karsten; Lister, Tim; Person, Michael J.

    2017-10-01

    On UT 7 March 2017, Orcus was predicted to occult a star with m=14.3. Observations were made at five observatories: the 0.6-m Astronomical Telescope of the University of Stuttgart (ATUS) at Sierra Remote Observatories (SRO), California; Las Cumbres Observatory’s 1-m telescope (ELP) at McDonald Observatory, Fort Davis, Texas; NASA’s 3-m InfraRed Telescope Facility (IRTF) on Mauna Kea, Hawaii; the 4.1-m Southern Astrophysical Research telescope (SOAR) on Cerro Pachón, Chile; and the 0.6-m Southeastern Association for Research in Astronomy telescope (SARA-CT) at Cerro Tololo, Chile. While observations at all sites were successful, only two—ELP and IRTF—observed solid-body occultation signatures. We will discuss the various predictions for this event and the reasons for the differences among them, including an offset of 130 mas for the star position from the position in the Gaia catalog. The sum of the positive and negative detections place constraints on the geometry of the Orcus/Vanth system, and we present our astrometric results for the geometric solution for this occultation. The implications of the light curve analyses are presented by Sickafoose et al., this conference.

  20. Usefullness of routine use of fecal occult blood test in a hospital setting

    Simona Ravnik

    2006-12-01

    Full Text Available Background: Fecal occult blood test, hematest, is a well excepted non-invasive method used for detecting different diseases of the gastrointestinal tract. It was proven in different randomized studies that usage of this simple method may facilitate further diagnostic and therapeutic treatment.Patients and methods: The retrospective analysis includes patients, which were admitted to the gastroenterological and endoscopy department of the General hospital Maribor in the last quarter of the year 2005. In all patients fecal occult blood test was performed.Results: We examined 200 patients, 104 women and 96 men, average age 63.9 years, SD±16.9, ranging from 21 to 97 years. Positive hematest was discovered in 76 patients (38 %. The source of hemorrhage from the upper digestive tract was confirmed in 37 patients (48.6 % of all positive tests and from the lower digestive tract in 34 patients (46 % of all positive tests. The most frequent causes of hemorrhage from the lower digestive tract were chronic inflammatory bowel disease (13.1 % of all positive tests, colorectal cancer (10.5 % and polyps (6.6 %. The source of hemorrhage was not located in five patients (6.6 % of all positive tests despite the accurate diagnostic procedure.Conclusions: By performing a fecal occult blood screening in non-symptomatic patients, we can make an essential step towards discovering different gastrointestinal diseases, even colorectal cancer in its early, limited form, when the effect of treatment is greatest.

  1. TITAN’S UPPER ATMOSPHERE FROM CASSINI/UVIS SOLAR OCCULTATIONS

    Capalbo, Fernando J.; Bénilan, Yves [Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA), UMR 7583 du CNRS, Universités Paris Est Créteil (UPEC) and Paris Diderot - UPD, 61 avenue du Général de Gaulle, F-94010, Créteil Cédex (France); Yelle, Roger V.; Koskinen, Tommi T., E-mail: fernando.capalbo@lisa.u-pec.fr [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States)

    2015-12-01

    Titan’s atmosphere is composed mainly of molecular nitrogen, methane being the principal trace gas. From the analysis of 8 solar occultations measured by the Extreme Ultraviolet channel of the Ultraviolet Imaging Spectrograph (UVIS) on board Cassini, we derived vertical profiles of N{sub 2} in the range 1100–1600 km and vertical profiles of CH{sub 4} in the range 850–1300 km. The correction of instrument effects and observational effects applied to the data are described. We present CH{sub 4} mole fractions, and average temperatures for the upper atmosphere obtained from the N{sub 2} profiles. The occultations correspond to different times and locations, and an analysis of variability of density and temperature is presented. The temperatures were analyzed as a function of geographical and temporal variables, without finding a clear correlation with any of them, although a trend of decreasing temperature toward the north pole was observed. The globally averaged temperature obtained is (150 ± 1) K. We compared our results from solar occultations with those derived from other UVIS observations, as well as studies performed with other instruments. The observational data we present confirm the atmospheric variability previously observed, add new information to the global picture of Titan’s upper atmosphere composition, variability, and dynamics, and provide new constraints to photochemical models.

  2. Cassini UVIS solar occultations by Saturn's F ring and the detection of collision-produced micron-sized dust

    Becker, Tracy M.; Colwell, Joshua E.; Esposito, Larry W.; Attree, Nicholas O.; Murray, Carl D.

    2018-05-01

    We present an analysis of eleven solar occultations by Saturn's F ring observed by the Ultraviolet Imaging Spectrograph (UVIS) on the Cassini spacecraft. In four of the solar occultations we detect an unambiguous signal from diffracted sunlight that adds to the direct solar signal just before or after the occultations occur. The strongest detection was a 10% increase over the direct signal that was enabled by the accidental misalignment of the instrument's pointing. We compare the UVIS data with images of the F ring obtained by the Cassini Imaging Science Subsystem (ISS) and find that in each instance of an unambiguous diffraction signature in the UVIS data, the ISS data shows that there was a recent disturbance in that region of the F ring. Similarly, the ISS images show a quiescent region of the F ring for all solar occultations in which no diffraction signature was detected. We therefore conclude that collisions in the F ring produce a population of small ring particles that can produce a detectable diffraction signal immediately interior or exterior to the F ring. The clearest example of this connection comes from the strong detection of diffracted light in the 2007 solar occultation, when the portion of the F ring that occulted the Sun had suffered a large collisional event, likely with S/2004 S 6, several months prior. This collision was observed in a series of ISS images (Murray et al., 2008). Our spectral analysis of the data shows no significant spectral features in the F ring, indicating that the particles must be at least 0.2 μm in radius. We apply a forward model of the solar occultations, accounting for the effects of diffracted light and the attenuated direct solar signal, to model the observed solar occultation light curves. These models constrain the optical depth, radial width, and particle size distribution of the F ring. We find that when the diffraction signature is present, we can best reproduce the occultation data using a particle population

  3. Atmospheric gravity wave detection following the 2011 Tohoku earthquakes combining COSMIC occultation and GPS observations

    Yan, X.; Tao, Y.; Xia, C.; Qi, Y.; Zuo, X.

    2017-12-01

    Several studies have reported the earthquake-induced atmospheric gravity waves detected by some new technologies such as airglow (Makela et al., 2011), GOCE (Garcia et al., 2013), GRACE (Yang et al., 2014), F3/C radio occultation sounding (Coïsson et al., 2015). In this work, we collected all occultation events on 11 March, and selected four events to analyze at last. The original and filtered podTEC is represented as function of the altitude of the impact parameter and UT of the four events. Then, the travel time diagrams of filtered podTEC derived from the events were analyzed. The occultation signal from one event (marked as No.73) is consistent with the previous results reported by Coïsson. 2015, which is corresponds to the ionospheric signal induced from tsunami gravity wave. What is noticeable, in this work, is that three occultation events of No.403, 77 and 118 revealed a disturbance of atmospheric gravity wave with velocity 300m/s, preceding the tsunami. It would probably be correspond to the gravity waves caused by seismic rupture but not tsunami. In addition, it can be seen that the perturbation height of occultation observation TEC is concentrated at 200-400km, corresponding ionosphere F region. The signals detected above are compared with GPS measurements of TEC from GEONET and IGS. From GPS data, traveling ionospheric disturbances were observed spreading out from the epicenter as a quasi-circular propagation pattern with the time. Exactly, we observed an acoustic wave coupled with Rayleigh wave starting from the epicenter with a speed of 3.0km/s and a superimposed acoustic-gravity wave moving with a speed of 800m/s. The acoustic-gravity wave generated at the epicenter and gradually attenuated 800km away, then it is replaced by a gravity wave coupled with the tsunami that moves with a speed of between 100 and 300m/s. It is necessary to confirm the propagation process of the waves if we attempt to evaluate the use of ionospheric seismology as a

  4. Vaginal Infections

    ... gov/ Home Body Your reproductive health Vaginal infections Vaginal infections Help for infections If you have pain, ... infections and how to prevent them. Types of vaginal infections top Two common vaginal infections are bacterial ...

  5. Infective Endocarditis

    ... Center > Infective Endocarditis Menu Topics Topics FAQs Infective Endocarditis En español Infective endocarditis is an infection of ... time, congestive heart failure (CHF). What causes infective endocarditis? The infection that leads to endocarditis can be ...

  6. Positioning irrigation of contrast cystography for diagnosis of occult vesicoureteric reflux: association with technetium-99m dimercaptosuccinic acid scans.

    Berger, Christoph; Becker, Tanja; Koen, Mark; Zeino, Mazen; Fitz, Friedrich; Beheshti, Mohsen; Wolf-Kohlmeier, Iris; Haim, Silke; Riccabona, Marcus

    2013-12-01

    Positioning irrigation of contrast (PIC) cystography identifies occult or PIC vesicoureteral reflux (PIC-VUR) in children with recurrent febrile urinary tract infections (UTI) but no vesicoureteric reflux (VUR) on standard voiding cystourethrogram (VCUG). We sought to identify the relationship between PIC-VUR and renal scarring in technetium-99m dimercaptosuccinic acid (DMSA) scans. We retrospectively analysed PIC cystograms and DMSA scans for 154 kidneys in 81 children (65 girls; 16 boys; median age, 4.7 years; range, 0.9-15.2). Renal scarring was graded on a scale of 0-3. DMSA scans were pathologic in 66 patients (81%). Children had experienced mean 3.8 febrile UTI (range 1-25). Forty-seven (58%) children had a history of reflux, including 15 (19%) with previous anti-reflux operations. Indications for PIC cystography were recurrence of febrile UTI after either bilateral negative VCUG (66 children) or unilateral VUR (15 children) with contralateral/bilateral scarring or reflux that had changed sides in subsequent VCUGs. PIC-VUR was bilateral in 63, unilateral in 12, and absent in 6 children. Statistically significant associations between PIC-VUR grade and severity of renal scarring were identified in inter-individual (n = 77, p = 0.017) and intra-individual (refluxing vs. nonrefluxing kidney; n = 12, p = 0.008) analyses. After excluding patients with history of VUR, statistical significance was maintained in inter-individual analysis (n = 49; p = 0.018). The data suggest an association between PIC-VUR and severity of renal scarring, and legitimise the use of PIC cystography in children with renal scarring due to recurrent febrile UTI but negative findings on VCUG. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  7. Occultism in an African context: a case for the Vhavenda-speaking people of the Limpopo Province

    T. D. Mashau

    2007-07-01

    Full Text Available Occultism in Africa is as old as the primal religion itself, or what came to be known as African Traditional Religion (ATR in mo- dern times. It dates back to time immemorial. Occultism in Africa has taken various forms and has manifested in different ways over the ages, i.e. spiritism, divination, witchcraft and ma- gic. The underlying premise of African occultism is the belief in a spiritual world with spiritual forces that have power to inflict harm on the living. In the traditional African worldview suffering of every sort – illness, barrenness, drought and death – is nor- mally explained in personal terms: “there is always somebody”. This “somebody” often belongs to the world of the occult: a “spirit” has brought pain to human beings and must therefore be repelled or accommodated. This is very common among the Vhavenda-speaking people of the Limpopo Province. This ar- ticle seeks to investigate how occultism is practised among these people and to provide a reformed perspective as to how people who are suffering under demonic attacks can be helped. Contrary to other Christian traditions that see exorcism as the only way out, reformed theology suggests a missio-pastoral approach in dealing with the problem.

  8. Spatial patterns of whole brain grey and white matter injury in patients with occult spastic diplegic cerebral palsy.

    Mu, Xuetao; Nie, Binbin; Wang, Hong; Duan, Shaofeng; Zhang, Zan; Dai, Guanghui; Ma, Qiaozhi; Shan, Baoci; Ma, Lin

    2014-01-01

    Spastic diplegic cerebral palsy (SDCP) is a common type of cerebral palsy (CP), which presents as a group of motor-impairment syndromes. Previous conventional MRI studies have reported abnormal structural changes in SDCP, such as periventricular leucomalacia. However, there are roughly 27.8% SDCP patients presenting normal appearance in conventional MRI, which were considered as occult SDCP. In this study, sixteen patients with occult SDCP and 16 age- and sex-matched healthy control subjects were collected and the data were acquired on a 3T MR system. We applied voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis to investigate whole brain grey and white matter injury in occult SDCP. By using VBM method, the grey matter volume reduction was revealed in the bilateral basal ganglia regions, thalamus, insula, and left cerebral peduncle, whereas the white matter atrophy was found to be located in the posterior part of corpus callosum and right posterior corona radiata in the occult SDCP patients. By using TBSS, reduced fractional anisotropy (FA) values were detected in multiple white matter regions, including bilateral white matter tracts in prefrontal lobe, temporal lobe, internal and external capsule, corpus callosum, cingulum, thalamus, brainstem and cerebellum. Additionally, several regions of white matter tracts injury were found to be significantly correlated with motor dysfunction. These results collectively revealed the spatial patterns of whole brain grey and white matter injury in occult SDCP.

  9. Clinical features of secondary glaucoma caused by lens suspensory ligament laxity or occult subluxation

    Yi Ma

    2018-04-01

    Full Text Available AIM: To investigate the clinical characteristics of secondary glaucoma caused by lens suspensory ligament laxity or occult subluxation, and to analyze the influence of operation on visual acuity and intraocular pressure(IOP. METHODS: Totally 38 cases(38 eyesof the secondary glaucoma caused by lens suspensory ligament laxity or occult subluxation in ophthalmology department of our hospital from December 2014 to December 2016 were enrolled and their medical records were analyzed retrospectively to observe the clinical characteristics of glaucoma. Preoperative mydriasis was carried out and surgical methods were chosen according to the lenses location and extent of suspensory ligament. Preoperative and postoperative anterior chamber depth, corneal endothelial cell density, IOP, visual field, visual acuity and complications were analyzed. RESULTS: The average intraocular pressure was 18.17±1.43mmHg at postoperatively 10d, which was significantly lower than 38.77±2.45mmHg before operation, the difference had statistical significance(PP>0.05. The postoperative anterior chamber depth was 2.45±0.44mm, which was significantly higher than 1.23±0.35mm before operation, the difference had statistical significance(P2 and decreased significantly, compared with 1735.32±340.32/mm2 before operation, the difference had statistical significance(PCONCLUSION: Clinical symptoms and signs of secondary glaucoma in patients with lens suspensory ligament laxity or occult subluxation are more complex, which needs to be distinguished with other types of glaucoma in clinical treatment, and its surgical methods shall be chosen according to different suspensory ligament site and lens subluxation scope.

  10. Prognosis for Mammographically Occult, Early-Stage Breast Cancer Patients Treated With Breast-Conservation Therapy

    Yang, Tzu-I. J.; Yang Qifeng; Haffty, Bruce G.; Moran, Meena S.

    2010-01-01

    Purpose: To compare mammographically occult (MamOcc) and mammographically positive (MamPos) early-stage breast cancer patients treated with breast-conservation therapy (BCT), to analyze differences between the two cohorts. Methods and Materials: Our two cohorts consisted of 214 MamOcc and 2168 MamPos patients treated with BCT. Chart reviews were conducted to assess mammogram reports and method of detection. All clinical-pathologic and outcome parameters were analyzed to detect differences between the two cohorts. Results: Median follow-up was 7 years. There were no differences in final margins, T stage, nodal status, estrogen/progesterone receptor status, or 'triple-negative' status. Significant differences included younger age at diagnosis (p o histology (p < 0.0001). At 10 years, the differences in overall survival, cause-specific survival, and distant relapse between the two groups did not differ significantly. The MamOcc cohort had more breast relapses (15% vs. 8%; p = 0.0357), but on multivariate analysis this difference was not significant (hazard ratio 1.0, 95% confidence interval 0.993-1.007, p = 0.9296). Breast relapses were mammographically occult in 32% of the MamOcc and 12% of the MamPos cohorts (p = 0.0136). Conclusions: Although our study suggests that there are clinical-pathologic variations for the MamOcc cohort vs. MamPos patients that may ultimately affect management, breast relapse after BCT was not significantly different. Breast recurrences were more often mammographically occult in the MamOcc cohort; consideration should be given to closer follow-up and alternative imaging strategies (ultrasound, breast MRI) for routine posttreatment examination. To our knowledge, this represents the largest series addressing the prognostic significance of MamOcc cancers treated with BCT.

  11. The effect of solar radio bursts on the GNSS radio occultation signals

    Yue, Xinan; Schreiner, William S.; Kuo, Ying-Hwa; Zhao, Biqiang; Wan, Weixing; Ren, Zhipeng; Liu, Libo; Wei, Yong; Lei, Jiuhou; Solomon, Stan; Rocken, Christian

    2013-09-01

    radio burst (SRB) is the radio wave emission after a solar flare, covering a broad frequency range, originated from the Sun's atmosphere. During the SRB occurrence, some specific frequency radio wave could interfere with the Global Navigation Satellite System (GNSS) signals and therefore disturb the received signals. In this study, the low Earth orbit- (LEO-) based high-resolution GNSS radio occultation (RO) signals from multiple satellites (COSMIC, CHAMP, GRACE, SAC-C, Metop-A, and TerraSAR-X) processed in University Corporation for Atmospheric Research (UCAR) were first used to evaluate the effect of SRB on the RO technique. The radio solar telescope network (RSTN) observed radio flux was used to represent SRB occurrence. An extreme case during 6 December 2006 and statistical analysis during April 2006 to September 2012 were studied. The LEO RO signals show frequent loss of lock (LOL), simultaneous decrease on L1 and L2 signal-to-noise ratio (SNR) globally during daytime, small-scale perturbations of SNR, and decreased successful retrieval percentage (SRP) for both ionospheric and atmospheric occultations during SRB occurrence. A potential harmonic band interference was identified. Either decreased data volume or data quality will influence weather prediction, climate study, and space weather monitoring by using RO data during SRB time. Statistically, the SRP of ionospheric and atmospheric occultation retrieval shows ~4% and ~13% decrease, respectively, while the SNR of L1 and L2 show ~5.7% and ~11.7% decrease, respectively. A threshold value of ~1807 SFU of 1415 MHz frequency, which can result in observable GNSS SNR decrease, was derived based on our statistical analysis.

  12. Ionospheric Remote Sensing using GPS Radio Occultation and Ultraviolet Photometry aboard the ISS

    Budzien, S. A.; Powell, S. P.; O'Hanlon, B.; Humphreys, T.; Bishop, R. L.; Stephan, A. W.; Gross, J.; Chakrabarti, S.

    2017-12-01

    The GPS Radio Occultation and Ultraviolet Photometer Co-located (GROUP-C) experiment launched to the International Space Station (ISS) on February 19, 2017 as part of the Space Test Program Houston #5 payload (STP-H5). After early orbit testing, GROUP-C began routine science operations in late April. GROUP-C includes a high-sensitivity far-ultraviolet photometer measuring horizontal nighttime ionospheric gradients and an advanced software-defined GPS receiver providing ionospheric electron density profiles, scintillation measurements, and lower atmosphere profiles. GROUP-C and a companion experiment, the Limb-Imaging Ionospheric and Thermospheric Extreme-Ultraviolet Spectrograph (LITES), offer a unique capability to study spatial and temporal variability of the thermosphere and ionosphere using multi-sensor approaches, including ionospheric tomography. Data are collected continuously across low- and mid-latitudes as the ISS orbit precesses through all local times every 60 days. The GROUP-C GPS sensor routinely collects dual-frequency GPS occultations, makes targeted raw signal captures of GPS and Galileo occultations, and includes multiple antennas to characterize multipath in the ISS environment. The UV photometer measures the 135.6 nm ionospheric recombination airglow emision along the nightside orbital track. We present the first analysis of ionospheric observations, discuss the challenges and opportunities of remote sensing from the ISS platform, and explore how these new data help address questions regarding the complex and dynamic features of the low and middle latitude ionosphere-thermosphere relevant to the upcoming GOLD and ICON missions.

  13. Detection of occult vertebral fractures by quantitative assessment of bone marrow attenuation values at MDCT

    Henes, Frank Oliver; Groth, Michael; Kramer, Harald; Schaefer, Christian; Regier, Marc; Derlin, Thorsten; Adam, Gerhard; Bannas, Peter

    2014-01-01

    Objectives: To determine a cut-off value of Hounsfield attenuation units (HU) at multidetector computed tomography (MDCT) for valid and reliable detection of bone marrow oedema (BME) related to occult vertebral fractures. Methods: 36 patients underwent both MDCT and Magnetic Resonance Imaging (MRI) for evaluation of vertebral fractures of the thoracolumbar spine and were included in this retrospective study. Two readers independently assessed HU values at MDCT in a total of 196 vertebrae. Reliability was assessed by intraclass correlation coefficient and Bland–Altman analysis. For each patient we determined the vertebra with the lowest HU value and calculated the HU-difference to each other vertebral body. HU-differences were subjected to receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy for detection of BME as determined by MRI, which served as the reference standard. Results of HU-measurements were compared with standard visual evaluation of MDCT. Results: HU measurements demonstrated a high interrater reliability (ICC = 0.984). ROC curve analysis (AUC = 0.978) exhibited an ideal cut-off value of 29.6 HU for detection of BME associated with vertebral fractures with an accuracy of 97.4% as compared to 93.4% accuracy of visual evaluation. Particularly, HU-measurements increased the sensitivity for detection of vertebral fractures from 78.0% to 92.7% due to the detection of 7 of 9 occult fractures that were missed by visual evaluation alone. Conclusions: Assessing bone marrow density by HU measurements using the cut-off of 29.6 HU is a valid and reliable tool for detection of BME related to occult vertebral fractures in MDCT. The introduced technique may allow more accurate treatment decisions and may make further diagnostic work-up with MRI unnecessary

  14. Detection of occult vertebral fractures by quantitative assessment of bone marrow attenuation values at MDCT

    Henes, Frank Oliver, E-mail: f.henes@uke.de [Department of Diagnostic and Interventional Radiology, Center for Radiology and Endoscopy, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Groth, Michael [Department of Diagnostic and Interventional Neuroradiology, Center for Radiology and Endoscopy, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Kramer, Harald [Department of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 Munich (Germany); Department of Radiology, University of Wisconsin – Madison, Clinical Science Center, 600 Highland Avenue, Madison, WI 53792 (United States); Schaefer, Christian [Department of Trauma-, Hand- and Reconstructive Surgery, Spine Center, Center for Surgical Sciences, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg (Germany); Regier, Marc; Derlin, Thorsten; Adam, Gerhard; Bannas, Peter [Department of Diagnostic and Interventional Radiology, Center for Radiology and Endoscopy, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    2014-01-15

    Objectives: To determine a cut-off value of Hounsfield attenuation units (HU) at multidetector computed tomography (MDCT) for valid and reliable detection of bone marrow oedema (BME) related to occult vertebral fractures. Methods: 36 patients underwent both MDCT and Magnetic Resonance Imaging (MRI) for evaluation of vertebral fractures of the thoracolumbar spine and were included in this retrospective study. Two readers independently assessed HU values at MDCT in a total of 196 vertebrae. Reliability was assessed by intraclass correlation coefficient and Bland–Altman analysis. For each patient we determined the vertebra with the lowest HU value and calculated the HU-difference to each other vertebral body. HU-differences were subjected to receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy for detection of BME as determined by MRI, which served as the reference standard. Results of HU-measurements were compared with standard visual evaluation of MDCT. Results: HU measurements demonstrated a high interrater reliability (ICC = 0.984). ROC curve analysis (AUC = 0.978) exhibited an ideal cut-off value of 29.6 HU for detection of BME associated with vertebral fractures with an accuracy of 97.4% as compared to 93.4% accuracy of visual evaluation. Particularly, HU-measurements increased the sensitivity for detection of vertebral fractures from 78.0% to 92.7% due to the detection of 7 of 9 occult fractures that were missed by visual evaluation alone. Conclusions: Assessing bone marrow density by HU measurements using the cut-off of 29.6 HU is a valid and reliable tool for detection of BME related to occult vertebral fractures in MDCT. The introduced technique may allow more accurate treatment decisions and may make further diagnostic work-up with MRI unnecessary.

  15. Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention

    Liskay, R.Michael

    2014-01-01

    Although Apc mutation is widely considered an initiating event in colorectal cancer, little is known about the earliest stages of tumorigenesis following sporadic Apc loss. Therefore, we have utilized a novel mouse model that facilitates the sporadic inactivation of Apc via frameshift reversion of Cre in single, isolated cells and subsequently tracks the fates of Apc-deficient intestinal cells. Our results suggest that consistent with Apc being a ‘gatekeeper’, loss of Apc early in life during intestinal growth leads to adenomas or increased crypt fission, manifested by fields of mutant but otherwise normal-appearing crypts. In contrast, Apc loss occurring later in life has minimal consequences, with mutant crypts being less prone to either increased crypt fission or adenoma formation. Using the stem cell-specific Lgr5-CreER mouse, we generated different sized fields of Apc-deficient crypts via independent recombination events and found that field size correlates with progression to adenoma. To evaluate this early stage prior to adenoma formation as a therapeutic target, we examined the chemopreventive effects of sulindac on Apc-deficient occult crypt fission. We found that sulindac treatment started early in life inhibits the morphologically occult spread of Apc-deficient crypts and thus reduces adenoma numbers. Taken together these results suggest that: (i) earlier Apc loss promotes increased crypt fission, (ii) a field of Apc-deficient crypts, which can form via occult crypt fission or independent neighboring events, is an important intermediate between loss of Apc and adenoma formation and (iii) normal-appearing Apc-deficient crypts are potential unappreciated targets for cancer screening and chemoprevention. PMID:23996931

  16. Astr 101 Students' Attitudes Towards Essays On Transits, Eclipses And Occultations

    D'Cruz, Noella L.

    2012-05-01

    Joliet Junior College, Joliet, IL offers a one semester introductory astronomy course each semester. We teach over 110 primarily non-science major students each semester. We use proven active learning strategies such lecture tutorials, think-pair-share questions and small group discussions to help these students develop and retain a good understanding of astrophysical concepts. Occasionally, we offer projects that allow students to explore course topics beyond the classroom. We hope that such projects will increase students' interest in astronomy. We also hope that these assignments will help students to improve their critical thinking and writing skills. In Spring 12, we are offering three short individual essay assignments in our face-to-face sections. The essays focus on transits, eclipses and occultations to highlight the 2012 transit of Venus. For the first essay, students will find images of transit and occultation events using the Astronomy Picture of the Day website and describe their chosen events. In addition, students will predict how variations in certain physical and orbital parameters would alter their particular events. The second essay involves transits, eclipses and occultations observed by spacecraft. Students will describe their transit event, their spacecraft's mission, orbital path, how the orbital path was achieved, etc. The third essay deals with transiting exoplanets. Students will choose at least two exoplanets from an exoplanet database, one of which has been discovered through the transit method. This essay will enable students to learn about detecting exoplanets and how they compare with our solar system. Details of the essay assignments and students' reactions to them will be presented at the meeting.

  17. Prediction of Occult Invasive Disease in Ductal Carcinoma in Situ Using Deep Learning Features.

    Shi, Bibo; Grimm, Lars J; Mazurowski, Maciej A; Baker, Jay A; Marks, Jeffrey R; King, Lorraine M; Maley, Carlo C; Hwang, E Shelley; Lo, Joseph Y

    2018-03-01

    The aim of this study was to determine whether deep features extracted from digital mammograms using a pretrained deep convolutional neural network are prognostic of occult invasive disease for patients with ductal carcinoma in situ (DCIS) on core needle biopsy. In this retrospective study, digital mammographic magnification views were collected for 99 subjects with DCIS at biopsy, 25 of which were subsequently upstaged to invasive cancer. A deep convolutional neural network model that was pretrained on nonmedical images (eg, animals, plants, instruments) was used as the feature extractor. Through a statistical pooling strategy, deep features were extracted at different levels of convolutional layers from the lesion areas, without sacrificing the original resolution or distorting the underlying topology. A multivariate classifier was then trained to predict which tumors contain occult invasive disease. This was compared with the performance of traditional "handcrafted" computer vision (CV) features previously developed specifically to assess mammographic calcifications. The generalization performance was assessed using Monte Carlo cross-validation and receiver operating characteristic curve analysis. Deep features were able to distinguish DCIS with occult invasion from pure DCIS, with an area under the receiver operating characteristic curve of 0.70 (95% confidence interval, 0.68-0.73). This performance was comparable with the handcrafted CV features (area under the curve = 0.68; 95% confidence interval, 0.66-0.71) that were designed with prior domain knowledge. Despite being pretrained on only nonmedical images, the deep features extracted from digital mammograms demonstrated comparable performance with handcrafted CV features for the challenging task of predicting DCIS upstaging. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  18. The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation.

    Ortiz, J L; Santos-Sanz, P; Sicardy, B; Benedetti-Rossi, G; Bérard, D; Morales, N; Duffard, R; Braga-Ribas, F; Hopp, U; Ries, C; Nascimbeni, V; Marzari, F; Granata, V; Pál, A; Kiss, C; Pribulla, T; Komžík, R; Hornoch, K; Pravec, P; Bacci, P; Maestripieri, M; Nerli, L; Mazzei, L; Bachini, M; Martinelli, F; Succi, G; Ciabattari, F; Mikuz, H; Carbognani, A; Gaehrken, B; Mottola, S; Hellmich, S; Rommel, F L; Fernández-Valenzuela, E; Bagatin, A Campo; Cikota, S; Cikota, A; Lecacheux, J; Vieira-Martins, R; Camargo, J I B; Assafin, M; Colas, F; Behrend, R; Desmars, J; Meza, E; Alvarez-Candal, A; Beisker, W; Gomes-Junior, A R; Morgado, B E; Roques, F; Vachier, F; Berthier, J; Mueller, T G; Madiedo, J M; Unsalan, O; Sonbas, E; Karaman, N; Erece, O; Koseoglu, D T; Ozisik, T; Kalkan, S; Guney, Y; Niaei, M S; Satir, O; Yesilyaprak, C; Puskullu, C; Kabas, A; Demircan, O; Alikakos, J; Charmandaris, V; Leto, G; Ohlert, J; Christille, J M; Szakáts, R; Farkas, A Takácsné; Varga-Verebélyi, E; Marton, G; Marciniak, A; Bartczak, P; Santana-Ros, T; Butkiewicz-Bąk, M; Dudziński, G; Alí-Lagoa, V; Gazeas, K; Tzouganatos, L; Paschalis, N; Tsamis, V; Sánchez-Lavega, A; Pérez-Hoyos, S; Hueso, R; Guirado, J C; Peris, V; Iglesias-Marzoa, R

    2017-10-11

    Haumea-one of the four known trans-Neptunian dwarf planets-is a very elongated and rapidly rotating body. In contrast to other dwarf planets, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system, and the Centaur Chiron was later found to possess something similar to Chariklo's rings. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea's equator and the orbit of its satellite Hi'iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea's spin period-that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea's largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.

  19. Radioguided breast surgery for occult lesion localization – correlation between two methods

    Gutfilen Bianca

    2008-08-01

    Full Text Available Abstract Background The detection of sub-clinical breast lesions has increased with screening mammography. Biopsy techniques can offer precision and agility in its execution, as well as patient comfort. This trial compares radioguided occult lesion localization (ROLL and wire-guided localization (WL of breast lesions. We investigate if a procedure at the ambulatorial level (ROLL could lead to a better aesthetic result and less postoperative pain. In addition, we intend to demonstrate the efficacy of radioguided localization and removal of occult breast lesions using radiopharmaceuticals injected directly into the lesions and correlate radiological and histopathological findings. Methods One hundred and twenty patients were randomized into two groups (59 WL and 61 ROLL. The patients were requested to score the cosmetic appearance of their breast after surgery, and a numerical rating scale was used to measure pain on the first postoperative day. Clearance margins were considered at ≥ 10 mm for invasive cancer, ≥ 5 mm for ductal carcinoma in situ, and ≥ 1 mm for benign disease. Patients were subsequently treated according to the definitive histological result. When appropriate, different statistical tests were used in order to test the significance between the two groups, considering a P value Results WL and ROLL located all the occult breast lesions successfully. In the ROLL group, the specimen volume was smaller and there were more cases with clear margins (P Conclusion ROLL is an effective method for the excision of non-palpable breast lesions. It enables more careful planning of the cutaneous incision, leading to better aesthetic results, less postoperative symptoms, and smaller volumes of excised tissue.

  20. The Transit Light Curve Project. VIII. Six Occultations of the Exoplanet TrES-3

    Winn, Joshua N.; Holman, Matthew J.; Shporer, Avi; Fernandez, Jose; Mazeh, Tsevi; Latham, David W.; Charbonneau, David; Everett, Mark E.

    2008-01-01

    We present photometry of the exoplanet host star TrES-3 spanning six occultations (secondary eclipses) of its giant planet. No flux decrements were detected, leading to 99%-confidence upper limits on the planet-to-star flux ratio of 0.00024, 0.0005, and 0.00086 in the i, z, and R bands respectively. The corresponding upper limits on the planet's geometric albedo are 0.30, 0.62, and 1.07. The upper limit in the i band rules out the presence of highly reflective clouds, and is only a factor of ...

  1. Goethe’s theory of colors between the ancient philosophy, middle ages occultism and modern science

    Victor Barsan

    2016-12-01

    Full Text Available Goethe’s rejection of Newton’s theory of colors is an interesting example of the vulnerability of the human mind—however brilliant it might be—to fanaticism. After an analysis of Goethe’s persistent fascination with magic and occultism, of his education, existential experiences, influences, and idiosyncrasies, the authors propose an original interpretation of his anti-Newtonian position. The relevance of Goethe’s Farbenlehre to physics and physiology, from the perspective of modern science, is discussed in detail.

  2. Investigation of particle sizes in Pluto's atmosphere from the 29 June 2015 occultation

    Sickafoose, Amanda A.; Bosh, A. S.; Person, M. J.; Zuluaga, C. A.; Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham, E. W.; McLean, I.; Wolf, J.; Abe, F.; Bida, T. A.; Bright, L. P.; Brothers, T.; Christie, G.; Collins, P. L.; Durst, R. F.; Gilmore, A. C.; Hamilton, R.; Harris, H. C.; Johnson, C.; Kilmartin, P. M.; Kosiarek, M. R.; Leppik, K.; Logsdon, S.; Lucas, R.; Mathers, S.; Morley, C. J. K.; Natusch, T.; Nelson, P.; Ngan, H.; Pfüller, E.; de, H.-P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.; Stockdale, C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristam, P. J.; Van Cleve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.; Wiedemann, M.

    2015-11-01

    The 29 June 2015 observations of a stellar occultation by Pluto, from SOFIA and ground-based sites in New Zealand, indicate that haze was present in the lower atmosphere (Bosh et al., this conference). Previously, slope changes in the occultation light curve profile of Pluto’s lower atmosphere have been attributed to haze, a steep thermal gradient, and/or a combination of the two. The most useful diagnostic for differentiating between these effects has been observing occultations over a range of wavelengths: haze scattering and absorption are functions of particle size and are wavelength dependent, whereas effects due to a temperature gradient should be largely independent of observational wavelength. The SOFIA and Mt. John data from this event exhibit obvious central flashes, from multiple telescopes observing over a range of wavelengths at each site (Person et al. and Pasachoff et al., this conference). SOFIA data include Red and Blue observations from the High-speed Imaging Photometer for Occultations (HIPO, at ~ 500 and 850 nm), First Light Infrared Test Camera (FLITECAM, at ~1800 nm), and the Focal Plan Imager (FPI+, at ~ 600 nm). Mt. John data include open filter, g', r', i', and near infrared. Here, we analyze the flux at the bottom of the light curves versus observed wavelength. We find that there is a distinct trend in flux versus wavelength, and we discuss applicable Mie scattering models for different particle size distributions and compositions (as were used to characterize haze in Pluto's lower atmosphere in Gulbis et al. 2015).SOFIA is jointly operated by the Universities Space Research Association, Inc. (USRA), under NASA contract NAS2-97001, and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901 to the University of Stuttgart. Support for this work was provided by the National Research Foundation of South Africa, NASA SSO grants NNX15AJ82G (Lowell Observatory), PA NNX10AB27G (MIT), and PA NNX12AJ29G (Williams College), and the NASA

  3. Electron number density profiles derived from radio occultation on the CASSIOPE spacecraft

    Shume, E. B.; Vergados, P.; Komjathy, A.

    2017-01-01

    This paper presents electron number density profiles derived from high resolution Global Positioning System (GPS) radio occultation (RO) observations performed using the Enhanced Polar Outflow Probe (e-POP) payload on the high inclination CAScade, Smallsat and IOnospheric Polar Explorer (CASSIOPE...... good agreement with density profiles estimated from ionosonde data, measured over nearby stations to the latitude and longitude of the RO tangent points, (2) in good agreement with density profiles inferred from GPS RO measured by the Constellation Observing System for Meteorology, Ionosphere...

  4. Impact of GPS Radio Occultation Refractivity Soundings on a Simulation of Typhoon Bilis (2006 upon Landfall

    Mien-Tze Kueh

    2009-01-01

    Full Text Available Typhoon Bilis which struck Taiwan in July 2006 was chosen to assess the potential impact of GPS radio occultation (RO refractivity soundings on numerical simulation using the WRF model. We found that this case elucidates the impact of the limited GPS RO soundings on typhoon prediction due to their favorable locations. In addition, on top of available precipitable water (PW and near-surface wind speed from SSM/I data, we have also explored their combined impacts on model prediction.

  5. GEROS-ISS: GNSS REflectometry, Radio Occultation and Scatterometry onboard the International Space Station

    Wickert, Jens; Cardellach, Estel; Bandeiras, Jorge

    2016-01-01

    GEROS-ISS stands for GNSS REflectometry, radio occultation, and scatterometry onboard the International Space Station (ISS). It is a scientific experiment, successfully proposed to the European Space Agency in 2011. The experiment as the name indicates will be conducted on the ISS. The main focus...... of GEROS-ISS is the dedicated use of signals from the currently available Global Navigation Satellite Systems (GNSS) in L-band for remote sensing of the Earth with a focus to study climate change. Prime mission objectives are the determination of the altimetric sea surface height of the oceans...

  6. Theory for the effects of turbulence in a planetary atmosphere on radio occultation

    Woo, R.; Ishimaru, A.

    1974-01-01

    Rytov's method is used to formulate the correlation functions for log-amplitude and phase fluctuations for both spherical and plane wave propagation in a turbulent medium whose correlation function for refractive index fluctuations is described by the product of a function of the average coordinate and a function of the difference coordinate. The results are applied to the study of radio occultation effects due to the atmosphere of Venus in the case of a flyby space probe. It is assumed that turbulence of isotropic and smoothly varying characteristics occurs in the Venusian atmosphere.

  7. Sonographic swelling of pronator quadratus muscle in patients with occult bone injury

    Sato, Junko; Ishii, Yoshinori; Noguchi, Hideo; Toyabe, Shin-ichi

    2015-01-01

    The disarranged fat stripe of the pronator quadratus muscle (PQ) on radiographs (the PQ sign) is reported to be predictive of subtle bone fractures. This study aimed to report the results of magnetic resonance imaging (MRI) study in the patients in whom bone injury was not radiographically detected around the wrist joint, and the PQ was sonographically swollen following acute trauma. We evaluated sonographically the PQ of 55 patients who showed normal radiographs following acute trauma. The sonographic appearance of the PQ was checked on both longitudinal and transverse images. On the longitudinal image, the probe was positioned along the flexor carpi radialis tendon. For the transverse image, we adopted the image of the same level in which the PQ of the unaffected hand showed maximal thickness. The PQ was considered to be swollen with disproportionate hyperechogenicity and/or thickening compared with the unaffected side at least in one of the two images. Of the 55 patients, 25 patients whose PQ was considered to be swollen underwent MRI study. PQ thickness in millimeters was retrospectively measured on longitudinal and transverse sonographic images. Twenty-three patients (92.0%) had occult bone injury, and two adult patients (8.0%) showed only wrist joint effusion on MRI. Among these 23, the distal radius was the most frequent location of the occult bone injury (20 patients; 9 [36.0%] with an occult fracture line and 11 [44.0%] with bone bruising). In longitudinal image, the mean value of the PQ thickness of affected hands was 6.2 (3.7–9.6 mm; standard deviation [SD], 1.5) and that of unaffected hands was 4.5 (2.3–6.7 mm; SD, 1.2), respectively. In transverse image, that of dominant and nondominant hands was 7.6 (4.6–13.2 mm; SD, 2.0) and 5.5 (3.6–7.5 mm; SD, 1.1), respectively. The mean difference in PQ thickness between affected and unaffected hands was 1.7 (0.1–5.0 mm; SD, 1.1) in longitudinal image and 2.0 (0.3–6.8 mm; SD, 1.7) in transverse image

  8. Astrology and other occult sciences in seventeenth-century New Spain.

    Avalos, Ana

    2006-01-01

    This article focuses on the relationship and mutual influence of astrology and other so-called occult sciences within the context of seventeenth-century New Spain. By presenting some case studies of inquisitorial trials against astrologers, it explores the interrelation between astrological and physiognomical ideas and practices in order to shed some light on the moral dimension of these natural philosophical fields of knowledge. During the early modern period, both astrology and physiognomy were regarded as tools for self-understanding and the understanding of others by means of interpretation of natural signs. Thus their history is key for understanding the shaping of the boundaries between the natural and the moral realms.

  9. Determinants of participation in colorectal cancer screening with faecal occult blood testing

    von Euler-Chelpin, My; Brasso, Klaus; Lynge, Elsebeth

    2009-01-01

    BACKGROUND: Colorectal cancer is one of the most common cancers in men and women. Participation rates in faecal occult blood testing (FOBT) screening activities are, however, relatively low. In terms of lowering the colorectal cancer mortality, high participation rates are essential, and therefore......, but determinants varied across countries and test settings. There was no systematic variation in participation across age groups. CONCLUSION: The participation pattern depends in part on local circumstances, which makes it difficult to point to a general strategy for increasing the uptake in FOBT screening...

  10. Unusual Case of Occult Brucella Osteomyelitis in the Skull Detected by Bone Scintigraphy

    Sohn, Myung Hee; Lim, Seok Tae; Jeong, Young Jin; Kim, Dong Wook; Jeong, Hwan Jeong; Lee, Chang Seob [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2010-06-15

    Brucellosis is a worldwide infectious disease of animals that can be transmitted to humans. Osteoarticular involvement is the most common complication of brucellosis. A 47-year-old man, who was a stock breeder, complained of myalgia with fever and chills for 2 weeks. The serology titers and blood cultures for brucellosis were positive. Bone scintigraphy demonstrated a focally increased uptake in the left supra orbital area. Plain radiographs showed an osteolytic lesion, and an MRI revealed signal abnormalities in the corresponding site. We present an unusual case of occult Brucella osteomyelitis in the frontal bone of the skull detected by done scintigraphy.

  11. THE 2011 JUNE 23 STELLAR OCCULTATION BY PLUTO: AIRBORNE AND GROUND OBSERVATIONS

    Person, M. J.; Bosh, A. S.; Levine, S. E.; Gulbis, A. A. S.; Zangari, A. M.; Zuluaga, C. A.; Sallum, S. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139-4307 (United States); Dunham, E. W.; Collins, P.; Bida, T.; Bright, L. [Lowell Observatory, Flagstaff, AZ (United States); Pasachoff, J. M.; Babcock, B. A.; Pandey, S.; Amrhein, D. [Williams College-Hopkins Observatory, Williamstown, MA (United States); Tholen, D. J. [Institute for Astronomy, University of Hawaii, Manoa, HI (United States); Taylor, B. [Boston University, Boston, MA (United States); Wolf, J.; Pfueller, E. [Deutsches SOFIA Institut, Universitaet Stuttgart, Pfaffenwaldring 29, D-70569 Stuttgart (Germany); Meyer, A., E-mail: mjperson@mit.edu [SOFIA Science Center, NASA Ames Research Center, MS 211-1, Moffett Field, CA 94035 (United States); and others

    2013-10-01

    On 2011 June 23, stellar occultations by both Pluto (this work) and Charon (future analysis) were observed from numerous ground stations as well as the Stratospheric Observatory for Infrared Astronomy (SOFIA). This first airborne occultation observation since 1995 with the Kuiper Airborne Observatory resulted in the best occultation chords recorded for the event, in three visible wavelength bands. The data obtained from SOFIA are combined with chords obtained from the ground at the IRTF, the U.S. Naval Observatory Flagstaff Station, and Leeward Community College to give the detailed state of the Pluto-Charon system at the time of the event with a focus on Pluto's atmosphere. The data show a return to the distinct upper and lower atmospheric regions with a knee or kink in the light curve separating them as was observed in 1988, rather than the smoothly transitioning bowl-shaped light curves of recent years. The upper atmosphere is analyzed by fitting a model to all of the light curves, resulting in a half-light radius of 1288 {+-} 1 km. The lower atmosphere is analyzed using two different methods to provide results under the differing assumptions of particulate haze and a strong thermal gradient as causes for the lower atmospheric diminution of flux. These results are compared with those from past occultations to provide a picture of Pluto's evolving atmosphere. Regardless of which lower atmospheric structure is assumed, results indicate that this part of the atmosphere evolves on short timescales with results changing the light curve structures between 1988 and 2006, and then reverting these changes in 2011 though at significantly higher pressures. Throughout these changes, the upper atmosphere remains remarkably stable in structure, again except for the overall pressure changes. No evidence of onset of atmospheric collapse predicted by frost migration models is seen, and the atmosphere appears to be remaining at a stable pressure level, suggesting it

  12. A unique airborne observation. [Martian atmospheric temperature and abundances from occultation of Epsilon Geminorum

    Elliot, J. L.; Dunham, E.; Church, C.

    1976-01-01

    The occultation of 3rd magnitude Epsilon Geminorum by Mars was observed using a 36-inch telescope equipped with a photoelectric photometer at the bent Cassegrain focus, carried aboard the Kuiper Airborne Observatory at altitudes up to 45,000 feet. Scintillation from the earth's atmosphere was greatly reduced in comparison with ground observations. The observations clearly show the central flash, caused by the symmetrical refraction of light by the atmosphere of Mars. The data are being analyzed to obtain temperature profiles and to assess the relative abundance of argon and carbon dioxide in the atmosphere of the planet.

  13. Spatial irregularities in Jupiter's upper ionosphere observed by Voyager radio occultations

    Hinson, D. P.; Tyler, G. L.

    1982-01-01

    Radio scintillations (at 3.6 and 13 cm) produced by scattering from ionospheric irregularities during the Voyager occultations are interpreted using a weak-scattering theory. Least squares solutions for ionospheric parameters derived from the observed fluctuation spectra yield estimates of (1) the axial ratio, (2) angular orientation of the anisotropic irregularities, (3) the power law exponent of the spatial spectrum of irregularities, and (4) the magnitude of the spatial variations in electron density. It is shown that the measured angular orientation of the anisotropic irregularities indicates magnetic field direction and may provide a basis for refining Jovian magnetic field models.

  14. COSMIC Radio Occultation technique for measurement of the tropopause during tropical cyclones

    Biondi, Riccardo; Neubert, Torsten; Syndergaard, Stig

    Basin during July 2008 and reached a maximum intensity of Category 3 and the typhoon Hondo, formed in the south Indian basin during February 2008 with maximum intensity of Category 4. Using measurements from a variety of earth observation satellites (A-Train constellation) and from aircraft together...... and they cool the tropopause layers. The GPS radio occultation technique is useful for studying severe weather phenomena because the GPS signals penetrate through clouds and allow measurements of atmospheric profiles related to temperature, pressure, and water vapour with high vertical resolution...

  15. Unusual Case of Occult Brucella Osteomyelitis in the Skull Detected by Bone Scintigraphy

    Sohn, Myung Hee; Lim, Seok Tae; Jeong, Young Jin; Kim, Dong Wook; Jeong, Hwan Jeong; Lee, Chang Seob

    2010-01-01

    Brucellosis is a worldwide infectious disease of animals that can be transmitted to humans. Osteoarticular involvement is the most common complication of brucellosis. A 47-year-old man, who was a stock breeder, complained of myalgia with fever and chills for 2 weeks. The serology titers and blood cultures for brucellosis were positive. Bone scintigraphy demonstrated a focally increased uptake in the left supra orbital area. Plain radiographs showed an osteolytic lesion, and an MRI revealed signal abnormalities in the corresponding site. We present an unusual case of occult Brucella osteomyelitis in the frontal bone of the skull detected by done scintigraphy.

  16. Diffusion tensor imaging of occult injury of optic radiation following optic neuritis in multiple sclerosis.

    Chen, Jiafeng; Zhu, Lijun; Li, He; Lu, Ziwen; Chen, Xin; Fang, Shaokuan

    2016-10-01

    Multiple sclerosis (MS) is easily detected by routine magnetic resonance imaging (MRI). However, it is not possible to detect early or occult lesions in MS by routine MRI, and this may explain the inconsistency between the severity of the lesions found by MRI and the degree of clinical disability of patients with MS. The present study included 10 patients with relapsing-remitting MS and 10 healthy volunteers. Each patient underwent routine 3.0 T MRI, diffusion tensor imaging (DTI), and diffusion tensor tractography (DTT). Optic nerve and optic radiation were analyzed by DTI and DTT. The fractional anisotropy (FA), mean diffusivity (MD), λ // , and λ ┴ values were measured. In the 10 patients with MS, 7 optic nerves were affected, and 13 optic nerves were not affected. Cranial MRI showed that optic nerve thickening and hyperintensity occurred in 2 patients with MS. In the directionally encoded color maps, a hypointensive green signal in the optic nerve was observed in 3 patients with MS. The FA values were significantly lower and the MD, λ // , and λ ┴ values were significantly higher in the affected and unaffected optic nerves and optic radiations in patients with MS in comparison with controls (P0.05). Diffusion tensor imaging is sensitive in the detection of occult injury of the optic nerve and optic radiation following optic neuritis. Diffusion tensor imaging may be a useful tool for the early diagnosis, treatment and management of MS.

  17. When the bell tolls on Bell's palsy: finding occult malignancy in acute-onset facial paralysis.

    Quesnel, Alicia M; Lindsay, Robin W; Hadlock, Tessa A

    2010-01-01

    This study reports 4 cases of occult parotid malignancy presenting with sudden-onset facial paralysis to demonstrate that failure to regain tone 6 months after onset distinguishes these patients from Bell's palsy patients with delayed recovery and to propose a diagnostic algorithm for this subset of patients. A case series of 4 patients with occult parotid malignancies presenting with acute-onset unilateral facial paralysis is reported. Initial imaging on all 4 patients did not demonstrate a parotid mass. Diagnostic delays ranged from 7 to 36 months from time of onset of facial paralysis to time of diagnosis of parotid malignancy. Additional physical examination findings, especially failure to regain tone, as well as properly protocolled radiologic studies reviewed with dedicated head and neck radiologists, were helpful in arriving at the diagnosis. An algorithm to minimize diagnostic delays in this subset of acute facial paralysis patients is presented. Careful attention to facial tone, in addition to movement, is important in the diagnostic evaluation of acute-onset facial paralysis. Copyright 2010 Elsevier Inc. All rights reserved.

  18. DM ORI: A YOUNG STAR OCCULTED BY A DISTURBANCE IN ITS PROTOPLANETARY DISK

    Rodriguez, Joseph E.; Stassun, Keivan G.; Lund, Michael B.; Weintraub, David A. [Department of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Center, Nashville, TN 37235 (United States); Cargile, Phillip [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Shappee, Benjamin J. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Siverd, Robert J. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Pepper, Joshua [Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015 (United States); Kochanek, Christopher S.; Gaudi, B. Scott; Stanek, Krzysztof Z.; Holoien, Thomas W.-S. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); James, David [Cerro Tololo InterAmerican Observatory, Casilla 603, La Serena (Chile); Kuhn, Rudolf B. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Beatty, Thomas G. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Prieto, Jose L. [Nucleo de Astronoma de la Facultad de Ingeniera, Universidad Diego Portales, Av. Ejercito 441, Santiago (Chile); Feldman, Daniel M.; Espaillat, Catherine C. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)

    2016-11-01

    In some planet formation theories, protoplanets grow gravitationally within a young star’s protoplanetary disk, a signature of which may be a localized disturbance in the disk’s radial and/or vertical structure. Using time-series photometric observations by the Kilodegree Extremely Little Telescope South project and the All-Sky Automated Survey for SuperNovae, combined with archival observations, we present the discovery of two extended dimming events of the young star, DM Ori. This young system faded by ∼1.5 mag from 2000 March to 2002 August and then again in 2013 January until 2014 September (depth ∼1.7 mag). We constrain the duration of the 2000–2002 dimming to be < 860 days, and the event in 2013–2014 to be < 585 days, separated by ∼12.5 years. A model of the spectral energy distribution indicates a large infrared excess consistent with an extensive circumstellar disk. Using basic kinematic arguments, we propose that DM Ori is likely being periodically occulted by a feature (possibly a warp or perturbation) in its circumstellar disk. In this scenario, the occulting feature is located >6 au from the host star, moving at ∼14.6 km s{sup −1} and is ∼4.9 au in width. This localized structure may indicate a disturbance such as that which may be caused by a protoplanet early in its formation.

  19. Evaluation of Refractivity Profiles from CHAMP and SAC-C GPS Radio Occultation

    Poli, Paul; Ao, Chi On; Joiner, Joanna; delaTorreJuarez, Manuel; Hoff, Raymond

    2002-01-01

    The GeoForschungsZentrum's Challenging Minisatellite Payload for Geophysical Research and Application (CHAMP, Germany-US) and the Comision Nacional de Actividades Especiales' Satelite de Aplicaciones Cientificas-C (SAC-C, Argentina-US) missions are the first missions to carry a second-generation Blackjack Global Positioning System (GPS) receiver. One of the new features of this receiver is its ability to sense the lower troposphere closer to the surface than the proof-of-concept GPS Meteorology experiment (GPS/MET). Since their launch, CHAMP and SAC-C have collected thousands of GPS radio occultations, representing a wealth of measurements available for data assimilation and Numerical Weather Prediction (NWP). In order to evaluate the refractivity data derived by the Jet Propulsion Laboratory (JPL) from raw radio occultation measurements, we use Data Assimilation Office (DAO) 6-hour forecasts as an independent state of the atmosphere. We compare CHAMP and SAC-C refractivity (processed by JPL) with refractivity calculated from the DAO global fields of temperature, water vapor content and humidity. We show statistics of the differences as well as histograms of the differences.

  20. Taiwan/TriG Radio Occultation Process System (TROPS): A Brief Introduction of Atmospheric Productions

    Huang, Cheng-Yung; Yeh, Wen-Hao; Tseng, Tzu-Pang; Chen, Linton J.

    2017-04-01

    Global Positioning System (GPS) Radio Occultation (RO) technique has been used to investigate the Earth's atmosphere since 1990s. In 2006, Taiwan has launched six low Earth orbit (LEO) satellites as a RO constellation mission, named FORMOSAT-3 /COSMIC (F-3/C). F-3/C mission can release 1500-2500 data sets per day for both neutral atmosphere and ionosphere. With the advent of Global Navigation Satellite System (GNSS) in ten years and FORMOSAT-7/COSMIC-2 (F-7/C-2) mission, 12 LEO satellites are planned to be launched and deployed in two clusters of 6-satellites into the designated low and high inclination orbits in 2017 and 2020(TBD), respectively. The amount of RO data set will increase to about 8000 set per day with the using of GNSS TriG (GPS, Glonass, Galileo) receivers. The first phase of FS-7 mission is designed to low inclination (24 deg) orbit to improve the ability of server weather forecasting, like typhoon and monsoon rainfall around tropical region. The second is high inclination (72 deg) for global distribution. In order to observe better water vapor profiles, the 4x3 antennas arrays will be on board to receive weak signals which pass through low troposphere around earth surface. This report will introduce the status of F-7/C-2 mission and atmospheric part of occultation data process software TROPS.

  1. Wavelength dependence of the effects of turbulence on average refraction angles in occultations by planetary atmospheres

    Haugstad, B.S.; Eshleman, V.R.

    1979-01-01

    Two recent adjacently published papers on the average effects of turbulence in radio and optical occultation studies of planetary atmospheres appear to disagree on the question of wavelength dependence. It is demonstrated here that in deriving a necessary condition for the applicability of their method. Hubbard and Jokipii neglect a factor which is proportional to the square of the ratio of the atmospheric or local Fresnel zone radius and the inner scale of turbulence. They also fail to establish sufficient conditions, thereby omitting as a further factor the square of the ratio of atmospheric scale height and the local Fresnel zone radius. The total descrepancy, which numerically is typically within several orders of magnitude of 10 11 for radio and 10 7 for optical occultations, means that their results correspond to geometrical optics and not to wave optics as claimed. Thus their results are inherently inapplicable in a discussion of the wavelength dependence of any parameter, such as the bias in the average refraction angle treated by Eshleman and Haugstad. We note that for power spectra characterized by the (--p) exponent of the turbulence wavenumber, the average turbulence-induced bias in refraction angles depends on the radiation wavelength as lambda/sup( p/--4)/2, or as lambda/sup en-dash1/6/ for Kolmogorov turbulence. Other features of the Hubbard-Jokipii analysis are also discussed

  2. A modification to the standard ionospheric correction method used in GPS radio occultation

    S. B. Healy

    2015-08-01

    Full Text Available A modification to the standard bending-angle correction used in GPS radio occultation (GPS-RO is proposed. The modified approach should reduce systematic residual ionospheric errors in GPS radio occultation climatologies. A new second-order term is introduced in order to account for a known source of systematic error, which is generally neglected. The new term has the form κ(a × (αL1(a-αL2(a2, where a is the impact parameter and (αL1, αL2 are the L1 and L2 bending angles, respectively. The variable κ is a weak function of the impact parameter, a, but it does depend on a priori ionospheric information. The theoretical basis of the new term is examined. The sensitivity of κ to the assumed ionospheric parameters is investigated in one-dimensional simulations, and it is shown that κ ≃ 10–20 rad−1. We note that the current implicit assumption is κ=0, and this is probably adequate for numerical weather prediction applications. However, the uncertainty in κ should be included in the uncertainty estimates for the geophysical climatologies produced from GPS-RO measurements. The limitations of the new ionospheric correction when applied to CHAMP (Challenging Minisatellite Payload measurements are noted. These arise because of the assumption that the refractive index is unity at the satellite, made when deriving bending angles from the Doppler shift values.

  3. Hard X-Ray Emission from Partially Occulted Solar Flares: RHESSI Observations in Two Solar Cycles

    Effenberger, Frederic; Costa, Fatima Rubio da; Petrosian, Vahé [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Oka, Mitsuo; Saint-Hilaire, Pascal; Krucker, Säm [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Liu, Wei [Bay Area Environmental Research Institute, 625 2nd Street, Suite 209, Petaluma, CA 94952 (United States); Glesener, Lindsay, E-mail: feffen@stanford.edu, E-mail: frubio@stanford.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2017-02-01

    Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal looptop source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their acceleration site, without footpoint contamination. To this end, a statistical study of partially occulted flares observed with Reuven Ramaty High-Energy Solar Spectroscopic Imager is presented here, covering a large part of solar cycles 23 and 24. We perform detailed spectra, imaging, and light curve analyses for 116 flares and include contextual observations from SDO and STEREO when available, providing further insights into flare emission that were previously not accessible. We find that most spectra are fitted well with a thermal component plus a broken power-law, non-thermal component. A thin-target kappa distribution model gives satisfactory fits after the addition of a thermal component. X-ray imaging reveals small spatial separation between the thermal and non-thermal components, except for a few flares with a richer coronal source structure. A comprehensive light curve analysis shows a very good correlation between the derivative of the soft X-ray flux (from GOES ) and the hard X-rays for a substantial number of flares, indicative of the Neupert effect. The results confirm that non-thermal particles are accelerated in the corona and estimated timescales support the validity of a thin-target scenario with similar magnitudes of thermal and non-thermal energy fluxes.

  4. ULTRA-WIDE-FIELD FUNDUS AUTOFLUORESCENCE FINDINGS IN PATIENTS WITH ACUTE ZONAL OCCULT OUTER RETINOPATHY.

    Shifera, Amde Selassie; Pennesi, Mark E; Yang, Paul; Lin, Phoebe

    2017-06-01

    To determine whether ultra-wide-field fundus autofluorescence (UWFFAF) findings in acute zonal occult outer retinopathy correlated well with perimetry, optical coherence tomography, and electroretinography findings. Retrospective observational study on 16 eyes of 10 subjects with AZOOR seen at a single referral center from October 2012 to March 2015 who had UWFFAF performed. Chi-square analysis was performed to compare categorical variables, and Mann-Whitney U test used for comparisons of nonparametric continuous variables. All eyes examined within 3 months of symptom onset (five of the five eyes) had diffusely hyperautofluorescent areas on UWFFAF. The remaining eyes contained hypoautofluorescent lesions with hyperautofluorescent borders. In 11/16 (68.8%) eyes, UWFFAF showed the full extent of lesions that would not have been possible with standard fundus autofluorescence centered on the fovea. There were 3 patterns of spread: centrifugal spread (7/16, 43.8%), centripetal spread (5/16, 31.3%), and centrifugal + centripetal spread (4/16, 25.0%). The UWFFAF lesions corresponded well with perimetric, optical coherence tomography, and electroretinography abnormalities. The UWFFAF along with optical coherence tomography can be useful in the evaluation and monitoring of acute zonal occult outer retinopathy patients.

  5. Atmospheric Drag, Occultation ‘N’ Ionospheric Scintillation (ADONIS mission proposal

    Hettrich Sebastian

    2015-01-01

    Full Text Available The Atmospheric Drag, Occultation ‘N’ Ionospheric Scintillation mission (ADONIS studies the dynamics of the terrestrial thermosphere and ionosphere in dependency of solar events over a full solar cycle in Low Earth Orbit (LEO. The objectives are to investigate satellite drag with in-situ measurements and the ionospheric electron density profiles with radio occultation and scintillation measurements. A constellation of two satellites provides the possibility to gain near real-time data (NRT about ionospheric conditions over the Arctic region where current coverage is insufficient. The mission shall also provide global high-resolution data to improve assimilative ionospheric models. The low-cost constellation can be launched using a single Vega rocket and most of the instruments are already space-proven allowing for rapid development and good reliability. From July 16 to 25, 2013, the Alpbach Summer School 2013 was organised by the Austrian Research Promotion Agency (FFG, the European Space Agency (ESA, the International Space Science Institute (ISSI and the association of Austrian space industries Austrospace in Alpbach, Austria. During the workshop, four teams of 15 students each independently developed four different space mission proposals on the topic of “Space Weather: Science, Missions and Systems”, supported by a team of tutors. The present work is based on the mission proposal that resulted from one of these teams’ efforts.

  6. Overt and occult vidian canal involvement in juvenile angiofibroma and its possible impact on recurrence.

    Thakar, Alok; Hota, Ashutosh; Bhalla, Ashu Seth; Gupta, Siddharth Datta; Sarkar, Chitra; Kumar, Rakesh

    2016-04-01

    Postexcision residual disease in the vidian canal is speculated to contribute to recurrence in juvenile angiofibroma. We composed a prospective cohort of 16 consecutive patients with juvenile angiofibroma (stages IIA-IIIB). The presurgical vidian canal assessment was done by contrast-enhanced CT (1.2 mm collimation). At surgery after complete tumor excision, the vidian canal tissue was sampled for histology. Postexcision drilling of the vidian canal was done in 8 of 15 patients to remove microscopic residual disease, with a 24 to 48 month follow-up period. Presurgical radiology indicated ipsilateral vidian canal enlargement (≥3 mm)/destruction in 13 of 16 patients. Radiologically occult involvement was documented only by histology in another 1 of 16 patients. Postexcision sampling of the vidian canal noted microscopic residual tumor in 3 of 15 patients. No recurrences were noted in 8 cases (0 of 8) with postexcision drilling of the vidian canal and 2 recurrences in 7 cases (2 of 7) with no drilling (p = .20). Vidian canal involvement in juvenile angiofibroma is almost universal (14 of 16) and may be occult to CT evaluation. The site may harbor microscopic residual tumor after seemingly complete excision. Surgical attention toward it may reduce recurrences. © 2015 Wiley Periodicals, Inc. Head Neck 38: E421-425, 2016. © 2015 Wiley Periodicals, Inc.

  7. Inverted Meckel's diverticulum as a cause of occult lower gastrointestinal hemorrhage

    Omar M Rashid; Joseph K Ku; Masayuki Nagahashi; Akimitsu Yamada; Kazuaki Takabe

    2012-01-01

    Meckel's diverticulum is a common asymptomatic congenital gastrointestinal anomaly,but rarely it can present with hemorrhage.Over the last few years inverted Meckel's diverticulum has been reported in the literature with increasing frequency as an occult source of lower gastrointestinal hemorrhage.Here,we report a case of a 54-year-old male,who was referred for surgical evaluation with persistent anemia and occult blood per rectum after a work up which failed to localize the source over 12 mo,including upper and capsule endoscopy,colonoscopy,enteroclysis,Meckel scan,and tagged nuclear red blood cell scan.An abdominal computed tomography scan showed a possible mid-ileal intussusception and intraluminal mass.During the abdominal exploration,inverted Meckel's diverticulum was diagnosed and resected.We review the literature,discuss the forms in which the disease presents,the diagnostic modalities utilized,pathological findings,and treatment.Although less than 40 cases have been reported in the English literature from 1978 to 2005,19 cases have been reported in the last 6 years alone (2006-2012) due to improved diagnostic modalities.Successful diagnosis and treatment of this disease requires a high index of clinical suspicion,which is becoming increasingly relevant to general gastroenterologists.

  8. Final binary star results from the ESO VLT Lunar occultations program

    Richichi, A. [National Astronomical Research Institute of Thailand, 191 Siriphanich Bldg., Huay Kaew Road, Suthep, Muang, Chiang Mai 50200 (Thailand); Fors, O. [Departament Astronomia i Meteorologia and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona (UB/IEEC), Martí i Franqués 1, E-08028 Barcelona (Spain); Cusano, F. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Ivanov, V. D., E-mail: andrea4work@gmail.com [European Southern Observatory, Ave. Alonso de Cordova 3107, Casilla 19001, Santiago 19 (Chile)

    2014-03-01

    We report on 13 subarcsecond binaries, detected by means of lunar occultations in the near-infrared at the ESO Very Large Telescope (VLT). They are all first-time detections except for the visual binary HD 158122, which we resolved for the first time in the near-infrared. The primaries have magnitudes in the range K = 4.5-10.0, and companions in the range K = 6.8-11.1. The magnitude differences have a median value of 2.4, with the largest being 4.6. The projected separations are in the range of 4-168 mas, with a median of 13 mas. We discuss and compare our results with the available literature. With this paper, we conclude the mining for binary star detections in the 1226 occultations recorded at the VLT with the ISAAC instrument. We expect that the majority of these binaries may be unresolvable by adaptive optics on current telescopes, and they might be challenging for long-baseline interferometry. However, they constitute an interesting sample for future larger telescopes and for astrometric missions such as GAIA.

  9. Subfracture insult to the human cadaver patellofemoral joint produces occult injury.

    Atkinson, P J; Haut, R C

    1995-11-01

    The current criterion used by the automotive industry for injury to the lower extremity is based on visible bone fracture. Studies suggest, however, that chronic joint degeneration may occur after subfracture impact loads on the knee. We hypothesized that subfracture loading of the patellofemoral joint could result in previously undocumented microtrauma in areas of high contact pressure. In the current study, seven patellofemoral joints from human cadavers were subjected to impact with successively greater energy until visible fracture was noted. Transverse and comminuted fractures of the patella were noted at 6.7 kN of load. Approximately 45% of the impact energy then was delivered to the contralateral joint. Subfracture loads of 5.2 kN resulted in no gross bone fracture in five of seven specimens. Histological examination of the patellae horizontal split fracture in the subchondral bone, at the tidemark, or at the interface of calcified cartilage and subchondral bone. The trauma appeared predominantly on the lateral facet, adjacent to or directly beneath preexisting fibrillation of the articular surface. Surface fibrillation was noted in histological sections of control patellae (not subjected to impact loading), but occult damages were not observed. Although the mechanism of this occult trauma is unknown, similar damage has been shown to occur from direct shear loading. As these microcracks can potentiate a disease process in the joint, this study may suggest that the current criterion for injury, based on bone fracture alone, is not sufficiently conservative.

  10. Morphologically occult systemic mastocytosis in bone marrow: clinicopathologic features and an algorithmic approach to diagnosis.

    Reichard, Kaaren K; Chen, Dong; Pardanani, Animesh; McClure, Rebecca F; Howard, Matthew T; Kurtin, Paul J; Wood, Adam J; Ketterling, Rhett P; King, Rebecca L; He, Rong; Morice, William G; Hanson, Curtis A

    2015-09-01

    Bone marrow (BM) biopsy specimens involved by systemic mastocytosis (SM) typically show multifocal, compact, dense aggregates of spindled mast cells (MCs). However, some cases lack aggregate formation and fulfill the World Health Organization 2008 criteria for SM, based on minor criteria. We identified 26 BM cases of KIT D816V-mutated, morphologically occult SM in the BM. All patients had some combination of allergic/MC activating symptoms. Peripheral blood counts were generally normal. BM aspirates showed 5% or less MCs, which were only occasionally spindled. BM biopsy specimens showed no morphologic classic MC lesions. Tryptase immunohistochemistry (IHC) demonstrated interstitial, individually distributed MCs (up to 5%) with prominent spindling, lacking aggregate formation. MCs coexpressed CD25 by IHC and/or flow cytometry. Spindled MCs constituted more than 25% of total MCs in all cases and more than 50% in 20 of 26 cases. Morphologically occult involvement of normal-appearing BM by SM will be missed without appropriate clinical suspicion and pathologic evaluation by tryptase and CD25 IHC and KIT D816V mutation analysis. On the basis of these findings, we propose a cost-effective, data-driven, evidence-based algorithmic approach to the workup of these cases. Copyright© by the American Society for Clinical Pathology.

  11. IMPORTANT NEMATODE INFECTIONS IN INDONESIA

    Sri Oemijati

    2012-09-01

    Full Text Available At least 13 species of intestinal nematodes and 4 species of blood and tissue nematodes have been reported infecting man in Indonesia. Five species of intestinal nematodes are very common and highly prevalent, especially in the rural areas and slums of the big cities. Those species are Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Trichuris trichiura and Oxyuris vermicularis, while Strongyloides stercoralis is disappearing. The prevalence of the soil transmitted helminths differs from place to place, depending on many factors such as the type of soil, human behaviour etc. Three species of lymph dwelling filarial worms are known to be endemic, the urban Wuchereria bancrofti is low endemic in Jakarta and a few other cities along the north coast of Java, with Culex incriminated as vector, high endemicity is found in Irian Jaya, where Anopheline mosquitoes act as vectors. Brugia malayi is widely distributed and is still highly endemic in many areas. The zoonotic type is mainly endemic in swampy areas, and has many species of Mansonia mosquitoes as vectors. B.timori so far has been found only in the south eastern part of the archipelago and has Anopheles barbirostris as vector. Human infections with animal parasites have been diagnosed properly only when adult stages were found either in autopsies or removed tissues. Cases of infections with A. caninum, A.braziliense, A.ceylanicum, Trichostrongylus colubriformis, T.axei and Oesophagostomum apiostomum have been desribed from autopsies, while infections with Gnathostoma spiningerum have been reported from removed tissues. Infections with the larval stages such as VLM, eosinophylic meningitis, occult filanasis and other could only be suspected, since the diagnosis was extremely difficult and based on the finding and identification of the parasite. Many cases of creeping eruption which might be caused by the larval stages of A.caninum and A.braziliense and Strongyloides stercoralis

  12. Occultations of Astrophysical Radio Sources as Probes of Planetary Environments: A Case Study of Jupiter and Possible Applications to Exoplanets

    Withers, Paul [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Vogt, Marissa F. [Center for Space Physics, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)

    2017-02-10

    Properties of planetary atmospheres, ionospheres, and magnetospheres are difficult to measure from Earth. Radio occultations are a common method for measuring these properties, but they traditionally rely on radio transmissions from a spacecraft near the planet. Here, we explore whether occultations of radio emissions from a distant astrophysical radio source can be used to measure magnetic field strength, plasma density, and neutral density around planets. In a theoretical case study of Jupiter, we find that significant changes in polarization angle due to Faraday rotation occur for radio signals that pass within 10 Jupiter radii of the planet and that significant changes in frequency and power occur from radio signals that pass through the neutral atmosphere. There are sufficient candidate radio sources, such as pulsars, active galactic nuclei, and masers, that occultations are likely to occur at least once per year. For pulsars, time delays in the arrival of their emitted pulses can be used to measure plasma density. Exoplanets, whose physical properties are very challenging to observe, may also occult distant astrophysical radio sources, such as their parent stars.

  13. MR imaging-guided sonography followed by fine-needle aspiration cytology in occult carcinoma of the breast

    A.I.M. Obdeijn (Inge-Marie); Brouwers-Kuyper, E.M.; M.M.A. Tilanus-Linthorst (Madeleine); T. Wiggers (Theo); M. Oudkerk (Matthijs)

    2000-01-01

    markdownabstractOBJECTIVE. In patients with axillary metastases as clinical evidence of possible occult breast cancer, a combined approach of MR imaging, sonography, and aspiration biopsy cytology was evaluated. SUBJECTS AND METHODS. Thirty-one women with metastatic adenocarcinoma in their

  14. Male occult triple-negative breast cancer with dermatomyositis: a case report and review of the literature

    Zhang L

    2017-11-01

    Full Text Available Le Zhang,1 Chenghua Zhang,2 Zhaoying Yang,1 Miao He,3 Lijuan Zhang,1 Shereen Ezzat,4 Xi Liang5 1Department of Breast Surgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin, China; 2Endoscopy Department, Jilin Cancer Hospital, Changchun, Jilin,China; 3Department of Anesthesia, The Second Hospital of Jilin University, Changchun, Jilin, China; 4Ontario Cancer Institute and The Endocrine Oncology Site Group, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada; 5Department of Breast Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China Abstract: Occult breast cancer is defined by the presence of axillary metastases without an identifiable primary breast tumor. Here, we report a rare case of a male occult breast cancer with dermatomyositis. We performed a modified radical mastectomy consisting of whole breast mastectomy and axillary lymph node dissection. Immunohistochemistry and fluorescent in situ hybridization analyses demonstrated an adenocarcinoma likely of breast origin, which was an occult triple-negative breast cancer. Interestingly, the patient’s previously noted periorbital dermatomyositis resolved promptly following surgical excision. Keywords: male breast cancer, occult breast cancer, triple-negative breast cancer, dermato­myositis 

  15. Detection of colorectal cancer in symptomatic outpatients without visible rectal bleeding: Validity of the fecal occult blood test

    Bjerregaard, Niels Christian; Tøttrup, Anders; Sørensen, Henrik Toft

    2009-01-01

    In 2002, a new diagnostic strategy in symptomatic outpatients without known established colorectal cancer risk factors aged 40 years or older was implemented in Denmark. Fecal occult blood test (Hemoccult Sensa®) was a part of that strategy in patients without visible rectal bleeding....

  16. Pluto's Atmosphere from the 2015 June 29 Ground-Based Stellar Occultation at the Time of the New Horizons Flyby

    Sicardy, B.; Talbot, J.; Meza, E.; Camargo, J.I.B.; Desmars, J.; Gault, D.; Herald, D.; Kerr, S.; Pavlov, H.; Braga-Ribas, F.; Jelínek, Martin

    2016-01-01

    Roč. 819, č. 2 (2016), L38/1-L38/8 ISSN 2041-8205 Institutional support: RVO:67985815 Keywords : Kuiper belt objects * occultations * planets and satellites Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.522, year: 2016

  17. Pluto occultation on 2015 June 29 UTC with central flash and atmospheric spikes just before the New Horizons flyby

    Pasachoff, Jay M.; Babcock, Bryce A.; Durst, Rebecca F.; Seeger, Christina H.; Levine, Stephen E.; Bosh, Amanda S.; Person, Michael J.; Sickafoose, Amanda A.; Zuluaga, Carlos A.; Kosiarek, Molly R.; Abe, Fumio; Nagakane, Masayuki; Suzuki, Daisuke; Tristram, Paul J.; Arredondo, Anicia

    2017-11-01

    We observed the occultation by Pluto of a 12th magnitude star, one of the two brightest occultation stars ever in our dozen years of continual monitoring of Pluto's atmosphere through such studies, on 2015 June 29 UTC. At the Univ. of Canterbury Mt. John Observatory (New Zealand), under clear skies throughout, we used a POETS frame-transfer CCD at 10 Hz with GPS timing on the 1-m McLellan telescope as well as an infrared camera on an 0.6-m telescope and three-color photometry at a slower cadence on a second 0.6-m telescope. At the Auckland Observatory, we used a POETS and a PICO on 0.5-m and 0.4-m telescopes, with 0.4 s and 2 s cadences, respectively, obtaining ingress observations before clouds moved in. The Mt. John light curves show a central flash, indicating that we were close to the center of the occultation path. Analysis of our light curves show that Pluto's atmosphere remains robust. The presence of spikes at both sites in the egress and ingress shows atmospheric layering. We coordinated our observations with aircraft observations (Bosh et al., 2017) with the Stratospheric Observatory for Infrared Astronomy (SOFIA). Our chords helped constrain the path across Pluto that SOFIA saw. Our ground-based and airborne stellar-occultation effort came only just over two weeks of Earth days and two Pluto days before the flyby of NASA's New Horizons spacecraft.

  18. Atmospheric influences on infrared-laser signals used for occultation measurements between Low Earth Orbit satellites

    S. Schweitzer

    2011-10-01

    Full Text Available LEO-LEO infrared-laser occultation (LIO is a new occultation technique between Low Earth Orbit (LEO satellites, which applies signals in the short wave infrared spectral range (SWIR within 2 μm to 2.5 μm. It is part of the LEO-LEO microwave and infrared-laser occultation (LMIO method that enables to retrieve thermodynamic profiles (pressure, temperature, humidity and altitude levels from microwave signals and profiles of greenhouse gases and further variables such as line-of-sight wind speed from simultaneously measured LIO signals. Due to the novelty of the LMIO method, detailed knowledge of atmospheric influences on LIO signals and of their suitability for accurate trace species retrieval did not yet exist. Here we discuss these influences, assessing effects from refraction, trace species absorption, aerosol extinction and Rayleigh scattering in detail, and addressing clouds, turbulence, wind, scattered solar radiation and terrestrial thermal radiation as well. We show that the influence of refractive defocusing, foreign species absorption, aerosols and turbulence is observable, but can be rendered small to negligible by use of the differential transmission principle with a close frequency spacing of LIO absorption and reference signals within 0.5%. The influences of Rayleigh scattering and terrestrial thermal radiation are found negligible. Cloud-scattered solar radiation can be observable under bright-day conditions, but this influence can be made negligible by a close time spacing (within 5 ms of interleaved laser-pulse and background signals. Cloud extinction loss generally blocks SWIR signals, except very thin or sub-visible cirrus clouds, which can be addressed by retrieving a cloud layering profile and exploiting it in the trace species retrieval. Wind can have a small influence on the trace species absorption, which can be made negligible by using a simultaneously retrieved or a moderately accurate background wind speed profile. We

  19. Polarimetric mountain based radio-occultation for rain detection: The ROHP-PAZ ground campaign

    Padulles, Ramon; Cardellach, Estel; Tomas, Sergio; de la Torre, Manuel; Turk, Joe

    2014-05-01

    The Radio Occultation and Heavy Precipitation experiment aboard the PAZ Low Earth Orbiter (ROHP-PAZ) is a mission of opportunity: The Spanish Ministry of Science and Innovation (MICINN) approved in 2009 a proposal to include a polarimetric Global Navigation Satellite System (GNSS) Radio-Occultation (RO) payload on board of the Spanish Earth Observation satellite PAZ. This will be a new technique that has never been tested before, that aims to improve the knowledge of precipitation through simultaneous thermodynamic and vertical rain profiles. Prior to the launch of the satellite, expected for 2014, a ground experimental campaign is being conducted with the goal of starting the process of identifying and understanding all the factors that might affect the polarimetric RO observables. The campaign is being carried out at the top of Puig Sesolles, a 1667m peak in the Natural Park of Montseny (41º46'24 N, 2º26'17 E), 50 km N-NE from Barcelona, with clear views over the horizon to the South (East to West) direction, an area in which intense precipitation events tend to occur a few times per year. The campaign uses a ICE-CSIC/IEEC's GOLD-RTR open-loop receiver initially designed for collecting GNSS signals reflected off the sea surface. The receiver has been adjusted to track occulting GNSS radio-links. A double polarization (H and V) GNSS antenna has been designed and manufactured by the Polytechnic University of Barcelona (UPC) team for this particular ground-based experiment. The antenna is a phase-array made of 7 elements, each of them being a square patch built using a Rogers 4003 substrate, and symmetrically fed by four probes. It provides a pattern of 12.9 dB peak gain, 45 degrees half-power beam-width, and <-35 dB cross-polar isolation at the peak (better than -30 dB in the main lobe). The preliminary results show that not only precipitation, but also other factors are affecting the GNSS signal, wich means that the polarimetric signal is richer than expected

  20. Vaginal prolapse repair with or without a midurethral sling in women with genital prolapse and occult stress urinary incontinence: a randomized trial.

    van der Ploeg, J Marinus; Oude Rengerink, Katrien; van der Steen, Annemarie; van Leeuwen, Jules H Schagen; van der Vaart, C Huub; Roovers, Jan-Paul W R

    2016-07-01

    We compared pelvic organ prolapse (POP) repair with and without midurethral sling (MUS) in women with occult stress urinary incontinence (SUI). This was a randomized trial conducted by a consortium of 13 teaching hospitals assessing a parallel cohort of continent women with symptomatic stage II or greater POP. Women with occult SUI were randomly assigned to vaginal prolapse repair with or without MUS. Women without occult SUI received POP surgery. Main outcomes were the absence of SUI at the 12-month follow-up based on the Urogenital Distress Inventory and the need for additional treatment for SUI. We evaluated 231 women, of whom 91 randomized as follows: 43 to POP surgery with and 47 without MUS. A greater number of women in the MUS group reported absence of SUI [86 % vs. 48 %; relative risk (RR) 1.79; 95 % confidence interval (CI) 1.29-2.48]. No women in the MUS group received additional treatment for postoperative SUI; six (13 %) in the control group had a secondary MUS. Women with occult SUI reported more urinary symptoms after POP surgery and more often underwent treatment for postoperative SUI than women without occult SUI. Women with occult SUI had a higher risk of reporting SUI after POP surgery compared with women without occult SUI. Adding a MUS to POP surgery reduced the risk of postoperative SUI and the need for its treatment in women with occult SUI. Of women with occult SUI undergoing POP-only surgery, 13 % needed additional MUS. We found no differences in global impression of improvement and quality of life.

  1. Local time dependence of the thermal structure in the Venusian equatorial region revealed by Akatsuki radio occultation measurements

    Ando, H.; Fukuhara, T.; Takagi, M.; Imamura, T.; Sugimoto, N.; Sagawa, H.

    2017-12-01

    The radio occultation technique is one of the most useful methods to retrieve vertical temperature profiles in planetary atmospheres. Ultra-Stable Oscillator (USO) onboard Venus Climate Orbiter, Akatsuki, enables us to investigate the thermal structure of the Venus atmosphere between about 40-90 km levels. It is expected that 35 temperature profiles will be obtained by the radio occultation measurements of Akatsuki until August 2017. Static stability derived from the temperature profiles shows its local time dependence above the cloud top level at low-latitudes equatorward of 25˚. The vertical profiles of the static stability in the dawn and dusk regions have maxima at 77 km and 82 km levels, respectively. A general circulation model (GCM) for the Venus atmosphere (AFES-Venus) reproduced the thermal structures above the cloud top qualitatively consistent with the radio occultation measurements; the maxima of the static stability are seen both in the dawn and dusk regions, and the local maximum of the static stability in the dusk region is located at a highler level than in the dawn region. Comparing the thermal structures between the radio occultation measurements and the GCM results, it is suggested that the distribution of the static stability above the cloud top could be strongly affected by the diurnal tide. The thermal tide influences on the thermal structure as well as atmospheric motions above the cloud level. In addition, it is shown that zonally averaged zonal wind at about 80 km altitude could be roughly estimated from the radio occultation measurements using the dispersion relation of the internal gravity wave.

  2. Stratospheric gravity wave activities inferred through the GPS radio occultation technique

    Wrasse, Cristiano Max; Takahashi, Hisao; Fechine, Joaquim; Denardini, Clezio Marcos; Wickert, Jens

    2007-01-01

    Stratospheric gravity wave activities were deduced from GPS radio occultation temperature profiles obtained by CHAMP satellite between 2001 and 2005. Potential energy profiles are used to analyze the gravity wave activity over South America. The results showed an inter-annual variation of the potential energy integrated between 24 and 34 km of altitude. The gravity wave activity is more concentrated around the equatorial region. In order to evaluate the seasonal variation of the gravity wave activity, a mean potential energy was determined over (10 deg N-10 deg S) and (100 deg W-20 deg W). The results showed a lower gravity wave activity during winter time, while during spring time the mean potential energy showed an increase in the wave activity. The results of the mean potential energy also showed that the gravity wave activity in the lower stratosphere exhibits a higher wave activity during 2002 and 2004 and a lower wave activity during 2003 and 2005. (author)

  3. Large Binocular Telescope Observations of Europa Occulting Io's Volcanoes at 4.8 μm

    Skrutskie, Michael F.; Conrad, Albert; Resnick, Aaron; Leisenring, Jarron; Hinz, Phil; de Pater, Imke; de Kleer, Katherine; Spencer, John; Skemer, Andrew; Woodward, Charles E.; Davies, Ashley Gerard; Defrére, Denis

    2015-11-01

    On 8 March 2015 Europa passed nearly centrally in front of Io. The Large Binocular Telescope observed this event in dual-aperture AO-corrected Fizeau interferometric imaging mode using the mid-infrared imager LMIRcam operating behind the Large Binocular Telescope Interferometer (LBTI) at a broadband wavelength of 4.8 μm (M-band). Occultation light curves generated from frames recorded every 123 milliseconds show that both Loki and Pele/Pillan were well resolved. Europa's center shifted by 2 kilometers relative to Io from frame-to-frame. The derived light curve for Loki is consistent with the double-lobed structure reported by Conrad et al. (2015) using direct interferometric imaging with LBTI.

  4. Using 18F FDG PET/CT to Detect an occult Mesenchymal Tumor Causing Oncogenic Osteomalacia

    Seo, Hyo Jung; Choi, Yun Jung; Kim, Hyun Jeong; Jeong, Yong Hyu; Cho, Arthur; Lee, Jae Hoon; Yun, Mijin; Lee, Jong Doo; Kang, Won Jun

    2011-01-01

    Oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by renal phosphate excretion, hypophosphatemia, and osteomalacia. This syndrome is often caused by tumors of mesenchymal origin. Patients with oncogenic osteomalacia have abnormal bone mineralization, resulting in a high frequency of fractures. Tumor resection is the treatment of choice, as it will often correct the metabolic imbalance. Although oncogenic osteomalacia is a potentially curable disease, diagnosis is difficult and often delayed because of the small size and sporadic location of the tumor. Bone scintigraphy and radiography best characterize osteoma lacia; magnetic resonance imaging findings are nonspecific. Here, we report a case of oncogenic osteomalacia secondary to a phosphaturic mesenchymal tumor that was successfully detected by 18F fluorodeoxyglucose positron emission tomography/computed tomography ( 18F FDG PET/CT). This case illustrates the advantages of 18F FDG PET/CT in detecting the occult mesenchymal tumor that causes oncogenic osteomalacia.

  5. Occult Plastic Intravitreal Foreign Body Retained for 30 Years: A Case Report

    Hsien-Chung Lin

    2006-10-01

    Full Text Available A 41-year-old man had suffered trauma to the right eye 30 years ago. In March 1996, he underwent trabeculectomy and peripheral iridectomy under the diagnosis of open angle glaucoma in the right eye. Autoperimetry at that time revealed visual field constriction. In addition, ocular examination showed that the cup/disc ratio of his right eye was increased. Cataract was diagnosed in September 2002 and cataract extraction was performed on October 22, 2002. A plastic intravitreal foreign body was detected during the operation. However, preoperative B-scan ultrasonography had failed to detect an intraocular foreign body (IOFB, and the previous fluorescein angiography had shown only retinal pigment epithelium changes. This case reminded us that we should be alert to an occult IOFB in the event of ocular trauma, even if none had been detected during prior imaging examinations.

  6. Sonography of occult rib and costal cartilage fractures: a case series.

    Mattox, Ross; Reckelhoff, Kenneth E; Welk, Aaron B; Kettner, Norman W

    2014-06-01

    The purpose of this case series is to describe the use of diagnostic ultrasound (US) in the detection of occult rib and costal cartilage fractures presenting as chest wall pain to a chiropractic clinic. Three patients presented with chest wall pain and tenderness. Two of the patients presented with acute chest wall injury and 1 carried a previous diagnosis of rib fracture after trivial trauma 2 months earlier. Diagnostic US was selected as a non-ionizing imaging tool for these patients after negative digital radiography studies. All fractures were considered isolated as there was no associated injury, such as pneumothorax. Both of the acute cases were followed up to complete healing (evidence of osseous union) using US. All patients eventually achieved pain-free status. In these cases, US was more sensitive than radiography for diagnosing these cases of acute rib and costal cartilage fractures. Early recognition of rib injury could avoid potential complications from local manipulative therapy.

  7. Upper Troposphere Lower Stratosphere structure during convective systems using GPS radio occultations

    Biondi, Riccardo

    The deep convective systems play a fundamental role in atmospheric circulation and climate. Thunderstorms and meso-scale convective systems produce fast vertical transport, redistributing water vapor and trace gases and influencing the thermal structure of the upper troposphere and lower...... stratosphere (UTLS) contributing to the troposphere-stratosphere transport and affecting the Earth global circulation and the climate changes. The Global Positioning System (GPS) Radio Occultation (RO) technique enables measurement of atmospheric density structure in any meteorological condition...... to the analysis of tropical storms for the future mission ACES will also be evaluated. Using data from the past and ongoing GPS RO missions we have defined an algorithm to detect the clouds top of the convective systems and their thermal structure. Other satellite and in-situ measurements co-located with GPS ROs...

  8. Modelling the phase curve and occultation of WASP-43b with SPIDERMAN

    Louden, Tom

    2017-06-01

    Presenting SPIDERMAN, a fast code for calculating exoplanet phase curves and secondary eclipses with arbitrary two dimensional surface brightness distributions. SPIDERMAN uses an exact geometric algorithm to calculate the area of sub-regions of the planet that are occulted by the star, with no loss in numerical precision. The speed of this calculation makes it possible to run MCMCs to marginalise effectively over the underlying parameters controlling the brightness distribution of exoplanets. The code is fully open source and available over Github. We apply the code to the phase curve of WASP-43b using an analytical surface brightness distribution, and find an excellent fit to the data. We are able to place direct constraints on the physics of heat transport in the atmosphere, such as the ratio between advective and radiative timescales at different altitudes.

  9. First operations of the SOIR occultation infrared spectrometer in Venus orbit.

    Nevejans, D.; Neefs, E.; Vandaele, A. C.; Muller, C.; Fussen, D.; Berkenbosch, S.; Clairquin, R.; Korablev, O.; Federova, A.; Bertaux, J. L.

    Since May 2006, the Venus-Express spacecraft is in its nominal orbit around VENUS and the SPICAV optical package has begun to acquire spectra. The SOIR extension to SPICAV is an echelle spectrometer associated to an AOTF (Acousto-Optical Tunable Filter) for the order selection, which performs solar occultation measurements in the IR region (2.2-4.3 µm) at a resolution of 0.1 cm-1 . The detailed optical study and design as well as the manufacturing were performed at the BIRA/IASB in collaboration with its industrial partners OIP and PEDEO. It was funded by the Belgian Federal Science Policy Office under the ESA PRODEX programme. The wavelength range allows a detailed chemical inventory of the Venus atmosphere above the cloud layer with an emphasis on vertical distribution of gases. The first results look promising and will be qualitatively presented.

  10. Clinical results of stereotactic heavy-charged-particle radiosurgery for intracranial angiographically occult vascular malformations

    Levy, R.P.; Fabrikant, J.I.; Phillips, M.H.; Frankel, K.A.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.; Lyman, J.T.

    1989-12-01

    Angiographically occult vascular malformations (AOVMs) of the brain have been recognized for many years to cause neurologic morbidity and mortality. They generally become symptomatic due to intracranial hemorrhage, focal mass effect, seizures or headaches. The true incidence of AOVMs is unknown, but autopsy studies suggest that they are more common than high-flow angiographically demonstrable arteriovenous malformations (AVMs). We have developed stereotactic heavy-charged-particle Bragg peak radiosurgery for the treatment of inoperable intracranial vascular malformations, using the helium ion beams at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron and Bevatron. This report describes the protocol for patient selection, radiosurgical treatment planning method, clinical and neuroradiologic results and complications encountered, and discusses the strengths and limitations of the method. 10 refs., 1 fig

  11. Clinical results of stereotactic heavy-charged-particle radiosurgery for intracranial angiographically occult vascular malformations

    Levy, R.P.; Fabrikant, J.I.; Phillips, M.H.; Frankel, K.A.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.; Lyman, J.T.

    1989-12-01

    Angiographically occult vascular malformations (AOVMs) of the brain have been recognized for many years to cause neurologic morbidity and mortality. They generally become symptomatic due to intracranial hemorrhage, focal mass effect, seizures or headaches. The true incidence of AOVMs is unknown, but autopsy studies suggest that they are more common than high-flow angiographically demonstrable arteriovenous malformations (AVMs). We have developed stereotactic heavy-charged-particle Bragg peak radiosurgery for the treatment of inoperable intracranial vascular malformations, using the helium ion beams at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron and Bevatron. This report describes the protocol for patient selection, radiosurgical treatment planning method, clinical and neuroradiologic results and complications encountered, and discusses the strengths and limitations of the method. 10 refs., 1 fig.

  12. Occult Leydig Cell Tumour Presenting as Bilateral Gynaecomastia. Case Report and Literature Review

    A. B. Patel

    2005-01-01

    Full Text Available Gynaecomastia is the most common benign breast disorder in men. Among the various causes, testicular malignancies are an uncommon, life-threatening condition requiring prompt diagnosis and treatment. The case of a 28-year-old man is discussed, who presented with a 6-month history of painful bilateral gynaecomastia with no abnormality on clinical or biochemical examination. The patient's symptoms spontaneously resolved within 4 weeks. He then represented 10 years later with similar symptoms and an associated secondary hypogonadism. Ultrasound imaging revealed a clinically occult, hypoechoic mass in the left testis (Leydig cell tumour on histology. Clinical and hormonal findings normalized following surgical excision. This report underlines the importance in clinical practice of ultrasonographic evaluation of the testis, in all patients with gynaecomastia, despite unremarkable findings on physical examination.

  13. Development of an Intervention for implementing Immunochemical Faecal Occult Blood Test in General Practice

    Juul, Jakob Søgaard; Vedsted, Peter; Bro, Flemming

    2016-01-01

    Denne korte artikel handler om udviklingen af en intervention til implementering af immunochemical faecal occult blood test (iFOBT) i almen praksis. Artiklen gennemgår processen fra de tidlige udviklingsstadier, over pilot-testning og frem til de endelige justeringer før selve implementeringen blev...... vurdering og viden om patienten. Kombinationen af teori og praksis viste sig at være en god måde at sikre hurtig ibrugtagning af en ny test i almen praksis til at identificere potentielle tegn på tarmkræft hos patienter. Særligt pilot-testning af interventionen viste sig at være værdifuld, fordi den...

  14. Immunochemical faecal occult blood test for colorectal cancer screening: a systematic review.

    Syful Azlie, M F; Hassan, M R; Junainah, S; Rugayah, B

    2015-02-01

    A systematic review on the effectiveness and costeffectiveness of Immunochemical faecal occult IFOBT for CRC screening was carried out. A total of 450 relevant titles were identified, 41 abstracts were screened and 18 articles were included in the results. There was fair level of retrievable evidence to suggest that the sensitivity and specificity of IFOBT varies with the cut-off point of haemoglobin, whereas the diagnostic accuracy performance was influenced by high temperature and haemoglobin stability. A screening programme using IFOBT can be effective for prevention of advanced CRC and reduced mortality. There was also evidence to suggest that IFOBT is cost-effective in comparison with no screening, whereby a two-day faecal collection method was found to be costeffective as a means of screening for CRC. Based on the review, quantitative IFOBT method can be used in Malaysia as a screening test for CRC. The use of fully automated IFOBT assay would be highly desirable.

  15. A research about characteristics of longitudinal variations of ES layers irregularities based on CHAMP occultation measurements

    Liao, Sunmin

    2018-04-01

    Based on the data of CHAMP occultation measurements, this paper makes a preliminary analysis of the longitudinal variations of ES irregular structure by using Fourier decomposition and reconstruction technique. It is found that the longitudinal variations of the ES irregular structure show the features of multiple wave-numbers, which is dominated by the wave number 1 to the wave number 5 components, and decrease from the amplitudes of the wave number 6 components. The features of wave number structures are very different in different DIP latitude and different seasons. The number of crests in summer and autumn is mostly 3 or 4 crest structures, while the number of crests in spring achieves 5 at DIP 15°N with small fluctuates, the crests number of winter is the least. In the multiple wave-numbers structure, the wave number 4 component shows a significant dependence on the season, mainly in the summer and autumn, particularly obvious from July to October.

  16. Quantification of abnormal intracranial pressure waves and isotope cisternography for diagnosis of occult communicating hydrocephalus

    Cardoso, E.R.; Piatek, D.; Del Bigio, M.R.; Stambrook, M.; Sutherland, J.B.

    1989-01-01

    Nineteen consecutive patients with suspected occult communicating hydrocephalus were investigated by means of clinical evaluation, neuropsychological testing, isotope cisternography, computed tomography scanning, and continuous intracranial pressure monitoring. Semi-quantitative grading systems were used in the evaluation of the clinical, neuropsychological, and cisternographic assessments. Clinical examination, neuropsychological testing, and computed tomography scanning were repeated 3 months after ventriculoperitoneal shunting. All patients showed abnormal intracranial pressure waves and all improved after shunting. There was close correlation between number, peak, and pulse pressures of B waves and the mean intracranial pressure. However, quantification of B waves by means of number, frequency, and amplitude did not help in predicting the degree of clinical improvement postshunting. The most sensitive predictor of favorable response to shunting was enlargement of the temporal horns on computed tomography scan. Furthermore, the size of temporal horns correlated with mean intracranial pressure. There was no correlation between abnormalities on isotope cisternography and clinical improvement

  17. Synchronous occult metastasising duodenal carcinoid and ovarian mucinous cystadenocarcinoma- Multiple primary malignancies in the same patient

    Devadass Clement W, Sridhar Honnappa, Aarathi R Rau, Sharat Chandra

    2014-01-01

    Full Text Available Gastrointestinal carcinoid tumors are uncommon neuroendocrine tumours that may be associated with synchronous or metachronous primary tumours of other histological type, most frequently colorectal adenocarcinomas. Primary ovarian mucinous adenocarcinomas have been reported to coincide with few other ovarian tumours and minority of these tumours may occur in association with Lynch syndrome. However association of duodenal carcinoid with ovarian mucinous adenocarcinoma is distinctly unusual and, to our knowledge, has not been previously described. We report a case of occult metastasising duodenal atypical carcinoid that was incidentally detected during surgical intervention performed for left ovarian mucinous cystadenocarcinoma in a middle aged female. The carcinoid tumour was Stage IIIB with regional nodal metastasis and the ovarian tumour was Stage IA with low grade histology.

  18. Internal gravity waves in Titan's atmosphere observed by Voyager radio occultation

    Hinson, D. P.; Tyler, G. L.

    1983-01-01

    The radio scintillations caused by scattering from small-scale irregularities in Titan's neutral atmosphere during a radio occultation of Voyager 1 by Titan are investigated. Intensity and frequency fluctuations occurred on time scales from about 0.1 to 1.0 sec at 3.6 and 13 cm wavelengths whenever the radio path passed within 90 km of the surface, indicating the presence of variations in refractivity on length scales from a few hundred meters to a few kilometers. Above 25 km, the altitude profile of intensity scintillations closely agrees with the predictions of a simple theory based on the characteristics of internal gravity waves propagating with little or no attenuation through the vertical stratification in Titan's atmosphere. These observations support a hypothesis of stratospheric gravity waves, possibly driven by a cloud-free convective region in the lowest few kilometers of the stratosphere.

  19. The atmosphere of Uranus - Results of radio occultation measurements with Voyager 2

    Lindal, G. F.; Lyons, J. R.; Sweetnam, D. N.; Eshleman, V. R.; Hinson, D. P.

    1987-01-01

    The Uranian atmosphere is investigated on the basis of S-band and X-band occultation observations (including measurements of Doppler frequency perturbations) obtained during the Voyager 2 encounter with Uranus in January 1986. The data are presented in extensive tables and graphs and characterized in detail. The atmosphere is assumed to have an H2/He abundance ratio of about 85/15, but also to contain small amounts of CH4 at above-cloud relative humidity 30 percent, cloud-base relative humidity 78 percent, and below-cloud mixing ratio 2.3 percent by number density. Other parameters estimated include magnetic-field rotation period 17.24 h, 1-bar equatorial radius 25,559 + or - 4 km, polar radius 24,973 + or - 20 km, equatorial acceleration of gravity 8.69 + or - 0.01 m/sec sq, and atmospheric temperature 76 + or - 2 K (assuming 85 + or - 3 percent H2).

  20. The atmosphere of Neptune - Results of radio occultation measurements with the Voyager 2 spacecraft

    Lindal, G. F.; Lyons, J. R.; Sweetnam, D. N.; Eshleman, V. R.; Hinson, D. P.

    1990-01-01

    This paper presents the vertical temperature and composition profiles of Neptune's troposphere and stratosphere, covering an altitude of 250 km, obtained from radio tracking data that were acquired during Voyager-2's occultation by Neptune, which began near 62 deg N planetographic latitude and ended near 45 deg S latitude. In the computations, the He/H2 abundance ratio 15/85 was adapted, which is consistent with solar abundance estimates and with recent results from Uranus. It was assumed that aerosols and heavier gases such as CH4, NH3, H2S, and H2O have a negligible effect on the microwave refractivity above the 0.5 bar pressure level.

  1. Use of the blue cotton screen method with endoscopy to detect occult esophageal foreign bodies.

    Xia, Yan; Zhang, Fan; Xu, Hong; Xu, Weiran

    2017-12-01

    More than 20,000 cases of upper gastrointestinal foreign bodies (FBs) have been reported in the last 5 years in China. Early detection and treatment is vital in these patients. Differential diagnosis of esophageal injury and occult esophageal foreign bodies is challenging, particularly in the case of non-radio-opaque foreign bodies. A diagnostic technique with high accuracy and low risk is needed for clinical practice. We describe successful use of the "blue cotton screen method" to detect esophageal foreign bodies in 2 patients. The advantages and disadvantages of various diagnostic modalities in the management of patients with foreign body ingestion are presented. This technique is safer and more effective than traditional methods for foreign body impaction in the esophageal cavity. It could be applied for screening and in the differential diagnosis of esophageal injury and FBs in the esophageal lumen.

  2. Total Artificial Heart Bridge to Transplantation for a Patient With Occult Intracardiac Malignancy: Case Report.

    Reich, H; Czer, L; Bannykh, S; De Robertis, M; Wolin, E; Amersi, F; Moriguchi, J; Kobashigawa, J; Arabia, F

    2015-09-01

    Malignancy is the leading cause of long-term morbidity and mortality after heart and other solid organ transplantation; therefore, great emphasis is placed on pre- and post-transplantation cancer screening. Even with meticulous screening during evaluation for heart transplant candidacy, an occult cancer may not be apparent. Here, we share the case of a 51-year-old man with refractory heart failure who underwent total artificial heart implantation as a bridge to transplantation with the surprise finding of an isolated deposit of metastatic carcinoid tumor nested within a left ventricular papillary muscle in his explanted heart. The primary ileal carcinoid tumor was identified and resected completely. After remaining cancer-free for 14 months, he was listed for heart transplantation and was transplanted 2 months later. He is currently 3.5 months out from heart transplantation and doing well, without evidence of recurring malignancy. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Effects of turbulence on average refraction angles in occultations by planetary atmospheres

    Eshleman, V. R.; Haugstad, B. S.

    1978-01-01

    Four separable effects of atmospheric turbulence on average refraction angles in occultation experiments are derived from a simplified analysis, and related to more general formulations by B. S. Haugstad. The major contributors are shown to be due to gradients in height of the strength of the turbulence, and the sense of the resulting changes in refraction angles is explained in terms of Fermat's principle. Because the results of analyses of such gradient effects by W. B. Hubbard and J. R. Jokipii are expressed in other ways, a special effort is made to compare all of the predictions on a common basis. We conclude that there are fundamental differences, and use arguments based on energy conservation and Fermat's principle to help characterize the discrepancies.

  4. Ernst Haeckel's biodynamics 1866 and the occult basis of organic farming

    Kutschera, Ulrich

    2016-01-01

    ABSTRACT One hundred and 50 years ago (Sept. 1866), Ernst Haeckel published a monograph entitled General Morphology of Organisms, wherein key terms, such as Protista, Monera, ontogeny, phylogeny, ecology and the ‘biogenetic law’ where introduced. In addition, Haeckel coined the word “biodynamics” as a synonym for “general physiology.” In contrast, Rudolf Steiner's “biodynamic agriculture,” which originated in 1924, and was promoted via Ehrenfried Pfeiffer's book of 1938 with the same title, is an occult pseudoscience still popular today. The misuse of Haeckel's term to legitimize disproven homeopathic principles and esoteric rules within the context of applied plant research is unacceptable. PMID:27322020

  5. Analysis of macular cone photoreceptors in a case of occult macular dystrophy

    Tojo N

    2013-05-01

    Full Text Available Naoki Tojo Tomoko Nakamura Hironori Ozaki Miyako Oka Toshihiko Oiwake Atsushi HayashiDepartment of Ophthalmology, University of Toyama, Toyama, JapanPurpose: To investigate changes in cone photoreceptors with adaptive optics (AO fundus imaging and spectral domain optical coherence tomography (SD-OCT in a case of occult macular dystrophy (OMD.Patient and methods: Both eyes of a 42-year-old woman diagnosed with OMD were examined. We used an AO fundus camera to obtain images of cone photoreceptors in the macula of the OMD subject and five healthy control subjects. Correlations between the AO images and the SD-OCT images were examined. Cone photoreceptors in eight areas in the macula of OMD and healthy control subjects were analyzed and compared.Results: SD-OCT showed a loss of the cone outer-segment tips line outside of the fovea in both eyes of the subject with OMD. The left eye with decreased visual acuity showed a discontinuous photoreceptor inner-segment and outer-segment line and cone outer-segment tips line at the fovea in SD-OCT and loss of cone mosaics as a dark spot in the AO image. In panoramic AO images and cone-density maps, less cone density was observed in a ring-like region outside the fovea than in the peripheral retina. In most of the areas examined, the cone densities were lower in the OMD eyes than in the healthy control eyes.Conclusions: Cone densities in the macula of the OMD patient were greatly decreased. AO images were found to be useful to evaluate morphologic changes in cone photoreceptors in patients with OMD.Keywords: occult macular dystrophy, adaptive optics, cone photoreceptor, cone analysis, optical coherence tomography

  6. Dynamic statistical optimization of GNSS radio occultation bending angles: advanced algorithm and performance analysis

    Li, Y.; Kirchengast, G.; Scherllin-Pirscher, B.; Norman, R.; Yuan, Y. B.; Fritzer, J.; Schwaerz, M.; Zhang, K.

    2015-08-01

    We introduce a new dynamic statistical optimization algorithm to initialize ionosphere-corrected bending angles of Global Navigation Satellite System (GNSS)-based radio occultation (RO) measurements. The new algorithm estimates background and observation error covariance matrices with geographically varying uncertainty profiles and realistic global-mean correlation matrices. The error covariance matrices estimated by the new approach are more accurate and realistic than in simplified existing approaches and can therefore be used in statistical optimization to provide optimal bending angle profiles for high-altitude initialization of the subsequent Abel transform retrieval of refractivity. The new algorithm is evaluated against the existing Wegener Center Occultation Processing System version 5.6 (OPSv5.6) algorithm, using simulated data on two test days from January and July 2008 and real observed CHAllenging Minisatellite Payload (CHAMP) and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) measurements from the complete months of January and July 2008. The following is achieved for the new method's performance compared to OPSv5.6: (1) significant reduction of random errors (standard deviations) of optimized bending angles down to about half of their size or more; (2) reduction of the systematic differences in optimized bending angles for simulated MetOp data; (3) improved retrieval of refractivity and temperature profiles; and (4) realistically estimated global-mean correlation matrices and realistic uncertainty fields for the background and observations. Overall the results indicate high suitability for employing the new dynamic approach in the processing of long-term RO data into a reference climate record, leading to well-characterized and high-quality atmospheric profiles over the entire stratosphere.

  7. Outcome analysis of salvage radiotherapy for occult cervical cancer found after simple hysterectomy

    Koh, Hyeon-Kang; Jeon, Wan; Kim, Hak-Jae; Wu, Hong-Gyun; Kim, Kyubo; Chie, Eui-Kyu; Ha, Sung-W.

    2013-01-01

    The objective was to analyze the outcomes of the patients, who received salvage radiotherapy for incidentally discovered cervical cancer following simple hysterectomy, and to identify the influence of intracavitary radiotherapy on treatment outcomes. Data from 117 patients with occult cervical cancer who underwent simple hysterectomy followed by salvage radiotherapy from September 1979 to November 2010 were collected. All the patients received external beam radiotherapy with (n=45) or without (n=72) intracavitary radiotherapy. Local control, disease-free survival, overall survival and treatment-related toxicity were investigated. The median follow-up time was 75 months. The 5- and 10-year local control/disease-free survival/overall survival rates were 93/87/87% and 90/84/83%, respectively. Among 98 patients who had no residual disease and negative resection margin on surgical specimens, 32 (33%) received intracavitary radiotherapy and 66 (67%) did not. There were no differences in patient and tumor characteristics between patients treated with and without intracavitary radiotherapy. The 5-year local control rate for the non-intracavitary radiotherapy group was 93 versus 94% for the intracavitary radiotherapy group (P=0.564); the disease-free survival rate was 88 versus 94% (P=0.894); the overall survival rate was 95 versus 85% (P=0.106), respectively. Among all patients, there were 5% of Grade 3 or higher late toxicities. Patients with occult invasive cervical cancer discovered following simple hysterectomy could be treated safely and effectively with salvage radiotherapy. For patients with no residual disease and negative resection margin, intracavitary radiotherapy could be omitted. (author)

  8. Integrating uncertainty propagation in GNSS radio occultation retrieval: from excess phase to atmospheric bending angle profiles

    J. Schwarz

    2018-05-01

    Full Text Available Global Navigation Satellite System (GNSS radio occultation (RO observations are highly accurate, long-term stable data sets and are globally available as a continuous record from 2001. Essential climate variables for the thermodynamic state of the free atmosphere – such as pressure, temperature, and tropospheric water vapor profiles (involving background information – can be derived from these records, which therefore have the potential to serve as climate benchmark data. However, to exploit this potential, atmospheric profile retrievals need to be very accurate and the remaining uncertainties quantified and traced throughout the retrieval chain from raw observations to essential climate variables. The new Reference Occultation Processing System (rOPS at the Wegener Center aims to deliver such an accurate RO retrieval chain with integrated uncertainty propagation. Here we introduce and demonstrate the algorithms implemented in the rOPS for uncertainty propagation from excess phase to atmospheric bending angle profiles, for estimated systematic and random uncertainties, including vertical error correlations and resolution estimates. We estimated systematic uncertainty profiles with the same operators as used for the basic state profiles retrieval. The random uncertainty is traced through covariance propagation and validated using Monte Carlo ensemble methods. The algorithm performance is demonstrated using test day ensembles of simulated data as well as real RO event data from the satellite missions CHAllenging Minisatellite Payload (CHAMP; Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC; and Meteorological Operational Satellite A (MetOp. The results of the Monte Carlo validation show that our covariance propagation delivers correct uncertainty quantification from excess phase to bending angle profiles. The results from the real RO event ensembles demonstrate that the new uncertainty estimation chain performs

  9. A vast increase in the use of CT scans for investigating occult hip fractures

    Jordan, Robert; Dickenson, Edward; Westacott, Daniel; Baraza, Njalalle; Srinivasan, Kuntrapka

    2013-01-01

    Background: Early diagnosis in neck of femur fractures has been shown to improve outcome. The National Institute for Clinical Excellence recommends if an occult hip fracture is suspected then an MRI should be performed and if not available within 24 h a CT should be considered. At our centre, emergency MRI is rarely available and so CT is commonly used. Objectives: Our study aims to analyse the trends in CT use over a five year period for the diagnosis of neck of femur fractures. Methods: Both the number of patients with a hip fracture and those undergoing a CT hip to diagnose an occult injury were identified across two district general hospitals between 2006–2007 and 2010–2011. The time from initial radiograph to CT and initial radiograph to operation were calculated. Results: In 2006–2007, of 547 hip fractures, 20 CT hips were performed and 6 reported as a fractured neck of femur (30%). In 2010–2011, of 499 hip fractures, 239 CT hips were performed and 65 fractures were recognised (27%). The mean time from radiograph until CT scan was 2.0 days in 2007 and 3.2 days in 2011, which was a statistically significant difference (p < 0.001). For those diagnosed using a CT scan the mean time from admission X-ray to surgery was 1.2 days in 2007 and 3.6 days in 2011. Conclusion: Clinicians are becoming increasingly reliant on CT for the diagnosis of hip fractures with our data suggesting further imaging is one factor that can delay time to diagnosis and theatre

  10. A vast increase in the use of CT scans for investigating occult hip fractures

    Jordan, Robert, E-mail: Robert.jordan@doctors.org.uk; Dickenson, Edward, E-mail: edwarddickenson@doctors.org.uk; Westacott, Daniel, E-mail: dan_westacott@hotmail.com; Baraza, Njalalle, E-mail: njaleb@Doctors.Org.Uk; Srinivasan, Kuntrapka, E-mail: bijusri@Yahoo.Co.Uk

    2013-08-15

    Background: Early diagnosis in neck of femur fractures has been shown to improve outcome. The National Institute for Clinical Excellence recommends if an occult hip fracture is suspected then an MRI should be performed and if not available within 24 h a CT should be considered. At our centre, emergency MRI is rarely available and so CT is commonly used. Objectives: Our study aims to analyse the trends in CT use over a five year period for the diagnosis of neck of femur fractures. Methods: Both the number of patients with a hip fracture and those undergoing a CT hip to diagnose an occult injury were identified across two district general hospitals between 2006–2007 and 2010–2011. The time from initial radiograph to CT and initial radiograph to operation were calculated. Results: In 2006–2007, of 547 hip fractures, 20 CT hips were performed and 6 reported as a fractured neck of femur (30%). In 2010–2011, of 499 hip fractures, 239 CT hips were performed and 65 fractures were recognised (27%). The mean time from radiograph until CT scan was 2.0 days in 2007 and 3.2 days in 2011, which was a statistically significant difference (p < 0.001). For those diagnosed using a CT scan the mean time from admission X-ray to surgery was 1.2 days in 2007 and 3.6 days in 2011. Conclusion: Clinicians are becoming increasingly reliant on CT for the diagnosis of hip fractures with our data suggesting further imaging is one factor that can delay time to diagnosis and theatre.

  11. Integrating uncertainty propagation in GNSS radio occultation retrieval: from excess phase to atmospheric bending angle profiles

    Schwarz, Jakob; Kirchengast, Gottfried; Schwaerz, Marc

    2018-05-01

    Global Navigation Satellite System (GNSS) radio occultation (RO) observations are highly accurate, long-term stable data sets and are globally available as a continuous record from 2001. Essential climate variables for the thermodynamic state of the free atmosphere - such as pressure, temperature, and tropospheric water vapor profiles (involving background information) - can be derived from these records, which therefore have the potential to serve as climate benchmark data. However, to exploit this potential, atmospheric profile retrievals need to be very accurate and the remaining uncertainties quantified and traced throughout the retrieval chain from raw observations to essential climate variables. The new Reference Occultation Processing System (rOPS) at the Wegener Center aims to deliver such an accurate RO retrieval chain with integrated uncertainty propagation. Here we introduce and demonstrate the algorithms implemented in the rOPS for uncertainty propagation from excess phase to atmospheric bending angle profiles, for estimated systematic and random uncertainties, including vertical error correlations and resolution estimates. We estimated systematic uncertainty profiles with the same operators as used for the basic state profiles retrieval. The random uncertainty is traced through covariance propagation and validated using Monte Carlo ensemble methods. The algorithm performance is demonstrated using test day ensembles of simulated data as well as real RO event data from the satellite missions CHAllenging Minisatellite Payload (CHAMP); Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC); and Meteorological Operational Satellite A (MetOp). The results of the Monte Carlo validation show that our covariance propagation delivers correct uncertainty quantification from excess phase to bending angle profiles. The results from the real RO event ensembles demonstrate that the new uncertainty estimation chain performs robustly. Together

  12. Effect of small-scale ionospheric variability on GNSS radio occultation data quality

    Verkhoglyadova, O. P.; Mannucci, A. J.; Ao, C. O.; Iijima, B. A.; Kursinski, E. R.

    2015-09-01

    Global Navigation Satellite Systems (GNSS) radio occultation (RO) measurements are sensitive to thin ionization layers and small-scale ionosphere structures. To evaluate error bounds and possible biases in atmospheric retrievals, we characterized ionospheric irregularities encountered in the affected profiles by analyzing the L1 signal-to-noise ratio (SNR) variability at E layer altitudes (from 90 km to 130 km). New metrics to analyze statistical effects of small-scale ionospheric irregularities on refractivity retrievals are proposed. We analyzed refractivity (N) retrievals with Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) ROs in 2011. Using refractivity from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis (NECMWF) as the reference data set, we studied statistical properties of the fractional refractivity bias (ΔN) defined by the difference (NECMWF - N)/NECMWF and averaged in the altitude range from 20 to 25 km for each individual profile. We found that (1) persistently larger variability of the L1 SNR as measured by the interquartile range (IQR) existed when the occultation tangent point was in the 90 km to 110 km altitude range than at higher E layer altitudes; (2) the upper limits on the fractional refractivity bias for COSMIC ROs are 0.06% (for daytime local time), 0.1% (for nighttime local time), and ~0.01% (for all local times); (3) distributions of ΔN are non-Gaussian (leptokurtic); (4) latitudinal distributions of small and large ΔN for different levels of ionospheric variability show large tails (NECMWF > N) occurring around the Himalaya and the Andes regions, which are possibly due to biases in ECMWF analysis. We conclude that the refractivity bias due to small-scale irregularities is small below 25 km altitude and can be neglected.

  13. Diagnosis of an isolated occult fracture of the posterior margin of the tibia with the SPECT/CT; Diagnostic d'une fracture occulte isolee de la marge posterieure du tibia par la TEMP-TDM

    Bourdon, A.; Granier, P.; Mourad, M. [Centre Hospitalier de Carcassonne Antoine-Gayraud, Service de Medecine Nucleaire, 11 - Carcassonne (France)

    2007-12-15

    We report the case of a 56-year-old woman, investigated for pains of the right ankle related to a trauma of an unspecified mechanism. The radiographic assessment was negative. The {sup 99m}Tc-HDP 3-phase bone scintigraphy highlighted, on the blood pool and the delayed images, a located lesion on the right ankle. The single photon emission computerized tomography guided by computerized tomography (SPECT-CT) showed a focused uptake on the posterior margin of the right tibia and a sharp lucent line within the tomo-scintigraphy spot of uptake. The diagnosis accepted was an isolated occult fracture of the posterior margin of the right tibia. The contribution of the {sup 99m}Tc-HDP 3-phase bone scintigraphy combined with the SPECT-CT in the diagnosis of the occult fractures is discussed. (N.C.)

  14. Immunochemical faecal occult blood tests have superior stability and analytical performance characteristics over guaiac-based tests in a controlled in vitro study.

    Lee, Chun Seng

    2011-06-01

    The aims of this study were (1) to determine the measurement accuracy of a widely used guaiac faecal occult blood test (gFOBT) compared with an immunochemical faecal occult blood test (iFOBT) during in vitro studies, including their analytical stability over time at ambient temperature and at 4°C; and (2) to compare analytical imprecision and other characteristics between two commercially available iFOBT methods.

  15. Are you afraid of the dark? Notes on the psychology of belief in histories of science and the occult.

    Sommer, Andreas

    2016-04-02

    The popular view of the inherent conflict between science and the occult has been rendered obsolete by recent advances in the history of science. Yet, these historiographical revisions have gone unnoticed in the public understanding of science and public education at large. Particularly, reconstructions of the formation of modern psychology and its links to psychical research can show that the standard view of the latter as motivated by metaphysical bias fails to stand up to scrutiny. After highlighting certain basic methodological maxims shared by psychotherapists and historians, I will try to counterbalance simplistic claims of a 'need to believe' as a precondition of scientific open-mindedness regarding the occurrence of parapsychological phenomena by discussing instances revealing a presumably widespread 'will to disbelieve' in the occult. I shall argue that generalized psychological explanations are only helpful in our understanding of history if we apply them in a symmetrical manner.

  16. [Occult medicine in the 20th century: pharmacotherapy by Demeter Georgievitz-Weitzer, known as Surya (1873 - 1949)].

    Helmstädter, Axel

    2011-01-01

    Demeter Georgievitz-Weitzer (1873-1949), called "Surya", Sanskrit for "sun", was an important representative of medical occultism in the first half of the 20th century. He worked as a journal editor and published a 13-volume book series about occult medicine, mainly written by himself. His hypotheses were closely related to the "Lebensreform" movement around 1900. Regarding diagnostics, he relied on astrology, cheiromancy, and clairvoyance, while therapeutics were dominated by diet and spagyric remedies according to Cesare Mattei (1809-1896) and Carl-Friedrich Zimpel (1801-1879). In his later years, he developed his own healing system, initially comprising eight, later only two preparations. Surya remedies were commercially available until the end of the 20th century,

  17. Are you afraid of the dark? Notes on the psychology of belief in histories of science and the occult

    Sommer, Andreas

    2016-01-01

    Abstract The popular view of the inherent conflict between science and the occult has been rendered obsolete by recent advances in the history of science. Yet, these historiographical revisions have gone unnoticed in the public understanding of science and public education at large. Particularly, reconstructions of the formation of modern psychology and its links to psychical research can show that the standard view of the latter as motivated by metaphysical bias fails to stand up to scrutiny. After highlighting certain basic methodological maxims shared by psychotherapists and historians, I will try to counterbalance simplistic claims of a ‘need to believe’ as a precondition of scientific open-mindedness regarding the occurrence of parapsychological phenomena by discussing instances revealing a presumably widespread ‘will to disbelieve’ in the occult. I shall argue that generalized psychological explanations are only helpful in our understanding of history if we apply them in a symmetrical manner. PMID:27226762

  18. Diagnosis of an isolated occult fracture of the posterior margin of the tibia with the SPECT/CT

    Bourdon, A.; Granier, P.; Mourad, M.

    2007-01-01

    We report the case of a 56-year-old woman, investigated for pains of the right ankle related to a trauma of an unspecified mechanism. The radiographic assessment was negative. The 99m Tc-HDP 3-phase bone scintigraphy highlighted, on the blood pool and the delayed images, a located lesion on the right ankle. The single photon emission computerized tomography guided by computerized tomography (SPECT-CT) showed a focused uptake on the posterior margin of the right tibia and a sharp lucent line within the tomo-scintigraphy spot of uptake. The diagnosis accepted was an isolated occult fracture of the posterior margin of the right tibia. The contribution of the 99m Tc-HDP 3-phase bone scintigraphy combined with the SPECT-CT in the diagnosis of the occult fractures is discussed. (N.C.)

  19. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    Plumb, Andrew A.; Ghanouni, Alex; Rees, Colin J.; Hewitson, Paul; Nickerson, Claire; Wright, Suzanne; Taylor, Stuart A.; Halligan, Steve; von Wagner, Christian

    2016-01-01

    Objective To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Methods Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as compl...

  20. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    Plumb, A. A.; Ghanouni, A.; Rees, C. J.; Hewitson, P.; Nickerson, C.; Wright, S.; Taylor, S. A.; Halligan, S.; von Wagner, C.

    2017-01-01

    OBJECTIVE: To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. METHODS: Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as com...

  1. Ultrasound Diagnosis of Either an Occult or Missed Fracture of an Extremity in Pediatric-Aged Children

    Cho, Kil Ho [Yeungnam University, Daegu (Korea, Republic of); Lee, Sung Moon [Keimyung University Dongsan Hospital, Daegu (Korea, Republic of); Lee, Young Hwan [Daegu Catholic University, Daegu (Korea, Republic of); Suh, Kyung Jin [Dongkuk University, Kyungju (Korea, Republic of)

    2010-02-15

    To report and assess the usefulness of ultrasound (US) findings for occult fractures of growing bones. For six years, US scans were performed in children younger than 15 years who were referred with trauma-related local pain and swelling of the extremities. As a routine US examination, the soft tissue, bones, and adjacent joints were examined in the area of discomfort, in addition to the asymptomatic contralateral extremity for comparison. Twenty-five occult fractures in 25 children (age range, five months-15 years; average age, 7.7 years) were confirmed by initial and follow-up radiograms, additional imaging studies, and clinical observation longer than three weeks. The most common site of occult fractures was the elbow (n = 9, 36%), followed by the knee (n = 7, 28%), ischium (n = 4, 16%), distal fibula (n = 3, 12%), proximal femur (n = 1, 4%), and humeral shaft (n = 1, 4%). On the retrograde review of the routine radiographs, 13 out of the 25 cases showed no bone abnormalities except for various soft tissue swelling. For the US findings, cortical discontinuity (direct sign of a fracture) was clearly visualized in 23 cases (92%) and was questionable in two (8%). As auxiliary US findings (indirect signs of a fracture), step-off deformities, tiny avulsed bone fragments, double-line appearance of cortical margins, and diffuse irregularity of the bone surfaces were identified. Performing US for soft tissue and bone surfaces with pain and swelling, with or without trauma history in the extremities, is important for diagnosing occult or missed fractures of immature bones in pediatric-aged children.

  2. Are you afraid of the dark? Notes on the psychology of belief in histories of science and the occult

    Sommer, Andreas

    2016-01-01

    This is the final version of the article. It first appeared from Taylor & Francis via https://doi.org/ 10.1080/13642537.2016.1170062 The popular view of the inherent conflict between science and the occult has been rendered obsolete by recent advances in the history of science. Yet, these historiographical revisions have gone unnoticed in the public understanding of science and public education at large. Particularly reconstructions of the formation of modern psychology and its links to...

  3. Pinworm Infection

    Pinworm infection Overview Pinworm infection is the most common type of intestinal worm infection in the United States and one of the most common worldwide. Pinworms are thin and white, measuring about 1/4 ...

  4. Sensitivity of airborne radio occultation to tropospheric properties over ocean and land

    F. Xie

    2018-02-01

    Full Text Available Airborne radio occultation (ARO measurements collected during a ferry flight at the end of the PRE-Depression Investigation of Cloud-systems in the Tropics (PREDICT field campaign from the Virgin Islands to Colorado are analyzed. The large contrast in atmospheric conditions along the flight path from the warm and moist Caribbean Sea to the much drier and cooler continental conditions provides a unique opportunity to address the sensitivity of ARO measurements to the tropospheric temperature and moisture changes. This long flight at nearly constant altitude (∼ 13 km provided an optimal configuration for simultaneous high-quality ARO measurements from two high-gain side-looking antennas, as well as one relatively lower gain zenith (top antenna. The omnidirectional top antenna has the advantage of tracking robustly more occulting satellites in all direction as compared to the limited-azimuth tracking of the side-looking antennas. Two well-adapted radio-holographic bending angle retrieval methods, full-spectrum inversion (FSI and phase matching (PM, were compared with the standard geometric-optics (GO retrieval method. Comparison of the ARO retrievals from the top antenna with the near-coincident ECMWF reanalysis-interim (ERA-I profiles shows only a small root-mean-square (RMS refractivity difference of ∼ 0.3 % in the drier upper troposphere from ∼ 5 to ∼ 11.5 km over both land and ocean. Both the FSI and PM methods improve the ARO retrievals in the moist lower troposphere and reduce the negative bias found in the GO retrieval due to atmospheric multipath. In the lowest layer of the troposphere, the ARO refractivity derived using FSI shows a negative bias of about −2 %. The increase of the refractivity bias occurs below 5 km over the ocean and below 3.5 km over land, corresponding to the approximate altitude of large vertical moisture gradients above the ocean and land surface, respectively. In comparisons to

  5. Assessment of occult cervical lymph node metastasis in primary squamous cell carcinoma of the head and neck by computed tomography

    Shakil, U.

    2015-01-01

    To determine the frequency of occult (node negative) cervical lymph node metastasis in primary head and neck squamous cell carcinoma, using contrast enhanced computed tomography (CT). Study Design: Cross sectional descriptive study. Place and Duration of Study: Study was conducted in Department of Radiology, Combined Military Hospital Rawalpindi. Duration of the study was 06 months i.e. from 19th February 2011 to 19th August 2011. Patients and Methods: A total of 141 cases, fulfilling the inclusion criteria, reporting to the radiology department, were included in the study after seeking written informed consent. All patients underwent contrast enhanced CT scan of the neck from base of skull to root of neck using Asteion Whole Body X-ray CT Scanner (Model TSX-021A). Images were evaluated for the presence or absence of cervical lymph node metastasis according to the cervical lymph node metastatic criteria at each level of the neck. Results: Of the 141 patients with clinically no head and neck squamous cell carcinoma, 45.4% were found to have lymph node metastases. Frequency of occult metastases in squamous cell carcinoma of oral cavity was 47.6%, oropharynx 23.5%, larynx 33.3% and hypopharynx 78.6%. Conclusion: In clinically node negative neck, the risk of lymph node metastases is significantly high in patients of head and neck squamous cell carcinoma in our population. All patients presenting with node negative neck should undergo CT scans for early detection of occult metastasis. (author)

  6. The use of 111In-labelled platelets for scintigraphic localization of gastrointestinal bleeding with special reference to occult bleeding

    Gjerloeff Schmidt, K.; Waever Rasmussen, J.; Grove, O.; Andersen, D.

    1986-01-01

    Gamma-camera imaging of the abdomen after injection of autologous 111 In-labelled platelets was applied for localization of gastrointestinal bleeding in a study of 22 patients. In 15 studies showing scintigraphic signs of bleeding, the clinical presentation included occult bleeding in 6, melaena in 4, and bloody stools in 5 patients. Scintigraphy could be done repeatedly for up to 1 week after a single tracer injection. The time interval between the injection and scintigraphic visualization of bleeding ranged from 10 min to 68 h, being longest in cases of occult bleeding. In most cases the scintigraphic findings were supported by other diagnostic modalities, including surgical removal of presumed sources of bleeding. In seven studies without scintigraphic signs of bleeding, a probable source of bleeding was identified by other means in one patient. The 111 In-platelet method seems to be a promising method for localization of gastrointestinal bleeding which may prove particularly useful in cases of occult or recurrent bleeding

  7. The “communication line” suggests occult posterior malleolar fracture associated with a spiral tibial shaft fracture

    Hou Zhiyong; Zhang Liping; Zhang Qi; Yao Shuangquan; Pan Jinshe; Irgit, Kaan; Zhang Yingze

    2012-01-01

    Objectives: To demonstrate radiographical characteristics of the relationship between distal spiral tibial shaft fractures and associated occult posterior malleolar fractures (PMF) that confirmed by CT and MRI. Materials and methods: X-rays for a ninety-six patients with spiral tibia fracture and associated PMF were reviewed. All patients additionally had an ankle CT. Patients with a negative CT scans underwent an ankle MRI. Radiographic observations included fracture location, characteristics, and a presence of a fracture line between the two injuries. Results: The spiral tibia fracture line was contiguous with PMF in 89 of 96 cases after evaluation with the CT and MRI. The line connecting the two injuries, which occurs between the medial inferior apex of the spiral tibia fracture line and the posterior superior apex of the PMF was identified as the “communication line”. In 47 of the 89 conjunction fractures, the “communication line” was detectable preoperatively and in 12 cases postoperatively by anteroposterior radiograph. By using the CT and MRI scans, we found that no “communication line” was present in only 7 cases. Conclusion: It is important to understand the nature of the association between distal spiral tibial shaft fractures and occult posterior malleolar fractures for optimal stabilization of the fracture and for appropriate rehabilitation. The “communication line” is a useful diagnostic clue for early recognition the occult PMF and alerts a closer evaluation of the lateral view and further CT examination.

  8. A game of two discs: a case of non-contiguous and occult cervical spine injury in a rugby player.

    O'Sullivan, Michael D; Piggot, Robert; Jaddan, Mutaz; McCabe, John P

    2016-03-14

    The aim of this case report was to highlight the application of magnetic resonance imaging (MRI) in elucidating serious and occult injuries in a single case of hyperflextion injury of a patient cervical spine (C-Spine). A chart and radiology review was performed to establish the sequence of care and how the results of imaging studies influenced the clinical management in this trauma case. Plain radiographs and computed tomography (CT) imaging modalities of the C-Spine revealed bilateral C4/C5 facetal subluxation with no obvious fractures; however, the MR imaging of the C-Spine revealed a non-contiguous and occult injury to C6/C7 disc with a posterior annular tear and associated disc extrusion. This altered the operative intervention that was initially planned. MR imaging proved an invaluable diagnostic addition in this particular case of cervical trauma in a rugby player following a hyperflextion injury, by revealing a serious non-contiguous and occult injury of the C-Spine. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2016.

  9. Atmospheric deposition of heavy metals due to dry, wet and occult deposition at the altitude profile Achenkirch

    Stopper, S.

    2001-12-01

    The goal of this work was to determine the height dependence of the three types of deposition throughout a one year time period to be able to get information about their elevational and seasonal behavior. In the time period from October 1998 to November 1999 measurements of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn in aerosol, rain and cloud water were conducted in the Achenkirch-Valley in Tyrol, Austria. Afterwards the dry and occult deposition were modeled. The estimated annual inputs of metals at the two measurement sites Christlumkopf (1758 m a.s.l.) Mueeggerkoel (940 m a.s.l.) and the limits of the national law for protection of forest are shown. The measured depositions at both sites were far below the legal regulations. Due to the much higher occult deposition ratio at the top of the mountain the total annual input at the Christlumkopf was higher than at the Mueeggerkoel. This indicates the potential importance of occult deposition. (author)

  10. Occult pneumothorax in blunt trauma: is there a need for tube thoracostomy?

    Zhang, M; Teo, L T; Goh, M H; Leow, J; Go, K T S

    2016-12-01

    Occult pneumothorax (OPTX) is defined as air within the pleural cavity that is undetectable on normal chest X-rays, but identifiable on computed tomography. Currently, consensus is divided between tube thoracostomy and conservative management for OPTX. The aim of this retrospective study is to determine whether OPTX can be managed conservatively and whether any adverse events occur under conservative management. Data on all trauma patients from 1 Jan 2010 to 31 December 2012 were obtained from our hospital's trauma registry. All patients with occult pneumothorax who had chest X-ray (CXR) and any CT scan visualizing the thorax were included. The exclusion criteria included those with penetrating wounds; CXR showing pneumothorax, hemothorax, or hemopneumothorax; those with prophylactic chest tube insertion before CT; and those with no CT diagnosis of OPTX. The complications of these patients were analyzed to determine if tube thoracostomy is necessary for OPTX and whether not inserting it would alter the outcome significantly. A total of 1564 cases were reviewed and 83 patients were included. Of these 83 patients, 35 (42.2 %) had tube thoracostomy after OPTX detection and 48 (57.8 %) were observed initially. Patients who had tube thoracostomy had similar ISS compared to those without (median ISS 17 vs. 18.5, p = 0.436). Out of the 48 patients who did not have tube thoracostomy on detection of an OPTX, 4 (8.3 %) had complications. In the group of 35 patients who had tube thoracostomy on detection of an OPTX, 7 (20 %) had complications. Of the 83 patients, a total of 12 patients had IPPV, of which 7 (58.3 %) had tube thoracostomy and 5 (41.7 %) did not. Patients who had tube thoracostomy under our care have a statistically significant likelihood of experiencing any complication compared to those without tube thoracostomy (odds ratio 9.92. The median length of stay was also longer (13 days) in those who had tube thoracostomy compared to those without (5

  11. Inversion, error analysis, and validation of GPS/MET occultation data

    A. K. Steiner

    Full Text Available The global positioning system meteorology (GPS/MET experiment was the first practical demonstration of global navigation satellite system (GNSS-based active limb sounding employing the radio occultation technique. This method measures, as principal observable and with millimetric accuracy, the excess phase path (relative to propagation in vacuum of GNSS-transmitted radio waves caused by refraction during passage through the Earth's neutral atmosphere and ionosphere in limb geometry. It shows great potential utility for weather and climate system studies in providing an unique combination of global coverage, high vertical resolution and accuracy, long-term stability, and all-weather capability. We first describe our GPS/MET data processing scheme from excess phases via bending angles to the neutral atmospheric parameters refractivity, density, pressure and temperature. Special emphasis is given to ionospheric correction methodology and the inversion of bending angles to refractivities, where we introduce a matrix inversion technique (instead of the usual integral inversion. The matrix technique is shown to lead to identical results as integral inversion but is more directly extendable to inversion by optimal estimation. The quality of GPS/MET-derived profiles is analyzed with an error estimation analysis employing a Monte Carlo technique. We consider statistical errors together with systematic errors due to upper-boundary initialization of the retrieval by a priori bending angles. Perfect initialization and properly smoothed statistical errors allow for better than 1 K temperature retrieval accuracy up to the stratopause. No initialization and statistical errors yield better than 1 K accuracy up to 30 km but less than 3 K accuracy above 40 km. Given imperfect initialization, biases >2 K propagate down to below 30 km height in unfavorable realistic cases. Furthermore, results of a statistical validation of GPS/MET profiles through comparison

  12. NEOCE: a new external occulting coronagraph experiment for ultimate observations of the chromosphere, corona and interface

    Damé, Luc; Fineschi, Silvano; Kuzin, Sergey; Von Fay-Siebenburgen, Erdélyi Robert

    Several ground facilities and space missions are currently dedicated to the study of the Sun at high resolution and of the solar corona in particular. However, and despite significant progress with the advent of space missions and UV, EUV and XUV direct observations of the hot chromosphere and million-degrees coronal plasma, much is yet to be achieved in the understanding of these high temperatures, fine dynamic dissipative structures and of the coronal heating in general. Recent missions have shown the definite role of a wide range of waves and of the magnetic field deep in the inner corona, at the chromosphere-corona interface, where dramatic and physically fundamental changes occur. The dynamics of the chromosphere and corona is controlled and governed by the emerging magnetic field. Accordingly, the direct measurement of the chromospheric and coronal magnetic fields is of prime importance. The solar corona consists of many localised loop-like structures or threads with the plasmas brightening and fading independently. The plasma evolution in each thread is believed to be related to the formation of filaments, each one being dynamic, in a non-equilibrium state. The mechanism sustaining this dynamics, oscillations or waves (Alfvén or other magneto-plasma waves), requires both very high-cadence, multi-spectral observations, and high resolution and coronal magnetometry. This is foreseen in the future Space Mission NEOCE (New External Occulting Coronagraph Experiment), the ultimate new generation high-resolution coronagraphic heliospheric mission, to be proposed for ESA M4. NEOCE, an evolution of the HiRISE mission, is ideally placed at the L5 Lagrangian point (for a better follow-up of CMEs), and provides FUV imaging and spectro-imaging, EUV and XUV imaging and spectroscopy, and ultimate coronagraphy by a remote external occulter (two satellites in formation flying 375 m apart minimizing scattered light) allowing to characterize temperature, densities and

  13. Modeling of the Enceladus water vapor jets for interpreting UVIS star and solar occultation observations

    Portyankina, Ganna; Esposito, Larry W.; Aye, Klaus-Michael; Hansen, Candice J.

    2015-11-01

    One of the most spectacular discoveries of the Cassini mission is jets emitting from the southern pole of Saturn’s moon Enceladus. The composition of the jets is water vapor and salty ice grains with traces of organic compounds. Jets, merging into a wide plume at a distance, are observed by multiple instruments on Cassini. Recent observations of the visible dust plume by the Cassini Imaging Science Subsystem (ISS) identified as many as 98 jet sources located along “tiger stripes” [Porco et al. 2014]. There is a recent controversy on the question if some of these jets are “optical illusion” caused by geometrical overlap of continuous source eruptions along the “tiger stripes” in the field of view of ISS [Spitale et al. 2015]. The Cassini’s Ultraviolet Imaging Spectrograph (UVIS) observed occultations of several stars and the Sun by the water vapor plume of Enceladus. During the solar occultation separate collimated gas jets were detected inside the background plume [Hansen et al., 2006 and 2011]. These observations directly provide data about water vapor column densities along the line of sight of the UVIS instrument and could help distinguish between the presence of only localized or also continuous sources. We use Monte Carlo simulations and Direct Simulation Monte Carlo (DSMC) to model the plume of Enceladus with multiple (or continuous) jet sources. The models account for molecular collisions, gravitational and Coriolis forces. The models result in the 3-D distribution of water vapor density and surface deposition patterns. Comparison between the simulation results and column densities derived from UVIS observations provide constraints on the physical characteristics of the plume and jets. The specific geometry of the UVIS observations helps to estimate the production rates and velocity distribution of the water molecules emitted by the individual jets.Hansen, C. J. et al., Science 311:1422-1425 (2006); Hansen, C. J. et al, GRL 38:L11202 (2011

  14. Occult pneumothorax in the blunt trauma patient: tube thoracostomy or observation?

    Wilson, Heather; Ellsmere, James; Tallon, John; Kirkpatrick, Andrew

    2009-09-01

    The term occult pneumothorax (OP) describes a pneumothorax that is not suspected on the basis of either clinical examination or initial chest radiography, but is subsequently detected on computed tomography (CT) scan. The optimal management of OP in the blunt trauma setting remains controversial. Some physicians favour placement of a thoracostomy tube for patients with OP, particularly those undergoing positive pressure ventilation (PPV), while others favour close observation without chest drainage. This study was conducted both to determine the incidence of OP and to describe its current treatment status in the blunt trauma population at a Canadian tertiary trauma centre. Of interest were the rates of tube thoracostomy vs. observation without chest drainage and their respective outcomes. A retrospective review was conducted of the Nova Scotia Trauma Registry. The data on all consecutive blunt trauma patients between October 1994 and March 2003 was reviewed. Outcome measures evaluated include length of stay, discharge status-dead vs. alive, intervention and time to intervention (tube thoracostomy and its relation to institution of PPV). Direct comparison was made between the OP with tube thoracostomy group and OP without tube thoracostomy group (observation or control group). They were compared in terms of their baseline characteristics and outcome measures. In 1881 consecutive blunt trauma patients over a 102-month period there were 307 pneumothoraces of which 68 were occult. Thirty five patients with OP underwent tube thoracostomy, 33 did not. Twenty nine (82.8%) with tube thoracostomy received positive pressure ventilation (PPV), as did 16 (48.4%) in the observation group. Mean injury severity score (ISS) for tube thoracostomy and observation groups were similar (25.80 and 22.39, p=0.101) whereas length of stay (LOS) was different (17.4 and 10.0 days, p=0.026). Mortality was similar (11.4% and 9.1%). There were no tension pneumothoraces. The natural history of

  15. [Intravitreal Ranibizumab Injection for the Treatment of Occult and Classic CNV in Exsudative AMD].

    Maier, M M; Feucht, N; Fegert, C; Fiore, B; Winkler von Mohrenfels, C; Lohmann, C

    2011-02-01

    Double-blind, randomised, placebo-controlled and multicentre studies have proven an increase in visual acuity in one-third of the patients receiving Ranibizumab (0.5 mg) injections, who suffer from exsudative AMD. The purpose of this study was to evaluate the early effects of intravitreal Ranibizumab therapy in patients with mainly occult neovascular AMD in clinical applications. In a retrospective cohort study, 91 eyes with occult and classic neovascular AMD were treated with intravitreal injections of Ranibizumab (0.5 mg) at 30-day intervals. The treatment effects were evaluated according to best corrected visual acuity, optical coherence tomography (OCT) and intraocular pressure at baseline as well as 1, 3 and 6 months after the beginning of therapy. Furthermore, fluorescein angiography (FLA) was performed at baseline as well as 3 and 6 months after therapy. 74 % of the patients lost fewer than 15 letters on the EDTRS-scale 6 months after the beginning of therapy. Visual acuity improved by more than 15 letters in 11 % of the patients. Central retinal thickness, measured by OCT, decreased statistically significantly in each control compared to baseline (1 month: p = 0.045; 3 months: p = 0.001; 6 months: p = 0.006). Leakage and membranes, evaluated in FA, worsened in 31 % of the patients; in 67 % the findings were stable. No increase in intraocular pressure was detected. Intravitreal application of Ranibizumab was safe and well tolerated. In the clinical situation, visual acuity was stabilised in the short term. As opposed to phase-III studies, no improvement in visual acuity could be accomplished. Cental retinal thickness decreased and findings in fluorescein angiography were stable within a 6-month follow-up period. It is necessary to perform monthly controls and proceed with VA- and OCT-based injections in order to maintain the therapeutic effect. Futher clinical evaluations of Ranibizumab will be necessary to evaluate its long-term treatment effects.

  16. Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: Significance of hepatitis B core antibodies screening

    Elbedewy, T.A.; Elashtokhy, H.A.; Rabee, E.S.; Kheder, G.E.

    2015-01-01

    Background: Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies. Aim of the work: To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy. Patients and methods: This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR). Results: Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation. Conclusion: The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

  17. Effects of electrotherapy in treatment of neurogenic bladder in children with occult spinal dysraphism

    Ćirović Dragana

    2009-01-01

    Full Text Available Introduction Neurogenic bladder can develop as a result of various degrees of neurogenic lesion in spina bifida. The degree of bladder dysfunction depends on the level and type of spina bifida. Due to results upon complete diagnostic protocols, treatment options are applied. Objective Comparison of therapy results of patients with occult spinal dysraphism with neurogenic bladder that under-went medicamentous therapy and medicamentous with electrotherapy treatment. Methods We had 49 patients with neurogenic bladder that were treated at the University Children's Hospital in Belgrade in the period 2003-2008. The first group of children received medicamentous therapy and the second group received medicamentous therapy with transcutaneous electric nerve stimulation. In both groups we evaluated 4 symptoms: daily enuresis, enuresis nocturna, urgency and frequency and 4 urodynamic parameters: lower bladder capacity, unstable contractions and residual urine and detrusor sphincter dyssynergia. Follow-up urodynamic evaluation was done after 3, 6 and 12 months respectively. Results Our findings pointed out a high statistical significance of improvement in all evaluated urodynamic parameters of neurogenic bladder (predominantly in bladder capacity in the group of children with combined therapy as well in resolution of symptoms (predominantly enuresis nocturna, urgency and frequency. Conclusion Combined therapy is more efficient in treatment of children with neurogenic bladder. Electrotherapy is non-invasive, easily applicable and has had a significant place in treatment of children with dysfunctional voiding.

  18. STarlight Absorption Reduction through a Survey of Multiple Occulting Galaxies (STARSMOG)

    Holwerda, Benne

    2014-10-01

    Dust absorption remains the poorest constrained parameter in both Cosmological distances and multi-wavelength studies of galaxy populations. A galaxy's dust distribution can be measured to great accuracy in the case of an overlapping pair of galaxies, i.e., when a foreground spiral galaxy accidentally overlaps a more distant, preferably elliptical galaxy. We have identified over 300 bona-fide overlapping pairs --well separated in redshift but close on the sky-- in the GAMA spectroscopic survey, taking advantage of its high completeness (98%) on small scales. We propose to map the fine-scale (~50pc) dust structure in these occulting galaxies, using HST/WFC3 SNAP observations. The resulting dust maps will (1) serve as an extinction probability for supernova lightcurve fits in similar type host galaxies, (2) strongly constrain the role of ISM structure in Spectral Energy Distribution models of spiral galaxies, and (3) map the level of ISM turbulence (through the spatial power-spectrum). We ask for SNAP observations with a parent list of 355 targets to ensure a complete and comprehensive coverage of each foreground galaxy mass, radius and inclination. The resulting extinction maps will serve as a library for SNIa measurements, galaxy SED modelling and ISM turbulence measurements.

  19. Radio-guided localization of clinically occult breast lesions (ROLL): a DGH experience

    Thind, C.R.; Desmond, S.; Harris, O.; Nadeem, R.; Chagla, L.S.; Audisio, R.A.

    2005-01-01

    AIM: Wire-guided localization (WGL) of clinically occult breast lesions is a well established technique. The aim of this study was to evaluate radio-guided localization (ROLL) within the breast screening service of a district general hospital. METHOD: The study group comprised 70 women who underwent ROLL under US and stereotaxis. This required an injection of Technetium-labelled colloidal albumen into the impalpable breast lesion. The women then proceeded to theatre, where localization was achieved with the use of a gamma probe. The lesion was identified by the presence of a high signal, caused by the injected isotope. The results of 70 consecutive cases in which a breast lesion was localized using ROLL were compared with the results of the latest 70 WGLs. RESULTS: All 140 lesions were successfully localized. However, the change in technique from WGL to ROLL offered significant benefits to patients. CONCLUSION: Our study demonstrated that ROLL is a practical and reliable localization technique. It can be implemented in hospital units without using valuable gamma camera time. The cost compares well with WGL. There is an improved cosmetic outcome for patients, and the very small quantity of radioactivity used is safe for both patients and staff

  20. The application of digital tomosynthesis in diagnosis of occult bone fracture

    Tian Jun; Gong Wuxian; Zhang Dianxing; Tian Ye; Huang Shiting

    2011-01-01

    Objective: To evaluate the digital tomosynthesis in the diagnosis of occult bone fracture. Methods: Both DR and DTS were performed in 135 cases with traumatic-induced pain. All the cases were suspected of bone fractures but with no abnormal findings in DR images. Two radiologists reviewed all the images and diagnosed in consensus. All cases were followed up and the imaging diagnoses were reviewed. Results: Bone fractures or joint dislocations of 61 cases were shown in DTS images but not in DR images, including atlanto-axial fracture and subluxation in 7 cases, articular fracture of limbs in 20 cases, bone fractures of wrist, hand and foot in 11 cases, fractures of cervical, thoracic and lumbar vertebra in 7 cases, fracture of sacrococcyx in 8 cases, fracture of nasal bone in 4 cases, fractures of' Sternum, rib, orbit and mandible in 1 case. Thirty-four cases with bone fractures were determined by using DTS in suspected cases and 17 cases were denied. Both DR and DTS images showed normal findings in 23 cases. Imaging diagnoses of all cases were consistent with the results of follow up. Conclusion: DTS can depict bone fractures especially in the deep and complex bony structures, which may improve the diagnostic accuracy of bone fracture. (authors)

  1. Bronchoscopic brachytherapy in roentgenologically occult cancer of the trachea and bronchus

    Ono, Ryosuke; Hirano, Hiroshi (National Cancer Center, Tokyo (Japan). Central Hospital)

    1994-12-01

    Bronchoscopic brachytherapy is a new technique presently being investigated for the treatment of cancer involving the tracheobronchial tree. This paper reports on the potential application of bronchoscopic brachytherapy to the local treatment of cancer of the respiratory tract. Bronchoscopic brachytherapy was performed on 8 patients with roentgenographically occult lung cancer after biopsies proved malignant lesions of the trachea and bronchus in each case. These patients came to the National Cancer Center Hospital during the period from September 1992 to December 1992. Among these 8 cases of malignant lesions of the trachea and bronchus, 5 malignant lesions of the bronchus were diagnosed by bronchoscopic ultrasonography prior to the bronchoscopic brachytherapy, and these 5 patients have completed at least three courses of this therapy carried out by means of a videobronchoscope. Among the 8 cases of malignant lesions of the trachea and bronchus, complete remission was obtained in 7 cases. Of the 8 patients, the death of one patient was caused by amyotrophic lateral sclerosis, while the remaining 7 patients have survived for 13-15 months (14.1 months on average) to date, without showing recurrence or metastasis. As for the complications involved in this treatment, only a light degree of excessive secretions was observed, and there was no abscess formation in any of the cases. (author).

  2. Bronchoscopic brachytherapy in roentgenologically occult cancer of the trachea and bronchus

    Ono, Ryosuke; Hirano, Hiroshi

    1994-01-01

    Bronchoscopic brachytherapy is a new technique presently being investigated for the treatment of cancer involving the tracheobronchial tree. This paper reports on the potential application of bronchoscopic brachytherapy to the local treatment of cancer of the respiratory tract. Bronchoscopic brachytherapy was performed on 8 patients with roentgenographically occult lung cancer after biopsies proved malignant lesions of the trachea and bronchus in each case. These patients came to the National Cancer Center Hospital during the period from September 1992 to December 1992. Among these 8 cases of malignant lesions of the trachea and bronchus, 5 malignant lesions of the bronchus were diagnosed by bronchoscopic ultrasonography prior to the bronchoscopic brachytherapy, and these 5 patients have completed at least three courses of this therapy carried out by means of a videobronchoscope. Among the 8 cases of malignant lesions of the trachea and bronchus, complete remission was obtained in 7 cases. Of the 8 patients, the death of one patient was caused by amyotrophic lateral sclerosis, while the remaining 7 patients have survived for 13-15 months (14.1 months on average) to date, without showing recurrence or metastasis. As for the complications involved in this treatment, only a light degree of excessive secretions was observed, and there was no abscess formation in any of the cases. (author)

  3. Fundus autofluorescence and optical coherence tomographic findings in acute zonal occult outer retinopathy.

    Fujiwara, Takamitsu; Imamura, Yutaka; Giovinazzo, Vincent J; Spaide, Richard F

    2010-09-01

    The purpose of this study was to investigate the fundus autofluorescence and optical coherence tomography findings in eyes with acute zonal occult outer retinopathy (AZOOR). A retrospective observational case series of the fundus autofluorescence and spectral domain optical coherence tomography in a series of patients with AZOOR. There were 19 eyes of 11 patients (10 women), who had a mean age of 49.1 +/- 13.9 years. Fundus autofluorescence abnormalities were seen in 17 of the 19 eyes, were more common in the peripapillary area, and were smaller in extent than the optical coherence tomography abnormalities. Nine eyes showed progression of hypoautofluorescence area during the mean follow-up of 69.7 months. The mean thickness of the photoreceptor layer at fovea was 177 microm in eyes with AZOOR, which was significantly thinner than controls (193 microm, P = 0.049). Abnormal retinal laminations were found in 12 eyes and were located over areas of loss of the photoreceptors. The subfoveal choroidal thickness was 243 microm, which is normal. Fundus autofluorescence abnormalities in AZOOR showed distinct patterns of retinal pigment epithelial involvement, which may be progressive. Thinning of photoreceptor cell layer with loss of the outer segments and abnormal inner retinal lamination in the context of a normal choroid are commonly found in AZOOR.

  4. Occult constrictive pericardial disease emerging 40 years after chest radiation therapy: a case report.

    Goten, Chiaki; Murai, Hisayoshi; Takashima, Shin-Ichiro; Kato, Takeshi; Usui, Soichiro; Furusho, Hiroshi; Saeki, Takahiro; Sakagami, Satoru; Takemura, Hirofumi; Kaneko, Shuichi; Takamura, Masayuki

    2018-05-31

    The main etiology of constrictive pericarditis (CP) has changed from tuberculosis to therapeutic mediastinal radiation and cardiac surgery. Occult constrictive pericardial disease (OCPD) is a covert disease in which CP is manifested in a condition of volume overload. A 60-year-old patient with a history of thoracic radiation therapy for non-Hodgkin's lymphoma (40 years earlier) was transferred to our hospital for treatment of repeated congestive heart failure. For a preoperative hemodynamic study, pre-hydration with intravenous normal saline (50 mL/hour) was used to manifest the pericardial disease and prevent contrast-induced nephropathy. The hemodynamic study showed a right ventricular dip-plateau pattern and discordance of right and left ventricular systolic pressures during inspiration, which was not seen in the volume-controlled state. These responses were concordant with OCPD. A pericardiectomy, aortic valve replacement, and mitral and tricuspid valve repair were performed. Postoperatively, the heart failure was controlled with standard medication. This case revealed a volume-induced change in hemodynamics in OCPD with severe combined valvular heart disease, which suggests the importance of considering OCPD in patients who had undergone radiation therapy 40 years before.

  5. Occult CSF flow disturbance of patients with Alzheimer type dementia and vascular dementia

    Kono, Kazuhiko; Sugita, Yasuko; Funaki, Chiaki

    1994-01-01

    We report results of Iotrolan CT-cisternography on 41 demented patients (13 males and 28 females) to find 'occult normal pressure hydrocephalus'. These patients were suspected to have CSF flow disturbance from clinical symptoms and simple brain CT scan findings. Their average age, duration of dementia, and score of Hasegawa's dementia scale (HDS) were 76.2 years, 5.9 years, 9.5/32.5,respectively. Before performing CT-cisternography, clinical diagnosis for their dementia were vascular dementia in 18 patients. Alzheimer type dementia in 12, suspect of NPH in 5, and other diagnoses in 6. From the results of cisternography, we found 13 patients with CSF flow disturbance (contrast material remained in the ventricle more than 48 hours after injection), and 17 patients with normal CSF flow. The former showed lower scores of HDS, higher urinary incontinence scores and smaller areas of the interhemispheric fissure on CT scan than the latter. But the former showed no significant difference from the latter in the average age, duration of dementia and width of the ventricles. (author)

  6. First assimilations of COSMIC radio occultation data into the Electron Density Assimilative Model (EDAM

    M. J. Angling

    2008-02-01

    Full Text Available Ground based measurements of slant total electron content (TEC can be assimilated into ionospheric models to produce 3-D representations of ionospheric electron density. The Electron Density Assimilative Model (EDAM has been developed for this purpose. Previous tests using EDAM and ground based data have demonstrated that the information on the vertical structure of the ionosphere is limited in this type of data. The launch of the COSMIC satellite constellation provides the opportunity to use radio occultation data which has more vertical information. EDAM assimilations have been run for three time periods representing quiet, moderate and disturbed geomagnetic conditions. For each run, three data sets have been ingested – only ground based data, only COSMIC data and both ground based and COSMIC data. The results from this preliminary study show that both ground and space based data are capable of improving the representation of the vertical structure of the ionosphere. However, the analysis is limited by the incomplete deployment of the COSMIC constellation and the use of auto-scaled ionosonde data. The first of these can be addressed by repeating this type of study once full deployment has been achieved. The latter requires the manual scaling of ionosonde data; ideally an agreed data set would be scaled and made available to the community to facilitate comparative testing of assimilative models.

  7. Gastric metastases originating from occult breast lobular carcinoma: diagnostic and therapeutic problems

    Russo Leila

    2008-07-01

    Full Text Available Abstract Background Breast cancer is the most frequent malignant tumour to metastasize into the gastrointestinal tract in female and is second only to malignant melanoma. Nevertheless gastrointestinal metastases arising from breast cancer are quite rare. The upper gastrointestinal tract is more frequently involved and lobular infiltrating carcinoma has a greater predilection compared to the ductal type. Case presentation The authors describe the case of a 70 years old woman with a preoperative diagnosis of gastric undifferentiated medullary – type carcinoma, which was the first manifestation of an occult breast carcinoma. The primary site of carcinoma was identified with the use of a panel of selected immunohistochemical markers. Conclusion Our goal in this case report is to increase the awareness of surgeons and clinicians to rule out the possibility of mammary origin in circumstance of gastric cancer occurring in female, even in patients without a previous or concurrent history of breast carcinoma. Although not a particularly common event, it is, nevertheless, reported in the literature. The differentiation between primary gastric carcinoma and metastatic breast carcinoma is essential for planning the correct therapeutic approach, in order to avoid the patient unnecessary surgery.

  8. Angiographically occult vascular malformation of the brain: MR imaging at 1.5 T

    Patel, S.C.; Sanders, W.P.; Fuentes, J.; Haggar, A.M.; Mehta, B.A.; Boulos, R.S.; Froelich, J.W.

    1986-01-01

    MR imaging was performed in nine patients with 12 angiographically occult arteriovenous malformations using a 1.5-T superconducting magnet; four additional patients were imaged using a 0.3-T system. All images were reviewed in conjunction with CT scans. The following observations were made. (1) Eleven of 14 supratentorial lesions were located at the junction of gray and white matter. (2) Exclusing acute hemorrhage, only two lesions displayed mild mass effect. (3) All lesions displayed central foci of high signal intensity, probably representing subacute hemorrhage. (4) All lesions but one showed a peripheral rim of low signal intensity which progressively lost signal with increasing T2 weighting. This most likely represents iron-containing hemosiderin deposition. (5) Lesions were best demonstrated with long repetition times and moderate T2 weighting (TR = 2,500 msec, TE = 25-100 msec). (6) All lesions but one were hyperdense on non-contrast-enhanced CT, although only three had unequivocal calcification. The possibility of hyperdensity due to blood or iron deposition is discussed

  9. Therapeutic Response for Functional Abdominal Pain in Children with Occult Constipation: Laxatives versus Prokinetic Drugs.

    Ha, Eun Kyo; Jang, Homin; Jeong, Su Jin

    2017-01-01

    The relationship between functional abdominal pain (FAP) and occult constipation (OC) in children who did not meet the Rome III criteria for constipation has rarely been reported. This study aimed to estimate the prevalence of OC in patients with FAP and to compare the effectiveness of prokinetic drugs and laxatives for FAP and OC. Pediatric outpatients (n = 212; aged 4-15 years) who satisfied the Rome III criteria for childhood FAP were divided into 2 groups based on Leech scores: group 1 pain severity was assessed after 2 weeks, 1 month, and 3 months. A total 52.4% (111/212) of patients had OC in this study. More patients who received laxatives had reduced pain scores compared with those who received prokinetic drugs. Those treated with laxatives in group 2 had a better response than those treated with prokinetic drugs throughout the study period (P < 0.001, P < 0.001, and P = 0.002 after 2 weeks, 1 month, and 3 months, respectively). OC was frequently encountered in children with FAP. Laxatives can be more effective than prokinetic drugs for relieving symptoms of FAP in children with a Leech score ≥ 8 and suspected OC.

  10. Hand gesture recognition in confined spaces with partial observability and occultation constraints

    Shirkhodaie, Amir; Chan, Alex; Hu, Shuowen

    2016-05-01

    Human activity detection and recognition capabilities have broad applications for military and homeland security. These tasks are very complicated, however, especially when multiple persons are performing concurrent activities in confined spaces that impose significant obstruction, occultation, and observability uncertainty. In this paper, our primary contribution is to present a dedicated taxonomy and kinematic ontology that are developed for in-vehicle group human activities (IVGA). Secondly, we describe a set of hand-observable patterns that represents certain IVGA examples. Thirdly, we propose two classifiers for hand gesture recognition and compare their performance individually and jointly. Finally, we present a variant of Hidden Markov Model for Bayesian tracking, recognition, and annotation of hand motions, which enables spatiotemporal inference to human group activity perception and understanding. To validate our approach, synthetic (graphical data from virtual environment) and real physical environment video imagery are employed to verify the performance of these hand gesture classifiers, while measuring their efficiency and effectiveness based on the proposed Hidden Markov Model for tracking and interpreting dynamic spatiotemporal IVGA scenarios.

  11. The Evolution and Application of Cardiac Monitoring for Occult Atrial Fibrillation in Cryptogenic Stroke and TIA.

    Miller, Daniel J; Shah, Kavit; Modi, Sumul; Mahajan, Abhimanyu; Zahoor, Salman; Affan, Muhammad

    2016-04-01

    The evaluation of the stroke and transient ischemic attack (TIA) patient has been historically predominated by the initial evaluation in the hospital setting. As the etiology of stroke has eluded us in approximately one third of all acute events, the medical community has been eager to seek the answer to this mystery. In recent years, we have seen an explosion of innovations and trends allowing for a more detailed post stroke assessment strategy aimed at the identification of occult atrial fibrillation as the etiologic cause for the cryptogenic event. This has been achieved through the evolution and aggressive application and study of prolonged and advanced cardiac monitoring. This review is aimed to clarify and elucidate the standard and novel cardiac monitoring methods that have become available for use by the medical community and expected in the higher level care of cryptogenic stroke and TIA patients. These cardiac monitoring methods and devices are as heterogeneous as our patient population and have their own advantages and disadvantages. Many factors may be taken into consideration in choosing the appropriate cardiac monitoring method and are highlighted for consideration in this review. With a judicious approach to investigating the cryptogenic stroke population, and applying a wealth of novel treatment options, we may move forward into a new era of stroke prevention.

  12. Occult intraocular trauma: evaluation of the eye in an austere environment.

    Sweet, Patrick H

    2013-03-01

    Physicians deployed to austere environments often encounter the challenge of needing to make clinical decisions based upon rudimentary history and physical examination. These skills, however, can be difficult for many to rely on, with the many subtleties of examining the eye, when they are normally accustomed to relying on sophisticated modalities to establish diagnosis. This case is a model for evaluating eye trauma in an austere or hostile environment. A 25-year-old male U.S. Marine was fired upon at a Mexican Army checkpoint where he sustained glass shrapnel injuries, the most serious being to his right eye. He was taken from a detention facility to a Mexican hospital, where he was evaluated and given the diagnosis of corneal laceration. Twelve hours later, a U.S. Navy physician arrived to evaluate the patient; he was allowed limited access to the patient. His ophthalmologic examination revealed a closed corneal laceration on the right eye, worse than 20/800 vision, absent red reflex, and obscured funduscopic examination. These findings made it impossible to rule out globe penetration. The patient was released 48 h later to a U.S. Naval Hospital, where intraocular foreign bodies were confirmed by imaging and he was taken to emergency surgery. This case illustrates that even under austere conditions, a focused history and evaluation can reveal the likelihood of occult intraocular foreign body, thereby triaging the patient for emergency surgery. Published by Elsevier Inc.

  13. AN OCCULTATION EVENT IN CENTAURUS A AND THE CLUMPY TORUS MODEL

    Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard, E-mail: erivers@ucsd.edu [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0424 (United States)

    2011-12-15

    We have analyzed 16 months of sustained monitoring observations of Centaurus A from the Rossi X-Ray Timing Explorer to search for changes in the absorbing column in the line of sight to the central nucleus. We present time-resolved spectroscopy which indicates that a discrete clump of material transited the line of sight to the central illuminating source over the course of {approx}170 days between 2010 August and 2011 February with a maximum increase in the column density of about 8.4 Multiplication-Sign 10{sup 22} cm{sup -2}. This is the best quality data of such an event that has ever been analyzed with the shape of the ingress and egress clearly seen. Modeling the clump of material as roughly spherical with a linearly decreasing density profile and assuming a distance from the central nucleus commensurate with the dusty torus, we found that the clump would have a diameter of (1.4-2.4) Multiplication-Sign 10{sup 15} cm with a central number density of n{sub H} = (1.8-3.0) Multiplication-Sign 10{sup 7} cm{sup -3}. This is consistent with previous results for a similar (though possibly much longer) occultation event inferred in this source in 2003-2004 and supports models of the molecular torus as a clumpy medium.

  14. AN OCCULTATION EVENT IN CENTAURUS A AND THE CLUMPY TORUS MODEL

    Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard

    2011-01-01

    We have analyzed 16 months of sustained monitoring observations of Centaurus A from the Rossi X-Ray Timing Explorer to search for changes in the absorbing column in the line of sight to the central nucleus. We present time-resolved spectroscopy which indicates that a discrete clump of material transited the line of sight to the central illuminating source over the course of ∼170 days between 2010 August and 2011 February with a maximum increase in the column density of about 8.4 × 10 22 cm –2 . This is the best quality data of such an event that has ever been analyzed with the shape of the ingress and egress clearly seen. Modeling the clump of material as roughly spherical with a linearly decreasing density profile and assuming a distance from the central nucleus commensurate with the dusty torus, we found that the clump would have a diameter of (1.4-2.4) × 10 15 cm with a central number density of n H = (1.8-3.0) × 10 7 cm –3 . This is consistent with previous results for a similar (though possibly much longer) occultation event inferred in this source in 2003-2004 and supports models of the molecular torus as a clumpy medium.

  15. [Faecal occult blood test for colorectal cancer screening: high quality for a good price].

    van Veldhuizen, Harriët; Bonfrer, J M G Hans; Kuipers, Ernst J

    2013-01-01

    The Dutch National Institute for Public Health and the Environment (RIVM) awarded the immunochemical faecal occult blood test (IFOBT) to FOB Gold of Sentinel following a European call for tenders. The contract-awarding procedure included the application of quality knock-out criteria, which were met by two suppliers. The decisive factor was the best price/quality ratio. A recent review indicated that, at present, no single IFOBT is better than any other. The decision to opt for a test manufactured by a different supplier than was used in the previous screening pilots made it necessary to re-determine the cut-off value. This value has now been set (88 ng/ml) and is confirmed by a laboratory test. Colonoscopy-related capacity planning, as well as its diagnostic yield, depends on numerous factors; therefore, the RIVM is currently monitoring the referral percentage and number of adenomas detected and is collaborating on quality terms. Any necessary adjustments are to be made during the introduction of the screening test.

  16. Spatial irregularities in Jupiter's upper ionosphere observed by voyager radio occultations

    Hinson, D.P.; Tyler, G.L.

    1982-07-01

    Dual frequency radio occultation experiments carried out with Voyagers 1 and 2 provided data on the spatial irregularities in Jupiter's ionosphere at four different locations. Sample spectra of weak fluctuations in amplitude and phase of the 3.6-cm and 13-cm wavelength radio signals can be interpreted by using the theory for scattering from an anisotropic power law phase screen. Least squares solutions for ionospheric parameters derived from the observed fluctuation spectra yielded estimates of (1) the axial ratio, (2) angular orientation of the anisotropic irregularities, (3) the power law exponent of the spatial spectrum of irregularities, and (4) the magnitude of the spatial variations in electron density. Equipment limitations and the method of analysis constrain the observations to irregularities of approximate size 1--200 km. No evidence of the inner or outer scale of the irregularities was found. For length scales in the range given, the three-dimensional spatial spectrum obeys a power law with exponent varying from -3.0 to -3.7, and the root mean square fractional variations in electron density are 1--15%. All observed irregularities appear to be anisotropic with axial ratios between 2:1 and 10:1. Ionospheric parameters vary with altitude and latitude. We conclude that the measured angular orientation of the anisotropic irregularities indicates magnetic field direction and may provide a basis for refining Jovian magnetic field models.

  17. Occult posterolateral rotatory dislocation of the elbow with olecranon fracture in a child: a case report

    Fujimori Takahito

    2012-09-01

    Full Text Available Abstract Introduction Acute posterolateral rotator elbow dislocation in a child is rare and can be easily misdiagnosed due to immaturity of the epiphysis. This is the first case of occult posterolateral rotator elbow dislocation in combination with an olecranon fracture. We report our experience with this case, which was not diagnosed correctly by plain radiographs. Case presentation An 11-year-old Asian boy suffered severe pain and swelling of his right elbow after his outstretched arm hit a car dashboard in a motor vehicle accident. Plain radiographs showed only a minimally displaced olecranon fracture and a tiny lateral epicondylar avulsion fracture. However, stress radiographs under general anesthesia revealed severe posterolateral rotatory instability. During surgery, we found that the cartilaginous lateral epicondylar apophysis was much larger than the epicondylar fragment on the radiographs. After the lateral epicondylar osteochondral fragment and lateral collateral ligament complex were fixed, the instability disappeared. Conclusion Our experience with this case shows that it is important to check for instability with pediatric elbow fractures, because a tiny avulsion fracture was able to cause severe posterolateral rotatory instability in a child.

  18. Polydimethylsiloxane: a new contrast material for localization of occult breast lesions

    Vitral, Geraldo Sérgio Farinazzo; Raposo, Nádia Rezende Barbosa

    2011-01-01

    The radioguided localization of occult breast lesions (ROLL) technique often utilizes iodinated radiographic contrast to assure that the local injection of 99m Tc-MAA corresponds to the location of the lesion under investigation. However, for this application, this contrast has several shortcomings. The objective of this study was to evaluate the safety, effectiveness and technical feasibility of the use of polydimethylsiloxane (PDMS) as radiological contrast and tissue marker in ROLL. The safety assessment was performed by the acute toxicity study in Wistar rats (n = 50). The radiological analysis of breast tissue (n = 32) from patients undergoing reductive mammoplasty was used to verify the effectiveness of PDMS as contrast media. The technical feasibility was evaluated through the scintigraphic and histologic analysis. We found no toxic effects of PDMS for this use during the observational period. It has been demonstrated in human breast tissue that the average diameter of the tissue marked by PDMS was lower than when marked by the contrast medium (p <0.001). PDMS did not interfere with the scintigraphic uptake (p = 0.528) and there was no injury in histological processing of samples. This study demonstrated not only the superiority of PDMS as radiological contrast in relation to the iodinated contrast, but also the technical feasibility for the same applicability in the ROLL

  19. Acute paraparesis as presentation of an occult follicular thyroid carcinoma: A case report

    José Miguel Baião

    Full Text Available Introduction: Follicular thyroid carcinoma is the second most frequent type of well differentiated thyroid tumours. It is usually confined to the thyroid gland, however it can metastasize in a later stage of the disease. Signs and symptoms associated with bone metastasis are rare as first clinical manifestations. Case report: An 84-year-old female complained with acute paraparesis. Magnetic resonance imaging revealed an extensive intraosseous infiltrating lesion compatible with a bone metastasis from an occult tumour. Biopsy samples were compatible with bone metastasis from a follicular thyroid carcinoma. The patient was submitted to total thyroidectomy followed by iodine ablative therapy. Discussion: Follicular thyroid carcinoma presentation with symptoms related to bone metastasis is rare. Patients with bone lesions, such as pathological fractures or compressive symptoms should be studied since they may have clinically unapparent lesions from an unknown tumour. Patients with FTC should be submitted to total thyroidectomy. Bone lesions may be addressed to improve quality of life however this decision depends on disease extent. Conclusion: Acute paraparesis is a rare form of presentation of thyroid carcinoma. These neoplasms must be taken into account when investigating metastasis to the bone from unknown neoplasms. Keywords: Acute paraparesis, Follicular thyroid carcinoma, Bone metastasis, Case report

  20. Immune reconstitution inflammatory syndrome after initiating highly active antiretroviral therapy in HIV-infected children

    Kilborn, Tracy; Zampoli, Marco

    2009-01-01

    The outcome of HIV infection has improved since the widespread availability of highly active antiretroviral therapy (HAART). Some patients, however, develop a clinical and radiological deterioration following initiation of HAART due to either the unmasking of occult subclinical infection or an enhanced inflammatory response to a treated infection. This phenomenon is believed to result from the restored ability to mount an immune response and is termed immune reconstitution inflammatory syndrome (IRIS) or immune reconstitution disease. IRIS is widely reported in the literature in adult patients, most commonly associated with mycobacterial infections. There is, however, a paucity of data documenting the radiological findings of IRIS in children. Radiologists need to be aware of this entity. As a diagnosis of exclusion it is essential that the radiological findings be assessed in the context of the clinical presentation. This article reviews the common clinical and radiological manifestations of IRIS in HIV-infected children. (orig.)

  1. Hepatitis B virus infection in Indonesia.

    Yano, Yoshihiko; Utsumi, Takako; Lusida, Maria Inge; Hayashi, Yoshitake

    2015-10-14

    Approximately 240 million people are chronically infected with hepatitis B virus (HBV), 75% of whom reside in Asia. Approximately 600000 of infected patients die each year due to HBV-related diseases or hepatocellular carcinoma (HCC). The endemicity of hepatitis surface antigen in Indonesia is intermediate to high with a geographical difference. The risk of HBV infection is high in hemodialysis (HD) patients, men having sex with men, and health care workers. Occult HBV infection has been detected in various groups such as blood donors, HD patients, and HIV-infected individuals and children. The most common HBV subgenotype in Indonesia is B3 followed by C1. Various novel subgenotypes of HBV have been identified throughout Indonesia, with the novel HBV subgenotypes C6-C16 and D6 being successfully isolated. Although a number of HBV subgenotypes have been discovered in Indonesia, genotype-related pathogenicity has not yet been elucidated in detail. Therefore, genotype-related differences in the prognosis of liver disease and their effects on treatments need to be determined. A previous study conducted in Indonesia revealed that hepatic steatosis was associated with disease progression. Pre-S2 mutations and mutations at C1638T and T1753V in HBV/B3 have been associated with advanced liver diseases including HCC. However, drug resistance to lamivudine, which is prominent in Indonesia, remains obscure. Although the number of studies on HBV in Indonesia has been increasing, adequate databases on HBV infection are limited. We herein provided an overview of the epidemiology and clinical characteristics of HBV infection in Indonesia.

  2. Water vapour and methane coupling in the stratosphere observed using SCIAMACHY solar occultation measurements

    S. Noël

    2018-04-01

    Full Text Available An improved stratospheric water vapour data set has been retrieved from SCIAMACHY/ENVISAT solar occultation measurements. It is similar to that successfully applied to methane and carbon dioxide. There is now a consistent set of data products for the three constituents covering the altitudes 17–45 km, the latitude range between about 50 and 70° N, and the period August 2002 to April 2012. The new water vapour concentration profiles agree with collocated results from ACE-FTS and MLS/Aura to within  ∼  5 %. A significant positive linear change in water vapour for the time 2003–2011 is observed at lower stratospheric altitudes with a value of about 0.015 ± 0.008 ppmv year−1 around 17 km. Between 30 and 37 km the changes become significantly negative (about −0.01 ± 0.008 ppmv year−1; all errors are 2σ values. The combined analysis of the SCIAMACHY methane and water vapour time series shows the expected anti-correlation between stratospheric methane and water vapour and a clear temporal variation related to the Quasi-Biennial Oscillation (QBO. Above about 20 km most of the additional water vapour is attributed to the oxidation of methane. In addition short-term fluctuations and longer-term variations on a timescale of 5–6 years are observed. The SCIAMACHY data confirm that at lower altitudes the amount of water vapour and methane are transported from the tropics to higher latitudes via the shallow branch of the Brewer–Dobson circulation.

  3. Occult inflammatory breast cancer: review of clinical, mammographic, US and pathologic signs

    Cumo, Francesca; Gaioni, Maria Berenice; Bonetti, Franco; Manfrin, Erminia; Remo, Andrea; Pattaro, Christian; Policlinico G.B. Rossi, Verona

    2005-01-01

    Purpose: To examine the clinical, radiologic and pathologic findings of occult inflammatory breast cancer (OIBC) in order to identify features useful for diagnosis. Materials and methods: We retrospectively reviewed the records of 19 women with OIBC observed at our Department between 1992 and 2001. We analysed the clinical history, mammographic, ultrasonographic, and pathologic findings and investigated overall survival (OS), prognostic variables and radio-pathologic correlations. Results: The most common mammographic findings were: diffusely density (52.63%), trabecular thickening (42.1%), mass (36.84%). The most common US findings were axillary lymphadenopathy (68,75%), skin thickening (43.75%) and mass (56.25%). At least one inflammatory sign was found in 14 women (74%) at mammography (subcutaneous thickening, trabecular thickening, diffuse increase of density) or at US (subcutaneous thickening, diffuse increase in echogenicity due to oedema, lymph vessel dilatation). Estrogen receptors (ER) were present in 63.2% and Progesterone receptors (PgR) in 36.8%. Significant prognostic variables were ER and Ki 67. Conclusions: The typical radiological pattern of clinical inflammatory breast carcinoma is less frequently present in OIBC; nevertheless the radiologist must pay attention because frequently OIBC presents just one radiological sign and this should be enough for a diagnostic suspicion. Moreover, the absence of clinical and radiological inflammatory signs does not exclude inflammatory breasts cancer because OIBC can manifest at imaging as a mass or isolated calcification. ER and PgR are positive in a high percentage of patients and confirm that OIBC has a better prognosis that clinical inflammatory breast cancer [it

  4. A Comprehensive Assessment of Radio Occultation Ionospheric Measurements at Mid-Latitudes

    Keele, C.; Brum, C. G. M.; Rodrigues, F. S.; Aponte, N.; Sulzer, M. P.

    2015-12-01

    The GPS radio occultation (RO) has become a widely used technique for global measurements of the ionospheric electron density (Ne). To advance our understanding of the accuracy of the RO profiles at mid latitudes, we performed a comprehensive comparison of RO measurements made by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites and observations of Ne profiles made by the Arecibo Observatory incoherent scatter radar (ISR). COSMIC is formed by six satellites in circular, 800 km altitude low-Earth orbit (LEO) at 72° inclination. The satellites orbit in their own plane, approximately 24° apart in ascending node. The satellites are equipped with dual-frequency GPS receivers capable of making measurements of the total electron content (TEC) along the signal path and, therefore, RO observations. The Arecibo ISR, located at(18.35°N, 66.75°W; ˜28.25°N dip latitude), operates at a frequency of 430 MHz with a maximum bandwidth of about 1 MHz. The large collecting area provided by the 300 m dish antenna combined with high peak power transmitters (2.0-2.5 MW) allows the radar to make accurate Ne measurements throughout the entire ionospheric F-region and topside heights. We analyzed 74 and 89 days of line feed and Gregorian data, respectively, collected between 2006 and 2014. There were 638 RO profiles measured within 10° of latitude and 20° of longitude from Arecibo Observatory and within ±10 minutes of the radar measurements. Preliminary analyses of the observations show patterns in the relationship between densities measured by the Arecibo ISR and densities estimated from the COSMIC ROs. We will present and discuss the behavior of the patterns. We will also present results of a numerical model representing the patterns and discuss the possibility of using this model to improve RO estimates of density profiles.

  5. Harmonic analysis of the ionospheric electron densities retrieved from FORMOSAT-3/COSMIC radio occultation measurements

    Masoumi, S.; Safari, A.; Sharifi, M.; Sam Khaniani, A.

    2011-12-01

    In order to investigate regular variations of the ionosphere, the least-squares harmonic estimation is applied to the time series of ionospheric electron densities in the region of Iran derived from about five years of Global Positioning System Radio Occultation (GPS RO) observations by FORMOSAT-3/COSMIC satellites. Although the obtained results are slightly different from the expected ones due to the low horizontal resolution of RO measurements, high vertical resolution of the observations enables us to detect not only the Total Electron Content (TEC) variations, but also periodic patterns of electron densities in different altitudes of the ionosphere. Dominant diurnal and annual signals, together with their Fourier series decompositions, and also periods close to 27 days are obtained, which is consistent with the previous analyses on TEC. In the equatorial anomaly band, the annual component is weaker than its Fourier decomposition periods. In particular, the semiannual period dominates the annual component, which is probably due to the effect of geomagnetic field. By the investigation of the frequencies at different local times, the semiannual signal is more significant than the annual one in the daytime, while the annual frequency is dominant at night. By the detection of the phases of the components, it is revealed that the annual signal has its maximum in summer at high altitudes, and in winter at lower altitudes. This suggests the effect of neutral compositions in the lower atmosphere. Further, the semiannual component peaks around equinox during the day, while its maximum mostly occurs in solstice at night. Since RO measurements can be used to derive TEC along the signal path between a GPS satellite and a receiver, study on the potentiality of using these observations for the prediction of electron densities and its application to the ionospheric correction of the single frequency receivers is suggested.

  6. Evaluating the lower-tropospheric COSMIC GPS radio occultation sounding quality over the Arctic

    Yu, Xiao; Xie, Feiqin; Ao, Chi O.

    2018-04-01

    Lower-tropospheric moisture and temperature measurements are crucial for understanding weather prediction and climate change. Global Positioning System radio occultation (GPS RO) has been demonstrated as a high-quality observation technique with high vertical resolution and sub-kelvin temperature precision from the upper troposphere to the stratosphere. In the tropical lower troposphere, particularly the lowest 2 km, the quality of RO retrievals is known to be degraded and is a topic of active research. However, it is not clear whether similar problems exist at high latitudes, particularly over the Arctic, which is characterized by smooth ocean surface and often negligible moisture in the atmosphere. In this study, 3-year (2008-2010) GPS RO soundings from COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) over the Arctic (65-90° N) show uniform spatial sampling with average penetration depth within 300 m above the ocean surface. Over 70 % of RO soundings penetrate deep into the lowest 300 m of the troposphere in all non-summer seasons. However, the fraction of such deeply penetrating profiles reduces to only about 50-60 % in summer, when near-surface moisture and its variation increase. Both structural and parametric uncertainties of GPS RO soundings were also analyzed. The structural uncertainty (due to different data processing approaches) is estimated to be within ˜ 0.07 % in refractivity, ˜ 0.72 K in temperature, and ˜ 0.05 g kg-1 in specific humidity below 10 km, which is derived by comparing RO retrievals from two independent data processing centers. The parametric uncertainty (internal uncertainty of RO sounding) is quantified by comparing GPS RO with near-coincident radiosonde and European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim profiles. A systematic negative bias up to ˜ 1 % in refractivity below 2 km is only seen in the summer, which confirms the moisture impact on GPS RO quality.

  7. POPULATION BASED COLORECTAL CANCER SCREENING: COMPARISON OF TWO FAECAL OCCULT BLOOD TESTS

    Miren Begoña eZubero

    2014-01-01

    Full Text Available Background: The aim of screening for colorectal cancer is to improve prognosis by the detection of cancer at its early stages. In order to inform the decision on the specific test to be used in the population-based programme in the Basque Autonomous Region (Spain, we compared two immunochemical faecal occult blood quantitative tests (I-FOBT. Methods: Residents of selected study areas, aged 50-69 years, were invited to participate in the screening. Two tests based on latex agglutination (OC-Sensor and FOB Gold were randomly assigned to different study areas. A colonoscopy was offered to patients with a positive test result. The cut-off point used to classify a result as positive, according to manufacturer’s recommendations, was 100 ng/ml for both tests. Results: The invited population included 37,999 individuals. Participation rates were 61.8% (n=11,162 for OC-Sensor and 59.1% (n=11,786 for FOB Gold, (p=0.008. Positive rate for OC-Sensor was 6.6% (n=737 and 8.5% (n=1,002 for FOB Gold, (pConclusions: OC-Sensor test appears to be superior for I-FOBT based CRC screening, given its acceptance, ease of use, associated small number of errors and its screening accuracy. FOB-Gold on the other hand, has higher rate of positive values, with more colonoscopies performed, it shows higher detection incidence rates, but involves more false positives.

  8. Cassini Radio Occultations of Saturn's Ionosphere: Modeling a Variable Influx of Water into Saturn's Atmosphere

    Moore, L.; Mendillo, M.

    2006-12-01

    The Saturn-Thermosphere-Ionosphere-Model (STIM), a global circulation model (GCM) of Saturn's upper atmosphere, is used to investigate a range of possible parameters that could lead to the profiles measured recently by the Radio Science Subsystem (RSS) aboard Cassini. Specifically, electron density observations of Saturn's equatorial ionosphere demonstrate a dawn/dusk asymmetry, a possible double peak, and a high degree of vertical structure and variability. On average, peak electron densities are larger at dusk than dawn (5400 cm-3 vs. 1700 cm-3) and the peak altitudes are lower at dusk than dawn (1880 km vs. 2360 km). Self-consistent, time-dependent 1D water diffusion calculations have been combined with the GCM in order to examine the possibility that a topside flux of neutral water into Saturn's atmosphere may provide a loss mechanism -- via charge exchange with protons -- that is sufficient to reproduce the observed ionosphere. Our previous modeling results indicated that a constant background influx of (0.5 -- 1.0) x 107 H2O cm-2 sec-1 was adequate in reproducing Cassini measurements on average [Moore et al., 2006], however the large observed variations in the vertical electron density profiles require additional complexities in the modeling. In this study we show that one possible source of the structuring observed in the electron density profiles could be from brief surges and/or reductions in the background water flux, which ultimately may be linked to geysers near Enceladus' southern pole. Moore, L., A.F. Nagy, A.J. Kliore, I. Mueller-Wodarg, J.D. Richardson, M. Mendillo (2006), Cassini radio occultations of Saturn's ionopshere: I. model comparisons using a constant water flux, submitted to GRL.

  9. A global perspective on atmospheric blocking using GPS radio occultation – one decade of observations

    L. Brunner

    2017-12-01

    Full Text Available Atmospheric blocking represents a weather pattern where a stationary high-pressure system weakens or reverses the climatological westerly flow at mid-latitudes for up to several weeks. It is closely connected to strong anomalies in key atmospheric variables such as geopotential height, temperature, and humidity. Here we provide, for the first time, a comprehensive, global perspective on atmospheric blocking and related impacts by using an observation-based data set from Global Positioning System (GPS radio occultation (RO from 2006 to 2016. The main blocking regions in both hemispheres and seasonal variations are found to be represented well in RO data. The effect of blocking on vertically resolved temperature and humidity anomalies in the troposphere and lower stratosphere is investigated for blocking regions in the Northern and Southern hemispheres, respectively. We find a statistically significant correlation of blocking with positive temperature anomalies, exceeding 3 K in the troposphere, and a reversal above the tropopause with negative temperature anomalies below −3 K in the lower stratosphere. Specific humidity is positively correlated with temperature throughout the troposphere with larger anomalies revealed in the Southern Hemisphere. At the eastern and equatorward side of the investigated blocking regions, a band of tropospheric cold anomalies reveals advection of cold air by anticyclonic motion around blocking highs, which is less distinct in the Southern Hemisphere due to stronger zonal flow. We find GPS RO to be a promising new data set for blocking research that gives insight into the vertical atmospheric structure, especially in light of the expected increase in data coverage that future missions will provide.

  10. Role of ultrasonography in detecting mammographically occult breast carcinoma in women with dense breasts.

    Corsetti, V; Ferrari, A; Ghirardi, M; Bergonzini, R; Bellarosa, S; Angelini, O; Bani, C; Ciatto, S

    2006-04-01

    The purpose of this study was to assess the usefulness of routine ultrasonography in women with negative mammography and dense breasts [Breast Imaging Reporting and Data System (BIRADS D3-4)]. We applied a protocol involving routine ultrasonography in a consecutive series of subjects with negative mammography and dense breasts. After evaluation by internal and external reviewers of cancers detected by ultrasonography performed to confirm negative mammography, we determined the additional cancer detection rate of ultrasonography and the cost of the protocol. Out of 17,883 total mammographies, 167 cancers were diagnosed (detection rate: 0.93%). Out of 257 suspicious mammographies, 138 cancers were detected. Out of 17,626 negative mammographies, 6,449 (36.5%) were classified as "dense breast" and underwent ultrasonography: 29 cancers were detected (detection rate: 0.44%, or 17.3% of total cancers). Out of 25 cancer cases reviewed, negative mammography and asymptomatic status was confirmed in 15 (detection rate 0.23%, or 8.9% of total cancers). The cancer detection rate was 0.11%, 0.22%, 0.32% and 0.14% for age groups 59, respectively. The cost per additional carcinoma detected by ultrasonography alone was euro 25,847.85 whereas that per examined woman was euro 21.68. The study confirms the possibility that ultrasonography can detect mammographically occult breast carcinoma in dense breasts. The evidence is insufficient to recommend this policy in routine screening practice but suggests that, at least in current clinical practice, adding ultrasonography in dense breasts may be useful despite the substantial costs.

  11. The impact of large scale ionospheric structure on radio occultation retrievals

    A. J. Mannucci

    2011-12-01

    Full Text Available We study the impact of large-scale ionospheric structure on the accuracy of radio occultation (RO retrievals. We use a climatological model of the ionosphere as well as an ionospheric data assimilation model to compare quiet and geomagnetically disturbed conditions. The presence of ionospheric electron density gradients during disturbed conditions increases the physical separation of the two GPS frequencies as the GPS signal traverses the ionosphere and atmosphere. We analyze this effect in detail using ray-tracing and a full geophysical retrieval system. During quiet conditions, our results are similar to previously published studies. The impact of a major ionospheric storm is analyzed using data from the 30 October 2003 "Halloween" superstorm period. At 40 km altitude, the refractivity bias under disturbed conditions is approximately three times larger than quiet time. These results suggest the need for ionospheric monitoring as part of an RO-based climate observation strategy. We find that even during quiet conditions, the magnitude of retrieval bias depends critically on assumed ionospheric electron density structure, which may explain variations in previously published bias estimates that use a variety of assumptions regarding large scale ionospheric structure. We quantify the impact of spacecraft orbit altitude on the magnitude of bending angle and retrieval error. Satellites in higher altitude orbits (700+ km tend to have lower residual biases due to the tendency of the residual bending to cancel between the top and bottomside ionosphere. Another factor affecting accuracy is the commonly-used assumption that refractive index is unity at the receiver. We conclude with remarks on the implications of this study for long-term climate monitoring using RO.

  12. Occult pneumothorax in Chinese patients with significant blunt chest trauma: incidence and management.

    Lee, Ka L; Graham, Colin A; Yeung, Janice H H; Ahuja, Anil T; Rainer, Timothy H

    2010-05-01

    Occult pneumothorax (OP) is a pneumothorax not visualised on a supine chest X-ray (CXR) but detected on computed tomography (CT) scanning. With increasing CT use for trauma, more OP may be detected. Management of OP remains controversial, especially for patients undergoing mechanical ventilation. This study aimed to identify the incidence of OP using thoracic CT as the gold standard and describe its management amongst Hong Kong Chinese trauma patients. Analysis of prospectively collected trauma registry data. Consecutive significantly injured trauma patients admitted through the emergency department (ED) suffering from blunt chest trauma who underwent thoracic computed tomography (TCT) between in calendar years 2007 and 2008 were included. An OP was defined as the identification (by a specialist radiologist) of a pneumothorax on TCT that had not been previously detected on supine CXR. 119 significantly injured patients were included. 56 patients had a pneumothorax on CXR and a further 36 patients had at least one OP [OP incidence 30% (36/119)]. Bilateral OP was present in 8/36 patients, so total OP numbers were 44. Tube thoracostomy was performed for 8/44 OP, all were mechanically ventilated in the ED. The remaining 36 OP were managed expectantly. No patients in the expectant group had pneumothorax progression, even though 8 patients required subsequent ventilation in the operating room for extrathoracic surgery. The incidence of OP (seen on TCT) in Chinese patients in Hong Kong after blunt chest trauma is higher than that typically reported in Caucasians. Most OP were managed expectantly without significant complications; no pneumothorax progressed even though some patients were mechanically ventilated. (c) 2010 Elsevier Ltd. All rights reserved.

  13. Atmospheric QBO and ENSO indices with high vertical resolution from GNSS radio occultation temperature measurements

    Wilhelmsen, Hallgeir; Ladstädter, Florian; Scherllin-Pirscher, Barbara; Steiner, Andrea K.

    2018-03-01

    We provide atmospheric temperature variability indices for the tropical troposphere and stratosphere based on global navigation satellite system (GNSS) radio occultation (RO) temperature measurements. By exploiting the high vertical resolution and the uniform distribution of the GNSS RO temperature soundings we introduce two approaches, both based on an empirical orthogonal function (EOF) analysis. The first method utilizes the whole vertical and horizontal RO temperature field from 30° S to 30° N and from 2 to 35 km altitude. The resulting indices, the leading principal components, resemble the well-known patterns of the Quasi-Biennial Oscillation (QBO) and the El Niño-Southern Oscillation (ENSO) in the tropics. They provide some information on the vertical structure; however, they are not vertically resolved. The second method applies the EOF analysis on each altitude level separately and the resulting indices contain information on the horizontal variability at each densely available altitude level. They capture more variability than the indices from the first method and present a mixture of all variability modes contributing at the respective altitude level, including the QBO and ENSO. Compared to commonly used variability indices from QBO winds or ENSO sea surface temperature, these new indices cover the vertical details of the atmospheric variability. Using them as proxies for temperature variability is also of advantage because there is no further need to account for response time lags. Atmospheric variability indices as novel products from RO are expected to be of great benefit for studies on atmospheric dynamics and variability, for climate trend analysis, as well as for climate model evaluation.

  14. Assessment of NOAA NUCAPS upper air temperature profiles using COSMIC GPS radio occultation and ARM radiosondes

    Feltz, M. L.; Borg, L.; Knuteson, R. O.; Tobin, D.; Revercomb, H.; Gambacorta, A.

    2017-09-01

    The U.S. National Oceanic and Atmospheric Administration (NOAA) recently began operational processing to derive vertical temperature profiles from two new sensors, Cross-Track Infrared Sounder and Advanced Technology Microwave Sounder, which were developed for the next generation of U.S. weather satellites. The NOAA-Unique Combined Atmospheric Processing System (NUCAPS) has been developed by NOAA to routinely process data from future Joint Polar Satellite System operational satellites and the preparatory Suomi-NPP satellite. This paper assesses the NUCAPS vertical temperature profile product from the upper troposphere into the middle stratosphere using radiosonde and GPS radio occultation (RO) data. Radiosonde data from the Department of Energy Atmospheric Radiation Measurement (ARM) program are=] compared to both the NUCAPS and GPS RO temperature products to evaluate bias and RMS errors. At all three fixed ARM sites for time periods investigated the NUCAPS temperature in the 100-40 hPa range is found to have an average bias to the radiosondes of less than 0.45 K and an RMS error of less than 1 K when temperature averaging kernels are applied. At a 95% confidence level, the radiosondes and RO were found to agree within 0.4 K at the North Slope of Alaska site and within 0.83 K at Southern Great Plains and Tropical Western Pacific. The GPS RO-derived dry temperatures, obtained from the University Corporation for Atmospheric Research Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission, are used as a common reference for the intercomparison of NUCAPS temperature products to similar products produced by NASA from Atmospheric Infrared Sounder (AIRS) and by European Organisation for the Exploitation of Meteorological Satellites from MetOp-B Infrared Atmospheric Sounding Interferometer (IASI). For seasonal and zonal scales, the NUCAPS agreement with AIRS and IASI is less than 0.5 K after application of averaging kernels.

  15. A Climate Benchmark of Upper Air Temperature Observations from GNSS Radio Occultation

    Ao, C. O.; Mannucci, A. J.; Leroy, S. S.; Verkhoglyadova, O. P.

    2017-12-01

    GPS (Global Positioning System), or more generally Global Navigation Satellite System (GNSS), radio occultation (RO) is a remote sensing technique that produces highly accurate temperature in the upper troposphere and lower stratosphere across the globe with fine vertical resolution. Its fundamental measurement is the time delay of the microwave signal as it travels from a GNSS satellite to the receiver in low Earth orbit. With a relatively simple physical retrieval, the uncertainty in the derived temperature can be traced rigorously through the retrieval chain back to the raw measurements. The high absolute accuracy of RO allows these observations to be assimilated without bias correction in numerical weather prediction models and provides an anchor for assimilating other types of observations. The high accuracy, coupled with long-term stability, makes RO valuable in detecting decadal temperature trends. In this presentation, we will summarize the current state of RO observations and show temperature trends derived from 15 years of RO data in the upper troposphere and lower stratosphere. We will discuss our recent efforts in developing retrieval algorithms that are more tailored towards climate applications. Despite the relatively robust "self-calibrating" nature of RO observations, disparity in receiver hardware and software may introduce subtle differences that need to be carefully addressed. While the historic RO data record came from relatively homogeneous hardware based largely on NASA/JPL design (e.g., CHAMP and COSMIC), the future data will likely be comprised of a diverse set of observations from Europe, China, and various commercial data providers. In addition, the use of non-GPS navigation systems will become more prevalent. We will discuss the challenges involved in establishing a long-term RO climate data record from a suite of research and operational weather satellites with changes in instrumentation and coverage.

  16. Ultra-High Resolution Orbit Determination of (486958) 2014 MU69: Predicting an Occultation with 1% of an Orbit

    Porter, Simon Bernard; Buie, Marc W.; Spencer, John R.; Folkner, William; Parker, Alex; Zangari, Amanda Marie; Verbiscer, Anne J.; Benecchi, Susan; Stern, S. Alan; Terrell, Dirk; Soto, Alejandro; Tamblyn, Peter; Wasserman, Lawrence H.; Young, Eliot F.; New Horizons MU69 Occultation Team

    2017-10-01

    In November 2015, the NASA New Horizons spacecraft burned its thrusters to intercept the cold classical Kuiper Belt Object (486958) 2014 MU69. Then, on July 17, 2017, five small telescopes in Chubut Province, Argentina recorded a solid body occultation of MU69. Both these events required an orbital solution of unprecedented accuracy, as will the January 1, 2019 flyby of MU69 by New Horizons. This was especially difficult because there were no precoveries of MU69 prior to July 2014, it is in an extremely crowded field near the galactic core, and it is faint enough to only be reliably detected by Hubble Space Telescope’s Wide Field Camera 3 (WFC3). To accomplish this, we performed an extremely detailed analysis of 237 WFC3 images, down to the subpixel distortion level, in order to produce individual probability distribution functions (PDFs) for the position of MU69 in each WFC3 image. We registered each WFC3 image against a pre-release version of the Gaia DR2 catalog, which produced even smaller residuals than the now-released DR1. We then combined these WFC3+Gaia PDFs with a high-precision few-body numerical integrator and a Monte Carlo Markov Chain (MCMC) sampler to produce a state vector PDF for MU69 at defined epoch. Propagating those state vectors from the epoch produces an instantaneous positional cloud for MU69 at any given time. This positional cloud was then directly translated into a shadow path uncertainty cloud in order to plan the MU69 occultation campaign. We will describe this process of fully propagating errors from WFC3 images to telescope sites on the ground, and also describe refinements for future guiding of New Horizons to its encounter with MU69. We thank NASA, Hubble, Gaia, CONAE, the city of Comodoro Rivadavia, and the government of Argentina for their assistance and support of the MU69 occultation campaign.

  17. Learning better deep features for the prediction of occult invasive disease in ductal carcinoma in situ through transfer learning

    Shi, Bibo; Hou, Rui; Mazurowski, Maciej A.; Grimm, Lars J.; Ren, Yinhao; Marks, Jeffrey R.; King, Lorraine M.; Maley, Carlo C.; Hwang, E. Shelley; Lo, Joseph Y.

    2018-02-01

    Purpose: To determine whether domain transfer learning can improve the performance of deep features extracted from digital mammograms using a pre-trained deep convolutional neural network (CNN) in the prediction of occult invasive disease for patients with ductal carcinoma in situ (DCIS) on core needle biopsy. Method: In this study, we collected digital mammography magnification views for 140 patients with DCIS at biopsy, 35 of which were subsequently upstaged to invasive cancer. We utilized a deep CNN model that was pre-trained on two natural image data sets (ImageNet and DTD) and one mammographic data set (INbreast) as the feature extractor, hypothesizing that these data sets are increasingly more similar to our target task and will lead to better representations of deep features to describe DCIS lesions. Through a statistical pooling strategy, three sets of deep features were extracted using the CNNs at different levels of convolutional layers from the lesion areas. A logistic regression classifier was then trained to predict which tumors contain occult invasive disease. The generalization performance was assessed and compared using repeated random sub-sampling validation and receiver operating characteristic (ROC) curve analysis. Result: The best performance of deep features was from CNN model pre-trained on INbreast, and the proposed classifier using this set of deep features was able to achieve a median classification performance of ROC-AUC equal to 0.75, which is significantly better (p<=0.05) than the performance of deep features extracted using ImageNet data set (ROCAUC = 0.68). Conclusion: Transfer learning is helpful for learning a better representation of deep features, and improves the prediction of occult invasive disease in DCIS.

  18. ACUTE ZONAL OCCULT OUTER RETINOPATHY: Structural and Functional Analysis Across the Transition Zone Between Healthy and Diseased Retina.

    Duncker, Tobias; Lee, Winston; Jiang, Fan; Ramachandran, Rithambara; Hood, Donald C; Tsang, Stephen H; Sparrow, Janet R; Greenstein, Vivienne C

    2018-01-01

    To assess structure and function across the transition zone (TZ) between relatively healthy and diseased retina in acute zonal occult outer retinopathy. Six patients (6 eyes; age 22-71 years) with acute zonal occult outer retinopathy were studied. Spectral-domain optical coherence tomography, fundus autofluorescence, near-infrared reflectance, color fundus photography, and fundus perimetry were performed and images were registered to each other. The retinal layers of the spectral-domain optical coherence tomography scans were segmented and the thicknesses of two outer retinal layers, that is, the total receptor and outer segment plus layers, and the retinal nerve fiber layer were measured. All eyes showed a TZ on multimodal imaging. On spectral-domain optical coherence tomography, the TZ was in the nasal retina at varying distances from the fovea. For all eyes, it was associated with loss of the ellipsoid zone band, significant thinning of the two outer retinal layers, and in three eyes with thickening of the retinal nerve fiber layer. On fundus autofluorescence, all eyes had a clearly demarcated peripapillary area of abnormal fundus autofluorescence delimited by a border of high autofluorescence; the latter was associated with loss of the ellipsoid zone band and with a change from relatively normal to markedly decreased or nonrecordable visual sensitivity on fundus perimetry. The results of multimodal imaging clarified the TZ in acute zonal occult outer retinopathy. The TZ was outlined by a distinct high autofluorescence border that correlated with loss of the ellipsoid zone band on spectral-domain optical coherence tomography. However, in fundus areas that seemed healthy on fundus autofluorescence, thinning of the outer retinal layers and thickening of the retinal nerve fiber layer were observed near the TZ. The TZ was also characterized by a decrease in visual sensitivity.

  19. Breast conservation in the setting of contemporary multimodality treatment provides excellent outcomes for patients with occult primary breast cancer.

    Rueth, Natasha M; Black, Dalliah M; Limmer, Angela R; Gabriel, Emmanuel; Huo, Lei; Fornage, Bruno D; Dogan, Basak E; Chavez-MacGregor, Mariana; Yi, Min; Hunt, Kelly K; Strom, Eric A

    2015-01-01

    To evaluate recurrence and survival for patients with occult (T0N+) breast cancer who underwent contemporary treatment, assessing outcomes for breast conservation and mastectomy. We performed a single-institution review of women with occult breast cancer presenting with axillary metastasis without identifiable breast tumor or distant metastasis. We excluded patients with tumors in the axillary tail or mastectomy specimen, patients with additional nonbreast cancer diagnoses, and patients with a history of breast cancer. Breast conservation was defined as axillary node dissection with radiation therapy, without breast surgery. We evaluated patient, tumor, treatment, and outcome variables. Patients were assessed for local, regional, and distant recurrences. Overall survival was calculated using the Kaplan-Meier method. Thirty-six patients met criteria for occult breast cancer. Most of these patients (77.8 %) had N1 disease. Fifty percent of cancers (n = 18) were estrogen receptor-positive; 12 (33.3 %) were triple-negative. All patients were evaluated with mammography. Thirty-five patients had breast ultrasound (97.2 %) and 33 (91.7 %) had an MRI. Thirty-four patients (94.4 %) were treated with chemotherapy and 33 (91.7 %) with radiotherapy. Twenty-seven patients (75.0 %) were treated with breast conservation. The median follow-up was 64 months. There were no local or regional failures. One distant recurrence occurred >5 years after diagnosis, resulting in a 5-years overall survival rate of 100 %. There were no significant survival differences between patients receiving breast conservation versus mastectomy (p = 0.7). Breast conservation-performed with contemporary imaging and multimodality treatment-provides excellent local control and survival for women with T0N+ breast cancer and can be safely offered instead of mastectomy.

  20. Symptoms of thyrotoxicosis, bone metabolism and occult atrial fibrillation in older women with mild endogenous subclinical hyperthyroidism.

    Rosario, Pedro Weslley; Carvalho, Marina; Calsolari, Maria Regina

    2016-07-01

    The objective of this study was to evaluate symptoms of thyrotoxicosis, bone turnover, bone mineral density (BMD) and occult atrial fibrillation (AF) in women ≥65 years with mild endogenous subclinical hyperthyroidism (SCH). Cross-sectional and case-control study. Signs and symptoms of thyrotoxicosis, serum carboxyterminal telopeptide (CTx) and procollagen type I N-terminal propeptide (PINP), BMD, resting electrocardiogram (ECG) and 72-h ECG monitoring were evaluated in 180 women ≥65 years, including 90 with mild SCH (TSH between 0·1 and 0·4 mIU/l) and 90 euthyroid controls matched for age and body mass index. Symptom Rating Scale scores did not differ between patients and controls. None of the patients with SCH scored 20 points, a score compatible with clinical thyrotoxicosis. Eighty patients with SCH (89%) obtained seven or fewer points, a score compatible with euthyroidism. No difference in serum CTx or PINP concentrations was observed between patients and controls. There was also no correlation between these markers and TSH, free T4 or total T3 levels. Finally, no difference in femoral neck or lumbar spine BMD was observed between patients with SCH and controls. Three patients with SCH (3·3%) and two euthyroid women (2·2%) had known AF or AF in the resting ECG. ECG monitoring for 72 h revealed episodes of occult AF in 1/87 patients with SCH and in 1/88 euthyroid women (1·1%). Mild endogenous SCH (TSH between 0·1 and 0·4 mIU/l) was not associated with symptoms of thyrotoxicosis, altered bone metabolism or a higher prevalence of occult AF in women ≥65 years. © 2015 John Wiley & Sons Ltd.

  1. Radio occultation studies of the Venus atmosphere with the Magellan spacecraft. 2: Results from the October 1991 experiments

    Jenkins, Jon M.; Steffes, Paul G.; Hinson, David P.; Twicken, Joseph D.; Tyler, G. Leonard

    1994-01-01

    On October 5 and 6, 1991, three dual-frequency ingress radio occultation experiments were conducted at Venus during consecutive orbits of the Magellan spacecraft. The radio signals probed a region of the atmosphere near 65 deg N, with a solar zenith angle of 108 deg, reaching below 35 km at 3.6 cm, and below 34 km at 13 cm (above a mean radius of 6052 km). The high effective isotropic radiated power (EIRP) of the Magellan spacecraft and highly successful attitude maneuvers allowed these signals to probe deeper than any previous radio occultation experiment and also resulted in the most accurate thermal and sulfuric acid vapor abundance profiles ever obtained at Venus through radio occultation techniques. The performance of the spacecraft and the experiment design are discussed in an accompanying paper. Average electron density profiles retrieved from the data possess peaks between 2600 and 6000/cu cm, well below typical values of 10,000/cu cm retrieved in 1979 by Pioneer Venus at similar solar zenith angles. Other basic results include vertical profiles of temperature, pressure, and density in the neutral atmosphere, 13- and 3.6-cm absorpttivity, and H2SO4 (g) abundance below the main cloud layer. H2SO4 (g) becomes significant below 50 km, reaching peaks between 18 and 24 ppm near 39 km before dropping precipitously below 38 km. These sharp decreases confirm the thermal decomposition of sulfuric acid vapor below 39 km. Since the Venus atmosphere rotated approximately 10 deg between experiments, the data contain information about the horizontal variability of the atmosphere. All derived profiles exhibit significant variations from orbit to orbit, indicating the presence of dynamical processes between 33 and 200 km. In particular, the orbit-to-orbit variations in temperature and in H2SO4 (g) abundance appear to be correlated, suggesting that a common mechanism may be responsible for the observed spatial variations.

  2. Poster 7: Could PAH or HAC explain the Titan's stratosphere absorption around 3.4 µm revealed by solar occultations?

    Cordier, Daniel; Cours, Thibaud; Rey, Michael; Maltagliati, Luca; Seignovert, Benoit; Biennier, Ludovic

    2016-06-01

    In 2006, during Cassini's 10th flyby of Titan (T10), Bellucci et al. (2009) observed a solar occultation by Titan's atmosphere through the solar port of the Cassini/VIMS instrument. These authors noticed the existence of an unexplained additional absorption superimposed to the CH4 3.3 µm band. Because they were unable to model this absorption with gases, they attributed this intriguing feature to the signature of solid state organic components. Kim et al. (2011) revisited the data collected by Bellucci et al. (2009) and they considered the possible contribution of aerosols formed by hydrocarbon ices. They specifically took into account C2H6, CH4, CH3CN, C5H12 and C6H12 ices. More recently, Maltagliati et al. (2015) analyzed a set of four VIMS solar occultations, corresponding to flybys performed between January 2006 and September 2011 at different latitudes. They confirmed the presence of the 3.3 µm absorption in all occultations and underlined the possible importance of gaseous ethane, which has a strong plateau of absorption lines in that wavelength range.In this work, we show that neither hydrocarbon ices nor molecular C2H6 cannot satisfactorily explain the observed absorption. Our simulations speak in favor of an absorption due to the presence of PAH molecules or HAC in the stratosphere of Titan. PAH have been already considered by Lopes-Puertas et al. (2013) at altitudes larger than ˜900 km and tentatively identified in the stratosphere by Maltagliati et al. (2015); PAH and HAC are good candidates for Titan's aerosols precursors.

  3. Infective Endocarditis

    ... Venous Thromboembolism Aortic Aneurysm More Infective Endocarditis Updated:Mar 29,2018 View an illustration of endocarditis Infective ... procedure. Web Booklets on Congenital Heart Defects These online publications describe many defects and the procedures used ...

  4. MRSA Infection

    ... to spread and sometimes become life-threatening. MRSA infections may affect your: Bloodstream Lungs Heart Bones Joints Prevention Preventing HA-MRSA In the hospital, people who are infected or colonized with MRSA ...

  5. Campylobacter Infections

    Campylobacter infection is a common foodborne illness. You usually get it from eating contaminated food, especially raw ... You can also get it from drinking contaminated water or raw milk, or handling infected animal feces ( ...

  6. Staph Infections

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... infection. People with skin problems like burns or eczema may be more likely to get staph skin ...

  7. Rotavirus Infections

    Rotavirus is a virus that causes gastroenteritis. Symptoms include severe diarrhea, vomiting, fever, and dehydration. Almost all ... the U.S. are likely to be infected with rotavirus before their 5th birthday. Infections happen most often ...

  8. Serious soft tissue infections of the head and neck

    Herr, R.D.; Murdock, R.T.; Davis, R.K.

    1991-01-01

    The head and neck contain a number of spaces that can be invaded by organisms of the mouth or by spread of cervical osteomyelitis. Infection in these spaces may progress from superficial infection to cellulitis to the formation of an abscess requiring immediate drainage. Spread of infection between spaces depends on anatomic location. Most patients require hospitalization and intravenous antibiotic therapy. Because a deep space infection may be occult, a high index of suspicion is required for diagnosis. Early recognition is necessary to avoid tissue damage, bacteremia or airway compromise. The possibility of deep space infection should be considered in any patient who does not respond to the usual treatment of an abscessed tooth or tonsillitis. This type of infection also should be considered in a toxic patient who has a fever of unknown origin, with or without blood cultures that show anaerobic organisms. Computed tomography or magnetic resonance imaging is usually necessary to locate the infection and to detect suppuration that will be amenable to surgical exploration and drainage. 25 references

  9. Fecal occult blood test for colorectal cancer screening: an evidence-based analysis.

    2009-01-01

    The colorectal cancer (CRC) screening project was undertaken by the Medical Advisory Secretariat (MAS) in collaboration with the Cancer Care Ontario (CCO).In November 2007, the Ontario Health Technology Advisory Committee (OHTAC) MAS to conduct an evidence-based analysis of the available data with respect to colorectal cancer diagnosis and prevention. The general purpose of the project was to investigate the effectiveness, cost effectiveness, and safety of the various methods and techniques used for colorectal cancer screening in average risk people, 50 years of age and older.The options currently offered for colorectal cancer screening were reviewed and five technologies were selected for review:Computed tomographic (CT) colonographyMagnetic resonance (MR) colonographyWireless capsule endoscopy (PillCam Colon)Fecal occult blood test (FOBT)Flexible sigmoidoscopyIn this review, colonoscopy was considered as the "gold standard" technique by which the effectiveness of all other modalities could be evaluated. An economic analysis was also conducted to determine cost-effectiveness of different screening modalities.Evidence-based analyses have been prepared for each of these technologies, as well as summary document that includes an economic analysis, all of which are presented at the MAS Web site: http://www.health.gov.on.ca/english/providers/program/mas/tech/techmn.html The objective of this evidence review is to examine the effectiveness and cost-effectiveness of fecal occult blood testing (FOBT), including guaiac FOBT (gFOBT) and immunochemical FOBT (iFOBT), for use in colorectal cancer (CRC) screening in asymptomatic, average-risk adults. Specifically: Is the use of gFOBT or iFOBT associated with a reduction in CRC and overall mortality?What are the sensitivity and specificity of gFOBT and iFOBT for the detection of 1) CRC and 2) large polyps (≥ 1 cm)? CRC is the most common cause of non-tobacco related cancer death in Canada. It has been estimated that in 2007, 7

  10. Risk stratification and detection of new colorectal neoplasms after colorectal cancer screening with faecal occult blood test

    Bjerrum, Andreas; Milter, Maya Christel; Andersen, Ole

    2015-01-01

    BACKGROUND: Limited data exist on adenoma surveillance as recommended in the European guidelines for quality assurance in colorectal cancer (CRC) screening and diagnosis after faecal occult blood test (FOBT) screening. OBJECTIVE: To assess the European guidelines for adenoma surveillance after CRC...... of CRC was higher in risk group C than A (RR 5.20, 95% confidence interval: 0.63-42.58), but not statistically significant. In risk group C, half of new advanced adenomas were detected within the first year and four of nine CRC were detected within 3 years. CONCLUSION: Risk stratification of adenoma...

  11. Occultations from an Active Accretion Disk in a 72-day Detached Post-Algol System Detected by K2

    Zhou, G.; Rappaport, S.; Nelson, L.

    2018-01-01

    Disks in binary systems can cause exotic eclipsing events. MWC 882 (BD –22 4376, EPIC 225300403) is such a disk-eclipsing system identified from observations during Campaign 11 of the K2 mission. We propose that MWC 882 is a post-Algol system with a B7 donor star of mass in a 72-day orbit around...... an A0 accreting star of mass . The disk around the accreting star occults the donor star once every orbit, inducing 19-day long, 7% deep eclipses identified by K2 and subsequently found in pre-discovery All-Sky Automated Survey and All Sky Automated Survey for Supernovae observations. We coordinated...

  12. Design and construction of a 76m long-travel laser enclosure for a space occulter testbed

    Galvin, Michael; Kim, Yunjong; Kasdin, N. Jeremy; Sirbu, Dan; Vanderbei, Robert; Echeverri, Dan; Sagolla, Giuseppe; Rousing, Andreas; Balasubramanian, Kunjithapatham; Ryan, Daniel; Shaklan, Stuart; Lisman, Doug

    2016-07-01

    Princeton University is upgrading our space occulter testbed. In particular, we are lengthening it to 76m to achieve flightlike Fresnel numbers. This much longer testbed required an all-new enclosure design. In this design, we prioritized modularity and the use of commercial off-the-shelf (COTS) and semi-COTS components. Several of the technical challenges encountered included an unexpected slow beam drift and black paint selection. Herein we describe the design and construction of this long-travel laser enclosure.

  13. Interplanetary scintillation observations of an unbiased sample of 90 Ooty occultation radio sources at 326.5 MHz

    Banhatti, D.G.; Ananthakrishnan, S.

    1989-01-01

    We present 327-MHz interplanetary scintillation (IPS) observations of an unbiased sample of 90 extragalactic radio sources selected from the ninth Ooty lunar occultation list. The sources are brighter than 0.75 Jy at 327 MHz and lie outside the galactic plane. We derive values, the fraction of scintillating flux density, and the equivalent Gaussian diameter for the scintillating structure. Various correlations are found between the observed parameters. In particular, the scintillating component weakens and broadens with increasing largest angular size, and stronger scintillators have more compact scintillating components. (author)

  14. Measurements of the upper troposphere and lower stratosphere during tropical cyclones using the GPS radio occultation technique

    Biondi, Riccardo; Neubert, Torsten; Syndergaard, Stig

    2011-01-01

    and Climate (COSMIC) were analyzed, focusing on two particular tropical cyclones with completely different characteristics, the hurricane Bertha, which formed in the Atlantic Basin during July 2008 and reached a maximum intensity of Category 3, and the typhoon Hondo, which formed in the south Indian Ocean...... during 2008 reaching a maximum intensity of Category 4. The result is positive, suggesting that the bending angle of a GPS radio occultation signal contains interesting information on the atmosphere around the tropopause, but not any information regarding the water vapour. The maximum percentage anomaly...

  15. A game of two discs: a case of non-contiguous and occult cervical spine injury in a rugby player

    O'Sullivan, Michael D.; Piggot, Robert; Jaddan, Mutaz; McCabe, John P.

    2016-01-01

    The aim of this case report was to highlight the application of magnetic resonance imaging (MRI) in elucidating serious and occult injuries in a single case of hyperflextion injury of a patient cervical spine (C-Spine). A chart and radiology review was performed to establish the sequence of care and how the results of imaging studies influenced the clinical management in this trauma case. Plain radiographs and computed tomography (CT) imaging modalities of the C-Spine revealed bilateral C4/C5...

  16. Shigella Infections

    ... Staying Safe Videos for Educators Search English Español Shigella Infections KidsHealth / For Parents / Shigella Infections What's in ... Doctor Print en español Infecciones por Shigella About Shigella Shigella are bacteria that can infect the digestive ...

  17. Noise reduction methods in the analysis of near infrared lunar occultation light curves for high angular resolution measurements

    Baug Tapas; Chandrasekhar Thyagarajan

    2013-01-01

    A lunar occultation (LO) technique in the near-infrared (NIR) provides angular resolution down to milliarcseconds for an occulted source, even with ground-based 1 m class telescopes. LO observations are limited to brighter objects because they require a high signal-to-noise ratio (S/N ∼40) for proper extraction of angular diameter values. Hence, methods to improve the S/N ratio by reducing noise using Fourier and wavelet transforms have been explored in this study. A sample of 54 NIR LO light curves observed with the IR camera at Mt Abu Observatory has been used. It is seen that both Fourier and wavelet methods have shown an improvement in S/N compared to the original data. However, the application of wavelet transforms causes a slight smoothing of the fringes and results in a higher value for angular diameter. Fourier transforms which reduce discrete noise frequencies do not distort the fringe. The Fourier transform method seems to be effective in improving the S/N, as well as improving the model fit, particularly in the fainter regime of our sample. These methods also provide a better model fit for brighter sources in some cases, though there may not be a significant improvement in S/N

  18. The role of computed tomography in the diagnosis and management of clinically occult post-traumatic small bowel perforation

    Ahmed, I.; Ahmed, N.; Bell, D.J.; Hughes, D.V.; Evans, G.H.; Howlett, D.C.

    2009-01-01

    Purpose: To evaluate the use of computed tomography [CT] in the diagnosis of occult post-traumatic small bowel perforation and to discuss the role of CT in the management of this patient group. Method: This review includes three patients who presented with mild abdominal symptoms following minor blunt abdominal trauma. Initial radiographs and laboratory investigations were unremarkable but their symptoms failed to resolve and contrast-enhanced CT was performed for further evaluation. Results: In each case the CT appearances were indicative of localised small bowel perforation, with no evidence of other visceral injury. In two patients pockets of free intraperitoneal air were present closely related to the second part of the duodenum suggesting injury at this site. In the third case, a thickened proximal jejunal loop was demonstrated with free air and fluid in the adjacent mesentery consistent with a focal perforation. These CT findings were subsequently confirmed at laparotomy. Conclusion: CT is an accurate diagnostic tool in the assessment of clinically and radiologically occult traumatic small bowel injury. The use of CT should be considered in patients who have unresolving abdominal symptoms even after apparently insignificant abdominal trauma.

  19. Detecting mammographically occult cancer in women with dense breasts using Radon Cumulative Distribution Transform: a preliminary analysis

    Lee, Juhun; Nishikawa, Robert M.; Rohde, Gustavo K.

    2018-02-01

    We propose using novel imaging biomarkers for detecting mammographically-occult (MO) cancer in women with dense breast tissue. MO cancer indicates visually occluded, or very subtle, cancer that radiologists fail to recognize as a sign of cancer. We used the Radon Cumulative Distribution Transform (RCDT) as a novel image transformation to project the difference between left and right mammograms into a space, increasing the detectability of occult cancer. We used a dataset of 617 screening full-field digital mammograms (FFDMs) of 238 women with dense breast tissue. Among 238 women, 173 were normal with 2 - 4 consecutive screening mammograms, 552 normal mammograms in total, and the remaining 65 women had an MO cancer with a negative screening mammogram. We used Principal Component Analysis (PCA) to find representative patterns in normal mammograms in the RCDT space. We projected all mammograms to the space constructed by the first 30 eigenvectors of the RCDT of normal cases. Under 10-fold crossvalidation, we conducted quantitative feature analysis to classify normal mammograms and mammograms with MO cancer. We used receiver operating characteristic (ROC) analysis to evaluate the classifier's output using the area under the ROC curve (AUC) as the figure of merit. Four eigenvectors were selected via a feature selection method. The mean and standard deviation of the AUC of the trained classifier on the test set were 0.74 and 0.08, respectively. In conclusion, we utilized imaging biomarkers to highlight differences between left and right mammograms to detect MO cancer using novel imaging transformation.

  20. Signal noise ratio analysis and on-orbit performance estimation of a solar occultation Fourier transform spectrometer

    Li, Bicen; Xu, Pengmei; Hou, Lizhou; Wang, Caiqin

    2017-10-01

    Taking the advantages of high spectral resolution, high sensitivity and wide spectral coverage, space borne Fourier transform infrared spectrometer (FTS) plays more and more important role in atmospheric composition sounding. The combination of solar occultation and FTS technique improves the sensitivity of instrument. To achieve both high spectral resolution and high signal to noise ratio (SNR), reasonable allocation and optimization for instrument parameters are the foundation and difficulty. The solar occultation FTS (SOFTS) is a high spectral resolution (0.03 cm-1) FTS operating from 2.4 to 13.3 μm (750-4100cm-1), which will determine the altitude profile information of typical 10-100km for temperature, pressure, and the volume mixing ratios for several dozens of atmospheric compositions. As key performance of SOFTS, SNR is crucially important to high accuracy retrieval of atmospheric composition, which is required to be no less than 100:1 at the radiance of 5800K blackbody. Based on the study of various parameters and its interacting principle, according to interference theory and operation principle of time modulated FTS, a simulation model of FTS SNR has been built, which considers satellite orbit, spectral radiometric features of sun and atmospheric composition, optical system, interferometer and its control system, measurement duration, detector sensitivity, noise of detector and electronic system and so on. According to the testing results of SNR at the illuminating of 1000 blackbody, the on-orbit SNR performance of SOFTS is estimated, which can meet the mission requirement.

  1. Validation of the Earth atmosphere models using the EUV solar occultation data from the CORONAS and PROBA 2 instruments

    Slemzin, Vladimir; Kuzin, Sergey; Berghmans, David; Pertsov, Andrey; Dominique, Marie; Ulyanov, Artyom; Gaikovich, Konstantin

    Absorption in the atmosphere below 500 km results in attenuation of the solar EUV flux, variation of its spectra and distortion of solar images acquired by solar EUV instruments operating on LEO satellites even on solar synchronous orbits. Occultation measurements are important for planning of solar observations from these satellites, and can be used for monitoring the upper atmosphere as well as for studying its response to the solar activity. We present the results of the occultation measurements of the solar EUV radiation obtained by the CORONAS-F/SPIRIT telescope at high solar activity (2002), by the CORONAS-Photon/TESIS telescope at low activity (2009), and by the SWAP telescope and LYRA radiometer onboard the PROBA 2 satellite at moderate activity (2010). The measured attenuation profiles and the retrieved linear extinction coefficients at the heights 200-500 km are compared with simulations by the NRLMSIS-00 and DTM2013 atmospheric models. It was shown that the results of simulations by the DTM2013 model are well agreed with the data of measurements at all stages of solar activity and in presence of the geomagnetic storm, whereas the results of the NRLMSISE-00 model significantly diverge from the measurements, in particular, at high and low activity. The research leading to these results has received funding from the European Union’s Seventh Programme for Research, Technological Development and Demonstration under Grant Agreement “eHeroes” (project No.284461, www.eheroes.eu).

  2. Computed tomography compared to magnetic resonance imaging in occult or suspect hip fractures. A retrospective study in 44 patients

    Collin, David; Goethlin, Jan H. [Sahlgrenska University Hospital, Department of Radiology, Moelndal (Sweden); Geijer, Mats [Lund University, Department of Medical Imaging and Physiology, Skaane University Hospital, Lund (Sweden)

    2016-11-15

    Computed tomography (CT) for evaluation of occult and suspect hip fractures has been proposed as a good second-line investigation. The diagnostic precision compared to magnetic resonance imaging (MRI) is unclear. To compare the diagnostic performance of CT and MRI in a retrospective study on patients with suspect and occult hip fractures. Forty-four elderly consecutive patients with low-energy trauma to the hip were identified where negative or suspect CT was followed by MRI. Primary reporting and review by two observers as well as the diagnostic performance of the two modalities were compared. Surgical treatment and clinical course were used as outcomes. Compared to the primary reports, the CT reviewers found fewer normal and no suspect cases. MRI changed the primary diagnoses in 27 cases, and in 14 and 15 cases, respectively, at review. There was no disagreement on MRI diagnoses. In our patient population, MRI was deemed a more reliable modality for hip fracture diagnosis in comparison to CT. For clinical decision making, MRI seems to have a higher accuracy than CT. A negative CT finding cannot completely rule out a hip fracture in patients where clinical findings of hip fracture persevere. (orig.)

  3. VizieR Online Data Catalog: Times of transits and occultations of WASP-12b (Patra+, 2017)

    Patra, K. C.; Winn, J. N.; Holman, M. J.; Yu, L.; Deming, D.; Dai, F.

    2017-08-01

    Between 2016 October and 2017 February, we observed seven transits of WASP-12 with the 1.2m telescope at the Fred Lawrence Whipple Observatory on Mt. Hopkins, Arizona. Images were obtained with the KeplerCam detector through a Sloan r'-band filter. The typical exposure time was 15s, chosen to give a signal-to-noise ratio of about 200 for WASP-12. The field of view of this camera is 23.1' on a side. We used 2*2 binning, giving a pixel scale of 0.68''. We measured two new occultation times based on hitherto unpublished Spitzer observations in 2013 December (program 90186, P.I. Todorov). Two different transits were observed, one at 3.6μm and one at 4.5μm. The data take the form of a time series of 32*32-pixel subarray images, with an exposure time of 2.0s per image. The data were acquired over a wide range of orbital phases, but for our purpose, we analyzed only the ~14000 images within 4hr of each occultation. (1 data file).

  4. Assessing the Risk of Occult Cancer and 30-day Morbidity in Women Undergoing Risk-reducing Surgery: A Prospective Experience.

    Bogani, Giorgio; Tagliabue, Elena; Signorelli, Mauro; Chiappa, Valentina; Carcangiu, Maria Luisa; Paolini, Biagio; Casarin, Jvan; Scaffa, Cono; Gennaro, Massimiliano; Martinelli, Fabio; Borghi, Chiara; Ditto, Antonino; Lorusso, Domenica; Raspagliesi, Francesco

    To investigate the incidence and predictive factors of 30-day surgery-related morbidity and occult precancerous and cancerous conditions for women undergoing risk-reducing surgery. A prospective study (Canadian Task Force classification II-1). A gynecologic oncology referral center. Breast-related cancer antigen (BRCA) mutation carriers and BRCAX patients (those with a significant family history of breast and ovarian cancer). Minimally invasive risk-reduction surgery. Overall, 85 women underwent risk-reducing surgery: 30 (35%) and 55 (65%) had hysterectomy plus bilateral salpingo-oophorectomy (BSO) and BSO alone, respectively. Overall, in 6 (7%) patients, the final pathology revealed unexpected cancer: 3 early-stage ovarian/fallopian tube cancers, 2 advanced-stage ovarian cancers (stage IIIA and IIIB), and 1 serous endometrial carcinoma. Additionally, 3 (3.6%) patients had incidental finding of serous tubal intraepithelial carcinoma. Four (4.7%) postoperative complications within 30 days from surgery were registered, including fever (n = 3) and postoperative ileus (n = 1); no severe (grade 3 or more) complications were observed. All complications were managed conservatively. The presence of occult cancer was the only factor predicting the development of postoperative complications (p = .02). Minimally invasive risk-reducing surgery is a safe and effective strategy to manage BRCA mutation carriers. Patients should benefit from an appropriate counseling about the high prevalence of undiagnosed cancers observed at the time of surgery. Copyright © 2017 AAGL. Published by Elsevier Inc. All rights reserved.

  5. Irritable bowel syndrome-type symptoms in patients with inflammatory bowel disease: a real association or reflection of occult inflammation?

    Keohane, John; O'Mahony, Caitlin; O'Mahony, Liam; O'Mahony, Siobhan; Quigley, Eamonn M; Shanahan, Fergus

    2010-08-01

    Do gastrointestinal symptoms in patients with inflammatory bowel disease (IBD) in apparent remission reflect the coexistence of irritable bowel syndrome (IBS) or subclinical inflammation? The aims of this study were as follows: (i) to prospectively determine the prevalence of IBS symptoms in IBD patients in remission; and (ii) to determine whether IBS symptoms correlate with levels of fecal calprotectin. Remission was defined by physician assessment: Crohn's disease (CD) activity index occult inflammation. Furthermore, calprotectin levels were significantly higher in CD and UC patients with criteria for IBS than in those without IBS-type symptoms. QOL scores were lower and HAD scores higher among UC patients with IBS symptoms in comparison to those who did not have IBS symptoms. IBS-like symptoms are common in patients with IBD who are thought to be in clinical remission, but abnormal calprotectin levels suggest that the mechanism in most cases is likely to be occult inflammation rather than coexistent IBS.

  6. Radio Occultation Experiments with Venus Express and Mars Express using the Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique

    Bocanegra Bahamon, T.; Gurvits, L.; Molera Calves, G.; Cimo, G.; Duev, D.; Pogrebenko, S.; Dirkx, D.; Rosenblatt, P.

    2017-12-01

    The Planetary Radio Interferometry and Doppler Experiment (PRIDE) is a technique that can be used to enhance multiple radio science experiments of planetary missions. By 'eavesdropping' on the spacecraft signal using radio telescopes from different VLBI networks around the world, the PRIDE technique provides precise open-loop Doppler and VLBI observables to able to reconstruct the spacecraft's orbit. The application of this technique for atmospheric studies has been assessed by observing ESA's Venus Express (VEX) and Mars Express (MEX) during multiple Venus and Mars occultation events between 2012 and 2014. From these observing sessions density, temperature and pressure profiles of Venus and Mars neutral atmosphere and ionosphere have been retrieved. We present an error propagation analysis where the uncertainties of the atmospheric properties measured with this technique have been derived. These activities serve as demonstration of the applicability of the PRIDE technique for radio occultation studies, and provides a benchmark against the traditional Doppler tracking provided by the NASA's DSN and ESA's Estrack networks for these same purposes, in the framework of the upcoming ESA JUICE mission to the Jovian system.

  7. The occultation of Epsilon Geminorum by Mars - Analysis of McDonald data. [turbulent scintillation in light curves

    Africano, J.; De Vaucouleurs, G.; Evans, D. S.; Finkel, B. E.; Nather, R. E.; Palm, C.; Silverberg, E.; Wiant, J.; Hubbard, W. B.; Jokipii, J. R.

    1977-01-01

    An analysis of observations of the occultation of Epsilon Gem by Mars on April 8, 1976, is presented. The data were obtained by three neighboring telescopes at McDonald Observatory. Intensity fluctuations on time scales of the order of 100 ms were observed simultaneously at the three telescopes. As the observations compare well with predictions of turbulent scintillation theory, it is concluded that such fluctuations were probably largely the effect of stellar scintillations in the Martian atmosphere. The stellar diameter is included as a parameter in the theory but in a way which differs from previously published interpretations of occultations of extended sources by planetary atmospheres. Scintillations govern the experimental uncertainty in the deduction of the scale height of the high Martian atmosphere. A density scale height of 9.9 + or - 2.5 km is obtained at an altitude of 74 + or - 8 km above the mean surface. For CO 2 gas, this result corresponds to a temperature of 190 + or - 50 K.

  8. ‘Trick’, ‘Manipulation’ and ‘Farce’: Albert Moll’s Critique of Occultism

    Wolffram, Heather

    2012-01-01

    In July 1925, the psychiatrist Albert Moll appeared before the district court in Berlin-Schöneberg charged with having defamed the medium Maria Vollhardt (alias Rudloff) in his 1924 book Der Spiritismus [Spiritism]. Supported by some of Berlin’s most prominent occultists, the plaintiff – the medium’s husband – argued that Moll’s use of terms such as ‘trick’, ‘manipulation’ and ‘farce’ in reference to Vollhardt’s phenomena had been libellous. In the three-part trial that followed, however, Moll’s putative affront to the medium – of which he was eventually acquitted – was overshadowed, on the one hand, by a debate over the scientific status of parapsychology, and on the other, by the question of who – parapsychologists, occultists, psychiatrists or jurists – was entitled to claim epistemic authority over the occult. This paper will use the Rudloff–Moll trial as a means of examining Moll’s critique of occultism, not only as it stood in the mid-1920s, but also as it had developed since the 1880s. It will also provide insight into the views of Germany’s occultists and parapsychologists, who argued that their legitimate bid for scientific credibility was hindered by Dunkelmänner [obscurantists] such as Albert Moll. PMID:23002297

  9. Excessive blinking and ataxia in a child with occult neuroblastoma and voltage-gated potassium channel antibodies.

    Allen, Nicholas M

    2012-05-01

    A previously healthy 9-year-old girl presented with a 10-day history of slowly progressive unsteadiness, slurred speech, and behavior change. On examination there was cerebellar ataxia and dysarthria, excessive blinking, subtle perioral myoclonus, and labile mood. The finding of oligoclonal bands in the cerebrospinal fluid prompted paraneoplastic serological evaluation and search for an occult neural crest tumor. Antineuronal nuclear autoantibody type 1 (anti-Hu) and voltage-gated potassium channel complex antibodies were detected in serum. Metaiodobenzylguanidine scan and computed tomography scan of the abdomen showed a localized abdominal mass in the region of the porta hepatis. A diagnosis of occult neuroblastoma was made. Resection of the stage 1 neuroblastoma and treatment with pulsed corticosteroids resulted in resolution of all symptoms and signs. Excessive blinking has rarely been described with neuroblastoma, and, when it is not an isolated finding, it may be a useful clue to this paraneoplastic syndrome. Although voltage-gated potassium channel complex autoimmunity has not been described previously in the setting of neuroblastoma, it is associated with a spectrum of paraneoplastic neurologic manifestations in adults, including peripheral nerve hyperexcitability disorders.

  10. The Two-Tier Fecal Occult Blood Test: Cost-Effective Screening

    Andrew J Rae

    1994-01-01

    Full Text Available The two-tier test represents a strategy combining HO Sensa and Hemeselect fecal occult blood tests (FOBTs with the aim of greater specificity and consequent economic advantages. If patients register a positive result on any HO Sensa guaiac test, they are once again tested by a hemoglobin-specific Hemeselect test. This concept was applied to a multicentre study involving persons 40 years or older. One component of the study enrolled 573 high risk patients while the second arm recruited an additional 1301 patients (52% asymptomatic/48% symptomatic stratified according to personal history and symptoms. The two-tier test produced fewer false positives than traditional tests in both groups evaluated in the study. In the high risk group, specificity (88.7% for two-tier versus 80.6% for Hemoccult and 69.5% for HO Sensa was higher and false positive rates were lower (11.3% for two-tier versus 19.5% for Hemoccultand 30.5% for HO Sensa for the two-tier test versus Hemoccult and HO Sensa FOBTs (95% CI for all colorectal cancers [CRCs] and polyps greater than 1 cm, α=0.05 . No significant differences in sensitivity were observed between tests in the same group. Also, in the high risk group, benefits of the two-tier test outweighed the costs. Due to the small number of cancers and polyps in the second arm of the study, presentation of data is meant to be descriptive and representative of trends in a ‘normal’ population. Nevertheless, specificity of the two-tier test was higher (96.8% for two-tier versus 87.2% for Hemoccult and 69.5% for HO Sensa and false positive rate lower (3.2% for two-tier versus 12.8% for Hemoccult and 22.3% for HO Sensa than either the Hemoccult or HO Sensa FOBT (95% CI for all CRCs and polyps greater than 1 cm. This initial study, focusing on the cost-benefit relationship of increased specificity, represents a new way of economically evaluating existing FOBTs.

  11. Solar occultation images analysis using Zernike polynomials ­— an ALTIUS imaging spectrometer application

    Dekemper, Emmanuel; Fussen, Didier; Loodts, Nicolas; Neefs, Eddy

    The ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) instrument is a major project of the Belgian Institute for Space Aeronomy (BIRA-IASB) in Brussels, Belgium. It has been designed to profit from the benefits of the limb scattering ge-ometry (vertical resolution, global coverage,...), while providing better accuracy on the tangent height knowledge than classical "knee" methods used by scanning spectrometers. The optical concept is based on 3 AOTF's (UV-Vis-NIR) responsible for the instantaneous spectral filtering of the incoming image (complete FOV larger than 100km x 100km at tangent point), ranging from 250nm to 1800nm, with a moderate resolution of a few nm and a typical acquisition time of 1-10s per image. While the primary goal of the instrument is the measurement of ozone with a good vertical resolution, the ability to record full images of the limb can lead to other applications, like solar occultations. With a pixel FOV of 200rad, the full high-sun image is formed of 45x45 pixels, which is sufficient for pattern recognition using moments analysis for instance. The Zernike polynomials form a complete othogonal set of functions over the unit circle. It is well suited for images showing circular shape. Any such image can then be decomposed into a finite set of weighted polynomials, the weighting is called the moments. Due to atmospheric refraction, the sun shape is modified during apparent sunsets and sunrises. The sun appears more flattened which leads to a modification of its zernike moment description. A link between the pressure or the temperature profile (equivalent to air density through the perfect gas law and the hydrostatic equation) and the Zernike moments of a given image can then be made and used to retrieve these atmospheric parameters, with the advantage that the whole sun is used and not only central or edge pixels. Some retrievals will be performed for different conditions and the feasibility of the method

  12. Size and Shape of Chariklo from Multi-epoch Stellar Occultations

    Leiva, R.; Sicardy, B.; Camargo, J. I. B.; Ortiz, J.-L.; Desmars, J.; Bérard, D.; Lellouch, E.; Meza, E.; Kervella, P.; Snodgrass, C.; Duffard, R.; Morales, N.; Gomes-Júnior, A. R.; Benedetti-Rossi, G.; Vieira-Martins, R.; Braga-Ribas, F.; Assafin, M.; Morgado, B. E.; Colas, F.; De Witt, C.; Sickafoose, A. A.; Breytenbach, H.; Dauvergne, J.-L.; Schoenau, P.; Maquet, L.; Bath, K.-L.; Bode, H.-J.; Cool, A.; Lade, B.; Kerr, S.; Herald, D.

    2017-10-01

    We use data from five stellar occultations observed between 2013 and 2016 to constrain Chariklo’s size and shape, and the ring reflectivity. We consider four possible models for Chariklo (sphere, Maclaurin spheroid, triaxial ellipsoid, and Jacobi ellipsoid), and we use a Bayesian approach to estimate the corresponding parameters. The spherical model has a radius R = 129 ± 3 km. The Maclaurin model has equatorial and polar radii a=b={143}-6+3 {km} and c={96}-4+14 {km}, respectively, with density {970}-180+300 {kg} {{{m}}}-3. The ellipsoidal model has semiaxes a={148}-4+6 {km}, b={132}-5+6 {km}, and c={102}-8+10 {km}. Finally, the Jacobi model has semiaxes a = 157 ± 4 km, b = 139 ± 4 km, and c = 86 ± 1 km, and density {796}-4+2 {kg} {{{m}}}-3. Depending on the model, we obtain topographic features of 6-11 km, typical of Saturn icy satellites with similar size and density. We constrain Chariklo’s geometric albedo between 3.1% (sphere) and 4.9% (ellipsoid), while the ring I/F reflectivity is less constrained between 0.6% (Jacobi) and 8.9% (sphere). The ellipsoid model explains both the optical light curve and the long-term photometry variation of the system, giving a plausible value for the geometric albedo of the ring particles of 10%-15%. The derived mass of Chariklo of 6-8 × 1018 kg places the rings close to 3:1 resonance between the ring mean motion and Chariklo’s rotation period. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  13. Quantitative Autofluorescence Intensities in Acute Zonal Occult Outer Retinopathy vs Healthy Eyes

    Boudreault, Katherine; Schuerch, Kaspar; Zhao, Jin; Lee, Winston; Cabral, Thiago; Yannuzzi, Lawrence A.; Tsang, Stephen H.; Sparrow, Janet R.

    2018-01-01

    IMPORTANCE Acute zonal occult outer retinopathy (AZOOR) remains a challenging diagnosis. Early recognition of the disease depends on advances in imaging modalities that can improve phenotyping and contribute to the understanding of the underlying pathogenesis. OBJECTIVES To expand the range of approaches available to assist in the identification of AZOOR by multimodal imaging and to analyze the fundus lesions by quantifying short-wavelength fundus autofluorescence (quantitative fundus autofluorescence [qAF]) and spectral-domain optical coherence tomography. DESIGN, SETTING, AND PARTICIPANTS In this observational study, patients underwent imaging at Columbia University Medical Center between November 2010 and March 2016 and were analyzed between September 2015 and August 2016. Six patients diagnosed as having AZOOR were studied by qAF and spectral-domain optical coherence tomography and were compared with 30 age and race/ethnicity–matched controls from a database of 277 healthy control eyes. MAIN OUTCOMES AND MEASURES In unaffected regions of the macula, qAF was calculated within predetermined circularly arranged segments (qAF8). In addition, qAF was measured within specified regions of interest positioned at the autofluorescent lesion border (AZOOR line). Electroretinograms and electro-oculograms were recorded in 5 of 6 patients. RESULTS Among 6 patients (age range, 26–61 years; 4 female; 4 of white race/ethnicity, 1 Asian, and 1 Hispanic), 5 exhibited an autofluorescent AZOOR line in short-wavelength fundus autofluorescence images, delineating the peripapillary lesion. The mean (SD) region-of-interest qAF measured on the AZOOR line was 60 (26) times higher than in healthy control eyes (P = .03) at equivalent fundus locations. The qAF8 within nondiseased macular regions were within the normal range. At the lesion border, spectral-domain optical coherence tomography revealed a loss of outer retinal integrity in all patients. Single-flash cone b-wave latency and

  14. Diagnosis of radiographically occult lumbar spondylolysis in young athletes by magnetic resonance imaging.

    Kobayashi, Atsushi; Kobayashi, Tsutomu; Kato, Kazuo; Higuchi, Hiroshi; Takagishi, Kenji

    2013-01-01

    The early stages of spondylolysis are extremely difficult to diagnose on plain radiography. Although several studies have examined changes in active spondylolysis on magnetic resonance imaging (MRI), no studies to date have determined the onset frequency of active spondylolysis detectable on MRI but occult on plain radiography. Moreover, the clinical features of active spondylolysis described in the literature do not facilitate the differentiation of this condition from other causes of low back pain. This study aimed to evaluate the usefulness of MRI in diagnosing active spondylolysis early and in determining the prevalence of active spondylolysis in cases where findings were not detected on plain radiography. In addition, specific clinical features to aid in the early detection of active spondylolysis were evaluated. Cohort study; Level of evidence, 3. Patients were 200 consecutive young athletes (144 boys and 56 girls; mean age, 14.1 ± 1.5 y) with low back pain. All patients were examined by plain radiography (188 with negative findings and 12 with unclear findings of spondylolysis) and MRI. Computed tomography (CT) was performed only for patients with high intensity changes of the pedicle observed on MRI. The presence or absence of low back pain was examined during lumbar spine extension and flexion. The Kemp test on the right and left sides and percussion of the vertebral spinous process were also performed. Ninety-seven (48.5%) patients showed evidence of active spondylolysis on MRI, findings that had been missed by plain radiography. These pars defects were organized into the following categories based on CT findings: nonlysis stage, 52; very early stage, 37; late early stage, 22; progressive stage, 10; and terminal stage, 0. No significant physical examination factors were identified that could assist in the early detection of active spondylolysis. The MRI results suggest a high rate of active spondylolysis in young athletes with low back pain who test

  15. Overview of the strategies and results of the 2017 occultation campaigns involving (486958) 2014 MU69

    Buie, Marc W.; Porter, Simon Bernard; Terrell, Dirk; Tamblyn, Peter; Verbiscer, Anne J.; Soto, Alejandro; Wasserman, Lawrence H.; Zangari, Amanda Marie; Skrutskie, Michael F.; Parker, Alex; Young, Eliot F.; Benecchi, Susan; Stern, S. Alan; New Horizons MU69 Occultation Team; New Horizons MU69 Occultation Team

    2017-10-01

    Three stellar occultation opportunities were identified in 2017 involving the New Horizons extended mission target: (486958) 2014 MU69. The first event was on 2017 June 3 and predicted to be visible from southern South America and southern Africa with a somewhat faint star with g’=15.33. The second event was on 2017 June 10 under very difficult observing conditions just 16° from a full moon and the faintest star of the three with g’=15.57. The third event was on 2017 July 17 and predicted to be visible from southern Argentina with the brightest star of the three with g’=12.60. We pursued each of these events with an observing plan and strategy tuned to the constraints imposed by observing conditions and the anticipated prediction uncertainties. The first and third events were amenable to a ground-based telescope deployment and we fielded 25 telescopes. The second event was possible only with SOFIA (Stratospheric Observatory For Infrared Astronomy). The deployment for the first event involved splitting resources between two continents and a strategy optimized to prevent a null result for a D=40km object. The second event was optimized for the search for dust and rings but had a 75% chance of a solid body event for a D=40 km size. The third event was driven by needing to prevent a null result on a D=10 km size and providing extra conservatism on the ground-track uncertainty while observing from the area of Comodoro Rivadavia, Argentina. All campaigns were successful in recording data essential for the constraint on dust or rings around MU69: June 3, 24 lightcurves; July 10, 1 lightcurve; July 17, 23 lightcurves. Only the last event was able to record solid-body chords from the object with 5 chords detected close to the predicted time and place. We will present an overview of the strategies and basic results of the campaigns. This work would not have been possible without the financial support of the New Horizons mission and NASA, astrometric support of the

  16. X-ray observations of two lunar occultations of the Crab Nebula

    Ku, W.H.M.

    1976-01-01

    The x-ray source in the Crab nebula was observed during two lunar occultations. The combined results of the two scans of the nebula indicate that the spatial distribution of the X-ray flux from the nebula is centered on a region 10'' to 15'' NW of the pulsar. The half-intensity size, as measured by the FWHM of the best Gaussian representation of each strip flux distribution, is 46.7'' +- 1.5'' along p.a. = 300 0 , and is 42'' +- 2'' along p.a. = 255 0 . A closer examination of the size of the nebular emission region measured along p.a. = 300 0 reveals that the size decreases significantly with increasing photon energy. A power-law function with an exponent of γ = -0.148 +- 0.012 characterizes the optical (approximately 2 eV) to X-ray (approximately 50 keV) size measurements well, but it fails to predict the observed sizes of the radio nebula. Power-law spectral indices derived for different regions of the nebula support this finding. These results are interpreted in terms of existing theoretical models for the motion of electrons in the nebula. The data obtained on 28 December 1974 also provide strong evidence for the existence of a low-luminosity soft X-ray component more than 60'' W of the pulsar. Such emission was not detected in data from the first scan, but the upper limit derived from those data is consistent with the existence of a soft extended source. Several plausible explanations for the origin of this radiation are considered including the interesting possibility of thermal emission from a supernova remnant shell. Data obtained near the time of emergence of the pulsar for both observations are examined for possible flux contribution from a discrete steady radiation source. The null result allows an upper limit of 4.7 x 10 6 0 K (99 percent confidence) to be established on the surface temperature of the neutron star associated with NP 0532. This result is used to set limits on some physical parameters of a neutron star

  17. OCCULT ANAL SPHINCTER INJURIES (OASIS IN DEPARTMENT OF PERINATOLOGY IN LJUBLJANA – INCIDENCE AND RISK FACTORS

    Katja Jakopič

    2018-02-01

    Full Text Available Background: Vaginal delivery is the most important risk factors for development of faecal incontinence, which significantly affects quality of life. Foreign studies show OASIS occur at 20 to 40 % of vaginal deliveries. In Slovenia we recognize sphincter injuries at 1.7 % of deliveries, while true incidence of OASIS in our population remains unknown. Caesarean section prevents anal sphincter injuries. Known risk factors in foreign studies include prolonged second stage of labour, fetal weight > 3500 g, malpresentation, forceps delivery, maternal age more than 35 years at the time of first delivery, first delivery. Few women complain about defecatory problems in puerperium unless they are directly asked about them, so true incidence of such injuries is grossly underestimated. Previously compensated anal sphincter dysfunction can clinically manifest as late as in menopause. The most probable cause is atrophy of muscle and fibrous tissue of pelvic floor and anal sphincter due to lack of estrogen support in this period. With anal ultrasound we tried to determine the incidence of occult damage to anal sphincter in primiparas after vaginal delivery and the relation of injury to symptoms 6 weeks after delivery and identify possible risk factors in our population. We also tried to find out how many patients with anal sphincter injury become symptomatic immediately after deliv- ery. Methods: From January to June 2009 we examined 26 primiparas after vaginal delivery in the Ljubljana Maternity Hospital with anal ultrasound and compared various data about the delivery from our national delivery form. We excluded all patients with caesarean section, recognized anal sphincter injury at the time of the delivery or previous anorectal surgery, history of irritable bowel syndrome or pre-existing inflammatory bowel disease. All patients completed a bowel-function questionnaire, which included questions about faecal urgency and involuntary passing of gas, liquid or

  18. DETECTION OF OCCULT LYMPH NODE TUMOR CELLS IN NODE-NEGATIVE GASTRIC CANCER PATIENTS.

    Pereira, Marina Alessandra; Ramos, Marcus Fernando Kodama Pertille; Dias, Andre Roncon; Yagi, Osmar Kenji; Faraj, Sheila Friedrich; Zilberstein, Bruno; Cecconello, Ivan; Mello, Evandro Sobroza de; Ribeiro, Ulysses

    2017-01-01

    The presence of lymph nodes metastasis is one of the most important prognostic indicators in gastric cancer. The micrometastases have been studied as prognostic factor in gastric cancer, which are related to decrease overall survival and increased risk of recurrence. However, their identification is limited by conventional methodology, since they can be overlooked after routine staining. To investigate the presence of occult tumor cells using cytokeratin (CK) AE1/AE3 immunostaining in gastric cancer patients histologically lymph node negative (pN0) by H&E. Forty patients (T1-T4N0) submitted to a potentially curative gastrectomy with D2 lymphadenectomy were evaluated. The results for metastases, micrometastases and isolated tumor cells were also associated to clinicopathological characteristics and their impact on stage grouping. Tumor deposits within lymph nodes were defined according to the tumor-node-metastases guidelines (7th TNM). A total of 1439 lymph nodes were obtained (~36 per patient). Tumor cells were detected by immunohistochemistry in 24 lymph nodes from 12 patients (30%). Neoplasic cells were detected as a single or cluster tumor cells. Tumor (p=0.002), venous (p=0.016), lymphatic (p=0.006) and perineural invasions (p=0.04), as well as peritumoral lymphocytic response (p=0.012) were correlated to CK-positive immunostaining tumor cells in originally negative lymph nodes by H&E. The histologic stage of two patients was upstaged from stage IB to stage IIA. Four of the 28 CK-negative patients (14.3%) and three among 12 CK-positive patients (25%) had disease recurrence (p=0.65). The CK-immunostaining is an effective method for detecting occult tumor cells in lymph nodes and may be recommended to precisely determine tumor stage. It may be useful as supplement to H&E routine to provide better pathological staging. A presença de metástase em linfonodos é um dos indicadores prognósticos mais importantes no câncer gástrico. As micrometástases têm sido

  19. Vaginal prolapse repair with or without a midurethral sling in women with genital prolapse and occult stress urinary incontinence: a randomized trial

    van der Ploeg, J. Marinus; Oude Rengerink, Katrien; van der Steen, Annemarie; van Leeuwen, Jules H. Schagen; van der Vaart, C. Huub; Roovers, Jan-Paul W. R.

    2016-01-01

    We compared pelvic organ prolapse (POP) repair with and without midurethral sling (MUS) in women with occult stress urinary incontinence (SUI). This was a randomized trial conducted by a consortium of 13 teaching hospitals assessing a parallel cohort of continent women with symptomatic stage II or

  20. Vaginal prolapse repair with or without a midurethral sling in women with genital prolapse and occult stress urinary incontinence : a randomized trial

    van der Ploeg, J Marinus; Rengerink, Katrien Oude; van der Steen, Annemarie; van Leeuwen, Jules H Schagen; van der Vaart, C Huub; Roovers, Jan-Paul W R

    INTRODUCTION AND HYPOTHESIS: We compared pelvic organ prolapse (POP) repair with and without midurethral sling (MUS) in women with occult stress urinary incontinence (SUI). METHODS: This was a randomized trial conducted by a consortium of 13 teaching hospitals assessing a parallel cohort of