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Sample records for occult scaphoid fracture

  1. Scaphoid Fracture of the Wrist

    MedlinePlus

    .org Scaphoid Fracture of the Wrist Page ( 1 ) The scaphoid is one of the small bones in the wrist. It is ... that the scaphoid is injured. Cause A scaphoid fracture is usually caused by a fall on an ...

  2. The Effect of Scaphoid Fracture Site on Scaphoid Instability Patterns

    PubMed Central

    Werner, Frederick W.; St-Amand, Hugo; Moritomo, Hisao; Sutton, Levi G.; Short, Walter H.

    2015-01-01

    Background Scaphoid fractures are common carpal fractures that are often misdiagnosed as wrist sprains and may go on to nonunion. The location of the fracture site may influence the stability of scaphoid nonunions. Purpose To determine whether the stability of a scaphoid nonunion depends upon the fracture's location, we tested the hypothesis that a simulated fracture distal to the apex of the scaphoid dorsal ridge will have greater interfragmentary motion than proximal. Methods Eleven cadaver wrists were moved through three wrist motions using a wrist simulator. In six wrists, a fracture was created distal to the scaphoid apex, and in five a fracture was created proximal to the apex. Sensors attached to the distal and proximal parts of each scaphoid measured the interfragmentary motion during wrist motion. Results In those wrists in which the scaphoid was sectioned distal to the apex, the distal fragment became significantly more unstable relative to the proximal fragment. It flexed, ulnarly deviated, and pronated. These motion changes were less when the scaphoid was sectioned proximally. Discussion Scaphoid fractures distal to the scaphoid apex will have greater interfragmentary motion. The mobility of the fragments at the fracture site is possibly a more important contributory factor of nonunion in scaphoid waist fractures than for proximal scaphoid fractures. Clinical Relevance Understanding the effect that the location of a scaphoid fracture has on the potential for nonunion may influence the modalities of treatment and follow-up. PMID:26855836

  3. Inter-observer agreement between 2-dimensional CT versus 3-dimensional I-Space model in the Diagnosis of Occult Scaphoid Fractures

    PubMed Central

    Drijkoningen, Tessa; Knoter, Robert; Coerkamp, Emile G.; Koning, Anton H.J.; Rhemrev, Steven J.; Beeres, Frank J.

    2016-01-01

    Background: The I-Space is a radiological imaging system in which Computed Tomography (CT)-scans can be evaluated as a three dimensional hologram. The aim of this study is to analyze the value of virtual reality (I-Space) in diagnosing acute occult scaphoid fractures. Methods: A convenient cohort of 24 patients with a CT-scan from prior studies, without a scaphoid fracture on radiograph, yet high clinical suspicion of a fracture, were included in this study. CT-scans were evaluated in the I-Space by 7 observers of which 3 observers assessed the scans in the I-Space twice. The observers in this study assessed in the I-Space whether the patient had a scaphoid fracture. The kappa value was calculated for inter- and intra-observer agreement. Results: The Kappa value varied from 0.11 to 0.33 for the first assessment. For the three observers who assessed the CT-scans twice; observer 1 improved from a kappa of 0.33 to 0.50 (95% CI 0.26-0.74, P=0.01), observer 2 from 0.17 to 0.78 (95% CI 0.36-1.0, P<0.001), and observer 3 from 0.11 to 0.24 (95% CI 0.0-0.77, P=0.24). Conclusion: Following our findings the I-Space has a fast learning curve and has a potential place in the diagnostic modalities for suspected scaphoid fractures. PMID:27847847

  4. Managing scaphoid fractures. How we do it?

    PubMed Central

    Gupta, Vikas; Rijal, Laxman; Jawed, Akram

    2013-01-01

    The scaphoid is the common carpal bone to be fractured. Proper clinical and radiological evaluation is required to establish it's diagnosis. The management of acute fractures includes conservative treatment with cast in minimally displaced to open reduction and internal fixation in case of displaced ones. The established nonunion requires open reduction, bone grafting and internal fixation. PMID:26403769

  5. Scaphoid fracture in the elite athlete.

    PubMed

    Belsky, Mark R; Leibman, Matthew I; Ruchelsman, David E

    2012-08-01

    Scaphoid fracture remains a common, potentially devastating, injury that can impair upper extremity function. Early recognition with proper imaging and treatment provides the best opportunity to heal and return to a normal activity level. Surgical treatment offers the patient a quicker return to the rehabilitation of the extremity and therefore an earlier return to elite play. There is evidence that healing occurs faster if the fractured scaphoid is fixed with internal fixation. Absolute compliance by the athlete and the training program that surrounds the athlete is critical to protect the wrist while maintaining the necessary conditioning of an elite athlete.

  6. [Diagnosis of the scaphoid bone : Fractures, nonunion, circulation, perfusion].

    PubMed

    Kahl, T; Razny, F K; Benter, J P; Mutig, K; Hegenscheid, K; Mutze, S; Eisenschenk, A

    2016-11-01

    The clinical relevance of scaphoid bone fractures is reflected by their high incidence, accounting for approximately 60 % among carpal fractures and for 2-3 % of all fractures. With adequate therapy most scaphoid bone fractures heal completely without complications. Insufficient immobilization or undiagnosed fractures increase the risk of nonunion and the development of pseudarthrosis.X-ray examination enables initial diagnosis of scaphoid fracture in 70-80 % of cases. Positive clinical symptoms by negative x‑ray results require further diagnostics by multi-slice spiral CT (MSCT) or MRI to exclude or confirm a fracture. In addition to the diagnosis and description of fractures MSCT is helpful for determining the stage of nonunion. Contrast enhanced MRI is the best method to assess the vitality of scaphoid fragments.

  7. Occult fractures of extremities.

    PubMed

    Ahn, Joong Mo; El-Khoury, Georges Y

    2007-05-01

    Recent advances in cross-sectional imaging, particularly in CT and MR imaging, have given these modalities a prominent role in the diagnosis of fractures of the extremities. This article describes the clinical application and imaging features of cross-sectional imaging (CT and MR imaging) in the evaluation of patients who have occult fractures of the extremities. Although CT or MR imaging is not typically required for evaluation of acute fractures, these modalities could be helpful in the evaluation of the occult osseous injuries in which radiographic findings are equivocal or inconclusive.

  8. Scaphoid Proximal Pole Fracture Following Headless Screw Fixation

    PubMed Central

    Rancy, Schneider K.; Zelken, Jonathan A.; Lipman, Joseph D.; Wolfe, Scott W.

    2015-01-01

    Background Headless screw fixation of scaphoid fractures and nonunions yields predictably excellent outcomes with a relatively low complication profile. However, intramedullary implants affect the load to failure and stress distribution within bone and may be implicated in subsequent fracture. Case Description We describe a posttraumatic fracture pattern of the scaphoid proximal pole originating at the previous headless screw insertion site in three young male patients with healed scaphoid nonunions. Each fracture was remarkably similar in shape and size, comprised the volar proximal pole, and was contiguous with the screw entry point. Treatment was challenging but successful in all cases. Literature Review Previous reports have posited that stress-raisers secondary to screw orientation may be implicated in subsequent peri-implant fracture of the femoral neck. Repeat scaphoid fracture after screw fixation has also been reported. However, the shape and locality of secondary fracture have not been described, nor has the potential role of screw fixation in the production of distinct fracture patterns. Clinical Relevance Hand surgeons must be aware of this difficult complication that may follow antegrade headless screw fixation of scaphoid fracture nonunion, and of available treatment strategies. PMID:26855840

  9. Simultaneous fracture of the waist of the scaphoid and the hook of the hamate.

    PubMed

    Komura, Shingo; Suzuki, Yasushi; Ikehata, Tatsuya

    2010-01-01

    A case of simultaneous fracture of the waist of the scaphoid and the hook of the hamate is presented. The scaphoid fracture was treated surgically with a headless compression screw, while the hook fracture was treated conservatively with cast immobilisation for eight weeks. Both fractures achieved bone union and the patient returned to work without any symptoms or complications. Only two cases of fractures of the scaphoid and hamate have been reported previously. However, both of them involved fracture of the body of the hamate. This is the first report of simultaneous fracture of the scaphoid and the hook of the hamate.

  10. SCAPHOID STRESS FRACTURE IN GYMNASTICS ATHLETE: A CASE REPORT.

    PubMed

    Nakamoto, João Carlos; Saito, Mateus; Cunha, Ana Paula; Luques, Isabela Ugo

    2009-01-01

    We present a case report of an 18 year-old gymnast who was diagnosed with a scaphoid stress fracture associated with a distal radial epiphysiolysis, reporting the treatment of choice. After a brief literature review about this rare association, the authors ask for attention concerning the importance of physical and image examination in making right diagnosis and finding associated injuries.

  11. Current concepts for the treatment of acute scaphoid fractures.

    PubMed

    Arsalan-Werner, A; Sauerbier, M; Mehling, I M

    2016-02-01

    Fractures of the scaphoid are common injuries, accounting for approximately 80 % of carpal fractures. Differentiation between stable and unstable fractures (Herbert classification) cannot be made with conventional X-rays, so evaluation by computed tomography should additionally be performed. Under most circumstances, minimally invasive surgery with cannulated screws is the treatment of choice. A longer cast immobilization after minimal-invasive surgery is not necessary. Conservative treatment still has a place if the fracture is not dislocated nor unstable, but operative treatment can be offered to reduce the period of cast immobilization. Displaced fractures have a greater risk for nonunion and therefore should be treated operatively. Proximal pole fractures are definitely unstable, requiring treatment with screw fixation. The surgical approach depends on the location of the fracture and the preference of the surgeon.

  12. Isolated fracture-dislocation of the scaphoid's proximal pole treated by scaphoid internal fixation and scapho-lunate ligament reconstruction.

    PubMed

    Rosati, Marco; Parchi, Paolo; Lisanti, Michele

    2009-05-01

    We present a case of irreducible palmar dislocation of the proximal fragment of a scaphoid fracture without carpal dislocation. We observed this lesion 2 days after the injury and we immediately operated the patient with a combined volar and dorsal access: using the Henry access we reduced the fracture and we inserted a cannulated screw to synthesize the scaphoid, using the dorsal access we repaired the complete rupture of the scapho-lunate ligament using a mini anchor. Stabilization among scaphoid, lunate and capitate was performed using Kirschner wires. X-ray showed fracture healing after 90 days. No clinical or radiographic evidence of carpal instability was revealed, on standard X-rays or on dynamic evaluations. No sign of avascular necrosis or degenerative arthritis was observed after 9 months.

  13. Transtrapezial Approach for Fixation of Acute Scaphoid Fractures: Rationale, Surgical Techniques, and Results: AAOS Exhibit Selection.

    PubMed

    Verstreken, Frederik; Meermans, Geert

    2015-05-20

    The ideal position for a screw used for scaphoid fixation is central. The purpose of this study was to compare the current volar percutaneous approaches used for scaphoid fracture fixation, explore different options to improve central screw placement, and describe our experience with the transtrapezial approach.

  14. Scaphoid Fracture in a Patient with a Scaphotrapezial Synostosis: A Case Report and Literature Review

    PubMed Central

    Ali, Mohammed; Fallahi, Farshid; Dehler, Thomas

    2017-01-01

    Introduction. Scaphotrapezial synostosis has been rarely reported in the literature and only one case underwent surgical treatment for scaphoid fracture. Presentation of Case. A 15-year-old male presented with a painful left wrist following a fall. The initial radiographs showed a displaced scaphoid proximal pole fracture and a Scaphotrapezial synostosis. The fracture was then fixed percutaneously with satisfactory outcome. Discussion. Scaphotrapezial synostoses are very rare and most found in patients with multiple congenital anomalies or as part of a hereditary syndrome. They have previously been reported; however, we found only one case reporting a concomitant scaphoid fracture. Conclusion. This is the second case of its kind to report surgical treatment of scaphoid fracture associated with a congenital Scaphotrapezial synostosis. PMID:28197353

  15. Retrospective review of 234 scaphoid fractures and nonunions treated with arthroscopy for union and complications.

    PubMed

    Slade, J F; Gillon, T

    2008-01-01

    The purpose of this paper is to retrospectively review 234 consecutive cases of scaphoid fractures and nonunions treated using arthroscopy with the dorsal percutaneous implantation of a headless compression screw for healing and complications. Solid union of fracture is determined by CT scan. We identified 126 acute injuries, including 65 proximal pole fractures; 67 grossly displaced fractures; 12 trans-scaphoid perilunate dislocations including four trans-scaphoid trans-capitate fractures; and ten combined scaphoid and distal radius fractures. 108 scaphoid nonunions were identified. 98 were correctly aligned and ten had a humpback deformity which was correctable using arthroscopic assisted reduction techniques at the time of surgery. 82 presented with a fracture gap 2mm or greater requiring percutaneous bone grafting. 12 cases of avascular necrosis (AVN) were identified by MRI. 20 nonunions had surgery performed at other institutions. The mean time to surgery for the nonunions was 20 months. 99% union rate of acute scaphoid fractures was obtained by 12 weeks, as determined by CT scan. Two complications were identified (3%). One case of delayed healing was identified. this delayed union was treated with percutaneous bone grafting and continued on to heal uneventfully. The other complication was a case of volar trans-scaphoid peri-lunate dislocation. While the fracture healed, the patient developed a traumatic dislocation requiring a capitate-lunate arthrodesis. Treatment of scaphoid nonunions resulted in ten cases of delayed healing, which were treated with repeat percutaneous bone grafting. This represented a 9% complication rate. of the ten cases of delayed unions that were re-bone grafted, four failed to heal by nine months. This resulted in a 96% union rate of our nonunion group by nine months. when acute fracture healing was compared to nonunions the average healing of acute fractures as determined by CT scanning measuring trabecular bridging was 12 weeks

  16. Acute coronal plane scaphoid fracture and scapholunate dissociation from an axial load: a case report.

    PubMed

    Shin, Alexander Y; Horton, Todd; Bishop, Allen T

    2005-03-01

    Coronal fractures of the scaphoid are rare and can be difficult to diagnose. Axial load injuries that result in a complete coronal fracture of the scaphoid associated with an acute scapholunate dissociation are exceedingly rare. In our patient the radiographic finding of wide scapholunate dissociation was obvious; however, the coronal scaphoid fracture was not recognized initially nor suspected. During surgery the coronal scaphoid fracture was identified, reduced anatomically, and fixed with a compression screw. The scapholunate ligament also was repaired. A good result was obtained with return to sports with extension of 60 degrees and flexion of 70 degrees , grip strength equal to that of the uninjured wrist, and no radiographic problems (arthrosis, avascular necrosis, nonunion).

  17. Trans-scaphoid perilunate dislocation with fractured carpal bones in a child.

    PubMed

    Ji, J-H; Shafi, M; Moon, C-Y; Park, S-E

    2010-02-01

    Transcarpal fractures and dislocations in children are rarely reported in the orthopedics literature. This is a report of a 10-year-old boy who sustained a trans-scaphoid perilunate dislocation with fractures across the carpal structure: these included injuries to the scaphoid, capitate and triquetrum bones. Treatment consisted in a closed reduction for the dislocation and using the dorsal approach of an open reduction with internal fixation of the fractures. The injury healed well with a full return of good wrist function. This unusual pattern of injury is described so that it may be more readily appreciated in the future.

  18. [Concomitant fractures of the radius and scaphoid with an elbow dislocation].

    PubMed

    El Andaloussi, Y; Bendriss, A; Bennouna, D; Ouarab, M

    2008-09-01

    A variety of associated injuries of the upper limb have been described in the literature. The authors report a case of bifocal fracture of the radius and a scaphoid fracture together with elbow dislocation. In our knowledge, this association of lesions has never previously been described.

  19. Incorrect radiographic evaluation after vascularized bone grafting for scaphoid fracture or nonunion

    PubMed Central

    Morin, Paul; Reindl, Rudy; Berry, Gregory K; Harvey, Edward J

    2011-01-01

    PURPOSE: The present study is a review of patients with scaphoid non-unions treated with a dorsal vascularized bone graft. The study highlights a subset of patients incorrectly diagnosed as graft failures. METHODS: A retrospective review of patients who received vascularized grafts for scaphoid nonunions was performed over a four-year period. The vascularized graft of choice for this group was the dorsal radial extensor compartment artery. RESULTS: Five patients from a scaphoid fracture group who were treated with vascularized grafts were diagnosed as being failures (average of five months). None of these patients had tenderness on palpation of the scaphoid, and they were scheduled for revised vascularized grafts. All patients at the time of surgery were found to have healed. These patients were treated with arthrolysis, resulting in healing and full range of motion. CONCLUSIONS: Scaphoid vascularized grafts may have a markedly delayed radiographic healing time. Reoperation to perform secondary vascularized procedures may result in unnecessary surgery. Early imaging following a scaphoid vascularized graft may be inaccurate and may demonstrate a continued nonunion. PMID:22379374

  20. Scaphoid fracture fixation: localization of bones through statistical model to ultrasound registration

    NASA Astrophysics Data System (ADS)

    Anas, Emran Mohammad Abu; Rasoulian, Abtin; St. John, Paul; Pichora, David; Mousavi, Parvin; Lessoway, Victoria A.; Seitel, Alexander; Hacihaliloglu, Ilker; Rohling, Robert; Abolmaesumi, Purang

    2015-03-01

    Percutaneous treatment of scaphoid fractures has found increasing interest in recent years as it promises to minimize soft-tissue damage, and minimizes the risk of infections and the loss of the joint stability. However, as this procedure is mostly performed on 2D fluoroscopic images, the accurate localization of the scaphoid bone for fracture fixation renders extremely challenging. In this work, we thus propose the integration of a statistical wrist model with 3D intraoperative ultrasound for accurate localization of the scaphoid bone. We utilize a previously developed statistical wrist model and register it to bone surfaces in ultrasound images using a probabilistic approach that involves expectation-maximization. We utilize local phase symmetry to detect features in noisy ultrasound images; in addition, we use shadow information in ultrasound images to enhance and set apart bone from other features. Feasibility experiments are performed by registering the wrist model to 3D ultrasound volumes of two different wrists at two different wrist positions. And the result indicates a potential of the proposed technique for localization of the scaphoid bone in ultrasound images.

  1. The influence of wire positioning upon the initial stability of scaphoid fractures fixed using Kirschner wires A finite element study.

    PubMed

    Ezquerro, F; Jiménez, S; Pérez, A; Prado, M; de Diego, G; Simón, A

    2007-07-01

    A finite element model of the carpal scaphoid and its joints was developed to study how wire positioning affects the initial stability of the fixation of scaphoid waist fractures using Kirschner wires. A transverse fracture of the scaphoid waist was simulated along with its fixation using five different two-wire configurations. The resulting models were subjected to a load simulating a 200N force passing through the wrist. Friction between bony fragments was taken into account; as the friction coefficient of cancellous bone is unknown, three different values were analysed. For each of these friction coefficient values, the smallest transverse interfragmentary displacements, and consequently maximum initial stability, were obtained for the model that simulated the maximum gap between wires in the plane of fracture. Results also show that for a similar gap in the plane of fracture, more stable fixation can be achieved when wires cross each other not only in the frontal plane of the hand, but also perpendicularly to it.

  2. Arthroscopically assisted percutaneous fixation for trans-scaphoid perilunate fracture dislocation.

    PubMed

    Jeon, I-H; Kim, H-J; Min, W-K; Cho, H-S; Kim, P-T

    2010-10-01

    Trans-scaphoid perilunate fracture dislocation is a complex carpal dislocation causing marked disruption of the carpal structures. Open treatment has been accepted as standard for this injury. We have used arthroscopically assisted percutaneous screw fixation and bone grafting to treat this injury in four patients. The functional outcome was good. All patients achieved solid union without nonunion or malunion. The complication and morbidity was relatively low; all patients had proper alignment and there was no evidence of instability or avascular necrosis or midcarpal arthritis.

  3. The Role of Lunate Morphology on Scapholunate Instability and Fracture Location in Patients Treated for Scaphoid Nonunion

    PubMed Central

    Kim, Byoung-Jin; Kovacevic, David; Lee, Young-Min; Seol, Jong-Hwan

    2016-01-01

    Background To determine the association between lunate morphology and the scapholunate instability using radiographic images, and investigate the association between lunate morphology and scaphoid fracture location. Methods Between January 2003 and December 2011, we retrospectively evaluated the plain radiographs and computed tomography (CT) images of 70 patients who underwent surgical intervention for a scaphoid nonunion, in order to determine the association between lunate type (I or II) and scapholunate instability or scaphoid fracture location. We determined the scaphoid fracture location using the fragment ratio and measured the radiolunate angle and capitate-triquetrum (C-T) distance. Results A type II lunate was present in 68.6% (48 of 70 cases). Mean fragment ratio of fracture location was 50.6% in the type II lunate group and 56.2% in the type I lunate group (p = 0.032). Sixteen of the 70 patients had dorsal intercalated segmental instability (DISI) deformities. Nine of 22 cases showed DISI deformity in type I lunate and 7 of 48 cases showed DISI deformity in type II lunate (p = 0.029). However, there were no significant differences between the presence of DISI deformity and fracture location (p = 0.15). Morphologic comparisons by both plain radiography and CT indicated a mean C-T distance in the type I lunate group (22 cases) of 2.3 mm and 5.0 mm in the type II lunate group (48 cases). The C-T distances were significantly correlated with lunate morphology (p = 0.001). Conclusions A type II lunate was associated with low incidence of DISI deformity and proximal location of fracture in patients presenting with a scaphoid nonunion. PMID:27247743

  4. Bone scanning in the detection of occult fractures

    SciTech Connect

    Batillas, J.; Vasilas, A.; Pizzi, W.F.; Gokcebay, T.

    1981-07-01

    The potential role of bone scanning in the early detection of occult fractures following acute trauma was investigated. Technetium 99m pyrophosphate bone scans were obtained in patients with major clinical findings and negative or equivocal roentgenograms following trauma. Bone scanning facilitated the prompt diagnosis of occult fractures in the hip, knee, wrist, ribs and costochondral junctions, sternum, vertebrae, sacrum, and coccyx. Several illustrative cases are presented. Roentgenographic confirmation occurred following a delay of days to weeks and, in some instances, the roentgenographic findings were subtle and could be easily overlooked. This study demonstrates bone scanning to be invaluable and definitive in the prompt detection of occult fractures.

  5. Routine Imaging after Operatively Repaired Distal Radius and Scaphoid Fractures: A Survey of Hand Surgeons

    PubMed Central

    Bohl, Daniel D.; Lese, Andrea B.; Patterson, Joseph T.; Grauer, Jonathan N.; Dodds, Seth D.

    2014-01-01

    Background There is currently no standard of care for imaging after hand and upper-extremity procedures, and current imaging practices have not been characterized. Questions/Purposes To characterize current imaging practices and to compare those practices to the best available evidence. Patients and Methods A survey was distributed to attending-level surgeons at a regional hand and upper-extremity surgery conference in the United States in 2013. 40 out of 75 surgeons completed the survey (53%). Results All results are presented for distal radius and scaphoid fractures, respectively. There was a high degree of variability between respondents in the number of radiographic series routinely ordered during follow-up of asymptomatic patients, with the number of series ranging from 1–6 and 1–6. On average, respondents did not order an excessive number of follow-up radiographs for asymptomatic patients, with means (± standard deviations) of 2.6 ± 1.0 and 3.3 ± 1.2 radiographic series. Radiographic series were taken at only 74% and 81% of postoperative visits with asymptomatic patients. Only 10% and 8% of respondents felt it was acceptable medical practice to save costs by ordering postoperative radiographs only when patients are symptomatic. Conclusions Among a sample of 40 fellowship-trained hand surgeons, these findings demonstrate a high degree of variability in number of radiographs obtained after operative repair of distal radius and scaphoid fractures. On average, respondents were relatively efficient with respect to total number of postoperative radiographs ordered. Level of Evidence Diagnostic study, level IV. PMID:25364636

  6. [First results with a resorbable MgYREZr compression screw in unstable scaphoid fractures show extensive bone cysts].

    PubMed

    Meier, Reinhard; Panzica, Martin

    2017-03-08

    Osteosynthesis with headless compression screws is an established treatment option for unstable scaphoid fractures. Common implants are made of titanium alloy or steel and usually remain in place. Due to implant density and ferromagnetic properties, artefacts are common in postoperative imaging procedures, e.g. MRI. Now resorbable implants made of magnesium alloy (MgYREZr) have become available. They have biomechanical properties equivalent to human bone and may be used as an alternative to the nonresorbable screw systems.5 patients with acute scaphoid fractures were treated with a double-threaded screw made of MgYREZr. The fractures included three type A2 fractures, one type B2 fracture, and one type B3 fracture. All patients underwent clinical and radiological follow-up postoperatively, 6 weeks, 3 and 6 months and 1 year after surgery. ROM, gross grip strength and pain (VAS) were documented. The Modified Mayo Wrist Score was used. Standard X-rays of the wrist were taken preoperatively and at all follow-up visits. A CT scan was performed at least before and three months after surgery. In all X-rays malunion, resorption of the implant, implant loosening, cysts and bone healing (bridging trabecular structures) were described.All patients had a very good wrist score (95-100 points) after one year. There were no clinical complications. However, the X-rays revealed extensive resorption cysts in 3 out of the 5 patients. It was only after 6 months that the fractures were consolidated enough to allow physical work. Due to this considerable osteolysis, we did not include any further patients. Due to the observed extensive bone cysts and the long time period for bone healing, MgYREZr compression screws are currently not recommended for clinical use in scaphoid fractures. Further fundamental research is necessary.

  7. Is Casting for Non-Displaced Simple Scaphoid Waist Fracture Effective? A CT Based Assessment of Union

    PubMed Central

    Grewal, Ruby; Suh, Nina; MacDermid, Joy C.

    2016-01-01

    Objective: The purpose of this study is to report the union rate and time to union for acute non-displaced scaphoid waist fractures treated with a short arm thumb spica cast. Methods: A database was searched (2006-2013) to identify acute undisplaced scaphoid waist fractures. Cases that were not given a trial of casting were excluded (n=33). X-rays, CT scans and health records for each patient were reviewed to extract data. Results: 172 patients met inclusion criteria. There were 138 males, 34 females, the mean age was 30 ± 16 years. The union rate was 99.4% (1 nonunion/172 subjects). The mean time to union was approximately 7.5 weeks (53 ± 37 days). Energy of injury, age or gender did not affect union rates or time to union. Cysts did not affect the union rate (p=0.73) but patients with cystic resorption along the fracture line required approximately 10 weeks for union (69 ± 60 days) compared to 7 weeks (51 ± 34 days) for those without cysts (p=0.05). Diabetes did not affect the union rate (p=0.81) but was found to increase the risk of delayed union (p=0.05). There was a weak, but statistically significant correlation between the number of days before the fracture was casted and the length of time needed to achieve union (r=0.27, p=0.001). Conclusion: Non-displaced scaphoid waist fractures have a high healing rate with appropriate identification and immobilization. Follow-up CT scans to assess healing can identify union within a shorter time frame (~7 weeks) than previously reported in the literature. PMID:27708739

  8. Reconstruction of Scaphoid Nonunion Fractures of the Proximal One Third With a Vascularized Bone Graft From the Distal Radius

    PubMed Central

    Jaminet, Patrick; Naegele, Beate; Pfau, Matthias; Schaller, Hans-Eberhard

    2014-01-01

    Objective: The treatment of proximal located scaphoid nonunion is a well-known and common problem. For these patients, we used a vascular pedicled bone graft of the distal radius. Methods: In the last 7 years, 75 patients were treated with the vascular pedicled bone graft. Retrospectively, patients’ data, healing rates, and factors influencing scaphoid healing were analyzed. Results: The overall healing rate in cases with proximal located nonunions (n = 54) was approximately 70%. Out of these 54 patients, 47 patients showed avascular proximal fragments. Multivariate analysis showed no significant impact for the factors age, smoking, duration of disease, or previous operation. Conclusions: In our negative selected patient group, we were able to achieve good results with the usage of a pedicled vascularized bone graft of the distal radius. Our results indicate a favorable outcome for the use of a pedicled vascularized distal radius bone graft in both scaphoid nonunion fractures of the proximal third, with or without an avascular proximal pole. PMID:25165493

  9. The validity of investigating occult hip fractures using multidetector CT

    PubMed Central

    Williams, Huw L M; Carpenter, Eleanor C; Lyons, Kathleen

    2016-01-01

    Objective: 10% of all hip fractures are occult on plain radiography, requiring further investigation to ascertain the diagnosis. MRI is presently the gold standard investigation, but frequently has disadvantages of time delay, resulting in increased hospital stay and mortality. Our aim was to establish whether multidetector CT (MDCT) is an appropriate first-line investigation of occult femoral neck (NOF) fractures. Methods: From 2013, we elected to use MDCT as the first-line investigation in patients believed to have an NOF fracture with negative plain films. These were reported by consultant musculoskeletal radiologists. We retrospectively analysed the data of consecutive patients presenting to the University Hospital of Wales, over 30 months with a clinical suspicion of a hip fracture. Results: 1443 patients were admitted during the study period. 209 (14.5%) patients had negative plain films requiring further investigation to exclude an NOF fracture, of which 199 patients had a CT. 93 patients had no fracture and 20 patients had isolated greater trochanter fractures. None of these patients progressed to develop an intracapsular femoral neck fracture at 4-month follow-up, although one patient sustained an extracapsular fracture following a high-energy fall whilst admitted. 26 femoral neck fractures were diagnosed on CT, whilst the remaining 60 patients were diagnosed with other pelvic ring fractures. Conclusion: When interpreted by experienced radiologists, MDCT has both sensitivity and specificity of 100%. Advances in knowledge: We recommend the use of MDCT as a safe and appropriate first-line investigation for NOF fractures. PMID:26838948

  10. Low-Intensity Pulsed Ultrasound Treatment for Scaphoid Fracture Nonunions in Adolescents

    PubMed Central

    Carlson, Erik J.; Save, Ameya V.; Slade, Joseph F.; Dodds, Seth D.

    2015-01-01

    Background Treatment of scaphoid nonunion is challenging, leading clinicians to pursue innovation in surgical technique and adjunctive therapies to improve union rates. Purpose The purpose of this study was to investigate the use of low-intensity pulsed ultrasound as an adjunctive treatment modality following surgical treatment of scaphoid nonunion in adolescent patients, for whom this therapy has not yet been FDA-approved. Patients and Methods We performed a retrospective review of adolescent patients with scaphoid nonunion treated surgically followed by adjunctive low-intensity pulsed ultrasound therapy. All patients underwent 20 minutes of daily ultrasound therapy postoperatively until there was evidence of bony healing, based on both clinical and radiographic criteria. Final healing was confirmed by > 50% bone bridging on CT scan. Results Thirteen of fourteen (93%) patients healed at a mean interval of 113 days (range 61–217 days). There were no surgical or postoperative complications. One patient developed heterotopic bone formation about the scaphoid. Conclusions Our study suggests that low-intensity pulsed ultrasound therapy can safely be utilized as an adjunctive modality in adolescents to augment scaphoid healing following surgical intervention. Level of Evidence Level IV, Case series PMID:25945296

  11. Investigating the Effect of Intra-articular Platelet-Rich Plasma Injection on Union: Pain and Function Improvement in Patients with Scaphoid Fracture.

    PubMed

    Namazi, Hamid; Kayedi, Toomaj

    2016-12-01

    Introduction Fracture of the scaphoid bone is the most common fracture of the carpus. However, the fracture union occurs late or may not heal. Sometimes, fracture healing requires prolong immobilization. Because of potential for joint stiffness, muscle atrophy, or the inability to use the hand during and after prolonged immobilization, there is great incentive to develop therapies that will accelerate bone healing and allow a quick return to work. To date, the effect of platelet-rich plasma (PRP) on scaphoid fracture has not been studied. We aimed to assess the effect of intra-articular PRP injection on union: pain, range of motion, and function in patients with scaphoid fracture. Hypothesis Union: pain reduction and functional improvement can be noticed after PRP use in scaphoid fracture. Materials and Methods A randomized controlled trial was designed with 14 patients with scaphoid fractures (Herbert type B2). Casting was done for them. Seven patients received intra-articular autologous PRP. Patients were followed up 2 weeks after casting using radiography and then at 2 months using radiography and computed tomography (CT) scan to check bone healing. Then patients were followed up for 3 and 6 months and after evaluation of healing by CT scan, the patient-rated wrist evaluation questionnaire was completed and the range of motion of the wrist was measured. Results Analysis revealed significant improvement in pain at rest, as well as during specific and usual activities following PRP injection in the case group. However, no statistically significant difference in wrist motion including radial and ulnar deviation, flexion, and extension was found in 6 months follow-up except some improvement in ulnar deviation after 3 months. However, this study showed that scaphoid union occurred earlier in the case group, but it was not statistically significant. Conclusion PRP may have a significant effect on pain reduction at rest and amount of difficulty in functions

  12. Impact of Different Screw Designs on Durability of Fracture Fixation: In Vitro Study with Cyclic Loading of Scaphoid Bones

    PubMed Central

    Gruszka, Dominik; Herr, Robert; Hely, Hans; Hofmann, Peer; Klitscher, Daniela; Hofmann, Alexander; Rommens, Pol Maria

    2016-01-01

    Purpose The use of new headless compression screws (HCSs) for scaphoid fixation is growing, but the nonunion rate has remained constant. The aim of this study was to compare the stability of fixation resulting from four modern HCSs using a simulated fracture model to determine the optimal screw design(s). Methods We tested 40 fresh-frozen cadaver scaphoids treated with the Acumed Acutrak 2 mini (AA), the KLS Martin HBS2 midi (MH), the Stryker TwinFix (ST) and the Synthes HCS 3.0 with a long thread (SH). The bones with simulated fractures and implanted screws were loaded uniaxially into flexion for 2000 cycles with a constant bending moment of 800 Nmm. The angulation of the fracture fragments was measured continuously. Data were assessed statistically using the univariate ANOVA test and linear regression analysis, and the significance level was set at p < 0.05. Results The median angulation of bone fragments φ allowed by each screw was 0.89° for AA, 1.12° for ST, 1.44° for SH and 2.36° for MH. With regards to linear regression, the most reliable curve was achieved by MH, with a coefficient of determination of R2 = 0.827. This was followed by AA (R2 = 0.354), SH (R2 = 0.247) and ST (R2 = 0.019). Data assessed using an adapted ANOVA model showed no statistically significant difference (p = 0.291) between the screws. Conclusions The continuous development of HCSs has resulted in very comparable implants, and thus, at this time, other factors, such as surgeons’ experience, ease of handling and price, should be taken into consideration. PMID:26741807

  13. Prevalence and clinical significance of occult fractures in children with radiograph-negative acute ankle injury

    PubMed Central

    Najaf-Zadeh, Abolfazl; Nectoux, Eric; Dubos, François; Happiette, Laurent; Demondion, Xavier; Gnansounou, Magloire; Herbaux, Bernard; Martinot, Alain

    2014-01-01

    Background and purpose Plain radiographs may fail to reveal an ankle fracture in children because of developmental and anatomical characteristics. In this systematic review and meta- analysis, we estimated the prevalence of occult fractures in children with acute ankle injuries and clinical suspicion of fracture, and assessed the diagnostic accuracy of ultrasound (US) in the detection of occult fractures. Methods We searched the literature and included studies reporting the prevalence of occult fractures in children with acute ankle injuries and clinical suspicion of fracture. Proportion meta-analysis was performed to calculate the pooled prevalence of occult fractures. For each individual study exploring the US diagnostic accuracy, we calculated US operating characteristics. Results 9 studies (involving 187 patients) using magnetic resonance imaging (MRI) (n = 5) or late radiographs (n = 4) as reference standard were included, 2 of which also assessed the diagnostic accuracy of US. Out of the 187 children, 41 were found to have an occult fracture. The pooled prevalence of occult fractures was 24% (95% CI: 18–31). The operating characteristics for detection of occult ankle fractures by US ranged in positive likelihood ratio (LR) from 9 to 20, and in negative LR from 0.04 to 0.08. Interpretation A substantial proportion of fractures may be overlooked on plain radiographs in children with acute ankle injuries and clinical suspicion of fracture. US appears to be a promising method for detection of ankle fractures in such children when plain radiographs are negative. PMID:24875057

  14. Occult fractures of the greater tuberosity of the humerus.

    PubMed

    Gumina, S; Carbone, S; Postacchini, F

    2009-02-01

    We studied the highest reported number of patients with occult fracture of the greater tuberosity of the humerus and we analysed why fracture was not diagnosed, shoulder function and prevalence of eventually associated rotator cuff tear (RCT). Twenty-four patients with a missed fracture of the greater tuberosity underwent MR study for a suspect RCT. We evaluated shoulder function and self-assessed comfort with the Constant score (CS) and Simple Shoulder Test (SST). Nine patients showed evidence of cuff tendinosis, 11 of partial (p) RCT (2: subscapularis; 6: supraspinatus and 3: supraspinatus and infraspinatus). All patients with pRCT were older than 40. Initially, the mean CS and SST were 54% and 5/12; at follow-up, values increased to 36% and 5 points. MR should be performed in patients apparently negative for fracture but with painful shoulders and decreased ROM. Of our patients, 45.8% had pRCT; nevertheless function recovery was verified in 16 weeks.

  15. Treatment of delayed/nonunion of scaphoid waist with Synthes cannulated scaphoid screw and bone graft.

    PubMed

    Inaparthy, P K; Nicholl, J E

    2008-12-01

    Fracture of the scaphoid bone is the most common fracture of the carpus, and frequently, diagnosis is delayed. The unique anatomy and blood supply of the scaphoid itself predisposes to delayed union or nonunion. The Synthes scaphoid screw is a cannulated headed screw, which provides superior compression compared with some other devices used to internally fix scaphoid nonunions. Our aim was to conduct a retrospective study looking at the union rate, time to union, and complications and correlating the outcome of treatment against the delay between injury and surgery and location of the fracture within the bone. This study is a review of a cohort of 30 patients treated with a cannulated Synthes scaphoid screw and corticocancellous bone grafting for scaphoid waist delayed union and nonunion at our center. We achieved 86% overall union rate. The patients with delayed union achieved a 100% union rate. Three out of four patients with persistent nonunion after surgery reported no pain and improved function. The failure rate was 75% in patients who had sustained their fracture more than 5 years previously. Our study demonstrates that delayed union of scaphoid waist fractures and scaphoid waist nonunions present for less than 5 years can be successfully treated by fracture compression and bone grafting.

  16. Treatment of Delayed/Nonunion of Scaphoid Waist with Synthes Cannulated Scaphoid Screw and Bone Graft

    PubMed Central

    Nicholl, J. E.

    2008-01-01

    Fracture of the scaphoid bone is the most common fracture of the carpus, and frequently, diagnosis is delayed. The unique anatomy and blood supply of the scaphoid itself predisposes to delayed union or nonunion. The Synthes scaphoid screw is a cannulated headed screw, which provides superior compression compared with some other devices used to internally fix scaphoid nonunions. Our aim was to conduct a retrospective study looking at the union rate, time to union, and complications and correlating the outcome of treatment against the delay between injury and surgery and location of the fracture within the bone. This study is a review of a cohort of 30 patients treated with a cannulated Synthes scaphoid screw and corticocancellous bone grafting for scaphoid waist delayed union and nonunion at our center. We achieved 86% overall union rate. The patients with delayed union achieved a 100% union rate. Three out of four patients with persistent nonunion after surgery reported no pain and improved function. The failure rate was 75% in patients who had sustained their fracture more than 5 years previously. Our study demonstrates that delayed union of scaphoid waist fractures and scaphoid waist nonunions present for less than 5 years can be successfully treated by fracture compression and bone grafting. PMID:18780015

  17. Prevalence of exclusively and concomitant pelvic fractures at magnetic resonance imaging of suspect and occult hip fractures.

    PubMed

    Collin, David; Geijer, Mats; Göthlin, Jan H

    2016-02-01

    Pelvic fractures may occur together with hip fractures as a result of low energy trauma. It is unclear whether they do require special attention. There are conflicting results in the literature about the prevalence of both concomitant hip and pelvic fractures as well as exclusive pelvic fractures. It has been reported that hip fractures and obturator ring fractures are mutually exclusive. To retrospectively analyze the prevalence of exclusively pelvic as well as concomitant hip and pelvic fractures in patients examined with MRI after low-energy trauma in elderly. During 9 years, 316 elderly patients had been examined with MRI for suspected or occult hip fracture after a fall. A fracture was diagnosed when MRI showed focal signal abnormalities in the subcortical bone marrow, with or without disruption of adjacent cortices. One observer reviewed all studies. A second observer verified all studies with hip fractures. Follow-up was available for all but two patients that died prior to hip surgery. The prevalence of concomitant pelvic and femoral neck or trochanteric fractures was statistically compared using chi-squared test for categorical variables. Hip fractures were found in 161 (51 %) patients of which 29 (9 %) had concomitant pelvic fractures. There were exclusively pelvic fractures in 82 (26 %) patients of which 65 (79 %) were on the traumatized side only. In 73 patients, there were no fractures. Occult or suspected hip fractures are not infrequently associated with pelvic fractures. Exclusively pelvic fractures are not uncommon.

  18. Absorbable scaphoid screw development: a comparative study on biomechanics

    PubMed Central

    Wang, Yi; Song, Muguo; Xu, Yongqing; He, Xiaoqing; Zhu, YueLiang

    2016-01-01

    Background The scaphoid is critical for maintaining the stability and movement of the wrist joints. This study aimed to develop a new internal fixator absorbable scaphoid screw (ASS) for fixation of the scaphoid waist after fracture and to test the biomechanical characteristics of ASS. Materials and methods An ASS was prepared using polylactic acids and designed based on scaphoid measurements and anatomic features. Twenty fractured scaphoid waist specimens were randomly divided into experimental and control groups (n=10/group). Reduction and internal fixation of the scaphoid were achieved with either Kirschner wires (K-wires) or ASS. A moving target simulator was used to test palmar flexion and dorsal extension, with the range of testing (waist movement) set from 5° of palmar flexion to 25° of dorsal extension. Flexion and extension were repeated 2,000 times for each specimen. Fracture gap displacements were measured with a computerized tomography scanning. Scaphoid tensile and bending strengths were measured by using a hydraulic pressure biomechanical system. Results Prior to biomechanical fatigue testing, fracture gap displacements were 0.16±0.02 mm and 0.22±0.02 mm in the ASS and K-wire groups, respectively. After fatigue testing, fracture gap displacements in the ASS and the K-wire groups were 0.21±0.03 mm and 1.52±0.07 mm, respectively. The tensile strengths for the ASS and K-wire groups were 0.95±0.02 MPa and 0.63±0.02 MPa, respectively. Conclusion Fixation using an ASS provided sufficient mechanical support for the scaphoid after fracture. PMID:27217756

  19. Neglected isolated scaphoid dislocation

    PubMed Central

    Baek, Jong-Ryoon; Cho, Seung Hyun; Lee, Yong Seuk; Roh, Young Hak

    2016-01-01

    The authors present a case of isolated scaphoid dislocation in a 40-year-old male that was undiagnosed for 2 months. The patient was treated by open reduction, Kirschner wire fixation, interosseous ligament repair using a suture anchor and Blatt's dorsal capsulodesis. At 6 years followup, his radiographs of wrist showed a normal carpal alignment with a scapholunate gap of 3 mm and no evidence of avascular necrosis (AVN) of the scaphoid. PMID:27904228

  20. The effects of Scaphoid and Colles casts on hand function.

    PubMed

    Karantana, A; Downs-Wheeler, M J; Webb, K; Pearce, C A; Johnson, A; Bannister, G C

    2006-08-01

    Although necessary for bone healing, immobilisation temporarily prevents hand function and may necessitate corrective physiotherapy later. Scaphoid and Colles casts are both commonly used to immobilize scaphoid fractures. Non-union rates are comparable with both casts. The Scaphoid cast incorporates the thumb, whereas the Colles cast leaves the thumb free. We compared the effect of the two casts on hand function in 20 healthy right-hand-dominant volunteers using the Jebsen-Taylor Hand Function Test. Data were obtained through a mixed between and within subject design. Both casts prolonged the time taken to complete the hand function test compared to controls. Testing in the Scaphoid cast took significantly longer than in the Colles cast.

  1. Occult posterolateral rotatory dislocation of the elbow with olecranon fracture in a child: a case report

    PubMed Central

    2012-01-01

    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. PMID:22943424

  2. Avascular necrosis of the scaphoid after three-ligament tenodesis for scapholunate dissociation: case report.

    PubMed

    De Smet, Luc; Sciot, Raf; Degreef, Ilse

    2011-04-01

    An unusual complication after tenodesis for scapholunate instability (Brunelli's technique) is described. More than 1 year after the procedure, a fracture of the scaphoid with collapse was observed. Further examination concluded there was avascular necrosis of the scaphoid. The patient was treated with a proximal row carpectomy.

  3. Sonography of Occult Rib and Costal Cartilage Fractures: A Case Series

    PubMed Central

    Mattox, Ross; Reckelhoff, Kenneth E.; Welk, Aaron B.; Kettner, Norman W.

    2014-01-01

    Objective 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. Clinical features 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. Intervention and outcomes 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. Conclusion 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. PMID:25685124

  4. Added value of interpreter experience in occult and suspect hip fractures: a retrospective analysis of 254 patients.

    PubMed

    Collin, David; Göthlin, Jan H; Nilsson, Martin; Hellström, Mikael; Geijer, Mats

    2016-06-01

    The influence of experience in categorizing suspect and occult fractures on radiography compared to MRI and clinical outcome has not been studied. The aim of this study is to evaluate the importance of experience in diagnosing normal or suspect hip radiographs compared to MRI. Primarily reported normal or suspect radiography in 254 patients with low-energy hip trauma and subsequent MRI was re-evaluated by two experienced reviewers. Primary readings and review were compared. The prevalence of fractures among normal and suspect radiographic studies was assessed. Clinical outcome was used as reference. At review of radiography, 44 fractures (17 %) were found. Significantly more fractures were found among suspect cases than among normal cases. At MRI, all 44 fractures were confirmed, and further 64 fractures were detected (25 %). MRI detected all fractures with no missed fractures revealed at follow-up. There were a significantly higher proportion of fractures at MRI among the suspect radiographic diagnoses for both the primary report and at review than among occult cases. The more experienced reviewers classified radiography examinations with higher accuracy than primary reporting general radiologists. There was almost complete agreement on MRI diagnoses.

  5. PSEUDARTHROSIS OF THE SCAPHOID IN IMMATURE SKELETONS

    PubMed Central

    de Lemos, Marcelo Barreto; Bentes, Ádria Simone Ferreira; Neto, Miguel Flores do Amaral; Spinelli, Leandro de Freitas; Severo, Antônio Lourenço; Lech, Osvandré

    2015-01-01

    This paper presents a review of the literature on pseudarthrosis of the scaphoid in skeletally immature individuals, taking into consideration its epidemiology, diagnosis and treatment, as well as its controversies. Knowledge of this subject makes it possible for patients to be given appropriate treatment immediately. Pseudarthrosis of the scaphoid in skeletally immature patients is a rare condition that results from error or lack of diagnosis of a fracture. Thus, careful clinical and radiographic examination should be performed in order to confirm or rule out this diagnosis. Several treatment methods have been reported and have shown good results. These include conservative plaster cast treatment, bone graft without osteosynthesis, bone graft with Kirschner wires, percutaneous screws and bone graft with compression screws. The treatment performed depends on the characteristics of the pseudarthrosis and the surgeon's experience. PMID:27042636

  6. Ultrasound Diagnosis of Either an Occult or Missed Fracture of an Extremity in Pediatric-Aged Children

    PubMed Central

    Lee, Sung-Moon; Lee, Young-Hwan; Suh, Kyung-Jin

    2010-01-01

    Objective To report and assess the usefulness of ultrasound (US) findings for occult fractures of growing bones. Materials and Methods 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. Results 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. Conclusion 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. PMID:20046499

  7. Calcaneo-Scaphoid Coalition.

    PubMed

    Seddon, H J

    1933-02-01

    Calcaneo-scaphoid coalition occurs in a number of forms, having one feature in common, namely, a skeletal abnormality of the calcaneo-scaphoid gap. The condition is congenital, but nothing is known of its causation. Ranking at first as merely an anatomical curiosity, it was later recognized to be frequently associated with spasmodic flat-foot. Probably 25% of all cases of spasmodic flat-foot show this skeletal anomaly in some form or other.Clinically, this variety of spasmodic flat-foot is indistinguishable from the better-known condition in which the bones are apparently normal. Diagnosis made radiographically; essential that an oblique lateral view of the foot should be taken.Causal relation of the condition to peroneal spasm.All the usual forms of treatment employed for the relief of spasmodic flat-foot fail when a calcaneo-scaphoid coalition is present. Resection of the offending bar is of no proven value, but may be worth further trial. If symptoms persist, subastragaloid arthrodesis is necessary.

  8. Anthropometry of the Human Scaphoid Waist by Three-Dimensional Computed Tomography.

    PubMed

    Smith, Jennifer; Hofmeister, Eric P; Renninger, Christopher; Kroonen, Leo T

    2015-01-01

    Published measurements for the scaphoid are scarce. The purpose of this study is to define anthropometric norms for the waist of the scaphoid to assist in optimizing bone graft quantity and implant use. Computed tomography images of the wrist were reviewed by three surgeons. Anthropometric data were gathered, including the scaphoid waist diameter in two dimensions and the scaphoid waist volume. Each study was measured twice, allowing for determination of inter- and intraobserver reliability. Forty-three studies were examined (23 female and 20 male). Average measurements of the scaphoid waist were 11.28 ± 0.26 mm in the sagittal plane and 8.70 ± 0.17 mm in the coronal plane, and the waist volume was 715 ± 33.0 mm3. Specific measures of the narrowest portion of the scaphoid are provided by this study. Measurements of the scaphoid waist through the use of three-dimensional imaging are an accurate method with good inter- and intraobserver reliability. The measurements obtained from this study can be applied to guide graft and implant selection for treatment of scaphoid waist fractures and nonunions.

  9. Transcapho perilunate dislocation with palmar extrusion of the scaphoid proximal pole.

    PubMed

    Marcuzzi, Augusto; Leigheb, Massimiliano

    2016-04-15

    Perilunate fracture-dislocations usually combine ligament ruptures, bone avulsions, and fractures in different patterns. Rarely a displaced fracture of the scaphoid can coexist with a scapho-lunate dissociation and can result in enucleation of the proximal pole. We report about a case of trans-scaphoid perilunate dislocation with palmar extrusion/enucleation of the scaphoid proximal pole, treated with scaphoid fracture open reduction and internal fixation with screw, scapho-lunate ligament repair with an anchor and vascularization of the scaphoid proximal pole with the 2nd intermetacarpal artery. At 52 months follow up we had good clinical and radiographic results. In conclusion, scientific literature including our experience about this rare complex lesion of the wrist is too weak to support an effective strategy of management but we think that the careful analysis of the single problems can be the key to solve the complexity. Goal of the treatment should be complete revascularization and healing of the scaphoid, avoiding non union and avascular necrosis; simultaneously a proper ligament reconstruction is fundamental to re-establish carpal stability. Prevention of carpal collapse for a SNAC o SLAC situation is essential to reach a good level of Quality of Life and satisfaction of the patient.

  10. Rapid prototyping of scaphoid and lunate bones.

    PubMed

    Gittard, Shaun D; Narayan, Roger J; Lusk, Jason; Morel, Pierre; Stockmans, Filip; Ramsey, Michael; Laverde, Claire; Phillips, Jack; Monteiro-Riviere, Nancy A; Ovsianikov, Aleksandr; Chichkov, Boris N

    2009-01-01

    In this study, a novel rapid prototyping technology was used to fabricate scaphoid and lunate bone prostheses, two carpal bones that are prone to avascular necrosis. Carpal prostheses were fabricated with an Envisiontec Perfactory SXGA stereolithography system using Envisiontec eShell 200 photocurable polymer. Fabrication was guided using 3-D models, which were generated using Mimics software (Materialise NV, Leuven, Belgium) from patient computer tomography data. The prostheses were fabricated in a layer-by-layer manner; approximately 50-microm thick layers were observed in the prostheses. Hardness and Young's modulus values of polymerized eShell 200 material were 93.8 +/- 7.25 MPa and 3050 +/- 90 MPa, respectively. The minimum compressive force required for fracture was 1360 N for the scaphoid prosthesis and 1248 N for the lunate prosthesis. Polymerized Envisiontec eShell material exhibited high human neonatal epidermal keratinocyte cell viability rate in an MTT assay. The results of this study indicate that small bone prostheses fabricated by stereolithography using eShell 200 polymer may have suitable geometry, mechanical properties, and cytocompatibility properties for in vivo use.

  11. PSEUDARTHROSIS OF THE TUBERCLE OF THE SCAPHOID BONE IN IMMATURE SKELETON: CASE REPORT

    PubMed Central

    Gomes, Eduardo Amarai; Armanelli, Felipe; Saliba, Gustavo Augusto Matos

    2015-01-01

    The aim of this study was to present a case report on pseudarthrosis of the scaphoid tubercle, a pathological condition that affects the young and active population. This entity often develops as a result of failure to make an early diagnosis and a late start to treatment. This report describes the case of a 15-year-old patient with a history of a neglected fracture of the scaphoid tubercle that occurred one year earlier and evolved to pseudarthrosis of the tubercle, which is an unusual location for this type of complication. The diagnosis was made from the clinical history and radiographic examination. The treatment was undertaken in accordance with the Matti-Russe technique, by means of a volar route, thus avoiding injury to the scaphoid vascularization, with good clinical and radiographic evolution. Pseudarthrosis of the scaphoid tubercle is a rare condition resulting from a fracture in an unusual location in the scaphoid bone, and it is important because it affects the young and active population. The correct diagnosis is only rarely made by radiologists or surgeons at the time of the fracture, because of failure to recognize this entity. This mistake delays and causes difficulty in treatments for the complications resulting from this kind of fracture. Therefore, it is essential to include this condition in differential diagnoses in order to avoid mistaken conduct. The treatment chosen was shown to be an effective option in this specific case. PMID:27047860

  12. Occult fracture of the lesser tuberosity in a 9-year-old female swimmer

    PubMed Central

    Aagaard, KE; Lunsjö, K

    2017-01-01

    The adolescent avulsion of the lesser tuberosity of the humerus has historically been considered as very rare. The youngest patient reported in the literature is 11 years old. We report a case of a 9-year-old girl who suffered a subscapularis tendon tear with an occult avulsion of the lesser tuberosity. Late repair restored function. Despite that late repair in this present case resulted in excellent outcome, we strongly recommend the additional axillary lateral view of the plain radiographs, as well as proper physical examination to facilitate early diagnosis. PMID:28122897

  13. Hip and buttock pain due to occult pelvic fractures: a case report

    PubMed Central

    Goldford, Richard J

    1996-01-01

    Pelvic fractures are a relatively uncommon presentation to a chiropractic office. A case is presented of pelvic fractures following a motor vehicle accident that initially went undetected despite a set of lumbar spine and pelvic radiographs. The condition was only discovered when the patient continued to suffer hip and buttock pain that was not improving in a reasonable period of time. Follow-up radiographs revealed well healing, stable pelvic fractures. The classification of pelvic fractures as well as the importance of a high index of suspicion in dealing with patients who have been involved in motor vehicle accidents is discussed. The importance of obtaining an accurate diagnosis and its relevance to duration of disability is highlighted. ImagesFigure 1Figure 2

  14. KBO Occultation

    NASA Astrophysics Data System (ADS)

    Rijsdijk, C.

    2016-12-01

    A recommendation to astronomers to observe an occultation by the Kuiper Belt Object KBO 2014MU69. Its first predicted stellar occultation, in early June 2017, of a 15th magnitude star, will be visible from Southern Africa.

  15. Bilateral dorsal trans-scaphoid perilunate fracture–dislocation: A case report

    PubMed Central

    Yildirim, Cengiz; Unuvar, Fatih; Keklikci, Kenan; Demirtas, Mehmet

    2014-01-01

    INTRODUCTION Perilunate dislocations represent one of the most devastating injuries to the carpus. Fortunately, these injuries are relatively rare, constituting approximately 10% of all carpal injuries. One of the problems associated with this injury is the difficulty of its accurate and early recognition. PRESENTATION OF CASE In this study, an uncommon case of bilateral dorsal trans-scaphoid perilunate fracture–dislocation following trauma has been reported. The injury was missed initially and the patient was subsequently operated after two weeks. Anatomic reduction was achieved by closed reduction. After closed reduction, percutaneous pin fixation of the carpus was performed using Kirschner wires. Finally, the scaphoid was stabilized with a headless screw percutaneously. The same procedure was repeated for the other wrist. This was followed by an uneventful post-operative period, with a satisfactory functional outcome at the two-year follow-up, despite non-union of the scaphoid in one side. DISCUSSION The case was examined in detail, and compared to the findings in the literature; observations regarding fracture prognosis were also made. Most authors agree that closed reduction is the initial treatment of choice for trans-scaphoid perilunate fracture–dislocations. In addition, treatment often requires intercarpal fixation within the proximal carpal row. CONCLUSION We believe that closed reduction in these cases should be attempted regarding the potential risks of avascular necrosis and non-union of the affected carpal bones due to open reduction. PMID:24705189

  16. Palmar divergent dislocation of scaphoid and lunate.

    PubMed

    Kang, Ho-Jung; Shim, Dong-Joon; Hahn, Soo-Bong; Kang, Eung-Shick

    2003-12-30

    A 28-year-old man presented with a palmar divergent dislocation of the scaphoid and lunate. He was treated with an open reduction and an internal fixation with two Kirschner's wires after the 25th day of trauma due to a neurological injury. The results were satisfactory after 18 months follow up without any evidence of avascular necrosis and traumatic arthritis of the scaphoid and lunate. The patient had no limitation in motion or intermittent wrist pain. We reported this case with a brief review of relevant literatures.

  17. Early active motion protocol following open reduction internal fixation of the scaphoid: A pilot study.

    PubMed

    Dunn, J-C; Kusnezov, N; Fares, A; Buccino, Z; Esquivel, D; Mitchell, J

    2017-02-01

    Scaphoid fractures are common injuries which traditionally have been treated with long periods of immobilization even after open reduction and internal fixation (ORIF). The purpose of this pilot investigation was two-fold: 1) describe a precise postoperative Early Active Motion (EAM) rehabilitation protocol following ORIF of scaphoid fractures and 2) record the outcomes of the EAM protocol. Eight consecutive patients having undergone ORIF of the scaphoid were enrolled in the EAM and followed for a minimum of 1 year. At 12 weeks, Disabilities of the Arm Shoulder and Hand (DASH) score, Mayo Wrist score, and range of motion values were obtained. At 1 year, a telephone survey was conducted and several data points were obtained including DASH and Mayo Wrist score, number of push-ups, satisfaction with surgery and ability to remain on active duty. All 8 patients were male, on active duty, with an average age of 26 years. Two patients used tobacco products and none had major health problems. All patients completed the EAM protocol and obtained CT; all CT exams demonstrated healing at 8 weeks. At 12 weeks postoperatively, the average DASH score was 8.8±16 (range: 0-47.5), Mayo wrist score was 88±10 (range: 75-100) and range of motion nearly symmetrical. At a mean final follow-up of 15.4 months postoperatively, the average DASH score was 1.1±1.7 (Range: 0-4.5), Mayo wrist score was 97.5±4 (range 90-100), average number of push-ups was 57 (40-70) at the prior Army Physical Fitness Test. All patients were satisfied with surgery and all remained on active duty at 1 year. There were no reported complications. The EAM protocol following scaphoid fracture ORIF is safe and effective. The EAM can reliably return patients back to high demand activity earlier than a traditional protocol.

  18. The use of MRI to detect occult fractures of the proximal femur: a study of 102 consecutive cases over a ten-year period.

    PubMed

    Sankey, R A; Turner, J; Lee, J; Healy, J; Gibbons, C E R

    2009-08-01

    An MR scan was performed on all patients who presented to our hospital with a clinical diagnosis of a fracture of the proximal femur, but who had no abnormality on plain radiographs. This was a prospective study of 102 consecutive patients over a ten-year period. There were 98 patients who fulfilled our inclusion criteria, of whom 75 were scanned within 48 hours of admission, with an overall mean time between admission and scanning of 2.4 days (0 to 10). A total of 81 patients (83%) had abnormalities detected on MRI; 23 (23%) required operative management. The use of MRI led to the early diagnosis and treatment of occult hip pathology. We recommend that incomplete intertrochanteric fractures are managed non-operatively with protected weight-bearing. The study illustrates the high incidence of fractures which are not apparent on plain radiographs, and shows that MRI is useful when diagnosing other pathology such as malignancy, which may not be apparent on plain films.

  19. Palmar dislocation of scaphoid and lunate.

    PubMed

    Idrissi, Khalid Koulali; Galiua, Farid

    2011-09-28

    A palmar dislocation of scaphoid and lunate is uncommon. We have found only 19 reported cases in the literature. We reported a simultaneous, divergent dislocation. The closed reduction followed by percutaneous pinning has given a good result without avascular necrosis of any carpal bone.

  20. Herbert screw fixation for scaphoid nonunions. An analysis of factors influencing outcome.

    PubMed

    Inoue, G; Shionoya, K; Kuwahata, Y

    1997-10-01

    A retrospective review of 160 cases of scaphoid nonunion treated by internal fixation using a Herbert screw with bone grafting was conducted at an average followup of 24 months. Definite radiographic union was achieved in 90% of cases. Based on Cooney's clinical scoring system, 80 cases had an excellent result, 37 had a good result, 33 had a fair result, and 10 had a poor result. Failure of union was related to the existence of avascular changes of the proximal fragment, instability of the fracture fragment, the prolonged delay in surgery, and the location of the fracture site. In the united scaphoids, the lengthy period of postoperative immobilization, the existence of osteoarthritis, and the prolonged delay in surgery were significant factors in the patient's functional outcome. Overall, the results do not support the view that a residual flexion deformity of the scaphoid is less likely to yield a satisfactory outcome, although it seems worthwhile to correct excessive angulation at the time of repair to promote an anatomic union, thereby preventing early arthritis. A bone graft with internal fixation using a Herbert screw and a shorter period of immobilization may give a satisfactory functional result when the nonunion is treated before the onset of arthritic changes in the wrist.

  1. The use of the free vascularised bone graft for nonunion of the scaphoid: a systematic review

    PubMed Central

    2014-01-01

    Background Fractures of the scaphoid are well known to be problematic especially when complicated by avascular necrosis, nonunion and carpal collapse. Fixation techniques have involved nonvascularised bone grafting; however, in the presence of avascular necrosis, generally poor union rates (47%) occur as identified by a meta-analysis performed by Merrell et al. The introduction of pedicled vascularised bone grafts showed further improvement; however, in the presence of carpal collapse, union rates as low as 50% have been reported by Chang et al. amongst others using the 1,2-intercompartmental supraretinacular artery pedicled graft. The difficulty lies in having a short pedicle with limited manoeuvrability to correct a humpback deformity and insert into the scaphoid cavity. Prior trauma to the soft tissues or distal radius may prohibit the use of pedicled grafts. The aim of this systematic review is to examine the published evidence for the use of free vascularised bone grafts in cases of scaphoid nonunion. Methods A systematic review was performed with the following defined search strategy on MEDLINE and Google Scholar: ((scaphoid nonunion) OR scaphoid pseudarthrosis) AND bone graft. Articles were reviewed and data compiled into tables for analysis. Statistical analysis was performed with determination of descriptive statistics, and differences between the groups were calculated using categorical variables and chi-square test. A p value of 0.05 or less was considered to be statistically significant. Results Two hundred and sixty-three articles were identified with a total of 12 articles meeting the inclusion criteria. Two hundred and forty-five cases of scaphoid nonunion were identified through the articles included in this systematic review. Fifty-six patients underwent free vascularised bone grafts from the medial femoral condyle with a 100% union rate and correction of humpback deformity, and 188 patients underwent free vascularised bone grafting from the iliac

  2. Treatment of Nonunion of Scaphoid Waist with Ni-Ti Shape-Memory Alloy Connector and Iliac Bone Graft

    NASA Astrophysics Data System (ADS)

    Cao, Lie-Hu; Xu, Shuo-Gui; Wu, Ya-Le; Zhang, Chun-Cai

    2011-07-01

    After fracture, the unique anatomy and blood supply of the scaphoid itself predisposes to nonunion. Scaphoid nonunion presents a formidable challenge to surgeons because of the difficulties for fixation, and the high failure rate after treatment. The Ni-Ti shape-memory alloy can provide compressive stress at the nonunion site, which is the key point for bone healing. Hence, we designed a shape-memory bone connector named arched shape-memory connector (ASC). We conducted a retrospective study looking at the union rate and complications and correlating the outcome of treatment with this device. The study reviewed a cohort of six consecutive patients presenting with scaphoid waist nonunion, who were treated with ASC and iliac cancellous bone grafting at our center from August 2002 to December 2007. The patients with nonunion achieved a 100% union rate. All the patients who achieved union had good pain relief and improved function. Our study demonstrates that scaphoid waist nonunions can be successfully treated by ASC and iliac bone grafting.

  3. Detection of occult, undisplaced hip fractures with a dual-energy CT algorithm targeted to detection of bone marrow edema.

    PubMed

    Reddy, T; McLaughlin, P D; Mallinson, P I; Reagan, A C; Munk, P L; Nicolaou, S; Ouellette, H A

    2015-02-01

    The purpose of this study is to describe our initial clinical experience with dual-energy computed tomography (DECT) virtual non-calcium (VNC) images for the detection of bone marrow (BM) edema in patients with suspected hip fracture following trauma. Twenty-five patients presented to the emergency department at a level 1 trauma center between January 1, 2011 and January 1, 2013 with clinical suspicion of hip fracture and normal radiographs were included. All CT scans were performed on a dual-source, dual-energy CT system. VNC images were generated using prototype software and were compared to regular bone reconstructions by two musculoskeletal radiologists in consensus. Radiological and/or clinical diagnosis of fracture at 30-day follow-up was used as the reference standard. Twenty-one patients were found to have DECT-VNC signs of bone marrow edema. Eighteen of these 21 patients were true positive and three were false positive. A concordant fracture was clearly seen on bone reconstruction images in 15 of the 18 true positive cases. In three cases, DECT-VNC was positive for bone marrow edema where bone reconstruction CT images were negative. Four patients demonstrated no DECT-VNC signs of bone marrow edema: two cases were true negative, two cases were false negative. When compared with the gold standard of hip fracture determined at retrospective follow-up, the sensitivity of DECT-VNC images of the hip was 90 %, specificity was 40 %, positive predictive value was 86 %, and negative predictive value was 50 %. Our initial experience would suggest that DECT-VNC is highly sensitive but poorly specific in the diagnosis of hip fractures in patients with normal radiographs. The value of DECT-VNC primarily lies in its ability to help detect fractures which may be subtle or undetectable on bone reconstruction CT images.

  4. Transstyloid, transscaphoid, transcapitate fracture: a variant of scaphocapitate fractures

    PubMed Central

    Burke, Neil G; Cosgrave, Ciaran H; O'Neill, Barry James; Kelly, Eamonn P

    2014-01-01

    Transstyloid, transscaphoid, transcapitate fractures are uncommon. We report the case of a 28-year-old man who sustained this fracture following direct trauma. The patient was successfully treated by open reduction internal fixation of the scaphoid and proximal capitate fragment, with a good clinical outcome at 1-year follow-up. This pattern is a new variant of scaphocapitate fracture as involves a fracture of the radial styloid as well. PMID:24686808

  5. Nontraumatic osteonecrosis of the distal pole of the scaphoid

    PubMed Central

    Garg, Bhavuk; Gupta, Himanshu; Kotwal, Prakash P

    2011-01-01

    Post traumatic osteonecrosis of distal pole of scaphoid is very rare. We present a case of 34 years old male, drill operator by occupation with nontraumatic osteonecrosis of distal pole of the scaphoid. The patient was managed conservatively and was kept under regular follow-up every three months. The patient was also asked to change his profession. Two years later, the patient had no pain and had mild restriction of wrist movements (less than 15 degrees in either direction). The radiographs revealed normal density of the scaphoid suggesting revascularization. PMID:21430877

  6. Grazing Occultations.

    ERIC Educational Resources Information Center

    Cunningham, Doug; Hlynialuk, John

    1983-01-01

    A "grazing occultation" occurs when a star or other astronomical body is covered up by the extreme northern or southern limb of the moon in its easterly motion about the earth. Graze phenomena, organizing a graze expedition, and the scientific/educational value of observing grazes are among the topics discussed. (JN)

  7. Palmar-divergent dislocation of the scaphoid and the lunate.

    PubMed

    Komura, Shingo; Yokoi, Tatsuo; Suzuki, Yasushi

    2011-03-01

    We describe a patient with palmar-divergent dislocation of the scaphoid and lunate. After successful closed reduction, the scapholunate and lunotriquetral ligaments were sutured through the dorsal approach, and the anterior capsule was sutured through the palmar approach. The scapholunate and lunotriquetral joints were fixed with Kirschner wires for 7 weeks. At the 1-year follow-up, magnetic resonance imaging showed no evidence of avascular necrosis of the scaphoid or lunate, and radiographs showed no evidence of the dorsal and volar intercalated segment instability patterns associated with carpal instability. However, flexion of the scaphoid and a break in Gilula's line remained. To our knowledge, this is the first report showing treatment of palmar-divergent dislocation of the scaphoid and lunate by suturing the carpal interosseous ligaments.

  8. Interfragmentary compression forces of scaphoid screws in a sawbone cylinder model.

    PubMed

    Hausmann, J T; Mayr, W; Unger, E; Benesch, T; Vécsei, V; Gäbler, C

    2007-07-01

    Various screws have been developed to stabilise fractures of the scaphoid. Commonly used are the Herbert, the HBS, the 3-mm AO and the Acutrak screws. Not long ago a new screw, the Twin Fix, was introduced. This is cannulated and similar in shape and appearance to the classical Herbert screw. In our test series we compared the maximum achievable compression forces of the Twin Fix screw with that of three other screws (AO, HBS and Acutrak screws). To avoid the variations of density, stiffness and rigidity in natural bone, a polyurethane sawbone-based test setup was used. The test series included 10 screws of each type. The compression force was measured using a special strain gauge. The mean compression force was significantly higher for the Twin Fix screw (8+/-1N) and the Acutrak screw (7.6+/-0.4/0.6N) in relation to the AO screw (6.8+/-1.0/1.4N) and HBS screw (2+/-1N). We found the Twin Fix and Acutrak screws to be promising in the treatment of scaphoid fractures.

  9. Osteoid osteoma of the scaphoid: magnetic resonance imaging vessel sign.

    PubMed

    Kussman, Steven R; Thompson, Michael; Chang, Eric Y

    2015-01-01

    Osteoid osteomas can be a challenging diagnosis, especially in smaller bones and, particularly, in the carpus. Clinical and imaging diagnosis may both be delayed due to other, more common, post-traumatic or inflammatory pathology in the same area. We present a case of a pathologically proven scaphoid osteoid osteoma with a feeding vessel sign on magnetic resonance imaging, previously described in long bones with computed tomography, as a helpful sign for accurate diagnosis in the scaphoid.

  10. Management of scaphoid nonunion with avascular necrosis using 1,2 intercompartmental supraretinacular arterial bone graft

    PubMed Central

    Dehghani, Mohamad; Soltanmohamadi, Mohamad; Tahririan, Mohammad Ali; Moezi, Mehdi; Daneshpajouhnejad, Parnaz; Zarezadeh, Abolghasem

    2014-01-01

    Background: 1,2 ICSRA, introduced by Aidembery et al., is a well-established technique, with up to 100% union rate among different studies. The purpose of our study was to evaluate the outcome of scaphoid nonunion undergoing 1,2 ICSRA bone graft in Iran. Materials and Methods: All participants who presented sequentially over a period of 24 months between 2010 and 2013 with nonunion scaphoid fracture with AVN in proximal pole were included in the study. Anteroposterior and lateral view plain radiographs of carpal bones were obtained for diagnosis of nonunion, and a diagnosis of avascular necrosis was made by MRI of the scaphoid. Subjects underwent 1,2 ICSRA bone graft surgery. Patients were assessed based on radiographs and the Mayo Wrist Score (MWS) questionnaire on before and after surgery. Data were analyzed using SPSS ver. 18 by paired t test. Results: Overall, 16 patients (100% male) were included in the study. Mean age of subjects was 27.50 ± 5.86 (18 to 38). Mean Mayo score was 36.63 ± 8.92 and 83.75 ± 9.22 before and 6 month after surgery, respectively, and the difference was statistically significant (P < 0.001). after 8 weeks, 10 (62.5%) had union, and after 12 weeks, all subjects had union. Nine (56.25%) of our patients had excellent functional outcome, 5 (31.25%) had good and 2 (12.5%) had satisfactory functional outcome. Conclusion: 1,2 ICSRA is a proper pedicle of vascularized bone graft due to the ease of visibility and dissection. The functional results and union rates were satisfactory in our study. PMID:25250299

  11. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  12. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  13. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  14. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  15. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  16. Proximal Scaphoid Arthroplasty Using the Medial Femoral Trochlea Flap

    PubMed Central

    Higgins, James P.; Burger, Heinze K.

    2013-01-01

    Background The medial trochlea of the femur (medial femoral trochlea, MFT) provides a source of convex osteocartilaginous vascularized bone that has been demonstrated to have a similar contour to the proximal scaphoid. This provides a potential solution for difficult recalcitrant proximal pole scaphoid nonunions. Materials and Methods Sixteen consecutive patients who underwent MFT proximal scaphoid arthroplasty were reviewed. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months. The results of this cohort were previously reported in detail but are summarized herein. Description of Technique The ability to reconstruct both bone and cartilage of the nonunion enables the surgeon to resect the nonunited proximal pole to prepare for scaphoid reconstruction. A segment of osteocartilaginous MFT is harvested in dimensions required by the scaphoid defect. The MFT segment is harvested on the transverse branch of the descending geniculate vessels. Fixation may be achieved with ease due to the size of the reconstructed segment. Results Computed tomography imaging demonstrated 15 of 16 reconstructed scaphoids achieving osseous union. Follow-up range of motion (ROM) of the wrist averaged 46.0° extension (range 28-80°) and 43.8° flexion (range 10-80°), which was similar to preoperative (average 45.7° extension and 43.0° flexion). Scapholunate angles remained unaffected (51.6° preoperatively and 48.6° postoperatively), indicating preservation of carpal relationships. Conclusions Vascularized MFT flaps provide a useful tool in the treatment of difficult proximal pole scaphoid nonunions. Early follow-up demonstrates high rate of achieving union with acceptable ROM and good pain relief. PMID:24436821

  17. [Fracture of the lunate--a rare injury].

    PubMed

    Höcker, K; Renner, J

    1995-09-01

    Fractures of the normal lunate--isolated or associated with fractures of the scaphoid or radius--are very rare. In the Traumatological Hospital Meidling/Vienna, 12 patients with acute fractures of the lunate bone were treated between 1983 and 1993. Dependent on the fracture-line and the intraosseous vascularity, partial or total avascular necrosis of the bone occurs in rare cases. In dislocated pole fractures, surgical intervention is indicated.

  18. In Vivo Kinematics of the Scaphoid, Lunate, Capitate, and Third Metacarpal in Extreme Wrist Flexion and Extension

    PubMed Central

    Rainbow, Michael J; Kamal, Robin N; Leventhal, Evan; Akelman, Edward; Moore, Douglas C; Wolfe, Scott W; Crisco, Joseph J

    2013-01-01

    the extremes of wrist motion, which occur during activities and injuries, and give insight into the possible etiologies of the scaphoid fractures, interosseous ligament injuries, and carpometacarpal bossing. PMID:23266007

  19. Using a tightRope® to treat a complex fracture of the trapezium

    PubMed Central

    Mohan, A; Sarkhel, T

    2014-01-01

    We present the case of a 23-year-old man with a combined scaphoid fracture and comminuted trapezium fracture, treated surgically with percutaneous fixation of the scaphoid fracture and concomitant Arthrex Mini TightRope® stabilisation of base of thumb metacarpal to base of index finger metacarpal. The patient made a good functional recovery, returning to usual activities within six weeks. We suggest that this technique could be used to treat complex trapezium fractures that cannot be reconstructed with surgery. PMID:25245724

  20. Extracorporeal shockwaves versus surgery in the treatment of pseudoarthrosis of the carpal scaphoid.

    PubMed

    Notarnicola, A; Moretti, L; Tafuri, S; Gigliotti, S; Russo, S; Musci, L; Moretti, B

    2010-08-01

    The peculiar anatomical characteristics and precarious vascularization of the carpal scaphoid are responsible for a difficult healing of fractures and a fairly frequent subsequent evolution to pseudoarthrosis. Recently, extracorporeal shockwaves therapy (ESWT) has yielded encouraging results in the treatment of pseudoarthrosis of various bone segments. We report a retrospective study comparing the results of application of three sessions of shockwaves therapy (SW) with energy flux density (EFD) impulses of 0.09 (SD = 0.02) mJ/mm(2) ESWT emitted by an electromagnetic generator in 58 patients (group I) affected by pseudoarthrosis of the carpal scaphoid, with the results of surgical treatment consisting of stabilization and bone graft according to the Matti-Russe technique, performed in 60 subjects (controls, group II). There were no statistically significant differences in the mean duration of the pseudoarthrosis (p = 0.46), sex distribution (p = 0.41) and mean age at recruitment (p = 0.95) between the two patient groups. Posttreatment clinical-functional assessment, based on the Mayo Wrist Score, showed a significantly improved score, rising from 28-74.6 in group I already after 2 mo (p < 0.001), with 86.3% of the results judged as satisfactory or excellent; in group II the mean score rose from 27.5-74.2 after 2 mo, with 83.4% of the results judged as satisfactory or excellent (p < 0.001). At the same two-months follow-up (FU), radiographic consolidation was shown in 75.9% of patients in group I and 76.7% in group II. These improvements persisted at the subsequent controls at six and 12 mo in both groups. The Mayo Wrist Score and X-rays did not show statistically significant differences at the various FU visits in the two groups (p > 0.05). On the basis of our data, we can conclude that the results of ESWT are comparable with those of surgical stabilization and bone graft in the treatment of scaphoid pseudoarthrosis. In view of their minimal invasiveness, shockwaves

  1. Pediatric Scaphoid Proximal Pole Nonunion With Avascular Necrosis.

    PubMed

    Jernigan, Edward W; Smetana, Brandon S; Patterson, J Megan M

    2016-12-24

    A 13-year-old, right hand-dominant, otherwise healthy boy presented with left wrist pain 19 months after a nonmotorized scooter injury. Radiographs and magnetic resonance imaging at presentation demonstrated proximal pole scaphoid nonunion with avascular necrosis of the proximal fragment. Operative and nonsurgical treatment options were discussed and the family elected for an attempt at nonsurgical management. The patient was placed in a short-arm thumb spica cast, with a window for a bone stimulator, for 14 weeks. At the conclusion of the treatment, the pain had resolved and x-ray and computed tomography scan demonstrated bony union. The authors recommend considering an initial trial of nonsurgical management for treatment of all pediatric scaphoid nonunions.

  2. Coexisting avascular necrosis of the scaphoid and lunate.

    PubMed

    Park, Il-Jung; Lee, Sang-Uk; Kim, Hyoung-Min

    2010-11-01

    Reports of coexisting avascular necrosis of more than one carpal bone are rare. We report coexisting avascular necrosis of the scaphoid and lunate in a 56-year-old woman with no history of using steroids or injury. We treated her with a radioscapholunate fusion with two angled 2.4 mm distal radius plates to stabilise the locking plate. At her 12-month follow up there was no evidence of non-union.

  3. Deep shadow occulter

    NASA Technical Reports Server (NTRS)

    Cash, Webster (Inventor)

    2010-01-01

    Methods and apparatus are disclosed for occulting light. The occulter shape suppresses diffraction at any given size or angle and is practical to build because it can be made binary to avoid scatter. Binary structures may be fully opaque or fully transmitting at specific points. The diffraction suppression is spectrally broad so that it may be used with incoherent white light. An occulter may also include substantially opaque inner portion and an at least partially transparent outer portion. Such occulters may be used on the ground to create a deep shadow in a short distance, or may be used in space to suppress starlight and reveal exoplanets.

  4. [Isolated dislocation of the carpal scaphoid. A case report with review of the literature].

    PubMed

    Cherif, M R; Ben Ghozlen, R; Chehimi, A; Annabi, H; Trabelsi, M; Mbarek, M; Ben Hassine, H

    2002-10-01

    Isolated dislocation of the carpal scaphoid is an extremely rare injury, which is usually accompanied by significant ligamento-capsular lesions. A review of the literature found only 21 reported cases. The aim of this report is to present a single case of isolated radio-palmar dislocation of the scaphoid treated conservatively, which provided a good functional result at 10 years follow up.

  5. Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets

    PubMed Central

    Erhart, Jochen; Unger, Ewald; Schefzig, Philip; Varga, Peter; Trulson, Inga; Gormasz, Anna; Trulson, Alexander; Reschl, Martin; Hagmann, Michael; Vecsei, Vilmos; Mayr, Winfried

    2016-01-01

    Background The current standard of care for operative repair of scaphoid fractures involves reduction and internal fixation with a single headless compression screw. However, a compression screw in isolation does not necessarily control rotational stability at a fracture or nonunion site. The single screw provides rotational control through friction and bone interdigitation from compression at the fracture site. We hypothesize that osteosyntheses with novel bone screw sets (BSS) equipped with anti-rotational elements provide improved rotational stability. Methods Stability of osteosynthesis under increasing cyclic torsional loading was investigated on osteotomized cadaveric scaphoids. Two novel prototype BSS, oblique type (BSS-obl.) and longitudinal type (BSS-long.) were compared to three conventional screws: Acutrak2®mini, HCS®3.0 and Twinfix®. Biomechanical tests were performed on scaphoids from single donors in paired comparison and analyzed by balanced incomplete random block design. Loading was increased by 50 mNm increments with 1,000 cycles per torque level and repeated until a rotational clearance of 10°. Primary outcome measure was the number of cycles to 10° clearance, secondary outcome measure was the maximum rotational clearance for each torque level. Findings BSS-obl. performed significantly better than Acutrak2®mini and HCS® (p = 0.015, p<0.0001). BSS-long. performed significantly better than HCS® (p = 0.010). No significant difference in performance between BSS-obl. and BSS-long. (p = 0.361), between BSS obl. and Twinfix® (p = 0.50) and BSS long. and Twinfix® (p = 0.667) was detected. Within the torque range up to 200 mNm, four of 21 (19%) BSS-long. and four of 21 (19%) BSS-obl. preparations showed early failure. The same loading led to early failure in four (29%) Twinfix®, seven (50%) Acutrak2®mini and 10 (71%) HCS® of 14 screw samples, respectively. Conclusions For both BSS and to a lesser extent for Twinfix® (as dual-component screw

  6. Scaphocapitate Fracture: Two Cases with Follow-Up over 5 Years

    PubMed Central

    Dailiana, Zoe H.; Papatheodorou, Loukia K.; Malizos, Konstantinos N.

    2015-01-01

    Background Combined scaphoid and capitate fractures of the wrist are rare entities, and delayed diagnosis is frequent. Scaphocapitate fractures may be associated with reversal of the capitate head 90° or 180° (Fenton syndrome). Different treatment options have been proposed, with variable results. Case Description We report two cases of scaphocapitate fractures of the wrist, diagnosed 3 and 15 days after the injury. The first patient suffered from Fenton syndrome, a combined displaced fracture of the waist of the scaphoid with 180° reversal of capitate head. The second patient had combined fractures of the scaphoid, capitate, and distal radius. In both our cases, anatomic reduction and internal fixation were achieved, resulting in union of all fractures. The long-term results, after 5.5 and 7 years respectively, were very satisfactory, both clinically and radiographically, without signs of avascular necrosis of the head of the capitate or the scaphoid. Literature Review Few reports of scaphocapitate fractures were found in literature. Mechanism of injury, treatment, and outcomes of the reported cases in correlation to our cases are discussed. Clinical Relevance Given the high rate of complications of scaphocapitate fractures, long-term follow-up is important to assess the natural history of the wrist joint after such injuries. The restoration of normal anatomic relationships can lead to a successful long-term functional outcome despite the severity of the injury. PMID:26261742

  7. Fractures

    MedlinePlus

    A fracture is a break, usually in a bone. If the broken bone punctures the skin, it is called an open ... falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the ...

  8. Concomitant avascular necrosis of the scaphoid and lunate.

    PubMed

    Bhardwaj, Praveen; Sharma, Chetna; Sabapathy, S Raja

    2012-01-01

    Simultaneous avascular necrosis of multiple carpal bones is rare. Concomitant avascular necrosis of scaphoid and lunate has been reported only once. We report one more case of this rare condition which can be a cause of wrist pain. Steroid intake is a known risk factor for avascular necrosis but in our case the patient had been taking herbal medicines for joint pain the composition of which was not known. Probably the presence of steroid in these medicines was the cause of avascular necrosis in this case.

  9. Complete dorsal dislocation of the carpal scaphoid with perilunate dorsal dislocation

    PubMed Central

    Kang, Jong Woo; Park, Jong Hoon; Suh, Dong Hun; Park, Jong Woong

    2016-01-01

    Complete dorsal dislocation of the carpal scaphoid combined with dorsal perilunate dislocation is an extremely rare carpal injury. We describe the case of a 23-year-old man who presented with a complete dorsal dislocation of the carpal scaphoid, combined with a perilunate dislocation. Surgical treatment was performed with open reduction and interosseus ligament repair. At 4 years follow up, the patient's wrist pain had completely resolved without limitations of wrist joint motion and without evidence of avascular necrosis of the carpal scaphoid. PMID:27512229

  10. Occulter Starshade Technology Development

    NASA Astrophysics Data System (ADS)

    Lisman, P. D.; Thomson, M.; Kissil, A.; Walkemeyer, P.; Polanco, O.

    2010-10-01

    Imaging Earth-like exoplanets with a free flying occulter requires developing a large, lightweight, flower-shaped, deployable structure with precisely controlled edge position and profile. In-plane tolerance requirements are considerably tighter than heritage antenna systems, but the more difficult to control out-of-plane tolerances are actually much looser. This paper presents a novel occulter mechanical design that delivers the required performance with a highly reliable deployment scheme. A very compact stowed volume is an added benefit that enables launching the occulter together with a 1 to 2m class telescope, using a single, currently available launch vehicle. Demonstrating the petal deployment function and compliance with key tolerance specifications is the focus of current technology efforts. A series of prototype models of increasing fidelity are planned, starting with a proof of concept model that is currently in fabrication. The occulter design and current development status is presented herein.

  11. Occultation by (136199) Eris

    NASA Astrophysics Data System (ADS)

    Jehin, E.; Manfroid, J.; Gillon, M.; Hutsemekers, D.; Magain, P.

    2010-11-01

    E. Jehin, J. Manfroid, M. Gillon, D. Hutsemekers, and P. Magain report that they observed an occultation of a star of magnitude I about 15.2 by the dwarf planet Eris (then at V about 18.7) on Nov. 6 using the new telescope TRAPPIST at the European Southern Observatory (La Silla). A series of 3-s exposures of a field of size 3' x 3' (1".3/pixel) were secured in fast-readout mode (with a deadtime of 1.5 s), starting at 01h50m UT for one hour. Seven frames centered at 02h19m34s UT allowed them to derive the start of the occultation as 02h19m16s.75 +/- 0s.75 and the end as 02h19m47s.6 +/- 0s.2, for a total occultation time of 30.4 +/- 1.0 seconds. The predictions (see above) made by the Rio de Janeiro group (Assafin et al., Nov. 5) and by J. L. Ortiz estimated the time of the occultation around 02h18m UT for Chile, in good agreement with the observations. During the occultation, a point source is detected with a magnitude corresponding to that of Eris. A small flux increase was also seen at the middle of the occultation, which might result from refraction in Eris' atmosphere (Elliot and Olkin 1996, Ann. Rev. Earth Planet. Sci. 24, 89). Eris is by far the most-remote solar-system object observed to date via stellar occultation, with a geocentric distance of about 96 AU. TRAPPIST is a project driven by the University of Liege, in close collaboration with the Observatory of Geneva, supported by the Belgian Fund for Scientific Research and the Swiss National Science Foundation.

  12. Pediatric Hand Fractures

    PubMed Central

    Nellans, Kate W.; Chung, Kevin C.

    2014-01-01

    Summary Pediatric hand fractures are common childhood injuries. Identification of the fractures in the emergency room setting can be challenging owing to the physes and incomplete ossification of the carpus that are not revealed in the xrays. Most simple fractures can be treated with appropriate immobilization through buddy taping, finger splints, or casting. If correctly diagnosed, reduced and immobilized, these fractures usually result in excellent clinical outcomes. However, fractures may require operative stabilization if they have substantial angulation or rotation, extend into the joint, or cannot be held in a reduced position with splinting alone. Most fractures can be treated operatively with closed reduction and percutaneous pinning if addressed within the first week following the injury. In children, the thick, vascular-rich periosteum and bony remodeling potential make anatomic reductions and internal fixation rarely necessary. Most fractures complete bony healing in 3-4 weeks, with the scaphoid being a notable exception. Following immobilization, children rarely develop hand stiffness and formal occupational therapy is usually not necessary. Despite the high potential for excellent outcomes in pediatric hand fractures, some fractures remain difficult to diagnose and treat. PMID:24209954

  13. Occultations, past and future

    NASA Astrophysics Data System (ADS)

    Evans, David S.

    Techniques and limitations of photoelectric observations of occultations are discussed. Methods are described for allowing for fringe effects which arise from real world deviations from a uniform limb, and for using the limb measurements to derive ephemerides for the moon. Procedures employed to identify and separate out the components of multiple star systems are reviewed, and techniques are presented for improving the acuity of photoelectric angular size measurements that are complementary to interferometric measurements. Finally, sample data are provided to illustrate anomalies observed in photoelectric occultation observations of Antares and Aldebaran.

  14. All about Occultation.

    ERIC Educational Resources Information Center

    Riddle, Bob

    2001-01-01

    Describes occultation events involving the moon, when the moon blocks the view of planets or stars. Describes other events such as a partial solar eclipse, a penumbral lunar eclipse, meteor showers, and moon phases. Provides a list of internet resources related to these events. (DLH)

  15. The Scaphoid Safe Zone: A Radiographic Simulation Study to Prevent Cortical Perforation Arising from Different Views

    PubMed Central

    Chang, Biao; Liu, Ruoxi; Zhu, Yun; Peng, Jiang; Zhao, Qing; Lu, Shibi

    2017-01-01

    Purpose The purpose of this study was to simulate and calculate the probability of iatrogenic perforation of the scaphoid cortical bone when internal fixation appeared to be safe on radiographs. The results will assist surgeons in determining proper screw placement. Methods Thirty scaphoids were reconstructed using computed tomography data and image-processing software. Different central axes were determined by the software to simulate the surgical views. The safe zone (SZ) and risk zone (RZ) were identified on the axial projection radiographs by comparing the scaphoid bone stenosis measured by the fluoroscopic radiographs with a three-dimensional reconstruction of the scaphoid stenosis. Each original axial projection radiograph was zoomed and compiled to match a calculated average image. The RZ, SZ, and probability of perforations in various quadrants were calculated. Results Using a volar view (approach), the mean risks of cortical perforation were 25% with screws and 36% with k-wires. Using a dorsal view (approach), the mean risks of cortical perforation were 18% with screws and 30% with k-wires. A high risk of perforation was detected at the ulnar–dorsal zone. Conclusion Surgeons should be wary of screws that appear to lie close to the scaphoid cortex on both anteroposterior (AP) and lateral radiographs, particularly in the ulnar–dorsal and radial–dorsal quadrants, because such screws are likely to perforate the cortex. The position of the internal fixator should be assessed using a diagram outlining the various SZs. Therapeutic, Level III. PMID:28114317

  16. Salvage of a post-traumatic arthritic wrist using the scaphoid as an osteochondral graft.

    PubMed

    Marcuzzi, A; Ozben, H; Russomando, A

    2014-09-01

    The authors describe a case of post-traumatic wrist arthritis with an osteochondral defect in the scaphoid fossa of the radius. The patient was treated with proximal row carpectomy, radial styloidectomy and reconstruction of the defect using the proximal half of the scaphoid as an autologous osteochondral graft. Pain relief was achieved while wrist motion and strength were improved. The carpal bones are a source of osteochondral grafts and can be used to expand the indications of motion-preserving wrist salvage procedures.

  17. The effect of ultrasound on the healing of muscle-pediculated bone graft in scaphoid non-union.

    PubMed

    Ricardo, Monreal

    2006-04-01

    The use of pedicled vascularised bone grafts from the distal radius makes it possible to transfer bone with a preserved circulation and viable osteoclasts and osteoblasts. Experiments performed at the basic science level has provided substantial evidence that low-intensity ultrasound can accelerate and augment the fracture healing process. Only an adequate double-blind trial comparing treatment by ultrasound stimulation in patients treated by similar surgical techniques can provide evidence of the true effect of ultrasound. This paper describes the results of such a trial. From 1999 to 2004, 21 fractures of the scaphoid with established non-union treated with vascularised pedicle bone graft were selected for inclusion in a double-blind trial. All patients were males, with an average age of 26.7 years (range 17-42 years) and an average interval between injury and surgery of 38.4 months (range 3 months-10 years). Low-intensity ultrasound was delivered using a TheraMed 101-B bone-growth stimulator (30 mW/cm2, 20 min/day), which was modified to accomplish double-blinding. These modifications did not affect the designated active units. The placebo units were adjusted to give no ultrasound signal output across the transducer. Externally, all units appeared identical but were marked with individual code numbers. Patients were randomly allocated to either an active or placebo stimulation. Follow-up averaged 2.3 years (range 1-4 years). All patients achieved fracture union (active and placebo groups), but compared with the placebo device (11 patients), the active device (ten patients) accelerated healing by 38 days (56+/-3.2 days compared with 94+/-4.8 days, p<0.0001, analysis of variance).

  18. Photoelectric observations of lunar occultations

    NASA Technical Reports Server (NTRS)

    Fekel, F. C.; Montemayor, T. J.; Barnes, T. G., III; Moffett, T. J.

    1980-01-01

    Photoelectric observations of 13 lunar occultation disappearances during a March 1979 Hyades passage are reported. Three double stars (SAO 93925 = Fin 342 = 70 Tau, SAO 93961 = ADS 3248, and SAO 95419 = Kui 24) and one possible double (SAO 93950 = 75 Tau) were detected. A brief description is given of the Purdue University pulse-counting photometer as modified for occultation observations.

  19. Total volar extrusion of the lunate and scaphoid proximal pole with concurrent scapholunate dissociation.

    PubMed

    Koh, Kyoung Hwan; Lim, Tae Kang; Park, Min Jong

    2012-09-01

    This article describes a case of a 24-year-old man with a total volar extrusion of the lunate and scaphoid proximal pole with concurrent scapholunate dissociation. The viability of the lunate and the proximal pole of the scaphoid are at high risk in this type of injury. Scaphoid nonunion, avascular necrosis of the lunate and proximal pole of the scaphoid, and carpal instability are inevitable unless the blood supply is restored. Thus, proximal row carpectomy at injury may be an acceptable option to avoid these complications and late sequelae, including chronic wrist pain and dysfunction. However, the authors attempted accurate reduction of the extruded bones and internal fixation.Final radiographs and magnetic resonance imaging 12 years postoperatively showed healing without avascular necrosis. Carpal indices involving the scapholunate angle, radiolunate angle, and carpal height ratio were similar in both wrists without evidence of carpal instability or collapse. Range of motion and grip power were 75% and 76%, respectively, compared with those of the uninjured wrist. Clinical scores showed good results, and the patient reported no pain during activities of daily living and was satisfied with his surgical results. Open reduction and internal fixation can be a viable option in this rare pattern of injury.

  20. The occult urothelial cancer.

    PubMed

    Ragonese, Mauro; Racioppi, Marco; D'Agostino, Daniele; Di Gianfrancesco, Luca; Lenci, Niccolò; Bientinesi, Riccardo; Palermo, Giuseppe; Sacco, Emilio; Pinto, Francesco; Bassi, Pier Francesco

    2016-05-24

    Transitional cell carcinoma (TCC) is the tumor that most frequently affects the urinary tract. The most common location is in the bladder; the diagnosis, as the follow-up, is based on urine cytology, endoscopic, and radiological examinations. Urinary cytology is an important non invasive tool used in the diagnosis and follow-up of patients with TCC. A positive urine cytology result is highly predictive of the presence of TCC, even in the presence of normal cystoscopy, because malignant cells may appear in the urine long time before any cystoscopically visible lesion becomes apparent. The presence of a positive urinary cytology, in the absence of clinical or endoscopic evidence of a TCC, can identify an occult urothelial cancer, located in any site of the urinary tract (upper urinary tract, bladder, prostatic urethra). Most of the urothelial tumors of the renal pelvis and ureters are diagnosed by radiological examinations, but we can observe a high rate of false negatives. In order to improve the diagnostic role of urinary cytology and other conventional examinations, numerous molecular markers have been identified; however, the real clinical application remains unclear. Photodynamic diagnosis and narrow band imaging (NBI) cystoscopy increase the diagnostic accuracy of endoscopic examinations in the presence of lesions not easily detectable. The aim of this review is to analyze the current diagnostic standards in the presence of occult urothelial cancer.

  1. The Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Russell, James M., III; Gordley, Larry L.; Park, Jae H.; Drayson, S. R.; Hesketh, W. D.; Cicerone, Ralph J.; Tuck, Adrian F.; Frederick, John E.; Harries, John E.; Crutzen, Paul J.

    1993-01-01

    The Halogen Occultation Experiment (HALOE) uses solar occultation to measure vertical profiles of O3, HCl, HF, CH4, H2O, NO, NO2, aerosol extinction, and temperature versus pressure with an instantaneous vertical field of view of 1.6 km at the earth limb. Latitudinal coverage is from 80 deg S to 80 deg N over the course of 1 year and includes extensive observations of the Antarctic region during spring. The altitude range of the measurements extends from about 15 km to about 60-130 km, depending on channel. Experiment operations have been essentially flawless, and all performance criteria either meet or exceed specifications. Internal data consistency checks, comparisons with correlative measurements, and qualitative comparisons with 1985 atmospheric trace molecule spectroscopy (ATMOS) results are in good agreement. Examples of pressure versus latitude cross sections and a global orthographic projection for the September 21 to October 15, 1992, period show the utility of CH4, HF, and H2O as tracers, the occurrence of dehydration in the Antarctic lower stratosphere, the presence of the water vapor hygropause in the tropics, evidence of Antarctic air in the tropics, the influence of Hadley tropical upwelling, and the first global distribution of HCl, HF, and NO throughout the stratosphere. Nitric oxide measurements extend through the lower thermosphere.

  2. Occult Fungal Scleritis

    PubMed Central

    Jeang, Lauren J.; Davis, Aaron; Madow, Brian; Espana, Edgar M.; Margo, Curtis E.

    2017-01-01

    Purpose To heighten awareness of occult fungal scleritis. Method Case report and review of the literature. Results A 73-year-old woman with diabetes mellitus was diagnosed for 3 months with immune-mediated scleritis and subsequently treated with corticosteroids. On referral, the patient had a scleral nodule with contiguous corneal infiltrate and hypopyon. Culture grew Fusarium species not further classified. The infection could not be controlled with antifungal therapy, and the eye was removed. No exogenous or endogenous source for the infection could be identified by clinical history or examination. Conclusion Fungal scleritis can develop in persons without a history of foreign body injury, minor trauma, or evidence of endogenous fungemia. A high index of suspicion for infectious scleritis must be maintained in persons with presumed immune-mediated scleritis who fail to respond to conventional therapy, particularly if they present with decreased visual acuity. PMID:28275602

  3. Pinhole occulter experiment

    NASA Technical Reports Server (NTRS)

    Ring, Jeff; Pflug, John

    1987-01-01

    Viewgraphs and charts from a briefing summarize the accomplishments, results, conclusions, and recommendations of a feasibility study using the Pinhole Occulter Facility (POF). Accomplishments for 1986 include: (1) improved IPS Gimbal Model; (2) improved Crew Motion Disturbance Model; (3) use of existing shuttle on-orbit simulation to study the effects of orbiter attitude deadband size on POF performance; (4) increased understanding of maximum performance expected from current actuator/sensor set; (5) use of TREETOPS nonlinear time domain program to obtain system dynamics describing the complex multibody flexible structures; (6) use of HONEY-X design tool to design and evaluate multivariable compensator for stability, robustness, and performance; (7) application of state-of-the-art compensator design methodology Linear Quadratic Gaussian/Loop Transfer Recovery (LQG/LTR); and (8) examination of tolerance required on knowledge of the POF boom flexible mode frequencies to insure stability, using structure uncertainty analysis.

  4. KPNO LUNAR OCCULTATION SUMMARY. III

    SciTech Connect

    Schmidtke, P. C.; Africano, J. L.

    2011-01-15

    The results for 251 lunar occultation events recorded at Kitt Peak National Observatory are presented, including 20 observations of known or suspected double stars and five measurements of stars with resolved angular diameters.

  5. Case of bilateral Galeazzi fractures associated with dislocation of the right elbow.

    PubMed

    Nanno, Mitsuhiko; Sawaizumi, Takuya; Takai, Shinro

    2011-01-01

    We report an unusual case of bilateral Galeazzi fractures associated with dislocation of the right elbow and fracture of the right scaphoid caused by a motorbike accident in a 32-year-old man. Bilateral radiuses were fixed with plates, and the right scaphoid was fixed with a screw after closed reduction of the right elbow. A satisfactory result was obtained with a return to work and no radiographic problems 7 years after surgery. The mechanism of the injury was thought to be a high-velocity fall on the outstretched hands combined with extreme pronation of the forearms and extension of the wrists and the elbows. This case had a favorable outcome following operative stabilization of the fracture-dislocations and early mobilization.

  6. [Occult hepatitis C virus infection].

    PubMed

    Carreño García, Vicente; Nebreda, Javier Bartolomé; Aguilar, Inmaculada Castillo; Quiroga Estévez, Juan Antonio

    2011-03-01

    Occult hepatitis C virus (HCV) infection is characterized by the detection of HCV-RNA in liver in the absence of anti-HCV and serum HCV-RNA determined by conventional techniques. The development of a new enzyme immunoassay for the detection of antibodies against a conserved epitope in the HCV core protein, together with the detection of HCV-RNA in peripheral blood mononuclear cells and in serum after concentrating the viral particles by ultracentrifugation, allow diagnosis of more than 90% of patients with occult HCV without the need to perform a liver biopsy. Histological damage in occult HCV infection ranges from minimal changes to liver cirrhosis and hepatocellular carcinoma, although in general this disease is less severe than classical chronic hepatitis C. A significant prevalence of occult HCV infection has been identified in risk groups such as hemodialysis patients and the family members of patients with occult hepatitis C. This occult HCV infection can also be found in subjects without clinical or biochemical evidence of liver disease.

  7. Intraosseous Ganglion Cyst of Scaphoid: An Uncommon Cause of Radial Wrist Pain.

    PubMed

    Salunke, Abhijeet Ashok; Singh, Saranjeet; Kanani, Himanshu; Chokshi, Jimmy; Nambi, G I; Raval, Pradyumna; Vala, Pathik; Jain, Shantanu; Chaudhari, Sanjay; Patel, Amit; Panchal, Ramesh

    2016-02-01

    Intraosseous ganglion cyst is a rare bone tumor and the lesion could often be missed. The diagnosis could be delayed so proper radiologic investigation and index of suspicion is necessary .Differential diagnoses of painful cystic radiolucent carpal lesion are osteoid osteoma, osteoblastoma and intraosseous ganglion. Curettage of the scaphoid lesion and filling of void with bone graft provides good functional outcomes. The cyst contains mucoid viscous material without epithelial or synovial lining. We present a case of 30 years old male with intraosseous ganglion cyst of scaphoid which was treated with curettage and bone grafting. Rarely ganglion cyst is found in small bones of hand and should be considered as differential diagnosis of chronic radial wrist pain.

  8. The arthroscopic treatment of avascular necrosis of the proximal pole following scaphoid nonunion.

    PubMed

    Ruch, D S; Chang, D S; Poehling, G G

    1998-10-01

    The authors describe a technique of treating scaphoid nonunions with associated avascular necrosis consisting of arthroscopic resection of the distal pole of the scaphoid combined with radial styloidectomy. The results at 2-year follow-up showed all three patients to have complete relief of their mechanical pain and improvement in their range of motion as well as high satisfaction with the procedure. Modified Mayo Wrist Scores were a mean preoperatively of 60 and postoperatively of 88. Postoperative radiographs showed no increase in the scapholunate gap. However, the capitolunate angle increased from a mean of 3 degrees to 13 degrees . There was no progression of degenerative changes noted. The advantages of this technique include (1) minimal morbidity, (2) relief of mechanical pain, and (3) improved range of motion with no early degenerative changes. The rate and severity of degenerative change following this procedure remain unknown.

  9. TREATMENT OF SCAPHOID NONUNION WITH OLECRANON BONE GRAFT AND COMPRESSION SCREW

    PubMed Central

    NEDER, ANTONIO TUFI; FRANCESCHINI, EDUARDO TRALDI; PARDINI, ARLINDO GOMES; RIBERTO, MARCELO; MAZZER, NILTON

    2016-01-01

    ABSTRACT Objective: To evaluate the outcome of olecranon bone graft and compression screw for the treatment of nonunion of the Lichtman type I scaphoid. Method: We evaluated 15 patients of 32 who underwent surgical treatment for nonunion of the Lichtman type I scaphoid with olecranon bone graft and screw compression. Results: We obtained 100% consolidation in our sample. The mean flexion of the wrist on the affected side was 68° and 75° on the non-affected side. The average extension was 63° and 72°, respectively. The average grip strength was 35 kgf. This corresponds to 98% of the handgrip strength of the non-affected side, which was 37 kgf. The DASH score averaged 5 points. Conclusion: We believe that the use of bone graft obtained from the olecranon and secured with cannulated screw is a resolute technique for cases of linear nonunion of the Lichtmann type I scaphoid. It has the advantages of a new anesthesia for removal of the graft and the access is easy, providing a good exposure for removal and good aesthetic results. Level of evidence IV. Case series. PMID:27217819

  10. Arthroscopic grafting of scaphoid nonunion - surgical technique and preliminary findings from 23 cases.

    PubMed

    Cognet, J-M; Louis, P; Martinache, X; Schernberg, F

    2017-02-01

    We report our experience with the arthroscopic treatment of 23 cases of scaphoid nonunion. We explain the surgical technique and describe the different steps needed to achieve bone union. We report our initial clinical and radiological results. This was a prospective non-randomized study. Inclusion criteria were a scaphoid nonunion without radiocarpal arthritis, without any time limit and without any selection as to nonunion location. Before the operation, patients underwent an X-Ray and CT scan or MRI. Schernberg's classification was used to evaluate the location of the nonunion. Internal fixation was performed with a screw or K-wires. Bone grafts were taken from the dorsal side of the distal radius using a T-Lok™ bone marrow biopsy needle (Argon Medical Devices, Plano, TX, USA). A CT scan was performed 3 months after the operation to determine whether union was achieved. Pain, strength and range of motion were evaluated before and after the operation. The patients' smoking habits were also documented. The average follow-up was 17.3 months (4-41). There were 20 men and 3 women with an average age of 26 years (17-63). The average duration of nonunion before the operation was 17 months (6-60). Based on Schernberg's classification, there was one type I, 12 type II and 10 type III nonunions. Wrist strength increased from 32 to 41kg. Union was obtained in all patients after an average of 4 months (3-12). Numerous treatments have been described for treating scaphoid nonunion: Matti-Russe, Fisk-Fernadez bone graft, vascularized bone graft, bone substitutes, etc. The success rate varies depending on the technique and study design. We have described an arthroscopic technique for treating scaphoid nonunion with very promising preliminary results. Arthroscopic debridement is needed to ensure good quality bone at the graft site, while preserving extrinsic vascularization. Traction is used during the operation to restore the scaphoid height, once debridement has been

  11. Testing for Occult Heartworm Infection

    PubMed Central

    Stogdale, L.

    1984-01-01

    Heartworm infection in dogs is endemic in southern Ontario but occurs only sporadically throughout the remainder of Canada. The disease may either be associated with microfilariae in the patient's blood, a patent infection, or it may be occult. This paper describes a case of occult dirofilariasis in a dog, with emphasis on the diagnosis. A patent infection could be missed if the clinician tests an insufficient amount of blood. He should perform multiple concentration tests using either the modified Knott's technique or a filtration method. Occult infections occur in prepatent or unisexual infections, when the worms become sterile following therapy, or when the host produces antibodies that result in the destruction of the microfilariae. The recent release of a kit which detects the presence of antibodies to the adult heartworms now enables veterinarians to make an accurate diagnosis in the vast majority of dogs. PMID:17422386

  12. Absent or occult pulmonary artery.

    PubMed Central

    Presbitero, P; Bull, C; Haworth, S G; de Leval, M R

    1984-01-01

    Of 12 patients with angiographically absent pulmonary artery, 11 were investigated surgically. The previously occult pulmonary artery was found in 10 patients, in five of whom a vestige of an intrapericardial artery was present and in five the artery was patent only at the hilus, a gap existing between the main pulmonary artery and the hilar vessel, and no artery was found in one. All patients with an intrapericardial artery had right ventricular outflow tract obstruction and a ductus descending vertically from underneath the aortic arch. In those without an intrapericardial vessel the occult artery was on the side opposite the aortic arch, and there was evidence of a ductus coming from the innominate artery on the side of the interruption. The occult pulmonary artery, where identified at operation, was usually joined initially to the systemic circulation. Ultimately, continuity between the hilar and main pulmonary artery may be established surgically. Where no intrapericardial vessel exists, however, a conduit may be required to bridge the gap. It seems advisable to search for the occult artery as early in life as is feasible in the hope that providing a blood supply will ensure development of the vessel and normal lung growth. Images PMID:6743435

  13. RSL Fusion with Excision of Distal Scaphoid and Triquetrum: A Cadaveric Study.

    PubMed

    Bain, Gregory Ian; Sood, Aman; Yeo, Chong Jin

    2014-02-01

    Radioscapholunate (RSL) fusion has been utilized for treatment of radiocarpal arthritis for patients with an intact midcarpal joint. This preserves midcarpal joint motion while alleviating pain. Dart thrower's motion (DTM), which has been emphasized recently, is mainly a midcarpal joint motion. Question A cadaveric study was designed to measure and compare the range of motion (ROM) of the human wrist before and after an RSL fusion, followed by distal scaphoid excision, and finally excision of the triquetrum. Methods Twelve embalmed adult cadaveric upper limbs were assessed. The wrist motion was measured with an electrogoniometer. Measurements of the flexion-extension plane and radial-ulnar deviation plane were obtained for baseline after capsulotomy, after simulated RSL fusion with memory staples, after distal scaphoidectomy, and after excision of the triquetrum. Results The effects of scaphoid and triquetrum excision were expressed as improvements in movement over that of the preceding step. RSL fusion alone resulted in a decrease of the flexion-extension (F-E) arc by 36% and the radioulnar deviation (R-U) arc by 30%. Excision of the distal scaphoid with RSL improved the F-E arc by 34% and the R-U arc by 34%. With excision of the triquetrum, the F-E arc improved further by 13% and the R-U arc by 21%. The ROM of the simulated RSL fusion with distal scaphoidectomy is improved with excising the triquetrum, mainly through an increase in ulnar deviation motion. RSL fusion with distal scaphoidectomy and triquetrectomy can be an alternative to total wrist arthrodesis for patients with an intact midcarpal joint.

  14. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Occult blood test. 864.6550 Section 864.6550 Food... DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test. (a) Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood...

  15. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Occult blood test. 864.6550 Section 864.6550 Food... DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test. (a) Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood...

  16. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Occult blood test. 864.6550 Section 864.6550 Food... DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test. (a) Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood...

  17. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Occult blood test. 864.6550 Section 864.6550 Food... DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test. (a) Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood...

  18. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Occult blood test. 864.6550 Section 864.6550 Food... DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test. (a) Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood...

  19. Triton stellar occultation candidates - 1992-1994

    NASA Technical Reports Server (NTRS)

    Mcdonald, S. W.; Elliot, J. T.

    1992-01-01

    A search for Triton stellar occultation candidates for the period 1992-1994 has been completed with CCD strip-scanning observations. The search reached an R magnitude of about 17.4 and found 129 candidates within 1.5 arcsec of Triton's ephemeris during this period. Of these events, around 30 occultations are expected to be visible from the earth, indicating that a number of Triton occultation events should be visible from major observatories. Even the faintest of the present candidate events could produce useful occultation data if observed with a large enough telescope. The present astrometric accuracy is inadequate to identify which of these appulse events will produce occultations on the earth; further astrometry is needed to refine the predictions for positive occultation identification. To aid in selecting candidates for additional astrometric and photometric studies, finder charts and earth-based visibility charts for each event are included.

  20. IUVS/MAVEN Stellar Occultations

    NASA Astrophysics Data System (ADS)

    Gröller, Hannes; Yelle, Roger; Montmessin, Franck; Lacombe, Gaetan; Schneider, Nicholas M.; Deighan, Justin; Jain, Sonal; Nakagawa, Hiromu; Jakosky, Bruce

    2016-10-01

    We present the latest results from stellar occultations observed with the Imaging Ultraviolet Spectrograph (IUVS) instrument on board of Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. So far 9 campaigns have been executed on average every two months since MAVEN began orbiting Mars. Approximately 50 occultations are recorded in each campaign. The IUVS instrument observes in two spectral regions, the far- and mid-UV. The FUV channel covers wavelengths from 110 to 190 nm and the MUV channel from 170 to 350 nm. By combining those two channels we cover the whole altitude range starting from around 30 km to 150 km. We present the geometric dependent CO2, O2, and O3 number densities from these occultations. The derived O2 mixing ratio varies between 1.5 × 10-3 and 5 × 10-3. In some of the MUV occultations we also can see aerosol extinction. In addition we present temperatures derived from the CO2 densities assuming hydrostatic equilibrium. We retrieved mean temperatures of around 180 K at lower altitudes, which decreasing with altitudes down to a mean of around 130 K at higher altitudes. We see a constantly cold layer with temperatures of 105 - 120 K at a pressure level at roughly 7 × 10-6 Pa, equivalent to an altitude of around 140 km. We also discuss possible wave structures with amplitudes between 5 and 15 K and wavelengths between 10 and 15 km in the obtained temperature profiles. The temperature profiles, retrieved with the IUVS instrument, are mostly in agreement with predicted values from the Mars Climate Database model, except where we see the cold layer around 140 km.

  1. Revisiting the 1988 Pluto Occultation

    NASA Astrophysics Data System (ADS)

    Bosh, Amanda S.; Dunham, Edward W.; Young, Leslie A.; Slivan, Steve; Barba née Cordella, Linda L.; Millis, Robert L.; Wasserman, Lawrence H.; Nye, Ralph

    2015-11-01

    In 1988, Pluto's atmosphere was surmised to exist because of the surface ices that had been detected through spectroscopy, but it had not yet been directly detected in a definitive manner. The key to making such a detection was the stellar occultation method, used so successfully for the discovery of the Uranian rings in 1977 (Elliot et al. 1989; Millis et al. 1993) and before that for studies of the atmospheres of other planets.On 9 June 1988, Pluto occulted a star, with its shadow falling over the South Pacific Ocean region. One team of observers recorded this event from the Kuiper Airborne Observatory, while other teams captured the event from various locations in Australia and New Zealand. Preceding this event, extensive astrometric observations of Pluto and the star were collected in order to refine the prediction.We will recount the investigations that led up to this important Pluto occultation, discuss the unexpected atmospheric results, and compare the 1988 event to the recent 2015 event whose shadow followed a similar track through New Zealand and Australia.

  2. Scaling Relation for Occulter Manufacturing Errors

    NASA Technical Reports Server (NTRS)

    Sirbu, Dan; Shaklan, Stuart B.; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2015-01-01

    An external occulter is a spacecraft own along the line-of-sight of a space telescope to suppress starlight and enable high-contrast direct imaging of exoplanets. The shape of an external occulter must be specially designed to optimally suppress starlight and deviations from the ideal shape due to manufacturing errors can result loss of suppression in the shadow. Due to the long separation distances and large dimensions involved for a space occulter, laboratory testing is conducted with scaled versions of occulters etched on silicon wafers. Using numerical simulations for a flight Fresnel occulter design, we show how the suppression performance of an occulter mask scales with the available propagation distance for expected random manufacturing defects along the edge of the occulter petal. We derive an analytical model for predicting performance due to such manufacturing defects across the petal edges of an occulter mask and compare this with the numerical simulations. We discuss the scaling of an extended occulter test-bed.

  3. Nose fracture

    MedlinePlus

    Fracture of the nose; Broken nose; Nasal fracture; Nasal bone fracture; Nasal septal fracture ... A fractured nose is the most common fracture of the face. It ... with other fractures of the face. Sometimes a blunt injury can ...

  4. Finite element modeling of the influence of hand position and bone properties on the Colles' fracture load during a fall.

    PubMed

    Buchanan, Drew; Ural, Ani

    2010-08-01

    Distal forearm fracture is one of the most frequently observed osteoporotic fractures, which may occur as a result of low energy falls such as falls from a standing height and may be linked to the osteoporotic nature of the bone, especially in the elderly. In order to prevent the occurrence of radius fractures and their adverse outcomes, understanding the effect of both extrinsic and intrinsic contributors to fracture risk is essential. In this study, a nonlinear fracture mechanics-based finite element model is applied to human radius to assess the influence of extrinsic factors (load orientation and load distribution between scaphoid and lunate) and intrinsic bone properties (age-related changes in fracture properties and bone geometry) on the Colles' fracture load. Seven three-dimensional finite element models of radius were created, and the fracture loads were determined by using cohesive finite element modeling, which explicitly represented the crack and the fracture process zone behavior. The simulation results showed that the load direction with respect to the longitudinal and dorsal axes of the radius influenced the fracture load. The fracture load increased with larger angles between the resultant load and the dorsal axis, and with smaller angles between the resultant load and longitudinal axis. The fracture load also varied as a function of the load ratio between the lunate and scaphoid, however, not as drastically as with the load orientation. The fracture load decreased as the load ratio (lunate/scaphoid) increased. Multiple regression analysis showed that the bone geometry and the load orientation are the most important variables that contribute to the prediction of the fracture load. The findings in this study establish a robust computational fracture risk assessment method that combines the effects of intrinsic properties of bone with extrinsic factors associated with a fall, and may be elemental in the identification of high fracture risk individuals

  5. Evaluation of Associated Carpal Bone Fractures in Distal Radial Fractures

    PubMed Central

    Heo, Youn Moo; Kim, Sang Bum; Yi, Jin Woong; Park, Cheol Yong; Yoon, Jeong Yong; Kim, Doo Hyun

    2013-01-01

    Background The purpose of this study was to investigate the frequency and distribution of associated carpal bone fractures (CBFs) in distal radial fractures (DRFs). Methods Three hundred and thirteen patients who underwent surgical treatment for DRFs between March 2007 and January 2010 were reviewed retrospectively. In this study, 223 patients who had preoperative computed tomography (CT) were included. We investigated the frequency and distribution of associated CBFs on CT scans. The relationship between the frequency of associated CBFs and patient factors such as age, gender, body mass index, and the mechanism of injury was assessed. Results CBFs were complicated in 46 of 223 DRFs (20.9%). The distribution of CBFs was 23 cases in the triquetrum, 16 in the lunate, 12 in the scaphoid, five in the hamate, and four in the pisiform. Among the 46 cases, a fracture of one carpal bone occurred in 36 cases, two in seven cases, three in two cases, and four in one case. In 10 of the 46 cases, associated CBFs occurred in more than two carpal bones. No significant differences were observed for age, sex, body mass index, or the mechanism of injury between patients with DRFs and CBFs and those without CBFs. Conclusions Because CBFs that mainly occur in the proximal carpal row are complicated in DRFs at a relatively high frequency, assessment of carpal bones using CT scans is beneficial. PMID:23730472

  6. Illinois occultation summary. II - 1979

    NASA Technical Reports Server (NTRS)

    Radick, R.; Lien, D.

    1982-01-01

    Lunar occultation records are presented for the third year of a continuing program. Included are 17 observations of stars brighter than seventh magnitude, 13 reappearances, four angular diameter measurements, and seven observations of stars that are either binary or may be double. The observations were made with Stromgren y filter, the u or b filter, or the FI filter described in the first paper of this series (Radick and Lien, 1980). Five observations, including four of Aldebaran, were made with two filters centered on or near H-alpha.

  7. Occult Carcinoma of the Bronchus

    PubMed Central

    Pearson, F. G.; Thompson, D. W.

    1966-01-01

    The term “occult carcinoma” is applied to those patients with carcinoma of the bronchus at an in situ or early invasive stage who have carcinoma cells in their sputum but have no recognizable evidence of tumour in the chest radiograph. In eight such patients at the Toronto General Hospital, the lesion was localized and treatment instituted. Our experience with these eight patients can be compared with that of 27 patients described in two similar studies. The lesions were commonly symptomatic. Localization, although sometimes difficult, was accomplished using information obtained during bronchoscopy and bronchography. The prognosis following adequate resection appeared excellent. No patient died of carcinoma during the post-treatment follow-up period, which was continued for a minimum of 18 months. Pathological evidence indicates that bronchial carcinoma at this occult stage can be diagnosed cytologically, is rarely multifocal and, as a localized neoplasm, is amenable to curative therapy. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 13 PMID:5929532

  8. Synovitis of the wrist joint caused by an intraarticular perforation of an osteoid osteoma of the scaphoid

    PubMed Central

    Bhardwaj, Praveen; Sharma, Chetna; Sabapathy, S Raja

    2012-01-01

    Uncommon location and atypical presentation of the osteoid osteomas of the scaphoid can pose a diagnostic challenge. Because of its intraarticular location, scaphoid osteoid osteoma can present with synovitis which is the more commonly reported presentation for other intraarticular locations like in hip and elbow and only rarely reported at the wrist. We report a case of perforation of the osteoid osteoma into the wrist joint, resulting in exuberant synovitis. The clinical significance of this report is to reinforce that synovitis can be a presentation of osteoid osteoma and it should be considered in the differential diagnosis of monoarticular arthritis. Prolonged synovitis may cause damage to the other joint surfaces of the wrist and hence carpal osteoid osteoma should be considered for early surgical excision. PMID:23162159

  9. The Lunar Occultation Observer (LOCO) mission concept

    NASA Astrophysics Data System (ADS)

    Miller, Richard S.

    2007-09-01

    The hard X-ray sky has tremendous potential for future discoveries and is one of the last electromagnetic regimes without a sensitive all-sky survey. A new approach to such a survey is to utilize the Moon as an occulting disk. The Lunar Occultation Observer (LOCO) mission concept, based on this Lunar Occultation Technique (LOT) and incorporating advanced inorganic scintillators as a detection medium, represents a sensitive and cost effective option for NASA's Beyond Einstein Black Hole Finder Probe or a future Explorer-class mission. We present the motivating factors for the LOT, outline developmental details and simulation results, as well as give preliminary estimates for source detection sensitivity.

  10. Stellar Occultation Studies of the Solar System

    NASA Technical Reports Server (NTRS)

    Elliot, James L.

    1998-01-01

    Earth-based observations of stellar occultations provide extremely high spatial resolution for bodies in the outer solar system, about 10,000 times better than that of traditional imaging observations. Stellar occultation data can be used to establish the structure of atmospheres and rings of solar system bodies at high spatial resolution. Airborne occultation observations are particularly effective, since the controlled mobility of the observing platform allows the observer to fly within the optimum part of the occultation shadow for most events that are visible from Earth. Airborne observations are carried out above any clouds and are nearly free of scintillation noise from the Earth's atmosphere. KAO occultation observations resulted in the first detection of gravity waves in the Martian atmosphere, discovery of the Uranian rings, the first detection of Pluto's atmosphere, the first Earth-based investigations of Triton's atmosphere, and the discovery of narrow jets from Chiron's nucleus. The first SOFIA occultation opportunity will be an investigation of Pluto's atmospheric structure in November, 2002, and will resolve a problem that has lingered since the KAO discovery observation fourteen years earlier. We plan to continue our successful airborne occultation program with the greatly enhanced capability provided by SOFIA. We propose here to replace our KAO occultation photometer with one having twice the throughput, half the noise, a somewhat wider wavelength range, four times the field of view, and ten times the frame rate to optimize its performance and to capitalize on the larger collecting area offered by SOFIA. It will also allow for simultaneous visible and IR occultation observations, greatly enriching the results that we can obtain from occultations. We call this new imaging occultation photometer HOPI (High-speed Occultation Photometer and Imager). HOPI will provide a signal-to-noise ratio two to four times that of our present photometer for a given

  11. Future Nanosatellite Constellation for Radio Occultation Measurements

    NASA Astrophysics Data System (ADS)

    Fallet, C.; Mahfouf, J. F.; Hauchechrne, A.; Mathieu, R.; Martin, T.; Capet, N.; Mandea, M.

    2016-08-01

    The future nanosatellite constellation for radio occultation measurements aims to provide 10000 occultations per day (horizon 2020). The radio occultation technique based on the refraction of an electromagnetic signal between a GNSS satellite (Global Navigation Satellite System) and a receiver satellite located o a low orbit provides a way to observe the Earth's atmosphere, especially its temperature, pressure and water vapor, but also the ionosphere. This technique is now considered a mature concept, the benefits clearly recognized by the communities of weather prediction, climatology and space weather. Activities are underway at CNES to define a low cost system and instrumental concept to satisfy the specifications of the different communities.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. Triton stellar occultation candidates: 1995-1999

    NASA Technical Reports Server (NTRS)

    Mcdonald, S. W.; Elliot, J. L.

    1995-01-01

    We have completed a search for candidates for stellar occultations by Triton over the years 1995-1999. CCd strip scan images provided star positions in the relevant sky area to a depth of about 17.5 R magnitude. Over this time period, we find that Triton passes within 1.0 arcsec of 75 stars. Appulses with geocentric minimum separations of less than 0.35 arcsec will result in stellar occultations, but further astrometry and photometry is necessary to refine individual predictions for identification of actual occultations. Finder charts are included to aid in further studies and prediction refinement. The two most promising potential occultations, Tr176 and Tr180, occur in 1997.

  14. McDonald's and the Occult.

    ERIC Educational Resources Information Center

    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)

  15. Scaling Relation for Occulter Manufacturing Errors

    NASA Technical Reports Server (NTRS)

    Sirbu, Dan; Shaklan, Stuart B.; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2015-01-01

    For directly imaging exoplanets, NASA is considering space mission designs that use an external occulter as the principal starlight suppression system. These occulter designs range in diameter from 16 to 40 meters and separation distance from 8,000 to 60,000 kilometers for telescopes with primary diameters of 0.5 to 4 meters. Occulter shapes are solutions to an optimization problem which seeks to maximize suppression in the shadow subject to constraints such as size, separation, and wavelengths. These designs are based on scalar diffraction theory and must be verified experimentally to demonstrate predicted on-orbit performance. Due to the large sizes and separations involved the experiment must be scaled to lab size. We are currently expanding the existing experimental test-bed at Princeton to enable scaling of occulters operating at flight Fresnel sizes. Here we examine the effect on suppression performance of edge defects and their scaling to test-bed size.

  16. Radio occultation measurements of the lunar ionosphere.

    NASA Astrophysics Data System (ADS)

    Pluchino, S.; Schillirò, F.; Salerno, E.; Pupillo, G.; Maccaferri, G.; Cassaro, P.

    Radio occultation measurements by using interplanetary probes is a well known technique to obtain information on planetary atmospheres. To further understand the morphology of the lunar ionosphere we performed radio occultation experiments by using the radio sounding technique. This method mainly consists in the analisys of the effects produced on the radio wave transmitted from the spacecraft to the Earth when it crosses the atmosphere. The wave amplitude and phase undergo modifications that are correlated to the physical parameters - i.e. electron density - of the crossed medium. The first data set was obtained during the lunar occultations of the European probe SMART-1 shortly before impacting the lunar soil on September 3rd, 2006. During this experiment several radio occultation measurements of the signal transmitted by the spacecraft were performed in S and X band by using the 32 meters radiotelescopes (at Medicina and Noto) of the Istituto di Radioastronomia - Istituto Nazionale di Astrofisica. Further experiments were performed during lunar occultations of Saturn and Venus. On May 22nd and June 18th 2007 the Cassini spacecraft, orbiting Saturn, and the Venus Express spacecraft, orbiting Venus, respectively were occulted by the Moon. The variation of the Total Electron Content (TEC) measured by our instruments (˜ 1013 el/m2) on this occasion is in agreement with values of the electron number density acquired by in situ measuments of the US Apollo missions and the USSR Luna 19 and 22 probes.

  17. Method of Modeling and Simulation of Shaped External Occulters

    NASA Technical Reports Server (NTRS)

    Lyon, Richard G. (Inventor); Clampin, Mark (Inventor); Petrone, Peter, III (Inventor)

    2016-01-01

    The present invention relates to modeling an external occulter including: providing at least one processor executing program code to implement a simulation system, the program code including: providing an external occulter having a plurality of petals, the occulter being coupled to a telescope; and propagating light from the occulter to a telescope aperture of the telescope by scalar Fresnel propagation, by: obtaining an incident field strength at a predetermined wavelength at an occulter surface; obtaining a field propagation from the occulter to the telescope aperture using a Fresnel integral; modeling a celestial object at differing field angles by shifting a location of a shadow cast by the occulter on the telescope aperture; calculating an intensity of the occulter shadow on the telescope aperture; and applying a telescope aperture mask to a field of the occulter shadow, and propagating the light to a focal plane of the telescope via FFT techniques.

  18. [The scaphoid-trapezium-trapezoid arthrosis. A clinical study 1982-1985].

    PubMed

    Wilhelm, K; Rolle, A; Hild, A

    1989-02-01

    The present study deals with patients in whom the diagnostic procedures applied in rhizoid arthrosis were considered to reveal scaphoid-trapezium-trapezoid (STT) arthrosis. Between 1982 and 1985, 21 of 396 rhizoid arthrosis patients developed symptoms of STT arthosis. Examination of the case histories showed that in 20 STT patients the pathogenesis included trauma. In addition, the majority of these 396 patients (71.5%) had to be retreated because of new traumata and the resultant problems. The time lapse between the first trauma considered sufficiently severe to have caused STT arthrosis and its diagnosis was up to 7.1 years. Our improved facilities for diagnosis of pathologic conditions of the wrist enabled us to distinguish four types of STT arthrosis. Persistent complex instability of the capsular ligament appears to be the major cause of post-traumatic STT arthrosis. Extended diagnostic techniques based on standardized radiograms allow the development of a design for treatment aimed at preventing posttraumatic STT of the hand as far as possible.

  19. Pollen and water limitation in Astragalus scaphoides, a plant that flowers in alternate years.

    PubMed

    Crone, Elizabeth E; Lesica, Peter

    2006-11-01

    Mast seeding is common in plant populations, but its causes have rarely been tested experimentally. We tested mechanisms of alternate-year flowering and fruit set in an iteroparous, bee-pollinated, herbaceous plant, Astragalus scaphoides, in semi-arid sagebrush steppe. Patterns of reproduction from 1986 to 1999 indicated that spring precipitation was a cue for synchronous flowering, and that increased pollination in high-flowering years was a fitness advantage of synchrony. We tested these patterns by adding supplemental water and pollen to plants in high- and low-flowering sites and years. Supplemental water had no effect on flowering or seed set, so water is not a proximate cue for reproduction, though it could be important over longer (>3 year) time scales. Supplemental pollination increased fruit set in low- but not high-flowering years, indicating that synchronous flowering increases pollination success. Many shorter-term studies also report increased fruit set after pollen supplementation, but not after resource addition. This pattern may reflect the fact that plants can store and reallocate resources, but not pollen, across multiple years. For animal-pollinated herbs such as these, uniting theories about pollination ecology and mast seeding may promote an understanding of the mechanisms that determine patterns of reproduction over time.

  20. Oligometastasis as a predictor for occult disease.

    PubMed

    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.

  1. First Stellar Occultation Observation with SOFIA

    NASA Astrophysics Data System (ADS)

    Dunham, Edward W.; Bida, T.; Bosh, A.; Collins, P.; Levine, S.; Person, M.; Pfueller, E.; Roeser, H.; Taylor, B.; Wiedemann, M.; Wolf, J.; Zuluaga, C.

    2012-01-01

    We successfully observed the 2011 June 23 UT stellar occultation by Pluto with the High-speed Imaging Photometer for Occultations (HIPO) instrument from Lowell Observatory and the Fast Diagnostic Camera (FDC) from the Deutches SOFIA Institut (DSI) mounted on the SOFIA telescope. A major prediction astrometry effort focused at MIT combined with the willingness of the SOFIA project to entertain the idea of an in-flight change to the flight plan allowed us to target the center of the occultation shadow. This was accomplished by means of an in-flight prediction update by satellite telephone and a real-time onboard flight plan modification to accommodate the prediction update. We obtained excellent results with both channels of HIPO and the FDC with each light curve showing a small, extended brightening while the star was occulted. We will discuss analysis results as well as SOFIA's considerable potential for future occultation work. We thank the SOFIA program for its willingness to attempt this challenging observation at such an early stage of SOFIA science operations. Lowell's SOFIA work was supported by a grant from USRA, MIT's prediction work was supported by the NASA Planetary Astronomy Program and the National Science Foundation, and the FDC work was supported by the DSI. We thank the US Naval Observatory Flagstaff Station for allowing us to use their facilities to obtain our prediction astrometry observations.

  2. Earth rotation derived from occultation records

    NASA Astrophysics Data System (ADS)

    Sôma, Mitsuru; Tanikawa, Kiyotaka

    2016-04-01

    We determined the values of the Earth's rotation parameter, ΔT = T T - UT, around AD 500 after confirming that the value of the tidal acceleration, dot{n}, of the lunar motion remained unchanged during the period between ancient times and the present. For determining of ΔT, we used contemporaneous occultations of planets by the Moon. In general, occultation records are not useful. However, there are some records that give us a stringent condition for the range of ΔT. Records of the lunar occultations in AD 503 and AD 513 are such examples. In order to assure the usefulness of this occultation data, we used contemporaneous annular and total solar eclipses, which have not been used in the preceding work. This is the first work in which the lunar occultation data have been used as primary data to determine the value of ΔT together with auxiliary contemporaneous annular and total solar eclipses. Our ΔT value is less than a smoothed value (Stephenson 1997) by at least 450 s. The result is consistent with our earlier results obtained from solar eclipses.

  3. Image Analysis of the 2012 Pluto (Near) Occultation

    DTIC Science & Technology

    2013-09-01

    Image Analysis of the 2012 Pluto (Near) Occultation Keith T. Knox Air Force Research Laboratory ABSTRACT Imagery was gathered at the AMOS...observatory on the 3.6-meter telescope for the expected occultation of a star by the dwarf planet, Pluto , on 29 June 2012. The imagery was taken at...5 Hz for 40 minutes before and after the expected time of occultation. The initial analysis of the photometry indicated that Pluto did not occult

  4. Occult hepatitis B virus infection

    PubMed Central

    Kwak, Min-Sun; Kim, Yoon Jun

    2014-01-01

    Occult hepatitis B virus (HBV) infection (OBI) refers to the presence of HBV DNA in the absence of detectable hepatitis B surface antigen. Since OBI was first described in the late 1970s, there has been increasing interest in this topic. The prevalence of OBI varies according to the different endemicity of HBV infection, cohort characteristics, and sensitivity and specificity of the methods used for detection. Although the exact mechanism of OBI has not been proved, intra-hepatic persistence of viral covalently closed circular DNA under the host’s strong immune suppression of HBV replication and gene expression seems to be a cause. OBI has important clinical significance in several conditions. First, OBI can be transmitted through transfusion, organ transplantation including orthotopic liver transplantation, or hemodialysis. Donor screening before blood transfusion, prophylaxis for high-risk organ transplantation recipients, and dialysis-specific infection-control programs should be considered to reduce the risk of transmission. Second, OBI may reactivate and cause acute hepatitis in immunocompromised patients or those receiving chemotherapy. Close HBV DNA monitoring and timely antiviral treatment can prevent HBV reactivation and consequent clinical deterioration. Third, OBI may contribute to the progression of hepatic fibrosis in patients with chronic liver disease including hepatitis C. Finally, OBI seems to be a risk factor for hepatocellular carcinoma by its direct proto-oncogenic effect and by indirectly causing persistent hepatic inflammation and fibrosis. However, this needs further investigation. We review published reports in the literature to gain an overview of the status of OBI and emphasize the clinical importance of OBI. PMID:25544873

  5. Chiron stellar occultation candidates: 1993-1996

    NASA Technical Reports Server (NTRS)

    Bus, S. J.; Wasserman, L. H.; Elliot, J. L.

    1994-01-01

    A photographic search was conducted for stars that may be occulted by the unusual solar system object (2060) Chiron during the period from fall 1993 through summer 1996. 44 candidates were identified to a limiting V magnitude of 16, and for which the minimum appulse separation with Chiron is predicted to be less than 2.5 arcsec. The successful observation of a stellar occultation by Chiron would give a direct measure of its diameter (currently estimated to be between 60 and 300 km), and would help considerably in constraining Chiron's surface properties and volatile makeup. If at the time of the occultation, Chiron exhibits a significant coma, there is also the potential for measuring the optical-depth profile of the dust in its inner coma.

  6. Occult primary, version 3.2014.

    PubMed

    Ettinger, David S; Handorf, Charles R; Agulnik, Mark; Bowles, Daniel W; Cates, Justin M; Cristea, Mihaela; Dotan, Efrat; Eaton, Keith D; Fidias, Panagiotis M; Gierada, David; Gilcrease, G Weldon; Godby, Kelly; Iyer, Renuka; Lenzi, Renato; Phay, John; Rashid, Asif; Saltz, Leonard; Schwab, Richard B; Shulman, Lawrence N; Smerage, Jeffrey B; Stevenson, Marvaretta M; Varadhachary, Gauri R; Zager, Jonathan S; Zhen, Weining Ken; Bergman, Mary Anne; Freedman-Cass, Deborah A

    2014-07-01

    The NCCN Guidelines for Occult Primary tumors provide recommendations for the evaluation, workup, management, and follow-up of patients with occult primary tumors (cancers of unknown primary). These NCCN Guidelines Insights summarize major discussion points of the 2014 NCCN Occult Primary panel meeting. The panel discussed gene expression profiling (GEP) for the identification of the tissue of origin and concluded that, although GEP has a diagnostic benefit, a clinical benefit has not been demonstrated. The panel recommends against GEP as standard management, although 20% of the panel believes the diagnostic benefit of GEP warrants its routine use. In addition, the panel discussed testing for actionable mutations (eg, ALK) to help guide choice of therapy, but declined to add this recommendation.

  7. Occultation evidence for an atmosphere on Pluto

    NASA Technical Reports Server (NTRS)

    Hubbard, W. B.; Hunten, D. M.; Dieters, S. W.; Hill, K. M.; Watson, R. D.

    1988-01-01

    Observations from different sources of Pluto occulting a 12th-magnitude star indicate an extended atmosphere around the planet. Here, data obtained from the 1 m telescope at the University of Tasmania, Hobart are interpreted in terms of a theory for occultation by an atmosphere whose thickness is comparable to the planetary radius. The data can be satisfactorily fitted with a methane atmosphere at plausible pressures and temperatures. The surface pressures inferred from this single chord are uncertain by an order of magnitude, but are consistent with spectroscopic constraints.

  8. The Radio Occultation Processing Package ROPP

    NASA Astrophysics Data System (ADS)

    Culverwell, I. D.; Lewis, H. W.; Offiler, D.; Marquardt, C.; Burrows, C. P.

    2015-01-01

    This paper describes the Radio Occultation Processing Package, ROPP, a product of the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF) developed by a large number of scientists over many years. A brief review of the concepts, functionality and structure of ROPP is followed by more detailed descriptions of its key capabilities. Example results from a full chain of processing using some of the ROPP tools are presented. Some current and prospective uses of ROPP are given. Instructions on how to access the code and its supporting documentation are provided.

  9. The Radio Occultation Processing Package, ROPP

    NASA Astrophysics Data System (ADS)

    Culverwell, I. D.; Lewis, H. W.; Offiler, D.; Marquardt, C.; Burrows, C. P.

    2015-04-01

    This paper describes the Radio Occultation Processing Package, ROPP, a product of the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF) developed by a large number of scientists over many years. A brief review of the concepts, functionality and structure of ROPP is followed by more detailed descriptions of its key capabilities. Example results from a full chain of processing using some of the ROPP tools are presented. Some current and prospective uses of ROPP are given. Instructions on how to access the code and its supporting documentation are provided.

  10. Altimetry Using GPS-Reflection/Occultation Interferometry

    NASA Technical Reports Server (NTRS)

    Cardellach, Estel; DeLaTorre, Manuel; Hajj, George A.; Ao, Chi

    2008-01-01

    A Global Positioning System (GPS)- reflection/occultation interferometry was examined as a means of altimetry of water and ice surfaces in polar regions. In GPS-reflection/occultation interferometry, a GPS receiver aboard a satellite in a low orbit around the Earth is used to determine the temporally varying carrier- phase delay between (1) one component of a signal from a GPS transmitter propagating directly through the atmosphere just as the GPS transmitter falls below the horizon and (2) another component of the same signal, propagating along a slightly different path, reflected at glancing incidence upon the water or ice surface.

  11. [Diagnosis difficulty in occult constrictive pericarditis].

    PubMed

    Massoure, P L; le Bouffos, V; Roubertie, F; Lafitte, S; Roudaut, R

    2005-10-01

    We report the case of a 42 years woman known to have a cardiac heart failure attributed to restrictive cardiomyopathy for want of any other plausible diagnosis. Evolution and repeted investigations finally permitted to rectify the diagnosis by revealing a constrictive pericarditis, remained occult 9 years during. The differentiation of restrictive cardiomyopathy and constrictive pericarditis has been a perennial problem in clinical cardiology. Diagnosis of constrictive pericarditis is based on associated signs sometimes too poor to go straight to thoracotomy. We discuss the mean to approach more precisely this uncommon pattern named occult constrictive pericarditis.

  12. Evaluation of bone remodeling in regard to the age of scaphoid non-unions

    PubMed Central

    Rein, Susanne; Hanisch, Uwe; Schaller, Hans-Eberhard; Zwipp, Hans; Rammelt, Stefan; Weindel, Stefan

    2016-01-01

    AIM: To analyse bone remodeling in regard to the age of scaphoid non-unions (SNU) with immunohistochemistry. METHODS: Thirty-six patients with symptomatic SNU underwent surgery with resection of the pseudarthrosis. The resected material was evaluated histologically after staining with hematoxylin-eosin (HE), tartrate resistant acid phosphatase (TRAP), CD 68, osteocalcin (OC) and osteopontin (OP). Histological examination was performed in a blinded fashion. RESULTS: The number of multinuclear osteoclasts in the TRAP-staining correlated with the age of the SNU and was significantly higher in younger SNU (P = 0.034; r = 0.75). A higher number of OP-immunoreactive osteoblasts significantly correlated with a higher number of OC-immunoreactive osteoblasts (P = 0.001; r = 0.55). Furthermore, a greater number of OP-immunoreactive osteoblasts correlated significantly with a higher number of OP-immunoreactive multinuclear osteoclasts (P = 0.008; r = 0.43). SNU older than 6 mo showed a significant decrease of the number of fibroblasts (P = 0.04). Smoking and the age of the patients had no influence on bone remodeling in SNU. CONCLUSION: Multinuclear osteoclasts showed a significant decrease in relation to the age of SNU. However, most of the immunhistochemical findings of bone remodeling do not correlate with the age of the SNU. This indicates a permanent imbalance of bone formation and resorption as indicated by a concurrent increase in both osteoblast and osteoclast numbers. A clear histological differentiation into phases of bone remodeling in SNU is not possible. PMID:27458552

  13. Photoelectric observations of lunar occultations. XI

    NASA Astrophysics Data System (ADS)

    Edwards, D. A.; Evans, D. S.; Fekel, F. C.; Smith, B. W.

    1980-04-01

    Occultation observations of 466 events are presented. These include diameter measures of Aldebaran under very bad conditions and a good diameter measure of 82 Vir. The list includes 91 reappearances and observations of 34 double or multiple stars, both new and previously known. The inconsistencies of the observations of Kui 88 are discussed. Further observations are most desirable.

  14. Stellar angular diameters from occultation observations.

    NASA Astrophysics Data System (ADS)

    Qian, B.-C.

    This paper reviews the history of measuring stellar angular diameters from lunar occultation observations and the techniques of data analysis. Several effects which can affect the results of measurement are discussed. The author finds that there may be systematic errors in angular diameters measured by various observatories for Aldebaran.

  15. Occult carcinoma of the thyroid gland.

    PubMed

    Arellano, L; Ibarra, A

    1984-09-01

    Ten occult carcinomas of the thyroid gland were found in 274 unselected autopsies at the Pathology Service, Hospital José Joaquín Aguirre, between December 1980 and March 1983. This is the lowest incidence among the most recent published series. The present results suggest that environmental factors play an important role in the etiology of this type of carcinoma.

  16. Photon counts from stellar occultation sources

    NASA Technical Reports Server (NTRS)

    Buglia, James J.

    1987-01-01

    The feasibility of using stars as radiation sources for Earth atmospheric occultation experiments is investigated. Exoatmospheric photon counts of the order of 10 to the 6th power photons/sq cm/sec are realized for the 15 visually brightest stars. Most photon counts appear to be marginally detectable unless photomultiplier or cascade detection devices can be used.

  17. Illinois occultation summary, 1. 1977 - 1978

    NASA Technical Reports Server (NTRS)

    Radick, R.; Lien, D.

    1980-01-01

    Instrumentation and data acquisition techniques used to record lunar occultations at the University of Illinois Prairie Observatory are described. Tables and graphs summarize data from 64 events which include 30 observations of stars brighter than 7th magnitude, 40 reappearances, 4 angular diameter measurements, 8 observations of binary stars, and 6 observations which may indicate multiplicity.

  18. Elbow Pain After a Fall: Nursemaid's Elbow or Fracture?

    PubMed

    Cohen-Rosenblum, Anna; Bielski, Robert J

    2016-06-01

    Nursemaid's elbow and elbow fractures are both common causes of acute elbow pain, but the mechanism of injury is quite different. In children, falls frequently go unwitnessed and children are often inaccurate when recounting the sequences of a fall, making the mechanism difficult to ascertain. A common clinical mistake is to treat all elbow injuries as a nursemaid's elbow. When the mechanism of injury is unknown, radiographs should be used to help make the diagnosis. Occult fractures, also known as "hairline" elbow fractures, may not be visible on initial X-rays, but clues to the diagnosis, especially the posterior fat pad, can be helpful in evaluation. When an occult fracture is suspected based on history and radiographic findings, the patient's elbow should be immobilized, not manipulated. This article also reviews successful reduction maneuvers for nursemaid's elbow. [Pediatr Ann. 2016;45(6):e214-e217.].

  19. Cassini Radio Occultation by Enceladus Plume

    NASA Astrophysics Data System (ADS)

    Kliore, A.; Armstrong, J.; Flasar, F.; French, R.; Marouf, E.; Nagy, A.; Rappaport, N.; McGhee, C.; Schinder, P.; Anabtawi, A.; Asmar, S.; Barbinis, E.; Fleischman, D.; Goltz, G.; Aguilar, R.; Rochblatt, D.

    2006-12-01

    A fortuitous Cassini radio occultation by Enceladus plume occurs on September 15, 2006. The occultation track (the spacecraft trajectory in the plane of the sky as viewed from the Earth) has been designed to pass behind the plume (to pass above the south polar region of Enceladus) in a roughly symmetrical geometry centered on a minimum altitude above the surface of about 20 km. The minimum altitude was selected primarily to ensure probing much of the plume with good confidence given the uncertainty in the spacecraft trajectory. Three nearly-pure sinusoidal signals of 0.94, 3.6, and 13 cm-wavelength (Ka-, X-, and S-band, respectively) are simultaneously transmitted from Cassini and are monitored at two 34-m Earth receiving stations of the Deep Space Network (DSN) in Madrid, Spain (DSS-55 and DSS-65). The occultation of the visible plume is extremely fast, lasting less than about two minutes. The actual observation time extends over a much longer time interval, however, to provide a good reference baseline for potential detection of signal perturbations introduced by the tenuous neutral and ionized plume environment. Given the likely very small fraction of optical depth due to neutral particles of sizes larger than about 1 mm, detectable changes in signal intensity is perhaps unlikely. Detection of plume plasma along the radio path as perturbations in the signals frequency/phase is more likely and the magnitude will depend on the electron columnar density probed. The occultation time occurs not far from solar conjunction time (Sun-Earth-probe angle of about 33 degrees), causing phase scintillations due to the solar wind to be the primary limiting noise source. We estimate a delectability limit of about 1 to 3E16 electrons per square meter columnar density assuming about 100 seconds integration time. Potential measurement of the profile of electron columnar density along the occultation track is an exciting prospect at this time.

  20. Treatment of Scaphoid Waist Nonunion Using Olecranon Bone Graft and Stryker Asnis Micro Cannulated Screw: A Retrospective Study—80 Case Studies and 6 Years of Follow-Up

    PubMed Central

    Poggetti, Andrea; Rosati, Marco; Castellini, Iacopo; Evangelisti, Gisberto; Battistini, Pietro; Parchi, Paolo; Lisanti, Michele

    2015-01-01

    Background Screw fixation and bone grafting are the gold standard for scaphoid waist nonunion without avascular necrosis. Question/Purpose Assesses the scaphoid waist nonunion healing rate with use of an uncommon cancellous bone graft (olecranon) and an unusual fixation system (Asnis Micro Cannulated Screw System; Stryker Inc., Kalamazoo, MI, USA). Material and Methods A series of 102 consecutive patients were treated for scaphoid waist nonunion (without deformity). Of these, 80 patients subjected to clinical (Modified Mayo Wrist Score (MMWS), Jamar hydraulic dynamometer) and radiographic examination before and after surgery were evaluated. Ipsilateral olecranon cancellous bone graft and the ASNIS Micro 3.0-mm diameter screw, were used. The average follow up was 6 years (min 3; max 10). Results Radiographic consolidation was achieved in 90% of patients; dorsal intercalated segment instability (DISI) deformities were corrected in 71.4% of cases. Ninety percent improved the range of motion of the wrist and grip strength. All patients showed a significant reduction of peak force in the operated hand. In 6.25% we observed clinical and radiographic screw head–trapezium impingement. Twenty-six patients developed a degenerative wrist sign. The MMWS yielded 68 optimal, 8 good, and 4 bad results. Conclusions To treat scaphoid waist nonunions without misalignment, low-profile headed screw and olecranon bone graft allowed a high consolidation rate with positive results to long-term follow-up. The Asnis Micro 3.0 mm diameter screw may be a suitable option for treating scaphoid waist nonunion. Level of Evidence IV. PMID:26261746

  1. Treatment of Scaphoid Waist Nonunion Using Olecranon Bone Graft and Stryker Asnis Micro Cannulated Screw: A Retrospective Study-80 Case Studies and 6 Years of Follow-Up.

    PubMed

    Poggetti, Andrea; Rosati, Marco; Castellini, Iacopo; Evangelisti, Gisberto; Battistini, Pietro; Parchi, Paolo; Lisanti, Michele

    2015-08-01

    Background Screw fixation and bone grafting are the gold standard for scaphoid waist nonunion without avascular necrosis. Question/Purpose Assesses the scaphoid waist nonunion healing rate with use of an uncommon cancellous bone graft (olecranon) and an unusual fixation system (Asnis Micro Cannulated Screw System; Stryker Inc., Kalamazoo, MI, USA). Material and Methods A series of 102 consecutive patients were treated for scaphoid waist nonunion (without deformity). Of these, 80 patients subjected to clinical (Modified Mayo Wrist Score (MMWS), Jamar hydraulic dynamometer) and radiographic examination before and after surgery were evaluated. Ipsilateral olecranon cancellous bone graft and the ASNIS Micro 3.0-mm diameter screw, were used. The average follow up was 6 years (min 3; max 10). Results Radiographic consolidation was achieved in 90% of patients; dorsal intercalated segment instability (DISI) deformities were corrected in 71.4% of cases. Ninety percent improved the range of motion of the wrist and grip strength. All patients showed a significant reduction of peak force in the operated hand. In 6.25% we observed clinical and radiographic screw head-trapezium impingement. Twenty-six patients developed a degenerative wrist sign. The MMWS yielded 68 optimal, 8 good, and 4 bad results. Conclusions To treat scaphoid waist nonunions without misalignment, low-profile headed screw and olecranon bone graft allowed a high consolidation rate with positive results to long-term follow-up. The Asnis Micro 3.0 mm diameter screw may be a suitable option for treating scaphoid waist nonunion. Level of Evidence IV.

  2. Stellar Occultation Probe of Triton's Atmosphere

    NASA Technical Reports Server (NTRS)

    Elliot, James L.

    1998-01-01

    The goals of this research were (i) to better characterize Triton's atmospheric structure by probing a region not well investigated by Voyager and (ii) to begin acquiring baseline data for an investigation of the time evolution of the atmosphere which will set limits on the thermal conductivity of the surface and the total mass of N2 in the atmosphere. Our approach was to use observations (with the Kuiper Airborne Observatory) of a stellar occultation by Triton that was predicted to occur on 1993 July 10. As described in the attached reprint, we achieved these objectives through observation of this occultation and a subsequent one with the KAO in 1995. We found new results about Triton's atmospheric structure from the analysis of the two occultations observed with the KAO and ground-based data. These stellar occultation observations made both in the visible and infrared, have good spatial coverage of Triton including the first Triton central-flash observations, and are the first data to probe the 20-100 km altitude level on Triton. The small-planet light curve model of Elliot and Young (AJ 103, 991-1015) was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude indicating that Triton's atmosphere is spherically symmetric at approximately 50 km altitude to within the error of the measurements. However, asymmetry observed in the central flash indicates the atmosphere is not homogeneous at the lowest levels probed (approximately 20 km altitude). From the average of the 1995 occultation data, the equivalent-isothermal temperature of the atmosphere is 47 +/- 1 K and the atmospheric pressure at 1400 km radius (approximately 50 km altitude) is 1.4 +/- 0.1 microbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989 (Strobel et al, Icarus 120, 266-289). The atmospheric

  3. Distal Radius Radiographic Indices and Perilunate Fracture Dislocation

    PubMed Central

    Bagherifard, Abolfazl; Jafari, Davod; Keihan Shokouh, Hassan; Motavallian, Ebrahim; Najd Mazhar, Farid

    2016-01-01

    Background Distal radius radiographic indices may play a role as risk factors in pathogenesis of Kienbock’s disease, scaphoid fracture and nonunion. Perilunate fracture dislocations are devastating wrist injuries, and their relationship and distal radius indices have not been addressed in the literature. Objectives The aim of this study was to evaluate the possible role of distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt as risk factors in the perilunate fracture dislocation injury of the wrist. Patients and Methods We studied distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt in 43 patients with perilunate fracture dislocations and compared them with 44 wrists in the control group. Results The mean values of the radial height, radial inclination, ulnar variance and volar tilt were 12.74 (5 - 18), 24.20 (7 - 35), -0.73 (-5 - 4) and 12.28 (2 - 20) in the patient group. These values were 12.68 (9 - 22), 23.22 (17 - 30), -0.11 (-4 - 3) and 11.05 (-3 - 20), respectively in the control group. There was no statistically significant difference between the two groups. Conclusions This study did not show that distal radius anatomical indices including the radial height, radial inclination, ulnar variance and volar tilt influence perilunate fracture dislocation as risk factors. PMID:27626004

  4. Shoulder Fractures

    MedlinePlus

    ... Journal of Hand Surgery (JHS) Home Anatomy Shoulder Fractures Email to a friend * required fields From * To * ... create difficulty with its function. Types of Shoulder Fractures The type of fracture varies by age. Most ...

  5. Stress Fractures

    MedlinePlus

    Stress fractures Overview By Mayo Clinic Staff Stress fractures are tiny cracks in a bone. They're caused by ... up and down or running long distances. Stress fractures can also arise from normal use of a ...

  6. Greenstick Fractures

    MedlinePlus

    Greenstick fractures Overview By Mayo Clinic Staff A greenstick fracture occurs when a bone bends and cracks, instead of breaking completely into separate pieces. The fracture looks similar to what happens when you try ...

  7. Current methods of radio occultation data inversion

    NASA Technical Reports Server (NTRS)

    Kliore, A. J.

    1972-01-01

    The methods of Abel integral transform and ray-tracing inversion have been applied to data received from radio occultation experiments as a means of obtaining refractive index profiles of the ionospheres and atmospheres of Mars and Venus. In the case of Mars, certain simplifications are introduced by the assumption of small refractive bending in the atmosphere. General inversion methods, independent of the thin atmosphere approximation, have been used to invert the data obtained from the radio occultation of Mariner 5 by Venus; similar methods will be used to analyze data obtained from Jupiter with Pioneers F and G, as well as from the other outer planets in the Outer Planet Grand Tour Missions.

  8. [Chronic hepatitis and occult HCV infection].

    PubMed

    Kowala-Piaskowska, Arleta; Mozer-Lisewska, Iwona; Pham, Tram N Q; Michalak, Tomasz I

    2010-01-01

    Hepatitis C virus (HCV) was discovered in 1989. HCV is a positive single-strand RNA. We all have thought, that HCV can replicate only in liver tissue, but now we know, that HCV can replicate in extrahepatic tissue as well. In about 48-86% of HCV infected patients, chronic hepatitis C (CHC) has been noticed and eventually, after tens of years, liver insufficiency, cirrhosis or hepatocellular carcinoma. The current recommended treatment for CHC is a combination of pegylated-interferon alpha and Ribavirin. Presently it is known, that HCV infection can persist as an occult infection. RNA HCV can be detected in patients after successful treatment for CHC or spontaneous elimination. Persistent HCV replication in hepatocytes or lymphoid cells would likely lead to continuous antigenic stimulation of the immune system. This prolonged replication may contribute to the immune tolerance of HCV, impairment of immune response and even further virus persistence. This occult infection grows more important in transplantation.

  9. CASSINI UVIS STELLAR OCCULTATION OBSERVATIONS OF SATURN's RINGS

    SciTech Connect

    Colwell, J. E.; Jerousek, R. G.; Pettis, D.; Bradley, E. T.; Esposito, L. W.; Sremcevic, M.

    2010-12-15

    The Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS) includes a high-speed photometer (HSP) that has observed more than 100 stellar occultations by Saturn's rings. Here, we document a standardized technique applied to the UVIS-HSP ring occultation datasets delivered to the Planetary Data System as higher level data products. These observations provide measurements of ring structure that approaches the scale of the largest common ring particles ({approx}5 m). The combination of multiple occultations at different viewing geometries enables reconstruction of the three-dimensional structure of the rings. This inversion of the occultation data depends on accurate calibration of the data so that occultations of different stars taken at different times and under different viewing conditions can be combined to retrieve ring structure. We provide examples of the structure of the rings as seen from several occultations at different incidence angles to the rings, illustrating changes in the apparent structure with viewing geometry.

  10. Study of transneptunian objects through stellar occultations

    NASA Astrophysics Data System (ADS)

    Benedetti-Rossi, G.; Sicardy, B.; Braga-Ribas, F.

    2014-07-01

    The physical parameters of the transneptunian objects (TNO's) such as size, shape, density, presence of atmosphere, provide important information on their formation and evolution. At more than 30 astronomical units (au) from the Sun, those objects receive low solar radiation and have low mutual collisions so they can be considered as remnants of the primordial outer Solar System. Besides that, information on TNO's is of great relevance when trying to establish a general formation scenario for the recently discovered planetary systems. The problem is that such bodies have a diameter smaller than 2300 km (Eris, one of the largest TNO, has 2326 km) and, when viewed from Earth, they subtend angles smaller than 50 milli-arcseconds, a fact that makes their resolution very poor with current imaging systems. One method to obtain very accurate information on the TNO's is the stellar-occultation technique. Sizes at kilometer accuracies and pressure at nanobar levels can be achieved with this method. Shape, mass, density and other physical parameters can also be derived using this technique. Since 2010, we observed stellar occultations of several TNO's (Varuna in 2010 and 2013; Eris in 2010; 2003 AZ_{84} in 2010 and 2011; Makemake in 2011; Quaoar in 2011 and two in 2012; 2002 KX_{14} in 2013; and finally Sedna in 2013) besides some other occultations of the Pluto system and of the largest Centaurs. We also predicted future events in 2014 and 2015 for the largest 40 TNO's and Centaurs. In this work, we will present new results obtained from recent stellar occultations of TNO's.

  11. Potential KBO Stellar Occultations: 2011-2015

    NASA Astrophysics Data System (ADS)

    Zangari, Amanda; Zuluaga, C. A.; Gulbis, A. A. S.; Elliot, J. L.; Person, M. J.; Bosh, A. S.

    2010-10-01

    We present the results of an occultation candidate search of the UCAC2 catalog for over 30 Kuiper Belt Objects and Centaurs [not including (134340) Pluto]. KBOs were selected based on absolute magnitude, distance from the sun and the number of oppositions observed. This search identified occultation candidate stars within 2.5 arcseconds of each minor planet's path from 2011-2015. As typical UCAC2 catalog uncertainties ranged from 0.05 to 0.5 arcseconds, and KBO ephemeris uncertainties for a well-observed object ranged from 0.2 to 0.6 arcseconds, this study seeks to identify the most promising potential occultations for further astrometric follow-up. Additional observations of stars and the potentially occulting body help determine the necessary star offsets and ephemeris corrections. Events have been grouped into the following categories: near-geocentric (any brightness), near-misses, stars of magnitude 13 or brighter (the dimmest star feasible with a large portable telescope), slow events, and events observable from telescope-rich regions of the Earth. These categories allow for planning campaigns involving wide-spread portable and fixed telescopes, or an airborne telescope (such as SOFIA). The two most promising events are an encounter of (28978) Ixion with a 10.63 magnitude star on 2012-04-16 and (84922) 2003 VS2 with a 14.83 magnitude star on 2011-11-01. KBOs such as (50000) Quaoar, (28978) Ixion, (55638) 2002 VE95, and (84922) 2003 VS2 encounter over 50 UCAC2 stars in the next five years and should be most carefully monitored. This work was supported, in part by NASA Grant NNX10AB27G.

  12. The JWST/NIRCam Coronagraph Flight Occulters

    NASA Technical Reports Server (NTRS)

    Krist, John E.; Balasubramanian, Kunjithapatham; Muller, Richard E.; Shaklan, Stuart B.; Kelly, Douglas M.; Wilson, Daniel W.; Beichman, Charles A.; Serabyn, Eugene; Mao, Yalan; Echternach, Pierre M.; Trauger, John T.; Liewer, Kurt M.

    2010-01-01

    The NIRCam instrument on the James Webb Space Telescope will have a Lyot coronagraph for high contrast imaging of extrasolar planets and circumstellar disks at lambda = 2 - 5 micrometers. Half-tone patterns are used to create graded-transmission image plane masks. These are generated using electron beam lithography and reactive ion etching of a metal layer on an antireflection coated sapphire substrate. We report here on the manufacture and evaluation of the flight occulters.

  13. Asteroidal occultation timed by four UK observers

    NASA Astrophysics Data System (ADS)

    McGee, H.

    2000-04-01

    The occultation of a 9th magnitude star by the minor planet (49) Pales at 01.00 on Monday January 17 was the first such event to be timed by more than one observer at different locations on the track in the UK (see Figure 1). It was also seen from Hungary, and by three sets of observers in Canada and the USA, but unfortunately heavy cloud prevented observation across most of Europe.

  14. [Occult hepatitis B virus infection in chronic hepatitis C].

    PubMed

    Jang, Jae Young; Park, Eui Ju

    2013-09-01

    Occult HBV infection is defined as the presence of HBV DNA in the liver (with or without detectable or undetectable HBV DNA in the serum) of individuals testing negative for HBsAg. Studies on occult HBV infection in hepatitis C patients have reported highly variable prevalence, because the prevalence of occult HBV infection varies depending on the hepatitis B risk factors and methodological approaches. The most reliable diagnostic approach for detecting occult HBV detection is through examination of liver DNA extracts. HCV has been suspected to strongly suppress HBV replication up to the point where it may be directly responsible for occult HBV infection development. However, more data are needed to arrive at a definitive conclusion regarding the role of HCV in inducing occult HBV infection. Occult HBV infection in chronic hepatitis C patients is a complex biological entity with possible relevant clinical implications. Influence of occult HBV infection on the clinical outcomes of chronic hepatitis C may be considered negative. However, recent studies have shown that occult HBV infection could be associated with the development of hepatocellular carcinoma and contribute to the worsening of the course of chronic liver disease over time in chronic hepatitis C patients. Nevertheless, the possible role of occult HBV infection in chronic hepatitis C is still unresolved and no firm conclusion has been made up until now. It still remains unclear how occult HBV infection affects the treatment of chronic hepatitis C. Therefore, in order to resolve current controversies and understand the pathogenic role and clinical impacts of occult HBV infection in chronic hepatitis C patients, well-designed clinical studies are needed.

  15. Io hot spots - Infrared photometry of satellite occultations

    NASA Technical Reports Server (NTRS)

    Goguen, J. D.; Matson, D. L.; Sinton, W. M.; Howell, R. R.; Dyck, H. M.

    1988-01-01

    Io's active hot spots, which are presently mapped on the basis of IR photometry of this moon's occultation by other Gallilean satellites, are obtained with greatest spatial resolution near the sub-earth point. A model is developed for the occultation lightcurves, and its fitting to the data defines the apparent path of the occulting satellite relative to Io; the mean error in apparent relative position of occulting satellites is of the order of 178 km. A heretofore unknown, 20-km diameter hot spot is noted on Io's leading hemisphere.

  16. The Northrop Grumman External Occulter Testbed: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Lo, Amy; Glassman, T.; Lillie, C.

    2007-05-01

    We have built a subscale testbed to demonstrate and validate the performance of the New Worlds Observer (NWO), a terrestrial planet finder external-occulter mission concept. The external occulter concept allows observations of nearby exo-Earths using two spacecraft: one carrying an occulter that is tens of meters in diameter and the other carrying a generic space telescope. The occulter is completely opaque, resembling a flower, with petals having a hypergaussian profile that enable 10-10 intensity suppression of stars that potentially harbor terrestrial planets. The baseline flight NWO system has a 30 meter occulter flying 30,000 km in front of a 4 meter class telescope. Testing the flight configuration on the ground is not feasible, so we have matched the Fresnel number of the flight configuration ( 10) using a subscale occulter. Our testbed consists of an 80 meter length evacuated tube, with a high precision occulter in the center of the tube. The occulter is 4 cm in diameter, manufactured with ¼ micron metrological accuracy and less than 2 micron tip truncation. This mimics a 30 meter occulter with millimeter figure accuracy and less than centimeter tip truncation. Our testbed is an evolving experiment, and we report here the first, preliminary, results using a single wavelength laser (532 nm) as the source.

  17. Several Well-observed Asteroidal Occultations in 2010

    NASA Astrophysics Data System (ADS)

    Timerson, Brad; Durech, J.; Abramson, H.; Brooks, J.; Caton, D.; Clark, D.; Conard, S.; Cooke, B.; Dunham, D. W.; Dunham, J.; Edberg, S.; Ellington, C.; Faircloth, J.; Herchak, S.; Iverson, E.; Jones, R.; Lucas, G.; Lyzenga, G.; Maley, P.; Martinez, L.; Menke, J.; Mroz, G.; Nolan, P.; Peterson, R.; Preston, S.; Rattley, G.; Ray, J.; Scheck, A.; Stamm, J.; Stanton, R.; Suggs, R.; Tatum, R.; Thomas, W.

    2011-10-01

    During 2010 IOTA observers in North America reported about 190 positive observations for 106 asteroid occultation events. For several asteroids, this included observations with multiple chords. For two events, an inversion model was available. An occultation by 16 Psyche on 2010 August 21 yielded a best-fit ellipse of 235.4 x 230.4 km. On 2010 December 24, an occultation by 93 Minerva produced a best-fit ellipse of 179.4 x 133.4 km. An occultation by 96 Aegle on 2010 October 29 yielded a best-fit ellipse of 124.9 x 88.0 km. An occultation by 105 Artemis on 2010 June 24 showed a best-fit ellipse of 125.0 x 92.0 km. An occultation by 375 Ursula on 2010 December 4 produced a best-fit ellipse of 125.0 km x 135.0 km. Of note are two events not summarized in this article. On 2010 August 31, an occultation by 695 Bella yielded a new double star. That event will be summarized in the JDSO. Finally, on 2010 April 6, an occultation of zeta Ophiuchi by 824 Anastasia was observed by 65 observers at 69 locations. Unfortunately a large shift in the path yielded only 4 chords. Results of that event, and all the events mentioned here, can be found on the North American Asteroidal Occultation Results web page.

  18. Cerebral Venous Air Embolism due to a Hidden Skull Fracture Secondary to Head Trauma

    PubMed Central

    Hosaka, Ai; Yamaguchi, Tetsuto; Yamamoto, Fumiko; Shibagaki, Yasuro

    2015-01-01

    Cerebral venous air embolism is sometimes caused by head trauma. One of the paths of air entry is considered a skull fracture. We report a case of cerebral venous air embolism following head trauma. The patient was a 55-year-old man who fell and hit his head. A head computed tomography (CT) scan showed the air in the superior sagittal sinus; however, no skull fractures were detected. Follow-up CT revealed a fracture line in the right temporal bone. Cerebral venous air embolism following head trauma might have occult skull fractures even if CT could not show the skull fractures. PMID:26693366

  19. UMBRAS: a matched occulter and telescope for imaging extrasolar planets

    NASA Astrophysics Data System (ADS)

    Schultz, Alfred B.; Jordan, Ian J.; Kochte, Mark; Fraquelli, Dorothy A.; Bruhweiler, Fred; Hollis, Jan M.; Carpenter, Kenneth G.; Lyon, Richard G.; DiSanti, Mike A.; Miskey, Cherie L.; Leitner, Jesse; Burns, Richard D.; Starin, Scott R.; Rodrigue, Melodi; Fadali, M. S.; Skelton, Dennis L.; Hart, Helen M.; Hamilton, Forrest C.; Cheng, Kwang-Ping

    2003-02-01

    We describe a 1-meter space telescope plus free-flying occulter craft mission that would provide direct imaging and spectroscopic observations of Jovian and Uranus-sized planets about nearby stars not detectable by Doppler techniques. The Doppler technique is most sensitive for the detection of massive, close-in extrasolar planets while the use of a free-flying occulter would make it possible to image and study stellar systems with planets comparable to our own Solar System. Such a mission with a larger telescope has the potential to detect earth-like planets. Previous studies of free-flying occulters reported advantages in having the occulting spot outside the telescope compared to a classical coronagraph onboard a space telescope. Using an external occulter means light scatter within the telescope is reduced due to fewer internal obstructions and less light entering the telescope and the polishing tolerances of the primary mirror and the supporting optics can be less stringent, thereby providing higher contrast and fainter detection limits. In this concept, the occulting spot is positioned over the star by translating the occulter craft, at distances of 1,000 to 15,000 kms from the telescope, on the sky instead of by moving the telescope. Any source within the telescope field-of-view can be occulted without moving the telescope. In this paper, we present our current concept for a 1-m space telescope matched to a free-flying occulter, the Umbral Missions Blocking Radiating Astronomical Sources (UMBRAS) space mission. An UMBRAS space mission consists of a Solar Powered Ion Driven Eclipsing Rover (SPIDER) occulter craft and a matched (apodized) telescope. The occulter spacecraft would be semi-autonomous, with its own propulsion systems, internal power (solar cells), communications, and navigation capability. Spacecraft rendezvous and formation flying would be achieved with the aid of telescope imaging, RF or laser ranging, celestial navigation inputs, and formation

  20. New perspectives in occult hepatitis C virus infection.

    PubMed

    Carreño, Vicente; Bartolomé, Javier; Castillo, Inmaculada; Quiroga, Juan Antonio

    2012-06-21

    Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C, indicate that occult HCV is a persistent infection that is not spontaneously eradicated. This is an updated report on diagnosis, epidemiology and clinical implications of occult HCV with special emphasis on anti-HCV negative cases.

  1. Neglected trans-scaphoid trans-styloid volar dislocation of the lunate. Late result following open reduction and K-wire fixation.

    PubMed

    Givissis, P; Christodoulou, A; Chalidis, B; Pournaras, J

    2006-05-01

    A rare case of radiocarpal dislocation is presented. The lunate and proximal pole of the scaphoid were displaced in a volar and proximal direction. The injury was missed initially and the patient was subsequently operated on six weeks later. Open reduction and internal fixation of the scaphoid was performed and this was followed by an uneventful postoperative period, with a satisfactory functional outcome at the eight-year follow-up, despite carpal instability non-dissociative-dorsal intercalated segmental instability configuration of the carpus. We believe that although open reduction in neglected cases carries the potential risks of avascular necrosis and nonunion of the affected carpal bones, an attempt should be made to restore the anatomy of the carpus.

  2. Retrieval Algorithms for the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Thompson, Robert E.; Gordley, Larry L.

    2009-01-01

    The Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) provided high quality measurements of key middle atmosphere constituents, aerosol characteristics, and temperature for 14 years (1991-2005). This report is an outline of the Level 2 retrieval algorithms, and it also describes the great care that was taken in characterizing the instrument prior to launch and throughout its mission life. It represents an historical record of the techniques used to analyze the data and of the steps that must be considered for the development of a similar experiment for future satellite missions.

  3. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Elliot, James; Kern, Susan; Zuluaga, Carlos; Gulbis, Amanda

    2010-02-01

    In order to observe an occultation of a bright star by a Kuiper Belt object the event must first be predicted as to where and when it will happen. These predictions require precise astrometry every few months of the largest Kuiper Belt objects. Through the occultation events the diameters, possible companions and possible tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This promises to be a completely new and powerful way of exploring the KBOs. We propose to continue to obtain very precise astrometry on the known brightest KBOs to determine more accurate orbits and thus reliable occultation predictions. In addition, we must also obtain accurate astrometry on faint field stars that the KBOs of interest may occult. On October 9, 2009 we predict KBO 55636 will occult a 13th magnitude star and this will be our first attempt to observe such an event.

  4. Radio occultation experiments with INAF-IRA radiotelescopes.

    NASA Astrophysics Data System (ADS)

    Pluchino, S.; Schillirò, F.; Salerno, E.; Pupillo, G.

    The Radio Occultation research program performed at the Medicina and Noto Radioastronomical Stations of the Istituto Nazionale di Astrofisica (INAF) - Istituto di Radioastronomia (IRA) includes observations of spacecraft by satellite and satellite by satellite events. The Lunar Radio Occultation (LRO) part of the program consists in collecting data of the lunar Total Electron Content (TEC), at different limb longitudes and at different time, in order to study long term variation of the Moon's ionosphere. The LRO program started at Medicina in September 2006 with the observation of the European probe SMART-1 during its impact on the lunar soil. It proceeded in 2007 with the observation of the lunar occultations of Saturn and Venus, and with the observation of Mars in 2008. On this occasion the probes Cassini, Venus Express, Mars Express, Mars Reconaissance Orbiter and Mars Odissey were respectively occulted by the moon. On Dec 1st 2008 a Venus lunar occultation occurred. On that occasion we performed the first Italian-VLBI (I-VLBI) tracking experiment by detecting the carrier signals coming from the Venus Express (VEX) spacecraft with both the IRA radiotelescopes together with the Matera antenna of the Italian Space Agency. The second part of the radio occultation program includes the observation of satellite by satellite occultation events, as well as mutual occultations of Jupiter satellites. These events are referred to as mutual phenomena (PHEMU). These observations are aimed to measure the radio flux variation during the occultation and to derive surface spatial characteristics such as Io's hot spots. In this work preliminary results of the Radio Occultation program will be presented.

  5. MRI Correlation of Radial Head Fractures and Forearm Injuries.

    PubMed

    Awan, Hisham; Goitz, Robert

    2017-03-01

    Background: Radial head fractures can be associated with soft tissue injuries of the forearm and wrist. The Essex-Lopresti injury can lead to significant morbidity, especially if the diagnosis is not made acutely. Better identification of such injuries is needed to allow optimal surgical treatment and prevent long-term sequelae. We used magnetic resonance imaging (MRI) to correlate the degree of soft tissue injuries with radial head fractures. Methods: Sixteen pairs of forearms with an associated radial head fracture in 15 patients prospectively underwent an MRI within 2 weeks of their injury. MRI findings were correlated with fracture type, associated soft tissue injury, and presence of symptomatic wrist pain. Results: According to the modified Mason classification, there were 8 type I, 5 type II, and 3 type III radial head fractures. Wrist pain was reported in 8 of 16 extremities, and 2 had associated wrist pathology, including an acute scaphoid fracture in 1 patient and a preexisting stage II scapholunate advanced collapse (SLAC) wrist in another patient. The MRI findings included an elbow effusion in all 16 patients, edema in the proximal third of the radius in 15 extremities, which extended to the middle third in 3 extremities, edema of the interosseous membrane (IOM) in 5 extremities, and edema of the soft tissues including the supinator and/or pronator quadratus in 13 extremities. Conclusions: Eighty percent of patients with edema of the IOM had associated wrist pain. Soft tissue injuries of the forearm did not correlate with the severity of the radial head fracture.

  6. Vascularized bone grafts for the treatment of carpal bone pathology.

    PubMed

    Derby, Brian M; Murray, Peter M; Shin, Alexander Y; Bueno, Reuben A; Mathoulin, Christophe L; Ade, Tim; Neumeister, Michael W

    2013-03-01

    Primary bone healing fails to occur in 5-15 % of scaphoid bones that undergo fracture fixation. Untreated, occult fractures result in nonunion up to 12 % of the time. Conventional bone grafting is the accepted management in the treatment algorithm of scaphoid nonunion if the proximal pole is vascularized. Osteonecrosis of the proximal scaphoid pole intuitively suggests a need for transfer of the vascularized bone to the nonunion site. Scaphoid nonunion treatment aims to prevent biological and mechanical subsidence of the involved bone, destabilization of the carpus, and early degenerative changes associated with scaphoid nonunion advanced collapse. Pedicled distal radius and free vascularized bone grafts (VBGs) offer hand surgeons an alternative treatment option in the management of carpal bone nonunion. VBGs are also indicated in the treatment of avascular necrosis of the scaphoid (Preiser's disease), lunate (Kienböck's disease), and capitate. Relative contraindications to pedicled dorsal radius vascularized bone grafting include humpback deformity, carpal instability, or collapse. The free medial femoral condyle bone graft has offered a novel treatment option for the humpback deformity to restore geometry of the carpus, otherwise not provided by pedicled grafts. In general, VBGs are contraindicated in the setting of a carpal bone without an intact cartilaginous shell, in advanced carpal collapse with degenerative changes, and in attempts to salvage small or collapsed bone fragments. Wrist salvage procedures are generally accepted as the more definitive treatment option under such circumstances. This manuscript offers a current review of the techniques and outcomes of VBGs to the carpal bones.

  7. [Atlas fractures].

    PubMed

    Schären, S; Jeanneret, B

    1999-05-01

    Fractures of the atlas account for 1-2% of all vertebral fractures. We divide atlas fractures into 5 groups: isolated fractures of the anterior arch of the atlas, isolated fractures of the posterior arch, combined fractures of the anterior and posterior arch (so-called Jefferson fractures), isolated fractures of the lateral mass and fractures of the transverse process. Isolated fractures of the anterior or posterior arch are benign and are treated conservatively with a soft collar until the neck pain has disappeared. Jefferson fractures are divided into stable and unstable fracture depending on the integrity of the transverse ligament. Stable Jefferson fractures are treated conservatively with good outcome while unstable Jefferson fractures are probably best treated operatively with a posterior atlanto-axial or occipito-axial stabilization and fusion. The authors preferred treatment modality is the immediate open reduction of the dislocated lateral masses combined with a stabilization in the reduced position using a transarticular screw fixation C1/C2 according to Magerl. This has the advantage of saving the atlanto-occipital joints and offering an immediate stability which makes immobilization in an halo or Minerva cast superfluous. In late instabilities C1/2 with incongruency of the lateral masses occurring after primary conservative treatment, an occipito-cervical fusion is indicated. Isolated fractures of the lateral masses are very rare and may, if the lateral mass is totally destroyed, be a reason for an occipito-cervical fusion. Fractures of the transverse processes may be the cause for a thrombosis of the vertebral artery. No treatment is necessary for the fracture itself.

  8. AKR occultation observed by KAGUYA (SELENE)

    NASA Astrophysics Data System (ADS)

    Hashimoto, K.; Kumamoto, A.; Kasahara, Y.; Ono, T.; Matsumoto, H.

    2008-12-01

    KAGUYA (SELENE) is a Japanese lunar orbiter launched on September 14, 2007. The Lunar Radar Sounder (LRS) is one of the scientific instruments on board KAGUYA. It consists of three subsystems: the sounder observation (SDR), the natural plasma wave receiver (NPW), and the wave form capture (WFC). The WFC measures two components of electric wave signals detected by the two orthogonal 30 m tip-to-tip antennas from 100Hz to 1MHz. WFC-H [1] observes plasma wave spectra in 1-1000kHz and AKR (auroral kilometric radiation) is often observed. Occultation of AKR occurs when the satellite goes behind the moon. Its frequency dependence and effects of the relative positions of the earth, the moon with the satellite will be evaluated. How the occultation is useful for the source estimation of AKR will be examined. Effects of a single rounded obstacle on diffraction [2] will also be examined. Background AKR emissions will be evaluated by Geotail observation if possible. Acknowledgments: The SELENE project has been organized by the Japan Aerospace Exploration Agency (JAXA). The authors express their thanks to all members of the SELENE project team. References [1] Y. Kasahara, Y. Goto, K. Hashimoto, T. Imachi, A. Kumamoto, T. Ono, and H. Matsumoto, Plasma Wave Observation Using Waveform Capture in the Lunar Radar Sounder on board the SELENE Spacecraft, Earth, Planets and Space, 60, 341-351, 2008. [2] Recommendation ITU-R P.526-8, Propagation by diffraction, ITU, 2003.

  9. Faster Processing for Inverting GPS Occultation Data

    NASA Technical Reports Server (NTRS)

    Ao, Chi

    2004-01-01

    A document outlines a computational method that can be incorporated into two prior methods used to invert Global Positioning System (GPS) occultation data [signal data acquired by a low-Earth-orbiting satellite as either this or the GPS satellite rises above or falls below the horizon] to obtain information on altitude-dependent properties of the atmosphere. The two prior inversion methods, known as back propagation and canonical transform, are computationally expensive because for each occultation, they involve numerical evaluation of a large number of diffraction-like spatial integrals. The present method involves an angular-spectrum-based phase-extrapolation approximation in which each data point is associated with a plane-wave component that propagates in a unique direction from the orbit of the receiving satellite to intersect a straight line tangent to the orbit at a nearby point. This approximation enables the use of fast Fourier transforms (FFTs), which apply only to data collected along a straight-line trajectory. The computation of the diffraction-like integrals in the angular-spectrum domain by use of FFTs takes only seconds, whereas previously, it took minutes.

  10. Processing GPS Occultation Data To Characterize Atmosphere

    NASA Technical Reports Server (NTRS)

    Hajj, George; Kursinski, Emil; Leroy, Stephen; Lijima, Byron; de la Torre Juarez, Manuel; Romans, Larry; Ao, Chi

    2005-01-01

    GOAS [Global Positioning System (GPS) Occultation Analysis System] is a computer program that accepts signal-occultation data from GPS receivers aboard low-Earth-orbiting satellites and processes the data to characterize the terrestrial atmosphere and, in somewhat less comprehensive fashion, the ionosphere. GOAS is very robust and can be run in an unattended semi-operational processing mode. It features sophisticated retrieval algorithms that utilize the amplitudes and phases of the GPS signals. It incorporates a module that, using an assumed atmospheric refractivity profile, simulates the effects of the retrieval processing system, including the GPS receiver. GOAS utilizes the GIPSY software for precise determination of orbits as needed for calibration. The GOAS output for the Earth s troposphere and mid-to-lower stratosphere consists of high-resolution (<1 km) profiles of density, temperature, pressure, atmospheric refractivity, bending angles of signals, and water-vapor content versus altitude from the Earth s surface to an altitude of 30 km. The GOAS output for the ionosphere consists of electron-density profiles from an altitude of about 50 km to the altitude of a satellite, plus parameters related to the rapidly varying structure of the electron density, particularly in the E layer of the ionosphere.

  11. Halogen Occultation Experiment (HALOE) optical filter characterization

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    1989-01-01

    The Halogen Occultation Experiment (HALOE) is a solar occultation experiment that will fly on the Upper Atmosphere Research Satellite to measure mixing ratio profiles of O3, H2O, NO2, NO, CH4, HCl, and HF. The inversion of the HALOE data will be critically dependent on a detailed knowledge of eight optical filters. A filter characterization program was undertaken to measure in-band transmissions, out-of-band transmissions, in-band transmission shifts with temperature, reflectivities, and age stability. Fourier Transform Infrared Spectrometers were used to perform measurements over the spectral interval 400/cm to 6300/cm (25 micrometers to 1.6 micrometers). Very high precision (0.1 percent T) in-band measurements and very high resolution (0.0001 percent T) out-of-band measurements have been made. The measurements revealed several conventional leaks at 0.01 percent transmission and greatly enhanced (1,000) leaks to the 2-element filters when placed in a Fabry-Perot cavity. Filter throughput changes by 5 percent for a 25 C change in filter temperature.

  12. Skull fracture

    MedlinePlus

    ... compress the underlying brain tissue (subdural or epidural hematoma). A simple fracture is a break in the bone without damage ... Causes of skull fracture can include: Head trauma Falls, automobile accidents, physical assault, and sports

  13. Rib Fractures

    MedlinePlus

    ... From Brain Injury Additional Content Medical News Rib Fractures By Thomas G. Weiser, MD, MPH, Department of ... Hemothorax Injury to the Aorta Pulmonary Contusion Rib Fractures Tension Pneumothorax Traumatic Pneumothorax (See also Introduction to ...

  14. Hand Fractures

    MedlinePlus

    ... Thumb Arthritis Thumb Sprains Trigger Finger Tumors Wrist Fracture Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety ... Tunnel Ganglion Cysts Thumb Arthritis Trigger Finger Wrist Fracture Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety ...

  15. Facial fractures.

    PubMed Central

    Carr, M. M.; Freiberg, A.; Martin, R. D.

    1994-01-01

    Emergency room physicians frequently see facial fractures that can have serious consequences for patients if mismanaged. This article reviews the signs, symptoms, imaging techniques, and general modes of treatment of common facial fractures. It focuses on fractures of the mandible, zygomaticomaxillary region, orbital floor, and nose. Images p520-a p522-a PMID:8199509

  16. Satellite Occultation Measurements-Contributions to Middle Atmosphere Science

    NASA Astrophysics Data System (ADS)

    McCormick, M. P.; Chu, W. P.

    2003-12-01

    Solar occultation measurements from earth-orbit began with two orbits of data from aboard Apollo during the Apollo-Soyuz test project flight in 1975. The instrument was called SAM for the Stratospheric Aerosol Measurement. It was a simple proof-of-principle, one-spectral channel experiment that led to the long-duration occultation measurement series beginning in 1978 with the launch of SAM II aboard Nimbus 7. SAGE I, II, and III followed with increasing instrument complexity and capability. SAGE II and III are presently in orbit providing excellent high vertically-resolved measurements of aerosol, ozone, and other constituents. Other occultation sensors for long-duration measurements were launched in the 1990s including HALOE and POAM. This paper will present a historical overview of satellite occultation missions from 1975 to the present. The fundamentals of the occultation technique will be presented along with its advantages and comparison with other remote sensors. The occultation sensors, to-date, have produced exceedingly important measurements that have contributed to atmospheric and climate science. These have included such measurements as: the naming and characterization of Polar Stratospheric Clouds; aerosol and ozone associated with the wintertime polar vortex phenomena; ozone, HCl and HF trends associated with the effects of CFCs; the impact of volcanic aerosols; and aerosol and cirrus cloud distributions and trends. As the lead-off paper in this session, examples of the above data will be presented. Finally, some "lessons-learned" from these occultation missions will be discussed.

  17. Occult hepatitis B virus and hepatitis C virus infections.

    PubMed

    Carreño, Vicente; Bartolomé, Javier; Castillo, Inmaculada; Quiroga, Juan Antonio

    2008-01-01

    Occult HBV infection is a well-recognised clinical entity characterised by the detection of HBV-DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). Occult HBV infection has been described not only in patients who have resolved an acute or chronic HBV infection but also in patients without any serological markers of a past HBV infection. Occult HBV infection in patients with chronic HCV infection may induce more severe liver disease and lower response rate to interferon treatment. The existence of occult HCV infections has been also reported more recently. Occult HCV infection is characterised by the presence of HCV-RNA in liver and peripheral blood mononuclear cells in the absence of detectable serum HCV-RNA. Occult HCV infection may occur under two different clinical situations: in hepatitis C antibody-(anti-HCV) negative and serum HCV-RNA-negative patients with abnormal liver function tests and in anti-HCV-positive patients who have no detectable serum HCV-RNA and who have normal liver enzymes. The clinical relevance of occult HCV infections is still under investigation.

  18. Review: Occult hepatitis C virus infection: still remains a controversy.

    PubMed

    Vidimliski, Pavlina Dzekova; Nikolov, Igor; Geshkovska, Nadica Matevska; Dimovski, Aleksandar; Rostaing, Lionel; Sikole, Aleksandar

    2014-09-01

    Occult hepatitis C virus (HCV) infection is characterized by the presence of HCV RNA in the liver cells or peripheral blood mononuclear cells of the patients whose serum samples test negative for HCV RNA, with or without presence of HCV antibodies. The present study reviews the existing literature on the persistence of occult hepatitis C virus infection, with description of the clinical characteristics and methods for identification of occult hepatitis C. Occult hepatitis C virus infection was detected in patients with abnormal results of liver function tests of unknown origin, with HCV antibodies and HCV RNA negativity in serum, and also in patients with spontaneous or treatment-induced recovery from hepatitis C. The viral replication in the liver cells and/or peripheral blood mononuclear cells was present in all clinical presentations of occult hepatitis C. The peripheral blood mononuclear cells represent an extra-hepatic site of HCV replication. The reason why HCV RNA was not detectable in the serum of patients with occult hepatitis C, could be the low number of circulating viral particles not detectable by the diagnostic tests with low sensitivity. It is uncertain whether occult hepatitis C is a different clinical entity or just a form of chronic hepatitis C virus infection. Data accumulated over the last decade demonstrated that an effective approach to the diagnosis of HCV infection would be the implementation of more sensitive HCV RNA diagnostic assays, and also, examination of the presence of viral particles in the cells of the immune system.

  19. A Digital Video System for Observing and Recording Occultations

    NASA Astrophysics Data System (ADS)

    Barry, M. A. Tony; Gault, Dave; Pavlov, Hristo; Hanna, William; McEwan, Alistair; Filipović, Miroslav D.

    2015-09-01

    Stellar occultations by asteroids and outer solar system bodies can offer ground based observers with modest telescopes and camera equipment the opportunity to probe the shape, size, atmosphere, and attendant moons or rings of these distant objects. The essential requirements of the camera and recording equipment are: good quantum efficiency and low noise; minimal dead time between images; good horological faithfulness of the image timestamps; robustness of the recording to unexpected failure; and low cost. We describe an occultation observing and recording system which attempts to fulfil these requirements and compare the system with other reported camera and recorder systems. Five systems have been built, deployed, and tested over the past three years, and we report on three representative occultation observations: one being a 9 ± 1.5 s occultation of the trans-Neptunian object 28978 Ixion (m v =15.2) at 3 seconds per frame; one being a 1.51 ± 0.017 s occultation of Deimos, the 12 km diameter satellite of Mars, at 30 frames per second; and one being a 11.04 ± 0.4 s occultation, recorded at 7.5 frames per second, of the main belt asteroid 361 Havnia, representing a low magnitude drop (Δm v = ~0.4) occultation.

  20. The occultation of Kappa Geminorum by Eros. [stellar occultation observed for asteroid size and shape

    NASA Technical Reports Server (NTRS)

    Oleary, B.; Marsden, B. G.; Dragon, R.; Hauser, E.; Mcgrath, M.; Backus, P.; Robkoff, H.

    1976-01-01

    The paper discusses predictions and observations of the occultation of Kappa Gem by (433) Eros on January 24, 1975. Several positive and negative observations made in western New England are described. Local circumstances for the occultation are reconstructed, and the size and shape of Eros are determined analytically as well as graphically. The calculations yield two extremes for the cross section: a circle 23 km in diameter or a somewhat irregular figure 20 km by 6 or 7 km. Arguments based on the expected albedo of the asteroid suggest that the circle should be warped into an ellipse 21 by 13 km or that the irregular figure might be one component of a dumbbell-like profile.

  1. The Research and Education Collaborative Occultation Network: A System for Coordinated TNO Occultation Observations

    NASA Astrophysics Data System (ADS)

    Buie, Marc W.; Keller, John M.

    2016-03-01

    We describe a new system and method for collecting coordinated occultation observations of trans-Neptunian objects (TNOs). Occultations by objects in the outer solar system are more difficult to predict due to their large distance and limited span of the astrometric data used to determine their orbits and positions. This project brings together the research and educational community into a unique citizen-science partnership to overcome the difficulties of observing these distant objects. The goal of the project is to get sizes and shapes for TNOs with diameters larger than 100 km. As a result of the system design it will also serve as a probe for binary systems with spatial separations as small as contact systems. Traditional occultation efforts strive to get a prediction sufficiently good to place mobile ground stations in the shadow track. Our system takes a new approach of setting up a large number of fixed observing stations and letting the shadows come to the network. The nominal spacing of the stations is 50 km so that we ensure two chords at our limiting size. The spread of the network is roughly 2000 km along a roughly north-south line in the western United States. The network contains 56 stations that are committed to the project and we get additional ad hoc support from International Occultation Timing Association members. At our minimum size, two stations will record an event while the other stations will be probing the inner regions for secondary events. Larger objects will get more chords and will allow determination of shape profiles. The stations are almost exclusively sited and associated with schools, usually at the 9-12 grade level. We present a full description of the system we have developed for the continued exploration of the Kuiper Belt.

  2. Occultations by Pluto and Charon - 1990-1999

    NASA Technical Reports Server (NTRS)

    Mink, Douglas J.; Klemola, Arnold R.; Buie, Marc W.

    1991-01-01

    The results of a photographic plate search for stars as faint as V = 16 which may be occulted by Pluto or Charon between January 1, 1990 and December 31, 1999 are presented. Circumstances for the closest approach of Pluto to 32 stars and Charon to 28 stars are presented. Photometric information is given for some of the brightest stars found in a search of the Space Telescope Guide Star Catalog for Pluto occultations. Finding charts from Space Telescope Guide Star plates are provided for some of the best events. The brightest star (V = 12.7) may be occulted by both Pluto and Charon on September 26, 1999.

  3. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Person, Michael; Zuluaga, Carlos; Bosh, Amanda

    2011-08-01

    Occultations by Kuiper Belt objects remain elusive events, requiring precision astrometry for these faint bodies in the outer solar system. Monthly astrometry provides data that are crucial for our KBO ephemeris correction models, which then allow accurate shadow track predictions. Through the occultation events the diameters, possible companions and tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This promises to be a powerful way of exploring the KBOs. We propose to obtain very precise astrometry on 20 of the brightest known KBOs to determine more accurate orbits and thus reliable occultation predictions.

  4. Out of the blue finger ischaemia and occult colorectal cancer.

    PubMed

    Schattner, Ami

    2017-03-08

    A woman aged 66 years with a history of unprovoked deep venous thrombosis (DVT) presented with persistent digital ischaemic changes of 2 of her right hand fingers. Physical examination was otherwise normal and extensive laboratory and imaging studies were unremarkable. A history of unprovoked DVT and the current episode of digital ischaemia prompted concern for underlying occult malignancy. Repeated history-taking revealed a strongly positive family history suggesting an occult colorectal cancer. Colonoscopy with biopsy revealed adenocarcinoma. Adenocarcinoma of the colon has rarely been associated with paraneoplastic acral vascular syndrome. This report suggests that occult malignancy needs to be considered in patients with focal digital ischaemia as this association is poorly unrecognised.

  5. Pluto Stellar Occultation on 2008 Aug 25

    NASA Astrophysics Data System (ADS)

    Buie, Marc W.; Young, L. A.; Young, E. F.; Olkin, C. B.; Terrell, D.; Parker, J. W.; Durda, D.; Stansberry, J. A.; Reitsema, H.; French, R. G.; Shoemaker, K.; Brown, M. E.; Schaller, E. L.; Bauer, J. M.; Young, J. W.; Wasserman, L. H.; Pasachoff, J. M.; Lust, N.; Fernandez, Y. R.; Dellinger, J. A.; Garossino, P. G. A.; Grigsby, B.; Stone, R. P. S.; Dillon, W. G.; Mezzalira, F.; Ryan, E. V.; Ryan, W.; Souza, S. P.; Williams, R.; Sexton, C.

    2009-01-01

    We report on a successful occultation of a star by Pluto that was observable over much of the south and western United States. The centerline was close to WIRO. We will present seven complete lightcurves from Crossley/Lick, WIRO, SBO/CU, Palomar, JPL/TMO, Sierra Stars Obs., and Magdalena Ridge Observatory. We have 2 partial lightcurves from Lowell Obs. and McDonald Obs. where data loss was caused by clouds. There were attempts at the Steward 90", George Observatory, and New Mexico Skies that were clouded out. The UCF station near Orlando was clearly an appulse. A number of other amateurs also succeeded in collecting data. Our presentation will provide a final geometric solution for the event as well as baseline fits to the atmospheric structure. This work was supported by NASA Planetary Astronomy grants NNX08AO626 and NNX08AO50G.

  6. Halogen occultation experiment intergrated test plan

    NASA Technical Reports Server (NTRS)

    Mauldin, L. E., III; Butterfield, A. J.

    1986-01-01

    The test program plan is presented for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in-house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This comprehensive test program was developed to demonstrate that the HALOE instrument meets its performance requirements and maintains integrity through UARS flight environments. Each component, subsystem, and system level test is described in sufficient detail to allow development of the necessary test setups and test procedures. Additionally, the management system for implementing this test program is given. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HC1, HF, NO, CH4, H2O, NO2, and CO2.

  7. What can the occult do for you?

    NASA Astrophysics Data System (ADS)

    Holwerda, B. W.; Keel, W. C.

    2017-03-01

    Interstellar dust is still a dominant uncertainty in Astronomy, limiting precision in e.g., cosmological distance estimates and models of how light is re-processed within a galaxy. When a foreground galaxy serendipitously overlaps a more distant one, the latter backlights the dusty structures in the nearer foreground galaxy. Such an overlapping or occulting galaxy pair can be used to measure the distribution of dust in the closest galaxy with great accuracy. The STARSMOG program uses Hubble to map the distribution of dust in foreground galaxies in fine (<100 pc) detail. Integral Field Unit (IFU) observations will map the effective extinction curve, disentangling the role of fine-scale geometry and grain composition on the path of light through a galaxy. The overlapping galaxy technique promises to deliver a clear understanding of the dust in galaxies: geometry, a probability function of dimming as a function of galaxy mass and radius, and its dependence on wavelength.

  8. Scaling An External Occulter Coronagraph Mission

    NASA Astrophysics Data System (ADS)

    Noecker, Martin C.

    2009-01-01

    An excellent candidate for the Terrestrial Planet Finder mission is an external occulter coronagraph like New Worlds Observer, in which the glare of the host star is blocked by an opaque starshade located between the star and the telescope which observes it. It has proven difficult to visualize and manage the interplay between starshade size and distance, telescope size, optical wavelength, and the depth of stellar suppression. The traditional method is to choose some parameters, calculate the stellar suppression, and iterate. This paper presents an alternate approach which exploits scaling relationships, allowing quick calculation of each new case and better visualization of the ramifications of a modest departure from that case. I apply this method to illustrate the pros and cons of a few different cases at different scales.

  9. The clinical significance of occult HBV infection

    PubMed Central

    Squadrito, Giovanni; Spinella, Rosaria; Raimondo, Giovanni

    2014-01-01

    The presence of hepatitis B virus (HBV) DNA in HBV surface antigen (HBsAg)-negative individuals is defined as occult HBV infection (OBI). OBI is related in some cases to infection with variant viruses (S-escape mutants) undetectable by HBsAg commercial kits. More frequently, however, it is due to infection with wild-type viruses that are strongly suppressed in their replication activity. OBI may be involved in different clinical contexts, including the transmission of the infection by blood transfusion or liver transplantation and its acute reactivation when an immunosuppressive status occurs. Moreover, much evidence suggests that it may contribute to the development of cirrhosis and may have an important role in hepatocarcinogenesis. PMID:24714731

  10. Clinical Utility of Chest Computed Tomography in Patients with Rib Fractures CT Chest and Rib Fractures

    PubMed Central

    Chapman, Brandon C.; Overbey, Douglas M.; Tesfalidet, Feven; Schramm, Kristofer; Stovall, Robert T.; French, Andrew; Johnson, Jeffrey L.; Burlew, Clay C.; Barnett, Carlton; Moore, Ernest E.; Pieracci, Fredric M.

    2016-01-01

    Background Chest CT is more sensitive than a chest X-ray (CXR) in diagnosing rib fractures; however, the clinical significance of these fractures remains unclear. Objectives The purpose of this study was to determine the added diagnostic use of chest CT performed after CXR in patients with either known or suspected rib fractures secondary to blunt trauma. Methods Retrospective cohort study of blunt trauma patients with rib fractures at a level I trauma center that had both a CXR and a CT chest. The CT finding of ≥ 3 additional fractures in patients with ≤ 3 rib fractures on CXR was considered clinically meaningful. Student’s t-test and chi-square analysis were used for comparison. Results We identified 499 patients with rib fractures: 93 (18.6%) had CXR only, 7 (1.4%) had chest CT only, and 399 (79.9%) had both CXR and chest CT. Among these 399 patients, a total of 1,969 rib fractures were identified: 1,467 (74.5%) were missed by CXR. The median number of additional fractures identified by CT was 3 (range, 4 - 15). Of 212 (53.1%) patients with a clinically meaningful increase in the number of fractures, 68 patients underwent one or more clinical interventions: 36 SICU admissions, 20 pain catheter placements, 23 epidural placements, and 3 SSRF. Additionally, 70 patients had a chest tube placed for retained hemothorax or occult pneumothorax. Overall, 138 patients (34.5%) had a change in clinical management based upon CT chest. Conclusions The chest X-ray missed ~75% of rib fractures seen on chest CT. Although patients with a clinical meaningful increase in the number of rib fractures were more likely to be admitted to the intensive care unit, there was no associated improvement in pulmonary outcomes. PMID:28144607

  11. Pluto's Lower Atmosphere from Stellar Occultations

    NASA Astrophysics Data System (ADS)

    Young, Leslie; Buie, M. W.; Olkin, C. B.; Young, E. F.; French, R. G.; Howell, R. R.

    2008-09-01

    Ever since the Pluto occultation of 1988, the nature of Pluto's lower atmosphere has been a mystery: the lightcurve shows a difference between the upper and lower atmosphere, but it has been unclear whether this is due to hazes, a steep thermal gradient, or a combination of the two (Elliot & Young, 1992 AJ 103, 991; Hubbard et al. 1990, Icarus, 84, 1) Recent high-quality lightcurves allow us to place limits on the haze in Pluto's atmosphere. Especially important is the dual-wavelength (0.5 and 0.8 micron) occultation observed from Mount John Observatory in New Zealand on 2007 July 31. This site was 60 ± 4 km from the central track of the shadow, and the lightcurves clearly show a central flash, or a brightening due to strong lateral refocusing and the convergence of multiple images around the limb of an elliptical atmosphere. These lightcurves constrain the structure of the lower atmosphere in three ways. First, the surface-grazing ray must have a large enough bending angle to reach the center of the shadow. Second, haze of sufficient optical depth to affect the main drop in the lightcurve will also decrease the height of the central flash. The height and location of the central flash can be well modeled with a clear atmosphere. Third, hazes of the size expected at Pluto will have a wavelength-dependent absorption, but the red and blue channels of the Mount John lightcurves show no variation with wavelength. We will discuss limits on the hazes, and place these limits in the context of Triton hazes, heating by dust, and New Horizons detection limits.

  12. A game of two discs: a case of non-contiguous and occult cervical spine injury in a rugby player

    PubMed Central

    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 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. PMID:26980714

  13. Occultations of stars by solar system objects. V - A photographic search for occultations by selected asteroids in 1984

    NASA Technical Reports Server (NTRS)

    Millis, R. L.; Wasserman, L. H.; Franz, O. G.; Bowell, E.; Klemola, A.

    1984-01-01

    Photographic plates taken with the 0.5-m Carnegie double astrograph have been used to identify upcoming asteroid occultations not found in earlier star catalog searches. Twenty-six occultations involving the minor planets 1 Ceres, 10 Hygiea, 52 Europa, 65 Cybele, 451 Patientia, 511 Davida, and 704 Interamnia were found in this search. Of particular interest is the occultation of BD + 8 deg 471 by 1 Ceres on November 13, 1984, which is predicted to be observable throughout much of Mexico and, perhaps, in the southern United States.

  14. Comparative study on the clinical and virological characteristics among patients with single occult hepatitis B virus (HBV), single occult hepatitis C virus (HCV) and occult HBV and HCV dual infection.

    PubMed

    Castillo, Inmaculada; Rodríguez-Iñigo, Elena; López-Alcorocho, Juan Manuel; Bartolomé, Javier; Pardo, Margarita; Carreño, Vicente

    2007-03-01

    Occult hepatitis B virus (HBV) and occult hepatitis C virus (HCV) infection are two recently described different forms of HBV and HCV infections. This work compares the clinical, virologic, and histologic characteristics of patients with occult dual infection to those of patients with single occult HBV or HCV infection. Seventy-six patients with abnormal liver function tests of unknown etiology (serum HBsAg, anti-HCV, HBV-DNA, and HCV-RNA negative) were included in the study. Viral genomes were tested in liver by real-time PCR and confirmed by in situ hybridization. Of the 76 patients, 17 had occult HBV infection (intrahepatic HBV-DNA positive, HCV-RNA negative), 35 had occult HCV infection (intrahepatic HCV-RNA positive, HBV-DNA negative) and 24 occult dual infection (intrahepatic HCV-RNA and HBV-DNA). No differences among the three groups were found regarding clinical and epidemiologic data. The median load of intrahepatic genomic and antigenomic HCV-RNA strands was similar between single occult HCV infection and occult HBV and HCV dual infection. The percentage of HCV-infected hepatocytes did not differ between these groups. In occult single HBV infection, intrahepatic levels of HBV-DNA and percentage of HBV-infected hepatocytes were similar to the group of patients with occult dual infection. Finally, no differences were found in histological liver damage among the three groups. In conclusion, liver disease in patients with occult dual infection was not more severe than in patients with single occult HBV or occult HCV infection. Moreover, in occult dual infection there is no a reciprocal inhibition of the viral genomes.

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

    NASA Astrophysics Data System (ADS)

    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

  16. The Mariner Jupiter/Saturn ring occultation experiment

    NASA Technical Reports Server (NTRS)

    Eshleman, V. R.

    1974-01-01

    Radio occultation measurements of Saturn's rings as measured by the Mariner Jupiter/Saturn radio science experiment are reported. These signal measurements provide information on size, distribution, and density of particle material found in the rings.

  17. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Elliot, James; Kern, Susan; Zuluaga, Carlos; Gulbis, Amanda

    2008-08-01

    In order to observe an occultation of a bright star by a Kuiper Belt object the event must first be predicted as to where and when it will happen. These predictions require precise astrometry every few months of the largest Kuiper Belt objects. Through the occultation events the diameters, possible companions and possible tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This promises to be a completely new and powerful way of exploring the KBOs. We propose to continue to obtain very precise astrometry on the known brightest KBOs to determine more accurate orbits and thus reliable occultation predictions. In addition, we must also obtain accurate astrometry on faint field stars that the KBOs of interest may occult.

  18. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Person, Michael; Zuluaga, Carlos; Bosh, Amanda

    2012-08-01

    Occultations by Kuiper Belt objects remain elusive events, requiring precision astrometry for these faint bodies in the outer solar system. Routine astrometry provides data that are crucial for our KBO ephemeris correction models, which then allow accurate shadow track predictions. Through the occultation events the diameters, possible companions and tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This is a powerful way to determine the physical characteristics of the KBOs. We propose to obtain very precise astrometry on 20 of the brightest known KBOs to determine more accurate orbits and thus reliable occultation predictions. We also require telescope time to obtain precise astrometry on possible stars that will be occulted by a KBO in the future.

  19. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Person, Michael; Zuluaga, Carlos; Bosh, Amanda

    2013-02-01

    Occultations by Kuiper Belt objects remain elusive events, requiring precision astrometry for these faint bodies in the outer solar system. Routine astrometry provides data that are crucial for our KBO ephemeris correction models, which then allow accurate shadow track predictions. Through the occultation events the diameters, possible companions and tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This is a powerful way to determine the physical characteristics of the KBOs. We propose to obtain very precise astrometry on 10 of the brightest known KBOs to determine more accurate orbits and thus reliable occultation predictions. We also require telescope time to obtain precise astrometry on possible stars that will be occulted by a KBO in the future.

  20. Radio occultation based on BeiDou satellite navigation

    NASA Astrophysics Data System (ADS)

    Jiang, Hu; Hu, Haiying; Shen, Xue-min; Gong, Wenbin; Zhang, Yonghe

    2014-11-01

    With the development of GNSS systems, it has become a tendency that radio occultation is used to sense the Earth's atmosphere. By this means, the moisture, temperature, pressure, and total electron content can be derived. Based on the sensing results, more complicated models for atmosphere might come into being. Meteorology well benefits from this technology. As scheduled, the BD satellite navigation system will have a worldwide coverage by the end of 2020. Radio occultation studies in China have been highlighted in the recent decade. More and more feasibilities reports have been published in either domestic or international journals. Herein, some scenarios are proposed to assess the coverage of radio occultation based on two different phases of BD satellite navigation system. Phase one for BD is composed of GEO,IGSO and several MEO satellites. Phase two for BD consists mostly of 24 MEO satellites, some GEO and IGSO satellites. The characteristics of radio occultation based on these two phases are presented respectively.

  1. First Results From The Taiwanese-American Occultation Survey (TAOS)

    SciTech Connect

    Zhang, Z; Bianco, F B; Lehner, M J; Coehlo, N K; Wang, J; Mondal, S; Alcock, C; Axelrod, T; Byun, Y; Chen, W P; Cook, K H; Dave, R; de Pater, I; Porrata, R; Kim, D; King, S; Lee, T; Lin, H; Lissauer, J J; Marshall, S L; Protopapas, P; Rice, J A; Schwamb, M E; Wang, S; Wen, C

    2008-08-22

    Results from the first two years of data from the Taiwanese-American Occultation Survey (TAOS) are presented. Stars have been monitored photometrically at 4 Hz or 5 Hz to search for occultations by small ({approx}3 km) Kuiper Belt Objects (KBOs). No statistically significant events were found, allowing us to present an upper bound to the size distribution of KBOs with diameters 0.5 km < D < 28 km.

  2. The rings of Uranus - Occultation profiles from three observatories

    NASA Technical Reports Server (NTRS)

    Elias, J. H.; Frogel, J. A.; French, R. G.; Matthews, K.; Meech, K. J.; Mink, D. J.; Nicholson, P. D.; Sicardy, B.; Liller, W.; Elliot, J. L.

    1983-01-01

    Occultation profiles for the nine confirmed Uranian rings obtained from Las Campanas, the European Southern Observatory, and Cerro Tololo on 15-16 August 1980 are compared. The alpha ring shows a 'double-dip' structure; the eta ring shows a broad and narrow component (similar to Saturn's F ring); and the epsilon ring shows six features that appear in the data from all three observatories. Diffraction fringes appear at the edges of several of the occultation profiles.

  3. Possible occultation by Pluto from US East Coast

    NASA Astrophysics Data System (ADS)

    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.

  4. Earth Occultation Monitoring with the Fermi Gamma Ray Burst Monitor

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2014-01-01

    Using the Gamma Ray Burst Monitor (GBM) on-board Fermi, we are monitoring the hard X-ray/soft gamma ray sky using the Earth occultation technique (EOT). Each time a source in our catalog is occulted by (or exits occultation by) the Earth, we measure its flux using the change in count rates due to the occultation. Currently we are using CTIME data with 8 energy channels spanning 8 keV to 1 MeV for the GBM NaI detectors for daily monitoring. Light curves, updated daily, are available on our website http://heastro.phys.lsu.edu/gbm. Our software is also capable of performing the Earth occultation monitoring using up to 128 energy bands, or any combination of those bands, using our 128-channel, 4-s CSPEC data. The GBM BGO detectors, sensitive from about 200 keV to 40 keV, can also be used with this technique. In our standard application of the EOT, we use a catalog of sources to drive the measurements. To ensure that our catalog is complete, our team has developed an Earth occultation imaging method. In this talk, I will describe both techniques and the current data products available. I will highlight recent and important results from the GBM EOT, including the current status of our observations of hard X-ray variations in the Crab Nebula.

  5. Occult hepatitis C virus infection among hemodialysis patients.

    PubMed

    Barril, Guillermina; Castillo, Inmaculada; Arenas, María Dolores; Espinosa, Mario; Garcia-Valdecasas, Juan; Garcia-Fernández, Nuria; González-Parra, Emilio; Alcazar, José María; Sánchez, Carmen; Diez-Baylón, José Carlos; Martinez, Pilar; Bartolomé, Javier; Carreño, Vicente

    2008-12-01

    Occult hepatitis C virus (HCV) infection (i.e., detectable HCV-RNA in the liver or peripheral blood mononuclear cells) in the absence of both serum HCV-RNA and anti-HCV antibodies has not been investigated in hemodialysis patients. In this study, real-time PCR and in situ hybridization was used to test for the presence of genomic and antigenomic HCV-RNA in peripheral blood mononuclear cells of 109 hemodialysis patients with abnormal levels of liver enzymes. Occult HCV infection, determined by the presence of genomic HCV-RNA, was found in 45% of the patients; 53% of these patients had ongoing HCV replication, indicated by the presence of antigenomic HCV-RNA. Patients with occult HCV infection had spent a significantly longer time on hemodialysis and had significantly higher mean alanine aminotransferase levels during the 6 mo before study entry. Logistic regression analysis revealed that mortality was associated with age >60 yr (odds ratio 3.30; 95% confidence interval 1.05 to 10.33) and the presence of occult HCV infection (odds ratio 3.84; 95% confidence interval 1.29 to 11.43). In conclusion, the prevalence of occult HCV infection is high among hemodialysis patients with persistently abnormal values of liver enzymes of unknown cause. The clinical significance of occult HCV infection in these patients requires further study.

  6. A comparison of the rates of union after cancellous iliac crest bone graft and Kirschner-wire fixation in the treatment of stable and unstable scaphoid nonunion.

    PubMed

    Park, H Y; Yoon, J O; Jeon, I H; Chung, H W; Kim, J S

    2013-06-01

    This study was performed to determine whether pure cancellous bone graft and Kirschner (K-) wire fixation were sufficient to achieve bony union and restore alignment in scaphoid nonunion. A total of 65 patients who underwent cancellous bone graft and K-wire fixation were included in this study. The series included 61 men and four women with a mean age of 34 years (15 to 72) and mean delay to surgery of 28.7 months (3 to 240). The patients were divided into an unstable group (A) and stable group (B) depending on the pre-operative radiographs. Unstable nonunion was defined as a lateral intrascaphoid angle > 45°, or a radiolunate angle > 10°. There were 34 cases in group A and 31 cases in group B. Bony union was achieved in 30 patients (88.2%) in group A, and in 26 (83.9%) in group B (p = 0.439). Comparison of the post-operative radiographs between the two groups showed no significant differences in lateral intrascaphoid angle (p = 0.657) and scaphoid length (p = 0.670) and height (p = 0.193). The radiolunate angle was significantly different (p = 0.020) but the mean value in both groups was < 10°. Comparison of the dorsiflexion and palmar flexion of movement of the wrist and the mean Mayo wrist score at the final clinical visit in each group showed no significant difference (p = 0.190, p = 0.587 and p = 0.265, respectively). Cancellous bone graft and K-wire fixation were effective in the treatment of stable and unstable scaphoid nonunion.

  7. Proximal Row Carpectomy for Coexisting Kienböck's Disease and Giant Intraosseous Ganglion of the Scaphoid: A Case Report and Review of the Literature

    PubMed Central

    Oellig, Florian; Sánchez, Tomás

    2014-01-01

    The etiologies of Keinböck's disease and intraosseous ganglion remain unknown. Both entities are rare and the coexistence of these two pathologies in the same patient and hand is even less frequent. We report the case of a 40-year-old man with a longstanding history of martial arts practice (karate) who developed an avascular necrosis of the lunate concomitant with a giant intraosseous ganglion of the scaphoid bone successfully managed by proximal row carpectomy. We review the literature of these two diseases. PMID:25530898

  8. Proximal Row Carpectomy for Coexisting Kienböck's Disease and Giant Intraosseous Ganglion of the Scaphoid: A Case Report and Review of the Literature.

    PubMed

    Morón, Miguel; Oellig, Florian; Sánchez, Tomás

    2014-01-01

    The etiologies of Keinböck's disease and intraosseous ganglion remain unknown. Both entities are rare and the coexistence of these two pathologies in the same patient and hand is even less frequent. We report the case of a 40-year-old man with a longstanding history of martial arts practice (karate) who developed an avascular necrosis of the lunate concomitant with a giant intraosseous ganglion of the scaphoid bone successfully managed by proximal row carpectomy. We review the literature of these two diseases.

  9. Diverse Applications of Occultation Data in Ozone Assimilation

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Uttley, P.

    2005-01-01

    Ozone profiles from solar occultation instruments provide invaluable information that can be used to evaluate the quality of assimilated ozone fields, from case studies to long-term phenomena. Occultation data can also be applied to include physical constraints while developing components of an assimilation system. Conversely, assimilation of occultation data can help in their validation, and it provides a framework for evaluation of the impact of occultation data on constraining global ozone fields within models. We illustrate these diverse applications by a series of examples using the ozone assimilation system at NASA/Goddard. In a case study, low ozone in the lower stratosphere due to transport of air from the Tropics to northern high latitudes that was captured by assimilation of Aura Microwave Limb Sounder (MLS) and Solar Backscatter Ultraviolet (SBUV) data, was found to agree with SAGE III data. For long-term monitoring, the quality of a multi-year SBUV-only assimilation was evaluated using monthly-mean time series of POAM, HALOE, and SAGE I1 data. We found realism in the representation of the annual cycle in ozone and in some aspects of interannual variability. Assimilation of POAM data was shown to improve the representation of lower stratospheric ozone, especially over Antarctica. More recently, we assimilated ILAS II ozone data in order to help in their validation. Solar occultation data are used to estimate parameters in a new model for forecast error variances that is being developed. These examples demonstrate the importance of occultation data for ozone assimilation, and potential of assimilation to increase the impact and the value of occultation data.

  10. Starshade Design for Occulter Based Exoplanet Missions

    NASA Technical Reports Server (NTRS)

    Thomson, Mark W.; Lisman, P. Douglas; Helms, Richard; Walkemeyer, Phil; Kissil, Andrew; Polanco, Otto; Lee, Siu-Chun

    2010-01-01

    We present a lightweight starshade design that delivers the requisite profile figure accuracy with a compact stowed volume that permits launching both the occulter system (starshade and spacecraft) and a 1 to 2m-class telescope system on a single existing launch vehicle. Optimal figure stability is achieved with a very stiff and mass-efficient deployable structure design that has a novel configuration. The reference design is matched to a 1.1m telescope and consists of a 15m diameter inner disc and 24 flower-like petals with 7.5m length. The total tip-to-tip diameter of 30m provides an inner working angle of 75 mas. The design is scalable to accommodate larger telescopes and several options have been assessed. A proof of concept petal is now in production at JPL for deployment demonstrations and as a testbed for developing additional elements of the design. Future plans include developing breadboard and prototype hardware of increasing fidelity for use in demonstrating critical performance capabilities such as deployed optical edge profile figure tolerances and stability thereof.

  11. Starshade design for occulter based exoplanet missions

    NASA Astrophysics Data System (ADS)

    Thomson, Mark W.; Lisman, P. Douglas; Helms, Richard; Walkemeyer, Phil; Kissil, Andrew; Polanco, Otto; Lee, Siu-Chun

    2010-07-01

    We present a lightweight starshade design that delivers the requisite profile figure accuracy with a compact stowed volume that permits launching both the occulter system (starshade and spacecraft) and a 1 to 2m-class telescope system on a single existing launch vehicle. Optimal figure stability is achieved with a very stiff and mass-efficient deployable structure design that has a novel configuration. The reference design is matched to a 1.1m telescope and consists of a 15m diameter inner disc and 24 flower-like petals with 7.5m length. The total tip-to-tip diameter of 30m provides an inner working angle of 75 mas. The design is scalable to accommodate larger telescopes and several options have been assessed. A proof of concept petal is now in production at JPL for deployment demonstrations and as a testbed for developing additional elements of the design. Future plans include developing breadboard and prototype hardware of increasing fidelity for use in demonstrating critical performance capabilities such as deployed optical edge profile figure tolerances and stability thereof.

  12. Gravity wave detection by GPS radio occultations

    NASA Astrophysics Data System (ADS)

    Schmidt, Torsten; Arras, Christina; De la Torre, Alejandro; Alexander, Peter; Llamedo, Pablo

    2016-07-01

    Gravity waves (GWs) play an important role for the general atmospheric circulation due to the related transport of energy and momentum between different regions of the atmosphere. The momentum mostly generated in the troposphere is transported to upper atmospheric levels where GWs break or dissipate and transfer their momentum to the background wind (GW drag). The deposit of GW momentum can occur in the complete altitude range from the upper troposphere-stratosphere, the mesosphere, and even in the thermosphere. A global observation of GW parameters (e.g. potential energy and vertical flux of absolute horizontal momentum) is only possible with satellite data. The radio occultation (RO) technique uses GPS signals received aboard low Earth orbiting satellites for atmospheric limb sounding. Atmospheric temperature profiles in the troposphere/stratosphere and ionospheric electron densities are derived with high vertical resolution. The GPS RO technique is sensitive to GWs with small ratios of vertical to horizontal wavelengths. In this presentation we give an overview about the derivation of GW parameters from RO temperature profiles, review some results of GW detection with RO data, and discuss the limitations of the RO technique. The focus of the presented results is (1) global GW activity in the upper troposphere and lower stratosphere for different seasons, (2) influence of the topography on GW activity from the troposphere to the ionosphere in the Andean region of South America, and (3) the variation of ionospheric sporadic E layers.

  13. Occult Hepatitis B (OBH) in Clinical Settings

    PubMed Central

    Alavian, Seyed Moayed; Miri, Seyed Mohammad; Hollinger, F. Blaine; Jazayeri, Seyed Mohammad

    2012-01-01

    Context Occult hepatitis B (OHB), or persistent HBV DNA in patients who are hepatitis B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to summarize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings. Evidence Acquisition OHB could be found in different population and clinical backgrounds including: viral co-infections (with either human immunodeficiency or hepatitis C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters. Results The exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and hepatocellular carcinoma development remains unknown. Conclusions Monitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection. PMID:23087749

  14. The treatment of scaphoid nonunion using the Ilizarov fixator without bone graft, a study of 18 cases

    PubMed Central

    2011-01-01

    Objectives Evaluating the safety and efficacy of the Ilizarov fine-wire compression/distraction technique in the treatment of scaphoid nonunion (SNU), without the use of bone graft. Design A retrospective review of 18 consecutive patients in one centre. Patients and Methods 18 patients; 17 males; 1 female, with a mean SNU duration of 13.9 months. Patients with carpal instability, humpback deformity, carpal collapse, avascular necrosis or marked degenerative change, were excluded. Following frame application the treatment consisted of three stages: the frame was distracted 1 mm per day until radiographs showed a 2-3 mm opening at the SNU site (mean 10 days); the SNU site was then compressed for 5 days, at a rate of 1 mm per day, with the wrist in 15 degrees of flexion and 15 degrees of radial deviation; the third stage involved immobilization with the Ilizarov fixator for 6 weeks. The technique is detailed herein. Results Radiographic (CT) and clinical bony union was achieved in all 18 patients after a mean of 89 days (70-130 days). Mean modified Mayo wrist scores improved from 21 to 86 at a mean follow-up of 37 months (24-72 months), with good/excellent results in 14 patients. All patients returned to their pre-injury occupations and levels of activity at a mean of 117 days. Three patients suffered superficial K-wire infections, which resolved with oral antibiotics. Conclusions In these selected patients this technique safely achieved bony union without the need to open the SNU site and without the use of bone graft. PMID:22067958

  15. Ankle fracture - aftercare

    MedlinePlus

    Malleolar fracture; Tri-malleolar; Bi-malleolar; Distal tibia fracture; Distal fibula fracture; Malleolus fracture ... Some ankle fractures may require surgery when: The ends of the bone are out of line with each other (displaced). The ...

  16. Contact areas of the scaphoid and lunate with the distal radius in neutral and extension: correlation of falling strategies and distal radial anatomy.

    PubMed

    Chen, Y R; Wu, Y F; Tang, J B; Giddins, G

    2014-05-01

    The functional neutral of wrist movement is about 10° extension yet the distal radius has a volar tilt. This has not previously been explained. Assuming that the contact area between the carpus and the distal radius increased in wrist extension this would also help stabilize the carpus on the distal radius in positions where typically there is greater loading. To test this hypothesis we reconstructed three-dimensional structures of the carpal bones and distal radius using computed tomography scans of 13 normal wrists. The contact areas of the scaphoid with the distal radius were measured and were found progressively increased from flexion 20°, neutral, extension 20°, to extension 40°. The maximal increases in the contact area of the scaphoid and the distal radius was at full wrist extension. No significant changes in the contact areas of the lunate with the distal radius were found between the different positions. The contact characteristics provide greater stability to the carpus on the distal radius, and to help spread forces from impact to the wrist reducing the transmitted peak forces and thus the risk of distal radius and carpal injuries.

  17. Predictors of the accuracy of quotation of references in peer-reviewed orthopaedic literature in relation to publications on the scaphoid.

    PubMed

    Buijze, G A; Weening, A A; Poolman, R W; Bhandari, M; Ring, D

    2012-02-01

    Using inaccurate quotations can propagate misleading information, which might affect the management of patients. The aim of this study was to determine the predictors of quotation inaccuracy in the peer-reviewed orthopaedic literature related to the scaphoid. We randomly selected 100 papers from ten orthopaedic journals. All references were retrieved in full text when available or otherwise excluded. Two observers independently rated all quotations from the selected papers by comparing the claims made by the authors with the data and expressed opinions of the reference source. A statistical analysis determined which article-related factors were predictors of quotation inaccuracy. The mean total inaccuracy rate of the 3840 verified quotes was 7.6%. There was no correlation between the rate of inaccuracy and the impact factor of the journal. Multivariable analysis identified the journal and the type of study (clinical, biomechanical, methodological, case report or review) as important predictors of the total quotation inaccuracy rate. We concluded that inaccurate quotations in the peer-reviewed orthopaedic literature related to the scaphoid were common and slightly more so for certain journals and certain study types. Authors, reviewers and editorial staff play an important role in reducing this inaccuracy.

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

    PubMed

    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.

  19. Radio Occultation Measurements of Pluto's Atmosphere with New Horizons

    NASA Astrophysics Data System (ADS)

    Hinson, D. P.; Linscott, I.; Tyler, G. L.; Bird, M. K.; Paetzold, M.; Strobel, D. F.; Summers, M. E.; Woods, W. W.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Young, L. A.; Ennico Smith, K.; Gladstone, R.; Greathouse, T.; Kammer, J.; Parker, A. H.; Parker, J. W.; Retherford, K. D.; Schindhelm, E.; Singer, K. N.; Steffl, A.; Tsang, C.; Versteeg, M.

    2015-12-01

    The reconnaissance of the Pluto System by New Horizons included radio occultations at both Pluto and Charon. This talk will present the latest results from the Pluto occultation. The REX instrument onboard New Horizons received and recorded uplink signals from two 70-m antennas and two 34-m antennas of the NASA Deep Space Network - each transmitting 20 kW at 4.2-cm wavelength - during a diametric occultation by Pluto. At the time this was written only a short segment of data at occultation entry (193°E, 17°S) was available for analysis. The REX measurements extend unequivocally to the surface, providing the first direct measure of the surface pressure and the temperature structure in Pluto's lower atmosphere. Preliminary analysis yields a surface pressure of about 10 microbars, smaller than expected. Data from occultation exit (16°E, 15°N) are scheduled to arrive on the ground in late August 2015. Those observations will yield an improved estimate of the surface pressure, a second temperature profile, and a measure of the diameter of Pluto with a precision of a few hundred meters.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. The Lunar Occultation Observer (LOCO) -- A Nuclear Astrophysics All-Sky Survey Mission Concept

    NASA Astrophysics Data System (ADS)

    Miller, R. S.; Bonamente, M.; Burgess, J. M.; Jenke, P.; Lawrence, D. J.; O'Brien, S.; Orr, M. R.; Paciesas, W. S.; Young, C. A.

    2009-03-01

    The Lunar Occultation Observer (LOCO) is a new γ-ray astrophysics mission concept expected to have unprecedented sensitivity in the nuclear regime. Operating in lunar orbit, LOCO will utilize lunar occultation imaging to survey and probe the cosmos.

  2. Observation and Interpretation of Lunar Occultations. Ph.D. Thesis; [Uranus and beta Capricorni

    NASA Technical Reports Server (NTRS)

    Radick, R. R.

    1978-01-01

    The importance of timings and high resolution astrometry in occultation observations is discussed as well as the occultation process itself. The design and operation of the telescope, photodetector, and data acquisition systems are described. Methods are presented for data analysis and model fitting. Observations of beta Capricorni and Uranus occultations are examined. General conclusions concerning occultation observations are explored and future activities at Prairie Observatory are discussed.

  3. The occultation of HIP 106829 by Titania

    NASA Astrophysics Data System (ADS)

    Sicardy, B.; Widemann, T.; Colas, F.; Lecacheux, J.; Pau, S.; Thuillot, W.; Beisker, W.; Birnbaum, C.; Hubbard, W. B.; Hill, R. E.; Porto, J.; López, E.; Cósias, R.; Pallo, Edgar; Percz, R.; Pulupa, D.; Simbaña, X.; Yajamín, A.; Recalde, E.

    2001-11-01

    The occultation of the bright star HIP 106829 (V= 7.2, type K0III, distance 170 pc) by the largest Uranian satellite Titania was successfully observed from Europe, several Atlantic and Caribbean islands, and from Southern America, around 2 UT, September 8, 2001. We report here preliminary results obtained from France (80-cm tel. Haute Provence, 100-cm tel. Pic du Midi), Aruba Island (20-cm tel.) and Ecuador (two 20-cm tel. and one 25-cm tel.), using CCD or video recordings, at repetition rates of several images per second. Various other observations, either visual or recorded, by amateurs from Great Britain, Spain, Portugal, Azores, Venezuela and Tobago are still being compiled at the submission date of this abstract. Preliminary examination of the data indicates that no atmosphere at the microbar level is detected near Titania's surface. A detailed analysis is still necessary, however, in order to detect (or put an upper limit on) a hypothetical atmosphere at the 0.1 microbar level or less. The timings of the event at various sites provide the position of Titania with respect to HIP 106829. This will yield the observed-calculated (O-C) shift to apply to Titania position (using the URA027+DE405 ephemeris) in the ICRF/J2000 system. Finally, the finite duration of the immersion and emersion of the star behind Titania will be used to constrain the physical size of this red giant star. Supports from the Programme National de Planétologie (France), Paris Observatory and the NASA Planetary Astronomy grant NAG5-4214 are acknowledged.

  4. Update on occult hepatitis B virus infection

    PubMed Central

    Makvandi, Manoochehr

    2016-01-01

    The event of mutations in the surface antigen gene of hepatitis B virus (HBV) results in undetectable hepatitis B surface antigen with positive/negative anti-hepatitis B core (anti-HBc) antibody status in serum and this phenomenon is named occult hepatitis B infection (OBI). The presence of anti-HBc antibody in serum is an important key for OBI tracking, although about 20% of OBI cases are negative for anti-HBc antibody. The diagnosis of OBI is mainly based on polymerase chain reaction (PCR) and real-time PCR assays. However, real-time PCR is a more reliable method than PCR. OBI is a great issue for the public health problem and a challenge for the clinical entity worldwide. The persistence of OBI may lead to the development of cirrhosis and hepatocellular carcinoma. With regard to OBI complications, the screening of HBV DNA by the highly sensitive molecular means should be implemented for: (1) patients with a previous history of chronic or acute HBV infection; (2) patients co-infected with hepatitis C virus/human immunodeficiency virus; (3) patients undergoing chemotherapy or anti-CD20 therapy; (4) recipients of organ transplant; (5) blood donors; (6) organ transplant donors; (7) thalassemia and hemophilia patients; (8) health care workers; (9) patients with liver related disease (cryptogenic); (10) hemodialysis patients; (11) patients undergoing lamivudine or interferon therapy; and (12) children in time of HBV vaccination especially in highly endemic areas of HBV. Active HBV vaccination should be implemented for the close relatives of patients who are negative for OBI markers. Thus, the goal of this review is to evaluate the rate of OBI with a focus on status of high risk groups in different regions of the world. PMID:27818588

  5. Fracture Management

    MedlinePlus

    ... to hold the fracture in the correct position. • Fiberglass casting is lighter and stronger and the exterior ... with your physician if this occurs. • When a fiberglass cast is used in conjunction with a GORE- ...

  6. Hip Fracture

    MedlinePlus

    ... make older people more likely to trip and fall — one of the most common causes of hip ... Taking steps to maintain bone density and avoid falls can help prevent hip fracture. Signs and symptoms ...

  7. Stellar Occultations from Airborne Platforms: 1988 to 2016

    NASA Astrophysics Data System (ADS)

    Bosh, Amanda S.; Dunham, Edward W.; Zuluaga, Carlos; Levine, Stephen; Person, Michael J.; Van Cleve, Jeffrey E.

    2016-10-01

    Observing a stellar occultation by a solar system body with an airborne telescope requires precise positioning of the observer within the shadow cast onto the Earth. For small bodies like Pluto and Kuiper Belt objects, smaller than the Earth, the challenge is particularly intense, with the accuracy of the astrometric and flight planning determining whether the observation succeeds or fails. From our first airborne occultation by Pluto in 1988 aboard the Kuiper Airborne Observatory (KAO), to our most recent event by Pluto in 2015 aboard the Stratospheric Observatory for Infrared Astronomy (SOFIA), we have refined our astrometric and flight planning systems to the point where we can now place an airborne observer into the small central flash zone. We will discuss the history of airborne observation of occultations while detailing the improvements in the astrometric processes. Support for this work was provided by NASA SSO grant NNX15AJ82G to Lowell Observatory.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Detection of occult metastasis in patients with breast cancer.

    PubMed

    Hawes, D; Neville, A M; Cote, R J

    2001-06-01

    The most important factor affecting the outcome of patients with invasive cancer is whether the tumor has spread, either regionally (to regional lymph nodes) or systemically. However, a proportion of patients with no evidence of systemic dissemination will develop recurrent disease after primary "curative" therapy. Clearly, these patients had occult systemic spread of disease that was undetectable by routinely employed methods (careful pathological, clinical, biochemical, and radiological evaluation). In addition, the success of adjuvant therapy is assumed to stem from its ability to eradicate occult metastases before they become clinically evident. Therefore, methods for the detection of occult metastases in patients with the earliest stage of cancer, i.e., prior to detection of metastases by any other clinical or pathological analysis, have received a great deal of attention.

  10. Benefits and harms of detecting clinically occult breast cancer.

    PubMed

    Amir, Eitan; Bedard, Philippe L; Ocaña, Alberto; Seruga, Bostjan

    2012-10-17

    Over the last few decades there has been an increase in the use of strategies to detect clinically occult breast cancer with the aim of achieving diagnosis at an earlier stage when prognosis may be improved. Such strategies include screening mammography in healthy women, diagnostic imaging and axillary staging in those diagnosed with breast cancer, and the use of follow-up imaging for the early detection of recurrent or metastatic disease. Some of these strategies are established, whereas for others there are inconsistent supportive data. Although the potential benefit of early detection of clinically occult breast cancer seems intuitive, use of such strategies can also be associated with harm. In this commentary, we provide an extended discussion on the potential benefits and harms of the routine and frequent use of screening interventions to detect clinically occult breast cancer and question whether we may be causing more harm than good.

  11. Designing asymmetric and branched petals for planet-finding occulters.

    PubMed

    Cady, Eric; Kasdin, N J; Shaklan, Stuart

    2010-01-18

    One of the proposed methods for finding small extrasolar planets is through use of an occulter, a spacecraft which flies in formation with a space-based telescope to block the light from a star, while leaving nearby planets unaffected. This is accomplished by placing the occulter far enough from the telescope to give it a small angular size, and by carefully choosing the shape to strongly suppress the starlight at the telescope aperture. For most designs, this shape takes the form of a number of bilaterally-symmetric structures called petals, arrayed about a circular central disk. In this paper, we show that the necessary number of petals may be reduced by the introduction of an asymmetry in the petal shape, and describe a a general procedure for producing such a shape by optimization for any occulter with petals. In addition, we show that permitting openings within each petal allows a number of additional modifications to be made without affecting the suppression.

  12. Virtopsy -- noninvasive detection of occult bone lesions in postmortem MRI: additional information for traffic accident reconstruction.

    PubMed

    Buck, Ursula; Christe, Andreas; Naether, Silvio; Ross, Steffen; Thali, Michael J

    2009-05-01

    In traffic accidents with pedestrians, cyclists or motorcyclists, patterned impact injuries as well as marks on clothes can be matched to the injury-causing vehicle structure in order to reconstruct the accident and identify the vehicle which has hit the person. Therefore, the differentiation of the primary impact injuries from other injuries is of great importance. Impact injuries can be identified on the external injuries of the skin, the injured subcutaneous and fat tissue, as well as the fractured bones. Another sign of impact is a bone bruise. The bone bruise, or occult bone lesion, means a bleeding in the subcortical bone marrow, which is presumed to be the result of micro-fractures of the medullar trabeculae. The aim of this study was to prove that bleeding in the subcortical bone marrow of the deceased can be detected using the postmortem noninvasive magnetic resonance imaging. This is demonstrated in five accident cases, four involving pedestrians and one a cyclist, where bone bruises were detected in different bones as a sign of impact occurring in the same location as the external and soft tissue impact injuries.

  13. Scintillations during occultations by planets. 1. An approximate theory. [fresnel region

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1975-01-01

    Scintillations observed during occultations of both stars and spacecraft by planetary atmospheres are discussed theoretically. The effects of severe flattening of the Fresnel zone or source image by defocusing on occultations are presented, along with temporal power spectra. Other topics discussed include atmospheric turbulence, saturation of scintillation, effects of saturation on occultation curves, and some methods for a more accurate determination of atmospheric structure.

  14. Lisfranc fractures.

    PubMed

    Wright, Amanda; Gerhart, Ann E

    2009-01-01

    Injuries of the tarsometatarsal, or Lisfranc, joint are rarely seen. Lisfranc fractures and fracture dislocations are among the most frequently misdiagnosed foot injuries in the emergency department. A misdiagnosed injury may have severe consequences including chronic pain and loss of foot biomechanics. Evaluation of a foot injury should include a high level of suspicion of a Lisfranc injury, and a thorough work-up is needed for correct diagnosis.

  15. Colles' fracture.

    PubMed

    Altizer, Linda L

    2008-01-01

    Many people "slip and fall", especially in the icy areas of the winter season. To prevent an injury to the head, most people put their hand out to hit the ground first, so the wrist usually gets injured. The most frequent injury from this type of "intervention" is a fracture to the distal radius and/or ulna, which is frequently called a "Colles' fracture."

  16. The Burst and Transient Source Experiment Earth Occultation Technique

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Wilson, C. A.; Paciesas, W. S.; Zhang, S. N.; Finger, M. H.; Koshut, T. M.; McCollough, M. L.; Robinson, C. R.; Rubin, B. C.

    2002-01-01

    An Earth orbiting detector sensitive to gamma-ray photons will see step-like occultation features in its count rate when a gamma-ray point source crosses the Earth's limb. This is due to the change in atmospheric attenuation of the gamma rays along the line of sight. In an uncollimated detector, these occultation features can be used to locate and monitor astrophysical sources provided their signals can be individually separated from the detector background. We show that the Earth occultation technique applied to the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) is a viable and flexible all-sky monitor in the low-energy gamma-ray and hard X-ray energy range (20 keV-1 MeV). The method is an alternative to more sophisticated photon imaging devices for astronomy and can serve well as a cost-effective science capability for monitoring the high energy sky. Here we describe the Earth occultation technique for locating new sources and for measuring source intensity and spectra without the use of complex background models. Examples of transform imaging, step searches, spectra, and light curves are presented. Systematic uncertainties due to source confusion, detector response, and contamination from rapid background fluctuations are discussed and analyzed for their effect on intensity measurements. A sky location-dependent average systematic error is derived as a function of Galactic coordinates. The sensitivity of the technique is derived as a function of incident photon energy and also as a function of angle between the source and the normal to the detector entrance window. Occultations of the Crab Nebula by the Moon are used to calibrate Earth occultation flux measurements independent of possible atmospheric scattering effects.

  17. Detection of Small Kuiper Belt Objects by Stellar Occultation

    NASA Astrophysics Data System (ADS)

    Georgevits, George

    2006-09-01

    We present here the results for the first attempt to survey the sub-kilometre radius KBO population by stellar occultation. Using the unique capabilities of the 1.2m UK Schmidt Telescope (Anglo Australian Observatory, Australia), in conjunction with the 6df Spectrograph, by simultaneously monitoring 100 suitably selected stars, we were able to embark upon an occultation observation program which yielded 7,000 hours of stellar light curves, with 10 millisecond resolution. Initial data reduction indicates that we have captured many events which resemble occultation events, in so far as the light curves of recorded events typically match that which may be expected when a small KBO occults a distant star. Logged events are spread over many pixels, with 10 pixels (corresponding to 100 milliseconds) being the typical event duration. By simultaneously monitoring many stars in the same field, false events are eliminated. Most runs monitored blue stars located at 2kpcs. As a sanity check, one night's observing monitored close F and G class stars in the same field. The event statistics for the distant and the close star cases are consistent with occultations caused by KBO's. As an additional confirmation, it was found that the observation results at 30o and 60o past opposition give the expected 50% fall in event rate due to the change in observing geometry. It is estimated that many of the events logged correspond to occultations which would be caused by objects down to 300m radius. As the next step, it is hoped to construct a purpose-built 2,000 fibre instrument and to conduct a complete survey of the Kuiper Belt. We wish to express our thanks to the Anglo Australian Observatory for their technical assistance and telescope time.

  18. Constraints on Pluto's Hazes from 2-Color Occultation Lightcurves

    NASA Astrophysics Data System (ADS)

    Hartig, Kara; Barry, T.; Carriazo, C. Y.; Cole, A.; Gault, D.; Giles, B.; Giles, D.; Hill, K. M.; Howell, R. R.; Hudson, G.; Loader, B.; Mackie, J. A.; Olkin, C. B.; Rannou, P.; Regester, J.; Resnick, A.; Rodgers, T.; Sicardy, B.; Skrutskie, M. F.; Verbiscer, A. J.; Wasserman, L. H.; Watson, C. R.; Young, E. F.; Young, L. A.; Buie, M. W.; Nelson, M.

    2015-11-01

    The controversial question of aerosols in Pluto's atmosphere first arose in 1988, when features in a Pluto occultation lightcurve were alternately attributed to haze opacity (Elliot et al. 1989) or a thermal inversion (Eshleman 1989). A stellar occultation by Pluto in 2002 was observed from several telescopes on Mauna Kea in wavelengths ranging from R- to K-bands (Elliot et al. 2003). This event provided compelling evidence for haze on Pluto, since the mid-event baseline levels were systematically higher at longer wavelengths (as expected if there were an opacity source that scattered more effectively at shorter wavelengths). However, subsequent occultations in 2007 and 2011 showed no significant differences between visible and IR lightcurves (Young et al. 2011).The question of haze on Pluto was definitively answered by direct imaging of forward-scattering aerosols by the New Horizons spacecraft on 14-JUL-2015. We report on results of a bright stellar occultation which we observed on 29-JUN-2015 in B- and H-bands from both grazing and central sites. As in 2007 and 2011, we see no evidence for wavelength-dependent extinction. We will present an analysis of haze parameters (particle sizes, number density profiles, and fractal aggregations), constraining models of haze distribution to those consistent with and to those ruled out by the occultation lightcurves and the New Horizons imaging.References:Elliot, J.L., et al., "Pluto's Atmosphere." Icarus 77, 148-170 (1989)Eshleman, V.R., "Pluto's Atmosphere: Models based on refraction, inversion, and vapor pressure equilibrium." Icarus 80 439-443 (1989)Elliot, J.L., et al., "The recent expansion of Pluto's atmosphere." Nature 424 165-168 (2003)Young, E.F., et al., "Search for Pluto's aerosols: simultaneous IR and visible stellar occultation observations." EPSC-DPS Joint Meeting 2011, held 2-7 October 2011 in Nantes, France (2011)

  19. Deriving Saturn's Zonal Winds from Cassini Radio Occultations

    NASA Astrophysics Data System (ADS)

    Flasar, F. Michael; Schinder, Paul J.

    2015-11-01

    Tracking cloud features from visible images have provided detailed maps of the meridional variation of the mean zonal winds on the giant planets, including Saturn. Filters at different wavelengths can provide information on the vertical structure of the zonal winds, but that is approximate, and the altitudes of winds observed with a given filter generally vary with location, because cloud heights do. Radio occultations provide vertical profiles of refractivity, pressure, and temperature vs. altitude. Zonal winds can be derived from the assumption of gradient wind balance, which relates the zonal wind to the change of geopotential height with latitude along an isobar. Occultations have the advantage that vertical profiles of winds can be obtained in the troposphere and stratosphere. There are, however, complicating factors. In general, the meridional distribution of occultation soundings is limited and unevenly distributed. Moreover, one needs to know the geometry of the occulting atmosphere to correctly account for the path of the refracted radio signal. The zonal winds matter, because they distort isobaric surfaces. For example, an inversion that includes Saturn's oblateness from uniform rotation, based on the Voyager System III period, would yield equatorial temperature profiles that are shifted by ~ 2 K relative to one that also includes the differential rotation associated with the cloud-tracked zonal winds. In retrieving vertical profiles of atmospheric variables from occultation soundings, one also needs an additional symmetry assumption to make the inversions tractable. Typically one uses the zonal winds based on cloud-tracking studies, and assumes they are axisymmetric and barotropic, so that both the gravitational and centrifugal forces are derivable from a potential, and the surfaces of constant geopotential height, pressure, and temperature coincide. This forms the basis for an iterative approach. The pressures and temperatures so retrieved from the

  20. Saturn's variable thermosphere from Cassini/UVIS occultations

    NASA Astrophysics Data System (ADS)

    Koskinen, T. T.; Sandel, B. R.; Yelle, R. V.; Strobel, D. F.; Müller-Wodarg, I. C. F.; Erwin, J. T.

    2015-11-01

    We retrieved the density and temperature profiles in Saturn's thermosphere from 26 stellar occultations observed by the Cassini/UVIS instrument. These results expand upon and complement the previous analysis of 15 Cassini/UVIS solar occultations by Saturn's upper thermosphere. We find that the exospheric temperatures based on the stellar occultations agree with the solar occultations and range from 380 K to 590 K. These temperatures are also consistent with the recent re-analysis of the Voyager/UVS occultations. The retrieved density profiles support our earlier inference that the shape of the atmosphere at low pressures is consistent with a meridional trend of increasing temperatures with absolute latitude. This implies a high-latitude heat source, such as auroral heating, although the existing circulation models that include auroral heating still underestimate the equatorial temperatures by overestimating the meridional temperature gradient. This suggests either that the circulation models are somehow incomplete or there is some other heat source at low to mid latitudes that is relatively less efficient than high-latitude heating. We also find evidence for the expansion of the exobase by about 500 km between 2006 and 2011 near the equator, followed by possible contraction after 2011. The expansion appears to be caused by significant warming of the lower thermosphere that anti-correlates with solar activity and may be connected to changes in global circulation. Lastly, we note that our density profiles are in good general agreement with the Voyager/UVS data. In particular, the Voyager density profiles are most consistent with the Cassini/UVIS stellar occultations from late 2008 and early 2009 that roughly coincide in season with the Voyager flybys.

  1. GRAS radio occultation on-board of Metop

    NASA Astrophysics Data System (ADS)

    von Engeln, A.; Andres, Y.; Marquardt, C.; Sancho, F.

    2011-01-01

    The GRAS radio occultation instrument is flying on Metop-A and belongs to the EPS (EUMETSAT Polar System). GRAS observes GPS satellites in occultation. Within this work, validation of GRAS closed-loop bending angle data against co-located ECMWF profiles extracted from model fields and occultations from the COSMIC constellation of radio occultation instruments is shown. Results confirm the high data quality and robustness, where GRAS shows lower bending angle noise against ECMWF than COSMIC and in terms of occultations per day, one GRAS ≈ two COSMIC satellites. This is partly due to the operational setup of EPS. For the investigation we focus on two observation periods where updates in the ECMWF (March 2009) and COSMIC processing (October 2009) have improved the statistics further. Bending angles biases agree to within 0.5% against ECMWF and to within 0.1% against COSMIC after the updates for altitudes between 8 and 40 km. In addition, we also analyze the impact of the Metop orbit processing on the derived GRAS bending angle data, where different GPS and Metop orbit solutions are analyzed. Results show that a batch based orbit processing would improve in particular the bending angle bias behavior at higher altitudes. Requirements for the operational processing of GRAS data are briefly outlined, options to ease the use of other positioning system satellites in the near future are discussed. A simplified analysis on the observation of several of these systems, e.g. GPS and Galileo, from one platform shows that about 16% of occultations are found within 300 km, ±3 h, thus providing similar information. A constellation of 2 GRAS like instruments would have only about 10% close-by.

  2. Boxer's fracture.

    PubMed

    Altizer, Linda

    2006-01-01

    Boxer's fracture is a common name for a fracture of the distal fifth metacarpal and received its name from one of its most common causes, punching an object with a closed fist. It can occur from a fistfight or from punching a hard object. The injury of a "Boxer's Fracture" earned the name from the way in which the injury occurred, punching an immovable object with a closed fist and no boxing mitt (Figure 1). Naturally, a "Boxer" usually punches his fist into his opponent's face or body. An angry person may perform the same action into a person, or into the wall. The third person may be performing a task and strike something with his fist with forceful action accidentally. In any event, if the closed fist "punches" into an immovable or firm object with force, the most frequent injury sustained would be a fracture of the fifth metacarpal neck. Some caregivers would also call a fourth metacarpal neck fracture a boxer's fracture.

  3. GOMOS: Gobal Ozone Monitoring by Occultation of Stars

    NASA Technical Reports Server (NTRS)

    Leppelmeier, G. W.; Kyrola, E.; Pellinen, R.; Merat, P.; Korpela, S.; Bertaux, J. L.; Chassefiere, E.; Dalaudier, F.; Megie, G.

    1994-01-01

    In this paper we report on the progress and status of the Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument, and imaging spectrometer under development for flight on the European Space Agency's Polar Orbiting Earth Mission (POEM-1) mission in 1998. Employing occultation of stars as a light probe of the Earth's atmosphere from a sun-sychronous polar orbit, the instrument will monitor ozone and other atmospheric trace gases over the entire globe. Atmospheric transmission resolution of approximately 1.7 km. When data are combined regionally, it will be possible to detect ozone concentration trends as small as 0.05 percent/year, depending on the degree of combination.

  4. Forthcoming Occultations of Astrometric Radio Sources by Planets

    NASA Technical Reports Server (NTRS)

    L'vov, Victor; Malkin, Zinovy; Tsekmeister, Svetlana

    2010-01-01

    Astrometric observations of radio source occultations by solar system bodies may be of large interest for testing gravity theories, dynamical astronomy, and planetary physics. In this paper, we present an updated list of the occultations of astrometric radio sources by planets expected in the coming years. Such events, like solar eclipses, generally speaking can only be observed in a limited region. A map of the shadow path is provided for the events that will occurr in regions with several VLBI stations and hence will be the most interesting for radio astronomy experiments.

  5. The mermaid malformation: cloacal exstrophy and occult spinal dysraphism.

    PubMed

    Cohen, A R

    1991-06-01

    Five infants with cloacal exstrophy underwent neurological evaluation and radiographic examination of the caudal spine shortly after birth. Each was found to have occult spinal dysraphism. Four had terminal myelocystoceles, and one had a lipomyelomeningocele. Pathological anatomy was confirmed during surgery for the release of the tethered spinal cords. The striking association between cloacal exstrophy and occult spinal dysraphism suggests a common developmental defect in the caudal pole of the embryo. A hypothesis is offered to explain this association. Terminal myelocystocele and lipomyelomeningocele appear to be part of a continuum of lesions associated with skin-covered spina bifida.

  6. Cassini UVIS highest resolution occultations of Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, Miodrag; Esposito, L. W.; Colwell, J.

    2013-10-01

    Since the beginning of the Cassini mission in 2004 the UVIS instrument has recorded >100 stellar occultations of Saturn's rings. Despite achieved radial resolutions of <1m true resolution is limited by the orbital motion of particles. These can move by almost 20m during a 1ms integration period, effectively smearing the ring profile. In order to achieve superior true resolution we designed a special type of observations, dubbed tracking occultations, where the spacecraft velocity projected onto the rings cancels the orbital motion of ring particles. The ring particles are thus nearly motionless in the field of view of UVIS instrument and essentially tracked. So far Cassini UVIS has recorded two "tracking" occultations of mid-A ring, one of the inner A ring, and one of the so called A ring ramp (a transition region between Cassini division and A ring). The occultations have at least 2m true resolution limited only by diffraction. The two mid-A ring occultations for the first time directly resolve the self-gravity (SG) Toomre like wakes. The SG wakes show as a train of opaque regions (tau>1.5) and nearly transparent gaps (tau<0.05). The observed opaque wakes can be as large as 200m, while transparent gaps are somewhat shorter (L<100m). The opaque and transparent regions are interspersed with material in an intermittent state (0.05occultation of the A ring ramp also reveals clear SG wakes. While the image is still of a chain of wakes and gaps, the wake region is not opaque nor is the transition between a gap and wake state as sharp. The structures are about 5 times smaller compared to mid-A ring, indicating a much smaller surface density. The inner A ring "tracking" occultation turns to be the most surprising since it doesn't show any clear SG wakes. While statistical and spectral analysis of the data show that some kind of structure is present there is no clear ubiquitous sign of classical SG wakes as in other 3 "tracking

  7. The occultation of AG+29 deg 398 by 98 Minerva

    NASA Technical Reports Server (NTRS)

    Millis, R. L.; Wasserman, L. H.; Bowell, E.; Franz, O. G.; Nye, R.; Osborn, W.; Klemola, A.

    1984-01-01

    On 22 Nov. 1982, the asteroid 93 Minerva occulted AG-29 deg 398 (= SAO 76O17A), a seventh magnitude star of AO spectral type. The data were best fitted by a circular limb profile having a diameter of 170.8 + or - 1.4 km, a value that agrees well with the published radiometric diameter for this asteroid. However, evidence of significant departure from a spherical shape is found in the occultation observations and in photometric measurements of Minerva. Additional observations are required to specify difinitively the three dimensional figure of Minerva.

  8. The occultation of AG + 29 deg 398 by 93 Minerva

    NASA Technical Reports Server (NTRS)

    Millis, R. L.; Wasserman, L. H.; Bowell, E.; Franz, O. G.; Nye, R.; Osborn, W.; Klemola, A.

    1985-01-01

    The occultation of AG + 29 deg 398 by 93 Minerva on 22 November 1982 was successfully observed at 10 sites. The data are best fitted by a circular limb profile having a diameter of 170.8 + or - 1.4 km, a value that agrees well with the published radiometric diameter for this asteroid. However, evidence of significant departure from a spherical shape is found in the occultation observations and in photometric measurements of Minerva made at Lowell Observatory over several months. Additional observations are needed to specify definitively the three-dimensional figure of Minerva.

  9. Cassini First Diametric Radio Occultation of Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Marouf, E.; French, R.; Rappaport, N.; Kliore, A.; Flasar, M.; Nagy, A.; Ambrosini, R.; McGhee, C.; Schinder, P.; Anabtawi, A.; Barbinis, E.; Goltz, G.; Thomson, F.; Wong, K.

    2005-05-01

    We present preliminary results expected from the first planned Cassini radio occultation observation of Saturn's rings, to be conducted on May 3rd, 2005. The path of Cassini as seen from Earth (the occultation track) has been designed to cross the rings from the west to the east ansa almost diametrically, allowing for occultation of all major ring features at two widely separated longitudes (about 180 deg apart). The duration of the geometric occultation is about 1.5 hours on each side. During the occultation, Cassini transmits through the rings three coherent monochromatic radio signals of wavelength 0.94, 3.6, and 13 cm (Ka-, X-, and S-band respectively), a capability unique to Cassini. The perturbed signals received at the Earth are recorded at the NASA DSN complexes at Goldstone and Canberra. Both direct and forward-scattered components of the signal may be identified in spectrograms of the received signals. The time history of the extinction of the direct signal is expected to yield high-spatial-resolution optical depth and phase shift profiles of ring structure. The timing of the occultation was optimized to allow probing the rings when the ring-opening-angle B (the angle between the line-of-sight and the ring plane) is relatively large (B = 23 deg), hence maximizing chances of measuring for the first time the structure of the relatively optically thick Ring B. In a similar experiment by Voyager in 1980, excessive signal attenuation along the long path within the nearly closed rings (B = 5.9 deg) limited the utility of the observations in relatively thick ring regions, in particular the main Ring B. For the Cassini optimized occultation geometry, a large B, slow radial velocity along the occultation track, and much improved phase stability of the reference ultrastable oscillator (USO) on board Cassini combine to promise achievable radial resolution approaching 100 m over a good fraction of the rings. Measurement of the amplitude and phase of the diffracted

  10. [Arthroscopically assisted treatment of ankle fractures].

    PubMed

    Braunstein, M; Baumbach, S F; Böcker, W; Mutschler, W; Polzer, H

    2016-02-01

    Acute ankle fractures are one of the most common fractures in adults with an incidence of 0.1-0.2 % per year. Operative treatment by open reduction and internal fixation (ORIF) is the standard method of treatment for unstable or dislocated fractures. The main goal of the operation is the anatomical realignment of the joint and restoration of ankle stability; nevertheless, anatomical reduction does not automatically lead to favorable clinical results. According to several studies the mid-term and in particular the long-term outcome following operative treatment is often poor with residual symptoms including chronic pain, stiffness, recurrent swelling and ankle instability. There is growing evidence that this poor outcome might be related to occult intra-articular injuries involving cartilage and soft tissues. In recent studies the frequency of fracture-related osteochondral lesions was reported to be approximately 64 %. By physical examination, standard radiography or even computed tomography (CT), these intra-articular pathologies cannot be reliably diagnosed; therefore, many authors emphasize the value of ankle arthroscopy in acute fracture treatment as it has become a safe and effective diagnostic and therapeutic procedure. Arthroscopically assisted open reduction and internal fixation (AORIF) allows control of the reduction as well examination of all intra-articular structures. If necessary, intra-articular pathologies can be addressed by removing ruptured ligaments and loose bodies, performing chondroplasty or microfracturing. So far there is no evidence that supplementary ankle arthroscopy increases the complication rate. On the other hand, the positive effect of AORIF has also not been clearly documented; nevertheless, there are clear indications that arthroscopically assisted fracture treatment is beneficial, especially in complex fractures.

  11. Oh Glorious Geometry: Eclipses, Transits, and Occultations

    NASA Astrophysics Data System (ADS)

    Sinclair, R. M.

    2016-01-01

    Astronomical objects are like a grand clockwork in the sky; they follow steady patterns in time. However, these bright objects we see are not just points of light but have finite dimensions and thus can get in each other's way. As a result, some stars puzzle us by brightening or dimming, or the Sun can frighten us by going out unexpectedly when something else blocks its light. There is nothing unusual about these eclipses, occultations, or transits—they are demonstrations of simple physics—and we take some for granted, like the rotation of Earth moving us into darkness each night. The periodic dimming of a bright star worried mankind for millennia and helped give astronomy a shove. And unexpected events, like a solar or lunar eclipse, can inspire awe and change the course of history. Now that we can observe through telescopes and travel by proxy throughout the solar system, we find the universe is rife with shadow and light shows. Those taking place within our solar system have been useful to astronomy (like the recent transits of Venus or the ever-present eclipses of the Jovian satellites), and were of considerable popular interest, allowing us to think beyond the confines of Earth. Now we detect distant exoplanets transiting their parent stars, announcing the presence of other solar systems in our corner of the Galaxy and changing the discussion about life elsewhere in the universe from mere speculation to plausible possibility. Distant galaxies can make visible ever-further galaxies by forming Einstein rings, allowing us to see behind them and make the structure of the universe more evident. This paper will discuss these phenomena, from those visible easily on Earth to those that can now be seen for the first time from probes in space. We will also discuss how this has expanded popular knowledge of the universe we live in. This paper is illustrated by a number of examples ranging from eclipses and transits throughout the solar system and the nearby stars to

  12. The clinical outcome after extra-articular colles fractures with simultaneous moderate scapholunate dissociation.

    PubMed

    Finsen, Vilhjalmur; Rajabi, Benjamin; Rod, Oyvind; Roed, Kristian; Alm-Paulsen, Paal Sandoe; Russwurm, Harald

    2014-05-01

    Background An increased scapholunate gap is sometimes seen in patients with a distal radial fracture. The question remains as to whether this represents a scapholunate ligament injury that requires treatment. Questions/purposes We wished to examine the natural history of an increased scapholunate gap in patients following an extra-articular distal radial fracture. Patients and Methods We reviewed 260 patients who had sustained a distal radial fracture at a mean of 6.2 (2.7-11.9) years previously and identified 12 extra-articular fractures with an increased gap between the lunate and scaphoid. The mean scapholunate gap was 2.6 (2.1-3.4) mm, and the mean scapholunate angle 62° (39°-90°). Controls were found among the remaining patients with extra-articular fractures. Selection criteria were same sex, age at fracture within 5 years, time between injury and review within 2 years, ulnar variance within 2 mm, and dorsal angulation within 5° of index patient. When more than one control fulfilled the criteria for an index patient, their values were averaged. In total there were 54 controls for the 12 index patients. Results The mean difference between index patients and controls in wrist range of motion was 4%, in grip strength 5%, in visual analog scale (VAS) for pain 1 (on a scale from 1 to 100), in Quick-DASH (Disability of the Arm, Shoulder, and Hand) score 5, and in PRWE score 1. The study was calculated to have the power to detect a difference in Quick-DASH scores and in Patient-Rated Wrist Evaluation (PRWE) scores of 14. Conclusions We conclude that at a mean follow up of 6.2 years following an extra-articular distal radial fracture, no surgical treatment is usually needed with a scapholunate gap of between 2.1-3.4 mm. Level of Evidence III, Case control study.

  13. GPS Radio Occultation With Champ: The First Year of The Experiment

    NASA Astrophysics Data System (ADS)

    Wickert, J.; Beyerle, G.; Marquardt, C.; Schmidt, T.; Reigber, Ch.; König, R.; Grunwaldt, L.

    The GPS radio occultation experiment onboard the German CHAMP (CHAllenging Minisatellite Payload) satellite was started on February 11, 2001. During an one hour measurement period seven occultation events were recorded. Already these first mea- surements indicated that in spite of the activated anti-spoofing (A/S) mode of the GPS the state-of-the-art GPS flight receiver combined with favorable antenna characteris- tics allows for global atmosphere sounding with high accuracy and vertical resolution. More than 50,000 occultations are expected as of April 2002. The first year of the CHAMP occultation experiment is reviewed. The occultation infrastructure at the Ge- oForschungsZentrum (GFZ) Potsdam and the operational occultation data processing is characterized. An overview of GFZSs operational data processing, the scientific data analysis and the results of the first year occultation experiment is given. The quality of CHAMPSs occultation data products (vertical atmospheric profiles) is evaluated. Re- sults of data analysis using wave optic methods are presented, e.g. contributions from signals, reflected from EarthSs surface, were found in the occultation data in about 20-30% of the measurements using a radio holographic analysis. Furthermore, the termination of the Selective Availability (SA) mode of the GPS made the application of less-than-double-differencing techniques for GPS occultation analysis feasible. Re- sults of occultation data processing using a space-based single differencing technique are compared with those generated by double differencing as a reference.

  14. The Effect of Diurnal Variations on Ionospheric Radio Occultations

    NASA Astrophysics Data System (ADS)

    Yelle, Roger V.; Koskinen, Tommi; Withers, Paul; Schinder, Paul J.; Moses, Julianne I.; Mueller-Wodarg, Ingo

    2016-10-01

    Radio occultations are a powerful technique for the study of atmospheres and ionospheres by planetary spacecraft. For missions to the outer solar system, the occultations always probe the terminator region of the planet. The analysis of radio occultations typically assumes symmetry along the ray path in the horizontal direction about the tangent point. While this is an excellent assumption for the neutral atmosphere where the scale length of horizontal gradients is large, it is suspect for the ionosphere where electron densities decrease rapidly from day to night. Diurnal variations in peak electron density are often several orders of magnitude and may occur over a region of a few degrees. We investigate the consequences of diurnal variations on ionospheric occultations with a ray tracing calculation for the angular deflection and frequency residual of the radio wave. The calculations are based on photochemical/diffusion models for the ionospheres of Saturn and Titan. Differences from analysis based on the assumption of horizontal symmetry are most pronounced in the bottom side ionosphere where chemical time constants are short.

  15. Pluto-Charon stellar occultation candidates - 1990-1995

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    A search to identify stars that might be occulted by Pluto or Charon during the period 1990-1995 and part of 1996 is studied. 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 the 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. The 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, about 32 of these events to be observable somewhere on earth are expected. 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. Stellar Occultations by Trans-Neptunian Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Wolf, Juergen

    2015-10-01

    Our solar system beyond Neptune's orbit is populated with numerous small objects, referred to as Trans-Neptunian Objects (TNOs). About 1400 TNOs are known today ranging in size from the most prominent one, Pluto (2370 km diameter), down to a few tens of kilometers. Most diameters have been determined by radiometric methods in the IR/FIR (SPITZER, HERSCHEL) with uncertainties in the 20% range. Only for Pluto and about 12 other objects have the projected diameters been measured more accurately by stellar occultations. A group of objects lingering between the orbits of Jupiter and Neptune, the Centaurs, are believed to have originated from TNOs. Two of them, Chariklo and Chiron, have recently drawn attention, as stellar occultations have revealed rings around them. Our proposed occultation observations with SOFIA shall add to the sparse knowledge on TNOs and Centaurs by determining more projected diameters and albedos. They have the potential of detecting moons, rings and atmospheres. We will use SOFIA's demonstrated capability of measuring occultations (Pluto 2011 & 2015) with its Focal Plane Imager (FPI) to observe up to five events on flight legs of approximately 30 min each. As most of these events cannot be predicted accurately enough more than a few months or weeks ahead of time, we propose these as targets of opportunity.

  17. Stellar Occultation Studies of Pluto, Triton, Charon, and Chiron

    NASA Technical Reports Server (NTRS)

    Elliot, James L.

    2002-01-01

    Bodies inhabiting the outer solar system are of interest because, due to the colder conditions, they exhibit unique physical processes. Also, some of the lessons learned from them can be applied to understanding what occurred in the outer solar system during its formation and early evolution. The thin atmospheres of Pluto and Triton have structure that is not yet understood, and they have been predicted to undergo cataclysmic seasonal changes. Charon may have an atmosphere - we don't know. Chiron exhibits cometary activity so far from the sun (much further than most comets), so that H2O sublimation cannot be the driving mechanism. Probing these bodies from Earth with a spatial resolution of a few kilometers can be accomplished only with the stellar occultation technique. In this program we find and predict stellar occultation events by small outer-solar system bodies and then attempt observations of the ones that can potentially answer interesting questions. We also develop new methods of data analysis for occultations and secure other observations that are necessary for interpretation of the occultation data.

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Occult Dirofilariosis in Dogs of North Eastern Region in India

    PubMed Central

    Borthakur, Sonjoy Kumar; Deka, Dilip Kumar; Islam, Saidul; Sarmah, Prabhat Chandra

    2016-01-01

    Background: The North Eastern Region in India is endemic for canine heartworm disease but in clinics accurate diagnosis is some times difficult. The aim of the present study was to determine the prevalence of occult infections for heartworm disease in canine in two geographical regions of North Eastern India. Methods: A total of 782 numbers of three categories of dogs namely, working dogs of military and paramilitary forces, pet dogs and stray dogs were screened for the presence of heartworm infection from August 2011 to July, 2012 in Guwahati (Assam) and Aizawl (Mizoram). Conventional, immunological and molecular techniques were followed for this epidemiological study. The criteria to determine the occult heartworm cases were based on the differences between heartworm positive cases in PCR test and antigen ELISA test. Results: The findings revealed an overall 22.69 percent occult case. The working dogs had highest prevalence (60%) followed by pet (29.16%) and stray dogs (17.75%). Conclusion: The highest percentage of occult heartworm infection was present in working dogs maintained under military or paramilitary forces. PMID:27047976

  20. The Structure of Enceladus' Plume from Cassini Occultation Observations

    NASA Astrophysics Data System (ADS)

    Hansen, C. J.; Esposito, L. W.; Buffington, B. B.; Colwell, J.; Hendrix, A. R.; Meinke, B. K.; Shemansky, D. E.; Stewart, I.; West, R. A.

    2011-12-01

    Cassini's Ultraviolet Imaging Spectrograph (UVIS) has observed 2 stellar and one solar occultation by Enceladus' water vapor plume. These observations have established that water is the primary constituent of the plume, allowed us to calculate the flux of water coming from the plume, and detected super-sonic jets of gas imbedded within the plume [1]. On 19 October 2011 two stars (epsilon and zeta Orionis) will simultaneously be occulted by the plume, and the signal of the two will be in separate pixels on the detector. This is a tangential occultation that will provide a horizontal cut through the plume at two altitudes. The two stars are separated by 24 mrad, or ~20 km, with the lower altitude star 18 km above the limb at its closest point. The groundtrack is similar to the 2010 solar occultation, but viewed from the other side of the plume. Results from this new data set with implications for the vertical structure of the plume and jets will be presented.

  1. A first demonstration of Mars crosslink occultation measurements

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    A series of three crosslink occultation experiments have been acquired between the Mars Odyssey and Mars Reconnaissance Orbiter spacecraft to probe the Martian atmosphere in 2007. While crosslink occultations between Earth-orbiting satellites have been used to profile the Earth's atmosphere and ionosphere since 1995, this represents the first demonstration of crosslink occultation measurements at another planet. 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. Analysis of the observed Doppler shift on each crosslink measurement reveals a clear signature of the Martian atmosphere, primarily the ionosphere. Inversion of the observed Doppler data yields vertical profiles of the Martian refractivity and electron density. The electron density profiles show the presence of two layers with peak densities and peak heights that are consistent with empirical model results. Our study demonstrates the feasibility and future potential of the crosslink radio occultation technique in the exploration of planetary atmospheres.

  2. Observational Results from the 2007 March 18 Pluto Stellar Occultation

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.; Babcock, B. A.; Souza, S. P.; McKay, A. J.; Person, M. J.; Elliot, J. L.; Gulbis, A. A.; Zuluaga, C. A.; Hill, J. M.; Ryan, E. V.; Ryan, W. H.

    2007-10-01

    Our consortium observed the 5-minute occultation by Pluto of the star we call P445.3 (2UCAC 25823784, UCAC magnitude 15.3; McDonald and Elliot, 2000, AJ 120, 1599) from sites in the American southwest on 2007 March 17/18 (18 March, UT). Shadow velocity was 6.8 km/s. The 2007 occultation grazed the atmosphere. We were able to use one of the 8.4-m mirrors of the Large Binocular Telescope Observatory, still in its engineering stage, though only with its facility guide camera and not with our Portable Occultation, Eclipse, and Transit System (POETS) CCD/GPS/computer instruments (Souza et al., 2006, PASP 118, 1550). Because of the accurate GPS timing, we were able to align the light curve obtained, which included only the second half of the occultation, with results from other telescopes, including the visible, beamsplit light curve obtained by our group with the 6.5-m MMT (Person et al., 2007, this meeting). We also used, with POETS, the 2.4-m Magdalena Ridge Observatory near Socorro, New Mexico; a partial light curve was obtained despite variable cloudiness throughout the 80 min observation. The location of this telescope was the farthest into the occultation path, and thus led to the deepest incursion into Pluto's atmosphere of the starlight of the major telescopes we used. Light curves were generated by frame-by-frame synthetic-aperture photometry. The large increase in atmospheric pressure we had earlier measured at the 2002 occultation compared with measurements at the first successful Pluto occultation, in 1988, has ceased, as shown by both the 2006 and the current, 2007 measurements. Acknowledgments: We thank Richard Green for granting Director's Discretionary time for the LBT observations. This work was partially funded by NASA Planetary Astronomy grants NNG05GG75G, NNG04GE48G, NNG04GF25G, and NNH04ZSS001N to Williams College and to MIT.

  3. Sensing Water Vapon via Spacecraft Radio Occultation Observations

    NASA Technical Reports Server (NTRS)

    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

  4. Fracture types (1) (image)

    MedlinePlus

    ... fracture which goes at an angle to the axis Comminuted - a fracture of many relatively small fragments Spiral - a fracture which runs around the axis of the bone Compound - a fracture (also called ...

  5. Hydraulic fracturing-1

    SciTech Connect

    Not Available

    1990-01-01

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  6. The 2010, February 19 stellar occultation by Varuna

    NASA Astrophysics Data System (ADS)

    Sicardy, Bruno; Colas, F.; Maquet, L.; Vachier, F.; Doressoundiram, A.; Roques, F.; Widemann, T.; Ortiz, J.; Assafin, M.; Braga-Ribas, F.; Camargo, J. I. B.; Vieira-Martins, R.; Andrei, A.; da Silva Neto, D.; Behrend, R.; Hund, F.; Hauser, M.; Wagner, S.; Slotegraaf, A.; Willasch, D.; Costa, M. de Jesus; Melo Sousa, P.; Faustino, E.; Prazeres, A.; Machado, S.; Dias do Nascimento, J.; Souza Barreto, E.; Amorim, A.; da Rocha Poppe, P.; Pereira, M. Geraldete; Jacques, C.; Loureiro Giacchini, B.; Collucci, A.; Ferreira da Costa, W.; Martins de Morais, V.

    2010-10-01

    On 2010, February 19, Varuna occulted UCAC2 star 41014042, as seen from regions in southern Africa and north-eastern Brazil. No occultation was observed neither from the station deployed in South Africa, nor from three other stations in Namibia. Out of twelve stations deployed in Brazil, seven had clouds or instrument malfunctions. Three were negative, one possibly positive (visual) is still being analyzed, and one is definitely positive from Sao Luis (CCD). This makes Varuna the most remote solar system object observed to date through a stellar occultation, with a geocentric distance of 6.4 billions km. The Sao Luis occultation has a duration of 52.5 +/- 0.5 sec, corresponding to a chord length of 1003 +/- 9 km projected in the plane of the sky. No atmospheric signature is apparent in the light curve. Since the closest observation to Sao Luis is negative at a transversal distance of 225 km (Quixada, CCD), a significantly elongated shape is required for Varuna. We will discuss our results in view of current independent estimations of Varuna's diameter combining IR thermal and visible data, with a typical value of 1050 km +/- 200 km (Lellouch et al. 2002, Stansberry et al., 2008). We will also discuss the fact that the occultation occurred near Varuna's maximum brightness along its 6.4 hr rotational (0.4-mag amplitude) light curve. Thus Varuna was observed at maximum apparent surface area, which also corresponds to maximum apparent oblateness for an ellipsoidal shape. Lellouch et al, Astron. Astrophys. 391, 1133-1139 (2002). Stansberry et al., in The Solar System beyond Neptune (eds Barucci, M. A.,Boehnhardt, H., Cruikshank, D. P. & Morbidelli, A.) 161-179 (Univ. Arizona Press, 2008). This work is partially supported by french ANR 08-BLAN-0177 "Beyond Neptune".

  7. OCCULTATION OBSERVATIONS OF SATURN'S B RING AND CASSINI DIVISION

    SciTech Connect

    French, Richard G.; McGhee, Colleen A.; Marouf, Essam A.; Rappaport, Nicole J.

    2010-04-15

    The outer edge of Saturn's B ring is strongly affected by the nearby 2:1 inner Lindblad resonance of Mimas and is distorted approximately into a centered elliptical shape, which at the time of the Voyager 1 and 2 encounters was oriented with its periapse toward Mimas. Subsequent observations have shown that the actual situation is considerably more complex. We present a complete set of historical occultation measurements of the B-ring edge, including the 1980 Voyager 1 and 1981 Voyager 2 radio and stellar occultations, the 1989 occultation of 28 Sgr, two independently analyzed occultations observed with the Hubble Space Telescope in 1991 and 1995, and a series of ring profiles from 12 diametric (ansa-to-ansa) occultations observed in 2005, using the Cassini Radio Science Subsystem (RSS). After making an approximate correction for systematic errors in the reconstructed spacecraft trajectories, we obtain orbit fits to features in the rings with rms residuals well under 1 km, in most cases. Fits to the B-ring edge in the RSS data reveal a systematic variation in the maximum optical depth at the very edge of the ring as a function of its orbital radius. We compare the B-ring measurements to an m = 2 distortion aligned with Mimas, and show that there have been substantial phase shifts over the past 25 years. Finally, we present freely precessing equatorial elliptical models for 16 features in the Cassini Division. The inner edges of the gaps are generally eccentric, whereas the outer edges are nearly circular, with ae < 0.5 km.

  8. Examining Pluto's atmosphere with SOFIA through stellar occultations

    NASA Astrophysics Data System (ADS)

    Person, Michael

    2012-10-01

    We propose to use SOFIA with HIPO, FLITECAM (subject to availability), and the FDC to observe two pairs of Pluto stellar occultations (four total), attempting in each case to observe from the center of Pluto's shadow path. Only an airborne platform such as SOFIA can allow us to directly place the telescope in the shadow paths of these brief events while mitigating the possibility of missing time-sensitive observations due to unfortunate weather systems. Occultation predictions will be updated throughout the period preceding the observations with the goal of achieving sufficient prediction accuracy at the event time to place SOFIA directly in the path of Pluto's central flash. Successful central flash observations will give us unprecedented information regarding Pluto's lower atmospheric structure and global sphericity. The combination of HIPO, FLITECAM, and the FDC will allow us to make simultaneous visible and IR measurements of the occultation light curves in several wavelengths, which are needed to differentiate between two currently competing explanations for the deficiency in the observed light refracted from Pluto's lower atmosphere (strong thermal gradients versus variable particulate extinction). Finally, we propose for two pairs of events in order to investigate the temporal variability of Pluto's atmosphere on several timescales to measure its ongoing evolution due to Pluto's rotation, changing seasonal obliquity (and resulting ice migration), and recession from the sun. These SOFIA observations will all be combined with our ground-based observing program to provide calibrating geometric information to the SOFIA occultation chords, allowing us to precisely pinpoint the actual passage of SOFIA through the occultation shadow path. Given the upcoming New Horizons encounter with the Pluto system in 2015, now is a critical time to provide context and supporting atmospheric information to this NASA mission.

  9. Recognition of skeletal fractures in infants: an autopsy technique.

    PubMed

    Love, Jennifer C; Sanchez, Luis A

    2009-11-01

    Complete recognition and documentation of injury pattern is crucial in the diagnosis of child abuse. Skeletal fractures regarded as highly specific to nonaccidental injury in infants include posterior rib, scapular, metaphyseal, and spinous process fractures. These injuries are often occult, especially when acute, to standard radiologic and autopsy procedures. The presented autopsy technique requires incising and reflecting skeletal muscles to expose the bones and costal osseous joints in situ, increasing the opportunity to recognize skeletal injury. Fractured or atypical appearing bones are removed and processed for complete evaluation. The bones are processed by macerating the soft tissue in a water soap bath at an elevated temperature. To aid in reconstruction of the decedent, long bones are replaced with wooden dowels and the chest cavity is packed with the organ bag. The technique is invasive and recommended for cases in which the pathologist has reasonable suspicion of acute or remote trauma.

  10. Condylar fractures.

    PubMed

    Sawhney, Raja; Brown, Ryan; Ducic, Yadranko

    2013-10-01

    The purpose of this article is to review the basic indications for different treatments of condylar and subcondylar fractures. It also reviews the steps of different surgical approaches to access the surgical area and explains the pros and cons of each procedure.

  11. Wave optics-based LEO-LEO radio occultation retrieval

    NASA Astrophysics Data System (ADS)

    Benzon, Hans-Henrik; Høeg, Per

    2016-06-01

    This paper describes the theory for performing retrieval of radio occultations that use probing frequencies in the XK and KM band. Normally, radio occultations use frequencies in the L band, and GPS satellites are used as the transmitting source, and the occultation signals are received by a GPS receiver on board a Low Earth Orbit (LEO) satellite. The technique is based on the Doppler shift imposed, by the atmosphere, on the signal emitted from the GPS satellite. Two LEO satellites are assumed in the occultations discussed in this paper, and the retrieval is also dependent on the decrease in the signal amplitude caused by atmospheric absorption. The radio wave transmitter is placed on one of these satellites, while the receiver is placed on the other LEO satellite. One of the drawbacks of normal GPS-based radio occultations is that external information is needed to calculate some of the atmospheric products such as the correct water vapor content in the atmosphere. These limitations can be overcome when a proper selected range of high-frequency waves are used to probe the atmosphere. Probing frequencies close to the absorption line of water vapor have been included, thus allowing the retrieval of the water vapor content. Selecting the correct probing frequencies would make it possible to retrieve other information such as the content of ozone. The retrieval is performed through a number of processing steps which are based on the Full Spectrum Inversion (FSI) technique. The retrieval chain is therefore a wave optics-based retrieval chain, and it is therefore possible to process measurements that include multipath. In this paper simulated LEO to LEO radio occultations based on five different frequencies are used. The five frequencies are placed in the XK or KM frequency band. This new wave optics-based retrieval chain is used on a number of examples, and the retrieved atmospheric parameters are compared to the parameters from a global European Centre for Medium

  12. Advanced Electrocardiography Can Identify Occult Cardiomyopathy in Doberman Pinschers

    NASA Technical Reports Server (NTRS)

    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 (<50 ventricular premature complexes, VPCs); and 2) 12 dogs with occult DCM: 11/12 dogs had increased M-mode measurements (LVIDd . 49mm and/or LVIDs . 40mm) and 5/11 dogs had also >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 < 0.05) between groups. Principal component factor analysis identified a 5-factor model with 81.4% explained variance. QRS dipolar and non-dipolar voltages, Cornell voltage criteria and QRS waveform residuum were increased significantly (P < 0.05), whereas mean HF QRS amplitude was decreased significantly (P < 0.05) in dogs with occult DCM. For the 5 selected parameters the prediction of occult DCM was performed using a binary logistic regression model with Chi-square tested significance (P < 0.01). ROC analyses showed that the five selected ECG parameters could identify occult ECG with sensitivity 89% and specificity 83%. Results suggest that 12-lead A-ECG might improve diagnostic value of short-duration ECG in earlier detection

  13. Probing Pluto's Atmosphere Using Ground-Based Stellar Occultations

    NASA Astrophysics Data System (ADS)

    Sicardy, Bruno; Rio de Janeiro Occultation Team, Granada Team, International Occultation and Timing Association, Royal Astronomical Society New Zealand Occultation Section, Lucky Star associated Teams

    2016-10-01

    Over the last three decades, some twenty stellar occultations by Pluto have been monitored from Earth. They occur when the dwarf planet blocks the light from a star for a few minutes as it moves on the sky. Such events led to the hint of a Pluto's atmosphere in 1985, that was fully confirmed during another occultation in 1988, but it was only in 2002 that a new occultation could be recorded. From then on, the dwarf planet started to move in front of the galactic center, which amplified by a large factor the number of events observable per year.Pluto occultations are essentially refractive events during which the stellar rays are bent by the tenuous atmosphere, causing a gradual dimming of the star. This provides the density, pressure and temperature profiles of the atmosphere from a few kilometers above the surface up to about 250 km altitude, corresponding respectively to pressure levels of about 10 and 0.1 μbar. Moreover, the extremely fine spatial resolution (a few km) obtained through this technique allows the detection of atmospheric gravity waves, and permits in principle the detection of hazes, if present.Several aspects make Pluto stellar occultations quite special: first, they are the only way to probe Pluto's atmosphere in detail, as the dwarf planet is far too small on the sky and the atmosphere is far too tenuous to be directly imaged from Earth. Second, they are an excellent example of participative science, as many amateurs have been able to record those events worldwide with valuable scientific returns, in collaboration with professional astronomers. Third, they reveal Pluto's climatic changes on decade-scales and constrain the various seasonal models currently explored.Finally, those observations are fully complementary to space exploration, in particular with the New Horizons (NH) mission. I will show how ground-based occultations helped to better calibrate some NH profiles, and conversely, how NH results provide some key boundary conditions

  14. Facial Fractures

    PubMed Central

    White, Lawrence M.; Marotta, Thomas R.; McLennan, Michael K.; Kassel, Edward E.

    1992-01-01

    Appropriate clinical radiographic investigation, together with an understanding of the normal radiographic anatomy of the facial skeleton, allows for precise delineation of facial fracutres and associated soft tissue injuries encountered in clinical practice. A combination of multiple plain radiographic views and coronal and axial computed tomographic images allow for optimal delineation of fracture patterns. This information is beneficial in the clinical and surgical management patients with facial injuries

  15. Antarctic Stratospheric Ozone from the Assimilation of Occultation Data

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Wargan, Krzysztof

    2004-01-01

    Ozone data from the solar occultation Polar Ozone and Aerosol Measurement (POAM) III instrument are included in the ozone assimilation system at NASA's Global Modeling and Assimilation Office, which uses Solar Backscatter UItraViolet/2 (SBUV/2) instrument data. Even though POAM data are available at only one latitude in the southern hemisphere on each day, their assimilation leads to more realistic ozone distribution throughout the Antarctic region, especially inside the polar vortex. Impacts of POAM data were evaluated by comparisons of assimilated ozone profiles with independent ozone sondes. Major improvements in ozone representation are seen in the Antarctic lower stratosphere during austral Winter and spring in 1998. Limitations of assimilation of sparse occultation data are illustrated by an example.

  16. Radio Occultation Measurements of the Lower Troposphere: A Simulation Study

    NASA Astrophysics Data System (ADS)

    Hurst, K. J.; Ao, C. O.; Mannucci, A. J.

    2011-12-01

    We use simulations to investigate the ability of the Radio Occultation technique to capture the vertical refractivity structure within the Atmospheric Boundary Layer. We first generate a suite of atmospheric profiles of pressure, temperature, water content, and boundary layer height, calculate a suite of forward models to get phase variations which are then run through standard Abel transform-based inversion methods to retrieve the input parameters. We are interested to see if the structure between the bottom and top of the ABL can be resolved in spite of the well known negative bias caused by the large refractivity gradients at the top of the ABL. This study can be used as a basis for comparison with other experimental radio occultation inversion methods.

  17. New insights to occult gastrointestinal bleeding: From pathophysiology to therapeutics

    PubMed Central

    Sánchez-Capilla, Antonio Damián; De La Torre-Rubio, Paloma; Redondo-Cerezo, Eduardo

    2014-01-01

    Obscure gastrointestinal bleeding is still a clinical challenge for gastroenterologists. The recent development of novel technologies for the diagnosis and treatment of different bleeding causes has allowed a better management of patients, but it also determines the need of a deeper comprehension of pathophysiology and the analysis of local expertise in order to develop a rational management algorithm. Obscure gastrointestinal bleeding can be divided in occult, when a positive occult blood fecal test is the main manifestation, and overt, when external sings of bleeding are visible. In this paper we are going to focus on overt gastrointestinal bleeding, describing the physiopathology of the most usual causes, analyzing the diagnostic procedures available, from the most classical to the novel ones, and establishing a standard algorithm which can be adapted depending on the local expertise or availability. Finally, we will review the main therapeutic options for this complex and not so uncommon clinical problem. PMID:25133028

  18. Digital solar edge tracker for the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    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.

  19. Status of the Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Reyes-Ruiz, Mauricio

    2014-11-01

    TAOS II is a next generation occultation survey with the goal of measuring the size distribution of the small objects (diameters between 0.5 and 30 km) in the Kuiper Belt. The project is a collaboration between the Academia Sinica Institute of Astronomy and Astrophysics, the Universidad Nacional Autonoma de Mexico, and the Harvard-Smithsonian Center for Astrophysics, The survey will operate three 1.3 m telescopes at San Pedro Martir Observatory in Baja California, Mexico. Each telescope will be equipped with a custom camera comprising a focal plane array of CMOS imagers. Each camera will be capable of reading out image data from 10,000 stars at a cadence of 20 Hz. All telescopes will monitor the same set of stars simultaneously to search for coincident occultation events while minimizing the false positive rate. This poster describes the project and reports on the progress of the development of the survey infrastructure.

  20. Titan's haze as seen by VIMS during solar occultation observations

    NASA Astrophysics Data System (ADS)

    Sotin, Christophe; Lawrence, Ken; Xu, Fang; West, Robert; Brown, Robert; Baines, Kevin; Buratti, Bonnie; Clark, Roger; Micholson, Phil

    2016-06-01

    This study describe solar occultation observations of Titan's atmosphere by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft. These observations include two recent observations made in the last few months. The solar occultation observations have been made at different latitudes and seasons, which allows us to investigate the variability of the density profile of aerosols. We present the line curves in the different atmospheric windows, and the data processing and the inversion method to retrieve vertical density profile. This unique data set provides information on Titan's opacity in the atmospheric windows, which is important to retrieve the surface properties. It also provides information on the cross-subsection of the aerosols as a function of wavelength in the wavelength range 1 to 5 micron.

  1. Advancing Technology for Starlight Suppression via an External Occulter

    NASA Technical Reports Server (NTRS)

    Kasdin, N. J.; Spergel, D. N.; Vanderbei, R. J.; Lisman, D.; Shaklan, S.; Thomson, M.; Walkemeyer, P.; Bach, V.; Oakes, E.; Cady, E.; Martin, S.; Marchen, L.; Macintosh, B.; Rudd, R. E.; Mikula, J.; Lynch, D.

    2011-01-01

    External occulters provide the starlight suppression needed for detecting and characterizing exoplanets with a much simpler telescope and instrument than is required for the equivalent performing coronagraph. In this paper we describe progress on our Technology Development for Exoplanet Missions project to design, manufacture, and measure a prototype occulter petal. We focus on the key requirement of manufacturing a precision petal while controlling its shape within precise tolerances. The required tolerances are established by modeling the effect that various mechanical and thermal errors have on scatter in the telescope image plane and by suballocating the allowable contrast degradation between these error sources. We discuss the deployable starshade design, representative error budget, thermal analysis, and prototype manufacturing. We also present our meteorology system and methodology for verifying that the petal shape meets the contrast requirement. Finally, we summarize the progress to date building the prototype petal.

  2. Detection of occult disease in tissue donors by routine autopsy.

    PubMed

    Otero, J; Fresno, M F; Escudero, D; Seco, M; González, M; Peces, R

    1998-01-01

    The transmission of infectious and neoplastic diseases is a potential risk of tissue allografting. In this study, we analyzed the occurrence of occult disease in tissue donors as detected by standard screening and autopsy. Whereas 18% of the potential donors initially evaluated were eliminated on the basis of their medical and social histories, laboratory screening and autopsy revealed that an additional 9% of tissue donors had undetected, transmissible disease that prohibited tissue donation. This report emphasizes once again the risk of occult disease being transplanted with grafts and the need for autopsy to reduce the likelihood of this occurring. If donor selection, appropriate screening tests, and autopsy are carefully carried out, the risk of transmitting diseases from tissue allografts can be kept to a minimum.

  3. Status of the Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Lehner, M.; Wang, S.; Zhang, Z.; Ho, P.; Yen, W.; Reyes-Ruiz, M.; Richer, M.; Cook, K.; Hsu, S.; Chen, H.; Chang, Y.; Hiriart, D.; Ricci, D.; Szentgyorgyi, A.; Norton, T.; Geary, J.; Furesz, G.; Alcock, C.; Byun, Y.

    2014-07-01

    The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small (˜1 km diameter) objects in the Transneptunian region and beyond. Such events are very rare (<10^{-3} events per star per year) and short in duration (˜200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronómico Nacional at San Pedro Mártir in Baja California, México. With a 2.3 square degree field of view and high-speed cameras comprising arrays of custom CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz. The survey will begin operation in 2016. This poster presents an update on the status of the site preparation and the technical development.

  4. Status of the Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Lehner, Matthew; Wang, Shiang-Yu; Alcock, Charles; Reyes-Ruiz, Mauricio; Castro, Joel; Chen, Wen Ping; Chu, You-Hua; Cook, Kem H.; Geary, John C.; Huang, Chung-Kai; Kim, Dae-Won; Norton, Timothy; Szentgyorgyi, Andrew; Yen, WeiLing; Zhang, Zhi-Wei; Figueroa, Liliana

    2016-10-01

    The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare ($<0.001 events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronomico Nacional at San Pedro Martir in Baja California, Mexico. With a 2.3 square degree field of view and a high speed camera comprising CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz. Construction of the site began in the fall of 2013, and the survey will begin in the summer of 2017. This poster will provide an update on the status of the survey development and the schedule leading to the beginning of survey operations.

  5. Status of the Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Lehner, Matthew J.; Wang, Shiang Yu; Reyes-Ruiz, Mauricio; Chu, You Hua; Lee, William; Zhang, Zhi Wei; Cook, Kem H.; Norton, Timothy; Szentgyorgyi, Andrew; Alcock, Charles

    2015-11-01

    The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare (<10-3 events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronómico Nacional at San Pedro Mártir in Baja California, México. With a 2.3 square degree field of view and a high speed camera comprising CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a nominal readout cadence of 20 Hz. Construction of the site began in the fall of 2013. We present here an update on the status of the TAOS II survey, including the site development, camera fabrication, and project schedule.

  6. KUIPER BELT OBJECT OCCULTATIONS: EXPECTED RATES, FALSE POSITIVES, AND SURVEY DESIGN

    SciTech Connect

    Bickerton, S. J.; Welch, D. L.; Kavelaars, J. J. E-mail: welch@physics.mcmaster.ca

    2009-05-15

    A novel method of generating artificial scintillation noise is developed and used to evaluate occultation rates and false positive rates for surveys probing the Kuiper Belt with the method of serendipitous stellar occultations. A thorough examination of survey design shows that (1) diffraction-dominated occultations are critically (Nyquist) sampled at a rate of 2 Fsu{sup -1}, corresponding to 40 s{sup -1} for objects at 40 AU, (2) occultation detection rates are maximized when targets are observed at solar opposition, (3) Main Belt asteroids will produce occultations light curves identical to those of Kuiper Belt Objects (KBOs) if target stars are observed at solar elongations of: 116{sup 0} {approx}< {epsilon} {approx}< 125 deg., or 131 deg. {approx}< {epsilon} {approx}< 141 deg., and (4) genuine KBO occultations are likely to be so rare that a detection threshold of {approx}>7-8{sigma} should be adopted to ensure that viable candidate events can be disentangled from false positives.

  7. All-Sky Earth Occultation Observations with the Fermi Gamma-Ray Burst Monitor

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, C. A.; Beklen, E.; Bhat, P. N.; Briggs, M.; Camero-Arranz, A.; Case, G.; Jenke, P.; Chaplin, V.; Cherry, M.; Connaughton, V.; Finger, M.; Haynes, R. H.; Preece, R.; Rodi, J.

    2009-01-01

    Using the Gamma Ray Burst Monitor (GBM) on-board Fermi, we are monitoring the hard X-ray/ soft gamma ray sky using the Earth occultation technique. Each time a source in our catalog is occulted by (or exits occultation by) the Earth, we measure its flux using the change in count rates due to the occultation. Currently we are using CTIME data with 8 energy channels spanning 8 keV to 1 MeV for the GBM NaI detectors and spanning 150 keV to 40 MeV for the GBM BGO detectors. Our preliminary catalog consists of galactic X-ray binaries, the Crab Nebula, and active galactic nuclei. In addition, to Earth occultations, we have observed numerous occultations with Fermi's solar panels.

  8. The Structure of Titan's Atmosphere from Cassini Radio Occultations

    NASA Technical Reports Server (NTRS)

    Schinder, Paul J.; Flasar, F. Michael; Marouf, Essam A.; French, Richard G.; McGhee, Colleen A.; Kliore, Arvydas J.; Rappaport, Nicole J.; Barbinis, Elias; Fleischman, Don; Anabtawi, Aseel

    2011-01-01

    We present results from the two radio occultations of the Cassini spacecraft by Titan in 2006, which probed mid-southern latitudes. Three of the ingress and egress soundings occurred within a narrow latitude range, 31.34 deg S near the surface, and the fourth at 52.8 deg S. Temperature - altitude profiles for all four occultation soundings are presented, and compared with the results of the Voyager 1 radio occultation (Lindal et al., 1983), the HASI instrument on the Huygens descent probe (Fulchignoni et al., 2005), and Cassini CIRS results (Flasar et al., 2005; Achterberg et al., 2008b). Sources of error in the retrieved temperature - altitude profiles are also discussed, and a major contribution is from spacecraft velocity errors in the reconstructed ephemeris. These can be reduced by using CIRS data at 300 km to make along-track adjustments of the spacecraft timing. The occultation soundings indicate that the temperatures just above the surface at 31-34 deg S are about 93 K, while that at 53 deg S is about 1 K colder. At the tropopause, the temperatures at the lower latitudes are all about 70 K, while the 53 deg S profile is again 1 K colder. The temperature lapse rate in the lowest 2 km for the two ingress (dawn) profiles at 31 and 33 deg S lie along a dry adiabat except within approximately 200m of the surface, where a small stable inversion occurs. This could be explained by turbulent mixing with low viscosity near the surface. The egress profile near 34 deg S shows a more complex structure in the lowest 2 km, while the egress profile at 53 deg S is more stable.

  9. Comparative Structure of Saturn's Rings from Cassini Radio Occultation Observations

    NASA Astrophysics Data System (ADS)

    Marouf, Essam A.; French, R. G.; Rappaport, N. J.; McGhee, C. A.; Wong, K.; Thomson, F. S.; Anabtawi, A.

    2007-10-01

    Radio occultations of Saturn's rings during the Cassini prime mission fall into three main groups, depending on the rings opening angle B. The first is a set of eight diametric occultations completed early in the mission (March-September/2005) when |B| was relatively large (19.5 to 23.5°). They permitted multiple-longitude profiling of relatively optically thick ring features, revealing detailed structure of enigmatic Ring B. The second is to be completed late in the mission when the rings are relatively closed (|B| < 10°). They will provide enhanced sensitivity to tenuous ring material, hence complementary information about small optical depth structure. Bridging the two groups is a third composed of two specially designed occultations recently completed (May-June/2007). They capture the intermediate range |B| 15°. Because the rings were still reasonably open, much of the structure was profiled. The different occultation geometry from the diametric group provided enhanced sensitivity to bending waves and other inclined features. We comparatively consider variability (or lack of) of observed ring structure with B and longitude. The variability when present can be true (dynamically forced features) or apparent (azimuthal asymmetry due to preferentially aligned gravitational wakes). The multiple-longitude coverage provides rich characterization of the true variability, including remarkable variations in the morphology of gap-embedded ringlets in Ring C, clear variations in the width of gaps in the Cassini Division, wavelike features in Ring C (the "Rosen Waves"), classical satellite wake profiles due to Pan, in addition to many density and few bending waves. For the apparent asymmetry, observed optical depth variations with B, viewing geometry, and wavelength constrain physical properties of the rings microstructure (particle sizes, particle-cluster sizes and orientation, spatial cluster density, vertical ring profile and physical thickness, ...). Complementary

  10. Occult hepatitis C virus infection in Iranian hemodialysis patients

    PubMed Central

    Eslamifar, Ali; Ramezani, Amitis; Ehteram, Hassan; Razeghi, Effat; Ahmadi, Farrokhlagha; Amini, Manouchehr; Banifazl, Mohammad; Etemadi, Gelavizh; Keyvani, Hossein; Bavand, Anahita; Aghakhani, Arezoo

    2015-01-01

    Background: Occult hepatitis C virus (HCV) infection is defined as the presence of HCV-RNA in liver or peripheral blood mononuclear cells (PBMCs) in the absence of detectable hepatitis C antibody (anti-HCV) or HCV-RNA in the serum. Low concentrations of HCV-RNA may be detected in PBMCs of hemodialysis (HD) patients and this could have a great impact on the management of HD patients. Objectives: The aim of this study was to detect the occult HCV infection in Iranian HD patients. Patients and Methods: A total of 70 anti-HCV negative HD patients from three dialysis units in Tehran, Iran were included in this study. In these cases, presence of HCV-RNA in plasma samples was tested by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR). In cases with negative anti-HCV and plasma HCV-RNA, genomic HCV-RNA was checked in PBMC specimens by RT-nested PCR. Results: Seventy anti-HCV negative HD patients were enrolled in the study. 32.85% and 1.43% of cases had elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) respectively. 7.14% of patients had elevated levels of both ALT and AST. HCV-RNA was negative in plasma samples of all anti-HCV negative HD subjects. The genomic HCV-RNA was not detected in any PBMC samples of HD cases with negative anti-HCV and plasma HCV-RNA. Conclusions: Occult HCV infection was not detected in our HD patients despite of elevated levels of liver enzymes in some participants. Further studies involving larger number of HD patients are required to elucidate the rate of occult HCV infection in HD cases. PMID:26457258

  11. Analyses for a Modernized GNSS Radio Occultation Receiver

    NASA Astrophysics Data System (ADS)

    Griggs, Erin R.

    Global Navigation Satellite System (GNSS) radio occultation (RO) is a remote sensing technique that exploits existing navigation signals to make global, real-time observations of the Earth's atmosphere. A specialized RO receiver makes measurements of signals originating from a transmitter onboard a GNSS spacecraft near the Earth's horizon. The radio wave is altered during passage through the Earth's atmosphere. The changes in the received signals are translated to the refractivity characteristics of the intervening medium, which enable the calculation of atmospheric pressure, temperature, and humidity. Current satellite missions employing GNSS RO have provided invaluable and timely information for weather and climate applications. Existing constellations of occultation satellites, however, are aging and producing fewer quality measurements. Replacement fleets of RO satellites are imperative to sustain and improve the global coverage and operational impact achieved by the current generation of RO satellites. This dissertation describes studies that facilitate the development of next generation RO receivers and satellite constellations. Multiple research efforts were conducted that aim to improve the quantity and quality of measurements made by a future satellite-based RO collection system. These studies range in magnitude and impact, and begin with a receiver development study using ground-based occultation data. Future RO constellations and collection opportunities were simulated and autonomous occultation prediction and scheduling capabilities were implemented. Finally, a comprehensive study was conducted to characterize the stability of the GNSS atomic frequency standards. Oscillator stability for a subset of satellites in the GNSS was found to be of insufficient quality at timescales relevant to RO collections and would degrade the atmospheric profiling capabilities of an RO system utilizing these signals. Recommendations for a high-rate clock correction network

  12. Pneumonitis associated with occult heartworm disease in dogs.

    PubMed

    Calvert, C A; Losonsky, J M

    1985-05-15

    Nine of 69 dogs with occult heartworm disease (13%) had allergic pneumonitis characterized by consistent clinical and radiographic signs. Although the clinical signs were severe, the degree of radiographic pulmonary arterial abnormalities was mild. Corticosteroid therapy resulted in rapid resolution of clinical and radiographic signs; thiacetarsamide therapy was then given without complications. This syndrome may not be recognized as heartworm-associated and may be confused with other disorders, some being associated with a poor prognosis and requiring different therapy.

  13. Pinhole Occulter Facility. [for X ray observations of sun

    NASA Technical Reports Server (NTRS)

    Dabbs, J. R.; Tandberg-Hanssen, E. A.; Routh, D. E.

    1984-01-01

    The Pinhole Occulter Facility (POF) is designed for X-ray observations of solar activity, coronal structure and solar wind generation, and coronal transients. The four telescopes or positioning counters, the self-deployable 32-m boom, and the pointing-control actuator of the POF are described. The development of the facility is discussed. The configuration of the POF and means of maintaining its attitude control are examined.

  14. Occult HCV Infection: The Current State of Knowledge

    PubMed Central

    Rezaee-Zavareh, Mohammad Saeid; Hadi, Reza; Karimi-Sari, Hamidreza; Hossein Khosravi, Mohammad; Ajudani, Reza; Dolatimehr, Fardin; Ramezani-Binabaj, Mahdi; Miri, Seyyed Mohammad; Alavian, Seyed Moayed

    2015-01-01

    Context Occult HCV infection (OCI) is defined as the presence of HCV-RNA in hepatocytes and the absence of HCV in the serum according to usual tests. We aimed to define OCI and provide information about the currently available diagnostic methods. Then we focus on specific groups that are at high risk of OCI and finally investigate immune responses to OCI and the available treatment approaches. Evidence Acquisition PubMed, Scopus and Google Scholar were comprehensively searched with combination of following keywords: “occult”, “hepatitis C virus” and “occult HCV infection”. The definition of OCI, diagnostic methods, specific groups that are at high risk and available treatment approaches were extract from literature. An analysis of available articles on OCI also was done based on Scopus search results. Results OCI has been reported in several high-risk groups, especially in hemodialysis patients and subjects with cryptogenic liver disease. Furthermore, some studies have proposed a specific immune response for OCI in comparison with chronic hepatitis C (CHC). Conclusions With a clinical history of approximately 11 years, occult HCV infection can be considered an occult type of CHC. Evidences suggest that considering OCI in these high-risk groups seems to be necessary. We suggest that alternative diagnostic tests should be applied and that there is a need for the participation of all countries to determine the epidemiology of this type of HCV infection. Additionally, evaluating OCI in blood transfusion centers and in patients who receive large amounts of blood and clotting factors, such as patients with hemophilia, should be performed in future projects. PMID:26734487

  15. First tsunami gravity wave detection in ionospheric radio occultation data

    DOE PAGES

    Coïsson, Pierdavide; Lognonné, Philippe; Walwer, Damian; ...

    2015-05-09

    After the 11 March 2011 earthquake and tsunami off the coast of Tohoku, the ionospheric signature of the displacements induced in the overlying atmosphere has been observed by ground stations in various regions of the Pacific Ocean. We analyze here the data of radio occultation satellites, detecting the tsunami-driven gravity wave for the first time using a fully space-based ionospheric observation system. One satellite of the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) recorded an occultation in the region above the tsunami 2.5 h after the earthquake. The ionosphere was sounded from top to bottom, thus providing themore » vertical structure of the gravity wave excited by the tsunami propagation, observed as oscillations of the ionospheric Total Electron Content (TEC). The observed vertical wavelength was about 50 km, with maximum amplitude exceeding 1 total electron content unit when the occultation reached 200 km height. We compared the observations with synthetic data obtained by summation of the tsunami-coupled gravity normal modes of the Earth/Ocean/atmosphere system, which models the associated motion of the ionosphere plasma. These results provide experimental constraints on the attenuation of the gravity wave with altitude due to atmosphere viscosity, improving the understanding of the propagation of tsunami-driven gravity waves in the upper atmosphere. They demonstrate that the amplitude of the tsunami can be estimated to within 20% by the recorded ionospheric data.« less

  16. First tsunami gravity wave detection in ionospheric radio occultation data

    SciTech Connect

    Coïsson, Pierdavide; Lognonné, Philippe; Walwer, Damian; Rolland, Lucie M.

    2015-05-09

    After the 11 March 2011 earthquake and tsunami off the coast of Tohoku, the ionospheric signature of the displacements induced in the overlying atmosphere has been observed by ground stations in various regions of the Pacific Ocean. We analyze here the data of radio occultation satellites, detecting the tsunami-driven gravity wave for the first time using a fully space-based ionospheric observation system. One satellite of the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) recorded an occultation in the region above the tsunami 2.5 h after the earthquake. The ionosphere was sounded from top to bottom, thus providing the vertical structure of the gravity wave excited by the tsunami propagation, observed as oscillations of the ionospheric Total Electron Content (TEC). The observed vertical wavelength was about 50 km, with maximum amplitude exceeding 1 total electron content unit when the occultation reached 200 km height. We compared the observations with synthetic data obtained by summation of the tsunami-coupled gravity normal modes of the Earth/Ocean/atmosphere system, which models the associated motion of the ionosphere plasma. These results provide experimental constraints on the attenuation of the gravity wave with altitude due to atmosphere viscosity, improving the understanding of the propagation of tsunami-driven gravity waves in the upper atmosphere. They demonstrate that the amplitude of the tsunami can be estimated to within 20% by the recorded ionospheric data.

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

    SciTech Connect

    Jatmiko, A. T. P.; Puannandra, G. P.; Hapsari, R. D.; Putri, R. A.; Arifin, Z. M.; Haans, G. K.; Hadiputrawan, I. P. W.

    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.

  18. Occult hepatitis B in HIV-HCV coinfected patients.

    PubMed

    Piroth, Lionel; Lafon, Marie-Edith; Binquet, Christine; Bertillon, Pascale; Gervais, Anne; Lootvoet, Enguerrand; Lang, Jean-Marie; De Jaureguiberry, Jean Pierre; Chene, Geneviève; Leport, Catherine

    2008-01-01

    The prevalence of occult hepatitis B infection in HIV infected patients is controversial, varying from less than 1% to 62% in different studies. Blood samples of 111 HIV-infected patients, HCV-positive, HBs antigen negative, followed in the APROCO-ANRS EP11 cohort, were used to detect HBV DNA by using 2 different validated assays (Cobas Amplicor HBV Monitor Test and INSERM U271 qualitative ultra-sensitive PCR), completed when positive by HBV real-time PCR. HBV DNA was found in 6 (5.4%, 95% CI 1.2%-9.6%) patients by at least 1 of these assays, but none tested positive in all 3 assays. All 6 patients had anti-HBc without anti-HBs antibodies; 5 were not on lamivudine. Their median CD4 and CD8 counts were significantly lower and their HIV viral load higher than in the other 105 patients. In conclusion, the prevalence of occult hepatitis B may vary significantly according to the molecular assay used, even though these assays are validated with high specificity and quite high sensitivity. Occult hepatitis B may be encountered in HIV-HCV coinfected patients without anti-HBV treatment, with anti-HBc but without anti-HBs antibodies, and relatively low immunity, suggesting a potential risk of further reactivation, as already sporadically reported.

  19. Design of a mirror pointing and occulting mechanism for the Ultraviolet Coronagraph Spectrometer (UVCS)

    NASA Technical Reports Server (NTRS)

    Highman, Clifton O.; Woolaway, Scott M.; Belmont, Kenneth L.

    1992-01-01

    The Mirror and Occulter Mechanism (MOM), a lightweight stable optical assembly which is a critical component to the Ultraviolet Coronagraph Spectrometer to be flown on the European SOHO spacecraft, is discussed. The MOM combines the functions of precision mirror pointing and occultation of stray light into a single package. The mirror mechanism and occulter mechanism designs are described and development testing and life testing activities are discussed.

  20. Magnitudes of selected stellar occultation candidates for Pluto and other planets, with new predictions for Mars and Jupiter

    NASA Technical Reports Server (NTRS)

    Sybert, C. B.; Bosh, A. S.; Sauter, L. M.; Elliot, J. L.; Wasserman, L. H.

    1992-01-01

    Occultation predictions for the planets Mars and Jupiter are presented along with BVRI magnitudes of 45 occultation candidates for Mars, Jupiter, Saturn, Uranus, and Pluto. Observers can use these magnitudes to plan observations of occultation events. The optical depth of the Jovian ring can be probed by a nearly central occultation on 1992 July 8. Mars occults an unusually red star in early 1993, and the occultations for Pluto involving the brightest candidates would possibly occur in the spring of 1992 and the fall of 1993.

  1. Similar Fracture Patterns in Human Nose and Gothic Cathedral.

    PubMed

    Lee, Shu Jin; Tse, Kwong Ming; Lee, Heow Pueh

    2015-10-01

    This study proposes that the bony anatomy of the human nose and masonry structure of the Gothic cathedral are geometrically similar, and have common fracture patterns. We also aim to correlate the fracture patterns observed in patients' midface structures with those seen in the Gothic cathedral using computational approach. CT scans of 33 patients with facial fractures were examined and compared with computer simulations of both the Gothic cathedral and human nose. Three similar patterns were found: (1) Cracks of the nasal arch with crumpling of the vertical buttresses akin to the damage seen during minor earthquakes; (2) lateral deviation of the central nasal arch and collapse of the vertical buttresses akin to those due to lateral forces from wind and in major earthquakes; and (3) Central arch collapse seen as a result of collapse under excessive dead weight. Interestingly, the finding of occult nasal and septal fractures in the mandible fractures with absence of direct nasal trauma highlights the possibility of transmission of forces from the foundation to the arch leading to structural failure. It was also found that the structural buttresses of the Gothic cathedral delineate the vertical buttresses in the human midface structure. These morphologic similarities between the human nose and Gothic cathedral will serve as a basis to study the biomechanics of nasal fractures. Identification of structural buttresses in a skeletal structure has important implications for reconstruction as reestablishment of structural continuity restores normal anatomy and architectural stability of the human midface structure.

  2. Misdiagnosis of Talar Body or Neck Fractures as Ankle Sprains in Low Energy Traumas

    PubMed Central

    Young, Ki-Won; Kim, Jin-Su; Cho, Hun-Ki; Choo, Ho-Sik; Park, Jang-Ho

    2016-01-01

    Background The talus has a very complex anatomical morphology and is mainly fractured by a major force caused by a fall or a traffic accident. Therefore, a talus fracture is not common. However, many recent reports have shown that minor injuries, such as sprains and slips during sports activities, can induce a talar fracture especially in the lateral or posterior process. Still, fractures to the main parts of the talus (neck and body) after ankle sprains have not been reported as occult fractures. Methods Of the total 102 cases from January 2005 to December 2012, 7 patients had confirmed cases of missed/delayed diagnosis of a talus body or neck fracture and were included in the study population. If available, medical records, X-rays, computed tomography scans, and magnetic resonance imaging of the confirmed cases were retrospectively reviewed and analyzed. Results In the 7-patient population, there were 3 talar neck fractures and 4 talar body fractures (coronal shearing type). The mechanisms of injuries were all low energy trauma episodes. The causes of the injuries included twisting of the ankle during climbing (n = 2), jumping to the ground from a 1-m high wall (n = 2), and twisting of the ankle during daily activities (n = 3). Conclusions A talar body fracture and a talar neck fracture should be considered in the differential diagnosis of patients with acute and chronic ankle pain after a minor ankle injury. PMID:27583114

  3. THE 1998 NOVEMBER 14 OCCULTATION OF GSC 0622-00345 BY SATURN. I. TECHNIQUES FOR GROUND-BASED STELLAR OCCULTATIONS

    SciTech Connect

    Harrington, Joseph; French, Richard G. E-mail: rfrench@wellesley.ed

    2010-06-10

    On 1998 November 14, Saturn and its rings occulted the star GSC 0622-00345. We observed atmospheric immersion with NSFCAM at the National Aeronautics and Space Administration's Infrared Telescope Facility on Mauna Kea, Hawaii. Immersion occurred at 55.{sup 0}5 S planetocentric latitude. A 2.3 {mu}m, CH{sub 4}-band filter suppressed reflected sunlight. Atmospheric emersion and ring data were not successfully obtained. We describe our observation, light curve production, and timing techniques, including improvements in aperture positioning, removal of telluric scintillation effects, and timing. Many of these techniques are known within the occultation community, but have not been described in the reviewed literature. We present a light curve whose signal-to-noise ratio per scale height is 267, among the best ground-based signals yet achieved, despite a disadvantage of up to 8 mag in the stellar flux compared to prior work.

  4. A search for stellar occultations by Uranus, Neptune, Pluto, and their satellites: 1990-1999

    NASA Technical Reports Server (NTRS)

    Mink, Douglas J.

    1991-01-01

    A search for occultations of stars by Uranus, Neptune, and Pluto between 1990 and 1999 was carried out by combining ephemeris information and star positions using very accurate occultation modeling software. Stars from both the Space Telescope Guide Catalog and photographic plates taken by Arnold Klemola at Lick Observatory were compared with planet positions from the JPL DE-130 ephemeris, with local modifications for Pluto and Charon. Some 666 possible occultations by the Uranian ring, 143 possible occultations by Neptune, and 40 possible occultations by Pluto and/or Charon were found among stars with visual magnitudes as faint as 16. Before the star positions could be obtained, the occultation prediction software was used to aid many observers in observing the occultation of 28 Sagitarii by Saturn in July 1989. As a test on other outer solar system objects, 17 possible occultations were found in a search of the Guide Star Catalog for occultations by 2060 Chiron, and interesting object between Saturn and Uranus which shows both cometary and asteroidal properties.

  5. High prevalence of occult hepatitis C virus infection in patients with chronic hepatitis B virus infection.

    PubMed

    Castillo, Inmaculada; Bartolomé, Javier; Quiroga, Juan Antonio; Carreño, Vicente

    2013-08-01

    Hepatitis C virus (HCV) infection in the absence of detectable antibodies against HCV and of viral RNA in serum is called occult HCV infection. Its prevalence and clinical significance in chronic hepatitis B virus (HBV) infection is unknown. HCV RNA was tested for in the liver samples of 52 patients with chronic HBV infection and 21 (40 %) of them were positive for viral RNA (occult HCV infection). Liver fibrosis was found more frequently and the fibrosis score was significantly higher in patients with occult HCV than in negative ones, suggesting that occult HCV infection may have an impact on the clinical course of HBV infection.

  6. A comparative study of chemical and immunological method of fecal occult blood test in the diagnosis of occult lower gastrointestinal bleeding.

    PubMed

    Yeasmin, F; Ali, M A; Rahman, M A; Sultana, T; Rahman, M Q; Ahmed, A N N

    2013-08-01

    Fecal occult blood test is the most widely used screening test for diagnosis of gastrointestinal bleeding disorders specially colorectal carcinoma. Among the various methods of fecal occult blood tests, chemical method is being used commonly, but the method has some drawbacks like low participation rate, high false positive rate, low sensitivity etc. To overcome these short comings, newer immunological method was introduced. This study evaluated the role of immunological method of fecal blood test in the diagnosis of occult lower GIT bleeding. Stool samples from two hundred patients were examined by both chemical and immunological method. The patients who were positive by any or both methods of occult blood test, were advised for colonoscopy. During colonoscopy tissues were taken for histopathology which was the gold standard of this study. Among 110 OBT positive patients pathological lesions were detected in 65 patients by colonoscopy and histopathology. The diseases detected by colonoscopy and histopathology 18 colorectal polyp, 8 colorectal cancer, 24 ulcerative lesions and 5 inflammatory bowel disease etc. Regarding comparative analysis of chemical and immunological method, the higher sensitivity (95.4% vs. 49.2%), specificity (44.4% vs. 37.8%), accuracy (74.5% vs. 44.5%), PPV (71.3% vs. 53.3%) and NPV (87% vs. 34%) of immunological method than chemical method was observed. Thus immunological method of fecal occult blood test was appeared to be a better alternative to conventional chemical method of fecal occult blood test in the diagnosis of occult lower GIT bleeding.

  7. Profiling the atmosphere with the airborne radio occultation technique

    NASA Astrophysics Data System (ADS)

    Muradyan, Paytsar

    The GNSS Instrument System for Multistatic and Occultation Sensing (GISMOS) was designed for dense sampling of meteorological targets using the airborne radio occultation (RO) technique. Airborne RO refers to an atmospheric limb sounding technique in which Global Positioning System (GPS) signals are recorded at a receiver onboard an aircraft as the satellites descend beyond the limb of the Earth. The GPS signals, that are unaffected by clouds and precipitation, experience refractive bending as well as a delay in the travel time through the atmosphere. Bending can be used to retrieve information about atmospheric refractivity, which depends on atmospheric moisture and temperature. The new system has the potential for improving numerical weather prediction (NWP) forecasts through assimilation of many high-resolution atmospheric profiles in an area of interest, compared to spaceborne RO, which samples sparsely around the globe. In February 2008, GISMOS was deployed on the National Science Foundation Gulfstream-V aircraft to make atmospheric observations in the Gulf of Mexico coastal region with an objective to test the performance of the profiling system. Recordings from this flight campaign made with the conventional phase lock loop GPS receivers descend from flight level to 5 km altitude. However, below that level strong refractivity gradients, especially those associated with the boundary layer, cause rapid phase accelerations resulting in loss of lock in the receiver. To extend the RO profiles deeper in the atmosphere, the GISMOS system was also equipped with a GPS Recording System (GRS) that records the raw RF signals. Post-processing this dataset in open-loop (OL) tracking mode enables reliable atmospheric profiling at lower altitudes. We present a comprehensive analysis of the performance of the airborne system OL tracking algorithm during a 5 hour flight on 15 February 2008. Excess phase and amplitude profiles for 5 setting and 5 rising occultations were

  8. Fracture Mechanics

    DTIC Science & Technology

    1974-01-31

    2219 -T851 aluminum (fractures at low stresses). The parameter KF is alloy compact specimens 1 2 and demonstrate consistent a function of specimen...Congress of 20. Walker, E. K., "The Effect of Stress Ratio Applied Mechanics, 1924. During Crack Propagation and Fatigue for 2024-T3 and 7015- T6 Aluminum ...34Stress- Corrosion Cracking in 12. Kaufman, J. G., and Nelson, F. G., "More Ti-6A1-4V Titanium Alloy in Nitrogen Tetroxide," on Specimen Size Effect in 2219

  9. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... to 2 weeks. If you have a small fracture and your bones did not move around much, ... to see a bone doctor (orthopedic surgeon). Some fractures require surgery to: Insert pins and plates to ...

  10. Hand fracture - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000552.htm Hand fracture - aftercare To use the sharing features on ... need to be repaired with surgery. Types of Hand Fractures Your fracture may be in one of ...

  11. Chopart fractures.

    PubMed

    Klaue, Kaj

    2004-09-01

    The Chopart articular space was described by François Chopart (1743-1795) as a practical space for amputations in cases of distal foot necrosis. It corresponds to the limit between the anatomical hind-foot and the mid-foot. The bones involved are the talus and the calcaneus proximally, and the navicular and the cuboid distally. This space thus holds two functionally distinct entities, the anterior part of the coxa pedis (an essential functional joint) and the calcaneo-cuboidal joint,which can be considered to be an "adaptive joint" within a normal foot. Trauma to this region may cause fractures and/or dislocations and, in high energy trauma,compartment syndromes. Principles of treatment are immediate reduction of dislocations and realignment of the medial and lateral column of the foot in length and orientation. Open reduction and internal fixation of talus and navicular fractures are often indicated to restore the "coxa pedis". Open reconstruction or fusion in correct length of the calcaneo-cuboidal joint is occasionally indicated. Salvage procedures in malunions include navicular osteotomies and calcaneo-cuboidal bone block fusions. Treatment of joint destructions, especially involving the talo-navicular joint, include triple arthrodesis.

  12. The Lunar Occultation Observer (LOCO) - A Nuclear Astrophysics All-Sky Survey Mission Concept

    NASA Astrophysics Data System (ADS)

    Miller, R. S.; Bonamente, M.; Burgess, J. M.; Harmon, B. A.; Jenke, P.; Lawrence, D. J.; O'Brien, S.; Orr, M. R.; Paciesas, W. S.; Young, C. A.

    2008-07-01

    The Lunar Occultation Observer (LOCO) is a new lunar-based concept to probe the nuclear astrophysics regime. It will be a pioneering mission in high-energy astrophysics: the first to employ occultation as the principle detection and imaging method.

  13. Comparative study between occult hepatitis C virus infection and chronic hepatitis C.

    PubMed

    Pardo, M; López-Alcorocho, J M; Rodríguez-Iñigo, E; Castillo, I; Carreño, V

    2007-01-01

    We have recently described the presence of occult hepatitis C virus (HCV) infection (HCV-RNA in liver in the absence of anti-HCV and serum HCV-RNA) in patients with persistently abnormal liver function tests of unknown aetiology. The aim of this study was to compare the characteristics of patients with occult HCV infection vs those of patients with chronic hepatitis C. We compared clinical features of 68 patients with occult HCV infection and 69 untreated chronic HCV patients (anti-HCV and serum HCV-RNA positive), matched for age, gender, duration of abnormal liver function tests and body mass index. Aspartate aminotransferase and alanine aminotransferase were higher (P < 0.001) in chronic HCV, but cholesterol and triglycerides were significantly higher in patients with occult HCV infection (P < 0.001 and P = 0.002). Chronic HCV patients had higher gamma-globulin (P = 0.005), alpha-foetoprotein (P < 0.001) and iron (P < 0.001) levels. Percentage of patients with necroinflammatory activity and fibrosis was higher (P < 0.001) in chronic HCV than in occult HCV infection. Mean percentage of infected hepatocytes was higher (P = 0.001) in chronic HCV (10.1%) than in occult HCV infection (5.3%). This occult HCV infection is a milder disease than chronic HCV, and this could be related to the significantly lower number of infected hepatocytes observed in occult HCV.

  14. Hepatitis C virus infection in the family setting of patients with occult hepatitis C.

    PubMed

    Castillo, Inmaculada; Bartolomé, Javier; Quiroga, Juan Antonio; Barril, Guillermina; Carreño, Vicente

    2009-07-01

    Family members of patients with chronic hepatitis C virus (HCV) infection are at increased risk of HCV infection but the prevalence of HCV among family members of patients with occult HCV infection is not known. Anti-HCV, serum HCV RNA and levels of liver enzymes were determined in 102 family members of 50 index patients with occult HCV infection and in 118 family members of 59 chronic hepatitis C index patients. HCV RNA and/or anti-HCV were detected in 10/102 (9.8%) relatives of patients with occult HCV infection and in 4/118 (3.4%) of patients with chronic hepatitis C. Fourteen additional family members (seven were relatives of index patients with occult HCV infection) had abnormal values of liver enzymes without serological markers of HCV infection. Two of these patients (who were relatives of two index patients with occult HCV infection) underwent a liver biopsy and were diagnosed with an occult HCV infection because HCV RNA was detected in the liver cells in the absence of serological HCV markers. In conclusion, the prevalence of HCV infection among family members of patients with occult HCV infection was similar to that found among family members of patients with chronic hepatitis C. This stresses the need to adopt strategies to prevent the transmission of HCV in the family setting of patients with occult HCV infection.

  15. The diameter of 88 Thisbe from its occultation of SAO 187124

    NASA Technical Reports Server (NTRS)

    Millis, R. L.; Wasserman, L. H.; Franz, O. G.; White, N. M.; Bowell, E.; Klemola, A.; Elliott, R. C.; Smethells, W. G.; Price, P. M.; Mckay, C. P.

    1982-01-01

    The 7 October, 1981 occultation of SAO 187124 by 88 Thisbe was observed at twelve sites. The occultation observations, together with information about the asteroid's light curve, gives a mean diameter for Thisbe of 232 + or - 10 km. This value is 10 percent larger than the previously published radiometric diameter of Thisbe.

  16. Diagnostic Ultrasonography of an Ankle Fracture Undetectable by Conventional Radiography: A Case Report

    PubMed Central

    Daniels, Clinton J.; Welk, Aaron B.; Enix, Dennis E.

    2016-01-01

    Objective The purpose of this study is to present diagnostic ultrasonography assessment of an occult fracture in a case of persistent lateral ankle pain. Clinical Features A 35-year-old woman presented to a chiropractic clinic with bruising, swelling, and pain along the distal fibula 3 days following an inversion ankle trauma. Prior radiographic examination at an urgent care facility was negative for fracture. Conservative care over the next week noted improvement in objective findings, but the pain persisted. Intervention and Outcome Diagnostic ultrasonography was ordered to assess her persistent ankle pain and showed a minimally displaced fracture of the fibula 4 cm proximal to the lateral malleolus. The patient was referred to her primary care physician and successfully managed with conservative care. Conclusion In this case, diagnostic ultrasonography was able to identify a Danis-Weber subtype B1 fracture that was missed by plain film radiography. PMID:27069430

  17. Radio Occultation Investigation of the Rings of Saturn and Uranus

    NASA Technical Reports Server (NTRS)

    Marouf, Essam A.

    1997-01-01

    The proposed work addresses two main objectives: (1) to pursue the development of the random diffraction screen model for analytical/computational characterization of the extinction and near-forward scattering by ring models that include particle crowding, uniform clustering, and clustering along preferred orientations (anisotropy). The characterization is crucial for proper interpretation of past (Voyager) and future (Cassini) ring, occultation observations in terms of physical ring properties, and is needed to address outstanding puzzles in the interpretation of the Voyager radio occultation data sets; (2) to continue the development of spectral analysis techniques to identify and characterize the power scattered by all features of Saturn's rings that can be resolved in the Voyager radio occultation observations, and to use the results to constrain the maximum particle size and its abundance. Characterization of the variability of surface mass density among the main ring, features and within individual features is important for constraining the ring mass and is relevant to investigations of ring dynamics and origin. We completed the developed of the stochastic geometry (random screen) model for the interaction of electromagnetic waves with of planetary ring models; used the model to relate the oblique optical depth and the angular spectrum of the near forward scattered signal to statistical averages of the stochastic geometry of the randomly blocked area. WE developed analytical results based on the assumption of Poisson statistics for particle positions, and investigated the dependence of the oblique optical depth and angular spectrum on the fractional area blocked, vertical ring profile, and incidence angle when the volume fraction is small. Demonstrated agreement with the classical radiative transfer predictions for oblique incidence. Also developed simulation procedures to generate statistical realizations of random screens corresponding to uniformly packed

  18. The two Titan stellar occultations of 14 November 2003

    NASA Astrophysics Data System (ADS)

    Sicardy, B.; Colas, F.; Widemann, T.; Bellucci, A.; Beisker, W.; Kretlow, M.; Ferri, F.; Lacour, S.; Lecacheux, J.; Lellouch, E.; Pau, S.; Renner, S.; Roques, F.; Fienga, A.; Etienne, C.; Martinez, C.; Glass, I. S.; Baba, D.; Nagayama, T.; Nagata, T.; Itting-Enke, S.; Bath, K.-L.; Bode, H.-J.; Bode, F.; Lüdemann, H.; Lüdemann, J.; Neubauer, D.; Tegtmeier, A.; Tegtmeier, C.; Thomé, B.; Hund, F.; deWitt, C.; Fraser, B.; Jansen, A.; Jones, T.; Schoenau, P.; Turk, C.; Meintjies, P.; Hernandez, M.; Fiel, D.; Frappa, E.; Peyrot, A.; Teng, J. P.; Vignand, M.; Hesler, G.; Payet, T.; Howell, R. R.; Kidger, M.; Ortiz, J. L.; Naranjo, O.; Rosenzweig, P.; Rapaport, M.

    2006-11-01

    We report the observation of two stellar occultations by Titan on 14 November 2003, using stations in the Indian Ocean, southern Africa, Spain, and northern and southern Americas. These occultations probed altitudes between ~550 and 250 km (~1 to 250 μbar) in Titan's upper stratosphere. The light curves reveal a sharp inversion layer near 515 +/- 6 km altitude (1.5 μbar pressure level), where the temperature increases by 15 K in only 6 km. This layer is close to an inversion layer observed fourteen months later by the Huygens HASI instrument during the entry of the probe in Titan's atmosphere on 14 January 2005 [Fulchignoni et al., 2005]. Central flashes observed during the first occultation provide constraints on the zonal wind regime at 250 km, with a strong northern jet (~200 m s-1) around the latitude 55°N, wind velocities of ~150 m s-1 near the equator, and progressively weaker winds as more southern latitudes are probed. The haze distribution around Titan's limb at 250 km altitude is close to that predicted by the Global Circulation Model of Rannou et al. (2004) in the southern hemisphere, but a clearing north of 40°N is necessary to explain our data. This contrasts with Rannou et al.'s (2004) model, which predicts a very thick polar hood over Titan's northern polar regions. Simultaneous observations of the flashes at various wavelengths provide a dependence of τ $\\propto$ λ-q, with q = 1.8 +/- 0.5 between 0.51 and 2.2 μm for the tangential optical depth of the hazes at 250 km altitude.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Fabrication of Soft-Edged Occulting Masks for Coronagraphs

    NASA Astrophysics Data System (ADS)

    Tolls, Volker; Aziz, M. J.; Raja, S.

    2009-01-01

    Direct imaging of extra-solar planets is important for determining the properties of individual planets and to study multi-planet systems. Obtaining spectra of extra-solar planets enables us to constrain the composition of planetary atmospheres and surfaces, their climates, their evolution, and their rotation periods. The Lyot coronagraph is one of the important techniques to acquire these spectra. In its simplest design it consists of a telescope, an occulter mask in the first focal plane, a Lyot stop in the following pupil plane, and the detector in the final focal plane. The goal of ongoing research is to achieve the best possible performance from a Lyot coronagraph. Among the study objects is the occulter mask. We are studying a new manufacturing method to overcome the main problems of occulter masks: undesired chromatic effects and intolerable phase distortions. Our method utilizes substrates covered with highly absorbing dye mixtures (optical density of 1 per micron) and focused ion beam (FIB) milling of the mask profiles into these dyes. By combining several dyes with pre-determined mixing ratios, we are able to control the chromaticity of the mask from decreasing to flat to increasing absorptivity with wavelengths. Phase effects occur in these masks only at the transition from the dye to its surrounding medium. The idea is to control these phase effects by embedding the masks in clear, phase-matching glass. This poster will present the progress we made in finding and characterizing suitable materials and the results of first optical tests of FIB machined mask-like structures in dye-doped PMMA. This work was supported by NASA through grant NNG04GC57G and NSF through grant AST-0750222, through SAO IR&D funding and by Harvard University. Central facilities were provided by Harvard's Center for Nanoscale Systems.

  1. Visualization and data sharing of COSMIC radio occultation dataset

    NASA Astrophysics Data System (ADS)

    Ho, Y.; Weber, W. J.; Chastang, J.; Murray, D.; McWhirter, J.; Integrated Data Viewer

    2010-12-01

    Visualizing the trajectory and the sounding profile of the COSMIC netCDF dataset, and its evolution through time is developed in Unidata's Integrated data Viewer (IDV). The COSMIC radio occultation data is located in a remote data server called RAMADDA, which is a content management system for earth science data. The combination of these two software packages provides a powerful visualization and analysis tools for sharing real time and archived data for research and education. In this presentation we would like to demonstrate the development and the usage of these two software packages.

  2. Occultation by a possible third satellite of neptune.

    PubMed

    Reitsema, H J; Hubbard, W B; Lebofsky, L A; Tholen, D J

    1982-01-15

    The 24 May 1981 close approach of Neptune to an uncataloged star was photoelectrically monitored from two observatories separated by 6 kilometers parallel to the occultation track. An 8.1-second drop in signal, recorded simultaneously at both sites, is interpreted as resulting from the passage of a third satellite of Neptune in front of the star. From the duration of the event, the derived minimum diameter for an object sharing Neptune's motion is 180 kilometers. If the object was in Neptune's equatorial plane and there are no significant errors in the prediction ephemeris, the object was located at a distance of 3 Neptune radii from Neptune's center.

  3. Massive gas gangrene secondary to occult colon carcinoma.

    PubMed

    Griffin, Andrew S; Crawford, Matthew D; Gupta, Rajan T

    2016-06-01

    Gas gangrene is a rare but often fatal soft-tissue infection. Because it is uncommon and the classic symptom of crepitus does not appear until the infection is advanced, prompt diagnosis requires a high index of suspicion. We present a case report of a middle-aged man who presented with acute onset lower-extremity pain that was initially thought to be due to deep vein thrombosis. After undergoing workup for pulmonary embolism, he was found to have massive gas gangrene of the lower extremity secondary to an occult colon adenocarcinoma and died within hours of presentation from multisystem organ failure.

  4. Occult invasive pituitary adenoma predisposing to fatal bacterial meningitis.

    PubMed

    Laszewski, M J; Moore, S A

    1990-01-01

    Pituitary adenomata are benign neoplasms which usually grow slowly and present with manifestations relating to an associated endocrinopathy or visual disturbance. Rarely these neoplasms will demonstrate a more aggressive behavior with extracranial extension and symptoms of upper airway obstruction or anosmia. Several reported cases suggest that although these neoplasms behave aggressively the overall survival and prognosis for these patients remains good. We present the clinical and postmortem findings of an occult invasive pituitary adenoma leading to the development of bacterial meningitis, coma and death. This communication stresses the necessity for the early diagnosis and treatment of the invasive adenomata to prevent the development of potentially fatal infectious sequelae.

  5. Occult lung cancer in patients with bullous emphysema

    PubMed Central

    Venuta, F.; Rendina, E. A.; Pescarmona, E. O.; De Giacomo, T.; Vizza, D.; Flaishman, I.; Ricci, C.

    1997-01-01

    BACKGROUND: The incidence of lung cancer is increased in patients with bullous emphysema. METHODS: A series of 95 patients undergoing excision of bullous lung tissue was reviewed to determine the incidence and long term outcome of occult carcinoma present in the resected material. RESULTS: Four patients (4.2%) had peripheral foci of large cell carcinoma in the resection specimen (three bullectomies and one lobectomy). CONCLUSIONS: Resected bullous lung tissue should be carefully examined for areas of bronchogenic carcinoma. The results of incidental complete excision are favourable. 




 PMID:9093350

  6. Halogen Occultation Experiment (HALOE) gas cell life test program

    NASA Technical Reports Server (NTRS)

    Sullivan, E. M.; Thompson, R. E.; Harvey, G. A.; Park, J. H.; Richardson, D. J.

    1983-01-01

    The Halogen Occultation Experiment (HALOE) will use gas filter correlation radiometry to measure the atmospheric concentration profiles of HCl, HF, NO, and CH4 from the Upper Atmosphere Research Satellite. The need to contain the gases for the gas filter measurements has resulted in the development of gas cells and the need for a life test program to demonstrate that the gas cells will perform their functions for extended periods (several years) of time. This report describes the tests in the life test program, the test apparatus used, and the analysis techniques developed. The report also presents data obtained during the first 14 months of the test program.

  7. Thermal design, analysis and testing of the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Foss, Richard A.; Smith, Dewey M.

    1987-01-01

    This paper briefly introduces the Halogen Occultation Experiment (HALOE) and describes the thermal requirements in some detail. The thermal design of the HALOE is described, together with the design process and the analytical techniques used to arrive at this design. The flight hardware has undergone environmental testing in a thermal vacuum chamber to validate the thermal design. The HALOE is a unique problem in thermal control due to its variable solar loading, its extremely sensitive optical components and the high degree of pointing accuracy required. This paper describes the flight hardware, the design process and its verification.

  8. The structure of Titan's atmosphere from Cassini radio occultations

    NASA Astrophysics Data System (ADS)

    Schinder, Paul J.; Flasar, F. Michael; Marouf, Essam A.; French, Richard G.; McGhee, Colleen A.; Kliore, Arvydas J.; Rappaport, Nicole J.; Barbinis, Elias; Fleischman, Don; Anabtawi, Aseel

    2011-10-01

    We present results from the two radio occultations of the Cassini spacecraft by Titan in 2006, which probed mid-southern latitudes. Three of the ingress and egress soundings occurred within a narrow latitude range, 31-34°S near the surface, and the fourth at 52.8°S. Temperature-altitude profiles for all four occultation soundings are presented, and compared with the results of the Voyager 1 radio occultation (Lindal, G.F., Wood, G.E., Hotz, H.B., Sweetnam, D.N., Eshleman, V.R., Tyler, G.L. [1983]. Icarus 53, 348-363), the HASI instrument on the Huygens descent probe (Fulchignoni, M. et al. [2005]. Nature 438, 785-791), and Cassini CIRS results (Flasar, F.M. et al. [2005]. Science 308, 975-978; Achterberg, R.K., Conrath, B.J., Gierasch, P.J., Flasar, F.M., Nixon, C.A. [2008b]. Icarus 194, 263-277). Sources of error in the retrieved temperature-altitude profiles are also discussed, and a major contribution is from spacecraft velocity errors in the reconstructed ephemeris. These can be reduced by using CIRS data at 300 km to make along-track adjustments of the spacecraft timing. The occultation soundings indicate that the temperatures just above the surface at 31-34°S are about 93 K, while that at 53°S is about 1 K colder. At the tropopause, the temperatures at the lower latitudes are all about 70 K, while the 53°S profile is again 1 K colder. The temperature lapse rate in the lowest 2 km for the two ingress (dawn) profiles at 31 and 33°S lie along a dry adiabat except within ˜200 m of the surface, where a small stable inversion occurs. This could be explained by turbulent mixing with low viscosity near the surface. The egress profile near 34°S shows a more complex structure in the lowest 2 km, while the egress profile at 53°S is more stable.

  9. [The significance of mammographic symptoms in clinically occult findings].

    PubMed

    de Waal, J C; 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% had 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.

  10. Saturn's Rings II. Particle Sizes Inferred from Stellar Occultation Data

    NASA Astrophysics Data System (ADS)

    French, Richard G.; Nicholson, Philip D.

    2000-06-01

    We derive power-law particle size distributions for each of Saturn's main ring regions, using observations of the 3 July 1989 stellar occultation of 28 Sgr from Palomar, McDonald, and Lick observatories. We use the Voyager PPS δ Sco optical depth profile to estimate and then remove the directly transmitted signal from the 28 Sgr observations, leaving high SNR scattered light profiles at wavelengths of 3.9, 2.1, and 0.9 μm. The angular distribution of this diffracted signal depends on the ring particle size distribution: the sharpness of the forward lobe is set by the largest particles, while the overall breadth and amplitude of the scattered signal reflect the abundance of smaller, cm-sized particles. From a simple one-dimensional scattering model, we estimate characteristic particle sizes in the A, B, and C rings, and obtain a good match to the detailed structure of the observed scattered light profiles. To accommodate more realistic particle size distributions and to take proper account of the geometry of the occultation, we then develop a two-dimensional forward-scattering model. We assume for simplicity a single power law particle size distribution for each major ring region, and we determine the index q and lower and upper size cutoffs amin and amax that provide the best match to all three data sets in each region. Our results in the A and C rings are fairly consistent with values of q and amax derived from Voyager radio occultation (RSS) measurements (Zebker et al. 1985). We extend their results by determining lower limits to the particle size distributions and by probing the B Ring. We find a rather flat ( q=2.75) and narrow size distribution for both the inner A Ring and the B Ring, with a surprisingly large amin=30 cm. From the detailed shape of the scattered signal in the A and B rings, we find amax=20 m, a factor of two larger than the RSS result. The fraction of cm-sized particles increases between the inner and outer A Ring and is greatest in the C

  11. Rosemary Hill Observatory lunar occultation summary for 1983-1984

    NASA Astrophysics Data System (ADS)

    Schneider, Glenn; Anderson, Chris

    1993-04-01

    The results from photometric observations of 21 previously unreported occultation disappearances obtained during the period from March 24, 1983 through March 12, 1984, with the University of Florida's Rosemary Hill Observatory 76-cm reflecting telescope are presented. Statistically significant determinations of stellar diameters are indicated for two stars: 32 Librae (12.2 mas) and BD + 22 deg 1032 (5.45 mas). Diameter measurements of marginal statistical significance are noted for two other stars (9 Cancri and 37 Capricorni). New duplicity determinations are reported for five stellar systems in this sample.

  12. The Burst and Transient Source Experiment (BATSE) Earth Occultation Catalog

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2004-01-01

    The hard X-ray sky was continuously monitored with the BATSE experiment on the Compton Gamma Ray observatory using the Earth Occultation method. Known sources were monitored twice every orbit and transients could be detected at about the approx. 50 mCrab level on a daily basis. I will summarize the results from our catalog of 179 monitored sources, highlighting observations of black holes and energy spectra for the 83 firmly detected sources and FITS files for all 179 sources. This web database can serve as a guide and comparison tool for future observations with EXIST.

  13. Sporadic E Morphology from GPS-CHAMP Radio Occultation

    NASA Technical Reports Server (NTRS)

    Wu, Dong L.; Ao, Chi O.; Hajj, George A.; de la Torre Juarez, Manuel; Mannucci, Anthony J.

    2005-01-01

    The scintillations of phase and amplitude in terms of signal-to-noise ratio (SNR) of the GPS radio occultation signal are caused by thin ionization layers. These thin irregular electron density layers in the E region ionosphere are often called sporadic E (Es). For a monthly retrieval of Es morphology we use the variances of the phase and SNR fluctuations of worldwide 6000 GPS/CHAMP occultations in the E region. The Es climatology is studied globally with the SNR and phase variances in terms of monthly zonal means, seasonal maps, and diurnal and long-term variations. The zonal mean variances reveal strong, extended Es activities at summertime midlatitudes but weak, confined activities in wintertime high latitudes, peaking at 105 km. Global maps at 105-km altitude show clear dependence of Es activities on the geomagnetic dip angle, where the summertime midlatitude Es occurs mostly at dip angles of 30 deg. - 60 deg. and the wintertime high-latitude enhancement occurs mostly at dip angles greater than 80 deg. The midlatitude Es variances exhibit a strong semidiurnal variation with peak hours near 0800 1000 and 2000 local solar time, respectively. The peak hours are delayed slightly with decreasing height, suggesting influences from the semidiurnal tide. To provide more insights on the observed SNR and phase variances, we model radio wave propagation for the CHAMP observing geometry under several perturbed cases in the E region ionosphere. The model simulations indicate that the SNR variance has the maximum response to Es perturbations at vertical wavelengths of 1.2 km, whereas the phase response maximizes at 2 km (for the 1-s variance analysis). The characteristic scale depends little on the truncation time used in the SNR variance analysis, but it increases with the truncation time for the phase variances. Initial studies show that reasonable global Es morphology can be produced on a monthly and seasonal basis with the CHAMP one-antenna occultations. Better results

  14. Limb profiles of the Moon from grazing occultation observations collected at RGO

    NASA Astrophysics Data System (ADS)

    Soma, Mitsuru; Kato, Yuji

    2002-09-01

    From lunar grazing occultation observations it is shown that the present lunar limb profile data have sometimes large errors, and therefore it is apparent that they need to be modified. For that purpose observations of grazing occultations collected at the Royal Greenwich Observatory until 1980 were analyzed and lunar limb profile data were obtained. As a result the number of the luanr limb profile data obtained from grazing occultations was almost doubled. These profile data are being used for the predictions of lunar grazing occultations in order to locate observers at better positions, so that they can also get good grazing occultation data to improve the lunar limb profiles. These profile data will be used in the future analyses of solar eclipse observations and of the possible errors of the Hipparcos proper motion system.

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

    NASA Technical Reports Server (NTRS)

    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.; Bosh, A.; Duffard, R.; Lellouch, E.; Tancredi, G.; Young, Leslie; Milam, Stefanie N.

    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.

  16. Detection of spatially extended sources in high energy astrophysics with special application to lunar occultation

    NASA Astrophysics Data System (ADS)

    Jenke, Peter Alexander

    2009-01-01

    Occultation is a technique that enables image reconstruction and source identification with a non-imaging detector. Such an approach is well suited for a future survey mission in nuclear astrophysics. In particular, the Lunar Occultation Technique (LOT) utilizes the Moon as an occulting object and is the basis of a new gamma-ray survey mission concept, the Lunar OCcultation Observer (LOCO). Techniques utilizing the LOT to detect spatially extended emission, from the Galactic plane or Galactic Center region, have been developed. Given knowledge of detector position in lunar orbit, combined with lunar ephemeris and relevant coordinate transformations, occultation time series can be used to reconstruct skymaps of these extended Galactic emitters. Monte-Carlo Markov Chains (MCMC), incorporating the Metropolis-Hastings algorithm for parametric model testing, form the basis of the technique. Performance of the imaging methodology, and its application to nuclear astrophysics will be presented.

  17. All-Sky Earth Occultation Observations with the Fermi Gamma Ray Burst Monitor

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, C. A.; Case, G.; Cherry, M.; Rodi, J.; Finger, M.; Camero-Arranz, A.; Chaplin, V.; Connaughton, V.; Berklen, E.; Haynes, R. H.; Bhat, P. N.; Briggs, M.; Preece, R.

    2009-01-01

    Using the Gamma Ray Burst Monitor (GBM) on-board Fermi, we are monitoring the hard X-ray/soft gamma ray sky using the Earth occultation technique. Each time a source in our catalog is occulted by (or exits occultation by) the Earth, we measure its flux by determining the change in count rate due to the occultation. Currently we are using CTIME data with 8 energy channels spanning 8 keV to 1 MeV for the GBM NaI detectors and spanning 150 keV to 40 MeV for the GBM BGO detectors. Our preliminary catalog consists of galactic X-ray binaries, the Crab Nebula, and active galactic nuclei. We will present early results. Regularly updated results can be found on our website http://gammaray.nsstc.nasa.gov/gbm/science/occultation.

  18. The 13 November 1984 occultation of BD +08 deg 0471 by (1) Ceres

    NASA Technical Reports Server (NTRS)

    Wasserman, L. H.; Millis, R. L.; Franz, O. G.; Ahearn, M. F.; Osborn, W.; Klemola, A.

    1985-01-01

    The 13 November 1984 occultation of BD +08 deg 0471 was discovered during a photographic search carried out with the 0.5 meter Carnegie Double Astrograph at Lick Observatory and the Lowell Observatory PDS microdensitometer. Such a search was stimulated by the curious fact that few favorably located occultations of AGK3 or SAO catalog starts by Ceres will occur during the 1980s. The occultation on 13 November, however, is a particularly good event. The star is 1000 cubic M in V, yielding a predicted drop at occultation of about 10%. Such a drop can be detected by small telescopes equipped with photoelectric photometers, but is too small to be seen visually. The track was predicted to cross the Caribbean, Florida, southern Texas, and Mexico. Based on this prediction, preparations were made to observe the event in Mexico using four portable occultation data systems.

  19. Search for serendipitous Oort cloud object occultation in X-rays

    NASA Astrophysics Data System (ADS)

    Shang, Jie-Rou; Liu, Chih-Yuan; Chang, Hsiang-Kuang

    2015-08-01

    Serendipitous occultation search is a way to study small objects in the outer Solar system like trans-Neptunian objects (TNOs) by extracting and analyzing the diffraction pattern in the occultation lights. There are already some reported detections in both optical and X-ray bands in this kind of search. Except for KBOs, this method also has the potential to extend the search to a distance as far away as the Oort cloud region (beyond a few thousands AU). As the distance is larger, a shorter wavelength is needed to have a smaller Fresnel scale, with which occultation may be more easily detected. Here we introduce the serendipitous occultation method we used in searching Oort cloud objects occultation, and present the results of using Rossi X-ray Timing Explorer/Proportional Counter Array data of Sco X-1 taken from 1996 February to 2012 January.

  20. Effect of Natural Fractures on Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

    Ben, Y.; Wang, Y.; Shi, G.

    2012-12-01

    Hydraulic Fracturing has been used successfully in the oil and gas industry to enhance oil and gas production in the past few decades. Recent years have seen the great development of tight gas, coal bed methane and shale gas. Natural fractures are believed to play an important role in the hydraulic fracturing of such formations. Whether natural fractures can benefit the fracture propagation and enhance final production needs to be studied. Various methods have been used to study the effect of natural fractures on hydraulic fracturing. Discontinuous Deformation Analysis (DDA) is a numerical method which belongs to the family of discrete element methods. In this paper, DDA is coupled with a fluid pipe network model to simulate the pressure response in the formation during hydraulic fracturing. The focus is to study the effect of natural fractures on hydraulic fracturing. In particular, the effect of rock joint properties, joint orientations and rock properties on fracture initiation and propagation will be analyzed. The result shows that DDA is a promising tool to study such complex behavior of rocks. Finally, the advantages of disadvantages of our current model and future research directions will be discussed.

  1. Fracture channel waves

    NASA Astrophysics Data System (ADS)

    Nihei, Kurt T.; Yi, Weidong; Myer, Larry R.; Cook, Neville G. W.; Schoenberg, Michael

    1999-03-01

    The properties of guided waves which propagate between two parallel fractures are examined. Plane wave analysis is used to obtain a dispersion equation for the velocities of fracture channel waves. Analysis of this equation demonstrates that parallel fractures form an elastic waveguide that supports two symmetric and two antisymmetric dispersive Rayleigh channel waves, each with particle motions and velocities that are sensitive to the normal and tangential stiffnesses of the fractures. These fracture channel waves degenerate to shear waves when the fracture stiffnesses are large, to Rayleigh waves and Rayleigh-Lamb plate waves when the fracture stiffnesses are low, and to fracture interface waves when the fractures are either very closely spaced or widely separated. For intermediate fracture stiffnesses typical of fractured rock masses, fracture channel waves are dispersive and exhibit moderate to strong localization of guided wave energy between the fractures. The existence of these waves is examined using laboratory acoustic measurements on a fractured marble plate. This experiment confirms the distinct particle motion of the fundamental antisymmetric fracture channel wave (A0 mode) and demonstrates the ease with which a fracture channel wave can be generated and detected.

  2. Progress in Turbulence Detection via GNSS Occultation Data

    NASA Technical Reports Server (NTRS)

    Cornman, L. B.; Goodrich, R. K.; Axelrad, P.; Barlow, E.

    2012-01-01

    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.

  3. Dust occultation at Titan measured by CDA onboard Cassini

    NASA Astrophysics Data System (ADS)

    Srama, Ralf; CDA science Team

    2016-10-01

    The Cosmic Dust Analyzer (CDA) onboard Cassini characterized successfully the dust environment at Saturn since 2004. The instrument measures the primary charge, speed, mass and composition of individual submicron and micron sized dust grains. The detection threshold scales with speed^3.5 such that the detection of fast nanograins (~100 km/s) is possible. Saturn's nanodust environment (streams) is studied many years. However, a special geometric condition of Saturn, Cassini and Titan during a Titan flyby in 2014 (DOY 65) provided a special dust occultation opportunity. Titan and its atmosphere blocked the stream of fast nanoparticles such that CDA registered a clear drop in impact rate around closest approach. An analysis of the data allows to constrain the source region of the nanograins, which is compatible with a source region in the ring plane at distances from Saturn between 4 and 8 Saturn radii. Backward and forward modeling was performed leading to dust grain sizes between 3 and 9 nm and speeds between 80 and 150 km/s. The new modeling results also show that Enceladus acts a direct source for nanodust streams leading to the observation of periodic impact rates in the outer Saturn system. Such periodicities were observed recently by CDA and showed a clear signature of the Enceladus orbital period. A second dust occultation opportunity using Titan is planned august 2016.

  4. Clinical presentation and metabolic features of overt and occult urolithiasis.

    PubMed

    Polito, Cesare; Apicella, Andrea; Marte, Antonio; Signoriello, Giuseppe; La Manna, Angela

    2012-01-01

    Although pediatricians are frequently confronted with patients presenting urolithiasis symptoms without obvious stones, the syndrome of occult urolithiasis may be still viewed with some skepticism. We have compared the clinical and metabolic features of 197 children with obvious calculi, 189 with microcalculi (diameter ≤ 3 mm based on renal sonography), and 114 with symptoms of urolithiasis and normal renal sonography findings. Only microcalculi and normal sonography subjects with a urinary abnormality potentially leading to urolithiasis were included in the study. Age at presentation increased significantly (p = 0.0001) in the groups in the order normal sonography to microcalculi to calculi groups. There was no significant difference among the three groups in terms of family history of urolithiasis, gender distribution, and degree of hypercalciuria, hyperuricosuria, hyperoxaluria, or hypocitraturia. The average frequency of pain attacks of patients with recurrent abdominal pain (RAP) ranged from 3.6 to 4.6 days of pain per month among the three groups, which is four to ninefold lower than that reported for children with functional or organic gastrointestinal RAP. The consistency of many clinical and urinary metabolic characteristics indicates a common underlying disorder in overt and occult urolithiasis. The increase of age at presentation from the normal sonography to microcalculi and calculi groups may reflect progressive crystal accretion leading ultimately to overt stone formation.

  5. Necrotizing fasciitis: Diagnosis and management of an occult infective focus

    PubMed Central

    Chandawarkar, Rajiv Y; Jessie, Timothy A; Pennington, Gary A; Wells, Mark D; Cervino, A Lawrence

    2004-01-01

    Necrotizing fasciitis is a life-threatening, fulminant disease that is a diagnostic and therapeutic challenge. Presenting with a triad of findings including progressive erythema, severe dermatological edema and severe pain disproportionate to the physical findings, this disease is a surgical emergency. Delayed diagnosis and surgical debridement lead to higher mortality. Early extensive surgical debridement, aggressive antibiotic therapy, invasive monitoring and intensive care management determine the outcome in most cases. In patients who fail to demonstrate clinical improvement, profound sepsis and its sequela –systemic inflammatory response – have frequently been implicated. It is these patients that need to be carefully re-evaluated for ‘hidden’ foci of infection that may be the real cause of the patient’s decline. Once detected, these occult foci can be surgically debrided, resulting in dramatic improvement. Two illustrative cases, one with occult endo- and panophthalmitis and the other with an unusual involvement of deeper muscle planes and the nodal basin, demonstrate this point. This consumptive process gathers momentum at an alarming speed, hence, the treatment must be aggressive and prompt. PMID:24115889

  6. The ionosphere of Europa from Galileo radio occultations.

    PubMed

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

    1997-07-18

    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.

  7. Stargazing from New Horizons: Ultraviolet Stellar Occultations by Pluto's Atmosphere

    NASA Astrophysics Data System (ADS)

    Kammer, Joshua A.; Stern, S. Alan; Weaver, Harold A.; Young, Leslie; Ennico, Kimberly; Olkin, Catherine B.; Gladstone, Randy; Summers, Michael; Steffl, Andrew; Greathouse, Thomas K.; Versteeg, Maarten; Retherford, Kurt D.; Parker, Joel Wm.; Schindhelm, Eric; Strobel, Darrell F.; New Horizons ATM Theme Team, New Horizons Science Team

    2016-10-01

    Not long after the New Horizons encounter with Pluto last July, the Alice ultraviolet imaging spectrograph observed signatures of UV absorption by Pluto's atmosphere during two distinct occultation events. During these events, UV bright stars (the Sun, as well as two B-type stars) passed behind Pluto as seen by the spacecraft, and the attenuated starlight revealed the clear presence of nitrogen, methane, and several other hydrocarbons. Their mixing ratios vary with altitude, including localized peaks in the density of minor hydrocarbons such as C2H2 and C2H4. At about 300 km above Pluto's surface, these particular species are found to have mixing ratios relative to CH4 of approximately 10% and 1%, respectively. While this overall composition was expected pre-New Horizons, the vertical profiles of these species were surprising. In this presentation I will discuss the analysis of these occultations, including several profiles of key atmospheric species, and how they might play a role in explaining the presence of high-altitude haze on this cold, small, distant planet.

  8. Occult endocrine dysfunction in patients with cirrhosis of liver

    PubMed Central

    Kumar, K. V. S. Hari; Pawah, A. K.; Manrai, Manish

    2016-01-01

    Background: Liver dysfunction leads to endocrine disturbance due to the alteration in protein metabolism or synthesis. We studied the presence of occult endocrine dysfunction in liver cirrhosis and compared the same with underlying etiology. Materials and Methods: We evaluated thirty patients with liver cirrhosis in this cross-sectional, observational study. All subjects were assessed for pituitary, thyroid, adrenal, and gonadal function. The patients were divided into Group 1 (cirrhosis, n = 30) and Group 2 (controls, n = 15) and the data were analyzed with appropriate statistical tests. Results: The study participants (20 males, 10 females) had a mean age of 54.5 ± 12.4 years and duration of the cirrhosis 5.1 ± 2.7 years. Four patients were in Child Class A, 11 and 15 patients were in Child Classes B and C, respectively. Eleven out of thirty patients (37%) had endocrine disorders, that include subclinical hypothyroidism (n = 3), primary hypothyroidism (n = 1), Sick Euthyroid syndrome (n = 3), central hypothyroidism (n = 2), secondary hypogonadism (n = 3) and growth hormone deficiency in three patients. Two patients had partial hypopituitarism and one patient had complete hypopituitarism. Conclusion: Occult endocrine dysfunction of thyroid and gonadal axes is common in patients with cirrhosis of the liver. The hormonal abnormalities are not different based on the etiology of the cirrhosis. PMID:28217586

  9. Observations of Three Stellar Occultations by Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Betzler, A. S.; Betzler, L. B. S.

    2017-03-01

    On June 12 1996 UT, three 11-12 R magnitude stars were occulted by comet Hale-Bopp. The passage of these stars through the cometary atmosphere was monitored at the Observatorio do Pico dos Dias (Brazil) using a 0.6 m telescope. We detected an absorption of starlight by the comet dust implying in a drop of (6± 1) × 10^{-2} magnitude of occulted star XPM 152-0898466 at a minimum distance of (4.3 ± 0.2)× 104 km from the central condensation. This result, combined with magnitude variations of other stars, suggests the detection of a jet in the coma. From our measurement of extinction, we infer that the opacity of the nucleus surface was τ ˜ 3 . The mean geometric albedo p of dust grains is (4.5 ± 0.7) × 10^{-3} . This low albedo may suggest a difference in the grain population associated to coma and jets.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. [Periprosthetic Acetabulum Fractures].

    PubMed

    Schreiner, A J; Stuby, F; de Zwart, P M; Ochs, B G

    2016-12-01

    In contrast to periprosthetic fractures of the femur, periprosthetic fractures of the acetabulum are rare complications - both primary fractures and fractures in revision surgery. This topic is largely under-reported in the literature; there are a few case reports and no long term results. Due to an increase in life expectancy, the level of patients' activity and the number of primary joint replacements, one has to expect a rise in periprosthetic complications in general and periprosthetic acetabular fractures in particular. This kind of fracture can be intra-, peri- or postoperative. Intraoperative fractures are especially associated with insertion of cementless press-fit acetabular components or revision surgery. Postoperative periprosthetic fractures of the acetabulum are usually related to osteolysis, for example, due to polyethylene wear. There are also traumatic fractures and fractures missed intraoperatively that lead to some kind of insufficiency fracture. Periprosthetic fractures of the acetabulum are treated conservatively if the implant is stable and the fracture is not dislocated. If surgery is needed, there are many possible different surgical techniques and challenging approaches. That is why periprosthetic fractures of the acetabulum should be treated by experts in pelvic surgery as well as revision arthroplasty and the features specific to the patient, fracture and prosthetic must always be considered.

  12. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

    Young, Ki Won; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. Results The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

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

    NASA Astrophysics Data System (ADS)

    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.

  14. All-Sky Earth Occultation Observations with the Fermi Gamma Ray Burst Monitor

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, C. A.; Beklen, E.; Bhat, P. N.; Briggs, M.; Camero-Arranz, A.; Case, G.; Chaplin, V.; Cherry, M.; Connaughton, V.; Finger, M.; Jenke, P.; Paciesas, W.; Preece, R.; Rodi, J.

    2010-01-01

    Using the Gamma Ray Burst Monitor (GBM) on-board Fermi, we are monitoring the hard X-ray/soft gamma ray sky using the Earth occultation technique. Each time a source in our catalog is occulted by (or exits occultation by) the Earth, we measure its flux using the change in count rates due to the occultation. Currently we are using CTIME data with 8 energy channels spanning 8 keV to 1 MeV for the GBM NaI detectors and spanning 150 keV to 40 MeV for the GBM BGO detectors. Our preliminary catalog consists of galactic X-ray binaries, the Crab Nebula, and active galactic nuclei. New sources are added to our catalog as they become active or upon request. In addition to Earth occultations, we have observed numerous occultations with Fermi's solar panels. We will present early results. Regularly updated results will be found on our website http://gammaray.nsstc.nasa.gov/gbm/science/occultation.

  15. [Fractures of the forefoot].

    PubMed

    Richter, M

    2011-10-01

    Fractures of the forefoot are common and comprise approximately two thirds of all foot fractures. Forefoot fractures are caused by direct impact or the effect of indirect force. The forces exerted can range from repetitive minor load (stress fractures) to massive destructive forces (complex trauma). The clinical course in forefoot fractures is typically more favourable than in fractures of the mid- and hindfoot. The incidence of complications like infection or pseudarthrosis is low. Exceptions are rare fractures of the proximal shaft of the fifth metatarsal and the sesamoids with higher pseudarthrosis rates. Malunited metatarsal fractures can cause painful conditions that should even be treated operatively. Differences in structure and function of the different forefoot areas and specific fracture types require an adapted management of these special injuries.

  16. Management of metacarpal fractures.

    PubMed

    McNemar, Thomas B; Howell, Julianne Wright; Chang, Eric

    2003-01-01

    Fractures of the hand are the most common fractures of the human skeleton. Metacarpal fractures account for 30% to 50% of all of hand fractures. The mechanisms of these injuries vary from axial loading forces to direct blows to the dorsal hand. Resulting deformities include malrotation, angulation, and shortening. Treatment modalities vary from nonoperative reduction to open reduction and internal fixation. The treatment algorithm is guided by the location of the fracture, the stability of the fracture, and the resultant deformity. Operative procedures, although they may lead to excellent radiographic reduction of fractures, often lead to debilitating stiffness from the inflammatory reaction of the surgical procedure. Operative fixation must be employed judiciously and offered only when confident that non-operative therapy can be improved on with operative intervention. This article reviews the various types of metacarpal fractures, with the treatment options available for each fracture. The indications for each treatment modality, postoperative care, and rehabilitation are presented.

  17. Stellar occultation observations of Neptune's rings: 1984-1988.

    NASA Astrophysics Data System (ADS)

    Nicholson, Philip D.; Mosqueira, Ignacio; Matthews, Keith

    1995-02-01

    Data from eight stellar occultations by Neptune between 1984 and 1988 are analyzed to set limits on the optical depths of the continuous Adams and Le Verrier Rings, and to search for previously unidentified occultations by the arcs in the Adams Ring. We employ the approach introduced by Sicardy et al. (1991), Icarus 89, 220-243) and convert the raw lightcurves to radial profiles of equivalent width E( r), the fraction of incident starlight removed by ring material at normal incidence integrated over a specified radial range, or "window." In order to optimize the search for narrow rings, the window length is fixed at 15 km. Radii in Neptune's equatorial plane are calculated using the Neptune pole direction determined by Jacobson et al. (1990), AIAA/AAS Astrodynamics Conference, pp. 157-167). Using data from the occultation of 20 August 1985, we set a 3 σ upper limit of 75 m on the equivalent width of the Adams Ring at a longitude 120° away from tile arc region, near the location of minimum ring brightness in the Voyager images (Showalter and Cuzzi 1994, in preparation). This limit is for a maximum ring width of 15 km; for a maximum ring width of 50 km, the corresponding upper limit is E ≤ 210 m. Combining the results from this data set with similar upper limits obtained by Sicardy et al. (1991) with a 50-km window size, and assuming that the Adams Ring is azimuthally homogeneous away from the arc region, we find that the equivalent width of this ring is ≤90 m at the 90% confidence level, or ≤ 5% of the measured equivalent width of the Egalité arc. A comparison of this result with the relative brightnesses of ring and arcs observed at low phase angles in Voyager images (Showalter and Cuzzi 1994) suggests either that the particles in the Adams Ring have higher albedos than those confined within the arcs, or that the width of the continuous ring significantly exceeds 50 km. The 20 August 1985 lightcurve has also yielded the first tentative earth

  18. [Stellar Occultation Studies of Small Bodies in the Outer Solar System: Accomplishments, Status, and Plans

    NASA Technical Reports Server (NTRS)

    Elliott, James

    2005-01-01

    Bodies residing in the outer solar system exhibit unique physical processes, and some of the lessons learned from them can be applied to understanding what occurred in the outer solar system during its formation and early evolution. Pluto, the largest known Kuiper Belt object (KBO), and its near twin Triton--an ex-KBO that has been captured by Neptune--have nitrogen atmospheres that are in vapor-pressure equilibrium with surface ice. These atmospheres are most sensitively probed from Earth by the technique of Stellar occultations, which can provide the temperature and pressure profiles of these atmospheres at a spatial resolution of a few kilometers. Recent results from occultations show that the surface pressure of Triton's atmosphere has been increasing and that the shape of the atmosphere deviates from its expected spherical figure. With the occultation technique we can also learn the sizes of smaller bodies that have formed in the outer solar system: Charon, the Centaurs, and KBOs. Our proposed program involves identifying occultation candidates, predicting occultations, observing occultations, analysis of the data, and synthesis of the occultation results with other data. The main goals for our proposed work are to (i) further observe occultations by Triton with the objectives of understanding its pressure changes, distortion, and enigmatic thermal structure (ii) determine whether the abrupt drop in Pluto's stellar occultation light curve is caused by a sharp thermal gradient near its surface or by atmospheric haze, (iii) further observations to characterize the potential collapse of Pluto's atmosphere as it recedes from the sun (information that should be of interest to the Pluto-Kuiper Express), ( iv ) determine Charon's radius more accurately than can be done with the mutual events to derive a better estimate of Charon's density, and ( v ) directly determine the size (and albedo) of Centaurs with the goal of more accurately estimating the sizes of KBOS.

  19. A pareto-optimal characterization of miniaturized distributed occulter/telescope systems

    NASA Astrophysics Data System (ADS)

    Koenig, Adam W.; D'Amico, Simone; Macintosh, Bruce; Titus, Charles J.

    2015-09-01

    Distributed occulter/telescope systems hold great promise in the field of direct exoplanet imaging. However, proposed missions using this concept such as the New Worlds Observer or Exo-S (NASA) are exceptionally large with occulter diameters of tens of meters and inter-spacecraft separations of tens of megameters, requiring deployment in deep space. The estimated costs associated with these missions are in the billions of dollars. In order to reduce the risk associated with these missions, it is desirable to first deploy a low-cost technology demonstrator mission to prove that the distributed occulter telescope concept is valid. To that end, this work assesses the feasibility of miniaturizing the optics of the distributed occulter/telescope to enable deployment on micro- or nano-satellites in earth orbit. A variant of the convex optimization formulation introduced by previous authors is used to generate a pareto-optimal characterization between the achievable occulter contrast and a set of critical design variables (occulter radius, inner working angle, science spectrum, etc). This characterization is performed for two different sets of engineering constraints, corresponding to different levels of design complexity. The results of this study are compared to the performance requirements for imaging targets of scientific interest, namely exozodiacal dust disks, in order to identify promising design envelopes. The result of this work is a comprehensive trade of the capabilities of miniaturized, binary, petal-shaped occulters. This research demonstrates that there exist miniaturized occulter geometries compatible with micro- or nano-satellites in earth orbit suitable for imaging exozodiacal dust disks. In addition, this study provides a valuable methodology and performance guidelines for future distributed occulter/telescope designs.

  20. Pluto's atmosphere from stellar occultations in 2012 and 2013

    NASA Astrophysics Data System (ADS)

    Dias-Oliveira, Alex; Sicardy, Bruno; Lellouch, Emmanuel; Vieira-Martins, Roberto; Assafin, Marcelo; Ignácio Bueno Camargo, Júlio; Braga-Ribas, Felipe; Gomes-Júnior, Altair; Bendetti-Rossi, Gustavo; Colas, François; Decock, Alice; Doressoundiram, Alain; Dumas, Christophe; Emílio, Marcelo; Fabrega Polleri, Joaquin; Gil-Hutton, Ricardo; Gillon, Michael; Girard, Julien; Hau, George; Ivanov, Valentin; Jehin, Emmanuel; Lecacheux, Jean; Leiva, Rodrigo; Lopez-Sisterna, Cecília; Mancini, Luigi; Manfroid, Jean; Maury, Alain; Meza, Erick; Morales, Nicolas; Nagy, Leslie; Opitom, Cyrielle; Ortiz, José Luiz; Pollock, Joe; Roques, Françoise; Snodgrass, Colin; François Soulier, Jean; Thirouin, Audrey; Vanzi, Leonardo; Widemann, Thomas; Reichart, Daniel; LaCluyze, Aaron; Haislip, Joshua B.; Ivarsen, Kevin; Dominik, Martin; Jørgensen, Uffe; Skottfelt, Jesper

    2015-11-01

    We present results from two Pluto stellar occultations observed on 18 July 2012 and 04 May 2013, and monitored respectively from five and six sites in South America. Both campaigns involved large telescopes (including the 8.2-m VLT at ESO/Paranal). The high SNR ratios and multi-chord coverage provide amoung the best Pluto atmospheric profiles ever obtained from the ground.We show that a spherically symmetric, clear (no-haze) and pure N2 atmosphere with a unique temperature profile satisfactorily fits the twelve lightcurves provided by the two events. We find, however, a small but significant increase of pressure of 6% (6-sigma level) between the two dates, with values of 2.16 ± 0.2 and 2.30 ± 0.01 μbar at the reference radius 1275 km, respectively.We provide atmospheric constrains between 1190 km and 1450 km from Pluto's center, and we determine the temperature profile with accuracy of a few km in vertical scale. Our model shows a stratosphere with strong positive gradient between 1190 km (at 36 K, 11 μbar) and r =1215 km (6.0 μbar), where a temperature maximum of 110 K is reached. Above it is a mesosphere with negative thermal gradient of -0.2 K/km up to 1,390 km (0.25 μbar), at which point, the mesosphere connects itself to a more isothermal upper branch at 81 K. This profile provides (assuming no troposphere) a Pluto surface radius of 1190 ± 5 km, consistent with preliminary values obtained by New Horizons. Currently measured CO abundances are too low to explain the negative mesospheric thermal gradient. We explore the possibility of an HCN (recently detected by ALMA) cooling. This model, however, requires largely supersaturated HCN. Zonal winds and vertical compositional variations of the atmosphere are also unable to explain the observed mesospheric trend.These events are the last useful ground-based occultations recorded before the 29 June 2015 occultation observed from Australia and New Zealand, and before the NASA's New Horizons flyby of July 2015

  1. Radio Occultation Measurements of Pluto's Atmosphere with New Horizons

    NASA Astrophysics Data System (ADS)

    Hinson, David P.; Linscott, Ivan; Young, Leslie; Stern, S. Alan; Bird, Mike; Ennico, Kimberly; Gladstone, Randy; Olkin, Catherine B.; Pätzold, Martin; Strobel, Darrell F.; Summers, Michael; Tyler, G. Leonard; Weaver, Harold A.; Woods, Will; New Horizons Science Team

    2016-10-01

    The reconnaissance of the Pluto System by New Horizons in July 2015 included a radio occultation at Pluto. The observation was performed with signals transmitted simultaneously by four antennas of the NASA Deep Space Network, two at the Goldstone complex in California and two at the Canberra complex in Australia. Each antenna radiated 20 kW without modulation at a wavelength of 4.17 cm. New Horizons received the four signals with its 2.1-m high-gain antenna, where the signals were split into pairs and processed independently by two identical REX radio science instruments. Each REX relied on a different ultra-stable oscillator as its frequency reference. The signals were digitized and filtered, and the data samples were stored on the spacecraft for later transmission to Earth. Six months elapsed before all data had arrived on the ground, and the results reported here are the first to utilize the complete set of observations. Pluto's tenuous atmosphere is a significant challenge for radio occultation sounding, which led us to develop a specialized method of analysis. We began by calibrating each signal to remove effects not associated with Pluto's atmosphere, including the diffraction pattern from Pluto's surface. We reduced the noise and increased our sensitivity to the atmosphere by averaging the results from the four signals, while using other combinations of the signals to characterize the noise. We then retrieved profiles of number density, pressure, and temperature from the averaged phase profiles at both occultation entry and exit. Finally, we used a combination of analytical methods and Monte Carlo simulations to determine the accuracy of the measurements. The REX profiles provide the first direct measure of the surface pressure and temperature structure in Pluto's lower atmosphere. There are significant differences between the structure at entry (193.5°E, 17.0°S, sunset) and exit (15.7°E, 15.1°N, sunrise), which arise from spatial variations in surface

  2. Charon's Size And Orbit From Double Stellar Occultations

    NASA Astrophysics Data System (ADS)

    Sicardy, Bruno; Braga-Ribas, F.; Widemann, T.; Jehin, E.; Gillon, M.; Manfroid, J.; Ortiz, J. L.; Morales, N.; Maury, A.; Assafin, M.; Camargo, J. I. B.; Vieira Martins, R.; Dias Oliveira, A.; Ramos Gomes, A., Jr.; Vanzi, L.; Leiva, R.; Young, L. A.; Buie, M. W.; Olkin, C. B.; Young, E. F.; Howell, R. R.; French, R. G.; Bianco, F. B.; Fulton, B. J.; Lister, T. A.; Bode, H. J.; Barnard, B.; Merritt, J. C.; Shoemaker, K.; Vengel, T.; Tholen, D. J.; Hall, T.; Reitsema, H. J.; Wasserman, L. H.; Go, C.

    2012-10-01

    Stellar occultations of a same star by both Pluto and Charon (double events) yield instantaneous relative positions of the two bodies projected in the plane of the sky, at 10km-level accuracy. Assuming a given pole orientation for Charon's orbit, double events provide the satellite plutocentric distance r at a given orbital longitude L (counted from the ascending node on J2000 mean equator), and finally, constraints on its orbit. A double event observed on 22 June 2008 provides r=19,564+/-14 km at L=153.483+/-0.071 deg. (Sicardy et al. 2011), while another double event observed on 4 June 2011 yields: r=19,586+/-15 km at L = 343.211+/-0.072 deg. (all error bars at 1-sigma level). These two positions are consistent with a circular orbit for Charon, with a semi-major axis of a=19,575+\\-10 km. This can be compared to the circular orbit found by Buie et al. (2012), based on Hubble Space Telescope data, with a=19,573+/-2 km. The 4 June 2011 stellar occultation provides 3 chords across Charon, from which a radius of Rc= 602.4+/-1.6 km is derived. This value can be compared to that obtained from the 11 July 2005 occultation: Rc= 606.0+/-1.5 km (Person et al. 2006) and Rc= 603.6+/-1.4 km (Sicardy et al. 2006). A third double event, observed on 23 June 2011 is under ongoing analysis, and will be presented. Buie et al. (2012), AJ 144, 15-34 (2012) Person et al, AJ 132, 1575-1580 (2006) Sicardy et al., Nature 439, 52-54 (2006) Sicardy et al., AJ 141, 67-83 (2011) B.S. thanks ANR "Beyond Neptune II". L.A.Y. acknowledges support by NASA, New Horizons and National Geographic grants. We thank B. Barnard, M.J. Brucker, J. Daily, C. Erikson, W. Fukunaga, C. Harlinten, C. Livermore, C. Nance, J.R. Regester, L. Salas, P. Tamblyn, R. Westhoff for help in the observations.

  3. Central Flash Analysis of the 29 June 2015 Occultation

    NASA Astrophysics Data System (ADS)

    Person, Michael J.; Bosh, A. S.; Sickafoose, A. A.; Zuluaga, C. A.; Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham, E. W.; McLean, I.; Wolf, J.; Abe, F.; Becklin, E.; Bida, T. A.; Bright, L. P.; Brothers, T. C.; 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. E.; Lucas, R.; Mathers, S.; Morley, C. J. K.; Natusch, T.; Nelson, P.; Ngan, H.; Pfueller, E.; Roeser, H.-P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.; Stockdale, C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristram, P. J.; Van Cleeve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.; Wiedemann, M.

    2015-11-01

    After an extensive prediction effort, the 29 June 2015 occultation by Pluto was observed from both airborne (Stratospheric Observatory for Infrared Astronomy - SOFIA) and numerous ground-based telescopes (Bosh et al. - this meeting). Real-time prediction updates allowed placement of the SOFIA telescope with its four detectors deep within the central-flash region of the atmospheric occultation. Fortuitously, the Mount John University Observatory (Lake Tekapo, New Zealand) was also within the central-flash region (Pasachoff et al. - this meeting). This happenstance resulted in multiple central-flash detections in several colors from each facility allowing direct comparison of different areas of the central-flash evolute.Here we examine and discuss the central-flash signatures from the highest signal-to-noise light curves from each facility. The relative orientations and asymmetries in the central flashes allow us to use them to tightly constrain the lower atmospheric ellipticity and orientation of likely winds with respect to Pluto’s figure. The ratio of the two separate central flashes is also a strong constraint on the geometric solution for the full occultation data set, and the absolute height of the central flashes with respect to those expected for a clear isothermal atmosphere places constraints on haze densities and thermal gradients in Pluto’s lower atmosphere. We can also compare the central-flash signatures in several colors (similar to Sickafoose et. al - this meeting) to establish bounds on haze-particle sizes in the lower atmosphere.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, in part, by NASA grants SSO NNX15AJ82G (Lowell Observatory), PA NNX10AB27G (MIT), and PA NNX12AJ29G (Williams College), as well as the National Research Foundation of

  4. On material fracture criteria

    NASA Astrophysics Data System (ADS)

    Kremnev, L. S.

    2017-01-01

    Based on the nonlinear mechanics of material fracture, a model of the fracture of materials with actual (discrete) structures has been constructed. The model is supported by proofs that crack resistance K 1 c and fracture toughness G 1 c obtained from the energy conservation law without using the assumptions adopted in the linear material fracture mechanics serve as the force and energy criteria in the nonlinear fracture mechanics. It has been shown that energy criterion G 1 c in the nonlinear mechanics is much greater than G 1 c in the linear fracture mechanics.

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

    SciTech Connect

    Chaudhuri, T.K.; Brantly, M.

    1984-04-01

    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.

  6. Resolving dynamic parameters of the August 2007 Titania and Ariel occultations by Umbriel

    NASA Astrophysics Data System (ADS)

    Miller, C.; Chanover, N. J.

    2009-03-01

    We observed the 15 August 2007 occultation of the uranian satellite Titania and the 19 August 2007 occultation of Ariel by Umbriel using the Agile high-speed photometer on the APO 3.5 m telescope. We find that the Titania event midpoint occurred at 09:16:39.20 UT and the Ariel event midpoint at 07:59:49.4 UT, which was 26.2 s and 37.4 s later than predicted, respectively. Our best fit impact parameter was 71.0 km for the Titania occultation and 476.9 km for the Ariel event, both of which were less than predicted.

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

    NASA Astrophysics Data System (ADS)

    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

  8. HITRAN spectroscopy evaluation using solar occultation FTIR spectra

    NASA Astrophysics Data System (ADS)

    Toon, Geoffrey C.; Blavier, Jean-Francois; Sung, Keeyoon; Rothman, Laurence S.; E. Gordon, Iouli

    2016-10-01

    High resolution FTIR solar occultation spectra, acquired by the JPL MkIV Fourier transform spectrometer from balloon, covering 650-5650 cm-1 at 0.01 cm-1 resolution, are systematically analyzed using the last four versions of the HITRAN linelist (2000, 2004, 2008, 2012). The rms spectral fitting residuals are used to assess the quality and adequacy of the linelists as a function of wavenumber and altitude. Although there have been substantial overall improvements with each successive version of HITRAN, there are nevertheless a few spectral regions where the latest HITRAN version (2012) has regressed, or produces residuals that far exceed the noise level. A few of these instances are investigated further and their causes identified. We emphasize that fitting atmospheric spectra, in addition to laboratory spectra, should be part of the quality assurance for any new linelist before public release.

  9. Occult pulmonary embolism: a common occurrence in deep venous thrombosis

    SciTech Connect

    Dorfman, G.S.; Cronan, J.J.; Tupper, T.B.; Messersmith, R.N.; Denny, D.F.; Lee, C.H.

    1987-02-01

    Ventilation-perfusion scans were used in a prospective study to determine the prevalence of occult pulmonary embolus in proven deep venous thrombosis. Fifty-eight patients without symptoms of pulmonary embolism, but with venographically proven deep venous thrombosis, were subjected to chest radiographs, /sup 99m/Tc macroaggregated-albumin perfusion scans, and /sup 133/Xe ventilation scans. Of the 49 patients with deep venous thrombosis proximal to the calf veins, 17 (35%) had high-probability scans. Of all 58 patients, only 12 (21%) had normal scans. When the study population was compared with a group of 430 patients described in reports of pulmonary perfusion in asymptomatic persons, a significantly higher percentage of high-probability scans was found in the study population with deep venous thrombosis. Baseline ventilation-perfusion lung scanning is valuable for patients with proven above-knee deep venous thrombosis.

  10. Radio occultation constellation deployment via impulses along the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Michael Yu.; Trofimov, Sergey P.; Chang, Hao-Chi

    2013-01-01

    The problem of radio occultation (RO) constellation deployment is examined. Of particular interest here is to study the feasibility of using passively stabilized small satellites. We consider a pair of satellites supplied with a passive magnetic attitude control system. The capsule containing two satellites is launched into a parking orbit and stabilized along the geomagnetic field direction. Then the satellites are pushed apart by a separation spring at some point of orbit. If necessary for braking, one or two thrusters may be placed along the stabilized axis of each satellite. Optimization of the separation point and velocity along with the ΔV required for possible braking thrust is carried out in accordance with some specific demands of RO missions. Atmospheric drag and Earth oblateness are taken into account as perturbations. It is shown that, depending on a mission scenario, the separation with either one braking thrust or no thrusts at all is preferable.

  11. Genetic variation of occult hepatitis B virus infection

    PubMed Central

    Zhu, Hui-Lan; Li, Xu; Li, Jun; Zhang, Zhen-Hua

    2016-01-01

    Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare. PMID:27053845

  12. The 1973 solar occultation of the Crab Nebula pulsar

    NASA Technical Reports Server (NTRS)

    Weisberg, J. M.

    1975-01-01

    The mean electron density of the solar corona was determined by measuring the dispersion of radiofrequency pulses from pulsar NP 0532 during the June 1973 solar occultation. Trends continued which were noticed in 1971 as solar activity declined. Model fitting results suggest that the corona continued to become even more concentrated toward the equator in 1973 than in 1971. The number density of electrons in most regions decreased. The best model of the distribution of corona electrons is suggested to be one with zero density at the poles. K-corona isophotes and contours of equal path-integrated density are presented for several models. Electron density versus date and position in the corona are tabulated. It is seen that there is no simple relationship between the onset of major solar activity and density or scattering enhancements.

  13. Signal analysis and radioholographic methods for airborne radio occultations

    NASA Astrophysics Data System (ADS)

    Wang, Kuo-Nung

    Global Positioning System (GPS) radio occultation (RO) is an atmospheric sounding technique utilizing the change in propagation direction and delay of the GPS signal to measure refractivity, which provides information on temperature and humidity. The GPS-RO technique is now operational on several Low Earth Orbiting (LEO) satellite missions. Nevertheless, when observing localized transient events, such as tropical storms, current LEO satellite systems cannot provide sufficiently high temporal and spatial resolution soundings. An airborne RO (ARO) system has therefore been developed for localized GPS-RO campaigns. The open-loop (OL) tracking in post-processing is used to cross-correlates the received Global Navigation Satellite System (GNSS) signal with an internally generated local carrier signal predicted from a Doppler model and extract the atmospheric refractivity information. OL tracking also allows robust processing of rising GPS signals using backward tracking, which will double the observed occultation event numbers. RO signals in the lower troposphere are adversely affected by rapid phase accelerations and severe signal power fading, however. The negative bias caused by low signal-to-noise ratio (SNR) and multipath ray propagation limits the depth of tracking in the atmosphere. Therefore, we developed a model relating the SNR to the variance in the residual phase of the observed signal produced from OL tracking, and its applicability to airborne data is demonstrated. We then apply this model to set a threshold on refractivity retrieval, based upon the cumulative unwrapping error bias, to determine the altitude limit for reliable signal tracking. To enhance the SNR and decrease the unwrapping error rate, the CIRA-Q climatological model and signal residual phase pre-filtering are utilized to process the ARO residual phase. This more accurately modeled phase and less noisy received signal are shown to greatly reduce the bias caused by unwrapping error at lower

  14. Clinical significance of occult hepatitis B virus infection.

    PubMed

    Romero, Miriam; Madejón, Antonio; Fernández-Rodríguez, Conrado; García-Samaniego, Javier

    2011-03-28

    Occult hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in serum) for individuals testing HBV surface antigen negative. Until recently, the clinical effect of OBI was unclear on the progression of liver disease; on the development of hepatocellular carcinoma; and on the risk for reactivation or transmission of HBV infection. Several studies suggest a high prevalence of OBI among patients with cryptogenic chronic liver disease, but its role in the progression to cirrhosis remains unclear. Although OBI has been well documented in human immunodeficiency virus (HIV)-positive patients, especially among those coinfected with hepatitis C virus, further studies are needed to determine its current clinical impact in HIV setting.

  15. Sun sensor boresight alignment testing for the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Moore, A. S.; Laney, V. S.; Mauldin, L. E., III

    1987-01-01

    The boresight alignment testing for the sun sensor assembly on the Halogen Occultation Experiment (HALOE) is described. The sun sensor assembly consists of three sensors that provide feedback signals for controlling dual axes gimbals. Two energy balancing silicon detectors are operated as wideband sensors in the azimuth and elevation axes. The third sensor is a silicon photodiode array operated as a narrow-band sensor in the elevation axis. These sensors are mounted on a common Invar structure which is mounted to the HALOE telescope. A blackbody was used as the stimulating source to perform the initial boresight alignment and this was checked with a heliostat solar look and a direct solar look. These tests are explained with a comparison between each source used.

  16. An overview of the halogen occultation experiment (HALOE)

    NASA Technical Reports Server (NTRS)

    Russell, James M., III

    1991-01-01

    The HALOE experiment will fly on the Upper Atmosphere Research Satellite (UARS) in the last quarter of 1991. The experiment uses the solar occultation limb sounding approach, in combination with gas filter and broadband radiometry to provide measurements of temperature profiles and key gases in the ClO(y), NO(y), and HO(y) chemical families of the middle atmosphere. The instrument has been characterized in great detail to determine gains, spectral response, noise, crosstalk, field-of-view, and thermal drift characteristics. A final end-to-end test using a gas cell to simulate the atmosphere demonstrated measurement repeatability to about 1 percent and agreement between measured and calculated signals to within about 1 percent to 3 percent. This latter agreement provides confidence in knowledge of both the hardware as well as the software.

  17. A rare case of occult splenic rupture after left pneumonectomy

    PubMed Central

    Acharya, Metesh N.; George, Robert S; Loubani, Mahmoud

    2016-01-01

    Cardiopulmonary resuscitation (CPR) techniques are now well-established and play a crucial role in improving survival in cardiac arrest. Recognized complications associated with CPR include injury to the upper abdominal viscera, including the liver, stomach and spleen. We present a rare case of occult splenic rupture following cardiac arrest in a 63-year-old male immediately after left pneumonectomy. We discuss potential mechanisms predisposing the spleen to injury in this case, and highlight the difficulty of promptly identifying such a traumatic injury within the confines of a cardiac arrest scenario. Clinicians should be aware that anatomical changes following thoracic surgery may render the intra-abdominal viscera at increased risk of injury following CPR. PMID:27190201

  18. Cloud identification in atmospheric trace molecule spectroscopy infrared occultation measurements.

    PubMed

    Kahn, Brian H; Eldering, Annmarie; Irion, Fredrick W; Mills, Franklin P; Sen, Bhaswar; Gunson, Michael R

    2002-05-20

    High-resolution infrared nongas absorption spectra derived from the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment are analyzed for evidence of the presence of cirrus clouds. Several nonspherical ice extinction models based on realistic size distributions and crystal habits along with a stratospheric sulfate aerosol model are fit to the spectra, and comparisons are made with different model combinations. Nonspherical ice models often fit observed transmission spectra better than a spherical Mie ice model, and some discrimination among nonspherical models is noted. The ATMOS lines of sight for eight occultations are superimposed on coincident geostationary satellite infrared imagery, and brightness temperatures along the lines of sight are compared with retrieved vertical temperature profiles. With these comparisons, studies of two cases of clear sky, three cases of opaque cirrus, and three cases of patchy cirrus are discussed.

  19. Glioma coexisting with angiographically occult cerebrovascular malformation: A case report

    PubMed Central

    Chen, Junhui; Chen, Lei; Zhang, Chunlei; He, Jianqing; Li, Peipei; Zhou, Jingxu; Zhu, Jun; Wang, Yuhai

    2016-01-01

    Angiographically occult cerebrovascular malformation (AOVM) is a type of complex cerebrovascular malformation that is not visible on digital subtraction angiography (DSA). Vascular malformation coexisting with glioma is clinically rare, and glioma coexisting with AOVM is even more rare. To the best of our knowledge, the present study is the first to report glioma coexisting with AOVM in the literature. The present study reports a rare case of glioma coexisting with AOVM in a 30-year-old male patient. Computed tomography (CT) scan revealed calcification, hemorrhage and edema in the right frontal lobe. CT angiography revealed a vascular malformation in the right frontal lobe, which was not observed on DSA. Finally, glioma coexisting with AOVM was confirmed by 2.0T magnetic resonance imaging and postoperative pathological examination. The present patient had a positive outcome and no neurological dysfunctions during the 6-month follow-up subsequent to surgery. PMID:27698825

  20. Clinicopathologic correlations and significance of clinically occult mammary lesions.

    PubMed

    Schwartz, G F; Feig, S A; Patchefsky, A S

    1978-03-01

    Experience with 189 clinically occult, i.e., nonpalpable breast lesions is presented. The described technique of localization and excision all but guarantees removal of even the smallest radiographically suspicious findings with an inconspicuous incision and minimal breast deformity. The incidence of carcinoma encountered in these 189 biopsies is 27.5%. Axillary node metastases were present in less than 25% of the invasive nonpalpable cancers, approximately half of what might have been expected if the lesions had been discovered in the usual manner. There were no patients with axillary node metastases among those with in situ ductal or microinvasive ductal carcinomas. This implies a better prognosis and lower death rate from breast cancer in these patients. Screening programs employing mammography, designed to detect breast cancers in this pre-palpable stage, are encountered as a means of uncovering a higher proportion of such cancers at an earlier stage in their natural histories.

  1. Data inversion algorithm development for the hologen occultation experiment

    NASA Technical Reports Server (NTRS)

    Gordley, Larry L.; Mlynczak, Martin G.

    1986-01-01

    The successful retrieval of atmospheric parameters from radiometric measurement requires not only the ability to do ideal radiometric calculations, but also a detailed understanding of instrument characteristics. Therefore a considerable amount of time was spent in instrument characterization in the form of test data analysis and mathematical formulation. Analyses of solar-to-reference interference (electrical cross-talk), detector nonuniformity, instrument balance error, electronic filter time-constants and noise character were conducted. A second area of effort was the development of techniques for the ideal radiometric calculations required for the Halogen Occultation Experiment (HALOE) data reduction. The computer code for these calculations must be extremely complex and fast. A scheme for meeting these requirements was defined and the algorithms needed form implementation are currently under development. A third area of work included consulting on the implementation of the Emissivity Growth Approximation (EGA) method of absorption calculation into a HALOE broadband radiometer channel retrieval algorithm.

  2. Exploring overstabilities in Saturn's a ring using two stellar occultations

    SciTech Connect

    Hedman, M. M.; Nicholson, P. D.; Salo, H.

    2014-07-01

    Certain regions of Saturn's rings exhibit periodic opacity variations with characteristic radial wavelengths of up to a few hundred meters that have been attributed to viscous overstabilities. The Visual and Infrared Mapping Spectrometer on board the Cassini spacecraft observed two stellar occultations of the star γ Crucis that had sufficient resolution to discern a subset of these periodic patterns in a portion of the A ring between 124,000 and 125,000 km from Saturn's center. These data reveal that the wavelengths and intensities of the patterns vary systematically across this region, but that these parameters are not strictly determined by the ring's average optical depth. Furthermore, our observations indicate that these opacity variations have an azimuthal coherence scale of around 3000 km.

  3. Occultation determination of Neptune's oblateness and stratospheric methane mixing ratio

    NASA Technical Reports Server (NTRS)

    Lellouch, E.; Hubbard, W. B.; Sicardy, B.; Vilas, F.; Bouchet, P.

    1986-01-01

    The occultation of a star by Neptune on August 20, 1985 was observed at 2.2 micron wavelength with telescopes at the European Southern Observatory (ESO) and the Cerro Tololo Inter-American Observatory (CTIO). The detection of a 'central flash' midway between immersion and emersion has allowed the determination of Neptune's oblateness and the atmospheric extinction at 2.2 microns, which is related to the stratospheric methane mixing ratio. An oblateness of (2.08 +0.19 or -0.18) x 10 to the 2nd is found and, assuming a stratospheric temperature of 120 K, a value of 0.6 percent is inferred (with an uncertainty of a factor of 10) for the methane mixing ratio (CH4/H2) at 0.3 mbar. The latter value may indicate supersaturation of methane in Neptune's stratosphere.

  4. Observing the moist troposphere with radio occultation signals from COSMIC

    NASA Astrophysics Data System (ADS)

    Sokolovskiy, S. V.; Rocken, C.; Lenschow, D. H.; Kuo, Y.-H.; Anthes, R. A.; Schreiner, W. S.; Hunt, D. C.

    2007-09-01

    New approaches for observing the moist troposphere using radio occultation (RO) signals transformed to impact parameter representation by radio-holographic (RH) methods are presented. Large changes in the RH bending angle are used as indicators of significant vertical refractivity gradients that often occur on top of the atmospheric boundary layer (ABL), convective cloud layers such as the trade-wind inversion, and other moist layers in the free troposphere. RH amplitude fluctuations are used as an indicator of turbulence in the moist troposphere. The approaches are demonstrated using RO data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) mission from September 2006. The global distributions of the ABL depths and tops of moist convective layers derived from COSMIC RO data correspond generally to the observed locations and structures of the Intertropical Convergence Zone and adjacent sub-tropical regions. The approaches are suitable for investigations of the temporal and spatial ABL variability.

  5. Radio Occultation Studies of Venus' Atmosphere with Magellan

    NASA Technical Reports Server (NTRS)

    Jenkins, Jon M.

    1998-01-01

    We have been conducting a systematic study of the middle and lower atmosphere of Venus through analysis of 20 radio occultation experiments conducted with the Magellan spacecraft between October, 1991, and August, 1994. These studies have revealed a rich but sparsely sampled trove of information regarding the structure, composition and dynamics of the Venus atmosphere. The five sets of experiments sampled a variety of latitudes. Basic results include vertical profiles of: (1) electron density in the ionosphere, (2) pressure, temperature, density, and static stability in the neutral atmosphere (from 33 km to 98 km), and (3) sulfuric acid vapor (H2SO4) abundance below the main cloud deck. Further analysis of the temperature profiles led to the discovery of small vertical-scale gravity waves in the neutral atmosphere. The retrieved profiles show intriguing zonal variations that might be due to planetary- scale waves. During the performance period of this grant, we have concentrated on reanalyzing the 15 experiments conducted in 1994 using improved trajectory files for Magellan provided by JPL, obtaining more reliable results, and on conducting an error analysis of the derived profiles. In addition, we have begun an analysis of microwave emission maps of Venus obtained at the Very Large Array (VLA) in April, 1996. This report is organized as follows: A summary of results is presented, giving representative examples of the various physical profiles retrieved from all the Magellan radio occultation studies, emphasizing latitudinal variations evident in the data. Next, a preliminary analysis of the VLA maps is given. A summary of activities follows the scientific results, detailing papers published and presented at various conferences. This report concludes with a "Conclusions and Suggestions for Future Work" section.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Lessons from Thirty Years of Solar Occultation Measurements

    NASA Astrophysics Data System (ADS)

    Thomason, L.; McCormick, M. P.; Zawodny, J. M.; Burton, S.

    Solar occultation measurements from space began with the launch of the Stratospheric Aerosol Measurement (SAM) aboard the Apollo Soyuz in 1975 and SAM II aboard Nimbus 7 in 1978. These instruments have been followed by a number of instrument using the solar occultation method including most notably the nearly 20-year mission of the Stratospheric Aerosol and Gas Experiment (SAGE II) launched aboard the Earth Radiation Budget Satellite in 1984 and continues to function to the present time. In this presentation, we will focus on the SAGE series of instruments including the recent SAGE III that has been in operation since 2002 and highlight some of the notable accomplishments of these missions. These include influential work in the describing the morphology of polar stratospheric cloud occurrences, ozone trends, and the effects of volcanic eruptions on stratospheric aerosol loading and its concomitant effect on chemistry and climate. We will also discuss evolutionary understanding of the handling of data from these instruments including developments that have lead to the recent series of releases of the SAGE II data set (6.0 through 6.2) and have provoked the need to reprocess archived data sets like SAM II and SAGE I. The new versions have been based on improved techniques for handling spacecraft ephemeris, more robust transmission algorithms, and learning how to deal with issues that arise when instruments far outlive their design lifetimes. We also discuss on going research that promises to significantly improve the current data sets including techniques to account for in-atmosphere changes of exo-atmospheric normalization data.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Cassini RSS occultation observations of density waves in Saturn's rings

    NASA Astrophysics Data System (ADS)

    McGhee, C. A.; French, R. G.; Marouf, E. A.; Rappaport, N. J.; Schinder, P. J.; Anabtawi, A.; Asmar, S.; Barbinis, E.; Fleischman, D.; Goltz, G.; Johnston, D.; Rochblatt, D.

    2005-08-01

    On May 3, 2005, the first of a series of eight nearly diametric occultations by Saturn's rings and atmosphere took place, observed by the Cassini Radio Science (RSS) team. Simultaneous high SNR measurements at the Deep Space Network (DSN) at S, X, and Ka bands (λ = 13, 3.6, and 0.9 cm) have provided a remarkably detailed look at the radial structure and particle scattering behavior of the rings. By virtue of the relatively large ring opening angle (B=-23.6o), the slant path optical depth of the rings was much lower than during the Voyager epoch (B=5.9o), making it possible to detect many density waves and other ring features in the Cassini RSS data that were lost in the noise in the Voyager RSS experiment. Ultimately, diffraction correction of the ring optical depth profiles will yield radial resolution as small as tens of meters for the highest SNR data. At Ka band, the Fresnel scale is only 1--1.5 km, and thus even without diffraction correction, the ring profiles show a stunning array of density waves. The A ring is replete with dozens of Pandora and Prometheus inner Lindblad resonance features, and the Janus 2:1 density wave in the B ring is revealed with exceptional clarity for the first time at radio wavelengths. Weaker waves are abundant as well, and multiple occultation chords sample a variety of wave phases. We estimate the surface mass density of the rings from linear density wave models of the weaker waves. For stronger waves, non-linear models are required, providing more accurate estimates of the wave dispersion relation, the ring surface mass density, and the angular momentum exchange between the rings and satellite. We thank the DSN staff for their superb support of these complex observations.

  10. Lidar and Occultation Remote Sensing Applied to Atmospheric Measurements

    NASA Astrophysics Data System (ADS)

    McCormick, M. P.

    2008-05-01

    The use of lidar began in the early 1960s soon after a laboratory laser was shown to Q-switch and emit short pulses of light. The lidar technique makes measurements typically through backscattering, fluorescence, attenuation and absorption, and has become more and more sophisticated over the years, being used at ground stations and aboard airplanes and spacecraft. Routine measurements of aerosols, clouds, ozone, and atmospheric constituents like wind speeds and direction are being made. The passive technique of solar, lunar and stellar occultation has been used aboard balloons, aircraft and spacecraft also beginning in the 1960s, and since 1975, aboard spacecraft. It is a technique that, like lidar, is capable of vertical profiling, and has produced global measurements of stratospheric aerosols and ozone on a routine basis since about 1978. This talk will present a walk through the history of the author's involvement in the development of and measurements using these two techniques. Record-setting data sets on stratospheric aerosols from a ground-based lidar and satellite measurements of global aerosols and ozone (SAM~II and SAGE series) will be presented. The naming and characterization of Polar Stratospheric Clouds will be described in the context of the ozone hole. Aircraft lidar campaigns to study the impact of volcanic aerosols will be described, as well as the use of airborne lidar to validate satellite occultation measurements. Finally, the proof-of-principle LITE Space Shuttle lidar experiment and the long duration unmanned CALIPSO lidar mission presently in orbit will be discussed along with example results. A look-back at these contributions will be followed by a look into the future.

  11. Staging and treatment of clinically occult breast cancer.

    PubMed

    Schwartz, G F; Feig, S A; Rosenberg, A L; Patchefsky, A S; Schwartz, A B

    1984-03-15

    Five hundred fifty-seven biopsies were performed for clinically occult mammary lesions, detected by mammography as clustered calcifications or nonpalpable masses within the breast. One hundred seventy-five cancers were demonstrated within this group, including 106 invasive carcinomas, 10 microinvasive carcinomas, 45 in situ ductal carcinomas, and 14 lobular carcinomas in situ (lobular neoplasia). No patient with in situ or microinvasive carcinoma had evidence of axillary node metastases in 33 specimens studied. However, a disturbingly high proportion of those patients with invasive carcinomas, approximately 35%, had histologically confirmed axillary node metastases, despite the small size of the primary tumors. These observations suggest that the use of the term "minimal" cancer is misleading when applied to invasive carcinoma. Staging systems for breast cancer have been imprecise when referring to nonpalpable lesions. Cancers detected as clustered calcifications only or as areas of parenchymal distortion without an accompanying mass are properly considered as T-0 cancers, with a suggested T-0(m) to indicate that the lesion was detected by mammography. However, when the mammogram indicates the presence of a mass that proves to be malignant, although the clinical examination may have been negative, the cancer should be staged according to the size of the mass on the mammogram, with the notation that it was detected by mammography, e.g., T-1(m), T-2(m), etc. The incidence of axillary node metastases even in these so-called occult cancers is significant, so that recommendations for treatment for any invasive cancer, regardless of its size, must take these observations into account. Similarly, the incidence of multifocal sites of cancer within the breast, even in the noninvasive cancers encountered, must be remembered when treatment is suggested.

  12. Progressive multifocal leukoencephalopathy in individuals with minimal or occult immunosuppression

    PubMed Central

    Gheuens, Sarah; Pierone, Gerald; Peeters, Patrick; Koralnik, Igor J.

    2010-01-01

    Background Progressive multifocal leukoencephalopathy (PML) is a deadly demyelinating disease of the brain, caused by reactivation of the polyomavirus JC (JCV). PML has classically been described in individuals with profound cellular immunosuppression such as patients with AIDS, hematological malignancies, organ transplant recipients or those treated with immunosuppressive or immunomodulatory medications for autoimmune diseases. Methods and case reports We describe five HIV seronegative patients with minimal or occult immunosuppression who developed PML including two patients with alcoholic cirrhosis, one with untreated dermatomyositis, and two with idiopathic CD4+ T cell lymphocytopenia. We performed a review of the literature to find similar cases. Results We found an additional 33 cases in the literature. Of a total of 38 cases, seven (18.4%) had hepatic cirrhosis, five (13.2%) had renal failure, including one with concomitant hepatic cirrhosis, two (5.2%) were pregnant women, two (5.2%) had concomitant dementia, one (2.6%) had dermatomyositis and 22 (57.9%) had no specific underlying diagnosis. Among these 22, five (22.7%) had low CD4+ T cell counts (0.080–0.294×109/L) and were diagnosed with idiopathic CD4+ lymphocytopenia, and one had borderline CD4+ T cell count of 0.308×109/L. The outcome was fatal in 27/38 (71.1%) cases within 1.5–120 months (median 8 months) from onset of symptoms, and 3/4 cases who harbored JCV-specific T cells in their peripheral blood had inactive disease with stable neurological deficits after 6–26 months of follow up. Discussion These results indicate that PML can occur in patients with minimal or occult immunosuppression and invite us to revisit the generally accepted notion that profound cellular immunosuppression is a prerequisite for the development of PML. PMID:19828476

  13. Chariklo's size, shape and orientation from stellar occultations

    NASA Astrophysics Data System (ADS)

    Bérard, Diane; Sicardy, Bruno; Assafin, Marcelo; Braga-Ribas, Felipe; Camargo, Julio; Vieira Martins, Roberto; Duffard, Rene; Ortiz, Jose Luis; Snodgrass, Colin; Jehin, Emmanuel; Pollock, Joe; Colas, François; Dauvergne, Jean Luc; Lecacheux, Jean; Maquet, Lucie; Sickafoose, Amanda A.; Bath, Karl Ludwig; Beisker, Wolfgang; Leiva, Rodrigo

    2015-11-01

    Chariklo is the largest Centaur object known to date, and it is surrounded by dense and narrow rings (Braga-Ribas et al. Nature 508, 72, 2014). The size, shape and orientation of the central body are important parameters to better understand the dynamics of the rings.In that context, we have analyzed three stellar occultations by Chariklo and its main ring observed on June 3, 2013, April 29, 2014 and June 28, 2014. Elliptical limb fitting to Chariklo’s main body occultation chords has been performed, where we denote a (resp. b) the semi-major (resp. semi-minor) axis of the limb. Preliminary results indicate that Chariklo’s limb is elliptical with axes ratio b/a~0.89. We obtain a~133 km and b~119 km, providing an equivalent radius of Requiv=√(ab)~126 km. The rms dispersion of the fit, about 4 km, is compatible with local topographic features on a small icy body. For comparison, an equivalent radius of Requiv= 119±5 km, based on thermal data, is given by Fornasier et al, AA 518, L11, 2014, while Duffard et al. AA 568, A79, 2014 estimate a= 122 km and b= 117 km.Our results are obtained under the simplifying assumption that the main ring is circular and that its center coincides with that of Chariklo. Caveats and error bars will be discussed, and dynamical implications will be presented. In particular, rough estimations of the ring apsidal precession rates will be given, as well as constraints on Chariklo's density.

  14. Unilateral retinopathy secondary to occult primary intraocular lymphoma

    PubMed Central

    Barile, Gaetano R.; Hood, Donald C.; Marr, Brian; Hussein, Shafinaz; Tsang, Stephen H.

    2014-01-01

    Purpose The purpose of the study is to report the clinical case of a 53-year-old woman whose presenting manifestation of primary intraocular lymphoma (PIOL) was unilateral retinal degeneration. Method A case report was created with review of clinical, imaging, electrophysiologic, and pathological investigations. Results A 53-year-old woman with a distant history of ocular herpes simplex developed progressive central visual loss and intermittent photopsia over 4 years in her right eye. Ophthalmic examination revealed reduced visual acuity OD, central scotoma, and minimal ocular findings. Autofluorescence and infrared imaging revealed mild reflectance changes in the temporal macula, and spectral-domain optical coherence tomography identified mild disruptions of inner segment/outer segment junctions in the subfoveal region of the right eye. A mild window defect was seen on fluorescein angiography. Electrophysiology with multifocal electroretinogram (ERG) revealed evidence of unilateral macular dysfunction. Full-field ERGs revealed progressive global retinal dysfunction over 6 months, with unilateral decreases in amplitude and implicit time shifts, as seen in cases of autoimmune retinopathies. The eye eventually exhibited mild vitreous cellular infiltration on ophthalmoscopic examination, and vitrectomy diagnosed B cell non-Hodgkin’s lymphoma. Further evaluation revealed no evidence of central nervous system or systemic disease, consistent with occult PIOL. Conclusions This case illustrates an atypical presentation of PIOL characterized by unilateral retinal disease presenting with symptoms and signs of macular dysfunction. Clinical and ERG features evolved into an acute zonal occult outer retinopathy (AZOOR)-like phenotype. PIOL should be considered in atypical cases of AZOOR with vitreal reactions, and some cases of AZOOR may be related to B cell lymphocyte disorders. PMID:24081663

  15. Fractures in anisotropic media

    NASA Astrophysics Data System (ADS)

    Shao, Siyi

    Rocks may be composed of layers and contain fracture sets that cause the hydraulic, mechanical and seismic properties of a rock to be anisotropic. Coexisting fractures and layers in rock give rise to competing mechanisms of anisotropy. For example: (1) at low fracture stiffness, apparent shear-wave anisotropy induced by matrix layering can be masked or enhanced by the presence of a fracture, depending on the fracture orientation with respect to layering, and (2) compressional-wave guided modes generated by parallel fractures can also mask the presence of matrix layerings for particular fracture orientations and fracture specific stiffness. This report focuses on two anisotropic sources that are widely encountered in rock engineering: fractures (mechanical discontinuity) and matrix layering (impedance discontinuity), by investigating: (1) matrix property characterization, i.e., to determine elastic constants in anisotropic solids, (2) interface wave behavior in single-fractured anisotropic media, (3) compressional wave guided modes in parallel-fractured anisotropic media (single fracture orientation) and (4) the elastic response of orthogonal fracture networks. Elastic constants of a medium are required to understand and quantify wave propagation in anisotropic media but are affected by fractures and matrix properties. Experimental observations and analytical analysis demonstrate that behaviors of both fracture interface waves and compressional-wave guided modes for fractures in anisotropic media, are affected by fracture specific stiffness (controlled by external stresses), signal frequency and relative orientation between layerings in the matrix and fractures. A fractured layered medium exhibits: (1) fracture-dominated anisotropy when the fractures are weakly coupled; (2) isotropic behavior when fractures delay waves that are usually fast in a layered medium; and (3) matrix-dominated anisotropy when the fractures are closed and no longer delay the signal. The

  16. Metatarsal stress fractures - aftercare

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000553.htm Metatarsal stress fractures - aftercare To use the sharing features on ... that connect your ankle to your toes. A stress fracture is a break in the bone that ...

  17. Infant skull fracture (image)

    MedlinePlus

    Skull fractures may occur with head injuries. Although the skull is both tough and resilient and provides excellent ... or blow can result in fracture of the skull and may be accompanied by injury to the ...

  18. Rib fracture - aftercare

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000539.htm Rib fracture - aftercare To use the sharing features on this page, please enable JavaScript. A rib fracture is a crack or break in one or ...

  19. Forearm Fractures in Children

    MedlinePlus

    .org Forearm Fractures in Children The forearm is the part of the arm between the wrist and the elbow. It is ... two bones: the radius and the ulna. Forearm fractures are common in childhood, accounting for more than ...

  20. Pediatric Thighbone (Femur) Fracture

    MedlinePlus

    .org Thighbone (Femur) Fractures In Children Page ( 1 ) The thighbone (femur) is the largest and strongest bone in the body. It can break ... Cause Statistics The most common cause of thighbone fractures in infants under 1 year old is child ...

  1. Nasal fracture (image)

    MedlinePlus

    A nasal fracture is a break in the bone over the ridge of the nose. It usually results from a blunt ... and is one of the most common facial fracture. Symptoms of a broken nose include pain, blood ...

  2. Bone fracture repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100077.htm Bone fracture repair - series—Indications To use the sharing features ... Go to slide 4 out of 4 Overview Fractures of the bones are classified in a number ...

  3. Femur fracture repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000166.htm Femur fracture repair - discharge To use the sharing features on this page, please enable JavaScript. You had a fracture (break) in the femur in your leg. It ...

  4. Lisfranc (Midfoot) Fractures

    MedlinePlus

    ... that disrupts multiple different joints and includes multiple fractures. Lisfranc injuries tend to damage the cartilage of ... include ligament strains and tears, as well as fractures and dislocations of bone (far right). (Le ) This ...

  5. Growth Plate Fractures

    MedlinePlus

    .org Growth Plate Fractures Page ( 1 ) The bones of children and adults share many of the same risks for injury. But because they ... to a unique injury called a growth plate fracture. Growth plates are areas of cartilage located near ...

  6. Hip fracture surgery

    MedlinePlus

    ... neck fracture repair; Trochanteric fracture repair; Hip pinning surgery; Osteoarthritis-hip ... You may receive general anesthesia before this surgery. This means ... spinal anesthesia. With this kind of anesthesia, medicine is ...

  7. Orbital fractures: a review

    PubMed Central

    Joseph, Jeffrey M; Glavas, Ioannis P

    2011-01-01

    This review of orbital fractures has three goals: 1) to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2) to explain how to assess and examine a patient after periorbital trauma, and 3) to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training. PMID:21339801

  8. Aspergilloma in a patient with an occult congenital pulmonary airway malformation.

    PubMed

    Yonker, Lael M; Mark, Eugene J; Canapari, Craig A

    2012-03-01

    We describe the case of a 14-year-old male who presented with a right upper lobe aspergilloma forming in a previously occult congenital pulmonary airway malformation. This is the first case describing an aspergilloma forming within a CPAM.

  9. The diameter of Juno from its occultation of AG + 0 deg 1022

    NASA Technical Reports Server (NTRS)

    Millis, R. L.; Wasserman, L. H.; Bowell, E.; Franz, O. G.; White, N. M.; Lockwood, G. W.; Nye, R.; Bertram, R.; Klemola, A.; Dunham, E.; Morrison, D.

    1981-01-01

    The occultation on Dec. 11, 1979, of AG + 0 deg 1022 by Juno was observed photoelectrically from 15 sites distributed across the occultation track. The observations are well represented by a mean elliptical limb profile having semimajor and semiminor axes of 145.2 + or 0.8 and 122.8 + or - 1.9 km, respectively. The corresponding effective diameter of Juno is 267 + or - 5 km, where the uncertainty has been conservatively increased to reflect the presence of limb irregularities clearly seen in the observations. Published radiometric and polarimetric diameters for Juno are 6% to 7% smaller than the occultation result. No secondary occultations attributable to possible satellites of Juno were recorded at any of 23 photoelectrically equipped observing sites.

  10. Martian CO2 and O2 abundances obtained from MAVEN/IUVS stellar occultations

    NASA Astrophysics Data System (ADS)

    Gröller, H.; Yelle, R. V.; Montmessin, F.; Lacombe, G.; Schneider, N. M.; Stewart, I.; Deighan, J.; McClintock, W. E.; Clarke, J. T.; Holsclaw, G. M.; Jakosky, B. M.

    2015-10-01

    We present CO2 and O2 density profiles from stellar occultations by the IUVS instrument onboard MAVEN. The first occultation by MAVEN was of αCru on February 8, 2015 and the first campaign of stellar occultations with 60 more observations of 11 different stars was executed from March 24, 2015 to March 26, 2015. To increase the longitudinal coverage, each star, except λSco, was observed 5 times;λ Sco was targeted 10 times. Density profiles from the first occultation are determined in the altitude range between 100 and 140 km. The derived O2 mixing ratio in this region is 1.6×10-3, in agreement with previous measurements.

  11. Search for serendipitous TNO occultation events in X-rays with Athena

    NASA Astrophysics Data System (ADS)

    Chang, Hsiang-Kuang; Liu, Chih-Yuan; Shang, Jie-Rou

    2015-09-01

    Trans-Neptunian Objects (TNOs), which include Kuiper Belt Objects (KBOs) and yet-to-discover Oort Cloud Objects, are an important population of members of the solar system. Its population properties, such as size distribution, carry information imprinted during the early epoch of the solar system formation. TNOs smaller than about ten kilometers are not directly observable. Their existence, however, may be detected through occultation events of background targets that they cause. Search for such serendipitous occultation events have been conducted in optical and X-ray bands. Since the Fresnel scale is about 30 times smaller in X-rays, using X-ray occultation events one may explore TNOs smaller than that can be done in optical bands. Here I will report X-ray sources suitable for such a study with Athena observations. The estimated Athena detection rate of occultation events, based on different model assumptions of TNO size distribution, will also be presented.

  12. [Epidemiological view of fracture risk].

    PubMed

    Fujiwara, Saeko

    2010-09-01

    Incidence of hip fracture increases exponentially with age. Women had two times higher hip fracture incidence than men. Major risk factors for the hip fracture are age, sex, bone mineral density, and previous fracture and others, but each risk factor contributes differently to development of the fracture by sites. Factors related to fall are important role in developing hip fracture.

  13. [Osteoporosis and Colles' fracture].

    PubMed

    Hindsø, K; Lauritzen, J B

    2001-10-01

    We describe the connection between osteoporosis and Colles' fractures of the distal radius from an epidemiological and aetiological point of view. In addition, the value of these fractures as markers of osteoporosis and future risk of fracture is assessed. Several studies have clearly shown an epidemiological association between osteoporosis and fractures of the distal radius, with the association strongest for women up to 65 years of age and for osteoporosis located in the forearm. The association weakens for other locations and for older women. Osteoporosis may have some aetiologic significance for the development of Colles' fractures, but several extraskeletal factors are of equal or further importance. The occurrence of a Colles' fracture in the first 10-15 years after the postmenopause indicates an increased relative risk of sustaining another fracture in the future. However the relative risk approaches one after a few years and, because of the comparatively low absolute risk in this age-group, Colles' fracture as a risk factor contributes little to an assessment of the lifetime fracture risk. In a few longitudinal studies, Colles' fractures could not predict the long-term risk of osteoporosis. The presence of a Colles' fracture should lead to considerations concerning the skeletal and extraskeletal causes of the fracture for the purpose of initiating preventive and therapeutic measures.

  14. Elbow fractures and dislocations.

    PubMed

    Little, Kevin J

    2014-07-01

    Elbow fractures are common in pediatric patients. Most injuries to the pediatric elbow are stable and require simple immobilization; however, more severe fractures can occur, often requiring operative stabilization and/or close monitoring. This article highlights the common fractures and dislocations about the pediatric elbow and discusses the history, evaluation, and treatment options for specific injuries.

  15. Performance of the hybrid externally occulted Lyot solar coronagraph. Application to ASPIICS

    NASA Astrophysics Data System (ADS)

    Rougeot, R.; Flamary, R.; Galano, D.; Aime, C.

    2017-02-01

    Context. High-contrast hybrid coronagraphs, which combine an external occulter and a Lyot-style coronagraph became a reality in recent years, despite the lack of analytic and numerical end-to-end performance studies. The solar coronagraph ASPIICS which will fly on the future ESA Formation Flying mission Proba-3 is a good example of such a hybrid coronograph. Aims: We aim to provide a numerical model to compute theoretical performance of the hybrid externally occulted Lyot-style coronagraph, which we then aim to compare to the performance of the classical Lyot coronagraph and the externally occulted solar coronagraph. We will provide the level and intensity distribution of the stray light, when the Sun is considered as an extended source. We also investigate the effect of different sizes for the internal occulter and Lyot stop. Methods: First, we have built on a recently published approach, to express the diffracted wave front from Fresnel diffraction produced by an external occulter at the entrance aperture of the coronagraph. Second, we computed the coherent propagation of the wave front coming from a given point of the Sun through the instrument. This is performed in three steps: from the aperture to the image of the external occulter, where the internal occulter is set, from this plane to the image of the entrance aperture, where the Lyot stop is set, and from there to the final image plane. Making use of the axis-symmetry, we considered wave fronts originating from one radius of the Sun and we circularly average the intensities. Our numerical computation used the parameters of ASPIICS. Results: The hybrid externally occulted Lyot coronagraph rejects sunlight below 10-8B⊙ from 1.3 R⊙ - in the particular configuration of ASPIICS. The Lyot coronagraph effectively complements the external occultation. We show that reducing the Lyot stop allows a clear gain in rejection, being even better than oversizing the internal occulter, that tends to exclude observations

  16. Retrieval of upper atmosphere pressure-temperature profiles from high resolution solar occultation spectra

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Russell, J. M., III; Park, J. H.; Namkung, J.

    1987-01-01

    Pressure-temperature profiles over the 18 to 75 km altitude range were retrieved from 0.01 cm(-1) resolution infrared solar absorption spectra recorded with the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer operating in the solar occultation mode during the Spacelab 3 shuttle mission (April 30 to May 1, 1985). The analysis method is described and preliminary results deduced for five occultation events are compared to correlative pressure-temperature measurments.

  17. Analysis of a Triple Star System Occulted By Saturn’s Rings

    NASA Astrophysics Data System (ADS)

    Bratcher, Allison; Colwell, J. E.; Bolin, B.

    2012-10-01

    On January 4, 2012, the Ultraviolet Imaging Spectrograph aboard the Cassini Spacecraft observed Saturn’s rings as they occulted the triple star system, Iota Orionis. Remarkably, the brightest star was occulted by the moon Prometheus, and we provide the timing information of first and last contact for navigation purposes and a chord across the moon. The large separation of the individual stars projected in the ring plane makes it possible to measure the profiles of narrow features in the rings as they were occulted by each of the three stars. This occultation thus provides a unique opportunity to measure short-scale longitudinal variations in narrow ringlets with stellar occultation data that usually provide only a single longitudinal sample. Iota Orionis has a low elevation angle (B=1.4 degrees) above the plane of the rings, enhancing the sensitivity of the occultation (by a factor of 1/sin(B)=41) to the optically thin regions of the rings such as the C Ring and the Cassini Division as well as faint ringlets in the Encke gap. We distinguished the three signals by creating a model triple star signal using data from another occultation. We were able to identify several faint, narrow ringlets, including two in the Encke gap, occulted by two of the three stars and more prominent ringlets, such as the Huygens ringlet, in all three stellar light curves. We present the equivalent widths of these ringlets in the data from this triple star system and limits on ring variability over the azimuthal separation of the stars that ranges from 6000 km at the inner C ring to 200 km at the outer A ring.

  18. Cytokine profiles and hepatic injury in occult hepatitis C versus chronic hepatitis C virus infection.

    PubMed

    Mousa, N; Eldars, W; Eldegla, H; Fouda, O; Gad, Y; Abousamra, N; Elmasry, E; Arafa, M

    2014-01-01

    Occult hepatitis C virus (HCV) infection is a new entity that should be considered when diagnosing patients with abnormal liver functions of unknown origin. This work was carried out to evaluate T-helper 1/T-helper 2 (Th1/Th2) cytokine profiles in patients with occult HCV infection versus chronic hepatitis C (CHC) infection, also to investigate any association between theses cytokines and liver histological features in both groups. Serum levels of Th1 cytokines (IL-2, IFN-gamma) and Th2 (IL-4 and IL-10) were measured in 35 patients with occult HCV infection compared to 50 patients with chronic hepatitis C infection and 30 healthy controls. We have found that Th1 cytokines were significantly increased in patients with CHC infection than in both occult HCV infection and control groups (p less than 0.001). On the other hand, serum IL-4 levels were higher in occult HCV infection than in CHC and control groups (p less than 0.001). Furthermore, serum IL-10 levels were higher in both patient groups vs control group (pless than 0.001), with no significant difference between CHC and occult HCV groups. Finally, only serum IL-10 levels were significantly higher among patients with high activity (A2-A3) than those with low activity (A0-A1) in both CHC and occult HCV groups (p=0.038, p=0.025, respectively). Patients with occult HCV infection exhibited a distinct immunoregulatory cytokine pattern that is shifted towards the Th2 arm.

  19. Seroprevalence of occult hepatitis B among Egyptian paediatric hepatitis C cancer patients.

    PubMed

    Raouf, H E; Yassin, A S; Megahed, S A; Ashour, M S; Mansour, T M

    2015-02-01

    Occult hepatitis B infection is characterized by the presence of hepatitis B virus (HBV) DNA in the serum in the absence of hepatitis B surface antigen (HBsAg). Prevalence of hepatitis C virus (HCV) infections in Egypt is among the highest in the world. In this study, we aim at analysing the rates of occult HBV infections among HCV paediatric cancer patients in Egypt. The prevalence of occult HBV was assessed in two groups of paediatric cancer patients (HCV positive and HCV negative), in addition to a third group of paediatric noncancer patients, which was used as a general control. All groups were negative for HBsAg and positive for HCV antibody. HBV DNA was detected by nested PCR and real-time PCR. HCV was detected by real-time PCR. Sequencing was carried out in order to determine HBV genotypes to all HBV patients as well as to detect any mutation that might be responsible for the occult phenotype. Occult hepatitis B infection was observed in neither the non-HCV paediatric cancer patients nor the paediatric noncancer patients but was found in 31% of the HCV-positive paediatric cancer patients. All the detected HBV patients belonged to HBV genotype D, and mutations were found in the surface genome of HBV leading to occult HBV. Occult HBV infection seems to be relatively frequent in HCV-positive paediatric cancer patients, indicating that HBsAg negativity is not sufficient to completely exclude HBV infection. These findings emphasize the importance of considering occult HBV infection in HCV-positive paediatric cancer patients especially in endemic areas as Egypt.

  20. Diffraction calculation of occultation light curves in the presence of an isothermal atmosphere

    NASA Technical Reports Server (NTRS)

    French, R. G.; Gierasch, P. J.

    1976-01-01

    From diffraction theory, light curves are calculated for stellar occultations by a planetary body with an isothermal atmosphere. The character of the resulting curves is determined by the scale height H, the Fresnel zone size l, the surface atmospheric refractivity, and the planetary radius. An exact general solution and two approximations are presented which are valid when H is much greater than l. The importance is assessed of accounting for diffraction effects of the limb when deducing atmospheric parameters from occultation light curves

  1. Occult Hepatitis B Virus Infection in a Previously Vaccinated Injection Drug User

    PubMed Central

    Powell, Eleanor A.; Razeghi, Sanam; Zucker, Stephen; Blackard, Jason T.

    2016-01-01

    Introduction: Occult hepatitis B virus (HBV) is defined by the presence of HBV DNA in patient sera in the absence of HBsAg. Occult HBV has been associated with hepatocellular carcinoma, reactivation during immune suppression, and transmission to others. While the hepatitis B vaccine is very effective at preventing chronic HBV infection, recent studies indicate it is less effective at preventing occult HBV following infant vaccination. No studies, however, have examined the efficacy of adult HBV vaccination at preventing occult HBV. Here, we present the first report of occult HBV following adult vaccination. Case Presentation: A 21-year old Caucasian female presented with tricuspid valve endocarditis secondary to methicillin-susceptible Staphylococcus aureus with non-ischemic cardiomyopathy. She reported active use of intravenous drugs. Her liver enzymes were elevated (ALT = 1873 IU/mL; AST = 4518 IU/mL), and she was found to have HCV and occult HBV. HBV viral loads ranged from 4608 - 8364 copies IU/mL during hospitalization. The patient’s HBV was sequenced and found to be genotype D3 without any known diagnostic escape mutations. Immune complexes that may have prevented HBsAg detection were not observed. Conclusions: HBV vaccination in infancy is effective at preventing chronic HBV infection but is less effective at preventing occult HBV infection. Similar studies examining the efficacy of adult HBV vaccination in preventing occult HBV have not been performed. This case highlights the importance of carefully determining the HBV status of high-risk individuals, as vaccination history and the presence of anti-HBs may not be adequate to rule out HBV infection, even in the absence of HBsAg. PMID:27148386

  2. Astrometry of Single-Chord Occultations: Application to the 1993 Triton Event

    NASA Technical Reports Server (NTRS)

    Olkin, Catherine B.; Elliot, J. L.; Bus, Schelte J.; McDonald, Stephen W.; Dahn, Conrad C.

    1996-01-01

    This paper outlines a method for reducing astrometric data to derive the closest approach time and distance to the center of an occultation shadow for a single observer. The method applies to CCD frames, strip scans or photographic plates and uses a set of field stars of unknown positions to define a common coordinate system for all frames. The motion of the occulting body is used to establish the transformation between this common coordinate system and the celestial coordinate system of the body's ephemeris. This method is demonstrated by application to the Tr6O occultation by Triton on 1993 July 10 UT. Over an interval of four nights that included the occultation time, 80 frames of Triton and Tr6O were taken near the meridian with the U.S. Naval Observatory (USNO) 61-inch astrometric reflector. Application of the method presented here to these data yields a closest approach distance of 359 +/- 133 km (corresponding to 0.017 +/- 0.006 arcsec) for the occultation chord obtained with the Kuiper Airborne Observatory (KAO). Comparison of the astrometric closest approach time with the KAO light-curve midtime shows a difference of 2.2 +/- 4.1 s. Relative photometry of Triton and Tr6O, needed for photometric calibration of the occultation light curve, is also presented.

  3. High-order ionospheric effects on electron density estimation from Fengyun-3C GPS radio occultation

    NASA Astrophysics Data System (ADS)

    Li, Junhai; Jin, Shuanggen

    2017-03-01

    GPS radio occultation can estimate ionospheric electron density and total electron content (TEC) with high spatial resolution, e.g., China's recent Fengyun-3C GPS radio occultation. However, high-order ionospheric delays are normally ignored. In this paper, the high-order ionospheric effects on electron density estimation from the Fengyun-3C GPS radio occultation data are estimated and investigated using the NeQuick2 ionosphere model and the IGRF12 (International Geomagnetic Reference Field, 12th generation) geomagnetic model. Results show that the high-order ionospheric delays have large effects on electron density estimation with up to 800 el cm-3, which should be corrected in high-precision ionospheric density estimation and applications. The second-order ionospheric effects are more significant, particularly at 250-300 km, while third-order ionospheric effects are much smaller. Furthermore, the high-order ionospheric effects are related to the location, the local time, the radio occultation azimuth and the solar activity. The large high-order ionospheric effects are found in the low-latitude area and in the daytime as well as during strong solar activities. The second-order ionospheric effects have a maximum positive value when the radio occultation azimuth is around 0-20°, and a maximum negative value when the radio occultation azimuth is around -180 to -160°. Moreover, the geomagnetic storm also affects the high-order ionospheric delay, which should be carefully corrected.

  4. High prevalence of occult hepatitis C virus infection in patients with primary and secondary glomerular nephropathies.

    PubMed

    Castillo, Inmaculada; Martinez-Ara, Jorge; Olea, Teresa; Bartolomé, Javier; Madero, Rosario; Hernández, Eduardo; Bernis, Carmen; Aguilar, Ana; Quiroga, Juan A; Carreño, Vicente; Selgas, Rafael

    2014-09-01

    The association of hepatitis C virus (HCV) infection and glomerulonephritis is well known. However, the relationship between immune-mediated glomerulonephritis and occult HCV, characterized by the presence of HCV-RNA in liver or in peripheral blood mononuclear cells in the absence of serological markers, is unknown. We tested this in 113 anti-HCV-negative patients; 87 with immune-mediated glomerulonephritis and 26 controls with hereditary glomerular nephropathies. All patients were serum HCV-RNA negative by conventional real-time PCR. Significantly, occult HCV-RNA (detectable viral RNA in peripheral blood mononuclear cells or in serum after ultracentrifugation) was found in 34 of 87 patients with immune-mediated glomerulonephritis versus 1 of 26 control patients. The serum creatinine levels were significantly higher in patients with immune-mediated glomerulonephritis with than in those without occult HCV (1.5 versus 1.1 mg/dl, respectively). A multivariate analysis adjusted for gender showed a significantly increased risk of occult HCV in patients with immune-mediated glomerulonephritis versus the controls (odds ratio of 13.29). Progression to end-stage renal disease tended to be faster in patients with immune-mediated glomerulonephritis and occult HCV than in the negative cases. Thus, occult HCV is strongly associated with immune-mediated glomerulonephritis and may have a role in the progression of the disease.

  5. Improving capabilities of broadband differential satellite navigation systems via radio occultation technology

    NASA Astrophysics Data System (ADS)

    Myslivtsev, T. O.; Nikiforov, S. V.; Pogoreltsev, A. I.; Savochkin, P. V.; Sakhno, I. V.; Semenov, A. A.; Troitsky, B. V.

    2016-07-01

    The existent satellite system for radio occultation monitoring the Earth's neutral atmosphere and ionosphere (COSMIC) provides data to consumers in the regions with limited possibilities of constructing dense measurement networks (e.g., in the World Ocean area). A forthcoming increase of LEO small spacecrafts and the deployment of new satellite radio navigation systems will result in a pronounced increase in the efficiency of radio occultation method and its space resolution. As a result, the Space-Based Augmentation Systems (SBAS) broadband differential system will become global, or the quality of corrections delivered to single-frequency consumers of individual systems, e.g., the Augmentation and Monitoring System, will be improved. Therefore, the methods for processing and analyzing obtained radio occultation data should be improved. A simple method to reconstruct the electron density profile at radio occultation points, based on the total electron content measurement on the satellite-satellite path and the IRI-type ionospheric model has been proposed. The method needs initial information, it does not require refraction measurements, and it is free of the assumption that the ionosphere is spherically stratified in the occultation region. Verification of the proposed method based on data for 121 radio occultation cases across Europe in May 2013 demonstrated good agreement with the vertical sounding data.

  6. Diffraction effects in a giant saw-toothed edge externally occulted solar coronagraph

    NASA Astrophysics Data System (ADS)

    Verroi, E.; Frassetto, F.; Naletto, G.

    2008-07-01

    Typical diffraction and vignetting effects associated to the use of both externally and internally occulted coronagraphs make the innermost solar corona quite unobserved. However, by increasing the distance between the coronagraph telescope and the external occulter to hundred of meters, it is possible to observe the solar corona down to 1.01 solar radii without vignetting. This is the case of ASPIICS (Association de Satellites Pour l'Imagerie et l'Interférométrie Coronographique Solaire), a mission proposed to ESA for the PROBA3 program for formation flying. ASPIICS foresees two satellites: the external occulter is located on one spacecraft, and the telescope on the other. In this work we present the results obtained by a theoretical analysis of the apodization of the external occulter. This technique allows the reduction of the diffracted light contribution. We have developed a code that can simulates the effects of the giant external occulter (1 m diameter) on the photospheric light, and calculates the intensity of the diffracted light on the coronagraph entrance aperture. It is possible, in this way, to analyze various shapes of the occulter edge. In particular, we have focused our attention in the case of the serrated disc with variable number of teeth of different length. We considered the simple occurrence of a point-like monochromatic source at infinity. The results show that, employing a toothed disc, improvement of the S/N ratio of many order of magnitude (whit respect to a simple circular flat disc) can be obtained.

  7. Proximal humerus fractures.

    PubMed

    Price, Matthew C; Horn, Pamela L; Latshaw, James C

    2013-01-01

    Proximal humerus fractures are among the most common fractures associated with osteoporosis. With an aging population, incidence of these fractures will only increase. The proximal humerus not only forms the lateral portion of the shoulder articulation but also has significant associations with musculoskeletal and neurovascular structures. As a result, fractures of the proximal humerus can significantly impact not only the function of the shoulder joint, but the health and function of the entire upper extremity as well. Understanding of these fractures, the management options, and associated nursing care, can help reduce morbidity rate and improve functional outcomes.

  8. Stress fractures in runners.

    PubMed

    McCormick, Frank; Nwachukwu, Benedict U; Provencher, Matthew T

    2012-04-01

    Stress fractures are a relatively common entity in athletes, in particular, runners. Physicians and health care providers should maintain a high index of suspicion for stress fractures in runners presenting with insidious onset of focal bone tenderness associated with recent changes in training intensity or regimen. It is particularly important to recognize “high-risk” fractures, as these are associated with an increased risk of complication. A patient with confirmed radiographic evidence of a high-risk stress fracture should be evaluated by an orthopedic surgeon. Runners may benefit from orthotics, cushioned sneakers, interval training, and vitamin/calcium supplementation as a means of stress fracture prevention.

  9. Fracture toughness of silicon

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Leipold, M. H.

    1980-01-01

    The paper presents a study to determine the fracture toughness and to characterize fracture modes of silicon as a function of the orientation of single-crystal and polycrystalline material. It is shown that bar specimens cracked by Knoop microhardness indentation and tested to fracture under four-point bending at room temperature were used to determine the fracture toughness values. It is found that the lowest fracture toughness value of single crystal silicon was 0.82 MN/m to the 3/2 in the 111 plane type orientation, although the difference in values in the 111, 110, and 100 planes was small.

  10. [Rarely seen fractures].

    PubMed

    Subaşi, M; Kapukaya, A; Kesemenli, C; Coban, V

    2001-10-01

    Rarely seen fractures are presented in this study. One case was a calcaneal spur, 2 cases osteochondroma pedicule fractures and talus posteromedial tubercle fracture due to direct trauma. Calcaneal spur and osteochondromas were removed surgically and posteromedial tubercle was treated by short-leg cast immobilization. In conclusion, we think that fractures of osteochondroma and calcaneal spur may be treated by surgical removal which do not cause any functional disorders after this operation, but fractures like the talus posteromedial tubercle should be treated conservatively by short-leg immobilization in the early period.

  11. Subsurface fracture spacing

    SciTech Connect

    Lorenz, J.C. ); Hill, R.E. )

    1991-01-01

    This study was undertaken in order to document and analyze the unique set of data on subsurface fracture characteristics, especially spacing, provided by the US Department of Energy's Slant Hole Completion Test well (SHCT-1) in the Piceance Basin, Colorado. Two hundred thirty-six (236) ft (71.9 m) of slant core and 115 ft (35.1 m) of horizontal core show irregular, but remarkably close, spacings for 72 natural fractures cored in sandstone reservoirs of the Mesaverde Group. Over 4200 ft (1280 m) of vertical core (containing 275 fractures) from the vertical Multiwell Experiment wells at the same location provide valuable information on fracture orientation, termination, and height, but only data from the SHCT-1 core allow calculations of relative fracture spacing. Within the 162-ft (49-m) thick zone of overlapping core from the vertical and deviated wellbores, only one fracture is present in vertical core whereas 52 fractures occur in the equivalent SHCT-1 core. The irregular distribution of regional-type fractures in these heterogeneous reservoirs suggests that measurements of average fracture spacing'' are of questionable value as direct input parameters into reservoir engineering models. Rather, deviated core provides data on the relative degree of fracturing, and confirms that cross fractures can be rare in the subsurface. 13 refs., 11 figs.

  12. Atraumatic sternum fracture

    PubMed Central

    Abrahamsen, Sebastian Ørskov; Madsen, Christina Friis

    2014-01-01

    The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have rarely been reported among elderly patients. Insufficiency fractures tend to occur in bones with decreased mechanical strength especially among elderly patients, in postmenopausal women and patients with underlying diseases. We describe a case of spontaneous sternum insufficiency fracture in a healthy man, with no known risk factors to fracture, or previous history of fractures. Sternum insufficiency fracture is a rare cause of chest pain. This case serves to remind the emergency physician to remain vigilant for other non-cardiac, non-pulmonary and non-traumatic causes of chest pain, especially among patients with known risk factors such as osteoporosis, chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus and patients on long-term steroid treatment. If diagnosed correctly, these patients can be discharged and treated as outpatients as this case emphasises. PMID:25326566

  13. Mechanics of Hydraulic Fractures

    NASA Astrophysics Data System (ADS)

    Detournay, Emmanuel

    2016-01-01

    Hydraulic fractures represent a particular class of tensile fractures that propagate in solid media under pre-existing compressive stresses as a result of internal pressurization by an injected viscous fluid. The main application of engineered hydraulic fractures is the stimulation of oil and gas wells to increase production. Several physical processes affect the propagation of these fractures, including the flow of viscous fluid, creation of solid surfaces, and leak-off of fracturing fluid. The interplay and the competition between these processes lead to multiple length scales and timescales in the system, which reveal the shifting influence of the far-field stress, viscous dissipation, fracture energy, and leak-off as the fracture propagates.

  14. Novel use of a radiolabelled antibody against stage specific embryonic antigen for the detection of occult abscesses in mammals

    DOEpatents

    Thakur, Madhukar L.

    1990-01-01

    The invention discloses improved reagents containing antibodies against stage specific embryonic antigen-1 antibodies and improved methods for detection of occult abscess and inflammation using the improved reagents.

  15. The Near Real Time Data Processing System For GPS Radio Occultation Data From Champ At Gfz Potsdam

    NASA Astrophysics Data System (ADS)

    Schmidt, T.; Wickert, J.; Marquardt, Ch.; Beyerle, G.; Reigber, Ch.; Wehrenpfennig, A.

    GPS radio occultation measurements onboard low earth orbiting satellites (CHAMP) offer a prominent method for global and continuous monitoring of the Earth's atmo- sphere. Data assimilation studies using radio occultation data have already shown that this new type of remote sensing technique improves the accuracy of global and re- gional weather analyses and predictions. The use of products obtained from radio occultation data as, e.g., refractivity, tem- perature, or humidity profiles, by weather service centers requires an operational data processing system generating and delivering data products automatically within a 3 hour time limit. Since one year such a near real time data processing system is oper- ated at GFZ Potsdam with radio occultation data from the German satellite CHAMP (Challenging Minisatellite Payload). This system, the CHAMP Atmospheric Processor (CAP), will be introduced. The con- trolling and scientific components including ground infrastructure, data flow and soft- ware modules are discussed. CAP is designed to be easily extendable by additional scientific modules or input data. Thus, it also allows for an extension to other single- or multi-satellite occultation missions as, e.g., GRACE to be launched in March 2002. By end of April 2002 more than 50.000 occultations will be recorded. Extensive statis- tics as daily and monthly averages of processed occultations and global distributions of occultation events from one year of CHAMP radio occultation data will be presented.

  16. An analysis of the Voyager 2 Ultraviolet Spectrometer occultation data at Uranus - Inferring heat sources and model atmospheres

    NASA Technical Reports Server (NTRS)

    Stevens, Michael H.; Strobel, Darrell F.; Herbert, Floyd

    1993-01-01

    Heat source information is derived here from the Voyager 2 Ultraviolet Spectrometer occultation data of Uranus. Analytic functions for the local heat dependence on altitude are used to obtain a temperature profile by solving the heat equation. The stellar entrance and exit occultation and a solar occultation are used to infer the thermal and density structure of the atmosphere. The least squares fit solution to the solar occultation data gives one source located at 1.8 x 10 exp -5 microbar with a strength of 0.056 +/- 0.01 erg/sq cm/s. Latitudinal temperature gradients are obtained.

  17. Orbit dynamics and geographical coverage capabilities of satellite-based solar occultation experiments for global monitoring of stratospheric constituents

    NASA Technical Reports Server (NTRS)

    Brooks, D. R.

    1980-01-01

    Orbit dynamics of the solar occultation technique for satellite measurements of the Earth's atmosphere are described. A one-year mission is simulated and the orbit and mission design implications are discussed in detail. Geographical coverage capabilities are examined parametrically for a range of orbit conditions. The hypothetical mission is used to produce a simulated one-year data base of solar occultation measurements; each occultation event is assumed to produce a single number, or 'measurement' and some statistical properties of the data set are examined. A simple model is fitted to the data to demonstrate a procedure for examining global distributions of atmospheric constitutents with the solar occultation technique.

  18. The contribution of occult precipitation to nutrient deposition on the west coast of South Africa.

    PubMed

    Nyaga, Justine M; Neff, Jason C; Cramer, Michael D

    2015-01-01

    The Strandveld mediterranean-ecosystem of the west coast of South Africa supports floristically diverse vegetation growing on mostly nutrient-poor aeolian sands and extending from the Atlantic Ocean tens of kilometers inland. The cold Benguela current upwelling interacts with warm onshore southerly winds in summer causing coastal fogs in this region. We hypothesized that fog and other forms of occult precipitation contribute moisture and nutrients to the vegetation. We measured occult precipitation over one year along a transect running inland in the direction of the prevailing wind and compared the nutrient concentrations with those in rainwater. Occult deposition rates of P, N, K, Mg, Ca, Na, Al and Fe all decreased with distance from the ocean. Furthermore, ratios of cations to Na were similar to those of seawater, suggesting a marine origin for these. In contrast, N and P ratios in occult precipitation were higher than in seawater. We speculate that this is due to marine foam contributing to occult precipitation. Nutrient loss in leaf litter from dominant shrub species was measured to indicate nutrient demand. We estimated that occult precipitation could meet the demand of the dominant shrubby species for annual N, P, K and Ca. Of these species, those with small leaves intercepted more moisture and nutrients than those with larger leaves and could take up foliar deposits of glycine, NO3(-), NH4(+) and Li (as tracer for K) through leaf surfaces. We conclude that occult deposition together with rainfall deposition are potentially important nutrient and moisture sources for the Strandveld vegetation that contribute to this vegetation being floristically distinct from neighbouring nutrient-poor Fynbos vegetation.

  19. The Contribution of Occult Precipitation to Nutrient Deposition on the West Coast of South Africa

    PubMed Central

    2015-01-01

    The Strandveld mediterranean-ecosystem of the west coast of South Africa supports floristically diverse vegetation growing on mostly nutrient-poor aeolian sands and extending from the Atlantic Ocean tens of kilometers inland. The cold Benguela current upwelling interacts with warm onshore southerly winds in summer causing coastal fogs in this region. We hypothesized that fog and other forms of occult precipitation contribute moisture and nutrients to the vegetation. We measured occult precipitation over one year along a transect running inland in the direction of the prevailing wind and compared the nutrient concentrations with those in rainwater. Occult deposition rates of P, N, K, Mg, Ca, Na, Al and Fe all decreased with distance from the ocean. Furthermore, ratios of cations to Na were similar to those of seawater, suggesting a marine origin for these. In contrast, N and P ratios in occult precipitation were higher than in seawater. We speculate that this is due to marine foam contributing to occult precipitation. Nutrient loss in leaf litter from dominant shrub species was measured to indicate nutrient demand. We estimated that occult precipitation could meet the demand of the dominant shrubby species for annual N, P, K and Ca. Of these species, those with small leaves intercepted more moisture and nutrients than those with larger leaves and could take up foliar deposits of glycine, NO3-, NH4+ and Li (as tracer for K) through leaf surfaces. We conclude that occult deposition together with rainfall deposition are potentially important nutrient and moisture sources for the Strandveld vegetation that contribute to this vegetation being floristically distinct from neighbouring nutrient-poor Fynbos vegetation. PMID:26017747

  20. Occultation Modeling for Radiation Obstruction Effects on Spacecraft Systems

    NASA Technical Reports Server (NTRS)

    de Carufel, Guy; Li, Zu Qun; Harvey, Jason; Crues, Edwin Z.; Bielski, Paul

    2016-01-01

    A geometric occultation model has been developed to determine line-of-sight obstruction of radiation sources expected for different NASA space exploration mission designs. Example applications includes fidelity improvements for surface lighting conditions, radiation pressure, thermal and power subsystem modeling. The model makes use of geometric two dimensional shape primitives to most effectively model space vehicles. A set of these primitives is used to represent three dimensional obstructing objects as a two dimensional outline from the perspective of an observing point of interest. Radiation sources, such as the Sun or a Moon's albedo is represented as a collection of points, each of which is assigned a flux value to represent a section of the radiation source. Planetary bodies, such as a Martian moon, is represented as a collection of triangular facets which are distributed in spherical height fields for optimization. These design aspects and the overall model architecture will be presented. Specific uses to be presented includes a study of the lighting condition on Phobos for a possible future surface mission, and computing the incident flux on a spacecraft's solar panels and radiators from direct and reflected solar radiation subject to self-shadowing or shadowing by third bodies.

  1. Scientific tradeoffs in pinhole/occulter facility accommodation

    NASA Technical Reports Server (NTRS)

    Hudson, Hugh S.

    1988-01-01

    The Pinhole/Occulter Facility (P/OF) consists of state-of-the-art instruments for the study of particle acceleration in the solar corona, and uses a large structure to obtain very high angular resolution. P/OF has been studied in the past as an attached payload for the Space Shuttle, and has been the subject of study by a NASA Science Working Group (P/OFSWG). Appendix A lists various technical studies and reports carried out under the auspices of P/OFSWG and the Program Development Office of NASA Marshall Space Flight Center. Under the rationalization of NASA flight opportunities following the Challenger disaster, and the beginning of the Space Station Freedom program, the sortie-mode deployment of P/OF seemed less efficient and desirable. Thus, NASA decided to reconsider P/OF for deployment on the Space Station Freedom. The technical studies for this deployment continue at the present and will evolve as our knowledge of Space Station architecture and capabilities increase. MSFC contracted with Teledyne Brown Engineering for these technical studies.

  2. Assimilation of GNSS radio occultation observations in GRAPES

    NASA Astrophysics Data System (ADS)

    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.

  3. Assimilation of GNSS radio occultation observations in GRAPES

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Xue, J.

    2014-11-01

    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 Environmental Prediction) analyses. Finally, as a result of the new on-board payload of the Chinese FengYun-3 (FY-3) satellites, the research status of the RO of FY-3 satellites is also presented.

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

    USGS Publications Warehouse

    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, C.; 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.

  5. Occult Hepatitis B Virus Infection in Chacma Baboons, South Africa

    PubMed Central

    Dickens, Caroline; Kew, Michael C.; Purcell, Robert H.

    2013-01-01

    During previous studies of susceptibility to hepatitis B virus (HBV) infection, HBV DNA was detected in 2/6 wild-caught baboons. In the present study, HBV DNA was amplified from 15/69 wild-caught baboons. All animals were negative for HBV surface antigen and antibody against HBV core antigen. Liver tissue from 1 baboon was immunohistochemically negative for HBV surface antigen but positive for HBV core antigen. The complete HBV genome of an isolate from this liver clustered with subgenotype A2. Reverse transcription PCR of liver RNA amplified virus precore and surface protein genes, indicating replication of virus in baboon liver tissue. Four experimentally naive baboons were injected with serum from HBV DNA–positive baboons. These 4 baboons showed transient seroconversion, and HBV DNA was amplified from serum at various times after infection. The presence of HBV DNA at relatively low levels and in the absence of serologic markers in the baboon, a nonhuman primate, indicates an occult infection. PMID:23631817

  6. Observations of stratospheric hydrogen fluoride by halogen occultation experiment (HALOE)

    NASA Technical Reports Server (NTRS)

    Luo, M.; Cicerone, R. J.; Russel, J. M., III; Huang, T. Y. W.

    1994-01-01

    The Halogen Occultation Experiment (HALOE) Hydrogen Fluoride (HF) channel on the Upper Atmospheric Research Satellite (UARS) is providing the first global measurements of stratospheric HF, the dominant flourine reservoir in the atmosphere. This paper describes the latitudinal and seasonal variations of HALOE-observed HF in terms of vertical profiles, altitude/latitude cross sections, and column abundances. The HF global distribution shows a 'tracerlike' structure and its column amount increases with latitude, in agreement with previous aircraft measurements of the HF column amount. A comparison between the HALOE HF column above 20 km and the ATMOS 1985 measurements is used to estimate the annual rate of increase of stratospheric HF. Exponential rates of 4.9-6.6%/yr and linear growth rates of 6-8.6%/yr in 1985 and 4.3-5.5%/yr in 1992-1993 are found. HALOE HF measurements during the 1993 Antarctic spring are briefly described. This species behaves like a conserved tracer and its distribution shows an area of enhanced mixing ratios correlated with the polar vortex that has a clear latitude boundary. Finally, simulated HF distributions by the National Center for Atmospheric Research (NCAR) two-dimensional model are used to compare with HALOE observations of HF. Reasonable agreements in the global structure and the absolute amount of HF are found. The differences between the model and the observed results indicate the need for improving treatment of atmospheric dynamics and fluorine-related chemical parameters in the model simulations.

  7. Halogen occultation experiment (HALOE) performance verification test procedure

    NASA Technical Reports Server (NTRS)

    Mauldin, L. E., III

    1986-01-01

    The Performance Verification Test Procedure is given for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This procedure is used for comprehensive performance testing of the HALOE instrument which occurs before, during, and after flight environmental tests. The radiometric performance tests include noise, drift, linearity, instantaneous field-of-view, cal wheel gas cell characterization, and self thermal emissions. Pointer/tracker performance tests include sun sensor performance, gimbal performance, control system performance, and boresight alignment. In addition, the instrument is tested functionally in simulated orbit sequences and all command operating modes are exercised. The data analysis required for each test is specified and pass/fail criteria are given where applicable. This test will fully demonstrate the HALOE instrument's ability to achieve science mission requirements. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HCl, HF, NO, CH4, H2O, NO2, and CO2.

  8. Aerosol effects and corrections in the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Hervig, Mark E.; Russell, James M., III; Gordley, Larry L.; Daniels, John; Drayson, S. Roland; Park, Jae H.

    1995-01-01

    The eruptions of Mt. Pinatubo in June 1991 increased stratospheric aerosol loading by a factor of 30, affecting chemistry, radiative transfer, and remote measurements of the stratosphere. The Halogen Occultation Experiment (HALOE) instrument on board Upper Atmosphere Research Satellite (UARS) makes measurements globally for inferring profiles of NO2, H2O, O3, HF, HCl, CH4, NO, and temperature in addition to aerosol extinction at five wavelengths. Understanding and removing the aerosol extinction is essential for obtaining accurate retrievals from the radiometer channels of NO2, H2O and O3 in the lower stratosphere since these measurements are severely affected by contaminant aerosol absorption. If ignored, aerosol absorption in the radiometer measurements is interpreted as additional absorption by the target gas, resulting in anomalously large mixing ratios. To correct the radiometer measurements for aerosol effects, a retrieved aerosol extinction profile is extrapolated to the radiometer wavelengths and then included as continuum attenuation. The sensitivity of the extrapolation to size distribution and composition is small for certain wavelength combinations, reducing the correction uncertainty. The aerosol corrections extend the usable range of profiles retrieved from the radiometer channels to the tropopause with results that agree well with correlative measurements. In situations of heavy aerosol loading, errors due to aerosol in the retrieved mixing ratios are reduced to values of about 15, 25, and 60% in H2O, O3, and NO2, respectively, levels that are much less than the correction magnitude.

  9. Using GPS radio occultations to infer the water vapor feedback

    NASA Astrophysics Data System (ADS)

    Vergados, Panagiotis; Mannucci, Anthony J.; Ao, Chi O.; Fetzer, Eric J.

    2016-11-01

    The air refractive index at L-band frequencies depends on the air's water vapor content and density. Exploiting this relationship, we derive for the first time a theoretical model to infer the specific humidity response to surface temperature variations, dq/dTs, given knowledge of how the air refractive index and temperature vary with surface temperature. We validate this model by using 1.2-1.6 GHz Global Positioning System Radio Occultation (GPS RO) observations from 2007 to 2010 at 250 hPa, where the water vapor feedback on surface warming is strongest. The dq/dTs estimation from GPS RO observations shows excellent agreement with previously published results and the responses estimated by using the Atmospheric Infrared Sounder and the NASA's Modern-Era Retrospective Analysis for Research and Applications data sets. Because of their high sensitivity to fractional changes in water vapor, current and future GPS RO observations show great promise in monitoring climate feedback and their trends.

  10. Seronegative occult hepatitis C virus infection: clinical implications.

    PubMed

    Carreño, Vicente

    2014-11-01

    Occult hepatitis C virus infection (OCI) was first described in anti-HCV and serum HCV-RNA negative patients with abnormal values of liver enzymes but who presented HCV-RNA in liver and in peripheral blood mononuclear cells. Up to now, two types of OCI are recognized: seronegative OCI (anti-HCV and serum HCV-RNA negative) and seropositive OCI (anti-HCV positive and serum HCV-RNA negative). The concept of OCI is still a matter of debate, probably because both types of OCI are not considered as different entities. This review focuses on seronegative OCI. The existence of seronegative OCI has been documented all around the world with the implication of different HCV genotypes (1-4). Seronegative OCI is associated with cryptogenic chronic hepatitis and liver cirrhosis and it may be involved in the appearance of hepatocellular carcinoma. Also seronegative OCI may increase the histological liver damage in chronic hepatitis B and in HIV-infected patients. It may have a negative influence in the natural history of hemodialysis patients and in immune-mediated glomerulonephritis. Seronegative OCI has been detected also in patients with haematological diseases, among healthy subjects and in drug users. Other publications indicate the potential infectivity of seronegative OCI in the setting of family members, sexual partners and liver transplantation. In summary, seronegative OCI may play a role in liver diseases and other human pathologies and may be present in healthy people but larger studies are needed to confirm these findings.

  11. Occult hepatitis C virus infection among Egyptian hemodialysis patients.

    PubMed

    Abdelrahim, Soha S; Khairy, Rasha; Esmail, Mona Abdel-Monem; Ragab, Mahmoud; Abdel-Hamid, Mohamed; Abdelwahab, Sayed F

    2016-08-01

    Occult hepatitis C virus (HCV) infection (OCI) was reported in an apparently disease-free state in the absence of liver disease, anti-HCV and HCV-RNA in the serum. The existing data examining the clinical significance of OCI and its potential as a source of HCV infection among hemodialysis patients are very limited. We examined the presence of OCI among patients on maintenance hemodialysis at Minia Governorate, Egypt; an HCV endemic country. A total of 81 subjects with negative markers for HCV were enrolled. HCV-RNA was tested in PBMCs by real-time PCR. For the 81 subjects, the average dialysis duration was 32.7 ± 21.7 months and the average ALT level (±SD) was 26 ± 12 U/L while that of AST was 29 ± 16 U/L. Out of the 81 subjects, three (3.7%) were HCV-RNA positive in PBMCs in the absence of serum anti-HCV and HCV-RNA indicating OCI. The viral load of the OCI subjects ranged from 172 to 4150 IU/ml. History of liver disease was positive in one of the three positive patients. These results highlight the potential risk of HCV transmission from patients within hemodialysis units in Egypt. J. Med. Virol. 88:1388-1393, 2016. © 2016 Wiley Periodicals, Inc.

  12. SOLAR OCCULTATION BY TITAN MEASURED BY CASSINI/UVIS

    SciTech Connect

    Capalbo, Fernando J.; Benilan, Yves; Yelle, Roger V.; Koskinen, Tommi T.; Sandel, Bill R.; Holsclaw, Gregory M.; McClintock, William E.

    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.

  13. Occult HBV Infection: A Faceless Enemy in Liver Cancer Development

    PubMed Central

    Morales-Romero, Jaime; Vargas, Gustavo; García-Román, Rebeca

    2014-01-01

    The hepatitis B virus (HBV) represents a worldwide public health problem; the virus is present in one third of the global population. However, this rate may in fact be higher due to occult hepatitis B virus infection (OBI). This condition is characterized by the presence of the viral genome in the liver of individuals sero-negative for the virus surface antigen (HBsAg). The causes of the absence of HBsAg in serum are unknown, however, mutations have been identified that produce variants not recognized by current immunoassays. Epigenetic and immunological host mechanisms also appear to be involved in HBsAg suppression. Current evidence suggests that OBI maintains its carcinogenic potential, favoring the progression of fibrosis and cirrhosis of the liver. In common with open HBV infection, OBI can contribute to the establishment of hepatocellular carcinoma. Epidemiological data regarding the global prevalence of OBI vary due to the use of detection methods of different sensitivity and specificity. In Latin America, which is considered an area of low prevalence for HBV, diagnostic screening methods using gene amplification tests for confirmation of OBI are not conducted. This prevents determination of the actual prevalence of OBI, highlighting the need for the implementation of cutting edge technology in epidemiological surveillance systems. PMID:24717680

  14. RELATIVE PHOTOMETRY OF HAT-P-1b OCCULTATIONS

    SciTech Connect

    Beky, Bence; Holman, Matthew J.; Noyes, Robert W.; Sasselov, Dimitar D.; Gilliland, Ronald L.; Bakos, Gaspar A.; Winn, Joshua N.

    2013-06-01

    We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of two occultations of the transiting exoplanet HAT-P-1b. By measuring the planet to star flux ratio near opposition, we constrain the geometric albedo of the planet, which is strongly linked to its atmospheric temperature gradient. An advantage of HAT-P-1 as a target is its binary companion ADS 16402 A, which provides an excellent photometric reference, simplifying the usual steps in removing instrumental artifacts from HST time-series photometry. We find that without this reference star, we would need to detrend the lightcurve with the time of the exposures as well as the first three powers of HST orbital phase, and this would introduce a strong bias in the results for the albedo. However, with this reference star, we only need to detrend the data with the time of the exposures to achieve the same per-point scatter, therefore we can avoid most of the bias associated with detrending. Our final result is a 2{sigma} upper limit of 0.64 for the geometric albedo of HAT-P-1b between 577 and 947 nm.

  15. Scientific Studies in Association with the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Mickley, Lorretta J.; Frederick, John E.

    1996-01-01

    This work examines measurements of ozone, NO, NO2, and HCl made by the Halogen Occultation Experiment (HALOE) to track chemical change in the stratosphere. In addition, HALOE observations of two long-lived species, HF and CH4, are used as tracers to distinguish between change due to transport processes and change due to chemistry. The first study investigates the response of NO(x), (NO and NO2) and ozone to the presence of large amounts of sulfate aerosol in the stratosphere following the 1991 eruption of Mount Pinatubo. As the Pinatubo aerosol cleared the atmosphere at 17 mb (about 27-28 km), the partitioning of total reactive nitrogen shifted more toward NO(x), and ozone amounts declined. This trend is opposite that observed at lower altitudes. The second study examines the chemical aftermath of severe ozone depletion over Antarctica in spring. When ozone levels drop to a threshold amount (about 1 ppm near 20 km), the partitioning of the total chlorine family shifts rapidly from reactive species to the reservoir molecule HCl. This sudden repartitioning shuts down further ozone loss and may be significant as filaments of air peel off the polar vortex and mix with mid-latitude air.

  16. Validation of 1 Year of Champ Radio Occultation Data

    NASA Astrophysics Data System (ADS)

    Marquardt, C.; Schöllhammer, K.; Schroedter, M.; Tomassini, M.; Beyerle, G.; Schmidt, T.; Wickert, J.; König, R.; Grunwaldt, L.; Reigber, Ch.

    The German polar-orbiting satellite CHAMP (Challenging mini-satellite Payload) was successfully launched in mid-2000. Equipped with a space borne GPS (Global Posi- tioning System) receiver provided by JPL (Jet Propulsion laboratory), CHAMP ex- ploits the signals of the global constellation of GPS satellites for the remote sensing of temperature and humidity in the atmosphere. This new remote sensing technique provides globally distributed, calibration free and weather independent measurements with - thanks to its limb geometry - high vertical resolution. In contrast to the earlier US proof-of-concept mission GPS/MET, CHAMP exhibits improved technical char- acteristics of the instrument and aims at quasi-continuous operation. Since its first successful radio occultation sounding in February 2001, CHAMP col- lected more than 40000 individual profiles of temperature and tropospheric moisture. By now, several multi-week periods of continuous measurements are available for all seasons, each one providing up to 200 daily soundings. We present a validation study of this data set against operational meteorological anal- yses, the global radiosonde network, and retrievals obtained from the ATOVS fam- ily of instruments (AMSU-A, AMSU-B, and HIRS) on board NOAA-16 for both stratospheric temperatures and tropospheric moisture. The performance of the pro- cessing system for strongly disturbed atmospheric conditions like those during the stratospheric major warming events in the early winter 2001/2002 will be addressed.

  17. [Epidemiology of hip fracture].

    PubMed

    Hagino, Hiroshi

    2006-12-01

    Age- and gender-specific numbers of patients with hip fracture increase with age and peaked at the age 80-84; however, age- and gender-specific incidences increase exponentially with age. According to the recent nation-wide survey, the most common cause of hip fractures was a simple fall, 68.8% sustained fractures in-doors, and the incidences were higher in the winter than the summer period. More than 90% of patients with hip fracture were treated surgically and about 3/4 of patients with femoral neck fractures were treated with hemi-arthroplasty. Hip fractures for Asian people including Japanese are lower than those for Caucasians living in Northern Europe and North America; however, recent reports from the Asian area indicated an increase in the incidence with time.

  18. Dyslipidemia and sternum fracture.

    PubMed

    Can, Cagdas; Gulactı, Umut; Sarıhan, Aydin; Topacoglu, Hakan

    2013-06-01

    Tenderness over the sternum is a clue for possible sternal fracture. Sternal fractures usually occur at the body or manubrium. Lateral chest radiography could detect a sternum fracture, but the diagnosis is usually made by chest tomography. Traumatic sternum fracture considered as a marker of seriously life-threatening, high-energy injury. In hyperlipidemia, oxidized lipids accumulate in vascular tissues and trigger atherosclerosis. Such lipids also deposit in bone tissues where they may promote osteoporosis. In the literature, there is no previously reported traumatic sternal fracture due to hyperlipidemia-induced osteoporosis. Here, we report a case of a combined mixed type familial hyperlipidemia-induced osteoporosis in which the patient having seat belt on had an unexpected sternum fracture in a low-energy motor vehicle accident.

  19. [Nasal fractures in adults].

    PubMed

    Sjöstedt, Sannia; Larsen, Christian Grønhøj; Bilde, Anders; von Buchwald, Christian

    2016-03-07

    The risk of complications warrants treatment of most dislocated nasal fractures. Other injuries including other facial fractures and septal haematoma must be treated if present at the initial presentation. The usual treatment for a simple nasal fracture is closed reduction in local anaesthesia after five to seven days. Complicated cases require open reduction in general anaesthesia. Later revision of the deviated nose may become necessary in patients suffering from complications such as persistent nasal stenosis and/or deformity.

  20. [Chondral and osteochondral fractures].

    PubMed

    Kayaoğlu, E Esin; Binnet, Mehmet S

    2007-01-01

    The incidence of traumatic chondral and osteochondral fractures and their role in the development of joint degeneration are not fully elucidated. While assessing traumatic knee injuries, one important criterion for the diagnosis of chondral fractures is to remember the possibility of a chondral or osteochondral fracture. Symptoms in osteochondral fractures are more obvious and cause severe pain and difficulty in movement of knee with hemarthrosis. The presence of hemarthrosis facilitates the diagnosis of an osteochondral fracture. Chondral and osteochondral fractures may be associated with other intra-articular pathologies. There are two main mechanisms of these fractures, including a direct effect causing avulsion or impaction and, a more common mechanism, flexion-rotation force to the knee, which is also the mechanism for an acute patellar dislocation. It is known that arthroscopic treatment is the best method for the diagnosis and treatment of chondral and osteochondral fractures. In osteochondral lesions, the aim of treatment is to restore the congruity of articular surfaces. In agreement with literature data, our clinical experience favors internal fixation as the most effective method for the treatment of osteochondral fractures.

  1. Natural fracture systems studies

    SciTech Connect

    Lorenz, J.C.; Warpinski, N.R.

    1992-09-01

    The objectives of this program are (1) to develop a basinal-analysis methodology for natural fracture exploration and exploitation, and (2) to determine the important characteristics of natural fracture systems for use in completion, stimulation, and production operations. Natural-fracture basinal analysis begins with studies of fractures in outcrop, core and logs in order to determine the type of fracturing and the relationship of the fractures to the lithologic environment. Of particular interest are the regional fracture systems that are pervasive in western US tight sand basins. A Methodology for applying this analysis is being developed, with the goal of providing a structure for rationally characterizing natural fracture systems basin-wide. Such basin-wide characterizations can then be expanded and supplemented locally, at sites where production may be favorable. Initial application of this analysis is to the Piceance basin where there is a wealth of data from the Multiwell Experiment (MWX), DOE cooperative wells, and other basin studies conducted by Sandia, CER Corporation, and the USGS (Lorenz and Finley, 1989, Lorenz et aI., 1989, and Spencer and Keighin, 1984). Such a basinal approach has been capable of explaining the fracture characteristics found throughout the southern part of the Piceance basin and along the Grand Hogback.

  2. Fracture detection logging tool

    DOEpatents

    Benzing, William M.

    1992-06-09

    A method and apparatus by which fractured rock formations are identified and their orientation may be determined includes two orthogonal motion sensors which are used in conjunction with a downhole orbital vibrator. The downhole vibrator includes a device for orienting the sensors. The output of the sensors is displayed as a lissajou figure. The shape of the figure changes when a subsurface fracture is encountered in the borehole. The apparatus and method identifies fractures rock formations and enables the azimuthal orientation of the fractures to be determined.

  3. SEGMENTAL CLAVICLE FRACTURE

    PubMed Central

    Grossi, Evander Azevedo

    2015-01-01

    The aim here was to present an unusual case of segmental clavicle fracture associated with ipsilateral rib fracture. Although the clavicle is very superficial, undetected cases of both types of fracture may occur, because these patients usually suffer multiple trauma. The case of a patient with a fracture of the diaphysis and lateral extremity of the clavicle is described: the patient was treated surgically and an excellent result was achieved. Similar cases in the literature are reviewed and their management is discussed. PMID:27047835

  4. [(Impending) pathological fracture].

    PubMed

    Sutter, P M; Regazzoni, P

    2002-01-01

    Pathological fractures will be encountered in increasing frequency due to more patients with cancer, surviving a longer period. The skeleton is the third most frequent localization for metastases. Breast cancer is still the most common primary tumor, but bone metastases from lung cancer seem to be diagnosed more and more. Despite of finding metastases most often in the spinal column, fractures are seen mostly at the femoral site. A pathological fracture and, in almost all cases, an impending fracture are absolute indication for operation. An exact definition of an "impending fracture" is still lacking; it is widely accepted, that 50 per cent of bone mass must be destroyed before visualization in X-ray is possible, thus defining an impending fracture. The score system by Mirels estimates the fracture risk by means of four parameters (localization, per cent of destructed bone mass, type of metastasis, pain). Improving quality of life, relieving pain, preferably with a single operation and a short length of stay are the goals of (operative) treatment. For fractures of the proximal femur, prosthetic replacement, for fractures of the subtrochanteric region or the shaft, intramedullary nails are recommended. Postoperative radiation therapy possibly avoids tumor progression. In patient with a good long term prognosis, tumor should be removed locally aggressive.

  5. Comparing different Ultraviolet Imaging Spectrograph (UVIS) occultation observations using modeling of water vapor jets

    NASA Astrophysics Data System (ADS)

    Portyankina, Ganna; Esposito, Larry W.; Hansen, Candice; Aye, Klaus-Michael

    2016-10-01

    Motivation: On March 11, 2016 the Cassini UVIS observed its 6th star occultation by Enceladus' plume. This observation was aimed to determine variability in the total gas flux from the Enceladus' southern polar region. The analysis of the received data suggests that the total gas flux is moderately increased comparing to the average gas flux observed by UVIS from 2005 to 2011 [1]. However, UVIS detected variability in individual jets. In particular, Baghdad 1 is more collimated in 2016 than in 2005, meaning its gas escapes at higher velocity.Model and fits: We use 3D DSMC model for water vapor jets to compare different UVIS occultation observations from 2005 to 2016. The model traces test articles from jets' sources [2] into space and results in coordinates and velocities for a set of test particles. We convert particle positions into the particle number density and integrate along UVIS line of sight (LoS) for each time step of the UVIS observation using precise observational geometry derived from SPICE [3]. We integrate all jets that are crossed by the LoS and perform constrained least-squares fit of resulting modeled opacities to the observed data to solved for relative strengths of jets. The geometry of each occultation is specific, for example, during solar occultation in 2010 UVIS LoS was almost parallel to tiger stripes, which made it possible to distinguish jets venting from different tiger stripes. In 2011 Eps Orionis occultation LoS was perpendicular to tiger stripes and thus many of the jets were geometrically overlapping. Solar occultation provided us with the largest inventory of active jets - our model fit detects at least 43 non-zero jet contributions. Stellar occultations generally have lower temporal resolution and observe only a sub-set of these jets: 2011 Eps Orionis needs minimum 25 non-zero jets to fit UVIS data. We will discuss different occultations and models fits, including the most recent Epsilon Orionis occultation of 2016.[1] Hansen et al

  6. Occult hepatitis B virus infection in liver transplant patients in a Brazilian referral center

    PubMed Central

    Ferrari, T.C.A.; Xavier, M.A.P.; Vidigal, P.V.T.; Amaral, N.S.; Diniz, P.A.; Resende, A.P.; Miranda, D.M.; Faria, A.C.; Lima, A.S.; Faria, L.C.

    2014-01-01

    Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant, probably due to the low prevalence of HBV infection in our population. PMID:25296362

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Using the EXIST Active Shields for Earth Occultation Observations of X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Wilson, Colleen A.; Fishman, Gerald; Hong, Jae-Sub; Gridlay, Jonathan; Krawczynski, Henric

    2005-01-01

    The EXIST active shields, now being planned for the main detectors of the coded aperture telescope, will have approximately 15 times the area of the BATSE detectors; and they will have a good geometry on the spacecraft for viewing both the leading and training Earth's limb for occultation observations. These occultation observations will complement the imaging observations of EXIST and can extend them to higher energies. Earth occultatio observations of the hard X-ray sky with BATSE on the Compton Gamma Ray Observatory developed and demonstrated the capabilities of large, flat, uncollimated detectors for this method. With BATSE, a catalog of 179 X-ray sources was monitored twice every spacecraft orbit for 9 years at energies above about 25 keV, resulting in 83 definite detections and 36 possible detections with 5-sigma detection sensitivities of 3.5-20 mcrab (20-430 keV) depending on the sky location. This catalog included four transients discovered with this technique and many variable objects (galactic and extragalactic). This poster will describe the Earth occultation technique, summarize the BATSE occultation observations, and compare the basic observational parameters of the occultation detector elements of BATSE and EXIST.

  9. [Life expectancy of clinically occult breast cancer. Study of a comparative patient sample since 1975].

    PubMed

    Paterok, E M; Neudert, M; Rosenthal, H; Richter, S; Säbel, N

    1993-05-01

    We have been observing 2 groups of 50 female patients with occult or clinical breast cancer each of whom was initially treated at the Gynaecologic Hospital of the University of Erlangen-Nürnberg between 1975 and 1978. During the follow-up period, 2 patients out of the group of occult cancer and 13 out of the group of clinical carcinoma died of their primary disease. Four women out of the group of occult cancer and 3 from the group of "clinical carcinoma" have developed recurrences. The differences in survival times according to Kaplan-Meier are immense, even if they are not significant owing to the small number of patients. But it is difficult to obtain and to evaluate larger groups of patients and longer follow-up periods due to the low percentage of occult cancer (7.7 to 10.5% only). There are 30 women out of the group of occult breast cancer living without relapse after an observation period up to 15 years. 27 patients out of the group of "clinical cancer" have not shown any evidence of recurrence up to now. This small difference after such a long follow-up period can be explained by the general life expectancy and by the age at initial treatment.

  10. VizieR Online Data Catalog: Occultation lights curves (Herald+ 2016)

    NASA Astrophysics Data System (ADS)

    Herald, Dave; Breit, Derek; Dunham, David; Frappa, Eric; Gault, Dave; George, Tony; Hayamizu, Tsutomu; Loader, Brian; Manek, Jan; Miyashita, Kazuhisa; Pavlov, Hristo; Preston, Steve; Soma, Mitsuru; Talbot, John; Timerson, Brad

    Lunar occultation light curves have been recorded since the mid-20th century using high-speed photomultipliers. Running at high cadence for high angular resolution, such recordings were usually made on large telescopes and limited to the brighter stars - and were not large in number. While a small number of video recordings of lunar and asteroidal occultations were made from about 1980, they became common from about the year 2000, when inexpensive low-light security cameras became available. As of 2016, almost all lunar and asteroidal occultation observations are recorded using video, with the video recording being measured using software packages such as Limovie [http://astro-limovie.info/limovie/limovie_en.html], and Tangra [http://www.hristopavlov.net/Tangra3/]. As a result, light curves are now routinely generated for almost all lunar and asteroidal occultation observations, especially those coordinated through the International Occultation Timing Association and related organisations around the world. This is resulting in large numbers of occultation light curves being obtained each year - albeit with some limitations on time resolution and signal-to-noise ratios. As of 2016, video recordings are mainly made using one or other of the two international video standards - NTSC, or PAL. Both NTSC and PAL use an interlaced video scan, whereby each frame of the video is comprised of two interlaced, time-sequential, fields. The frame rate of an NTSC system is 29.97 frames/sec (59.94 fields/sec), while that for PAL is 25 frames/sec ( 50 fields/sec). Consistent with broadcast television standards, the majority of video cameras used for recording occultations use 8-bit CCD's. However some video recordings are made using progressive scan, 12 to 16-bit digital video systems. For lunar occultations, the temporal resolution is governed by a combination of the frame (or field) rate of the video recording, and the rate of motion of the moon. The typical topocentric motion of

  11. Risk factors predictive of occult cancer detection in patients with unprovoked venous thromboembolism

    PubMed Central

    Ihaddadene, Ryma; Corsi, Daniel J.; Lazo-Langner, Alejandro; Shivakumar, Sudeep; Zarychanski, Ryan; Tagalakis, Vicky; Solymoss, Susan; Routhier, Nathalie; Douketis, James; Le Gal, Gregoire

    2016-01-01

    Risk factors predictive of occult cancer detection in patients with a first unprovoked symptomatic venous thromboembolism (VTE) are unknown. Cox proportional hazard models and multivariate analyses were performed to assess the effect of specific risk factors on occult cancer detection within 1 year of a diagnosis of unprovoked VTE in patients randomized in the Screening for Occult Malignancy in Patients with Idiopathic Venous Thromboembolism (SOME) trial. A total of 33 (3.9%; 95% CI, 2.8%-5.4%) out of the 854 included patients received a new diagnosis of cancer at 1-year follow-up. Age ≥ 60 years (hazard ratio [HR], 3.11; 95% CI, 1.41-6.89; P = .005), previous provoked VTE (HR, 3.20; 95% CI, 1.19-8.62; P = .022), and current smoker status (HR, 2.80; 95% CI, 1.24-6.33; P = .014) were associated with occult cancer detection. Age, prior provoked VTE, and smoking status may be important predictors of occult cancer detection in patients with first unprovoked VTE. This trial was registered at www.clinicaltrials.gov as #NCT00773448. PMID:26817957

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

    PubMed Central

    Mahmood, Ismail; Tawfeek, Zainab; El-Menyar, Ayman; Zarour, Ahmad; Afifi, Ibrahim; Kumar, Suresh; Latifi, Rifat; Al-Thani, Hassan

    2015-01-01

    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. PMID:25785199

  13. Analysis of zygomatic fractures.

    PubMed

    Hwang, Kun; Kim, Dong Hyun

    2011-07-01

    The purpose of this study was to evaluate the natural history of zygomatic fractures in 469 cases over 14 years. The medical records of patients seeking treatment for zygomatic fractures were reviewed. The zygomatic fractures were classified as monopod, dipod, or tripod fractures for most patients. The monopod fractures included (1) zygomaticofrontal, (2) zygomaticomaxillary, and (3) zygomatic arch fractures. The dipod fractures were subclassified into 3 types according to combination of the previously mentioned 3 sites, which were 1 and 2, 1 and 3, and 2 and 3. Tripod fracture included all 1, 2, and 3. Among 469 cases of zygomatic fractures, tripod fractures (n = 238, 50.7%), zygomaticomaxillary fracture (n = 121, 25.8%), and isolated fracture of the zygomatic arch (n = 98 20.9%) formed most of the cases (n = 457, 97.4%). About one-half cases were tripod fractures (n = 238, 50.7%), and another half cases were monopod fractures (n = 220, 46.9%). Only 11 cases (2.4%) were dipod fractures. Most of the monopod fractures were zygomaticomaxillary (n = 121, 25.8%) and zygomatic arch fractures (n = 98, 20.9%). Among the dipod fractures, no cases of zygomaticofrontal and zygomatic arch fractures were reported. An open reduction was performed in 73.8% (346 cases), closed reduction in 24.5% (115 cases), and conservative treatment in only 1.7%. In tripod fracture (n = 238), an open reduction and internal fixation was performed for most of the cases (n = 225, 94.5%), and closed reduction was performed in only 11 cases (4.6%). In monopod zygomaticomaxillary fracture (n = 121), internal fixation was performed for most of the cases (n = 108, 89.3%), and closed reduction was performed in only 9 cases (7.7%). However, in monopod fracture of the zygomatic arch (n = 98), most of the cases (n = 95, 96.9%) were treated with closed reduction; open reduction was performed in only 1 case (1.0%). At zygomaticofrontal area (n = 241), internal fixation was performed in most of the cases (n

  14. The Process of Hydraulic Fracturing

    EPA Pesticide Factsheets

    Hydraulic fracturing, know as fracking or hydrofracking, produces fractures in a rock formation by pumping fluids (water, proppant, and chemical additives) at high pressure down a wellbore. These fractures stimulate the flow of natural gas or oil.

  15. Compression fractures of the back

    MedlinePlus

    Vertebral compression fractures ... the most common cause of this type of fracture. Osteoporosis is a disease in which bones become ... the spine, such as multiple myeloma Having many fractures of the vertebrae can lead to kyphosis . This ...

  16. Hip Fractures among Older Adults

    MedlinePlus

    ... training for health care providers. Learn More Hip Fractures Among Older Adults Recommend on Facebook Tweet Share ... older. What You Can Do to Prevent Hip Fractures You can prevent hip fractures by taking steps ...

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

    NASA Astrophysics Data System (ADS)

    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 < 3.0. We propose a simple correction to VIMS Titan data to account for atmospheric attenuation and diffuse scatter-ing in the 5-mm and 2.7-2.8 mm windows, generally applicable for airmass < 3.0. The narrow 2.75-mm absorption feature, dividing the window into two sub-windows, present in all on-planet measurements is not present in the occultation data, and its strength is reduced at the cloud tops, suggesting the responsible molecule is concentrated in the lower troposphere or on the sur-face. Our empirical correction to Titan's surface reflectance yields properties shifted closer to water ice for the majority of the low

  18. Feasibility of blocking detection in observations from radio occultation

    NASA Astrophysics Data System (ADS)

    Brunner, Lukas; Steiner, Andrea Karin; Scherllin-Pirscher, Barbara; Jury, Martin

    2015-04-01

    Blocking describes an atmospheric situation in which the climatological westerly flow at mid latitudes is weakened or reversed. This is caused by a persistent high pressure system which can be stationary for several days to weeks. In the Northern Hemisphere blocking preferably occurs over the Atlantic/European and the Pacific regions. In recent years blocking has been under close scientific investigation due to its effect on weather extremes, triggering heat waves in summer and cold spells in winter. So far, scientific literature mainly focused on the investigation of blocking in reanalysis and global climate model data sets. However, blocking is underestimated in most climate models due to small-scale processes involved in its evolution. For a detection of blocking, most commonly applied methods are based on the computation of meridional geopotential height gradients at the 500 hPa level. Therefore measurements with adequate vertical, horizontal, and temporal resolution and coverage are required. We use an observational data set based on Global Positioning System (GPS) Radio Occultation (RO) measurements fulfilling these requirements. RO is a relatively new, satellite based remote sensing technique, delivering profiles of atmospheric parameters such as geopotential height, pressure, and temperature. It is characterized by favorable properties like long-term stability, global coverage, and high vertical resolution. Our data set is based on the most recent WEGC RO retrieval. Here we report on a feasibility study for blocking detection and analysis in RO data for two exemplary blocking events: the blocking over Russia in summer 2010 and the blocking over Greenland in late winter 2013. For these two events about 700 RO measurements per day are available in the Northern Hemisphere. We will show that the measurement density and quality of RO observations are favorable for blocking analysis and can therefore contribute to blocking research.

  19. TWENTY-FIVE SUBARCSECOND BINARIES DISCOVERED BY LUNAR OCCULTATIONS

    SciTech Connect

    Richichi, A.; Fors, O.; Cusano, F.; Moerchen, M.

    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. Strategies to Improve Repeat Fecal Occult Blood Testing Cancer Screening

    PubMed Central

    Davis, Terry C.; Arnold, Connie L.; Bennett, Charles L.; Wolf, Michael S.; Reynolds, Cristalyn; Liu, Dachao; Rademaker, Alfred

    2013-01-01

    Background A comparative effectiveness intervention by this team improved initial fecal occult blood testing (FOBT) rates from 3% to 53% among community clinic patients. The purpose of this study was to evaluate the effectiveness and costs associated with a literacy-informed intervention on repeat FOBT testing. Methods Between 2008 and 2011, a three-arm quasi-experiential comparative effectiveness evaluation was conducted in 8 community clinics in Louisiana. Clinics were randomly assigned to receive: enhanced care, a screening recommendation and FOBT kit annually; a brief educational intervention where patients additionally received a literacy appropriate pamphlet and simplified FOBT instructions; or nurse support where a nurse manager provided the education and followed up with phone support. In year 2 all materials were mailed. The study consisted of 461 patients, ages 50–85, with a negative initial FOBT. Results Repeat FOBT rates were 38% enhanced care, 33% education, and 59% with nurse support (p=0.017). After adjusting for age, race, gender, and literacy, patients receiving nurse support were 1.46 times more likely to complete repeat FOBT screening than those receiving education (95% CI 1.14–1.06, p=0.002) and 1.45 times more likely than those in enhanced care but this was not significant (95% CI 0.93–2.26 p=0.10). The incremental cost per additional person screened was $2,450 for nurse over enhanced care. Conclusion A mailed pamphlet and FOBT with simplified instructions did not improve annual screening. Impact Telephone outreach by a nurse manager was effective in improving rates of repeat FOBT yet this may be too costly for community clinics. PMID:24192009